2019
Brault, Andre; Hoult, Neil A
Distributed Reinforcement Strains: Measurement and Application Journal Article
In: ACI Structural Journal, vol. 116, no. 4, pp. 115-127, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{brault2019distributed,
title = {Distributed Reinforcement Strains: Measurement and Application},
author = { Andre Brault and Neil A Hoult},
doi = {10.1139/cgj-2017-0163},
year = {2019},
date = {2019-01-01},
journal = {ACI Structural Journal},
volume = {116},
number = {4},
pages = {115-127},
abstract = {Distributed reinforcement strain measurements could provide invaluable information for reinforced concrete (RC) model development and evaluation. A technique to measure distributed reinforcement strains using fiber optic sensors in RC elements is developed, which is more cost-effective and less time-consuming than existing methods. Nine RC beams were tested in three-point bending to evaluate the measurements, which were found to be accurate when compared to electrical strain gauges and theoretical predictions. This is the first instance where distributed fiber optic sensors have measured reinforcement strains accurately after cracking; however, strains well above yield were not reliably measured. Relating reinforcement strains with corresponding crack width measurements highlighted differences in how cracks initiate from crack to crack in a single specimen. Lastly, the experimental data were used to evaluate the potential for existing models to be used to predict reinforcement strains from external crack width measurements for RC assessment purposes.},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
Distributed reinforcement strain measurements could provide invaluable information for reinforced concrete (RC) model development and evaluation. A technique to measure distributed reinforcement strains using fiber optic sensors in RC elements is developed, which is more cost-effective and less time-consuming than existing methods. Nine RC beams were tested in three-point bending to evaluate the measurements, which were found to be accurate when compared to electrical strain gauges and theoretical predictions. This is the first instance where distributed fiber optic sensors have measured reinforcement strains accurately after cracking; however, strains well above yield were not reliably measured. Relating reinforcement strains with corresponding crack width measurements highlighted differences in how cracks initiate from crack to crack in a single specimen. Lastly, the experimental data were used to evaluate the potential for existing models to be used to predict reinforcement strains from external crack width measurements for RC assessment purposes.
Nurmi, Sara; Hoult, Neil A; Howell, Simon D
Distributed strain monitoring of two-way slabs Journal Article
In: Engineering Structures, vol. 189, pp. 580–588, 2019, ISSN: 0141-0296.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{nurmi2019distributed,
title = {Distributed strain monitoring of two-way slabs},
author = { Sara Nurmi and Neil A Hoult and Simon D Howell},
doi = {10.1016/j.engstruct.2019.04.002},
issn = {0141-0296},
year = {2019},
date = {2019-01-01},
journal = {Engineering Structures},
volume = {189},
pages = {580--588},
publisher = {Elsevier},
abstract = {Two-way slab design and assessment is often based on conservative approaches due to a lack of data regarding slab behaviour. Distributed fibre optic strain sensors have the potential to provide extensive data sets for both lab experiments and field assessments. A proof of concept study was undertaken that involved four two-way slabs, with varying reinforcement ratios and levels of axial restraint, that were instrumented with distributed fibre optic strain sensors and tested under a central point load. The slabs with less reinforcement demonstrated a ductile flexural failure while the more heavily reinforced slabs failed due to punching shear. The axial restraint system developed for this research provided partial restraint and enhanced the capacity of both restrained specimens compared to the control specimens. The strain data enabled differences in support conditions (both vertical and axial) to be identified. Additionally, the data enabled the onset of reinforcement yielding to be captured and thus proved it to be a promising approach for measuring the beneficial of effects of membrane action. The results of the experiments were compared to a yield-line analysis and were found to be within 5% for the unrestrained specimens and within 10% for the axially restrained specimens despite the fact that two specimens failed in punching shear.},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
Two-way slab design and assessment is often based on conservative approaches due to a lack of data regarding slab behaviour. Distributed fibre optic strain sensors have the potential to provide extensive data sets for both lab experiments and field assessments. A proof of concept study was undertaken that involved four two-way slabs, with varying reinforcement ratios and levels of axial restraint, that were instrumented with distributed fibre optic strain sensors and tested under a central point load. The slabs with less reinforcement demonstrated a ductile flexural failure while the more heavily reinforced slabs failed due to punching shear. The axial restraint system developed for this research provided partial restraint and enhanced the capacity of both restrained specimens compared to the control specimens. The strain data enabled differences in support conditions (both vertical and axial) to be identified. Additionally, the data enabled the onset of reinforcement yielding to be captured and thus proved it to be a promising approach for measuring the beneficial of effects of membrane action. The results of the experiments were compared to a yield-line analysis and were found to be within 5% for the unrestrained specimens and within 10% for the axially restrained specimens despite the fact that two specimens failed in punching shear.
Malek, Amirmasoud; Scott, Allan; Pampanin, Stefano; Hoult, Neil A
Postyield Bond Deterioration and Damage Assessment of RC Beams Using Distributed Fiber-Optic Strain Sensing System Journal Article
In: Journal of Structural Engineering, vol. 145, no. 4, pp. 04019007, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{malek2019postyield,
title = {Postyield Bond Deterioration and Damage Assessment of RC Beams Using Distributed Fiber-Optic Strain Sensing System},
author = { Amirmasoud Malek and Allan Scott and Stefano Pampanin and Neil A Hoult},
doi = {10.1061/(ASCE)ST.1943-541X.0002286},
year = {2019},
date = {2019-01-01},
journal = {Journal of Structural Engineering},
volume = {145},
number = {4},
pages = {04019007},
publisher = {American Society of Civil Engineers},
abstract = {Postyield steel–concrete bond has been the subject of considerable investigations using pull-out or direct tensile tests; however, the degradation in bond due to reinforcement yielding in RC beams subjected to lateral loading has not been fully scrutinized. Conventional measuring instruments (strain gauges or LVDTs) cannot precisely measure strain distribution along the yielded reinforcing bar with a minimum level of interference to the bond. Therefore, this study reports the postyield behavior of bond in RC cantilever beams subjected to monotonic lateral loading monitored using a distributed fiber-optic strain sensing system (DFOSSS). The DFOSSS enabled accurate monitoring of deformations of the embedded reinforcing bars and the strains on the concrete surface. This allowed slip, steel stress, bond stress, bond deterioration length, and the locations of cracks to be determined. Using the new values for maximum bond stress, a model was proposed to predict pre- and postyield bond behavior, including steel strain effect. Finally, the mean bond stress values were presented for the simple assessment of bond strength in both pre- and postyield regions.
},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
Postyield steel–concrete bond has been the subject of considerable investigations using pull-out or direct tensile tests; however, the degradation in bond due to reinforcement yielding in RC beams subjected to lateral loading has not been fully scrutinized. Conventional measuring instruments (strain gauges or LVDTs) cannot precisely measure strain distribution along the yielded reinforcing bar with a minimum level of interference to the bond. Therefore, this study reports the postyield behavior of bond in RC cantilever beams subjected to monotonic lateral loading monitored using a distributed fiber-optic strain sensing system (DFOSSS). The DFOSSS enabled accurate monitoring of deformations of the embedded reinforcing bars and the strains on the concrete surface. This allowed slip, steel stress, bond stress, bond deterioration length, and the locations of cracks to be determined. Using the new values for maximum bond stress, a model was proposed to predict pre- and postyield bond behavior, including steel strain effect. Finally, the mean bond stress values were presented for the simple assessment of bond strength in both pre- and postyield regions.
Brault, Andre; Hoult, Neil A; Greenough, Tom; Trudeau, Ian
Monitoring of beams in an RC building during a load test using distributed sensors Journal Article
In: Journal of Performance of Constructed Facilities, vol. 33, no. 1, pp. 04018096, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{brault2019monitoring,
title = {Monitoring of beams in an RC building during a load test using distributed sensors},
author = { Andre Brault and Neil A Hoult and Tom Greenough and Ian Trudeau},
doi = {10.1061/(ASCE)CF.1943-5509.0001250},
year = {2019},
date = {2019-01-01},
journal = {Journal of Performance of Constructed Facilities},
volume = {33},
number = {1},
pages = {04018096},
publisher = {American Society of Civil Engineers},
abstract = {The understanding of the complex behavior of reinforced concrete elements in situ would be aided if distributed strain measurements were captured during load tests, potentially leading to more accurate assessments and load ratings, and optimized future designs. This research investigates the use of distributed fiber optic sensors (FOS) to monitor three beams in a newly constructed RC building during a load test. It is the first case where an FOS technique capable of monitoring distributed strains, distributed deflections, and crack widths simultaneously is implemented in the field. The FOS data captured inflection points, moment transfer at the supports, crack locations, and crack openings. The FOS also captured deflected shapes, enabling maximum deflections to be determined without prior knowledge of where they would occur. Lastly, the measured results from the load test were compared to design model predictions for each element. },
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
The understanding of the complex behavior of reinforced concrete elements in situ would be aided if distributed strain measurements were captured during load tests, potentially leading to more accurate assessments and load ratings, and optimized future designs. This research investigates the use of distributed fiber optic sensors (FOS) to monitor three beams in a newly constructed RC building during a load test. It is the first case where an FOS technique capable of monitoring distributed strains, distributed deflections, and crack widths simultaneously is implemented in the field. The FOS data captured inflection points, moment transfer at the supports, crack locations, and crack openings. The FOS also captured deflected shapes, enabling maximum deflections to be determined without prior knowledge of where they would occur. Lastly, the measured results from the load test were compared to design model predictions for each element.
BROTH, ZACHARY E; HOULT, NEIL A
Distributed Sensing to Assess Bond Degradation Journal Article
In: Structural Health Monitoring 2019, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{broth2019distributed,
title = {Distributed Sensing to Assess Bond Degradation},
author = { ZACHARY E BROTH and NEIL A HOULT},
doi = {10.12783/shm2019/32295},
year = {2019},
date = {2019-01-01},
journal = {Structural Health Monitoring 2019},
abstract = {It is well known that reinforced concrete beams with low shear span to depth ratios have higher shear capacity due to the change in load carrying mechanism from beam action to arching action. However, up until now it has not been possible to understand the development of these mechanisms, which in turn makes it difficult to assess these beams. Distributed fiber optic strain sensing offers the ability to capture strain distributions along the full length of the reinforcement. When coupled with dynamic sensing capability, it then becomes possible to capture the formation of bond degradation that leads to arching action, as well as the impact that load cycling has on further bond degradation. In this study two beams were tested with identical shear span lengths but different effective depths, resulting in different a / d ratios. One beam carried load through beam action while the other beam carried load, once degradation had taken place, through arching action. The beams were loaded, then cycled for 3600 cycles, before being tested to failure. The behavior of the two beams is investigated by comparing the deflection and longitudinal strain behavior during the load cycles and just before failure. Significant differences in the longitudinal strain distribution developed during the tests, clearly highlighting the formation of arching action in the specimen with the smaller a / d ratio. The results of these experiments could be used to refine assessment techniques such as code models and finite element analysis.},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
It is well known that reinforced concrete beams with low shear span to depth ratios have higher shear capacity due to the change in load carrying mechanism from beam action to arching action. However, up until now it has not been possible to understand the development of these mechanisms, which in turn makes it difficult to assess these beams. Distributed fiber optic strain sensing offers the ability to capture strain distributions along the full length of the reinforcement. When coupled with dynamic sensing capability, it then becomes possible to capture the formation of bond degradation that leads to arching action, as well as the impact that load cycling has on further bond degradation. In this study two beams were tested with identical shear span lengths but different effective depths, resulting in different a / d ratios. One beam carried load through beam action while the other beam carried load, once degradation had taken place, through arching action. The beams were loaded, then cycled for 3600 cycles, before being tested to failure. The behavior of the two beams is investigated by comparing the deflection and longitudinal strain behavior during the load cycles and just before failure. Significant differences in the longitudinal strain distribution developed during the tests, clearly highlighting the formation of arching action in the specimen with the smaller a / d ratio. The results of these experiments could be used to refine assessment techniques such as code models and finite element analysis.
Barker, C; Hoult, NA; Le, H; Tolikonda, V
Evaluation of a Railway Bridge Using Distributed and Discrete Strain Sensors Proceeding
ICE Publishing 2019.
@proceedings{barker2019evaluation,
title = {Evaluation of a Railway Bridge Using Distributed and Discrete Strain Sensors},
author = { C Barker and NA Hoult and H Le and V Tolikonda},
doi = {10.1680/icsic.64669.533},
year = {2019},
date = {2019-01-01},
booktitle = {International Conference on Smart Infrastructure and Construction 2019 (ICSIC) Driving data-informed decision-making},
pages = {533--539},
organization = {ICE Publishing},
keywords = {},
pubstate = {published},
tppubtype = {proceedings}
}
Brault, AR; Hoult, NA
Assessment of Reinforced Concrete Structures with Distributed Fibre Optic Sensors Inproceedings
In: International Conference on Smart Infrastructure and Construction 2019 (ICSIC) Driving data-informed decision-making, pp. 541–548, ICE Publishing 2019.
Links | BibTeX | Tags: Fibre Optic Sensors
@inproceedings{brault2019assessment,
title = {Assessment of Reinforced Concrete Structures with Distributed Fibre Optic Sensors},
author = { AR Brault and NA Hoult},
doi = {10.1680/icsic.64669.541},
year = {2019},
date = {2019-01-01},
booktitle = {International Conference on Smart Infrastructure and Construction 2019 (ICSIC) Driving data-informed decision-making},
pages = {541--548},
organization = {ICE Publishing},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {inproceedings}
}
Liu, Yuchen; Moore, Ian D; Hoult, Neil A
Dynamic, Three Dimensional Response of a Corrugated Steel Arch Culvert Technical Report
2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@techreport{liu2019dynamic,
title = {Dynamic, Three Dimensional Response of a Corrugated Steel Arch Culvert},
author = { Yuchen Liu and Ian D Moore and Neil A Hoult},
url = {https://trid.trb.org/view/1573011},
year = {2019},
date = {2019-01-01},
abstract = {A metal arch culvert has been instrumented with optical fibres and tested under static and dynamic vehicle loads. The axis of the 2.75 m span semi-circular culvert was skewed at 45 degrees from the centreline of the roadway overhead. Distributed strain profiles around the circumference were successfully captured by the static and dynamic optical fibre systems. Calculated distributions of live load thrust showed that peak thrusts were obtained near the crown. The high magnitudes of moment compared to thrust suggest that for this shallow buried culvert, bending moments are likely as important as thrust forces and it would be preferable if they were not routinely neglected in the design standards. Dynamic testing led to thrusts and moments under the front wheels of the test truck that were from 1.07 to 1.85 times larger than those from the rear wheels. Measurements became noisier and more data were lost with increase in speed. The pavement led to a 10% decrease in thrusts in the static tests, but this influence became small as the speed increased, until velocity of 30 km/h. While the pavement had little influence on thrusts, it had a large impact on bending moments. In both static and dynamic tests, bending moments for wheels on the road pavement reduced by approximately 30%. Thrust and moment envelopes were prepared, to provided peak (most positive and least negative) values around the circumference. Envelope plots demonstrated that many locations near the crown experienced thrusts higher than those at the springlines. The development of the culvert response envelopes was greatly facilitated by the use of optic fibres (many strain gauges would be required to obtain this kind of data).},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {techreport}
}
A metal arch culvert has been instrumented with optical fibres and tested under static and dynamic vehicle loads. The axis of the 2.75 m span semi-circular culvert was skewed at 45 degrees from the centreline of the roadway overhead. Distributed strain profiles around the circumference were successfully captured by the static and dynamic optical fibre systems. Calculated distributions of live load thrust showed that peak thrusts were obtained near the crown. The high magnitudes of moment compared to thrust suggest that for this shallow buried culvert, bending moments are likely as important as thrust forces and it would be preferable if they were not routinely neglected in the design standards. Dynamic testing led to thrusts and moments under the front wheels of the test truck that were from 1.07 to 1.85 times larger than those from the rear wheels. Measurements became noisier and more data were lost with increase in speed. The pavement led to a 10% decrease in thrusts in the static tests, but this influence became small as the speed increased, until velocity of 30 km/h. While the pavement had little influence on thrusts, it had a large impact on bending moments. In both static and dynamic tests, bending moments for wheels on the road pavement reduced by approximately 30%. Thrust and moment envelopes were prepared, to provided peak (most positive and least negative) values around the circumference. Envelope plots demonstrated that many locations near the crown experienced thrusts higher than those at the springlines. The development of the culvert response envelopes was greatly facilitated by the use of optic fibres (many strain gauges would be required to obtain this kind of data).
Brault, Andre; Hoult, Neil
Monitoring reinforced concrete serviceability performance using fiber-optic sensors Journal Article
In: ACI Structural Journal, vol. 116, no. 1, pp. 57, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors
@article{brault2019monitoringb,
title = {Monitoring reinforced concrete serviceability performance using fiber-optic sensors},
author = { Andre Brault and Neil Hoult},
doi = {10.14359/51710870},
year = {2019},
date = {2019-01-01},
journal = {ACI Structural Journal},
volume = {116},
number = {1},
pages = {57},
publisher = {American Concrete Institute},
abstract = {Monitoring the serviceability performance of reinforced concrete (RC) structures in the field provides critical data for informing RC modeling, analysis, and design. Currently, there is a lack of monitoring technology that can capture the complex behavior of RC elements in place, in detail, while also being feasible to imple-ment. A technique of using fiber-optic sensors to simultaneously monitor both distributed RC beam deflections and crack widths is developed and described. Thirteen beam specimens with varying properties were tested in three-point bending to evaluate the technique against other sensor technologies. The results showed that distributed beam deflections can be accurately measured up until load levels approaching failure, while crack widths can be measured up until a width of 0.3 mm (0.0118 in.). The technique is practical to implement and provides robust data sets not achievable with other sensing technologies, making it an effective option for field-monitoring applications.},
keywords = {Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
Monitoring the serviceability performance of reinforced concrete (RC) structures in the field provides critical data for informing RC modeling, analysis, and design. Currently, there is a lack of monitoring technology that can capture the complex behavior of RC elements in place, in detail, while also being feasible to imple-ment. A technique of using fiber-optic sensors to simultaneously monitor both distributed RC beam deflections and crack widths is developed and described. Thirteen beam specimens with varying properties were tested in three-point bending to evaluate the technique against other sensor technologies. The results showed that distributed beam deflections can be accurately measured up until load levels approaching failure, while crack widths can be measured up until a width of 0.3 mm (0.0118 in.). The technique is practical to implement and provides robust data sets not achievable with other sensing technologies, making it an effective option for field-monitoring applications.
Wheeler, Lisa N; Take, W Andy; Hoult, Neil A; Le, Hoat
Use of fiber optic sensing to measure distributed rail strains and determine rail seat forces under a moving train Journal Article
In: Canadian Geotechnical Journal, vol. 56, no. 1, pp. 1–13, 2019.
Abstract | Links | BibTeX | Tags: Fibre Optic Sensors, Railway
@article{wheeler2019use,
title = {Use of fiber optic sensing to measure distributed rail strains and determine rail seat forces under a moving train},
author = { Lisa N Wheeler and W Andy Take and Neil A Hoult and Hoat Le},
doi = {10.1139/cgj-2017-0163},
year = {2019},
date = {2019-01-01},
journal = {Canadian Geotechnical Journal},
volume = {56},
number = {1},
pages = {1--13},
publisher = {NRC Research Press},
abstract = {Rayleigh backscatter fiber optic sensing permits dynamic strains to be measured along an optical fiber with a gauge spacing and temporal resolution sufficient for rail applications. However, this sensing technology is highly sensitive to vibration. A 7.5 m long section of rail was instrumented with optical fiber and strain measurements were recorded during passage of a freight train slowed to 8–11 km/h. This strategy to minimize rail vibration was successful in permitting distributed dynamic rail strains to be measured under freight car loading. The measured rail strains were used to determine the rail shear forces, which were then used with the static wheel loads to determine the rail seat load for 14 consecutive sleepers as the train passed over the field monitoring site. These data were then combined with measurements of dynamic rail displacement captured using digital image correlation to infer the rail seat load–deflection relationships for individual sleepers. These relationships were observed to provide significantly more detailed information about unsupported voids and the sleeper contact stiffnesses than the traditional consideration of the relationship between applied load and rail deflection and highlights how track behavior at a monitored location can be dependent on the conditions and behavior of neighbouring sleeper.},
keywords = {Fibre Optic Sensors, Railway},
pubstate = {published},
tppubtype = {article}
}
Rayleigh backscatter fiber optic sensing permits dynamic strains to be measured along an optical fiber with a gauge spacing and temporal resolution sufficient for rail applications. However, this sensing technology is highly sensitive to vibration. A 7.5 m long section of rail was instrumented with optical fiber and strain measurements were recorded during passage of a freight train slowed to 8–11 km/h. This strategy to minimize rail vibration was successful in permitting distributed dynamic rail strains to be measured under freight car loading. The measured rail strains were used to determine the rail shear forces, which were then used with the static wheel loads to determine the rail seat load for 14 consecutive sleepers as the train passed over the field monitoring site. These data were then combined with measurements of dynamic rail displacement captured using digital image correlation to infer the rail seat load–deflection relationships for individual sleepers. These relationships were observed to provide significantly more detailed information about unsupported voids and the sleeper contact stiffnesses than the traditional consideration of the relationship between applied load and rail deflection and highlights how track behavior at a monitored location can be dependent on the conditions and behavior of neighbouring sleeper.
Poldon, Jack J; Hoult, Neil A; Bentz, Evan C
Distributed Sensing in Large Reinforced Concrete Shear Test Journal Article
In: ACI Structural Journal, vol. 116, no. 5, pp. 235–245, 2019.
Abstract | Links | BibTeX | Tags: Civil Infrastructure, Fibre Optic Sensors
@article{poldon2019distributed,
title = {Distributed Sensing in Large Reinforced Concrete Shear Test},
author = { Jack J Poldon and Neil A Hoult and Evan C Bentz},
doi = {10.14359/51716765 },
year = {2019},
date = {2019-01-01},
journal = {ACI Structural Journal},
volume = {116},
number = {5},
pages = {235--245},
publisher = {American Concrete Institute},
abstract = {A large reinforced concrete (RC) beam designed to fail in shear was experimentally tested and monitored with distributed sensing technologies. Fiber-optic sensors (FOS) were used to monitor the strain along the flexural and shear reinforcement, and digital image correlation (DIC) was used to measure strains and displace-ments on the concrete surface. Measurements from the distributed sensing technologies were found to be in agreement with conven-tional sensors when tensile elongation and midspan deflection were analyzed prior to the development of extensive shear cracks. Results showed that cracking on the concrete surface was correlated with peaks in the FOS strain data for both the flexural and shear reinforcement. Combined distributed measurement (CDM) plots presented the full beam response at a given load. A method of moni-toring the distributed shear strain was proposed and used to assess the behavior with increasing load and showed that prior to failure, approximately 45% of the beam displacement was due to shear strain. The presented measurement technique using FOS and DIC is shown to enable a more detailed study of shear failures, specifi-cally, in a fashion that enables the quantification of the individual response of reinforcing steel and concrete under loading},
keywords = {Civil Infrastructure, Fibre Optic Sensors},
pubstate = {published},
tppubtype = {article}
}
A large reinforced concrete (RC) beam designed to fail in shear was experimentally tested and monitored with distributed sensing technologies. Fiber-optic sensors (FOS) were used to monitor the strain along the flexural and shear reinforcement, and digital image correlation (DIC) was used to measure strains and displace-ments on the concrete surface. Measurements from the distributed sensing technologies were found to be in agreement with conven-tional sensors when tensile elongation and midspan deflection were analyzed prior to the development of extensive shear cracks. Results showed that cracking on the concrete surface was correlated with peaks in the FOS strain data for both the flexural and shear reinforcement. Combined distributed measurement (CDM) plots presented the full beam response at a given load. A method of moni-toring the distributed shear strain was proposed and used to assess the behavior with increasing load and showed that prior to failure, approximately 45% of the beam displacement was due to shear strain. The presented measurement technique using FOS and DIC is shown to enable a more detailed study of shear failures, specifi-cally, in a fashion that enables the quantification of the individual response of reinforcing steel and concrete under loading
Adebola, Titilope; Moore, Ian; Hoult, Neil
Use of Optical Fibers to Investigate Strength Limit States for Pressure Pipe Liners Incollection
In: Pipelines 2019: Multidisciplinary Topics, Utility Engineering, and Surveying, pp. 161–169, American Society of Civil Engineers Reston, VA, 2019.
Abstract | Links | BibTeX | Tags: Civil Infrastructure, Fibre Optic Sensors
@incollection{adebola2019use,
title = {Use of Optical Fibers to Investigate Strength Limit States for Pressure Pipe Liners},
author = { Titilope Adebola and Ian Moore and Neil Hoult},
doi = {10.1061/9780784482506.017},
year = {2019},
date = {2019-01-01},
booktitle = {Pipelines 2019: Multidisciplinary Topics, Utility Engineering, and Surveying},
pages = {161--169},
publisher = {American Society of Civil Engineers Reston, VA},
abstract = {Cured in place pipe liners have been used for almost twenty years to repair cast iron water pipes, and research over that time has established that liner performance may be controlled by the local strain concentrations that develop where liners span across perforations in the wall of the cast iron pipe. Finite element analyses performed in a previous research study quantified the impact of those strain concentrations, but the difficulties associated with experimental strain measurements have resulted in little experimental support for the findings of that theoretical study. This paper reports on strain measurements obtained using optical fiber strain sensors installed along the inside surface of the repaired pipe and the outside of the liner where it is exposed at a perforation in the pipe wall. In addition to outlining the techniques used to obtain those measurements, the strain values are compared to theoretical calculations to assess the performance of the simple design model currently in use for selecting liner thickness. The measurements support the use of the current ASTM design rules for pressure pipe liners spanning across small sized perforations (up to 50 mm diameter in a pipe of 155 mm diameter). },
keywords = {Civil Infrastructure, Fibre Optic Sensors},
pubstate = {published},
tppubtype = {incollection}
}
Cured in place pipe liners have been used for almost twenty years to repair cast iron water pipes, and research over that time has established that liner performance may be controlled by the local strain concentrations that develop where liners span across perforations in the wall of the cast iron pipe. Finite element analyses performed in a previous research study quantified the impact of those strain concentrations, but the difficulties associated with experimental strain measurements have resulted in little experimental support for the findings of that theoretical study. This paper reports on strain measurements obtained using optical fiber strain sensors installed along the inside surface of the repaired pipe and the outside of the liner where it is exposed at a perforation in the pipe wall. In addition to outlining the techniques used to obtain those measurements, the strain values are compared to theoretical calculations to assess the performance of the simple design model currently in use for selecting liner thickness. The measurements support the use of the current ASTM design rules for pressure pipe liners spanning across small sized perforations (up to 50 mm diameter in a pipe of 155 mm diameter).
Motaharifar, Mohammad; Taghirad, Hamid D; Hashtrudi-Zaad, Keyvan; Mohammadi, Seyed Farzad
Control of Dual-User Haptic Training System With Online Authority Adjustment: An Observer-Based Adaptive Robust Scheme Journal Article
In: IEEE Transactions on Control Systems Technology, 2019, ISSN: 1558-0865.
Abstract | Links | BibTeX | Tags: Haptics, Simulation
@article{motaharifar2019control,
title = {Control of Dual-User Haptic Training System With Online Authority Adjustment: An Observer-Based Adaptive Robust Scheme},
author = { Mohammad Motaharifar and Hamid D Taghirad and Keyvan Hashtrudi-Zaad and Seyed Farzad Mohammadi},
doi = {10.1109/TCST.2019.2946943},
issn = {1558-0865},
year = {2019},
date = {2019-01-01},
journal = {IEEE Transactions on Control Systems Technology},
publisher = {IEEE},
abstract = {The design problem for the control a dual-user haptic surgical training system is studied in this article. The system allows the trainee to perform the task on a virtual environment, while the trainer is able to interfere in the operation and correct probable mistakes made by the trainee. The proposed methodology allows the trainer to transfer the task authority to or from the trainee in real time. The robust adaptive nature of the controller ensures position tracking. The stability of the closed-loop system is analyzed using the input-to-output stability approach and the small-gain theorem. Simulation and experimental results are presented to validate the effectiveness of the proposed control scheme.},
keywords = {Haptics, Simulation},
pubstate = {published},
tppubtype = {article}
}
The design problem for the control a dual-user haptic surgical training system is studied in this article. The system allows the trainee to perform the task on a virtual environment, while the trainer is able to interfere in the operation and correct probable mistakes made by the trainee. The proposed methodology allows the trainer to transfer the task authority to or from the trainee in real time. The robust adaptive nature of the controller ensures position tracking. The stability of the closed-loop system is analyzed using the input-to-output stability approach and the small-gain theorem. Simulation and experimental results are presented to validate the effectiveness of the proposed control scheme.
Mokogwu, Chiedu Nnaji; Razi, Kamran; Hashtrudi-Zaad, Keyvan
Experimental Assessment of Absolute Stability in Bilateral Teleoperation Journal Article
In: IEEE Transactions on Haptics, 2019, ISSN: 2329-4051.
Abstract | Links | BibTeX | Tags: Motion Control, Robotics
@article{mokogwu2019experimental,
title = {Experimental Assessment of Absolute Stability in Bilateral Teleoperation},
author = { Chiedu Nnaji Mokogwu and Kamran Razi and Keyvan Hashtrudi-Zaad},
doi = {10.1109/TOH.2019.2949819},
issn = {2329-4051},
year = {2019},
date = {2019-01-01},
journal = {IEEE Transactions on Haptics},
publisher = {IEEE},
abstract = {Absolute stability analysis of bilateral teleoperation systems are typically model-based. Under borderline conditions of absolute stability, depending on the degree of uncertainty in the dynamic model of the teleoperator and existing noise, the system may behave as potentially unstable when the model-based analysis predicts otherwise. In this article, we propose a methodology to experimentally verify the absolute stability of master-slave teleoperation systems. Since absolute stability demands bounds of all possible environments, we achieve this by conducting only three experiments that are often experienced in teleoperation: free slave, mass-carrying slave and locked slave (rigid environment). We will validate and compare our proposed method with the benchmark Llewellyns absolute stability criterion. Furthermore, we will examine the robustness of the proposed method and will provide guidelines for choosing the mass for the mass-carrying load condition.},
keywords = {Motion Control, Robotics},
pubstate = {published},
tppubtype = {article}
}
Absolute stability analysis of bilateral teleoperation systems are typically model-based. Under borderline conditions of absolute stability, depending on the degree of uncertainty in the dynamic model of the teleoperator and existing noise, the system may behave as potentially unstable when the model-based analysis predicts otherwise. In this article, we propose a methodology to experimentally verify the absolute stability of master-slave teleoperation systems. Since absolute stability demands bounds of all possible environments, we achieve this by conducting only three experiments that are often experienced in teleoperation: free slave, mass-carrying slave and locked slave (rigid environment). We will validate and compare our proposed method with the benchmark Llewellyns absolute stability criterion. Furthermore, we will examine the robustness of the proposed method and will provide guidelines for choosing the mass for the mass-carrying load condition.
Laija, Victor A Luna; Cleveland, Daniel; Hashtrudi-Zaad, Keyvan
Uncoupled stability of a haptic system with position-velocity sampling Inproceedings
In: 2019 IEEE World Haptics Conference (WHC), pp. 473–478, IEEE 2019, ISBN: 978-1-5386-9461-9.
Abstract | Links | BibTeX | Tags: Haptics, Motion Control, Simulation
@inproceedings{laija2019uncoupled,
title = {Uncoupled stability of a haptic system with position-velocity sampling},
author = { Victor A Luna Laija and Daniel Cleveland and Keyvan Hashtrudi-Zaad},
doi = {10.1109/WHC.2019.8816076},
isbn = {978-1-5386-9461-9},
year = {2019},
date = {2019-01-01},
booktitle = {2019 IEEE World Haptics Conference (WHC)},
pages = {473--478},
organization = {IEEE},
abstract = {In typical haptic simulation systems, sampled position from encoders is utilized to compute the virtual environment force. For dynamic environments, velocity is numerically approximated using sampled position. In this paper, we analytically studied the uncoupled stability of a haptic simulation system when the discrete velocity needed to implement a damper-spring virtual environment came from sampling analog velocity. Since typical analog velocity sensors add inertia to the system or contain ripple, we implemented a high-pass filter to estimate the analog velocity from a potentiometer analog position output. We analytically and experimentally assessed the uncoupled stability for this system for various filter cut-off frequencies and sampling rates.},
keywords = {Haptics, Motion Control, Simulation},
pubstate = {published},
tppubtype = {inproceedings}
}
In typical haptic simulation systems, sampled position from encoders is utilized to compute the virtual environment force. For dynamic environments, velocity is numerically approximated using sampled position. In this paper, we analytically studied the uncoupled stability of a haptic simulation system when the discrete velocity needed to implement a damper-spring virtual environment came from sampling analog velocity. Since typical analog velocity sensors add inertia to the system or contain ripple, we implemented a high-pass filter to estimate the analog velocity from a potentiometer analog position output. We analytically and experimentally assessed the uncoupled stability for this system for various filter cut-off frequencies and sampling rates.
Motaharifar, Mohammad; Taghirad, Hamid D; Hashtrudi-Zaad, Keyvan; Mohammadi, Seyed Farzad
Control synthesis and ISS stability analysis of a dual-user haptic training system based on S-shaped function Journal Article
In: IEEE/ASME Transactions on Mechatronics, vol. 24, no. 4, pp. 1553–1564, 2019, ISSN: 1941-014X.
Abstract | Links | BibTeX | Tags: Haptics, Healthcare, Simulation
@article{motaharifar2019controlb,
title = {Control synthesis and ISS stability analysis of a dual-user haptic training system based on S-shaped function},
author = { Mohammad Motaharifar and Hamid D Taghirad and Keyvan Hashtrudi-Zaad and Seyed Farzad Mohammadi},
doi = {10.1109/TMECH.2019.2917448},
issn = {1941-014X},
year = {2019},
date = {2019-01-01},
journal = {IEEE/ASME Transactions on Mechatronics},
volume = {24},
number = {4},
pages = {1553--1564},
publisher = {IEEE},
abstract = {The controller design and stability analysis of a dual user training haptic system is studied. Most of the previously proposed control methodologies for this system have not simultaneously considered special requirements of surgery training and stability analysis of the nonlinear closed-loop system which is the objective of this paper. In the proposed training approach, the trainee is allowed to freely experience the task and be corrected as needed, while the trainer maintains the task dominance. A special S-shaped function is suggested to generate the corrective force according to the magnitude of motion error between the trainer and the trainee. The closed-loop stability of the system is analyzed considering the nonlinearity of the system components using the Input-to-State Stability approach. Simulation and experimental results show the effectiveness of the proposed approach.},
keywords = {Haptics, Healthcare, Simulation},
pubstate = {published},
tppubtype = {article}
}
The controller design and stability analysis of a dual user training haptic system is studied. Most of the previously proposed control methodologies for this system have not simultaneously considered special requirements of surgery training and stability analysis of the nonlinear closed-loop system which is the objective of this paper. In the proposed training approach, the trainee is allowed to freely experience the task and be corrected as needed, while the trainer maintains the task dominance. A special S-shaped function is suggested to generate the corrective force according to the magnitude of motion error between the trainer and the trainee. The closed-loop stability of the system is analyzed considering the nonlinearity of the system components using the Input-to-State Stability approach. Simulation and experimental results show the effectiveness of the proposed approach.
Lugez, Elodie; Sadjadi, Hossein; Joshi, Chandra P; Hashtrudi-Zaad, Keyvan; Akl, Selim G; Fichtinger, Gabor
Field distortion compensation for electromagnetic tracking of ultrasound probes with application in high-dose-rate prostate brachytherapy Journal Article
In: Biomedical Physics & Engineering Express, vol. 5, no. 3, pp. 035026, 2019.
Abstract | Links | BibTeX | Tags: Healthcare, Tracking
@article{lugez2019field,
title = {Field distortion compensation for electromagnetic tracking of ultrasound probes with application in high-dose-rate prostate brachytherapy},
author = { Elodie Lugez and Hossein Sadjadi and Chandra P Joshi and Keyvan Hashtrudi-Zaad and Selim G Akl and Gabor Fichtinger},
doi = {10.1088/2057-1976/ab12b6},
year = {2019},
date = {2019-01-01},
journal = {Biomedical Physics & Engineering Express},
volume = {5},
number = {3},
pages = {035026},
publisher = {IOP Publishing},
abstract = {Purpose: Electromagnetic (EM) tracking of ultrasound (US) probes has been introduced to expand US imaging capabilities and benefit challenging procedures. However, various instruments—including the US probe itself—may introduce dynamic distortions to the EM field, and compromise the EM measurements. Basic filtering methods, such as those provided by manufacturers, are usually inefficient as they do not allow for field distortion compensation. We propose to use a simultaneous localization and mapping (SLAM) algorithm to track the transrectal US (TRUS) probe while dynamically detect, map, and correct the EM field distortions. Methods: Combining the motion model of the tracked probe, the observations made by a few redundant EM sensors, and the field distortions map, the SLAM algorithm relied on an extended Kalman filter (EKF) to estimate the tracking measurements. The SLAM technique was experimentally validated in a brachytherapy suite. Tracking of a TRUS probe was performed by means of an Ascension trakSTAR tracking system and four EM sensors. In addition, an optical tracking system was employed to provide a ground truth to our data. The performance of the SLAM technique was analysed by varying pertinent parameters, such as the number of redundant measurements and the motion trajectory. Probe trajectories included longitudinal translation, rotation, and freehand motions (consisting of simultaneous longitudinal translation and rotation motions) in order to comprehensively simulate imaging scenarios. Finally, the accuracy of the SLAM estimations was compared with that of the standard filtering methods provided by the manufacturer, as well as that of a simpler sensor fusion technique. Results: SLAM efficiently reduced position tracking errors up to 46.4% during freehand motions of the TRUS probe. Moreover, higher SLAM estimation accuracies were observed as the number of redundant measurements increased. While both TRUS probe motions did not yield a clinically significant trend on position tracking accuracy, orientation measurements were considerably improved during translation of the TRUS probe. Conclusions: The SLAM technique was effective in increasing the tracking accuracy of the TRUS probe. Higher number of redundant sensors and favorable sensor configurations improved the SLAM estimations of EM measurements. In turn, SLAM can further encourage the introduction of EM tracking assistance in clinical procedures such as prostate brachytherapy.},
keywords = {Healthcare, Tracking},
pubstate = {published},
tppubtype = {article}
}
Purpose: Electromagnetic (EM) tracking of ultrasound (US) probes has been introduced to expand US imaging capabilities and benefit challenging procedures. However, various instruments—including the US probe itself—may introduce dynamic distortions to the EM field, and compromise the EM measurements. Basic filtering methods, such as those provided by manufacturers, are usually inefficient as they do not allow for field distortion compensation. We propose to use a simultaneous localization and mapping (SLAM) algorithm to track the transrectal US (TRUS) probe while dynamically detect, map, and correct the EM field distortions. Methods: Combining the motion model of the tracked probe, the observations made by a few redundant EM sensors, and the field distortions map, the SLAM algorithm relied on an extended Kalman filter (EKF) to estimate the tracking measurements. The SLAM technique was experimentally validated in a brachytherapy suite. Tracking of a TRUS probe was performed by means of an Ascension trakSTAR tracking system and four EM sensors. In addition, an optical tracking system was employed to provide a ground truth to our data. The performance of the SLAM technique was analysed by varying pertinent parameters, such as the number of redundant measurements and the motion trajectory. Probe trajectories included longitudinal translation, rotation, and freehand motions (consisting of simultaneous longitudinal translation and rotation motions) in order to comprehensively simulate imaging scenarios. Finally, the accuracy of the SLAM estimations was compared with that of the standard filtering methods provided by the manufacturer, as well as that of a simpler sensor fusion technique. Results: SLAM efficiently reduced position tracking errors up to 46.4% during freehand motions of the TRUS probe. Moreover, higher SLAM estimation accuracies were observed as the number of redundant measurements increased. While both TRUS probe motions did not yield a clinically significant trend on position tracking accuracy, orientation measurements were considerably improved during translation of the TRUS probe. Conclusions: The SLAM technique was effective in increasing the tracking accuracy of the TRUS probe. Higher number of redundant sensors and favorable sensor configurations improved the SLAM estimations of EM measurements. In turn, SLAM can further encourage the introduction of EM tracking assistance in clinical procedures such as prostate brachytherapy.
Chakraborti, Tathagata; Muise, Christian; Agarwal, Shubham; Lastras, Luis A
MAi: An Intelligent Model Acquisition Interface for Interactive Specification of Dialogue Agents Inproceedings
In: Proceedings of the AAAI Conference on Artificial Intelligence, pp. 9849–9850, 2019.
Abstract | Links | BibTeX | Tags: Artificial Intelligence
@inproceedings{chakraborti2019mai,
title = {MAi: An Intelligent Model Acquisition Interface for Interactive Specification of Dialogue Agents},
author = { Tathagata Chakraborti and Christian Muise and Shubham Agarwal and Luis A Lastras},
doi = {10.1609/aaai.v33i01.33019849 },
year = {2019},
date = {2019-01-01},
booktitle = {Proceedings of the AAAI Conference on Artificial Intelligence},
volume = {33},
pages = {9849--9850},
abstract = {The state of the art in automated conversational agents for enterprise (e.g. for customer support) require a lengthy design process with experts in the loop who have to figure out and specify complex conversation patterns. This demonstration looks at a prototype interface that aims to bring down the expertise required to design such agents as well as the time taken to do so. Specifically, we will focus on how a metawriter can assist the domain-writer during the design process and how complex conversation patterns can be derived from simplifying abstractions at the interface level.},
keywords = {Artificial Intelligence},
pubstate = {published},
tppubtype = {inproceedings}
}
The state of the art in automated conversational agents for enterprise (e.g. for customer support) require a lengthy design process with experts in the loop who have to figure out and specify complex conversation patterns. This demonstration looks at a prototype interface that aims to bring down the expertise required to design such agents as well as the time taken to do so. Specifically, we will focus on how a metawriter can assist the domain-writer during the design process and how complex conversation patterns can be derived from simplifying abstractions at the interface level.
Sreedharan, Sarath; Chakraborti, Tathagata; Muise, Christian; Kambhampati, Subbarao
A General Framework for Synthesizing and Executing Self-Explaining Plans for Human-AI Interaction Inproceedings
In: ICAPS Workshop on Explainable Planning (XAIP), 2019.
Abstract | Links | BibTeX | Tags: Artificial Intelligence, Human Machine Interaction, Planning
@inproceedings{sreedharan2019general,
title = {A General Framework for Synthesizing and Executing Self-Explaining Plans for Human-AI Interaction},
author = { Sarath Sreedharan and Tathagata Chakraborti and Christian Muise and Subbarao Kambhampati},
url = {https://openreview.net/pdf?id=H1gyE6hm5V},
year = {2019},
date = {2019-01-01},
booktitle = {ICAPS Workshop on Explainable Planning (XAIP)},
abstract = {In this work, we present a general formulation for decision making in human-in-the-loop planning problems where the human's expectations about an autonomous agent may differ from the agent's own model. We show how our formulation for such multi-model planning problems allows us to capture existing approaches to this problem and also be used to generate novel explanatory behaviors. Our formulation also reveals a deep connection between multi-model planning and epistemic planning and we show how we can leverage classical planning compilations designed for epistemic planning for solving multi-model planning problems. We empirically show how this new compilation provides a computational advantage over previous approaches that separate reasoning about model reconciliation and identifying the agent's plan.},
keywords = {Artificial Intelligence, Human Machine Interaction, Planning},
pubstate = {published},
tppubtype = {inproceedings}
}
In this work, we present a general formulation for decision making in human-in-the-loop planning problems where the human's expectations about an autonomous agent may differ from the agent's own model. We show how our formulation for such multi-model planning problems allows us to capture existing approaches to this problem and also be used to generate novel explanatory behaviors. Our formulation also reveals a deep connection between multi-model planning and epistemic planning and we show how we can leverage classical planning compilations designed for epistemic planning for solving multi-model planning problems. We empirically show how this new compilation provides a computational advantage over previous approaches that separate reasoning about model reconciliation and identifying the agent's plan.
Sohrabi, Shirin; Muise, Christian; Rofrano, John; Kalia, Anup; Hwang, Jinho; Yabin, Dang; Jie, Ma; Zhuoxuan, Jiang
Towards Automated Planning for Enterprise Services: Opportunities and Challenges Inproceedings
In: Service-Oriented Computing: 17th International Conference, ICSOC 2019, Toulouse, France, October 28--31, 2019, Proceedings, pp. 64, Springer Nature 2019, ISBN: 978-3-030-33702-5.
Abstract | Links | BibTeX | Tags: Artificial Intelligence, Planning
@inproceedings{sohrabi2019towards,
title = {Towards Automated Planning for Enterprise Services: Opportunities and Challenges},
author = { Shirin Sohrabi and Christian Muise and John Rofrano and Anup Kalia and Jinho Hwang and Dang Yabin and Ma Jie and Jiang Zhuoxuan},
doi = {10.1007/978-3-030-33702-5_6},
isbn = {978-3-030-33702-5},
year = {2019},
date = {2019-01-01},
booktitle = {Service-Oriented Computing: 17th International Conference, ICSOC 2019, Toulouse, France, October 28--31, 2019, Proceedings},
volume = {11895},
pages = {64},
organization = {Springer Nature},
abstract = {Existing Artificial Intelligence (AI) driven automation solutions in enterprises employ machine learning, natural language processing, and chatbots. There is an opportunity for AI Planning to be applied, which offers reasoning about action trajectories to help build automation blueprints. AI Planning is a problem-solving technique, where knowledge about available actions and their consequences is used to identify a sequence of actions, which, when applied in a given initial state, satisfy a desired goal. AI Planning has successfully been applied in a number of domains ranging from space applications, logistics and transportation, manufacturing, robotics, scheduling, e-learning, enterprise risk management, and service composition. In this paper, we discuss experience in building automation solutions that employ AI planning for use in enterprise IT and business services, such as change and event management, migration and transformation and RPA composition. We discuss challenges in adoption of AI planning across the enterprise from implementation and deployment perspectives.},
keywords = {Artificial Intelligence, Planning},
pubstate = {published},
tppubtype = {inproceedings}
}
Existing Artificial Intelligence (AI) driven automation solutions in enterprises employ machine learning, natural language processing, and chatbots. There is an opportunity for AI Planning to be applied, which offers reasoning about action trajectories to help build automation blueprints. AI Planning is a problem-solving technique, where knowledge about available actions and their consequences is used to identify a sequence of actions, which, when applied in a given initial state, satisfy a desired goal. AI Planning has successfully been applied in a number of domains ranging from space applications, logistics and transportation, manufacturing, robotics, scheduling, e-learning, enterprise risk management, and service composition. In this paper, we discuss experience in building automation solutions that employ AI planning for use in enterprise IT and business services, such as change and event management, migration and transformation and RPA composition. We discuss challenges in adoption of AI planning across the enterprise from implementation and deployment perspectives.
2018
Caldwell, J.; Kealey, R.; Fernando, H.; Marshall, J. A.
Design requirements and operational concepts for a robotic underground scissor bolter Technical Report
Maclean Engineering under NSERC Engage project EGP 523529-18 2018.
BibTeX | Tags:
@techreport{Caldwell2018,
title = {Design requirements and operational concepts for a robotic underground scissor bolter},
author = {J. Caldwell and R. Kealey and H. Fernando and J. A. Marshall},
year = {2018},
date = {2018-10-01},
institution = {Maclean Engineering under NSERC Engage project EGP 523529-18},
keywords = {},
pubstate = {published},
tppubtype = {techreport}
}
Watson, C.; Marshall, J. A.
Estimating underground mine ventilation friction factors from low-density 3D data acquired by a moving LiDAR Journal Article
In: International Journal of Mining Science and Technology, 2018.
@article{Watson2018,
title = {Estimating underground mine ventilation friction factors from low-density 3D data acquired by a moving LiDAR},
author = {C. Watson and J. A. Marshall},
doi = {10.1016/j.ijmst.2018.03.009},
year = {2018},
date = {2018-03-01},
journal = {International Journal of Mining Science and Technology},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Watson, C.; Marshall, J. A.
Estimating underground mine ventilation friction factors from low-density 3D data acquired by a moving LiDAR Journal Article
In: International Journal of Mining Science and Technology, 2018.
@article{Watson2018b,
title = {Estimating underground mine ventilation friction factors from low-density 3D data acquired by a moving LiDAR},
author = {C. Watson and J. A. Marshall},
doi = {10.1016/j.ijmst.2018.03.009},
year = {2018},
date = {2018-03-01},
journal = {International Journal of Mining Science and Technology},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Dekker, L.
Industrial-Scale Autonomous Wheeled-Vehicle Path Following by Combining Iterative Learning Control with Feedback Linearization Masters Thesis
“Queen’s University”, 2018.
BibTeX | Tags:
@mastersthesis{Dekker2018,
title = {Industrial-Scale Autonomous Wheeled-Vehicle Path Following by Combining Iterative Learning Control with Feedback Linearization},
author = {L. Dekker},
year = {2018},
date = {2018-01-01},
school = {“Queen’s University”},
keywords = {},
pubstate = {published},
tppubtype = {mastersthesis}
}
Hewitt, R.; Boukas, E.; Azkarate, M.; Pagnamenta, M.; Marshall, J. A.; Gasteratos, A.; Visentin, G.
e Katwijk beach planetary rover dataset Journal Article
In: International Journal of Robotics Research, vol. Vol. 37, no. No. 1, pp. 3-12, 2018.
@article{HewittR2018,
title = {e Katwijk beach planetary rover dataset},
author = {R. Hewitt and E. Boukas and M. Azkarate and M. Pagnamenta and J. A. Marshall and A. Gasteratos and G. Visentin},
doi = {10.1177/0278364917737153},
year = {2018},
date = {2018-01-01},
journal = {International Journal of Robotics Research},
volume = {Vol. 37},
number = {No. 1},
pages = {3-12},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2017
Point cloud registration with virtual interest points from implicit quadric surface intersections Inproceedings
In: 2017 International Conference on 3D Vision (3DV 2017), Qingdao, China, 2017.
BibTeX | Tags:
@inproceedings{nokey,
title = {Point cloud registration with virtual interest points from implicit quadric surface intersections},
year = {2017},
date = {2017-10-01},
booktitle = {2017 International Conference on 3D Vision (3DV 2017)},
address = {Qingdao, China},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Design of a novel auto-rotating UAV platform for underground mine cavity surveying Inproceedings
In: 2017 SME Annual Conference & Expo and CMA’s 119th National Western Mining Conference & Exhibition, Denver, CO, 2017.
BibTeX | Tags:
@inproceedings{nokey,
title = {Design of a novel auto-rotating UAV platform for underground mine cavity surveying},
year = {2017},
date = {2017-02-01},
booktitle = {2017 SME Annual Conference & Expo and CMA’s 119th National Western Mining Conference & Exhibition},
address = {Denver, CO},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Dobson, A. A.; Marshall, J. A.; Larsson, J.
Admittance control for robotic loading: Design and experiments with a 1-tonne loader and a 14-tonne load-haul-dump machine Journal Article
In: Special issue on Field and Service Robotics of the Journal of Field Robotics, vol. Vol. 34, no. No. 1, pp. 123-150, 2017, (Invited Paper).
@article{Dobson2017,
title = {Admittance control for robotic loading: Design and experiments with a 1-tonne loader and a 14-tonne load-haul-dump machine},
author = {A. A. Dobson and J. A. Marshall and J. Larsson},
doi = {10.1002/rob.21654},
year = {2017},
date = {2017-01-01},
journal = {Special issue on Field and Service Robotics of the Journal of Field Robotics},
volume = {Vol. 34},
number = {No. 1},
pages = {123-150},
note = {Invited Paper},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
2016
Gallant, M. J.; Marshall, J. A.
Automated rapid mapping of joint orientations with mobile LiDAR Journal Article
In: International Journal of Rock Mechanics and Mining Sciences, vol. Vol. 390, pp. 1-14, 2016.
@article{Gallant2016,
title = {Automated rapid mapping of joint orientations with mobile LiDAR},
author = {M. J. Gallant and J. A. Marshall},
doi = {10.1016/j.ijrmms.2016.09.014},
year = {2016},
date = {2016-12-01},
journal = {International Journal of Rock Mechanics and Mining Sciences},
volume = {Vol. 390},
pages = {1-14},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Pasternak, M.; Marshall, J. A.
On the design and selection of vehicle coordination policies for underground mine production ramps Journal Article
In: International Journal of Mining Science and Technology, vol. vol. 26, no. no. 5, 2016.
@article{Pasternak2016,
title = {On the design and selection of vehicle coordination policies for underground mine production ramps},
author = {M. Pasternak and J. A. Marshall},
doi = {10.1016/j.ijmst.2016.05.014},
year = {2016},
date = {2016-09-01},
journal = {International Journal of Mining Science and Technology},
volume = {vol. 26},
number = {no. 5},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Gallant, M. J.; Marshall, J. A.
The LiDAR Compass: Extremely lightweight heading estimation with axis maps Journal Article
In: Robotics and Autonomous Systems, vol. Vol. 82, pp. 35-45, 2016.
@article{GallantMJ2016,
title = {The LiDAR Compass: Extremely lightweight heading estimation with axis maps},
author = {M. J. Gallant and J. A. Marshall},
doi = {10.1016/j.robot.2016.04.005},
year = {2016},
date = {2016-08-01},
journal = {Robotics and Autonomous Systems},
volume = {Vol. 82},
pages = {35-45},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
HDPR: A mobile testbed for current and future rover technologies Inproceedings
In: 4th International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS 2016), Beijing, China, 2016.
BibTeX | Tags:
@inproceedings{nokey,
title = {HDPR: A mobile testbed for current and future rover technologies},
year = {2016},
date = {2016-06-01},
booktitle = {4th International Symposium on Artificial Intelligence, Robotics and Automation in Space (i-SAIRAS 2016)},
address = {Beijing, China},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Gallant, M. J.; Marshall, J. A.
Automated three-dimensional axis mapping with a mobile platform Inproceedings
In: 2016 IEEE International Conference on Robotics and Automation (ICRA), Stockholm, Sweden, 2016.
@inproceedings{Gallant2016b,
title = {Automated three-dimensional axis mapping with a mobile platform},
author = {M. J. Gallant and J. A. Marshall},
doi = {10.1109/ICRA.2016.7487236},
year = {2016},
date = {2016-05-01},
booktitle = {2016 IEEE International Conference on Robotics and Automation (ICRA)},
address = {Stockholm, Sweden},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Robotics in Mining Book
Springer Handbook of Robotics, 2nd edition, 2016, (Invited Chapter 59, Part F).
@book{Marshall2016,
title = {Robotics in Mining},
doi = {10.1007/978-3-319-32552-1_59},
year = {2016},
date = {2016-01-01},
publisher = {Springer Handbook of Robotics, 2nd edition},
note = {Invited Chapter 59, Part F},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Gallant, M. J.; Marshall, J. A.
Two-dimensional axis mapping using LiDAR Journal Article
In: IEEE Transactions on Robotics,, vol. vol. 32, no. no.1, pp. 150-160, 2016.
@article{GallantM2016,
title = {Two-dimensional axis mapping using LiDAR},
author = {M. J. Gallant and J. A. Marshall},
doi = {10.1109/TRO.2015.2506162},
year = {2016},
date = {2016-01-01},
journal = {IEEE Transactions on Robotics,},
volume = {vol. 32},
number = {no.1},
pages = {150-160},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Simela, J.
Towards Automated Underground Mine Surveying: Integration of Mobile Mapping with Georeferenced Geometric Beacons PhD Thesis
“Queen’s University”, 2016.
BibTeX | Tags:
@phdthesis{Simela2016,
title = {Towards Automated Underground Mine Surveying: Integration of Mobile Mapping with Georeferenced Geometric Beacons},
author = {J. Simela},
year = {2016},
date = {2016-01-01},
school = {“Queen’s University”},
keywords = {},
pubstate = {published},
tppubtype = {phdthesis}
}
2012
Surgenor, Brian A; Bühl, Michael; Slawin, Alexandra M Z; Woollins, Derek J; Kilian, Petr
Isolable Phosphanylidene Phosphorane with a Sterically Accessible Two-Coordinate Phosphorus Atom Journal Article
In: Angewandte Chemie International Edition, vol. 51, no. 40, pp. 10150-10153, 2012.
Abstract | Links | BibTeX | Tags: density functional calculations, donor-acceptor systems, multiple bonds, phosphorus, structure elucidation
@article{https://doi.org/10.1002/anie.201204998,
title = {Isolable Phosphanylidene Phosphorane with a Sterically Accessible Two-Coordinate Phosphorus Atom},
author = {Brian A Surgenor and Michael Bühl and Alexandra M Z Slawin and Derek J Woollins and Petr Kilian},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.201204998},
doi = {https://doi.org/10.1002/anie.201204998},
year = {2012},
date = {2012-01-01},
journal = {Angewandte Chemie International Edition},
volume = {51},
number = {40},
pages = {10150-10153},
abstract = {'P' undressed: A stable phosphanylidene phosphorane with a sterically accessible (naked) two-coordinate P is reported (see structure). Coordination to Pd0 reveals its phosphine donor/phosphinidene acceptor (R3P→PR′) nature by exposing its phosphinidene-like reactivity.},
keywords = {density functional calculations, donor-acceptor systems, multiple bonds, phosphorus, structure elucidation},
pubstate = {published},
tppubtype = {article}
}
'P' undressed: A stable phosphanylidene phosphorane with a sterically accessible (naked) two-coordinate P is reported (see structure). Coordination to Pd0 reveals its phosphine donor/phosphinidene acceptor (R3P→PR′) nature by exposing its phosphinidene-like reactivity.
2000
Singh, Gursarbjot; Woods, Joshua
2D and 3D Numerical Modelling of Exposed Steel Base Plate Connections under Cyclic Loading Journal Article
In: Canadian Journal of Civil Engineering, vol. 0, no. ja, pp. null, 2000.
Abstract | Links | BibTeX | Tags:
@article{doi:10.1139/cjce-2021-0463,
title = {2D and 3D Numerical Modelling of Exposed Steel Base Plate Connections under Cyclic Loading},
author = {Gursarbjot Singh and Joshua Woods},
url = {https://doi.org/10.1139/cjce-2021-0463},
doi = {10.1139/cjce-2021-0463},
year = {2000},
date = {2000-04-04},
urldate = {0000-01-01},
journal = {Canadian Journal of Civil Engineering},
volume = {0},
number = {ja},
pages = {null},
abstract = {The degree of fixity at the base of steel gravity columns with exposed base plate connections is often assumed in analysis and design. However, past experiments have shown these connections do provide lateral stiffness and strength that could contribute to the load carrying capacity of a structure. The goal of this study is to develop a numerical modelling approach for exposed steel base plate connections that can capture their nonlinear cyclic behaviour, including their stiffness, strength, and energy dissipation capacity. Two modelling approaches are proposed, one that is suitable for detailed study of connection behaviour and another comparatively simple approach that can be used in nonlinear time-history analysis of a structure. Results from the two methodologies are compared with experimental data from the literature and the results show that both approaches can capture the nonlinear cyclic response of the studied connections. Limitations of the proposed modelling approach are also discussed.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The degree of fixity at the base of steel gravity columns with exposed base plate connections is often assumed in analysis and design. However, past experiments have shown these connections do provide lateral stiffness and strength that could contribute to the load carrying capacity of a structure. The goal of this study is to develop a numerical modelling approach for exposed steel base plate connections that can capture their nonlinear cyclic behaviour, including their stiffness, strength, and energy dissipation capacity. Two modelling approaches are proposed, one that is suitable for detailed study of connection behaviour and another comparatively simple approach that can be used in nonlinear time-history analysis of a structure. Results from the two methodologies are compared with experimental data from the literature and the results show that both approaches can capture the nonlinear cyclic response of the studied connections. Limitations of the proposed modelling approach are also discussed.
0000
Marshall, Joshua A.
The robot revolution is here: How it’s changing jobs and businesses in Canada Journal Article
In: The Conversation, 0000.
BibTeX | Tags:
@article{Marshall2021,
title = {The robot revolution is here: How it’s changing jobs and businesses in Canada},
author = {Joshua A. Marshall},
journal = {The Conversation},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kearns, Oliver; Moore, Ian D.; Hoult, Neil A.
Erosion Experiments on Culverts and Sewers Using a New Test Facility Book Chapter
In: Pipelines 2022, pp. 294-303, 0000.
Abstract | Links | BibTeX | Tags:
@inbook{doi:10.1061/9780784484296.035,
title = {Erosion Experiments on Culverts and Sewers Using a New Test Facility},
author = {Oliver Kearns and Ian D. Moore and Neil A. Hoult},
url = {https://ascelibrary.org/doi/abs/10.1061/9780784484296.035},
doi = {10.1061/9780784484296.035},
booktitle = {Pipelines 2022},
pages = {294-303},
abstract = {Leakage through joints in rigid sewers or corrosion-induced perforations in corrugated steel culverts can result in ingress of groundwater and erosion of the surrounding fill. The loss of ground support may then compromise the ability of the sewer or culvert to support earth or vehicle loads. A new test facility at Queen’s University has been developed to undertake erosion experiments to measure the impact of erosion on sewer and culvert behavior. Use of the 5 m long, 3 m wide, and 4.5 m deep test pit to investigate the response of large diameter pipes under deep burial has been described previously, and this paper describes its use for erosion experiments. This is illustrated by outlining a test conducted on a corrugated steel pipe with 0.9 m diameter and perforations along the haunches. This test pipe was instrumented with optical fiber sensors around crests and valleys of the corrugated plate. It was then placed in the pit and backfilled with sand. After initial burial, wheel pair loading on the ground surface was applied through a steel plate, and strains were measured around the pipe circumference. Those strains then were used to obtain the distributions of hoop thrust and circumferential bending moment for this “intact soil” condition. The test pit permits experiments in saturated ground, and after raising the level of the groundwater, leakage through the perforations commenced, causing erosion of the surrounding fill. After lowering the groundwater level to stop the erosion, surface loading was again applied, and the resulting strains measured for the steel culvert with this deteriorated (eroded soil) condition. Comparisons of the pre-erosion and post-erosion responses reveal that there are very significant changes in the patterns and magnitudes of circumferential bending moment, with a large bending moment developing where the soil support was removed by erosion.},
keywords = {},
pubstate = {published},
tppubtype = {inbook}
}
Leakage through joints in rigid sewers or corrosion-induced perforations in corrugated steel culverts can result in ingress of groundwater and erosion of the surrounding fill. The loss of ground support may then compromise the ability of the sewer or culvert to support earth or vehicle loads. A new test facility at Queen’s University has been developed to undertake erosion experiments to measure the impact of erosion on sewer and culvert behavior. Use of the 5 m long, 3 m wide, and 4.5 m deep test pit to investigate the response of large diameter pipes under deep burial has been described previously, and this paper describes its use for erosion experiments. This is illustrated by outlining a test conducted on a corrugated steel pipe with 0.9 m diameter and perforations along the haunches. This test pipe was instrumented with optical fiber sensors around crests and valleys of the corrugated plate. It was then placed in the pit and backfilled with sand. After initial burial, wheel pair loading on the ground surface was applied through a steel plate, and strains were measured around the pipe circumference. Those strains then were used to obtain the distributions of hoop thrust and circumferential bending moment for this “intact soil” condition. The test pit permits experiments in saturated ground, and after raising the level of the groundwater, leakage through the perforations commenced, causing erosion of the surrounding fill. After lowering the groundwater level to stop the erosion, surface loading was again applied, and the resulting strains measured for the steel culvert with this deteriorated (eroded soil) condition. Comparisons of the pre-erosion and post-erosion responses reveal that there are very significant changes in the patterns and magnitudes of circumferential bending moment, with a large bending moment developing where the soil support was removed by erosion.