The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Daniel Bourbonnais - One of the best experts on this subject based on the ideXlab platform.
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relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons
Archives of Physical Medicine and Rehabilitation, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:Abstract Desroches G, Aissaoui R, Bourbonnais D. Relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Objective To determine the relationship between the Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Design Convenience sample. Setting Motion analysis laboratory. Participants Older manual wheelchair users (N=14; age, 68.2±5.2y) were tested. Interventions Kinematic and kinetic data were collected during manual wheelchair propulsion at a speed between 0.96 and 1.01m/s for 10 seconds and at a power output around 22.4W on a wheelchair ergometer. Main Outcome Measures Net shoulder joint moments were computed with an inverse dynamic model. The mechanical use of the Forces at the pushrim and the mechanical fraction of effective Force were measured during propulsion. Results Mechanical use and mechanical fraction of effective Force had a positive and significant correlation with the net internal ( P P P P P Conclusions The results suggest that because the Resultant Force at the pushrim has a greater tangential component and a greater proportion of the maximal voluntary Force, most of the net moments around the shoulder are higher. Thus the optimal way of propelling, from a mechanical point of view (ie, tangential), may not be advantageous for manual wheelchair users.
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The Effect of Resultant Force at the Pushrim on Shoulder Kinetics During Manual Wheelchair Propulsion: A Simulation Study
IEEE Transactions on Biomedical Engineering, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:The aim of this study was to determine, by simulation on real data, the effect of modifying the direction or effectiveness of a given Force amplitude on the load sustained by the shoulder estimated by joint Forces and moments. Kinematics and kinetics data were recorded on 14 manual wheelchair users (68.2plusmn5.2 years) for 10 s at sub-maximal speed (0.96-1.01 m/s). The simulation consisted in modifying Force effectiveness at the pushrim while maintaining the same initial Force amplitude. Shoulder kinetics were computed for simulated Resultant Forces from radial to tangent directions and also for initial Force effectiveness. The results show that as the Force was simulated tangent to the wheel, there was a significant increase in the average proximal and anterior shoulder joint Forces. Also, significant increases in average internal rotation, flexion in the sagittal and horizontal plane moments were reported. Higher shoulder kinetics could accelerate the onset of fatigue and increase the risk of injury. A single-case analysis revealed an improvement window for Force effectiveness (~10%) in which shoulder kinetics were not substantially increased. Our results provide useful information on what would happen to shoulder kinetics if we were able to teach manual wheelchair users to modify their Force pattern at the pushrim. The results suggest that for an elderly population, it is not wise to aim at producing a mechanically optimal Resultant Force at the pushrim (i.e., tangent). Smaller increases of the initial Force effectiveness would be preferable.
Guillaume Desroches - One of the best experts on this subject based on the ideXlab platform.
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relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons
Archives of Physical Medicine and Rehabilitation, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:Abstract Desroches G, Aissaoui R, Bourbonnais D. Relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Objective To determine the relationship between the Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Design Convenience sample. Setting Motion analysis laboratory. Participants Older manual wheelchair users (N=14; age, 68.2±5.2y) were tested. Interventions Kinematic and kinetic data were collected during manual wheelchair propulsion at a speed between 0.96 and 1.01m/s for 10 seconds and at a power output around 22.4W on a wheelchair ergometer. Main Outcome Measures Net shoulder joint moments were computed with an inverse dynamic model. The mechanical use of the Forces at the pushrim and the mechanical fraction of effective Force were measured during propulsion. Results Mechanical use and mechanical fraction of effective Force had a positive and significant correlation with the net internal ( P P P P P Conclusions The results suggest that because the Resultant Force at the pushrim has a greater tangential component and a greater proportion of the maximal voluntary Force, most of the net moments around the shoulder are higher. Thus the optimal way of propelling, from a mechanical point of view (ie, tangential), may not be advantageous for manual wheelchair users.
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The Effect of Resultant Force at the Pushrim on Shoulder Kinetics During Manual Wheelchair Propulsion: A Simulation Study
IEEE Transactions on Biomedical Engineering, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:The aim of this study was to determine, by simulation on real data, the effect of modifying the direction or effectiveness of a given Force amplitude on the load sustained by the shoulder estimated by joint Forces and moments. Kinematics and kinetics data were recorded on 14 manual wheelchair users (68.2plusmn5.2 years) for 10 s at sub-maximal speed (0.96-1.01 m/s). The simulation consisted in modifying Force effectiveness at the pushrim while maintaining the same initial Force amplitude. Shoulder kinetics were computed for simulated Resultant Forces from radial to tangent directions and also for initial Force effectiveness. The results show that as the Force was simulated tangent to the wheel, there was a significant increase in the average proximal and anterior shoulder joint Forces. Also, significant increases in average internal rotation, flexion in the sagittal and horizontal plane moments were reported. Higher shoulder kinetics could accelerate the onset of fatigue and increase the risk of injury. A single-case analysis revealed an improvement window for Force effectiveness (~10%) in which shoulder kinetics were not substantially increased. Our results provide useful information on what would happen to shoulder kinetics if we were able to teach manual wheelchair users to modify their Force pattern at the pushrim. The results suggest that for an elderly population, it is not wise to aim at producing a mechanically optimal Resultant Force at the pushrim (i.e., tangent). Smaller increases of the initial Force effectiveness would be preferable.
Y S Tarng - One of the best experts on this subject based on the ideXlab platform.
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Detection of tool failure in end milling
Journal of Materials Processing Technology, 1996Co-Authors: Y S Tarng, M.c. ChenAbstract:Abstract The use of an unsupervised adaptive resonance theory neural network to process the Resultant Force spectrum for the detection of tool failure in end-milling operations is reported in the paper. In this approach, an in-process identification of varying cutting geometries and complex cutting dynamics is not required for tool failure detection. The unsupervised neural network can classify the features of the Resultant Force spectrum under varying cutting conditions. As a result, tool failure can be detected when tool-failure features start to appear in end-milling operations. Experimental results are presented to confirm the feasibility of the proposed detection system.
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On-line detection of tool breakage in milling
Mechanical Systems and Signal Processing, 1991Co-Authors: Y S TarngAbstract:Abstract The quasi-mean Resultant Force has been proven to be very useful for sensing tool breakage in milling. It has been also shown that the quasi-mean Resultant Force is proportional to the quasi-mean Resultant displacement of spindle. Therefore, a system for on-line detection of tool breakage in milling has been developed in this paper by using the difference of the quasi-mean Resultant displacement of spindle. The threshold value for tool breakage detection under varying cutting conditions can be determined by a teaching method. Theoretical studies and experimental results in milling operations are presented to support the proposed system for detection of tool breakage in the real-time analysis.
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measurement of quasi mean Resultant Force using the vibrational signal of spindle in milling
International Journal of Machine Tools & Manufacture, 1991Co-Authors: Y S TarngAbstract:The quasi-mean Resultant Force has been proven to be useful on the real-time process control and tool monitoring in milling operations. This paper presents a new way to measure the quasi-mean Resultant Force using the vibrational displacement signal of spindle. The quasi-mean Resultant Force can be obtained by subtracting the spindle run-out pattern from the average displacement signal per tooth period, then multiplying a constant, k∗. This new approach is illustrated by computational simulations and experimental cutting tests.
Rachid Aissaoui - One of the best experts on this subject based on the ideXlab platform.
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relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons
Archives of Physical Medicine and Rehabilitation, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:Abstract Desroches G, Aissaoui R, Bourbonnais D. Relationship between Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Objective To determine the relationship between the Resultant Force at the pushrim and the net shoulder joint moments during manual wheelchair propulsion in elderly persons. Design Convenience sample. Setting Motion analysis laboratory. Participants Older manual wheelchair users (N=14; age, 68.2±5.2y) were tested. Interventions Kinematic and kinetic data were collected during manual wheelchair propulsion at a speed between 0.96 and 1.01m/s for 10 seconds and at a power output around 22.4W on a wheelchair ergometer. Main Outcome Measures Net shoulder joint moments were computed with an inverse dynamic model. The mechanical use of the Forces at the pushrim and the mechanical fraction of effective Force were measured during propulsion. Results Mechanical use and mechanical fraction of effective Force had a positive and significant correlation with the net internal ( P P P P P Conclusions The results suggest that because the Resultant Force at the pushrim has a greater tangential component and a greater proportion of the maximal voluntary Force, most of the net moments around the shoulder are higher. Thus the optimal way of propelling, from a mechanical point of view (ie, tangential), may not be advantageous for manual wheelchair users.
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The Effect of Resultant Force at the Pushrim on Shoulder Kinetics During Manual Wheelchair Propulsion: A Simulation Study
IEEE Transactions on Biomedical Engineering, 2008Co-Authors: Guillaume Desroches, Rachid Aissaoui, Daniel BourbonnaisAbstract:The aim of this study was to determine, by simulation on real data, the effect of modifying the direction or effectiveness of a given Force amplitude on the load sustained by the shoulder estimated by joint Forces and moments. Kinematics and kinetics data were recorded on 14 manual wheelchair users (68.2plusmn5.2 years) for 10 s at sub-maximal speed (0.96-1.01 m/s). The simulation consisted in modifying Force effectiveness at the pushrim while maintaining the same initial Force amplitude. Shoulder kinetics were computed for simulated Resultant Forces from radial to tangent directions and also for initial Force effectiveness. The results show that as the Force was simulated tangent to the wheel, there was a significant increase in the average proximal and anterior shoulder joint Forces. Also, significant increases in average internal rotation, flexion in the sagittal and horizontal plane moments were reported. Higher shoulder kinetics could accelerate the onset of fatigue and increase the risk of injury. A single-case analysis revealed an improvement window for Force effectiveness (~10%) in which shoulder kinetics were not substantially increased. Our results provide useful information on what would happen to shoulder kinetics if we were able to teach manual wheelchair users to modify their Force pattern at the pushrim. The results suggest that for an elderly population, it is not wise to aim at producing a mechanically optimal Resultant Force at the pushrim (i.e., tangent). Smaller increases of the initial Force effectiveness would be preferable.
Warren R. Devries - One of the best experts on this subject based on the ideXlab platform.
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Adaptive Pole Placement Force Control of End Milling
1990 American Control Conference, 1990Co-Authors: Francis M. Kolarits, Warren R. DevriesAbstract:This paper presents the design, simulation and experimental evaluation of a discrete time adaptive pole placement (APP) controller for end milling. In this controller design, the specification of the reference Resultant Force level and maximum feedrate constraint are based on surface finish/error considerations through use of a mechanistic dynamic process model for prediction of the cutting Forces and the geometry of the end milled wall and floor surfaces. In addition, an analog signal processing circuit which holds the peak Resultant Force signal over each spindle revolution permits application of the controller to both slot and peripheral end milling. Experimental results show good agreement with the simulated APP controller Force regulation performance and surface profile geometries. The APP approach is demonstrated to be an effective control strategy whether the process zeros are stable or not.