The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated a...The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange＇s equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb＇s law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCR which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated： the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.展开更多
We analyze the effects of possible noise sources on a fence structure micromachined capacitive accelerometer system by modeling and simulation to improve its performance. Simulation results show that a mismatch betwee...We analyze the effects of possible noise sources on a fence structure micromachined capacitive accelerometer system by modeling and simulation to improve its performance. Simulation results show that a mismatch between the two initial sensing capacitors of the accelerometer or a mismatch between the two capacitance-voltage conversion circuits has a great effect on the output noise floor. When there is a serious mismatch, the noise induced by a sinusoidal carrier is the major noise source. When there is no or only a slight mismatch, the differential capacitance-voltage conversion circuits become the main noise source. The simulation results were validated by experiments and some effective approaches are proposed to improve the system resolution.展开更多
基金supported by the National Natural Science Foundation of China (Grants 11372018, 11772021)
文摘The main purpose of this paper is to present a linear complementarity problem （LCP） method for a planar passive dynamic walker with round feet based on an event-driven scheme. The passive dynamic walker is treated as a planar multi-rigid-body system. The dynamic equations of the passive dynamic walker are obtained by using Lagrange＇s equations of the second kind. The normal forces and frictional forces acting on the feet of the passive walker are described based on a modified Hertz contact model and Coulomb＇s law of dry friction. The state transition problem of stick-slip between feet and floor is formulated as an LCR which is solved with an event-driven scheme. Finally, to validate the methodology, four gaits of the walker are simulated： the stance leg neither slips nor bounces; the stance leg slips without bouncing; the stance leg bounces without slipping; the walker stands after walking several steps.
基金Project (No. NCET-06-0514) supported by the Program for New Century Excellent Talents in University of China
文摘We analyze the effects of possible noise sources on a fence structure micromachined capacitive accelerometer system by modeling and simulation to improve its performance. Simulation results show that a mismatch between the two initial sensing capacitors of the accelerometer or a mismatch between the two capacitance-voltage conversion circuits has a great effect on the output noise floor. When there is a serious mismatch, the noise induced by a sinusoidal carrier is the major noise source. When there is no or only a slight mismatch, the differential capacitance-voltage conversion circuits become the main noise source. The simulation results were validated by experiments and some effective approaches are proposed to improve the system resolution.
