Gait simulation of new robot for human walking on sand

Abstract

In order to simulate the gait of human walking on different terrains a new robot with six degrees of freedom was proposed. Based on sand bearing characteristic compliance control was introduced to control system in horizontal and vertical movement directions at the end of the robot, and position control in attitude. With Matlab/Simulink toolbox, the system control models were established, and the bearing characteristics of rigid ground, hard sand, soft sand and softer sand were simulated. The results show that 0, 0.62, 0.89 and 1.12 mm are the maximal subsidences of the four kinds of ground along the positive direction of x-axis, respectively, and 0, −0.96, −1.99 and −3.00 mm are the maximal subsidences along the negative direction of x-axis, respectively. Every subsidence along y-axis is negative, and 0, −4.12, −8.23 and −12.01 mm are the maximal subsidences of the four kinds of ground, respectively. Simulation results show that the subsidence of footboard points to inferior anterior in early stage of stand phase, while points to posterior aspect in late stage. The subsidence tends to point to posterior aspect in the whole. These results are basically consistent with the gait characteristics of human walking on sand. Gait simulation of the robot for human walking on sand is achieved.

Keywords

robot / gait simulation / sand bearing characteristic / compliance control

References

[1] HesseS., UhlenbrockD.. Mechanized gait trainer for restoration of gait[J]. Journal of Rehabilitation Research and Development, 2000, 37(6): 701-708

[2] HesseS., SchmidtH., WernnerC.. Machines to support motor rehabilitation after stroke[J]. Journal of Rehabilitation Research and Development, 2006, 43(5): 671-678

[3] XiaoS.-j., ChenC.-fu.. Mechanical mechanism analysis of tension type anchor based on shear displacement method[J]. J Cent South Univ Technol, 2008, 15(1): 106-111

[4] SchmidtH., PiorkoF., BernhardtR., KruqerJ., HesseS.. Synthesis of perturbations for gait rehabilitation robots[C]. Proceedings of IEEE International Conference on Rehabilitation Robotics, 2005, Chicago, IEEE Press: 74-77

[5] PathakP. M., MukherjeeA., DasguptaA.. Impedance control of space robot[J]. International Journal of Modelling and Simulation, 2006, 26(4): 316-322

[6] HuntK. J., JackL. P., PennycottA., PerretC., BaumbergerM., KakebeekeT. H.. Control of work rate-driven exercise facilitates cardiopulmonary training and assessment during robot-assisted gait in incomplete spinal cord injury[J]. Biomedical Signal Processing and Control, 2008, 3(1): 19-28

[7] HidlerJ. M., WallA. E.. Alterations in muscle activation patterns during robotic-assisted walking[J]. Clinical Biomechanics, 2005, 20(2): 184-193

[8] TongX.-q., ShenM., ChenG.-liang.. Impedance control characteristic of active reactor[J]. Journal of Xi’an University of Technology, 2007, 23(1): 25-28

[9] TsujiT., TanakaY.. Tracking control properties of human-robotic systems based on impedance control[C]. Transactions on Systems, Man and Cybernetics, Part A (Systems & Humans), 2005, Hiroshima, Hiroshima University Press: 523-535

[10] RiddleB., NelsonC.. Impedance control for critically coupled cavities[C]. International Frequency Control Symposium and Exhibition, 2005, Vancouver, Naval Observatory: 488-493

[11] ZhangK.-jian.Vehicle terramechanics[M], 2002, Beijing, Defense Industry Press: 156-178

[12] WongJ. Y., ReeceA. R.. Prediction of rigid wheel performance based on the analysis of soil wheel stresses[J]. Journal of Terramechanics(Part I), 1967, 4(1): 81-98

[13] CapiG., NasuY., BarolliL., MitobeK., YamanoM.. Real time generation of humanoid robot optimal gait for going upstairs using intelligent algorithms[J]. Industrial Robot, 2001, 28(6): 489-497

[14] ThangavadiveluS., TaylorR., ClarkS., SlocombeJ.. Measuring soil properties to predict tractive performance of an agricultural drive tire[J]. Journal of Terramechanics, 1994, 31(4): 215-225

[15] IagnemmaK., KangS., ShiblyH., DubowskyS.. Online terrain parameter estimation for wheeled mobile robots with application to planetary rovers[J]. IEEE Transactions on Robotics, 2004, 20(5): 921-927