The Gait Planning And Optimization Of Quadruped Robot

The general mobile robot includes wheeled robot and tracked robot,however,when faced with the mountains,hills and other unstructured terrain,it is necessary to develop quadruped robot to deal with such a complex environment.Hydraulic quadruped biorobot has the advantages of high load capacity,strong adaptability,and good motion performance and so on,it has become a research hotspots in the field of mobile robot in recent years.In this paper,we have developed a hydraulic quadruped bio-robot as the experimental platform and research object,the work of gait planning and its optimization method of quadruped robot was studied in depth.The main research work and contributions are as follows:(1)The optimization design based on gait parameters.The optimization of step sequence focusing on static gait stability of quadruped robot problem,the optimal step sequence based on the stability margin of the support polygon is studied.Quadruped robot moving in different step sequence has a significant impact on motion stability and energy consumption.Using the method of exhaustion to compare all possible step orders,the motion performance of quadruped robot in different step sequence are analyzed by comparing adjusting frequency of the center gravity and stability margin.A series of simulation experiments were carried out to verify the proposed optimization method,and finally the optimal step of the robot in static gait was obtained.The optimization of stride length use the strategy of function fitting with the velocity and the evaluation function.It is required that the optimization of stride length can be derived from the forward speed of specific demand,so that the optimization of stride length can be realized.(2)The optimization design based on foot trajectory.The influence of quadruped robot's motion performance by changing the local geometric characteristics of foot trajectory was studied.The effectiveness of the optimization design of the foot trajectory was verified through the optimization and adjustment of the Bezier curves and the simulation analysis.The experimental result shows that the study in the relationship between the geometric characteristics of the foot trajectory and the motion performance of the quadruped robot greatly improved motion performance of the robot.(3)The optimization design based on the body lateral adjustment,and a new optimization method based on intelligent optimization algorithm was proposed.This paper designed two kinds of optimization models based on the body intermittent lateral adjustment and continuous lateral adjustment.And focusing on static gait planning problem when the quadruped robot was adjusting laterally,a new method based on particle swarm optimization(PSO)was proposed to optimize the lateral adjustment parameter.The design variable was the body lateral adjustment parameter in motion.Stability,linearity and other motion performances were considered comprehensively in the objective function.Besides,the simulation experiments were carried out to verify the proposed optimization method in MATLAB and ADAMS.Experimental results show the searching of global optimal parameters can be done quickly and efficiently by the proposed algorithm,such that the robot can achieve a good performance during static gait.(4)The structure design and the idea of the physical prototype of the hydraulic quadruped bio-robot are expounded systematically in the paper.And a large number of physical prototype experiments are carried out such as the Walking speed test,the Loading capacity test,the Self-balancing capacity test,the Climbing ability test,the Automatic following capability test,and the Lateral impact resistance test,which played a crucial role in the improvement and verification of theoretical study,and also proved the value of the results of this paper.From the bottom of the optimization design based on gait parameters,to the middle of the optimization design based on the foot trajectory,and then to the top of the optimization design based on the body lateral adjustment,besides,an optimization method based on intelligent optimization algorithm was proposed.Focusing on the problem of static gait optimization of quadruped robot we did full range of research and analysis in this paper.Through the virtual prototype simulation and physical prototype experiment,it has certain theoretical innovation and engineering practice value.Finally through the virtual prototype simulation and physical prototype experiment verified the theoretical innovation and engineering practice value of this paper.