Study On Stability Adjustment Strategy Of Hexapod Robot With Leg Injury

In the unstructured environment,the road condition is rugged,the weather condition is bad,and the external impact is severe.During the operation of hexapod robot,the failure of the leg joint chain often occurs due to environmental factors and self damage.The leg injury or joint failure of the robot limits the movement ability of the foot,destroys the overall stability of the robot,and then reduces the movement ability of the robot body.Limited by the harsh environment and working conditions,it is difficult for maintenance personnel to enter some areas to repair and replace the robot.In view of the damage and failure of some legs of hexapod robot,the research on the stability control strategy after the leg injury is helpful to enhance the survival ability of robot in the harsh environment,and the research work is of great significance.In this paper,based on the above objectives,the advantages of redundant degrees of freedom of hexapod robot are brought into full play.According to the type characteristics of hexapod robot after each leg injury,the corresponding stability adjustment strategy is proposed,and the stability recovery effect after adjustment is verified by experiments.The following are the main research contents of this subject:The mechanical structure design and control system construction of the hexapod robot are carried out based on the body structure of the foot insect and the knowledge of robotics.The hexagonal fuselage with obvious control advantages is adopted,and the leg structure adopts carbon plate hollow structure,which not only makes the robot lightweight,but also ensures the structure firm and reliable.The precise force sensor and gyroscope are used to collect the dynamic stress and body attitude angle of the hexapod robot when it is walking,which lays the foundation for further optimizing the control algorithm.Based on the kinematic analysis of a single leg of a hexapod robot,the pose of the end point of the foot in the global coordinate system is obtained,and the joint angles are obtained through inverse kinematics to realize the accurate control of the leg.The expression of the workspace of the single leg and the workspace of the foot at any height of the robot is solved,which paves the way for the research of the stability restoration measures of the six legged robot with leg damage.Based on the research of stability determination methods and influencing factors,and combined with the characteristics of hexapod robot,two static stability determination methods are used as the determination method in this paper.The model of hexapod robot is simplified,and the main influencing factors of its stability in the process of movement are analyzed theoretically,which provides an improved idea for adjusting strategy.In order to study all kinds of situations of six legged robot after leg injury systematically,this paper classifies them according to the number and position of damaged legs.For each type of damage,the stability margin is calculated according to the obtained foot end motion space,and the motion stage and unstable state with poor stability are obtained.In order to improve the stability of the six legged robot with leg injury,the corresponding adjustment strategy is proposed through numerical solution.Build different experimental scenarios,design multiple groups of comparative experiments,and collect multiple technical index data.The experimental phenomena of hexapod robot walking in normal gait,before and after adjustment of Hexapod Robot with single leg injury,and before and after adjustment of two types of bipedal injury hexapod robot were observed and analyzed.The experimental data show that the walking stability of the six legged robot is improved after adjustment,which verifies the correctness and effectiveness of the adjustment strategy.