Instability Adjustment Strategy And Gait Planning For Hexapod Robot Single Leg Failure

When the hexapod robot moves in a dangerous or catastrophic environment,the legs are prone to failure and cannot be repaired manually in a timely manner.If the faulty robot can find a gait that allows it to continue to move according to the current situation,it is believed that the robot can perform fault-tolerant motion in the current fault situation,which will improve the suitability of the hexapod robot in an unknown environment.In this paper,the stability of the support leg failure occurs during the movement of the hexapod robot,and the new gait is generated according to the remaining normal legs according to the current situation.There are four parts to the content:First of all,when the hexapod robot in the triangular gait movement,the support leg when the single leg failure of the situation of instability analysis;The force,torque balance and real-time center of gravity of the single-leg failure of hexapod robot were analyzed.The stability analysis of the single-leg failure of hexapod robot is carried out by the combination of zero torque point method and force-angle stability cone method to determine whether the robot has been unsteady and turned over.Secondly,according to the characteristics of the single-legged failure of the hexapod robot unsteady and overturned,an effective support plane is constructed.The analysis solution of adjusting the foot end of the adjusted leg can reach the space is calculated,and the method of adjusting the maximum strength arm of the adjusted leg is used to select the footing point of the adjustment leg;The constraints of joint drive and adjustment time are sought,and the footdrop point of the adjustment leg is confirmed during the adjustment time.When the one-legged of the hexapod robot reaches static stability,adjust the body position to the initial position of the next moving state.And then,according to the instability determination process,the dynamic stability of the single-legged failure of the hexapod robot is analyzed,and a relatively stable set of fault-tolerant gait is obtained.The basic rhythmic motion signal is obtained by analyzing the CPG network topology and weight matrix.An adaptive fault-tolerant gait control method based on the hub mode generator?CPG?is designed to construct the rhythmic occurrence layer?RG?and the pattern occurrence layer?PF?of the CPG model respectively.Numerical simulation of the failure of A₄ legs is carried out,and the joint output signal curve under adaptive fault-tolerant gait is obtained through MATLAB simulation.At last,the model and control system of the robot are constructed by Adams and MATLAB joint simulation,and the instability adjustment strategy and adaptive fault-tolerant gait are simulated and verified respectively.The results show that the instability adjustment strategy can prevent the robot from over seating the body by the one-legged failure during the movement.The simulation comparison of CPG-based adaptive fault-tolerant gait with conventional fault-tolerant gait is compared,and the adaptive fault-tolerant gait has been verified to have better stability and effectiveness by comparing and collecting data information such as force,driving force moment and stability margin at the foot end.