Design And Implementation Of Motion Control System For Small Hexapod Robot

Hexapod robot is suitable for load-bearing walking on unstructured terrain because of its strong motion ability,load capacity and relatively high stability.Therefore,it has broad application prospects.At the same time,the characteristics of the Hexapod robot,such as many legs connecting rods,complex electrical system and various software tasks,bring challenges to the coordinated synchronization and real-time control of the robot control system.At present,the common control system of hexapod robot is complex in hardware and software,high in economic cost and time cost,and mostly suitable for large-scale heavyduty robots.The main research content of this thesis is to design and implement a small hexapod robot motion control system with strong real-time,large data bandwidth,high reliability and good economy.This thesis starts with the structural characteristics of the robot studied,analyzes the forward and inverse kinematics of the control object,and determines the requirements of task decomposition,hierarchical division and computation,data bandwidth and real-time of the control system.STM32 controller,RS485 bus and a variety of sensors are selected to build the hardware platform of the control system.The scheme design of the control system is completed.The robot's gait planning chooses 3+3 gaits which have advantages in speed and carrying capacity.The swing phase and supporting foot trajectory are planned by polynomial curve.Through planning of the landing angle of the end leg,the mapping relationship between the foot velocity and the joint velocity is solved by numerical method when the Jacobian matrix is a singular matrix in the case of redundancy of degrees of freedom,and the motion planning of the robot is completed.According to the scheme design of control system and the top-down design idea,the software task module division is determined in this thesis.The key tasks of RS485+DMA bus communication,multi-channel AD+DMA conversion,motion planning and motion control based on kinematics are described in detail.The realization process of interruption priority,task scheduling logic flow and timing synchronization mechanism of software tasks is described.The measures to ensure the reliability of the system are briefly described,and the software design and implementation of the control system are completed.Finally,test examples are designed to test the key tasks of the system,which proves that the system has high real-time performance and reliability.Complete the experiments of motor following characteristics,single leg motion control and coordinated synchronous swing of lower leg of different controllers.These experiments prove that the system has good performance at low cost,meets the main requirements of the system,and has high application value.