Research On The Joint Control System Of A Modular Multi-Legged Walking Robot

Due to its good adaptability to complex terrain and high flexibility, multi-legged walking robots have become a research hotspot. To obtain good dynamic characteristics, the base-level control system is very important. It is mainly responsible for controlling the joints'motion and coordinating different joints to control the robot's movement. This paper focuses on the robot's joint control system of a modular multi-legged walking robot, which is located on the base level of the control system. The work is as follows:According to the mechanism characteristics of the modular multi-legged walking robot, the distributed control system architecture based on CAN bus is presented. The architecture consists of the robot's body control level and the base driving level which are respectively responsible for the motion planning and driving control. The robot's motion control is accomplished by the two system's coordination.The modular joint control system architecture is proposed. The joint control system based on CAN bus, which is located on the base level of the robot's distributed control system architecture, is designed and realized. The microprocessor, dedicated motion controlling and driving chip, optical encoder are adopted to realize the joints'closed-loop servo motion control. CAN bus is introduced as the communication interface for different modules and it supports the multi joints'real-time control effectively.The expansive software architecture featuring three abstract layers is proposed, which include the hardware-independent layer, defined-function layer and application layer. Such architecture gives support to the control system's modularization. The characteristics of the architecture are studied. Its application in the motor control and CAN bus communication program is discussed in detail. According to the requirements of the joint control system, the protocol of the CAN bus communication is researched into.The joint control system is proved effective through experiments on the single joint's motion control and multi joints'coordination. The suggestions of improving the robot's motion performance are proposed.