Research Of Controller For Hydraulic Quadruped Robot

As a typical legged robot, quadruped robot attracts extensive attention because of its high flexibility, stability and loaded capability when moving in complicated terrain. The real-time and stable control is an important guarantee for quadruped robot to accomplish complex tasks. Therefore, according to the real-time and stable control requirements, this article carrys on motion planning and controller desinging based on the quadruped robot.According to the characteristics of hydraulic quadruped robot, with hydraulic single leg of quadruped robot as the research object, this article uses the D-H method to analyze the direct and inverse kinematicsand and convert the motion from the joint space to hydraulic drive space; In order to realize single leg's vertical jumping movement, this article designs the tail end track and simulats it with ADAMS for verifing the validity of kinematics calculation and gait planning.According to the control requirements of robot, an overall framework of distributed multi CPU controller based on CAN bus is proposed; According to the overall architecture of the controller, hardware requirements for the various levels of the controller is analyzed, for motion planning and control layer, hardware PCI104 single board computer is selected as the core processor, CAN communication card and AD card are composed of main hardware; Through the analysis of the function and performance demand of quadruped robot, combined with PCI104 advantages in resources, multithreaded software design plan based on QNX real-time systems is proposed, and combined with the characteristics of the thread function, its priority and scheduling strategy is provided. Therefore, main task threads are implemented.As for executive layer, DSP is selected as the core processor, the minimum system circuit and expansion circuit are analyzed; for the software, the CAN bus communication program is designed;A Fuzzy-PID algorithm is designed to control the position servo actuator, and through compared simulating and experiment of tracking step response signal to verify its relative advantages to conventional PID.In order to prove the individual modules can realize the corresponding functions, the block test of the controller is desinged; For testing overall controller's reliability and the accuracy of the simulation results,the single leg jumping experiment is designed.