Motion Control And Implementation Of Quadruped Robot’s Single Leg And Rotating Platform

Hydraulic quadruped robot, as one of typical representatives of the mechanical-electronhydraulic technology, which has its unique environmental adaptability, large load capacity, goodstability and the high mobility, is becoming an important development direction in the field of therobots. The stable movement gait and reliable motion control system are the key technique of therobots. Here a hydraulic quadruped robot was focused. The dynamics model of robot’s single leg wasconstructed. The dynamics characteristic of the robot and the position control of the single leg wereanalyzed. Furthermore, a three-channel servo valve driver circuit, stepper motor controller based onFPGA and the test system of test bench rotation angle were designed.Firstly, the robot dynamics model of single leg was properly analyzed and simplified with theLagrange equations of mechanics, so as to provide important mechanical basis for dynamic stabilityresearch of robots. On this basis of the dynamics model, the linear quadratic control was selected afterthe analysis and comparison of the result which acquired by torque method and linear quadraticcontrol method.Secondly, according to the driving characteristics of hydraulic cylinder and servo valve of thehydraulic quadruped robot, the three-channel servo valve driving circuit was designed. The printedcircuit board was developed subsequently after simulation analysis in Multisim, and poweramplification of weak control signal was also realized. The circuit board was tested with a controllingmodel built by the hardware-in-the-loop simulation test system, the causes of the phenomenoncharacteristics of test results were analyzed, providing the basis for the control method improvementof robot.Finally, in order to study the control mechanism of the robot at different tilt angles， the stepmotor controller based on FPGA was designed to control rotation of the platform. The platform canrotate at a constant speed or a constant acceleration/deceleration. The automatic measurement systemof the platform rotation angle was composed by microcontroller chip and AD chip. The system canautomatically acquire the date by serial communication.