Control Strategy for Hydraulic Hybrid Servo Drive System of Heavy Load Robot

Abstract

A kind of compound servo drive system is designed using the characteristics of hydraulic motor large torque and servo motor high accuracy positioning. Proportional pressure valve, proportional flow valve and electromagnetic directional valve was used to control hydraulic motor for tracking servo motor drive control and to achieve servo motor control for weight load of large torque and high accuracy positioning. Pressure, speed control strategy of using PID control is proposed based on the above hydraulic tracking drive system, achieve precise control for trajectory of robot articulated arm under heavy load conditions. And according to the requirements of the pressure, flow rate and reversing in the process of compound servo drive, a torque, speed and direction of the switching control strategy is put forward. Mathematical model is established and simulated based on tracking control system. The experiments indicate: under heavy load conditions, response speed, torque and angle control accuracy of hydraulic hybrid drive system meet the requirements with this control method and torque, speed switching control strategy.