Computed-Torque and Variable-Structure Multi-Variable Control of a Hydraulic Industrial Robot

The paper considers the application of a mathematical model proposed for the control of hydraulic robots with large supply pressure. The model of the Workmaster hydraulic robot, formerly manufactured by Thorn EMI Robotics, is simplified and used for the computed-torque and variable-structure control applications both in simulation and in practice. The model-based controllers are examined, and new insight is gained into the working of hydraulic robots. The use of pressure feedback for compensating the supply-line dynamics is practically demonstrated.