Hydraulic actuator analysis for industrial robot multivariable control

This paper aims to obtain a general mathematical function for hydraulic actuators which can be used for the design of multivariable controllers. The paper shows that the current/torque relationships of linear and rotary actuators may be represented as first order, resulting overall in a third order input/output function for robots with large supply pressure. The model caters for the greatest source of instability in hydraulic systems, namely …