Fast hybrid position / force control of a parallel kinematic load simulator for 6-DOF Hardware-in-the-Loop axle tests

This contribution presents a hybrid position/force control strategy which is used to operate a hydraulic hexapod in contact with a complex environment. The hexapod serves as an excitation unit in a Hardware-in-the-Loop axle test rig. It is used to reproduce measured or simulated road excitations on the wheel carrier of a MacPherson suspension strut which is rigidly connected to it via a wheel force transducer. The overall test rig system provides a novel method for the development and testing of mechatronic vehicle axles. Following a short introduction and description of the test rig, the modeling and control of the hexapod is presented. Test rig measurements for a square force and position input as well as a sinusoidal force input are provided to evaluate the control performance achieved thus far.