Controller design based on viscoelasticity dynamics model and experiment for flexible drive unit

Abstract

In order to ensure that the system has the advantage of light weight and vibration absorption, the steel rope is used as a flexible transmission part. A flexible drive unit (FDU) is developed, whose features are guided by steel rope, increasing force by the movable pulley group, modular, convenient and flexible. Dynamics model for controller is deduced based on the constitutive equation of viscoelasticity. Controller is designed for position control and is based on the viscoelasticity dynamics model compensation control strategy proposed. The control system is based on the TURBO PMAC multi-axis motion control card. Prototype loading experiments and velocity experiments results show that the FDU can reach 2 Hz with no load and the max speed of 30 (°)/s. The FDU has the capability of the load torque 11.2 N·m and the speed of 24 (°)/s simultaneously, and the frequency response is 1.3 Hz. The FDU can be used to be the pitch joint of hip for biped robot whose walking speed is 0.144 km/h theoretically.

Keywords

flexible drive unit / steel rope drive / viscoelasticity dynamic model / speed-load characteristic

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