Development of Semi-active Universal Joint with Rotational Magnetorheological Fluid Damper for Unmanned Ground Vehicle

Tough unmanned ground vehicles (UGVs) ordinally move on level grounds. However, several types of tough UGVs have been designed and developed for locomotion on uneven grounds. They are employed in agricultural robots, disaster robots, and robots used for hazardous applications. Especially, semi-active damping elements are one of the smart structures and potential solutions for highly stable locomotive robots. In this study, we propose a vibration control unit with a Magnetorheological Fluid (MRF)-based semi-active universal joint (SAUJ) for stable delivery equipment that can be attached to a UGV operating on uneven ground. The basic structure and controller of the SAUJ are proposed. In addition, its performance is experimentally evaluated on the ground and a moving UGV. According to the experimental results, vibration control of the SAUJ successfully decreased the perturbation of a pendulum swing due to the acceleration of the UGV.