A Novel Variable Stiffness Suspension System for Improved Stability and Control of Tactile Mobile Manipulators

Mobile manipulators (MM) have proven valuable in assisting humans in industrial settings. However, their strict separation from humans in controlled environments limits their effectiveness. Efforts have been made to bridge this gap for physical human-robot interaction (pHRI), leading to the development of collaborative mobile manipulators (CMM). Nonetheless, unpredictable environments continue to present challenges. This paper introduces an innovative suspension design for mobile bases (MBs) to enhance the safety and au- tonomy of CMMs. We propose an electromechanical approach leveraging variable stiffness and combining passive springs with adaptive transmission mechanisms. Through simulation, physical prototype development, and experimental validation, we demonstrate the effectiveness of our approach in stabilizing the MB against external disturbances. Our findings provide valuable insights for the development of CMMs in dynamic environments.