Motion control method of seat-style Omnidirectional mobile walker using a digital acceleration control method

Regaining walking capability is a long-term and difficult process for patients and therapists alike. To reduce the therapists' burden, the authors and their colleagues developed a seat-style omnidirectional mobile walker (SOMW) to sustain patients helping them to recover muscle strength in their lower limbs. Physical therapists can design specific recovery paths for different patients and store them in the SOMW. However, tracking errors caused by friction on different types of ground seriously affect the rehabilitation. Therefore, this paper designs a motion controller based on the digital acceleration control method to promote the performance of the SOMW. First, according to the structure of the robot, the kinematics and kinetics models are derived. The simulation of the digital acceleration control algorithm is then executed and achieves a satisfactory performance. Finally, the results of experiments performed on the prototype robot verify the feasibility and effectiveness of the digital acceleration control method on tracking control of the SOMW.