Performance of Impedance Control-Based Strategies in Power-Assisted Wheelchairs: A Predictive Simulation Study

Area of Science:

• Robotics and Biomechanics
• Assistive Technology
• Human-Machine Interaction

Background:

• Manual wheelchair propulsion leads to upper extremity strain.
• Power-assisted wheelchairs (PAWs) reduce user effort and injury risk.
• Impedance control offers natural user-wheelchair interaction and disturbance rejection.

Purpose of the Study:

• Investigate the benefits and drawbacks of impedance control for PAWs.
• Evaluate impedance control performance across various simulated locomotion scenarios.
• Identify areas for improvement in PAW control strategies.

Main Methods:

• Utilized predictive simulations with a biomechanically realistic upper extremity model.
• Solved an optimal control problem for user-wheelchair interaction.
• Simulated steady-state and transient locomotion on level and ramp surfaces.

Main Results:

• Impedance control effectively reduced user effort and matched reference models.
• Inertia was more impactful in transient maneuvers; friction dominated steady-state locomotion.
• Constant-parameter linear reference models led to inefficient energy dissipation during recovery.

Conclusions:

• Impedance control is promising for PAWs but requires refinement.
• Optimizing reference models or incorporating energy regeneration can enhance efficiency.
• This study pioneers PAW impedance control analysis using predictive simulation and realistic models.