Design of a robotic walking simulator for neurological rehabilitation

The restoration of walking capability is a key goal for patients after suffering from a stroke, traumatic brain injury or spinal cord injury. The paper describes a robotic device which enables the therapist to let the machine move the patients feet on programmable foot trajectories. On this device the patients feet are permanently fixed on two footplates. Force sensors are mounted on the footplates with compliance control algorithms for online adaptation of the foot trajectories to the patients walking capabilities. Furthermore, the kinematic and kinetic design parameters of the robotic system enable the machine to be used as a universal walking simulator, not just for rehabilitation purposes. In the haptic mode, the machine behaves as a haptic foot device for a variety of virtual ground conditions. Due to the high dynamic range needed to guide real walking trajectories, conventional industrial robots are not suitable for this task. Hence the authors developed a special robot system with high dynamics. This paper describes the development aspects of the design process of the new walking simulator.