A Series elastic Robot for Back pain Rehabilitation
This paper addresses the robot assisted rehabilitation of back pain, an epidemic health problem affecting a large portion of the population. The design is composed of two springs in series connected to an end effector via a pair of antagonistic cables. The spring and cable arrangement forms an elastic coupling from the actuator to the output shaft. An input output torque model of the series elastic mechanism is established and studied numerically. The study also illustrates the variation of the mechanism's effective stiffness by changing the springs' position. In addition, we built a prototype of the robotic mechanism and design experiments with a robotic manipulator to experimentally investigate its dynamic characteristics. The experimental results confirm the predicted elasticity between the input motion and the output torque at the end effector. We also observe an agreement between the data generated by the torque model and data collected from the experiments. An experiment with a full scale robot and a human subject is carried out to investigate the human robot interaction and the mechanism behavior.