Control methods and the performance of the robotic testing system for human musculoskeletal joints

Biomechanical testing of human musculoskeletal joints not only requires qualified testing machines and devices, but also needs an excellent control method to obtain better experimental results. In this paper, we take the human functional spinal unit (FSU) as an example to study how to improve the performance of the robotic testing system. First, the mechanical characteristics of FSU are described and the simplified model (rigid body-spring system) for the specimen is given. Because the location of the center of rotation (COR) of the specimen affects the performance of the system, a comprehensive analysis on the location of COR is carried out. The performance of the robotic testing system can also be improved through the improvement of the control method. Two control methods have been proposed in this paper: one is the improved hybrid control, the other is fuzzy logic control.