Optimal Posture Determination Methods for Variable Stiffness Tendon Driven Arms

Under the human environment, robot arms are desired to have safety and versatility. There is a tendon driven arm using nonlinear springs as a mechanism that meets the requirement. By using springs, this mechanism can ensure safety at the time of contact. Moreover, by using nonlinear springs, it is possible to mechanically adjust the stiffness of the arm. Determining the arm posture is important to maximize the performance of the robot. In this paper, we focus on the posture which minimizes the burden by distributing the required torque to each actuator when the robots perform tasks. I proposed the algorithm that simply determines the optimal posture (Method 1) and the algorithm that reduces calculation cost by using the tension difference limit (Method2). I confirmed equivalent posture determination by both methods and compared calculation cost. I confirmed calculation cost can be shortened by the Method2.