ABSTRACT: In this talk, I will first show several types of robots which interact with their environments demanding for compliancy in actuation system. I will then explain my previous efforts on force control using adjustable compliancy series elastic actuators with electromagnetic motor and adjustable stiffness series elasticity. After this, I will explain about our activities on conceptual design of new mechanisms of adjustable stiffness artificial tendons (ASAT). As to prevent the complexity, I will present a simplified model of a walking robot. In addition, as for the bipedal robots for efficient locomotion, the ASATs have been attached at the ankle joint of the robot to study their effects on reducing the energy losses during "Collision" phase. In general, I will introduce our results out of simulations. By the results, I will introduce a new simplified model of a bipedal robot to prevent the complexity and to study the complete walking cycle. The front leg of the robot includes foot, leg with a locked knee and ASAT at ankle joint. The trailing leg of the robot assumed as a mass less adjustable stiffness spring. ASAT stores the energy during "Collision" phase of each step of walking. Then it will return the energy during "Rebound" phase. The potential energy stored in trailing leg injects to the robot during double support phase. Then, I will demonstrate that velocity of the robot can be controlled by controlling the energy difference between injecting energy from trailing leg and energy losses during "Collision" phase. At the end, I will show the results of the simulation and will open the discussion. |