Biped Walking Control
Currently, most biped robot use electric motor actuator. However, the motor has a disadvantage in that the weight is heavy and the output is low relative to the weight and is not robust against the external shock. In order to overcome disadvantage of motor, we used pneumatic actuator. It has an advantage that the output is high in weight and the external shock absorption is possible by using the compressibility of the air itself. Therefore, we adopted a double-acting cylinder-type pneumatic actuator that can simultaneously control the stiffness of the actuator and the force in both directions.
This study mainly consists of developing algorithms for pressure and position control of pneumatic actuators. Currently, robots are in the form of a one-legged robot that looks like human legs. Therefore, the leap of one-legged robot and control of actuator for jumping are studied. The robot uses a double-acting cylinder type pneumatic actuator and verifies the performance of the actuator through position control based on pressure control. For the jumping, we propose a jump control strategy using the ground reaction force acting on the robot to make a stable transition from a landed system to a flight system. For the landing, we propose a stable landing strategy using stiffness and damping control of pneumatic actuators to reduce the impact force when landing.
From the viewpoint of switched system control, research of one-legged hopping is a precedent study for bipedal walking. We designed a one-legged robot based on pneumatic actuators and proposed jumping and landing control algorithms.