LEG JOINT ASSIST DEVICE FOR LEG TYPE MOVABLE ROBOT

摘要

An assist device 14 has a spring means 15 that produces an auxiliary driving force, by elastic energy, acting on the joint 8 of a leg 3. The spring means 15 is a gas spring having a cylinder 17 and a piston 18, and the bending and stretching motion between link members 4, 5 in the joint 8 is transmitted through a motion transmitting means 16 having a link arm 22 and the like. The spring means 15 is designed so that the auxiliary driving force increases with increasing knee bend angle theta until the knee bend angle theta reaches a predetermined angle and so that after the predetermined angle has been exceeded, the auxiliary driving force becomes lower than the driving force corresponding to the predetermined angle. This makes it possible to effectively lighten the burden on an actuator for the joint 8 of a leg type movable robot and hence to secure a satisfactory energy utilization efficiency and to achieve reduction in size of the construction.