Patent ID: 8251930

Claim:
A walking assistance device comprising: a body-mounted assembly adapted to be attached to a waist or torso or a thigh of a user; a pair of foot-mounted assemblies which are to be respectively attached to the feet of legs of the user; a pair of leg links which connects the foot-mounted assemblies and the body-mounted assembly, respectively; a first joint constituting a portion that connects each leg link and the body-mounted assembly; a second joint provided at a middle of each leg link, a third joint constituting a portion that connects each leg link and each foot-mounted assembly, and a pair of actuators that drives the second joints of the leg links, each of the foot-mounted assemblies including a ground contact portion adapted to come in contact with the ground such that a floor reaction force for supporting the user and the walking assistance device on a floor surface acts in a state wherein a leg of the user becomes a standing leg, the walking assistance device further comprising: a floor reaction force detecting element configured to detect a floor reaction force acting on the ground contact portion of each foot-mounted assembly, the floor reaction force being detected as a three-dimensional floor reaction force vector; and an actuator control element configured to calculate a target value for a magnitude of a supporting force to be transmitted to each leg link in the floor reaction force vector and to control each of the actuators such that a supporting force having the magnitude of the target value is transmitted to the leg link from the foot-mounted assembly, wherein the actuator control element calculates the target value by an operation consisting of multiplying an absolute value of the detected floor reaction force vector of each foot-mounted assembly by a preset ratio, wherein the actuator control element is configured to set the target value for the magnitude of the supporting force to be transmitted to the leg link of a free leg of the user to zero.