Patent ID: 8551027

Claim:
An assist device including a power source, an actuator, and a control device for controlling an operation of the actuator by adjusting a supplied electricity from the power source to the actuator, for assisting a motion of or relieving a body burden of an agent by acting an output generated by the operation of the actuator to a body of the agent via a contact element; wherein the control device comprises: a state monitoring means which measures a state of charge of the power source or an available electricity thereof; a first control means which adjusts the output of the actuator, on condition that the state of charge of the power source or the available electricity thereof is equal to or less than a first threshold value, so that a motion assist rate of the assist device becomes lower than in a case where the state of charge of the power source or the available electricity thereof exceeds the first threshold value and also decreases by a greater degree as the state of charge of the power source or the available electricity thereof becomes lower; and a second control means which stops the operation of the actuator, on condition that the state of charge of the power source or the available electricity thereof is equal to or less than a second threshold value which is smaller than the first threshold value, wherein the first control means decreases the motion assist rate of the assist device by shortening a first period in which the output of the actuator is relatively high among a motion period of the agent, and on the other hand extending a second period in which the output of the actuator is lower than in the first period, wherein the assist device comprises a motor as the actuator, and wherein the first control means breaks the movement of the agent by controlling the output of the motor during the second period to be in reverse polarity to the output of the motor during the first period, so as to generate a regenerative electric power by the motor.