Target joint support moments of each leg are determined by estimating joint moments of the each leg necessary for the person A wearing a leg motion support orthosis ( 1 ) to make a motion independently and according to the estimated joint moments. Moreover, floor reaction forces for the support orthosis ( 1 ) to make a motion independently are estimated, and then estimated values of actual joint support moments actually applied from the support orthosis ( 1 ) to the joints of the each leg of the person (A) are found by using the estimated floor reaction forces and outputs of the force sensor ( 22 ) provided in a leg link portion ( 4 ) of the support orthosis ( 1 ). Torque generation units ( 15 ) and ( 16 ) of the support orthosis ( 1 ) are controlled in such a way that the estimated values of the actual joint support moments are coincident with the target joint support moments. Thereby, the leg motion of the person can be supported. Moreover, it effectively prevents forces other than the necessary forces to support the leg motion of the person from acting on the person and enables the person to make a leg motion with feeling as if the person were not wearing the leg motion support orthosis as fully as possible.
Support moment control method for leg motion support orthosis