Patent ID: 9566705
Date: 2017-02-14
CPC Classifications: A61F,A61H,B25J,Y10S

Claim:
1. A method for the control of an exoskeleton comprising a plurality of segments and one or more powered joints associated with lower limbs of a user, the method comprising: obtaining a configuration of a body of the user associated with the exoskeleton with respect to an inertia reference frame and an angular velocity of each of the powered joints; estimating an effect of gravity on the lower limbs of the user based on the configuration; computing a first control torque for each of the powered joints that at least partially reduces the effect of gravity on an associated one of the lower limbs of the user based on the configuration; calculating a gravitational energy gradient for each of the powered joints based on a product of the respective angular velocity and the respective first control torque; attenuating the first control torque for each of the powered joints by an attenuation amount selected according to a sign of the respective gravitational energy gradient to yield a second control torque for each of the powered joints; and applying a final control torque via each of the powered joints, the final control torque based, at least in part, on the respective second control torque, wherein the attenuation amount is zero when the sign is positive, and wherein the attenuation amount is equal to the respective first control torque when the sign is negative.