Patent ID: 7771373
Filing Date: 2010-08-10
Classification: A61H,B25J

Abstract:
1. A control device of a walking assisting device, wherein the walking assisting device has a left and right side and is provided with a seating part that receives from above a part of a weight of a user sitting thereon, a pair of right and left thigh frames joined respectively to the seating part through an intermediary of first joints, a pair of right and left crus frames joined respectively to the thigh frames through an intermediary of second joints, a pair of right and left foot-worn assemblies that are respectively joined to the crus frames through an intermediary of third joints and respectively configured for attaching to the feet of a right and left leg of the user and for coming into contact with the ground when the legs of the user become standing legs, an actuator for the left side of the device for driving the second joint among the joints of a left leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the left side, and an actuator for the right side of the device for driving a second joint among joints of a right leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the right side, wherein the control device comprises: a treading force measuring element adapted to calculate a treading force of each leg of the user based on a force detection value indicated by an output of a first force sensor provided in each of the foot-worn assemblies; a second force sensor provided between a bottom end of the crus frame and the third joint of each leg link or between the third joint and the foot-worn assembly of each leg link; a force-to-be-controlled actual value measuring element adapted to calculate, as an actual value of a force-to-be-controlled, a force actually transmitted from the floor to the crus frame of each leg link based on a force detection value indicated by an output of the second force sensor; a desired assist ratio setting means for setting a desired assist ratio, which is a desired value of a ratio of a force to be supplied by the walking assisting device in a total treading force, which is a total sum of the treading forces of the legs of the user, relative to the total treading force; a desired lifting share determining means for determining a desired lifting share which is a desired value of a share of the left leg link and a desired lifting share which is the desired value of a share of the right leg link in an upward lifting force to be applied to the user from the seating part by multiplying the treading force of each leg of the user, which has been measured by the treading force measuring element, by the desired assist ratio; a distributing element adapted to calculate a distribution of a supporting force required to support, on the floor, a weight obtained by subtracting a total weight of the portions below the second force sensors of the walking assisting device from a total weight of the walking assisting device, or a supporting force required to support the total weight of the walking assisting device on the floor to the leg links on the basis of a ratio between the treading force of the left leg and the treading force of the right leg of the user, which have been measured by the treading force measuring means, thereby determining a share of the left leg link and a share of the right leg link of the supporting force as a desired device supporting force share of each leg link; a force-to-be-controlled desired value determining means for determining a desired value of the force-to-be-controlled of the left leg link based on a total sum of a desired lifting share of the left leg link and a desired device supporting force share of the left leg link and also for determining a desired value of the force-to-be-controlled of the right leg link based on a total sum of a desired lifting share of the right leg link and a desired device supporting force share of the right leg link; and an actuator controller adapted to control the actuator for the left side of the device on the basis of the actual value of the force-to-be-controlled of the left leg link and the desired value of the force-to-be-controlled of the left leg link such that a difference between the actual value of the force-to-be-controlled and the desired value of the left leg link approximates zero and for controlling the actuator for the right side of the device on the basis of the actual value of the force-to-be-controlled of the right leg link and the desired value of the force-to-be-controlled of the right leg link such that a difference between the actual value of the force-to-be-controlled and the desired value of the right leg link approximates zero.