Harmonic Drive Systems Inc.

Nagoya Institute of Technology

Masafumi Yamamoto

Makoto Iwasaki

Yoshifumi Okitsu

Yuki Kato

A positioning control device of an actuator provided with a strain wave gearing has a full-closed control system for feeding back a position of a load shaft, and driving and controlling a motor so as to position the load shaft at a target position. The full-closed control system has an H&#x221e; compensator designed so that, when a generalized plant having angular transmission error in the strain wave gearing as a disturbance input is assumed, an H&#x221e; norm of a transfer function from the disturbance input of the generalized plant to an evaluation output is a predetermined value or less. Mechanical vibration during positioning response caused by angular transmission error in the strain wave gearing can be reliably suppressed.

Positioning control device of actuator provided with strain wave gearing using H-&#x221e; control

A positioning control system is provided with a state-feedback control system with a state observer as a full-closed control system for driving and controlling a motor so that a load shaft, which is an output shaft of a strain wave gearing, is positioned at a target position on the basis of a load shaft position actually detected. The state observer estimates a motor shaft position and a motor velocity based on a control input for the motor and the load shaft position. The state-feedback control system feeds back the state quantity of the object of control using the load shaft position as well as estimated motor shaft position and estimated motor velocity obtained by the state observer. It is possible to suppress resonant vibration caused by angular transmission error in the strain wave gearing and perform highly accurate positioning.

Positioning control device for actuator provided with strain wave gearing using full-closed control with state observer

A positioning control system for an actuator provided with a strain wave gearing is provided with: a semi-closed feedback controller FB(s) that controls a load shaft position &#x3b8;on the basis of a feedback motor shaft position &#x3b8;; and a feedforward linearization compensator configured by incorporating a nonlinear plant model for an object to be controlled into a feedback linearization compensator using an exact linearization technique. The feedforward linearization compensator uses a forward-calculated state quantity estimated value x* to calculate a feedforward current instruction i*and a feedforward motor position instruction &#x3b8;*to be input into the feedback controller FB(s). A positioning error caused by a non-linear element (non-linear spring property, relative rotational synchronization component, and non-linear friction) of the strain wave gearing is compensated for by the feedforward linearization compensator.

Positioning control system for actuator provided with wave gear device

In a positioning apparatus for an actuator, a sliding mode controller for compensating for nonlinear characteristics of a wave gear device of the actuator generates a control input u to a controlled object, based on a position command &#x3b8;* and a state variable x for expressing the controlled object. The controlled object is defined in the following formula.* The switching surfaces of the sliding mode control system are defined by a variable S expressed in the following formula. The control input u is the sum of the linear-state feedback control term uand the nonlinear control input u where &#x3c3; is the switching function, and k is the switching gain.

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Azumino, Japan

Masafumi Yamamoto