Nagoya Institute of Technology

Harmonic Drive Systems Inc.

Denso Corporation

Fuji Machine Mfg. Co., Ltd.

Hitachi Via Mechanics Ltd.

Makoto Iwasaki

Yoshifumi Okitsu

Kozo Sasaki

Yoshifumi Morita

Hiroyuki Ukai

Masafumi Yamamoto

Nobuyuki Matsui

Yuki Kato

Yasuhiko Mukai

Toshio Yajima

Hiroshi Ishikawa

Jirou Hayashi

Hiroyasu Otake

Nobuhiko Makino

Ryo Kano

Norio Tsuchida

Souichi Toyama

Takayoshi Kawai

Yaichi Okubo

Hiromu Hirai

Noriyuki Ido

Jiro Hayashi

Noriaki Hirose

Kazuhiro Ichikawa

Takeshi Wada

Yuya Yamamoto

Akihiko Sawada

Hiroshi Sawaragi

Keisuke Nagiri

Kentaro Torii

Motohiro Kawafuku

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 control system calculates inputs to a control target that has m inputs and n outputs (m=n, each of m and n is a natural number that is more than one), while designating a plurality of combinations of the inputs and the outputs. A feedback controller calculates, with respect to each designated combination, a control input to a non-interference controller based on a difference between a target value and a current value of the control quantity to make the current value follow the target value. The non-interference controller executes, with respect to each designated combination, a non-interference control to reduce influence due to mutual interference between n control quantities. This reduces the number of combinations of the inputs and the outputs, the combinations whose mutual interference needs considering; thereby, the non-interference control may be easily achieved.

Vehicle steering control system

An apparatus for estimating a transfer function of at target object having divided systems is disclosed. The apparatus acquires an estimation equation to estimate the transfer function of the target object, and determines, for each arithmetic operation in the estimation equation, whether the arithmetic operation is an addition or a multiplication. For the multiplication, the apparatus performs the multiplication of frequency response characteristics in the frequency domain. For addition, the apparatus converts the frequency response characteristics into time response characteristics, performs the addition of the time response characteristics in the time domain, and reconverts a result of the addition into the frequency domain.

Transfer function estimation apparatus, method and program

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.

Positioning apparatus for actuator with wave gear device

According to a method for performing adaptive friction compensation of an actuator including a wave gear drive, there is used as a friction compensation current applied to a motor drive current a static friction compensation current iwhen a motor shaft stops with a deviation, and a Coulomb friction compensation current iin other circumstances. The static friction compensation current iis obtained by adding a compensation amount iof a monotonically increasing ramp function to a compensation amount iof a step function, and a step-function compensation amount iis used as the Coulomb friction compensation current i. Since the amount of friction compensation can be changed adaptively based on the data during positioning-control response, a motor shaft can be stabilized at a target angle without prominent accompanying vibration, even if the ambient temperature changes and the friction characteristics of the wave gear drive fluctuate.

Method for performing adaptive friction compensation in an actuator accounting for variation in friction characteristics of wave gear drive accompanying change in temperature

A method for controlling positioning of an actuator having a wave gear device uses an exact linearization technique to compensate effects relative to positioning control of a load shaft caused by the non-linear spring characteristics of the wave gear device. A plant model is constructed from the actuator, and linearized using the exact linearization technique; measurements are taken of non-linear elastic deformation of the wave gear device relative to load torque; the non-linear spring model &#x3c4;g(&#x3b8;tw) is defined using a cubic polynomial with the constant defined as zero to allow the measurement results to be recreated; and the current input into the model and motor position of the model when a load acceleration command is a command value are entered into a processor arranged as a semi-closed loop control system for controlling positioning of the load shaft, as a feed-forward current command and a feed-forward motor position command.

Method for controlling positioning of actuator comprising wave gear device

A positioning system () provided with an actuator () having a wave gear device () is driven and controlled by a semi-closed loop control for controlling the load position of a load device () based on the motor position of a motor shaft () of a motor (). In a method for compensating for an angular transmission error by compensating for a motor shaft synchronous component &#x3b8;Sync that occurs in synchrony with the motor position and is a relative rotation-synchronous component that includes an angular transmission error component of the wave gear device (), the positioning system () is represented as a two-inertia model, and the motor shaft synchronous component &#x3b8;Sync is represented as an oscillation source for producing a twisting action between the two inertia bodies in the two-inertia model. A motor current command iref is corrected by a compensation current command icomp calculated so as to allow the effect of the motor shaft synchronous component &#x3b8;Sync on the load position to be compensated in this case, and a motor position command r is corrected by a motor position correction signal &#x3b8;comp calculated in order to compensate for the effect of the motor shaft synchronous component &#x3b8;Sync.

Method for compensating for angular transmission error of wave gear device

There is provided a control apparatus that controls a motor of an electric power steering system to assist a steering effort of an operator. The control apparatus includes a sensor, a parameter computer, a difference computer, a target torque computer, and a motor driver. The parameter computer computes a current value of one of physical parameters of one of constituents of the electric power steering system based on a steering parameter determined by the sensor referring to an equation of motion. The difference computer computes a difference between the current value of the one of the physical parameters computed by the parameter computer and a predetermined value of the one of the physical parameters. The target torque computer computes a target torque of the motor which compensates for the difference between the current value and the predetermined value of the one of the physical parameters.

Control apparatus for electric power steering system

An operating apparatus including a main body, a movable member, a drive unit having a drive source, and a control unit controlling the drive source to control the position of the movable member relative to the main body. The control unit including a position control system and an acceleration control system. The position control system including a position command portion, a first feedforward compensator outputting a first operation command to the drive source, a second feedforward compensator, a positional-information acquiring device obtaining information related to the position of the movable member, and a first feedback compensator outputting a second operation command to the drive source. The acceleration control system including an acceleration-information acquiring device obtaining information related to an acceleration of the main body, a third feedforward compensator, a second feedback compensator outputting a third operation command to the drive source.

Operating apparatus

The non-linear elastic deformation component included in the angular transmission error of an actuator provided with a wave gear drive is a component of the angular transmission error occurring due to elastic deformation of a flexible externally-toothed gear when the direction of rotation of the motor shaft changes. This component can be analyzed by driving the motor in a sine-wave shape. A model of the non-linear elastic deformation component (non-linear model) obtained from the analysis results is used to store data or a function for compensating for this component in a motor-control device. Compensation for the non-linear elastic deformation component (&#x3b8;) is added to a motor-shaft angle command (&#x3b8;*) as a compensation input (N&#x3b8;*) for feed-forward compensation. As a result, the non-linear elastic deformation component (&#x3b8;) can be effectively reduced, and the positioning precision of the actuator can be improved.

Method for compensating for angular transmission error of an actuator

In a steering system having a variable gear transmission system and an electrical power steering system, respective compensation amounts for first and second electric motors are produced by a first mathematical model. The compensation amounts are added to command values (v, v) to generate final command signals (i, i) to the respective electric motors. According to the above structure and operation, a mutual interference between two control systems can be suppressed.

Control device for electrical power steering system

A difference between each position command data outputted in a form of a step signal from a high-level controller and its corresponding detected position data of a movable body is integrated by an integral compensator to position the movable body. Assuming, for example, that the movable body is a steerable mirror, digital filters are arranged to compensate the value of an initial state of an angular displacement and the value of an initial state of an angular velocity, respectively, and respective impulse responses of the digital filters as additional input elements are added to an output terminal of the integral compensator. For higher effectiveness, internal state variables of the digital filters can desirably be cleared to zero whenever an angle (position) command data is received.

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Nagoya, Japan

Makoto Iwasaki