Kazuya Sato - Academia.edu (original) (raw)

Papers by Kazuya Sato

Transactions of the Institute of Systems, Control and Information Engineers, 2006

Proceedings of International Conference on Leading Edge Manufacturing in 21st century : LEM21, 2007

In the machine tool industry and the semiconductor manufacture fields, the necessity of high prec... more In the machine tool industry and the semiconductor manufacture fields, the necessity of high precision and fast response for NC machines is rapidly spreading. In general, it is well known that a positioning control system contains nonlinear friction force, it may cause a serious disadvantage on control performances such as tracking errors, limit cycles and undesired stick-slip motion at very low motion velocity. In order to achieve the high level control performance, the frictional effects have to be removed. In this paper, we proposed a novel PID control method which is based on the idea of sliding mode control for nonlinear friction compensation in a table drive system. Experimental results are given to show the effectiveness of our proposed PID control method compared with the conventional PID method. Especially, the tracking error of our proposed PID control was reduced by more than 2/3 compared to the case of the conventional PID control at the end of a stroke.

IEEJ Transactions on Industry Applications, 2005

An adaptive friction compensation method based on notion of H ∞ optimality is proposed. It is ass... more An adaptive friction compensation method based on notion of H ∞ optimality is proposed. It is assumed that the static and dynamic characteristics of friction are captured by the dynamic LuGre model. Neural-Network (NN) is used to parameterize the nonlinear characteristic function of the friction model. An adaptive NN based controller is given, and an approximation error in NN is regarded as exogenous disturbance to the system. Consequently, in the resulting control system, the L 2 gains from the disturbance to generalized outputs are made less than prescribed positive constants. For the practical applications, σ-modification method and dead-zone method are applied to the estimation strategies. To illustrate the effectiveness of our proposed method, experimental results are shown.

IFAC Proceedings Volumes, 2008

This paper examines the problem of link position tracking control for robot manipulators with inp... more This paper examines the problem of link position tracking control for robot manipulators with input toque uncertainty. It is assumed that the input torque uncertainty can be regarded as dead-zone phenomena at each link of manipulator and all the system parameters for robotic manipulator and dead-zone model are unknown. The proposed method ensures that the unknown parameters are estimated adaptively, besides, an approximated errors of input nonlinearities and external disturbances are attenuated by means of H ∞ control performance. In spite of considering the nonlinear adaptive H ∞ control problems, based on our proposed method, the compensator can design without solving the Hamilton-Jacobi-Isaacs equation. Numerical simulation results are given to illustrate the effectiveness of our proposed method.

Journal of System Design and Dynamics, 2012

The design method of a robust adaptive trajectory tracking control strategy of nonholonomic wheel... more The design method of a robust adaptive trajectory tracking control strategy of nonholonomic wheeled mobile robots is discussed. The aim is to develop a dynamics control system, because kinematics control laws of mobile robots is well known. The resulting dynamics control strategy can compensate not only the physical parameters of mobile robot, but also the input torque uncertainty and the input torque disturbance based on adaptive H ∞ method. Numerical simulations are given to show the effectiveness of the proposed method.

2006 SICE-ICASE International Joint Conference, 2006

ABSTRACT An adaptive Hscrinfin control for systems with input nonlinearity is proposed in this pa... more ABSTRACT An adaptive Hscrinfin control for systems with input nonlinearity is proposed in this paper. It is assumed that the dead-zone and hysteresis models can be described as unknown parameters term and bounded disturbance term, an adaptive Hscrinfin control method is given. Proposed control strategy does not include a discontinuous function, therefore, it can avoid to cause the chattering phenomena. Moreover, in the closed-loop control system, the Lscr2 gains from the disturbance to generalized outputs are made less than prescribed positive constants. The effectiveness of the proposed method is demonstrated by experimental results

IFAC Proceedings Volumes, 2004

This paper considers a tracking control of a servo mechanism with friction. It is assumed that th... more This paper considers a tracking control of a servo mechanism with friction. It is assumed that the static and dynamic characteristics of friction are captured by the dynamic LuGre model. Based on notion of H ∞ optimality, an adaptive friction compensation strategy is proposed. Neural-Network (NN) is used to parameterize the nonlinear characteristic function of the friction model. In this proposed method, unknown friction parameters and NN weight vector are updated by estimating strategy. Moreover, an approximation error in NN is regarded as an exogenous disturbance to the system, the L 2 gains from the disturbance to generalized outputs are made less than prescribed positive constants. To cope with the practical applications, dead-zone modification method is also applied to the unknown parameter estimating strategies. Experimental results are shown to illustrate the effectiveness of our proposed method.

Electrical Engineering in Japan, 2010

This paper concerns with a tracking control of a servo mechanism with friction. An adaptive frict... more This paper concerns with a tracking control of a servo mechanism with friction. An adaptive friction compensation strategy based on notion of H∞ optimality is proposed. It is assumed that the friction dynamics is described by the LuGre model. Neural-network (NN) is used to parameterize the nonlinear characteristic function of the LuGre model. Unknown friction parameters and NN weight are updated by estimating strategy in this proposed method. Moreover, an approximation error in NN is regarded as an exogenous disturbance to the system, the L2 gains from the disturbance to generalized outputs are made less than prescribed positive constants, σ-modification method is also applied to the unknown parameter estimation methods to cope with the practical applications. Experimental results are shown to illustrate the effectiveness of our proposed method.