Control Model for Large‐Sized Gantry Type Linear Motor Slider

At present, many industrial carrier devices utilize linear motor sliders. However, a heavier load requires a linear motor (which is an example of a direct drive device) to get higher power, compared with a rotary motor with a ball screw slider (which is an example of an indirect drive device). In order to obtain higher power at a lower cost, a linear slider with multiple motors can be utilized, for example, a gantry type linear motor slider. Moving the gantry type slider requires two linear motors that are set up in parallel to enable synchronization control. Some conventional synchronization control methods have been proposed for the parallel twin linear slider; however, a large‐scaled gantry type linear motor slider has two unique problems: mechanical distortion caused by the limitations of installation environment and coupling caused by joints with low stiffness. This paper proposes a control model to solve these problems, and an identification method of each parameter. Furthermore, the effectiveness of the control model is verified by comparison with simulation results and experimental results.     

Combined linear electric motors for robotic systems

The principles of design, construction, and characteristics of special linear electric drives based on combined linear induction motors (CLIMs) for moving robotic trolleys in sealed radiation chambers have been considered. Existing systems have been equipped with gear motors having a cable power supply or chain conveyors. In addition, the mechanisms of electromagnetic coupling have been used. Conventional LIMs with complex control systems or frequency converters are sometimes used in such systems. The proposed construction of electric drives based on CLIMs is much simpler and more reliable. These motors consist of induction driving units and braking units based on permanent magnets. Acting together, these units make it possible to obtain a low speed of trolleys without using any complicated control system or frequency converters. Experimental research and industrial implementation have shown the effectiveness of application of the proposed special CLIMs, the use of which improves the performance and reliability of equipment in a radioactive environment.     

磁悬浮平面电机的解耦控制策略

用于光刻加工的磁悬浮平面电机的6个运动自由度之间存在着紧密的电磁和力学耦合。为实现各运动自由度的解耦控制,提出了直线电机型电磁执行器的电流控制模型、基于模式力的解耦动力学模型和平面电机解耦控制策略。模式力使各自由度的动力学模型不再存在耦合,且都为简单的2阶线性系统。设计了样机的X位置伺服控制器,仿真结果表明该控制器使解耦后的X位置控制达到了预期的动、静态性能,并具有良好的抗扰性和鲁棒性。     

Sensorless controls of salient‐pole permanent magnet synchronous motors using extended electromotive force models

In this paper, we propose a new mathematical model for synchronous motors and a sensorless control method based on it. To control permanent magnet synchronous motors, knowledge of rotor position and velocity are necessary. Heretofore, expensive sensors have been used to detect rotor position information. Although many sensorless control methods based on the electromotive force (EMF) have been developed for non‐salient‐pole permanent magnet motors, they cannot be applied for salient‐pole motors without approximation because of complications in the mathematical model; this is turn may lead to problems of instability. To solve this problem, we propose an extended electromotive force model for synchronous motors. The proposed model has a simple structure, making position estimation possible without approximation. Experimental results show that the proposed model and method are valid. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(3): 55–64, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10257     

Position control for ultrasonic motors using backstepping control and dead‐zone compensation with fuzzy inference

The ultrasonic motor has comparatively high nonlinearity which varies with driving conditions, and possesses a variable dead zone in control input associated with the applied load torque. The dead zone is a problem for industrial applications and it is important to eliminate the dead zone in order to improve control performance. This paper proposes a new position control scheme for ultrasonic motors to overcome the dead zone. The dead zone is compensated by fuzzy inference, and backstepping control performs accurate position control. Compared with model reference adaptive control, which uses an augmented error, backstepping control can analyze a transient response. Mathematical models are formulated and experimental results show the effectiveness of the proposed position control scheme. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 149(1): 69–77, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20016     

Optimality for the linear quadratic non‐Gaussian problem via the asymmetric Kalman filter

In the linear non‐Gaussian case, the classical solution of the linear quadratic Gaussian (LQG) control problem is known to provide the best solution in the class of linear transformations of the plant output if optimality refers to classical least‐squares minimization criteria. In this paper, the adaptive linear quadratic control problem is solved with optimality based on asymmetric least‐squares approach, which includes least‐squares criteria as a special case. Our main result gives explicit solutions for this optimal quadratic control problem for partially observable dynamic linear systems with asymmetric observation errors. The main difficulty is to find the optimal state estimate. For this purpose, an asymmetric version of the Kalman filter based on asymmetric least‐squares estimation is used. We illustrate the applicability of our approach with numerical results. Copyright © 2004 John Wiley & Sons, Ltd.     

Adaptive output tracking for a class of non‐linear time‐delay systems

In this paper the output tracking control problem for a class of non‐linear time delay systems with some unknown constant parameters is addressed. Such a problem is solved in the case that the non‐linear time‐delay system has full delay relative degree and stable internal dynamics. It is supposed moreover that the output and its time derivatives until n?1, where n is the length of the state vector (euclidean part), do not depend explicitly on the unknown parameters. This work is the first step towards the application of the methodologies of adaptive control for non‐linear delayless systems, based on tools of differential geometry, to non‐linear time‐delay systems too. Copyright © 2004 John Wiley & Sons, Ltd.     

A practical design of multiloop robust PID control systems

In this paper, a new design scheme of multiloop predictive self‐tuning PID controllers is proposed for multivariable systems. The proposed scheme first uses a static precompensator as an approximately decoupling device in order to roughly reduce the interaction terms of the controlled object. The static matrix precompensator is adjusted by an on‐line estimator. Furthermore, by regarding the approximately decoupled system as a series of single‐input single‐output subsystems, a single‐input single‐output PID controller is designed for each subsystem. The PID parameters are calculated on‐line based on the relationship between the PID control and the generalized predictive control laws. The proposed scheme is numerically evaluated on a simulation example. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(3): 63–71, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10284     

Design of multi‐input multi‐output minimum‐phase state control system with decoupling and feedforward compensation

This paper discusses the design of decoupling control for a multi‐input multi‐output (MIMO) linear system. A new configuration of the prepositional tandem matrix is presented as a decoupling compensator, and minimum‐phase state control is applied to the resulting decoupled system. In general, non‐minimum‐phase characteristics often accompany decoupled systems. Feedforward compensation makes the non‐minimum‐phase effect of each decoupled scalar system change to the delay time. A numerical example is given for the MIMO linear system, which conventionally results in non‐minimum‐phase systems. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(2): 53–61, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21117     

基于DSP的直线电机位置伺服控制策略研究

在综合分析直线电机位置伺服控制系统的动静态性能及抗干扰能力的基础上，对其位置伺服控制策略进行了研究，开发了一套基于DSP的直线电机位置伺服控制系统。该伺服系统提出了用模糊自适应PID控制方法和干扰观测器补偿技术来提高系统的动静态性能，且可以补偿因外力等对系统造成的干扰。重点分析了位置角对系统的影响，进而提出了模型参考自适应算法对位置角进行校正以消除直线电机定位时出现的振荡。实验结果表明，所提出的位置伺服控制系统具有高的动、静态性能。     

基于逆系统方法感应电动机调速系统的分析及控制

感应电动机反馈线性化方法的优点之一，是在电机参数准已知且转子磁通能够准确观测的前提下，可将感应电动机数学模型妥耦成互相独立的转速子系统和磁通子系统。     

Sensorless control of synchronous reluctance motors based on extended electromotive force model and inductance measurement

In this paper, sensorless control for synchronous reluctance motors (SynRMs) without signal injection and an inductance measurement for position estimation are proposed. In the case of SynRMs, accuracy of inductances is the most important factor in realizing precise position estimation because inductances are largely varied by a magnetic saturation phenomenon. Therefore, the inductance measurement method, which can measure appropriate inductances for position estimation, is important as well as a sensorless control method. The inductance measurement based on the observer is discussed, and the measurement method and the parameter adjustment method for improved stability of the closed loop are proposed. The proposed method can measure inductances easily and be applied for permanent magnet synchronous motors, too. Finally, the proposed sensorless control method is verified experimentally. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 160(4): 70– 80, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/ eej.20274     

永磁同步电动机逆系统解耦控制

提出了一种永磁同步电动机（PMSM）的逆系统线性化解耦控制方法。首先,通过非线性状态反馈获得PMSM的逆系统,将多变量、非线性、强耦合的PMSM动态解耦成转速与定子电流两个低阶的线性子系统,然后,分别设计线性控制器对转速与定子电流子系统进行闭环控制。仿真结果表明：提出的控制方案具有优良的动态和静态性能,且对负载变化具有较强鲁棒性。     

微机控制直线电机驱动电镀流水线系统

介绍了一套直线感应电机驱动的电镀流水线及控制系统，设计了基于速度环单神经元PID调节的以转子磁场定向的矢量控制系统，采用AT89C51芯片和PM50RSA120功率模块组成驱动控制系统。根据位置反馈信号实现速度控制。文中给出了现场试验的结果，并对部分实际问题进行了讨论。     

A new model reference adaptive control for linear time‐varying systems

Recent results on the adaptive control of linear time‐varying systems have considered mostly the case in which the range or rate of parameter variations is small. In this paper, a new state feed‐back model reference adaptive control is developed for systems with bounded arbitrary parameter variations. The important feature of the proposed adaptive control is an uncertainty estimation algorithm, which guarantees almost zero tracking error. Note that the conventional parameter estimation algorithm in the adaptive control guarantees only bounded tracking error. Copyright © 2000 John Wiley & Sons, Ltd.     

Designing and modeling a linear electric motor for vibration-technology machines

One industrial application of linear motors is as working-body drives of vibration-technology machines. Such drives allow manufacturing of equipment with very low energy consumption and material costs. This paper presents the results of research on substantiation of the prospects of application of linear electric motors as drive vibration-technology machines. The results of designing a linear dc motor are presented. This paper describes the design of the electric motor and its operation in the hold-down and vibrating modes. The main technical characteristics of the motor are given. Simulation of the electric-motor electromagnetic field based on symmetrical setting of the task for the Poisson equation was performed with a view to specifying and verifying the preliminary calculation data. The results of the calculations and simulations show that it is possible to create low-cost, manufacturable, and reliable electrical motors for a linear vibratory actuator.     

The contact problem of hard contact materials linear ultrasonic motors

Hard contact materials, such as AL₂O₃ ceramic, have been used widely to improve motion accuracy of linear ultrasonic motors (LUSM). Nevertheless, experimental results show that, for this kind of LUSM, the contact frequency between the stator and the slider is far less than the frequency of the driving signals, which prevents the vibration energy of the stator from being utilized fully. However, almost all existing theoretical models assume that the stator and slider will come into contact in each driving signal cycle, which lead to the great difference between the theoretical results and the actual situation. In order to solve this problem, theoretical analysis and experimental investigation on the micro-impact processes of hard contact materials linear ultrasonic motors (HLUSM) are conducted in this research. Some parameters, which are closely related to the contact state, have been investigated through modelling the high frequency micro-amplitude contact behaviour on the contact interface in normal direction. It is found that the stiffness of the stator supporting spring, the high frequency vibration amplitude of the driving tip and the low-frequency response amplitude of the stator centre of mass (COM) are important factors affecting the contact frequency. Simulation and experimental results show that increasing the value of the stiffness of the stator supporting spring and decreasing the amplitude of the low-frequency response of stator COM can improve the contact frequency. Moreover, experimental results show that the output power of the linear ultrasonic motor is effectively improved in the ideal contact state. The efficiency is improved by approximately 50 %.     

Wide range drive of hybrid stepping motor with flux‐weakening control

Because the application range of motors for position control is extending in industry, hybrid stepping motors that can realize position control easily have become popular. However, stepping motors have some disadvantages: the possibility of pull‐out under certain load conditions, and low efficiency due to iron loss. Consequently, a system designer must choose the motor‐driver combination very carefully. This paper proposes high‐efficiency drive of a hybrid stepping motor in a wide speed range by vector control, without the occurrence of pull‐out. It is shown that lead angle control is equivalent to flux‐weakening control, and that the maximum torque depends on the maximum inverter voltage at high speed. The effect of iron loss suppression by flux‐weakening control is verified experimentally. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 174(4): 68–74, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21022     

长定子直线电机驱动的传输系统

介绍了一种新型物流输送系统，该系统采用长定子直线电机驱动，直线电机次级推动悬挂的货物运动。系统由可编程逻辑控制器和主控计算机控制，文中还对长定子直线电机分段驱动方式进行了探讨。     

Quantized feedback stabilization of linear discrete‐time systems with constraints

This paper addresses the quantization of control systems. The state of the system is quantized by means of a quantizer. In addition, constraints on the input and/or state are considered explicitly. For a linear system with no constraints, some quantized feedback control methods have been proposed. In this paper, a control methodology for a constrained system is proposed. Specifically, the idea of a positively invariant set is introduced so that the performance is improved while the constraints are satisfied. The effectiveness of the proposed method is verified through both simulation and experiment. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(3): 53–61, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21122