Development and control of a low-cost linear variable-reluctance motor for precision manufacturing automation

Based on TI' s chip DRV8312 to realize the speed and position control for linear motor. The driving circuit principle based on DRV8312 to introduce the system composition and the hardware design, through the DSP software programming to realize the fast servo control for linear motor. The program setting and Hall signal verification, the inverter circuit and the back EMF validation, PWM duty ratio and speed response experiments proved that the proposed scheme is realizable and reliable.

In the machine tool industry and the semiconductor manufacture fields, the necessity of high precision and fast response 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. This paper presents a novel nonlinear friction compensation approach based on the idea of P, PI/I-P+FF control with sliding mode compensator for a high precision stage using a synchronous piezoelectric device driver. P, PI/I-P+FF control consists of Proportional position control and Proportional-Integral/Integral-Proportional velocity control with velocity Feed-Forward compensator. Experimental results are given to show the effectiveness of our proposed control method compared to the conventional P, PI/I-P+FF control method. Especially, the positioning error of our proposed control was reduced by more than 2/3 compared to the case of the conventional control at a stepping motion.

Most advanced manufacturing processes require highspeed and high precision motion control for material transfer, packaging, assembly, and electrical wiring. Examples are surface mounting of electronic components, wire bonding of semiconductor chips, and assembly of watches and hard disks. To achieve precise motion control, most of these high-performance manufacturing machines use rotary d.c. or a.c. motors as the prime motion actuator, and couple their output shafts to mechanical motion translators (e.g. reduction gear, belt, ball screw, etc.). Though this is the most widely used method, it has disadvantages of reduced accuracy, complex mechanical structure, difficult adjustments and alignments, high production cost, and low reliability. in this paper, the author proposes a new direction in high performance machine design, and suggests that future high performance motion systems should be designed through "simplifying the mechanics through specialized direct-drive actuators and advanced control methodologies". For this purpose, this paper investigates a class of variable reluctance (VR) direct-drive motion actuators for high performance machines. The paper looks into several specialized motion actuator systems designed by the author, (including limited stroke actuator, gripper, artificial limb, linear motion device, and planar motion device), highlights their features and advantages, and describes the challenges of controlling these devices.

Most advanced manufacturing processes require high-speed and high precision motion control for material transfer, packaging, assembly, and electrical wiring. Examples are surface mounting of electronic components, wire bonding of semiconductor chips, and assembly of watches and hard disks. To achieve precise motion control, most of these high-performance manufacturing machines use rotary DC or AC motors as the prime motion actuator, and couple their output shafts to mechanical motion translators (e.g. reduction gear, belt, ball screw, etc.). Though this is the most widely used method, it has disadvantages of reduced accuracy, complex mechanical structure, difficult adjustments and alignments, high production cost, and low reliability. In this paper, the author proposes a new direction in high performance machine design, and suggests that future high performance motion systems should be designed through “simplifying the mechanics through specialized direct-drive actuators and advanced control methodologies”. For this purpose, this paper investigates a class of variable reluctance (VR) direct-drive motion actuators for high performance machines. The paper looks into several specialized motion actuator system design, (including limited stroke actuators, embedded artificial limb, linear motion devices, and planar motion devices), highlights their features and advantages, and describes the challenges of controlling these devices

Motion control of mechatronic systems with uncertainties and physical constraints, while ensuring robustness and achieving better performance, such as high tracking accuracy and fast response, has always been a hot topic. However, the most current related works only focus on how to guarantee system stability under constraints, and few consider comprehensive performance. This paper investigates gated recurrent unit (GRU)-based compensation adaptive robust control (ARC) for uncertain linear motor–driven stage system with state and input constraints. To achieve rapid and precise motion control, a dual-loop control structure is employed, where GRU and ARC are the outer loop and the inner loop, respectively. First, the ARC control law is used to deal with the parameters uncertainty and external disturbances in the system, which further improves the tracking accuracy. A GRU neural network is then constructed and capable of implementing precise prediction ahead of the actual system output. Through choosing suitable loss function and training model, it can effectively minimize prediction error under state and input constraints. Comparative experiment results demonstrate the superiority and validity of the proposed scheme on the basis of GRU and ARC.

This study presents an adaptive grey control (AGC) system for a linear piezoelectric ceramic motor (LPCM) driven by a newly designed hybrid resonant inverter. First, the motor configuration and driving circuit of an LPCM are introduced, and its hypothetical dynamic model is described briefly. Since the dynamic characteristics and motor parameters of the LPCM are highly nonlinear and time varying, an AGC system is therefore investigated based on the principle of computed torque control (CTC) and grey method to achieve high-precision position control under wide operation range. In this control system, a grey uncertainty predictor is utilized to estimate the lumped uncertainty on line to relax the requirement of the unknown uncertainty in the design of a computed torque position controller. In addition, the effectiveness of the proposed strategies is verified by numerical simulations and experimental results.

The electrohydraulic shaking table with actuation redundancy is widely used in the field of structural seismic and geohazard testing and research. To achieve more precise control of it, additional methods are required to suppress the internal force between actuators, building upon the six-degree of freedom (DOF) position control. This paper presents an analysis of two control methods: multi-mode control and cascade control. The high-performance electrohydraulic shaking table, equipped with eight actuators, serves as a case study. The multi-mode control approach introduces two distorted modes of the table to obtain a definitive solution for the actuator’s drive signals. By incorporating these modes, the internal force between actuators can be effectively mitigated. On the other hand, the cascade control method achieves control over the actuators’ force by incorporating eight inner loop force controllers. This approach has also proven effective in reducing the internal force between actuators. Analysis and experimental results demonstrate the efficacy of both methods in mitigating the internal force between actuators. Moreover, the cascade control method exhibits versatility and is not restricted by the number of actuators, making it a suitable choice for systems with more than eight actuators.

This article makes a comparative analysis between the vector control, and the method of direct electromagnetic force control of linear induction motors. The dynamic models of linear induction motors applying the two control methods are presented. For verification of the effective control of linear induction motors comparative simulations are made.

Linear Induction Motor (LIM) is widely used in rail transit, precision positioning, and industrial automation due to its high efficiency, simple structure, and low maintenance cost. However, the dynamic performance of linear induction motors is affected by nonlinear characteristics and parameter variations, making accurate state and speed estimation crucial for achieving higher performance control. Traditional estimation methods often have limitations and are difficult to meet the increasing demand for control accuracy. In this paper, an adaptive higher-order sliding mode observer (AHOSMO) based synchronous state and speed estimation method for linear induction motors is proposed to address the shortcomings of traditional estimation methods in terms of accuracy and robustness. Considering the boundary effect of linear induction motors, a higher-precision mathematical model is established. Based on the above model, the proposed observer combines the adaptive law and the higher-order sliding mode method to estimate the rotor fluxes and LIM speed, as well as the speed-dependent parameters <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\gamma,\alpha,\beta,\varsigma,\eta,\delta$</tex-math></inline-formula>. The application of a super-twisting algorithm (STA) guarantees finite-time convergence for LIM state variable estimation. By employing the higher-order sliding mode algorithm, continuous inputs can be generated without the chattering phenomenon. Numerical simulation and experimental results show that the proposed AHOSMO can quickly and accurately estimate the synchronous state and velocity of the LIM under different operating conditions. Compared with existing methods, the AHOSMO demonstrates significant advantages in estimation accuracy and anti-interference capability. The research results provide a new technical approach for higher-performance control of linear induction motors, which is of great significance for promoting their application in the field of high-precision positioning.

This chapter describes the sliding-mode control of permanent magnet synchronous motor (PMSM) servo systems. The typical structure of the systems consists of the position, velocity, and current control loops. The design of three controllers, position controller, speed controller, and current controller, and a filter in speed loop has been described respectively, aimed at reaching high-performances of PMSM servo systems, such as fast response, strong robustness, and high precision. The digitization of terminal sliding-mode (TSM) controllers of PMSM servo system has been discussed for the purpose of practical implementation.

This paper presents the position control strategy for permanent magnet linear synchronous motor (PMLSM) that can be applied to the surface mount device (SMD) placement system. The position controller has been implemented as a simple PID controller with acceleration and speed feed-forward. The disturbance force due to the mass variation makes the performance of the total system degraded. In this paper, the disturbance force due to the mass variation is compensated by using novel disturbance observer. For the feasibility of the PID controller and disturbance observer have been verified by the simulation and experimental results.

Position control and vibration control of the underactuated flexible robot in operational space is implemented. Firstly, the dynamic equations in operational space are derived using the assumed modes method. And kinematics and dynamics of the system are analyzed. Secondly, position control method of the underactauted flexible manipulator in the operational space is proposed. Because the elastic vibration of flexible links can not be eliminated only via position control, based on position control strategy, vibration control schemes are presented. The simulation of a 2DOF underactuated flexible manipulator indicates that position and vibration control methods have great effects on increasing end manipulation accuracy, reducing tracking errors and improving dynamic characteristics, which also verifies the validity of control strategies. Thus, for the underactuated flexible robot, both the position control and the vibration control are implemented simultaneously.

Active disturbance rejection control (ADRC) has been widely used in the permanent magnet linear synchronous motor (PMLSM) drive system for its strong anti‐disturbance ability and fast response speed. However, a large number of adjustment parameters add difficulties to its application. To solve this problem, a novel sliding mode‐based active disturbance rejection control (SM‐ADRC) with autotuned parameters is proposed in this paper. In this control strategy, the SM is incorporated with extended state observer (ESO) and nonlinear state error feedback (NLSEF) to reduce the number of adjustment parameters. The simulated annealing particle swarm optimization (SAPSO) algorithm is carried out to achieve the optimal configuration and realize parameter self‐tuning. The experimental results of the PMLSM speed servo system demonstrate the proposed control method has better suppression of chattering effect, disturbance rejection ability and fast dynamic response. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

Sliding mode controller using a new adaptive algorithm is presented, which is utilized to estimate the uncertainty bounds for the position control of permanent magnet linear synchronous motor (PMLSM) drive system,so that the control effort is improved. Furthermore, space vector modulation (SVM) is adopted to decrease the vector deviation, Simulated and experimental results show that the proposed adaptive sliding mode position control scheme provides high- performance dynamic characteristics and strong robustness with regard to parameter variations and external load disturbances. Based on the TMS320F2812, the control system was built and the experience result is shown.

A high-precision, high-performance motion control system is significant in transportation systems and industrial applications. At present, a new series of complementary and modular linear flux-switching permanent magnet (CMLFSPM) motors with different mover/stator pole pitch ratio have attracted much attention. However, the research about the high-precision position control of these LFSPM motors is absent in literature. Therfore, the closed-loop position control performance of the CMLFPM motor based on mover flux-oriented control is investigated in this paper. The simulation and experiment results validate the effectiveness of the proposed control strategies of the CMLFSPM motor.