Swing-arm-type PZT dual actuator with fast seeking for optical disk drive

 In this paper, a swing-arm-type dual positioning mechanism using a voice coil motor (VCM) and bimorph PZT actuators is proposed for the possible application to the future optical disc drive actuator. A VCM is used as a coarse motion actuator, and a set of piezoelectric actuators is used for fine motion. The two pairs of PZT actuators are arranged in parallel and are carefully designed to deflect in `S' shape such that tension and compression forces are generated simultaneously and thus the hysteresis is minimized. The static and dynamic analyses are performed and the parameter studies on the key dimensions of the set of PZT actuators are investigated. For fast seeking motion, time optimal control scheme combined with PD algorithm is adopted for the fast seeking motion of VCM. Positive position feedback (PPF) control is used to suppress residual vibration for the PZT actuator beams by activating it at the end of VCM swing motion. The feasibility of the suggested actuator system and the control scheme is demonstrated through simulations and experiments. Received: 5 July 2001/Accepted: 21 December 2001     

Intelligent control of DC motor driven electromechanical fin actuator

In this paper modeling, simulation and control of an electromechanical actuator (EMA) system for aerofin control (AFC) with permanent magnet brush DC motor driven by a constant current driver are investigated. Nonlinear model of the EMA-AFC system has been developed and experimentally verified in actuator test bench. Model has been used as the starting point for PID position controller synthesis. To improve performances of the system, computational intelligence has been applied. Genetic PID optimization, genetic algorithm (GA) optimized fuzzy supervisory PID control and finally GA optimized nonlinear PID algorithm modification are proposed. Improved transient response and system behavior have also been experimentally validated.     

Settling control with reference redesign for dual actuator hard disk drive systems

This paper considers settling control of a recording head for a dual actuator system for hard disk drives consisting of a coarse actuator (voice coil motor, VCM) and a fine actuator (peizoelectric transducer, PZT). The design method proposed in this paper is called the dual actuator reference trajectory re-design (RTRD). In this method, the design is divided into three steps. In the first step, the coarse actuator loop is designed to achieve stability and basic performance. In the second step, the fine actuator path is designed by loop shaping for superior performance of the overall system. Finally, the reference signals are generated for both the coarse and fine actuators by minimizing the square integral of jerk during the transition. The reference signals are updated or redesigned in real time as the recording head approaches the target track for smooth landing and minimal residual vibration. The “soft switching” technique is applied for gradually introducing the fine actuator (PZT actuator), which may shorten the settling time and achieve a smooth settling response. The effectiveness of the proposed approach is evaluated by simulations.     

Track-following control of a dual-stage hard disk drive using a neuro-control system

This paper describes the track-following control of a dual-stage hard disk drive system using neural-networks. A neural-network approach to on-line learning control, and a real-time implementation for a dual-stage hard disk drive, are presented. The use of the dual-stage actuator in hard disk drive systems has become a means of achieving increased servo actuator bandwidth. The dual-stage actuator presented here uses a voice-coil motor (VCM) as a coarse actuator, and a piezoelectric actuator (PZT) as a fine actuator. The control system consists of a series combination of both a plant with a feedback loop and a neural-network with a feedforward loop. The neural-network functions as the reference input filter, and it organizes a new reference signal to the closed-loop circuit. Numerical and experimental results for the track-following control system of the dual-stage hard disk drive show the validity of the proposed neuro-control system.     

Discrete time output feedback sliding mode control for nonlinear MIMO system: a stepper motor case

This article, presents discrete sliding mode control algorithm using multirate output feedback for control of stepper motor. The algorithm developed by the authors uses past output samples and past control inputs. When all the states of the system are neither physical variable nor available for measurement, multirate output feedback can be used. The stepper motor is known to be a differentially flat system. The dynamics of the stepper motor are highly nonlinear, hence feedback linearization based on endogenous feedback has been used. The linear model is obtained and multirate output feedback-based discrete sliding mode control has been designed. The discrete sliding mode control with multirate output feedback has been applied for regulator as well as tracking case for the motor. The proposed algorithm uses only two outputs. It is essentially shown that first output needs to be sampled only once and second output must be sampled at least thrice in every τ sampling interval in order to achieve acceptable performance. The system parameter variation has been considered and the results obtained are found to be satisfactory. Thus, it has been shown that discrete sliding mode control algorithm using multirate output feed back can be extended to a class of nonlinear MIMO system.     

基于MQTT的步进电机远程控制方案实现

远程实验的仪器操作与动态数据测量离不开步进电机,针对远程实验步进电机控制需要,设计了一个基于MQTT通信和嵌入式的电机远程控制方案.在Windows Azure云计算平台上搭建基于MQTT的Mosquitto服务器,接收来自Web端发送的命令,推送至步进电机控制器,实现对步进电机的使能、方向、速度等控制.采用该方案利用远程Web端操控电机,对电机进行实时测试,结果表明,该方案可以实现对步进电机准确、实时、可靠的远程控制,电机以150 Hz驱动频率运行时位置误差为0.21％,可应用于相关远程实验中.     

基于输入频率模型的步进电机失步非线性补偿

步进电机受输入脉冲频率的影响,开环控制时会出现失步和过冲等非线性特征,影响控制系统的精度.通过研究不同输入频率下步进电机的输出特性,利用系统辨识的方法,建立步进电机非线性依赖输入频率的数学模型.基于所得步进电机的脉冲-频率辨识模型,利用逆补偿方法,对非线性的影响进行补偿.实验结果表明,对于步进电机驱动的传动装置,该方案可有效消除因失步或过冲引起的非线性误差,提高了定位精度,该方法简单可靠,可为类似传动系统的非线性补偿提供参考.     

基于MC9S12XS128的自由摆平板模糊PID控制系统研究

以16位单片机MC9S12XS128为控制核心,选用MMA8452三轴的数字加速度传感器作为系统的检测模块,设计和实现了基于自由摆平板的跟踪运动控制系统;选用混合式步进电机作为执行机构,实现平板的倾角调节.针对步进电机的高度非线性特点,设计和实现了模糊PID控制器来完成步进电机运动的位置控制.试验结果表明,所设计的控制器能在一定范围内满足系统的动、静态特性控制要求.     

Analysis and test of a new MEMS micro-actuator

A large-deformation and low-voltage micro actuator is proposed in this paper to overcome the problems of high voltage and undersized deformation of electrostatic micro actuator. The principle of the proposed actuator is based on vertical-horizontal bending. Dynamic equations of the micro actuator under axial and horizontal loading are built based on Lagrange–Maxwell electromechanical dynamics equations. In addition, the influences of thermal stress, axial electrostatic force and squeezing force are analyzed. Furthermore, the horizontal distributed load and axial load are equivalent to horizontal centralized load based on the Runge–Kutta algorithm and finite difference method. The relationships of deformation with driving voltage, regulation voltage, and axial compression quantity and temperature difference are achieved by simulation. Simulation results show that the deformation of the proposed actuator is as high as 10.861 μm when the driving voltage is 16 V. The deformation of proposed micro actuator is larger than that of the existing one. Finally, the simulation results are verified by experiment and agree well with experiment results.     

基于MSP430的太阳光源跟踪控制系统设计

为了提高太阳能电池板的能量转换效率,提出了一种基于MSP430的太阳光源跟踪控制系统。系统设计原理采用光强比较法,硬件部分设计了光强信号采集电路、以MSP430为核心的主控制器、步进电机驱动电路等;软件部分采用模块化编程,加入数字滤波和控制算法。系统实现了刘信号采集与处理、电机驱动等模块的控制,能够快速准确跟踪太阳光源。运行实验结果表明,系统运行稳定,控制灵活,达到预期的设计目标。     

基于STM32F4的电机控制系统设计

为改善步进电机堵转、失步、超步等问题,提高步进精度,使步进电机能够快速准确定位,提出基于STM32F4微控制器的步进电机控制系统设计。通过改变PWM输出定时器的预分频值控制电机转速,直线阶梯形升降速算法实现调速;采用DMA方式控制电机脉冲数量,实现位置精确控制。实验以及实际应用情况表明,阶梯形升降速算法以及DMA方式位置控制算法能够满足一般要求,系统误差为±0.01度。系统精确度高、性能可靠、扩展性强,具有较高的应用价值。     

Modified BVD model of PZT actuator using high-voltage square pulse method for micropumps

The field of micro–electro–mechanical systems and microfabrication has produced micro-total-analysis systems, which are widely used in medicine, diagnostics, and biological and chemical research. For the development of high precision drug delivery systems, micropumps with a lead zirconate titanate (PZT) actuator, which has a fast response time and high resolution, are most likely to be applied in implementations. To improve the performance of PZT micropumps utilized in the microfluidics field, suitable models are required to enable the optimization of the PZT actuator driving circuits. This study proposes a modified Butterworth–Van Dyke (BVD) model which consists of a BVD model in series with an electrical resistance that describes a PZT actuator driven by a square pulse with a relatively high voltage and low frequency for micropump applications. Experiments were conducted to assess parameters of the model at various voltages; they indicate that the electrical resistance is essential for modeling the PZT actuator of the micropump. The electrical model was verified using a SPICE simulation, whose numerical results were compared with the experimental data for the current response of the PZT actuator. The results show a close correlation between the simulation of the electrical model and the measurements of the PZT actuator under real operating conditions.     

无活塞压缩微型制冷机驱动控制系统设计

针对无活塞压缩微型制冷机用直线步进电机往复运动的特点,提出了基于DSP控制的直线步进电机驱动控制系统,设计出以TMS320LF2407A为核心的系统硬件控制电路和软件流程;实验结果表明该系统所驱动的制冷机不仅起步平稳,减速阶段的末端冲击小,而且具有加减速控制方便、简单等优点。     

基于SPWM数字驱动技术的指针式航向复示器的研究

借鉴低速同步电机的驱动特点,提出了一种全数字式SPWM波数字细分驱动技术,将其应用到船舶电罗经复示器的电机控制系统中,实现了一种新型的全数字式步进电机控制系统,具有航向初始位置自动调整、自动跟踪和自动校正的功能。     

Position control of a PM stepper motor by exact linearization

The authors consider the position control of a permanent magnet (PM) stepper motor using the exact linearization method. This nonlinear controller takes into account the full dynamics of the stepper motor. In particular, the phase shift between voltage and current in each phase is automatically taken into account. The feedback linearization controller makes the stepper motor into a fast accurate positioning system. The authors consider the feedback linearization technique for the PM stepper motor and show, when the detent torque is neglected, how it quite naturally leads to the well-known DQ transformation of electric machine theory. The authors indicate how constant load torques may be asymptotically rejected by using a nonlinear observer     

A low cost,high performance insulin delivery system based on PZT actuation

A low driving voltage, low cost, high performance insulin delivery system based on PZT actuation is presented in this paper, which consists of two functional units, namely, micropump unit and electronic control unit. The PZT micropump is the core of micropump unit and is the key base to ultimately realize insulin precision delivery of the whole system. The electronic control unit is the important auxiliary unit for the realization of the whole system function. To obtain a higher working performance under low voltage, a serial structure with two chambers and three check valves is adopted in the design of PZT micropump. In place of silicon and glass, main parts of micro-pump unit are manufactured using the polymers which have good biocompatibility, stability and low cost. Through the systematic experimental test for the prototype of PZT insulin delivery system in lab, the maximum backpressure of 14.64 kPa is recorded at applied voltage of 36 V and working frequency of 160 Hz, the maximum flow rate of 5.74 ml/min is obtained in the condition of 36 V and 300 Hz. Under the voltage of 36 V and working frequency of 200 Hz, the micro-dosage pumped by PZT micro-pump displays a good linear characteristic with the number of driving impulses. The minimum resolution of insulin delivery can obtain 3 × 10^?4 ml (0.03 U insulin at the concentration of 100 U).     

嵌入式系统的多路步进电机控制系统的设计

设计并实现了一种基于FreeRTOS的多路步进电机控制系统,运用于小型流水线。系统控制电路采用STM32F4系列的微控制器,结合小功率步进电机驱动器A4984以及嵌入式以太网控制器W5500,完成硬件设计,后对其进行软件开发,设计出可以实时控制并改变电机脉冲起始频率、最大频率、电机转动方向、电机脉冲总数、加速脉冲数以及减速脉冲数等参数的上位机模块。在电机驱动中加入改进型S型算法,有效的优化步进电机初始速率增加过快导致的步进电机失步和过冲现象。在实际项目的验证过程中,证明该系统具有良好的稳定性。     

一种矿井巷道断面瞬时监测系统设计

针对矿井巷道断面人工测量方式费时费力、误差大以及现有巷道断面测量仪检测速度慢、无法实现上位机实时监测等问题,提出了一种基于PLC和ZigBee网络的矿井巷道断面瞬时监测系统的设计方案。该系统中,PLC输出2个6 400个/s的高速脉冲序列,分别用于控制步进电动机旋转和驱动脉冲式激光测距仪测距;HC0,HC1高速计数器分别对2个脉冲序列计数;步进电动机步进角设置为0.45°;激光测距仪旋转1周后,PLC计算出巷道断面的周长和面积,并将计算结果通过ZigBee网络发送至上位机进行实时显示。实验结果表明,该系统每隔10s更新显示巷道断面的周长和面积,周长测量的相对误差不超过0.5%,面积测量的相对误差不超过0.9%。     

AVR单片机的天然气发动机电控系统设计

针对车用压缩天然气（CNG）发动机进行电控系统的开发研究。电控单元以AVR系列单片机为核心,采用多片式结构;设计了传感器调理电路和执行器驱动电路;通过控制怠速步进电机以调节旁通空气量,采用PID算法对发动机怠速转速进行闭环控制;采用脉宽调制（PWM）方式控制天然气喷射阀的喷射量;通过控制初级点火线圈的通电时间和断电时刻,实现点火能量和点火正时的主动控制。     

步进驱动系统大振荡机理与轨迹优化控制

为了解决步进驱动系统运动控制中的振荡、 丢步和失调等问题, 改善步进驱动系统的控制性能, 优化步进驱动系统的控制, 通过研究步进驱动系统的微步驱动控制过程, 建立了步进驱动系统的微步驱动数学模型, 提出了步进驱动系统的仿真建模方法, 通过仿真模型的数值模拟分析了大振荡、丢步及失调问题的产生原因并 建立了大振荡及丢步的机理模型, 在此基础上进一步提出了基于稳态截止频率的速度轨迹优化控制方法. 最后, 通过一个实例进行了实验验证. 结果表明: 该建模方法能够准确地描述步进驱动系统的特性, 速度轨迹优化控制方法能够有效地消除摆臂系统的大振荡、 丢步、失调等严重问题, 显著提高了摆臂系统运动平稳性及精密定位能力.