On the Mode-Matched Control of MEMS Vibratory Gyroscope via Phase-Domain Analysis and Design

This paper investigates a novel method for the mode-matched control of a microelectromechanical systems (MEMS) vibratory gyroscope through a phase-domain analysis. Compared with the previous works, the proposed method presents a simple and robust automatic mode tuning scheme for sensitivity enhancement. In designing the mode-matched control loop, the resonant characteristics of the driving axis are used as the reference mode. Then, the phase difference between sense and drive modes at the resonant frequency of drive mode is used to generate a control signal for phase error regulation. For the control loop design, a linear phase-locked loop is adapted. Through the simulation using practical MEMS gyroscope parameters, the mode-matching performance and robustness of the designed control loop is demonstrated. It is also shown that coupling effect yields no degradation of output sensitivity. Finally, the experimental results obtained by implementing the electronics of mode-matched control verify the feasibility of the proposed method.      

基于DRV595的激光器恒温控制系统

半导体激光器的输出波长和功率随温度变化而变化,为了确保激光器工作性能,须对其进行恒温控制。采用脉冲宽度调制功率驱动器DRV595驱动半导体制冷器的方法,设计了一种双向大电流输出的高精度温度控制系统。在S域对系统进行了建模分析,搭建经典比例-积分-微分控制器,采用桥式采样电阻,纯硬件电路实现,结构简单,省掉了数字控制器的复杂软件编写。在常温试验中取得了±0.03℃的控制精度,DRV595集成脉冲宽度调制和双向MOSFET,输出电流最大为±4A。双向电流驱动半导体热电制冷器,实现了无死区控制。结果表明,脉冲宽度调制方式驱动和低输出级电阻大大降低了功率耗散。该系统工作稳定、功耗低、控制精度较高,具有实用价值。     

结构解耦四质量块微陀螺仪的设计与制备

提出了一种新型的结构解耦四质量块陀螺仪的结构设计以及制备方法。采用梳齿电极的设计和推挽法消除了静电驱动力的二倍频分量,并对折叠梁结构进行仿真分析和优化,有效地实现了对驱动和检测模态的结构解耦。针对陀螺仪的结构,设计了可行的工艺方案并进行实际加工,采用SOI和阳极键合工艺,最终制作出四质量块陀螺仪样品。仿真得到驱动和检测模态的谐振频率差为7Hz,表明其结构的高度对称性。谐响应分析下陀螺仪最大位移为1 290nm,驱动框架最大位移差为60.75nm,检测框架最大位移为305.24nm,取得了理想的解耦效果。     

微机械轮式陀螺仪的结构分析

以轮式陀螺仪为研究对象,利用有限元方法分析了主要结构尺寸对其固有频率的影响。根据驱动模态和敏感模态的频率匹配,优化了陀螺的结构尺寸;通过谐响应分析确定了频率和振幅的关系,为结构设计和制备工艺提供了理论指导。     

一种新型解耦硅微机械陀螺的设计

提出了一种新型静电驱动微机械陀螺结构,采用两组对称的梳齿结构作为驱动电极,同时采用中央质量块栅格和与驱动电极相同的梳齿两种结构检测感应模态的振动,每种结构设计两组独立的检测电极,分别采用差分方式进行检测,有效提高了陀螺的灵敏度。该陀螺结构的驱动模态和感应模态振动相互解耦,振动特性相似,固有频率、阻尼系数和品质因数等参数接近。采用有限元法分析了该结构的参数和特性,介绍了结构的制作流程。该结构谐振频率高、阻尼系数小,可达到较高的测量分辨率和准确率。     

Chattering reduction in the position control of induction motorusing the sliding mode

An induction motor position control system based on the sliding mode control is presented. In the sliding mode control, the control function is discontinuous on the hyperplane, which causes harmful effects such as current harmonics and acoustic noise in the motor drive application. A low-pass filter is introduced between the sliding mode controller output and the motor controller input to reduce these effects. Although the filter smooths the motor input current and alleviates the vibration at the final reference position, it may cause sluggish response in transient condition. To overcome the problem, a variable-bandwidth filter is proposed. In steady state, the bandwidth of the filter is made to be narrow to mitigate the ripple components while it is widened during the transient to improve the response. To achieve such an operation, the bandwidth of the filter is adjusted according to the error function. The proposed method shows good performance, which is confirmed through computer simulation and experiments     

旋转弹用轴向减旋平台控制系统设计

轴向减旋平台为高旋弹药姿态的高精度测量提供了一个有效的解决方案。针对弹载轴向减旋平台小体积、高动态等方面的要求,设计了一种适用于弹载环境的减旋控制系统。该系统采用模拟信号控制方式,通过对陀螺仪输出信号的实时处理与伺服驱动器参数的匹配调节,实现了对伺服系统的精确、匹配控制,为小量程、高精度的MEMS器件提供了一个微旋的测试环境。经试验验证,该设计减旋控制精度小于35°/s,有效抑制了弹体高旋对姿态测量的影响。     

An analog drive loop for a capacitive MEMS gyroscope

The linear model and the design of an analog drive loop for the drive (primary) resonator in a capacitive gyroscope are presented. Four different types of gain control topologies are compared and analyzed with both P- and PI-type controllers. The simple model proposed in the paper allows the small signal properties of the loop to be predicted. The theoretical models based on the small signal analysis are compared to the simulated and measured results. A proportional amplitude controller, together with the rest of the drive loop, is implemented using a high-voltage 0.35-μm CMOS technology and a nominal supply of 3 V. Clock generation using a PLL and the drive loop signal as the reference are also discussed in the paper.     

面向蜂巢式微机电陀螺模态交换工作模式的卡尔曼滤波

该文对模态交换工作模式下的蜂巢式微机电陀螺进行了噪声成分分析,并建立了噪声模型。提出采用卡尔曼滤波降低陀螺输出白噪声的方法,从而提升陀螺的静态性能,该方法可用于惯性寻北。实验结果表明,经滤波后陀螺输出在采样时间1 s下与未滤波前的平滑时间100 s下的陀螺输出噪声水平相当。陀螺输出白噪声幅值降低,从而缩短寻北时间。实际应用中,最短寻北时间可由卡尔曼滤波初值收敛后的时间进行标定。     

四轴飞行器的姿态研究与设计

本设计是绍兴市大学生科技创新项目。四轴飞行器作为低空低成本的遥感平台,在各个领域应用广泛。其驱动系统有四个输入却有六个输出,所以它是一个非线性,高度耦合,欠驱动系统。本文介绍四轴飞行器的一个实现方案,设计了一种用加速度传感器矫正陀螺仪零点漂移的方法,并且用PID控制器去控制四个电机的转速来实现稳定飞行。     

Control of a Z-axis MEMS vibrational gyroscope

This paper describes the design of the control loops in a z-axis, MEMS vibrational gyroscope operating in a vacuum enclosure. In this device, a silicon mass is driven through electrostatic actuator so that it has a sinusoidal linear motion, with a controlled speed. The design of a suitable controller, capable of maintaining the required speed and with prescribed restoring capabilities after shocks is briefly described in the paper. Attached to the driving mass, a second mass, free to move in the direction orthogonal to the motion of the first mass, is subjected to a Coriolis force, proportional to the product of the first mass speed by z-axis rotational speed. The sensing of the Coriolis force and, in turn, of the z-axis rotational speed, is performed in closed loop fashion, with a 1-bit quantized actuation. The restoring force that brings the motion of the second mass to zero is equivalent to the output bit stream of a band-pass sigma-delta converter and contains the information of the Coriolis force. The design of this second control loop and a detailed analysis on the signal-to-noise ratio achievable with the proposed design is reported.     

一种低功耗三相无刷电机驱动控制器的设计

介绍了一种基于数字信号逻辑运算理论的低功耗三相无刷电机驱动控制器。调速PWM信号、换向逻辑、霍尔位置信号等输入信号经运算处理后,产生6路与电机换相顺序相对应的控制信号,用来控制三相全桥驱动电机负载。该驱动控制器具有静态电流小、输出电流大、抗干扰能力强、集成过流保护等特点,可广泛应用于三相电机控制、伺服电机驱动、万向节控制等领域。     

Multiple drug hemodynamic control by means of a supervisory-fuzzyrule-based adaptive control system: validation on a model

A control device that uses an expert system approach for a two input-two output system has been developed and evaluated using a mathematical model of the hemodynamic response of a dog. The two inputs are the infusion rates of two drugs: sodium nitroprusside (SNP) and dopamine (DPM). The two controlled variables are the mean arterial pressure and the cardiac output. The control structure is dual mode, i.e., it has two levels: a critical conditions (coarse) control mode and a noncritical conditions (fine) control mode. The system switches from one to the other when threshold conditions are met. Different “controller parameters sets”-including the values. For the threshold conditions-can be given to the system which will lead to different controller outputs. Both control modes are rule-based, and supervisory capabilities are added to ensure adequate drug delivery. The noncritical control mode is a fuzzy logic controller. The system includes heuristic features typically considered by anesthesiologists, like waiting periods and the observance of a “forbidden dosage range” for DPM infusion when used as an inotrope. An adaptation algorithm copes with the wide range of sensitivities to SNP found among different individuals, as well as the time varying sensitivity frequently observed in a single patient. The control device is eventually tested on a nonlinear model, designed to mimic the conditions of congestive heart failure in a dog. The test runs show a highest overshoot of 3 mmHg with nominal SNP sensitivity. When tested with different simulated SNP sensitivities, the controller adaptation produces a faster response to lower sensitivities, and reduced oscillations to higher sensitivities. The simulations seem to show that the system is able to drive and adequately keep the two hemodynamic variables within prescribed limits     

舰载测量雷达船摇稳定回路设计

速率陀螺敏感于天线空间运动角速率,故可将陀螺感受的角速率信息作为反馈信息构成负反馈回路,通过加入船摇扰动前馈补偿环节,实现稳定回路的复合控制。再通过误差校正后将船摇补偿输出到功放,驱动天线方位及俯仰运动,达到隔离船摇扰动对天线指向影响的目的。设计已成功应用于舰载测量雷达的研制中,经对雷达性能测试,船摇隔离度达到50 dB。     

A supervisory fuzzy neural network controller for slider-crank mechanism

A supervisory fuzzy neural network (FNN) controller is proposed to control a nonlinear slider-crank mechanism in this study. The control system is composed of a permanent magnet (PM) synchronous servo motor drive coupled with a slider-crank mechanism and a supervisory FNN position controller. The supervisory FNN controller comprises a sliding mode FNN controller and a supervisory controller. The sliding mode FNN controller combines the advantages of the sliding mode control with robust characteristics and the FNN with on-line learning ability. The supervisory controller is designed to stabilize the system states around a defined bound region. The theoretical and stability analyses of the supervisory FNN controller are discussed in detail. Simulation and experimental results are provided to show that the proposed control system is robust with regard to plant parameter variations and external load disturbance.     

A VSS speed controller with model reference response for inductionmotor drive

This paper is mainly concerned with the development of a variable-structure system (VSS) controller with model reference speed response for an induction motor drive. An indirect-field-oriented (IFO) induction motor drive is first implemented, and its dynamic model at a nominal operating condition is estimated from measured data. Then, a two-degrees-of-freedom linear model-following controller (2DOFLMFC) is designed to meet the prescribed tracking and load regulation speed responses at the nominal case. As the variations of system parameters and operating condition occur, the prescribed control specifications may not be satisfied further. To improve this, a VSS controller is developed to generate a compensation control signal to reduce the control performance degradation. The proposed VSS controller is easy to implement, since only the output variable is sensed. The existence condition of sliding-mode control is derived, and the chattering suppression during the static period is also considered. Good model-following tracking and load regulation speed responses are obtained by the designed VSS controller. Effectiveness of the proposed controller and the performance of the resulting drive system are confirmed by some simulation and measured results     

Nonlinear robust control of a vector-controlled synchronousreluctance machine

This paper presents the implementation of Slotine's approach of sliding mode control for position control of a vector-controlled synchronous reluctance machine. A comparison is undertaken between the performance of a fixed gain controller and two sliding mode controllers for both the regulator and servo cases. Invariant performance is obtained using Slotine's approach of sliding mode control compared to a fixed gain controller. Robustness to parameter variation is an important feature of this technique. This can be achieved through the control law design, assuming parameter variation bounds are known. These improvements are demonstrated for variations in the load inertia. Machine inductance ripple affects the quality of achievable position control. A state-space model for the machine to incorporate this effect yields drive simulation results that agree with presented experimental results     

基于超前-滞后校正的微机械陀螺正交误差补偿

提出了一种基于超前-滞后校正的微机械陀螺正交误差补偿方法。根据振动式陀螺仪的驱动模态和检测模态运动特征,推导了包含正交误差的陀螺系统动力学方程,提出了一种正交误差闭环反馈回路。运用超前-滞后校正,设计了闭环控制环节,将正交误差输出补偿到陀螺表头传感元件；同时,在陀螺仪接口电路部分,设计了由正交输出量控制的VGA模块,进一步补偿正交误差。结果表明,提出的超前-滞后闭环补偿回路相比于PID控制器,响应速度更快,稳定性更好,陀螺的正交稳态误差从23.5 mV减小到0.41 mV,误差补偿效果明显,有效提高了陀螺的测量精度。     

Output tracking of uncertain fractional-order nonlinear systems via a novel fractional-order sliding mode approach

In this paper, a board class of uncertain fractional-order nonlinear systems is considered. A novel fractional-order sliding mode controller for output tracking of a time-varying reference signal is designed which can conquer the uncertainties and guarantees the asymptotic convergence of the system output toward the desired time-varying reference signal. For this purpose, an appropriate sliding surface is designed where maintaining the system’s states on this surface leads to asymptotic vanishing of error signal. Moreover, by tacking the fractional derivative of order α from the sliding surface, the convergence of system’s trajectories into the sliding surface in a finite time is proven. Finally, in order to verify the theoretical results, the proposed method is applied to a fractional-order gyroscope model and computer simulations show the efficiency of the proposed method in output tracking.     

基于光纤陀螺的车载稳定平台控制方式研究

从光纤陀螺的固有特性入手, 结合车载系统对稳定平台的需求,对基于光纤陀螺的稳定平台控制系统进行了分析研究.针对稳定平台不同的工作方式,分析设计了3种不同的控制措施:静态快速定位、动态稳定保持、手动单杆控制.并对静态快速定位工作方式下的数字控制器进行了设计及仿真.