基于MC9S12DG128单片机智能车设计与实现

本智能车控制系统采用飞思卡尔16位单片机作为唯一的核心控制单元,加以直流电机、舵机、光电传感器和电源电路以及其他电路构成。由安装在车前部的反射式红外传感器负责采集信号,并将采集到的电平信号传入核心控制单元,核心控制单元对信号进行判别处理后,由PWM4发生模块发出PWM波,分别对转向舵机和直流电机进行控制,完成智能车的转向与前进。智能车后轮上装有霍尔传感器,用来采集车轮转速反馈的脉冲信号,并经由核心控制单元进行PID控制算法处理后会自动调节输入到电机驱动模块的PWM波占空比,从而控制小车的速度。寻迹由RPR220型光电管完成。     

基于AT89S51单片机的PWM专用信号发生器的设计

介绍一种脉冲涡流无损检测系统所使用的多波形专用PWM信号发生器的设计.该信号发生器以单片机为核心控制单元,通过对外围芯片的控制来实现对输出波形的频率、电压幅值、占空比的连续调节,并能对运行信号参数进行实时显示.经实验验证,该信号发生器便于观察和调节,完全满足脉冲涡流检测系统所需激励信号的要求.     

“电动单元组合仪表应用技术”讲座——第二讲 DDZ-Ⅱ型调节器的特性与使用方法

一、调节器的组成和调节规律的实现方法DDZ-Ⅱ型调节器是 DDZ-Ⅱ型电动单元组合仪表中的一个主要单元。调节器接受变送单元输出的0～10mA 直流电流信号(即被调量信号),将此信号与设定值相比较而得到偏差信号,然后按偏差的大小和变化情况,进行比例、积分、微分运算,给出调节信号,去控制执行器的动作,实现自动调节。调节器的主要品种有比例积分调节器(即 PI 调节     

随机变批次长度的反馈辅助PD型量化迭代学习控制

针对离散线性系统,研究批次长度随机变化的反馈辅助PD型量化迭代学习控制问题.考虑系统信号经量化后传输到控制器或执行器的情况,给出两种量化方案:跟踪误差信号量化和控制输入信号量化.基于两种不同的量化信号,在批次长度和初始条件随机变化前提下设计反馈辅助PD型迭代学习控制算法.采用扇形界的处理方法和堆积系统框架,推导数学期望下的学习收敛条件:在误差信号量化情况下,所提出控制算法可以保证跟踪误差渐近收敛到零;在控制输入信号量化情况下,所提出控制算法能够保证跟踪误差有界收敛.仿真示例对比验证了两种量化方案下所提出方法的有效性和优越性.     

一种含纯滞后对象的模型预测反馈的控制方法

本文提出一种适于对象含大纯滞后的控制算法，其基本思路是在系统的反馈通道上，建立一个与对象相当的参考模型，但不要求该模型与对象模型有特定的关系，利用对象输出与含纯滞后参考模型输出的差异来校正不含纯滞后的该模型输出，以此作为系统的反馈信号实现反馈控制，此法简单，不需复杂的运算，经仿真有比较满意的效果。     

一种用于调幅接收机AGC的设计与实现

在调幅接收机控制中,为使接收机输出信号的幅值恒定,通常需要对接收机进行自动增益控制,传统设计方法利用模拟环路来控制.提出一种用于数字控制的调幅接收机的快速自动增益控制的设计方法,通过对接收机本振AGC和中放AGC两级联合调节,加上快速自动增益控制算法,可以大大减小调节时间提高效率.在对系统进行理论分析的基础上,进行了仿真,与传统方法进行对比,说明了方法的可行性.最后将该方法应用于具体的项目实践,验证了理论分析的正确性和有效性.     

改进型自抗扰控制在局部通风机风速调节中的应用研究

针对现有用于矿井局部通风机风速调节的自抗扰控制算法存在控制信号波动剧烈,进而造成变频器和电动机产生冲击振荡的问题,提出了一种改进型自抗扰控制算法。该算法采用反正切函数与幂函数相结合的改进方法,反正切函数用于增强控制算法的线性程度,保证函数在原点处有更好的平滑性,幂函数用于保证控制算法的跟踪速度,加快控制算法的收敛速度。将改进型自抗扰控制算法应用到煤矿井下局部通风机风速调节中,经过该算法处理过的电压信号作为局部通风机变频器的输入信号,输出频率信号改变异步电动机的转速,最终实现局部通风机风速的动态调节。仿真结果表明,与现有PID控制算法、自抗扰控制算法相比,改进型自抗扰控制算法在控制速度和抗干扰能力方面有明显提高,可实现局部通风机风速的快速稳定调节。     

采用现场可编程门阵列的多电平D类功率放大器控制策略

介绍了一种新颖的基于级联型多电平拓扑结构的开关式的功率放大器,采用多电平技术来改善D类功率放大器输出品质,采用先进的现场可编程门阵列来实现相移PWM技术,其开关频率是单个单元开关频率的2N倍,该触发信号发生器通过数据采集单元接收A/D转换的调制波信号,通过多路载波移相控制单元产生多路相移的三角载波及其反向信号,经比较控制单元产生PWM触发信号波形,并通过死区控制单元进行死区保护控制处理.通过闭环控制保证输出信号的跟随品质,着重研究了闭环控制的控制策略,试验结果表明,采用该控制策略实现的D类功率放大器,系统带宽较宽,具有较好的瞬时响应和输出品质.     

集散型控制系统的设计与应用 第五讲 DCS的现场控制级(顺序控制功能)

<正>一 概述我们介绍了DCS现场控制级的连续调节功能.连续调节控制(包括各种控制算法,如PID、串级、超前滞后补偿等)是根据输入给定与反馈信号之间的差别大小来进行调节的,输出和执行机构也多为连续调整.顺序控制则突出顺序(或逻辑)的作用,即控制执行是根据预先规定的顺序(或逻辑关系)进行信息处理而产生控制输出.顺序控制在各厂家DCS中有着不同的叫法(如顺序控制,批量控制、逻辑控制,梯形图控制等),它们所支持的功能及实现方法也有差别.总的说来,顺序控制的功能和应用大致可分为:1、在批量控制中各工序的控制、全工序的管理、与其它工序的同步等.     

基于STM32的力传感器信号采集与处理系统设计

用于表征机器人人机交互(HRI)过程中力学特性变化的三轴力传感器的数据需要实时采集以反馈给控制系统.考虑到交互过程中传感器的信号会受到随机噪声干扰,影响控制系统的准确性和精度.设计了一种基于运算放大器和STM32微处理器的传感器信号采集和处理系统.传感器微弱信号经放大调理后送至STM32模数转换接口,对传感器输出信号进行数字滤波,并对整个系统进行算法验证.信号分析表明:该系统有效抑制了随机干扰信号,为控制系统提供了稳定的采样精度.     

西门子变频器的应用 第3讲 MM4系列变频器在PID中的应用

PID控制是闭环控制中的一种常见形式。反馈信号取自传动系统的输出端,当输出量偏离所要求的给定值时,反馈信号成比例变化。在输入端,给定信号与反馈信号相比较,存在一个偏差值。对该偏差值,经过PID调节,变频器通过改变输出频率,迅速、准确地消除传动系统的偏差,回复到给定值。本文阐述了MM4系列变频器的PID功能。     

Dynamics of nonlinear feedback control

Feedback control in neural systems is ubiquitous. Here we study the mathematics of nonlinear feedback control. We compare models in which the input is multiplied by a dynamic gain (multiplicative control) with models in which the input is divided by a dynamic attenuation (divisive control). The gain signal (resp. the attenuation signal) is obtained through a concatenation of an instantaneous nonlinearity and a linear low-pass filter operating on the output of the feedback loop. For input steps, the dynamics of gain and attenuation can be very different, depending on the mathematical form of the nonlinearity and the ordering of the nonlinearity and the filtering in the feedback loop. Further, the dynamics of feedback control can be strongly asymmetrical for increment versus decrement steps of the input. Nevertheless, for each of the models studied, the nonlinearity in the feedback loop can be chosen such that immediately after an input step, the dynamics of feedback control is symmetric with respect to increments versus decrements. Finally, we study the dynamics of the output of the control loops and find conditions under which overshoots and undershoots of the output relative to the steady-state output occur when the models are stimulated with low-pass filtered steps. For small steps at the input, overshoots and undershoots of the output do not occur when the filtering in the control path is faster than the low-pass filtering at the input. For large steps at the input, however, results depend on the model, and for some of the models, multiple overshoots and undershoots can occur even with a fast control path.     

Global asymptotic tracking for nonminimum‐phase nonlinear systems in output feedback form

The problem of global asymptotic tracking by output feedback is studied for a class of nonminimum‐phase nonlinear systems in output feedback form. It is proved that the problem is solvable by an n‐dimensional output feedback controller under the two conditions: (a) the nonminimum‐phase nonlinear system can be rendered minimum‐phase by a virtual output; and (b) the internal dynamics of the nonlinear system driven by a desired signal and its derivatives has a bounded solution trajectory. With the help of a new coordinate transformation, a constructive method is presented for the design of a dynamic output tracking controller. An example is given to validate the proposed output feedback tracking control scheme.     

Fractional order predictive sliding-mode control for a class of nonlinear input-delay systems: singular and non-singular approach

Nonlinear models of physical systems usually suffer from input delay and external disturbances. Moreover, when a delayed state is in the input signal gain, it can be non-singular or singular. So, designing a robust controller in a nonlinear system with input and state delay, suitable for non-singular and singular input signal gain, is imperative. The main contribution of our study is to design a new state feedback fractional order predictive sliding mode control (FOPSMC) procedure which not only guarantees the stability of a nonlinear system with known constant input and state delay but also controls the output signal to the desired value. Firstly, a predictor is designed for the system to achieve an input-delay-free one. Then, a state feedback FOPSMC is proposed based on a fractional order sliding signal for a nonlinear system with non-singular control gain. Also, a state feedback FOPSMC and a fractional order sliding mode observer (FOSMO) for the virtual disturbance are designed for singular control gain situation. It is proved analytically, through the Lyapunov stability criteria, that both control procedures can stabilise the system and can control the output signal to the desired value, effectively. Finally, the simulation results verify the effectiveness of the analytical achievements.     

Adaptive Non‐Backstepping Fuzzy Control for a Class of Uncertain Nonlinear Systems with Unknown Dead‐Zone Input

Based on the approximation property of fuzzy logic systems, we propose a novel non‐backstepping adaptive tracking control algorithm for a class of single input single output (SISO) strict‐feedback nonlinear systems with unknown dead‐zone input. In this algorithm, we introduce some novel state variables and coordinate transforms to convert the strict‐feedback form into a normal one, and it is not necessary to consider the traditional approximation‐based the backstepping scheme. Due to new states variables being unavailable, the tracking control is changed from a state‐feedback one to an output‐feedback one. So, observers need to be designed to estimate the indirect nonmeasurable states. According to Lyapunov stability analysis method, the developed controller can guarantee that all of the signals in the closed‐loop system will be ultimately uniformly bounded (UUB), and the output can track the reference signal very well. Simulation results are presented to show the effectiveness of the proposed approach.     

Feedback control and output feedback control for the stabilisation of switched Boolean networks

This paper presents the feedback control and output feedback control for the stabilisation of switched Boolean network. A necessary condition for the existence of a state feedback controller for the stabilisation of switched Boolean networks under arbitrary switching signal is derived first, and constructive procedures for feedback control and output feedback control design are provided. An example is introduced to show the effectiveness of this paper.     

Static output-feedback controller design for a fish population system

This paper examines the problem of output feedback control of a Takagi–Sugeno (TS) fuzzy fishery system. The considered system is the continuous age structured model of an exploited population that includes a nonlinear stock–recruitment relationship. The effort is used as control term, the age classes as states and the quantity of captured fish per unit of effort as measured output. In order to stabilize the stock states around the references equilibrium, which means biologically the sustainability of the fish stock, the output feedback controller is adopted, rather than a controller based on the state observer. An algorithm based on the linear matrix inequality is proposed to compute the static output feedback gain. Simulation results of the continuous fishery systems confirm the effectiveness of the proposed design.     

Decoupling of Measurable Signals via Self-Bounded Controlled Invariant Subspaces: Minimal Unassignable Dynamics of Feedforward Units for Prestabilized Systems

A dynamic feedforward scheme allows measurable signal decoupling to be solved independently of other problems simultaneously present in the design of a control system like, e.g., stabilization, robustness, insensitivity to disturbances. The synthesis procedure, based on the properties of self-bounded controlled invariant subspaces, ensures the minimal complexity of the feedforward unit, in terms of minimal unassignable dynamics and minimal dynamic order, in the case of left-invertible systems and, on some specific conditions, also in the case of non-left-invertible systems. The output dynamic feedback set up to guarantee stability (or, more generally, robustness or insensitivity properties) does not affect the complexity of the feedforward unit, since the peculiar layout where the feedback unit receives an additional input from the precompensator preserves, in the extended system, exactly the same set of unassignable internal eigenvalues of the minimal self-bounded controlled invariant subspace as that defined for the original system. The overall control structure turns out to be a two-degree-of-freedom controller completely devised in the geometric context     

Fradkov Theorem-Based Control of MIMO Nonlinear Lurie Systems

Consideration was given to the problem of adaptive output control of the class of MIMO (Multiple Input Multiple Output) systems that are functionally and parametrically uncertain. An approach to the design of the control law ensuring stabilization of the MIMO nonlinear Lurie system, that is, a system consisting of the linear part (strictly minimum-phase unit) and nonlinear static feedback unit, was proposed on the basis of the Fradkov theorem on feedback passification of linear systems.     

A battery charge controller realized by a flyback converter with digital primary side regulation for mobile phones

A flyback converter with digital control designed and implemented for a lithium battery charging system is proposed in this study. As opposed to the requirement of both voltage and current feedbacks for a conventional flyback converter, this study proposes a converter structure that needs only one voltage feedback to stabilize converter output for implementing the designed battery charging techniques. This single feedback of voltage is made possible by so-called “primary side regulation (PSR)”, which in hardware senses the output voltage using an auxiliary winding in the isolating transformer of the flyback converter that is operated in DC–DC discontinuous current mode. The adoption of PSR also enables the elimination of the opto-coupler that is often used in conventional converters for feedback signals. Another essential part of the converter is the proposition of a new a duty control method which regulate successfully the output current by only one feedback voltage signal. The proposed battery charging design consists of three consecutive modes, trickle current (TC), CC and CV. At TC and CC, a duty control method is adopted, which is able to regulate the output current by sensing only the output voltage. Both simulation and experimental results show a 7 % error deviated from targeted output current. As for CV, a proportional-integral controller is designed and implemented to regulate the output voltage. The overall experimental results show a favorable performance of the proposed charging method with proposed PSR-flyback converter.