一种用于修磨的机器人的PID控制法

为磨平钢坯细微缝隙的修磨机器人(SGR)提出了一种PID控制法。这种控制法利用前馈力矩作为总体补偿和一个反馈力矩校正轨线跟踪误差,其优点在于它的积分作用消除了机器人的稳态跟踪误差。最后,给出了SGR机器人的计算机仿真结果,验证了此控制法的有效性。

超级电容器储能系统中DC/DC变换器先进PID控制改进方法

针对超级电容器储能系统中的DC/DC变换器为高阶、非线性的系统,采用传统的PID控制难以应对负载、电压突变等复杂情况,提出了一种将Fletcher-Reeves共轭梯度法控制的BP神经网络控制器与PID相结合的先进PID控制改进方法,解决了DC/DC变换器传统控制算法中稳态误差大、控制响应时间长的问题。同时也建立了微网模型,并应用改进算法进行了仿真。仿真结果表明,所提出的改进方法能够有效地改善DC/DC变换器端电压的控制效果,使超级电容器储能系统能有效地平抑微网在并网状态下PCC点的功率波动。

PID–模糊控制联用法在塑料加工工艺控制方面的研究进展

主要综述了PID–模糊控制法和自整定PID–模糊控制法在塑料注塑加工过程中温度、压力等工艺参数监控中的应用。PID–模糊控制法分别利用模糊控制法和PID法对参数变化的动态过程和稳态过程进行监控,兼具了模糊控制法和PID法的优点,既具有较高的控制精度,又具有较快的响应速率。另外,在这种高精度监控方法的监控下,所制备的塑料制品的质量也较高。

双CPU逐点积分法点焊恒电流控制器研制

根据点焊与单片机的特点,探索用双CPU进行点焊恒电流控制,解决利用逐点积分法计算点焊焊接电流有效值占用CPU时间多的难题。研制的双CPU控制器,一个8031CPU负责键盘、焊接过程控制、群控和触发角控制等,另一个8031CPU专职负责电流的采集、积分计算、显示,算出电流有效值后,送给上一个CPU与设定值进行比较,调整触发角,实现恒电流控制。

基于模糊PID控制的灌浆压力稳定控制系统研究

介绍了所研究的灌浆压力稳定控制系统,该系统运用传感器技术、微机技术与控制技术对灌浆过程中的压力参数进行了在线检测和稳定控制,设计了传感器与主机的接口,以80C196单片机作为核心部件,采用模糊控制算法自动整定PID的参数Kp,Ki,Kd,使PID控制器能够通过改变调节信号来控制执行机构,从而使灌浆系统保持给定压力。

PID控制器参数整定及其改进方法

简要介绍了PID控制器及其参数整定方法中的Z-N法、继电反馈法和基于锁相环的参数整定法。并且利用计算机辅助设计软件Mablab对典型被控对象进行了仿真。

基于PCS7的聚合反应器系统控制策略仿真实现

聚合反应是高分子放热反应生产过程,反应器内温度高、压力大,被控变量具有时滞、大惯性和时变等特点。该文分析了工艺流程、控制要求与对象特性,设计了混合罐液位及B料流量比例控制、反应器液位及C料流量比例控制、闪蒸罐液位控制、反应器温度控制、闪蒸罐压力控制、反应产物流量控制6个控制回路,采用变梯度初始开度法PID控制算法;利用西门子PCS7过程控制系统平台和SMPT1000高级多功能过程控制实训装置对上述控制策略进行了验证;研究结果表明,策略控制效果很好,达到了"稳、准、快、省"的控制要求和节能要求。

ADRC FRACTIONAL ORDER PID CONTROLLER DESIGN OF HYPERSONIC FLIGHT VEHICLE

Active disturbance rejection controller（ADRC）uses tracking-differentiator（TD）to solve the contradiction between the overshoot and the rapid nature.Fractional order proportion integral derivative（PID）controller improves the control quality and expands the stable region of the system parameters.ADRC fractional order（ADRFO）PID controller is designed by combining ADRC with the fractional order PID and applied to reentry attitude control of hypersonic vehicle.Simulation results show that ADRFO PID controller has better control effect and greater stable region for the strong nonlinear model of hypersonic flight vehicle under the influence of external disturbance,and has stronger robustness against the perturbation in system parameters.

涂料产品VOC检测方法研究

涂料产品VOC检测是控制室内装饰装修材料有害物质含量的重要措施。本文主要对涂料产品VOC检测方法的内容,检测方法的主要影响因素及这一检测方法的发展方向进行了探究。

Optimal fuzzy PID controller with adjustable factors based on flexible polyhedron search algorithm

A new kind of optimal fuzzy PID controller is proposed, which contains two parts. One is an on line fuzzy inference system, and the other is a conventional PID controller. In the fuzzy inference system, three adjustable factors x p, x i , and x d are introduced. Their functions are to further modify and optimize the result of the fuzzy inference so as to make the controller have the optimal control effect on a given object. The optimal values of these adjustable factors are determined based on the ITAE criterion and the Nelder and Mead′s flexible polyhedron search algorithm. This optimal fuzzy PID controller has been used to control the executive motor of the intelligent artificial leg designed by the authors. The result of computer simulation indicates that this controller is very effective and can be widely used to control different kinds of objects and processes.

A novel PID controller tuning method based on optimization technique

An approach for parameter estimation of proportional-integral-derivative(PID) control system using a new nonlinear programming(NLP) algorithm was proposed.SQP/IIPM algorithm is a sequential quadratic programming(SQP) based algorithm that derives its search directions by solving quadratic programming(QP) subproblems via an infeasible interior point method(IIPM) and evaluates step length adaptively via a simple line search and/or a quadratic search algorithm depending on the termination of the IIPM solver.The task of tuning PI/PID parameters for the first-and second-order systems was modeled as constrained NLP problem. SQP/IIPM algorithm was applied to determining the optimum parameters for the PI/PID control systems.To assess the performance of the proposed method,a Matlab simulation of PID controller tuning was conducted to compare the proposed SQP/IIPM algorithm with the gain and phase margin(GPM) method and Ziegler-Nichols(ZN) method.The results reveal that,for both step and impulse response tests,the PI/PID controller using SQP/IIPM optimization algorithm consistently reduce rise time,settling-time and remarkably lower overshoot compared to GPM and ZN methods,and the proposed method improves the robustness and effectiveness of numerical optimization of PID control systems.

PID Controller Design Based on the Time Domain Information of Robust IMC Controller Using Maximum Sensitivity

The IMC(Internal Model Control) controller based on robust tuning can improve the robustness and dynamic performance of the system.In this paper,the robustness degree of the control system is investigated based on Maximum Sensitivity(Ms) in depth.And the analytical relationship is obtained between the robustness specification and controller parameters,which gives a clear design criterion to robust IMC controller.Moreover,a novel and simple IMC-PID(Proportional-Integral-Derivative) tuning method is proposed by converting the IMC controller to PID form in terms of the time domain rather than the frequency domain adopted in some conventional IMC-based methods.Hence,the presented IMC-PID gives a good performance with a specific robustness degree.The new IMC-PID method is compared with other classical IMC-PID rules,showing the flexibility and feasibility for a wide range of plants.

Genetic Optimization Algorithm of PID Decoupling Control for VAV Air-Conditioning System

Variable-air-volume (VAV) air-conditioning system is a multi-variable system and has multi coupling control loops. While all of the control loops are working together, they interfere and influence each other. A multivariable decoupling PID controller is designed for VAV air-conditioning system. Diagonal matrix decoupling method is employed to eliminate the coupling between the loop of supply air temperature and that of thermal-space air temperature. The PID controller parameters are optimized by means of an improved genetic algorithm in floating point representations to obtain better performance. The population in the improved genetic algorithm mutates before crossover, which is helpful for the convergence. Additionally the micro mutation algorithm is proposed and applied to improve the convergence during the later evolution. To search the best parameters, the optimized parameters ranges should be amplified 10 times the initial ideal parameters. The simulation and experiment results show that the decoupling control system is effective and feasible. The method can overcome the strong coupling feature of the system and has shorter governing time and less over-shoot than non-optimization PID control.

IMC-PID tuning method based on sensitivity specification for process with time-delay

To overcome the deficiencies addressed in the conventional PID control and improve the dynamic performance and robustness of the system, a simple design and parameters tuning approach of internal model control-PID （IMC-PID） controller was proposed for the first order plus time-delay （FOPTD） process and the second order plus time-delay （SOPTD） process. By approximating the time-delay term of the process model with the first-order Taylor series, the expressions for IMC-PID controller parameters were derived, and they had only one adjustable parameter 2 which was directly related to the dynamic performance and robustness of the system. Moreover, an analytical approach of selecting 2 was given based on the maximum sensitivity Ms. Then, the robust tuning of the system could be achieved according to the value of Ms. In addition, the proposed method could be extended to the integrator plus time-delay （IPTD） process and the first order delay integrating （FODI） process. Simulation studies were carried out on various processes with time-delay, and the results show that the proposed method could provide a better dynamic performance of both the set-point tracking and disturbance rejection and robustness against parameters perturbation.

Fractional order PID control for steer-by-wire system of emergency rescue vehicle based on genetic algorithm

Aiming at dealing with the difficulty for traditional emergency rescue vehicle(ECV)to enter into limited rescue scenes,the electro-hydraulic steer-by-wire(SBW)system is introduced to achieve the multi-mode steering of the ECV.The overall structure and mathematical model of the SBW system are described at length.The fractional order proportional-integral-derivative(FOPID)controller based on fractional calculus theory is designed to control the steering cylinder’s movement in SBW system.The anti-windup problem is considered in the FOPID controller design to reduce the bad influence of saturation.Five parameters of the FOPID controller are optimized using the genetic algorithm by maximizing the fitness function which involves integral of time by absolute value error(ITAE),peak overshoot,as well as settling time.The time-domain simulations are implemented to identify the performance of the raised FOPID controller.The simulation results indicate the presented FOPID controller possesses more effective control properties than classical proportional-integral-derivative(PID)controller on the part of transient response,tracking capability and robustness.

Damping controller design based on FO-PID-EMA in VSC HVDC system to improve stability of hybrid power system

Wind energy sources have different structures and functions from conventional power plants in the power system.These resources can affect the exchange of active and reactive power of the network.Therefore,power system stability will be affected by the performance of wind power plants,especially in the event of a fault.In this paper,the improvement of the dynamic stability in power system equipped by wind farm is examined through the supplementary controller design in the high voltage direct current(HVDC)based on voltage source converter(VSC)transmission system.In this regard,impacts of the VSC HVDC system and wind farm on the improvement of system stability are considered.Also,an algorithm based on controllability(observability)concept is proposed to select most appropriate and effective coupling between inputs-outputs(IO)signals of system in different work conditions.The selected coupling is used to apply damping controller signal.Finally,a fractional order PID controller(FO-PID)based on exchange market algorithm(EMA)is designed as damping controller.The analysis of the results shows that the wind farm does not directly contribute to the improvement of the dynamic stability of power system.However,it can increase the controllability of the oscillatory mode and improve the performance of the supplementary controller.

The Application of Microcontroller and PID Technology on the Control of Motor Drive

This paper describes the incremental PID control algorithm and the basic principles of motor soft start, and introduced STM32F103RB8 basic performance microcontroller, combined with incremental PID control advantages, and gives MCU in motor soft start process control application. Practice shows that the incremental PID applications, simplifying the control ideas to improve the performance of the current loop control, limiting the starting current, smooth start-up speed, and achieved good results motor start.

Acid-pickling plates and strips speed control system by microwave heating based on self-adaptive fuzzy PID algorithm

Double self-adaptive fuzzy PID algorithm-based control strategy was proposed to construct quasi-cascade control system to control the speed of the acid-pickling process of titanium plates and strips. It is very useful in overcoming non-linear dynamic behavior, uncertain and time-varying parameters, un-modeled dynamics, and couples between the automatic turbulence control (ATC) and the automatic acid temperature control (AATC) with varying parameters during the operation process. The quasi-cascade control system of inner and outer loop self-adaptive fuzzy PID controller was built, which could effectively control the pickling speed of plates and strips. The simulated results and real application indicate that the plates and strips acid pickling speed control system has good performances of adaptively tracking the parameter variations and anti-disturbances, which ensures the match of acid pickling temperature and turbulence of flowing with acid pickling speed, improving the surface quality of plates and strips acid pickling, and energy efficiency.

Multi-objective optimization based on Genetic Algorithm for PID controller tuning

To get the satisfying performance of a PID controller, this paper presents a novel Pareto-based multi-objective genetic algorithm (MOGA), which can be used to find the appropriate setting of the PID controller by analyzing the pareto optimal surfaces. Rated settings of the controller by two criteria, the error between output and reference signals and control moves, are listed on the pareto surface. Appropriate setting can be chosen under a balance between two criteria for different control purposes. A controller tuning problem for a plant with high order and time delay is chosen as an example. Simulation results show that the method of MOGA is more efficient compared with traditional tuning methods.

The study of film tension control system based on RBF neural network and PID

In the BOPP （Biaxially Oriented Polypropylene） production line, the tension size and smooth film received change volume has a decisive effect on the rolling quality, casting machine is a complicated electromechanical control system, tension control of casting machine are the main factors that influence the production quality. Analyzed the reason and the tension control mathematical model generation casting machine tension in the BOPP production line, for the constant tension control of casting machine, put forward a kind of improved PID control method based on RBF neural network. By the method of Jacobian information identification of RBF neural network, combined with the incremental PID algorithm to realize the self-tuning tension control parameters, control simulation and implementation of the model using Matlab software programming. The simulation results show that, the improved algorithm has better control effect than the general PID.