平衡截断法在带式输送机系统模型降阶中的应用

长距离带式输送机系统本身非常复杂,建立的动力学模型阶数较高,控制器的设计较为困难,本文利用平衡截断降阶法将高阶带式输送机系统模型化简为低阶的系统模型,在H2范数下对高阶与低阶系统的传递函数之间的误差进行评价,并从频域对其进行对比分析。     

大型带式输送机动态建模及模型降阶

通过有限元方法建立大型带式输送机的动态模型,并通过基于系数矩阵的有序实Schur分解的模型降阶法对带式输送机系统模型进行降阶处理,得到低阶模型,绘出其频率特性Bode图,比较降阶前后系统的频率特性。     

Model predictive control for a class of systems with isolated nonlinearity

The paper is concerned with an overall convergent nonlinear model predictive control design for a kind of nonlinear mechatronic drive systems. The proposed nonlinear model predictive control results in the improvement of regulatory capacity for reference tracking and load disturbance rejection. The design of the nonlinear model predictive controller consists of two steps: the first step is to design a linear model predictive controller based on the linear part of the system at each sample instant, then an overall convergent nonlinear part is added to the linear model predictive controller to combine a nonlinear controller using error driven. The structure of the proposed controller is similar to that of classical PI optimal regulator but it also bears a set-point feed forward control loop, thus tracking ability and disturbance rejection are improved. The proposed method is compared with the results from recent literature, where control performance under both model match and mismatch cases are enlightened.     

带式输送机液压张紧装置控制策略的研究

张紧装置是带式输送机安全稳定运行的关键设备,由于带式输送机系统的非线性和运行的大滞后性,本文设计一种滑模模糊控制的液压自动张紧系统,在滑模控制切换面的设计中采用模糊逻辑的内插性能,给出了液压系统的原理图,应用matlab对带式输送机的张紧力进行分析,仿真结果表明基于滑模模糊控制的液压张紧装置响应迅速,控制效果好。     

基于遗传禁忌算法的带式输送机直接转矩控制系统

带式输送机电气传动系统好坏直接关系到生产过程的安全可靠性和经济性。针对传统带式输送机电气系统启动加速度不平稳,容易引起皮带跑偏甚至撕裂皮带的安全事故,本文提出了一种改进遗传禁忌算法的PID控制器来实现直接转矩控制的转速闭环方案。该方案建立了误差绝对值时间积分性能指标的最小目标函数和禁忌变异算子的数学模型。结果表明,改进PID控制器具有超调量和调节时间小、抗干扰性强、鲁棒性好的优点,有助于解决系统皮带跑偏甚至撕裂的问题。     

PLC在TSD32型伸缩式皮带输送车控制系统中的应用

针对目前普遍采用比例阀放大器控制皮带速度的皮带输送机，既成本高、不能扩展功能，又有不易维护等问题，提出了一种新型的伸缩式皮带输送车电气控制方案，它采用可编程控制器（PLC）主模块和EM235模拟模块，对输入值和反馈值进行采样，编写程序来控制比例阀，从而控制皮带速度．介绍了此电控系统的控制需求、PLC的选型以及部分程序流程．通过TSD32型皮带输送车在现场试运行时表现的优越性能，验证了此电控方案的正确性．     

基于多系统协调的密封舱压力智能化控制

掘进面地层水土压力和密封舱压力相平衡是盾构机安全掘进的关键,密封舱压力控制是当前盾构研究的热点。研究根据场切深指数(Field penetration index, FPI)及扭矩切深指数(Torque penetration index, TPI)指标判断土体参数,实现地质的在线识别,为盾构机推力、扭矩和推进速度的设定提供依据。根据质量守恒定律并考虑盾构密封舱渣土的可松性,建立土压平衡盾构密封舱压力控制机理模型,并通过模型预测控制器进行多系统协调控制。对比常规比例-积分-微分(Proportion- integration-differentiation, PID)控制器,多系统协调控制具有更优的控制性能,使盾构机处于工况稳定,掘进快速,节能高效的理想状态。     

基于DSP的机械臂约束预测控制系统设计

针对机械臂的实时控制问题,基于约束预测控制,提出了一种机械臂实时运动控制方法。介绍了机械臂动力学模型并进行了线性化处理,以降低算法复杂度、保证实时性。设计了轨迹跟踪控制器和约束预测控制器,其中轨迹跟踪控制器采用最优反馈控制律,可确保机械臂按参考轨迹运动;而约束预测控制器则在考虑机械臂物理约束的情况下,为跟踪控制器提供最优参考轨迹。以DSP作为核心控制器,搭建了机械臂控制系统,同时给出了硬件和软件设计方法。以梯形和三次多项式轨迹为例,进行了系统功能测试,测试结果表明了所述控制系统的可行性和有效性。     

Finite element based model predictive control for active vibration suppression of a one-link flexible manipulator

This paper presents a unique approach for active vibration control of a one-link flexible manipulator. The method combines a finite element model of the manipulator and an advanced model predictive controller to suppress vibration at its tip. This hybrid methodology improves significantly over the standard application of a predictive controller for vibration control. The finite element model used in place of standard modelling in the control algorithm provides a more accurate prediction of dynamic behavior, resulting in enhanced control. Closed loop control experiments were performed using the flexible manipulator, instrumented with strain gauges and piezoelectric actuators. In all instances, experimental and simulation results demonstrate that the finite element based predictive controller provides improved active vibration suppression in comparison with using a standard predictive control strategy.     

基于VC++设计钢丝绳芯皮带电磁在线监测系统

为了保证皮带输送机的安全运行,发挥钢丝绳芯皮带在全生命周期中的最大效益,以TCK-GMS600弱磁检测器为基础,在VC++6.0集成开发环境下,应用DAQBench(Data Acquisition Bench)控件和多线程技术,开发了钢丝绳芯输送带电磁在线监测系统,实现了数据采集和存储、曲线实时显示、缺陷识别等功能,为钢丝绳芯皮带的健康维护奠定基础。     

具有状态约束的电液伺服系统模型参考鲁棒自适应控制

针对电液伺服系统中的模型不确定性和状态约束问题,设计了一种模型参考鲁棒自适应控制(MRRAC)方法。将电液伺服系统的近似模型作为模型预测控制(MPC)的设计对象,在设计过程中考虑状态约束,并生成受约束的状态期望,作为后续伺服控制方法的参考指令。为了克服液压系统中的模型不确定性,基于反步法设计了鲁棒自适应控制器(RAC),实现了兼顾模型不确定性和状态约束的伺服控制。基于Lyapunov稳定性理论证明了所设计控制策略的闭环渐近稳定性,且系统所有信号均有界。仿真结果表明,控制器对于系统模型不确定性具有较强的鲁棒性,且可实现对指定状态的有效约束,充分验证了该控制策略的有效性。     

液压软制动系统在下运式带式输送机中的应用

为了探究下运式带式输送机在不同运行工况下的制动策略，提出了液压软制动系统，通过建立数学模型对其进行分析研究，采用液压软制动作为突发断电和紧急停车的安全制动方式，解决特殊工况下的安全问题。借助Simulink和AMESim两款仿真软件对各工况下的制动过程进行了仿真研究，结合下运式带式输送机的运行特性搭建了模拟运行试验台，对所设计的制动系统进行了试验研究。结果表明：“四象限变频回馈制动+液压软制动” 的电液复合制动能够实现带式输送机在正常供电工况下的安全停车，且液压软制动系统在突发断电和紧急停车过程中有良好的制动效果，为下运式带式输送机的制动特性研究提供了借鉴。     

Improved linear quadratic and proportional control system for improved liquid level system regulation in a coke fractionation tower

A new linear quadratic regulation (LQ) control plus a proportional (P) control system is proposed for the level regulation in an industrial coke fractionation tower. The process is first stabilized using a P controller and then a subsequent LQ controller is designed for the P control system. The P control system is modeled as a generalized first order plus dead time (FOPDT) process using step-response test and the LQ-P controller is designed through a new state space structure. Performance in terms of regulatory and servo issues were investigated. Simulation results showed that the proposed method is more robust and improves performance than traditional model predictive control.     

Robust current control-based generalized predictive control with sliding mode disturbance compensation for PMSM drives

This paper addresses the current control of permanent magnet synchronous motor (PMSM) for electric drives with model uncertainties and disturbances. A generalized predictive current control method combined with sliding mode disturbance compensation is proposed to satisfy the requirement of fast response and strong robustness. Firstly, according to the generalized predictive control (GPC) theory based on the continuous time model, a predictive current control method is presented without considering the disturbance, which is convenient to be realized in the digital controller. In fact, it's difficult to derive the exact motor model and parameters in the practical system. Thus, a sliding mode disturbance compensation controller is studied to improve the adaptiveness and robustness of the control system. The designed controller attempts to combine the merits of both predictive control and sliding mode control, meanwhile, the controller parameters are easy to be adjusted. Lastly, the proposed controller is tested on an interior PMSM by simulation and experiment, and the results indicate that it has good performance in both current tracking and disturbance rejection.     

面向CAD/CAE集成的带式输送机变型设计

针对带式输送机传统设计过程中存在的问题,提出了面向CAD和CAE模型集成的带式输送机变型设计技术,在CATIA软件和Ansys软件中分别建立带式输送机CAD模型和CAE模型,并将设计规则嵌入到模型中,运用数据库技术将CAD模型和CAE模型进行集成,通过编程语言开发了带式输送机变型设计系统,实现了带式输送机结构和尺寸上的变型设计,极大地缩短了开发周期。     

边缘扩展的皮带撕裂支持向量机视觉检测

提出了基于视觉的皮带撕裂监测方法,并构建了皮带撕裂视觉监控系统。针对皮带输送机运行过程中由于干扰导致的图像退化,采用维纳滤波方法实现了退化图像的复原。为实时识别高速运动的皮带裂纹,采用CamShift算法对快速移动的皮带裂纹序列目标图像进行跟踪与捕捉。采用Canny算子对皮带裂纹进行边缘提取,并通过增加一个δ值,使检测到的裂纹边缘向外扩张,从而增加检测到的皮带裂纹权重,获得鲁棒性更高的边缘检测效果。最后,构建了SVM皮带裂纹预报模型,以皮带裂纹图像的像素面积及长宽比几何特征量作为模型输入量,对皮带裂纹状态进行预报。实验表明,提出的皮带撕裂检测方法是有效的。     

Analysis of asymmetrical effect of tension forces in conveyor belt on the idler roll contact forces in the idler housing

This paper analyses an impact of asymmetrical tension forces, which are occurring in the conveyor belt, on the contact forces in the guiding idlers. It describes causes of an increased wear-out of the conveyor belts due to an asymmetric tensioning of the transport belt. There were investigated five measuring points loaded with a symmetrical and asymmetrical tensioning of a specimen section of the pipe conveyor transport belt, using the Friedman test for the factor of asymmetry. The tension force determines also changes of the contact force layouts in the individually investigated idler rolls. A newly developed method was applied in order to identify states of the particular experimental phases for the process of the transport belt tensioning and relaxation. This method is based on differences of the contact force time behaviours. It is possible to present a hypothesis, taking into consideration the obtained results that a side slipping of the running conveyor belt is caused by the tension force asymmetry also on the real operational conditions.     

基于 EDEM 的输送带动态跑偏仿真分析

针对带式输送机在运输物料过程中由于落料不均易出现输送带跑偏的问题,通过离散元法进行分析。运用单因素控制变量法进行 EDEM 仿真计算,分析了不同落料高度、不同落料速度及不同湿度状态下对物料流在导料槽出料口处速度与输送带跑偏的影响。通过对比与研究发现,物料落料高度、落料速度及物料颗粒湿度对带式输送机转运系统会产生影响,在此情况下单一改变某一参数会降低输送带跑偏趋势。研究发现,在一定条件下输送带跑偏趋势随落料高度增加而增加,也随落料速度增加而增加,但是与物料湿度成相反趋势,即物料湿度增大,输送带跑偏趋势减小。同时需注意物料湿度增加,物料附着导料槽影响下段输送带受料。     

带式输送机动力学及其计算机仿真的研究

针对大型带式输送机动态设计问题,建立了起动和停机过程的动力学模型,其特点是综合考虑了阻力的作用、输送带为粘弹性、拉紧装置分为2自由度。讨论了停机方式和计算方式的关系。提出了一种梯形加速度起动曲线。以多驱动带式输送机系统为对象,采用跟踪控制方法建立了控制起动、停机过程的动态分析算法。开发了动态设计软件BCD.20,通过对实际系统的仿真,证明了算法和软件的正确性;得出控制起动方式输送机有较好的受力状态,不同的停机方式输送带的张力分布是不同的等结论。     

Constrained off-line synthesis approach of model predictive control for networked control systems with network-induced delays

This paper investigates the off-line synthesis approach of model predictive control (MPC) for a class of networked control systems (NCSs) with network-induced delays. A new augmented model which can be readily applied to time-varying control law, is proposed to describe the NCS where bounded deterministic network-induced delays may occur in both sensor to controller (S–A) and controller to actuator (C–A) links. Based on this augmented model, a sufficient condition of the closed-loop stability is derived by applying the Lyapunov method. The off-line synthesis approach of model predictive control is addressed using the stability results of the system, which explicitly considers the satisfaction of input and state constraints. Numerical example is given to illustrate the effectiveness of the proposed method.