双臂空间机器人系统末端惯性空间轨迹的反馈跟踪控制

本文讨论了载体位置不受控制的双臂空间机器人系统的载体姿态与机械臂末端抓手协调运动的控制问题。结合系统的动量守恒关系对双臂空间机器人系统的运动学、动力学作了分析,推导出了系统的载体姿态与机械臂末端抓手协调运动的增广广义Jacobi关系。并以此为基础,给出在载体位置不受控制的情况下,惯性坐标系内双臂空间机器人系统的载体姿态与机械臂末端抓手协调运动的反馈跟踪控制规律。研究结果表明,在系统动力学模型及参数较精确确定的情况下,本文提出的控制方案能够有效地控制双臂空间机器人机械臂的末端抓手与载体姿态准确地完成指定的运动,而不需对其载体的位置进行主动控制。仿真计算结果证实了方法的有效性。

基于单状态变量的永磁同步电机混沌跟踪控制

永磁同步电机(PMSM)作为一种状态变量多、耦合性强的非线性系统,在实际运行过程中容易出现分岔、混沌等动力学行为。由于这些非线性行为的存在,使得PMSM系统在某些工作条件下会产生混沌振荡状态,从而影响电机传动系统的稳定运行。为此,提出一种基于单状态变量的反馈跟踪控制方法,有效抑制了PMSM系统的混沌行为,使系统能够跟踪到预先设置的期望参考值,不仅控制速度快,且跟踪后的PMSM系统与预设目标系统之间的误差值为零。此外,所提出的控制方法没有系统内部的一些约束条件,只需通过选取合适的控制增益E,就可以使系统跟踪到任意预设值,大大提高了控制器的适用性。通过大量数值仿真实验,证明了该方法的有效性。

电站中速磨的模糊跟踪控制及仿真

针对电站中速磨的控制难题,提出了一种模糊状态反馈跟踪控制方案。利用内模原理的特性来改善模糊跟踪控制系统的性能,使得被控非线性对象的输出变量可以渐进跟踪期望的变化轨迹。采用T-S建模方法来对中速磨进行建模并得到其T-S模糊模型。针对中速磨的T-S模糊模型设计模糊状态反馈跟踪控制系统并进行仿真,结果表明系统的输出可以很好地跟踪给定的轨迹。

三自由度直升机实验平台及姿态跟踪控制器设计

介绍了设计的三自由度直升机模型的系统构成,建立了系统的俯仰轴控制模型,并依此设计了俯仰轴的状态反馈跟踪控制器与神经网络自适应控制器。为实现设备的在线实时控制编写了基于VC的上位机软件用于控制设备、调试参数以及观察系统的姿态跟踪控制效果。基于Matlab将两种控制器仿真后在实验平台上验证并对比分析,实验结果表明,神经网络自适应控制器能更稳定更好地实现三自由度直升机的姿态跟踪控制。

基于瞬时无功理论的并联DSTATCOM控制器的研究

介绍一种由DSP56F803 DSP型16位单片机和嵌入式实时多任务uc/os-Ⅱ操作系统构成的低压农网配电静止同步补偿器DSTATCOM。利用瞬时无功理论和瞬时无功电流值进行直接跟踪反馈控制的方法,平滑双向动态调节无功功率,保证了无功功率的动态平衡,减少能量损耗。同时采用多任务软件设计方案,使得系统软件具有程序结构性好,变动和维护方便,各任务的实时性得到了保证。

基于微分几何的E-ECHPS车辆转向稳定性控制

为了提高装备电控液压助力转向系统(E-ECHPS)的车辆高速紧急转向稳定性,提出了基于微分几何的线性参考模型反馈跟踪控制策略;建立了包括整车动力学模型、轮胎模型、转向系统模型和ESC模型的非线性动力学模型,通过整车试验和台架试验验证了模型的正确性;推导了系统的仿射非线性状态方程,考虑到轮胎、液压系统和ESC的非线性,运用微分几何理论对系统进行精确线性化得到输入输出伪线性系统;建立了包含转向系统的线性参考模型,为了实现对线性参考模型理想状态的跟踪,构造了反馈跟踪控制器;以方向盘转矩为输入进行了有控制和无控制下的阶跃转向仿真和单移线仿真,结果表明:施加反馈跟踪控制可以显著提高车辆在高速紧急转向工况下的操纵稳定性,为E-ECHPS系统的控制策略设计提供了理论依据。

动态电压恢复器的Fuzzy-PID控制策略的研究

针对电网电压跌落问题,主要研究了单相动态电压恢复器的Fuzzy-PID控制策略。首先对动态电压恢复器的原理和构成进行了简单介绍,并推导出系统方程。然后对电压环反馈控制和二维模糊控制器分别进行了设计,搭建仿真模型。应用Fuzzy-PID自调节控制实现了对负载电压的快速补偿,并对补偿电压进行FFT分析。仿真结果验证了方法的正确性与有效性。

露天矿山运输车辆无人驾驶纵向精准停车控制策略研究

目前,在矿区复杂路况下,露天矿山运输车辆自动驾驶排卸时存在着溜车、冲撞挡墙和急刹车等一系列现象,严重影响车辆纵向精准停车。对此,文章提出了一种面向露天矿山无人驾驶运输车辆的分布式纵向自适应精准停车控制策略。首先,其上层控制器根据状态反馈跟踪控制方法计算得到车辆的期望加速度,再根据坡道阻力和滚动摩擦力计算得到车辆的理论加速度;然后,由下层控制器采用逆动力学方式控制车辆的油门开度及电制动力百分比,实现倒车过程中的车速平稳。现场实车测试结果表明,采用所设计的分布式控制方法,极大地改善了溜车、冲撞挡墙和因速度过高而出现的急刹车等问题,并实现了距离终点仅0.19 m的停车精度,较采用“前馈+PI控制”策略的0.50 m停车精度具有较大程度的提升。

平移式柔性机器人的反馈跟踪控制

本文考虑Ｘ－Ｙ平移式柔性机器人控制系统．单杆负载柔性臂系统可以描述为分布参数模型，我们对系统提出了较为一般的控制策略，在机器人手臂的根部和自由端设计观测器和跟踪反馈控制器，并利用算子半群理论证明了负载柔性机器人系统在所采用的跟踪反馈控制下是全局渐近稳定的．

可重复使用飞行器的保性能姿态跟踪控制方法

针对可重复使用飞行器再入姿态跟踪控制问题,在考虑执行器饱和、气动参数摄动和外部扰动的情况下,提出了一种保性能姿态跟踪控制方案。通过构造预设性能函数,使姿态跟踪误差在预先设置的包络内演化,保证了系统的瞬态和稳态性能;其次,借助于高增益扩张状态观测器解决了气动参数摄动和外部扰动的问题;之后,基于反步控制框架,设计了一种低复杂度的输出反馈扰动补偿控制方法,保证跟踪误差的收敛性。与已有方法相比,所设计的方法不包含一些复杂的非线性动力学近似技术,如神经网络等,降低了参数调节的复杂性,且无需对虚拟控制律重复微分,避免了"微分爆炸"问题。同时,Lyapunov稳定性分析表明,该方法能够保证误差变量的预期收敛以及其他闭环系统信号的有界性。最后,通过对比仿真验证了所提方法的有效性及可行性。

Dynamic modelling and PFL-based trajectory tracking control for underactuated cable-driven truss-like manipulator

In recent years,an innovative underactuated robot was developed,named as underactuated cable-driven trusslike manipulator(UCTM),to be suitable in aerospace applications.However,there has been strong consensus that the stabilization of planar underactuated manipulators without gravity is a great challenge since the system includes a second order nonholonomic constraint and most classical control methods are not suitable for this kind of system.Furthermore,the complexity of the truss-like structure results in tremendous difficulty of computational complicacy and high nonlinearity during dynamic modelling in addition to controller design.It is paramount to solve these difficulties for UCTM's future applications.To solve the above difficulties,this paper presents a dynamic modelling method for UCTM and a trajectory tracking control method based on partial feedback linearization(PFL)that fulfills the control goal of moving UCTM from its original position to a desired position by tracking a given trajectory of the joint angles.To achieve this,a model equivalent method is proposed to make UCTM equivalent with a three-link manipulator in the sense of dynamic behavior.Then the Lagrangian equation combined with complex vector method is proposed in the dynamic modelling process of UCTM,which simplifies the derivation procedure.Based on the established dynamic model,a coordinate transformation method is proposed to transform the control force matrix into the conventional form of an underactuated system,so that the control force can be separated from the unactuated term.The PFL method in combination with the LQR control method is then proposed to realize the targets that the joint angles can track given desired trajectory.Simulation experiments are conducted to verify the correctness and effectiveness of the proposed methods.

Research on improved active disturbance rejection control of continuous rotary motor electro-hydraulic servo system

In order to meet the precision requirements and tracking performance of the continuous rotary motor electro-hydraulic servo system under unknown strong non-linear and uncertain strong disturbance factors,such as dynamic uncertainty and parameter perturbation,an improved active disturbance rejection control(ADRC)strategy was proposed.The state space model of the fifth order closed-loop system was established based on the principle of valve-controlled hydraulic motor.Then the three parts of ADRC were improved by parameter perturbation and external disturbance;the fast tracking differentiator was introduced into linear and non-linear combinations;the nonlinear state error feedback was proposed using synovial control;the extended state observer was determined by nonlinear compensation.In addition,the grey wolf algorithm was used to set the parameters of the three parts.The simulation and experimental results show that the improved ADRC can realize the system frequency 12 Hz when the tracking accuracy and response speed meet the requirements of double ten indexes,which lay foundation for the motor application.

Direct Adaptive Fuzzy Based Backstepping Control of Semi Strict Feedback Nonlinear Systems

In this paper, a direct adaptive fuzzy tracking control is proposed for a class of uncertain single-input single-output nonlinear semi-strict feedback systems. Based on Takagi-Sugeno type fuzzy systems, a direct adaptive fuzzy tracking controller is developed by using the backstepping approach. The main advantage of the developed method is that for an n-th order system, only one parameter is needed to be adjusted online. It is proven that, under the appropriate assumptions, the developed scheme can achieve that the output system converges to a small neighborhood of the reference signal and all the signals in the closed-loop system remain bounded. The efficacy of the proposed algorithm is investigated by an illustrative simulation example of one link robot.

H_∞ reference tracking control design for a class of nonlinear systems with time-varying delays

This paper investigates the H∞ trajectory tracking control for a class of nonlinear systems with time- varying delays by virtue of Lyapunov-Krasovskii stability theory and the linear matrix inequality （LMI） technique. A unified model consisting of a linear delayed dynamic system and a bounded static nonlinear operator is introduced, which covers most of the nonlinear systems with bounded nonlinear terms, such as the one-link robotic manipulator, chaotic systems, complex networks, the continuous stirred tank reactor （CSTR）, and the standard genetic regulatory network （SCRN）. First, the definition of the tracking control is given. Second, the H∞ performance analysis of the closed-loop system including this unified model, reference model, and state feedback controller is presented. Then criteria on the tracking controller design are derived in terms of LMIs such that the output of the closed-loop system tracks the given reference signal in the H∞ sense. The reference model adopted here is modified to be more flexible. A scaling factor is introduced to deal with the disturbance such that the control precision is improved. Finally, a CSTR system is provided to demonstrate the effectiveness of the established control laws.