电液伺服加载系统控制方法的改进研究

电液伺服加载系统用于仿真飞行器在空中飞行所受到的气动力状况,有效的消除由舵机的主动运动所引起的多余力是电液伺服加载中的核心问题.针对此问题采用经典的结构不变性原理设计消扰控制器进行消扰时所存在的消扰器微分阶数较高,信号的品质不好,实现起来比较困难等缺陷,选取了不同的反馈输出信号进行改进设计,降低消扰器阶数,并通过测量内部反馈信号来补偿伺服阀的流量变化.建立了电液伺服加载系统数学模型,并利用该模型对改进设计进行仿真验证.试验结果表明:改进设计系统满足预期指标要求,较好地消除了加载系统跟踪的滞后,有效减少多余力,效果令人满意.     

电液伺服加载系统的鲁棒控制方法研究

针对舵机的主动运动对电液伺服加栽系统的强干扰所引起的多余力,设计一种鲁棒控制器并结合传统的PID控制方法来进行消除.建立数学模型并进行仿真,结果表明:动态鲁棒补偿器很好地起到了抑制外干扰的效果.     

某旋翼加载系统分析

在进行某旋翼加载系统试验时,核心是减小多余力影响问题。文中分析了两种方法,前馈补偿和基于结构不变性原理补偿方法。前馈控制通过测量位置系统的伺服阀位移,该位移是位置干扰的函数,补偿多余力影响包括补偿伺服阀死去非线性影响。基于不变性原理补偿是实际应用中通过测量位置系统的速度,在位置系统输出和加载系统输入之间加入的补偿通道。该文研究某旋翼加载系统的多余力动态补偿及其有效性,仿真显示了补偿效果和两种方法的对比。仿真结果表明, 两种方法都有很好的多余力消除效果,可根据实际情况进行选择。     

试验台多通道加载系统的控制方法研究

试验台多通道加载系统是一种半实物仿真设备,能够在试验室条件下经济、有效地模拟飞机在飞行过程中所受到的舵面气动力矩载荷.通过分析加载系统多余力产生的机理,采用基于结构不变性原理的多余力补偿方法,加载系统可以有效地抑制舵机运动引起的干扰,实现较高的动态加载精度.     

舵机电动加载系统多余力抑制策略研究

多余力是导弹舵机电动加载系统中存在强位置干扰的主要因素,为使电动加载系统的仿真度和可靠性进一步提高,必须对多余力进行抑制。文章在建立舵机电动加载系统数学模型的基础上,分析了多余力产生的机理,并采用前馈补偿原理对多余力进行了补偿,从根本上减小位置干扰的影响。仿真结果显示,系统精度及抗干扰能力有进一步提高,说明该方法是可行有效的。     

振动与力加载耦合的电液伺服控制

振动与力加载耦合的电液伺服系统具有集成模拟被测试件在振动与加载耦合工况下动态性能的优势,针对振动模拟对力加载系统产生的干扰多余力问题,提出了一种力干扰观测器,以提高加载力跟踪精度.首先,建立了振动与力加载耦合的电液伺服控制系统的数学仿真模型;其次,利用递推增广最小二乘算法辨识了力加载系统闭环传递函数;然后,利用零相差跟踪技术设计了力加载系统的前馈逆模型;最后,设计了力干扰观测器,搭建了水平向振动与力加载耦合的电液伺服系统实验台,仿真和实验验证了提出的力干扰观测器可有效降低由于振动扰动而产生的干扰多余力.     

弹翼尾翼加载控制系统研究

研究以数字信号处理器和以直接转矩控制输出的伺服驱动器为核心的导弹弹翼尾翼加载控制系统的系统结构、控制策略、工作原理及实现方法,详细分析加载系统中多余力矩的产生及抑制方法,解决电动加载系统关键性的两个难点,即快速性和多余力消除.实验结果表明,系统能真实地模拟弹翼及尾翼在飞行展开过程中的气流阻力,满足加载系统的快速性要求.     

飞机舵机电液加载系统的多余力抑制方法研究

针对飞机舵机电液加载系统出现的多余力问题,建立系统数学模型,分析与多余力密切相关的因素,提出改进型CMAC神经网络控制器与积分分离式PID控制器复合控制的方法;改进型CMAC神经网络控制器实现前馈控制,以产生舵机加速度的力信号和加载力误差信号作为输入,提高了系统的加载精度和响应速度;积分分离式PID控制器实现反馈控制,克服了经典PID控制器易产生积分过渡的缺点,提高了系统的动态性能;仿真结果表明,复合控制器不仅能够有效抑制多余力,而且使系统具有良好跟踪效果,完全能够达到系统控制性能指标的要求。     

导弹舵面电动加载系统控制器设计

基于高速数字信号处理器的导弹舵面电动加载系统具有很高的动态跟踪速度,但加载过程中多余力能否准确及时地消除还是影响加载系统整体性能的重要因素;设计了一款以TMS320F28335高性能浮点型DSP为运算核心,扩展了外围信号调理电路的加载控制器,采用CAN总线通信完成与上位机的数据交换,通过角加速度的精确测量快速实时计算多余力,并通过角度的预测实现加载力矩超前加载,消除了由于执行机构的延迟所产生的动态跟踪的延迟.     

直线舵机加载台控制系统建模与设计

设计了一种新的直线气动舵机加载结构,该结构通过摆杆运动将力矩电机的旋转运动变为直线运动,在电机转动角度不大的情况下实现了对舵机的直线加载.首先,给出了直线舵机加载台组成及其工作原理分析,并建立了气动舵机加载系统的数学模型.然后,采用PID控制加复合前馈和力矩速度反馈的复合控制策略对舵机加载系统进行了设计.最后,通过对直...     

遥操作机器人的新型力反馈算法*

在采用液压挖掘机改造的遥操作机器人双向伺服控制系统中,针对大臂和前臂两个自由度构建力反馈控制算法。以准确地获取从端机器人与环境的作用力,使反馈力能够更好地反映从端工作状况为目的,采用构建干扰力补偿项的方法消除干扰力对反馈力的影响;以机器人转角为输入,以空载时检测到的液压缸作用力为输出,通过径向基函数构建干扰力补偿项,此补偿项可对多种因机器人的机械本体动力学特性产生的干扰力之合力进行补偿。实验证明,在以液压机构为从手的双向力反馈系统中,通过构建干扰力补偿项的方法提高力反馈效果的方法是可行的,采用的带有干扰力     

轧机两侧液压伺服位置系统自抗扰同步控制

针对轧机传动侧和操作侧液压伺服位置系统存在不一致性而引起两侧位置不同步的问题, 提出一种自抗扰同步控制方法.首先建立了液压伺服位置同步系统动态机理模型, 并在考虑两侧位置伺服系统都具有参数摄动及外负载波动的情况下, 设计了扩张状态观测器对同步系统中不确定性和不一致性进行估计, 并采用状态误差反馈律给予主动补偿, 同时消除同步误差. 仿真和实验结果表明, 所提出的同步控制方法能够使两侧液压伺服位置系统动态响应和稳态特性保持一致, 并提高了单侧子系统的动态性能及抗干扰能力.     

液压位置伺服系统同步的控制

针对无缝钢管生产线轧机两侧液压位置伺服系统内部参数不同和外界干扰不一致造成轧辊压下位置不同步的问题,设计了基于模糊输出反馈的液压位置伺服同步控制系统,并从理论上证明了该控制系统的稳定性。仿真结果表明,在轧机两侧内部参数不同和外部干扰差异的情况下,基于模糊输出反馈的液压位置伺服同步控制系统不仅具有较短的同步时间并且跟随误差更小。     

交流伺服电机速度与位置环的一体化鲁棒控制

提出一种交流伺服系统的离散域复合控制方案,可实现在未知负载条件下的准确位置控制。基于永磁同步电机伺服系统中位置与速度环组成的数学模型,以电机转角位置作为系统的测量反馈信号,设计一个降阶线性扩展状态观测器对电机转速（未量测）和未知负载扰动加以估计,并用于反馈控制和扰动补偿。采用TMS320F2812DSP在一台实际的永磁同步电机上进行了实验测试,结果表明伺服系统能在未知负载情况下实现平稳和准确的目标位置跟踪,且对负载和参数差异具有较好的鲁棒性。这种控制方案可方便地应用于相关的伺服系统。     

Variable structure servomechanism design and applications to overspeed protection control

A new class of variable structure feedback systems capable of rejecting a persistent disturbance is developed. This type of system which is called the VS servo is structurally similar to linear multivariable servomechanisms. Its behavior on the switching manifold and its internal stability and output regulation properties are examined using the theory of variable structure systems and sliding modes and existing results on high gain feedback.The concepts of the VS servo are particularly well suited for the study of ‘emergency’ control system design. The design of the VS servo is applied to the problem of overspeed protection control for large steam turbines. This study leads to an understanding of the generic difficulty associated with the application of overspeed protection control to large coal fired power plants and provides a feedback control structure with considerable promise for such applications. In addition, the paper serves as a useful illustration of the flexibility and potential applicability of variable structure designs. The effect of actuator parasitic dynamics is considered.     

Continuous-time optimal robust servo-controller design with internal model principle

The linear quadratic design of an optimal robust servo–controller for a continuous–time control system is described. It introduces a servo–control performance measure which accommodates the internal model principle. The measure selectively discounts penalties on control effort of desirable frequencies and provides complete flexibility in the selection of weighting matrices. The proposed servo–controller uses plant state feedback, signal state feedforward and a servo–compensator for ensuring robust asymptotic command tracking and disturbance rejection. An informal alternate proof of the internal model principle in the state variable domain is presented using an operator-transformation technique. Where necessary, observers are used to complement the servo-controller. The proposed optimal robust servo–controller yields the expected superior performance in terms of response and error minimization. An illustrative example is given.     

Tracking control of electro-hydraulic servo multi-closed-chain mechanisms with the use of an approximate nonlinear internal model

This paper studied the trajectory-tracking problem of a hydraulic servo multi-closed-chain mechanism. The nonaffine nonlinear characteristic of the electro-hydraulic actuator and its time-varying uncertainty load resulting from the multi-closed-chain mechanism was taken into consideration in the proposed novel nonlinear control algorithm, that is, the approximate internal model control (AIMC) integrated with a position feedback control in cascade control design. This algorithm improves the trajectory-tracking performance of the hydraulic servomechanism (HSM). To reduce the difficulty in directly utilizing the AIMC for the HSM position trajectory, the complex electro-hydraulic mechanical system was divided into two subsystems: nonaffine nonlinear, and linear. The AIMC controller was designed for the nonaffine nonlinear subsystem to realize velocity trajectory tracking control, whereas a position feedback control was derived for the linear subsystem. The position trajectory tracking control was achieved by congruently combining the AIMC, and the position feedback control based on a recursive design idea. In addition, a complete state-space mathematical model for the HSM was developed and illustrated through simulations and experiments. Based on the proposed approach and the AIMC, the desired position and velocity trajectory tracking was examined on a hydraulic forging manipulator. The stability of the proposed method was analytically derived. Results of the simulations and experiments performed with the hydraulic manipulator demonstrated the effectiveness of the proposed approach.     

高性能永磁同步电机位置伺服系统建模与仿真

永磁同步电动机由于其优越的性能而广泛应用于精确的伺服控制系统中,但其绕组相电流和转速具有强耦合性,而且永磁同步电机的模型的不确定性影响了控制器的精度.文中首先建立了基于PID控制器的交流伺服系统,在此基础上又提出了一种基于自抗扰控制器的高性能永磁同步电动机位置控制器,并建立了基于该控制器的永磁同步电动机伺服系统仿真模型.仿真实验证明,与基于PID控制器的交流伺服系统相比较,基于自抗扰控制器的交流伺服系统的优越的跟踪性能和抗扰性能.     

The velocity control of an electro‐hydraulic displacement‐controlled system using adaptive fuzzy controller with self‐tuning fuzzy sliding mode compensation

Hydraulic servo control systems have been used widely in industry. Within the realm of hydraulic control systems, conventional hydraulic valve‐controlled systems have higher response and lower energy efficiency, whereas hydraulic displacement‐controlled servo systems have higher energy efficiency. This paper aims to investigate the velocity control performance of an electro‐hydraulic displacement‐controlled system (EHDCS), where the controlled hydraulic cylinder is altered by a variable displacement axial piston pump to achieve velocity control. For that, a novel adaptive fuzzy controller with self‐tuning fuzzy sliding‐mode compensation (AFC‐STFSMC) is proposed for velocity control in EHDCS. The AFC‐STFSMC approach combining adaptive fuzzy control and the self‐tuning fuzzy sliding‐mode control scheme, has the advantages of the capability of automatically adjusting the fuzzy rules and of reducing the fuzzy rules. The proposed AFC‐STFSMC scheme can design the sliding‐mode controller with no requirement on the system dynamic model, and it can be free of chattering, thereby providing stable tracking control performance and robustness against uncertainties. Moreover, the stability of the proposed scheme via the Lyapunov method is proven. Therefore, the velocity control of EHDCS controlled by AFC‐STFSMC is implemented and verified experimentally in different velocity targets and loading conditions. The experimental results show that the proposed AFC‐STFSMC method can achieve good velocity control performance and robustness in EHDCS with regard to parameter variations and external disturbance. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society