具有死区预补偿的非线性预测函数控制

死区特性是一类典型的非线性，它对系统最直接的影响是造成稳态误差。针对工业控制系统中广泛存在的死区非线性特性，通过引入死区非线性预补偿器，使系统转化为广义线性系统，完全消除了死区非线性特性对系统的影响，然后针对此广义线性系统进行预测函数控制算法的设计。利用Matlab软件仿真表明，该非线性预测函数控制方法是一种计算简单、跟踪性能好、误差较小的有效的控制方法。     

一类不确定非仿射非线性系统自适应模糊控制

针对一类非仿射非线性系统提出了自适应模糊控制方法,该方法把不确定非线性系统表示为定常线性子系统加非线性项的形式,然后采用模糊逻辑系统设计补偿器来消除非线性项的影响。引入时变死区函数对模糊逻辑系统中的未知参数进行自适应调节,并对时变死区设计了自适应律。证明了该方法可使闭环系统的所有信号均有界,且使跟踪误差收敛到原点的小邻域内。仿真结果表明了该方法的有效性。     

一类不确定系统的动态输出反馈镇定

考察同时含有匹配和非匹配不确定性的一类非线性系统的输出反馈镇定问题。首先讨论仿射非线性的情形,然后讨论一类非仿射非线性情形。分别为所论系统构造了输出反馈动态补偿器,该补偿器可以实现对所论非线性不确定系统的动态输出反馈指数的镇定。     

电液比例位置同步线性自抗扰控制

电液比例位置同步液压系统受到元件安装精度、死区非线性以及系统参数摄动等因素的影响,导致两侧子系统性能不一致进而引起位置不同步.针对这一问题,提出由位置控制器、死区补偿器、同步控制器组成的复合控制方案.首先,建立电液比例位置控制系统数学模型,并分析系统内部参数摄动及比例阀死区特性对同步控制精度造成的影响.在此基础上,设计线性自抗扰同步控制器,实现对系统内外扰动的实时估计与主动补偿,同时为提高液压缸动态性能,减小稳态误差,设计了比例阀死区补偿器.仿真和实验结果表明,自抗扰控制器有效地抑制了内外扰动,提高了位置同步控制精度,而死区补偿器的引入改善了系统动态响应性能,降低了稳态位置同步误差.     

具有未知非线性死区的自适应模糊控制

基于滑模控制原理,利用模糊系统的逼近能力,提出一种自适应模糊控制方法．该方法提出一种简化非线性死区输入模型,取消了非线性死区输入模型的倾斜度相等以及死区边界对称的条件,还取消了非线性死区输入模型各种参数已知的条件．该方法通过引入逼近误差的自适应补偿项来消除建模误差和参数估计误差的影响．理论分析证明了闭环系统是半全局一致终结有界,跟踪误差收敛到零．仿真结果表明了该方案的有效性．     

带有死区输入的非线性系统的自适应控制

针对一类具有死区非线性输入的非线性系统,同时考虑系统中存在未建模不确定项,设计了自适应控制器及未知参数的自适应估计率.该控制器使得闭环系统全局稳定且实现了输出信号对参考信号的精确跟踪.仿真结果进一步证实了该控制器能对未知死区及未建模动态进行有效的补偿。     

具有间隙与补偿的分线性预测控制

本文通过引入间隙非线性预补偿器,讨论了具有间隙非线性特性及白噪声干扰的系统的预测控制问题。     

电弧炉电极调节系统的自适应死区补偿控制

电弧炉电极调节系统存在死区非线性,这将给控制系统带来稳态误差,甚全会造成系统不稳定.为此,针对断点不对称且斜率不相等的死区特性,提出一种自适心死区补偿方法.通过引入死区逆非线性环节,并在线更新未知的死区逆参数,达到完全补偿死区的效果.利用Lyapunov方法证明了参数估计误差的收敛性.仿真结果验证了所提出方法的有效性.     

PWM用于控制非线性系统的研究

针对常见非线性系统，文章提出一种PWM控制器的设计方案。采用MATLAB中的S-Function构建了一个PWM控制器。并通过对饱和非线性和死区非线性的大量仿真实验，结果证明了这种控制方案的可行性和优点。     

具有扇区非线性和死区的混沌系统的跟踪控制

研究控制系统优化问题,由于系统具有扇区非线性和死区的混沌系统的跟踪控制,针对系统的稳定性和跟踪响应特性优化问题,首先通过滑模控制的方法,设计了一个时变滑模控制器并提出了控制规律。利用李雅普诺夫稳定性理论,证明了控制器能够有效的实现Duffing混沌系统的状态跟踪给定的充分光滑信号,Duffing混沌系统在时变滑模控制器下不受输入非线性、死区以及外部噪声等因素的影响。实验结果证明在死区原点对称和死区原点非对称情况下,控制器跟踪的有效性能满足系统的要求,为系统设计提供了支持。     

Adaptive and Robust Stabilization of Feedforward Nonlinear Systems Driven by Symmetric and Non‐symmetric Dead‐zone Inputs

The stabilization of feedforward nonlinear systems subject to hard‐input nonlinearities is a challenging problem due to the presence of input uncertainties. This paper deals with adaptive control of a class of feedforward nonlinear systems driven by unknown dead‐zone inputs. The unknown dead‐zone input nonlinearity is assumed to be either symmetric or non‐symmetric. The control design is based on the combination of the invariant‐manifold stabilization technique with the classical adaptive and robust compensation methods. Simulation results showed that the presence of the dead‐zone inputs in the system dynamics can be handled even for arbitrary large dead‐zone parameters.     

基于性能指标约束的一类输入死区非线性系统最优控制

针对一类考虑指定性能和带有输入死区约束的严格反馈非线性系统,本文提出了一种自适应模糊最优控制方法.采用模糊逻辑系统逼近系统的未知非线性函数及代价函数,利用backstepping方法及命令滤波技术,设计前馈控制器.针对仿射形式的误差系统,结合自适应动态规划技术,设计最优反馈控制器.采用指定性能控制方法,将系统跟踪误差约束在指定范围内.利用死区斜率信息解决具有死区输入的非线性系统的控制问题.基于Lyapunov稳定性理论,证明闭环系统内所有信号是一致最终有界的.最后仿真结果验证了本文方法的可行性和有效性.     

电机非线性补偿控制的相平面分析

基于非线性系统理论,以相平面图为工具,研究电机的非线性补偿控制方法.以纯电动车转角控制系统为例,建立闭环非线性控制的模型,分析非线性环节对控制系统带来的不利影响,提出死区非线性补偿的控制方法.Matlab分析证明,该方法是合理、可行的.     

Experimental study on fine motion control of underwater robots

This paper considers thruster dead zones and saturation limits, which are nonlinear elements that complicate fine motion control of underwater robots. If the vehicle is configured with redundant thrusters, the respective dead zones and their surrounding nonlinear regions could be avoided by implementing a null motion solution for the command input of the vehicle. This solution is derived from the vehicle's geometry and is realized before the application of the motion control algorithm. The result is an improvement in system performance exclusive of the implemented controller type. The approach is illustrated through simulation and experiment with an underwater robot, ODIN.     

Optimal-tuning nonlinear PID control of hydraulic systems

An optimal-tuning nonlinear PID controller design strategy is proposed for hydraulic systems. After an analysis of these systems, an analytic physical dynamical model with dead-zone nonlinearity is derived. A nonlinear PID control scheme with the inverse of the dead zone is introduced to overcome the dead zone in the hydraulic systems. An optimal PID controller is designed to satisfy some desired time-domain performance requirements. Using an estimated process model, the optimal-tuning PID control provides optimal PID parameters even when the process dynamics are time variant. This strategy is implemented in an environment composed of dSPACE, MATLAB, SIMULINK and Real-Time Workshop. The performance of the controller is demonstrated on a hydraulic position control test rig.     

Robust adaptive output feedback control of a class of discrete‐time nonlinear systems with nonlinear uncertainties and unknown control directions

In this paper, robust adaptive output feedback control is studied for a class of discrete‐time nonlinear systems with functional nonlinear uncertainties of the Lipschitz type and unknown control directions. In order to construct an output feedback control, the system is transformed into the form of a nonlinear autoregressive moving average with eXogenous inputs (NARMAX) model. In order to avoid the noncausal problem in the control design, future output prediction laws and parameter update laws with the dead‐zone technique are constructed on the basis of the NARMAX model. With the employment of the predicted future outputs, a constructive output feedback adaptive control is proposed, where the discrete Nussbaum gain technique and the dead‐zone technique are used in parameter update laws. The effect of the functional nonlinear uncertainties is compensated for, such that an asymptotic tracking performance is achieved, whereas other signals in the closed‐loop systems are guaranteed to be bounded. Simulation studies are performed to demonstrate the effectiveness of the proposed approach. Copyright © 2012 John Wiley & Sons, Ltd.     

An improved nonlinear modelling and identification methodology of a servo-pneumatic actuating system with complex internal design for high-accuracy motion control applications

Precise and smooth motion control of servo-pneumatic actuating systems can be improved only by using appropriate mathematical models and identification procedures. In this paper, an improved modelling and parameter identification methodology of a servo-pneumatic linear drive unit with complex internal design that takes into account the influence of dead volume in terms of system dynamics has been developed. The proposed modelling methodology considers the nonlinear mass flow characteristic, dead zone of the valve, polytropic temperature model, heat transfer and nonlinear friction behavior. Experimental results indicates that a proper identification of the dead volume improves model accuracy in terms of pressure dynamics, piston velocity and piston position and therefore the proposed modelling methodology can be a good starting point to design better motion controllers in the field of servo-pneumatic actuating systems.     

Adaptive Fuzzy Event-triggered Control for a Class of Switched Nonlinear Systems with Dead Zone Nonlinearity

International Journal of Control, Automation and Systems - In this paper, an adaptive fuzzy event-triggered control scheme is investigated for a class of nonlinear switched systems with dead zone...     

输出非对称死区的非严格反馈非线性系统控制

本文研究了具有输出非对称死区和状态含未知控制方向的非严格反馈非线性系统, 设计了稳定的自适应 神经网络控制器. 首先, 针对输出非对称死区的问题, 本文采用死区逆的方法, 构造光滑模型逼近原死区模型. 其 次, 在控制器设计过程中, 基于障碍Lyapunov函数的构造, 动态面控制和反步法, 设计出自适应控制信号, 虚拟控制 信号和实际控制信号. 通过稳定性分析, 证明所设计的神经网络控制器可以保证闭环系统内所有信号是半全局一致 最终有界. 最后, 通过MATLAB数值仿真, 说明所设计控制器的有效性.