一种新型两自由度柔性并联机械手的动力学建模和运动控制

对一种新型两自由度柔性并联机械手的动力学模型和运动控制进行研究。首先,考虑刚—柔耦合影响,利用假设模态法和Lagrange乘子法,推导出系统的动力学方程,该方程为微分—代数方程组。为了设计控制器,采用坐标分块法将该微分—代数方程组化为二阶微分方程组。然后,根据机械手的控制要求,采用滑模变结构方法设计控制器,该控制器能跟踪所期望的运动轨迹,同时柔性构件的弹性振动得到抑制。仿真结果表明该控制器的可行性和有效性。     

模糊滑模控制在交流伺服系统的应用

针对交流伺服系统存在不确定性和多干扰性的特点,将模糊控制和滑模变结构控制结合起来,设计了一种模糊滑模控制器,用于交流伺服系统的位置控制。仿真结果表明,该控制器能较好地实现对指令信号的跟踪,并且使交流伺服系统具有较强的鲁棒性。     

线性不确定性电液位置伺服系统的前馈补偿滑模鲁棒跟踪控制研究

针对线性不确定性系统的鲁棒跟踪控制问题,提出了一种前馈补偿滑模鲁棒跟踪控制方法,并证明了采用该方法所构成的闭环系统是李亚普诺夫意义下渐近稳定的,将该控制器设计方法应用于某结构疲劳试验机电液位置伺服控制系统,验证了所设计控制器的有效性。仿真和实时控制结果均证明：对存在不确定性的结构疲劳试验机电液位置伺服系统,应用该研究所提出的具有前馈补偿的滑模鲁棒跟踪控制器,能较有效地削弱常规VSC所固有的抖振现象,在不同的负载条件下跟踪不同频率的正弦信号均能获得良好的跟踪精度,控制器对系统的不确定性呈现较强的鲁棒性。     

基于ADAMS与MATLAB的机械手控制系统仿真研究

利用ADAMS虚拟仿真技术,搭建了机械手虚拟仿真系统,提高了机械手控制系统的设计效率。首先在ADAMS中建立机械手的三维模型,通过ADAMS与MATLAB的接口模块ADAMS/Controls,将模型导入MATLAB中,然后设计了一个模糊控制器,利用MATLAB/SIMULINK模块搭建了机械手的联合仿真控制系统,仿真结果表明,在该系统带载与空载时,所设计的控制器都能实现机械手对于阶跃信号的高精度快速跟踪。     

一种新型两自由度柔性并联机械手的主动振动控制及其仿真

针对一种新型两自由度柔性并联机械手,在含有压电元件的有限元模型基础上,基于模态理论和滑模变结构理论,研究其振动主动控制问题。采用有限元法和模态理论建立系统的动力学模型。根据系统的性能要求,采用最优化方法确定滑移面,基于Lyapunov直接法设计滑模控制器。控制器能对系统的前几阶模态实施控制,实现机械手的振动主动控制。仿真结果表明,该控制器可有效地抑制柔性构件产生的弹性振动,减小并联机械手动平台的位置误差,从而验证了该控制器的可行性和有效性。     

气动机械手轨迹的Terminal滑模控制方法

应用Terminal滑模控制方法对三轴直角坐标型气动机械手进行连续轨迹控制。首先建立了气动位置伺服系统的数学模型,然后运用Terminal滑模控制对机械手进行轨迹控制。仿真研究结果表明,采用高阶非线性的Terminal滑模控制方法,可以使该机械手对空间直线轨迹的跟踪误差只在未达到收敛点的时间段内较大,在到达收敛点后能完全跟踪目标轨迹。     

4自由度机械手的滑模变结构轨迹跟踪控制

针对机械手的高度非线性、强耦合的特性,依据滑模变结构控制理论,提出了一种机械手的滑模变结构的控制方法,并对其进行仿真。仿真结果证明该方法对4自由度机械手的轨迹跟踪的有效和准确性。     

基于生物激励神经动力学的AGV轨迹跟踪控制

提出了一种基于门限偶极子生物神经元模型和快速终端滑模控制策略的轨迹跟踪控制算法,使AGV在存在初始速度跳变的情况下能顺利实现小车的轨迹跟踪控制。首先由运动学控制器产生一个理想控制律,接着利用神经动力学思想解决初始速度跳变问题,最后用快速终端滑模控制器进一步提高跟踪精度。该控制器的输出有界且光滑,整个控制系统全局快速渐进稳定。计算机仿真结果验证了该控制器的有效性。     

基于复合控制策略的柔性关节机械手轨迹跟踪研究

目前常用的柔性关节机械手运动控制策略设计中,存在的主要问题是关节的加速度与跃度必须准确已知,这对测量带来了极大的困难,同时会对系统引入测量噪声.为解决该问题,提出了复合控制策略.将系统分为刚体模型与柔性模型的组合,对两个模型分别设计控制器以达到机械手关节轨迹跟踪的目的.以一个双臂柔性关节机械手轨迹跟踪为例,仿真结果表明,该复合控制策略可以实现柔性关节机械手的轨迹跟踪要求,具有一定的可行性.     

模糊滑模变结构控制在DCT电控离合器的应用

针对离合器系统的强非线性、难以建立精确的数学模型等特点,设计了滑模变结构控制器,利用模糊控制器来调整滑模趋近律参数的方法来消弱系统抖振动现象,建立了无刷直流电机的数学模型。用MAT—LAB软件进行了仿真验证,并和传统PID控制器作比较。仿真结果表明,该控制器跟踪指令信号性能良好,且具有较强的稳定性。     

Integral backstepping sliding mode control for underactuated systems: Swing-up and stabilization of the Cart–Pendulum System

In this paper an integral backstepping sliding mode controller is proposed for controlling underactuated systems. A feedback control law is designed based on backstepping algorithm and a sliding surface is introduced in the final stage of the algorithm. The backstepping algorithm makes the controller immune to matched and mismatched uncertainties and the sliding mode control provides robustness. The proposed controller ensures asymptotic stability. The effectiveness of the proposed controller is compared against a coupled sliding mode controller for swing-up and stabilization of the Cart–Pendulum System. Simulation results show that the proposed integral backstepping sliding mode controller is able to reject both matched and mismatched uncertainties with a chattering free control law, while utilizing less control effort than the sliding mode controller.     

A new optimal sliding mode controller design using scalar sign function

This paper presents a new optimal sliding mode controller using the scalar sign function method. A smooth, continuous-time scalar sign function is used to replace the discontinuous switching function in the design of a sliding mode controller. The proposed sliding mode controller is designed using an optimal Linear Quadratic Regulator (LQR) approach. The sliding surface of the system is designed using stable eigenvectors and the scalar sign function. Controller simulations are compared with another existing optimal sliding mode controller. To test the effectiveness of the proposed controller, the controller is implemented on an aluminum beam with piezoceramic sensor and actuator for vibration control. This paper includes the control design and stability analysis of the new optimal sliding mode controller, followed by simulation and experimental results. The simulation and experimental results show that the proposed approach is very effective.     

Optimal second order sliding mode control for linear uncertain systems

In this paper an optimal second order sliding mode controller (OSOSMC) is proposed to track a linear uncertain system. The optimal controller based on the linear quadratic regulator method is designed for the nominal system. An integral sliding mode controller is combined with the optimal controller to ensure robustness of the linear system which is affected by parametric uncertainties and external disturbances. To achieve finite time convergence of the sliding mode, a nonsingular terminal sliding surface is added with the integral sliding surface giving rise to a second order sliding mode controller. The main advantage of the proposed OSOSMC is that the control input is substantially reduced and it becomes chattering free. Simulation results confirm superiority of the proposed OSOSMC over some existing.     

Development of a GPC-based sliding mode controller

This article presents a sliding mode controller that uses a generalized predictive controller in the reaching mode. The proposed predictive sliding mode controller is developed from a first-order-plus-deadtime model that represents a good approximation to many chemical processes. The predictive sliding mode controller has six tuning parameters and the tuning rules are given in the paper. Four simulation examples show the features of the proposed controller, which overcomes some of the disadvantages of sliding mode control and generalized predictive control strategies.     

Sliding mode controllers for a tempered glass furnace

This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system׳s parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results.     

A novel adaptive sliding mode control with application to MEMS gyroscope

This paper presents a new adaptive sliding mode controller for MEMS gyroscope; an adaptive tracking controller with a proportional and integral sliding surface is proposed. The adaptive sliding mode control algorithm can estimate the angular velocity and the damping and stiffness coefficients in real time. A proportional and integral sliding surface, instead of a conventional sliding surface is adopted. An adaptive sliding mode controller that incorporates both matched and unmatched uncertainties and disturbances is derived and the stability of the closed-loop system is established. The numerical simulation is presented to verify the effectiveness of the proposed control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as the consistent estimation of gyroscope parameters including angular velocity and large robustness to parameter variations and external disturbances.     

Sliding mode control with PID sliding surface and experimental application to an electromechanical plant

In this study, a sliding mode control system with a proportional+integral+derivative (PID) sliding surface is adopted to control the speed of an electromechanical plant. A robust sliding mode controller is derived so that the actual trajectory tracks the desired trajectory despite uncertainty, nonlinear dynamics, and external disturbances. The proposed sliding mode controller is chosen to ensure the stability of overall dynamics during the reaching phase and sliding phase. The stability of the system is guaranteed in the sense of the Lyapunov stability theorem. The chattering problem is overcome using a hyperbolic function for the sliding surface. Experimental results that are compared with the results of conventional PID verify that the proposed sliding mode controller can achieve favorable tracking performance, and it is robust with regard to uncertainties and disturbances.     

防抱制动系统参数自适应滑模变结构控制器的研究

首先针对具有参数不确定性的二阶非线性系统提出了自适应滑模变结构的控制算法 ,该算法的基本思想是用自适应策略来估计不确定系统的参数 ,根据估计出的参数值 ,来设计滑模控制器 ,优点是无须事先已知不确定参数的边界 ,并且由于在自适应变结构控制采用了消颤措施 (增加了消颤项 ) ,能削弱常规滑模控制所引起的颤振现象 ,也能提高单纯的自适应控制的鲁棒性能。而后将这一控制策略应用于防抱死制动系统 (ABS)的研究中 ,设计了防抱死制动系统的自适应滑模变结构控制器 ,通过计算机仿真 ,验证了该控制方案在 ABS应用中的可行性和有效性     

A new fractional-order sliding mode controller via a nonlinear disturbance observer for a class of dynamical systems with mismatched disturbances

This paper investigates the stabilization and disturbance rejection for a class of fractional-order nonlinear dynamical systems with mismatched disturbances. To fulfill this purpose a new fractional-order sliding mode control (FOSMC) based on a nonlinear disturbance observer is proposed. In order to design the suitable fractional-order sliding mode controller, a proper switching surface is introduced. Afterward, by using the sliding mode theory and Lyapunov stability theory, a robust fractional-order control law via a nonlinear disturbance observer is proposed to assure the existence of the sliding motion in finite time. The proposed fractional-order sliding mode controller exposes better control performance, ensures fast and robust stability of the closed-loop system, eliminates the disturbances and diminishes the chattering problem. Finally, the effectiveness of the proposed fractional-order controller is depicted via numerical simulation results of practical example and is compared with some other controllers.     

Robust adaptive control for a MEMS vibratory gyroscope

This paper presents an adaptive sliding mode controller for a microelectromechanical systems (MEMS) vibratory z-axis gyroscope. The proposed adaptive sliding mode controller can real-time estimate the angular velocity and the damping and stiffness coefficients. The stability of the closed-loop system can be guaranteed with the proposed adaptive sliding mode control strategy. The numerical simulation for MEMS gyroscope is investigated to show the effectiveness of the proposed control scheme. It is shown that the proposed adaptive sliding mode control scheme offers several advantages such as real-time estimation of gyroscope parameters and large robustness to parameter variations and external disturbance.