Stabilization of CSTR w ith Self-tuning Sliding Mode Controller Using T-S Fuzzy Linearization

A self-tuning reaching law based sliding mode control(SMC)theory is proposed to stabilize the nonlinear continuous stirred tank reactor(CSTR).T-S fuzzy logic is used to build a global fuzzy state-space linear model.Combing the traits of SMC and CSTR,three fuzzy rules can meet the requirements of controlled system.The self-tuning switch control law which can drive the state variables to the sliding surface as soon as possible is designed to ensure the robustness of uncertain fuzzy system.Lyapunov equation is applied to proving the stability of the sliding surface.The simulations show that the proposed approach can achieve desired performance with less chattering problem.

Robust fuzzy sliding-mode control for T-S model based permanent magnet synchronous motor

A fuzzy sliding-mode control (FSMC) scheme based on T-S fuzzy models was proposed for the permanent magnet synchronous motor (PMSM) drive system to solve the speed tracking problem. A T-S fuzzy model was firstly formed to represent the nonlinear system of PMSM. For converting the tracking control into a stabilization problem, a new control design was proposed to define the internal desired states. Then, the FSMC controller for PMSM system with parameter variation and load disturbance was designed based on the fuzzy model. The performance of the proposed controller was verified by experimental results on PMSM system. The results show that the FSMC scheme can drive the dynamics of PMSM into a designated sliding surface in finite time and guarantee the property of asymptotical stability. The information of upper bound of modeling errors as well as perturbations is not required when using the FSMC controller.

柔性臂杆、柔性关节空间机械臂T-S模糊轨迹跟踪及双柔振动并行综合控制

针对存在参数不确定和外界干扰的柔性臂杆、柔性关节空间机械臂追踪期望运动的问题,设计了基于T-S模糊模型的滑模鲁棒控制方案和双柔性振动并行控制方案。首先,设计了关节柔性补偿器以提高系统的等效关节刚度。其次,利用反馈线性化技术建立了系统追踪期望轨迹的误差动力学方程,通过对系统Lyapunov稳定性证明来选择滑模控制参数;简化并改进T-S模糊推理规则,提出了模糊滑模鲁棒控制方法,可解决滑模控制的抖振问题并具有计算量少、控制力矩小的优点。再次,提出了柔性臂杆振动模态的直接反馈控制方案,解决了双柔性并行综合控制的问题。最后,运用逐步仿真的方法,对比仿真结果,证实了所设计轨迹跟踪、双柔性并行综合控制方案的有效性和稳定性。

Design of TakagiSugeno fuzzy model based nonlinear sliding model controller

A design method is presented for Takagi-Sugeno （T-S） fuzzy model based nonlinear sliding model controller. First, the closed-loop fuzzy system is divided into a set of dominant local linear systems according to operating sub-regions. In each sub-region the fuzzy system consists of nominal linear system and a group of interacting systems. Then the controller composed two parts is designed. One part is designed to control the nominal system, the other is designed to control the interacting systems with sliding mode theory. The proposed controller can improve the robusmess and gnarantee tracking performance of the fuzzy system. Stability is guaranteed without finding a common positive definite matrix.

Finite-Time Fuzzy Sliding Mode Control for Nonlinear Descriptor Systems

This article addresses the finite-time boundedness(FTB)problem for nonlinear descriptor systems.Firstly,the nonlinear descriptor system is represented by the Takagi-Sugeno(T-S)model,where fuzzy representation is assumed to be appearing not only in both the state and input matrices but also in the derivative matrix.By using a descriptor redundancy approach,the fuzzy representation in the derivative matrix is reformulated into a linear one.Then,we introduce a fuzzy sliding mode control(FSMC)law,which ensures the finite-time boundedness(FTB)of closed-loop fuzzy control systems over the reaching phase and sliding motion phase.Moreover,by further employing the descriptor redundancy representation,the sufficient condition for designing FSMC law,which ensures the FTB of the closed-loop control systems over the entire finite-time interval,is derived in terms of linear matrix inequalities(LMIs).Finally,a simulation study with control of a photovoltaic(PV)nonlinear system is given to show the effectiveness of the proposed method.

电子节气门控制策略仿真研究

为缩短电子节气门控制策略的开发时间,优化内燃机汽车的动力性与排放性,建立了电子节气门系统数学模型,对其存在的非线性因素进行了分析,对比了PID控制策略、模糊控制策略及滑模变结构控制策略在电子节气门控制系统上的控制效果。利用Matlab/Simulink建立3种控制策略的仿真模型,实验结果表明,滑模变结构控制在控制精度和响应速度方面具有很好的控制性能,模糊控制的控制效果中等,PID控制效果相对较差但控制算法简单便于实现。

基于电液比例的加热炉步进梁控制算法研究

步进梁起着在炉内运送钢坯的作用,它由固定梁和移动梁构成。由于移动梁与钢坯的总重量达数百吨,对其实施速度和位移的精准控制非常困难。运钢过程中常出现2种情况:1)电液比例方向阀的中位死区特性以及整个液压传动机构的机械延迟导致系统响应延迟。2)在经过等高位后,移动梁托起钢坯使得负载阶跃式增加,液压缸运动的速度出现较大静差,无法跟踪给定。针对以上问题,给出了一种基于闭环的模糊滑模控制方法,在MATLAB环境下与PID控制、等效滑模控制进行了比较研究。结果表明,模糊滑模控制有效地克服了步进梁在PID或等效滑模控制中容易出现静差大及速度振荡等问题,同时也克服了系统的载荷扰动及液压系统本身油液非线性带来的系统参数不确定性的问题,使系统的动静态性能均得到了大幅度提升。

Torsional vibration active control of hybrid construction machinery complex shafting

Due to the coaxial connection of engine, motor and pump, the dynamic characteristics of hybrid construction machinery are changed, which generates a new torsional vibration problem of multi-power sources. To reduce the torsional vibration of the hybrid construction machinery complex shafting, torsional vibration active control was proposed. The three-mass model of coaxial shafting of hybrid construction machinery was established. The PID control and the fuzzy sliding mode control were chosen to weaken torsional vibration by controlling the motor speed and torque. The simulation results show that the fuzzy sliding mode control has 12% overshoot of the PID control when the engine torque changes. The active control is effective and can realize smooth power switch.