A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-...A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-based controller designed. The pneumatic muscles were controlled by three proportional position valves, and the air cylinder was controlled by a proportional pressure valve. As the forward kinematics of this structure had no analytical solution, the control strategy should be designed in joint space. A cross-coupling integral adaptive robust controller(CCIARC) which combined cross-coupling control strategy and traditional adaptive robust control(ARC) theory was developed by back-stepping method to accomplish trajectory tracking control of the parallel platform. The cross-coupling part of the controller stabilized the length error in joint space as well as the synchronization error, and the adaptive robust control part attenuated the adverse effects of modelling error and disturbance. The force character of the pneumatic muscles was difficult to model precisely, so the on-line recursive least square estimation(RLSE) method was employed to modify the model compensation. The projector mapping method was used to condition the RLSE algorithm to bound the parameters estimated. An integral feedback part was added to the traditional robust function to reduce the negative influence of the slow time-varying characteristic of pneumatic muscles and enhance the ability of trajectory tracking. The stability of the controller designed was proved through Laypunov's theory. Various contrast controllers were designed to testify the newly designed components of the CCIARC. Extensive experiments were conducted to illustrate the performance of the controller.展开更多
This paper describes the synthesis of robust and non-fragile H∞ state feedback controllers for a class of uncertain jump linear systems with Markovian jumping parameters and state multiplicative noises. Under the ass...This paper describes the synthesis of robust and non-fragile H∞ state feedback controllers for a class of uncertain jump linear systems with Markovian jumping parameters and state multiplicative noises. Under the assumption of a complete access to the norm-bounds of the system uncertainties and controller gain variations, sufficient conditions on the existence of robust stochastic stability and γ-disturbance attenuation H∞ property are presented. A key feature of this scheme is that the gain matrices of controller are only based on It, the observed projection of the current regime rt.展开更多
For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the de...For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the desired set point. The controller design relies on converting the cart's dynamics to an advantageous form, and the robust linear feedback control laws steer the cart's position and orientation errors to zero exponentially. Simulation results show the effectiveness of the proposed control law.展开更多
The largest robust stability radius r(P0) of a system P0 is defined as the radius of the largest ball Bmax in the gap metric centered at P0 which can be stabilized by one single controller. Any controller which stabil...The largest robust stability radius r(P0) of a system P0 is defined as the radius of the largest ball Bmax in the gap metric centered at P0 which can be stabilized by one single controller. Any controller which stabilizes Bmax is called an optimally robust controller of P0. Any controller, regarded as a system, should have its own largest robust stability radius also. In this paper it is shown that the largest robust stability radius of any optimally robust controller of P0 is larger than or equal to r(Po). Moreover, the variation of the closed-loop transfer matrix caused by the perturbation of the system is estimated.展开更多
控制力矩陀螺(control moment gyroscope,CMG)框架伺服系统常受到外部扰动力矩和内部参数摄动等多源扰动影响,导致其控制性能降低,本文重点针对参数摄动对框架伺服系统造成的影响,提出了基于H_(2)/H_(∞)复合控制的CMG框架伺服系统扰动...控制力矩陀螺(control moment gyroscope,CMG)框架伺服系统常受到外部扰动力矩和内部参数摄动等多源扰动影响,导致其控制性能降低,本文重点针对参数摄动对框架伺服系统造成的影响,提出了基于H_(2)/H_(∞)复合控制的CMG框架伺服系统扰动抑制方法.在常规H_(∞)鲁棒控制方法中引入电机参数摄动量,在保证对外部力矩扰动具有鲁棒性的基础上,提升对内部参数摄动影响的抑制能力;结合H_(2)控制策略,提出基于状态反馈H_(2)/H_(∞)复合控制方法,在保证稳态性能的同时进一步提升系统动态响应速度.所提出的复合控制方法能够有效降低多源扰动导致的速度波动,提升系统的动态响应速度.展开更多
递推最小二乘(Recursive Least Squares,RLS)算法因其简单、快速的特点,在微振动自适应控制领域被广泛应用。由于微振动主动控制系统中扰动环境的特殊性及复杂性,需要重点考虑微振动控制中所采用的参数自适应算法在参数估计过程中的鲁...递推最小二乘(Recursive Least Squares,RLS)算法因其简单、快速的特点,在微振动自适应控制领域被广泛应用。由于微振动主动控制系统中扰动环境的特殊性及复杂性,需要重点考虑微振动控制中所采用的参数自适应算法在参数估计过程中的鲁棒性。针对多输入多输出(Multiple Input Multiple Output,MIMO)微振动主动控制系统,基于无限冲激响应(Infinite Impulse Response,IIR)滤波器,提出一种结合死区和归一化的MIMO鲁棒参数自适应算法,并给出其详细的算法推导与收敛性分析。在此基础上,通过构建三自由度微振动主动振动控制实验系统,针对单频窄带扰动、双频窄带扰动展开了对比实验分析,相关的实验结果验证了所提出鲁棒参数自适应算法的可行性和鲁棒性。展开更多
基金This work was supported by the National Natural Science Foundation of China （61374054, 61203007）, and Natural Science Foundation Research Projection of Shaanxi Province （2013JQ8038）.
基金Project(51375430)supported by the National Natural Science Foundation of China
文摘A pneumatic parallel platform driven by an air cylinder and three circumambient pneumatic muscles was considered. Firstly, a mathematical model of the pneumatic servo system was developed for the MIMO nonlinear model-based controller designed. The pneumatic muscles were controlled by three proportional position valves, and the air cylinder was controlled by a proportional pressure valve. As the forward kinematics of this structure had no analytical solution, the control strategy should be designed in joint space. A cross-coupling integral adaptive robust controller(CCIARC) which combined cross-coupling control strategy and traditional adaptive robust control(ARC) theory was developed by back-stepping method to accomplish trajectory tracking control of the parallel platform. The cross-coupling part of the controller stabilized the length error in joint space as well as the synchronization error, and the adaptive robust control part attenuated the adverse effects of modelling error and disturbance. The force character of the pneumatic muscles was difficult to model precisely, so the on-line recursive least square estimation(RLSE) method was employed to modify the model compensation. The projector mapping method was used to condition the RLSE algorithm to bound the parameters estimated. An integral feedback part was added to the traditional robust function to reduce the negative influence of the slow time-varying characteristic of pneumatic muscles and enhance the ability of trajectory tracking. The stability of the controller designed was proved through Laypunov's theory. Various contrast controllers were designed to testify the newly designed components of the CCIARC. Extensive experiments were conducted to illustrate the performance of the controller.
基金Supported by National Natural Science Foundation of P. R. China (60274012)
文摘This paper describes the synthesis of robust and non-fragile H∞ state feedback controllers for a class of uncertain jump linear systems with Markovian jumping parameters and state multiplicative noises. Under the assumption of a complete access to the norm-bounds of the system uncertainties and controller gain variations, sufficient conditions on the existence of robust stochastic stability and γ-disturbance attenuation H∞ property are presented. A key feature of this scheme is that the gain matrices of controller are only based on It, the observed projection of the current regime rt.
基金Supported by National Natural Science Foundation of P. R. China (60274005, 60334030)
文摘For regulating the dynamic nonholonomic mobile cart with parameter uncertainties, a time-varying robust control law is derived to yield globally exponential convergence of cart's position and orientation to the desired set point. The controller design relies on converting the cart's dynamics to an advantageous form, and the robust linear feedback control laws steer the cart's position and orientation errors to zero exponentially. Simulation results show the effectiveness of the proposed control law.
文摘The largest robust stability radius r(P0) of a system P0 is defined as the radius of the largest ball Bmax in the gap metric centered at P0 which can be stabilized by one single controller. Any controller which stabilizes Bmax is called an optimally robust controller of P0. Any controller, regarded as a system, should have its own largest robust stability radius also. In this paper it is shown that the largest robust stability radius of any optimally robust controller of P0 is larger than or equal to r(Po). Moreover, the variation of the closed-loop transfer matrix caused by the perturbation of the system is estimated.
文摘控制力矩陀螺(control moment gyroscope,CMG)框架伺服系统常受到外部扰动力矩和内部参数摄动等多源扰动影响,导致其控制性能降低,本文重点针对参数摄动对框架伺服系统造成的影响,提出了基于H_(2)/H_(∞)复合控制的CMG框架伺服系统扰动抑制方法.在常规H_(∞)鲁棒控制方法中引入电机参数摄动量,在保证对外部力矩扰动具有鲁棒性的基础上,提升对内部参数摄动影响的抑制能力;结合H_(2)控制策略,提出基于状态反馈H_(2)/H_(∞)复合控制方法,在保证稳态性能的同时进一步提升系统动态响应速度.所提出的复合控制方法能够有效降低多源扰动导致的速度波动,提升系统的动态响应速度.
文摘针对新能源汽车充电(G2V)三相整流器为研究对象,研究基于模型预测控制(model predictive control,MPC)的充电控制策略。传统的MPC算法需要准确的系统模型参数,而当控制器中使用的模型参数与主电路实际参数不匹配时,控制性能可能发生恶化,影响整流器充电控制性能。针对此问题,该文将系统参数不匹配作为扩张状态观测器(extended state observer,ESO)扩张出来的扰动项而进行估计,并将扰动进行补偿,从而设计一种基于ESO的MPC充电控制策略。该方法仅使用了系统的输入和输出数据,而不需要精确的系统模型,因此即使模型参数不匹配时,ESO也能够将不匹配项作为扰动而对预测电流进行准确估计,从而提高MPC对参数变化及不匹配的鲁棒性。仿真与实验结果验证了该方法的可行性和有效性。
