【作者】 黄祖毅；

【导师】 姜学智；

【作者基本信息】 清华大学 ， 动力工程及工程热物理， 2004， 硕士

【摘要】 一般的热工对象具有较强的非线性,系统参数随着工况变化而具有较大的变化。论文结合增益调度控制方法、状态反馈控制理论和PID控制器设计方法,得到一些适用于非线性热工对象全工况运行的控制方案。论文采用结合状态反馈控制、Kharitonov 理论、广义Hermite-Biehler定理等理论进行稳定性分析,并通过计算机仿真进行验证的研究方法,研究了增益调度的设计方法及其在热工对象中的应用。取得了下列主要成果:[1]基于状态反馈控制理论,得到了一种稳态工况之间简单可行的控制器参数计算方法,避免了经典增益调度插值算法所面临的实时解两个线性矩阵不等式以及采用矩阵进行插值运算的问题,并应用于非线性机炉协调工况变换的控制问题上;[2]针对非线性控制器切换问题,通过设计控制器的无扰切换方法,得到全工况控制器参数的选择方法,并应用于单级倒立摆的摆角全程控制和位移控制中。这部分内容是把增益调度理论扩展到使用不同形式控制器的对象全工况控制问题上;[3]基于 Kharitonov 理论,针对一类二阶对象,设计了保证系统稳定的PI增益调度方法,并应用于车用分轴燃气轮机的全程控制中。这部分内容是增益调度和PI 控制器相结合的一种方案。[4]通过仿真研究,得到一种适用热工对象变工况控制的增益调度应用方案,包括:对未知系统的阶次和参数同时辨识的系统辨识方法,以及基于广义Hermite-Biehler定理的保证系统稳定的PID无扰切换方法。这个方案应用在核电站蒸汽发生器的水位控制仿真模型中。它为增益调度在工业生产过程,尤其是在热工对象变工况控制领域的应用提供一定的设计经验。研究结果显示了增益调度在热工控制问题上有一定的应用前景。更多还原

【Abstract】 Thermal objects are usually nonlinear systems whose parameters vary in a large region. In this dissertation, some control schemes based on gain scheduled and state feedback control theory and PID controller were proposed to control the nonlinear parameter-varying thermal objects. In present dissertation, through the stability analysis with the state feedback control, Kharitonov theory, and generalized Hermite-Biehler theorem, gain scheduled was studied for thermal control problems, which were confirmed by the computer simulations. Firstly, a stability-preserving interpolation method was proposed to compute the controller parameters in the operation regions between those equilibrium points. It averted the problem of real-time computation for two matrix inequations and interpolation with matrixes, which the classical gain scheduled interpolation method had to meet. This method was implemented in controlling a three-input and three-output nonlinear boiler-turbine unit with parameters varying in a wide range. Secondly, bumpless switching methods were proposed to extend gain scheduled to those plants which used different form controllers in the operation region. These methods were implemented in global control for the angle and distance of the inverted pendulum. Thirdly, based on Kharitonov theory, stability-preserving gain-scheduled PI controllers were designed for a kind of two-order plants whose parameters varied in a large range. This method was applied in a separate-axis gas turbine for automobile use with operation points varying globally. In addition, this method provided a scheme to combine gain scheduled and PI controllers. Finally, based on simulation study, a control scheme for the nonlinear unknown system, especially for thermal objects, was provided. It included a system identification method proposed to identify the order and parameters of an unknown system and PID-controller bumpless <WP=5>switching method which was based on the generalized Hermite-Biehler theorem to guarantee the system stability. This control scheme was confirmed to control a simulation model of the nuclear steam generator water level. In addition, this control scheme provided design experience for gain scheduled to be implemented in industry, especially in thermal object control. The study of this dissertation illusrtated the promising future of gain scheduled in thermal object control.更多还原