基于解耦和滑模的三轴转台控制方法研究

发布时间：2019-04-19 11:29

【摘要】：三轴转台是测试惯性导航器件的专用测试设备，其精度直接决定了惯性导航器件的精度，从而直接影响了各类航天器的性能，对于国家航空航天事业的发展具有极其重要的意义。航空航天技术飞速发展，相应的飞行器和装备设备也有了更高的性能要求，因此对惯性导航器件的精度有了更高的要求。作为惯性导航器件测试设备的三轴转台，其精度要求高于被测器件，因此也面临着朝高精度、大加速度方向发展的挑战。在三轴转台进行多轴运动时，各轴系之间会产生科里奥利力和离心力，并通过作用力矩和反作用力矩相互影响，，使得三轴转台成为具有强耦合性的系统，而这种耦合会极大增加控制难度，并影响转台的性能和精度。针对三轴转台强耦合的问题，本文运用动力学有关知识建立了三轴转台的数学模型，求得三轴转台的微分方程。设计了基于反馈线性化的解耦控制律，将三轴转台的三个轴分解为相互独立的三个单输入单输出的系统，并利用Simulink搭建系统模型进行仿真，从仿真的结果可以看出，本文所设计的非线性解耦控制具有较好的效果。针对三轴转台运行过程中的非周期性扰动问题，本文设计了一种基于时变滑模的控制算法，以时变滑模面代替传统滑模面，使得系统状态始终在滑模面上运动，解决了传统滑模控制在到达阶段时鲁棒性较差的问题。在该控制算法中引入积分项，可以有效削弱抖振，使得稳态误差减小；并将时变滑模面分段，加快了系统的响应速度；最后，在三轴转台实验平台上进行实验验证，将积分时变滑模控制与PID以及普通滑模控制的实验结果进行对比。实验结果表明，本文所采用的积分时变滑模控制算法能够更快跟踪给定信号，且具有较强的鲁棒性。针对三轴转台运行过程中的周期性扰动问题，同时考虑到系统中存在参数不确定和时变的特点，引入了参数自适应；然后对本文所设计的参数自适应迭代学习控制律进行收敛性分析；并在三轴角转台实验平台上进行实验验证。实验结果表明，本文设计的参数自适应迭代学习控制律，与传统参数固定PD型迭代学习控制律相比，使得三轴转台的跟踪性能有了明显的提升。
[Abstract]:The three-axis turntable is a special testing equipment for testing inertial navigation devices. Its precision directly determines the precision of inertial navigation devices, thus directly affects the performance of all kinds of spacecraft. It is of great significance for the development of national aerospace industry. With the rapid development of aerospace technology, the corresponding aircraft and equipment have higher performance requirements, so the precision of inertial navigation devices is higher. As an inertial navigation device testing equipment, the accuracy of the three-axis turntable is higher than that of the tested device, so it is also facing the challenge of developing towards high precision and high speed. In the multi-axis motion of the three-axis turntable, there will be Coriolis force and centrifugal force between the shafts, and through the interaction of the moment of force and the moment of reaction, the three-axis turntable will become a system with strong coupling. This coupling will greatly increase the difficulty of control and affect the performance and accuracy of the turntable. In order to solve the problem of strong coupling of the three-axis turntable, the mathematical model of the three-axis turntable is established by using the knowledge of dynamics, and the differential equation of the three-axis turntable is obtained. The decoupling control law based on feedback linearization is designed. The three axes of the three-axis turntable are decomposed into three independent single-input and single-output systems, and the system model is built with Simulink. The simulation results show that the three axes of the three-axis turntable can be divided into three independent single-input and single-output systems. The nonlinear decoupling control designed in this paper has a good effect. In order to solve the problem of non-periodic disturbance in the operation of three-axis turntable, a control algorithm based on time-varying sliding mode is designed in this paper. The time-varying sliding mode surface is used to replace the traditional sliding mode surface, so that the state of the system is always moving on the sliding mode surface. The problem of poor robustness of the traditional sliding mode control at the arrival stage is solved. This control algorithm can effectively weaken buffeting and reduce the steady-state error, and segment the time-varying sliding mode surface to accelerate the response speed of the system, which can reduce the buffeting effectively and reduce the steady-state error in the control algorithm. Finally, the experimental results of the integrated time-varying sliding mode control are compared with those of PID and common sliding mode control on the experimental platform of three-axis turntable. The experimental results show that the integrated time-varying sliding mode control algorithm used in this paper can track the given signal more quickly and has strong robustness. In view of the periodic disturbance in the operation of the three-axis turntable and taking into account the uncertain and time-varying characteristics of the parameters in the system, the adaptive parameters are introduced. Then the convergence of the parameter adaptive iterative learning control law designed in this paper is analyzed and verified on the experimental platform of triaxial angle turntable. The experimental results show that the parameter adaptive iterative learning control law designed in this paper improves the tracking performance of the three-axis turntable obviously compared with the traditional PD-type iterative learning control law with fixed parameters.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：V249.3

【共引文献】