基于自适应控制的直线电机位置控制研究

发布时间：2018-07-02 09:11

本文选题：直线电机位置控制 + 快速响应　；参考：《浙江理工大学》2017年硕士论文

【摘要】：永磁直线电机是一个具有明显非线性特性的时变系统对象,直线电机扰动和参数变化更敏感。此外,由于周期性齿槽力和力波动,使得某些有铁芯的线性电机受到显著的非线性效应,常用的控制结构直接用于具有高频响特性的直线电机时,无法充分发挥直线电机的高速性能。为此本文应用相对成熟的自适应控制策略,针对直线电机的强非线性及时变特性,在系统辨识的基础上,从模型参考自适应控制和自校正控制两个方向研究直线电机位置控制。以实际中三阶点对点的轨迹(S型加减速)为输入,采用局部参数最优的MIT方案、基于全局稳定性方案和自校正控制方案来设计控制器,经仿真和实验效果对比证明在Lyapunov控制器下获得更小的超调量和更短的调节时间,具有更好的控制性能,达到了直线电机对位置信号快速响应的要求和较高位置精度的要求。本文搭建了永磁同步直线电机数学模型,基于辨识原理创作了通用的系统辨识软件,根据直线电机实际位置输入输出,辨识出直线电机传递函数参数。用PID闭环来消除电流环和速度环未建模部分对模型精准度的影响,通过与实际前馈迭代辨识出来的精确模型对比,获得直线电机位置闭环传递函数。在保证原有特性下合理降阶,并将降阶的传递函数与原有传递函数位置输出和bode图对比,证明其合理性,获得简化永磁同步直线电机二阶数学模型。进一步的针对其模型,采用模型参考自适应控制局部参数最优MIT方法和李雅普诺夫方法设计位置闭环控制器,并详细讨论两种方法构造的自适应控制律稳定性和控制器参数选择。解决了控制器增益和轨迹信号快速跟踪响应权衡问题,以及复杂控制器结构对应多增益参数、多初值的选择问题,确定了二阶控制器并达到较满意效果。进一步的详细阐述了将在线辨识和控制器的设计结合起来的自校正控制,并进行仿真实验。最后根据本文提出的基于自适应控制的直线电机位置控制算法,利用MATLAB软件进行仿真实验,以及系统辨识软件离线实验,分析局部参数最优MIT方法和李雅普诺夫方法设计位置闭环控制器效果,证明了算法的有效性,为直线电机位置控制进一步研究做了铺垫。
[Abstract]:Permanent magnet linear motor (PMLM) is a time-varying system with obvious nonlinear characteristics, which is more sensitive to disturbance and parameter change. In addition, due to the periodic tooth groove force and force fluctuation, some linear motors with iron core are subjected to significant nonlinear effects. The commonly used control structures are directly used in linear motors with high frequency response characteristics. Unable to give full play to the high speed performance of linear motor. In this paper, a relatively mature adaptive control strategy is used to study the position control of linear motor from two directions: model reference adaptive control and self-tuning control, aiming at the strong nonlinear and time-varying characteristics of linear motor. Taking the third-order point-to-point trajectory (S-type acceleration and deceleration) as input, the controller is designed based on the global stability scheme and self-tuning control scheme, using the MIT scheme with the best local parameters. The results of simulation and experiment show that the control performance of the linear motor can be improved by obtaining smaller overshoot and shorter adjusting time under the Lyapunov controller, which can meet the requirement of fast response of the linear motor to the position signal and the requirement of higher position accuracy. In this paper, the mathematical model of permanent magnet synchronous linear motor (PMSLM) is built. Based on the identification principle, a general system identification software is created, and the parameters of the linear motor transfer function are identified according to the input and output of the LSM's actual position. Pid closed loop is used to eliminate the influence of current loop and velocity loop on the accuracy of the model. By comparing with the accurate model identified by feedforward iteration, the position closed loop transfer function of linear motor is obtained. The reduced order transfer function is compared with the position output of the original transfer function and bode diagram to prove its reasonableness and to obtain the simplified second-order mathematical model of permanent magnet synchronous linear motor. For its model, a position closed loop controller is designed by using the model reference adaptive control local parameter optimal MIT method and Lyapunov method. The stability of adaptive control law constructed by two methods and the selection of controller parameters are discussed in detail. The tradeoff problem of fast tracking response between controller gain and trajectory signal and the choice of complex controller structure corresponding to multiple gain parameters and multiple initial values are solved. The second order controller is determined and satisfactory results are achieved. Furthermore, the self-tuning control which combines online identification and controller design is described in detail, and the simulation experiment is carried out. Finally, according to the position control algorithm of linear motor based on adaptive control proposed in this paper, the MATLAB software is used to carry out the simulation experiment, and the off-line experiment of the system identification software. The effect of local parameter optimal MIT method and Lyapunov method on the design of position closed-loop controller is analyzed. The effectiveness of the algorithm is proved. The results provide a basis for further research on position control of linear motor.
【学位授予单位】：浙江理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM359.4;TP273

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