【作者】 白玉成；

【导师】 唐小琦； 陈吉红；

【作者基本信息】 华中科技大学 ， 机械电子工程， 2009， 博士

【摘要】 随着电力电子技术、稀土永磁材料、微电子技术和控制理论的发展，永磁同步伺服驱动系统在工业国防等领域得到广泛应用。然而受技术水平等因素的影响，高档永磁同步伺服驱动系统市场仍受国外垄断。为打破这种垄断局面，使我国经济发展不受制于人，对高档伺服驱动系统的研究刻不容缓。本文在国家973项目和国家自然科学基金项目的支持下，在前人研究的基础上对交流永磁同步伺服驱动控制策略进一步深入研究。立足解决永磁同步电机的高精度、高速度、高响应、高平稳性控制难题。另外，对伺服驱动系统现场总线接口技术也做了深入的研究，以实现伺服驱动系统网络化接口。具体研究内容如下：典型的位置伺服系统多采用电流(力矩)环、速度环和位置环组成的三环反馈控制系统，电流环是内环，电流控制性能直接影响了位置和速度控制性能。目前电流控制多采用基于电流反馈控制的矢量控制方案，这是一种近似的解耦控制方案，该方案存在dq轴耦合效应和力矩电流漂移现象等缺陷。为此，提出两种可行的补偿方法，这两种方法是依靠电机控制模型对dq轴电流给定电流信号进行预处理，从而实现dq轴电流的完全解耦控制，这些方法对力矩电流漂移现象也有良好的抑制作用。电动机超低速控制性能是关系电机位置控制精度的一个重要因素，受编码器分辨率限制，常规M／T测速法对超低速检测存在检测死区和检测延迟，这将影响电动机超低速运行的稳定性。为此，提出两种新方法来改善伺服控制系统的超低速检测性能，第一种方法是改进型M／T法，它可以有效减小普通M／T法测速死区对伺服系统性能的影响，第二种方法是基于恒捷度模型的瞬时速度计算法，它是假定每个速度采样周期内转子的捷度是恒定的，然后利用解析几何理论构造瞬时速度计算模型，该方法能够同时减小测速死区和测速延迟，为系统超低速控制性能提供前提。转矩波动是影响伺服驱动系统低速稳定性、高速平稳性和位置控制精度的一个重要因素。造成转矩波动的因素有很多，其中永磁体磁链波动是一个重要原因。通过对永磁体磁链波动特性和成因分析，设计了一种模型参考自适应辨识方法(MARS)对磁链波动进行辨识，并提出了磁链波动补偿策略，以减小磁链波动对电磁转矩的影响。实验表明，这些方法对提高电机高速运行时的位置控制精度有积极作用。永磁同步电动机较异步电动机具有功率密度大、转子发热量小、结构紧凑等优点。用永磁同步电动机做主轴传动正在成为一个新的研究方向。普通永磁同步电动机为了实现力矩随电流线性可控，一般将励磁电流设为零，这种控制策略将导致电机的最高转速不能超过额定转速，转矩输出能力也不能满足主轴电机的要求。为此，提出了一种最优路径弱磁控制策略，可以大大提高电动机的最高运行速度，同时保证在任何转速下转矩良好可控性。伺服驱动总线接口技术可以了解决高档数控系统通讯带宽瓶颈问题，使伺服驱动装置能够以更高的精度和更快的速度接受上位机指令运行。以太网技术以成熟的技术、较高的带宽成为总线型数控系统极具潜力的实现方案。通过对总线型数控系统实时性和同步性要求的分析，指出普通以太网CSMA／CD机制的在数控系统应用上的缺陷。为此，提出两种：基于工业以太网的数控系统的实现方案，一种是基于普通网络芯片的软实时方案，另一种是基于专用硬件结构的硬实时方案。针对伺服驱动装置对总线接口的特殊要求，提出电流环同步校正原理和三次样条拟合的位置细分技术原理。应用和实验证实了该项技术的可行性和有效性。更多还原

【Abstract】 AC servo system is used widely with the development of power electronic technology, rare-earth permanent magnet, microelectronic technology and control theory. While foreign enterprises monopolize high-grade servo system maket for technology and other factors in china. The research on high-grade servo system brooks no delay to ensure that the economic development will not be restricted. The control strategies on AC servo system are studied in this thesis based on the predecessors’s research, and the thesis is supplied by the national 973 projects and national natural science foundation. The issues such as high speed, high precision, high response and high stability control are discussed in this thesis. In addition, the field bus interface technonogy is also analyzed to realize servo system networking. The details are shown as follows.Typical servo involves three loop feedback controls, such as current-loop, speed-loop and position-loop. The current-loop is the inner loop, which effects on the speed performance of motors. The vector control scheme based on current feedback control is extensively applied. But this scheme can only approximate decoupling control. In fact, the effect of dq-axis current coupling and the phenomenon of torque current drifting are existed. So, two methods to solve these issues are proposed. With these methods, the current control precision can be improved.The ultra-low speed control performance of permanent magnet synchronous motor is the significant factor to position-precision control. The conventional M/T method affects the stability of motor, which is characterized by detection dead-time and delay for the resolution of encoder. Two new methods to improve the ultra-low speed control performance of ac servo system are described in this thesis. One is improved M/T method, which could minimize the influence of speed detection dead time and smooth the measurement. Another is instantaneous speed detection method based on constant jerk model, which assumes the rotor jerk is constant at the interval of sampling period. The instantaneous speed is calculated by analytic geometry. This method can minimize the speed detection dead time and detection delay, which is the premise of low-speed control.The torque fluctuate would affect the stability of low-speed control, the stability of high-speed control and precision of position control. Many factors are related to this fluctuate, one of them is the permanent magnet flux fluctuate. The model reference adaptive identification method (MARS) used to identify the permanent magnet flux is proposed, and the compensation methods is also put forward. The experiment confirmed that the method is useful to the position precision.There are many advantages for the permanent magnet synchronous motor (PMSM) than AC induction motor (ACIM) such as higher power density, lower heating on the rotor and compacter structure. So, PMSM are also suitable to use as spindle motor. To realize that the torque could linear control by Iq, The conventional method is set excitation-current (Id) to zero, which would result in the max speed can not exceed the rated speed, and the torque output can not meet the demand of spindle motor. An optimal route field-weakening control strategy is proposed, which could greatly increase the max speed of rotor. At the mean time it could also keep the torque controllability at any speed.The bus interface technology could solve the issue of communication band-wide limitation in CNC system. The servo could also get the faster and more accuracy command from superior unit with bus interface technology. Ethernet, with the virtue of mature technology and fast communication, become the trend of networking CNC system. The limitation of mechanism of CSMA/CD used in CNC system is confirmed, through analysis to the synchronism and the real-time property. Two realization scheme to establish networking CNC system are proposed, one is based on conventional Ethernet chip (called soft real-time scheme), another is based on expert hardware structure (called hard real-time scheme). In addition, the principle of current-loop-rectify and position subdivision base on cubic spline fitting are proposed. The feasibility and effectiveness are confirmed by application and experiment.更多还原