【作者】 徐跃；

【导师】 王太勇；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2009， 博士

【摘要】 高速高精度运动控制是现代机器制造工业的重要研究领域之一,是高速加工中心的核心,对提高生产效率和产品质量具有十分重要的作用。本文针对高性能数控系统受外部扰动、非线性、模型和参数不确定等因素造成加工误差的情况,系统地研究了高性能运动控制在数控系统中的应用,从单轴控制和多轴耦合控制两个方面研究了误差避免和误差补偿控制问题。在实际应用中,系统往往要求伺服系统即能对参考信号有良好的跟踪性能,又能对干扰有较强的抑制能力。让一个控制器同时达到两方面的最佳要求,这是难以实现的。在数控机床伺服进给系统中,对跟踪性能和抗扰性能要求都很高,都要达到最佳效果。因此迫切要求实现二自由度控制。即:使跟踪性能为最佳的控制器参数和抑制扰动特性为最佳的控制器参数的调节,能分别独立进行,不需要折中处理,使两方面特性均达到最佳状态。本文以二自由PID控制器设计和基于改进内模控制的二自由度控制器设计两方面探讨二自由度控制器设计。控制系统单独的反馈控制已经越来越难以满足实际控制的需求,因此前馈控制作为一种新型的控制形式单独或与反馈控制控制一起以混合控制的形式应用到工程实践中。论文从伺服控制基本的三环控制结构入手,结合前馈控制思想,提出了基于摩擦模型和切削力预测模型的前馈补偿模型。在同步控制以及多轴协调控制领域轮廓误差(实际轨迹上的点到参考轨迹的法向距离)往往是比位置误差(采样时刻实际位置与参考位置之间的距离)更为重要的性能指标。论文从简化的位置伺服系统数学模型为基础,讨论了运动轨迹系统的伺服增益设计与轮廓误差的关系。定量给出了跟踪误差和轮廓误差的关系,分析了轴特性与轮廓误差之间的关系,得出一些有用的结论。并提出了基于模糊控制的轮廓误差控制器设计方案。为了实现实际的运动控制,同时作为本课题的技术载体,论文设计了一款基于DSP的运动控制卡。为了突破DSP硬件对控制轴数的限制,设计开发了基于CPLD的编码器反馈电路。软件方面设计了速度检测算法、输入信号数字滤波算法以及陷波滤波器等,这些软件算法可以去除输入信号的干扰成分,保证信号的正确输入,保证内部运动控制算法的有效计算。最后,在硬件电路板的设计过程中做了电磁兼容设计。更多还原

【Abstract】 High-speed high accuracy motion control is recognized as one of the most important areas in manufacturing, which is the kernel technique in high-speed machining center playing an important role in increasing the productivity and quality of manufacturing. Disturbance, nonlinearities, model and parameter’s un-match are factors which induce blunders in high performance CNC (Computer Numerical Control) system. This dissertation researches the high motion control algorithms’implementation on the CNC system. Researches blunder avoiding and blunder compensation through single-axle control and max-axles coupling control.In actual applications, servo systems not only asked to have perfect tracing performance but also need to have good anti-interference performance which is hard for single-freedom controller. CNC systems have high requirements for above two aspects so it need two-freedom controller which can independently adjust tracing parameters and disturbance parameters. This dissertation researches two-freedom controller based on PID algorithm and improved inner model theory.Control system’s single feedback structure is hard to meet actual projects, so a new control structure feed-forward mostly appears in actual projects as the form of single or combined with feedback. This dissertation firstly research servo control system’s triple structure, then combines with feed-forward system and put forward a feed-forward compensation model which based on friction model and cutting resistance forecasting model.In synchronism and max-axles-coordination control domain contour error is more important than tracing error. This dissertation discusses the relationship between motion tracing system’s gain and contour error through simple model of position servo system. Analyzing quantify relationship between tracing error and contour error, relationship between axle-character and contour error and giving some conclusions. At last, this dissertation designs a solve-scheme which based on Fuzzy control for contour error.In order to meet the requirement of actual requirement and also as the carrier of author’s subject matter, this dissertation designs a motion control card which based on DSP. There is a CPLD encoder feedback circuit which breaks through DSP chip’s limit, on the card. Speed detection algorithm, input signal’s smoothing filter and notch filter are designed which can smooth disturb component, improving input signal’s qualitative, assurance inner control algorithm’s effective account. In addition, electromagnetism problem was discussed during hardware design procedure.更多还原