Total control of fast coordinate measuring machines
Total control of fast coordinate measuring machines
复制标题
快速坐标测量机的总体控制
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
M. Grimble
中科院分区：
文献类型：
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作者：
M. Katebi;T. Lee;M. Grimble
三坐标测量机的设计已经发生了根本性的变化，其目标是提高速度和测量精度。这是通过用高速数字处理器代替模拟部件和用大功率电子设备代替机械部件来实现的。然而，控制系统几乎没有改变。同时满足速度和精度的要求。为了确保总体控制，需要设计、实现和调谐每个臂的四个相互作用的反馈回路（电流、速度、位置和振动回路）和一个前馈回路（轮廓回路）。这为三个臂提供了总共15个控制回路。与传统的控制系统不同，控制变量可用于反馈，探头位置是困难和昂贵的测量。本文开发了一种最佳控制，使速度和测量精度最大化，同时调整和调试时间最小化。所提出的控制设计方案采用分层的方法将系统分解成更小的子系统。首先优化电流和速度环。然后，它表明，MIMO控制问题可以解耦成三个SIMO控制问题。设计了两自由度最优控制器来控制测头位置和手臂振动。前馈控制器的自动生成通过引入的模型的轮廓。给出了仿真和实验结果。<
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The design of CMM has undergone a radical change with the aim of improving speed and measurement accuracy. This is achieved by substituting the analogue component with high speed digital processors and the mechanical components by high power electronic devices. The control system is, however, hardly changed. Requirements of speed and accuracy should be simultaneously satisfied. To ensure the total control, four interacting feedback loops, (current, velocity, position and vibration loops) for each arm, and one feedforward loop, (profile loop) need to be designed, implemented and tuned. This gives a total of 15 control loops for the three arms. Unlike the conventional control system where the controlled variable is available for feedback, the probe position is difficult and expensive to measure. The paper develops an optimal control such that the speed and the measurement accuracy are maximised while the tuning and commissioning time are minimised. The proposed control design scheme uses a hierarchical approach to decompose the system into smaller subsystems. The current and velocity loops are firstly optimised. It is then shown that the MIMO control problem can be decoupled into three SIMO control problems. A two DOF optimal controller is developed to control probe position and arm vibration. The feedforward controller is automatically generated by introducing the model of the profile. Simulation and experimental results are given.<
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