Development of High-Precision and High-Resolution Servo-Controllers, That Have High Noise-Rejection Ability

用于数控机床和机器人的高分辨率控制器的最大速度不够高，不足以避免在强电气噪声环境下的误操作。因为控制器需要低通滤波器，其截止频率足够低，以消除从位置传感器(如旋转或线性编码器)获得的两相信号中涉及的电气噪声。编码器分辨率越高，两相信号的输出越低，两相信号的S/N值随分辨率的提高而降低。这意味着必须使用低通滤波器才能使控制器无误操作。本研究项目利用T.Emura提出的两相锁相环，开发了一种具有高噪声抑制能力的高速、高分辨率伺服控制器。这种两相锁相环可以使低通滤波器的截止频率极高。因此，可以提高伺服控制器的速度。首先，试制了一台模拟式伺服控制器。虽然模拟型具有很好的特性，但它的缺点是电路非常复杂，制作成本很高。因此，针对数字伺服控制器电路简单、制作成本低的特点，对其进行了性能测试，实验结果表明，该数字伺服控制器在分辨率、运算速度、噪声抑制能力等方面都具有很好的特性，说明该助学金项目取得了很好的效果。

Maximum speed of high-resolution controllers for NC machines and robots is not high enough to avoid misoperation under strong electrical noise environment. Because the controllers require low-pass filters whose cutoff frequency is sufficiently low for removing electrical noise involved in two-phase signals obtained from position sensors such as rotary or linear encoders. If resolution of encoder becomes higher, the output of two-phase signals becomes lower, and S/N of two-phase signals decreases as the resolution increases. This means that we must use the low-pass filters to work the controller without misoperation.This research project developed a high-speed and high-resolution servo-controller that has high noise rejection ability by using two-phase type PLL proposed by T.Emura. This two-phase type PLL can make the cutoff frequency of low-pass filter extremely higher. Therefore, we can raise the speed of servo-controller. First, an analog type servo-controller was made for trial. Though the analog type has very good characteristics, it has a weak point that its circuit is very complex and making cost is very expensive. Therefore, next, a digital type servo-controller was made for trial, because the circuits of digital one is simple and the making cost becomes lower.Performance of the digital type servo-controller was tested, and experimental results showed that it has very good characteristics in resolution, operational speed, noize rejection ability, etc. This means that very excellent results was obtained by the project of this grant-in-aid.