Spindle position/speed control unit
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsTakahiro Hayashida, Hiroaki Okachi, Mahito Unno
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Abstract
The invention relates to a spindle speed/position control system for use in a numerically controlled machine tool such as a lathe. To improve the measurement of spindle speed and position, detected elements are attached directly to the rotatable spindle. A waveform shaping circuit takes the outputs of speed and position detecting sensors, and outputs a variety of sinusoidal and pulse signals. The sinusoidally varying signals are employed in speed detection while the pulse signals are used for position detection and control.
Claims13
A speed and position control system for a rotatable element, comprising;
- a rotatable element;
- sensor means located adjacent said rotatable element;
- at least one detected element fixed directly to said rotatable element and detected by said sensor means;
- said sensor means generating a first signal having a periodicity of once per revolution of said rotatable element, a second sinusoidally varying signal having a plurality of cycles per revolution of said rotatable element, and a third sinusoidally varying signal having the same plurality of cycles per revolution of said rotatable element as said second signal but being out of phase with respect to said second signal;
- waveform shaping means for converting said second and third signals into pulse signal trains, and for outputting said converted signals along with said second and third signals;
- and
- means for controlling the speed or position of said rotary element, said controlling means employing at least said second and third signals for speed control and at least said converted signals for position control.
Dependencies are inferred from the claim text.