EP0012619A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Machine tool drive motor control system
Assignee: Fanuc Corp
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Filing: 1979-12-14
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Granted: —
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Expires: 1999-12-14
Abstract
Abstract A rotary member, for example a spindle shaft (7) of a machine tool, can be brought to rest at a selected orientation without the use of a mechanical brake. A detector (9) supplies signals representing orientation of the shaft (7) to an orientation control circuit (4) which synthesizes a control signal which takes a zero value when the shaft (7) is in the selected orientation, and non-zero values when the shaft (7) is displaced from the selected orientation. The control signal is selectively employed as a speed command signal in a control loop for controlling the rotational speed of shaft (7) so that the shaft (7) comes to rest, when the control signal takes the zero value, at the selected orientation.
Inventors
- 👤 Yoshinori Kohzai
- 👤 Yoshiki Fujioka
- 👤 Naoto Ota
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 09:06
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/39; G05B2219/00; G05B2219/30; G05B2219/49; G05B2219/49273
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
191 words
Rotation control apparatus, comprising rotary drive means and a rotatable member arranged to be rotated by the drive means, and a speed control loop arranged for controlling the speed of the rotary drive means in such a way that actual speed of the rotary drive means, represented by a speed feedback signal in the loop, is caused to coincide with a desired speed represented by a speed command signal, characterized by an orientation detector, arranged to sense rotation of the rotary drive means and the rotatable member, and operable to deliver orientation representing signals which vary cyclically in value in the course of complete rotations, an orientation control circuit arranged to receive the said orientation representing signals and to synthesize therefrom a function which, in the course of complete rotations, represents respective orientations by individual function values and takes a zero value for a preselected orientation, and stop control means selectively operable to terminate rotation at the preselected orientation by forming a control loop, termed the position control loop, wherein the said function is applied- as a speed command signal, so that rotation terminates when the function takes the zero value.
Claim 2
Dependent Claim
191 words
Rotation control apparatus, comprising rotary drive means and a rotatable member arranged to be rotated by the drive means, and a speed control loop arranged for controlling the speed of the rotary drive means in such a way that actual speed of the rotary drive means, represented by a speed feedback signal in the loop, is caused to coincide with a desired speed represented by a speed command signal, characterized by an orientation detector, arranged to sense rotation of the rotary drive means and the rotatable member, and operable to deliver orientation representing signals which vary cyclically in value in the course of complete rotations, an orientation control circuit arranged to receive the said orientation representing signals and to synthesize therefrom a function which, in the course of complete rotations, represents respective orientations by individual function values and takes a zero value for a preselected orientation, and stop control means selectively operable to terminate rotation at the preselected orientation by forming a control loop, termed the position control loop, wherein the said function is applied- as a speed command signal, so that rotation terminates when the function takes the zero value.
Claim 3
Dependent Claim
60 words
Apparatus as claimed in claim 1, wherein the orientation control circuit is operable selectively to synthesize respective such functions, taking respective zero values for respective preselected orientations mutually displaced at 90° intervals around a complete rotation, by switching between the orientation representing signals, whereby the stop control means can bring about termination of rotation at any one of four orientations.
Claim 4
Dependent Claim
30 words
Apparatus as claimed in claim 1 or 2, wherein the or each function changes in value monotonically in the course of complete rotations and is symmetrical about the zero value.
Claim 5
Dependent Claim
33 words
Apparatus as claimed in claim 1, 2 or 3, wherein the or each function varies about the zero value in proportion to angular displacement from the preselected orientation corresponding to the zero value.
Claim 6
Dependent Claim
45 words
Apparatus as claimed in any preceding claim, wherein the stop control means are selectively operable to bring about formation of the said position control loop by applying the or any selected said function to the speed control loop in place of the speed command signal.
Claim 7
Dependent Claim
36 words
Apparatus as claimed in any preceding claim, wherein the orientation detector is a resolver having a secondary winding arranged to receive an excitation signal and two primary windings which generate sine and cosine orientation representing signals.
Claim 8
Dependent Claim
35 words
Apparatus as claimed in claim 6, wherein the orientation control circuit includes a clock generator, a timing circuit, a resolver excitation circuit, a synchronous rectifier circuit, a quadrant discrimination circuit and a wave synthesizing circuit.
Claim 9
Dependent Claim
64 words
Apparatus as claimed in claim 7 read as appended to claim 2, wherein the orientation control circuit further includes a function selection circuit having a switching circuit for switching between the sine and cosine orientation representing signals, operable so that a selected function takes a zero value when the sine signal has a zero value and the cosine signal has a maximum positive value.
Claim 10
Dependent Claim
19 words
Apparatus as claimed in any preceding claim, wherein the said rotary drive means is a machine tool drive motor.
Claim 11
Dependent Claim
12 words
A machine tool, having rotation control apparatus as claimed in claim 9.
References Cited (Backward Citations)
No citation records indexed.
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