Electricity: motive power systems – Positional servo systems – Multiple mode systems
Patent
1986-05-19
1987-03-03
Dobeck, Benjamin
Electricity: motive power systems
Positional servo systems
Multiple mode systems
318625, 318661, 318594, 318595, G05B 1118
Patent
active
046478272
DESCRIPTION:
BRIEF SUMMARY
CROSS-REFERENCED TO RELATED APPLICATION
This application is related to U.S. application Ser. No. 688,049, filed Dec. 11, 1984 (now U.S. Pat. No. 4,575,666) which is assigned to the assignee of the subject application.
BACKGROUND OF THE INVENTION
This invention relates to a system for detecting the absolute position of each of a plurality of operating axes by servo-controlling a servomotor and, more particularly, to an absolute position detecting system for a servocontrol system which is operative to detect the absolute positions of the operating axes on the basis of the respective detected outputs of resolvers and absolute encoders made rotatable at a predetermined speed ratio together with the servomotor, so that the detections of those absolute positions can be selectively performed for the respective operating axes.
In order to position a moving part of an industrial robot or the like with a high degree of accuracy, servomotors subject to servocontrol are widely used.
FIG. 1 is a block circuit diagram for explaining servocontrol, showing an example in which the operating axes of an industrial robot or the like are positionally controlled by an NC (numerical control) apparatus. In FIG. 1: reference numeral 101 indicates a paper tape which is punched with numeral control (NC) command data such as positioning information for machining or M, S, T function information; and numeral 102 indicates an NC apparatus for enabling a tape reader (described below) to read NC data from the paper tape 101, decode the NC data read from the paper tape 101 to send out the data (e.g., if the data are the M, S and T function commands), to a machine or to output the same, or if they are moving commands Zc, to a pulse distributor at a later stage. The NC apparatus 102 comprises a processor 102a for executing arithmetic processings in accordance with a control program; a program memory 102b for storing a predetermined control program; a data memory 102c for storing data; an operator's panel 102d for effecting control operations; a tape reader/puncher 102e; a display 102f; an input/output port 102g; a present position counter 102h; and an address/data bus 102j connecting them.
Indicated at numeral 103 is a pulse distributor which executes a well-known pulse distribution arithmetic operation on the basis of the moving commands Zc, to generate distributed pulses Ps having a frequency dependent on a command speed. A well-known acceleration/deceleration circuit 104 accelerates the pulse speed of the distributed pulse train Ps linearly when this pulse train is generated, or decelerates the same linearly at the end of said pulse train to generate a pulse train Pi. A motor 105 drives an operating axis, and a pulse coder 106 generates one feedback pulse FP each time the motor 105 rotates through a predetermined interval. An error computing memory 107 which is constructed of a reversible counter, for example, stores the difference or error Er between the number of the input pulses Pi generated by the acceleration/deceleration circuit 104 and the number of the feedback pulses FP. Incidentally, that error computing memory is constructed, as shown, of an arithmetic circuit 107a for computing the difference between Pi and FP, and an error register 107b for storing the error Er. Specifically, the error computing memory 107 counts up the input pulses Pi each time they are generated, if the motor 105 is commanded to revolve forward so that it is revolving in accordance with the command, and counts down the content of the feedback pulses FP each time they are generated, thereby to store the error Er between the input pulse number and the feedback pulse number in the error register 107b. Numeral 108 indicates a digital-analog (DA) converter for generating an analog voltage proportional to the content of the error register 107b, and numeral 109 indicates a speed control circuit. Incidentally, the error computing memory 107 and converter 108 together form a motor position controller.
Next, the operations of the construction of the conventional
REFERENCES:
patent: 3151282 (1964-09-01), Fisher
patent: 3673585 (1972-06-01), Tripp
patent: 4023085 (1977-05-01), Bishop
patent: 4207505 (1980-06-01), Falk et al.
patent: 4310790 (1982-01-01), Marquis
patent: 4339708 (1982-07-01), Desbiens et al.
patent: 4529922 (1985-07-01), Ono
Miyashita Hideo
Naruo Hatsumi
Sakakibara Shinsuke
Toyoda Kenichi
Dobeck Benjamin
Fanuc Ltd.
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