GB2144241A

GB2144241A - Microprocessor control system for a servo drive of a knitting machine

Info

Publication number: GB2144241A
Application number: GB08416930A
Authority: GB
Inventors: Joerg Hainich; Hans-Uwe Poppe; Hubert Tasch; Gerhard Baar
Original assignee: Kombinat Textima VEB
Current assignee: Kombinat Textima VEB
Priority date: 1983-07-27
Filing date: 1984-07-03
Publication date: 1985-02-27
Also published as: DE3417665A1; DD218490A1; GB2144241B; GB8416930D0; CH663807A5

Abstract

The aim of the invention is to simplify the microcomputer control and to enable the use of economical microcomputers whilst simultaneously reducing the complexity of the software, and to effect the control and adjustment of specific servo drive functions as far as possible independently of the CPU of the microcomputer. A microprogram control unit 7 comprising a non-volatile memory 8 which contains a micro-control programme for the servo drives 21 and a gate circuit 9, is connected between the microcomputer 2 and its peripheral units 20' in such a way that the data register 6 of the microcomputer is connected via an additional data bus 14 with the gate circuit 9, and a branch 16 of the clock line 17 of a pulse emitter 25,27 is connected to this gate circuit and a further branch 13 of this clock line is connected to the address bus 10 of the microprogram control unit. <IMAGE>

Description

SPECIFICATION Microprocessor control svstem for a servo drive of a knittinq machine The invention relates to a microprocessor control system for a servo drive of a knitting machine, for example a flat knitting machine.

German Offenlegungsschrift 2 301 847 discloses an electronic control of a flat knitting machine using a microprocessor. In this machine the control or regulation of all the control elements takes place via the CPU of the microprocessor which processes a control program contained in its memories together with the pattern data, and supplies control signals to the servo drives via multiplexers in accordance with marker pulses which are continuously processed by the CPU.

The CPU and the memory of the microprocessor are thus continuously involved in the control or regulation of the servo drives. Since in the case of knitting machines, a plurality of servo drives have to be controlled or regulated with a high clock frequency, it has only been possible up to now to carry out this control with comparatively expensive microprocessors and complex software.

The aim of the invention is to simplify the microprocessor control and to enable the use of less expensive microprocessor systems for the control of knitting machines with less complex software.

The present invention provides for the control or regulation of specific servo drive functions as far as possible independently of the CPU of the micro processor.

According to the invention there is provided a microprocessor control system for a knitting machine having a servo drive, comprising a control unit for providing control signals to the servo drive, the control unit including programmed memory means for use in developing the control signals, and means for addressing the memory means in dependence upon signals representative of movement of the servo drive, and microprocessor means arranged to control operation of the control unit.

In accordance with the invention, there is disposed between the microprocessor and its peripheral units a microprogram control unit with a nonvolatile memory which contains a micro-control program for the servo drives and a gate circuit connected in such a way that the data register of the microprocessor is connected with the gate circuit via an additional data bus, a branch of the clock line of the pulse emitter being connected to the gate circuit and a further branch of the clock line being connected to the address bus of the microprogram control unit.

The invention will now be described in further detail with reference to an embodiment thereof shown in block diagrammatic form in the single Figure of the accompanying drawing, which shows a detail of the control of a flat knitting machine.

The central processing unit (CPU) 1 of the microprocessor or microcomputer 2 is connected via the microcomputer bus 3 with the memory 4. The memory 4 consists in a known manner of a ROM which acts as a program store for the computer and a RAM which stores the pattern program. The data, address and control information is conveyed via the microcomputer bus 3. The micro computer bus 3 is also connected to a control register 5 and a data register 6. The control register 5 and the data register 6 act as interfaces between the microcomputer 2 and the microprogram control unit 7.

This microprogram control unit 7 comprises a non volatile memory (ROM) 8, which contains the program of the microprogramme control unit 7, and a gate circuit 9. The control lines 11 from the control register 5 of the microcomputer 2 are supplied to the address bus 10 of the microprogram control unit 7. The address bus 10 comprises the feedback bus 12, the clock lines 13 and the control line 11 and communicates with the non-volatile memory 8. For the purposes of presetting the microprogram control unit 7 with a reference input in accordance with the program for the emission of the control information to the servo drive, the data register 6 is connected with the gate circuit 9 via the data bus 14. The data bus 15 of the microprogram control unit 7 and the clock line 16 are connected to the gate circuit 9. The clock lines 13, 16 are combined with the clock line 17.The output lines of the gate circuit 9 form the control bus 18 of the microprogram control unit 7. An interrupt and malfunction signal is connected to the control register 5 of the micro computer 2 via line 19. The microprogram control unit 7 is connected to peripheral units 20' via output line 20. The peripheral units comprise a servo drive 21 which is controlled via the output line 20, variable-gain amplifier 22 (a conventional power amplifier) and the output line 23, by means of the microprogram control unit 7. In order to ascertain the actual value of the servo drive movement the servo drive 21 is connected to a commercially available pulse emitter 25 via a coupling section 24 which is known per se. This forms from the servo drive functions corresponding electrical signals at the output of the pulse emitter 25.The servo drive 21 may be, for example, in the case of a flat knitting machine, the control magnet which is driven at a high clock frequency for the selection of individual needles. The pulse emitter 25 is connected to a pulse shaper 27 via pulse emitter output 26. The above-mentioned clock line 17 is connected to the pulse shaper 27.

In operation, the microcomputer 2 processes from the memory 4 the control program from the ROM and the pattern data from the RAM in order to control the flat knitting machine. In this respect, the control of the servo drive 21 takes place via the microprogram control unit 7 connected between the microcomputer 2 and the peripheral units 20'.

For this purpose address, control and data information is supplied by the microcomputer in a known manner via the microcomputer bus 3, and the memory 4, the control register 5 and the data register 6 are addressed via the microcomputer bus 3. In accordance with the program at the beginning of an operating cycle of the flat knitting machine, the binary control information is supplied to the data register 6, which information is then supplied to the gate circuit 9 via the data bus 14 and is stored therein in order to set the microprogram control unit 7 to a specific reference condition. This reference condition ensures the emission of the control signal to the servo drive synchronously with the needle, i.e. clock pulses. The pulse emitter produces a constant number of pulses corresponding to the needle sequence in a known manner.These pulses which are directed in accordance with the carriage feed direction, are shaped in the pulse shaper 27 by triggering and are supplied to the gate circuit 9 via the clock lines 17, 16 and to the non-volatile memory 8 via the clock lines 17, 13. The pulse reaching the gate circuit 9 causes the latter to be connected through and there fore the gating of the stored information to the control bus 18. This control signal on the control bus 18 contains in its individual bit positions the input control information for the servo drive, and in addition a condition signal and an interrupt and malfunction signal which is supplied via the line 19 to the control register 5. The condition signal is supplied via feedback bus 12, together with the clock pulses, to the address bus 10.

The clock information and the information supplied via the control line 11 from the control register 5 produce an input signal. The input signal and the condition signal together provide the address of the sequence condition and the address of the output signal on the data bus 15 in accordance with a micro-control program for the servo drive 21 input, into the non-volatile memory 8. The output signal and the sequence condition address are available at the data bus 15 and are taken up by the gate circuit 9 by means of a clock pulse on the clock line 16 and are stored therein until sequential information or resetting by the microcomputer 2 is received via the data register 6 and the data bus 14.

The through-connection of the output vector and the sequence condition vector by the gate circuit 9 takes place in the sequence of the clock pulses supplied via the clock line 16. This therefore ensures that the control process for the servo drive 21 is synchronised with the micro program sequence. Specific bits of the control signal on the control bus 18 effect a positive or negative re-adjustment of the servo drive 21 to the preset reference value. A further bit of the control signal serves for the feedback of specific conditions to the control register 5 of the microcomputer 2.

Claims

1. A microprocessor control system for a knitting machine having a servo drive, comprising a control unit for providing control signals to the servo drive, the control unit including programmed memory means for use in developing the control signals, and means for addressing the memory means in dependence upon signals representative of movement of the servo drive, and microprocessor means arranged to control operation of the control unit.

2. A microprocessor control system according to claim 1 wherein the control unit comprises a gate circuit for gating signals from the memory means to the servo drive, the gate circuit being responsive to said movement signal, and wherein said micro processor is arranged to provide signals for use in addressing the memory means.

3. A microprocessor control system according to claim 2 wherein said microprocessor means is arranged to supply data signals to the gate circuit.

4. A microprocessor control system according to claim 2 or 3 wherein selected bits from the output of the gate circuit contribute to the address for the memory means.

5. A microprocessor control system according to any preceding claim and including the servo drive.

6. A microprocessor control system according to claim 5 wherein the servo drive includes a servo drive motor, and a pulse generator for producing electrical pulses indicative of incremental units of movement effected by the servo drive.

7. A microprocessor control'system substantially as hereinbefore described with reference to the drawing.

8. A flat knitting machine including a system according to any preceding claim.

9. A microcomputer control system for the servo drives of knitting machines, having a microcomputer whose peripheral units are, formed by the control elements to be controlled, the control amplifier, the pulse emitter and the pulse shaper, wherein a microprogram control unit having a nonvolatile memory which contains a micro-control program for the servo drives and a gate circuit are connected between the microcomputer and its peripheral units in such a way that the data register of the micro computer is connected via an additional data bus with the gate circuit, and in that a branch of the clock line of the pulse emitter is connected to this gate circuit and a further branch of the clock line is connected to the address bus of the microprogram control unit.

10. A knitting machine having servo drives and a microprocessor control system wherein adjustment of the servo drives can be performed independently of the CPU of the microprocessor control system.