GB2233475A

GB2233475A - Two-state object control system

Info

Publication number: GB2233475A
Application number: GB8914151A
Authority: GB
Inventors: Stanislav Vasilievic Emelyanov; Mikhail Zakharovich Shovkun; Alexandr Mikhailovic Shubladze; Jury Alexandrovich Golubev; Vyacheslav Anatolievic Lobanov; Alexandr Evenievich Toropov
Original assignee: INST UPRAVLENIA
Current assignee: INST UPRAVLENIA
Priority date: 1989-06-20
Filing date: 1989-06-20
Publication date: 1991-01-09
Also published as: GB8914151D0

Abstract

A two-state object control system comprises comparator unit (1) with inputs (2, 3) thereof connected to controlled object (5) and reference signal setup unit (7), respectively. Input (15) of controlled object (5) is connected to analogue to pulse train converter (12). Output (8) of comparator unit (1) is connected to proportional and floating controller (9), with the output (18) thereof connected to analogue to pulse train converter (12). <IMAGE>

Description

TWO STATE OBJECT CONTROL SYSTEM This invention relates to the field of automatic control, in particular to two-state object control systems.

This invention can be successfully used in process control systems to control prooesses with variable in time parameters (e.g. in well drilling control systems).

The invention resides in that a two-state object control system comprises a comparator unit with one input thereof connected to the output of the controlled object, a reference signal setup unit with the output thereof connected to the input of the comparator unit, and a proportional and floating controller with the input thereof connected to the output of the comparator unit and with the output thereof electrically connected to the controlled object, further comprises an analogue to pulse train converter with the input thereof connected to the output of the proportional and floating controller and with the output thereof connected to the output of the controlled object.

It is expedient that the analogue to pulse train converter of the two-state object control system comprise a pulse duration modulator with the out put thereof connected to the respective inputs of the analogue signal generator and the adder, the other input whereof connexted to the output of the analogue signal generator.

It is desirable that the analogue signal generator in the analogue to pulse train converter of the two-state object control system be comprised of an inertial filter, with the output thereof connected to the inputs of two responsive to limiting signal levels pulse shaping circuits, an adder with the inputs thereof connected to the respective outputs of the responsive to limiting signal levels pulse shaping circuits, and an integrator with the input thereof connected to the alder output.

It is reasonable that each of the responsive to limiting signal levels pulse shaping circuits in the two-state object control system be comprised of electrically connected in series reference signal sensor, null detector with other input thereof constituting the input of the responsive to limiting signal levels pulse shaping circuit, and a uni-vibrator.

This invention provides retaining within prescribed limits of the controlled obbectcs output coordinate, thus improving the accuracy of object control.

The invention will now be described in greater detail with reference to specific embodiments thereof and accompanying drawings, wherein: Fig. 1 shows the skeleton diagram of the two-state object control system according to the invention; Fig. 2 shows the skeleton diagram of analogue to pulse train conversion in th two-state object control system according to the invention; Fig. 3 shows the skeleton diagram of the analogue signal generator in the analogue to pulse train converter shown in Sig. 2, according to the inven- tion; Fig. 4 shows the skeleton diagram of the responsive to limiting signal level pulse shaping circuit in the analogue signal generator shown in Fig. 3, according to the invention.

A two-state object control system according to the invention comprises comparator unit 1 (Fig. 1) with inputs 2, 3 thereof connected, respectively, to output 4 of controlled object 5 and to output 6 of reference signal setup unit 7. Output 8 of comparator unit 1 is connected to input 10 of proportional and floating controller 9, the output 11 thereof connected to analogue to pulse train converter 12 input 13. Output 14 of snalogue to pulse train converter 12 is connected to input 15 of controlled object 5.

The analogue to pulse train converter 12 comprises pulse duration modulator 16 (Fig. 2) with the output 17 thereof connected to inputs 18 and 19, respectively, of adder 20 and analogue signal generator 21. The other input 22 of adder 20 is connected to output 23 of analogue signal generator 21.

Analogue signal generator 21 comprises inertial filter 24 (Fig. 3) with the output thereof connected to the inputs 28. and 29, respectively, of two responsive to limiting signal levels pulse shaping circuits 26 and 27, with their outputs 30 and 31, respectively, connected to inputs 33 and 34 of adder 32, output 35 whereof is connected to input 37 of integrator 36.

Each of the responsive to limiting signal levels pulse shaping circuits 26, 27 comprises reference signal setup unit 38 with output 39 thereof connected to null detector 40 input 41. The output 42 of null detector 40 is connected to uni-vibrator 43 input 44.

The two-state object control system functioning shall be described for the case, when the controlled object 5 (Fig. 1) is the braking assembly of drill rig wench (not shown in the Figure).

Input 3 of comparator unit 1 (Fig. 1) is continuously fed by the reference signal from reference signal setup unit 7. With the start of controlled object 5 operation a signal from its output 4 is passed to comparator unit 1 input 2. This signal, describing the rate of braking assembly wench rotation, is compared in comparator 1 to the reference signal and the result generated at output 8 of comparator unit 1 is passed to input 10 of proportional and floating controller 9.This signal is the error signal and represents the degree of rotation speed deviation from its rated value at the current moment of times After passing controller 9 this signal from its output 11 is applied to input 13 of analogue to pulse train converter 12, wherein pulse trains of verying duty factor, depending on the input signal, are generated, to be summed with an analogue signal of a polarity determined by the control error signal and applied to input 15 of controlled object 5.

Analogue to pulse train converter 12 functions as follows.

The processed signal from output 11 of proportional and floating controller 9 is applied to the input of pulse duration modulator 16 (Fig. 2) which constitutes input 13 of analogue to pulse train converter 12. The modulated signal from output 17 of pulse duration modulator 16 arrives at inputs 18, 19 of adder 20 and inertial filter 24 (Fig. 3), respectively, in analogue signal generator 21. After filtering, the signal from filter 24 is passed to inputs 28, 29 of responsive to limiting signal level pulse shaping circuits 26, 27, respectively, wherein reference signal setup units 38 (Fig. 4) and null detectors 40 are preset to the upper and lower limiting values, respectively, of the duration-modulated pulses from pulse duration modulator 16 (Fig. 2).In this manner, the signals at inputs 28, 29 (Figs. 3,4 ) on arrival at the respective null detector 40 are compared to either the upper or the lower limiting values, respectively, of the reference signal from the corresponding reference signal setup unit 38. The resulting signal from the outputs of both pulse shaping circuits 26, 27 arrive at inputs 44 of corresponding uni-vibrators 43.

If the filtered signal level fslls within the range between the upper and'lower limiting values of the reference signals univiDrators 43 will not generate a signal at their respective outputs 30, 31 (Figs. 3,4) and inputs 33, 34 of adder 32 will not receive an input signal. In case the filtered signal level equals the upper or lower limiting value of the reference signal, uni-vibrator 43 of the corresponding pulse shaping circuit 26, 27 will be triggered and will output a pulse of specified duration to inputs 33 or 34 of adder 32, to be passed from adder 32 output 35 to input 37 of integrator 36 and thereafter to input 22 adder 20 (Fig. 2). Thus analogue signal generator 21 regulates the varying in time hysteresic characteristic which described the varying rate of drum rotation caused by its outline.

Adder 20 performs summation of the pulse signal from pulse duration modulator 16 with the analogue signal from analogue signal generator 21 and the summed signal is passed from its output 14 (Figs. 1, ,) to input 15 of controlled object 5.

Thus, according to the invention, the rate of winch drum rotation is regulated to within a preset range, this facilitating its operation and enhancing the productivity.

Claims

WHAT WE CLAIi IS:

1. A two-state object control system, comprising a comparator unit with one input thereof connected to the output of the controlled object; a reference signal setup unit with the output thereof connected to the comparator unit input; a proportional and floating controller with the input thereof connected to the output of the comparator unit; and an analogue to pulse train converter with the input thereof connected to the output: of the proportional and floating controller and with the output thereof connected to the input of the controlled object.

2. he two-state object control system as substantially set forth in Claim 1, wherein the analogue to pulse train converter comprises a pulse duration modulator with the output thereof connected to the respective inputs of an analogue signal generator and of an adder, the other input whereof is connected to the output of the analogue signal generator.

3. The two-state object control system. as substantially set forth in Claim 2, wherein the analogue signal generator in the analogue to pulse train converter comprises an inertial filter with the output thereof connected to the inputs of two responsive to limiting signal levels pulse shaping circuits, an adder with the inputs thereof connected to the respective outputs of the two pulse shaping circuits, and an integrator with the input thereof connected to the adder output.

4. The two-state object control system as substas tially set forth in Claim 3, wherein each of the respective to limiting signal levels pulse shaping circuits comprises electrically connected in series ref e- rence signal setup unit, a null detector with the other input thereof constituting the input of the pulse shaping circuit responsive to the limiting level of the signal, and an uni-vibrator.

5. The two-state object control system as substantially set forth in any of the preceeding Claims and as described herein above with reference to the accompanying drawings.