SU1399527A1 - Method of controlling position relay pneumatic drive - Google Patents

Abstract

This invention relates to reciprocating drives. The purpose of the invention is to improve the positioning accuracy and speed of the drive. Piston 2 is moved and its positioning is performed by throttling compressed air coming in and out of cavities 4, 5 of the pneumatic actuator by changing the cross-sectional area of the throttles 9 and 10. Using the sensor 6 mounted on the piston 2, the magnitude of the linear displacement is determined the piston and the current coordinate (TC) and depending on the ratio of the TC to the difference of the full stroke and the TC simultaneously change the RPS of the chokes 9 and tO using the control elements 11 and 12 of the control system. At the same time, the PPS of the throttle of the cavity, which decreases with the movement of the piston, is reduced, and the PPS of the drossel of the increasing cavity increases. 1 il.

Description

CO with

ate 1chE

1139952

This invention relates to mechanical engineering, in particular to reciprocating pneumatic actuators.

The purpose of the invention is to improve the accuracy of the positioning and speed.

The drawing shows a diagram of the device that implements the proposed method.

The device contains a cylinder 1, a piston 2 with a rod 3 installed in it with the formation of cavities 4 and 5. A sensor 6 is installed on the rod 3 to measure the current coordinate. In the supply and exhaust channels 7 and 8, chokes 9 and 10 are installed with adjustable by means of control elements

ten

11 and 12

accordingly

area g, g 2 flow areas. Control elements 11 and 12 and sensor 6 are connected to a control system (not shown).

The control method is as follows.

By filing in the cavity 4 and 5 of cylinder 1 and release from. them compressed. air under pressure through the corresponding channels 7 and 8 move the piston 2 to the desired position and hold it in that position. Using the sensor 6 mounted on the rod 3 of the cylinder 1, the linear displacement of the piston 2 is measured during its full stroke N. This further determines the relative magnitude of the current linear displacement X of the radial 2 from the extreme initial position X j in the cylinder to the magnitude of the difference of the full stroke H and this current value x.

j

0

,

20

25

thirty

35

At the same time, depending on the ratio found, by controlling elements 11 and 12, controlling the control system, change the areas f and f2 of the flow sections of the throttles 9 and 10. At the same time, they increase the area of the flow area of the chokes. 9 in the channel 7 communicated with the cavity 4, the volume of which is currently increasing, and reduce the area of the flow area of the throttles 10 communicated with the cavity 5, the volume of which is currently decreasing.

Claims (1)

Invention Formula A method of controlling a positional relay pneumatic actuator by changing the amount of compressed air entering the pneumatic actuator cavities and being discharged from them by throttling the feed and exhaust channels with controlled area of the flow section through passage openings, in order to increase positioning accuracy and speed, determine the magnitude of the current coordinate and the ratio of this quantity to the magnitude of the difference between the full stroke and the current coordinate and, depending on these quantities, simultaneously from ene dissolved passage section areas of the two cavities, wherein the cavity reduces the passage sectional area decreasing with movement of the piston, and increase the sectional area of the passageway of increasing cavity.