阅读说明：本技术 一种供液速度和位置开环控制方法 (Liquid supply speed and position open-loop control method ) 是由 王峰 陈金成 于 2021-07-22 设计创作，主要内容包括：本发明公开了一种供液速度和位置开环控制方法。在液压支架控制阀的输入输出端设置压力传感器,检测液压支架控制阀的输入输出端的压力变化,结合控制阀的流量-压力特性,计算获得输入液压支架液压缸的流量,再转换获得液压支架液压缸的活塞速度；通过对液压支架液压缸的活塞速度进行时间积分,获得液压支架液压缸的活塞位移,再反馈到控制阀控制流量。本发明方法无需在液压支架液压缸上设置位移传感器,同时可以降低传统液压支架液压缸闭环控制的设计难度。(The invention discloses a liquid supply speed and position open-loop control method. Arranging a pressure sensor at the input end and the output end of the hydraulic support control valve, detecting the pressure change of the input end and the output end of the hydraulic support control valve, calculating to obtain the flow of the hydraulic support hydraulic cylinder by combining the flow-pressure characteristic of the control valve, and converting to obtain the piston speed of the hydraulic support hydraulic cylinder; the piston displacement of the hydraulic support hydraulic cylinder is obtained by time integration of the piston speed of the hydraulic support hydraulic cylinder and then fed back to the control valve to control the flow. According to the method, a displacement sensor is not required to be arranged on the hydraulic cylinder of the hydraulic support, and the design difficulty of closed-loop control of the hydraulic cylinder of the traditional hydraulic support can be reduced.)

1. An open-loop control method for the liquid supply speed and the liquid supply position comprises a pump station (1), a control valve (3) and a hydraulic support hydraulic cylinder (5), wherein the outlet of the pump station (1) is output to the hydraulic support hydraulic cylinder (5) through the control valve (3), and the outlet of the hydraulic support hydraulic cylinder (5) is communicated to an oil tank; the method is characterized in that:

and the inlet and the outlet of the control valve (3) are respectively provided with a pressure sensor, and the two pressure sensors are respectively used for detecting the pressure of the input end and the pressure of the output end of the control valve (3).

The pump station (1) is a hydraulic device or equipment for outputting a hydraulic power source.

The control valve (3) is used for controlling the hydraulic support hydraulic cylinder (5).

2. A liquid supply speed and position open loop control method as claimed in claim 1, wherein:

calculating to obtain the flow input into the hydraulic support hydraulic cylinder (5) according to the pressure difference at two ends of the control valve (3) and the flow-pressure characteristic of the control valve, and obtaining the piston speed of the hydraulic support hydraulic cylinder (5) according to the piston area conversion of the hydraulic support hydraulic cylinder (5); and then, the piston speed of the hydraulic support hydraulic cylinder (5) is subjected to time integration to obtain the piston displacement of the hydraulic support hydraulic cylinder (5), and the piston displacement is fed back to the control valve (3) to control the flow.

3. A liquid supply speed and position open loop control method as claimed in claim 2, wherein:

the piston speed of the hydraulic support hydraulic cylinder (5) is calculated by the following formula:

v＝Q/A

where v is the speed of the cylinder, Q is the input flow to the cylinder, and A is the cylinder piston area.

4. A liquid supply speed and position open loop control method as claimed in claim 1, wherein:

the hydraulic support hydraulic cylinder (5) is a hydraulic actuator in a coal mining hydraulic system.

Technical Field

The invention relates to a method for controlling oil supply liquid, in particular to a method for controlling the liquid supply speed and the position in an open loop mode, which is particularly suitable for a hydraulic support for fully mechanized coal mining.

Background

The hydraulic system of the hydraulic support of the fully mechanized mining face is an open hydraulic system, and the functions of a pushing conveyor, a lifting frame, a pulling hydraulic support, a lifting frame and the like of the hydraulic support are realized by operating an execution oil cylinder of the support through a manual operation valve or an electro-hydraulic control valve. In a traditional support hydraulic system, a hydraulic support hydraulic cylinder is provided with a position sensor, a closed-loop control method is adopted to detect the current displacement of a hydraulic support, the current displacement and the expected displacement are input into a PID controller, and the speed and position control is realized by adjusting the opening of a control valve. The design difficulty of the closed-loop system is high, and how to design an effective open-loop control hydraulic system becomes a key.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides an open-loop control method for the liquid supply speed and the position, which realizes the open-loop control of adjusting the opening of a control valve, solves the problems of closed-loop design and control, and avoids the arrangement of a displacement sensor on a hydraulic cylinder of a hydraulic support and the problems caused by the arrangement of the displacement sensor.

The technical scheme adopted by the invention is as follows:

the hydraulic support hydraulic system comprises a pump station, a control valve and a hydraulic support hydraulic cylinder, wherein the outlet of the pump station is output to the hydraulic support hydraulic cylinder through the control valve, and the outlet of the hydraulic support hydraulic cylinder is communicated to an oil tank; and the inlet and the outlet of the control valve are respectively provided with a pressure sensor, and the two pressure sensors are respectively used for detecting the pressure of the input end and the output end of the control valve.

The pump station is a hydraulic device or equipment for outputting a hydraulic power source.

The control valve is used for controlling the hydraulic support hydraulic cylinder.

Calculating to obtain the flow input into the hydraulic support hydraulic cylinder according to the pressure difference at the two ends of the control valve and the flow-pressure characteristic of the control valve, and obtaining the piston speed of the hydraulic support hydraulic cylinder according to the piston area conversion of the hydraulic support hydraulic cylinder; and then, the piston speed of the hydraulic support hydraulic cylinder is subjected to time integration to obtain the piston displacement of the hydraulic support hydraulic cylinder, and the piston displacement is fed back to the control valve to control the flow.

The piston speed of the hydraulic support hydraulic cylinder is calculated by the following formula:

v＝Q/A

where v is the speed of the cylinder, Q is the input flow to the cylinder, and A is the cylinder piston area.

The hydraulic support hydraulic cylinder is a hydraulic actuator in a coal mining hydraulic system.

The invention has the beneficial effects that:

according to the method, a displacement sensor is not required to be arranged on the hydraulic cylinder of the hydraulic support, and the design difficulty of closed-loop control of the hydraulic cylinder of the traditional hydraulic support can be reduced.

Drawings

FIG. 1 is a schematic diagram of the system of the present invention.

FIG. 2 is a schematic diagram of the method of the present invention.

In the figure: 1-a pump station, 2-a first pressure sensor, 3-a control valve, 4-a second pressure sensor and 5-a hydraulic support hydraulic cylinder.

Detailed Description

The invention is described in further detail below with reference to the figures and the embodiments.

As shown in figure 1, the hydraulic support system comprises a pump station 1, a control valve 3 and a hydraulic support hydraulic cylinder 5, wherein an inlet of the pump station 1 is connected to an oil tank, an outlet of the pump station 1 is output to the hydraulic support hydraulic cylinder 5 through the control valve 3, and an outlet of the hydraulic support hydraulic cylinder 5 is communicated with the oil tank.

As shown in fig. 1, a pressure sensor is respectively arranged at the inlet and the outlet of the control valve 3, a first pressure sensor 2 is arranged at the inlet of the control valve 3, a second pressure sensor 4 is arranged at the outlet of the control valve 3, the two pressure sensors are respectively used for detecting the pressure at the input end and the output end of the control valve 3, and a displacement sensor is not required to be arranged on the hydraulic support cylinder.

The output pressure of the control valve 3, i.e. the input pressure of the hydraulic support cylinder 5, depends on the load of the hydraulic support cylinder 5.

The open-loop control method of the invention has the following control principle and process:

as shown in fig. 2, the flow rate of the hydraulic support hydraulic cylinder 5 is obtained by calculation according to the pressure difference between the two ends of the control valve 3 and the flow rate-pressure characteristic of the control valve, and the piston speed of the hydraulic support hydraulic cylinder 5 is obtained by the piston area conversion of the hydraulic support hydraulic cylinder 5; and then, the piston speed of the hydraulic support hydraulic cylinder 5 is subjected to time integration to obtain the piston displacement of the hydraulic support hydraulic cylinder 5, and the piston displacement is fed back to the control valve 3 to control the flow, so that the movement of the piston is accurately controlled.

The piston velocity of the hydraulic support cylinder 5 is calculated by the following formula:

v＝Q/A

where v is the speed of the cylinder, Q is the input flow to the cylinder, and A is the cylinder piston area.

The piston displacement of the hydraulic support hydraulic cylinder 5 is calculated by the following formula:

s ═ vdt controls the output flow of valve 3, i.e., the input flow Q to the cylinder, as calculated by:

Q＝xk(p1-p2)

where k is a flow coefficient, which can be obtained from a flow-pressure characteristic curve of the control valve, p1 is a control valve input end pressure, p2 is a control valve output end pressure, and x is an opening degree of the control valve.

The output pressure of the control valve 3, i.e. the input pressure of the hydraulic support cylinder 5, depends on the load of the hydraulic support cylinder 5.

Under the condition that the pressure at the input end and the output end of the control valve 3 is known, the control of the output flow of the control valve 3 can be realized by adjusting the opening of the control valve, so that the open-loop control of the piston speed and the displacement is realized.

Therefore, the open-loop control method of the invention combines the flow-pressure characteristic of the control valve and controls the flow input into the hydraulic cylinder by controlling the pressure of the input end of the control valve, thereby realizing the control of the speed and the position of the hydraulic cylinder of the hydraulic support.

The hydraulic support hydraulic cylinder 5 is a hydraulic actuator in a coal mining hydraulic system.

The foregoing detailed description is intended to be illustrative of the invention, which is only one, but not all embodiments of the invention. Any modification and variation made within the spirit of the present invention and the scope of the claims are within the scope of the present invention.