Disclosure of Invention
The invention aims to overcome the defects of the prior art and provides a pressure reducing device and a closed-loop control method for pressure output regulation of the pressure reducing device, which are used for reducing high-pressure air at the upstream of a gas path to a required pressure value and stably outputting the high-pressure air.
To achieve the above object, in a first aspect, a closed-loop control method for pressure output regulation is characterized in that the closed-loop control method comprises:
the method comprises the steps that a decompression device receives a power-on signal and enters an initial adjustment mode, and a processor of the decompression device obtains a preset first pressure target value;
the pressure sensor detects the output pressure of the pressure reducing valve in the initial state and sends the output pressure to the processor;
the processor calculates a first angle according to the first pressure target value and the output pressure in the initial state, and correspondingly generates a first control instruction;
the motor rotates a first angle according to a first control instruction, and drives an adjusting screw of the pressure reducing valve to rotate through a transmission mechanism, so that the output pressure of the pressure reducing valve is changed;
when the deviation of the output pressure and the first pressure target value is smaller than or equal to a preset threshold value, the pressure reducing device enters a normal adjusting mode;
in the normal regulation mode, the pressure sensor detects the real-time output pressure of the pressure reducing valve in real time; when the deviation between the real-time output pressure and the first pressure target value is larger than a preset threshold value, the processor calculates to obtain a second angle according to the first pressure target value and the real-time output pressure, and correspondingly generates a second control instruction, so that the motor rotates the second angle according to the second control instruction to finely adjust the real-time output pressure;
and when the deviation between the real-time output pressure and the first pressure target value is continuously greater than a preset threshold value within a preset time length, the pressure reducing device enters a fault mode, the processor generates a pressure deviation alarm signal and outputs a stop instruction to control the motor to stop rotating.
Preferably, when the processor receives an emergency mode switching signal input from the outside, the pressure reduction device enters an emergency mode, and acquires a second pressure target value input from the outside.
Preferably, a pressure switch arranged on an output branch of the pressure reducing valve detects the output pressure of the pressure reducing valve, and the pressure switch is switched off when the output pressure exceeds a limit value of the pressure switch; and the processor controls the motor to stop rotating according to the detected opening signal of the pressure switch.
Preferably, the first angle is greater than the second angle.
In a second aspect, referring to the pressure reduction apparatus of the closed-loop control method for pressure output regulation of the first aspect, the pressure reduction apparatus includes: the device comprises a gas circuit board, a motor, a pressure reducing valve, a transmission mechanism, a pressure switch, a pressure sensor, a pressure measuring point component and a processor;
the motor, the pressure reducing valve, the transmission mechanism, the pressure switch, the pressure sensor, the pressure measuring point component and the processor are respectively arranged on the gas circuit board;
the processor is respectively electrically connected with the motor, the pressure switch and the pressure sensor and is used for controlling the rotation of the motor;
the motor is connected with the pressure reducing valve through the transmission mechanism; under the action of the transmission mechanism, the motor adjusts the output pressure of the pressure reducing valve through rotation;
the pressure sensor and the pressure switch are sequentially arranged on an output branch of the pressure reducing valve; the pressure sensor is used for detecting the output pressure of the pressure reducing valve; the pressure switch is used for controlling the connection and disconnection between the pressure reducing valve and gas circuit equipment using the output pressure of the pressure reducing valve;
the pressure measuring point component is arranged on an output branch of the pressure reducing valve, and the pressure measuring point of the pressure measuring point component and the detecting point of the pressure sensor are at the same position.
Preferably, the transmission mechanism comprises a V-belt, a first toothed disc and a second toothed disc;
the first fluted disc penetrates through and is fixed on a rotating shaft of the motor, and the second fluted disc penetrates through and is fixed on an adjusting screw of the pressure reducing valve; a V belt is wound on the first fluted disc and the second fluted disc; and the V belt is respectively in meshing transmission with the first fluted disc and the second fluted disc.
According to the pressure reducing device and the closed-loop control method for pressure output regulation, provided by the embodiment of the invention, the high-pressure air at the upstream of the air path is reduced to the required pressure value for output, and is automatically corrected in real time according to the output pressure, so that the fluctuation range of the output pressure is reduced, the stable output of the output pressure is realized, and the service life of the downstream air path equipment is prolonged.
Detailed Description
The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.
According to the pressure reducing device and the closed-loop control method for pressure output regulation, provided by the invention, the high-pressure air at the upstream of the air path is reduced to the required pressure value for output, and is automatically corrected in real time according to the output pressure, so that the fluctuation range of the output pressure is reduced, the stable output of the output pressure is realized, and the service life of the downstream air path equipment is prolonged.
Fig. 1 is a schematic structural view of a pressure reducing device according to an embodiment of the present invention, fig. 2 is a schematic structural view of a pressure reducing device according to an embodiment of the present invention, and the structure and principle of the pressure reducing device according to the present invention are described with reference to fig. 1 and 2.
The pressure reducing device includes: the device comprises a gas circuit board 1, a motor 2, a transmission mechanism 3, a pressure reducing valve 4, a pressure sensor 5, a pressure measuring point component 6, a pressure switch 7 and a processor 8 (not shown in the figure).
The motor 2, the transmission mechanism 3, the pressure reducing valve 4, the pressure sensor 5, the pressure measuring point component 6, the pressure switch 7 and the processor 8 are respectively arranged on the gas circuit board 1. The processor 8 is electrically connected with the motor 2, the pressure switch 7 and the pressure sensor 5 respectively and used for controlling the rotation of the motor 2. The motor 2 is connected with the pressure reducing valve 4 through the transmission mechanism 3, and under the action of the transmission mechanism 3, the motor 2 adjusts the output pressure of the pressure reducing valve 4 through rotation. The pressure sensor 5 and the pressure switch 7 are arranged in this order in the outlet branch of the pressure reducing valve 4. The pressure measuring point component 6 is arranged on an output branch of the pressure reducing valve 4, and the pressure measuring point of the pressure measuring point component 6 and the detecting point of the pressure sensor 5 are at the same position.
The transmission mechanism 3 includes a first toothed disc 31, a second toothed disc 32, and a V-belt 33 (none of which are shown). The first gear 31 is fixed on the rotating shaft of the motor 2, and the second gear 32 is fixed on the adjusting screw of the pressure reducing valve 4. The first toothed disc 31 and the second toothed disc 32 are wound with a V-belt 33, and the V-belt 33 is in meshing transmission with the first toothed disc 31 and the second toothed disc 32 respectively.
In a preferred embodiment, the motor 2 may be a stepping motor, a servo motor or a dc motor. The transmission mechanism 3 can adopt a synchronous belt mode and a chain transmission mode.
The gas circuit board 1 is used for accommodating and supporting other devices and is communicated with a gas circuit. The transmission mechanism 3 is used for converting the rotation angle of the motor 2 into the rotation angle of an adjusting screw of the pressure reducing valve 4. The processor 8 is used for controlling the rotation angle of the motor 2 according to the output pressure of the pressure reducing valve 4 and a preset target value. The motor 2 is used to adjust the output pressure of the pressure reducing valve 4 by rotation. The pressure reducing valve 4 is used to adjust the output pressure according to the rotation angle of the motor 2. The pressure sensor 5 is used to detect the output pressure of the pressure reducing valve 4. The pressure sensor 5, the motor 2 and the pressure reducing valve 4 form a closed loop. The pressure switch 7 is used for controlling the on-off of the pressure reducing valve 4 and the gas circuit equipment using the output pressure of the pressure reducing valve 4, and is disconnected when the output pressure of the pressure reducing valve 4 reaches a certain condition, and a signal is fed back to control the motor 2 to stop rotating. The pressure measuring point part 6 is used for manually detecting the output pressure of the pressure reducing valve 4.
Note that the rotation angle of the motor 2 is directional. The motor 2 rotates forwards, the output pressure of the pressure reducing valve 4 is increased, the motor 2 rotates backwards, and the output pressure of the pressure reducing valve 4 is reduced. The pressure reducing valve 4 is typically in the range of 0-1000kPa, which determines the range of the rotation angle of the adjusting screw and indirectly also the range of the rotation angle of the motor 2. The output pressure of the pressure reducing valve 4 is linearly related to the rotation angle thereof.
Fig. 3 is a flowchart of a closed-loop control method for pressure output adjustment according to an embodiment of the present invention, and as shown in fig. 3, the steps of the closed-loop control method for pressure output adjustment based on the pressure reducing device are as follows.
101, a decompression device receives a power-on signal and enters an initial regulation mode, and a processor of the decompression device acquires a preset first pressure target value;
specifically, the pressure reducing device enters an initial mode upon being powered on, and a pressure value required by downstream gas circuit equipment, namely a first pressure target value, is acquired in the initial mode. The first pressure target value can be input manually or calculated comprehensively according to the connected downstream gas path equipment.
102, detecting output pressure of a pressure reducing valve in an initial state by a pressure sensor, and sending the output pressure to a processor;
specifically, in the initial mode, the processor adjusts according to the output pressure of the pressure reducing valve after each adjustment.
103, calculating by the processor according to the first pressure target value and the output pressure in the initial state to obtain a first angle, and correspondingly generating a first control instruction;
specifically, the relationship between the rotation angle of the motor and the change value of the output pressure of the pressure reducing valve is as shown in formula 1:
ΔP=(z1/z2)P0alpha (formula 1)
Wherein Δ P is a variation value of an output pressure of the pressure reducing valve, Z1Is the number of teeth of the first toothed disc, Z, on the rotary shaft of the motor2Number of teeth, P, of a second toothed disc on an adjusting screw of the pressure relief valve0The pressure change value is the pressure change value of the pressure reducing valve rotating by a unit angle, and alpha is the rotating angle of the motor.
As can be seen from equation 1, the first and second toothed discs can be increased without increasing the accuracy of the pressure sensor and the motorThe gear ratio of the fluted disc, the change value of the output pressure of the reducing valve caused by the motor rotating by a unit angle can be reduced as much as possible under the condition of the mechanical characteristic of the reducing valve, so that the adjusting precision is improved. Namely, when the gear ratio of the first fluted disc to the second fluted disc is n, the motor rotates for a certain angle, and the change value of the output pressure of the pressure reducing valve is P1; when the gear ratio of the first fluted disc and the second fluted disc is changed into 2n, the motor rotates by the same angle, and the change value of the output pressure of the pressure reducing valve is P1And/2, thereby improving the adjustment accuracy thereof.
104, rotating the motor by a first angle according to a first control instruction, and driving an adjusting screw of the pressure reducing valve to rotate through a transmission mechanism so as to change the output pressure of the pressure reducing valve;
specifically, the first angle is directional, when the first angle is positive, the motor rotates positively, the output pressure of the pressure reducing valve is increased, and when the first angle is negative, the motor rotates negatively, the output pressure of the pressure reducing valve is reduced.
Step 105, judging whether the deviation of the output pressure and the first pressure target value is less than or equal to a preset threshold value by the processor;
when the deviation of the output pressure and the first pressure target value is less than or equal to a preset threshold value, the pressure reducing device enters a normal regulation mode and executes step 106; when the deviation of the output pressure from the first pressure target value is greater than a preset threshold, step 102 is performed.
106, detecting the real-time output pressure of the pressure reducing valve in real time by using a pressure sensor;
specifically, the pressure sensor monitors the real-time output pressure of the pressure reducing valve in real time, and the processor corrects the real-time output pressure of the pressure reducing valve in time when the real-time output pressure of the pressure reducing valve deviates.
Step 107, judging whether the deviation of the real-time output pressure and the first pressure target value is greater than a preset threshold value by the processor;
when the deviation of the real-time output pressure from the first pressure target value is greater than the preset threshold, executing step 108; when the deviation between the real-time output pressure and the first pressure target value is less than or equal to a preset threshold, executing step 107;
step 108, the processor calculates a second angle according to the first pressure target value and the real-time output pressure, and correspondingly generates a second control instruction, so that the motor rotates the second angle according to the second control instruction to finely adjust the real-time output pressure;
specifically, the first angle is greater than the second angle. In the initial mode, the deviation of the output pressure of the pressure reducing valve from the first pressure target value is generally large, and therefore the first angle is also generally large. In the normal mode, the deviation of the output pressure of the pressure reducing valve from the first pressure target value is again greater than the preset threshold value due to the deviation of mechanical components in the pressure reducing valve caused by long-time operation, and therefore the real-time output pressure of the pressure reducing valve needs to be adjusted. At the moment, the pressure sensor monitors the real-time output pressure of the pressure reducing valve in real time, so that the deviation of the output pressure of the pressure reducing valve and the first pressure target value is small, and the second angle, which is required to rotate by a corresponding motor, is also small.
Step 109, the processor judges whether the deviation between the real-time output pressure and the first pressure target value is continuously greater than a preset threshold value within a preset time length;
when the deviation between the real-time output pressure and the first pressure target value is continuously greater than a preset threshold value within a preset time length, the pressure reducing device enters a failure mode, and step 110 is executed; when the deviation of the real-time output pressure from the first pressure target value is not continuously greater than the preset threshold value within the preset time period, step 109 is executed,
and step 110, generating a pressure deviation alarm signal by the processor, outputting a stop instruction, and controlling the motor to stop rotating.
Specifically, when the pressure reducing device is in a failure mode, the transmission mechanism can be detached, the output pressure of the pressure measuring point component is monitored by using the handheld pressure gauge, and the adjusting screw of the pressure reducing valve is screwed by using the wrench, so that the output pressure of the pressure reducing valve is manually adjusted.
In a preferred scheme, in order to prolong the service life of downstream gas circuit equipment, a pressure switch is arranged on an output branch of the pressure reducing valve, so that the output pressure of the pressure reducing valve is prevented from being too large or too small. In the normal mode, a pressure switch provided on an output branch of the pressure reducing valve detects an output pressure of the pressure reducing valve, and the pressure switch is turned off when the output pressure exceeds a limit value of the pressure switch. The processor controls the motor to stop rotating according to the detected off signal of the pressure switch, and generates a lower electric signal of the pressure reducing device. The device comprises two pressure switches, wherein one pressure switch is used for detecting the upper limit value of the output pressure, the other pressure switch is used for detecting the lower limit value of the output pressure, and the output pressure is comprehensively controlled between the upper limit value and the lower limit value through the two pressure switches.
In a further preferred aspect, when the pressure reducing device is in an emergency and needs to increase the downstream output pressure, that is, when the processor receives an externally input emergency mode switching signal, the pressure reducing device enters the emergency mode and acquires the externally input second pressure target value. The output pressure of the pressure reducing valve is adjusted according to the second pressure target value.
For example, an urban rail vehicle must be braked emergently due to a self fault or a line fault, and the parking is realized at the shortest distance, but the downstream braking equipment is limited by the output pressure of a pressure reducing device, the braking capability is limited, and the processor realizes the short-distance parking according to the received emergency mode switching signal. In the emergency mode, the processor masks the signal of the pressure switch.
According to the pressure reducing device and the closed-loop control method for pressure output regulation of the pressure reducing device, high-pressure air at the upstream of the air path is reduced to a required pressure value to be output, automatic correction is performed in real time according to the output pressure, the fluctuation range of the output pressure is reduced, stable output of the output pressure is achieved, and therefore the service life of downstream air path equipment is prolonged.
Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in hardware, a software module executed by a processor, or a combination of the two. A software module may reside in Random Access Memory (RAM), memory, Read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present invention, and are not intended to limit the scope of the present invention, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.