阅读说明：本技术 一种单电源驱动的电磁阀故障检测装置及方法 (Single-power-supply-driven electromagnetic valve fault detection device and method ) 是由 叶骞 卢剑锋 于 2020-04-28 设计创作，主要内容包括：本发明公开了一种单电源驱动的电磁阀故障检测装置及方法,包括检测电流变化的电流传感器,转为驱动电压为5V直流电压的稳压电路,判断电流上升时间的电压比较器以及采集信号的单片机。本发明还公开了一种电磁阀故障检测方法,利用电磁阀线圈通电过程中由于电感存在导致的电流缓慢上升现象,通过电流传感器放大电流信号为电压信号,并与设定的比较电压通过电压比较器比较,得到电流上升过程的下降沿,通过与门结合驱动电压的上升沿,得到代表电磁阀电流上升时间的方波信号,采集信号并计算高电平时间可以得到无故障情况下的电流上升至工作状态的时间间隔,保存至单片机EEPROM。一旦检测到的时间间隔变化较大则代表电磁阀存在故障。(The invention discloses a single-power-supply-driven electromagnetic valve fault detection device and method, which comprise a current sensor for detecting current change, a voltage stabilizing circuit for converting the current sensor into a direct-current voltage with the driving voltage of 5V, a voltage comparator for judging the rising time of current and a single chip microcomputer for collecting signals. The invention also discloses a method for detecting the fault of the electromagnetic valve, which comprises the steps of amplifying a current signal into a voltage signal by using a current sensor according to the current slow rising phenomenon caused by the existence of an inductor in the electrifying process of the electromagnetic valve coil, comparing the voltage signal with a set comparison voltage by using a voltage comparator to obtain the falling edge of the current rising process, obtaining a square wave signal representing the current rising time of the electromagnetic valve by combining the rising edge of the driving voltage with an AND gate, collecting the signal and calculating the high level time to obtain the time interval of the current rising to the working state under the fault-free condition, and storing the time interval to the single chip EEPROM. A large change in the detected time interval indicates a malfunction of the solenoid valve.)

1. A single power supply driven electromagnetic valve fault detection device comprises an RC (resistor-capacitor) filtering and LDO (low dropout regulator) voltage stabilizing circuit, wherein the RC filtering and LDO voltage stabilizing circuit is used for converting electromagnetic valve driving voltage into direct current 5V; the method is characterized in that: it includes input terminals CN2-1, CN2-2 for connecting a driving power supply. The fluctuating square wave driving voltage forms direct current driving voltage after being filtered by RC, and the output voltage is converted into the power supply voltage of the singlechip, the current sensor and the voltage comparator through the regulation of the voltage stabilizing circuit.

2. The single power supply driven solenoid valve failure detection device of claim 1, wherein the comparison voltage is controlled by a single chip microcomputer outputting a PWM signal.

3. The single power supply driven solenoid valve failure detection device according to claim 2, characterized in that: the current sensor is connected in parallel with two ends of the sampling resistor connected with the electromagnetic valve, and the output voltage of the current sensor after being compared with the comparison voltage is subjected to AND operation with the input reference voltage.

4. A single power supply driven electromagnetic valve fault detection method is characterized by comprising the following steps:

1) initially detecting and determining Vcp and adjusting the power supply voltage of each part to 5V: CN1 is connected to the solenoid valve, and CN2 is connected to the driving voltage. Regulating R7 and R8 to the output of the voltage regulator circuit at 5V according to the driving voltage, taking proper voltage Vcp according to the Sout value received by the singlechip, and outputting corresponding PWM signals according to the Vcp value

2) Selecting a current rising and falling edge: after the electromagnetic valve is opened, the current in the circuit rises to the peak value due to the existence of the inductance of the electromagnetic valve, obvious rising time exists when the rising time in the Dout signal is finished can be obtained according to the selection of Vcp And the voltage comparison of the voltage comparator, the rising edge of the input reference signal Vinp is accurate starting electrifying time, And the high-level rising And falling edge signal And which accurately represents the rising time of the current can be obtained by combining the AND gate with Vinp And Dout

3) And the And signal is connected with a D2 port of the singlechip for collection, And high level time, namely current rise time T0, is calculated. And the calculation result T0 under the normal working condition is stored in the singlechip for storage. In the following operating condition, the fault detection device is operated all the time, and if the rising time of the current detected at a certain time end deviates from a large range of T0, the fault of the electromagnetic valve is represented.

Technical Field

The invention belongs to an electromagnetic valve fault detection application device, which is used for fault detection of a switch electromagnetic valve under the drive of a single power supply.

Background

The electromagnetic valve fault detection on the existing market is additionally supplied with power and can detect the fault under the power-off state of the electromagnetic valve. Not only influences the work operation of solenoid valve itself, can't discover the problem in time when appearing slight trouble moreover.

Disclosure of Invention

In order to solve the above problems, the present invention provides a single power supply driven solenoid valve failure detection apparatus and method.

The technical scheme adopted by the invention for realizing the purpose is as follows: based on the phenomenon that current slowly rises due to the existence of inductance in the electrifying process of a solenoid valve coil, a current signal is amplified into a voltage signal through a current sensor and is compared with a comparison voltage formed by a single chip microcomputer PWM through an integrating circuit through a voltage comparator to obtain the falling edge of the current rising process, a square wave signal representing the current rising time of the solenoid valve is obtained through the combination of an AND gate and the rising edge of a driving voltage, the signal is collected, the high level time is calculated to obtain the time interval of the current rising to the working state under the condition of no fault, and the time interval is stored in a single chip microcomputer EEPROM. A large change in the detected time interval indicates a malfunction of the solenoid valve.

In order to achieve the purpose of saving energy, the power supply voltage of the current sensor, the voltage comparator and the singlechip in the technical scheme is completely provided by converting input driving voltage into 5V through RC filtering and an LDO voltage stabilizing circuit, and the fault detection can be carried out at any time when the electromagnetic valve works.

For different electromagnetic valves, the fault detection can be realized for different electromagnetic valves by adjusting the sampling resistor and the PWM output of the single chip microcomputer.

The invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, which illustrate embodiments of the invention.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a fault detection module for a single power supply solenoid valve according to the present invention

FIG. 2 shows the input voltage of the present invention converted to 5V by RC filtering and LDO voltage regulator

FIG. 3 shows the signal acquisition and PWM signal output part of the single chip microcomputer

FIG. 4 shows a part of the single chip microcomputer outputting PWM signal converted into DC voltage by the second-order integrating circuit

FIG. 5 is a current sensor and voltage comparator section

Detailed Description

Embodiments of the present invention will now be described with reference to the accompanying drawings.