阅读说明：本技术 一种数字液压缸工作状态非介入实时监测系统及使用方法 (Digital hydraulic cylinder working state non-intervention real-time monitoring system and using method ) 是由 马长林 于传强 郝琳 唐圣金 李锋 程洪杰 冯永保 候帅 陈珊 于 2021-08-04 设计创作，主要内容包括：本发明属于机电检测技术领域,具体涉及一种数字液压缸工作状态非介入式实时监测系统及方法。包括工控机、数据采集器、非接触式电流传感器和位移传感器,位移传感器安装于数字液压缸活塞杆与缸体之间,非接触式电流传感器信号输出端和位移传感器信号输出端均连接于数据采集器,数据采集器与工控机之间通过USB线连接。该系统的使用方法包括：步骤1：启动数字液压缸；步骤2：获取驱动器输出的电流信号并自动判断；步骤3：计算出数字液压缸位移值；步骤4：实际位移值与数字液压缸位移值比较,判断是否正常,正常返回步骤3,故障则进入下一步；步骤5：显示数字液压缸故障状态,一次监测过程结束。(The invention belongs to the technical field of electromechanical detection, and particularly relates to a non-intrusive real-time monitoring system and a non-intrusive real-time monitoring method for the working state of a digital hydraulic cylinder. The displacement sensor is installed between a piston rod and a cylinder body of the digital hydraulic cylinder, a signal output end of the non-contact current sensor and a signal output end of the displacement sensor are both connected to the data collector, and the data collector is connected with the industrial personal computer through a USB line. The use method of the system comprises the following steps: step 1: starting the digital hydraulic cylinder; step 2: acquiring a current signal output by a driver and automatically judging; and step 3: calculating the displacement value of the digital hydraulic cylinder; and 4, step 4: comparing the actual displacement value with the displacement value of the digital hydraulic cylinder, judging whether the actual displacement value is normal or not, returning to the step 3 normally, and entering the next step when the fault occurs; and 5: and displaying the fault state of the digital hydraulic cylinder, and finishing the primary monitoring process.)

1. The utility model provides a non-intervention real-time monitoring system of digital pneumatic cylinder operating condition which characterized in that: the device comprises an industrial personal computer, a data acquisition unit, a non-contact current sensor, a driver and a displacement sensor, wherein the non-contact current sensor is electrically connected between the driver and a stepping motor, the displacement sensor is installed between a piston rod and a cylinder body of a digital hydraulic cylinder, the signal output end of the non-contact current sensor and the signal output end of the displacement sensor are both connected to the data acquisition unit, and the data acquisition unit is connected with the industrial personal computer through a USB wire.

2. The digital hydraulic cylinder working state non-intervention real-time monitoring system of claim 1, wherein: the non-contact type current sensor is a perforated non-contact type current sensor.

3. The use method of the digital hydraulic cylinder working state non-intervention real-time monitoring system according to claim 1 or 2, characterized by comprising the following steps: the method comprises the following steps:

step 1: starting a digital hydraulic cylinder working state non-intervention real-time monitoring system;

step 2: the industrial personal computer obtains a current signal which is output by the driver and controls the stepping motor in real time through the data acquisition unit, and obtains the total number of the effective pulses input at one time;

and step 3: the industrial personal computer calculates the displacement value of the digital hydraulic cylinder according to the relation among the total number of the once input control pulse, the number of the pulse control signals and the action displacement of the hydraulic cylinder;

and 4, step 4: the industrial personal computer acquires signals of the displacement sensor to obtain an actual displacement value, compares the actual displacement value with the calculated displacement value of the digital hydraulic cylinder, judges whether the digital hydraulic cylinder works normally or not according to a displacement error criterion, returns to the step 3 if the digital hydraulic cylinder works normally, and enters the next step if the digital hydraulic cylinder fails;

and 5: and displaying the fault state of the digital hydraulic cylinder, and finishing the primary monitoring process.

4. The use method of the digital hydraulic cylinder working state non-intervention real-time monitoring system according to claim 3, characterized by comprising the following steps: the step 2 specifically comprises the following steps:

step 2.1: initialization of parameters, including signal threshold a₁Number of single-phase effective pulses n₁Maximum value of one action time t of 0_maxEtc.;

step 2.2: the industrial personal computer obtains a current signal which is output by the driver and controls the stepping motor in real time through the data acquisition unit;

step 2.3: the industrial personal computer judges whether the current signal acquired in the step 2.2 has a normal pulse signal, if so, the next step is carried out, and if not, the step 2.2 is returned;

step 2.4: starting a timer;

step 2.5: judging whether the current signal is a rising edge or not, if not, jumping to the step 2.9, and if so, entering the next step;

step 2.6: judging whether the current signal exceeds the signal threshold a set in the step 2.1₁If the signal threshold value a is not exceeded₁Then go to step 2.9, if the signal threshold a is exceeded₁Entering the next step;

step 2.7: adding 1 to the number of single-phase effective pulses, and entering the next step;

step 2.8: judging whether the timing time t is greater than t_maxIf yes, entering the next step, otherwise, returning to the step 2.5;

step 2.9: and outputting the total number of the effective pulses, and finishing one-time monitoring.

5. The use method of the digital hydraulic cylinder working state non-intervention real-time monitoring system according to claim 4, characterized in that: and 2.3, simultaneously acquiring three-phase pulse control signals by using a non-contact current sensor, wherein two phases are positive signals, one phase is a negative signal, obtaining three-stage stepped signals, and respectively setting three different thresholds a₁、a₂、a₃When the threshold value is a₁Through the steps ofStep 2.2-2.9, obtaining the effective pulse number n₁When the threshold value is a₂Obtaining the number n of the effective pulses through the steps 2.2-2.9₂When the threshold value is a₃Obtaining the number n of the effective pulses through the steps 2.2-2.9₃The total pulse number n of the stepping motor is n₁+n₂+n₃。

6. The use method of the digital hydraulic cylinder working state non-intervention real-time monitoring system according to claim 5, characterized by comprising the following steps: the step 3 comprises the following specific steps:

when the screw pitch is S and the pulse period of the stepping motor is N pulses/rotation, the calculated displacement value X of the digital hydraulic cylinder is as follows:

X＝n×S/N

wherein N is the total pulse number input to the stepping motor, S is the screw pitch of the digital hydraulic cylinder, and the pulse period of the stepping motor is N pulses/revolution.

7. The use method of the digital hydraulic cylinder working state non-intervention real-time monitoring system according to claim 6, characterized by comprising the following steps: the step 4 comprises the following specific steps:

the actual displacement value X_SComparing the error value of the calculated displacement value X with an error criterion, wherein the error criterion is as follows: Δ X ═ X_S-X|≤[ΔX]Wherein [ Delta X]For allowable displacement error value, when Δ X is less than or equal to [ Δ X ]]And if not, the working state of the digital hydraulic cylinder is a fault.

Technical Field

The invention belongs to the technical field of electromechanical detection, and particularly relates to a non-intrusive real-time monitoring system and method for the working state of a digital hydraulic cylinder.

Background

The digital hydraulic cylinder, also called a numerical control oil cylinder, is a single hydraulic component with a built-in closed loop and an open loop, and can convert pulses into precise power drive to realize micron-sized control precision.

The general single-stage spiral feedback type digital hydraulic cylinder is composed of a stepping motor, a sliding sleeve, a sliding valve body, a valve core, a screw rod, a feedback nut, a piston rod, a cylinder body and the like. The piston rod is of a hollow structure, and a screw is arranged in the piston rod; the feedback nut is fixedly connected with the piston; the screw and the valve core adopt an integrated structure, one end of the valve core is provided with a key groove for installing a sliding key and is connected with a stepping motor shaft through a sliding sleeve, and one end of the screw is matched with a feedback nut on the piston. When the valve core is driven by the stepping motor to rotate, the valve core can axially move under the action of the nut, so that the flowing direction of hydraulic oil is changed, the oil cylinder piston is pushed to extend or retract, and meanwhile, the valve core is reset and closed through the nut pair, and position closed loop feedback is formed. In practical application, under the condition of sudden load change or excessively low oil pressure, after a valve core acts and a valve port is opened, a piston does not act or does not act in place, closed-loop feedback of the position cannot be formed at the moment, the valve core cannot reset, and the valve core is separated from a sliding sleeve, the digital hydraulic cylinder cannot normally work and needs to be stopped for maintenance. In order to avoid the fault phenomenon, at present, when the digital hydraulic cylinder is controlled to act by using an engineering system with the structure and without a matched detection device, a person is required to observe the working condition of the digital hydraulic cylinder, the abnormality needs to be reported quickly, time and labor are wasted, human factors influence exists, the failure report and the false report of the fault can occur, and the fault is difficult to find in time.

Disclosure of Invention

The invention aims to provide a digital hydraulic cylinder working state non-intervention monitoring system aiming at the problem that the fault of a digital hydraulic cylinder system used in engineering is difficult to diagnose in time, which is used for judging the working state of a hydraulic cylinder in real time and can automatically judge in time when the fault is abnormal.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the utility model provides a non-intervention real-time monitoring system of digital pneumatic cylinder operating condition, includes industrial computer, data collection station, non-contact current sensor, driver and displacement sensor, non-contact current sensor electricity is connected between driver and step motor, displacement sensor installs between digital pneumatic cylinder piston rod and cylinder body, non-contact current sensor signal output part and displacement sensor signal output part all connect in data collection station, pass through the USB line connection between data collection station and the industrial computer.

Preferably, the contactless current sensor is a punched contactless current sensor.

A use method of a digital hydraulic cylinder working state non-intervention real-time monitoring system comprises the following steps:

step 1: starting a digital hydraulic cylinder working state non-intervention real-time monitoring system;

step 2: the industrial personal computer obtains a current signal which is output by the driver and controls the stepping motor in real time through the data acquisition unit, and obtains the total number of the effective pulses input at one time;

and step 3: the industrial personal computer calculates the displacement value of the digital hydraulic cylinder according to the relation among the total number of the once input control pulse, the number of the pulse control signals and the action displacement of the hydraulic cylinder;

and 4, step 4: the industrial personal computer acquires signals of the displacement sensor to obtain an actual displacement value, compares the actual displacement value with the calculated displacement value of the digital hydraulic cylinder, judges whether the digital hydraulic cylinder works normally or not according to a displacement error criterion, returns to the step 3 if the digital hydraulic cylinder works normally, and enters the next step if the digital hydraulic cylinder fails;

and 5: and displaying the fault state of the digital hydraulic cylinder, and finishing the primary monitoring process.

Preferably, the step 2 specifically comprises the following steps:

step 2.1: initialization of parameters, including signal threshold a₁Number of single-phase effective pulses n₁Maximum value of one action time t of 0_maxEtc.;

step 2.2: the industrial personal computer obtains a current signal which is output by the driver and controls the stepping motor in real time through the data acquisition unit;

step 2.3: the industrial personal computer judges whether the current signal acquired in the step 2.2 has a normal pulse signal, if so, the next step is carried out, and if not, the step 2.2 is returned;

step 2.4: starting a timer;

step 2.5: judging whether the current signal is a rising edge or not, if not, jumping to the step 2.9, and if so, entering the next step;

step 2.6: judging whether the current signal exceeds the signal threshold a set in the step 2.1₁If the signal threshold value a is not exceeded₁Then go to step 2.9, if the signal threshold a is exceeded₁Entering the next step;

step 2.7: adding 1 to the number of single-phase effective pulses, and entering the next step;

step 2.8: judging whether the timing time t is greater than t_maxIf yes, entering the next step, otherwise, returning to the step 2.5;

step 2.9: and outputting the total number of the effective pulses, and finishing one-time monitoring.

Preferably, in step 2.3, a non-contact current sensor is used to acquire three-phase pulse control signals simultaneously, wherein two phases are positive signals and one phase is negative signals, so as to obtain three-level stepped signals, and three stepped signals are respectively setDifferent threshold values a₁、a₂、a₃When the threshold value is a₁Obtaining the number of effective pulses n through the steps 2.2-2.9₁When the threshold value is a₂Obtaining the number n of the effective pulses through the steps 2.2-2.9₂When the threshold value is a₃Obtaining the number n of the effective pulses through the steps 2.2-2.9₃The total pulse number n of the stepping motor is n₁+n₂+n₃。

Preferably, the step 3 specifically comprises the following steps:

when the screw pitch is S and the pulse period of the stepping motor is N pulses/rotation, the calculated displacement value X of the digital hydraulic cylinder is as follows:

X＝n×S/N

wherein N is the total pulse number input to the stepping motor, S is the screw pitch of the digital hydraulic cylinder, and the pulse period of the stepping motor is N pulses/revolution.

Preferably, the step 4 comprises the following specific steps:

the actual displacement value X_SComparing the error value of the calculated displacement value X with an error criterion, wherein the error criterion is as follows: Δ X ═ X_S-X|≤[ΔX]Wherein [ Delta X]For allowable displacement error value, when Δ X is less than or equal to [ Δ X ]]And if not, the working state of the digital hydraulic cylinder is a fault.

Compared with the prior art, the invention has the beneficial effects that:

(1) the non-intrusive real-time monitoring of the working state of the digital hydraulic cylinder of the engineering system is realized.

(2) The real-time judgment of the faults of the digital hydraulic cylinder is realized, and the reliable work and the safety of the digital hydraulic cylinder system are ensured.

(3) The method provides a simple and convenient method for detecting the safe and reliable working state of the digital hydraulic cylinder system used in the existing engineering, and is successfully applied.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention.

In the drawings:

FIG. 1 is a block diagram of a non-intrusive real-time monitoring system for the working state of a digital hydraulic cylinder;

FIG. 2 is a flow chart of a method for using the non-intrusive real-time monitoring system for the working state of the digital hydraulic cylinder;

fig. 3 is a waveform diagram of a three-step acquired signal.

Detailed Description

The preferred embodiments of the present invention will be described in conjunction with the accompanying drawings, and it will be understood that they are described herein for the purpose of illustration and explanation and not limitation. Example (b):

referring to the attached drawings 1-3, the non-intervention real-time monitoring system for the working state of the digital hydraulic cylinder comprises an industrial personal computer, a data acquisition unit, a non-contact current sensor, a driver and a displacement sensor, wherein the industrial personal computer is used for detecting a current pulse signal of a stepping motor controlled and input by the driver and an actual displacement value of the digital hydraulic cylinder in real time, calculating a theoretical displacement value and an actual displacement value of the digital hydraulic cylinder according to the accumulated pulse number, comparing the theoretical displacement value and the actual displacement value, judging the working state of the digital hydraulic cylinder and giving a prompt of whether a fault occurs.

The non-contact type current sensor is electrically connected to a connecting cable between the driver and the stepping motor, the non-contact type current sensor is MIK-DJI-5A and is used for detecting a current pulse signal between the driver and the stepping motor, the sensor belongs to a non-contact type sensor, and a control lead input into the stepping motor can penetrate through a signal acquisition hole of the sensor, so that the existing equipment does not need to be dismantled and modified, and the using number of the sensors can be reduced. The current signals are selected from three phases, wherein one positive signal and two negative signals are acquired.

The displacement sensor is installed between a piston rod and a cylinder body of the digital hydraulic cylinder, is in an optoNCDT1302-100 model and is used for detecting the extension length of the piston rod of the digital hydraulic cylinder. The signal output end of the non-contact current sensor and the signal output end of the displacement sensor are both connected to a data acquisition unit, the model of the data acquisition unit is YAV-16AD, and the data acquisition unit is connected with an industrial personal computer through a USB wire.

A use method of a digital hydraulic cylinder working state non-intervention real-time monitoring system comprises the following steps:

step 1: starting a digital hydraulic cylinder working state non-intervention real-time monitoring system;

step 2: the industrial computer obtains driver output control step motor's current signal in real time through data collection station, obtains the total number of once inputing effective pulse, specifically includes:

step 2.1: initialization of parameters, including signal threshold a₁Number of single-phase effective pulses n₁Maximum value of one action time t of 0_maxEtc.;

step 2.2: the industrial personal computer obtains a current signal which is output by the driver and controls the stepping motor in real time through the data acquisition unit;

step 2.3: the industrial personal computer judges whether the current signal acquired in the step 2.2 has a normal pulse signal, if so, the next step is carried out, and if not, the step 2.2 is returned;

step 2.4: starting a timer;

step 2.5: judging whether the current signal is a rising edge or not, if not, jumping to the step 2.9, and if so, entering the next step;

step 2.6: judging whether the current signal exceeds the signal threshold a set in the step 2.1₁If the signal threshold value a is not exceeded₁Then go to step 2.9, if the signal threshold a is exceeded₁Entering the next step;

step 2.7: adding 1 to the number of single-phase effective pulses, and entering the next step;

step 2.8: judging whether the timing time t is greater than t_maxIf yes, entering the next step, otherwise, returning to the step 2.5;

step 2.9: and outputting the total number of the effective pulses, and finishing one-time monitoring.

And 2.3, simultaneously acquiring three-phase pulse control signals by using the non-contact current sensor, wherein two phases are positive signals, and one phase is a negative signal to obtainAnd three different threshold values a are respectively set₁、a₂、a₃When the threshold value is a₁Obtaining the number of effective pulses n through the steps 2.2-2.9₁When the threshold value is a₂Obtaining the number n of the effective pulses through the steps 2.2-2.9₂When the threshold value is a₃Obtaining the number n of the effective pulses through the steps 2.2-2.9₃The total pulse number n of the stepping motor is n₁+n₂+n₃。

And step 3: the industrial personal computer calculates the displacement value of the digital hydraulic cylinder according to the relation among the total number of the once input control pulse, the number of the pulse control signals and the action displacement of the hydraulic cylinder, and the calculation of the displacement value X of the digital hydraulic cylinder specifically comprises the following steps:

when the screw pitch is S and the pulse period of the stepping motor is N pulses/rotation, the calculated displacement value X of the digital hydraulic cylinder is as follows:

X＝n×S/N

wherein N is the total pulse number input to the stepping motor, S is the screw pitch of the digital hydraulic cylinder, and the pulse period of the stepping motor is N pulses/revolution.

And 4, step 4: the industrial personal computer collects the signals of the displacement sensor to obtain the actual displacement value X_SAnd comparing the digital hydraulic cylinder displacement value with the calculated digital hydraulic cylinder displacement value X, wherein the error criterion is as follows: Δ X ═ X_S-X|≤[ΔX]Wherein [ Delta X]For allowable displacement error value, when Δ X is less than or equal to [ Δ X ]]If the working state of the digital hydraulic cylinder is normal, returning to the step 3, otherwise, if the working state of the digital hydraulic cylinder is fault, entering the next step;

and 5: and displaying the fault state of the digital hydraulic cylinder, and finishing the primary monitoring process.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, which are described in the specification and illustrated only to illustrate the principle of the present invention, but that various changes and modifications may be made therein without departing from the spirit and scope of the present invention, which fall within the scope of the invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.