Oil level monitoring method and system based on ultrasonic waves

Abstract

The invention provides an ultrasonic-based oil level monitoring method, which comprises the following steps that: an ultrasonic sensor module periodically transmits ultrasonic waves to oil in an oil tank and receives echo signals fed back by the oil, and the ultrasonic sensor module is mounted at the top end in the oil tank and has a certain distance from the liquid level of the oil; the oil level monitoring device determines the starting time of transmitting ultrasonic waves in each period of the ultrasonic sensor module and the time of receiving an oil liquid feedback echo signal for the first time in the same period so as to calculate the single round-trip time of the ultrasonic waves in the oil tank in each period; calculating the oil level value of the oil in each period according to the propagation speed of the ultrasonic waves compensated in the oil tank by combining the environment temperature outside the oil tank; wherein the oil level value is the distance between the ultrasonic sensor module and the oil level. By implementing the invention, the problems of low oil level monitoring precision, low management efficiency and oil resource overflow waste of the oil tank in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic detection, and particularly relates to an oil level monitoring method and system based on ultrasonic waves. Background Art

[0002] In recent years, information technology has been widely applied in the industrial field, namely application systems based on simple automation and complex automation. Oil storage facilities such as oil depots and fuel tanks are used to store oil resources in farms and industrial enterprises. Of course, the oil levels in these facilities need to be monitored in real time to prevent negative consequences and obtain necessary oil level information. When monitoring the oil resources in the facilities, it is necessary to rely on a remote monitoring and data acquisition system to collect data according to preset values, and transmit the processed information to users when necessary, or assist in decision-making in complex situations.

[0003] However, the traditional oil level monitoring method relies on manual continuous monitoring through instruments, with extremely low measurement accuracy and difficulty in achieving automation. In addition, the traditional oil level monitoring method cannot manage the oil storage capacity of the fuel tank, resulting in low management efficiency of the fuel tank storage. Once the oil storage capacity is too low, it can only be manually refilled, which may cause oil spillage and waste, leading to excessive additional costs. Summary of the Invention

[0004] The technical problem to be solved by the embodiments of the present invention is to provide an oil level monitoring method and system based on ultrasonic waves, which can solve the problems of low accuracy of fuel tank oil level monitoring, low management efficiency, and oil resource spillage and waste in the prior art.

[0005] To solve the above technical problem, the embodiments of the present invention provide an oil level monitoring method based on ultrasonic waves. The method includes the following steps:

[0006] The ultrasonic sensor module periodically emits ultrasonic waves to the oil in a specified fuel tank and receives the echo signal reflected by the oil; wherein, the ultrasonic sensor module is installed at the inner top of the fuel tank and has a certain distance from the liquid level of the oil.

[0007] The oil level monitoring device determines the start time of the ultrasonic wave emitted by the ultrasonic sensor module in each period and the time when the echo signal reflected by the oil is first received in the same period, so as to calculate the single round-trip time of the ultrasonic wave in the fuel tank in each period, and combine the propagation speed of the ultrasonic wave compensated in the fuel tank with the ambient temperature outside the fuel tank to calculate the oil level value of the oil in each period; wherein, the oil level value is the distance between the ultrasonic sensor module and the liquid level of the oil.

[0008] Wherein, the oil level monitoring device uses the formula Calculate the oil level value H of the oil in each cycle; where,

[0009] t is the single round trip time of the ultrasonic wave acquired in the current cycle; C(T) is the propagation speed of the ultrasonic wave in the oil tank after compensation in the current cycle, and C(T)=331.4+0.6T; T is the ambient temperature outside the oil tank in the current cycle.

[0010] Wherein, the method further comprises:

[0011] The oil level monitoring device corrects the calculated oil level value of the oil in each cycle based on a preset linear regression correction model; wherein the linear regression correction model is fitted based on the least squares method.

[0012] Wherein, the method further comprises:

[0013] If the oil level monitoring device determines that the corrected oil level value within a certain cycle is greater than the first threshold value, it is determined that the oil in the oil tank is too low and needs to be replenished within the cycle, and an external oil pump is turned on to fill the oil tank with oil until the next cycle of the cycle is reached or the oil level reaches a specified overflow scale line, and the oil pump is stopped; wherein the overflow scale line is set by an oil level measuring instrument preset in the oil tank.

[0014] Wherein, the method further comprises:

[0015] If the oil level monitoring device determines that the corrected oil level value within a certain period is less than the second threshold value, it is determined that the oil in the oil tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

[0016] Wherein, the method further comprises:

[0017] Before the ultrasonic sensor module periodically transmits ultrasonic waves to the oil in the designated oil tank, the ultrasonic sensor module is calibrated to filter noise interference of the echo signal received by the ultrasonic sensor module.

[0018] The embodiment of the present invention further provides an ultrasonic-based oil level monitoring system, comprising an interconnected oil level monitoring device and an ultrasonic sensor module; wherein:

[0019] The ultrasonic sensor module is used to periodically transmit ultrasonic waves to the oil in the specified oil tank and receive the echo signal fed back by the oil; wherein the ultrasonic sensor module is installed at the top of the inner part of the oil tank and has a certain distance from the liquid surface of the oil;

[0020] The oil level monitoring device is used to determine the start time of the ultrasonic wave emission in each cycle of the ultrasonic sensor module and the time of the first receipt of the oil feedback echo signal in the same cycle, so as to calculate the single round trip time of the ultrasonic wave in the oil tank in each cycle, and calculate the oil level value of the oil in each cycle by combining the propagation speed of the ultrasonic wave in the oil tank after compensation by the ambient temperature outside the oil tank; wherein the oil level value is the distance between the ultrasonic sensor module and the liquid surface of the oil.

[0021] The ultrasonic sensor module adopts HC-SR04 sensor with an operating frequency of 40kHz, and includes a transmitter TCT40-16T and a receiver TCT40-16R.

[0022] Wherein, the oil level monitoring device is also used to correct the calculated oil level value of the oil in each cycle based on a preset linear regression correction model; wherein, the linear regression correction model is fitted based on the least squares method.

[0023] Wherein, the oil level monitoring device is further used for, if it is determined that the corrected oil level value in a certain cycle is greater than a first threshold value, then determining that the oil in the oil tank is too low in the cycle and needs to be replenished, and starting an external oil pump to fill the oil tank with oil until the next cycle of the cycle arrives or the oil level reaches a specified overflow scale line, then stopping the oil pump; wherein, the overflow scale line is set by an oil level measuring instrument preset in the oil tank;

[0024] If it is determined that the corrected oil level value within a certain period is less than the second threshold value, it is determined that the oil in the oil tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein, the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

[0025] Implementing the embodiments of the present invention has the following beneficial effects:

[0026] 1. Compared with the traditional method of continuous monitoring by manual instruments, the present invention periodically transmits ultrasonic waves to the oil in the specified oil tank through the ultrasonic sensor module and receives the echo signal fed back by the oil. The single round trip time of the ultrasonic wave in the oil tank in each cycle is determined in the oil level monitoring device, and the oil level value of the oil in each cycle is quickly calculated in combination with the compensation speed of the ultrasonic wave based on the external ambient temperature. This not only realizes the automatic oil level measurement, but also improves the measurement accuracy, thereby solving the problem of low accuracy of oil tank oil level monitoring in the prior art;

[0027] 2. The present invention monitors the oil level value of the oil in the fuel tank through an oil level monitoring device in cooperation with an ultrasonic sensor module, and controls the start and stop of the oil pump to manage the oil volume in the fuel tank when the monitored oil level value is too low or too high, thereby improving the management efficiency of the oil and solving the problem of oil resource overflow and waste in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, obtaining other drawings based on these drawings still belongs to the scope of the present invention.

[0029] Figure 1 It is a flowchart of an oil level monitoring method based on ultrasonic for an embodiment of the present invention;

[0030] Figure 2 It is a schematic structural diagram of an oil level monitoring system based on ultrasonic for an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the drawings.

[0032] As Figure 1 shown, in an embodiment of the present invention, an oil level monitoring method based on ultrasonic is provided, and the method includes the following steps:

[0033] Step S1: The ultrasonic sensor module periodically emits ultrasonic waves to the oil in the specified fuel tank and receives the echo signal feedback from the oil; wherein, the ultrasonic sensor module is installed at the inner top end of the fuel tank and has a certain distance from the liquid level of the oil.

[0034] The specific process is as follows: First, install the ultrasonic sensor module inside the fuel tank and at the top of the fuel tank, and have a certain distance from the liquid level of the oil; second, establish communication between the ultrasonic sensor module and the oil level monitoring device outside the fuel tank; then, before the ultrasonic sensor module periodically (such as once every 5 s) emits ultrasonic waves to the oil in the specified fuel tank, calibrate the ultrasonic sensor module to filter the noise interference of the echo signal received by the ultrasonic sensor module; finally, use the calibrated ultrasonic sensor module to periodically emit ultrasonic waves to the oil in the specified fuel tank and receive the echo signal feedback from the oil.

[0035] In one example, the ultrasonic sensor module uses an HC-SR04 type sensor with a working frequency of 40 kHz, and includes a transmitter TCT40-16T and a receiver TCT40-16R.

[0036] Among them, the detection angle of the transmitter TCT40-16T is a conical beam of 15°, and as the propagation distance increases, the diameter of the oil surface area covered by the beam linearly expands. The corresponding calculation formula is:

[0037]

[0038] Among them, D is the diameter of the oil surface area that the beam can cover, H is the straight-line distance from the ultrasonic sensor to the oil surface, and θ is 15°.

[0039] It should be noted that the detection angle refers to the conical diffusion of the sound wave beam emitted by the ultrasonic sensor module in space, with a cone angle vertex angle of 15° and a half angle of 7.5°.

[0040] Among them, the receiver TCT40-16R detects the reflected wave, and the obtained echo signal is amplified and filtered by a CX20106A chip with a band-pass center frequency of 40 kHz to filter out the noise and interference signals in the echo signal, thereby obtaining the echo signal.

[0041] Step S2: The oil level monitoring device determines the start time of the ultrasonic wave emitted by the ultrasonic sensor module in each cycle and the time of the first reception of the oil liquid feedback echo signal in the same cycle, so as to calculate the single round-trip time of the ultrasonic wave in the fuel tank in each cycle, and combine the ambient temperature outside the fuel tank with the compensated propagation speed of the ultrasonic wave in the fuel tank to calculate the oil level value of the oil liquid in each cycle; among them, the oil level value is the distance between the ultrasonic sensor module and the liquid level of the oil liquid.

[0042] The specific process is as follows. First, the oil level monitoring device obtains the emission cycle of the ultrasonic sensor module and the start time of the ultrasonic wave emitted in each cycle; secondly, the oil level monitoring device obtains the time of the echo signal returned each time the ultrasonic wave reaches the oil liquid in each cycle; then, the absolute value of the difference between the start time of the ultrasonic wave emitted in the same cycle and the time of the first reception of the oil liquid feedback echo signal is output as the single round-trip time of the ultrasonic wave in the fuel tank in each cycle; then, the ambient temperature T outside the fuel tank in each cycle is obtained, and according to the formula C(T)=331.4 + 0.6T, the propagation speed of the ultrasonic wave in the fuel tank in each cycle is compensated to obtain the compensated propagation speed C(T) of the ultrasonic wave in each cycle; finally, through the formula Calculate the oil level value H of the oil fluid in each cycle. It should be noted that in the formula C(T) = 331.4 + 0.6T, the ideal propagation speed of ultrasonic waves is 331.4 m / s.

[0043] In the embodiment of the present invention, considering the measurement error, a compensation algorithm is used to correct the oil level value of the oil fluid to improve the measurement accuracy. Therefore, the method further includes: the oil level monitoring device corrects the calculated oil level value of the oil fluid in each cycle based on a preset linear regression correction model; wherein, the linear regression correction model is fitted based on the least squares method.

[0044] In one example, by fitting a linear equation, the least squares method is used to compensate for the systematic error:

[0045]

[0046] where x i is the input value, y i is the output value, through the assumed linear relationship:

[0047] y i = ax i + b

[0048] The objective function therein is:

[0049] Then construct the design matrix X and the observation vector Y:

[0050]

[0051] The normal equation is:

[0052] θ = (X T X) -1 X T Y, where

[0053] Solve a and b respectively to obtain the corrected data result.

[0054]

[0055] Finally, evaluate the error through the mean square error (MSE):

[0056]

[0057] In an embodiment of the present invention, in order to realize automatic control of the oil level in the oil tank, the method further includes: if the oil level monitoring device determines that the corrected oil level value within a certain period is greater than a first threshold value (that is, the oil level is lower than the lower limit of the oil tank), it is determined that the oil in the oil tank is too low and needs to be replenished within the period, and an external oil pump (not shown) is started to fill the oil tank with oil until the next period of the period is reached or the oil level reaches a specified overflow scale line (not shown) and the oil pump is stopped; wherein, the overflow scale line is set by an oil level measuring instrument preset in the oil tank.

[0058] Alternatively, if the oil level monitoring device determines that the corrected oil level value within a certain period is less than the second threshold value (that is, the oil level is higher than the upper limit of the fuel tank), it is determined that the oil in the fuel tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

[0059] like Figure 2 As shown in the figure, an ultrasonic-based oil level monitoring system is provided in an embodiment of the present invention, comprising an interconnected oil level monitoring device 2 and an ultrasonic sensor module 1; wherein,

[0060] The ultrasonic sensor module 1 is used to periodically transmit ultrasonic waves to the oil in the specified oil tank and receive the echo signal fed back by the oil; wherein the ultrasonic sensor module 1 is installed at the top of the inner part of the oil tank and has a certain distance from the liquid surface of the oil;

[0061] The oil level monitoring device 2 is used to determine the start time of the ultrasonic wave emission in each cycle of the ultrasonic sensor module 1 and the time of first receiving the oil feedback echo signal in the same cycle, so as to calculate the single round trip time of the ultrasonic wave in the oil tank in each cycle, and calculate the oil level value of the oil in each cycle by combining the propagation speed of the ultrasonic wave in the oil tank after compensation by the ambient temperature outside the oil tank; wherein, the oil level value is the distance between the ultrasonic sensor module 1 and the liquid surface of the oil.

[0062] The ultrasonic sensor module 1 adopts a HC-SR04 sensor with an operating frequency of 40 kHz, and includes a transmitter TCT40-16T and a receiver TCT40-16R.

[0063] The oil level monitoring device 2 is also used to correct the calculated oil level value of the oil in each cycle based on a preset linear regression correction model; wherein the linear regression correction model is fitted based on the least squares method.

[0064] The oil level monitoring device 2 is further used to determine that the oil in the oil tank is too low and needs to be replenished if it is determined that the corrected oil level value in a certain cycle is greater than a first threshold value, and start an external oil pump to fill the oil tank with oil until the next cycle of the cycle arrives or the oil level reaches a specified overflow scale line, and then stop the oil pump; wherein the overflow scale line is set by an oil level measuring instrument preset in the oil tank;

[0065] If it is determined that the corrected oil level value within a certain period is less than the second threshold value, it is determined that the oil in the oil tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein, the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

[0066] Implementing the embodiments of the present invention has the following beneficial effects:

[0067] 1. Compared with the traditional method of continuous monitoring by manual instruments, the present invention periodically transmits ultrasonic waves to the oil in the specified oil tank through the ultrasonic sensor module and receives the echo signal fed back by the oil. The single round trip time of the ultrasonic wave in the oil tank in each cycle is determined in the oil level monitoring device, and the oil level value of the oil in each cycle is quickly calculated in combination with the compensation speed of the ultrasonic wave based on the external ambient temperature. This not only realizes the automatic oil level measurement, but also improves the measurement accuracy, thereby solving the problem of low accuracy of oil tank oil level monitoring in the prior art;

[0068] 2. The present invention uses an oil level monitoring device in conjunction with an ultrasonic sensor module to monitor the oil level in the oil tank, and when the oil level is detected to be too low or high, controls the start and stop of the oil pump to manage the oil capacity in the oil tank, thereby improving the oil management efficiency and solving the problem of oil resource overflow and waste in the prior art.

[0069] A person skilled in the art can understand that all or part of the steps in the above-mentioned embodiment method can be completed by instructing related hardware through a program, and the program can be stored in a computer-readable storage medium, such as ROM / RAM, disk, CD-ROM, etc.

[0070] The above disclosure is only the preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. An ultrasonic-based oil level monitoring method, characterized in that, The method comprises the following steps: The ultrasonic sensor module periodically transmits ultrasonic waves to the oil in the specified oil tank and receives the echo signal fed back by the oil; wherein the ultrasonic sensor module is installed at the top of the inner part of the oil tank and has a certain distance from the liquid surface of the oil; The oil level monitoring device determines the start time of the ultrasonic emission of the ultrasonic sensor module in each cycle and the time of the first receipt of the oil feedback echo signal in the same cycle, so as to calculate the single round trip time of the ultrasonic wave in the oil tank in each cycle, and calculates the oil level value of the oil in each cycle by combining the propagation speed of the ultrasonic wave in the oil tank after compensation by the ambient temperature outside the oil tank; wherein the oil level value is the distance between the ultrasonic sensor module and the liquid surface of the oil.

2. The ultrasonic-based oil level monitoring method according to claim 1, characterized in that, The oil level monitoring device calculates the oil level value H of the oil fluid in each period through the formula ; where t is the single round trip time of the ultrasonic wave acquired in the current cycle; C(T) is the propagation speed of the ultrasonic wave in the oil tank after compensation in the current cycle, and C(T)=331.4+0.6T; T is the ambient temperature outside the oil tank in the current cycle.

3. The ultrasonic-based oil level monitoring method according to claim 1, characterized in that The method further comprises: The oil level monitoring device corrects the calculated oil level value of the oil in each cycle based on a preset linear regression correction model; wherein the linear regression correction model is fitted based on the least squares method.

4. The ultrasonic-based oil level monitoring method according to claim 3, characterized in that The method further comprises: If the oil level monitoring device determines that the corrected oil level value within a certain cycle is greater than the first threshold value, it is determined that the oil in the oil tank is too low and needs to be replenished within the cycle, and an external oil pump is turned on to fill the oil tank with oil until the next cycle of the cycle is reached or the oil level reaches a specified overflow scale line, and the oil pump is stopped; wherein the overflow scale line is set by an oil level measuring instrument preset in the oil tank.

5. The ultrasonic-based oil level monitoring method according to claim 4, characterized in that, The method further comprises: If the oil level monitoring device determines that the corrected oil level value within a certain period is less than the second threshold value, it is determined that the oil in the oil tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

6. The ultrasonic-based oil level monitoring method according to claim 1, wherein, The method further comprises: Before the ultrasonic sensor module periodically transmits ultrasonic waves to the oil in the designated oil tank, the ultrasonic sensor module is calibrated to filter noise interference of the echo signal received by the ultrasonic sensor module.

7. An ultrasonic-based oil level monitoring system, characterized in that, The invention comprises an interconnected oil level monitoring device and an ultrasonic sensor module; wherein, The ultrasonic sensor module is used to periodically transmit ultrasonic waves to the oil in the specified oil tank and receive the echo signal fed back by the oil; wherein the ultrasonic sensor module is installed at the top of the inner part of the oil tank and has a certain distance from the liquid surface of the oil; The oil level monitoring device is used to determine the start time of the ultrasonic wave emission in each cycle of the ultrasonic sensor module and the time of the first receipt of the oil feedback echo signal in the same cycle, so as to calculate the single round trip time of the ultrasonic wave in the oil tank in each cycle, and calculate the oil level value of the oil in each cycle by combining the propagation speed of the ultrasonic wave in the oil tank after compensation by the ambient temperature outside the oil tank; wherein the oil level value is the distance between the ultrasonic sensor module and the liquid surface of the oil.

8. The ultrasonic-based oil level monitoring system according to claim 7, characterized in that, The ultrasonic sensor module adopts HC-SR04 sensor with an operating frequency of 40kHz and includes a transmitter TCT40-16T and a receiver TCT40-16R.

9. The ultrasonic-based oil level monitoring system according to claim 7, wherein The oil level monitoring device is also used to correct the calculated oil level value of the oil in each cycle based on a preset linear regression correction model; wherein the linear regression correction model is fitted based on the least squares method.

10. The ultrasonic-based oil level monitoring system according to claim 8, characterized in that, The oil level monitoring device is further used for determining that the oil in the oil tank is too low and needs to be replenished in a certain cycle if it is determined that the corrected oil level value in a certain cycle is greater than a first threshold value, and starting an external oil pump to fill the oil tank with oil until the next cycle of the cycle is reached or the oil level reaches a specified overflow scale line, and then stopping the oil pump; wherein the overflow scale line is set by an oil level measuring instrument preset in the oil tank; If it is determined that the corrected oil level value within a certain period is less than the second threshold value, it is determined that the oil in the oil tank is too high within the period, and when the oil pump is detected to be working, the oil pump is further forced to stop working; wherein, the second threshold value is less than the first threshold value, and its value is equal to the vertical distance between the ultrasonic sensor module and the overflow scale line.

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