CN109470338B - Urea tank liquid level calibration method and device - Google Patents
Urea tank liquid level calibration method and device Download PDFInfo
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- CN109470338B CN109470338B CN201811628366.8A CN201811628366A CN109470338B CN 109470338 B CN109470338 B CN 109470338B CN 201811628366 A CN201811628366 A CN 201811628366A CN 109470338 B CN109470338 B CN 109470338B
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Abstract
The invention provides a urea tank liquid level calibration method and a device, which are applied to the technical field of automobiles. The method of the application combines the specific conditions of the liquid level sensor to determine the corresponding relation between the output voltage of the liquid level sensor and the liquid level proportion of the urea tank, can avoid the problems caused by the individual difference of the liquid level sensor, and effectively improves the accuracy of determining the liquid level proportion of the urea tank.
Description
Technical Field
The invention belongs to the technical field of automobiles, and particularly relates to a urea tank liquid level calibration method and device.
Background
Vehicles using diesel engines are mostly provided with a urea tank, and urea solution for treating tail gas is contained in the tank. In order to ensure the effect of tail gas treatment, the liquid level of the urea tank needs to be accurately known, and alarm information is sent out when the liquid level of the urea tank is lower than a preset limit value so as to remind a driver of timely replenishing the urea solution.
In the prior art, all be provided with level sensor in the urea case, the driving computer can obtain the magnitude of voltage from level sensor's output collection, and simultaneously, the inside corresponding relation of magnitude of voltage and liquid level proportion of demarcating in advance of driving computer, the magnitude of voltage that the driving computer obtained according to concrete collection can confirm the liquid level of urea case.
However, due to the consistency of the liquid level sensors, even if the liquid level sensors of the same type are used for the liquid level of the same urea tank, the output voltage value may have deviation, so that the urea liquid level determined by a traveling crane computer according to the corresponding relation between the pre-calibrated voltage value and the liquid level proportion is inaccurate, and the normal use is influenced.
Disclosure of Invention
In view of this, the present invention aims to provide a urea tank liquid level calibration method and apparatus, which improve the accuracy of determining the urea tank liquid level ratio according to the voltage value of a liquid level sensor, and the specific scheme is as follows:
in a first aspect, the invention provides a urea tank liquid level calibration method, which comprises the following steps:
monitoring the voltage value of the liquid level sensor;
when the voltage value of the liquid level sensor is reduced to be less than or equal to a preset voltage threshold value from being greater than the preset voltage threshold value, acquiring the voltage value of the liquid level sensor, and starting timing;
if the voltage value of the liquid level sensor is changed to the next voltage value before the timing duration reaches the preset time threshold, returning to execute the voltage value of the liquid level sensor;
and if the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor is not monitored to change to the next voltage value, respectively determining the obtained liquid level proportion corresponding to the voltage value of each liquid level sensor, and completing calibration.
Optionally, the respectively determining the obtained liquid level ratio corresponding to the voltage value of each liquid level sensor includes:
if the number of the obtained voltage values of the liquid level sensors is smaller than or equal to a preset number, respectively determining the liquid level proportion corresponding to the obtained voltage values of the liquid level sensors as a corresponding preset liquid level proportion;
if the obtained number of the voltage values of the liquid level sensors is larger than the preset number, screening the voltage values of the liquid level sensors with the preset number according to a first preset rule;
determining a liquid level proportion base number representing a liquid level proportion change gradient;
and respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to the liquid level proportion base number and a second preset rule.
Optionally, the first preset rule is:
the voltage values of the liquid level sensors obtained by screening are sequentially increased, the difference value of the voltage values of the two adjacent liquid level sensors is gradually reduced,
or the like, or, alternatively,
the voltage values of the liquid level sensors obtained through screening are sequentially decreased progressively, and the difference value of the voltage values of two adjacent liquid level sensors is gradually increased.
Optionally, the second preset rule is:
the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained through screening is a multiple of the base number of the liquid level proportion, and the variation trend of the difference value of the two adjacent liquid level proportions is consistent with the variation trend of the difference value of the voltage values of the two adjacent liquid level sensors in the first preset rule.
Optionally, the urea tank liquid level calibration method provided by the first aspect of the present invention further includes:
after calibration is completed, if the monitored voltage value of the liquid level sensor is smaller than the currently acquired voltage value of any one liquid level sensor, the step of acquiring the voltage value of the liquid level sensor is returned to.
Optionally, the urea tank liquid level calibration method provided by the first aspect of the present invention further includes:
and if the monitored voltage value of the liquid level sensor is larger than a preset voltage threshold value, sending first alarm information.
Optionally, the urea tank liquid level calibration method provided by the first aspect of the present invention further includes:
and after the calibration is finished, if the voltage value of the liquid level sensor corresponding to the specified liquid level proportion is monitored, sending second alarm information.
In a second aspect, the present invention provides a urea tank liquid level calibration apparatus, including:
the monitoring unit is used for monitoring the voltage value of the liquid level sensor;
the acquisition unit is used for acquiring the voltage value of the liquid level sensor and starting timing when the voltage value of the liquid level sensor is reduced from being larger than a preset voltage threshold to being smaller than or equal to the preset voltage threshold;
the first circulation unit is used for triggering the acquisition unit to acquire the voltage value of the liquid level sensor if the voltage value of the liquid level sensor changes to the next voltage value before the timing duration reaches the preset time threshold;
and the determining unit is used for respectively determining the obtained liquid level proportion corresponding to the voltage value of each liquid level sensor if the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor is not monitored to change to the next voltage value, so as to finish calibration.
Optionally, the determining unit, when determining the liquid level ratio corresponding to the obtained voltage value of each liquid level sensor, specifically includes:
if the number of the obtained voltage values of the liquid level sensors is smaller than or equal to a preset number, respectively determining the liquid level proportion corresponding to the obtained voltage values of the liquid level sensors as a corresponding preset liquid level proportion;
if the obtained number of the voltage values of the liquid level sensors is larger than the preset number, screening the voltage values of the liquid level sensors with the preset number according to a first preset rule;
determining a liquid level proportion base number representing a liquid level proportion change gradient;
and respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to the liquid level proportion base number and a second preset rule.
Optionally, the urea tank liquid level calibration apparatus provided by the second aspect of the present invention further includes:
and the second circulating unit is used for triggering the acquiring unit to acquire the voltage value of the liquid level sensor if the monitored voltage value of the liquid level sensor is smaller than the currently acquired voltage value of any one liquid level sensor after calibration is finished.
Based on the technical scheme, the urea tank liquid level calibration method and the device provided by the invention monitor the voltage value of the liquid level sensor, indicate that the urea tank is connected when the voltage value of the liquid level sensor is reduced to be less than or equal to the preset voltage threshold from being greater than the preset voltage threshold, prepare to add urea solution, acquire the voltage value of the liquid level sensor, start timing at the same time, if the timing duration reaches the preset time threshold, monitor that the voltage value of the liquid level sensor changes to the next voltage value, acquire the changed voltage value, restart timing, and cycle until the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor does not change to the next voltage value, indicate that the urea solution is filled, and then determine the liquid level proportion corresponding to the voltage value of each liquid level sensor, and completing calibration. According to the urea tank liquid level calibration method provided by the invention, after the urea tank is connected, the corresponding relation between the output voltage of the liquid level sensor and the urea tank liquid level ratio is determined by combining the specific conditions of the liquid level sensor.
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 introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic diagram of a liquid level sensor in an embodiment of the invention;
FIG. 2 is a schematic diagram of the level detection of the level sensor in an embodiment of the present invention;
FIG. 3 is a flow chart of a urea tank liquid level calibration method provided by an embodiment of the invention;
FIG. 4 is a block diagram of a urea tank liquid level calibration apparatus according to an embodiment of the present invention;
FIG. 5 is a block diagram of another urea tank level calibration apparatus according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1, fig. 1 is a schematic structural diagram of a liquid level sensor in an embodiment of the invention, the liquid level sensor arranged in a urea tank is provided with a floating block, the floating block is gradually raised under the action of buoyancy along with the gradual increase of urea solution in the urea tank, and the position of the floating block is consistent with the liquid level of the urea solution at any time. Further, referring to fig. 2, fig. 2 is a schematic diagram of liquid level detection of a liquid level sensor in the embodiment of the present invention, in the embodiment shown in fig. 2, PINs 1 and PIN2 are output ports of the liquid level sensor, and an ECU (Electronic control unit) is connected to PINs 1 and PIN2 to obtain a voltage value of the liquid level sensor. At the same time, the position of the float of the level sensor changes, causing the state of the switches RS1 to RSx in the schematic diagram shown in fig. 2 to change. Specifically, when no urea solution exists in the urea tank and the floating block is at the lowest position, all the switches are in an open state, the voltage value between PIN1 and PIN2 measured by the ECU is the largest, correspondingly, as the urea solution increases, the floating block rises to drive the corresponding switches to be closed (the closing sequence is: RSx is closed first, RS1 is closed last, and x represents the number of the switches), and it is conceivable that each time one switch is closed, the corresponding resistor (one of R1-Rx, and x represents the number of the resistors corresponding to the switches) is short-circuited, so that the voltage measured by the ECU is gradually reduced. Therefore, as can be seen from the contents of fig. 1 and 2, the lower the position of the float, the higher the resistance value of the entire level sensor, and the higher the corresponding voltage measured by the ECU. The greater the number of switches and corresponding resistor settings, the more accurate the level height change of the reaction.
Based on the above premise, referring to fig. 3, fig. 3 is a flowchart of a urea tank liquid level calibration method provided by an embodiment of the present invention, where the flowchart may include:
and S100, monitoring the voltage value of the liquid level sensor.
In the existing production line of the whole vehicle, after the engine is installed on the whole vehicle, the ECU can obtain a corresponding working power supply, so that the urea tank liquid level calibration method provided by the embodiment of the invention starts to monitor the voltage value of the liquid level sensor after the ECU is connected with the corresponding power supply.
It should be noted that, in order to avoid that a driver or other personnel fills the urea solution into the urea tank when the vehicle is not started or a key of the vehicle is not inserted (at this time, a circuit system of the vehicle is not powered on and does not work formally), according to the method provided by the embodiment of the present invention, the ECU can still obtain the voltage value of the liquid level sensor under the aforementioned conditions, and further execute the subsequent steps to complete the calibration of the liquid level of the urea tank.
Step S110, determining whether the voltage value of the liquid level sensor is decreased from being greater than the preset voltage threshold to being less than or equal to the preset voltage threshold, if so, executing step S120, otherwise, returning to execute step S100.
Under the condition that the urea tank is not installed and the liquid level sensor is not connected with the ECU, the voltage value of the liquid level sensor measured by the ECU is larger than a preset voltage threshold value. Therefore, if the voltage value of the liquid level sensor is greater than the preset voltage threshold value, it can be determined that the liquid level sensor is not connected with the ECU, for example, a new urea tank is not installed, or the connection between the liquid level sensor and the ECU is broken, or a driver is replacing the urea tank and the liquid level sensor.
Correspondingly, if the voltage value of the liquid level sensor is monitored to be smaller than or equal to the preset voltage threshold value, the liquid level sensor is proved to be stably connected with the ECU.
Therefore, based on the above, a determination condition for determining whether the calibration process needs to be started in the embodiment of the present application can be obtained, that is, when it is monitored that the voltage value of the liquid level sensor is decreased from being greater than the preset voltage threshold to being less than or equal to the preset voltage threshold, the calibration process can be started, and step S120 is executed. The determination condition can cover the situation that the urea tank needs to be calibrated in the use process of the urea tank, such as the situation that the urea tank is installed for the first time before a new vehicle is off-line, and the liquid level sensor is connected with the ECU for the first time; and the situation that the urea tank and the liquid level sensor are replaced in the use process of the vehicle, and the like.
Optionally, based on the schematic structural diagram of the urea tank liquid level sensor and the voltage measurement principle, the preset voltage threshold may be a voltage value of the liquid level sensor that can be monitored when the urea tank is empty. Namely, after the liquid level sensor of the urea box is connected with the ECU, the ECU can monitor the maximum voltage value.
And step S120, acquiring a voltage value of the liquid level sensor and starting timing.
When the voltage value of the liquid level sensor is monitored to be reduced from being larger than the preset voltage threshold value to being smaller than or equal to the preset voltage threshold value, the voltage value of the liquid level sensor can be obtained, and timing is started at the same time.
It is conceivable that the voltage value obtained at this time is the voltage value corresponding to the urea tank being empty, i.e. the liquid level ratio being 0%.
Step S130, determining whether the voltage value of the liquid level sensor changes to the next voltage value before the time length reaches the preset time threshold, if yes, returning to step S120, and if not, executing step S140.
In general, after the urea tank is installed, that is, after the liquid level sensor is connected with the ECU, the urea solution filling process is started, and the urea solution filling process is usually performed continuously, so that the floating block of the liquid level sensor gradually rises with the increase of the urea solution, and accordingly, the ECU can monitor a plurality of different voltage values.
However, in practice, it is unpredictable whether the urea tank is filled all at once. For example, in a whole vehicle plant, when a urea solution is filled into a new vehicle, the urea tank is often not filled; for example, after the driver replaces the urea tank, the urea tank may be filled up at one time, so that the ECU may obtain all the corresponding voltage values, and the driver may also only fill a part of the urea tank, and in such a case, the ECU may obtain only a part of the voltage values.
Therefore, timing is performed after each different voltage value is acquired, and if the voltage value of the liquid level sensor changes to the next voltage value before the timing duration reaches the preset time threshold, the step S120 is executed again to acquire the changed voltage value, and timing is restarted at the same time; if the timing duration reaches the preset time threshold value, but the voltage value of the liquid level sensor is not monitored to change to the next voltage value, the urea solution filling process is judged to be finished, and the subsequent steps can be started.
And S140, respectively determining the liquid level proportion corresponding to the obtained voltage value of each liquid level sensor, and completing calibration.
After the urea solution filling process is judged to be finished, the liquid level proportion corresponding to the obtained voltage value of each liquid level sensor needs to be determined, and then calibration is completed.
Alternatively, as known from the operating principle of the controller such as the ECU, the ECU implements the desired function by executing a series of machine codes pre-stored in the ECU, and corresponding data parameters are necessarily involved in the process of executing the corresponding codes. Therefore, in order to implement the urea tank liquid level calibration method provided by the embodiment of the application, the obtained voltage values of the liquid level sensors need to be stored. For this purpose, in the present embodiment, a corresponding storage space is provided in the memory for storing a preset number of voltage values and liquid level ratios corresponding to the respective voltage values.
The storage space for storing the voltage values of the respective level sensors and the level ratios corresponding to the voltage values is not the same storage space as the storage space for storing all the acquired voltage values of the level sensors. The setting position of the storage space is not limited in the embodiment of the application.
It should be further noted that the number of storage spaces for storing the voltage values of the respective level sensors and the level ratios corresponding to the voltage values is limited, i.e. at most a preset number of voltage values and level ratios of the urea tank corresponding to the respective voltage values can be stored in the storage spaces. The storage space for storing the acquired voltage values of all the liquid level sensors does not limit the number of the liquid level sensors, so that the requirements of different liquid level sensors are met, and the voltage values output by the liquid level sensors are stored as comprehensively as possible.
Based on the above premises, in the process of respectively determining the liquid level proportion corresponding to the voltage values of the obtained liquid level sensors, two situations can be divided:
in the first case: the number of the obtained voltage values of the liquid level sensor is less than or equal to the preset number.
In this case, the storage space for storing the voltage values of the respective liquid level sensors and the liquid level ratios corresponding to the voltage values cannot be used completely or just used completely, and at this time, the liquid level ratios corresponding to the respective liquid level sensors are determined to correspond to the preset ratios.
For example, the preset number is 11, that is, a storage space for storing the voltage values of the 11 liquid level sensors and the liquid level ratios corresponding to the voltage values is preset in the memory, and the storage form may be as shown in table 1.
TABLE 1
| U0 | U1 | U2 | U3 | U4 | U5 | U6 | U7 | U8 | U9 | U10 |
| R0％ | R1％ | R2％ | R3％ | R4％ | R5％ | R6％ | R7％ | R8％ | R9％ | R10％ |
As shown in Table 1, U0-U10 are used for storing the voltage values of the liquid level sensor, and R0-R10% are used for storing the liquid level ratios corresponding to the voltage values.
If the obtained voltage values of the liquid level sensors are less than 11, for example, 5 voltage values are obtained and are respectively represented by U0 ', U1', U2 ', U3' and U4 ', and U0' > U1 '> U2' > U3 '> U4', the liquid level ratio corresponding to the obtained 5 voltage values is determined as the preset liquid level ratio, specifically, see table 2.
TABLE 2
| U0’ | U1’ | U2’ | U3’ | U4’ | U5 | U6 | U7 | U8 | U9 | U10 |
| 0％ | 10％ | 20％ | 30％ | 40％ | R5％ | R6％ | R7％ | R8％ | R9％ | R10％ |
It should be noted that, in table 2, the voltage values corresponding to U5 to U10 are all null values, and correspondingly, R5% to R10% are also null values, and of course, R5% to R10% may also be given specific preset liquid level ratios, and only the corresponding voltage values are processed as null values.
In the second case: the number of the obtained voltage values of the liquid level sensor is more than the preset number,
under the condition, the voltage values of the liquid level sensors in the preset number need to be obtained through screening according to a first preset rule, a liquid level proportion base number representing the liquid level proportion change gradient is further determined, and after the liquid level proportion base number is obtained, the liquid level proportions corresponding to the voltage values of the liquid level sensors obtained through screening are respectively determined according to a second preset rule.
Wherein, the first preset rule is as follows:
if the voltage values of the liquid level sensors obtained by screening are sorted from small to large, the voltage values obtained by screening are sequentially increased, and the difference value of two adjacent voltage values shows a gradually reduced variation trend;
correspondingly, if the voltage values of the liquid level sensors obtained by screening are sorted from large to small, the voltage values obtained by screening are sequentially decreased, and the difference value of two adjacent voltage values shows a gradually increasing change trend.
The second predetermined rule is:
the liquid level proportion corresponding to the voltage values of the liquid level sensors obtained through screening is a multiple of the base number of the liquid level proportion, and the variation trend of the difference value of the two adjacent liquid level proportions is consistent with the variation trend of the difference value of the voltage values of the liquid level sensors obtained through screening, namely if the difference value of the voltage values shows a gradually-decreasing variation trend, correspondingly, the difference value of the liquid level proportion also shows a gradually-decreasing variation trend; if the difference of the voltage values shows a gradually increasing trend, correspondingly, the difference of the liquid level proportion also shows a gradually increasing trend.
In the second case, how to determine the liquid level ratio corresponding to the voltage value of each liquid level sensor will be described with reference to the specific examples shown in tables 1 and 2.
Taking the obtained voltage values of the 15 liquid level sensors as an example, a method for determining the liquid level proportion corresponding to the voltage value of each liquid level sensor, which meets the first preset rule and the second preset rule, is provided.
It is conceivable that, no matter how the aforementioned preset number is specifically set, and the actually obtained specific number of voltage values of the liquid level sensor, in the preset storage space (from the first bit of the storage space to the last bit of the storage space, the stored voltage values are sequentially reduced, and this storage manner is taken as an example), the voltage value of the first bit is determined, that is, the obtained maximum voltage value is obtained, and accordingly, the liquid level ratio corresponding to the maximum voltage value is also determined, that is, 0%; in addition, the voltage value of the last bit of the preset storage space is determined, that is, the obtained minimum voltage value is obtained, and correspondingly, the liquid level ratio corresponding to the minimum voltage value is also determined, that is, 100%. Thus, in the second case, the contents of the first and last bits can be determined directly.
After removing the first and last voltage values and the corresponding liquid level ratios, the subsequent screening process is as follows:
m is (N-2)/9, where N is the total number of voltage values obtained for the level sensor, in this example 15, N-2 is the number of remaining unscreened voltage values, and 9 is the number of remaining storage spaces, and the voltage values are selected in descending order.
If 1< M <2, screening the rest voltage values one by one in sequence, and calculating the M value after each screening until M <3 is more than or equal to 2;
if M is more than or equal to 2 and less than 3, screening the rest voltage values in sequence every other voltage value, and calculating the M value after each screening until M is more than or equal to 3 and less than 4;
and if M is more than or equal to 3 and less than 4, sequentially screening the rest voltage values every two voltage values, and so on until all the obtained voltage values of the liquid level sensor are screened, so as to obtain the preset number of voltage values.
Specifically, N is 15, and 13 voltage values remain after the first bit and the last bit are determined. 13/9 is equal to 1.44, then the subsequent voltage values are filled in sequence one by one;
after filling 4, 13-4-8 voltage values remain, 9-5-4 voltage values remain, and 8/4-2 voltage values subsequently fill every other 1 voltage value into the subsequent storage space.
After screening a preset number of voltage values of the liquid level sensors, a liquid level proportion base number which represents a liquid level proportion change gradient needs to be further determined. Specifically, the liquid level ratio base may be expressed as:
100%/(N-1), where N is the number of voltage values obtained for the level sensor.
In this example, the base of the liquid level proportion is 7.14%.
And after the liquid level proportion base number is obtained, respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to a second preset rule.
As mentioned above, the specific value of each liquid level ratio should be a multiple of the base number of the liquid level ratio, and has the same variation trend with the screened voltage value.
In the above embodiment, after the calculation in the foregoing steps, the finally obtained corresponding relationship may be as shown in table 3.
TABLE 3
| U0’ | U1’ | U2’ | U3’ | U4’ | U5’ | U7’ | U9’ | U11’ | U13’ | U14’ |
| 0％ | 7.14％ | 14.28％ | 21.42％ | 28.56％ | 35.7％ | 49.98％ | 64.26％ | 78.54％ | 92.82％ | 100％ |
The corresponding relation between the voltage values of the liquid level sensors and the liquid level proportion obtained through the processing in the steps enables the urea tank to have high sensitivity and accuracy under the condition that the liquid level of the urea tank is low, the voltage values are selected densely, the change of the liquid level of the urea tank can be expressed more accurately, and when the liquid level of the urea tank is high, the high sensitivity is not needed to be provided, and therefore the voltage values are selected sparsely.
Optionally, after the liquid level proportion corresponding to the voltage value of each liquid level sensor shown in table 3 is obtained, the corresponding relation between the voltage value of each liquid level sensor and the liquid level proportion may be stored according to a certain preset format, so as to facilitate subsequent use.
In summary, according to the urea tank liquid level calibration method provided by the application of the invention, after the urea tank is connected, the corresponding relation between the output voltage of the liquid level sensor and the urea tank liquid level ratio is determined by combining the specific conditions of the liquid level sensor.
Optionally, as described above, the specific urea solution filling process is uncontrollable, and it is possible that after a calibration process is completed, the urea tank is not filled with the urea solution, since the ECU continuously monitors the voltage of the liquid level sensor, after the calibration is completed, if the voltage value of the liquid level sensor monitored by the ECU is smaller than the voltage value of any one of the liquid level sensors currently obtained, that is, more urea solution is filled in the urea tank than the last calibration time, and the floating block of the liquid level sensor rises to a higher position, it is necessary to continuously obtain the voltage value of the liquid level sensor based on the existing data, and determine the liquid level ratio corresponding to each voltage value again.
Optionally, after the ECU starts to monitor the voltage of the liquid level sensor, if the voltage value of the liquid level sensor is monitored to be greater than the preset voltage threshold, which indicates that the urea tank is not correctly installed, the ECU may send first alarm information to notify a driver or other personnel of repairing a corresponding fault.
Optionally, after the calibration is completed, if the ECU monitors the voltage value of the liquid level sensor corresponding to the specified liquid level ratio, second alarm information is sent. For example, in the actual use process of the vehicle, in order to avoid the urea solution in the urea tank from being consumed, a liquid level ratio may be pre-specified, the specified liquid level ratio is as well as the first-level and last-level liquid level ratios in the calibration process, which are all preset and unchangeable, and the work required in the calibration process is to determine the voltage value corresponding to the specified liquid level ratio. After calibration is completed, if the ECU monitors a corresponding voltage value, and then the urea tank is judged to be in the specified liquid level proportion at present, second alarm information is sent.
Taking the content shown in table 3 as an example, the regulation specifies that when the liquid level of the urea tank is lower than 5%, a second alarm message needs to be sent, and according to the calculation, the voltage value corresponding to 5% cannot be monitored, so that the liquid level ratio corresponding to the second position can be designated as 5%, and in the calibration process, the voltage value corresponding to the designated liquid level ratio is determined to be U1'. Further, to improve the sensitivity of the alarm function, the specified level ratio may also be set to a value less than 5%, which is optional.
The urea tank liquid level calibration device provided by the embodiment of the invention is introduced below, and the urea tank liquid level calibration device described below can be regarded as a functional module framework which needs to be arranged in central equipment for realizing the urea tank liquid level calibration method provided by the embodiment of the invention; the following description may be cross-referenced with the above.
Fig. 4 is a structural block diagram of a urea tank liquid level calibration device provided in an embodiment of the present invention, and referring to fig. 4, the device may include:
the monitoring unit 10 is used for monitoring the voltage value of the liquid level sensor;
the acquiring unit 20 is configured to acquire the voltage value of the liquid level sensor and start timing when the voltage value of the liquid level sensor is reduced from being greater than a preset voltage threshold to being less than or equal to the preset voltage threshold;
the first circulation unit 30 is configured to trigger the obtaining unit to obtain the voltage value of the liquid level sensor if the voltage value of the liquid level sensor changes to a next voltage value before the timing duration reaches a preset time threshold;
and the determining unit 40 is configured to determine, if the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor is not monitored to change to a next voltage value, a liquid level ratio corresponding to the obtained voltage value of each liquid level sensor, and complete calibration.
Optionally, the determining unit 40 is configured to, when determining the obtained liquid level ratio corresponding to the voltage value of each liquid level sensor, specifically include:
if the number of the obtained voltage values of the liquid level sensors is smaller than or equal to a preset number, respectively determining the liquid level proportion corresponding to the obtained voltage values of the liquid level sensors as a corresponding preset liquid level proportion;
if the obtained number of the voltage values of the liquid level sensors is larger than the preset number, screening the voltage values of the liquid level sensors with the preset number according to a first preset rule;
determining a liquid level proportion base number representing a liquid level proportion change gradient;
and respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to the liquid level proportion base number and a second preset rule.
Optionally, referring to fig. 5, fig. 5 is a block diagram of another urea tank liquid level calibration apparatus provided in the embodiment of the present invention, where the apparatus may further include, on the basis of the embodiment shown in fig. 4:
and the second circulating unit 50 is configured to trigger the obtaining unit 20 to obtain the voltage value of the liquid level sensor if the monitored voltage value of the liquid level sensor is smaller than the currently obtained voltage value of any one of the liquid level sensors after the calibration is completed.
Those of skill would further appreciate that the various illustrative elements 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 directly in hardware, in a software module executed by a processor, or in 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 previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (6)
1. A urea tank liquid level calibration method is characterized by comprising the following steps:
monitoring the voltage value of the liquid level sensor;
when the voltage value of the liquid level sensor is reduced to be less than or equal to a preset voltage threshold value from being greater than the preset voltage threshold value, acquiring the voltage value of the liquid level sensor, and starting timing;
if the voltage value of the liquid level sensor is changed to the next voltage value before the timing duration reaches the preset time threshold, returning to execute the voltage value of the liquid level sensor;
if the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor is not monitored to change to the next voltage value, if the number of the obtained voltage values of the liquid level sensor is less than or equal to the preset number, respectively determining the liquid level proportion corresponding to the obtained voltage value of each liquid level sensor as the corresponding preset liquid level proportion;
if the obtained number of the voltage values of the liquid level sensors is larger than the preset number, screening the voltage values of the liquid level sensors with the preset number according to a first preset rule;
determining a liquid level proportion base number representing a liquid level proportion change gradient;
respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to the liquid level proportion base number and a second preset rule, and completing calibration;
wherein the first preset rule is as follows:
the voltage values of the liquid level sensors obtained by screening are sequentially increased, the difference value of the voltage values of the two adjacent liquid level sensors is gradually reduced,
or the like, or, alternatively,
the voltage values of the liquid level sensors obtained through screening are sequentially decreased, and the difference value of the voltage values of two adjacent liquid level sensors is gradually increased;
the second preset rule is as follows:
the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained through screening is a multiple of the base number of the liquid level proportion, and the variation trend of the difference value of the two adjacent liquid level proportions is consistent with the variation trend of the difference value of the voltage values of the two adjacent liquid level sensors in the first preset rule.
2. The method of urea tank level calibration according to claim 1, further comprising:
after calibration is completed, if the monitored voltage value of the liquid level sensor is smaller than the currently acquired voltage value of any one liquid level sensor, the step of acquiring the voltage value of the liquid level sensor is returned to.
3. The method of urea tank level calibration according to claim 1, further comprising:
and if the monitored voltage value of the liquid level sensor is larger than a preset voltage threshold value, sending first alarm information.
4. The method of urea tank level calibration according to claim 1, further comprising:
and after the calibration is finished, if the voltage value of the liquid level sensor corresponding to the specified liquid level proportion is monitored, sending second alarm information.
5. The utility model provides a urea case liquid level calibration device which characterized in that includes:
the monitoring unit is used for monitoring the voltage value of the liquid level sensor;
the acquisition unit is used for acquiring the voltage value of the liquid level sensor and starting timing when the voltage value of the liquid level sensor is reduced from being larger than a preset voltage threshold to being smaller than or equal to the preset voltage threshold;
the first circulation unit is used for triggering the acquisition unit to acquire the voltage value of the liquid level sensor if the voltage value of the liquid level sensor changes to the next voltage value before the timing duration reaches the preset time threshold;
the determining unit is used for respectively determining the liquid level proportion corresponding to the acquired voltage value of each liquid level sensor as a corresponding preset liquid level proportion if the timing duration reaches the preset time threshold and the voltage value of the liquid level sensor is not monitored to change to the next voltage value and if the acquired number of the voltage values of the liquid level sensor is less than or equal to the preset number;
if the obtained number of the voltage values of the liquid level sensors is larger than the preset number, screening the voltage values of the liquid level sensors with the preset number according to a first preset rule;
determining a liquid level proportion base number representing a liquid level proportion change gradient;
respectively determining the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained by screening according to the liquid level proportion base number and a second preset rule, and completing calibration;
wherein the first preset rule is as follows:
the voltage values of the liquid level sensors obtained by screening are sequentially increased, the difference value of the voltage values of the two adjacent liquid level sensors is gradually reduced,
or the like, or, alternatively,
the voltage values of the liquid level sensors obtained through screening are sequentially decreased, and the difference value of the voltage values of two adjacent liquid level sensors is gradually increased;
the second preset rule is as follows:
the liquid level proportion corresponding to the voltage value of the liquid level sensor obtained through screening is a multiple of the base number of the liquid level proportion, and the variation trend of the difference value of the two adjacent liquid level proportions is consistent with the variation trend of the difference value of the voltage values of the two adjacent liquid level sensors in the first preset rule.
6. The urea tank level calibration device of claim 5, further comprising:
and the second circulating unit is used for triggering the acquiring unit to acquire the voltage value of the liquid level sensor if the monitored voltage value of the liquid level sensor is smaller than the currently acquired voltage value of any one liquid level sensor after calibration is finished.
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| CN110455376B (en) * | 2019-07-15 | 2021-07-06 | 广东省计量科学研究院（华南国家计量测试中心） | Vehicle urea filling machine calibrating device and implementation method thereof |
| CN112729490A (en) * | 2021-01-13 | 2021-04-30 | 上海星融汽车科技有限公司 | Vehicle urea tank liquid level calibration method and system and vehicle ECU |
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| CN104729620A (en) * | 2013-12-19 | 2015-06-24 | 西安兴仪科技股份有限公司 | Liquid level measuring instrument with alarming function |
| CN103727991B (en) * | 2014-01-17 | 2016-08-17 | 北京航空航天大学 | Vehicle fuel tank fuel quantity calibration system and scaling method |
| CN104330135B (en) * | 2014-10-23 | 2017-09-29 | 北京遥测技术研究所 | A kind of continuous liquid level analog simulation method |
| CN107975409B (en) * | 2017-12-25 | 2020-08-21 | 潍柴动力股份有限公司 | Urea tank liquid level display method and device |
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