Liquid level detection system, liquid level detection method and vehicle controller

Abstract

The invention provides a liquid level detection system, a liquid level detection method and a vehicle controller. The system comprises a liquid level sensor, a sensor power supply circuit, a liquid level signal acquisition circuit and a control module, the control module is configured to output an opening signal to the sensor power supply circuit when a liquid level detection scene requirement exists so as to control the liquid level sensor to be in a power-on state; when the liquid level detection scene requirement does not exist, a turn-off signal is output to the sensor power supply circuit so as to control the liquid level sensor to be in a power-off state; the liquid level signal acquisition circuit is configured to acquire voltage data of the input end of the liquid level sensor when the liquid level sensor is in a power-on state; the control module is configured to obtain the liquid level state information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor. Power supply and signal acquisition of the liquid level sensor can be carried out only under the situation that liquid level detection needs exist, and therefore liquid level misjudgment caused by long-term power-on of the liquid level sensor can be prevented.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to a liquid level detection system, a liquid level detection method and a vehicle controller. Background Art

[0002] Windshield wiper and washing is a basic vehicle body function that ensures clear vision and driving safety. It uses a pump motor to spray the washing liquid in the washing liquid tank through a pipe onto the front ( / rear) windshield of the car. When the washing liquid level in the washing liquid tank is too low, this function will fail. Users cannot directly sense the liquid level status. A liquid level sensor can be installed in the washing liquid tank to collect voltage signals related to the washing liquid level status (normal / liquid shortage) and send them to the vehicle controller (ECU). The vehicle controller then determines the liquid level status of the washing liquid based on the voltage signal and issues an alarm reminder when there is a lack of liquid, so that users can replenish the washing liquid in time to avoid failure of the windshield wiper and washing function.

[0003] There is a simple, low-cost liquid level sensor that uses the conductivity of the solution. Its working principle is as follows Figure 1 As shown in the figure, it is a working principle diagram of a liquid level sensor. In simple terms, two detection rods A and B are inserted at the bottom of the washing liquid tank, connected to the power supply and ground respectively. When there is washing liquid, it can be equivalent to an equivalent resistor (R_liquid) and an external resistor (R_pup) in series to form a closed circuit. When there is no washing liquid, R_liquid is close to infinity, and the circuit is equivalent to an open circuit. The voltage at point A is different in these two cases. By collecting the voltage V_detect at point A, the liquid level status can be judged according to the voltage range of V_detect - whether there is washing liquid or not.

[0004] When this sensor is working, the entire washer fluid tank is equivalent to an electrolytic cell, and the two detection rods A and B of the sensor are equivalent to the cathode and anode respectively. Electrolytic deposition reaction and electrolytic corrosion reaction will occur at the two poles (i.e., the two detection rods A and B). Therefore, after working for a long time, the detection rods A and B will undergo significant changes in morphology and resistance due to corrosion or metal deposition, which may lead to collection voltage deviation and liquid level misjudgment in severe cases; and the washing liquid may also change its composition due to the electrolytic reaction, resulting in a poor washing effect. In addition, the wiper washing liquid is consumed slowly, so there is no need for real-time detection. If the sensor is powered on for a long time, it will also increase the power consumption of the entire vehicle and waste energy.

[0005] It should be noted that the information disclosed in the background technology section of the invention is only intended to deepen the understanding of the general background technology of the invention, and should not be regarded as an admission or suggestion in any form that the information constitutes prior art already known to those skilled in the art. Summary of the invention

[0006] The object of the present invention is to provide a liquid level detection system, a liquid level detection method and a vehicle controller, which can power the liquid level sensor and collect signals only when there is a need for liquid level detection, thereby preventing misjudgment of the liquid level due to long-term power supply of the liquid level sensor.

[0007] To achieve the above object, the present invention provides a liquid level detection system, the liquid level detection system comprises a liquid level sensor, a sensor power supply circuit, a liquid level signal acquisition circuit and a control module, the input end of the sensor power supply circuit is connected to the control module, the input end of the liquid level signal acquisition circuit is connected to the output end of the sensor power supply circuit, the output end of the liquid level signal acquisition circuit is connected to the control module, and the input end of the liquid level sensor is connected to the liquid level signal acquisition circuit;

[0008] The liquid level sensor includes two detection rods and is configured to be placed in a liquid storage tank to be detected;

[0009] The control module is configured to output an on signal to the sensor power supply circuit when there is a liquid level detection scenario requirement, so as to control the sensor power supply circuit to be in a conducting state, thereby controlling the liquid level sensor to be in a powered-on state; and to output an off signal to the sensor power supply circuit when there is no liquid level detection scenario requirement, so as to control the sensor power supply circuit to be in a disconnected state, thereby controlling the liquid level sensor to be in a powered-off state;

[0010] The liquid level signal acquisition circuit is configured to collect voltage data of the input end of the liquid level sensor and transmit the data to the control module when the liquid level sensor is in a powered-on state;

[0011] The control module is configured to obtain the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor.

[0012] Optionally, the sensor power supply circuit includes a conversion circuit and a switching circuit, the input end of the conversion circuit is configured to connect to a power supply, the output end of the conversion circuit is connected to the switching circuit, the input end of the switching circuit is connected to the control module, the output end of the switching circuit is connected to the input end of the liquid level sensor, the conversion circuit is configured to regulate and stabilize the power supply, and the switching circuit is configured to be in an on state or an off state under the control of an on / off signal output by the control module, thereby controlling the liquid level sensor to be in a powered-on state or a powered-off state.

[0013] Optionally, the switching circuit includes a first transistor, a second transistor, a first resistor, a second resistor and a first capacitor, the emitter of the first transistor and the first end of the first resistor are both connected to the output end of the conversion circuit, the base of the first transistor is connected to the second end of the first resistor, and the collector of the first transistor is connected to the input end of the liquid level sensor; the first end of the second resistor is connected to the second end of the first resistor, the second end of the second resistor is connected to the collector of the second transistor, the base of the second transistor is connected to the control module, the emitter of the second transistor is grounded, the first end of the first capacitor is connected to the base of the first transistor, and the second end of the first capacitor is connected to the collector of the first transistor.

[0014] Optionally, the liquid level signal acquisition circuit includes a sampling resistor and a filtering circuit, the first end of the sampling resistor is connected to the output end of the sensor power supply circuit, the input end of the liquid level sensor and the input end of the filtering circuit are both connected to the second end of the sampling resistor, and the output end of the filtering circuit is connected to the control module.

[0015] Optionally, the filtering circuit includes a second capacitor, a third resistor and a third capacitor, the first end of the third resistor is connected to the second end of the sampling resistor and the first end of the second capacitor, the second end of the third resistor is connected to the first end of the third capacitor and the control module, and the second end of the second capacitor and the second end of the third capacitor are both grounded.

[0016] Optionally, the control module is configured to determine that the liquid level state of the liquid storage tank to be detected is liquid if the voltage value at the input end of the liquid level sensor is within the preset voltage range; if the voltage value at the input end of the liquid level sensor exceeds the preset voltage range for a duration greater than or equal to a first time threshold, then determine that the liquid level state of the liquid storage tank to be detected is liquid-deficient.

[0017] Optionally, the control module is further configured to determine whether the liquid level sensor fails based on voltage data at the input end of the liquid level sensor; or upload the liquid level status information of the liquid storage tank to be detected to the cloud.

[0018] Optionally, the liquid level detection system also includes a liquid level display module and an alarm module that are communicatively connected to the control module, the liquid level display module is configured to display the liquid level status information of the liquid storage tank to be detected, and the alarm module is configured to issue an alarm reminder when the control module determines that the liquid level status of the liquid storage tank to be detected is lack of liquid.

[0019] To achieve the above object, the present invention also provides a liquid level detection method, the liquid level detection method comprising:

[0020] Determine whether there is a need for liquid level detection scenarios;

[0021] If yes, an on signal is output to the sensor power supply circuit to control the sensor power supply circuit to be in a conducting state, thereby controlling the liquid level sensor located in the liquid storage tank to be detected to be in a powered-on state;

[0022] Controlling the liquid level signal acquisition circuit to acquire voltage data of the input end of the liquid level sensor;

[0023] The liquid level status information of the liquid storage tank to be detected is obtained according to the voltage data of the input end of the liquid level sensor.

[0024] Optionally, obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor includes:

[0025] Preprocessing the voltage data to obtain preprocessed voltage data, wherein the preprocessing includes at least one of filtering processing and invalid value processing;

[0026] The liquid level status information of the liquid storage tank to be detected is obtained according to the preprocessed voltage data.

[0027] Optionally, obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor includes:

[0028] If the duration of the voltage value at the input end of the liquid level sensor exceeding the preset voltage range is greater than or equal to the first time threshold, it is determined that the liquid level state of the liquid storage tank to be detected is lack of liquid.

[0029] Optionally, the liquid level detection method provided by the present invention further includes:

[0030] Determining whether the duration of the liquid level sensor being in the power-on state exceeds a second time threshold;

[0031] If so, an off signal is output to the sensor power supply circuit to control the sensor power supply circuit to be in an off state, thereby controlling the liquid level sensor located in the liquid storage tank to be detected to be in a power-off state.

[0032] To achieve the above object, the present invention also provides a vehicle controller, which includes a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the liquid level detection method described above is implemented.

[0033] In order to achieve the above object, the present invention also provides another vehicle controller, which includes the sensor power supply circuit, liquid level signal acquisition circuit and control module in the liquid level detection system described above.

[0034] Compared with the prior art, the liquid level detection system, liquid level detection method and vehicle controller provided by the present invention have the following beneficial effects:

[0035] The liquid level detection system provided by the present invention includes a liquid level sensor, a sensor power supply circuit, a liquid level signal acquisition circuit and a control module, wherein the input end of the sensor power supply circuit is connected to the control module, the input end of the liquid level signal acquisition circuit is connected to the output end of the sensor power supply circuit, the output end of the liquid level signal acquisition circuit is connected to the control module, and the input end of the liquid level sensor is connected to the liquid level signal acquisition circuit; the liquid level sensor includes two detection rods and is configured to be placed in a liquid storage tank to be detected; the control module is configured to output an open signal to the sensor power supply circuit when there is a liquid level detection scenario requirement. signal to control the sensor power supply circuit to be in the on state, thereby controlling the liquid level sensor to be in the powered-on state; when there is no liquid level detection scenario requirement, an off signal is output to the sensor power supply circuit to control the sensor power supply circuit to be in the off state, thereby controlling the liquid level sensor to be in the powered-off state; the liquid level signal acquisition circuit is configured to collect the voltage data of the input end of the liquid level sensor and transmit it to the control module when the liquid level sensor is in the powered-on state; the control module is configured to obtain the liquid level status information of the liquid storage tank to be detected based on the voltage data of the input end of the liquid level sensor. It can be seen that by adopting the liquid level detection system provided by the present invention, it is possible to realize the power supply and signal acquisition of the liquid level sensor only in the scenario where there is a liquid level detection requirement, thereby effectively preventing the problem of liquid level misjudgment caused by the long-term power supply of the liquid level sensor, and at the same time it can also reduce power consumption and reduce energy waste. In addition, by adopting the liquid level detection system provided by the present invention, it is also possible to prevent the problems such as shortened life cycle of the liquid level sensor and deterioration of the liquid (such as washing liquid) in the liquid storage tank caused by the long-term operation of the liquid level sensor (i.e., being powered on for a long time), thereby avoiding the safety risks and reduced user experience caused by the failure of the function corresponding to the liquid (such as the wiper washing function). In addition, the liquid level detection system provided by the present invention can also expand the application scenarios of this cheap, simple and stable liquid level sensor composed of two metal bars, which is conducive to reducing the cost of liquid level detection.

[0036] Since the liquid level detection method and vehicle controller provided by the present invention belong to the same inventive concept as the liquid level detection system provided by the present invention, the liquid level detection method and vehicle controller provided by the present invention at least have all the beneficial effects of the liquid level detection system provided by the present invention. For details, please refer to the relevant description above, so the beneficial effects of the liquid level detection method and vehicle controller provided by the present invention will not be described one by one here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a working principle diagram of a liquid level sensor;

[0038] Figure 2 A schematic diagram of the block structure of a liquid level detection system provided in one embodiment of the present invention;

[0039] Figure 3 A schematic diagram of the circuit structure of a switch circuit provided in one embodiment of the present invention;

[0040] Figure 4 A schematic flow chart of a liquid level detection method provided in one embodiment of the present invention;

[0041] Figure 5 It is a schematic diagram of the block structure of a vehicle controller in one embodiment of the present invention.

[0042] The reference numerals are as follows:

[0043] Liquid level sensor-100; Detection rods-A, B; Equivalent resistance-R_liquid;

[0044] Sensor power supply circuit-200; conversion circuit-210; switch circuit-220; first transistor-Q1; second transistor-Q2; first resistor-R1; second resistor-R2; first capacitor-C1; power supply-VCC;

[0045] Liquid level signal acquisition circuit-300; sampling resistor-R_pup; filter circuit-310; second capacitor-C2; third resistor-R3; third capacitor-C3;

[0046] Control module-400;

[0047] Liquid level display module-500;

[0048] Alarm module-600;

[0049] Processor-710; communication interface-720; memory-730; communication bus-740. DETAILED DESCRIPTION

[0050] The following is a further detailed description of the liquid level detection system, liquid level detection method and vehicle controller proposed in the present invention in combination with the accompanying drawings and specific embodiments. According to the following description, the advantages and features of the present invention will be clearer. It should be noted that the drawings are in a very simplified form and use non-precise proportions, which are only used to conveniently and clearly assist in explaining the purpose provided by the present invention. In order to make the purposes, features and advantages of the present invention more obvious and easy to understand, please refer to the accompanying drawings. It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the present invention. Any structural modification, change in proportional relationship or adjustment of size, under the same or similar conditions as the effects that can be produced by the present invention and the purposes that can be achieved, should still fall within the scope of the technical content disclosed by the present invention.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements. The singular forms "a", "an" and "the" include plural objects, the term "or" is generally used in a sense including "and / or", the term "several" is generally used in a sense including "at least one", and the term "at least two" is generally used in a sense including "two or more". In addition, the terms "first", "second" and "third" are used for descriptive purposes only and are not to be understood as indicating or suggesting relative importance or implicitly indicating the number of the indicated technical features.

[0052] In addition, in the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0053] The core idea of ​​the present invention is to provide a liquid level detection system, a liquid level detection method and a vehicle controller, which can power the liquid level sensor and collect signals only when there is a need for liquid level detection, thereby preventing misjudgment of the liquid level due to long-term power supply of the liquid level sensor.

[0054] It should be noted that the liquid level detection method provided by the present invention can be applied to the liquid level detection system and vehicle controller provided by the present invention, and the liquid level detection system and vehicle controller provided by the present invention can be configured on a vehicle. It should also be noted that, as those skilled in the art can understand, the liquid level detection system and liquid level detection method provided by the present invention are not only applicable to the liquid level detection scenarios of liquids such as wiper washing fluid, battery coolant, engine coolant, etc., but also applicable to other scenarios where the quantification requirements of liquid level data are not high, and the present invention does not limit this. In addition, it should be noted that, as those skilled in the art can understand, the "vehicle" referred to herein includes general motor vehicles, such as passenger vehicles including sports utility vehicles (SUVs), buses, trucks, and various commercial vehicles, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, fuel cell vehicles, and other alternative fuel vehicles (such as fuels obtained from resources other than petroleum).

[0055] To realize the above idea, the present invention provides a liquid level detection system, please refer to Figure 2 , which is a schematic diagram of the block structure of a liquid level detection system provided by one embodiment of the present invention. Figure 2As shown, the liquid level detection system provided by the present invention includes a liquid level sensor 100, a sensor power supply circuit 200, a liquid level signal acquisition circuit 300 and a control module 400, the input end of the sensor power supply circuit 200 is connected to the control module 400, the input end of the liquid level signal acquisition circuit 300 is connected to the output end of the sensor power supply circuit 200, the output end of the liquid level signal acquisition circuit 300 is connected to the control module 400, and the input end of the liquid level sensor 100 is connected to the liquid level signal acquisition circuit 300; the liquid level sensor 100 includes two detection rods (not shown in the figure) and is configured to be placed in a liquid storage tank to be detected (not shown in the figure); the control module 400 is configured to, when there is a liquid level detection scenario requirement, send a signal to the control module 400 to the liquid level sensor 100. The sensor power supply circuit 200 outputs an on signal to control the sensor power supply circuit 200 to be in a conducting state, thereby controlling the liquid level sensor 100 to be in a powered-on state; when there is no liquid level detection scenario requirement, an off signal is output to the sensor power supply circuit 200 to control the sensor power supply circuit 200 to be in a disconnected state, thereby controlling the liquid level sensor 100 to be in a powered-off state; the liquid level signal acquisition circuit 300 is configured to collect voltage data at the input end of the liquid level sensor 100 and transmit it to the control module 400 when the liquid level sensor 100 is in a powered-on state; the control module 400 is configured to obtain the liquid level status information of the liquid storage tank to be detected based on the voltage data at the input end of the liquid level sensor 100.

[0056] It can be seen that by adopting the liquid level detection system provided by the present invention, it is possible to realize the power supply and signal acquisition of the liquid level sensor 100 only in the scenario where there is a need for liquid level detection, thereby effectively preventing the problem of liquid level misjudgment caused by the long-term power supply of the liquid level sensor 100, and at the same time reducing power consumption and reducing energy waste. In addition, by adopting the liquid level detection system provided by the present invention, it is also possible to prevent the problems such as the shortening of the life cycle of the liquid level sensor 100 and the deterioration of the liquid (such as washing liquid) in the liquid storage tank caused by the long-term operation of the liquid level sensor 100 (i.e., being in the power-on state for a long time), thereby avoiding the safety risks and reduced user experience caused by the failure of the function corresponding to the liquid (such as the wiper washing function). In addition, the liquid level detection system provided by the present invention can also expand the application scenarios for the inexpensive, simple and stable liquid level sensor 100 composed of two metal bars, which is conducive to reducing the cost of liquid level detection.

[0057] It should be noted that, as those skilled in the art can understand, the sensor power supply circuit 200, the liquid level signal acquisition circuit 300 and the control module 400 can be integrated on the same controller (e.g., ECU, vehicle controller), and the control module 400 can be, but not limited to, an MCU (Microcontroller Unit), and the on and off of the sensor power supply circuit 200 does not affect other functions of the controller (e.g., ECU, vehicle controller). It should also be noted that, as those skilled in the art can understand, the control module 400 is integrated with an analog-to-digital conversion unit, and the analog-to-digital conversion unit is configured to convert the analog voltage data output by the liquid level signal acquisition circuit 300 into digital voltage data.

[0058] Please continue to refer to Figure 2 ,like Figure 2 As shown, in some exemplary embodiments, the sensor power supply circuit 200 includes a conversion circuit 210 and a switch circuit 220, the input end of the conversion circuit 210 is configured to connect to the power supply VCC, the output end of the conversion circuit 210 is connected to the switch circuit 220, the input end of the switch circuit 220 is connected to the control module 400, and the output end of the switch circuit 220 is connected to the input end of the liquid level sensor 100, the conversion circuit 210 is configured to adjust and stabilize the power supply VCC, and the switch circuit 220 is configured to be in an on state or an off state under the control of the on / off signal output by the control module 400, so as to control the liquid level sensor 100 to be in a power-on state or a power-off state. Thus, the stable output of the voltage V_power can be achieved through the conversion circuit 210, and the on-off control of the output of the voltage V_power can be achieved through the switch circuit 220.

[0059] It should be noted that, as those skilled in the art can understand, the present invention does not limit the specific structure of the conversion circuit 210, and the conversion circuit 210 can adopt a circuit structure known to those skilled in the art that can play a role in voltage regulation and voltage stabilization, for example, the conversion circuit 210 can be a PMIC (Power Management IC). It should also be noted that, as those skilled in the art can understand, Figure 2 V_QT in represents the voltage at the output terminal of the conversion circuit 210 .

[0060] Please continue to refer to Figure 3 , which is a schematic diagram of the circuit structure of the switch circuit 220 provided in one embodiment of the present invention. Figure 3As shown, in some exemplary embodiments, the switch circuit 220 includes a first transistor Q1, a second transistor Q2, a first resistor R1, a second resistor R2 and a first capacitor C1, the emitter of the first transistor Q1 and the first end of the first resistor R1 are both connected to the output end of the conversion circuit 210, the base of the first transistor Q1 is connected to the second end of the first resistor R1, and the collector of the first transistor Q1 is connected to the input end of the liquid level sensor 100; the first end of the second resistor R2 is connected to the second end of the first resistor R1, the second end of the second resistor R2 is connected to the collector of the second transistor Q2, the base of the second transistor Q2 is connected to the control module 400, the emitter of the second transistor Q2 is grounded, the first end of the first capacitor C1 is connected to the base of the first transistor Q1, and the second end of the first capacitor C1 is connected to the collector of the first transistor Q1. Specifically, when the control module 400 outputs an on signal, the second transistor Q2 is turned on, and under the voltage division effect of the first resistor R1 and the second resistor R2, the first transistor Q1 is also turned on, so that the entire sensor power supply circuit 200 is in a conducting state, and can output a voltage V_power, and then the liquid level sensor 100 is in a powered-on state. When the control module 400 outputs an off signal, the second transistor Q2 is disconnected, and at this time, the first resistor R1 and the second resistor R2 cannot form a loop and cannot play a role in voltage division, so that the first transistor Q1 cannot be turned on, the entire sensor power supply circuit 200 is in a disconnected state, and cannot output a voltage V_power, and then the liquid level sensor 100 is in a powered-off state. In addition, by connecting the first capacitor C1 in parallel at both ends of the base and the collector of the first transistor Q1, the entire sensor power supply circuit 200 can be protected and the normal use of the entire sensor power supply circuit 200 can be ensured.

[0061] Please continue to refer to Figure 2 ,like Figure 2As shown, in some exemplary embodiments, the liquid level signal acquisition circuit 300 includes a sampling resistor R_pup and a filter circuit 310, the first end of the sampling resistor R_pup is connected to the output end of the sensor power supply circuit 200, the input end of the liquid level sensor 100 and the input end of the filter circuit 310 are both connected to the second end of the sampling resistor R_pup, and the output end of the filter circuit 310 is connected to the control module 400. Thus, the sampling resistor R_pup can play a voltage dividing role, so that the voltage V_detect at the input end of the liquid level sensor 100 is obviously different when there is liquid and when there is no liquid, so that the control module 400 can clearly distinguish between the two states of liquid and lack of liquid according to the voltage data at the input end of the liquid level sensor 100. The filter circuit 310 can filter the voltage data at the input end of the liquid level sensor 100, effectively filter out the AC component in the voltage data, and further improve the accuracy of the liquid level detection result of the liquid level detection system provided by the present invention.

[0062] Specifically, the liquid level signal acquisition circuit 300 can be equivalent to a voltage divider circuit with a power supply voltage of V_power, a resistance of a sampling resistor R_pup and an equivalent resistor R_liquid (equivalent resistor R_liquid between detection rods A and B) in series. Since when there is a lack of liquid (for example, there is no washing liquid), the equivalent resistance R_liquid is equivalent to infinity, and the voltage V_detect at the input end of the liquid level sensor 100 is close to V_power; when there is liquid (for example, there is washing liquid), the equivalent resistance R_liquid fluctuates greatly due to factors such as the composition of the liquid (for example, washing liquid), and the voltage V_detect at the input end of the liquid level sensor 100 is less than V_power from close to 0Ω to MΩ level. Therefore, the current liquid level state can be determined by collecting the voltage V_detect at the input end of the liquid level sensor 100. In addition, when there is liquid (for example, washing liquid), the equivalent resistance R_liquid fluctuates greatly due to factors such as the composition of the liquid (for example, washing liquid), ranging from close to 0Ω to the MΩ level. Therefore, by selecting a sampling resistor R_pup with a suitable resistance value, it can be ensured that the voltage data at the input end of the liquid level sensor 100 collected by the liquid level signal acquisition circuit 300 does not overlap in the signal intervals in the presence / absence of liquid, so that the control module 400 can clearly distinguish between the two states of liquid presence and liquid absence based on the voltage data at the input end of the liquid level sensor 100.

[0063] Please continue to refer to Figure 2 ,like Figure 2As shown, in some exemplary embodiments, the filter circuit 310 includes a second capacitor C2, a third resistor R3 and a third capacitor C3, the first end of the third resistor R3 is connected to the second end of the sampling resistor R_pup and the first end of the second capacitor C2, the second end of the third resistor R3 is connected to the first end of the third capacitor C3 and the control module 400, and the second end of the second capacitor C2 and the second end of the third capacitor C3 are both grounded. Thus, the second capacitor C2, the third resistor R3 and the third capacitor C3 can form a π-type filter circuit 310, effectively improving the filtering effect, and further improving the accuracy of the liquid level detection result of the liquid level detection system provided by the present invention.

[0064] Please continue to refer to Figure 2 ,like Figure 2 As shown, in some exemplary embodiments, the liquid level detection system further includes a liquid level display module 500 that is communicatively connected to the control module 400, and the liquid level display module 500 is configured to display the liquid level status information of the liquid storage tank to be detected. Thus, by setting the liquid level display module 500 to display the detected liquid level status information, it is convenient for the user to intuitively know the specific liquid level detection result, so that the user can take corresponding countermeasures in time when there is a lack of liquid. Specifically, the liquid level display module 500 can be, but is not limited to, a terminal device such as a mobile phone, an instrument panel, and a large car screen.

[0065] Please continue to refer to Figure 2 ,like Figure 2 As shown, in some exemplary embodiments, the liquid level detection system further includes an alarm module 600 that is communicatively connected to the control module 400, and the alarm module 600 is configured to issue an alarm reminder when the control module 400 determines that the liquid level state of the liquid storage tank to be detected is lack of liquid. Thus, by setting the alarm module 600 to issue an alarm reminder when there is a lack of liquid, it is convenient for the user to add liquid in time when there is a lack of liquid, so as to ensure the normal use of the function corresponding to the liquid (such as the wiper washing function). Specifically, the specific alarm forms of the alarm module 600 include but are not limited to controlling the speaker to output an alarm prompt tone, the lack of liquid indicator light on the instrument panel flashing, and pushing a liquid addition reminder message to the user's mobile phone.

[0066] In some exemplary embodiments, the control module 400 is configured to pre-process the voltage data to obtain pre-processed voltage data, wherein the pre-processing includes at least one of filtering processing and invalid value processing, and then obtain the liquid level status information of the liquid storage tank to be detected based on the pre-processed voltage data. Therefore, by first performing filtering processing and invalid value processing on the collected voltage data, the accuracy of liquid level judgment can be further improved.

[0067] In some exemplary embodiments, the control module 400 is configured to obtain the liquid level status information of the liquid storage tank to be detected based on the voltage data of the input end of the liquid level sensor 100 and the preset voltage range. Specifically, when the voltage value of the input end of the liquid level sensor 100 is within the preset voltage range, the liquid level status of the liquid storage tank to be detected is determined to be liquid; when the voltage of the input end of the liquid level sensor 100 exceeds the preset voltage range (i.e., greater than the highest voltage value of the preset voltage range), the liquid level status of the liquid storage tank to be detected is determined to be lack of liquid. It should be noted that, as can be understood by those skilled in the art, the preset voltage range can be obtained according to experimental calibration, and different preset voltage ranges are calibrated for liquids of different components.

[0068] Furthermore, the control module 400 is configured to determine that the liquid level state of the liquid storage tank to be detected is lack of liquid if the voltage value at the input end of the liquid level sensor 100 exceeds the preset voltage range for a duration greater than or equal to the first time threshold. Thus, by determining that the detection result of the liquid level state is lack of liquid only when the voltage value at the input end of the liquid level sensor 100 exceeds the preset voltage range (i.e., greater than the highest voltage value of the preset voltage range) for a duration greater than or equal to the first time threshold (e.g., 10s), the problem of misjudgment of the liquid level caused by vehicle bumps or uneven liquid surface during liquid addition can be effectively avoided, and the occurrence of frequent false alarms and false alarm cancellations can also be effectively avoided. It should be noted that, as can be understood by those skilled in the art, the specific value of the first time threshold can be set according to actual conditions, and the present invention does not limit this.

[0069] In some exemplary embodiments, the control module 400 is further configured to determine whether the liquid level sensor 100 is faulty based on the voltage data at the input end of the liquid level sensor 100. Specifically, assuming that the voltage V_power output by the sensor power supply circuit 200 is 5V, when the liquid level sensor 100 is working normally, the resistance value of the equivalent resistor R_liquid is 1kΩ to 2MΩ (with liquid) and infinity (lack of liquid), and accordingly, the voltage V_detect at the input end of the liquid level sensor 100 is between 1V and 5V. When the liquid level sensor 100 is short-circuited, the resistance value of the equivalent resistor R_liquid is equivalent to 0, and the voltage V_detect at the input end of the liquid level sensor 100 is close to 0V. Therefore, a reasonable voltage range of V_detect can be set according to the resistance range of the equivalent resistor R_liquid. If the collected V_detect is lower than this range, it can be determined that the liquid level sensor 100 has a short-circuit fault. For example, if the reasonable voltage range of the voltage V_detect at the input end of the liquid level sensor 100 is between 1V and 5V, and the collected V_detect is lower than 1V, it can be determined that the liquid level sensor 100 has a short circuit fault.

[0070] In some exemplary embodiments, the control module 400 is further configured to upload the liquid level status information of the liquid storage tank to be detected to the cloud. Thus, by uploading the liquid level status information to the cloud, cloud backup of the liquid level status data can be achieved, so that the data value can be fully mined through big data analysis: such as judging user habits and liquid (such as washing liquid) expiration cycle, etc., which is conducive to the iteration of vehicle functions and long-term route optimization.

[0071] In some exemplary embodiments, the control module 400 is further configured to perform the following operations:

[0072] Determine whether the duration of the liquid level sensor 100 being in the power-on state exceeds a second time threshold;

[0073] If so, an off signal is output to the sensor power supply circuit 200 to control the sensor power supply circuit 200 to be in an off state, thereby controlling the liquid level sensor 100 located in the liquid storage tank to be detected to be in a power-off state.

[0074] Therefore, by controlling the sensor power supply circuit 200 to be in a disconnected state when the liquid level sensor 100 is powered on for too long, and then shutting down the liquid level sensor 100, it is possible to further prevent the liquid level sensor 100 from being powered on for a long time, thereby preventing the life cycle of the liquid level sensor 100 from being shortened, the liquid in the liquid storage tank (such as washing liquid) from being deteriorated, and the liquid level from being misjudged. It should be noted that, as can be understood by those skilled in the art, the specific value of the second time threshold (for example, the second time threshold can be set to 20s) can be set according to actual conditions, and the present invention does not limit this.

[0075] Based on the same inventive concept, the present invention also provides a liquid level detection method, which is applied to the liquid level detection system described above. Figure 4 , which is a flow chart of a liquid level detection method provided by one embodiment of the present invention. Figure 4 As shown, the liquid level detection method provided by the present invention comprises the following steps:

[0076] Step S100: determine whether there is a liquid level detection scenario requirement.

[0077] Step S200: If yes, an on signal is output to the sensor power supply circuit 200 to control the sensor power supply circuit 200 to be in a conducting state, thereby controlling the liquid level sensor 100 located in the liquid storage tank to be detected to be in a powered-on state.

[0078] Step S300 , controlling the liquid level signal acquisition circuit 300 to acquire voltage data at the input end of the liquid level sensor 100 .

[0079] Step S400: Acquire the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor 100.

[0080] Therefore, the liquid level detection method provided by the present invention only performs power supply and signal acquisition of the liquid level sensor 100 when there is a need for liquid level detection, thereby effectively preventing the problem of liquid level misjudgment caused by the long-term power supply of the liquid level sensor 100, and at the same time reducing power consumption and reducing energy waste. In addition, by adopting the liquid level detection method provided by the present invention, it is also possible to prevent the problems such as shortening the life cycle of the liquid level sensor 100 and deterioration of the liquid (such as washing liquid) in the liquid storage tank caused by the long-term operation of the liquid level sensor 100 (i.e., being powered on for a long time) and thereby avoiding the safety risks and reduced user experience caused by the failure of the function corresponding to the liquid (such as the wiper washing function). In addition, the liquid level detection method provided by the present invention can also expand the application scenarios for the inexpensive, simple and stable liquid level sensor 100 composed of two metal bars, which is conducive to reducing the cost of liquid level detection.

[0081] In some exemplary implementations, if at least one of the following conditions is met, it is determined that there is a liquid level detection scenario requirement:

[0082] Receive a liquid level detection control instruction;

[0083] The whole vehicle is powered on;

[0084] The function corresponding to the liquid in the liquid storage tank to be detected is turned on.

[0085] It should be noted that, as can be understood by those skilled in the art, the liquid level detection instruction may be sent by other controllers or by the user through the car large screen.

[0086] In some exemplary embodiments, the step of obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor 100 includes:

[0087] Preprocessing the voltage data to obtain preprocessed voltage data, wherein the preprocessing includes at least one of filtering processing and invalid value processing;

[0088] The liquid level status information of the liquid storage tank to be detected is obtained according to the preprocessed voltage data.

[0089] In some exemplary embodiments, the step of obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor 100 includes:

[0090] If the voltage value at the input end of the liquid level sensor 100 is within the preset voltage range, it is determined that the liquid level state of the liquid storage tank to be detected is liquid;

[0091] If the duration of the voltage value at the input end of the liquid level sensor 100 exceeding the preset voltage range is greater than or equal to the first time threshold, it is determined that the liquid level state of the liquid storage tank to be detected is lack of liquid.

[0092] In some exemplary embodiments, the liquid level detection method provided by the present invention further includes:

[0093] Determine whether the duration of the liquid level sensor 100 being in the power-on state exceeds a second time threshold;

[0094] If so, an off signal is output to the sensor power supply circuit 200 to control the sensor power supply circuit 200 to be in an off state, thereby controlling the liquid level sensor 100 located in the liquid storage tank to be detected to be in a power-off state.

[0095] In some exemplary embodiments, the liquid level detection method provided by the present invention further includes:

[0096] If the liquid level state of the liquid storage tank to be detected is determined to be lack of liquid, an alarm is issued.

[0097] In some exemplary embodiments, the liquid level detection method provided by the present invention further includes:

[0098] The liquid level status information of the liquid storage tank to be detected is uploaded to the cloud.

[0099] In some exemplary embodiments, the liquid level detection method provided by the present invention further includes:

[0100] Whether the liquid level sensor 100 fails is determined based on the voltage data at the input end of the liquid level sensor 100 .

[0101] Based on the same inventive concept, the present invention also provides a vehicle controller, please refer to Figure 5 , which is a schematic block diagram of a vehicle controller provided by one embodiment of the present invention. Figure 5 As shown, the vehicle controller provided by the present invention includes a processor 710 and a memory 730, and a computer program is stored on the memory 730. When the computer program is executed by the processor 710, the liquid level detection method described above is implemented. Since the vehicle controller provided by the present invention and the liquid level detection method provided by the present invention belong to the same inventive concept, the vehicle controller provided by the present invention at least has all the beneficial effects of the liquid level detection method provided by the present invention. For details, please refer to the relevant description of the beneficial effects of the liquid level detection method provided by the present invention in the above text, so the beneficial effects of the vehicle controller provided by the present invention will not be repeated here.

[0102] like Figure 5 As shown, the vehicle controller provided by the present invention also includes a communication interface 720 and a communication bus 740, wherein the processor 710, the communication interface 720, and the memory 730 communicate with each other through the communication bus 740. The communication bus 740 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus 740 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus. The communication interface 720 is used for communication between the above-mentioned vehicle controller and other devices.

[0103] The processor 710 referred to in the present invention may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor 710 is the control center of the vehicle controller, and various interfaces and lines are used to connect various parts of the entire vehicle controller.

[0104] The memory 730 can be used to store the computer program. The processor 710 implements various functions of the vehicle controller by running or executing the computer program stored in the memory 730 and calling the data stored in the memory 730. The memory 730 may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable memory (PROM), electrically programmable memory (EPROM), electrically erasable programmable memory (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of illustration and not limitation, random access memory is available in a variety of forms, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous random access memory (SDRAM), double data rate synchronous random access memory (DDRSDRAM), enhanced synchronous random access memory (ESDRAM), synchronous link (Synchlink) dynamic random access memory (SLDRAM), memory bus (Rambus) direct random access memory (RDRAM), direct memory bus dynamic random access memory (DRDRAM), and memory bus dynamic random access memory (RDRAM), etc.

[0105] Based on the same inventive concept, the present invention also provides another vehicle controller, which includes the sensor power supply circuit 200, the liquid level signal acquisition circuit 300 and the control module 400 described above. Since the vehicle controller provided by the present invention and the liquid level detection system provided by the present invention belong to the same inventive concept, the vehicle controller provided by the present invention at least has all the beneficial effects of the liquid level detection system provided by the present invention. For details, please refer to the relevant description of the beneficial effects of the liquid level detection system provided by the present invention above, so the beneficial effects of the vehicle controller provided by the present invention will not be described one by one here.

[0106] In summary, compared with the prior art, the liquid level detection system, liquid level detection method and vehicle controller provided by the present invention have the following beneficial effects:

[0107] The present invention can realize the power supply and signal acquisition of the liquid level sensor 100 only when there is a need for liquid level detection, thereby effectively preventing the problem of liquid level misjudgment caused by the long-term power supply of the liquid level sensor 100, and at the same time reducing power consumption and reducing energy waste. In addition, by adopting the present invention, it is also possible to prevent the problems such as the shortening of the life cycle of the liquid level sensor 100 and the deterioration of the liquid (such as washing liquid) in the liquid storage tank caused by the long-term operation of the liquid level sensor 100 (that is, being powered on for a long time) and thereby avoiding the safety risks and reduced user experience caused by the failure of the function corresponding to the liquid (such as the wiper washing function). In addition, the present invention can also expand the application scenarios of the inexpensive, simple and stable liquid level sensor 100 composed of two metal bars, which is conducive to reducing the cost of liquid level detection.

[0108] It should be noted that the computer program code for performing the operation of the present invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages-such as Java, Smalltalk, C++, and also conventional procedural programming languages-such as "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as an independent software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer can be connected to the user's computer through any type of network-including a local area network (LAN) or a wide area network (WAN), or can be connected to an external computer (for example, using an Internet service provider to connect through the Internet).

[0109] It should be noted that the devices and methods disclosed in the embodiments of this article can also be implemented in other ways. The device implementation described above is only schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of this article. In this regard, each box in the flowchart or block diagram can represent a part of a module, program or code, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function, and the module, program segment or part of the code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented by a dedicated hardware-based system for performing a specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. In addition, the functional modules in the various embodiments of this document may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0110] It should also be noted that the above description is only a description of the preferred embodiment of the present invention, and is not any limitation on the scope of the present invention. Any changes and modifications made by a person skilled in the art in the field of the present invention based on the above disclosure are within the scope of protection of the present invention. Obviously, a person skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A liquid level detection system, characterized in that: It includes a liquid level sensor, a sensor power supply circuit, a liquid level signal acquisition circuit and a control module, wherein the input end of the sensor power supply circuit is connected to the control module, the input end of the liquid level signal acquisition circuit is connected to the output end of the sensor power supply circuit, the output end of the liquid level signal acquisition circuit is connected to the control module, and the input end of the liquid level sensor is connected to the liquid level signal acquisition circuit; The liquid level sensor includes two detection rods and is configured to be placed in a liquid storage tank to be detected; The control module is configured to output an on signal to the sensor power supply circuit when there is a liquid level detection scenario requirement, so as to control the sensor power supply circuit to be in a conducting state, thereby controlling the liquid level sensor to be in a powered-on state; and to output an off signal to the sensor power supply circuit when there is no liquid level detection scenario requirement, so as to control the sensor power supply circuit to be in a disconnected state, thereby controlling the liquid level sensor to be in a powered-off state; The liquid level signal acquisition circuit is configured to collect voltage data of the input end of the liquid level sensor and transmit the data to the control module when the liquid level sensor is in a powered-on state; The control module is configured to obtain the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor.

2. The liquid level detection system according to claim 1, characterized in that: The sensor power supply circuit includes a conversion circuit and a switch circuit. The input end of the conversion circuit is configured to connect to a power supply. The output end of the conversion circuit is connected to the switch circuit. The input end of the switch circuit is connected to the control module. The output end of the switch circuit is connected to the input end of the liquid level sensor. The conversion circuit is configured to regulate and stabilize the power supply. The switch circuit is configured to be in an on state or an off state under the control of an on / off signal output by the control module, thereby controlling the liquid level sensor to be in a powered-on state or a powered-off state.

3. The liquid level detection system according to claim 2, characterized in that: The switching circuit includes a first triode, a second triode, a first resistor, a second resistor and a first capacitor. The emitter of the first triode and the first end of the first resistor are both connected to the output end of the conversion circuit, the base of the first triode is connected to the second end of the first resistor, and the collector of the first triode is connected to the input end of the liquid level sensor; the first end of the second resistor is connected to the second end of the first resistor, the second end of the second resistor is connected to the collector of the second triode, the base of the second triode is connected to the control module, the emitter of the second triode is grounded, the first end of the first capacitor is connected to the base of the first triode, and the second end of the first capacitor is connected to the collector of the first triode.

4. The liquid level detection system according to claim 1, characterized in that: The liquid level signal acquisition circuit includes a sampling resistor and a filtering circuit, the first end of the sampling resistor is connected to the output end of the sensor power supply circuit, the input end of the liquid level sensor and the input end of the filtering circuit are both connected to the second end of the sampling resistor, and the output end of the filtering circuit is connected to the control module.

5. The liquid level detection system according to claim 4, characterized in that: The filtering circuit includes a second capacitor, a third resistor and a third capacitor, the first end of the third resistor is connected to the second end of the sampling resistor and the first end of the second capacitor, the second end of the third resistor is connected to the first end of the third capacitor and the control module, and the second end of the second capacitor and the second end of the third capacitor are both grounded.

6. The liquid level detection system according to claim 1, characterized in that: The control module is configured to determine that the liquid level state of the liquid storage tank to be detected is liquid if the voltage value of the input end of the liquid level sensor is within a preset voltage range; if the voltage value of the input end of the liquid level sensor exceeds the preset voltage range for a duration greater than or equal to a first time threshold, then determine that the liquid level state of the liquid storage tank to be detected is liquid-deficient.

7. The liquid level detection system according to claim 1, characterized in that: The control module is also configured to determine whether the liquid level sensor fails based on voltage data at the input end of the liquid level sensor; or upload the liquid level status information of the liquid storage tank to be detected to the cloud.

8. The liquid level detection system according to claim 1, characterized in that: The liquid level detection system also includes a liquid level display module and an alarm module that are communicatively connected to the control module. The liquid level display module is configured to display the liquid level status information of the liquid storage tank to be detected, and the alarm module is configured to issue an alarm reminder when the control module determines that the liquid level status of the liquid storage tank to be detected is lack of liquid.

9. A liquid level detection method, characterized in that: The liquid level detection method comprises: Determine whether there is a need for liquid level detection scenarios; If yes, an on signal is output to the sensor power supply circuit to control the sensor power supply circuit to be in a conducting state, thereby controlling the liquid level sensor located in the liquid storage tank to be detected to be in a powered-on state; Controlling the liquid level signal acquisition circuit to acquire voltage data of the input end of the liquid level sensor; The liquid level status information of the liquid storage tank to be detected is obtained according to the voltage data of the input end of the liquid level sensor.

10. The liquid level detection method according to claim 9, characterized in that: The step of obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor comprises: Preprocessing the voltage data to obtain preprocessed voltage data, wherein the preprocessing includes at least one of filtering processing and invalid value processing; The liquid level status information of the liquid storage tank to be detected is obtained according to the preprocessed voltage data.

11. The liquid level detection method according to claim 9, characterized in that: The step of obtaining the liquid level status information of the liquid storage tank to be detected according to the voltage data of the input end of the liquid level sensor comprises: If the duration of the voltage value at the input end of the liquid level sensor exceeding the preset voltage range is greater than or equal to the first time threshold, it is determined that the liquid level state of the liquid storage tank to be detected is lack of liquid.

12. The liquid level detection method according to claim 9, characterized in that: The liquid level detection method further comprises: Determining whether the duration of the liquid level sensor being in the power-on state exceeds a second time threshold; If so, an off signal is output to the sensor power supply circuit to control the sensor power supply circuit to be in an off state, thereby controlling the liquid level sensor located in the liquid storage tank to be detected to be in a power-off state.

13. A vehicle controller, characterized in that: The method comprises a processor and a memory, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the liquid level detection method according to any one of claims 9 to 12 is implemented.

14. A vehicle controller, characterized in that: The invention comprises a sensor power supply circuit, a liquid level signal acquisition circuit and a control module in the liquid level detection system according to any one of claims 1 to 8.

Images