Liquid level diagnosis system, liquid level diagnosis method and vehicle

Abstract

The invention discloses a liquid level diagnosis system, a liquid level diagnosis method and a vehicle. The liquid level diagnosis system comprises a diagnosis circuit, a wire harness connector and a liquid level sensor. The diagnosis circuit comprises a voltage dividing unit and a controller. The voltage dividing unit is provided with a voltage input end and a voltage output end, the voltage input end is used for being connected with reference voltage, and the voltage output end is connected with the controller. The liquid level sensor comprises a first resistor, a second resistor and a switch matched with the electromagnetic buoy; the first end of the first resistor is connected with the voltage dividing unit through the wire harness connector, the second end of the first resistor is connected with the first end of the second resistor, the second end of the second resistor is grounded, and the switch is connected with the second resistor in parallel. And the controller is used for judging that at least one of the wire harness connector, the first resistor and the second resistor has an open circuit condition when the received voltage of the voltage output end is within a first preset range. The design can effectively improve the safety and reliability of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of vehicles, in particular to a liquid level diagnosis system, a liquid level diagnosis method and a vehicle. BACKGROUND

[0002] With the development of vehicle functional safety, higher requirements are put forward for the safety of the whole vehicle, and therefore more diagnoses need to be added to increase the safety and reliability of the vehicle.

[0003] In the related art, the liquid level sensor can only diagnose whether the brake fluid of the vehicle's oil can is in a normal state or a liquid shortage state, and cannot diagnose the faults of the liquid level sensor itself and the connection line part between the liquid level sensor and the controller, resulting in low safety and reliability of the vehicle. SUMMARY

[0004] The embodiments of the present application provide a liquid level diagnosis system, a liquid level diagnosis method and a vehicle, which can solve the problem in the related art that the liquid level sensor can only diagnose whether the brake fluid of the vehicle's oil can is in a normal state or a liquid shortage state, and cannot diagnose the faults of the liquid level sensor itself and the connection line part between the liquid level sensor and the controller, resulting in low safety and reliability of the vehicle.

[0005] In a first aspect, the embodiments of the present application provide a liquid level diagnosis system; the liquid level diagnosis system comprises a diagnosis circuit, a wire harness connector and a liquid level sensor, the diagnosis circuit comprises a voltage dividing unit and a controller, the voltage dividing unit has a voltage input end and a voltage output end, the voltage input end is used to connect a reference voltage, the voltage output end is connected with the controller, the liquid level sensor comprises a first resistor, a second resistor and a switch matched with an electromagnetic float, a first end of the first resistor is connected with the voltage dividing unit through the wire harness connector, a second end of the first resistor is connected with a first end of the second resistor, a second end of the second resistor is grounded, and the switch is connected in parallel with the second resistor, and the controller is used to determine that at least one device of the wire harness connector, the first resistor and the second resistor exists an open circuit condition when receiving a voltage of the voltage output end in a first preset range.

[0006] Based on the liquid level diagnosis system of the embodiments of the present application, by designing the first resistor, the second resistor and the voltage dividing unit, the first resistor, the second resistor and the voltage dividing unit form a voltage dividing circuit, the controller can determine whether the components in the system exist an open circuit condition according to the size of the voltage output by the voltage output end, and the controller is used to determine that at least one device of the wire harness connector, the first resistor and the second resistor exists an open circuit condition when receiving a voltage of the voltage output end in a first preset range, so that the liquid level diagnosis system can effectively diagnose whether the liquid level sensor itself exists an open circuit condition, and can also effectively diagnose whether the wire harness connector between the liquid level sensor and the diagnosis circuit exists an open circuit condition, thereby effectively improving the safety and reliability of the vehicle.

[0007] In a second aspect, the embodiments of the present application provide a liquid level diagnosis method. The method is implemented by the liquid level diagnosis system described above, and the method comprises:

[0008] obtaining the voltage output by the voltage output terminal;

[0009] when the voltage output by the voltage output terminal is within the first preset range, determining that at least one of the wire harness connector, the first resistor and the second resistor is in an open circuit condition;

[0010] when the voltage output by the voltage output terminal is within the second preset range, determining that the wire harness connector is in a short circuit to ground condition.

[0011] The liquid level diagnosis method according to the embodiments of the present application can effectively diagnose whether the liquid level sensor itself is in an open circuit condition, and can effectively diagnose whether the wire harness connector between the liquid level sensor and the diagnosis circuit is in an open circuit condition or a short circuit to ground condition, thereby effectively improving the safety and reliability of the vehicle.

[0012] In a third aspect, the embodiments of the present application provide a vehicle. The vehicle comprises the liquid level diagnosis system described above.

[0013] The vehicle according to the embodiments of the present application can effectively diagnose whether the liquid level sensor itself is in an open circuit condition, and can effectively diagnose whether the wire harness connector between the liquid level sensor and the diagnosis circuit is in an open circuit condition or a short circuit to ground condition, thereby effectively improving the safety and reliability of the vehicle. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0015] Figure 1 FIG. 1 is a structural schematic diagram of the liquid level diagnosis system in an embodiment of the present application;

[0016] Figure 2 FIG. 2 is a structural schematic diagram of the wire harness connector in an open circuit condition in an embodiment of the present application;

[0017] Figure 3A flowchart of a liquid level diagnosis method in an embodiment of the present application is shown in the figure;

[0018] Figure 4 A flowchart of a liquid level diagnosis method in another embodiment of the present application is shown in the figure.

[0019] Fig. 1 shows a liquid level diagnosis system; 10, diagnosis circuit; 11, voltage dividing unit; R3, third resistor; R4, fourth resistor; R5, fifth resistor; C1, capacitor; 12, controller; 13, second circuit board; 20, wiring harness connector; 21, wiring harness body; 22, first connector; 221, first male plug; 222, first female plug; 23, second connector; 231, second male plug; 232, second female plug; 30, liquid level sensor; R1, first resistor; R2, second resistor; K1, switch; 31, first circuit board; VOUT, voltage output terminal; VBAT, reference voltage. DETAILED DESCRIPTION

[0020] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and should not be used to limit the present application.

[0021] Referring to Figure 1 the figure, the present application proposes a liquid level diagnosis system 1, which can effectively improve the safety and reliability of a vehicle.

[0022] The liquid level diagnosis system 1 comprises a diagnosis circuit 10, a wiring harness connector 20 and a liquid level sensor 30. The diagnosis circuit 10 comprises a voltage dividing unit 11 and a controller 12; the voltage dividing unit 11 has a voltage input terminal and a voltage output terminal VOUT, the voltage input terminal is used to connect a reference voltage VBAT, and the voltage output terminal VOUT is connected with the controller 12. The liquid level sensor 30 comprises a first resistor R1, a second resistor R2 and a switch K1 cooperating with an electromagnetic float; a first end of the first resistor R1 is connected with the voltage dividing unit 11 through the wiring harness connector 20, a second end of the first resistor R1 is connected with a first end of the second resistor R2, a second end of the second resistor R2 is grounded, and the switch K1 is connected in parallel with the second resistor R2. The controller 12 is used to determine that there is an open circuit condition in at least one of the wiring harness connector 20, the first resistor R1 and the second resistor R2 when receiving a voltage of the voltage output terminal VOUT within a first preset range.

[0023] The specific structure of the liquid level diagnosis system 1 will be described below. Figures 1-2 The specific structure of the liquid level diagnosis system 1 will be described below.

[0024] As Figure 1 shown, the liquid level diagnosis system 1 comprises a diagnosis circuit 10, a wiring harness connector 20 and a liquid level sensor 30.

[0025] The diagnostic circuit 10 is a circuit structure used in the liquid level diagnostic system 1 to cooperate with the liquid level sensor 30 to diagnose whether the components in the system are in open circuit or short circuit.

[0026] The diagnostic circuit 10 comprises a voltage dividing unit 11 and a controller 12.

[0027] The voltage dividing unit 11 is a voltage dividing part of the diagnostic circuit 10, which can be composed of multiple resistors only, or composed of multiple resistors and a capacitor C1. The specific circuit structure of the voltage dividing unit 11 will be introduced in detail below.

[0028] The voltage dividing unit 11 has a voltage input end and a voltage output end VOUT; the voltage input end is used to connect a reference voltage VBAT, and the voltage output end VOUT is connected with the controller 12.

[0029] The controller 12 is a control part of the diagnostic circuit 10, which can be an MCU (Microcontroller Unit).

[0030] The wiring harness connector 20 is a connection structure of the liquid level diagnostic system 1, which is used to connect the diagnostic circuit 10 and the liquid level sensor 30, so that the diagnostic circuit 10 is electrically connected with the liquid level sensor 30. The specific structure of the wiring harness connector 20 will be introduced in detail below.

[0031] The liquid level sensor 30 is a detection device used in the liquid level diagnostic system 1 to detect the liquid level of the liquid storage container, and is also a circuit structure used in the liquid level diagnostic system 1 to cooperate with the diagnostic circuit 10 to diagnose whether the components in the system are in open circuit or short circuit.

[0032] The liquid level sensor 30 comprises a first resistor R1, a second resistor R2, and a switch K1 used to cooperate with an electromagnetic float.

[0033] The first resistor R1 is one of the voltage dividing elements of the liquid level sensor 30, and the specific resistance value of the first resistor R1 is not limited here, which can be reasonably designed by the designer according to actual needs.

[0034] The second resistor R2 is another voltage dividing element of the liquid level sensor 30, and the specific resistance value of the second resistor R2 is not limited here, which can be reasonably designed by the designer according to actual needs.

[0035] Switch K1 serves as an on-off device of the liquid level sensor 30, and switch K1 has an open state and a closed state; when the liquid level of the liquid storage container is in a normal state, the electromagnetic buoy floats on the liquid surface with a higher liquid level. At this time, the distance between the electromagnetic buoy and the switch K1 is relatively far, and the switch K1 is not sufficient to close under the action of the magnetic attraction of the electromagnetic buoy, that is, the switch K1 is in an open state; when the liquid level of the liquid storage container is in a liquid-deficient state, the electromagnetic buoy floats on the liquid surface with a lower liquid level. At this time, the distance between the electromagnetic buoy and the switch K1 is relatively close, and the switch K1 is sufficient to close under the action of the magnetic attraction of the electromagnetic buoy, that is, the switch K1 is in a closed state.

[0036] The first end of the first resistor R1 is connected to the voltage dividing unit 11 through the wiring harness connector 20, the second end of the first resistor R1 is connected to the first end of the second resistor R2, the second end of the second resistor R2 is grounded, and the switch K1 is connected in parallel to the second resistor R2.

[0037] The first resistor R1, the second resistor R2 and the voltage divider unit 11 form a voltage divider circuit, and the controller 12 can determine whether there is a circuit breakage in a component in the system according to the magnitude of the voltage outputted by the voltage output terminal VOUT. Specifically, the controller 12 is configured to determine whether there is a circuit breakage in at least one of the wiring harness connector 20, the first resistor R1 and the second resistor R2 when the voltage received from the voltage output terminal VOUT is within a first preset range (e.g., Figure 2 As shown). Specific values ​​within the first preset range are not limited herein, and designers may reasonably design the range based on actual needs. It is also understandable that when at least one of the wiring harness connector 20, the first resistor R1, and the second resistor R2 is short-circuited, the voltage at the voltage output terminal VOUT is calculated solely by the voltage divider unit 11 and the reference voltage VBAT through voltage division. Therefore, the specific values ​​within the first preset range are determined by the equivalent resistance value of the voltage divider unit 11 and the reference voltage VBAT.

[0038] It should be noted that the liquid level diagnostic system 1 may also include a prompt module (not shown in the figure), and the controller 12 is connected to the prompt module. When the controller 12 receives that the voltage at the voltage output terminal VOUT is within a first preset range, the controller 12 sends a first prompt signal to the prompt module. The prompt module makes a corresponding prompt based on the first prompt signal, and the user can immediately take corresponding countermeasures based on the prompt. It is understandable that for prompt modules with different forms of expression, the prompts made by prompt modules with different forms of expression based on the first prompt signal are also different; for example, when the prompt module includes a player, the prompt corresponds to a voice prompt; for another example, when the prompt module includes an indicator light, the prompt corresponds to a light prompt.

[0039] Based on the liquid level diagnosis system 1 in the embodiments of the present application, by designing the first resistor R1, the second resistor R2 and the voltage dividing unit 11, the first resistor R1, the second resistor R2 and the voltage dividing unit 11 form a voltage dividing circuit, and the controller 12 can determine whether there is an open circuit condition of the components in the system according to the voltage output by the voltage output terminal VOUT, and the controller 12 is configured to determine that at least one of the wire harness connector 20, the first resistor R1 and the second resistor R2 has an open circuit condition when the voltage output by the voltage output terminal VOUT is within the first preset range, so that the liquid level diagnosis system 1 can effectively diagnose whether the liquid level sensor 30 itself has an open circuit condition, and can also effectively diagnose whether the wire harness connector 20 between the liquid level sensor 30 and the diagnosis circuit 10 has an open circuit condition, thereby effectively improving the safety and reliability of the vehicle.

[0040] It can be understood that, as shown in Figure 1 The first resistor R1, the second resistor R2 and the voltage dividing unit 11 constitute a voltage dividing circuit, and the controller 12 can also determine whether there is a short circuit to ground condition of the components in the system according to the voltage output by the voltage output terminal VOUT. Specifically, the controller 12 is also configured to determine that the wire harness connector 20 has a short circuit to ground condition when the voltage output by the voltage output terminal VOUT is within the second preset range. Here, the specific value of the second preset range is not limited, and the designer can reasonably design according to actual needs; and it can be understood that when the wire harness connector 20 has a short circuit to ground condition, the voltage of the voltage output terminal VOUT is close to zero at this time, and considering the fluctuation of the ground terminal, the controller 12 can determine that the wire harness connector 20 is in a short circuit to ground condition when the voltage of the voltage output terminal VOUT is less than 0.15V. When the controller 12 receives the voltage of the voltage output terminal VOUT within the second preset range, the controller 12 sends a second prompt signal to the prompt module, and the prompt module makes a corresponding prompt according to the second prompt signal, and the user can take corresponding measures immediately according to the prompt.

[0041] As shown in Figure 1 The voltage dividing unit 11 includes a third resistor R3, a fourth resistor R4 and a fifth resistor R5; the first end of the third resistor R3 is connected to the voltage input terminal for connecting the reference voltage VBAT; the first end of the fourth resistor R4 is connected to the second end of the third resistor R3, and the first end of the fourth resistor R4 is also connected to the first end of the first resistor R1 through the wire harness connector 20; the first end of the fifth resistor R5 is connected to the second end of the fourth resistor R4, and the first end of the fifth resistor R5 is also connected to the controller 12 as the voltage output terminal VOUT, and the second end of the fifth resistor R5 is grounded. The first preset range is set according to the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT.

[0042] Wherein, the specific resistance values of the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are not limited herein, and a designer can make reasonable design according to actual needs. When at least one of the wiring harness connector 20, the first resistor R1 and the second resistor R2 is in an open circuit condition, the voltage of the voltage output end VOUT is only calculated by the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT through voltage division, and thus the specific value of the first preset range is determined by the resistance values of the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT.

[0043] As shown in Figure 1 , the voltage dividing unit 11 further includes a capacitor C1, and the capacitor C1 is connected in parallel with the fifth resistor R5 (i.e., a first plate of the capacitor C1 is connected with a first end of the fifth resistor R5, and a second plate of the capacitor C1 is connected with a second end of the fifth resistor R5). By designing the capacitor C1, the capacitor C1 and the fourth resistor R4 form an RC filter circuit, which can effectively filter out the alternating component.

[0044] Specifically, the capacitance of the capacitor C1 is 10nF. By reasonably designing the capacitance of the capacitor C1, high-frequency noise will not enter the controller 12, thereby avoiding the occurrence of no judgment, and at the same time, playing a role in protecting the controller 12.

[0045] It can be understood that the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 form a voltage dividing circuit, and the controller 12 can also determine whether the liquid level of the liquid storage container is in a normal state according to the size of the voltage output by the voltage output end VOUT. Specifically, the controller 12 is further configured to determine that the liquid level of the liquid storage container is in a normal state when receiving the voltage of the voltage output end VOUT being in a third preset range; in the normal state, the switch K1 is open, and the third preset range is set according to the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT. The specific value of the third preset range is not limited herein, and a designer can make reasonable design according to actual needs; and it can be understood that when the liquid level of the liquid storage container is in the normal state, the switch K1 is open, and the second resistor R2 is not short-circuited by the switch K1, at this time the voltage of the voltage output end VOUT is calculated by the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT through voltage division, and thus the specific value of the third preset range is determined by the resistance values of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT. When the controller 12 receives the voltage of the voltage output end VOUT being in the third preset range, the controller 12 sends a third prompt signal to the prompt module, and the prompt module makes corresponding prompt according to the third prompt signal.

[0046] It can be understood that, as shown in Figure 1 The first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 constitute a voltage dividing circuit, and the controller 12 can also determine whether the liquid level of the liquid storage container is in the liquid shortage state according to the voltage output by the voltage output terminal VOUT. Specifically, the controller 12 is further configured to determine that the liquid level of the liquid storage container is in the liquid shortage state when the voltage of the voltage output terminal VOUT is in the fourth preset range. In the liquid shortage state, the switch K1 is closed under the action of the electromagnetic float, and the fourth preset range is set according to the first resistor R1, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT. Here, the specific value of the fourth preset range is not limited, and the designer can reasonably design according to actual needs; and it can be understood that when the liquid level of the liquid storage container is in the liquid shortage state, the switch K1 is closed under the action of the electromagnetic float, and the second resistor R2 is short-circuited by the switch K1. At this time, the voltage of the voltage output terminal VOUT is calculated by voltage dividing the first resistor R1, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT; therefore, the specific value of the fourth preset range is determined by the resistance values of the first resistor R1, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT. When the controller 12 receives the voltage of the voltage output terminal VOUT in the fourth preset range, the controller 12 sends a fourth prompt signal to the prompt module, and the prompt module makes a corresponding prompt according to the fourth prompt signal. The user can take appropriate measures according to the prompt.

[0047] It should be noted that the specific resistance values of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 are not limited, and the designer can reasonably design the resistance values of the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4 and the fifth resistor R5 so that there is no overlap between the first preset range, the third preset range and the fourth preset range, so as to avoid the possibility of false judgment.

[0048] The voltage of the voltage output terminal VOUT is calculated for the four different scenarios of open circuit, short circuit to ground, normal state and liquid shortage state as follows:

[0049] 1. When the open circuit condition: the voltage of the voltage output terminal VOUT is calculated by voltage dividing the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT; in consideration of the accuracy of each resistor being 1%, and reserving 20% margin, it is specifically:

[0050] VOUT_min = VBAT x (1 - 20%) x R5 x (1 - 1%) / (R3 x (1 + 1%) + R4 x (1 + 1%) + R5 x (1 - 1%)) - Equation 1

[0051] VOUT_max = VBAT x (1 + 20%) x R5 x (1 + 1%) / (R3 x (1 - 1%) + R4 x (1 - 1%) + R5 x (1 + 1%)) - Equation 2

[0052] By substituting R3 = 10K, R4 = 68K, R5 = 24K into the above Equation 1 and Equation 2, we can get:

[0053] VOUT_min = 0.1854 x VBAT - Equation 3

[0054] VOUT_max = 0.2867 x VBAT - Equation 4

[0055] From the above, when R3 = 10K, R4 = 68K, R5 = 24K, the first preset range is 0.1854 x VBAT < VOUT < 0.2867 x VBAT, if the voltage of the voltage output terminal VOUT obtained by the controller 12 is in the range, it is determined that at least one of the wiring harness connector 20, the first resistor R1 and the second resistor R2 is in an open circuit condition.

[0056] 2-Short circuit to ground condition: the voltage of the voltage output terminal VOUT is close to zero, considering the fluctuation of the ground terminal, therefore the second preset range is set as VOUT < 0.15V, if the voltage of the voltage output terminal VOUT obtained by the controller 12 is in the range, it is determined that the wiring harness connector 20 is in a short circuit to ground condition.

[0057] 3-Normal state: the voltage of the voltage output terminal VOUT is calculated by the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, the fifth resistor R5 and the reference voltage VBAT voltage division; in consideration of the accuracy of each resistor being 1% and reserving 20% margin, it is specifically:

[0058] VOUT_min = VBAT x (1 - 20%) x R5 x (1 - 1%) x ((R4 x (1 + 1%) + R5 x (1 - 1%)) x (R1 x (1 - 1%) + R2 x (1 - 1%)) / (R1 x (1 - 1%) + R2 x (1 - 1%) + R4 x (1 + 1%) + R5 x (1 - 1%)) / ((((R4 x (1 + 1%) + R5 x (1 - 1%)) x (R1 x (1 - 1%) + R2 x (1 - 1%)) / (R1 x (1 - 1%) + R2 x (1 - 1%) + R4 x (1 + 1%) + R5 x (1 - 1%)) + R3 x (1 + 1%)) / (R4 x (1 + 1%) + R5 x (1 - 1%)) - Equation 5

[0059] VOUT_max = VBAT x (1 + 20%) x R5 x (1 + 1%) x ((R4 x (1 - 1%) + R5 x (1 + 1%)) x (R1 x (1 + 1%) + R2 x (1 + 1%)) / (R1 x (1 + 1%) + R2 x (1 + 1%) + R4 x (1 - 1%) + R5 x (1 + 1%)) / ((((R4 x (1 - 1%) + R5 x (1 + 1%)) x (R1 x (1 + 1%) + R2 x (1 + 1%)) / (R1 x (1 + 1%) + R2 x (1 + 1%) + R4 x (1 - 1%) + R5 x (1 + 1%)) + R3 x (1 - 1%)) / (R4 x (1 - 1%) + R5 x (1 + 1%)) - Equation 6

[0060] By substituting R1 = 2K, R2 = 10K, R3 = 10K, R4 = 68K, R5 = 24K into the above Equation 5 and Equation 6, we can obtain:

[0061] VOUT_min = 0.1049 x VBAT - Equation 7

[0062] VOUT_max = 0.1650 x VBAT - Equation 8

[0063] From the above, when R1 = 2K, R2 = 10K, R3 = 10K, R4 = 68K, R5 = 24K, the third preset range is: 0.1049 x VBAT < VOUT < 0.1650 x VBAT, if the voltage of the voltage output end VOUT obtained by the controller 12 is in the range, it is determined that the liquid level of the liquid container is in a normal state.

[0064] 4- When the liquid level is low: the voltage of the voltage output end VOUT is calculated by the first resistance R1, the third resistance R3, the fourth resistance R4, the fifth resistance R5 and the reference voltage VBAT; in the case of considering that the accuracy of each resistance is 1% and reserving 20% margin, it is specifically:

[0065] VOUT_min = VBAT x (1 - 20%) x R5 x (1 - 1%) x ((R4 x (1 + 1%) + R5 x (1 - 1%)) x R1 x (1 - 1%) / (R1 x (1 - 1%) + R4 x (1 + 1%) + R5 x (1 - 1%)) / ((((R4 x (1 + 1%) + R5 x (1 - 1%)) x R1 x (1 - 1%)) / (R1 x (1 - 1%) + R4 x (1 + 1%) + R5 x (1 - 1%)) + R3 x (1 + 1%)) / (R4 x (1 + 1%) + R5 x (1 - 1%)) --- Equation 9

[0066] VOUT_max = VBAT x (1 + 20%) x R5 x (1 + 1%) x ((R4 x (1 - 1%) + R5 x (1 + 1%)) x R1 x (1 + 1%) / (R1 x (1 + 1%) + R4 x (1 - 1%) + R5 x (1 + 1%)) / ((((R4 x (1 - 1%) + R5 x (1 + 1%)) x R1 x (1 + 1%)) / (R1 x (1 + 1%) + R4 x (1 - 1%) + R5 x (1 + 1%)) + R3 x (1 - 1%)) / (R4 x (1 - 1%) + R5 x (1 + 1%)) --- Equation 10

[0067] R1 = 2K, R3 = 10K, R4 = 68K, and R5 = 24K into the above Equation 9 and Equation 10 can obtain:

[0068] VOUT_min = 0.0331 x VBAT --- Equation 11

[0069] VOUT_max = 0.0529 x VBAT --- Equation 12

[0070] It can be known from the above that, when R1 = 2K, R3 = 10K, R4 = 68K, and R5 = 24K, the fourth preset range is: 0.0331 x VBAT < VOUT < 0.0529 x VBAT, and if the voltage of the voltage output end VOUT obtained by the controller 12 is in the range, it is determined that the liquid level of the liquid storage container is in the liquid shortage state.

[0071] It should be noted that, by designing the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5, the first resistor R1, the second resistor R2, the third resistor R3, the fourth resistor R4, and the fifth resistor R5 form a voltage dividing circuit, and the controller 12 can determine the four different scenarios of the open circuit condition, the short circuit to ground condition, the normal state, and the liquid shortage state according to the size of the voltage output by the voltage output end VOUT, compared with the related art which can only determine the two scenarios of the normal state and the liquid shortage state, the function of the liquid level diagnosis system 1 in the present application is more perfect.

[0072] The liquid level diagnosis system 1 further comprises a power supply module (not shown in the figure) for supplying power to the liquid level diagnosis system 1; the voltage input end is connected with the power supply module to access the reference voltage VBAT. Wherein, only in the case of 6.5V < VBAT < 18V, the diagnosis is carried out, and the result of the calculation is valid. Specifically, the power supply module is a vehicle-mounted small battery, so the reference voltage VBAT accessed by the voltage input end is usually 13.5V, and the controller 12 will sample this voltage and participate in the diagnosis calculation based on the sampling value.

[0073] As shown in Figure 1 The wire harness connector 20 comprises a wire harness body 21, a first connector 22 and a second connector 23; one end of the wire harness body 21 is connected with the first connector 22, and the other end of the wire harness body 21 is connected with the second connector 23; the first end of the first resistor R1 is connected with the first connector 22, and the voltage dividing unit 11 is connected with the second connector 23. By designing the wire harness body 21, the first connector 22 and the second connector 23, the effective electrical connection between the first end of the first resistor R1 and the voltage dividing unit 11 can be realized, so that the effective electrical connection between the liquid level sensor 30 and the diagnosis circuit 10 can be realized.

[0074] Specifically, the liquid level sensor 30 further comprises a first circuit board 31, and the first resistor R1, the second resistor R2 and the switch K1 are arranged on the first circuit board 31; the diagnosis circuit 10 further comprises a second circuit board 13, and the voltage dividing unit 11 and the controller 12 are arranged on the second circuit board 13. The first connector 22 comprises a first male plug 221 and a first female plug 222, one of the first male plug 221 and the first female plug 222 is arranged on the first circuit board 31 and connected with the first end of the first resistor R1, and the other of the first male plug 221 and the first female plug 222 is connected with one end of the wire harness body 21. The second connector 23 comprises a second male plug 231 and a second female plug 232, one of the second male plug 231 and the second female plug 232 is arranged on the second circuit board 13 and connected with the voltage dividing unit 11, and the other of the second male plug 231 and the second female plug 232 is connected with the other end of the wire harness body 21. By designing the first connector 22 as the first male plug 221 and the first female plug 222, so that one end of the wire harness body 21 can be detachably connected with the first circuit board 31 through the first male plug 221 and the first female plug 222; by designing the second connector 23 as the second male plug 231 and the second female plug 232, so that the other end of the wire harness body 21 can be detachably connected with the second circuit board 13 through the second male plug 231 and the second female plug 232, so as to facilitate the replacement of the damaged wire harness connector 20 in the later period.

[0075] The present application provides a liquid level diagnosis method, which is realized by the above-mentioned liquid level diagnosis system 1. Please refer to Figure 3 ,Figure 3 A flowchart of a liquid level diagnosis method in an embodiment of the present application is shown in FIG. 1. As shown in FIG. 1, the liquid level diagnosis method comprises the following steps: Figure 3

[0076] Step S0: Obtain the voltage output by the voltage output terminal VOUT.

[0077] Step S2: When the voltage received by the voltage output terminal VOUT is within a first preset range, determine that at least one of the wire harness connector 20, the first resistor R1 and the second resistor R2 is in an open circuit condition.

[0078] In step S2, the specific value of the first preset range is not limited here, and a designer can make reasonable design according to actual needs. It should be noted that when the voltage received by the voltage output terminal VOUT is within the first preset range, it can be that only the wire harness connector 20 is in an open circuit condition, or only the first resistor R1 is in an open circuit condition, or only the second resistor R2 is in an open circuit condition, or the wire harness connector 20 and the first resistor R1 are in an open circuit condition, or the wire harness connector 20 and the second resistor R2 are in an open circuit condition, or the first resistor R1 and the second resistor R2 are in an open circuit condition, or the wire harness connector 20, the first resistor R1 and the second resistor R2 are all in an open circuit condition.

[0079] Step S4: When the voltage received by the voltage output terminal VOUT is within a second preset range, determine that the wire harness connector 20 is in a short circuit to ground condition.

[0080] In step S4, the specific value of the second preset range is not limited here, and a designer can make reasonable design according to actual needs.

[0081] Based on the liquid level diagnosis method in the embodiment of the present application, when the voltage received by the voltage output terminal VOUT is within the first preset range, it is determined that at least one of the wire harness connector 20, the first resistor R1 and the second resistor R2 is in an open circuit condition, and when the voltage received by the voltage output terminal VOUT is within the second preset range, it is determined that the wire harness connector 20 is in a short circuit to ground condition, so that it can effectively diagnose whether the liquid level sensor 30 itself is in an open circuit condition, and whether the wire harness connector 20 between the liquid level sensor 30 and the diagnosis circuit 10 is in an open circuit condition or a short circuit to ground condition, thereby effectively improving the safety and reliability of the vehicle.

[0082] Further, please refer to Figure 4 , Figure 4 A flowchart of a liquid level diagnosis method in another embodiment of the present application is shown in FIG. 2. As shown in FIG. 2, the liquid level diagnosis method further comprises step S6: Figure 4

[0083] ​​Step S6: when the voltage of the voltage output terminal VOUT is in the third preset range, it is determined that the liquid level of the liquid storage container is in a normal state, in which the switch K1 is open.

[0084] In step S6, the specific value of the third preset range is not limited here, and a designer can make reasonable design according to actual needs.

[0085] Further, as shown in the figure, the liquid level diagnosis method further includes step S8: Figure 4

[0086] Step S8: when the voltage of the voltage output terminal VOUT is in the fourth preset range, it is determined that the liquid level of the liquid storage container is in a liquid shortage state, in which the switch K1 is closed under the action of the magnetic float.

[0087] In step S8, the specific value of the fourth preset range is not limited here, and a designer can make reasonable design according to actual needs.

[0088] It should be noted that there is no overlap between the first preset range, the second preset range, the third preset range and the fourth preset range, so as to avoid the possibility of misjudgment.

[0089] The application provides a vehicle (not shown in the figure), which comprises the above-mentioned liquid level diagnosis system 1, which can effectively diagnose whether the liquid level sensor 30 itself has a breakage condition, and can also effectively diagnose whether the wire harness connector 20 between the liquid level sensor 30 and the diagnosis circuit 10 has a breakage condition, thereby effectively improving the safety and reliability of the vehicle.

[0090] The same or similar reference numerals in the drawings of the embodiments correspond to the same or similar components; in the description of the application, it should be understood that if the terms "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation of the patent, for those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0091] The above only describes the preferred embodiments of the application and does not limit the application, any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.​

Claims

1. A liquid level diagnostic system, characterized in that: include: The diagnostic circuit includes a voltage dividing unit and a controller, wherein the voltage dividing unit has a voltage input terminal and a voltage output terminal, wherein the voltage input terminal is used to connect to a reference voltage, and the voltage output terminal is connected to the controller; Wiring harness connector; A liquid level sensor comprising a first resistor, a second resistor, and a switch coordinated with an electromagnetic float, wherein a first end of the first resistor is connected to the voltage divider unit via the wiring harness connector, a second end of the first resistor is connected to a first end of the second resistor, a second end of the second resistor is grounded, and the switch is connected in parallel with the second resistor; The controller is configured to determine that a circuit breaker exists in at least one of the wiring harness connector, the first resistor, and the second resistor when receiving a voltage at the voltage output terminal that is within a first preset range.

2. The liquid level diagnostic system according to claim 1, wherein: The controller is further configured to determine that a short-to-ground condition exists in the wiring harness connector when the voltage received from the voltage output terminal is within a second preset range.

3. The liquid level diagnostic system according to claim 1 or 2, characterized in that: The voltage dividing unit includes: a third resistor, wherein a first end of the third resistor serves as the voltage input end and is used to connect the reference voltage; a fourth resistor, wherein a first end of the fourth resistor is connected to the second end of the third resistor, and a first end of the fourth resistor is further connected to the first end of the first resistor via the wiring harness connector; a fifth resistor, wherein a first end of the fifth resistor is connected to the second end of the fourth resistor, the first end of the fifth resistor is also connected to the controller as the voltage output end, and a second end of the fifth resistor is grounded; The first preset range is set according to the third resistor, the fourth resistor, the fifth resistor, and the reference voltage.

4. The liquid level diagnostic system according to claim 3, wherein: The voltage dividing unit further includes a capacitor, and the capacitor is connected in parallel with the fifth resistor.

5. The liquid level diagnostic system according to claim 3, wherein: The controller is also used to determine that the liquid level of the liquid storage container is in a normal state when the voltage received at the voltage output end is within a third preset range; in the normal state, the switch is disconnected, and the third preset range is set according to the first resistor, the second resistor, the third resistor, the fourth resistor, the fifth resistor and the reference voltage.

6. The liquid level diagnostic system according to claim 3, wherein: The controller is also used to determine that the liquid level of the liquid storage container is in a liquid-deficient state when the voltage received at the voltage output end is within a fourth preset range; in the liquid-deficient state, the switch is closed under the action of the electromagnetic float, and the fourth preset range is set according to the first resistor, the third resistor, the fourth resistor, the fifth resistor and the reference voltage.

7. A liquid level diagnosis method, characterized in that: The method is implemented by the liquid level diagnostic system according to any one of claims 1 to 6; the method comprises: Get the voltage output from the voltage output terminal; When receiving that the voltage at the voltage output terminal is within a first preset range, determining that at least one of the wiring harness connector, the first resistor, and the second resistor has a circuit breaker condition; When the voltage received from the voltage output terminal is within a second preset range, it is determined that a short-to-ground condition exists in the wiring harness connector.

8. The liquid level diagnosis method according to claim 7, characterized in that: When the voltage received from the voltage output terminal is within a third preset range, it is determined that the liquid level of the liquid storage container is in a normal state. In the normal state, the switch is disconnected.

9. The liquid level diagnosis method according to claim 8, characterized in that: When the voltage received from the voltage output terminal is within a fourth preset range, it is determined that the liquid level of the liquid storage container is in a liquid-deficient state; in the liquid-deficient state, the switch is closed under the action of the electromagnetic float.

10. A vehicle, characterized in that: The liquid level diagnostic system comprises the liquid level diagnostic system according to any one of claims 1 to 6.

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