An alarm device and method for reflecting the water level of a diesel filter

Abstract

The present invention provides an alarm device and method for reflecting the water level of a diesel filter. The device and method include two parts: one is a self-test of the water level sensor function to detect whether the water level sensor function is normal; the other is a water level detection to detect whether the water level in the filter is high enough to conduct the probe, thereby determining whether to light up the water level alarm light. If the water level in the filter exceeds the probe and lasts for more than a preset time, a water level alarm is issued, and the water level alarm light is on, prompting the owner to drain the water. The present invention can accurately reflect the water level in the filter and avoid false alarms. It can perform a self-test to determine whether the function is normal when the entire vehicle is powered on, avoiding the situation where the water level exceeds the probe and there is no alarm or false alarm during driving; it can also accurately monitor whether the water level in the filter has actually submerged the probe and accurately alarm, and determine whether to light up the alarm light by the output duration of the high level, filtering out many false alarms (such as the probe being occasionally turned on due to shaking).

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to an alarm device and method for reflecting the water level of a diesel filter. Background Art

[0002] Current diesel vehicles are all equipped with a diesel filter. Because diesel contains a small amount of water, it is necessary to filter out the water and impurities. When the filtered water exceeds a certain amount, an alarm is triggered, reminding the owner to drain the filtered water. This prevents the filter paper from becoming soaked due to the increased amount of filtered water, leading to diesel filter failure, and ultimately difficulty starting the vehicle. Water can also enter the engine along with the diesel, causing engine failure. Therefore, the owner is required to manually drain the water according to the water level alarm to prevent malfunctions.

[0003] In the prior art, to promptly remind vehicle owners to drain the water, a water level sensor is installed at the bottom of the diesel filter. This sensor has two probes. When the water level rises to the position of the two probes, the probes are connected, and an alarm light comes on, prompting the vehicle owner to drain the water. If the water level does not connect the two probes, the alarm light will not come on. Because it has no internal protection circuit and cannot self-check whether its function is normal, changes in vehicle speed during driving will cause the liquid inside the diesel filter to slosh. This will cause the two probes to connect intermittently when encountering water, and thus cause the water level alarm light to light intermittently, causing complaints from vehicle owners. In addition, when the water level sensor malfunctions, it cannot be discovered in advance. At this time, if the water level in the filter rises and connects the two probes, the water level alarm light will not light. As mentioned above, the filtered water will increase, causing the filter paper inside the filter to be soaked by water, resulting in diesel filter failure, which will ultimately make it difficult to start the vehicle. Water will also enter the engine along with the diesel, causing engine failure. Summary of the Invention

[0004] In response to the defects in the prior art, the purpose of the present invention is to provide an alarm device and method for reflecting the water level of a diesel filter, which can effectively circumvent the problems existing in the prior art. Even if the liquid inside the diesel filter shakes violently, it will not cause the water level alarm light to light up intermittently. In the present invention, the water level sensor communicates with the vehicle ECU and combines the ECU program to identify whether the water level sensor is working normally, and promptly detects whether the water level sensor is faulty, thereby preventing the actual water level from overflowing the probe and the alarm light from not lighting up.

[0005] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical solution:

[0006] According to a first aspect of the present invention, there is provided an alarm method for reflecting the water level of a diesel filter, comprising the following steps:

[0007] S1: Water level sensor self-test to determine whether the water level sensor functions normally, including:

[0008] When the vehicle is powered on but not started, and the vehicle key is in the ON position, the ECU provides a first preset voltage to the water level sensor, and the water level sensor outputs a level signal to the ECU. The ECU determines whether the level signal is a first preset high level within an initial preset time:

[0009] If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0010] If the result is yes, the ECU determines that the first water level alarm function is normal, the water level alarm light is on, and after the aforementioned initial preset time, the ECU continues to determine whether the level signal is the first preset low level:

[0011] If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0012] If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends;

[0013] S2: If the water level sensor functions normally, perform a water level test to determine whether the water level in the filter is high enough to pass the probe. Specifically, the test includes:

[0014] When the vehicle is in the starting state, the ECU provides a second preset voltage to the water level sensor:

[0015] If the water level sensor outputs the second preset low level, the ECU determines that the water level is low and the water level alarm light goes off;

[0016] If the water level sensor outputs the second preset high level and the duration exceeds the preset time within a driving cycle, the ECU determines that the water level is high and the water level warning light turns on;

[0017] If the water level sensor outputs the second preset high level and the duration does not exceed the preset time within a driving cycle, the ECU will determine it as a false alarm and the water level warning light will not light up.

[0018] Preferably, the first preset voltage and the second preset voltage are the same, both being 12V.

[0019] Preferably, the first preset high level and the second preset high level are the same, both being >10V.

[0020] Preferably, the first preset low level and the second preset low level are the same, both being <0.5V.

[0021] Preferably, the initial preset time is 1 to 3 seconds; the preset duration is 10 seconds.

[0022] According to a second aspect of the present invention, there is provided a water level alarm device for a diesel filter, comprising: a function self-test module and a water level detection module, wherein the function self-test module is used to determine whether a water level sensor is functioning normally; and the water level detection module is used to determine whether the water level in the filter is high enough to contact a probe when the water level sensor is functioning normally, thereby determining whether to light a water level alarm light.

[0023] The function self-test module can be used when the vehicle is powered on but not started and the vehicle key is in the ON position:

[0024] The ECU provides a first preset voltage to the water level sensor, and the water level sensor outputs a level signal to the ECU. The ECU determines whether the level signal is a first preset high level within an initial preset time:

[0025] If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0026] If the result is yes, the ECU determines that the first water level alarm function is normal, the water level alarm light is on, and after the aforementioned initial preset time, the ECU continues to determine whether the level signal is the first preset low level:

[0027] If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0028] If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends;

[0029] The water level detection module can enable:

[0030] The ECU continuously supplies 12V power to the water level sensor: If the water level sensor outputs the second preset low level, the ECU determines that the water level is low, and the water level alarm light goes off;

[0031] If the water level sensor outputs the second preset high level and the duration exceeds the preset time within a driving cycle, the ECU determines that the water level is high and the water level warning light turns on;

[0032] If the water level sensor outputs the second preset high level and the duration does not exceed the preset time within a driving cycle, the ECU will determine it as a false alarm and the water level warning light will not light up.

[0033] Preferably, the first preset voltage and the second preset voltage are the same, both being 12V.

[0034] Preferably, the first preset high level and the second preset high level are the same, both being >10V.

[0035] Preferably, the first preset low level and the second preset low level are the same, both being <0.5V.

[0036] Preferably, the initial preset time is 1 to 3 seconds; the preset duration is 10 seconds.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The alarm device and method for reflecting the water level of the diesel filter provided by the present invention can perform self-detection to see whether the function is normal when the entire vehicle is powered on, thereby avoiding the situation where no alarm is given and false alarm occurs when the water level is higher than the probe during driving; and the present invention can accurately monitor whether the water level in the filter is actually submerging the probe, and accurately alarm, and determine whether the alarm light is on through the output time of the high level, filtering out many false alarms (such as the probe being occasionally turned on due to shaking). BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0040] Figure 1 This is a flow chart of the water level sensor function self-test process described in Example 1 of the present invention;

[0041] Figure 2 This is a flow chart of the water level detection process described in Example 1 of the present invention;

[0042] Figure 3 This is the circuit diagram of the water level sensor function self-test process;

[0043] Figure 4 This is the circuit diagram of the water level sensor alarm process when it encounters water;

[0044] Figure 5 The circuit diagram of the water level sensor also has the output short-circuit protection function. DETAILED DESCRIPTION

[0045] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0046] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for protection, but merely represents selected embodiments of the present application. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments in the present application without creative work are within the scope of protection of the present application.

[0047] It should be noted that similar numbers and letters represent similar items in the following figures. Therefore, once an item is defined in one figure, it does not need to be further defined or explained in subsequent figures. In addition, all directional indications in this application (such as up, down, left, right, front, back, bottom...) are only used to explain the relative position relationship, movement, etc. between the components under a specific posture (as shown in the figures). If the specific posture changes, the directional indication will also change accordingly. Furthermore, the descriptions of "first", "second", etc. in the application are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features.

[0048] Example 1

[0049] This embodiment provides an alarm method for reflecting the water level of a diesel filter, which includes two parts. The first part is a self-test of the water level sensor function, which is used to detect whether the water level sensor function is normal (OUT outputs a high-level water level alarm light and is on, OUT outputs a low-level water level alarm light and is off); the second part is a water level detection, which detects whether the water level in the filter is high enough to conduct the probe, thereby determining whether the water level alarm light is on. If the water level in the filter exceeds the probe and lasts for more than a preset time, a water level alarm is issued, and the water level alarm light is on, prompting the owner to drain the water. If the water level in the filter does not exceed the probe, or the water conducts the probe for a short time due to sloshing but the duration does not exceed the preset time, the water level alarm light will not be on. This can correctly reflect the water level in the filter and avoid false alarms.

[0050] This embodiment provides an alarm method for reflecting the water level of the diesel filter, such as Figure 1 and Figure 2 As shown, the specific steps include:

[0051] S1: Water level sensor self-test to determine whether the water level sensor functions normally, including:

[0052] When the vehicle is powered on but not started, and the vehicle key is in the ON position, the ECU provides a preset voltage to the water level sensor (in this embodiment, the preset voltage is 12V). The water level sensor outputs a level signal to the ECU, which determines whether the level signal is a preset high level within an initial preset time (in this embodiment, the preset high level is >10V, and the initial preset time is 1 to 3 seconds):

[0053] If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0054] If the result of the determination is yes, the ECU determines that the first water level alarm function is normal, and the water level alarm light turns on. After the aforementioned initial preset time (i.e., after 3 seconds), the ECU determines whether the level signal is a preset low level (in this embodiment, the preset low level refers to <0.5V):

[0055] If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0056] If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends;

[0057] S2: If the water level sensor functions normally, perform a water level test to determine whether the water level in the filter is high enough to touch the probe, thereby determining whether the water level alarm light is on. Specifically, the following steps are performed:

[0058] When the vehicle is in the starting state, the ECU continuously supplies 12V power to the water level sensor:

[0059] If the water level sensor outputs a preset low level (in this embodiment, the preset low level is <0.5V), it indicates that the water level in the diesel filter is so low that the two probes are not connected. Therefore, the ECU determines that the water level is low and there is no need to drain the water. The water level warning light does not light up.

[0060] If the water level sensor outputs a preset high level (in this embodiment, the preset high level is >10V) within a driving cycle and the duration exceeds a preset time (in this embodiment, the preset time is 10s), the ECU determines that the water level is high and needs to be drained, and the water level warning light turns on;

[0061] If the water level sensor outputs a preset high level (in this embodiment, the preset high level is >10V) within a driving cycle and the duration does not exceed the preset time (in this embodiment, the preset time is 10s), the ECU will determine it as a false alarm, no water needs to be drained, and the water level warning light will not light up.

[0062] Example 2

[0063] This embodiment provides an alarm device for reflecting the water level of a diesel filter, which includes two major modules. One is a water level sensor function self-test module, which is used to detect whether the water level sensor function is normal (OUT outputs a high-level water level alarm light and is on, OUT outputs a low-level water level alarm light and is off); the other is a water level detection module, which is used to detect whether the water level in the filter is high enough to conduct the probe, thereby determining whether to light up the water level alarm light. If the water level in the filter exceeds the probe and lasts for more than a preset time, a water level alarm is issued and the water level alarm light is on, prompting the owner to drain the water. If the water level in the filter does not exceed the probe, or the water conducts the probe for a short time due to sloshing but the duration does not exceed the preset time, the water level alarm light will not light up. This can correctly reflect the water level in the filter and avoid false alarms.

[0064] The water level alarm device for a diesel filter provided in this embodiment includes:

[0065] A water level sensor function self-test module and a water level detection module. The water level sensor function self-test module is used to determine whether the water level sensor functions normally. The water level detection module is used to determine whether the water level in the filter is high enough to conduct the probe when the water level sensor self-tests normally, thereby determining whether to light up the water level alarm light.

[0066] The water level sensor function self-test module can, when the vehicle is powered on but not started, and the vehicle key is in the ON position, cause the ECU to provide a preset voltage (in this embodiment, the preset voltage is 12V) to the water level sensor, and the water level sensor to output a level signal to the ECU. The ECU determines whether the level signal is a preset high level within an initial preset time (in this embodiment, the preset high level is greater than 10V, and the initial preset time is 1 to 3 seconds):

[0067] If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0068] If the result of the determination is yes, the ECU determines that the first water level alarm function is normal, and the water level alarm light turns on. After the aforementioned initial preset time (i.e., after 3 seconds), the ECU determines whether the level signal is a preset low level (in this embodiment, the preset low level refers to <0.5V):

[0069] If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends;

[0070] If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends;

[0071] The water level detection module can enable the ECU to continuously supply 12V power to the water level sensor when the vehicle is in the starting state:

[0072] If the water level sensor outputs a preset low level (in this embodiment, the preset low level is <0.5V), it indicates that the water level in the diesel filter is so low that the two probes are not connected. Therefore, the ECU determines that the water level is low and there is no need to drain the water. The water level warning light does not light up.

[0073] If the water level sensor outputs a preset high level (in this embodiment, the preset high level is >10V) within a driving cycle and the duration exceeds a preset time (in this embodiment, the preset time is 10s), the ECU determines that the water level is high and needs to be drained, and the water level warning light turns on;

[0074] If the water level sensor outputs a preset high level (in this embodiment, the preset high level is >10V) within a driving cycle and the duration does not exceed the preset time (in this embodiment, the preset time is 10s), the ECU will determine it as a false alarm, no water needs to be drained, and the water level warning light will not light up.

[0075] The following describes the circuit diagram of the water level sensor in the above two embodiments of the present invention:

[0076] Figure 3 The circuit diagram shows the self-test process of the water level sensor function.

[0077] 1. The vehicle starts to power on (input voltage 12V), within 1 to 3 seconds:

[0078] At the moment of power-on, the base of Q2 is grounded to a low level, and the collector and emitter of Q2 are in the on state;

[0079] The base of Q3 is connected to the emitter of Q2, which is high level, so the collector and emitter of Q3 are in non-conducting state.

[0080] The voltage at the amplifier "+" is C1, and C1 is 0V. (The voltage at the amplifier "-" terminal is a constant value, and the specific value depends on the voltage divider of R2 and R3);

[0081] When “-”>“+”, the operational amplifier outputs a low level, which reaches the base of Q1 through R4, controlling the switch Q1 to turn on. Since Q3 is blocked and Q1 and Q2 are turned on, OUT continuously outputs a high level of >10V (about 11.3V). The ECU controls the water level alarm light to turn on according to the high level signal output by OUT.

[0082] 2. Power-on self-test (input voltage 12V), after 3 seconds:

[0083] The "+" terminal of the amplifier is the voltage of C1. After charging for 1 to 3 seconds, the voltage of C1 exceeds the voltage of the "-" terminal of the amplifier. At this time, "-" is less than "+", and the operational amplifier outputs a high level (about 11V). This high level reaches the base of Q1 through R4, and the control switch Q1 is not turned on. Since the conduction state of Q2 and Q3 does not change, Q1 and Q3 are not turned on, and Q2 is turned on, so OUT continuously outputs a low level of less than 0.5V, and the water level alarm light goes out.

[0084] Figure 4 The circuit diagram shows the process of the water level sensor alarming when encountering water:

[0085] When probe a and probe b are connected by water, R7 is connected to the voltage divider, causing the voltage at the "+" end of the amplifier circuit to drop suddenly, making "-" > "+", and the amplifier "-" > "+". The operational amplifier outputs a low level, which reaches the base of Q1 through R4 and controls the switch Q1 to turn on;

[0086] The conduction state of Q2 and Q3 does not change;

[0087] Since Q3 is blocked and Q1 and Q2 are connected, OUT continuously outputs a high level of >10V (about 11.3V). The ECU controls the water level alarm light to light up according to the high level signal output by OUT.

[0088] In addition, if Figure 5 As shown, the circuit of the water level sensor also has the output short-circuit protection function to ground:

[0089] 1. When the water level is low, probes a and b are disconnected, and within the first 1-3 seconds of the water level sensor's self-test, Q3 is disconnected, Q1 and Q2 are connected, and OUT continuously outputs a high level greater than 10V (approximately 11.3V). At this time, if OUT and GND are connected, Q1's output current increases sharply, the voltage at point A decreases, and the potential at point C drops to a low level, turning on Q3. The voltage at point B increases, turning off Q2. Since Q2 is turned off, there is no voltage at Q1's collector, resulting in no output from Q1's transistor and the high current being cut off, thus providing protection.

[0090] 2. When the water level is low, probe a and probe b are not connected, and the water level sensor function self-test process ends. Q1 and Q3 are blocked, Q2 is connected, OUT and GND are connected. Since Q1 is blocked, no large current will flow.

[0091] 3. When the water level is high, probes a and b conduct, Q3 is blocked, Q1 and Q2 conduct, and OUT continuously outputs a high level greater than 10V (approximately 11.3V). At this point, if OUT and GND conduct, Q1's output current increases sharply, the voltage at point A decreases, and the potential at point C drops to a low level, turning Q3 on. The voltage at point B increases, turning Q2 off. Q2's off state eliminates voltage at Q1's collector, resulting in no output from Q1's transistor and thus cutting off the high current, thus providing protection. If OUT and GND conduct, since Q1 is blocked, no high current flows.

[0092] The alarm device and method provided by the present invention can perform self-detection to determine whether the function is normal when the entire vehicle is powered on, thereby avoiding the situation where no alarm occurs or false alarm occurs when the water level exceeds the probe during driving; it can also accurately monitor whether the water level in the filter is actually submerging the probe and accurately alarm, and determine whether to light up the alarm by the high-level output time, filtering out many false alarms (such as the occasional conduction of the probe due to shaking); at the same time, it can effectively prevent the output (OUT) from short-circuiting to ground (GND) and causing a large current, thereby effectively protecting the entire circuit.

[0093] The above describes the specific embodiments of the present invention. Based on the above description, relevant personnel can make various changes and modifications without departing from the scope of the technical concept of this invention.

Claims

1. An alarm method for reflecting the water level of a diesel filter, characterized in that: The steps include: S1: Water level sensor self-test to determine whether the water level sensor functions normally, including: When the vehicle is powered on but not started, and the vehicle key is in the ON position, the ECU provides a first preset voltage to the water level sensor, and the water level sensor outputs a level signal to the ECU. The ECU determines whether the level signal is a first preset high level within an initial preset time: If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends; If the result is yes, the ECU determines that the first water level alarm function is normal, the water level alarm light is on, and after the aforementioned initial preset time, the ECU continues to determine whether the level signal is the first preset low level: If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends; If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends; S2: If the water level sensor functions normally, perform a water level test to determine whether the water level in the filter is high enough to pass the probe. Specifically, the test includes: When the vehicle is in the starting state, the ECU provides a second preset voltage to the water level sensor: If the water level sensor outputs the second preset low level, the ECU determines that the water level is low and the water level alarm light goes off; If the water level sensor outputs the second preset high level and the duration exceeds the preset time within a driving cycle, the ECU determines that the water level is high and the water level warning light turns on; If the water level sensor outputs the second preset high level and the duration does not exceed the preset time within a driving cycle, the ECU will determine it as a false alarm and the water level warning light will not light up; The initial preset time is 1 to 3 seconds; the preset duration is 10 seconds.

2. The alarm method for reflecting the water level of a diesel filter according to claim 1, characterized in that: The first preset voltage and the second preset voltage are the same, both being 12V.

3. The alarm method for reflecting the water level of a diesel filter according to claim 1, characterized in that: The first preset high level and the second preset high level are the same, both being greater than 10V.

4. The alarm method for reflecting the water level of a diesel filter according to claim 1, characterized in that: The first preset low level and the second preset low level are the same, both being less than 0.5V.

5. An alarm device for reflecting the water level of a diesel filter, characterized in that: include: A function self-test module and a water level detection module. The function self-test module is used to determine whether the water level sensor functions normally. The water level detection module is used to determine whether the water level in the filter is high enough to conduct the probe when the water level sensor functions normally, thereby determining whether to light up the water level alarm light; The function self-test module can be used when the vehicle is powered on but not started and the vehicle key is in the ON position: The ECU provides a first preset voltage to the water level sensor, and the water level sensor outputs a level signal to the ECU. The ECU determines whether the level signal is a first preset high level within an initial preset time: If the result is no, the ECU determines that the first water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends; If the result is yes, the ECU determines that the first water level alarm function is normal, the water level alarm light is on, and after the aforementioned initial preset time, the ECU continues to determine whether the level signal is the first preset low level: If the result is no, the ECU determines that the second water level alarm function is abnormal, the self-test fault light turns on, and the self-test ends; If the result is yes, the ECU determines that the second water level alarm function is normal, the water level alarm light goes out, and the self-test ends; The water level detection module can enable: The ECU continuously supplies 12V power to the water level sensor: If the water level sensor outputs the second preset low level, the ECU determines that the water level is low, and the water level alarm light goes off; If the water level sensor outputs the second preset high level and the duration exceeds the preset time within a driving cycle, the ECU determines that the water level is high and the water level warning light turns on; If the water level sensor outputs the second preset high level and the duration does not exceed the preset time within a driving cycle, the ECU will determine it as a false alarm and the water level warning light will not light up; The initial preset time is 1 to 3 seconds; the preset duration is 10 seconds.

6. The alarm device for reflecting the water level of a diesel filter according to claim 5, characterized in that: The first preset voltage and the second preset voltage are the same, both being 12V.

7. The alarm device for reflecting the water level of a diesel filter according to claim 5, characterized in that: The first preset high level and the second preset high level are the same, both being greater than 10V.

8. The alarm device for reflecting the water level of a diesel filter according to claim 5, characterized in that: The first preset low level and the second preset low level are the same, both being less than 0.5V.

Images