Vehicle underpinning monitoring and lifting method based on air suspension system

Abstract

The invention relates to a vehicle underpinning monitoring and lifting method based on an air suspension system, and the method comprises the following specific steps: S1, judging the motion state of a vehicle according to the actual gear state and the vehicle speed of the vehicle, and judging that the vehicle is in a static state if the actual gear of the vehicle is a P gear and the vehicle speed is smaller than a preset threshold value; s2, recognizing the motion state of the vehicle, judging whether the vehicle is in a static state or not, whether a received height gear is lowered or not, whether an air suspension needs height lowering adjustment or not, whether a motor and an electromagnetic valve work normally or not, and whether there is no fault or overheating or not, if yes, entering the next step, otherwise, directly ending, and if not, entering the next step; the method has the characteristics that the stability and robustness of the system are improved, the misjudgment phenomenon is avoided, and the vehicle safety is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle underbody monitoring, and particularly to a vehicle underbody monitoring and lifting method based on an air suspension system. Background Art

[0002] With the significant progress of domestic air suspension technology and cost reduction through localization, the market demand for air suspension systems has further expanded. The air suspension system can adjust the body height, which not only provides consumers with a more comfortable driving and riding experience, but also provides conveniences such as easy getting on and off the vehicle and easy loading and unloading of goods. However, the adjustable body height also brings some potential problems. For example, when the driver parks the vehicle in a place with a raised obstacle below, if the convenient getting on and off or convenient loading and unloading mode is triggered at this time, then during the process of the vehicle height decreasing adjustment, it is very likely to press on the obstacle and cause the vehicle to bottom out. If the user fails to recognize that the vehicle has bottomed out and directly drives the vehicle at this time, it may cause damage to the vehicle chassis and pose a safety hazard.

[0003] The method adopted in the prior art is to compare the deflation speed of the airbag at a preset moment in the air spring system with a preset deflation speed threshold in response to a body height decrease command to determine whether the vehicle is in a bottomed-out state. If the deflation speed of the airbag at the preset moment is less than the preset threshold, it is immediately considered that the vehicle is bottomed out. However, this method has the following problems: 1. In response to the body height decrease command triggered by the user, the preconditions do not consider whether the user's descent operation command is successfully issued, nor do they consider the actual working states of the motor and solenoid valve in the air suspension system. Suppose the user performs a descent operation on the in-vehicle large screen, but the descent command is not issued; or the descent command is normally issued, but the motor or solenoid valve in the air suspension system actually does not work, then it will misjudge that the vehicle has entered the bottomed-out state; 2. Affected by many factors such as environmental temperature, vehicle load, and the characteristics of the height sensor, the deflation speed of the airbag is very likely to be very small at a certain moment. Just by judging that the vehicle is in a bottomed-out state because the deflation speed of the airbag at a certain moment is less than the threshold, it is easy to have the situation where the vehicle is not bottomed out but enters wrongly, and the stability and robustness of the system are poor, affecting the normal use and functional experience of the user for the air suspension system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a vehicle underbody monitoring and lifting method based on an air suspension system, which has the characteristics of improving system stability and robustness, avoiding misjudgment phenomena, and ensuring vehicle safety.

[0005] The technical solution adopted by the present invention to solve its technical problems is: to provide a vehicle underbody monitoring and lifting method based on an air suspension system, including the following specific steps:

[0006] S1: Determine the motion state of the vehicle according to the actual gear state and vehicle speed of the vehicle. If the actual gear of the vehicle is in P gear and the vehicle speed is less than the preset threshold, it is determined that the vehicle is in a static state;

[0007] S2: Identify the motion state of the vehicle, determine whether the vehicle is in a static state, whether the received height gear becomes lower, whether the air suspension needs height reduction adjustment, whether the motor and solenoid valve are working properly, and whether there is no fault or overheating. When all the above conditions are met, proceed to the next step; otherwise, end directly.

[0008] S3: Start timing from zero on the timer and record the current air suspension height as H1, where H1 is the preset threshold.

[0009] S4: When it is determined that the vehicle is in a static state, the received height gear becomes lower, and the air suspension height is adjusted to decrease, start timing and determine the preset time T. When the timer is timing, the height of the air suspension changes. When the timer has not reached T, it is necessary to determine whether the vehicle is in a static state and has received a downward adjustment command. If the result is yes, the timer continues to time; otherwise, end directly. When the timer reaches the preset time T, record the change in the air suspension height controlled to decrease during the T period, record the parameter as H2, and calculate the height difference ΔH between height H2 and height H1, where ΔH = H1 - H2.

[0010] S5: Determine whether ΔH is less than the preset threshold. If yes, proceed to the next step; otherwise, return to step S3.

[0011] S6: Output the vehicle bottoming state. When it is determined that the vehicle is in a bottoming state, send a command to prohibit the air suspension height from decreasing and prompt the driver to manually raise it to an appropriate height gear through the central control screen.

[0012] S7: When the driver manually raises the vehicle or the air suspension system automatically raises the vehicle when starting, the central control screen cancels the output of the vehicle bottoming state; otherwise, the central control screen always displays that the vehicle is in a bottoming state.

[0013] In step S2, the air suspensions of the four wheels are monitored in real time. When the downward command is DOWN_FL, the height change of the left front (FL) is monitored during the T period. When the downward command is DOWN_FR, the height change of the right front (FR) is monitored during the T period. When the downward command is DOWN_FA (front axle), the height changes of both the left front and the right front are monitored simultaneously during the T period, so as to accurately determine the position of the vehicle bottoming.

[0014] In S6, after it is monitored that the vehicle is in a bottoming state, the air suspension system controller will prohibit height reduction adjustment, and at the same time transmit the bottoming state to the central control screen through the vehicle CAN communication. After receiving the bottoming state sent by the air suspension controller on the central control screen, it will display a text reminder, and there are no special restrictions on the text prompt.

[0015] In step S7, after it is determined that the vehicle triggers bottoming or the bottoming state of the vehicle is released, that is, after the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state when the vehicle was powered off is read from the memory.

[0016] When the target height gear received by the air suspension system changes, the previous target height gear will be memorized. For example: when the target height gear changes from "standard" to "lower", the air suspension system will memorize "standard". When the vehicle triggers bottoming during the descent process, the air suspension system will gray out the "lower" and gears lower than "lower", and only the "standard" and gears higher than "standard" are selectable. After receiving the "standard" and gears higher than "standard", control the air suspension system to raise the height. After the height rise is completed, the bottoming state of the vehicle is cleared, and the grayed-out air suspension height gear buttons are restored to be selectable.

[0017] When it is determined that the vehicle is in a bottoming state and it is monitored that the actual gear of the vehicle changes from P gear to other gears, it means that the driver is ready to start. At this time, the air suspension system will automatically raise the vehicle height to the memorized previous target height gear.

[0018] After it is determined that the vehicle triggers bottoming or the bottoming state of the vehicle is released, that is, after the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state when the vehicle was powered off is read from the memory.

[0019] Identify the motion state of the vehicle. When the vehicle is stationary, simultaneously monitor the height reduction instruction and the working states of the motor and the solenoid valve corresponding to the instruction in the air suspension system. If all the above three conditions are met, start timing. During the preset time period, monitor the height of the air suspension corresponding to the instruction that drops. If it is less than or equal to the preset threshold, it is determined that the vehicle is in a bottoming state. The height signal of the air suspension is processed by low-pass filtering, which can eliminate the interference of height signal fluctuations. This method can improve the stability and robustness of the vehicle bottoming recognition of the air suspension system and avoid the situation of misjudging that the vehicle enters the bottoming state.

[0020] Monitor the air suspension descent instructions, the working states of the solenoid valves corresponding to the instructions, and the height changes of the corresponding air suspensions at the four wheels respectively. This method can identify which position has bottomed and prompt the driver, so that when the driver gets out of the vehicle to check, they can find the obstacle faster.

[0021] After it is recognized that the vehicle has bottomed out, first, a command to prohibit the air suspension height from continuing to decrease is sent. Second, a text prompt saying "The vehicle has bottomed out. Please manually raise the vehicle height" will appear on the central control screen. At the same time, the current and lower height gear positions on the central control screen will be grayed out, and the driver can only click on a height gear higher than the current height to avoid misoperation by the driver. When it is recognized that the driver has performed a lifting operation, the text prompt on the central control screen will be cleared, and the height gear buttons will be restored. This method enables the driver to clearly perceive that the vehicle has bottomed out and get out of the vehicle in time to check the vehicle status.

[0022] If the driver fails to see the text prompt due to negligence, then when the driver is about to start, an upward control command will be automatically sent to the air suspension system to automatically raise the height of the air suspension system. At the same time, the text prompt on the central control screen will be cleared, and the height gear buttons will be restored. This method can automatically raise the height of the vehicle's air suspension when the vehicle has bottomed out and there is no driver operation, avoiding damage to the vehicle chassis and ensuring the safety of vehicle driving.

[0023] After it is recognized that the vehicle has bottomed out, the vehicle bottoming state is immediately stored in the memory, and the bottoming state will not be lost after power-off. After the vehicle is powered on again, the air suspension system reads the memory data. If the state stored in the memory is that the vehicle has bottomed out, then a text prompt will appear on the central control screen, and the non-adjustable buttons will be grayed out. This method uses an immediate storage method, enabling the vehicle to correctly read whether the vehicle is in a bottomed-out state after being powered on again in multiple scenarios such as normal power-off, abnormal power-off, battery power-off, or software upgrade. This method can, when it has been recognized that the vehicle has bottomed out but the driver has not noticed and the driver operates the vehicle to power off and leaves the vehicle, immediately prompt the driver that the vehicle has bottomed out and the air suspension height needs to be manually raised when the driver gets in the vehicle, or automatically raise the air suspension height when the driver intends to start.

[0024] Advantageous effects: The present invention relates to a method for monitoring and lifting vehicle bottoming based on an air suspension system, which has the characteristics of improving system stability and robustness, avoiding misjudgment phenomena, and ensuring vehicle safety. Description of the Drawings

[0025] Figure 1 is a flowchart of the present invention. Detailed Embodiments

[0026] The following further elaborates the present invention in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0027] Embodiments of the present invention relate to a method for monitoring and lifting a vehicle bottoming based on an air suspension system, including the following specific steps:

[0028] S1: According to the actual gear state and vehicle speed of the vehicle, judge the motion state of the vehicle. If the actual gear of the vehicle is in the P gear and the vehicle speed is less than a preset threshold, it is judged that the vehicle is in a static state;

[0029] S2: Identify the motion state of the vehicle, judge whether the vehicle is in a static state, whether the received height gear becomes lower, whether the air suspension needs to be adjusted for height reduction, whether the motor and solenoid valve are working properly, and whether there is no fault or overheating. When all the above conditions are met, proceed to the next step; otherwise, directly end;

[0030] S3: The timer starts timing from zero, and records the current air suspension height as H1, where H1 is a preset threshold;

[0031] S4: When it is determined that the vehicle is in a static state, the received height gear becomes lower, and the air suspension height is adjusted downward, start timing, and determine the preset time T. When the timer is timing, the height of the air suspension changes. When the timer has not reached T, it is necessary to judge whether the vehicle is in a static state and receives a downward adjustment instruction. If the result is yes, the timer continues to time; otherwise, directly end; When the timer reaches the preset time T, record the change in the air suspension height controlled during the T period, record the parameter as H2, and calculate the height difference ΔH between the height H2 and the height H1, ΔH = H1 - H2;

[0032] S5: Judge whether ΔH is less than the preset threshold. If yes, proceed to the next step; otherwise, return to step S3;

[0033] S6: Output the vehicle bottoming state. When it is determined that the vehicle is in a bottoming state, send a command to prohibit the air suspension height from decreasing, and prompt the driver to manually raise it to an appropriate height gear through the central control screen;

[0034] S7: When the driver manually raises the vehicle or the air suspension system automatically raises the vehicle when starting, the central control screen cancels the output of the vehicle bottoming state; otherwise, the central control screen always displays that the vehicle is in a bottoming state.

[0035] In step S2, the air suspensions of the four wheels are monitored in real time. When the downward instruction is DOWN_FL, monitor the height change of the left front (FL) during the T period. When the downward instruction is DOWN_FR, monitor the height change of the right front (FR) during the T period. When the downward instruction is DOWN_FA (front axle), monitor the height changes of the left front and the right front simultaneously during the T period, so as to accurately determine the position of the vehicle bottoming.

[0036] In S6, after it is monitored that the vehicle is in a bottoming state, the air suspension system controller will prohibit the height reduction adjustment. At the same time, it will transmit the bottoming state to the central control screen through the vehicle CAN communication. After receiving the bottoming state sent by the air suspension controller, the central control screen will display a text reminder, and there is no special restriction on the text prompt.

[0037] In step S7, after it is determined that the vehicle triggers bottoming or the bottoming state of the vehicle is released, that is, after the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state of the vehicle when it was powered off will be read from the memory.

[0038] When the target height gear received by the air suspension system changes, it will remember the previous target height gear. For example: when the target height gear changes from "standard" to "lower", the air suspension system will remember "standard". When the vehicle triggers bottoming during the descent, the air suspension system will gray out the "lower" and gears lower than "lower", and only the "standard" and gears higher than "standard" are selectable. After receiving the "standard" and gears higher than "standard", it controls the air suspension system to raise the height. After the height rise is completed, the bottoming state of the vehicle will be cleared, and the grayed-out air suspension height gear buttons will be restored to be selectable.

[0039] When it is determined that the vehicle is in a bottoming state and it is monitored that the actual gear of the vehicle changes from the P gear to other gears, it means that the driver is ready to start. At this time, the air suspension system will automatically raise the vehicle height to the previous target height gear remembered.

[0040] After it is determined that the vehicle triggers bottoming or the bottoming state of the vehicle is released, that is, after the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state of the vehicle when it was powered off will be read from the memory.

Claims

1. A vehicle bottom support monitoring and lifting method based on an air suspension system, characterized in that: The specific steps include: S1: judging the motion state of the vehicle according to the actual gear position and speed of the vehicle; if the actual gear position of the vehicle is P gear and the speed is less than a preset threshold, judging that the vehicle is in a static state; S2: Identify the vehicle's motion state, determine whether the vehicle is static, whether the received height gear is lowered, whether the air suspension needs to be lowered, whether the motor and solenoid valve are working properly, whether there is no fault or overheating. If all of the above conditions are true, proceed to the next step, otherwise end directly; S3: The timer starts counting from zero and records the current air suspension height as H1, where H1 is the preset threshold; S4: When it is determined that the vehicle is in a static state, the height gear received becomes lower, and the height of the air suspension is adjusted to be lowered, the timing is started and the preset time T is determined. When the timer is timing, the height of the air suspension changes. When the timer has not reached T, it is necessary to determine whether the vehicle is in a static state and receives a lowering adjustment instruction. If the result is yes, the timer continues to time, otherwise it ends directly; when the timer reaches the preset time T, the height change of the air suspension controlled to be lowered within the T time period is recorded, and the recorded parameter is H2. The height difference between the height H2 and the height H1 is calculated ΔH, ΔH = H1-H2; S5: Determine whether ΔH is less than a preset threshold, if yes, proceed to the next step, otherwise return to step S3; S6: Output the vehicle bottoming state. If it is determined that the vehicle is in the bottoming state, send a command to prohibit the air suspension from descending, and prompt the driver to manually raise the air suspension to a suitable height position through the central control screen; S7: When the driver manually lifts the vehicle or the air suspension system automatically lifts the vehicle when starting, the central control screen stops outputting the vehicle's bottoming status. Otherwise, the central control screen always displays that the vehicle is in the bottoming status.

2. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 1 is characterized in that: In step S2, the air suspension of the four wheels is monitored in real time. When the descent command is DOWN_FL, the height change of the left front (FL) in the T time period is monitored. When the descent command is DOWN_FR, the height change of the right front (FR) in the T time period is monitored. When the descent command is DOWN_FA (front axle), the height changes of the left and right front in the T time period are monitored at the same time. In this way, the bottom position of the vehicle can be accurately determined.

3. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 1 is characterized in that: In S6, after monitoring that the vehicle is in the bottoming state, the air suspension system controller will prohibit height descent adjustment and transmit the bottoming state to the central control screen through the vehicle CAN communication. After the central control screen receives the bottoming state sent by the air suspension controller, a text reminder will be displayed, and there are no special restrictions on the text reminder.

4. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 1, characterized in that: In step S7, after determining that the vehicle triggers the bottoming or the vehicle bottoming state is released, that is, after the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state of the vehicle when it was powered off is read from the memory.

5. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 1, characterized in that: When the target height gear received by the air suspension system changes, the last target height gear will be memorized. For example, when the target height gear changes from "standard" to "lower", the air suspension system will memorize "standard". When the vehicle bottoming out is triggered during the vehicle's descent, the air suspension system will gray out the "lower" and lower gears, leaving only the "standard" and higher gears available. When the "standard" and higher gears are received, the air suspension system will be controlled to rise in height. After the height rise is completed, the vehicle bottoming out status will be cleared, and the grayed-out air suspension height gear button will be restored to optional.

6. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 5, characterized in that: When it is determined that the vehicle is in the bottoming state, after monitoring that the actual gear position of the vehicle has changed from P gear to other gear positions, it means that the driver is ready to start. At this time, the air suspension system will automatically raise the vehicle height to the last memorized target height gear position.

7. The vehicle bottom support monitoring and lifting method based on the air suspension system according to claim 1, characterized in that: When it is determined that the vehicle triggers the bottoming or the vehicle bottoming state is released, that is, when the bottoming state changes, the bottoming state will be immediately stored in the non-volatile memory. When the vehicle is powered on again, the state of the vehicle when it was powered off is read from the memory.

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