Control method and system of air suspension

Abstract

The invention discloses a control method and system of an air suspension, and relates to the technical field of automobile suspension control, and the control method comprises the steps that a vehicle state signal is obtained in real time through CAN communication control; determining the working mode of the suspension; generating sensor data; and formulating a suspension control strategy according to a diagnosis result. The technical problems that an existing air suspension control technology is difficult to accurately adapt to the vehicle driving state, cannot obtain accurate vehicle state signals in real time and is single in fault diagnosis mode are solved, and the purposes that the air suspension accurately switches the working modes according to the vehicle real-time driving state, the vehicle state signals are accurately obtained in time, and the fault diagnosis efficiency is improved are achieved. And meanwhile, a comprehensive fault diagnosis system is constructed, and the technical effects of vehicle driving comfort, control stability and safety are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive suspension control, and particularly to the technical field of a control method and system for an air suspension. Background Art

[0002] In the field of automotive suspension control, air suspensions are increasingly widely used, and their performance directly affects the driving experience, safety, and stability of vehicles. Currently, traditional air suspension control technologies mainly rely on simple sensor feedback and fixed control logic. In common application scenarios, although this technology can maintain basic suspension functions, with the advancement of the development trends of vehicle intelligence and high performance, its limitations have become increasingly prominent.

[0003] When the existing technology controls an air suspension, it is difficult to accurately perceive complex and changing vehicle driving states, resulting in a lag in suspension height adjustment and an inability to match the vehicle working conditions in real time. Moreover, the fault diagnosis method is single and can only detect some obvious faults, unable to detect potential problems in a timely manner, which not only affects the comfort of the vehicle but also poses a hidden danger to driving safety. Summary of the Invention

[0004] This application solves the technical problems that the existing air suspension control technology is difficult to accurately adapt to vehicle driving states, unable to obtain accurate vehicle state signals in real time, and has a single fault diagnosis method. This application obtains vehicle state signals in real time through CAN communication, and based on these signals, uses height adjustment control to dynamically switch the air suspension and determine the suspension working mode. At the same time, a sensing unit is activated to monitor the air suspension in real time to generate sensor data, and then fault diagnosis control is performed in combination with the sensor data. According to the diagnosis results, a suspension control strategy is formulated. Through the coordinated operation of multiple links, it accurately adapts to different vehicle driving conditions, discovers and processes potential faults of the air suspension in a timely manner, enables the air suspension system to operate stably and efficiently, and improves the comfort and safety of vehicle driving.

[0005] In view of the above technical problems, this application proposes a technical solution for a control method and system for an air suspension.

[0006] In a first aspect, this application provides a control method for an air suspension, wherein the method includes: obtaining vehicle state signals in real time through CAN communication control; based on the vehicle state signals, using height adjustment control to dynamically switch the air suspension and determine the suspension working mode; according to the suspension working mode, activating a sensing unit to monitor the air suspension in real time to generate sensor data; performing fault diagnosis control in combination with the sensor data, and formulating a suspension control strategy according to the diagnosis results.

[0007] Second aspect, the present application provides a control system for an air suspension. Wherein, the system includes: a state signal acquisition module, which acquires vehicle state signals in real time through CAN communication control; a working mode determination module, which dynamically switches the air suspension by using height adjustment control based on the vehicle state signals to determine the suspension working mode; a sensor data generation module, which is used to start a sensing unit to monitor the air suspension in real time according to the suspension working mode and generate sensor data; a control strategy formulation module, which combines the sensor data to execute fault diagnosis control and formulates a suspension control strategy according to the diagnosis result.

[0008] One or more technical solutions are proposed in the present application, which at least have the following technical effects:

[0009] The present application acquires vehicle state signals in real time through CAN communication control to clarify the data source. Then, based on the vehicle state signals, using height adjustment control and in accordance with the constraint conditions set by the historical height switching records, the signals are compared with the conditions to activate the instructions, and multiple working modes are switched to output the determined suspension working mode. Then, according to the suspension working mode, a sensing unit including multiple sensors is started, and each sensor detects and integrates relevant data to obtain sensor data. After that, in combination with the sensor data, fault diagnosis is carried out respectively from three aspects: sensors, CAN communication, and actuators. The diagnostic results are generated through data fusion alignment, and a suspension control strategy is formulated and implemented according to the results. During this process, if there are invalid situations in the acquired vehicle state parameters, a preset fault handling strategy is adopted to ensure the stable operation of the system, achieving the technical effects that the air suspension accurately switches the working mode according to the real-time driving state of the vehicle, timely and accurately obtains the vehicle state signals, and at the same time constructs a comprehensive fault diagnosis system, improving the comfort, handling stability and safety of vehicle driving.

[0010] The above content outlines the present application for solving a control method and system for an air suspension. The technical solution steps of the present application will be described in detail in the following specific embodiments to facilitate those skilled in the art to clearly and completely understand the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly introduced below. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0012] Figure 1It is a schematic flowchart of a control method for an air suspension provided by an embodiment of the present application.

[0013] Figure 2 It is a schematic structural diagram of a control system for an air suspension provided by an embodiment of the present application.

[0014] Explanation of reference numerals: State signal acquisition module 1, Working mode determination module 2, Sensor data generation module 3, Control strategy formulation module 4. Specific embodiments

[0015] The present application obtains vehicle state signals through CAN communication control, sets and compares switching constraint conditions based on the vehicle state signals to determine the suspension working mode. The sensing unit (including suspension height, thermistor, pressure sensor) is started to monitor and integrate data to obtain sensor data. Sensor, CAN communication, and actuator fault diagnosis are combined with the sensor data, and the suspension control strategy is formulated by integrating the diagnosis results. If there are invalid situations in the obtained vehicle state parameters, a preset fault handling strategy is adopted. According to the determined suspension working mode, the air suspension is adjusted to the corresponding height (such as automatic adjustment in the static mode, prohibited adjustment in the cornering mode, and height reduction in the high-speed mode), and continuous monitoring and adjustment are carried out to ensure the stable operation of the system, achieving the technical effects that the air suspension accurately switches the working mode according to the real-time driving state of the vehicle, timely and accurately obtains the vehicle state signals, and at the same time constructs a comprehensive fault diagnosis system, improving the comfort, handling stability, and safety of vehicle driving.

[0016] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0017] It should be noted that any variations of the terms "including" and "having" are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or server that includes a series of steps or units is not necessarily limited to those clearly listed steps or units, but may include other steps or modules that are not clearly listed or are inherent to these processes, methods, products, or devices.

[0018] Embodiment 1, as Figure 1 shown, a control method for an air suspension, wherein the method includes:

[0019] Step A100: Real-time obtain vehicle state signals through CAN communication control.

[0020] In the embodiment of the present application, CAN communication control receives multiple vehicle state parameters through the CAN bus, judges these parameters, and when any parameter in the state judgment result is determined to be invalid, adopts a preset fault handling strategy to generate a fault handling result, and based on this result, retrieves the corresponding vehicle state signal for output control. The vehicle state signal is composed of multiple vehicle state parameters and serves as the basic data for subsequent operations.

[0021] Specifically, multiple vehicle state parameters are received through the CAN bus and judged to generate a state judgment result. If there are invalid parameters, a preset fault handling strategy is adopted to obtain a fault handling result, and then based on this, the corresponding vehicle state signal is retrieved for output, so as to realize the real-time acquisition of vehicle state signals through CAN communication control. The specific steps are described in detail in A110 - A130.

[0022] Through this series of judgment steps, the vehicle state signals are comprehensively obtained, providing accurate data support for subsequent precise control of the air suspension based on these signals, such as height adjustment, working mode switching, etc.

[0023] Step A200: Based on the vehicle state signal, adopt height adjustment control to dynamically switch the air suspension and determine the suspension working mode.

[0024] In the embodiment of the present application, the suspension working mode sets switching constraint conditions by retrieving the historical height switching record, compares the vehicle state signal with it, activates the switching instruction to control the working mode switching, and based on this, matches the vehicle state signal to determine the target working mode, that is, the suspension working mode. The air suspension height adjustment methods are different in different modes, including maintenance mode, parking mode, static mode, low-speed mode, medium-speed mode, high-speed mode, and cornering mode.

[0025] Optionally, when determining the suspension working mode based on the vehicle state signal, first retrieve the historical height switching record to set switching constraint conditions, then compare the vehicle state signal with the constraint conditions to generate a comparison result, then activate the switching instruction according to the comparison result to control the switching of multiple working modes, and finally match the vehicle state signal from multiple working modes to determine the target working mode and use it as the suspension working mode. The specific steps are described in detail in A210 - A240.

[0026] Step A300: According to the suspension working mode, start the sensing unit to monitor the air suspension in real time and generate sensor data.

[0027] In the embodiment of the present application, the sensing unit is an important part of the air suspension control system responsible for real-time monitoring of the suspension state, including a suspension height sensor, a thermistor sensor, and a pressure sensor.

[0028] In an embodiment of the present application, the sensing unit is activated according to the suspension working mode. The sensing unit consists of a suspension height sensor, a thermistor, and a pressure sensor. The suspension height sensor detects the relative height between the vehicle body and the chassis to generate a voltage signal. The thermistor sensor detects the temperature of the air compressor and calculates the real-time temperature value in combination with a preset relationship. The pressure sensor detects the air pressure in the air storage tank. When the air pressure is lower than the threshold, the compressor is activated to replenish the air to the target air pressure value. Finally, these voltage signals, real-time temperature value, and target air pressure value are associated and integrated to determine the sensor data. The specific steps are described in detail in A310 - A350.

[0029] Step A400: Perform fault diagnosis control in combination with the sensor data, and formulate a suspension control strategy according to the diagnosis result.

[0030] In the embodiment of the present application, the fault diagnosis control diagnoses sensor faults, CAN communication faults, and actuator faults. The suspension control strategy is a regulation method for the air suspension formulated according to the diagnosis result by performing fault diagnosis control in combination with the sensor data.

[0031] Specifically, when performing fault diagnosis control in combination with the sensor data, sensor fault diagnosis, CAN communication fault diagnosis, and actuator fault diagnosis are respectively performed based on the sensor data to generate corresponding diagnosis results. Then, these three diagnosis results are data - fused and aligned to obtain a comprehensive and accurate air suspension fault diagnosis result, providing a basis for formulating subsequent control strategies. The specific steps are described in detail in A410 - A440.

[0032] Finally, a suspension control strategy is formulated according to this comprehensive diagnosis result. When formulating the suspension control strategy, those skilled in the art need to take corresponding measures according to the comprehensive diagnosis result for different fault types. If a certain sensor fault is diagnosed, the faulty sensor may be replaced, the backup sensor data may be used, or the control algorithm may be adjusted; if there is a CAN communication fault, try to repair the communication line, switch the communication protocol, or reduce the data transmission frequency; if it is an actuator fault, the working parameters of the actuator will be adjusted or redundant actuators will be enabled, etc., so as to ensure the stable operation of the air suspension system and improve the comfort and safety of vehicle driving.

[0033] Furthermore, step A100 in the method provided by the embodiment of the present application includes:

[0034] A110: Receive multiple vehicle state parameters through the CAN bus, judge the multiple vehicle state parameters, and generate a state judgment result.

[0035] A120: When any one of the parameters in the state judgment result is determined to be invalid, a preset fault handling strategy is adopted to generate a fault handling result.

[0036] A130: Based on the fault handling result, the corresponding vehicle status signal is retrieved and outputted.

[0037] In the embodiment of the present application, the CAN bus is a method for receiving multiple vehicle status parameters and providing a transmission path for obtaining vehicle status signals. The status judgment results include power mode legitimacy judgment, engine / motor status legitimacy judgment, vehicle speed legitimacy judgment, steering angle legitimacy judgment, and height setting request legitimacy judgment. The preset fault handling strategy is the response method adopted when any parameter in the status judgment result is judged to be invalid. The fault handling results include using the last valid value, disabling the current signal, or switching to the default control mode.

[0038] Specifically, firstly, with the help of the CAN communication control method, multiple vehicle status parameters are received through the CAN bus, including a power mode signal, an engine / motor status signal, a vehicle speed signal, a steering angle signal, and an air suspension height setting request signal.

[0039] Next, these parameters are judged according to specific judgment logic. For the power mode signal, the power is identified according to the BCM_Power signal (a signal in the vehicle CAN communication, used to identify the legitimacy and validity of the power supply). If the power is illegal or invalid, the default value is the last valid value. If it is illegal or invalid for many consecutive times and other messages are normal, the BCM (body control module) module is judged to be faulty, and the message data is no longer used as the comparison signal of the ON gear signal in this power-on cycle, thereby generating the power mode legitimacy judgment result.

[0040] For the engine / motor status signal, the legality and validity of the power status are identified according to the EMS_Engine (a signal in the vehicle CAN communication, from the engine management system) signal. When the engine / motor is illegal or invalid, the fault is directly defaulted to the last confirmed valid value. If it is illegal or invalid for multiple consecutive times and other messages are normal, the EMS (engine management system) module is judged to be faulty and fault processing is entered. The message data switching mode is no longer used in this power-on cycle. Instead, "ON gear" + "vehicle speed> Akm / h" is used as the judgment condition for engine start, thereby obtaining the result of the engine / motor status legality judgment.

[0041] In terms of vehicle speed signal, the legality and validity of the vehicle speed are identified based on the ABS_VehicleSpeed signal (the vehicle speed signal in vehicle CAN communication, collected and provided by the anti-lock braking system). If the vehicle speed is illegal or invalid, the fault is directly reduced to "standard" and the last confirmed valid value is used by default. If it is illegal or invalid for multiple consecutive times and other messages are normal, it is determined that the ABS module has a fault, and the fault handling process is entered. The body height returns to the "standard" position, manual height adjustment is prohibited, and the message data switching mode is not used in this power-on cycle. Only the ON gear signal is detected, and the vehicle speed legality judgment result is generated accordingly.

[0042] For the steering angle signal, the legality and validity are identified based on the SAS_SteeringAngle signal (the steering angle signal in vehicle CAN communication). When the steering angle is illegal or invalid, the fault is directly reduced to "standard" and the last confirmed valid value is used by default. If it is illegal or invalid for multiple consecutive times and other messages are normal, it is determined that the SAS (steering angle sensor) module has a fault, and the fault handling process is entered. The body height returns to the "standard" position, manual height adjustment is prohibited. If it is already in the cornering mode, it exits the cornering mode and enters the corresponding speed mode. The message data switching mode is not used in this power-on cycle, and the steering angle legality judgment result is generated accordingly.

[0043] For the air suspension height setting request signal, the legality and validity are judged based on the FICM_AirSuspensionHeightSetRequest signal (the air suspension height setting request signal in vehicle CAN communication). If the height setting request is illegal or invalid, the last confirmed valid value is used by default. If it is illegal or invalid for multiple consecutive times and other messages are normal, it is determined that the FICM (fuel injection control) module has a fault, and the fault handling process is entered. The body height returns to the "standard" position, manual height adjustment is prohibited, and the message data of this power-on cycle is not used. Finally, the height setting request legality judgment result is formed. These judgment results are summarized to obtain the status judgment result.

[0044] Then, once any parameter in the status judgment result is determined to be invalid, a preset fault handling strategy is adopted. This strategy includes: using the last valid value to ensure the continuity of vehicle status signals; disabling the current signal to prevent incorrect signals from interfering with system operation; switching to the default control mode to maintain the basic functions of the air suspension.

[0045] Finally, the corresponding vehicle status signals are retrieved and output based on the fault handling result. If the fault handling result is to use the last valid value, the system will call the last valid vehicle status signal for output; if it is to disable the current signal, the system will skip the current invalid signal and select other normal vehicle status signals for output; if it is to switch to the default control mode, the system will output the vehicle status signals applicable to the default control mode.

[0046] The vehicle state signals after these processes provide an accurate and reliable data basis for subsequent operations such as determining the suspension working mode based on the vehicle state, performing real-time monitoring, and fault diagnosis control, enabling the air suspension system to more precisely adapt to different operating states of the vehicle.

[0047] Furthermore, step A200 in the method provided by the embodiments of the present application includes:

[0048] A210: Retrieve the historical height switching records to set switching constraint conditions.

[0049] A220: Compare the vehicle state signal with the switching constraint conditions to generate a comparison result.

[0050] A230: Activate a switching instruction according to the comparison result, and perform switching control on multiple working modes through the switching instruction.

[0051] A240: Match the vehicle state signal based on the multiple working modes to determine the target working mode, and use the target working mode as the suspension working mode.

[0052] In the embodiments of the present application, the historical height switching records are the data basis for setting the switching constraint conditions, and retrieving them provides a reference for determining the suspension working mode. The switching constraint conditions are the triggering conditions of different working modes set based on the historical height switching records. The comparison result is the result generated after comparing the vehicle state signal with the switching constraint conditions. The target working mode is the working mode determined after matching the vehicle state signal based on multiple working modes, and finally used as the suspension working mode.

[0053] Optionally, first, according to the relevant principles of the height adjustment control method, retrieve the historical height switching records to set the switching constraint conditions. Among them, the static mode trigger condition is set that the BCM_Power and EMS_EngineStatus (a signal in vehicle CAN communication generated by the engine management system) signals are legal and valid and the ABS_VehicleSpeed vehicle speed signal ≤ A km / h. In the vehicle stationary or low-speed stable state, this condition can maintain a stable suspension height and ensure vehicle smoothness. The low-speed mode trigger condition is that the BCM_Power and EMS_EngineStatus signals are legal and valid and A km / h < ABS_VehicleSpeed vehicle speed signal ≤ B km / h, and at the same time, the air compressor is allowed to start to replenish the air storage tank, taking into account the dynamic adjustment of the suspension height and the air pressure replenishment requirements during medium and low-speed driving. The cornering mode trigger condition is that the BCM_Power and EMS_EngineStatus signals are legal and valid, B km / h < ABS_VehicleSpeed vehicle speed signal and SAS_SteeringAngle steering angle > ζ deg (a threshold parameter related to the steering angle used to judge whether the vehicle enters the cornering mode), and maintain T 4 s (a key time parameter used to judge whether the vehicle enters or exits the cornering mode). When the vehicle takes a high-speed turn, according to this condition, the vehicle speed and steering angle are comprehensively judged to ensure the suspension cornering performance.

[0054] Next, compare the vehicle state signals obtained in real time, that is, the ABS_VehicleSpeed vehicle speed signal, EMS_EngineStatus engine status signal, SAS_SteeringAngle steering angle signal, etc. obtained through the CAN communication control method, with the above switching constraint conditions. Specifically, compare the vehicle speed with "ABS_VehicleSpeed vehicle speed signal ≤ A km / h" in the static mode, "A km / h < ABS_VehicleSpeed vehicle speed signal ≤ B km / h" in the low-speed mode, and "B km / h < ABS_VehicleSpeed vehicle speed signal" in the cornering mode respectively; compare the engine status with "EMS_EngineStatus signal is legal and valid" in the static mode; compare the steering angle with "SAS_SteeringAngle steering angle > ζ deg and maintain T 4 s" in the cornering mode, and then generate a comparison result. This comparison result can intuitively show which working mode trigger condition the current vehicle state meets.

[0055] Then, after the comparison between the vehicle state signal and the switching constraint conditions is completed, if the comparison result shows that the vehicle state meets the trigger condition of a certain working mode, the corresponding switching instruction will be activated. For example, when parameters such as vehicle speed and engine state meet the trigger conditions of the static mode, the static mode switching instruction is activated. This instruction controls the suspension system. Based on the deviation between the desired signal and the measured signal output by the suspension main control chip, the air spring drive module adjusts the duty cycle of the PWM (Pulse Width Modulation) waveform in real time, drives the air supply unit to complete inflation and deflation, and realizes the automatic adjustment of the air suspension height, achieving the switching from the current working mode to the static mode. Similarly, if other mode conditions such as the cornering mode or the high-speed mode are met, the corresponding instructions will also be activated to control the switching of multiple working modes to adapt to different driving states of the vehicle and realize the dynamic adjustment of the working mode.

[0056] Finally, based on multiple working modes, the vehicle state signal is matched to determine the target working mode, which is used as the suspension working mode. The specific steps are described in detail in A241 - A245.

[0057] Through this series of steps, the air suspension can more accurately adapt to different driving states of the vehicle and improve the overall performance of the vehicle.

[0058] Furthermore, step A240 in the method provided by the embodiment of the present application includes:

[0059] A241: The target working mode includes a static working mode, a cornering working mode, or a high-speed working mode.

[0060] A242: When the target working mode is the static working mode, perform automatic height adjustment on the height of the air suspension to generate static height parameters.

[0061] A243: When the target working mode is the cornering working mode, prohibit height adjustment of the air suspension to generate cornering height parameters.

[0062] A244: When the target working mode is the high-speed working mode, lower the height of the air suspension to generate high-speed height parameters.

[0063] A245: Screen according to the static height parameters, the cornering height parameters, and the high-speed height parameters to determine the suspension working mode.

[0064] Specifically, first, it is clear that the target working mode includes static, cornering, and high-speed working modes. During actual operation, the vehicle state is constantly changing, and the system needs to select the appropriate mode according to different states.

[0065] When vehicle status signals such as the vehicle speed signal (ABS_VehicleSpeed) and the engine status signal (EMS_EngineStatus) obtained through the CAN communication control method indicate that the vehicle speed is lower than A km / h (the actual value of A depends on the vehicle design, assumed to be 30 km / h here), and the EMS_EngineStatus signal shows that the engine status is legal and valid, the vehicle matches the static working mode at this time. In this mode, the suspension main control chip in the air spring controller controls the duty cycle of the PWM waveform in real time according to the signals fed back by sensors such as the suspension height sensor and the gas electromagnetic distribution valve pressure sensor, combines the preset control algorithm, drives the air supply unit to adjust the internal air pressure of the air suspension, and then generates static height parameters suitable for the vehicle to park statically or drive smoothly at low speed, so as to ensure the smoothness of the vehicle.

[0066] When the vehicle is driving, if the vehicle speed signal (ABS_VehicleSpeed) is higher than B km / h (assumed to be 60 km / h here), and the steering angle signal (SAS_SteeringAngle) continuously exceeds ζ deg (assumed to be 15 degrees) and remains for T 4 s seconds (assumed to be 3 seconds), the system determines that the vehicle enters the corner working mode. In this mode, to ensure the stability of the vehicle when driving in a corner, the system prohibits height adjustment of the air suspension and maintains the current height, thereby generating corner height parameters and effectively avoiding affecting the vehicle's center of gravity and handling performance due to height changes.

[0067] If the vehicle is in a high-speed driving state and the vehicle speed signal (ABS_VehicleSpeed) reaches or exceeds C km / h (assumed to be 80 km / h), the vehicle matches the high-speed working mode. To reduce the vehicle's wind resistance and improve driving stability, the system controls the air supply unit to adjust the suspension height through operations such as exhaust to generate high-speed height parameters.

[0068] Finally, the system makes a screening judgment based on the generated static height parameters, corner height parameters, and high-speed height parameters. The system continuously and real-time compares the current vehicle status with the trigger conditions corresponding to each parameter. When the vehicle is in a stationary or low-speed stable state and meets the trigger conditions of the static mode (that is, the BCM_Power and EMS_EngineStatus signals are legal and valid and the ABS_VehicleSpeed vehicle speed signal ≤ A km / h), it is determined that the suspension working mode is the static working mode; if the vehicle takes a high-speed corner and meets the trigger conditions of the corner mode (that is, the BCM_Power and EMS_EngineStatus signals are legal and valid, B km / h < ABS_VehicleSpeed vehicle speed signal, and SAS_SteeringAngle rotation angle > ζ deg, and remains for T 4If the vehicle is in a curved road working mode; when the vehicle is in a high-speed straight driving state and meets the trigger conditions of the high-speed mode (that is, the BCM_Power and EMS_EngineStatus signals are legal and valid and Ckm / h < ABS_VehicleSpeed vehicle speed signal), the suspension working mode is determined to be the high-speed working mode.

[0069] Through the precise matching of the above steps, the air suspension system can make the best response according to the real-time state of the vehicle, improving the overall performance of the vehicle.

[0070] Further, step A300 in the method provided by the embodiment of the present application includes:

[0071] A310: Activate the sensing unit based on the suspension working mode, and the sensing unit includes a suspension height sensor, a thermistor sensor, and a pressure sensor.

[0072] A320: Detect the relative height between the vehicle body and the chassis through the suspension height sensor and generate a voltage signal.

[0073] A330: Detect the temperature of the air compressor through the thermistor sensor, and calculate the real-time temperature value in combination with the preset temperature-resistance relationship.

[0074] A340: Detect the air pressure in the air storage tank through the pressure sensor. When the air pressure is lower than the threshold value, start the compressor to replenish air until the target air pressure value is reached.

[0075] A350: Correlate and integrate the voltage signal, the real-time temperature value, and the target air pressure value to determine the sensor data.

[0076] In the embodiment of the present application, the sensing unit is a component activated according to the suspension working mode. The temperature-resistance relationship is preset and is used to calculate the corresponding relationship of the real-time temperature value according to the resistance change when the thermistor sensor detects the temperature of the air compressor.

[0077] Specifically, first, activate the sensing unit according to the determined suspension working mode. The sensing unit is composed of a suspension height sensor, an air compressor temperature sensor (i.e., a thermistor sensor), and a gas electromagnetic distribution valve pressure sensor (i.e., a pressure sensor).

[0078] The suspension height sensor works based on the Hall effect principle. During vehicle driving, when the relative height between the vehicle body and the chassis changes, it will cause a change in the magnetic field, and then generate a voltage signal related to the height. Taking the vehicle passing over a speed bump as an example, at this time, the relative height between the vehicle body and the chassis changes, and the suspension height sensor can quickly respond and output a corresponding voltage signal, which can accurately reflect the height change. The ESCU (Electronic Suspension Control Unit) can sense the height changes of the vehicle body on both the left and right sides in real time through the two height sensors on the left and right.

[0079] The air compressor temperature sensor is used to detect the temperature of the air compressor. It utilizes the characteristic that the resistance of the thermistor itself changes with temperature, and combines the preset temperature-resistance relationship to calculate the real-time temperature value. For example, it is preset that a certain thermistor has a resistance of 10 kΩ at 25 °C, and the resistance changes according to a specific law for every 1 °C increase in temperature. By measuring the current resistance value, the real-time temperature value can be accurately calculated based on this preset relationship, which provides key data for judging the working state of the air compressor. After the air pump starts, the ESCU will detect both the surface temperature and the continuous working time of the air pump at the same time. When overheating occurs, overheat protection takes precedence over timeout protection. That is, within the Ts working time after the air pump starts, if over-temperature is detected, the air pump will be immediately stopped; if over-temperature is not detected within Ts, the air pump will be immediately stopped after it is detected that the continuous working time exceeds Ts.

[0080] The gas electromagnetic distribution valve pressure sensor is used to detect the air pressure in the air storage tank. When it detects that the air pressure in the air storage tank is lower than the set threshold (assumed to be 4 MPa, and the actual threshold depends on the system design), the ESCU will automatically start the air compressor to replenish air to the air storage tank until the air pressure reaches the target air pressure value (assumed to be 5 MPa, also depending on the system design). This process ensures the stability of the air pressure in the air storage tank and maintains the normal operation of the air suspension.

[0081] Finally, the voltage signal generated by the suspension height sensor, the real-time temperature value calculated by the air compressor temperature sensor, and the air pressure value obtained by the gas electromagnetic distribution valve pressure sensor are correlated and integrated. First, these different types of data are normalized to convert them into a unified data format or range. Then, those skilled in the art assign corresponding weights to each type of data according to the importance of each data to the air suspension system or through the correlation analysis of historical data. Then, weighted calculation is performed on the normalized data according to the set weights, and the calculation results are summarized to form a set of sensor data that comprehensively reflects the real-time state of the air suspension.

[0082] The sensor data obtained through the above steps comprehensively reflects the working state of the air suspension, which is used for subsequent fault diagnosis and control strategy formulation, so as to achieve precise control of the air suspension and improve the comfort and safety of vehicle driving.

[0083] Further, step A400 in the method provided by the embodiments of the present application includes:

[0084] A410: Perform sensor fault diagnosis according to the sensor data, and generate a sensor fault diagnosis result.

[0085] A420: Perform CAN communication fault diagnosis according to the sensor data, and generate a CAN communication fault diagnosis result.

[0086] A430: Perform actuator fault diagnosis according to the sensor data, and generate an actuator fault diagnosis result.

[0087] A440: Perform data fusion alignment on the sensor fault diagnosis result, the CAN communication fault diagnosis result, and the actuator fault diagnosis result to obtain a diagnosis result.

[0088] Specifically, first, perform sensor fault diagnosis based on the sensor data. By analyzing the voltage signal generated by the suspension height sensor, first circuit fault data is generated; based on the real-time temperature value calculated by the thermistor sensor and combined with its temperature-resistance relationship, second circuit fault data is generated; according to the target air pressure value detected by the pressure sensor, circuit fault diagnosis is performed on the pressure sensor to generate third circuit fault data. These data are integrated to form a sensor fault diagnosis result, and the specific steps are detailed in A411 - A414.

[0089] Next, carry out CAN communication fault diagnosis work. CAN communication fault diagnosis covers three aspects: CAN communication offline fault diagnosis, CAN message loss fault diagnosis, and CAN message data invalid fault diagnosis.

[0090] When the system detects CAN communication offline, it means that there may be a physical fault in the CAN bus or a problem in the CAN module circuit, which will cause serious difficulties in data transmission between vehicle components. At this time, the system will immediately send a fault code with a fault level of "serious fault" at a frequency of 5Hz and save it in the DTC (Diagnostic Trouble Code) information area to provide clear guidance for maintenance personnel to troubleshoot faults. At the same time, the ESCU defaults to the high-speed mode to ensure that the vehicle still has basic driving ability in an emergency.

[0091] In the case where other CAN messages are received normally, if a certain message is not received by the ESCU after more than 10 times the sending period, the system will determine that the message is lost; if the ESCU receives a certain message value that is invalid, it will be determined as the message data invalid fault. For these two faults, the system will send a fault code with a fault level of "minor fault" at a frequency of 5Hz and save it in the DTC information area.

[0092] When a message loss or data invalidation fault occurs, the system will react differently according to the message type. For example, when the ESCU determines that the ABS (antilock braking system) message is lost or invalid, it will default to the high-speed mode; when it determines that the SAS (steering angle sensor) message is lost or invalid, it will default to the cornering mode; and when it determines that such problems occur in other messages except ABS and SAS, the ESCU will not take any action for the time being.

[0093] After that, the system will continuously perform detections. Once the tests pass for 4 consecutive cycles, it indicates that the CAN communication has returned to normal. At this time, the system will clear the corresponding fault records, and then generate a complete and accurate CAN communication fault diagnosis result, providing a reliable basis for subsequent vehicle control and fault handling.

[0094] Then, actuator fault diagnosis is carried out, which specifically includes multiple aspects such as solenoid valve fault diagnosis, air storage tank inflation fault diagnosis, and exhaust timeout fault diagnosis.

[0095] In the solenoid valve fault diagnosis, the ESCU will detect the short-circuit or open-circuit status of the loads of the left airbag solenoid valve, right airbag solenoid valve, air storage tank solenoid valve, and exhaust tank solenoid valve. Once such a fault in the solenoid valve is detected, the ESCU will immediately send a fault code including the fault level of "serious fault" and the fault location at a frequency of 5 Hz and save it into the DTC information area. At the same time, the height adjustment function of the air suspension is prohibited to prevent abnormal suspension adjustment caused by actuator faults, facilitating the subsequent maintenance personnel to quickly locate and solve problems.

[0096] Regarding the inflation of the air storage tank, if the air pressure does not increase by 0.2 bar within 20 seconds, the ESCU will determine it as an air storage tank inflation fault, which may be caused by factors such as air pump failure, air leakage in the air circuit, or air leakage in the air storage tank. At this time, the ESCU will also send a fault code with the fault level of "serious fault" and including the fault location to the DTC information area at a frequency of 5 Hz, prohibit the height adjustment function, and record the fault information.

[0097] In terms of exhaust timeout fault diagnosis, when the ESCU performs the airbag exhaust operation and the exhaust time exceeds the preset threshold (assumed to be 10 seconds), it is determined as an exhaust timeout fault, which may be caused by mechanical faults of the left or right airbag solenoid valve, mechanical faults of the exhaust valve, air circuit blockage, etc. The ESCU will send a fault code with the fault level of "serious fault" and the fault location to the DTC information area at a frequency of 5 Hz and prohibit the height adjustment at the same time.

[0098] Finally, integrate and analyze situations such as solenoid valve failures, air storage tank inflation failures, and exhaust timeout failures to generate comprehensive and accurate actuator fault diagnosis results, providing a strong basis for fault troubleshooting and repair of the air suspension system.

[0099] Finally, align the data of the sensor fault diagnosis results, CAN communication fault diagnosis results, and actuator fault diagnosis results through data fusion, and integrate and process the sensor, CAN communication, and actuator fault diagnosis results. First, unify the data format and range, synchronize the time reference, and then perform correlation analysis based on the fault type and location, assign weights to different diagnosis results and perform weighted calculations to obtain a comprehensive index reflecting the overall severity of the system failure. Finally, present the results in the form of charts, reports, or specific codes to facilitate maintenance personnel to understand the fault situation and formulate maintenance strategies.

[0100] By comprehensively analyzing the fault diagnosis results in these different aspects, fully understand the fault condition of the air suspension system and obtain accurate diagnosis results. Based on this diagnosis result, targeted suspension control strategies can be formulated subsequently, so as to ensure the stable operation of the air suspension system under various complex conditions and improve the safety and comfort of vehicle driving.

[0101] Furthermore, step A410 in the method provided by the embodiment of the present application includes:

[0102] A411: Based on the voltage signal, perform circuit fault diagnosis on the suspension height sensor to generate first circuit fault data.

[0103] A412: Based on the real-time temperature value, perform circuit fault diagnosis on the thermistor sensor to generate second circuit fault data.

[0104] A413: Based on the target air pressure value, perform circuit fault diagnosis on the pressure sensor to generate third circuit fault data.

[0105] A414: Add the first circuit fault data, the second circuit fault data, and the third circuit fault data to the sensor fault diagnosis result.

[0106] In the embodiment of the present application, the first circuit fault data is the data obtained after performing circuit fault diagnosis on the voltage signal generated by the suspension height sensor. The second circuit fault data is the data generated by performing circuit fault diagnosis on the real-time temperature value calculated by the thermistor sensor. The third circuit fault data is the data generated by performing circuit fault diagnosis based on the target air pressure value obtained by the pressure sensor.

[0107] In one embodiment, first, circuit fault diagnosis is performed on the suspension height sensor by using the voltage signal generated by it. Since the suspension height sensor operates based on the Hall effect principle, under normal circumstances, the relative height change between the vehicle body and the chassis will cause it to generate a corresponding voltage signal. If the voltage signal shows abnormal fluctuations, exceeds the normal range, or has no response when the vehicle body height changes, it indicates that there may be a circuit fault, and then the first circuit fault data is generated.

[0108] Next, circuit fault diagnosis is performed on the thermistor sensor based on the real-time temperature value calculated by it. The thermistor sensor uses the characteristic that the resistance changes with temperature to detect the temperature of the air compressor. If the deviation between the real-time temperature value and the actual operating temperature of the compressor is too large, and after excluding the factor of abnormal heat generation of the compressor itself, it can be inferred that there is a problem with the circuit of the thermistor sensor, thereby generating the second circuit fault data.

[0109] Then, circuit fault diagnosis is performed on the pressure sensor based on the target air pressure value obtained by it. The pressure sensor converts the air pressure in the air storage tank into a voltage signal for the ECSU to collect and process. If the collected air pressure value is abnormal, after excluding the faults of components such as the air storage tank and the air circuit, it can be determined that there is a circuit fault in the pressure sensor, and thus the third circuit fault data is generated.

[0110] Finally, the first circuit fault data, the second circuit fault data, and the third circuit fault data are summarized to form a complete sensor fault diagnosis result. This result can clearly present the circuit fault conditions of each sensor, provide a strong basis for the subsequent maintenance personnel to quickly locate and solve problems, help ensure the stable operation of the air suspension system, and improve the safety and comfort of the vehicle.

[0111] By performing circuit fault diagnosis on the voltage signal of the suspension height sensor, the real-time temperature value of the thermistor sensor, and the target air pressure value of the pressure sensor respectively, the technical effect of accurately locating the circuit faults of each sensor and then ensuring the stable operation of the air suspension system is achieved.

[0112] In summary, the control method of an air suspension provided by the embodiment of the present application has the following technical effects:

[0113] In this application, an interaction link is constructed between vehicle status signal acquisition and suspension control. CAN communication technology is used to transmit data. Through operations such as sensor unit acquisition and specific algorithm calculation, integrated sensor data is obtained and analyzed and processed in the fault diagnosis module. Through sensor fault diagnosis, CAN communication fault diagnosis, and actuator fault diagnosis, combined with the data fusion alignment mechanism, a suspension control strategy is formulated based on the diagnosis results and dynamically adjusted to ensure the stable operation of the air suspension system, achieving the technical effects that the air suspension accurately switches the working mode according to the real-time driving status of the vehicle, timely and accurately obtains the vehicle status signal, and at the same time constructs a comprehensive fault diagnosis system, improving the comfort, handling stability, and safety of vehicle driving.

[0114] Embodiment 2, as Figure 2 shown, based on the same inventive concept as the foregoing Embodiment 1, an embodiment of this application provides a control system for an air suspension, and the system includes:

[0115] A status signal acquisition module 1, which acquires vehicle status signals in real time through CAN communication control.

[0116] A working mode determination module 2, which dynamically switches the air suspension based on the vehicle status signal using height adjustment control to determine the suspension working mode.

[0117] A sensor data generation module 3, which is used to start the sensor unit to monitor the air suspension in real time according to the suspension working mode and generate sensor data.

[0118] A control strategy formulation module 4, which combines the sensor data to execute fault diagnosis control and formulates a suspension control strategy according to the diagnosis results.

[0119] Further, the status signal acquisition module 1 is used to perform the following steps:

[0120] Receive multiple vehicle status parameters through the CAN bus, judge the multiple vehicle status parameters, and generate a status judgment result.

[0121] When any parameter in the status judgment result is determined to be invalid, a preset fault handling strategy is adopted to generate a fault handling result.

[0122] Based on the fault handling result, the corresponding vehicle status signal is retrieved for output.

[0123] Further, the working mode determination module 2 is used to perform the following steps:

[0124] Retrieve the historical height switching record to set the switching constraint condition.

[0125] Compare the vehicle state signal with the switching constraint conditions to generate a comparison result.

[0126] Activate a switching instruction according to the comparison result, and perform switching control on multiple working modes through the switching instruction.

[0127] Match the vehicle state signal based on the multiple working modes to determine the target working mode, and use the target working mode as the suspension working mode.

[0128] Furthermore, the working mode determination module 2 is used to execute the following steps:

[0129] The target working mode includes a static working mode, a cornering working mode, or a high-speed working mode.

[0130] When the target working mode is the static working mode, automatically adjust the height of the air suspension to generate static height parameters.

[0131] When the target working mode is the cornering working mode, prohibit height adjustment of the air suspension to generate cornering height parameters.

[0132] When the target working mode is the high-speed working mode, lower the height of the air suspension to generate high-speed height parameters.

[0133] Screen according to the static height parameters, the cornering height parameters, and the high-speed height parameters to determine the suspension working mode.

[0134] Furthermore, the sensor data generation module 3 is used to execute the following steps:

[0135] Activate the sensing unit based on the suspension working mode, and the sensing unit includes a suspension height sensor, a thermistor sensor, and a pressure sensor.

[0136] Detect the relative height between the vehicle body and the chassis through the suspension height sensor to generate a voltage signal.

[0137] Detect the temperature of the air compressor through the thermistor sensor, and calculate the real-time temperature value in combination with the preset temperature-resistance relationship.

[0138] Detect the air pressure in the air storage tank through the pressure sensor, and when the air pressure is lower than the threshold, start the compressor to replenish air until the target air pressure value is reached.

[0139] Correlate and integrate the voltage signal, the real-time temperature value, and the target air pressure value to determine the sensor data.

[0140] Furthermore, the control strategy formulation module 4 is used to execute the following steps:

[0141] Perform sensor fault diagnosis according to the said sensor data, and generate a sensor fault diagnosis result.

[0142] Perform CAN communication fault diagnosis according to the said sensor data, and generate a CAN communication fault diagnosis result.

[0143] Perform actuator fault diagnosis according to the said sensor data, and generate an actuator fault diagnosis result.

[0144] Perform data fusion alignment on the said sensor fault diagnosis result, the said CAN communication fault diagnosis result, and the said actuator fault diagnosis result to obtain a diagnosis result.

[0145] Furthermore, the control strategy formulation module 4 is used to execute the following steps:

[0146] Perform circuit fault diagnosis on the suspension height sensor based on the said voltage signal, and generate first circuit fault data.

[0147] Perform circuit fault diagnosis on the thermistor sensor based on the said real-time temperature value, and generate second circuit fault data.

[0148] Perform circuit fault diagnosis on the pressure sensor based on the said target air pressure value, and generate third circuit fault data.

[0149] Add the said first circuit fault data, the said second circuit fault data, and the said third circuit fault data to the sensor fault diagnosis result.

[0150] The control system of an air suspension provided by an embodiment of the present invention can execute the control method of an air suspension provided by any embodiment of the present invention, and has corresponding functional modules and beneficial effects for executing the method.

[0151] Although the present application makes various references to certain modules in the system according to the embodiments of the present application, however, any number of different modules can be used and run on the user terminal and / or the server. The included various units and modules are only divided according to the functional logic, but are not limited to the above division, as long as the corresponding functions can be realized; in addition, the specific names of the functional units are only for the convenience of mutual distinction and do not limit the protection scope of the present invention.

[0152] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application. In some cases, the actions or steps recorded in the present application can be executed in a sequence different from that in the embodiments and still achieve the desired results. Additionally, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for controlling an air suspension, characterized in that: The method comprises: Obtain vehicle status signals in real time through CAN communication control; Based on the vehicle status signal, dynamically switching the air suspension using height adjustment control to determine the suspension working mode; According to the suspension working mode, the sensor unit is started to monitor the air suspension in real time and generate sensor data; Fault diagnosis control is performed in combination with the sensor data, and a suspension control strategy is formulated according to the diagnosis result.

2. The air suspension control method according to claim 1, characterized in that: The vehicle status signal is obtained in real time through CAN communication control, and the method includes: receiving a plurality of vehicle status parameters via a CAN bus, judging the plurality of vehicle status parameters, and generating a status judgment result; When any parameter in the state judgment result is judged to be invalid, a preset fault handling strategy is adopted to generate a fault handling result; Based on the fault processing result, a corresponding vehicle status signal is retrieved and outputted.

3. The air suspension control method according to claim 1, characterized in that: Based on the vehicle state signal, the air suspension is dynamically switched by height adjustment control to determine the suspension working mode, the method comprising: Retrieve historical height switching records to set switching constraints; Comparing the vehicle state signal with the switching constraint condition to generate a comparison result; activating a switching instruction according to the comparison result, and performing switching control on a plurality of working modes through the switching instruction; Based on the matching of the multiple working modes with the vehicle state signal, a target working mode is determined, and the target working mode is used as the suspension working mode.

4. The air suspension control method according to claim 3, characterized in that: Based on the matching of the multiple working modes with the vehicle state signal, a target working mode is determined, and the target working mode is used as the suspension working mode. The method includes: The target working mode includes a static working mode, a curve working mode or a high-speed working mode; When the target working mode is a static working mode, automatically adjusting the height of the air suspension to generate a static height parameter; When the target working mode is the curve working mode, the height adjustment of the air suspension is prohibited, and a curve height parameter is generated; When the target working mode is a high-speed working mode, the height of the air suspension is lowered to generate a high-speed height parameter; The suspension working mode is determined by screening according to the static height parameter, the curve height parameter and the high-speed height parameter.

5. The air suspension control method according to claim 1, characterized in that: According to the suspension working mode, the sensing unit is started to monitor the air suspension in real time and generate sensor data, the method comprising: activating a sensing unit based on the suspension working mode, the sensing unit comprising a suspension height sensor, a thermistor sensor, and a pressure sensor; The relative height between the vehicle body and the chassis is detected by the suspension height sensor to generate a voltage signal; The temperature of the air compressor is detected by the thermistor sensor, and the real-time temperature value is calculated in combination with a preset temperature-resistance relationship; The pressure sensor is used to detect the air pressure in the air storage tank. When the air pressure is lower than a threshold, the compressor is started to replenish air until the target air pressure value is reached. The voltage signal, the real-time temperature value, and the target air pressure value are correlated and integrated to determine sensor data.

6. The air suspension control method according to claim 5, characterized in that: Performing fault diagnosis control in combination with the sensor data, the method includes: Perform sensor fault diagnosis according to the sensor data to generate a sensor fault diagnosis result; Perform CAN communication fault diagnosis according to the sensor data and generate CAN communication fault diagnosis results; Performing actuator fault diagnosis according to the sensor data to generate an actuator fault diagnosis result; The sensor fault diagnosis result, the CAN communication fault diagnosis result, and the actuator fault diagnosis result are data fused and aligned to obtain a diagnosis result.

7. The air suspension control method according to claim 6, characterized in that: Performing sensor fault diagnosis according to the sensor data to generate a sensor fault diagnosis result, the method comprising: performing circuit fault diagnosis on the suspension height sensor based on the voltage signal to generate first circuit fault data; Performing circuit fault diagnosis on the thermistor sensor based on the real-time temperature value to generate second circuit fault data; Performing circuit fault diagnosis on the pressure sensor based on the target air pressure value to generate third circuit fault data; The first circuit fault data, the second circuit fault data, and the third circuit fault data are added to the sensor fault diagnosis result.

8. A control system for an air suspension, characterized in that: A method for controlling an air suspension according to any one of claims 1 to 7, the system comprising: A status signal acquisition module, wherein the status signal acquisition module acquires the vehicle status signal in real time through CAN communication control; A working mode determination module, wherein the working mode determination module dynamically switches the air suspension using height adjustment control based on the vehicle state signal to determine the suspension working mode; A sensor data generation module, the sensor data generation module is used to start the sensor unit to monitor the air suspension in real time according to the suspension working mode and generate sensor data; A control strategy formulation module is used to perform fault diagnosis control in combination with the sensor data and formulate a suspension control strategy according to the diagnosis result.

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