A static and dynamic vehicle posture adjustment unit and adjustment method

Abstract

The present application belongs to the field of hydraulic electric control of engineering vehicles, and relates to a vehicle posture adjusting unit and adjusting method based on static and dynamic states. The vehicle posture adjusting unit comprises a motherboard component, a main control expansion board, a power supply board, a collection board, a driving board, a shell and an upper cover plate. Rectangular connectors and circular connectors are welded on the motherboard card, and the motherboard card is fixed on the lower cover plate. The main control expansion board, the power supply board, the collection board and the driving board are connected to the motherboard card through quick-connection rectangular connectors, and the motherboard card is fixed to the shell through a lock. The upper cover plate is fixed above the shell. The present application introduces a dynamic optimization function on the basis of static adjustment function, that is, when the vehicle is driving at a constant speed in a straight line, the dynamic data collection and height adjustment are used to make the heights of the groups of supporting points consistent. When the vehicle is driving, the relative movement between the groups of wheels and the ground can release the uncontrollable friction during the static adjustment, and the state of the vehicle after the dynamic optimization is closer to the ideal state of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of hydraulic control of engineering vehicles, and relates to a vehicle attitude adjustment unit based on static and dynamic states. BACKGROUND

[0002] At present, the adjustability and passability of vehicles are improved by using adjustable oil-gas suspension technology, and the technical problem of the length characteristic of the elastic element of the traditional suspension being unadjustable is solved. According to the 4-point leveling scheme, the support points (each oil-gas suspension is a support point) of a vehicle with more than 2 axles are divided into 4 groups, i.e. left front, left rear, right front and right rear 4 groups, one oil-gas spring with less influence on the vehicle bottom surface is selected as the group reference, the heights of each group are collected, and the height difference between each group of oil-gas springs and the set reference is calculated, and through the hydraulic leveling system, each group of oil-gas springs is driven to move a specified distance at a synchronous speed, thereby completing the height adjustment of the multi-axle vehicle.

[0003] At present, the vehicle attitude adjustment is mainly static vehicle attitude adjustment. When static adjustment is performed, due to the suspension structure, there is a certain horizontal displacement of the wheel tread during adjustment, and the ground flatness, the friction between the tire and the ground and many other factors cause the friction to be large and uncertain. When the vehicle load changes, the vehicle attitude controller is also difficult to detect the influence, and it is difficult to finally adjust the effect. Especially in the field working condition, there is a large gap between the final adjustment state of the vehicle and the ideal state. SUMMARY

[0004] (I) Object of the present application

[0005] The object of the present application is to provide a vehicle attitude adjustment unit based on static and dynamic states. The dynamic optimization function is introduced on the basis of the static adjustment function, i.e. when the vehicle is driving at a constant speed in a straight line, the height of each group of support points tends to be consistent through the steps of dynamic data collection and height adjustment. When the vehicle is driving, the relative motion of each wheel group and the ground can release the uncontrollable friction during static adjustment, and therefore the state of the vehicle after dynamic optimization is closer to the ideal state of the vehicle.

[0006] (II) Technical solution of the present application

[0007] The dynamic optimization function puts forward new requirements for the data collection capability of the unit and the determination of the vehicle state. The integrated active detection unit is used for the determination of the driving state of the vehicle. The ADC resource can be dynamically allocated according to the requirements of the core algorithm of the vehicle attitude adjustment unit, the high sampling rate of the focus channel is realized, and similarly, the sampling rate of the non-focus channel can be reduced or completely closed to release the ADC resource. The static adjustment and dynamic optimization adjustment functions of the vehicle attitude are realized without significantly increasing the hardware cost.

[0008] The application provides a vehicle posture adjusting unit integrating motion detection, which dynamically allocates ADC resources without significantly increasing cost, and has great improvement in operation, data collection accuracy and sampling rate required by dynamic vehicle posture optimization algorithm.

[0009] One aspect of the application provides a static and dynamic vehicle posture adjusting unit, which comprises a motherboard component 1, a main control expansion board 2, a power supply board 3, an acquisition board 4, a drive board 5, a shell 6 and an upper cover plate 7.

[0010] Further, the main control expansion board is provided with a main control circuit, a main communication SPI drive circuit, an active detection unit, a data storage unit FMRam, a CAN2.0A / B communication circuit unit, an expansion port drive circuit, a SWIO port for debugging and an RS232 circuit.

[0011] The main communication SPI drive circuit is connected with the drive board A, the drive board B and the acquisition board.

[0012] The active detection unit is mainly used for setting an active shaft according to the installation state when the vehicle posture adjusting unit is installed on a vehicle, continuously measuring the acceleration on the active shaft, and judging that the vehicle is in a moving state when the absolute value of the acceleration is higher than a set value for n times in succession.

[0013] The data storage unit FMRam is used for recording vehicle posture state information and saving system key setting parameters;

[0014] The CAN2.0A / B communication circuit unit is mainly responsible for communication with the whole vehicle, receiving whole vehicle commands and reporting data;

[0015] The extension port driving circuit is used for driving the valve group; the extension port driving circuit is externally expanded by 8 paths, wherein 1 path is used for driving the state indicator lamp installed on the shell, the lamp is always on when the system is silent, the lamp flashes at a frequency of 2 Hz when the system performs vehicle posture adjustment action, and the lamp flashes at a frequency of 10 Hz when the system fails; the other 7 paths are used for driving the valve group, whether to be used depends on the total driving path number;

[0016] The debugging circuit SWIO port is used for online debugging of the vehicle posture adjustment unit.

[0017] Further, the main control circuit mainly comprises a single-chip microcomputer STM32F407, a clock oscillation circuit, a reset circuit and a power filter circuit.

[0018] Further, when the vehicle posture adjustment unit is installed, 1 movable shaft should be perpendicular to the vehicle bottom surface, and the 2nd movable shaft points to the vehicle head direction; after the vehicle posture adjustment unit is installed on the vehicle body, the second movable shaft parallel to the vehicle bottom surface is configured as a movable detection shaft, so that the vehicle in the active state can be detected when the vehicle turns, accelerates or decelerates.

[0019] Further, the power board card provides suitable power supply for each part of the vehicle posture adjustment unit. The power board card provides independent digital power supply 3.3V 2W for the two driving board cards A and B, provides independent analog power supply 5V 2W for the acquisition board card, and provides isolated digital power supply 5V 2W and 3.3V 1W for the main control expansion board card.

[0020] Further, the acquisition board card 4 is integrally designed with an ADC device, a single-chip microcomputer, an ADC acquisition front-end circuit and a sensor power supply control option;

[0021] The ADC device is provided with a first-order anti-aliasing analog filter, a stack sequencer and a digital first-order sine filter, and the focus channel high sampling rate is realized by setting a custom stack sequence; when the vehicle is running, the different oversampling rates of the digital first-order sine filter can be set to improve the sampling rate or reduce the sampling rate when a wider dynamic response range is required;

[0022] The single-chip microcomputer uses STM32F4XX, communicates with the ADC device by using DMA+FMSC, uses TIM single trigger to notify the main control expansion board card that the data is ready, and adopts SPI full-duplex slave mode to interact with the main control expansion board card.

[0023] Sensor power control option, mainly responsible for when the vehicle posture adjustment unit is in silence, the sensor power supply can be turned off to save energy consumption; when the vehicle posture adjustment unit is about to be active, first control the driving MOS tube to open the power supply to each sensor, detect the sensor power supply state, initialize the ADC, and then start data collection and run the core algorithm; when the sensor fails or the power line is short-circuited to the ground, the F self-restoring fuse will be disconnected due to overcurrent, and the abnormality can be detected from PTEST, at this time, alarm processing and prevention of core algorithm running are performed to ensure that the vehicle state is out of control due to incorrect data;

[0024] The ADC sampling front-end circuit is used to expand the ADC collection channels of the collection board and collect the sensor signals without synchronization collection requirements.

[0025] Further, the driving board card 5 is responsible for driving each valve group of the vehicle posture adjustment unit, and real-time load online determination is performed for all output channels, and driving current sampling is used for load health state evaluation; the driving board card 5 is integrated with a driving circuit and a single-chip microcomputer;

[0026] The single-chip microcomputer on the driving board card receives driving information from the main control expansion board card through an SPI port, sets the output state of the corresponding output port KZ through an IO port, simultaneously collects and compares the output of the comparator and the driving current feedback ISADC in real time and uninterruptedly, and feeds back the state information of all driving output ends to the main control expansion board card through an SPI bidirectional bus, for system fault diagnosis.

[0027] The MOS tube driving circuit is integrated with a current feedback pin IS, which is divided by resistors R4 and R6, and is connected to an ISADC collector after current limiting by resistor R3, so as to monitor the real-time current of the load and evaluate the load health state.

[0028] The second aspect of the present application provides a static vehicle posture adjustment method, comprising the following steps:

[0029] 1) starting the vehicle height task after receiving the CAN bus adjustment command;

[0030] 2) the single-chip microcomputer on the main control expansion board card determines whether the current vehicle state meets the adjustment requirements, that is, the current vehicle state speed is 0 and the engine speed is greater than 600 revolutions;

[0031] If not, end the process and report the end condition; the main control circuit single-chip microcomputer marks the state data information, and the adjustment fails;

[0032] If it is met, the next step is entered;

[0033] 3) the main control circuit single-chip microcomputer initializes the adjustment key parameters and sets the adjustment target;

[0034] 4) According to the current state of the vehicle, set each support point action label;

[0035] Firstly, the vehicle lowering process is executed; the support points needing adjustment are detected and labeled, and are included in the oil spring synchronization algorithm participation table, the driving output table, and the position determination table embedded in the main control circuit single-chip microcomputer in the next control cycle. According to the instructions of each support point action label, the driving circuit of the driving board drives the valve group combination switch to execute the lowering action. The oil spring synchronization algorithm is executed once in a control cycle to ensure that the length error of each oil spring is less than a set value. The main control circuit single-chip microcomputer combines the oil spring movement speed collected by the acquisition board card in the last control cycle to comprehensively estimate and determine the driving output. The valve group state changes at most once. Then, the vehicle lowering process is returned, and a new control process is started;

[0036] At the same time, in a corresponding determination cycle of a control cycle, the single-chip microcomputer on the main control expansion board card executes once the support point data update, the vehicle posture state protection determination, and the position determination. If any of the vehicle posture state protection determination and the position determination is met, the lowering process is terminated, i.e., the control cycle and the determination cycle are ended, and the next step is executed. If not, the next control cycle and the determination cycle are executed until the time is up.

[0042] 5) Each support point action label;

[0038] The vehicle lifting process is executed; the support points needing adjustment are detected and labeled, and are included in the oil spring synchronization algorithm participation table, the driving output table, and the position determination table in the next control cycle. According to the instructions of each support point action label, the driving board card drives the vehicle posture adjustment unit to execute the lifting action. The oil spring synchronization algorithm is executed once in a control cycle to ensure that the length error of each oil spring is less than a set value. The single-chip microcomputer on the driving board card combines the oil spring movement speed in the last control cycle to comprehensively estimate and determine the driving output. The valve group state changes at most once. Then, the vehicle lifting process is returned, and a new control process is started;

[0039] At the same time, in a corresponding determination cycle of a control cycle, the support point data update, the vehicle posture state protection determination, and the position determination are executed once. If any of the vehicle posture state protection determination and the position determination is met, the lifting process is terminated, i.e., the control cycle and the determination cycle are ended, and the next step is executed. If not, the next control cycle and the determination cycle are executed until the time is up.

[0040] 6) Adjustment wheel;

[0041] After one adjustment cycle, the vehicle state is adjusted after 1s and enters the next adjustment cycle, and the adjustment cycle is executed 3-5 times to complete the adjustment of the vehicle state, end the process, report the end condition, report the adjustment state information to the CAN bus, and then mark the state data in the data storage unit FMRam for use in the dynamic vehicle posture adjustment process.

[0042] The static vehicle posture adjustment process is completed.

[0043] The third aspect of the present application provides a dynamic vehicle posture adjustment method, comprising the following steps:

[0044] 1) After the static vehicle posture adjustment process is completed, the dynamic vehicle posture adjustment monitoring task is started, and when the vehicle speed is greater than 1 and less than 10, the dynamic vehicle posture adjustment process is automatically started and the monitoring task is ended, and the next step is entered.

[0045] 2) The support point data is collected by the board card for high-speed collection, and the collection lasts for N seconds.

[0046] 3) The main control circuit single-chip microcomputer compares the average value of the data with the last static adjustment target, and determines whether the support point with the maximum deviation in the data table is within the target value range.

[0047] If the support point with the maximum deviation is within the target value range, the task is ended, the function pointer is emptied, and the dynamic vehicle posture adjustment process is ended.

[0048] If the support point with the maximum deviation is not within the target value range, the next step is performed.

[0049] 4) The main control circuit single-chip microcomputer compares the average vehicle height.

[0050] If the lowest support point is lower than the target value, the main control circuit single-chip microcomputer outputs an instruction to the driving circuit of the driving board card to drive the support point to rise for n seconds.

[0051] If the highest support point is higher than the target value, the main control circuit single-chip microcomputer outputs an instruction to the driving circuit of the driving board card to drive the support point to fall for n seconds.

[0052] After the falling and rising operations for n seconds, the current adjustment sub-process is ended, the adjustment cycle number is incremented by 1, and step 2) is entered to start a new adjustment cycle. After the dynamic vehicle posture adjustment process is recursively executed for a specified number of times, the process is ended.

[0053] Further, during the data collection process, if the steering wheel angle > a or the activity is set, the data collection is paused until both conditions are met to continue the data collection process.

[0054] The present application has the following advantages:

[0055] 1. The system is easily expandable. Simply replacing the motherboard with one of different slot numbers allows for expansion or reduction of the number of output channels and acquisition channels. Corresponding function boards (main control expansion boards, acquisition boards, and driver boards are different types of function boards) can directly use existing boards.

[0056] 2. Controllers of the same series with different input / output types have the same functional boards, which can effectively reduce the types of spare parts and the difficulty of maintenance.

[0057] 3. For different needs, different functional boards can be replaced in-situ to quickly implement different functional controllers. ADC hardware resources can be dynamically allocated to increase the sampling rate of currently key ADC channels, providing more reference data for upper-level adjustment programs.

[0058] 4. When the system is idle, the power supply to the ADC hardware and external sensors can be turned off, and the output board and acquisition board can be set to sleep mode to reduce power consumption and system heat generation, which is in line with the concept of energy conservation and emission reduction.

[0059] 5. The motion detection unit can detect the vehicle's current motion status and allows the execution of different adjustment commands in different states such as stationary, accelerating, and constant speed. For example, it does not accept vehicle attitude adjustment when the vehicle is not stationary.

[0060] 6. This invention utilizes a master board structure to avoid internal wire connections, and the expandable board-type structure facilitates further expansion of the controller. Attached Figure Description

[0061] Figure 1 Schematic diagram of the vehicle attitude adjustment unit structure;

[0062] Figure 2 Master card diagram;

[0063] Figure 3 Vehicle posture adjustment calculation unit detects the XYZ axis directions;

[0064] Figure 4 System topology;

[0065] Figure 5 System power architecture;

[0066] Figure 6 Sensor power supply topology and power supply detection;

[0067] Figure 7 : 2*8 channel synchronous ADC front-end and parallel port acquisition chip connection;

[0068] Figure 8 : ADC sampling analog front end;

[0069] Figure 9: Drive circuit and drive current configuration

[0070] Figure 10 : Static adjustment flow chart

[0071] Figure 11 : Dynamic optimization flow chart. DETAILED DESCRIPTION

[0072] The following will be described in detail in combination with the accompanying drawings Figures 1 to 11 The present application is further described in detail as follows:

[0073] Figure 1 As shown in the drawings, the vehicle posture adjustment unit based on static and dynamic provided by the application mainly consists of a motherboard component (1), a main control expansion board card (2), a power board card (3), an acquisition board card (4), a drive board card (5), a shell (6), and an upper cover plate (7).

[0074] The motherboard component (1) mainly consists of a motherboard card (as shown in the drawings), a rectangular connector, a round connector, and a lower cover plate. Figure 2 The rectangular connector and the round connector are welded on the motherboard card, and the motherboard card is fixed to the lower cover plate by screws and nuts. The drive board card 5 is two pieces, which are drive board card A and drive board card B. Each of the main control expansion board card (2), the power board card (3), the acquisition board card (4), and the drive board card (5) is connected to the motherboard card through a quick-connection rectangular connector, and the motherboard card is fixed to the shell (6) through a lock.

[0075] The main control expansion board card is integrally provided with a main control circuit, a main communication SPI drive circuit, a movable detection unit, a data storage unit FMRam, a CAN2.0A / B communication circuit unit, an expansion port drive circuit, a SWIO port for debugging, and an RS232 circuit.

[0076] The main control circuit mainly consists of a single-chip microcomputer STM32F407, a clock oscillation circuit, a reset circuit, and a power filter circuit.

[0077] The main communication SPI drive circuit enhances the input and output drive capability of the SPI bus by ADuM415, and is connected to the drive board card A, the drive board card B, and the acquisition board card.

[0078] The activity detection unit is composed of ADXL355 of ADI company. The 3-axis acceleration of the activity detection unit is continuously measured, when the vehicle posture adjusting unit is installed on the vehicle, the activity axis is set according to the installation state, the acceleration on the activity axis is continuously measured, when the absolute value of the acceleration is higher than the set value a for n times continuously, it is judged that the vehicle is in the activity state, combined with the vehicle speed signal, the current state of the vehicle can be judged: static, uniform straight-line driving or other state. When the vehicle is in the static state, the static vehicle posture adjusting algorithm and other specified algorithm processes are called; when the vehicle is in the uniform straight-line driving state, the dynamic vehicle posture optimization algorithm is called.

[0079] The data storage unit FMRam is used for recording the vehicle posture state information and saving the key set parameters of the system.

[0080] The CAN2.0A / B communication circuit unit is 2-way, mainly responsible for communication with the whole vehicle, receiving the whole vehicle command and reporting data.

[0081] The expansion port driving circuit is an effective supplement for driving the valve group and different driving types, and is externally expanded by 8 ways, of which 1 way is used for driving the state indicating lamp installed on the shell, the lamp is always on when the system is silent, the lamp flashes at a frequency of 2Hz when the system performs vehicle posture adjusting action, and the lamp flashes at a frequency of 10Hz when the system fails; the other 7 ways are used for driving the valve group, whether to be used depends on the overall driving number.

[0082] The main control expansion board is configured in the SPI full-duplex host mode, and the two driving board cards and the acquisition board card are connected to form a SPI bus framework of one master and three slaves through the motherboard card, the main control expansion board initiates SPI communication according to the data ready signal of the acquisition board card, and information interaction between the board cards is performed.

[0083] The debugging circuit SWIO port is used for online debugging of the vehicle posture adjusting unit, the RS232 circuit can be used for IAP system upgrade and system state monitoring, and when the wireless module is externally connected, it can be upgraded to wireless remote monitoring.

[0084] As shown in Figure 3 The activity detection unit integrated on the main control expansion board 2 of the application is in the direction of the overall XYZ axis. When the vehicle posture adjusting unit is installed, one of the activity axes should be perpendicular to the vehicle bottom surface, and the second activity axis points to the vehicle head direction, and when installed on the vehicle body, the two axes parallel to the vehicle bottom surface can be configured as the activity detection axes by software, when the vehicle turns, accelerates or decelerates, the activity state of the vehicle can be detected, at this time, the dynamic adjustment is inhibited.

[0085] As shown in Figure 4The system topology of the present application is shown, the main control expansion board card is connected with the driving board card A, the driving board card B and the collection board card through the high-speed SPI1 bus respectively, is connected with the active detection unit through the high-speed SPI2 bus, is connected with the FMRAM through the IIC, and the main control expansion board card is integrated with 2-way CAN2.0A / B circuit; the FMRAM is used for storing the historical data generated by system self-learning. The driving board card A, the driving board card B and the collection board card 4 are connected with the external port aviation connector through the mother board card.

[0086] As Figure 5 The system power supply framework of the present application is shown, the power supply board card provides suitable power supply for each part of the vehicle attitude adjusting unit. The power supply board card provides independent digital power supply 3.3V 2W for the two driving board cards A and B, provides independent analog power supply 5V 2W for the collection board card, provides isolated digital power supply 5V 2W and 3.3V 1W for the main control expansion board card, and all power supply paths are delayed in power-on.

[0087] The collection board card 4 is integrated with the ADC device AD7616 (ADI company product, with a first-order anti-aliasing analog filter, a stack sequencer, a digital first-order sinc filter), a single-chip microcomputer, an ADC collection front-end circuit and a sensor power supply control option. The ADC device AD7616 realizes high sampling rate (throughput rate) of the focus channel through setting the self-defined stack sequence; when the vehicle is running, the different oversampling rates of the digital first-order sinc filter can be set to improve the sampling rate or reduce the sampling rate when a wider dynamic response range is required, so that the signal-to-noise ratio can be improved. The single-chip microcomputer uses STM32F4XX, communicates with the ADC device AD7616 using DMA+FMSC, uses TIM single trigger to notify the main control expansion board card that the data is ready, and is configured in SPI full-duplex slave mode to interact with the main control expansion board card. The collection board card is equipped with a sensor power supply control option, which can turn off the sensor power supply to save energy consumption when the system is silent. The displacement and pressure signals at the same position are synchronously sampled and processed according to the system characteristics of vehicle attitude adjustment.

[0088] As Figure 6The collection board card 4 of the application shown has the function of providing the sensor power supply option, and a controllable driving MOS tube is arranged at the power supply end VCC, each path is provided with an F self-recovery fuse, and the power supply state is detected after the voltage division of resistors R1 and R2. When the vehicle posture adjusting unit is in silence, the sensor power supply can be turned off to save power consumption; when the vehicle posture adjusting unit is about to be activated, the driving MOS tube is first controlled to open to power up each sensor, the sensor power supply state is detected, the ADC is initialized, and then the data collection and core algorithm are started. When the sensor fails or the power supply line is short-circuited to the ground, the F self-recovery fuse will be disconnected due to overcurrent, and the abnormality can be detected at PTEST, at which time the alarm is processed and the core algorithm is prevented from running, so as to ensure that the vehicle does not lose control due to incorrect data.

[0089] As shown in the figure, Figure 7 The synchronous sampling ADC front-end circuit configuration of the collection board card 4 of the application is shown. The single-chip microcomputer on the collection board card 4 is connected with the ADC device through a parallel interface FMSC, a default stack sequence is set by power-on initialization, that is, the sampling rate of the focus channel 5 is five times that of the general channel, and a certain length of cache is constructed in the memory to serve as a software sequencer. A certain period of time, a certain time interval of sampling data can be collected and read, and after further collection in the RAM, the data is sent to the control board, so as to reduce the frequent disturbance of reading data to the main control expansion board card to the greatest extent. After receiving the data, the main control expansion board card can collect and process the data. The sampling rate and sampling interval are ensured, and the requirement for the response time of the main control expansion board card is reduced. When the vehicle is in a driving state and needs to be dynamically optimized, the main control expansion board card will first instruct the collection board card to reconfigure the sequencer in a dynamic sequence mode, close the sampling of the general channel, and put all the ADC device sampling resources into the focus channel to improve the sampling rate and expand the sampling bandwidth.

[0090] As shown in the figure, Figure 8 The ADC sampling front-end circuit of the collection board card 4 of the application is shown. The ADC sampling front-end circuit includes a precision sampling resistor R27, a C17, an operational amplifier U2, a resistor R26, and a resistor R25. The current signal input by the external sensor is converted into a voltage signal through the precision sampling resistor R27. The R27 and the C17 form a first-order RC filter circuit. The R26 is used to limit the current flowing into the operational amplifier U2. When the input signal exceeds the power supply rail, the clamping diode in the operational amplifier U2 will be turned on. By setting a proper R2 value, the current flowing through the clamping diode can be limited to a safe level, so that hardware damage will not occur. The operational amplifier U2 is in a follower state, and the input signal impedance is converted and sent to the ADC port of the single-chip microcomputer. This circuit is used to expand the ADC collection number of the collection board card and collect the sensor signals without synchronization collection requirements (such as the collection of pump station pressure signals).

[0091] The drive board card 5 is responsible for driving each valve group of the vehicle posture adjusting unit, and performs online load determination on all output channels in real time, and samples the driving current for load health state evaluation. Each drive board card integrates 22 same driving channels. According to actual requirements, the system can be configured with N drive board cards (N≥0, 0 for pure data acquisition, 2 in this example, but not limited to 2).

[0092] As shown in Figure 9 The drive board card 5 of the application is integrated with a driving circuit and a single-chip microcomputer.

[0093] The driving circuit includes MOS tubes, resistors R1, R2, R4, R6, R3, ISADC, and a comparator. Taking one of the 22 driving circuits as an example, the MOS tube switch load (solenoid valve) controls the on-off of the oil circuit through the IO port KZ of the single-chip microcomputer, and the resistor R1 connected in parallel with the MOS tube generates a pull current. The freewheeling diode is connected to the driving output end and the power supply ground end, and the inductive load freewheels and reduces external electromagnetic radiation. The resistor R2 is connected to the driving output end and the comparator, and is used for load state monitoring. When the load is online, the load resistance is much smaller than R1, the driving end voltage is low, and the comparator output is high. Similarly, when the load is offline, the comparator output is low.

[0094] The current feedback pin IS of the driving MOS tube is used, the resistors R4 and R6 are used for voltage division, and the resistor R3 is used for current limiting and then connected to the ISADC for collection, so as to monitor the real-time current of the load and evaluate the health state of the load. For example, when the driving current is 0.4<I<1.4A, the load is healthy. The load failure is comprehensively judged in combination with the comparator feedback.

[0095] The single-chip microcomputer on the drive board card receives the driving information from the main control expansion board through the SPI port, sets the output state of the corresponding output port KZ through the IO port, simultaneously and continuously collects the output of the comparator and the driving current feedback ISADC in real time, sorts out the state information of all driving output ends according to the above circuit characteristics, and feeds back to the main control expansion board through the SPI bidirectional bus for system fault diagnosis.

[0096] As shown in Figure 10 The static vehicle posture adjusting process of the application is as follows:

[0097] 1) Start the vehicle height task after receiving the CAN bus adjusting command;

[0098] 2) Determine whether the current vehicle state meets the adjusting requirements, i.e. the current vehicle state is that the vehicle speed is 0 and the engine speed is greater than 600 revolutions;

[0099] If not, end the process and report the end condition; mark the state data information, and the adjustment fails.

[0100] If it is met, go to the next step;

[0101] 3) The main control circuit single-chip initializes the key parameters and sets the adjustment target;

[0102] 4) According to the current state of the vehicle, set the action labels of each support point in the vehicle lowering process;

[0103] First, execute the vehicle lowering process; detect the support points that need to be adjusted and label them, and include them in the oil spring synchronization algorithm participation table, the drive output table, and the position determination table in the next control cycle; according to the action label instructions of each support point, execute the lowering action by the valve group combination switch; execute the oil spring synchronization algorithm once in a control cycle to ensure that the length error of each oil spring is less than the set value; determine the drive output by combining the comprehensive estimation of the oil spring movement speed in the previous control cycle, and change the valve group state at most once; then return to the vehicle lowering process and wait for the start of the new control process;

[0104] At the same time, in a corresponding determination cycle of a control cycle, execute the support point data update, vehicle posture state protection determination, and position determination once; if any of the vehicle posture state protection determination and the position determination is met, terminate the lowering process, end the control cycle and the determination cycle, and execute the next step; if it is not met, execute the next control cycle and the determination cycle until the time is up;

[0105] 5) Set the action labels of each support point in the vehicle raising process;

[0106] Execute the vehicle raising process; detect the support points that need to be adjusted and label them, and include them in the oil spring synchronization algorithm participation table, the drive output table, and the position determination table embedded in the main control circuit single-chip in the next control cycle; according to the action label instructions of each support point, drive the valve group combination switch to execute the raising action by the drive circuit of the drive board; execute the oil spring synchronization algorithm once in a control cycle to ensure that the length error of each oil spring is less than the set value; determine the drive output by the drive circuit of the drive board in combination with the comprehensive estimation of the oil spring movement speed in the previous control cycle, and change the valve group state at most once; then return to the vehicle raising process and wait for the start of the new control process;

[0107] At the same time, in a corresponding determination cycle of a control cycle, the single-chip on the main control expansion board executes the support point data update, vehicle posture state protection determination, and position determination once; if any of the vehicle posture state protection determination and the position determination is met, terminate the raising process, end the control cycle and the determination cycle, and the vehicle posture adjustment unit executes the next step; if it is not met, execute the next control cycle and the determination cycle until the time is up;

[0108] 6) Adjustment round;

[0109] After one adjustment cycle is completed, the process goes to step 3) to enter the next adjustment cycle after a delay of 1s. After 3-5 adjustment cycles are performed, the vehicle state adjustment is completed, the process is ended, the end condition is reported, the adjustment state information is reported to the CAN bus, and then the state data is marked and stored in the FMRam for use in the dynamic vehicle posture adjustment process.

[0110] The static vehicle posture adjustment process is ended.

[0111] The control cycle time is 1s, and the determination cycle time is 3ms. If the protection adjustment is triggered at any time, the current adjustment process is forcibly stopped, and the next step is transferred. The end reason (time, adjustment end condition, etc.) is reported when the process is ended.

[0112] As shown in Figure 11 The dynamic vehicle posture adjustment process of the present application is as follows:

[0113] 1) After the static vehicle posture adjustment process is completed, the dynamic vehicle posture adjustment monitoring task is started. When the vehicle speed is greater than 1 and less than 10, the dynamic vehicle posture adjustment process is automatically started and the monitoring task is ended, and the next step is entered.

[0114] 2) The support point data is collected by the board card for high-speed collection, and the collection lasts for N seconds.

[0115] 3) The main control circuit microcontroller compares the average value of the data with the last static adjustment target to determine whether the support point with the maximum deviation in the data table is within the target value range.

[0116] If the support point with the maximum deviation is within the target value range, the task is ended, the function pointer is emptied, and the dynamic vehicle posture adjustment process is ended.

[0117] If the support point with the maximum deviation is not within the target value range, the next step is performed.

[0118] 4) The main control circuit microcontroller compares the average vehicle height.

[0119] If the lowest support point is lower than the target value, the main control circuit microcontroller outputs an instruction to the drive circuit of the drive board card to drive the support point to rise for n seconds.

[0120] If the highest support point is higher than the target value, the main control circuit microcontroller outputs an instruction to the drive circuit of the drive board card to drive the support point to fall for n seconds.

[0121] After the falling or rising operation for n seconds, the current adjustment sub-process is ended, the adjustment cycle number is incremented by 1, step 2) is entered to start a new adjustment cycle, and the dynamic vehicle posture adjustment process is recursively performed for a specified number of times, and then the process is ended.

[0122] In the present application, during the data collection process, if the steering wheel angle > a or the activity is set, the data collection is suspended, and the data collection process is continued until both conditions are met.

Claims

1. A vehicle attitude adjustment unit based on static and dynamic principles, characterized in that, The vehicle attitude adjustment unit includes: a motherboard component, a main control expansion board, a power supply board, a data acquisition board, a drive board, a housing, and a top cover. The motherboard component mainly consists of a motherboard card, a rectangular connector, a circular connector, and a bottom cover. The rectangular connector and the circular connector are soldered onto the motherboard card, and the motherboard card is fixed to the bottom cover. The aforementioned boards are connected to the motherboard card via quick-connect rectangular connectors, and the motherboard card is fixed to the housing via a locking device. The top cover is fixed to the top of the housing. The main control expansion board integrates the main control circuit, the main communication SPI driver circuit, and the active detection unit; the main control circuit includes a microcontroller; the main control expansion board is connected to driver board A, driver board B, and acquisition board respectively via the high-speed SPI1 bus, and is connected to the active detection unit via the high-speed SPI2 bus. The main communication SPI driver circuit is connected to driver board A, driver board B, and acquisition board respectively; The activity detection unit is mainly used when the vehicle attitude adjustment unit is installed on the vehicle. According to the installation status, the active axis is set, and the acceleration on the active axis is continuously measured. When its absolute value is higher than the set value 'a' for n consecutive times, the vehicle is determined to be in an active state. Combined with the vehicle speed signal, the current state of the vehicle is determined: stationary or uniform straight-line driving state. When the vehicle is stationary: the vehicle speed is 0 and the engine speed is greater than 600 rpm, the static vehicle attitude adjustment steps are invoked. 1) Upon receiving the CAN bus adjustment command, the vehicle height task is initiated; 2) The microcontroller on the main control expansion board determines whether the vehicle is currently stationary; If the condition is not met, the process ends and the termination condition is reported; the microcontroller of the main control circuit marks the status data information, indicating adjustment failure. If it meets the requirements, proceed to the next step; 3) Initialize and adjust key parameters and set adjustment targets for the microcontroller of the main control circuit; the adjustment target is that the height of each support point tends to be consistent, and the key parameters are the length error of the air spring and the movement speed of the air spring; 4) Set action labels for each support point based on the current status of the vehicle; First, the vehicle lowering process is executed; the support points that need adjustment are detected and tagged, and included in the hydraulic spring synchronization algorithm participation table, drive output table, and position determination table embedded in the main control circuit microcontroller of the next control cycle. According to the action tag instructions of each support point, the drive circuit of the drive board drives the valve group combination switch to perform the lowering action; the hydraulic spring synchronization algorithm is executed once within one control cycle to ensure that the length error of each hydraulic spring is less than the set value. The main control circuit microcontroller determines the drive output based on the hydraulic spring movement speed collected by the acquisition board of the previous control cycle. The valve group state changes at most once; then, the process returns to the vehicle lowering process, waiting for the start of a new control process. Meanwhile, within a judgment cycle corresponding to a control cycle, the microcontroller on the main control expansion board performs a data update of each support point, a vehicle posture protection judgment, and a positioning judgment. If any one of the vehicle posture protection judgment or positioning judgment is satisfied, the descent process is terminated and the next step is executed; if not, the next control cycle and judgment cycle are executed until the time expires. 5) Action labels for each support point; The vehicle lifting process is executed; the support points that need adjustment are detected and tagged, and included in the hydraulic spring synchronization algorithm participation table, drive output table, and position determination table for the next control cycle. According to the action tag instructions of each support point, the drive circuit of the drive board drives the valve group combination switch to perform the lifting action; the hydraulic spring synchronization algorithm is executed once in one control cycle to ensure that the length error of each hydraulic spring is less than the set value. The microcontroller on the drive board determines the drive output based on the movement speed of the hydraulic spring in the previous control cycle. The valve group state changes at most once; then the process returns to the vehicle lifting process and waits for the new control process to start. Meanwhile, within a judgment cycle corresponding to a control cycle, the data update of each support point, the vehicle posture protection judgment, and the positioning judgment are performed once. If any one of the vehicle posture protection judgment or the positioning judgment is satisfied, the ascent process is terminated and the next step is executed; if not satisfied, the next control cycle and judgment cycle are executed until the time expires. 6) Regulating the cycle of reincarnation; After completing one adjustment cycle, the next adjustment cycle begins after a 1-second delay. After the adjustment cycle is executed 3-5 times, the process ends, the termination condition is reported, the adjustment status information is reported, and then the status data is marked for use in the dynamic vehicle posture adjustment process. This concludes the static vehicle posture adjustment process. When the vehicle is traveling at a constant speed in a straight line and the speed is greater than 1 and less than 10, the dynamic vehicle posture optimization step is invoked. 1) After completing the static vehicle posture adjustment process, start the dynamic vehicle posture adjustment monitoring task. When the vehicle speed is greater than 1 and less than 10, the dynamic vehicle posture adjustment process will be started automatically and the monitoring task will be ended, and the next step will be taken. 2) The data acquisition board collects support point data at high speed for N seconds and obtains the average data value; 3) The microcontroller in the main control circuit compares the average value of the data with the target value of the last static adjustment to determine whether the support point with the largest deviation in the data table is within the target value range; If the support point with the maximum deviation is within the target value range, the task ends, the function pointer is cleared, and the dynamic vehicle posture adjustment process ends. If the support point of the maximum deviation is not within the target value range, proceed to the next step; 4) The main control circuit's microcontroller performs an average vehicle height comparison; If the lowest support point is lower than the target value, the microcontroller of the main control circuit outputs a command to the drive circuit of the drive board to drive the support point to rise for n seconds. If the highest support point is higher than the target value, the microcontroller of the main control circuit outputs a command to the drive circuit of the drive board to drive the support point to descend for n seconds. After the lowering / raising operation lasts for n seconds, the current adjustment sub-process ends, the adjustment cycle count is incremented by 1, and the process proceeds to step 2), starting a new adjustment cycle. The dynamic vehicle posture adjustment process recursively repeats for the specified number of times before ending the process.

2. The vehicle attitude adjustment unit as described in claim 1, characterized in that, When installing the vehicle attitude adjustment unit, the first movable axis should be perpendicular to the bottom surface of the vehicle, and the second movable axis should point towards the front of the vehicle. After the vehicle attitude adjustment unit is installed on the vehicle body, a second movable axis parallel to the bottom surface of the vehicle is configured as the movable detection axis.

3. The vehicle attitude adjustment unit as described in claim 1, characterized in that, The drive board is used to drive the valve group combination switches of the vehicle attitude adjustment unit, perform real-time online load determination for all output channels, and sample the drive current for load health status assessment; the drive board integrates drive circuit and microcontroller. The microcontroller on the driver board receives driver information from the main control expansion board via the SPI port, sets the output status of the corresponding output port KZ via the IO port, and simultaneously collects the output of the comparator, the drive current feedback ISADC, and the status information of all drive output terminals in real time. This information is then fed back to the main control expansion board via the SPI bidirectional bus for system fault diagnosis. The MOSFET in the drive circuit has a built-in current feedback pin IS. After voltage division by resistors R4 and R6 and current limiting by resistor R3, the current is collected by the ISADC to monitor the real-time load current for load health status assessment.

4. The vehicle attitude adjustment unit as described in claim 1, characterized in that, The power supply board provides independent digital power of 3.3V 2W for driver board A and driver board B, independent analog power of 5V 2W for the acquisition board, and isolated digital power of 5V 2W and 3.3V 1W for the main control expansion board.

5. The vehicle attitude adjustment unit as described in claim 1, characterized in that, The data acquisition board integrates ADC devices, a microcontroller, ADC acquisition front-end circuitry, and sensor power control options. The microcontroller is an STM32F4XX microcontroller; The sensor power control option is mainly responsible for turning off the sensor power supply when the vehicle attitude adjustment unit is in a silent state, thus saving energy consumption. When the vehicle attitude adjustment unit is about to move, it first controls the drive MOSFET to turn on to power on each sensor, and at the same time detects the power supply status of the sensor, initializes the ADC, and then starts data acquisition and runs the core algorithm. When a sensor fails or the power line is short-circuited to ground, the F self-resetting fuse will trip due to overcurrent. The abnormality can be detected at PTEST. At this time, an alarm is triggered and the core algorithm is stopped from running to ensure that the vehicle does not lose control due to erroneous data. The ADC sampling front-end circuit is used to expand the number of ADC acquisition channels on the acquisition board, as well as to acquire sensor signals that do not require synchronous acquisition.

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