Method for controlling a combination switch of a gear lever of a vehicle with integrated vehicle weighing function

Abstract

The present application relates to a kind of integrated car-mounted weighing function's automobile gear combination switch control method, belong to the technical field of automobile electronic control.The present application aims at solving the technical problems that existing gear controller function is single, car-mounted weighing system independent setting leads to high cost, wiring complex.The present application includes: electronic gear shifting module, for detecting gear position and parking button state;Combination switch module, for detecting wiper, light and other switch state;Vehicle-mounted weighing module, for the height sensor of four wheels is powered and receives its PWM signal, according to calibration parameter and vehicle height variation quantity calculates vehicle total weight, front and rear axle load ratio and four-wheel load;Communication module, through CAN FD bus sends gear signal, switch signal and weighing signal.The present application integrates weighing function in gear controller, improves weighing precision by inclination compensation, and realizes the real-time display and overload warning of load information, with the advantages of high integration, low cost, good precision.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission and control, and in particular to a control method for a combination switch of a car column shifter that integrates on-board weighing function. Background Technology

[0002] As a core node in the vehicle's electronic and electrical architecture, the column shifter combination switch controller (EGS controller) currently integrates two main functions: electronic shifting and combination switch control. For example, Chinese patent CN119353408A discloses a column shifter combination switch that achieves precise shift sensing and reliable P-gear function through gear transmission and Hall effect sensors, offering advantages such as accurate RND gear position output and noise reduction. However, existing column shifter controllers are relatively simple in function, and their hardware resources and communication interfaces are not fully utilized, failing to meet the functional integration requirements of intelligent vehicle development.

[0003] In the field of vehicle-mounted weighing technology, existing solutions mostly employ independent control modules. For example, Chinese patent CN208376524U discloses a system that achieves real-time load monitoring through a weighing module installed between the vehicle frame and the floor of the vehicle body. However, its control module and actuator are both independently set up. Furthermore, to address the weighing accuracy issue under complex conditions such as slopes, Chinese patent CN218724633U discloses a weighing device suitable for steep road surfaces. It achieves slope inclination compensation measurement by adjusting the sensor installation angle. However, these existing vehicle-mounted weighing systems generally require the addition of independent control units, sensors, and wiring harnesses, which not only increases the overall vehicle material cost and wiring complexity, but also isolates the weighing function from the vehicle's original functions such as the shift lever control, failing to achieve effective reuse of hardware resources and data links.

[0004] In summary, existing technologies suffer from limitations such as limited functionality of column shifter controllers and low integration with onboard weighing systems, resulting in high costs. Specifically, on the one hand, conventional column shifter controllers lack real-time monitoring capabilities for vehicle load, making it difficult to provide a data foundation for overload warnings. On the other hand, independently configured onboard weighing systems not only increase hardware costs, but their slope weighing accuracy also requires further optimization, and they lack deep integration with existing vehicle control systems (such as EGS controllers).

[0005] Therefore, how to integrate high-precision vehicle weighing functions into the shifter controller without significantly increasing hardware costs, and achieve accurate weighing under slope conditions, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the aforementioned technical problems, the purpose of this invention is to provide a control method for a car column shifter combination switch that integrates vehicle weighing function.

[0007] The present invention discloses a vehicle column shifter combination switch control method integrating vehicle weighing function. The method is based on a column shifter combination switch controller distributed within the vehicle. This controller internally comprises an electronic shift module, a combination switch module, a vehicle weighing module, a communication module, and a power management module. Each module is connected to an automotive-grade MCU (Microcontroller Unit) within the controller. The controller also contains an EEPROM (Electrically Erasable Programmable Read-Only Memory) storage unit connected to the automotive-grade MCU. The power management module is connected to the vehicle's power supply. The communication module is connected to a vehicle network node via a CAN FD (Controller Area Network Flexible Data Bus). The vehicle network node includes a vehicle tilt sensor and a central control screen. The vehicle weighing module is connected to four height sensors distributed throughout the vehicle's suspension system. The vehicle column shifter combination switch control method includes the following steps:

[0008] Step 1: The power management module supplies power to the internal modules of the controller and the four height sensors. After the controller completes initialization, the vehicle weighing module collects the PWM signals (pulse width modulation signals) output by the four height sensors.

[0009] Step 2: The automotive-grade MCU converts the duty cycle of the acquired PWM signal into the corresponding change in vehicle height at the wheel, in mm.

[0010] Step 3: The automotive-grade MCU determines whether the vehicle has completed the no-load calibration. If the calibration has not been completed, the no-load calibration process is executed; if the calibration has been completed, the no-load calibration parameters pre-stored in the EEPROM storage unit are read.

[0011] Step 4: The automotive-grade MCU calculates the independent load on the four wheels based on the vehicle calibration parameters and the change in vehicle height, and simultaneously acquires the vehicle slope data output by the vehicle tilt sensor.

[0012] Step 5: The automotive-grade MCU determines whether the vehicle's slope is less than 3%. If the slope is not less than 3%, the weighing calculation is paused. If the slope is less than 3%, tilt compensation is performed, and then the total vehicle weight and the front and rear axle load ratio are calculated sequentially. The unit of the total vehicle weight is kg.

[0013] Step Six: The automotive-grade MCU sends the weighing-related data to the central control screen via the CAN FD bus through the communication module for display.

[0014] Furthermore, in the above-mentioned vehicle column shifter combination switch control method integrating vehicle weighing function, step three, the execution of the empty vehicle calibration process includes the following sub-steps:

[0015] Step 1: Send a calibration trigger command to the controller through the no-load calibration routine service of the UDS protocol (referred to as Routine 0x5025 service) to start the no-load calibration process;

[0016] Step 2: The controller collects the PWM signals from the four height sensors when the vehicle is unloaded and horizontally placed, and converts them into the unloaded reference height value of each wheel, in mm.

[0017] Step 3: Based on the average unloaded reference height of 20 vehicles of the same model, calculate the equivalent elastic coefficient of the front and rear axles suspension to generate unloaded vehicle calibration parameters. The unit of the equivalent elastic coefficient of the front and rear axles suspension is kg / mm.

[0018] Step 4: Write the no-load calibration parameters into the controller's EEPROM storage unit, and read the calibration parameters through the calibration data read identifier of the UDS protocol.

[0019] Furthermore, in the aforementioned control method for a car column shifter combination switch integrating vehicle weighing function, step five, the execution of tilt angle compensation, includes the following sub-steps:

[0020] First: The automotive-grade MCU calculates the height measurement deviation caused by the vehicle's slope data, with the unit being mm;

[0021] Secondly: Subtract the height measurement deviation from the actual measured change in vehicle height to obtain the effective change in height caused only by the vehicle load, in mm.

[0022] Finally: the effective height change is used as the input parameter for subsequent weight calculation.

[0023] Furthermore, in the aforementioned integrated vehicle weighing function vehicle column shifter combination switch control method, step five, the calculation of the total vehicle weight includes the following sub-steps:

[0024] Step A: Retrieve the equivalent elastic coefficient of the front axle suspension system (unit: kg / mm) and the equivalent elastic coefficient of the rear axle suspension system pre-stored in the EEPROM storage unit. The units of the equivalent elastic coefficient of the front axle suspension system and the equivalent elastic coefficient of the rear axle suspension system are kg / mm.

[0025] Step B: Calculate the total vehicle weight using the formula: Total vehicle weight = Equivalent elastic coefficient of front axle suspension system × (Change in vehicle height of left front wheel + Change in vehicle height of right front wheel) + Equivalent elastic coefficient of rear axle suspension system × (Change in vehicle height of left rear wheel + Change in vehicle height of right rear wheel); where the unit of vehicle height change is mm and the unit of total vehicle weight is kg.

[0026] Furthermore, in the aforementioned vehicle column shifter combination switch control method integrating vehicle weighing function, step five, the calculation of the front and rear axle load ratio, includes the following sub-steps:

[0027] Step 1: Calculate the total load of the two front axle wheels and the total load of the two rear axle wheels, in kg. The total load of the two front axle wheels is the sum of the independent loads of the left front wheel and the right front wheel, and the total load of the two rear axle wheels is the sum of the independent loads of the left rear wheel and the right rear wheel.

[0028] Step 2: Calculate the front axle load ratio using the formula: Front axle load ratio = Sum of loads on both front axles ÷ Total vehicle weight × 100%;

[0029] Step 3: Calculate the rear axle load ratio using the formula: Rear axle load ratio = (Total load of the two rear wheels ÷ Total weight of the vehicle) × 100%.

[0030] Furthermore, in the aforementioned method for controlling a car column shifter combination switch with integrated vehicle weighing function, step six includes the following sub-steps:

[0031] First: The communication module connects to the vehicle's CAN FD bus through an internal CAN FD transceiver. The CAN FD bus has an arbitration field communication rate of 500Kbps and a data field communication rate of 2Mbps.

[0032] Secondly, the automotive-grade MCU sends weighing-related data to the vehicle network nodes in a fixed cycle of 10ms.

[0033] Furthermore, in the aforementioned method for controlling a car column shifter combination switch with integrated vehicle weighing function, step six further includes a tare and zeroing control step:

[0034] Step 1: The automotive-grade MCU receives the tare reset command sent by the central control screen via the CAN FD bus;

[0035] Step 2: The automotive-grade MCU records the currently calculated total vehicle weight as tare weight. When calculating the total vehicle weight later, the corresponding tare weight will be automatically deducted, and the net weight data of the cargo will be output to the central control screen. The units of the tare weight and the net weight data of the cargo are both kg.

[0036] Furthermore, in the aforementioned method for controlling a car column shifter combination switch with integrated vehicle weighing function, step six, the display control of the central control screen includes the following sub-steps:

[0037] First: When the current axle load ratio is less than 30% or greater than 70%, the load ratio status will be displayed as red (unreasonable range).

[0038] Secondly: When the current axle load ratio is greater than or equal to 30% and less than 40%, or greater than 60% and less than or equal to 70%, the load ratio status will be displayed as a yellow offset range;

[0039] Finally: When the current axle load ratio is greater than or equal to 40% and less than or equal to 60%, the load ratio status will be displayed as green and within the reasonable range.

[0040] Furthermore, in the aforementioned method for controlling a car column shifter combination switch with integrated vehicle weighing function, the basic column shifter control steps are executed simultaneously with step one, including:

[0041] First: The electronic shift module collects the status signals of the shift lever position and the parking gear button, and the combination switch module collects the status signals of the wipers, turn signals, headlights, and washer switches;

[0042] Secondly, both types of status signals are transmitted to the automotive-grade MCU for processing, and then sent to the vehicle network via the communication module.

[0043] Furthermore, the aforementioned control method for the automotive column shifter combination switch integrating vehicle weighing function also includes sensor fault detection and handling steps, including:

[0044] First: The automotive-grade MCU monitors the PWM signals output by the four height sensors in real time. The effective duty cycle of the PWM signal is 5% to 95%, corresponding to a vehicle height change range of 0 to 100 mm.

[0045] Secondly: When the duty cycle of the PWM signal is less than 5% or greater than 95%, the corresponding height sensor is determined to be faulty, and the corresponding DTC fault code is recorded (referred to as the diagnostic fault code).

[0046] Finally: The automotive-grade MCU sends an invalid weighing data value to the vehicle network through the communication module. The invalid value is the hexadecimal value 0x1FFF.

[0047] By means of the above-described solution, the present invention has at least the following advantages:

[0048] 1. High degree of functional integration. This invention integrates the vehicle weighing function into the column shifter combination switch controller, realizing the multi-functionality of the controller, avoiding the need for a separate weighing controller, and reducing the overall vehicle cost and wiring complexity.

[0049] 2. This invention makes full use of the existing hardware resources of the EGS controller, including MCU computing resources, CAN FD communication interface, power management module, and diagnostic link. Only the height sensor interface circuit needs to be added to realize the complete weighing function. The hardware modification is small, the development cost is low, and it can be quickly adapted to the column shifter controller platform of existing mass-produced vehicles.

[0050] 3. High weighing accuracy. This invention adopts an algorithm that uses independent weighing for all four wheels and separate calculations for the front and rear axles, and introduces a tilt compensation mechanism and slope threshold control, which effectively improves the accuracy of vehicle weighing. Under level road conditions, the weighing accuracy can reach ±5kg; under conditions with a slope of less than 3%, the weighing accuracy can reach ±10kg.

[0051] 4. The EGS controller collects signals from four height sensors in real time and transmits weighing data at high frequency via the CAN FD bus. The large screen can display vehicle load information in real time and provide real-time overload warnings.

[0052] 5. Simple calibration method. This invention provides an automatic calibration method for the empty vehicle weight on the production line. Calibration can be completed through UDS diagnostic commands. The calibration data is stored in EEPROM and is not lost when power is off. It also supports recalibration at 4S stores, which is convenient for recalibration after vehicle maintenance.

[0053] 6. This invention supports a large-screen soft switch zeroing function, allowing users to perform tare operation at any time as needed, suitable for various complex load-bearing scenarios.

[0054] 7. High safety performance. This invention meets the functional safety ASIL B level requirements and has a complete fault detection and fail-safe handling mechanism. When a sensor fails, the controller records the DTC fault code and sends an invalid value to the large screen to indicate the sensor failure. Simultaneously, the weighing function and the basic gear shifting function are electrically isolated, ensuring that a failure in the weighing function will not affect the normal operation of the vehicle's basic gear shifting, light, and wiper control functions, thus guaranteeing vehicle driving safety.

[0055] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0056] Figure 1 This is a schematic diagram illustrating the implementation process of a combination switch control method for automotive column shifters that integrates vehicle weighing functions. Detailed Implementation

[0057] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0058] like Figure 1This paper describes a control method for an integrated vehicle weighing function for a column shifter combination switch. Specifically, the execution entity of this method is an integrated vehicle weighing function column shifter combination switch controller, hereinafter referred to as the EGS controller. The EGS controller internally comprises an electronic shift module, a combination switch module, a vehicle weighing module, a communication module, and a power management module. Each module is electrically connected to an automotive-grade microcontroller unit (MCU) within the controller. An electrically erasable programmable read-only memory (EEPROM) is electrically connected to the MCU within the controller. The input terminal of the power management module is connected to the vehicle power supply, and the output terminal is electrically connected to all modules within the controller. The communication module is electrically connected to the vehicle network nodes via a CAN FD bus. The vehicle network nodes include the vehicle tilt sensor, the central control screen, and the vehicle OBD diagnostic interface. The signal acquisition terminal of the vehicle weighing module is electrically connected one-to-one with four height sensors distributed throughout the vehicle's suspension system. Specifically, the EGS controller is named "Column Gear Assembly," which includes an overload warning function. The controller operates at a voltage range of 9V to 16V, and its static current in sleep mode does not exceed 100μA. The controller meets the ASIL B level requirements for automotive functional safety. This invention fully integrates the entire vehicle weighing process into the existing column gear combination switch controller hardware platform commonly used in mass-produced vehicles. Only four sensor signal acquisition circuits need to be added; no separate independent weighing control ECU is required, significantly reducing overall vehicle material costs and wiring complexity.

[0059] According to a preferred embodiment of the present invention, the power management module internally incorporates automotive-grade power management chips. The input terminals of these automotive-grade power management chips are connected to both the vehicle's constant power and IGN power supplies. The output terminals are electrically connected to the electronic shift module, combination switch module, vehicle weighing module, communication module, automotive-grade MCU, and EEPROM storage unit. The power management module provides a stable operating power supply to all modules within the controller and also provides 5V DC power to the four height sensors distributed throughout the vehicle's suspension system. During implementation, the power management module implements vehicle network management and sleep / wake-up functions. The controller's wake-up sources include IGN power-on wake-up, CAN FD bus network wake-up, and parking gear button trigger wake-up. When the vehicle power is off and there is no communication activity on the CAN FD bus for a preset duration, the power management module controls the controller to enter a sleep state. In the sleep state, the static current does not exceed 100μA, meeting the vehicle's low-power design requirements. Simultaneously, the power management module integrates overvoltage protection circuits, overcurrent protection circuits, reverse connection protection circuits, and electrostatic discharge protection circuits. Each height sensor's power supply circuit is independently designed. A short circuit or overcurrent fault in one power supply circuit will not affect the normal power supply to other circuits, nor will it affect the basic functions of the electronic shift module or combination switch module. The power management module collects the power supply voltage and current data of each height sensor in real time and transmits it to the automotive-grade MCU for auxiliary fault diagnosis.

[0060] The automotive-grade MCU used in this invention is the core control unit of the EGS controller. It employs a 32-bit automotive-grade multi-core microcontroller, meeting AEC-Q100 Grade 1 automotive-grade certification requirements. It integrates multiple independent timer capture channels, one CANFD controller peripheral, multiple AD acquisition channels, and general-purpose I / O ports. All peripheral resources of the automotive-grade MCU meet the ASIL B level requirements for automotive functional safety. Simultaneously, the automotive-grade MCU pre-stores a complete control program, comprising five categories: basic shifter control program, on-board weighing control program, calibration management program, fault diagnosis program, and communication management program. The automotive-grade MCU executes all control programs cyclically with a fixed 10ms master cycle. The basic shifter control task and the on-board weighing control task are executed synchronously within the same 10ms fixed cycle task, eliminating the need for additional independent task cycles. This fully utilizes the computing resources of the existing MCU in the shifter controller, requiring no replacement with a higher-specification MCU chip, resulting in minimal hardware modifications and low development costs.

[0061] During implementation, the signal acquisition terminal of the electronic shift module is electrically connected to the vehicle's gear shift lever and parking gear button. Internally, the electronic shift module includes a gear shift lever position detection circuit and a parking gear button detection circuit. The gear shift lever position detection circuit accurately detects the three gear positions: Reverse (R), Neutral (N), and Drive (D). The parking gear button detection circuit accurately detects the pressed and released state of the parking gear button. The signal output terminal of the electronic shift module is directly connected to the I / O acquisition port of the automotive-grade MCU, transmitting gear position and parking gear button status signals to the MCU in real time. Simultaneously, the electronic shift module's detection circuit employs a dual-redundant design, completely electrically isolated from the power supply circuit of the on-board weighing module. A failure in one circuit will not affect the normal operation of other modules. The automotive-grade MCU performs anti-jitter processing on the acquired gear position and button signals, with a preset anti-jitter time of 20ms to prevent false triggering caused by vehicle vibration. After completing signal parsing and verification, the automotive-grade MCU sends the valid shift signal and parking gear request signal to the vehicle controller through the communication module to realize the vehicle's electronic shift control.

[0062] For ease of implementation, the signal acquisition terminal of the combination switch module is electrically connected to the vehicle's wiper switch, turn signal switch, headlight switch, and washer fluid spray switch. Internally, the combination switch module features multiple independent switch status detection circuits, each corresponding to a vehicle control switch, accurately detecting the on / off state of the corresponding switch. The signal output terminal of the combination switch module is directly connected to the I / O acquisition port of the automotive-grade MCU, enabling real-time transmission of all switch status signals to the MCU. Simultaneously, each detection circuit of the combination switch module is equipped with independent electrostatic discharge (ESD) protection devices and filtering circuits to filter out electromagnetic interference from the vehicle's electrical environment, ensuring the accuracy of signal acquisition. The automotive-grade MCU performs anti-jitter processing on the acquired switch status signals; the anti-jitter time for the turn signal and headlight switches is preset to 10ms, and for the wiper and washer fluid switches, it is preset to 50ms, preventing false triggering caused by switch contact jitter. After the automotive-grade MCU completes the parsing and verification of the switch status signal, it sends the valid switch control signal to the vehicle body controller through the communication module to realize the control of the vehicle's high beam headlights, overtaking lights, turn signals, front wipers, washer fluid switch, and follow-me-home function.

[0063] Furthermore, the vehicle-mounted weighing module employed in this invention internally features four independent pulse width modulation signal capture circuits, hereinafter referred to as PWM signal capture circuits. The input terminal of each PWM signal capture circuit is electrically connected one-to-one to the signal output terminal of a height sensor, and the output terminal of each PWM signal capture circuit is electrically connected to the timer capture channel of an automotive-grade MCU. Simultaneously, four height sensors are respectively installed on the suspension systems of the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle. These height sensors are used to detect changes in vehicle height at the corresponding positions. The power supply for the height sensors is provided by the power management module. The duty cycle of the PWM signal output by the height sensors ranges from 5% to 95%, corresponding to a vehicle height change range of 0 to 100 mm. When the vehicle load increases, the vehicle height decreases, and the duty cycle of the PWM signal output by the height sensors changes accordingly. The PWM signal duty cycle and the change in vehicle height are linearly correlated. Moreover, the PWM signal capture circuits can filter and shape the PWM signal output by the height sensors to remove signal distortion caused by electromagnetic interference in the vehicle's electrical environment. The automotive-grade MCU captures PWM signals from four height sensors simultaneously through four timer capture channels, with a capture accuracy of no less than 1μs. It can accurately calculate the period and high-level duration of the PWM signal, and then calculate the real-time duty cycle of the PWM signal.

[0064] The communication module used in this invention internally integrates a CAN FD transceiver. The signal terminals of the CAN FD transceiver connect to the CAN FD controller peripheral built into the automotive-grade MCU, while the bus terminals connect to the vehicle's CAN FD bus. The communication module enables bidirectional data exchange between the EGS controller and other network nodes in the vehicle via the CAN FD bus. The CAN FD bus has an arbitration field communication rate of 500Kbps and a data field communication rate of 2Mbps, fully reusing the existing CAN FD communication interface of the shift controller without requiring additional communication hardware. Furthermore, the CAN FD bus interface circuit of the communication module integrates a common-mode inductor, a TVS electrostatic discharge transistor, and a terminating resistor, supporting standard and extended frame data formats of the CAN FD bus, as well as bus wake-up, bus offline processing, and error retransmission functions. During use, the automotive-grade MCU sends weighing-related data to the vehicle's CAN FD bus via a fixed period of 10ms. At the same time, it sends shift signals and combination switch status signals to the vehicle network via a fixed period of 20ms, realizing the synchronous transmission of data between basic control functions and weighing functions.

[0065] To facilitate data storage, the EEPROM storage unit used in this invention employs an automotive-grade electrically erasable programmable read-only memory chip. The EEPROM storage unit connects to the automotive-grade MCU via an SPI bus, with a communication rate of no less than 1 Mbps. The EEPROM storage unit is internally divided into multiple independent storage partitions, including a calibration data storage partition, a fault code storage partition, and a configuration parameter storage partition. During implementation, the calibration data storage partition stores unloaded vehicle calibration parameters, including the unloaded reference height values ​​of the four height sensors, the equivalent elastic coefficient of the front axle suspension system, the equivalent elastic coefficient of the rear axle suspension system, the calibration timestamp, and calibration personnel information. The fault code storage partition stores DTC fault codes recorded during controller operation. The configuration parameter storage partition stores the controller's functional configuration parameters, including CAN FD bus communication parameters, overload alarm thresholds, load ratio display range parameters, and sensor effective signal range parameters. Meanwhile, each storage partition of the EEPROM memory unit is equipped with an independent write protection mechanism. Data writing operations can only be performed on the corresponding partition after the automotive-grade MCU has passed the preset security access verification process, preventing unauthorized data tampering and ensuring the security of calibration data and configuration parameters. Each time the automotive-grade MCU powers on and initializes, it reads all data in the EEPROM memory unit and verifies the data validity using the CRC32 cyclic redundancy check algorithm. If the verification fails, the data is deemed abnormal, the corresponding fault code is recorded, and basic functions are executed using preset default parameters, ensuring the basic operational safety of the controller.

[0066] Based on the weighing function provided by this invention, the basic weighing algorithm is designed based on Hooke's Law, where the vehicle load and vehicle height change linearly. The core formula is: W = K × δH. Where W is the vehicle load in kg; K is the spring constant in kg / mm; and δH is the change in vehicle height in mm. Since the vehicle has two independent suspension systems (front and rear), this invention calculates the total vehicle weight by calculating the front and rear axles separately and then adding them together. This avoids calculation errors caused by differences in front and rear suspension parameters. The formula for calculating the total vehicle weight is: Weight = Kfront × (dLleft front + dLright front) + Krear × (dLleft rear + dLright rear). Where Kfront is the equivalent spring constant of the front axle suspension system in kg / mm. Krear is the equivalent spring constant of the rear axle suspension system in kg / mm. dL front left wheel, dL front right wheel, dL rear left wheel, and dL rear right wheel represent the changes in vehicle height for the corresponding wheels, in mm; Weight represents the total weight of the vehicle, in kg.

[0067] Preferably, the load distribution between the front and rear axles can be calculated. The EGS controller calculates the load distribution ratio between the front and rear axles in real time using the following formulas: Front axle load ratio = Front axle load ÷ (Load of two front axle wheels + Load of two rear axle wheels) × 100%; Rear axle load ratio = Rear axle load ÷ (Load of two front axle wheels + Load of two rear axle wheels) × 100%. The front axle load is the sum of the independent loads of the left and right front wheels, and the rear axle load is the sum of the independent loads of the left and right rear wheels. Simultaneously, four-wheel load calculation can be performed. During implementation, the EGS controller calculates the independent load of each of the four wheels. The formula for calculating the load on a single wheel is: Single wheel load = Corresponding axle suspension equivalent elastic coefficient × Corresponding wheel body height change. The left and right front wheels are calculated using the equivalent elastic coefficient of the front axle suspension system, while the left and right rear wheels are calculated using the equivalent elastic coefficient of the rear axle suspension system. All four wheel load signals use 12-bit resolution, and the physical value conversion relationship is: Physical value = XX × 1kg, with invalid values ​​fixed at 0x1FFF. The prerequisites for four-wheel load calculation are: vehicle power supply is in the Comfortable / ON position, CAN FD communication is normal, and vehicle slope is less than 3%. If any of the prerequisites are not met, the four-wheel load calculation is suspended, and invalid values ​​are sent to the vehicle network to avoid display abnormalities caused by invalid data.

[0068] The control method of this invention is executed synchronously in the 10ms fixed-cycle control task of the automotive-grade MCU. After the automotive-grade MCU completes initialization each time it is powered on, it executes the following steps in a loop:

[0069] Step 1: The power management module supplies power to all modules inside the controller and the four height sensors. The controller completes hardware initialization, program initialization, and communication interface initialization. Configuration parameters and calibration data are read from the EEPROM storage unit by the automotive-grade MCU to verify data validity. Simultaneously, the on-board weighing module acquires the PWM signals output from the four height sensors, and the automotive-grade MCU obtains the real-time duty cycle data of the four PWM signals through a timer capture channel.

[0070] Simultaneously with this step, the basic control steps for the column shifter are executed. These steps involve the electronic shift module acquiring the status signals of the shift lever position and the parking gear button, and the combination switch module acquiring the status signals of the wipers, turn signals, headlights, and washer fluid switches. Both types of status signals are transmitted to an automotive-grade MCU for processing. After the automotive-grade MCU performs signal debouncing and validity verification, the signals are sent to the vehicle network via the communication module.

[0071] Step Two: The automotive-grade MCU converts the duty cycle of the acquired PWM signal into the corresponding change in vehicle height at the wheels, measured in mm. The automotive-grade MCU pre-stores a linear correspondence table between the PWM signal duty cycle and the change in vehicle height. Based on the acquired real-time duty cycle data, the MCU calculates the real-time vehicle height value for the corresponding wheels using table lookup and interpolation. Combined with the unloaded baseline height value, the change in vehicle height is calculated using the formula: Change in vehicle height = Unloaded baseline height value - Real-time vehicle height value.

[0072] Step 3: The automotive-grade MCU determines whether the vehicle has completed the no-load calibration. If the calibration has not been completed, the no-load calibration process is executed; if the calibration has been completed, the no-load calibration parameters pre-stored in the EEPROM storage unit are read.

[0073] Step 4: The automotive-grade MCU calculates the independent load on the four wheels based on the vehicle's calibration parameters and the change in vehicle height, and simultaneously acquires the vehicle slope data output by the vehicle tilt sensor.

[0074] Step 5: The automotive-grade MCU determines whether the vehicle's slope is less than 3%. If the slope is not less than 3%, the weighing calculation is paused. If the slope is less than 3%, tilt compensation is performed, and then the total vehicle weight and the front and rear axle load ratio are calculated sequentially.

[0075] Step Six: The automotive-grade MCU sends the weighing-related data to the central control screen via the CAN FD bus through the communication module for display.

[0076] To better implement this invention, vehicle weight calibration must be completed before the vehicle leaves the factory. The calibration process is triggered and executed through the Unified Diagnostic Service Protocol, hereinafter referred to as the UDS protocol. After calibration, the calibration data is permanently stored in the EEPROM storage unit. After vehicle repair or replacement of suspension components, the calibration can be re-executed through the same process. The specific implementation steps of the no-load calibration process are as follows:

[0077] Step 1: Calibration Prerequisite Verification. The automotive-grade MCU first verifies whether all calibration prerequisites are met. These prerequisites include: the vehicle is empty, with no driver or cargo; the vehicle is on level ground; tire pressure is within the normal range; the controller power is ON; CAN FD communication is normal; and the four height sensors are functioning correctly. If any condition is not met, the automotive-grade MCU will refuse to initiate the calibration process and return a calibration rejection message to the vehicle diagnostic tool.

[0078] Step 2: Calibration process trigger. After all the preconditions are met, the calibration trigger command is sent to the controller through the no-load calibration routine service of the UDS protocol, namely the Routine 0x5025 service, to start the no-load calibration process. This fully reuses the existing UDS diagnostic link of the shifter controller, without the need for additional diagnostic protocol development.

[0079] Step 3: Baseline Data Acquisition. The controller continuously acquires 100 sets of PWM signals from the four height sensors. After removing the maximum and minimum values, the average of the remaining data is taken and converted into the unloaded baseline height value for each wheel, eliminating calibration deviations caused by acquisition errors.

[0080] Step 4: Calibration Parameter Calculation. The average unloaded reference height of 20 vehicles of the same model on the production line is taken as the calibration basis. Combined with the design parameters of the vehicle's suspension system, the equivalent elastic coefficients of the front axle suspension system and the rear axle suspension system are calculated to generate complete unloaded vehicle calibration parameters. This eliminates individual differences in the suspension of individual vehicles and improves the consistency of weighing accuracy for batch models.

[0081] Step 5: Calibration Data Storage and Verification. Write the no-load calibration parameters into the controller's EEPROM storage unit. After writing, the automotive-grade MCU rereads the written data for verification. If verification is successful, a calibration completion flag is recorded, and a calibration success message is returned to the diagnostic tool. If verification fails, the corresponding fault code is recorded, and a calibration failure message is returned to the diagnostic tool. After calibration, the stored calibration parameters can be read using the calibration data read identifier DID 0x5015 of the UDS protocol.

[0082] In actual implementation, when a vehicle is on a slope, the vehicle body tilt causes a change in suspension height unrelated to the load, affecting weighing accuracy. This invention introduces a tilt angle compensation algorithm and slope threshold safety control. The specific implementation steps are as follows:

[0083] Step 1: Tilt Angle Data Acquisition. The automotive-grade MCU receives the vehicle's longitudinal slope data from the vehicle's tilt angle sensor via the CAN FD bus, with a data update cycle of 10ms. The automotive-grade MCU performs a moving average filter on the received slope data to remove numerical fluctuations caused by vehicle vibration, obtaining stable vehicle slope data.

[0084] Step 2: Slope Threshold Determination. The automotive-grade MCU determines whether the vehicle's slope is less than 3%. When the slope exceeds 3%, it pauses the calculation of four-wheel load, total vehicle weight, and front-to-rear axle load ratio to avoid excessive errors, and simultaneously sends a weighing pause prompt to the central control screen. When the slope is less than 3%, it initiates tilt angle compensation calculation.

[0085] Step 3: Tilt Compensation Calculation. The automotive-grade MCU, based on the vehicle's wheelbase, track width, suspension mounting position, and real-time slope data, uses a pre-defined geometric model to calculate the height measurement deviation for each wheel caused by vehicle tilt. The height measurement deviation is subtracted from the measured change in vehicle height to obtain the effective height change caused solely by vehicle load. This effective height change is used as the input parameter for subsequent weight calculations, eliminating the influence of the slope on the weight calculation results.

[0086] Furthermore, to meet certain specific usage requirements, a tare zeroing operation can be implemented. This invention features a soft-switch zeroing function during implementation. Specifically, the EGS controller supports tare zeroing via a soft switch on the central control screen, suitable for net weight measurement when the vehicle has fixed auxiliary equipment. The implementation steps are roughly as follows:

[0087] Step 1: Reset Command Received. The automotive-grade MCU receives the tare reset switch signal sent by the central control screen in real time via the CAN FD bus.

[0088] Step 2: Tare weight recording. After receiving a valid zeroing command, the automotive-grade MCU records the currently calculated total vehicle weight as the tare weight and stores it in the MCU's internal RAM.

[0089] Step 3: Net weight calculation. During the subsequent weighing calculation, the automotive-grade MCU automatically subtracts the pre-recorded tare weight from the calculated total vehicle weight to obtain the cargo net weight data.

[0090] Step 4: Data Transmission. The automotive-grade MCU transmits the net weight data to the central control screen via the CAN FD bus for display.

[0091] In terms of communication and display control during the implementation of this invention, the EGS controller sends weighing-related information via the CAN FD bus. Specifically, the CAN FD bus has an arbitration field communication rate of 500Kbps and a data field communication rate of 2Mbps. The automotive-grade MCU cyclically sends weighing-related data to the vehicle's CAN FD bus at a fixed period of 10ms. This weighing-related data includes the total vehicle weight, independent loads on all four wheels, front and rear axle load ratio, load ratio range status, sensor fault status, calibration data validity status, and data validity identifier. The central control screen receives the weighing signals sent by the EGS controller, enabling load ratio display, four-wheel load display, overload warning, and a zeroing button function. The specific implementation rules for the large screen display are as follows:

[0092] 1. Load Ratio Display Rules. The central control screen displays the load ratio status according to the following interval rules based on the received front and rear axle load ratio data:

[0093] Unreasonable range, displayed in red: Front axle load ratio X < 30% or X > 70%.

[0094] Bias range, displayed in yellow: 30% ≤ X < 40% or 60% <X≤70%。

[0095] Within a reasonable range, displayed in green: 40%≤X≤60%.

[0096] 2. Four-wheel load display. The central control screen displays the independent load values ​​of the left front wheel, right front wheel, left rear wheel, and right rear wheel in real time; when the load data is an invalid value of 0x1FFF, a sensor fault prompt is displayed in the corresponding position.

[0097] 3. Overload Alert. When the total weight of the vehicle exceeds the maximum permissible load, the EGS controller sends an overload alarm signal, triggering a red flashing indicator and an audible alarm on the central control screen, providing real-time overload alerts.

[0098] 4. Zeroing button function. The central control screen is equipped with a tare zeroing soft switch button. When the user presses the button, the central control screen sends a zeroing switch signal to the EGS controller, triggering the tare zeroing operation.

[0099] Furthermore, this invention meets the ASIL B level requirements for automotive functional safety, possessing comprehensive sensor fault detection, data validity verification, and fault-tolerant handling mechanisms. Failures in the weighing function do not affect the normal operation of the vehicle's basic gear shifting, light, and wiper control functions. The EGS controller detects height sensor faults in real time, and the automotive-grade MCU monitors the PWM signals output by the four height sensors in real time. When the PWM signal duty cycle exceeds the effective range (<5% or >95%), the corresponding height sensor is determined to be faulty. After fault confirmation, the automotive-grade MCU records the corresponding DTC fault code and simultaneously sends an invalid weighing data value of 0x1FFF to the vehicle network. Upon receiving the invalid value, the central control screen displays a sensor fault message for the corresponding location.

[0100] Each time the automotive-grade MCU powers on, it performs a CRC check on the calibration data stored in the EEPROM. If the check fails, the calibration data is deemed abnormal, the corresponding DTC fault code is recorded, the weighing function is disabled, and a calibration abnormality prompt is sent to the central control screen. While the weighing function is disabled, the controller's electronic shifting and combination switch functions remain completely unaffected. Simultaneously, the automotive-grade MCU monitors the CAN FD bus communication status in real time. When the bus experiences offline or packet loss faults, it records the corresponding DTC fault code, suspends weighing data transmission, and enters fault-safe mode to ensure the normal operation of the basic shifting and combination switch functions.

[0101] The following typical application scenarios are used to illustrate the conventional application scenarios of this invention.

[0102] Example 1: Routine load monitoring scenario.

[0103] During normal vehicle operation, the EGS controller executes the weighing calculation process cyclically every 10ms, calculating the vehicle's total weight, four-wheel load, and front-to-rear axle load ratio in real time. Simultaneously, the data is sent to the central control screen for display. The driver can view the vehicle's load status in real time through the central control screen. When the load exceeds the vehicle's maximum permissible load, the central control screen triggers an overload alarm, promptly reminding the driver to eliminate the overload safety hazard.

[0104] During vehicle operation, the controller monitors the vehicle's gradient data in real time. When the vehicle travels to a slope with a gradient of 3% or more, the controller pauses the weighing calculation. When the vehicle returns to a level road with a gradient of less than 3%, the controller automatically resumes the weighing calculation.

[0105] Example 2: Cargo weighing scenario.

[0106] When a user needs to measure the weight of goods, first park the vehicle on a level surface, power on the vehicle to the ON position, and after the controller completes initialization, it enters normal weighing mode. The user then clicks the tare / zero soft switch on the central control screen, which sends a zeroing command to the EGS controller. The EGS controller records the current total weight of the vehicle as the tare weight, completing the tare operation.

[0107] After the user completes loading the goods, the EGS controller calculates the total weight of the vehicle in real time, automatically deducts the pre-recorded tare weight, obtains the net weight data of the goods, and sends the net weight data to the central control screen for display in real time. The user can directly read the actual weight of the loaded goods through the central control screen.

[0108] Example 3: Axle load monitoring scenario.

[0109] When a user loads unevenly, the EGS controller calculates the front-to-rear axle load ratio in real time and displays this status on the central control screen. When the load ratio is in the red (unreasonable) range, the central control screen issues a load distribution anomaly warning to the user, suggesting they adjust the load position. When the load ratio is in the yellow (offset) range, the central control screen issues a load distribution offset warning. Users can adjust the load placement according to these warnings to bring the front-to-rear axle load ratio into the green (reasonable) range, ensuring vehicle stability and braking safety.

[0110] Furthermore, the orientations or positional relationships described in this invention are based on the orientations or positional relationships shown in the accompanying drawings. They are only for the purpose of facilitating the description of this invention and simplifying the description, and are not intended to indicate or imply that the device or structure referred to must have a specific orientation, or to operate in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0111] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for a car column shifter combination switch integrating vehicle weighing function, characterized in that: The control method for the automotive column shifter combination switch is based on a controller distributed throughout the vehicle. This controller includes an electronic shift module, a combination switch module, an on-board weighing module, a communication module, and a power management module. Each module is connected to an automotive-grade MCU within the controller. The controller also contains an EEPROM storage unit connected to the automotive-grade microcontroller. The power management module is connected to the vehicle's power supply. The communication module is connected to a vehicle network node via a CAN FD bus. This vehicle network node includes a vehicle tilt sensor and a central control screen. The on-board weighing module is connected to four height sensors distributed throughout the vehicle's suspension system. The automotive column shifter combination switch control method includes the following steps: Step 1: The power management module supplies power to the internal modules of the controller and the four height sensors. After the controller completes initialization, the vehicle weighing module collects the PWM signals output by the four height sensors. Step 2: The automotive-grade MCU converts the duty cycle of the acquired PWM signal into the corresponding change in vehicle height at the wheel, in mm. Step 3: The automotive-grade MCU determines whether the vehicle has completed the no-load calibration. If the calibration has not been completed, the no-load calibration process is executed. If the calibration has been completed, the no-load calibration parameters pre-stored in the EEPROM storage unit are read. The no-load calibration parameters include the no-load reference height values ​​of the four height sensors, the equivalent elastic coefficient of the front axle suspension system, the equivalent elastic coefficient of the rear axle suspension system, the calibration timestamp, and the calibration personnel information. Step 4: The automotive-grade MCU calculates the independent load on each of the four wheels based on the vehicle calibration parameters and the change in vehicle height, and simultaneously acquires the vehicle slope data output by the vehicle tilt sensor; the formula for calculating the single wheel load is: Single wheel load = equivalent elastic coefficient of suspension of the corresponding axle × change in vehicle height of the corresponding wheel; Step 5: The automotive-grade MCU determines whether the vehicle's slope is less than 3%. If the slope is not less than 3%, the weighing calculation is paused; if the slope is less than 3%, tilt compensation is performed, and then the total vehicle weight and the front-to-rear axle load ratio are calculated sequentially. The total vehicle weight is in kg. The tilt compensation includes the following sub-steps: First, the automotive-grade MCU calculates the height measurement deviation caused by the vehicle's tilt based on the vehicle's slope data, in mm; second, the height measurement deviation is subtracted from the measured change in vehicle height to obtain the effective height change caused only by the vehicle's load, in mm; finally, the effective height change is used as the input parameter for subsequent weight calculations. The calculation of the total vehicle weight includes the following sub-steps: Step A: Retrieve the equivalent elastic coefficients of the front axle suspension system and the rear axle suspension system pre-stored in the EEPROM storage unit. The units of the equivalent elastic coefficients of the front axle suspension system and the rear axle suspension system are kg / mm; Step B: Calculate the total vehicle weight using the formula: Total vehicle weight = Equivalent elastic coefficient of the front axle suspension system × (Change in vehicle height of the left front wheel + Change in vehicle height of the right front wheel) + Equivalent elastic coefficient of the rear axle suspension system × (Change in vehicle height of the left rear wheel + Change in vehicle height of the right rear wheel); where the unit of the change in vehicle height is mm, and the unit of the total vehicle weight is kg; The calculation of the front and rear axle load ratio includes the following sub-steps: Step 1: Calculate the sum of the loads on the two front axle wheels and the sum of the loads on the two rear axle wheels, in kg. The sum of the loads on the two front axle wheels is the sum of the independent loads on the left and right front wheels, and the sum of the loads on the two rear axle wheels is the sum of the independent loads on the left and right rear wheels; Step 2: Calculate the front axle load ratio using the formula: Front axle load ratio = (Sum of loads on the two front axle wheels ÷ Total vehicle weight × 100%); Step 3: Calculate the rear axle load ratio using the formula: Rear axle load ratio = (Sum of loads on the two rear axle wheels ÷ Total vehicle weight × 100%). Step Six: The automotive-grade MCU sends the weighing-related data to the central control screen via the CAN FD bus through the communication module for display.

2. The method of claim 1, wherein the integrated vehicle-mounted weighing function and gear combination switch control method is characterized by: In step three, the execution of the no-load calibration process includes the following sub-steps: Step 1: Send a calibration trigger command to the controller through the no-load calibration routine service of the UDS protocol to start the no-load calibration process; Step 2: The controller collects the PWM signals of the four height sensors when the vehicle is unloaded and horizontally placed, and converts them into the no-load reference height value of each wheel, in mm; Step 3: Based on the average value of the no-load reference height values ​​of 20 vehicles of the same model, calculate the equivalent elastic coefficient of the suspension of the front axle and the rear axle to generate no-load calibration parameters, in kg / mm; Step 4: Write the no-load calibration parameters into the EEPROM storage unit of the controller, and read the calibration parameters through the calibration data read identifier of the UDS protocol.

3. The automotive column shifter combination switch control method with integrated vehicle weighing function according to claim 1, characterized in that: Step six includes the following sub-steps: First: The communication module connects to the vehicle's CAN FD bus through its internal CAN FD transceiver. The arbitration field communication rate of the CAN FD bus is 500Kbps, and the data field communication rate is 2Mbps. Secondly, the automotive-grade MCU sends weighing-related data to the vehicle network nodes in a fixed cycle of 10ms.

4. The control method for the automotive column shifter combination switch integrating vehicle weighing function according to claim 1, characterized in that: Step six also includes a tare clearing control step: Step 1: The automotive-grade MCU receives the tare clearing command sent by the central control screen via the CAN FD bus; Step 2: The automotive-grade MCU records the currently calculated total vehicle weight as the tare weight, and automatically deducts the corresponding tare weight when calculating the total vehicle weight in subsequent calculations, and outputs the net weight data of the cargo to the central control screen; The units of the tare weight and the net weight data of the cargo are both kg.

5. The automotive column shifter combination switch control method with integrated vehicle weighing function according to claim 1, characterized in that: In step six, the display control of the central control screen includes the following sub-steps: First: when the current axle load ratio is less than 30% or greater than 70%, the load ratio status is displayed as red (unreasonable range); Second: when the current axle load ratio is greater than or equal to 30% and less than 40%, or greater than 60% and less than or equal to 70%, the load ratio status is displayed as yellow (offset range); Finally: when the current axle load ratio is greater than or equal to 40% and less than or equal to 60%, the load ratio status is displayed as green (reasonable range).

6. The control method for the automotive column shifter combination switch integrating vehicle weighing function according to claim 1, characterized in that: While step one is being executed, the basic control steps for the column shifter are being executed simultaneously, including: First, the electronic shift module collects the status signals of the shift lever position and the parking gear button, and the combination switch module collects the status signals of the wipers, turn signals, headlights, and washer switches; Second, both types of status signals are transmitted to the automotive-grade MCU for processing and then sent to the vehicle network via the communication module.

7. The automotive column shifter combination switch control method with integrated vehicle weighing function according to claim 1, characterized in that: It also includes sensor fault detection and handling steps, including: First, the automotive-grade MCU monitors the PWM signals output by the four height sensors in real time. The effective duty cycle range of the PWM signal is 5% to 95%, corresponding to a vehicle height variation range of 0 to 100 mm. Second, when the duty cycle of the PWM signal is less than 5% or greater than 95%, the corresponding height sensor is determined to be faulty, and the corresponding DTC fault code is recorded. Finally, the automotive-grade MCU sends an invalid weighing data value to the vehicle network through the communication module. The invalid value is the hexadecimal value 0x1FFF.

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