Combination pressure correction method and system based on load torque budget, vehicle-mounted terminal and vehicle

Abstract

The invention relates to the field of clutch control, and particularly provides a combination pressure correction method and system based on load torque budgeting, a vehicle-mounted terminal and a vehicle, and the method comprises the steps: judging the type of a current working condition according to the power-on state of a controller, driving direction change information and a clutch trigger signal; according to the current working condition type, calling and executing an adaptive load torque budget strategy to generate a budget torque value; and according to the budget torque value and the wet clutch friction torque model, a required clutch control pressure value is obtained, and a basic pressure value output by the clutch combination characteristic curve is replaced with the clutch control pressure value so as to perform correction control on the combination pressure. The control lag is reduced, the torque prediction accuracy and the pressure matching degree are improved, impact shaking in the starting / reversing / gear shifting process is effectively restrained, excessive sliding friction or rough combination of the clutch is avoided, the service life of the clutch is prolonged, the operation difficulty is reduced, and the operation precision and comfort are improved.

Description

Technical Field

[0001] This invention relates to the field of clutch control, and more specifically to a method, system, vehicle terminal, and vehicle for correcting engagement pressure based on load torque budget. Background Technology

[0002] Because tractors operate in a variety of environments with complex working conditions, and the engagement and disengagement control of wet clutches during starting and shifting depends on the load to ensure the smoothness of the entire process, determining the tractor's load and working condition and providing accurate pressure build-up values ​​becomes crucial for clutch control correction.

[0003] Traditional control methods often rely on a single, pre-calibrated clutch engagement pressure curve, or simply make real-time fine adjustments based on signals such as throttle opening and engine speed. Tractor operating environments are complex and varied, with significant differences in system load under different conditions such as heavy-load plowing, hill starts, and travel on soft ground. Fixed or reactive control strategies cannot achieve rapid and smooth clutch engagement under all conditions, often resulting in noticeable shocks during starting or reversing, or overheating and abnormal wear due to prolonged clutch slippage. Most related technologies are "sensor-driven" feedback or feedforward-feedback composite control, adjusting pressure by monitoring changes in parameters such as engine speed and output shaft speed after the clutch engagement process begins. This method has inherent lag, failing to provide a precise pressure value matching the actual load demand at the initial stage of clutch engagement. Especially during power reversal (F / R switching), the load state changes instantaneously, and the system response delay can easily lead to reversing jerks or power interruptions, severely impacting driving experience and operational efficiency. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a method, system, vehicle terminal, and vehicle based on load torque budget combined with pressure correction. This reduces control lag, improves torque prediction accuracy and pressure matching, effectively suppresses shocks and vibrations during starting / reversing / shifting, avoids excessive clutch slippage or rough engagement, extends clutch life, reduces operational difficulty, and enhances operational precision and comfort.

[0005] In a first aspect, the technical solution of the present invention provides a combined pressure correction method based on load torque budget, comprising the following steps: Based on the controller's power-on status, driving direction change information, and clutch trigger signal, determine the current operating condition type; the operating condition types include initial power-on condition, driving direction change condition, gear shifting condition, and semi-clutch condition. Based on the current operating condition, an appropriate load torque budgeting strategy is retrieved and executed to generate a budgeted torque value. Specifically, the load torque budgeting strategy adapted to the initial power-on condition is based on the torque information from the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition is based on the torque information before the change of travel direction and the target direction gear ratio; the load torque budgeting strategy adapted to the gear shift condition is based on the torque information before clutch engagement; and the load torque budgeting strategy adapted to the semi-clutch condition is based on the torque information before clutch engagement and the target gear ratio. Based on the budgeted torque value and the wet clutch friction torque model, the required clutch control pressure value is obtained. The base pressure value output by the clutch engagement characteristic curve is then replaced with this clutch control pressure value to correct and control the engagement pressure.

[0006] Secondly, the technical solution of the present invention provides a combined pressure correction system based on load torque budget, comprising: The operating condition judgment module is used to determine the current operating condition type based on the controller's power-on status, driving direction change information, and clutch trigger signal; the operating condition types include initial power-on condition, driving direction change condition, gear shifting condition, and half-clutch condition. The budgeted torque value generation module is used to retrieve and execute an adapted load torque budgeting strategy to generate a budgeted torque value based on the current operating condition type. Specifically, the load torque budgeting strategy adapted to the initial power-on condition calculates the torque value based on the torque information from the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition calculates the torque value based on the torque information before the change of travel direction and the target direction speed ratio; the load torque budgeting strategy adapted to the gear shift condition calculates the torque value based on the torque information before clutch engagement; and the load torque budgeting strategy adapted to the semi-clutch condition calculates the torque value based on the torque information before clutch engagement and the target gear ratio. The pressure correction control module is used to obtain the required clutch control pressure value based on the budgeted torque value and the wet clutch friction torque model, and replace the base pressure value output by the clutch engagement characteristic curve with the clutch control pressure value to correct and control the engagement pressure.

[0007] Thirdly, the technical solution of the present invention provides a vehicle-mounted terminal, comprising: Memory for storing combined pressure correction programs based on load torque budget; A processor is configured to implement the steps of the load torque budget-based combined pressure correction method described above when executing the combined pressure correction procedure.

[0008] Fourthly, the technical solution of the present invention provides a vehicle equipped with the above-mentioned vehicle-mounted terminal.

[0009] As can be seen from the above technical solutions, this application has the following advantages: by comprehensively analyzing the controller's power-on status, driving direction change information, and clutch trigger signal, the vehicle status is intelligently identified into four types: initial power-on condition, driving direction change condition, gear shifting condition, and semi-clutch condition, so as to understand the driver's true intention at different times, and to make targeted correction control, improve the accuracy of torque value prediction, and thus optimize the combined pressure correction control effect. This involves retrieving and executing a suitable load torque budget strategy to generate a budgeted torque value. Instead of waiting for load changes to occur before adjustment, it pre-calculates the torque requirements matching the current and expected loads before the clutch engagement begins, reducing control lag. This allows the clutch to apply pressure close to the target value at the initial engagement stage, significantly shortening the time to achieve torque synchronization and facilitating rapid and smooth engagement. The budgeted torque value is then combined with a wet clutch friction torque model to derive a precise clutch control pressure value. This pressure value is input into the clutch engagement characteristic curve for correction control. The pressure setting has a high degree of matching with the actual load, effectively suppressing shocks and vibrations during starting, reversing, and shifting, improving smoothness, avoiding excessive slippage, heat generation, and wear due to insufficient pressure, and preventing rough engagement caused by excessive pressure. This extends clutch lifespan, and the driver receives a consistent and expected clutch engagement feel under various loads, reducing operational difficulty and improving operational accuracy and comfort. Attached Figure Description

[0010] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of a combined pressure correction method based on load torque budget provided in an embodiment of the present invention.

[0012] Figure 2 This is a schematic diagram of the control strategy flow for a specific embodiment.

[0013] Figure 3 This is a schematic block diagram of a combined pressure correction system based on load torque budget, provided for an embodiment of the present invention.

[0014] Figure 4 This is a schematic diagram of the structure of a vehicle-mounted terminal provided in an embodiment of the present invention. Detailed Implementation

[0015] To make the purpose, features, and advantages of this application more apparent and understandable, specific embodiments and accompanying drawings will be used to clearly and completely describe the technical solution protected by this application. Obviously, the embodiments described below are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0016] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this application and in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0017] Figure 1 This is a schematic flowchart of a pressure correction method based on load torque budget provided in an embodiment of the present invention. Figure 1 The executing entity can be a combined pressure correction system based on load torque budget. The combined pressure correction method based on load torque budget provided in this embodiment of the invention is executed by a computer device, and correspondingly, the combined pressure correction system based on load torque budget runs within the computer device. Depending on different requirements, the order of the steps in this flowchart can be changed, and some steps can be omitted.

[0018] like Figure 1 As shown, the method includes the following steps.

[0019] S1 determines the current operating condition type based on the controller's power-on status, driving direction change information, and clutch trigger signal; the operating condition types include initial power-on condition, driving direction change condition, gear shifting condition, and half-clutch condition.

[0020] S2, based on the current operating condition type, retrieve and execute the appropriate load torque budgeting strategy to generate a budgeted torque value; wherein, the load torque budgeting strategy adapted to the initial power-on condition: budgets the torque value based on the torque information of the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition: budgets the torque value based on the torque information before the change of travel direction and the target direction speed ratio; the load torque budgeting strategy adapted to the shifting condition: budgets the torque value based on the torque information before clutch engagement; the load torque budgeting strategy adapted to the half-clutch condition: budgets the torque value based on the torque information before clutch engagement and the target gear ratio.

[0021] S3, based on the budgeted torque value and the wet clutch friction torque model, obtains the required clutch control pressure value, and replaces the base pressure value output by the clutch engagement characteristic curve with this clutch control pressure value to correct and control the engagement pressure.

[0022] As a refinement and extension of the specific implementation of the above embodiments, in order to fully explain the specific implementation process of this embodiment, the following will provide possible embodiments to describe the specific implementation of the above steps in a non-limiting manner.

[0023] In some optional implementations, step S1 achieves the working condition determination through the following steps S101 to S10.

[0024] S101 collects the controller's power-on flag, the current driving direction signal output by the transmission, and the digital or analog signal emitted by the clutch triggering device.

[0025] The controller power-on flag is derived from the controller hardware's power-on reset circuit or the underlying driver software. When the controller resumes power supply from a completely powered-off state, this flag is set to the "initial power-on" state; during subsequent operation, unless a complete power-off occurs again, this flag remains in the "normal operation" state.

[0026] The current driving direction signal originates from the transmission control unit (TCU) or gear position sensor, and is typically transmitted via a Controller Area Network (CAN) bus in message form or through hard-wired input. The signal is a discrete value used to characterize the current mechanical state of the transmission, generally defined as: forward gear (F, e.g., high level), neutral gear (N, e.g., neutral level), and reverse gear (R, e.g., low level). The system reads and buffers the latest value of this signal in each control cycle.

[0027] If it is a clutch button, its switching signal is acquired. The signal is valid (e.g., high level) when the button is pressed and invalid when released. If it is a clutch pedal, the analog voltage signal output from the pedal position sensor or the digital value after analog-to-digital conversion (ADC) is acquired. The system sets a valid threshold. When the signal value exceeds this threshold, the clutch trigger signal is considered valid.

[0028] S102, if the controller power-on flag indicates that this is the initial power-on, and no valid non-neutral driving direction signal has been recorded since the initial power-on, then the current working condition is determined to be the initial power-on working condition.

[0029] If the controller power-on flag acquired by S101 is "initial power-on", and since the flag was set this time, the system has never acquired any valid non-neutral (i.e., F or R) driving direction signal, then the current operating condition is determined to be "initial power-on operating condition".

[0030] Specifically, the controller internally maintains a Boolean variable, such as `hasMovedFromNeutral`, which is cleared to zero upon initial power-on. This variable is set whenever a valid F or R signal is detected. Therefore, the condition is equivalent to: (Power-on flag == Initial power-on) && (hasMovedFromNeutral == FALSE). This logic ensures that this operating condition is only classified as such when the vehicle is completely stationary and there is no intention to move after power-on.

[0031] Once this operating condition is determined, the process will directly jump to the torque budget process corresponding to the "initial power-on condition" and will no longer proceed with the subsequent S103-S105 judgments.

[0032] S103, otherwise continuously compare the current value of the driving direction signal with the value of the previous control cycle.

[0033] If the conditions of S102 are not met, it means that the vehicle is already in operation, i.e., it is not the first cold start, and the system begins to monitor whether the driving direction has been actively changed.

[0034] Specifically, in each control cycle, the driving direction signal current_gear collected in the current cycle is compared with the signal value previous_gear stored in the previous control cycle. previous_gear is updated by current_gear at the end of each cycle.

[0035] By comparing across cycles, the signal change edges, which can be either rising or falling edges, can be reliably detected, thereby capturing events where the driver's operation of the gear shift lever causes a change in driving direction.

[0036] S104, if the current value is not in neutral and is different from the value of the previous control cycle, it is determined that a change in driving direction has occurred, and the current working condition is changed to a driving direction change working condition.

[0037] This step is used to detect dynamic events such as shifting from forward / reverse or shifting from neutral to drive.

[0038] Based on the continuous comparison in S103, if the value of current_gear is not in neutral (N) and the value of current_gear is different from that of previous_gear, it is immediately determined that a change in driving direction has occurred, and the current working condition is changed to "change in driving direction working condition".

[0039] It should be noted that the condition "the current value is not neutral (N)" is necessary. For example, shifting from drive (F) to neutral (N), although the direction value changes, is usually a preparation for gear shifting or a parking process, not the "power reversal while moving" that this embodiment focuses on. Only when the signal is stable at F or R (not N) is it considered a valid direction change command.

[0040] This decision is an event-triggered logic; once the condition is met, the operating condition type is immediately locked. After the decision, the process jumps to the torque budgeting flow for the "change of direction of travel" operating condition.

[0041] S105, otherwise check whether the clutch trigger signal reaches the effective threshold. If the clutch trigger signal is effective and the driving direction signal remains unchanged before and after the trigger, determine whether there is a change in the gear selection signal. If the gear signal changes, it is determined to be a gear shifting condition. If the gear signal does not change, it is determined to be a half-clutch condition.

[0042] If the condition of S104 is not met, i.e. the driving direction has not changed, the system will further investigate the specific intention of the clutch trigger.

[0043] First, the system checks whether the clutch trigger signal has reached a valid threshold. If it has not, the current cycle will not be considered a gear shift or a partial clutch engagement, and the process will end. When the clutch is effectively triggered and the driving direction remains unchanged before and after the trigger, the system needs to distinguish whether the driver's intention is a gear shift or a partial clutch engagement, such as low-speed creep or fine positioning.

[0044] The system monitors for changes in the gear selection signal. This signal may originate from discrete gear request signals generated by the shift lever or paddles, or target gear command messages issued by the transmission controller. If a change in this gear selection signal is detected during clutch engagement, it is determined to be a "shifting condition." This corresponds to upshifting or downshifting in the same direction of travel (e.g., in F gear). If clutch engagement is active but no change in the gear selection signal is detected, it is determined to be a "partial clutch condition." This typically corresponds to the driver depressing the clutch pedal for fine-tuning vehicle speed, starting on a slope, or traversing complex terrain. In this situation, the gear ratio does not change, but fine control of clutch slippage is required.

[0045] In some optional implementations, the load torque budgeting strategy adapted to the initial power-on condition in step S2 budgets the torque value based on the torque information of the previous driving cycle, specifically including the following steps S2011 to S2013.

[0046] S2011, In the previous driving cycle, when an engine shutdown signal or controller power-down command is detected, the driving cycle is considered to have ended; before ending, the control system continuously collects and caches the engine torque percentage data under stable operating conditions, with a collection time of [duration period missing]. .

[0047] This step solidifies the load data from the previous driving cycle and is executed at the end of the previous driving cycle. The goal is to collect and save data that can represent the load characteristics of this operation.

[0048] The control system monitors signals in real time indicating that the vehicle and powertrain have entered a stopped state. The current driving cycle is considered to have ended when either of the following conditions is met: receiving a shutdown confirmation message from the engine control unit (ECU) via the CAN bus, or receiving a power-down preparation command from the vehicle power management system.

[0049] In the final period before the end of the cycle, the control system initiates a data acquisition task. The data acquisition target is the "engine stable operating torque percentage". This signal is usually provided by the engine ECU via the CAN bus, indicating the percentage of the engine's actual output torque at the current speed relative to its maximum possible torque at that speed, typically ranging from 0% to 100%. Compared to absolute torque values, percentage values ​​eliminate the influence of engine speed and more purely reflect load requirements.

[0050] To avoid data interference from transient processes such as rapid acceleration and deceleration, stability conditions are added during data acquisition. For example, the torque percentage value at a given moment is only considered valid data and stored in the buffer if both the engine speed fluctuation rate and the throttle opening change rate are continuously below a preset threshold.

[0051] S2012, will The torque percentage data sequence collected over a period of time was processed by arithmetic averaging to obtain a representative torque value. The value is then written into the controller's non-volatile memory.

[0052] Preferably, an E²PROM or Flash memory is used. Before writing, the data can be verified and calculated, and then stored together. This step is used to implement the memory function, ensuring that the data is retained even after the controller is completely powered off.

[0053] S013, after the initial power-on condition of the current driving cycle is triggered, reads a representative torque value from the non-volatile memory. ;Will This will be used directly as the budgeted torque value for the initial power-on condition. .

[0054] The representative torque value stored in the non-volatile memory can be read to verify its validity. Once verified, the value can be directly used as the budgeted torque value for the initial power-on condition. This value corresponds to the subsequent first budgeted torque value.

[0055] In one specific implementation, the data sampling source is the last 10 seconds before the engine was shut down. The average percentage of stable engine torque during these 10 seconds is taken as the budget torque for the current start. This solves the "cold start amnesia" problem, allowing the tractor to remember the load state at the end of the last work, and providing a reasonable start estimate for the new work.

[0056] In some optional implementations, the load torque budgeting strategy adapted to the change of travel direction in step S2 budgets the torque value based on the torque information before the change of travel direction and the target direction speed ratio, specifically including the following steps S2021 to S2015.

[0057] S2021 monitors the driving direction signal in real time. When the signal value changes from forward gear to reverse gear, from reverse gear to forward gear, or from neutral gear to forward gear or reverse gear, it is determined that a change in direction event has occurred.

[0058] Real-time monitoring of discrete driving direction signals (F / N / R) from the transmission. A valid "direction change event" is determined when any of the following signal transitions is detected: Forward (F) → Reverse (R); Reverse (R) → Forward (F); Neutral (N) → Drive (F) (for starting and specifying direction); Neutral (N) → Reverse (R) (starting and specifying direction).

[0059] This is achieved by comparing the current signal value with the cached value from the previous cycle in each control cycle.

[0060] S2022, In response to the change-of-direction event, retrieve the data prior to the time of the change-of-direction event from the circular buffer. The internally recorded percentage data of engine torque under stable operating conditions.

[0061] Upon event triggering, the system immediately retrieves data representing the pre-commutation load state from the most recent past. A first-in-first-out (FIFO) cyclic buffer is used, which continuously records the engine's stable torque percentage data during controller operation, with the data update frequency synchronized with the control cycle.

[0062] At the moment the direction change event occurs, the system immediately retrieves the information from the buffer up to the time prior to the event. All data records within the time period. This is a preset time window, preferably 0.8 to 1.2 seconds, such as 1 second. This window is long enough to smooth out minor load fluctuations and obtain a stable load "snapshot"; yet short enough to ensure the timeliness of the data and accurately reflect the load state before the switching action is about to occur.

[0063] S2023: Calculate the arithmetic mean of the extracted engine stable operating condition torque percentage data, and use it as the base engine torque percentage value before the change of direction. .

[0064] S2024, Based on the target driving direction signal, determine the target transmission path; from the preset speed ratio mapping table, query the equivalent transmission speed ratio corresponding to the current engine speed range and the target direction. .

[0065] Based on the driving direction signal after a direction change event, i.e., the target direction, F or R, the new transmission path through which power needs to be transmitted is determined. The controller pre-stores an "equivalent transmission ratio". A mapping table. This table is indexed by engine speed and driving direction. For a given current engine speed and target direction, the corresponding mapping table can be looked up. . It represents the total torque amplification factor from the engine crankshaft output end to the target direction wet clutch friction pair input end. This value integrates the transmission ratio of the forward / reverse planetary gear set and related shaft teeth in the gearbox.

[0066] S2025, multiply the base torque value by the equivalent speed ratio to obtain the budgeted torque value that the clutch needs to transmit in the target direction. ,Right now .

[0067] This represents the percentage of torque required by the engine to overcome the load in the original direction. It is a conversion coefficient that maps the engine's torque demand to the physical torque that the clutch disc needs to withstand through a specific gear transmission chain in the target direction. The physical meaning is to allow the wheels to obtain the same traction force as before the reversal to overcome the original load after the reversal. The target clutch needs to prepare the estimated torque value to be transmitted, which corresponds to the subsequent second budget torque value.

[0068] The data source is the last second before the direction change, and the average torque value within that second is taken. Since the clutch / gear transmission paths for forward and reverse are different (different speed ratios), the engine torque needs to be converted to the clutch in the target direction. This embodiment solves the "reversing shock" problem by considering the change in the transmission chain, ensuring that the torque transmitted when the clutch engages after the reversing matches the actual load requirements, and avoiding sudden forward or backward lurching caused by different speed ratios.

[0069] In some optional implementations, the load torque budgeting strategy adapted to the shifting condition in step S2 budgets the torque value based on the torque information before the clutch engagement, specifically including steps S2031 to S2032.

[0070] S2031, from the clutch engagement moment, retrospectively... Extract the engine torque percentage data for that time period from the circular buffer.

[0071] The clutch trigger moment refers to the moment when the clutch pedal position sensor signal first exceeds a preset effective threshold. This threshold is calibrated and corresponds to the starting point when the clutch begins to enter the controllable slip zone; it is typically set slightly above the position where the clutch is fully disengaged.

[0072] A FIFO (First-In, First-Out) buffer is also used to continuously record engine torque percentage data. Within the same control cycle where the clutch engagement event is confirmed, the system immediately backtracks from the FIFO buffer by a fixed time window. Extract from the time of triggering to the time before triggering. All data points recorded within this time period.

[0073] In the preferred embodiment, Set to 0.8 to 1.2 seconds, for example, 1 second. This window is sufficient to capture the steady-state load before triggering, while being extremely short, ensuring very high data timeliness and strong correlation with driver intent.

[0074] S2032, the extracted data is filtered and averaged to obtain the torque percentage value representing the load state before gear shift. ; will be obtained Directly used as the budgeted torque value under half-clutch operating conditions .

[0075] The result Directly used as the budgeted torque value under half-clutch operating conditions This means that the torque the clutch, according to the system's budget, needs to transmit is numerically equal to a percentage of the engine's output torque before engagement. Under this condition, the gear ratio remains unchanged. The conversion relationship from engine torque percentage to wheel drive force is constant. Therefore, the engine torque percentage itself directly and linearly reflects the demand of the drive wheels. This value... This corresponds to the third budgeted torque value.

[0076] In some optional implementations, the load torque budgeting strategy adapted to the half-clutch condition in step S2 budgets the torque value based on the torque information before the clutch engagement and the target gear ratio, specifically including steps S2041 and S2042.

[0077] S2041, based on the transmission controller message or gear position sensor signal, determines the target gear and queries the transmission ratio of that gear. .

[0078] Once the clutch trigger signal is valid and a shift condition is determined, the system immediately determines the target gear in one of the following two ways: read the "target gear command message" sent by the transmission control unit (TCU) via the CAN bus; or if the system does not have a TCU message, it infers the target gear by monitoring the sensor signal of the gear selector lever or button, combining it with the current gear, and based on the preset shift logic.

[0079] The controller has a pre-stored "gear-transmission ratio mapping table". Based on the determined target gear number, the corresponding gear can be directly retrieved from this table. Value. This value represents the total gear ratio from the engine crankshaft to the transmission output shaft at the target gear. Different gears have different ratios. Different values ​​represent different torque amplification factors and vehicle speed ranges.

[0080] S2042, torque percentage value With transmission ratio Multiply by this to obtain the estimated torque value that the clutch in the target gear needs to transmit. ,Right now .

[0081] This value This corresponds to the third budgeted torque value.

[0082] The data for shifting / partial clutch operation comes from the average torque value within the last second before the clutch pedal is depressed / shift is triggered. Shifting requires calculation based on the gear ratio of the old and new gears because the force transmitted to the wheels differs when the engine outputs the same torque in different gears. The estimated torque needs to be adjusted based on the target gear. For partial clutch operation, this average value is used directly without gear ratio calculation because the goal here is precise control of slippage, not changing the transmission ratio. This addresses the issues of "shifting jerks" and "precise control," considering gear changes during shifting to ensure smooth power delivery, and directly responding to engine load during partial clutch engagement to achieve sensitive creep control.

[0083] In some optional implementations, after the budgeted torque value is calculated using the adaptation strategy in step S2, the budgeted torque value is further adjusted based on the operating environment to further improve engagement smoothness, specifically including the following steps 1) and 2).

[0084] Step 1), parameter calculation.

[0085] Based on the real-time slope angle provided by the vehicle attitude sensor Calculate the slope compensation coefficient ,in The gradient influence weighting coefficient is calibrated based on the vehicle's total weight and transmission system characteristics, and is typically between 0.2 and 0.8. When going uphill... It is a positive value when going downhill. It is a negative value.

[0086] Based on engine speed change rate Calculate the dynamic compensation coefficient ,in This is a dynamic response weighting coefficient, calibrated experimentally, typically between 0.1 and 0.3, used to suppress speed noise while effectively responding to the driver's intention to accelerate rapidly. The engine's rated speed is given by sgn(), which is a sign function used to distinguish between acceleration (positive) and deceleration (negative).

[0087] Based on the type of currently attached work implement, retrieve its nominal resistance torque from the preset database. As a fixed compensation amount .

[0088] Step 2), adjust the preset torque value.

[0089] The budgeted torque values ​​for the initial power-on condition, the direction-of-travel change condition, the gear shift condition, and the semi-clutch condition, obtained based on the load torque budget strategy, are respectively denoted as the first budgeted torque value, the second budgeted torque value, the third budgeted torque value, and the fourth budgeted torque value.

[0090] Calculation of initial power-on conditions During a cold start, the vehicle may be parked on different slopes and connected to different implements. Therefore, compensation for the current stationary slope and the current implements is added on top of the memorized "historical load".

[0091] Calculate the working conditions for changing the direction of travel. When changing direction, in addition to the current gradient, the acceleration / deceleration trend of the engine at the moment before changing direction should also be considered. For example, when suddenly changing direction while accelerating rapidly, a larger clutch torque is needed to overcome the vehicle's inertia.

[0092] Calculate the shifting conditions ; Calculation of the half-clutch working condition During gear shifting or fine creeping, the current gradient is an external factor affecting the clutch load. The dynamic rate of change may be caused by the driver's active operation and is not used as the primary basis for compensation under this condition, in order to maintain control stability.

[0093] In some optional implementations, step S3 employs the classical physical model of the friction torque of a wet multi-plate clutch, expressed by the following formula:

[0094] in, The theoretical torque transmitted by the clutch (N·m) is the final budgeted torque value obtained from the calculation.

[0095] The dynamic friction coefficient between friction pairs is a variable related to the clutch disc material, lubricant properties, and sliding speed. It is usually calibrated as a function of sliding speed by bench testing.

[0096] The hydraulic control pressure (Pa) acting on the clutch piston is the quantity to be determined. : Effective bearing area of ​​a single friction pair (m²); The effective number of friction pairs; : The outer and inner radii of the friction plate (m).

[0097] Based on the real-time slippage speeds of the clutch's driving and driven plates, the current friction coefficients are obtained from a table. Substituting the budgeted torque value, friction coefficients, and constants determined by the clutch's physical structure into the above formula, the required clutch control pressure value is obtained. The constants determined by the clutch's physical structure are the effective number of friction pairs and the calculated values ​​corresponding to the outer and inner radii of the friction plates. .

[0098] The clutch engagement characteristic curve has two input values: the first is engine speed or throttle opening, and the second is the clutch transmitted torque or vehicle load. The output value is the baseline target clutch pressure. The clutch engagement characteristic curve defines the recommended clutch pressure benchmark for smooth engagement under various steady-state operating conditions.

[0099] The clutch control pressure value is input into the control logic of the engagement characteristic curve as a key correction value or high-order setpoint: during the torque build-up phase of the clutch engagement process, the system replaces the "basic pressure" retrieved from the engagement characteristic curve based on the current engine speed and throttle with the clutch control pressure value.

[0100] After generating the final target pressure setpoint, the controller sends the digital target pressure setpoint to the clutch pressure control valve via the CAN bus or a dedicated drive circuit. The pressure control valve adjusts the hydraulic oil flow and pressure output to the clutch piston cylinder based on the received electrical signal. A pressure sensor installed in the clutch oil circuit monitors the actual oil pressure in real time and feeds it back to the controller. The PID controller within the controller continuously compares the actual oil pressure with the target pressure, dynamically adjusting the commands sent to the pressure control valve until the actual pressure accurately matches the target pressure.

[0101] The following provides a specific embodiment. Figure 2 This is a schematic diagram of the control strategy flow for this specific embodiment, as shown below. Figure 2 As shown, the control strategy includes the following stages.

[0102] 1) System initialization and memory loading phase First, the system enters the "Initial Operation" check. If the result is "Yes" (Initial Operation), it indicates that the controller is initially powered on and the vehicle has not yet moved, i.e., the initial power-on condition. The system will directly execute the "Read Historical Data from EEPROM" operation to obtain the representative torque value stored at the end of the previous driving cycle. This path corresponds to the cold start torque budget strategy, realizing the cross-cycle transfer of load memory. If the result is "No," it indicates that the controller has entered normal operation, and the system will begin to monitor the driver's dynamic operation commands in real time.

[0103] 2) Real-time event monitoring and operating condition identification stage under normal operation In the "normal operation" state, the system monitors two types of key signals in parallel, forming a hierarchical judgment structure.

[0104] Level 1: Event capture of change of direction of travel (edge ​​detection).

[0105] The system simultaneously checks for "rising edge of forward command set?" and "rising edge of reverse command set?". If either check is "yes", it indicates a change in driving direction (e.g., N→F / R or F→R), and immediately classifies it as a change in driving direction. Depending on the target direction, it enters either the "change in driving direction" or "change in reverse" branch. In this branch, the system executes the load torque budgeting strategy logic adapted to the change in driving direction: it calls the corresponding torque budgeting function and calculates the clutch budget torque value based on the load data instant before the direction change and the speed ratio of the target direction.

[0106] Second layer: Intention determination of fine-grained operation in the same direction (state detection).

[0107] If no direction change event is detected (i.e., both rising edges indicate "No"), the process converges and enters the same-direction operation judgment layer based on the current driving state. The system checks "Forward command set?" and "Reverse command set?" in parallel.

[0108] The forward / reverse command setting is "yes": This indicates that the vehicle is currently in either a continuous forward gear or a continuous reverse gear. This is a prerequisite for handling gear shifting or partial clutch engagement.

[0109] Both are "No": This indicates that the vehicle is in neutral (N) mode. If a clutch operation occurs at this time, the budget strategy will not be executed, and the basic default clutch control will be used instead.

[0110] 3) Differentiation between shifting and semi-clutch operation After confirming that the vehicle is in a continuous forward or reverse state, the process further investigates the specific intent of clutch engagement. When valid clutch engagement is detected, the system immediately determines whether it is accompanied by a "gear change?".

[0111] If a gear change is detected, it is determined to be a gear shifting condition (forward or reverse shifting). The system will execute a load torque budgeting strategy adapted to the semi-clutch condition, calculating the budgeted torque value based on the average torque before clutch engagement multiplied by the target gear ratio.

[0112] If no gear change is detected, it is determined to be a semi-clutch condition (forward semi-clutch condition or reverse semi-clutch condition). The system will execute a load torque budgeting strategy adapted to the gear shifting condition, directly using the average torque before clutch engagement as the budgeted torque value.

[0113] 4) Stress calculation, execution, and data closure phase All operating condition branches ultimately converge to "clutch torque control," which receives the budgeted torque values ​​generated by each path, back-calculates the required precise control pressure value Preq based on the wet clutch friction torque model, and drives the hydraulic system to execute closed-loop pressure control to complete the smooth engagement of the clutch.

[0114] At the same time, the system will trigger the "store representative torque value to EEPROM" operation at the appropriate time (such as before the end of the driving cycle) to save the load characteristics of the current cycle and provide a data basis for the next possible "initial power-on condition", thereby forming an intelligent learning and adaptive closed loop across working cycles.

[0115] The foregoing has described in detail an embodiment of a combined pressure correction method based on load torque budget. Based on the combined pressure correction method based on load torque budget described in the above embodiment, this invention also provides a combined pressure correction system based on load torque budget corresponding to the method.

[0116] Figure 3 This is a schematic block diagram of a combined pressure correction system based on load torque budget provided in an embodiment of the present invention. In this embodiment, the combined pressure correction system 300 based on load torque budget can be divided into multiple functional modules according to the functions it performs. A module, as referred to in this invention, is a series of computer program segments that can be executed by at least one processor and perform a fixed function, and is stored in memory.

[0117] The working condition judgment module 310 is used to determine the current working condition type based on the controller's power-on status, driving direction change information, and clutch trigger signal; the working condition types include initial power-on working condition, driving direction change working condition, gear shifting working condition, and half-clutch working condition.

[0118] The budgeted torque value generation module 320 is used to retrieve and execute an adapted load torque budgeting strategy to generate a budgeted torque value based on the current operating condition type. Specifically, the load torque budgeting strategy adapted to the initial power-on condition calculates the torque value based on the torque information from the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition calculates the torque value based on the torque information before the change of travel direction and the target direction speed ratio; the load torque budgeting strategy adapted to the gear shift condition calculates the torque value based on the torque information before clutch engagement; and the load torque budgeting strategy adapted to the semi-clutch condition calculates the torque value based on the torque information before clutch engagement and the target gear ratio.

[0119] The pressure correction control module 330 is used to obtain the required clutch control pressure value based on the budgeted torque value and the wet clutch friction torque model, and replace the basic pressure value output by the clutch engagement characteristic curve with the clutch control pressure value to correct and control the engagement pressure.

[0120] The load torque budget-based combined pressure correction system of this embodiment is used to implement the aforementioned load torque budget-based combined pressure correction method. Therefore, the specific implementation of this system can be found in the embodiment section of the load torque budget-based combined pressure correction method above. Thus, its specific implementation can be referred to the description of the corresponding embodiments, and will not be elaborated here.

[0121] Furthermore, since the load torque budget-based combined pressure correction system of this embodiment is used to implement the aforementioned load torque budget-based combined pressure correction method, its function corresponds to the function of the above method, and will not be repeated here.

[0122] Figure 4 A schematic diagram of a vehicle-mounted terminal 400 provided in an embodiment of the present invention includes: a processor 410, a memory 420, and a communication unit 430. The processor 410 is used to implement the process steps of the above-described embodiment of the combined pressure correction method based on load torque budget when implementing the combined pressure correction program based on load torque budget stored in the memory 420.

[0123] This invention provides a vehicle equipped with the aforementioned vehicle-mounted terminal 400.

[0124] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A combined pressure correction method based on load torque budget, characterized in that, Includes the following steps: The current operating condition type is determined based on the controller's power-on status, changes in driving direction, and clutch trigger signal. Operating conditions include initial power-on, change of direction, gear shifting, and semi-clutch operation. Based on the current operating condition, an appropriate load torque budgeting strategy is retrieved and executed to generate a budgeted torque value. Specifically, the load torque budgeting strategy adapted to the initial power-on condition is based on the torque information from the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition is based on the torque information before the change of travel direction and the target direction gear ratio; the load torque budgeting strategy adapted to the gear shift condition is based on the torque information before clutch engagement; and the load torque budgeting strategy adapted to the semi-clutch condition is based on the torque information before clutch engagement and the target gear ratio. Based on the budgeted torque value and the wet clutch friction torque model, the required clutch control pressure value is obtained. The base pressure value output by the clutch engagement characteristic curve is then replaced with this clutch control pressure value to correct and control the engagement pressure.

2. The combined pressure correction method based on load torque budget according to claim 1, characterized in that, Based on the controller's power-on status, changes in driving direction, and clutch trigger signals, the current operating condition type is determined, specifically including: The system collects the power-on flag of the controller, the current driving direction signal output by the transmission, and the digital or analog signal emitted by the clutch triggering device. If the controller's power-on flag indicates that this is the initial power-on, and no valid non-neutral driving direction signal has been recorded since the initial power-on, then the current operating condition is determined to be the initial power-on operating condition. Otherwise, continuously compare the current value of the driving direction signal with the value of the previous control cycle; If the current value is not in neutral and is different from the value of the previous control cycle, it is determined that a change in driving direction has occurred, and the current working condition is changed to a driving direction change working condition. Otherwise, check whether the clutch trigger signal has reached the valid threshold; If the clutch trigger signal is valid and the driving direction signal remains unchanged before and after triggering, determine whether there is a change in the gear selection signal. If the gear signal changes, it is determined to be a gear shifting condition. If the gear signal does not change, it is determined to be a half-clutch condition.

3. The combined pressure correction method based on load torque budget according to claim 1, characterized in that, The load torque budgeting strategy adapted to the initial power-on condition budgets the torque value based on the torque information from the previous driving cycle, specifically including: In the previous driving cycle, the cycle ended when an engine shutdown signal or controller power-down command was detected. Before ending, the control system continuously collected and cached the engine torque percentage data under stable operating conditions for a period of time. ; Will The torque percentage data sequence collected over a period of time was processed by arithmetic averaging to obtain a representative torque value. And write the value into the controller's non-volatile memory; After the initial power-on condition of the current driving cycle is triggered, a representative torque value is read from the non-volatile memory. ;Will This will be used directly as the budgeted torque value for the initial power-on condition. .

4. The combined pressure correction method based on load torque budget according to claim 1, characterized in that, The load torque budgeting strategy adapted to the change of travel direction operating conditions budgets the torque value based on the torque information before the change of travel direction and the speed ratio of the target direction, specifically including: The system monitors the driving direction signal in real time. When the signal value changes from forward gear to reverse gear, from reverse gear to forward gear, or from neutral gear to forward gear or reverse gear, it is determined that a change of direction event has occurred. When a response direction change event occurs, retrieve the data from the circular buffer up to the time preceding the event. Internally recorded engine torque percentage data under stable operating conditions; The arithmetic mean of the extracted engine torque percentage data under stable operating conditions was calculated and used as the base engine torque percentage value before the change of direction. ; Based on the target driving direction signal, determine the target transmission path; from the preset speed ratio mapping table, query the equivalent transmission speed ratio corresponding to the current engine speed range and the target direction. ; Multiplying the base torque value by the equivalent speed ratio yields the budgeted torque value that the clutch needs to transmit in the target direction. ,Right now .

5. The combined pressure correction method based on load torque budget according to claim 1, characterized in that, The load torque budgeting strategy adapted to shift conditions budgets torque values ​​based on torque information before clutch engagement, specifically including: Starting from the moment the clutch is engaged, look back backwards. Extract the engine torque percentage data for that time period from the circular buffer; The extracted data is filtered and averaged to obtain the percentage value of torque representing the load state before gear shift. ; will be obtained Directly used as the budgeted torque value under half-clutch operating conditions .

6. The combined pressure correction method based on load torque budget according to claim 5, characterized in that, The load torque budgeting strategy adapted to the semi-clutch operating condition budgets the torque value based on the torque information before clutch engagement and the target gear ratio, specifically including: Based on the transmission controller message or gear position sensor signal, determine the target gear and query the transmission ratio of that gear. ; Torque percentage value With transmission ratio Multiply by this to obtain the estimated torque value that the clutch in the target gear needs to transmit. ,Right now .

7. The combined pressure correction method based on load torque budget according to claim 1, characterized in that, The method also includes the following steps: Based on the real-time slope angle provided by the vehicle attitude sensor Calculate the slope compensation coefficient ,in The slope influence weighting coefficient; Based on engine speed change rate Calculate the dynamic compensation coefficient ,in For dynamic response weighting coefficients, The engine's rated speed is given by sgn(), which is a sign function. Based on the type of currently attached work implement, retrieve its nominal resistance torque from the preset database. As a fixed compensation amount ; The budgeted torque values ​​for the initial power-on condition, the direction-of-travel change condition, the gear shift condition, and the semi-clutch condition, obtained based on the load torque budget strategy, are respectively denoted as the first budgeted torque value, the second budgeted torque value, the third budgeted torque value, and the fourth budgeted torque value. Calculation of initial power-on conditions ; Calculate the working conditions of changing the direction of travel. ; Calculate the shifting conditions ; Calculation of the half-clutch working condition .

8. A combined pressure correction system based on load torque budget, characterized in that, include: The operating condition judgment module is used to determine the current operating condition type based on the controller's power-on status, driving direction change information, and clutch trigger signal; Operating conditions include initial power-on, change of direction, gear shifting, and semi-clutch operation. The budgeted torque value generation module is used to retrieve and execute an adapted load torque budgeting strategy to generate a budgeted torque value based on the current operating condition type. Specifically, the load torque budgeting strategy adapted to the initial power-on condition calculates the torque value based on the torque information from the previous driving cycle; the load torque budgeting strategy adapted to the change of travel direction condition calculates the torque value based on the torque information before the change of travel direction and the target direction speed ratio; the load torque budgeting strategy adapted to the gear shift condition calculates the torque value based on the torque information before clutch engagement; and the load torque budgeting strategy adapted to the semi-clutch condition calculates the torque value based on the torque information before clutch engagement and the target gear ratio. The pressure correction control module is used to obtain the required clutch control pressure value based on the budgeted torque value and the wet clutch friction torque model, and replace the base pressure value output by the clutch engagement characteristic curve with the clutch control pressure value to correct and control the engagement pressure.

9. A vehicle-mounted terminal, characterized in that, include: Memory for storing combined pressure correction programs based on load torque budget; A processor, configured to implement the steps of the load torque budget-based joint pressure correction method as described in any one of claims 1 to 7 when executing the load torque budget-based joint pressure correction procedure.

10. A vehicle, characterized in that, It is equipped with the vehicle-mounted terminal as described in claim 9.

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