A method and system for adaptive shifting of AMT gears in commercial vehicles

Abstract

This invention relates to the field of vehicle transmission control, and discloses an adaptive shift control method and system for commercial vehicles using an automated manual transmission (AMT). The method includes acquiring basic physical parameters and analyzing the estimated vehicle mass and gradient; activating a basic upshift command; determining the calculated torque and calculating the initial power margin; combining this with the maximum specific parasitic power of the air compressor to generate an equivalent power sum; if the sum is not less than the shift maintenance threshold, invoking the decoupling threshold formula to execute accessory decoupling arbitration; calculating the predicted vehicle speed and final power margin; if the arbitration passes and the final power margin is not less than the maintenance threshold, issuing a disengagement command and an upshift permission command; otherwise, intercepting the command. When the state machine emergency mechanism is triggered, a safe gear is engaged based on the comparison between the actual disengagement time and the emergency trigger time. This invention effectively improves the success rate of shifting and overall vehicle safety under heavy load and climbing conditions by predicting and decoupling air circuit accessories before shifting to compensate for driving force, combined with active speed adjustment matching under abnormal operating conditions.

Description

Technical Field

[0001] This invention relates to the field of vehicle transmission control, specifically to an adaptive control method and system for AMT (Automated Manual Transmission) gear shifting in commercial vehicles. Background Technology

[0002] Commercial vehicle automated mechanical transmissions (AMTs) typically rely on a control unit to automatically perform gear shifts based on parameters such as vehicle speed, engine speed, and throttle opening. During gear shifts, clutch disengagement causes a brief interruption in power transmission from the power source to the drive wheels. Commercial vehicles generally have large vehicle weights and complex operating conditions, thus requiring a high degree of power continuity during gear shifts.

[0003] Existing AMT shift control strategies typically execute clutch disengagement and gear shifting directly after triggering an upshift command, lacking prior assessment of power reserves during shifts. Under heavy loads or when climbing hills, vehicle speed drops rapidly during power interruptions. Simultaneously, the air compressor in the vehicle's pneumatic system, acting as a mechanical accessory, continuously consumes engine power. Current control methods fail to comprehensively consider and dynamically manage the parasitic load on the air compressor during shift decisions, resulting in insufficient actual power delivered to the wheels after a shift to maintain the target gear, easily leading to gear drops or poor power delivery.

[0004] Furthermore, the shifting decisions of the AMT system rely on real-time calculations of the vehicle's mass and road gradient. Current mass and gradient calculations primarily involve directly extracting data from underlying sensors and performing algebraic operations. When the vehicle travels on bumpy roads, vertical impacts to the vehicle body cause transient fluctuations in the relevant sensor signals. Due to the lack of anti-disturbance mechanisms for road impacts, the basic physical parameters received by the control unit are prone to distortion, leading to deviations in the mass and gradient calculated by the system, thus affecting the accuracy of shifting decisions under adverse road conditions.

[0005] Furthermore, during gear shifting, if sudden abnormal conditions occur such as insufficient air pressure in the air system or intervention of the electronic braking system, existing systems often employ a single interruption recovery logic. Because they fail to combine the timing of the abnormal trigger with the actual physical disengagement state of the clutch, if gear shifting is forcibly stopped when the transmission is already disconnected without an active speed matching mechanism, the vehicle is prone to transmission shock due to prolonged power loss or excessive speed difference, increasing the risk of loss of vehicle control. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a method and system for adaptive shift control of AMT gears in commercial vehicles, which solves the limitations of existing AMT gear shift control technologies in critical power prediction and accessory load management, low-level parameter acquisition and disturbance rejection, and emergency intervention in abnormal shift states.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The first aspect of this invention provides an adaptive shift control method for an automated manual transmission (AMT) in a commercial vehicle, comprising the following steps:

[0009] Obtain the vehicle's basic physical parameters and parse out the estimated vehicle mass and slope values;

[0010] The basic upshift command is initiated, the calculated torque is determined based on the basic physical parameters, and the initial power margin is calculated using the initial prediction formula in combination with the estimated mass of the whole vehicle and the estimated slope value.

[0011] Based on the initial power margin and the obtained maximum specific parasitic power of the air compressor, an equivalent power sum is generated. When the equivalent power sum is not less than the preset shift maintenance threshold, the decoupling threshold formula is called according to the basic physical parameters to execute the attached decoupling arbitration. After generating the arbitration pass status word, the hysteresis speed formula is called to calculate the predicted speed according to the basic physical parameters. The final power margin is calculated in combination with the final margin formula.

[0012] When the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold, the air compressor disengagement command is sent to the air circuit control unit, and the upshift permission command is sent to the automatic transmission control unit after the air compressor feedback signal is in actual disengagement state; otherwise, the basic upshift command is intercepted to maintain the original gear.

[0013] When the emergency mechanism of the state machine is triggered based on the basic physical parameters, the emergency trigger time is recorded and a gas supply command is sent to the air circuit control unit. If the emergency trigger time is greater than the actual separation time confirmed by the basic physical parameters, an active speed adjustment matching command is sent to control the automatic transmission control unit to engage the safe gear obtained based on the predicted vehicle speed.

[0014] Furthermore, the steps for obtaining the vehicle's basic physical parameters and resolving the estimated vehicle mass and slope values ​​include:

[0015] The basic physical parameters obtained by the measurement nodes include wheel speed sensor signals, longitudinal acceleration signals, output torque signals, engine speed signals, airbag pressure signals, air tank pressure signals, air compressor feedback signals, transmission status signals, and braking request signals from the electronic braking system, and include at least one of the following: air suspension height signals and vertical acceleration signals.

[0016] The wheel speed sensor signal is converted into the current vehicle speed, and the derivative of the current vehicle speed is obtained by performing a derivative operation. Based on the airbag pressure signal, the estimated mass of the whole vehicle is calculated through the chassis static balance relationship and the preset center of gravity distribution model. Based on the vehicle longitudinal dynamics equation, combined with the vehicle speed derivative, the longitudinal acceleration converted from the longitudinal acceleration signal, the estimated mass of the whole vehicle, and the output torque signal, the estimated slope value is calculated. When the basic physical parameters only include the air suspension height signal, the air suspension height signal is subjected to first-order time-domain difference to obtain the height change rate. Based on the height change rate, the vertical acceleration of the vehicle body is obtained as an impact index through second-order difference operation.

[0017] When both air suspension height and vertical acceleration signals are included, or only vertical acceleration signals are included, the vehicle's vertical acceleration is directly obtained as an impact indicator through a differential operation based on the vertical acceleration signal. When the absolute value of the impact indicator is greater than the preset impact judgment threshold, the vehicle is determined to be in a vehicle impact disturbance state, and the zero-order hold is used to maintain the slope estimate and the estimated mass of the whole vehicle from the previous effective sampling period.

[0018] Furthermore, the steps of engaging the basic upshift command, determining the calculated torque based on basic physical parameters, and calculating the initial power margin using the initial prediction formula in conjunction with the estimated vehicle mass and gradient value include:

[0019] With the basic upshift command engaged and the current gear transmission connection maintained, the current vehicle speed, converted from the wheel speed sensor signal based on the basic physical parameters, is converted into the expected RPM through kinematic back-calculation. The expected RPM is then used as an index to call the engine external characteristic curve to obtain the target maximum torque. When the air compressor feedback signal is in an unloaded state, the target maximum torque is determined as the calculated torque. When the air compressor feedback signal is in a loaded state, the mechanical resistance torque of the air compressor at the engine speed obtained based on the engine speed signal is obtained as the accessory resistance. The target maximum torque is then subtracted from the accessory resistance to determine the calculated torque.

[0020] The initial prediction formula is called, and the calculated torque, the preset target gear ratio, the preset final reduction ratio, and the preset mechanical efficiency are multiplied together. The result of the multiplication is divided by the preset wheel radius to obtain the actual driving force at the wheel end. The combined driving resistance calculated based on the current vehicle speed and the slope estimate converted from the wheel speed sensor signal is subtracted from the actual driving force at the wheel end. The difference is divided by the estimated mass of the whole vehicle and multiplied by the current vehicle speed to calculate the initial power margin.

[0021] Furthermore, based on the initial power margin and the obtained maximum specific parasitic power of the air compressor, an equivalent power sum is generated. When the equivalent power sum is not less than the preset shift maintenance threshold, the steps of executing the attached decoupling arbitration by calling the decoupling threshold formula based on the basic physical parameters include:

[0022] When the air compressor feedback signal is in the loading state, the maximum specific parasitic power of the air compressor is obtained based on the preset upper bound mapping table of air compressor parasitic power; the initial power margin and the maximum specific parasitic power of the air compressor are summed to generate the equivalent power sum value; when the equivalent power sum value is not less than the shift maintenance threshold, the slope estimation value, the braking request signal in the basic physical parameters and the estimated vehicle mass are respectively input into the preset one-dimensional mapping table of slope and air pressure correction, the braking state response table and the one-dimensional compensation table of mass and air pressure load, and the dynamic working condition correction amount including slope correction amount, braking correction amount and mass correction amount is obtained by table lookup operation;

[0023] The decoupling threshold formula is invoked to add the preset basic permissible pressure, slope correction, braking correction, and mass correction. The sum is then compared with the preset lower limit of air pressure, and the maximum value is taken as the permissible pressure threshold. The air tank pressure corresponding to the air tank pressure signal in the basic physical parameters is compared with the permissible pressure threshold to perform the attached decoupling arbitration.

[0024] Furthermore, after generating the arbitration pass status word, the steps of calling the hysteresis speed formula to calculate the predicted vehicle speed based on the basic physical parameters, and combining it with the final margin formula to calculate the final power margin include:

[0025] When the air tank pressure obtained from the air tank pressure signal in the basic physical parameters is greater than the permissible pressure threshold, and the braking request signal is "no braking request," while the air compressor feedback signal is in a loaded state, an arbitration pass status word is generated; the hysteresis speed formula is called, the product of the longitudinal acceleration obtained from the longitudinal acceleration signal and the preset response hysteresis time is added to the current vehicle speed converted from the wheel speed sensor signal, and the sum is compared with zero to obtain the predicted vehicle speed; the dynamic expected speed is obtained by kinematic back-calculation based on the predicted vehicle speed, and the dynamic maximum torque is obtained by calling the engine external characteristic curve using the dynamic expected speed as an index;

[0026] Using a multidimensional lookup table function, the engine speed, air tank pressure, and air compressor feedback signal obtained from the engine speed signal are converted into the dynamic net power increment that can be released after decoupling the air compressor. The final margin formula is called, and the predicted actual driving force at the wheel end is obtained by replacing the original calculated torque with the dynamic maximum torque. The driving resistance calculated based on the predicted vehicle speed and slope estimate is subtracted from the predicted actual driving force at the wheel end. The difference is divided by the estimated mass of the whole vehicle and multiplied by the predicted vehicle speed. Then, the dynamic net power increment is added to calculate the final power margin.

[0027] Furthermore, when the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold, an air compressor disengagement command is issued to the air circuit control unit, and an upshift permission command is issued to the automatic transmission control unit after the air compressor feedback signal indicates actual disengagement. Otherwise, the steps to intercept the basic upshift command and maintain the original gear include:

[0028] Upon receiving the arbitration pass status word and when the final power margin is not less than the shift maintenance threshold, the system issues an air compressor disengagement command to the air circuit control unit and continuously monitors the air compressor feedback signal. When the air compressor feedback signal is detected to have changed to an actual disengagement state, or when the waiting time calculated from the issuance of the air compressor disengagement command exceeds the preset response lag time, the system synchronously issues an upshift permission command to the automatic transmission control unit. If the arbitration pass status word is not received, or the final power margin is less than the shift maintenance threshold, the system intercepts the basic upshift command to maintain the original gear.

[0029] Furthermore, when the emergency mechanism of the state machine is triggered based on the basic physical parameters, the steps of recording the emergency trigger time and issuing a gas supply command to the gas circuit control unit include:

[0030] When the braking request signal in the basic physical parameters indicates a braking request, or when the air tank pressure obtained from the air tank pressure signal is less than the preset dynamic recovery threshold, the state machine emergency mechanism is triggered. After the state machine emergency mechanism is triggered, the current system time is recorded as the emergency trigger time, and an air supply command is sent to the air circuit control unit. The actual disengagement time corresponding to the clutch disengagement state is confirmed based on the transmission status signal in the basic physical parameters.

[0031] Furthermore, the method also includes a control step when the emergency trigger time is not greater than the actual separation time confirmed by the basic physical parameters:

[0032] When the emergency trigger time is less than or equal to the actual separation time, it is confirmed that the clutch disengagement state has not been physically disconnected; the air compressor disengagement command is cancelled to maintain the original gear operation and maintain the transmission connection between the power source and the drive wheel.

[0033] Furthermore, when the emergency trigger time is greater than the actual separation time confirmed by the basic physical parameters, the steps of issuing an active speed matching command to control the automatic transmission control unit to engage the safe gear calculated based on the predicted vehicle speed include:

[0034] When the emergency trigger time is longer than the actual separation time, the predicted vehicle speed is combined with the preset final drive ratio and the inherent speed ratio of each available candidate gear. The theoretical synchronous speed of each available candidate gear is calculated by kinematic back-calculation and used as the speed matching value. By comparing the speed matching value of each available candidate gear with the speed boundary allowed by the storage control unit, after eliminating gears with overspeed and low-speed abnormal conditions, the physical gear that minimizes the absolute speed difference between the speed matching value and the engine speed obtained from the engine speed signal in the basic physical parameters is selected as the safe gear. An active speed adjustment matching command is sent to the automatic transmission control unit to control it to engage the safe gear, and the storage control unit is scheduled to adjust the engine speed.

[0035] A second aspect of the present invention provides an adaptive shift control system for an AMT (Automated Manual Transmission) in a commercial vehicle, comprising:

[0036] The state perception module is used to acquire the basic physical parameters of the vehicle and parse out the estimated mass and slope of the whole vehicle.

[0037] The power forecast module is used to initiate basic upshift commands, determine the calculated torque based on basic physical parameters, and calculate the initial power margin using the initial prediction formula in combination with the estimated mass of the whole vehicle and the estimated slope value.

[0038] The decoupling arbitration module is used to generate an equivalent power sum value based on the initial power margin and the obtained maximum specific parasitic power of the air compressor. When the equivalent power sum value is not less than the preset shift maintenance threshold, the module calls the decoupling threshold formula to execute the attached decoupling arbitration based on the basic physical parameters. After generating the arbitration pass status word, the module calls the hysteresis speed formula to calculate the predicted speed based on the basic physical parameters and calculates the final power margin in combination with the final margin formula.

[0039] The timing execution module is used to send an air compressor disengagement command to the air circuit control unit when the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold. After the air compressor feedback signal is in the actual disengagement state, it sends an upshift permission command to the automatic transmission control unit. Otherwise, it intercepts the basic upshift command to maintain the original gear.

[0040] The active safety module is used to record the emergency trigger time and send an air supply command to the air circuit control unit when the state machine emergency mechanism is triggered based on the basic physical parameters. When the emergency trigger time is greater than the actual separation time confirmed by the basic physical parameters, it sends an active speed adjustment and matching command to control the automatic transmission control unit to engage the safe gear obtained based on the predicted vehicle speed.

[0041] This invention provides a method and system for adaptive shift control of automated manual transmissions (AMT) in commercial vehicles. It offers the following advantages:

[0042] 1. Upon receiving an upshift command, this invention engages the gear. By calculating the power margin and performing accessory decoupling arbitration, it confirms the power reserve status before the actual shift action occurs. When it is determined that the conventional power is insufficient, it actively issues an air compressor disengagement command to cut off the load on the air circuit accessories and compensates the parasitic power released by the air compressor to the drive wheel end. This control logic solves the problem of gear drop and shift interruption caused by insufficient power in commercial vehicles under heavy load or climbing conditions, and improves the success rate of engaging the target gear.

[0043] 2. This invention generates vehicle body impact indicators using air suspension height and vertical acceleration signals. When a road impact is detected, a zero-order hold latches the estimated vehicle mass and slope values ​​from the previous cycle. Simultaneously, a multi-dimensional lookup table is used to output dynamic operating condition corrections to adjust the permissible pressure threshold. This process suppresses the interference of transient fluctuation signals caused by road bumps on basic parameters, improving the calculation accuracy of shift control parameters and the system's anti-disturbance capability under adverse road conditions.

[0044] 3. When braking intervention or low air pressure in the air reservoir triggers the emergency mechanism, this invention determines the mechanical state of the clutch by comparing the actual disengagement time with the emergency trigger time. For cases where the clutch has not yet physically disengaged, the disengagement command is promptly revoked to maintain the original gear operation. For cases where the clutch has already disengaged, the theoretical synchronous speed is calculated using kinematic back-calculation, and the storage control unit is scheduled to actively adjust the speed to engage the safe gear with the smallest absolute speed difference. This mechanism prevents the risk of loss of control caused by transmission disconnection or speed mismatch in abnormal gear shifting conditions. Attached Figure Description

[0045] Figure 1 This is a diagram of an AMT (Automated Manual Transmission) shift adaptive control system architecture for commercial vehicles according to the present invention.

[0046] Figure 2 This is a flowchart of an adaptive shift control method for an AMT (Automated Manual Transmission) in a commercial vehicle according to the present invention.

[0047] Figure 3 This is a flowchart of the multi-source state sensing and dynamic parameter analysis of the present invention;

[0048] Figure 4 This is a flowchart illustrating the basic upshift command suspension and initial power margin look-ahead process of the present invention.

[0049] Figure 5 This is a flowchart of the safety arbitration and feedforward compensation recalculation process for braking priority according to the present invention.

[0050] Figure 6 This is a flowchart illustrating the cross-domain joint instruction issuance and physical timing execution of the present invention;

[0051] Figure 7This is a graph comparing the vehicle speed over time in a representative upshift event of an application embodiment of the present invention, using the conventional method and the method of the present invention.

[0052] Figure 8 A bar chart comparing the upshifting results of the conventional method and the method of the present invention in the test cycle of an application embodiment of the present invention;

[0053] Figure 9 This is a graph showing the comparison of the gas storage tank pressure and the permissible pressure threshold over time in a continuous undulating road section, as an application embodiment of the present invention. Detailed Implementation

[0054] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0055] Please see the appendix Figure 1 This invention provides an AMT (Automated Manual Transmission) shift adaptive control system for commercial vehicles; measurement nodes are distributed in the chassis and power domain of the commercial vehicle, and the measurement nodes are communicatively connected to the state analysis module to collect the vehicle's operating status;

[0056] The system controls the AMT (Automated Manual Transmission) to perform gear shifting actions through the automatic transmission control unit, controls the air compressor with a controllable clutch to switch between loaded and disengaged states through the air circuit control unit, and receives braking request signals from the electronic braking system. All control modules work together to form a closed-loop adaptive control architecture. The system includes:

[0057] The state analysis module receives fundamental physical parameters reflecting the vehicle's operating state from measurement nodes during vehicle operation. It performs filtering and parameter calculation, and uses the chassis static equilibrium relationship and the vehicle's longitudinal dynamic equations to deduce the estimated vehicle mass and slope, as well as the vehicle's vertical acceleration. When the vehicle is determined to be under impact disturbance, the state analysis module uses a zero-order hold to maintain the slope and estimated vehicle mass from the previous valid sampling period, thus suppressing the impact of transient road impacts on the mass and slope estimation results. Simultaneously, based on the current vehicle speed and the maintained slope and estimated vehicle mass, the state analysis module continues to calculate the overall driving resistance.

[0058] The power forward module is used to suspend the basic upshift command when the automatic transmission control unit outputs it, temporarily preventing the clutch disengagement action from being sent to the actuator. The power forward module obtains the target maximum torque through kinematic backpropagation, determines the current calculated torque based on the air compressor feedback signal, and calls the initial prediction formula to convert the calculated torque, estimated vehicle mass, and estimated gradient value into an initial power margin.

[0059] The safety arbitration module is used to obtain the initial power margin. When the initial power margin is less than the preset shift maintenance threshold and the air compressor feedback signal is in the loading state, the maximum specific parasitic power of the air compressor is obtained based on the preset upper bound mapping table of air compressor parasitic power. The initial power margin and the maximum specific parasitic power of the air compressor are summed to obtain the equivalent power sum value, and the equivalent power sum value is compared with the shift maintenance threshold.

[0060] When the vehicle is determined to be in the decoupling candidate range, the safety arbitration module calls the decoupling threshold formula to obtain the permissible pressure threshold, and then performs the attached decoupling arbitration. Under the conditions of meeting air pressure safety and no braking request, the safety arbitration module generates an arbitration passed status word, then calls the hysteresis speed formula to obtain the predicted vehicle speed, and calls the final margin formula to calculate the final power margin after feedforward compensation.

[0061] The timing execution module receives various status words and executes cross-domain joint control. It outputs control logic based on status words that do not require decoupling, status words that pass arbitration, or status words that are decoupling invalid. When power maintenance conditions are met, the timing execution module sends an air compressor disengagement command to the air circuit control unit. Upon detecting that the air compressor feedback signal has converted to an actual disengagement state or that the waiting time exceeds the response hysteresis time, it sends an upshift permission command to the automatic transmission control unit. In abnormal conditions such as brake intervention or insufficient air reservoir pressure, the timing execution module triggers the state machine emergency mechanism and sends an air supply command to the air circuit control unit. Based on the comparison between the actual disengagement time corresponding to the clutch disengagement state and the emergency trigger time, the timing execution module intercepts the basic upshift command to maintain the original gear, or calculates the speed matching value based on kinematics and sends an active speed matching command to control the automatic transmission control unit to engage a safe gear.

[0062] See appendix Figure 2 , Figure 2 This is a flowchart of a method according to an embodiment of the present invention. The present invention also provides an adaptive shift control method for an AMT (Automated Manual Transmission) in a commercial vehicle, comprising the following steps:

[0063] S1, Multi-source State Perception and Dynamic Parameter Analysis. The state analysis module uses measurement nodes to acquire basic physical parameters reflecting the vehicle's operating state, and analyzes the estimated vehicle mass and slope values ​​through the chassis static equilibrium relationship and the vehicle's longitudinal dynamic equations. Simultaneously, the state analysis module uses a zero-order hold to maintain the slope and estimated vehicle mass values ​​from the previous effective sampling period under vehicle impact disturbance conditions.

[0064] S2, Basic Upshift Command Suspension and Initial Power Margin Detection. When the automatic transmission control unit outputs a basic upshift command, the power prediction module suspends the basic upshift command, temporarily refraining from issuing a clutch disengagement action to the actuator. Subsequently, the power prediction module obtains the target maximum torque through kinematic back-calculation and calls the initial prediction formula to convert the determined calculated torque into an initial power margin.

[0065] S3, Braking Priority Safety Arbitration and Feedforward Compensation Recalculation. The safety arbitration module sums the initial power margin with the air compressor's maximum specific parasitic power to obtain an equivalent power sum, and compares this equivalent power sum with the shift holding threshold. When the vehicle is determined to be in the decoupling candidate interval, the safety arbitration module calls the decoupling threshold formula to obtain the permissible pressure threshold to perform the attached decoupling arbitration. After generating the arbitration pass status word, it calls the hysteresis speed formula to obtain the predicted vehicle speed, and then calls the final margin formula to calculate the final power margin.

[0066] S4, Cross-Domain Joint Command Issuance and Physical Timing Execution. The timing execution module outputs control logic based on the received status words (no decoupling required, arbitration passed, or decoupling invalid). It first issues an air compressor disengagement command to the air circuit control unit and, after confirming disengagement, issues an upshift permission command, or intercepts the basic upshift command. In the event of triggering the state machine emergency mechanism, the timing execution module issues an air supply command and, based on the comparison between the emergency trigger time and the actual separation time, maintains the original gear operation, or issues an active speed matching command to control the automatic transmission control unit to engage a safe gear.

[0067] See appendix Figure 3 In this embodiment, step S1, multi-source state perception and dynamic parameter analysis, obtains basic physical parameters through the state analysis module using measurement nodes, and analyzes the estimated vehicle mass and slope value through the chassis static balance relationship and vehicle longitudinal dynamic equation. The zero-order holder maintains the slope estimate and estimated vehicle mass of the previous effective sampling period under the vehicle body impact disturbance state.

[0068] S101, the state analysis module collects the vehicle's operating status through measurement nodes distributed in the chassis and power domain, and obtains the basic physical parameters that reflect the vehicle's operating status.

[0069] Specifically, the status resolution module receives message data from each underlying sensor node in real time via the vehicle local area network bus. The acquired basic physical parameters include wheel speed sensor signals, longitudinal acceleration signals, output torque signals, engine speed signals, airbag pressure signals, air tank pressure signals, air compressor feedback signals, transmission status signals, and braking request signals from the electronic braking system, and include at least one of the following: air suspension height signals and vertical acceleration signals.

[0070] Specifically, wheel speed sensor signals are acquired by independent wheel speed sensors on the coaxial wheel ends; longitudinal and vertical acceleration signals are acquired by multi-axis accelerometers of the chassis inertial measurement unit; air suspension height signals are acquired by height linkage sensors, and airbag pressure signals are acquired by pressure sensors connected to the air suspension airbags; output torque and engine speed signals are extracted from messages stored in the control unit; air compressor feedback signals are fed back by the air circuit control unit or the air compressor clutch actuator; air tank pressure signals are acquired by the pressure transmitter of the autonomous braking air circuit; transmission status signals are fed back by the automatic transmission control unit; and braking request signals are generated and sent by the electronic control unit of the electronic braking system based on brake pedal requests or active braking control requests.

[0071] S102, the state analysis module performs analysis operations based on the basic physical parameters, converting the wheel speed sensor signal in the basic physical parameters into the current vehicle speed.

[0072] In the specific calculation, the arithmetic mean of the wheel speed sensor signals on the left and right sides of the non-drive shaft is first calculated to obtain the average wheel end speed. Then, by multiplying the average wheel end speed by the preset wheel radius, it is converted into the current vehicle speed in the form of absolute linear translation speed.

[0073] Similarly, the state parsing module converts the longitudinal acceleration signal, engine speed signal, and air tank pressure signal from the basic physical parameters into longitudinal acceleration, engine speed, and air tank pressure with physical dimensions, respectively, based on the linear calibration coefficients of the underlying communication matrix. For this type of basic linear numerical mapping of physical signals, those skilled in the art can implement it according to the underlying chip manual or communication protocol; the conversion principle is well-known in the field and will not be elaborated further here.

[0074] The state analysis module calculates the derivative of the current vehicle speed and extracts the airbag pressure signal from the basic physical parameters. Based on the preset airbag bearing area and the chassis static equilibrium relationship, it converts the airbag pressure signal into the normal bearing force of the corresponding axle. The preset airbag bearing area is set according to the effective cross-sectional compression parameters of the air suspension airbag at the standard design axle load height, for example, 0.03m. 2 up to 0.05m 2The chassis static balance relationship is established by summing the vertical support forces corresponding to the airbag pressure of each axle and dividing by the gravitational acceleration.

[0075] Subsequently, based on a pre-defined center of gravity distribution model, the normal load-bearing capacity is used to calculate the estimated vehicle mass. This model is an algebraic proportional calculation based on the vehicle's physical geometry. The specific calculation process involves dividing the obtained normal load-bearing capacity of each axle by the corresponding static axle load distribution ratio to obtain the estimated vehicle mass. This static axle load distribution ratio is set according to the physical center of gravity position of the commercial vehicle under unloaded and fully loaded conditions; for example, the front axle load ratio ranges from 0.20 to 0.35, and the rear axle load ratio ranges from 0.65 to 0.80.

[0076] Simultaneously, based on the vehicle's longitudinal dynamics equations, and combining the vehicle speed derivative, longitudinal acceleration, estimated vehicle mass, and output torque signal from fundamental physical parameters, the estimated slope value is calculated. The vehicle's longitudinal dynamics equations are constructed by simultaneously solving for the driving force and various driving resistances.

[0077] The specific calculation process is as follows: multiply the physical torque value corresponding to the output torque signal, the current total speed ratio of the transmission system, and the preset mechanical efficiency, and then divide by the preset wheel radius to calculate the actual driving force at the wheel end.

[0078] The slope resistance is obtained by subtracting rolling resistance, air resistance, and acceleration resistance from the actual driving force at the wheel end in sequence; the acceleration resistance is obtained by multiplying the estimated mass of the whole vehicle by the derivative of the vehicle speed.

[0079] Divide the slope resistance by the product of the estimated mass of the vehicle and the acceleration due to gravity to obtain the sine of the estimated slope.

[0080] The state analysis module combines longitudinal acceleration for observation compensation and calculates the current road slope estimate using inverse trigonometric function relationships.

[0081] S103, the state analysis module performs filtering operations on the basic physical parameters of the input storage control unit, first determining the signal type of the basic physical parameters.

[0082] When both air suspension height and vertical acceleration signals are included, the vehicle's vertical acceleration is obtained first through a differential operation based on the vertical acceleration signal with higher fidelity.

[0083] When only the vertical acceleration signal is available, the vehicle's vertical jerk is obtained directly from the vertical acceleration signal through a single differential operation. When only the air suspension height signal is available, the vehicle's vertical jerk is obtained from the height change rate corresponding to the air suspension height signal through a second differential operation. Before performing the second differential operation, a first-order time-domain differential operation must be performed on the air suspension height signal to obtain the height change rate. The above numerical differential operations are all implemented by subtracting data from adjacent fixed sampling periods and dividing by the single-step time step.

[0084] The vertical acceleration of the vehicle body is used as the impact indicator. When the absolute value of the impact indicator exceeds a preset impact threshold, the vehicle is determined to be in a state of body impact disturbance. The preset impact threshold is set based on the boundary of the maximum rate of change of body impact acceleration caused by commercial vehicles driving on typical pothole roads, for example, 1.5 m / s². 3 Up to 3.0 m / s 3 When the absolute value of the impact index is less than or equal to the impact judgment threshold, the calculated slope estimate and the estimated vehicle mass are used as the update values ​​for the current effective sampling period.

[0085] When the vehicle is determined to be under body impact disturbance, in order to avoid suspension parameter distortion caused by high-frequency road impact, the state analysis module uses a zero-order hold to maintain the slope estimate and vehicle mass estimate of the previous effective sampling period, and suspends the introduction of unsteady parameters calculated in the current effective sampling period, so as to reduce the interference of transient impact on the evaluation of gravity drag components.

[0086] If the control system is in the initial valid sampling period and there is no historical sampling data, the preset default estimate value is assigned to the slope estimate value and vehicle estimate value of the previous valid sampling period. The preset default estimate value is set according to the nominal unloaded weight and zero-slope horizontal road surface parameters calibrated by the commercial vehicle at the factory. For example, the default vehicle estimate value is 12,000 kg and the default slope estimate value is 0 rad.

[0087] While maintaining the stability of the above parameters, the state analysis module continues to calculate the current vehicle speed and overall driving resistance normally, ensuring the continuity of the feedforward parameter update flow.

[0088] See appendix Figure 4 In this embodiment, the S2 step of suspending the basic upshift command and the initial power margin look-ahead module puts the basic upshift command in a suspended state, obtains the target maximum torque through kinematic back-calculation, and calls the initial prediction formula to convert the calculated torque into the initial power margin.

[0089] S201, when the automatic transmission control unit outputs a basic upshift command, the power forward module puts the basic upshift command in a suspended state and temporarily suspends the clutch disengagement action sent to the actuator.

[0090] When commercial vehicles perform upshifts under complex conditions such as heavy loads or climbing hills, if the power is directly disconnected, the vehicle speed is likely to decrease significantly due to accessory loads and road resistance. To address this, the power forwarding module delays the execution timing of physical gear shifts by suspending the control logic, providing the necessary calculation time window for the vehicle's energy assessment and accessory decoupling determination.

[0091] While maintaining the current gear transmission connection, the power forward module converts the current vehicle speed into the expected speed through kinematic inverse calculation based on the preset target gear ratio; the target gear ratio is set according to the inherent gear ratio of the next higher gear in the automatic transmission, for example, the range can be 0.75 to 1.45.

[0092] The specific calculation process of kinematic back-reasoning is as follows: divide the current vehicle speed by the preset wheel radius to obtain the real-time rotational angular velocity of the drive wheel end, and then multiply the real-time rotational angular velocity of the drive wheel end by the preset final reduction ratio and the target gear ratio in sequence to calculate the synchronous speed that the engine needs to reach after upshifting. This synchronous speed is the expected speed. The final reduction ratio is set according to the gear ratio of the final reducer of the vehicle drive axle, for example, the range can be 2.8 to 4.5.

[0093] The power forecasting module uses the expected engine speed as an index to retrieve the engine's external characteristic curve and obtains the target maximum torque through a lookup operation. For the lookup operation involving data mapping from the external characteristic curve, those skilled in the art can perform a two-dimensional search based on the engine external characteristic torque table pre-stored within the controller and obtained from bench calibration tests. The specific lookup operation is as follows:

[0094] Using the expected engine speed as the sole input index, the engine external characteristic torque table is retrieved from the automatic transmission control unit or the storage control unit. This engine external characteristic torque table is a single-variable mapping table with engine speed as the horizontal axis and the maximum theoretical output shaft torque of the engine corresponding to the engine speed as the output value. The target maximum torque is obtained by looking up the table through linear interpolation.

[0095] The target maximum torque reflects the maximum output torque that the engine hardware itself can provide at the expected speed after the vehicle is engaged in the target gear.

[0096] S202, the power forward-looking module judges the air compressor feedback signal in the basic physical parameters.

[0097] To ensure the reliability of the control algorithm in the event of sensor malfunction or signal loss, if the system detects that the air compressor feedback signal is lost in the communication bus or the data frame is invalid, it will default to a loaded state to ensure the conservatism of the power assessment and driving safety.

[0098] When the air compressor feedback signal is in an unloaded state, the power forward module generates a state word that does not require decoupling and determines the target maximum torque as the calculated torque. The unloaded state corresponds to the working condition where the air compressor clutch is physically disengaged or the unloading valve is fully open. At this time, the air compressor itself does not consume additional output shaft power from the engine.

[0099] When the air compressor feedback signal is in the loading state, the power forward module determines the target maximum torque after deducting the accessory resistance as the calculated torque. The loading state means that the air compressor is in the pumping condition of building up air pressure, and the engine needs to consume some torque to overcome the operating resistance of the air compressor.

[0100] The detailed calculation process for deducting accessory resistance is as follows: the mechanical resistance torque of the air compressor measured by bench calibration at the current engine speed is defined as accessory resistance. The accessory resistance is subtracted from the target maximum torque obtained from the aforementioned table, and the difference is used as the benchmark for subsequent dynamic evaluation and determined as the calculated torque.

[0101] Subsequently, the powertrain forecasting module calls the initial prediction formula to convert the calculated torque, estimated vehicle mass, and estimated gradient into an initial power margin. The initial prediction formula reflects the transient net residual power per unit mass that can be maintained at the moment the target gear is engaged, assuming the vehicle has completed an upshift and no accessory decoupling intervention has been implemented. The initial prediction formula is:

[0102] ;

[0103] In the formula: This is the initial power margin, and its dimension is power per unit mass. Estimate the weight of the entire vehicle; To calculate torque; The target gear ratio; Main reduction ratio; This is the preset mechanical efficiency, which is set based on the efficiency of the transmission system bench test, for example, the range can be 0.85 to 0.95; The radius of the wheel; The summation symbol; The overall driving resistance is calculated based on the current vehicle speed and the estimated gradient. Current vehicle speed; This is an estimated slope value.

[0104] The overall driving resistance is constructed by summing rolling resistance, air resistance, and slope resistance. Rolling resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, road rolling resistance coefficient, and the cosine of the estimated slope. The road rolling resistance coefficient is set based on empirical values ​​for typical paved roads, for example, it can range from 0.006 to 0.010. Air resistance is calculated by multiplying the air resistance coefficient, frontal area, and the square of the current vehicle speed, and then multiplying by half the air density. Slope resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, and the sine of the estimated slope.

[0105] After completing the above numerical calculations, the power forward-looking module will output the initial power margin and the state word that does not require decoupling, as the basic data support for cross-domain energy collaborative decision-making.

[0106] See appendix Figure 5 In this embodiment, the safety arbitration and feedforward compensation recalculation of the braking priority step S3 uses the safety arbitration module to sum the initial power margin and the maximum specific parasitic power of the air compressor to obtain the equivalent power sum value, and compares the equivalent power sum value with the shift maintenance threshold. After generating the arbitration pass status word, the hysteresis speed formula is called to obtain the predicted vehicle speed, and the final margin formula is called to calculate the final power margin.

[0107] S301, when the safety arbitration module determines that the initial power margin is less than the preset shift maintenance threshold and the air compressor feedback signal in the basic physical parameters is in the loading state, it obtains the maximum specific parasitic power of the air compressor based on the preset upper bound mapping table of air compressor parasitic power, and sums the initial power margin with the maximum specific parasitic power of the air compressor to obtain the equivalent power sum value.

[0108] When the sum of equivalent power is less than the preset shift maintenance threshold, a decoupling invalid status word is directly generated; when the sum of equivalent power is greater than or equal to the shift maintenance threshold, the vehicle is determined to be in the decoupling candidate interval.

[0109] After entering the decoupling candidate region, the safety arbitration module obtains the dynamic operating condition correction amount through a lookup operation based on the slope estimate, the braking request signal in the basic physical parameters, and the estimated vehicle mass. The dynamic operating condition correction amount includes the slope correction amount, the braking correction amount, and the mass correction amount.

[0110] The specific acquisition process is as follows: input the estimated slope value into a pre-configured one-dimensional mapping table of slope and air pressure correction, and look up the corresponding slope correction amount; input the braking request signal in the basic physical parameters into a preset braking state response table. If a braking request is detected, the table outputs a very large positive penalty value as the braking correction amount; input the estimated vehicle mass into a preset one-dimensional compensation table of mass and air pressure load, and look up the corresponding mass correction amount.

[0111] After obtaining the above correction values, the safety arbitration module calls the decoupling threshold formula to convert the preset lower limit of air pressure, the preset basic permissible pressure, the slope correction value, the braking correction value, and the mass correction value into permissible pressure thresholds. The decoupling threshold formula is as follows:

[0112] ;

[0113] In the formula: For permitted pressure threshold; This is a function to find the maximum value. This is the lower limit of air pressure; Basic licensing pressure; The slope correction value is set to a positive value for downhill slopes and a negative value for uphill slopes. As a braking correction, the braking request signal in the basic physical parameters is given a maximum positive penalty value when there is a braking request, so as to numerically negate the decoupling. This is the quality correction amount.

[0114] Among them, the maximum specific parasitic power of the air compressor represents the quotient of the maximum power consumed by the air compressor when the vehicle's power system is running at full load, divided by the total mass of the vehicle, and can range from 0.8W / kg to 1.5W / kg; the shift holding threshold is set according to the minimum unit mass power required for a commercial vehicle to smoothly complete a shift under no power interruption conditions, and can range from 4.5W / kg to 7.0W / kg; the lower limit of air pressure is set according to the regulatory critical pressure required for the commercial air pressure braking system to meet the maximum braking efficiency in a single operation, and can range from 0.45MPa to 0.55MPa; the basic permissible pressure is set according to the safety pressure benchmark for maintaining the loop circulation of the braking system under normal cruising conditions in a plain with no load, and can range from 0.65MPa to 0.75MPa.

[0115] S302, the security arbitration module performs arbitration operations based on the permission pressure threshold.

[0116] When the pressure in the air tank exceeds the permissible pressure threshold, and the braking request signal in the basic physical parameters is "no braking request," while the air compressor feedback signal in the basic physical parameters is "loaded," the safety arbitration module generates an arbitration pass status word.

[0117] The arbitration operation uses both numerical calculation and Boolean logic for dual safety redundancy checks to ensure that the accessory decoupling action is only permitted when the current air pressure in the air tank can cover the consumption risk caused by the air compressor shutdown and there is no real intention to brake.

[0118] S303: Due to the non-negligible mechanical and pneumatic response delay between the issuance of control commands to the action of the pneumatic solenoid valve and the physical disengagement of the air compressor clutch, the vehicle speed will decrease due to driving resistance during this delay period.

[0119] To address this, the safety arbitration module, after generating the arbitration pass status word, calls the hysteresis speed formula to convert the current vehicle speed, longitudinal acceleration, and preset response hysteresis time into a predicted vehicle speed, thereby eliminating the error in energy assessment caused by hardware action delay. The hysteresis speed formula is as follows:

[0120] ;

[0121] In the formula: To predict vehicle speed; It is longitudinal acceleration; For response delay time.

[0122] The response hysteresis time is set based on the combined delay measurement value of system communication and valve body action, for example, the range can be from 0.3s to 0.8s.

[0123] Based on the predicted vehicle speed and the target gear ratio, the dynamic expected speed is obtained through kinematic inverse calculation, and the dynamic maximum torque is obtained by calling the engine external characteristic curve.

[0124] The specific calculation process of kinematic back-calculation is as follows: the predicted vehicle speed is divided by the preset wheel radius to obtain the predicted drive wheel end angular velocity. Then, the predicted drive wheel end angular velocity is multiplied by the preset final drive ratio and the target gear ratio to obtain the dynamic expected speed. Subsequently, using the dynamic expected speed as the input index, the dynamic maximum torque is obtained by querying the pre-stored engine external characteristic data table through one-dimensional linear interpolation.

[0125] Meanwhile, through multidimensional lookup table functions, the air compressor feedback signals in the engine speed, air tank pressure and basic physical parameters are converted into the dynamic net power increment that can be released after the air compressor is decoupled.

[0126] The specific table lookup operation is as follows: using the three-dimensional data table of air compressor parasitic power characteristics embedded in the controller, with the current engine speed as the first input dimension and the current air tank pressure as the second input dimension; when it is confirmed that the air compressor feedback signal is in a loading state, a two-dimensional interpolation retrieval is performed in the three-dimensional data table to calculate the actual mechanical power consumed by the air compressor in pumping work, and this value is determined as the dynamic net power increment.

[0127] The safety arbitration module calls the final margin formula to convert the predicted vehicle speed, dynamic net power increment, estimated vehicle mass, and gradient estimate into the final power margin. The final margin formula is:

[0128] ;

[0129] In the formula: This is the final power margin, and its dimension is power per unit mass. This represents the dynamic maximum torque. The overall driving resistance is calculated based on the predicted vehicle speed and the estimated gradient. To predict vehicle speed; This represents the dynamic net power increment.

[0130] The overall driving resistance is constructed by adding up rolling resistance, air resistance, and slope resistance.

[0131] Rolling resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, road rolling resistance coefficient, and the cosine of the estimated slope; air resistance is calculated by multiplying the air resistance coefficient, frontal area, and the square of the predicted vehicle speed, and then multiplying by half the air density; gradient resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, and the sine of the estimated slope. The vehicle speed variable in all resistance calculations is recalculated using the predicted vehicle speed, completing a feedforward recalculation of the dynamic energy.

[0132] See appendix Figure 6 In this embodiment, the S4 step cross-domain joint instruction issuance and physical timing execution are carried out by the timing execution module based on the no-decoupling status word, the arbitration passed status word, or the decoupling invalid status word. The module outputs the upshift permission instruction and the air compressor disengagement instruction, or triggers the state machine emergency mechanism to issue the air supply instruction and maintain the original gear or control the automatic transmission control unit to engage a safe gear.

[0133] S401, the timing execution module outputs control logic based on the received status word.

[0134] When a status word requiring no decoupling is received and the initial power margin is greater than or equal to the shift maintenance threshold, the timing execution module directly issues an upshift command to the automatic transmission control unit. This upshift command is transmitted via the vehicle communication bus to resume the previously suspended shift process.

[0135] When the arbitration pass status word is received and the final power margin is greater than or equal to the shift maintenance threshold, the timing execution module sends an air compressor disconnect command to the air circuit control unit and continuously monitors the air compressor feedback signal in the basic physical parameters.

[0136] Once the air compressor feedback signal is detected to be in an actual disengaged state, or the waiting time since the command was issued is greater than the response lag time, the timing execution module synchronously issues an upshift permission command to the automatic transmission control unit to avoid deadlock in the shifting process due to signal feedback failure.

[0137] When a decoupling invalid status word is received or the final power margin is less than the shift maintenance threshold, it is determined that even if the power consumption of the air compressor is cut off, the remaining net power of the vehicle is still insufficient to support the vehicle to drive stably in the target gear. The timing execution module intercepts the basic upshift command and maintains the original gear operation to prevent the vehicle speed from decreasing due to insufficient power after upshifting.

[0138] S402, when the timing execution module receives a braking request signal in the basic physical parameters, indicating a braking request, or when the pressure in the gas storage tank is less than the preset dynamic recovery threshold, the state machine emergency mechanism is triggered.

[0139] The dynamic recovery threshold is set based on the lower limit of the air storage pressure value that the air pressure braking system can maintain safe braking performance under continuous braking conditions. For example, the range can be from 0.55MPa to 0.65MPa.

[0140] After the state machine emergency mechanism is triggered, the timing execution module records the current system time as the emergency trigger time, intercepts the basic upshift command, and sends an air supply command to the air circuit control unit to force the air compressor to resume full-load air supply, giving priority to ensuring the air pressure supply of the service braking system.

[0141] Subsequently, the timing execution module confirms the actual disengagement time corresponding to the clutch disengagement state based on the transmission status signal in the basic physical parameters, and compares the timing values ​​of the emergency trigger time with the actual disengagement time.

[0142] When the emergency trigger time is less than or equal to the actual separation time, it indicates that the clutch has not yet completed the disengagement action when the emergency mechanism is triggered. The timing execution module cancels the air compressor disengagement command to maintain the original gear operation and maintain the transmission connection between the power source and the drive wheel.

[0143] When the emergency trigger time is greater than the actual separation time, it indicates that the clutch is in a physically disengaged state. The timing execution module calculates the speed matching value based on the predicted vehicle speed through kinematic back-calculation.

[0144] The specific kinematic back-calculation process is as follows: the predicted vehicle speed is divided by the preset wheel radius to obtain the predicted drive wheel end angular velocity. Then, the predicted drive wheel end angular velocity is multiplied by the preset main reduction ratio and the inherent speed ratio of each available candidate gear in turn to calculate the theoretical synchronous speed required for each candidate gear, which is used as the speed matching value.

[0145] The timing execution module obtains the safe gear based on the speed matching value and the engine speed. Specifically, it compares the speed matching value of each candidate gear with the speed boundary allowed by the storage control unit. After eliminating gears that would cause overspeed or abnormal low-speed conditions, it selects the physical gear that minimizes the absolute speed difference between the speed matching value and the engine speed as the safe gear.

[0146] After confirming the safe gear position, the timing execution module issues an active speed adjustment and matching command to control the automatic transmission control unit to engage the safe gear. This active speed adjustment and matching command can schedule the stored control unit to adjust the engine speed, and close the clutch after the speed is synchronized, so as to quickly restore the power transmission path under abnormal operating conditions.

[0147] To further aid in understanding the technical solutions of the embodiments of the present invention, a specific application example is given below.

[0148] In this application example, a 18-ton commercial truck is traveling on a provincial highway. The vehicle is in 8th gear at a current speed of 58 km / h. The automatic transmission control unit issues a basic upshift command to shift from 8th to 9th gear based on the basic shift logic. The vehicle is currently carrying 70% of its nominal load. The road section is a slight uphill slope of approximately 0.5°. The ambient temperature is 25°C, the air pressure is standard, and the road surface is dry asphalt. The air compressor is under load, replenishing the air tank. The power forwarding module puts the basic upshift command in the suspended state and initiates an energy margin assessment.

[0149] The state resolution module has completed the basic physical parameter resolution. The key parameters for the current effective sampling period are:

[0150] Estimated vehicle weight Slope estimate Current vehicle speed That is, 16.111 m / s², longitudinal acceleration The air tank pressure is 0.73 MPa, the braking request signal is no braking request, and the air compressor feedback signal is in the loading state.

[0151] The system parameters are set as follows:

[0152] Target gear ratio Main reduction ratio mechanical efficiency Wheel radius Shift maintenance threshold The maximum specific parasitic power of the air compressor Lower limit of air pressure Basic licensing pressure Response lag time Road rolling resistance coefficient air drag coefficient windward area ;

[0153] The preset one-dimensional mapping table for slope and air pressure correction outputs the slope correction amount for a 0.5° uphill condition. The preset one-dimensional compensation table for mass and air pressure load outputs a mass correction amount for a 18000kg load condition. Braking correction amount .

[0154] The power forecasting module determines that the air compressor feedback signal indicates a loaded state, therefore the accessory resistance needs to be deducted. Using the current engine speed as an index, the bench calibration data is consulted, and the mechanical resistance torque of the air compressor under the current operating conditions is 75 Nm. Subsequently, using the expected engine speed as an index, the target maximum torque is obtained by consulting a lookup table based on the engine's external characteristic curve. The calculated torque is determined after deducting the resistance of the accessories. .

[0155] Before calling the initial prediction formula, the dynamic forecasting module first constructs the overall driving resistance. Rolling resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, road rolling resistance coefficient, and the cosine of the estimated slope; the result is 1412.52 N. Air resistance is calculated by multiplying the air resistance coefficient, frontal area, and the square of the current vehicle speed, then multiplying by half the air density; the result is 878.37 N. Gradient resistance is obtained by multiplying the estimated vehicle mass, gravitational acceleration, and the sine of the estimated slope; the result is 1541.44 N. The overall driving resistance is then calculated by summing these three factors. .

[0156] Substitute the above parameters into the initial prediction formula:

[0157] ;

[0158] Calculation results show that the initial power margin Less than the shift maintenance threshold If no intervention is taken after upshifting, the net driving power per unit mass is insufficient to maintain stable driving of the vehicle at the current slope.

[0159] After obtaining the initial power margin, the safety arbitration module determines that the initial power margin is less than the shift maintenance threshold and the air compressor feedback signal is in a loaded state. It then sums the initial power margin with the air compressor's maximum specific parasitic power to obtain the equivalent power sum value. The equivalent power sum is greater than the shift sustaining threshold of 5.5 W / kg, indicating that the vehicle is in the decoupling candidate range.

[0160] The safety arbitration module uses the decoupling threshold formula based on the dynamic operating condition correction to calculate the permissible pressure threshold.

[0161] ;

[0162] The current air tank pressure of 0.73MPa is greater than the permissible pressure threshold of 0.72MPa, and the braking request signal is "no braking request". The air compressor feedback signal is "loaded". Based on this, the safety arbitration module generates an arbitration passed status word.

[0163] After generating the arbitration pass status word, the safety arbitration module calls the hysteresis speed formula:

[0164] ;

[0165] To predict vehicle speed By back-calculating the kinematics to obtain the expected engine speed, the dynamic maximum torque is obtained by retrieving the engine's external characteristic curve. Simultaneously, using a multi-dimensional lookup table function, with engine speed of 854 rpm, air tank pressure of 0.73 MPa, and air compressor feedback signal, the actual mechanical power consumed by the air compressor during pumping was calculated to be 6675 W. This was then divided by the estimated vehicle mass to obtain the dynamic net power increment. .

[0166] The overall driving resistance was reconstructed based on the predicted vehicle speed. Rolling resistance remained unchanged at 1412.52 N, air resistance was recalculated at 875.15 N based on the predicted speed, and gradient resistance remained unchanged at 1541.44 N. The overall driving resistance... .

[0167] Substitute into the final margin formula:

[0168] ;

[0169] Final power margin The power consumption is greater than the shift maintenance threshold of 5.5W / kg. After the timing execution module receives the arbitration pass status word and determines that the final power margin meets the standard, it first sends an air compressor disengagement command to the air circuit control unit to release the parasitic power of the air compressor. After detecting that the air compressor feedback signal has changed to the actual disengagement state, it sends an upshift permission command to the automatic transmission control unit. The vehicle completes the upshift operation from 8th to 9th gear while ensuring power maintenance.

[0170] To verify the technical effect of the present invention, the method of the present invention was compared with the conventional method (which only relies on the conventional shifting rules of vehicle speed and throttle opening, without cross-domain accessory decoupling and feedforward recalculation mechanism) for comparative testing.

[0171] The test vehicle was the aforementioned 18-ton commercial truck. The test route was a mixed road, including straight sections, undulating sections, and continuous slopes, with a total length of approximately 45km. Shift events, vehicle speed changes, and air tank pressure data were recorded under both control methods. During the test cycle, the automatic transmission control unit issued 22 basic upshift commands from 8th to 9th gear.

[0172] The conventional method was used to execute the operation on these 22 instructions, and the results were as follows: 14 effective upshifts; 6 failed upshifts (manifested as insufficient power after upshifting, with vehicle speed decreasing by more than 4 km / h within 3 seconds); and 2 effective interceptions (interceptions passively triggered by the underlying anti-stalling strategy under extreme low-speed conditions).

[0173] The method of this invention performs energy margin assessment on the same 22 commands, and the results are as follows: 16 effective upshifts (including 9 upshifts directly when the initial power margin meets the standard, and 7 upshifts approved when the final power margin meets the standard after decoupling the air compressor); 0 failed upshifts; and 6 effective interceptions (actively identifying operating conditions where power cannot be maintained even after decoupling and intercepting the basic upshift command). The method of this invention increases the number of effective upshifts to 16 and completely eliminates failed upshift events.

[0174] See appendix Figure 7 The conventional method blindly upshifts at 0s, and due to insufficient engine reserve power and continuous consumption of shaft power by the air compressor, the vehicle speed continuously decreases from 58km / h to about 52km / h, affecting driving smoothness. The method of this invention performs decoupling arbitration and compensation recalculation before upshifting to ensure power margin before shifting. After upshifting, the vehicle speed only experiences a very slight transient fluctuation and then stabilizes at about 57km / h.

[0175] See appendix Figure 8 The active interception mechanism of the present invention replaces the passive anti-stalling interception of the conventional method, and the effective interception count reaches 6 times. At the same time, through cross-domain joint control, the present invention reduced the number of failed upshifts to 0 in 22 commands in this experiment, improving the upshift success rate and driving safety of commercial vehicles under complex working conditions.

[0176] See appendix Figure 9 , Figure 9 The dashed line represents the permissible pressure threshold calculated by the method of this invention, and the dotted line represents the fixed pressure safety lower limit used by conventional methods. For example... Figure 9 As shown, on downhill sections, braking demand increases, and the method of this invention raises the permissible pressure threshold to 0.76 MPa to ensure braking safety; on uphill sections where there is no braking demand, the permissible pressure threshold dynamically decreases to 0.69 MPa. The area where the solid line of the air reservoir pressure lies above the dashed line of the permissible pressure threshold forms a decoupling window. The method of this invention utilizes this decoupling window to release the parasitic power of the air compressor, successfully supporting additional upshifting operations on uphill sections, overcoming the power waste problem caused by the conventional method using a fixed lower limit of air pressure safety.

[0177] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for adaptive shifting control of an AMT (Automated Manual Transmission) in commercial vehicles, characterized in that, Includes the following steps: Obtain the vehicle's basic physical parameters and parse out the estimated vehicle mass and slope values; The basic upshift command is initiated, the calculated torque is determined based on the basic physical parameters, and the initial power margin is calculated using the initial prediction formula in combination with the estimated mass of the whole vehicle and the estimated slope value. Based on the initial power margin and the obtained maximum specific parasitic power of the air compressor, an equivalent power sum is generated. When the equivalent power sum is not less than the preset shift maintenance threshold, the decoupling threshold formula is called according to the basic physical parameters to execute the attached decoupling arbitration. After generating the arbitration pass status word, the hysteresis speed formula is called to calculate the predicted speed based on the basic physical parameters. The final power margin is calculated in combination with the final margin formula. When the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold, the air compressor disengagement command is sent to the air circuit control unit, and the upshift permission command is sent to the automatic transmission control unit after the air compressor feedback signal is in actual disengagement state; otherwise, the basic upshift command is intercepted to maintain the original gear. When the emergency mechanism of the state machine is triggered based on the basic physical parameters, the emergency trigger time is recorded and a gas supply command is sent to the air circuit control unit. If the emergency trigger time is greater than the actual separation time confirmed by the basic physical parameters, an active speed adjustment and matching command is sent to control the automatic transmission control unit to engage a safe gear based on the predicted vehicle speed.

2. The commercial vehicle AMT shift adaptive control method according to claim 1, characterized in that, The steps for obtaining the vehicle's basic physical parameters and resolving them to derive the estimated vehicle mass and gradient include: The basic physical parameters obtained by the measurement nodes include wheel speed sensor signals, longitudinal acceleration signals, output torque signals, engine speed signals, airbag pressure signals, air tank pressure signals, air compressor feedback signals, transmission status signals, and braking request signals from the electronic braking system, and include at least one of air suspension height signals and vertical acceleration signals. The wheel speed sensor signal is converted into the current vehicle speed, and the derivative of the current vehicle speed is obtained by performing a derivative operation on the current vehicle speed; Based on the airbag pressure signal, the estimated mass of the whole vehicle is calculated by using the chassis static balance relationship and the preset center of gravity distribution model; Based on the vehicle's longitudinal dynamics equations, combined with the vehicle speed derivative, the longitudinal acceleration converted from the longitudinal acceleration signal, the estimated mass of the whole vehicle, and the output torque signal, the estimated slope value is calculated. When the basic physical parameters only include the air suspension height signal, the air suspension height signal is subjected to first-order time-domain difference to obtain the height change rate, and the vehicle vertical acceleration is obtained as an impact index based on the height change rate through second-order difference operation. When the air suspension height signal and the vertical acceleration signal are included simultaneously, or when only the vertical acceleration signal is included, the vehicle vertical acceleration is directly obtained as the impact index based on the vertical acceleration signal through a differential operation. When the absolute value of the impact index is greater than the preset impact judgment threshold, the vehicle is determined to be in a body impact disturbance state, and the zero-order hold is used to maintain the slope estimate and the estimated vehicle mass of the previous effective sampling period.

3. The commercial vehicle AMT shift adaptive control method according to claim 1, characterized in that, The steps of engaging the basic upshift command, determining the calculated torque based on the aforementioned basic physical parameters, and calculating the initial power margin using the initial prediction formula in conjunction with the estimated vehicle mass and slope value include: While the basic upshift command output by the automatic transmission control unit is engaged and the current gear transmission connection is maintained, the current vehicle speed, which is converted from the wheel speed sensor signal in the basic physical parameters, is converted into the expected speed through kinematic back-reasoning. The engine external characteristic curve is then called with the expected speed as an index to obtain the target maximum torque. When the air compressor feedback signal is in an unloaded state, the target maximum torque is determined as the calculated torque; When the air compressor feedback signal is in a loaded state, the mechanical resistance torque of the air compressor at the engine speed obtained based on the engine speed signal is obtained as the accessory resistance, and the target maximum torque is subtracted from the accessory resistance to determine the calculated torque; The initial prediction formula is called to multiply the calculated torque, the preset target gear ratio, the preset final reduction ratio, and the preset mechanical efficiency, and the result of the multiplication is divided by the preset wheel radius to obtain the actual driving force at the wheel end. The initial power margin is calculated by subtracting the combined driving resistance calculated based on the current vehicle speed converted from the wheel speed sensor signal and the estimated slope value from the actual driving force at the wheel end, dividing the difference by the estimated mass of the whole vehicle and multiplying by the current vehicle speed.

4. The commercial vehicle AMT shift adaptive control method according to claim 2, characterized in that, The steps of generating an equivalent power sum based on the initial power margin and the obtained maximum specific parasitic power of the air compressor, and executing the appendix decoupling arbitration by calling the decoupling threshold formula based on the basic physical parameters when the equivalent power sum is not less than the preset shift maintenance threshold, include: When the air compressor feedback signal is in a loaded state, the maximum specific parasitic power of the air compressor is obtained based on a preset upper bound mapping table of air compressor parasitic power. The equivalent power sum is generated by summing the initial power margin with the maximum specific parasitic power of the air compressor. When the equivalent power sum is not less than the shift maintenance threshold, the slope estimate, the braking request signal in the basic physical parameters and the estimated vehicle mass are respectively input into the preset slope and air pressure correction one-dimensional mapping table, braking state response table and mass and air pressure load one-dimensional compensation table, and the dynamic working condition correction amount including slope correction amount, braking correction amount and mass correction amount are obtained by table lookup operation. The decoupling threshold formula is called to add the preset basic permissible pressure, the slope correction amount, the braking correction amount and the mass correction amount, and the sum is compared with the preset lower limit of air pressure. The maximum value obtained is taken as the permissible pressure threshold. The gas cylinder pressure corresponding to the gas cylinder pressure signal in the basic physical parameters is compared with the permissible pressure threshold to perform the appendix decoupling arbitration.

5. The commercial vehicle AMT shift adaptive control method according to claim 4, characterized in that, The steps involved in generating the arbitration pass status word, calling the hysteresis speed formula to calculate the predicted vehicle speed based on fundamental physical parameters, and combining this with the final margin formula to calculate the final power margin include: When the pressure of the air storage tank obtained from the air storage tank pressure signal in the basic physical parameters is greater than the permissible pressure threshold, and the braking request signal is no braking request, and the air compressor feedback signal is in the loading state, the arbitration passed status word is generated. The hysteresis speed formula is called, and the product of the longitudinal acceleration obtained from the longitudinal acceleration signal and the preset response hysteresis time is added to the current vehicle speed converted from the wheel speed sensor signal. The sum is then compared with zero to obtain the maximum value, and the predicted vehicle speed is obtained. Based on the predicted vehicle speed, the dynamic expected speed is obtained by kinematic back-calculation, and the dynamic maximum torque is obtained by calling the engine external characteristic curve using the dynamic expected speed as an index. By using a multidimensional lookup table function, the engine speed, the air tank pressure, and the air compressor feedback signal obtained from the engine speed signal are converted into the dynamic net power increment that can be released after the air compressor is decoupled. The final power margin is calculated by calling the final margin formula, replacing the original calculated torque with the dynamic maximum torque, obtaining the predicted actual driving force at the wheel end, subtracting the comprehensive driving resistance calculated based on the predicted vehicle speed and the estimated slope value from the predicted actual driving force at the wheel end, dividing the difference by the estimated vehicle mass and multiplying by the predicted vehicle speed, and then adding the dynamic net power increment.

6. The commercial vehicle AMT shift adaptive control method according to claim 1, characterized in that, When the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold, an air compressor disengagement command is issued to the air circuit control unit, and an upshift permission command is issued to the automatic transmission control unit after the air compressor feedback signal indicates actual disengagement. Otherwise, the steps to intercept the basic upshift command and maintain the original gear include: Upon receiving the arbitration pass status word, and when the final power margin is not less than the shift maintenance threshold, the system sends the air compressor disconnect command to the air circuit control unit and continuously monitors the air compressor feedback signal. When the air compressor feedback signal is detected to change to the actual disengagement state, or when the waiting time calculated from the issuance of the air compressor disengagement command is greater than the preset response hysteresis time, the upshift permission command is synchronously issued to the automatic transmission control unit. If the arbitration pass status word is not received, or if the final power margin is less than the shift maintenance threshold, the basic upshift command is intercepted to maintain the original gear.

7. The commercial vehicle AMT shift adaptive control method according to claim 2, characterized in that, When the emergency mechanism of the state machine is triggered based on the aforementioned basic physical parameters, the steps of recording the emergency trigger time and issuing a gas supply command to the gas circuit control unit include: When the braking request signal in the basic physical parameters indicates a braking request, or when the pressure of the gas storage tank obtained based on the gas storage tank pressure signal is less than the preset dynamic recovery threshold, the state machine emergency mechanism is triggered. After the state machine emergency mechanism is triggered, the current system time is recorded as the emergency trigger time, and the gas supply command is sent to the gas circuit control unit. The actual disengagement time corresponding to the clutch disengagement state is determined based on the transmission status signal in the basic physical parameters.

8. The commercial vehicle AMT shift adaptive control method according to claim 7, characterized in that, It also includes control steps when the emergency trigger time is not greater than the actual separation time confirmed by the basic physical parameters: When the emergency trigger time is less than or equal to the actual separation time, it is confirmed that the clutch disengagement state has not yet been physically disconnected; Cancel the air compressor disengagement command to maintain the original gear operation and keep the transmission connection between the power source and the drive wheel.

9. The commercial vehicle AMT shift adaptive control method according to claim 7, characterized in that, When the emergency trigger time is greater than the actual separation time confirmed by basic physical parameters, the steps for issuing an active speed matching command to control the automatic transmission control unit to engage a safe gear calculated based on the predicted vehicle speed include: When the emergency trigger time is greater than the actual separation time, the predicted vehicle speed is combined with the preset main reduction ratio and the inherent speed ratio of each available candidate gear. The theoretical synchronous speed of each available candidate gear is calculated by kinematic back-calculation and used as the speed matching value. By comparing the speed matching value of each available candidate gear with the speed boundary allowed by the storage control unit, after eliminating gears with abnormal operating conditions of overspeed and low speed, the physical gear that minimizes the absolute speed difference between the speed matching value and the engine speed obtained based on the engine speed signal in the basic physical parameters is selected as the safe gear. The active speed matching command is sent to the automatic transmission control unit to control it to engage the safe gear, and the storage control unit is scheduled to adjust the engine speed.

10. An adaptive shift control system for AMT (Automated Manual Transmission) in commercial vehicles, characterized in that, An adaptive shift control method for a commercial vehicle AMT as described in any one of claims 1-9 includes: The state perception module is used to acquire the basic physical parameters of the vehicle and parse out the estimated mass and slope of the whole vehicle. The power forecasting module is used to initiate the basic upshift command, determine the calculated torque based on the basic physical parameters, and calculate the initial power margin using the initial prediction formula in combination with the estimated mass of the whole vehicle and the estimated slope value. The decoupling arbitration module is used to generate an equivalent power sum value based on the initial power margin and the obtained maximum specific parasitic power of the air compressor. When the equivalent power sum value is not less than the preset shift maintenance threshold, the module calls the decoupling threshold formula to execute the attached decoupling arbitration based on the basic physical parameters. After generating the arbitration pass status word, the module calls the hysteresis speed formula to calculate the predicted speed based on the basic physical parameters and calculates the final power margin in combination with the final margin formula. The timing execution module is used to send an air compressor disengagement command to the air circuit control unit when the arbitration pass status word is received and the final power margin is not less than the shift maintenance threshold. After the air compressor feedback signal is in the actual disengagement state, it sends an upshift permission command to the automatic transmission control unit. Otherwise, it intercepts the basic upshift command to maintain the original gear. The active safety module is used to record the emergency trigger time and send an air supply command to the air circuit control unit when the state machine emergency mechanism is triggered based on the basic physical parameters. When the emergency trigger time is greater than the actual separation time confirmed by the basic physical parameters, it sends an active speed adjustment and matching command to control the automatic transmission control unit to engage the safe gear obtained based on the predicted vehicle speed.

Images