An integrated adaptive shifting control method, system, and storage medium for multiple targets.

Abstract

This invention relates to an adaptive shifting control method, system, and storage medium that integrates multiple following objectives. The method includes: predicting the vehicle's driving conditions based on a pre-constructed Markov chain of vehicle driving conditions; solving for the optimal gear sequence that achieves the best fuel economy while meeting the vehicle's power requirements based on the predicted driving condition information; during gear shifting according to the optimal gear sequence, reducing the impact during clutch engagement through PID control, while simultaneously detecting the wear and temperature of the clutch friction plates and feeding this data back to the TCU to control the clutch engagement speed and clamping force. This invention enables the vehicle to achieve optimal fuel economy while meeting power requirements, and also considers clutch reliability, thus realizing multi-objective demand control.

Description

Technical Field

[0001] This invention relates to the field of vehicle driving shift control technology, and in particular to an adaptive shift control method, system and storage medium that integrates multiple following targets. Background Technology

[0002] With the booming development of the automotive industry, automatic transmission technology has become increasingly mature. Furthermore, due to the advantages of automatic transmission vehicles, such as ease of operation, convenient shifting, and high ride comfort, more and more vehicles are equipped with automatic transmissions. The difference between automatic and manual transmissions lies in the fact that automatic transmissions can automatically shift gears according to a pre-set shift control strategy during vehicle operation. The shift control strategy is paramount in automatic transmissions, significantly impacting fuel economy, power, and reliability. Therefore, the shift strategy directly affects the overall performance of the vehicle during actual road driving. Conducting research on shift control strategies and identifying strategies that improve overall vehicle performance will play a positive role in promoting the development of the automotive industry.

[0003] In recent years, extensive research has been conducted both domestically and internationally on vehicle shift control strategies. Kim et al. used robust control strategies to estimate motor torque and transmission system torque, effectively reducing shift shock and improving shift quality; Tamba et al. jointly controlled the speed and torque of the motor and clutch to reduce shift time and extend the life of friction plates; KIM et al. solved the shift MAP using a DP algorithm, improving vehicle economy without sacrificing power and achieving global optimization of the control system; GUO et al., based on the fundamental principles of model predictive control, constructed specific optimization problems and used the minimum principle and numerical solution algorithms to complete online optimization of vehicle gears.

[0004] However, in the existing studies, most control strategies are formulated based on only one or two control requirements, and the corresponding parameters are found for control tracking. The shortcoming is that they only take into account a single control target requirement, often ignoring other vehicle performance requirements, which affects the overall performance of the vehicle. Summary of the Invention

[0005] To address the aforementioned problems, the purpose of this invention is to provide an adaptive shift control method, system, and storage medium that integrates multiple following objectives, enabling vehicles to achieve optimal fuel economy while ensuring clutch reliability, thus realizing multi-objective demand control.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: an adaptive shift control method integrating multiple following targets, comprising: predicting the vehicle's driving conditions based on a pre-constructed Markov chain of vehicle driving conditions; based on the predicted driving condition information, solving for the optimal gear sequence with the best fuel economy while meeting the requirements of vehicle power performance; during the shifting process according to the optimal gear sequence, reducing the impact during clutch engagement through PID control, and simultaneously detecting the wear and temperature of the clutch friction plates and feeding them back to the TCU to control the clutch engagement speed and clamping force.

[0007] Furthermore, the construction of the Markov chain for vehicle driving conditions includes:

[0008] Select a certain time segment t as the discrete time interval of driving conditions, and divide the vehicle's driving conditions into a discrete and continuous state sequence based on this time interval.

[0009] Read the CAN bus data of the vehicle in motion to obtain the vehicle's speed and time information, and collect the vehicle's acceleration information in real time;

[0010] The obtained vehicle speed, acceleration, and time information are used as inputs to the Markov model. The future speed and acceleration of the vehicle are predicted through the Markov chain. The speed and acceleration in the local prediction time domain are superimposed to obtain the predicted values ​​of global speed and acceleration.

[0011] Furthermore, the requirements for vehicle dynamics are as follows: the gear sequence that satisfies the constraint u+u1∈{1,2,3,…m} must meet the torque requirements of the vehicle under the current operating conditions, where u is the gear shifting operation signal, u∈{-1,0,1}, u1 is the forward gear of the vehicle, u1∈{1,2,3,…,m}, and m represents the highest forward gear of the vehicle.

[0012] Furthermore, the optimal gear for achieving the best fuel economy is determined using a greedy algorithm, including:

[0013] Read the Markov chain to predict the vehicle's state s at the next time step t+1. t+1 Including the vehicle speed v at the next moment t+1 and acceleration a t+1 ;

[0014] For all selectable gears 1-m, calculate the state S at the current time in gear i. t Transition to the next time step state S t+1 Total fuel consumption required;

[0015] Select the gear that minimizes total fuel consumption, set that gear as the current gear, update the vehicle speed, and update time t to t+1;

[0016] When the predicted end time of the vehicle's journey is reached, the process ends, a unique shift sequence is determined, and the shift sequences from each predicted time domain are superimposed to form the shift control sequence across all time domains, which is the optimal gear sequence.

[0017] Furthermore, PID control is used to reduce the impact during clutch engagement, including:

[0018] When the deviation between the clutch input shaft speed and the clutch output shaft speed is less than zero, the PID controller outputs the throttle opening adjustment value and checks whether the throttle opening to be reduced to meets the vehicle's power requirements. If it does, the PID controller sends the throttle opening value calculated by the PID controller to the ECU; otherwise, the PID controller sends the minimum throttle opening value that meets the power requirements at this time to the ECU.

[0019] When the deviation between the clutch input shaft speed and the clutch output shaft speed is zero, a signal is sent to the ECU to maintain this throttle opening.

[0020] When the deviation between the clutch input shaft speed and the clutch output shaft speed is greater than 350 r / min, the ECU is sent with the value of the throttle opening to be increased.

[0021] Furthermore, the wear and temperature of the clutch friction plates are detected, including:

[0022] When the temperature of the clutch surface is detected to exceed the preset temperature limit of the engagement surface, a command is sent to the TCU to adjust the clamping force of the clutch friction plate to the maximum, so that the clutch friction plate engages at the fastest speed.

[0023] When the wear of the clutch friction plate exceeds 1 / 4 of its thickness, a command is sent to the TCU to adjust the clutch friction plate clamping force to the maximum, so that the friction plate can be engaged as quickly as possible during gear shifting.

[0024] Furthermore, when the wear of the clutch friction plate exceeds 1 / 4 of its thickness, the system also includes: if a speed difference is detected between the clutch input shaft and the output shaft after the clutch is fully engaged, a command is sent to the driver to remind them to replace the friction plate in time.

[0025] An adaptive shift control system integrating multiple following targets includes: a prediction module, which predicts the vehicle's driving conditions based on a pre-constructed Markov chain of vehicle driving conditions; a gear solving module, which, based on the predicted driving condition information, solves for the optimal gear sequence that achieves the best fuel economy for the vehicle while meeting the requirements of vehicle power performance; and a control module, which, during the shifting process according to the optimal gear sequence, reduces the impact during clutch engagement through PID control, and simultaneously detects the wear and temperature of the clutch friction plates, feeding this information back to the TCU to control the clutch engagement speed and clamping force.

[0026] A computer-readable storage medium storing one or more programs, the one or more programs including instructions that, when executed by a computing device, cause the computing device to perform any of the methods described above.

[0027] A computing device includes: one or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing any of the methods described above.

[0028] The present invention has the following advantages due to the adoption of the above technical solutions:

[0029] 1. In constructing the vehicle driving condition model, this invention uses Markov chains to predict the actual driving conditions of the vehicle, making the driving condition model closer to the real driving conditions and more conducive to the formulation of shifting strategies.

[0030] 2. When solving for the shift sequence with the best fuel economy, this invention uses a greedy algorithm to solve for the local optimal solutions in each time domain one by one, and then superimposes them to form the global optimal solution. Compared with directly solving for the global optimal solution, the algorithm is simpler and more conducive to real-time calculation.

[0031] 3. This invention uses a compound temperature field model of clutch friction plates to measure the temperature of clutch friction plates and a compound calculation model of clutch wear to calculate the degree of clutch wear. It adjusts the speed and clamping force during clutch engagement, which slows down the wear of clutch friction plates, extends the life of the friction plate clutch, and improves the reliability of the clutch.

[0032] 4. This invention achieves optimal fuel economy while ensuring vehicle power performance, and also takes into account the reliability of the vehicle's clutch, thus realizing multi-objective demand control. Attached Figure Description

[0033] Figure 1 This is a flowchart of the adaptive shift control method integrating multiple following targets in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram illustrating the prediction of vehicle driving conditions using Markov chains in an embodiment of the present invention.

[0035] Figure 3 This is a schematic diagram of the greedy method for finding the shift sequence in an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of PID control in an embodiment of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of 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, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] To address the problem in existing technologies that focus on only one or two control requirements and track their corresponding parameters, thus neglecting other vehicle performance requirements and affecting overall vehicle performance, this invention provides an adaptive shift control method, system, and storage medium that integrates multiple following targets. In formulating the shift strategy, the vehicle's driving conditions must first be known. A Markov process is a random transition from one state to another in a state space; the state at a given moment depends only on the state at the previous moment and is independent of other states. During vehicle operation, the driving state exhibits randomness and no aftereffect, thus conforming to a Markov process. Therefore, by discretizing the vehicle's driving time and treating the driving conditions as discrete yet continuous states, a Markov chain can be used to predict the vehicle's driving process.

[0040] The predicted vehicle speed, acceleration, and other driving condition information are used as input to the greedy algorithm. Combined with the torque information output from the output shaft, the greedy strategy finds a gear sequence in the prediction time domain, enabling the vehicle to achieve optimal fuel economy while satisfying power requirements. The core idea of ​​the greedy method is that local optimal solutions can lead to global optimal solutions. This involves decomposing the problem into a series of subproblems, applying the greedy method to each subproblem to obtain a local optimal solution, and then merging all the local optimal solutions into a global optimal solution. When using the greedy method to solve for the optimal gear sequence, the local optimal gear sequence is first solved within the set prediction time domain. Then, the local optimal gear sequences are superimposed to form the global optimal solution. During vehicle operation, there are three shifting operations: upshifting, downshifting, and maintaining the current gear. Therefore, the shifting operation signal is defined as u∈{-1,0,1}. Since forward driving usually accounts for the majority of the driving conditions, this invention only studies the forward driving process, and the gear can be represented as u1∈{1,2,3,…,m}.

[0041] During vehicle operation, gear shifts are performed based on a gear sequence obtained using a greedy algorithm. To reduce vehicle shock during shifting, a PID controller is used to control the clutch engagement process. Reasonable control parameters are set to track the speed of the clutch friction plates during engagement, minimizing shock during shifting. Simultaneously, the clutch friction plate temperature is measured using a composite temperature field model, and the clutch wear level is calculated using a composite clutch wear calculation model. Temperature and wear parameters are fed back to the vehicle's TCU, and the PID control parameters are then adjusted to delay clutch friction plate damage and improve clutch reliability. Since the temperature of the clutch friction plate contact surface cannot be directly measured, a composite temperature field model is used to calculate the temperature. This model integrates temperatures measured by an infrared non-contact thermometer and a contact temperature sensor installed on the vehicle, along with temperatures calculated using the friction plate heat generation formula, to obtain a temperature that closely approximates the clutch friction plate contact surface. The composite clutch wear calculation model detects the clutch displacement during engagement and the output shaft torque, inputting these data into a pre-trained training set to obtain information on friction plate wear.

[0042] This invention can track vehicle parameters such as speed, acceleration, torque, throttle opening, and clutch speed difference to achieve relatively balanced control of the three tracking targets. Furthermore, it can adjust the control parameters in real time (adaptive) according to the vehicle's current driving conditions. Compared with other existing control methods, this invention simultaneously considers the economy, power, and reliability of the vehicle's gear shifting process, which is beneficial to improving the overall vehicle performance.

[0043] In one embodiment of the present invention, an adaptive shift control method integrating multiple tracking targets is provided. This method tracks parameters such as vehicle speed, acceleration, torque, throttle opening, and clutch speed difference. It uses Markov chains, greedy strategies, and PID control strategies to achieve balanced control of the vehicle's power performance, fuel economy, and driving reliability, enabling adaptive adjustment during driving and improving overall vehicle performance. In this embodiment, as... Figure 1 As shown, the method includes the following steps:

[0044] 1) Predict the vehicle's driving conditions based on a pre-constructed Markov chain of vehicle driving conditions.

[0045] 2) Based on the predicted driving condition information, the optimal gear sequence with the best fuel economy is obtained while meeting the requirements of vehicle power performance.

[0046] 3) During the gear shifting process according to the optimal gear sequence, the impact during clutch engagement is reduced by PID control. At the same time, the wear and temperature of the clutch friction plates are detected and fed back to the TCU to control the clutch engagement speed and clamping force.

[0047] In step 1) above, the construction of the Markov chain for the vehicle's driving conditions includes the following steps:

[0048] 1.1) Select a certain time segment t as the discrete time interval of driving conditions, and divide the driving conditions of the vehicle into a discrete and continuous state sequence based on this time interval.

[0049] 1.2) Read the CAN bus data of the vehicle in motion to obtain the vehicle's speed and time information, and collect the vehicle's acceleration information in real time; the vehicle's acceleration information can be collected in real time by an acceleration sensor installed on the vehicle.

[0050] 1.3) The obtained vehicle speed, acceleration and time information are used as input to the Markov model. The future speed and acceleration of the vehicle are predicted by the Markov chain. The speed and acceleration in the local prediction time domain are superimposed to obtain the predicted values ​​of global speed and acceleration.

[0051] In this embodiment, as Figure 2 As shown, the specific calculation method for predicting vehicle driving conditions based on a pre-constructed Markov chain of vehicle driving conditions is as follows:

[0052] (1) State definition:

[0053] Let the vehicle's velocity and acceleration be represented by v and a, respectively. Then the vehicle's state can be represented as a tuple (va). Assuming a time step of t, the vehicle's state will transition within each time step, from the current state (v...a)... i a i Transition to the next state (v) i+1 a i+1 Therefore, a state transition matrix P can be constructed. According to the Markov chain assumption, the transition probabilities depend only on the previous state; therefore, the state transition probabilities can be expressed as:

[0054] P=P((v i+1 a i+1 )|(v i a i ))

[0055] (2) State transition probability matrix: The state transition of the training vehicle in the past x time steps under normal driving conditions, and the state transition probability is estimated using these data.

[0056] Specifically, the historical data can be divided into x time steps, each containing the vehicle's speed and acceleration values. Then, the transition probability from one state to another at each time step can be calculated. The elements of the state transition matrix can be calculated using the following formula:

[0057]

[0058] Where, Count(v i a i v i+1 a i+1 ) is counting from state (v) in historical data. i a i ) to state (v i+1 a i+1 The number of times ) is counted, Count(v i a i ) is the count state (v) in historical data. i a i () number of times.

[0059] (3) Predicting driving conditions: With the state transition matrix, Markov chains can be used to predict future vehicle speed and acceleration.

[0060] Specifically, suppose the current state is (v i a i Based on the state transition matrix P, the probability of the vehicle being in each state within the next time step can be calculated. Based on these probabilities, the expected values ​​of the future velocity and acceleration can be calculated, i.e.:

[0061]

[0062]

[0063] Among them, v i+1 and a i+1 Let represent the velocity and acceleration in the next predicted time step, respectively. In this way, a Markov chain can be used to predict the vehicle's future velocity and acceleration. By superimposing the velocities and accelerations in the local prediction time domain, the predicted global velocity and acceleration values ​​are obtained.

[0064] In step 2) above, the throttle opening information of the vehicle is read through the vehicle CAN bus, and the obtained information such as the vehicle's speed and acceleration in the local time domain is input into the greedy method. The vehicle's shift signal is controlled in the current time domain. Under the condition of satisfying the vehicle's power performance, combined with the vehicle's throttle opening information, the vehicle has the best fuel economy in the current time domain.

[0065] Specifically, the requirements for vehicle dynamics are as follows: the shift sequence that satisfies the constraint u+u1∈{1,2,3,...,m} must meet the torque requirements of the vehicle under the current operating conditions, where u is the shift operation signal, u∈{-1,0,1}, u1 is the forward gear of the vehicle, u1∈{1,2,3,...,m}, and m represents the highest forward gear of the vehicle.

[0066] In step 2) above, if Figure 3 As shown, the optimal gear for achieving the best fuel economy in a vehicle is determined using a greedy algorithm, which includes the following steps:

[0067] 2.1) Read the Markov chain to predict the vehicle's state s at the next time step t+1. t+1 Including the vehicle speed v at the next moment t+1 and acceleration a t+1 ;

[0068] In this embodiment, before executing step 2.1), initialization processing is required to initialize the current time as t=0, the vehicle speed as v0, and the gear as i0.

[0069] 2.2) For all selectable gears 1-m, calculate the state S at the current time in gear i. t Transition to the next time step state S t+1 Total fuel consumption required f i (S t S t+1 );

[0070] Specifically, the formula for calculating the fuel consumption F of the vehicle in the current gear is as follows:

[0071]

[0072] Where f(v(t), a(t), θ(t), i(t)) represents the fuel consumption per unit time under the conditions of vehicle speed v, acceleration a, gradient θ, and gear i. t0 and t1 represent the start and end times of the journey, respectively.

[0073] In this embodiment, the engine's power consumption is used to approximate the fuel consumption. Under normal circumstances, the engine output torque T is related to the accelerator pedal opening τ and the engine's maximum torque T. max (n) is related, that is, T = τT max (n). The engine's efficiency is related to its output torque and speed; therefore, the engine's power consumption P can be expressed as:

[0074]

[0075] In the formula, η represents mechanical efficiency and n represents engine speed.

[0076] The total power consumption of the engine in the prediction time domain is:

[0077]

[0078] 2.3) Select a value that minimizes total fuel consumption f i (S t S t+1 Find the smallest gear i, use that gear i as the current gear, and update the vehicle speed v. t+1 And update time t to t+1;

[0079] Where, gear i is:

[0080]

[0081] 2.4) When the end time of the vehicle's journey is predicted, the process ends, the most suitable gear is selected, a unique shift sequence is determined, and the shift sequences of each predicted time domain are superimposed to form the shift control sequence in the entire time domain, which is the optimal gear sequence.

[0082] In step 3) above, according to the shift sequence, when the vehicle issues a shift command, the TCU issues a shift signal and the shift execution system starts to work. At this time, the clutch disengages first, the engine and the transmission are disconnected, then the target gear is engaged, and finally the clutch engages. During the shift process, the clutch engagement stage causes the greatest impact on the vehicle, so this invention only focuses on the clutch engagement process.

[0083] During clutch engagement, the rate of change of angular velocity difference during the speed synchronization phase affects the rate of change of torque, thus influencing the overall vehicle impact. Therefore, a PID controller is used for closed-loop control of the engine target speed during this phase. The deviation between the clutch input shaft speed v and the clutch output shaft speed v1, Δv = v - v1, is used as the input, and the throttle opening is used as the output. The control target is Δv → 0, thereby reducing the impact during clutch engagement. Simultaneously, a composite temperature detection model for the friction plates is used to monitor the temperature of the clutch friction plate surface to prevent overheating and burning of the friction plates. Based on empirical values, the temperature of the clutch friction plate engagement surface generally does not exceed 270℃; therefore, 260℃ is taken as the temperature limit for the clutch engagement surface.

[0084] Based on practical experience, when the speed difference during clutch engagement is between 500-1000 r / min, the impact during clutch engagement in most vehicles meets the requirements for vehicle shift shock. In this invention, to reduce shift shock, PID control is used to track the speed difference during clutch engagement, and the vehicle's throttle opening is adjusted to try to make the speed difference approach zero. However, increasing the vehicle's throttle opening will inevitably increase fuel consumption. To balance fuel economy, a threshold of 350 r / min is set for the speed difference between the clutch input and output shafts. That is, when the clutch speed difference is less than 350 r / min, the vehicle's throttle opening is not automatically increased, sacrificing the reliability (shock) of gear shifting. When the clutch speed difference exceeds 350 r / min, to meet the vehicle shock requirements, PID output is used to adjust the vehicle's throttle opening to minimize the clutch speed difference, sacrificing fuel economy in this case.

[0085] The PID controller is:

[0086]

[0087] Among them, K p K i K d These are the proportional coefficient, integral coefficient, and derivative coefficient, respectively. In practical applications, their specific values ​​are determined based on the specific vehicle model information. R is the clutch friction plate thickness, and R1 is the clutch friction plate wear amount. Specifically, such as... Figure 4 As shown, PID control reduces the impact during clutch engagement and improves vehicle reliability, including the following steps:

[0088] 3.1.1) When the deviation between the clutch input shaft speed and the clutch output shaft speed is less than zero, the PID controller outputs the throttle opening adjustment value. Since the throttle opening needs to be reduced at this time, it checks whether the throttle opening to be reduced to meet the vehicle's power performance (torque). If it does, it sends the throttle opening value calculated by the PID controller to the ECU. Otherwise, it sends the minimum throttle opening value that meets the power performance requirements at this time to the ECU.

[0089] The deviation Δv between the clutch input shaft speed and the clutch output shaft speed is: Δv = v - v1.

[0090] 3.1.2) When the deviation between the clutch input shaft speed and the clutch output shaft speed is zero, a signal is sent to the ECU to maintain this throttle opening.

[0091] 3.1.3) When the deviation between the clutch input shaft speed and the clutch output shaft speed is greater than 350 r / min, the ECU is sent with the desired increase in throttle opening. However, to prevent excessive increase in throttle opening from affecting the driver, the increase in throttle opening shall not exceed 10%.

[0092] In step 3) above, the wear and temperature of the clutch friction plates need to be detected throughout the entire gear shifting process, including the following steps:

[0093] 3.2.1) When the temperature of the clutch surface is detected to exceed the preset temperature limit of the engagement surface, a command is sent to the TCU to adjust the clamping force of the clutch friction plate to the maximum, so that the clutch friction plate engages at the fastest speed, preventing excessive slippage during speed adjustment from causing the clutch plate temperature to become too high and burning the clutch friction plate.

[0094] In this embodiment, the preset temperature limit of the bonding surface is 260°C.

[0095] 3.2.2) When the wear of the clutch friction plate exceeds 1 / 4 of its thickness, a command is sent to the TCU to adjust the clutch friction plate clamping force to the maximum, so that the friction plate can be engaged at the fastest speed during gear shifting, thereby reducing wear and increasing the life of the clutch plate.

[0096] In this embodiment, when the wear of the clutch friction plate is detected to exceed 1 / 4 of its thickness, the following steps are also included:

[0097] 3.2.3) If a speed difference is detected between the clutch input shaft and the output shaft after the clutch is fully engaged, i.e. the clutch friction plate is slipping, an instruction is sent to the driver to remind him to replace the friction plate in time.

[0098] In this embodiment, when the wear of the clutch friction plate exceeds 1 / 4 of its thickness, the clutch friction plate is considered to be severely worn. The 1 / 4 thickness figure is an empirical value for most vehicles; however, due to differences in clutch design, materials, and other factors, this empirical value needs to be adjusted appropriately based on the specific vehicle model.

[0099] Example: The method of the present invention will be further illustrated through a specific example of controlling gear shifting.

[0100] 1) Read the current speed v and acceleration a information from the vehicle's CAN bus and use it as the input to the Markov chain. Taking one time domain as an example, calculate the vehicle speed and acceleration information for the next time domain based on the state transition matrix obtained through pre-training.

[0101]

[0102]

[0103] 2) Input the predicted speed and acceleration information into the greedy algorithm. Taking 3 to 4 gear as an example, the following formula is used to solve for the next time domain 4 gear with the best fuel economy. Check whether this gear meets the requirements of vehicle power (torque). If it meets the requirements, send an upshift signal to the TCU. If it does not meet the power requirements, generate a shift signal to keep the original gear.

[0104]

[0105]

[0106] 3) When the TCU receives an upshift command, the clutch disengages, a new gear is engaged, and the clutch begins to engage. During engagement, the speed difference between the clutch output shaft and input shaft is detected. If the speed difference is greater than 350 r / min, PID control is used to track the speed difference, increasing the vehicle's throttle opening to meet reliability (impact) requirements at the expense of fuel economy. When the speed difference is between ±350 r / min, PID control is not used to adjust the throttle opening to meet fuel economy requirements at the expense of reliability. When the speed difference is less than -350 r / min, PID control is used to track the speed difference, decreasing the vehicle's throttle opening. However, it is necessary to determine whether the pre-decreased throttle opening value meets the power (torque) requirements. If not, the throttle opening value is reduced to exactly the power requirement.

[0107] 4) Throughout the gear shifting process, the temperature and wear of the clutch friction plates need to be monitored. If the clutch surface temperature exceeds 260°C, a command is sent to the TCU to maximize the clutch friction plate clamping force, ensuring the clutch engages as quickly as possible to prevent excessive slippage during speed adjustment, which could cause the clutch plates to overheat and burn. If significant wear is detected, a command is sent to the TCU to maximize the clutch friction plate clamping force, ensuring the friction plates engage as quickly as possible during gear shifting to reduce wear and extend clutch life. If a speed difference exists between the clutch input and output shafts after full clutch engagement (i.e., clutch slippage), a command is sent to the driver to remind them to replace the friction plates promptly.

[0108] In one embodiment of the present invention, an adaptive shift control system integrating multiple following targets is provided, comprising:

[0109] The prediction module predicts the vehicle's driving conditions based on a pre-built Markov chain of vehicle driving conditions.

[0110] The gear selection module, based on the predicted driving condition information, solves for the optimal gear sequence that achieves the best fuel economy for the vehicle while meeting the requirements of vehicle power performance.

[0111] The control module reduces the impact during clutch engagement through PID control during gear shifting based on the optimal gear sequence. At the same time, it detects the wear and temperature of the clutch friction plates and feeds this information back to the TCU to control the clutch engagement speed and clamping force.

[0112] In the above embodiments, the construction of the Markov chain for vehicle driving conditions includes:

[0113] Select a certain time segment t as the discrete time interval of driving conditions, and divide the vehicle's driving conditions into a discrete and continuous state sequence based on this time interval.

[0114] Read the CAN bus data of the vehicle in motion to obtain the vehicle's speed and time information, and collect the vehicle's acceleration information in real time;

[0115] The obtained vehicle speed, acceleration, and time information are used as inputs to the Markov model. The future speed and acceleration of the vehicle are predicted through the Markov chain. The speed and acceleration in the local prediction time domain are superimposed to obtain the predicted values ​​of global speed and acceleration.

[0116] In the above embodiments, the requirements for vehicle power performance are as follows: the gear sequence that satisfies the constraint condition u+u1∈{1,2,3,…,m} must meet the torque requirements of the vehicle under the current operating conditions, where u is the gear shifting operation signal, u∈{-1,0,1}, u1 is the forward gear of the vehicle, u1∈{1,2,3,…,m}, and m represents the highest forward gear of the vehicle.

[0117] In the above embodiments, the optimal gear for achieving the best fuel economy of the vehicle is obtained using a greedy method, including:

[0118] Read the Markov chain to predict the vehicle's state s at the next time step t+1. t+1 Including the vehicle speed v at the next moment t+1 and acceleration a t+1 ;

[0119] For all selectable gears 1-m, calculate the state S at the current time in gear i. t Transition to the next time step state S t+1 Total fuel consumption required;

[0120] Select the gear that minimizes total fuel consumption, set that gear as the current gear, update the vehicle speed, and update time t to t+1;

[0121] When the predicted end time of the vehicle's journey is reached, the process ends, a unique shift sequence is determined, and the shift sequences from each predicted time domain are superimposed to form the shift control sequence across all time domains, which is the optimal gear sequence.

[0122] In the above embodiments, reducing the impact during clutch engagement through PID control includes:

[0123] When the deviation between the clutch input shaft speed and the clutch output shaft speed is less than -350 r / min, the PID controller outputs the throttle opening adjustment value and checks whether the throttle opening to be reduced to meets the vehicle's power requirements. If it does, it sends the throttle opening value calculated by the PID controller to the ECU; otherwise, it sends the minimum throttle opening value that meets the power requirements at this time to the ECU.

[0124] When the deviation between the clutch input shaft speed and the clutch output shaft speed is zero, a signal is sent to the ECU to maintain this throttle opening.

[0125] When the deviation between the clutch input shaft speed and the clutch output shaft speed is greater than 350 r / min, the ECU is sent with the value of the throttle opening to be increased.

[0126] In the above embodiments, the detection of wear and temperature of the clutch friction plates includes:

[0127] When the temperature of the clutch surface is detected to exceed the preset temperature limit of the engagement surface, a command is sent to the TCU to adjust the clamping force of the clutch friction plate to the maximum, so that the clutch friction plate engages at the fastest speed.

[0128] When the wear of the clutch friction plate exceeds 1 / 4 of its thickness, a command is sent to the TCU to adjust the clutch friction plate clamping force to the maximum, so that the friction plate can be engaged as quickly as possible during gear shifting.

[0129] In the above embodiments, when the wear of the clutch friction plate exceeds 1 / 4 of its thickness, the method further includes: if a speed difference is detected between the clutch input shaft and the output shaft after the clutch is fully engaged, a command is sent to the driver to prompt timely replacement of the friction plate.

[0130] The system provided in this embodiment is used to execute the above-described method embodiments. For specific processes and details, please refer to the above embodiments, which will not be repeated here.

[0131] In summary, the balance between the vehicle's power performance, fuel economy, and reliability is as follows:

[0132] (1) First, the vehicle's power requirements must be met. When using a greedy strategy to find the gear with the best fuel economy, it is necessary to determine whether the predicted gear meets the power (output torque) requirements. If not, the gear should be selected again. When the PID control needs to reduce the throttle opening, it is determined whether the throttle opening value to be reduced meets the power (output torque) requirements. If not, the throttle opening is reduced to a value that just meets the power requirements.

[0133] (2) Under the premise of meeting the power requirements, in order to balance the fuel economy and reliability of the vehicle, a threshold value for the speed difference is set. When the absolute value of the speed difference is greater than this threshold value, in order to reduce the impact of the vehicle during gear shifting, the fuel economy of the vehicle is sacrificed, and the throttle opening of the vehicle is adjusted to meet the reliability requirements. When the absolute value of the speed difference is less than this threshold value, the impact of gear shifting is within an acceptable range, and the reliability is sacrificed to meet the fuel economy requirements.

[0134] (3) During the clutch engagement process, the temperature of the clutch friction plate surface is detected. When the surface temperature exceeds the safe temperature of the friction plate, a command is sent to the TCU to engage the friction plate with the fastest speed and the maximum clamping force to prevent long-term sliding friction from burning the friction plate. At this time, the impact requirement is sacrificed to ensure the life of the friction plate.

[0135] (4) Throughout the vehicle's operation, the wear of the clutch is monitored. When the wear of the clutch friction plates is excessive, a command is sent to the TCU to engage the clutch at the fastest speed and maximum clamping force during each gear shift, reducing the wear of the friction plates. In this case, the impact requirement is sacrificed to extend the life of the friction plates. At the same time, when it is detected that there is a speed difference between the input and output shafts when the clutch is fully engaged, i.e., the clutch friction plates are slipping, the driver is prompted to replace the friction plates in time.

[0136] In one embodiment of the present invention, a computing device is provided, which can be a terminal and may include: a processor, a communication interface, memory, a display screen, and an input device. The processor, communication interface, and memory communicate with each other via a communication bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and a computer program. When the computer program is executed by the processor, it implements an adaptive shift control method integrating multiple following targets. The internal memory provides an environment for the operation of the operating system and computer program in the non-volatile storage medium. The communication interface is used for wired or wireless communication with external terminals. Wireless communication can be achieved through Wi-Fi, a management network, NFC (Near Field Communication), or other technologies. The display screen can be a liquid crystal display or an e-ink display. The input device can be a touch layer covering the display screen, or buttons, a trackball, or a touchpad mounted on the casing of the computing device, or an external keyboard, touchpad, or mouse. The processor can call logical instructions stored in the memory.

[0137] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and sold or used as independent products, and can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0138] In one embodiment of the present invention, a computer program product is provided, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, and when the program instructions are executed by a computer, the computer is able to perform the methods provided in the above-described method embodiments.

[0139] In one embodiment of the present invention, a non-transitory computer-readable storage medium is provided, which stores server instructions that cause a computer to perform the methods provided in the above embodiments.

[0140] The computer-readable storage medium provided in the above embodiments has a similar implementation principle and technical effect to the above method embodiments, and will not be described again here.

[0141] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0142] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0143] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An adaptive shifting control method integrating multiple following targets, characterized in that, include: Based on a pre-constructed Markov chain of vehicle driving conditions, the driving conditions of the vehicle are predicted. Based on the predicted driving condition information, and while meeting the vehicle's power requirements, the optimal gear sequence for achieving the best fuel economy is determined using a greedy method. This method includes: reading the Markov chain to predict the vehicle's state s at the next time step t+1. t+1 Including the vehicle speed v at the next moment t+1 and acceleration a t+1 For all selectable gears 1-m, calculate the state S at the current time in gear i. t Transition to the next time step state S t+1 Total fuel consumption required; Select the gear that minimizes total fuel consumption, use that gear as the current gear, update the vehicle speed, and update time t to t+1; when the predicted end time of the vehicle's journey is reached, the process ends, a unique shift sequence is determined, and the shift sequences of each predicted time domain are superimposed to form the shift control sequence in the entire time domain, which is the optimal gear sequence. During gear shifting based on the optimal gear sequence, PID control is used to reduce the impact during clutch engagement. At the same time, the wear and temperature of the clutch friction plates are detected and fed back to the TCU to control the clutch engagement speed and clamping force.

2. The adaptive shifting control method integrating multiple following targets as described in claim 1, characterized in that, The construction of the Markov chain for vehicle driving conditions includes: Select a certain time segment t as the discrete time interval of driving conditions, and divide the vehicle's driving conditions into a discrete and continuous state sequence based on this time interval. Read the CAN bus data of the vehicle in motion to obtain the vehicle's speed and time information, and collect the vehicle's acceleration information in real time; The obtained vehicle speed, acceleration, and time information are used as inputs to the Markov model. The future speed and acceleration of the vehicle are predicted through the Markov chain. The speed and acceleration in the local prediction time domain are superimposed to obtain the predicted values ​​of global speed and acceleration.

3. The adaptive shifting control method integrating multiple following targets as described in claim 1, characterized in that, The requirements for vehicle dynamics are as follows: the gear sequence that satisfies the constraint u+u1∈{1,2,3,…,m} must meet the torque requirements of the vehicle under the current operating conditions, where u is the gear shifting operation signal, u∈{-1,0,1}, u1 is the forward gear of the vehicle, u1∈{1,2,3,…,m}, and m represents the highest forward gear of the vehicle.

4. The adaptive shifting control method integrating multiple following targets as described in claim 1, characterized in that, PID control is used to reduce the impact during clutch engagement, including: When the deviation between the clutch input shaft speed and the clutch output shaft speed is less than zero, the PID controller outputs the throttle opening adjustment value and checks whether the throttle opening to be reduced to meets the vehicle's power requirements. If it does, the PID controller sends the throttle opening value calculated by the PID controller to the ECU; otherwise, the PID controller sends the minimum throttle opening value that meets the power requirements at this time to the ECU. When the deviation between the clutch input shaft speed and the clutch output shaft speed is zero, a signal is sent to the ECU to maintain this throttle opening. When the deviation between the clutch input shaft speed and the clutch output shaft speed is greater than 350 r / min, the ECU is sent with the value of the throttle opening to be increased.

5. The adaptive shifting control method integrating multiple following targets as described in claim 1, characterized in that, The wear and temperature of the clutch friction plates are measured, including: When the temperature of the clutch surface is detected to exceed the preset temperature limit of the engagement surface, a command is sent to the TCU to adjust the clamping force of the clutch friction plate to the maximum, so that the clutch friction plate engages at the fastest speed. When the wear of the clutch friction plate exceeds 1 / 4 of its thickness, a command is sent to the TCU to adjust the clutch friction plate clamping force to the maximum, so that the friction plate can be engaged as quickly as possible during gear shifting.

6. The adaptive shifting control method integrating multiple following targets as described in claim 5, characterized in that, When the wear of the clutch friction plate exceeds 1 / 4 of its thickness, the following is also included: if a speed difference is detected between the clutch input shaft and the output shaft after the clutch is fully engaged, an instruction is sent to the driver to remind him to replace the friction plate in time.

7. An adaptive shift control system integrating multiple following targets, used to implement the adaptive shift control method integrating multiple following targets as described in any one of claims 1 to 6, characterized in that, include: The prediction module predicts the vehicle's driving conditions based on a pre-built Markov chain of vehicle driving conditions. The gear selection module, based on the predicted driving condition information, solves for the optimal gear sequence that achieves the best fuel economy for the vehicle while meeting the requirements of vehicle power performance. The control module reduces the impact during clutch engagement through PID control during gear shifting based on the optimal gear sequence. At the same time, it detects the wear and temperature of the clutch friction plates and feeds this information back to the TCU to control the clutch engagement speed and clamping force.

8. A computer-readable storage medium for storing one or more programs, characterized in that, The one or more programs include instructions that, when executed by a computing device, cause the computing device to perform any of the methods described in claims 1 to 6.

9. A computing device, characterized in that, include: One or more processors, a memory, and one or more programs, wherein the one or more programs are stored in the memory and configured to be executed by the one or more processors, the one or more programs including instructions for performing any of the methods described in claims 1 to 6.

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