A gear limiting method, apparatus and electronic device

Abstract

This application discloses a gear-limiting method, apparatus, and electronic device. The method includes: obtaining the rolling resistance coefficient of the current road surface; calculating the gear position using the rolling resistance coefficient to obtain a limited gear position; and obtaining a decision gear position, which is the gear position determined by the default automatic shifting decision. The rolling resistance coefficient in the default automatic shifting decision is a fixed value, and the limited gear position restricts the decision gear position. This method can limit the gear position determined by the default automatic shifting decision in real time based on the rolling resistance coefficient of the current road surface, effectively avoiding gear position problems that occur when the vehicle experiences different resistance levels.

Description

Technical Field

[0001] This application relates to the field of vehicle engineering, and more specifically, to a gear limiting method, apparatus, and electronic device. Background Technology

[0002] With technological advancements, automatic transmission vehicles have gradually replaced manual transmission vehicles. In automatic transmission vehicles, the automatic gearbox determines the gear and automatically shifts based on a default automatic shifting decision. However, when the road surface experiences significant changes in resistance, the default automatic shifting decision struggles to flexibly determine the appropriate gear for the current road conditions, easily leading to frequent gear changes. For example, when a vehicle is traveling on a smooth, dry road and the road ahead becomes muddy, the resistance on muddy roads differs from that on smooth, dry roads. If the automatic shifting decision for smooth, dry roads is applied, the current gear might be too high. This results in insufficient traction, causing the vehicle to slow down. When the speed drops to the downshift speed, a downshift is triggered. After downshifting, the vehicle has sufficient traction, and the speed increases. When the speed rises to the upshift speed, an upshift is triggered, resulting in frequent gear changes. Therefore, the current automatic shifting decision method leads to the problem of frequent gear changes. Summary of the Invention

[0003] In view of this, this application provides a gear limiting method, apparatus and electronic device for solving the problem of frequent gear shifting in vehicles.

[0004] To achieve the above objectives, the proposed solution is as follows:

[0005] A gear limiting method, the method comprising:

[0006] Obtain the rolling resistance coefficient of the current road surface;

[0007] The rolling resistance coefficient is used to calculate the gear position and obtain the limited gear position.

[0008] Obtain the decision gear, which is the gear determined by the default automatic shift decision; the rolling resistance coefficient in the default automatic shift decision is a fixed value;

[0009] The decision gear is restricted by the aforementioned limiting gear.

[0010] Optionally, obtaining the rolling resistance coefficient of the current road surface includes:

[0011] The least squares algorithm is used to evaluate the objective equation.

[0012] F t -F i -F w-m / t×(V2-V1)=mgcosθ×f

[0013] The rolling resistance coefficient f of the current road surface is estimated to obtain the rolling resistance coefficient, where F t For vehicle power, F i For slope resistance, F w Let t be the air resistance, t be the vehicle travel time, m be the vehicle mass, V1 be the initial instantaneous velocity of the vehicle during the time interval t, V2 be the final instantaneous velocity of the vehicle during the time interval t, g be the gravitational acceleration, f be the rolling resistance coefficient, and θ be the slope angle.

[0014] Optionally, the step of using the rolling resistance coefficient to calculate the gear position and obtain the limiting gear position includes:

[0015] Obtain calculation parameters, which include at least one of the following: input torque of automatic transmission, rear gear ratio, efficiency of vehicle transmission system, vehicle tire radius, vehicle mass, gravitational acceleration, slope angle, drag coefficient, vehicle frontal area, air density, vehicle current speed, vehicle rotational mass conversion factor, and vehicle acceleration.

[0016] The limiting gear is obtained by using the rolling resistance coefficient and the calculation parameters.

[0017] Optionally, obtaining the limiting gear using the rolling resistance coefficient and the calculation parameters includes:

[0018] Substitute the rolling resistance coefficient and the calculation parameters into the formula:

[0019] (T in ×i GearMax ×i0×η T ) / r w =mgcosα×f+1 / 2(C D +A×ρ×v 2 )+mgsinα+δ M i is obtained by calculating ×(dv / dt). GearMax , among which, T in i is the input torque of the automatic transmission. GearMax Let i0 be the transmission ratio, i0 be the transmission ratio of the rear car, and η be the transmission ratio. T r is the efficiency of the vehicle transmission system. w Let m be the radius of the vehicle tire, g be the mass of the vehicle, f be the acceleration due to gravity, α be the rolling resistance coefficient, and C be the slope angle. D Let A be the drag coefficient, ρ be the vehicle's frontal area, v be the air density, and δ be the vehicle's current speed. M Here is the conversion factor for the vehicle's rotational mass, and dv / dt is the vehicle's acceleration;

[0020] i GearMax The corresponding gear is determined to be the restricted gear.

[0021] Optionally, limiting the decision gear through the limiting gear includes:

[0022] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0023] And / or,

[0024] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0025] And / or,

[0026] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0027] And / or,

[0028] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0029] Optional, also includes:

[0030] If the limiting gear is equal to the decision gear, then the target gear of the vehicle is either the limiting gear or the decision gear.

[0031] Optional, also includes:

[0032] If the vehicle is in a state of waiting to shift up, the vehicle speed loss is calculated and the engine speed of the vehicle after shifting is predicted based on the vehicle speed loss. The state of waiting to shift up is a state in which both the limiting gear and the decision gear are greater than the current gear of the vehicle.

[0033] If the engine speed is lower than the preset speed protection threshold, the vehicle will delay upshifting.

[0034] Optionally, calculating the vehicle speed loss and predicting the engine speed of the vehicle after shifting based on the speed loss includes:

[0035] Obtain the vehicle's driving resistance and shift time;

[0036] The drag acceleration is obtained through the driving resistance;

[0037] Through the formula:

[0038] v loss =a 阻 ×t shift The vehicle speed loss v is calculated. loss , where a 阻 Let t be the drag acceleration. shift The shift time is mentioned.

[0039] Through the formula:

[0040] n after =[(vv loss )×60×i0×i geartarget ] / 2πr w The engine speed n of the vehicle after the gear shift is obtained. after The predicted value, where v is the current speed of the vehicle, r w v is the radius of the vehicle tires. loss The speed loss, i0 is the rear gear ratio, i geartarget The gear ratio is the gear ratio corresponding to the target gear of the vehicle, where the target gear is either the limiting gear or the decision gear.

[0041] A gear limiting device, the device comprising:

[0042] Rolling resistance coefficient acquisition unit, used to acquire the rolling resistance coefficient of the current road surface;

[0043] A gear limit acquisition unit is used to calculate the gear limit using the rolling resistance coefficient;

[0044] A decision gear acquisition unit is used to acquire a decision gear, wherein the decision gear is the gear determined by the default automatic shift decision; the rolling resistance coefficient in the default automatic shift decision is a fixed value;

[0045] A limiting unit is used to limit the decision gear through the limiting gear.

[0046] An electronic device, comprising a memory and a processor;

[0047] The memory is used to store programs;

[0048] The processor is used to execute the program to implement each step of the gear limiting method described above.

[0049] This application provides a gear-limiting method, device, and electronic device. The method calculates a limited gear based on the rolling resistance coefficient of the current road surface, limits the decision gear based on the limited gear, and determines the vehicle's final target gear by comparing the limited gear and the decision gear. This method can limit the gear determined by the default automatic shift decision in real time based on the rolling resistance coefficient of the current road surface, effectively avoiding gear-related problems when the vehicle experiences different resistance levels. Attached Figure Description

[0050] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0051] Figure 1 A flowchart illustrating a gear-position limiting method provided in an embodiment of this application;

[0052] Figure 2 This is a schematic diagram of the structure of a gear limiting device provided in an embodiment of this application;

[0053] Figure 3 This is a hardware structure block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

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

[0055] like Figure 1 As shown in the figure, this application provides a gear limiting method, which may include:

[0056] S10. Obtain the rolling resistance coefficient of the current road surface;

[0057] S11. Use the rolling resistance coefficient to calculate the gear position and obtain the limiting gear.

[0058] S12. Obtain the decision gear, which is the gear determined by the default automatic shift decision; the rolling resistance coefficient in the default automatic shift decision is a fixed value;

[0059] S13. Limit the decision gear by limiting the gear position.

[0060] Different road surfaces exert varying resistance on vehicles; for example, the resistance of a gravel road differs from that of a smooth road. The rolling resistance coefficient is the ratio of the thrust required for a wheel to roll under certain conditions to the wheel load. Because different road surfaces have different resistances, the thrust required by the vehicle under the same wheel load varies, and consequently, the rolling resistance coefficient differs. The rolling resistance coefficient can be obtained through various means; in this embodiment, it can be obtained through sensing devices or calculated from empirical data. The rolling resistance coefficient is related to the road surface's driving resistance, which affects the vehicle's speed. Vehicle speed corresponds to the vehicle's gear, so in this embodiment, the vehicle's gear can be calculated using the rolling resistance coefficient. A gear limit is a setting that restricts the vehicle's gear selection. During upshifting, the highest gear is limited; during downshifting, the lowest gear is limited. By limiting the vehicle's gears, frequent gear changes are effectively avoided. The default automatic shift decision is a built-in shift decision in the vehicle's program. This default automatic shift decision mainly calculates the vehicle's current gear, i.e., the decision gear, based on vehicle speed, engine speed, and a fixed rolling resistance coefficient. Because the default automatic shift decision uses a fixed rolling resistance coefficient when calculating the vehicle's gear, it cannot flexibly calculate the vehicle's gear according to the resistance of different road surfaces, leading to gear problems such as frequent shifting. Due to the shortcomings of the default automatic shift decision, this embodiment can restrict the decision gear calculated by the default automatic shift decision based on a limiting gear, effectively reducing the possibility of gear problems.

[0061] This application provides a gear-limiting method. This method calculates a limited gear based on the rolling resistance coefficient of the current road surface, limits the decision gear based on the limited gear, and determines the vehicle's final target gear by comparing the limited gear and the decision gear. This method can limit the gear determined by the default automatic shifting decision in real time based on the rolling resistance coefficient of the current road surface, effectively avoiding gear problems that occur when the vehicle experiences different resistance levels. Furthermore, it effectively reduces the problem of insufficient power and frequent gear shifting when the vehicle experiences high driving resistance.

[0062] According to another gear limiting method provided in the embodiments of this application, Figure 1 Step S10 shown may specifically include:

[0063] The least squares algorithm is used to evaluate the objective equation.

[0064] F t -F i -F w -m / t×(V2-V1)=mgcosθ×f

[0065] The rolling resistance coefficient f of the current road surface is estimated to obtain the rolling resistance coefficient, where F t For vehicle power, F i For slope resistance, F w Let t be the air resistance, t be the vehicle travel time, m be the vehicle mass, V1 be the initial instantaneous velocity of the vehicle during the time interval t, V2 be the final instantaneous velocity of the vehicle during the time interval t, g be the gravitational acceleration, f be the rolling resistance coefficient, and θ be the slope angle.

[0066] The objective equation is the formula for calculating the rolling resistance coefficient. Optionally, the objective equation can be obtained by transforming existing formulas and theorems, or it can be directly written. In this embodiment, it is obtained through the vehicle dynamics equation: F t =F f +F w +F i +F j The momentum theorem, F×Δt=m×Δv, is derived by transformation, where F j Acceleration resistance is the inertial force that helps the vehicle maintain a constant speed while moving. Since the vehicle is assumed to be in a non-accelerated state when estimating the rolling resistance coefficient, F... j =0. Since the rolling resistance coefficient varies depending on the road surface and tire model, theoretical calculations are complex and the parameters involved are difficult to obtain. Therefore, this application estimates the rolling resistance parameter. In this embodiment, when estimating the rolling resistance coefficient using the least squares method, reasonable enabling conditions need to be set, i.e., the conditions for using the objective equation. Since the ideal state is when the vehicle's power system is fully engaged, there are no external forces or other energy consumption besides rolling resistance, gradient resistance, air resistance, and acceleration resistance, this embodiment can set the enabling condition to be that during non-shifting processes, the vehicle speed needs to be greater than the starting speed (when the vehicle is starting, the clutch is in a slipping state, and clutch slippage is an additional energy consumption), and the vehicle is in a non-braking state. This enabling condition can effectively simulate the ideal state of the vehicle. This embodiment can substitute multiple sets of sample values ​​into the objective equation and estimate the rolling resistance coefficient of the current road surface using the least squares method. Vehicle power F t The air resistance F can be calculated based on the transmitter speed. w The gradient resistance F is related to vehicle speed. i Vehicle speed can be accurately obtained, which is related to road slope, and road slope and slope angle θ can be accurately obtained through sensors.

[0067] According to another gear limiting method provided in the embodiments of this application, Figure 1 Step S11 shown may include step one and step two:

[0068] Step 1: Obtain calculation parameters, which include at least one of the following: input torque of automatic transmission, rear gear ratio, efficiency of vehicle transmission system, vehicle tire radius, vehicle mass, gravitational acceleration, slope angle, drag coefficient, vehicle frontal area, air density, vehicle current speed, vehicle rotational mass conversion factor, and vehicle acceleration.

[0069] Step 2: Obtain the limiting gear through the rolling resistance coefficient and calculation parameters.

[0070] The calculated parameters can be vehicle-related parameters, used together with the rolling resistance coefficient to calculate the vehicle's limiting gear. The calculated parameters are not limited to those mentioned above. The automatic transmission's input torque, rear-wheel drive ratio, vehicle transmission system efficiency, current vehicle speed, and vehicle acceleration can be directly obtained from the vehicle's current state. Vehicle tire radius, vehicle mass, drag coefficient, frontal area, and vehicle rotational mass conversion factor are default vehicle parameters and can be considered known quantities. Gravitational acceleration and air density can also be considered known quantities, and the slope angle can be obtained through sensors. The rear gear ratio is the gear ratio of the final drive reducer in the vehicle's drive axle; the efficiency of the vehicle's transmission system is the percentage of energy lost from the engine's output power before it reaches the wheels; the drag coefficient is a mathematical parameter determined through wind tunnel and glide slope experiments. It is used to calculate the air resistance of a vehicle during driving. The drag coefficient can be a default parameter for the vehicle, such as the drag coefficient of a traditional gasoline-powered vehicle, which is in the range of 0.28 to 0.4 Cd; the vehicle's frontal area is the projected area in the vehicle's direction of travel, which can be obtained through measurement using a three-dimensional digital model. If the three-dimensional data is incomplete, it can be measured through the overall layout drawing; the vehicle's rotational mass conversion factor is used when calculating the vehicle's acceleration resistance. This factor converts the inertial drag torque of the rotational mass into the inertial drag of the translational mass. The value of this factor is approximately in the range of [1.1, 1.4]. Since the calculation parameters are related to the vehicle's real-time state and the rolling resistance coefficient is related to road surface resistance, this embodiment can calculate the vehicle's limiting gear based on the rolling resistance coefficient and the calculation parameters.

[0071] In another gear limiting method provided according to an embodiment of this application, step two may include steps three and four:

[0072] Step 3: Substitute the rolling resistance coefficient and calculation parameters into the formula:

[0073] (T in ×i GearMax ×i0×η T ) / r w =mgcosα×f+1 / 2(C D +A×ρ×v 2)+mgsinα+δ M i is obtained by calculating ×(dv / dt). GearMax , among which, T in i is the input torque of the automatic transmission. GearMax η is the transmission ratio, i0 is the rear car transmission ratio, and η is the transmission ratio. T For the efficiency of the vehicle transmission system, r w Let m be the vehicle tire radius, g be the vehicle mass, f be the gravitational acceleration, α be the rolling resistance coefficient, and C be the slope angle. D Here, A is the drag coefficient, ρ is the vehicle's frontal area, v is the air density, and δ is the vehicle's current speed. M dv / dt is the vehicle's rotational mass conversion factor, and dv / dt is the vehicle's acceleration.

[0074] Step 4: Set i GearMax The corresponding gear is determined to be a restricted gear.

[0075] In this embodiment, the transmission ratio i is calculated using the rolling resistance coefficient and calculation parameters. GearMax This allows us to obtain different transmission ratios under different rolling resistance coefficients. The transmission ratio, also known as the speed ratio, refers to the ratio of the rotational speeds of the input shaft to the output shaft. A higher rolling resistance coefficient indicates greater vehicle resistance, a higher transmission ratio, and a lower gear; conversely, a lower rolling resistance coefficient indicates less vehicle resistance, a lower transmission ratio, and a higher gear. Since different transmission ratios correspond to different gears, the vehicle's maximum gear can be determined based on the real-time calculated transmission ratio.

[0076] According to another gear limiting method provided in the embodiments of this application, Figure 1 Step S13 shown may specifically include:

[0077] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0078] And / or,

[0079] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0080] And / or,

[0081] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0082] And / or,

[0083] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0084] And / or,

[0085] If the limiting gear is equal to the decision gear, then the vehicle's target gear is either the limiting gear or the decision gear.

[0086] The limiting gear can be used to restrict the decision-making gear, effectively preventing the vehicle from shifting into a high gear under high resistance or a low gear under low resistance. The limiting gear can effectively reduce the possibility of gear selection issues under varying resistance levels. When the decision-making gear is greater than the limiting gear, the target gear can be determined as the decision-making gear; when the decision-making gear is less than the limiting gear, the limiting gear does not restrict the decision-making gear, and the target gear can be determined as the decision-making gear.

[0087] In another gear limiting method provided according to the embodiments of this application, steps six to nine may also be included:

[0088] Step Six: If the vehicle is in a position to upshift, proceed to Step Seven;

[0089] Step 7: Calculate the vehicle speed loss and predict the engine speed after shifting based on the speed loss. The upshift state is when both the limiting gear and the decision gear are greater than the vehicle's current gear.

[0090] Step 8: If the engine speed is lower than the preset speed protection threshold, proceed to step 9;

[0091] Step 9: Delay upshifting the vehicle.

[0092] Automatic transmission shifting involves power interruption, during which the clutch disengages, leaving the vehicle without power. Due to the lack of power and road resistance, the vehicle experiences speed loss during shifting. This speed loss is more pronounced on roads with high resistance, leading to low engine speeds after the shift. Low engine speed results in insufficient power, and in severe cases, the target gear may be impossible to engage. To effectively avoid this, this embodiment predicts the engine speed after the target gear is determined and uses the predicted value to decide whether immediate shifting is possible. This embodiment addresses upshifting; if downshifting is required, it can be done directly. A preset speed protection threshold, determined experimentally, is a known value in this embodiment. If the engine speed after shifting exceeds the preset speed protection threshold, normal upshifting is possible.

[0093] In another gear limiting method provided according to an embodiment of this application, step seven may include steps ten to fourteen:

[0094] Step 10: Obtain the vehicle's driving resistance and shift time;

[0095] Step 11: Obtain drag acceleration through driving resistance;

[0096] Step 12: Using the formula:

[0097] v loss =a 阻 ×t shift Calculate the vehicle speed loss v loss , where a 阻 For drag acceleration, t shift This refers to the shift time;

[0098] Step Thirteen: Using the formula:

[0099] n after =[(vv loss )×60×i0×i geartarget ] / 2πr w Obtain the engine speed n of the vehicle after shifting gears. after The predicted value, where v is the vehicle's current speed, r w v is the radius of the vehicle tires. loss Speed ​​loss, i0 is the rear gear ratio, i geartarget This refers to the gear ratio corresponding to the target gear of the vehicle, where the target gear is either a limiting gear or a decision gear.

[0100] The driving resistance can be calculated based on the rolling resistance coefficient, and the shift time can be determined empirically, with its value being an average. In this embodiment, after obtaining the driving resistance, the formula is:

[0101] F 阻 =m×a 阻

[0102] The resistance acceleration is calculated. In this embodiment, the target gear of the vehicle has been determined, so the gear ratio i corresponding to the target gear can be used. geartarget Calculate the engine speed n of the vehicle after shifting gears. after The predicted value. This embodiment can calculate the predicted engine speed after gear shifting based on the rolling resistance coefficient, and limit the predicted engine speed after gear shifting by setting a preset speed protection threshold. This can effectively avoid situations where the vehicle's power is insufficient or even unable to complete the gear shift due to excessively low engine speed after shifting.

[0103] Corresponding to the gear limiting method provided in the embodiments of this application, the embodiments of this application also provide a gear limiting device.

[0104] like Figure 2 As shown, this application embodiment provides a gear limiting device, which may include:

[0105] Rolling resistance coefficient acquisition unit 100 is used to acquire the rolling resistance coefficient of the current road surface;

[0106] The gear limit acquisition unit 110 is used to calculate the gear using the rolling resistance coefficient to obtain the gear limit.

[0107] The decision gear acquisition unit 120 is used to acquire the decision gear, which is the gear determined by the default automatic shift decision; the rolling resistance coefficient in the default automatic shift decision is a fixed value.

[0108] The limiting unit 130 is used to limit the decision gear by limiting the gear position.

[0109] In another gear limiting device provided according to an embodiment of this application, the rolling resistance coefficient acquisition unit 100 can be specifically configured as follows:

[0110] The least squares algorithm is used to evaluate the objective equation.

[0111] F t -F i -F w -m / t×(V2-V1)=mgcosθ×f

[0112] The rolling resistance coefficient f of the current road surface is estimated to obtain the rolling resistance coefficient, where F t For vehicle power, F i For slope resistance, F w Let t be the air resistance, t be the vehicle travel time, m be the vehicle mass, V1 be the initial instantaneous velocity of the vehicle during the time interval t, V2 be the final instantaneous velocity of the vehicle during the time interval t, g be the gravitational acceleration, f be the rolling resistance coefficient, and θ be the slope angle.

[0113] In another gear limiting device provided according to an embodiment of this application, the gear limiting acquisition unit 110 may include:

[0114] The calculation parameter subunit is used to obtain calculation parameters, which include at least one of the following: input torque of automatic transmission, rear gear ratio, efficiency of vehicle transmission system, vehicle tire radius, vehicle mass, gravitational acceleration, slope angle, drag coefficient, vehicle frontal area, air density, vehicle current speed, vehicle rotational mass conversion factor, and vehicle acceleration.

[0115] The gear calculation subunit is used to obtain the limiting gear through the rolling resistance coefficient and calculation parameters.

[0116] In another gear limiting device provided according to an embodiment of this application, the gear calculation subunit may include:

[0117] The formula calculation sub-unit is used to input the rolling resistance coefficient and calculation parameters into the formula:

[0118] (T in ×i GearMax ×i0×η T ) / r w =mgcosα×f+1 / 2(C D +A×ρ×v 2 )+mgsinα+δ M i is obtained by calculating ×(dv / dt). GearMax , among which, T in i is the input torque of the automatic transmission. GearMax η is the transmission ratio, i0 is the rear car transmission ratio, and η is the transmission ratio. T For the efficiency of the vehicle transmission system, r w Let m be the vehicle tire radius, g be the vehicle mass, f be the gravitational acceleration, α be the rolling resistance coefficient, and C be the slope angle. D Here, A is the drag coefficient, ρ is the vehicle's frontal area, v is the air density, and δ is the vehicle's current speed. M dv / dt is the vehicle's rotational mass conversion factor, and dv / dt is the vehicle's acceleration.

[0119] The gear corresponding subunit is used to set i GearMax The corresponding gear is determined to be a restricted gear.

[0120] In another gear limiting device provided according to an embodiment of this application, the limiting unit 130 is specifically configured as follows:

[0121] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0122] And / or,

[0123] If both the limiting gear and the decision gear are greater than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0124] And / or,

[0125] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is greater than the decision gear, then the vehicle's target gear is determined as the decision gear.

[0126] And / or,

[0127] If both the limiting gear and the decision gear are less than the vehicle's current gear, and the limiting gear is less than the decision gear, then the vehicle's target gear is determined as the limiting gear.

[0128] Another gear limiting device provided according to an embodiment of this application may further include:

[0129] If the limiting gear is equal to the decision gear, then the gear determination subunit is triggered;

[0130] The gear selection subunit is used to determine the target gear of the vehicle as either a limiting gear or a decision gear.

[0131] Another gear limiting device provided according to an embodiment of this application may further include:

[0132] If the vehicle is in a state of waiting to upshift, the loss calculation subunit is triggered;

[0133] The loss calculation subunit is used to calculate the vehicle speed loss and predict the engine speed of the vehicle after shifting based on the speed loss. The upshift state is when both the limiting gear and the decision gear are greater than the current gear of the vehicle.

[0134] If the engine speed is lower than the preset speed protection threshold, the delayed upshift subunit will be triggered;

[0135] Delayed upshift subunit, used to delay upshifting in vehicles.

[0136] In another gear limiting device provided according to an embodiment of this application, the aforementioned loss calculation subunit may include:

[0137] The gear parameter acquisition subunit is used to obtain the vehicle's driving resistance and shift time;

[0138] The drag acceleration acquisition subunit is used to obtain drag acceleration through driving resistance.

[0139] The vehicle speed loss calculation subunit is used to calculate the speed loss using the following formula:

[0140] v loss =a 阻 ×t shift Calculate the vehicle speed loss v loss , where a 阻 For drag acceleration, t shift This refers to the shift time;

[0141] The engine speed prediction subunit is used to predict engine speed using the formula:

[0142] n after =[(vv loss )×60×i0×igeartarget ] / 2πr w Obtain the engine speed n of the vehicle after shifting gears. after The predicted value, where v is the vehicle's current speed, r w v is the radius of the vehicle tires. loss Speed ​​loss, i0 is the rear gear ratio, i geartarget This refers to the gear ratio corresponding to the target gear of the vehicle, where the target gear is either a limiting gear or a decision gear.

[0143] like Figure 3 As shown, this application embodiment also provides an electronic device 70, including at least one processor 701, and at least one memory 702 and a bus 703 connected to the processor 701; wherein, the processor 701 and the memory 702 communicate with each other through the bus 703; the processor 701 is used to call program instructions in the memory 702 to execute the above-mentioned gear limiting method. The electronic device 70 in this document can be a server, PC, PAD, mobile phone, etc.

[0144] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. 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... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0145] In a typical configuration, the device includes one or more processors (CPUs), memory, and a bus. The device may also include input / output interfaces, network interfaces, etc.

[0146] Memory may include non-persistent memory in computer-readable storage media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and memory includes at least one memory chip. Memory is an example of a computer-readable medium.

[0147] Computer-readable storage media include both permanent and non-permanent, removable and non-removable media that can store information by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0148] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0149] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0150] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0151] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A gear position limiting method, characterized in that, The method includes: Obtaining the rolling resistance coefficient of the current road surface; Using the rolling resistance coefficient to calculate the gear position and obtaining the restricted gear position; Obtaining the decision gear position, where the decision gear position is the gear position determined by the default automatic shifting decision; the rolling resistance coefficient in the default automatic shifting decision is a fixed value; Restricting the decision gear position by the restricted gear position; Where, the using the rolling resistance coefficient to calculate the gear position and obtaining the restricted gear position includes: Obtaining calculation parameters, where the calculation parameters include at least one of the input torque of the automatic transmission, the rear axle transmission ratio, the efficiency of the vehicle transmission system, the vehicle tire radius, the vehicle mass, the gravitational acceleration, the slope angle, the wind resistance coefficient, the vehicle frontal area, the air density, the current vehicle speed, the vehicle rotating mass conversion coefficient, and the vehicle acceleration; Substituting the rolling resistance coefficient and the calculation parameters into the formula: (T in × i GearMax × i0 × η T ) / r w = mg cos α × f + 1 / 2 (C D + A × ρ × v 2 ) + mgsinα + δ M × (dv / dt) Calculate to obtain i GearMax , where T in is the input torque of the automatic transmission, i GearMax is the transmission ratio, i0 is the rear axle transmission ratio, η T is the efficiency of the vehicle transmission system, r w is the radius of the vehicle tire, m is the mass of the vehicle, g is the acceleration due to gravity, f is the rolling resistance coefficient, α is the slope angle, C D is the air resistance coefficient, A is the frontal area of the vehicle, ρ is the air density, v is the current speed of the vehicle, δ M is the conversion coefficient of the rotating mass of the vehicle, dv / dt is the acceleration of the vehicle; Determine the corresponding gear position as the restricted gear position; GearMax Determine the corresponding gear position as the restricted gear position; The restricting the decision gear position by the restricted gear position includes: If both the restricted gear position and the decision gear position are greater than the current gear position of the vehicle, and the restricted gear position is greater than the decision gear position, then determining the target gear position of the vehicle as the decision gear position; If both the restricted gear position and the decision gear position are greater than the current gear position of the vehicle, and the restricted gear position is less than the decision gear position, then determining the target gear position of the vehicle as the restricted gear position; If both the restricted gear position and the decision gear position are less than the current gear position of the vehicle, and the restricted gear position is greater than the decision gear position, then determining the target gear position of the vehicle as the decision gear position; If both the restricted gear position and the decision gear position are less than the current gear position of the vehicle, and the restricted gear position is less than the decision gear position, then determining the target gear position of the vehicle as the restricted gear position.

2. The method according to claim 1, wherein The obtaining the rolling resistance coefficient of the current road surface includes: Using the least squares algorithm for the target equation F t -F i -F w -m / t × (V2 - V1) = mgcosθ × f Estimate the rolling resistance coefficient f of the current road surface in it to obtain the rolling resistance coefficient, where F t is the vehicle power, F i is the slope resistance, F w is the air resistance, t is the vehicle driving time, m is the vehicle mass, V1 is the starting instantaneous speed of the vehicle within the t time period, V2 is the ending instantaneous speed of the vehicle within the t time period, g is the acceleration due to gravity, f is the rolling resistance coefficient, and θ is the slope angle.

3. The method according to claim 1, wherein It further includes: If the restricted gear position is equal to the decision gear position, then the target gear position of the vehicle is the restricted gear position or the decision gear position.

4. The method according to claim 1, wherein It further includes: If the vehicle is in a state of waiting to upshift, then calculating the vehicle speed loss amount of the vehicle and predicting the engine speed of the vehicle after shifting according to the vehicle speed loss amount, where the state of waiting to upshift is the state where both the restricted gear position and the decision gear position are greater than the current gear position of the vehicle; If the engine speed is lower than the preset speed protection threshold, then the vehicle delays upshifting.

5. The method according to claim 4, wherein The calculating the vehicle speed loss amount of the vehicle and predicting the engine speed of the vehicle after shifting according to the vehicle speed loss amount includes: Obtaining the driving resistance and the shifting time of the vehicle; Obtaining the resistance acceleration through the driving resistance; Through the formula: v loss = a 阻 × t shift Calculate to obtain the vehicle speed loss v loss , where a 阻 is the drag acceleration, and t shift is the shift time; Through the formula: n after =[(v - v loss )×60×i0×i geartarget / 2πr w Obtain the predicted value of the engine speed n of the vehicle after shifting gears, where v is the current vehicle speed of the vehicle, r after is the radius of the vehicle tire, v w is the vehicle speed loss, i0 is the rear axle transmission ratio, i loss is the transmission ratio corresponding to the target gear of the vehicle, and the target gear is the restricted gear or the decision gear.​​ 6. A gear position limiting device, characterized in that, The device includes: A rolling resistance coefficient obtaining unit, configured to obtain the rolling resistance coefficient of the current road surface; A restricted gear position obtaining unit, configured to use the rolling resistance coefficient to calculate the gear position and obtain the restricted gear position; A decision gear position obtaining unit, configured to obtain the decision gear position, where the decision gear position is the gear position determined by the default automatic shifting decision; the rolling resistance coefficient in the default automatic shifting decision is a fixed value; A restricting unit, configured to restrict the decision gear position by the restricted gear position; Among them, the restricted gear obtaining unit includes: A calculation parameter sub-unit, configured to obtain calculation parameters, where the calculation parameters include at least one of the input torque of the automatic transmission, the rear axle transmission ratio, the efficiency of the vehicle transmission system, the vehicle tire radius, the vehicle mass, the gravitational acceleration, the slope angle, the wind resistance coefficient, the vehicle frontal area, the air density, the current vehicle speed, the vehicle rotating mass conversion coefficient, and the vehicle acceleration; A gear calculation sub-unit, configured to obtain the restricted gear based on the rolling resistance coefficient and the calculation parameters; The gear calculation sub-unit includes: A formula calculation sub-unit, configured to substitute the rolling resistance coefficient and the calculation parameters into the formula: (T in × i GearMax × i0 × η T ) / r w = mgcosα × f + 1 / 2 (C D + A × ρ × v 2 ) + mgsinα + δ M × (dv / dt) Calculate to obtain i GearMax , where T in is the input torque of the automatic transmission, i GearMax is the transmission ratio, i0 is the rear axle transmission ratio, η T is the efficiency of the vehicle transmission system, r w is the radius of the vehicle tire, m is the vehicle mass, g is the acceleration due to gravity, f is the rolling resistance coefficient, α is the slope angle, C D is the wind resistance coefficient, A is the frontal area of the vehicle, ρ is the air density, v is the current speed of the vehicle, δ M is the conversion coefficient of the rotating mass of the vehicle, dv / dt is the vehicle acceleration; The gear position corresponding subunit is used to determine the gear position corresponding to i GearMax as the restricted gear position; The restriction unit is specifically configured as follows: If both the restricted gear and the decision gear are greater than the current gear of the vehicle, and the restricted gear is greater than the decision gear, then the target gear of the vehicle is determined to be the decision gear; If both the restricted gear and the decision gear are greater than the current gear of the vehicle, and the restricted gear is less than the decision gear, then the target gear of the vehicle is determined to be the restricted gear; If both the restricted gear and the decision gear are less than the current gear of the vehicle, and the restricted gear is greater than the decision gear, then the target gear of the vehicle is determined to be the decision gear; If both the restricted gear and the decision gear are less than the current gear of the vehicle, and the restricted gear is less than the decision gear, then the target gear of the vehicle is determined to be the restricted gear.

7. An electronic device, characterized in that, It includes a memory and a processor; The memory is used for storing programs; The processor is used for executing the program to implement each step of the gear restriction method according to any one of claims 1-5.

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