Intelligent distributed drive system based on snow-covered road

Abstract

The application discloses a kind of intelligent distributed drive system based on snow-covered road, including vehicle information acquisition module, distributed drive index analysis module, driving force regulating module, driving efficiency determination module, drive feedback module.The vehicle information acquisition module is used to collect the driving data of vehicle, and the distributed drive index analysis module is used to collect and calculate each index parameter corresponding to each wheel, and the driving force regulating module is used to adjust the driving force of each distributed drive wheel according to the total index K of each wheel state;The driving efficiency determination module is used to evaluate whether the adjustment of driving force regulating module for driving force meets the driving demand, including objective evaluation index calculation module, subjective evaluation index calculation module and comprehensive index judgment module;Drive feedback module is used for vehicle to exit the kind of intelligent distributed drive system based on snow-covered road.

Description

Technical Field

[0001] This invention relates to an intelligent distributed drive system based on snow-covered roads. Background Technology

[0002] Distributed drive is a vehicle safety technology that ensures driving safety and achieves more efficient, flexible, and intelligent vehicle operation by distributing power to multiple drive units or wheels. This technology plays a crucial role in the future development of automobiles and provides an innovative direction for the development of future intelligent transportation systems. However, current research largely focuses on the power and performance of drive motors, with relatively little research on the integration of drive systems with snow-covered environments. Furthermore, the factors considered regarding the impact of snow-covered environments on driving force are relatively singular, making it difficult to reflect the true extent to which the driving environment affects the magnitude and distribution of driving force. As a vital component of intelligent driving technology, distributed drive systems are crucial for vehicle development. Therefore, to address the aforementioned issues, this invention proposes an intelligent distributed drive system based on snow-covered roads. Summary of the Invention

[0003] The purpose of this invention is to provide an intelligent distributed drive system based on snow-covered roads to solve the problems encountered in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: an intelligent distributed drive system based on snow-covered roads includes: an on-board information acquisition module, a distributed drive index analysis module, a drive force adjustment module, a drive efficiency determination module, and a drive feedback module;

[0005] The vehicle information acquisition module is used to collect vehicle driving data, including: the vehicle's actual load mass m. e The vehicle's rated load capacity m a The vehicle's speed v, the tire's cross-sectional width Br, the original tread depth d0, and the depth of tread wear d. w The turning radius R corresponding to each wheel, the acceleration signal P1 received by the accelerator pedal, the acceleration signal P received by the drive motor, and the maximum value F of the vertical force on the ground for each tire. Zmax The minimum value F among the vertical forces on the ground for each tire Zmin The average vertical force on the ground for each tire Tire rotational angular velocity w, tire rolling radius r, and snow cover area S along a road section. j The total area of ​​this section of road is S all The snow depth H, and the maximum value φ of the road adhesion coefficient for each tire's corresponding contact surface. max The minimum value φ of the road adhesion coefficient of each tire's corresponding contact surface.min The mass of water in the snow m w ;

[0006] The distributed drive index analysis module is used to collect and calculate various index parameters for each wheel, including:

[0007] S1. Establish a driving force model for the vehicle during driving, including the driving force F of each wheel. Xq Satisfying the formula:

[0008]

[0009] Where m represents the vehicle mass, a represents the vehicle acceleration, and F... c F represents the longitudinal force on the ground applied to the driven wheels of the vehicle. w F represents the overall air resistance of the vehicle. i This represents the overall vehicle slope resistance, and n represents the number of drive wheels;

[0010] S2. Calculate the state score of each drive tire according to the following formula, including:

[0011] S2.1 Calculate the vehicle state sub-index K1 according to the following formula.

[0012]

[0013] Where w1 and w2 represent weighting coefficients;

[0014] k 11 k represents the drive mode coefficient; when the vehicle is a distributed rear-wheel drive system, k 11 =0.8, when the vehicle is a distributed front-wheel drive, k 11 =1.0, when the vehicle is a distributed four-wheel drive, k 11 =1.2, in other cases, k 11 =1.0;

[0015] k 12 This represents the drive motor type coefficient. When the drive wheel is an internal rotor hub motor, k 12 =1.2, when the drive wheel is an external rotor hub motor, k 12 =1.1, when the drive motor is a wheel-side motor, k 12 =1.0;

[0016] k 13 This represents the motor cooling coefficient, whose value depends on the cooling performance of each drive motor. When the motor cooling performance is poor, k... 13 =0.9, when the motor cooling performance is good, k 13 =1.0;

[0017] k 14Denotes the remaining load capacity coefficient of the vehicle, whose value depends on the proportion η of the vehicle that can still be loaded. Among them m e Denotes the actual loading mass of the vehicle, m a Denotes the rated loading mass of the vehicle. When η ≤ 30%, k 14 = 1.2. When 30% < η ≤ 70%, k 14 = 1.0. When η > 70%, k 14 = 0.8;

[0018] k 15 Denotes the communication delay coefficient, whose value is equal to the time interval Δt between the drive motor that receives the control signal from the central controller earliest and the drive motor that receives the signal latest;

[0019] k 16 Denotes the air deflector coefficient, whose value depends on the driving speed v of the vehicle and whether the vehicle has an air deflector. When the vehicle speed v is greater than or equal to 80 km / h and the vehicle is equipped with an air deflector, k 16 = 1.3. When the vehicle speed v is less than 80 km / h and the vehicle is equipped with an air deflector, k[[ID=二十六]] 16 = 1.1. When the vehicle speed v is greater than or equal to 80 km / h and the vehicle does not have an air deflector, k 16 = 0.8. When the vehicle speed v is less than 80 km / h and the vehicle does not have an air deflector, k 16 = 1.0;

[0020] S2.2 Calculate each tire performance sub-index K2 according to the following formula

[0021]

[0022] Among them, w3 and w4 denote the weight coefficients;

[0023] k 21 Denotes the tread rubber coefficient, whose value depends on the measured value L of the A-type Shore hardness of the rubber of each tire. When L ≤ 60, k 21 = 1.2. When 60 < L ≤ 70, k 21 = 1.0. When L > 70, k 21 = 0.8;

[0024] k 22 Denotes the tire pressure coefficient. When the tire pressure is maintained within the manufacturer's recommended range, k 22 = 1.3. In other cases, k 22 = 1.0;

[0025] k 23Represents the tire type coefficient. When the driving wheel tire is a common snow - proof tire, k 23 = 1.2. When the driving wheel tire is a studded snow tire, k 23 = 1.4. In other cases, k 23 = 1.0;

[0026] k 24 Represents the tire width coefficient, whose value depends on the cross - sectional width Br of each tire. When Br ≤ 200 mm, k 24 = 0.8. When 200 mm < Br ≤ 250 mm, k 24 = 1.0. When Br > 250 mm, k 24 = 1.2;

[0027] k 25 Represents the tire wear coefficient, which depends on the respective tread wear coefficients of the tires where d0 represents the original depth of each tire tread, and d w represents the worn depth of each tire tread. When ψ < 25%, k 25 = 0.5. When 25% ≤ ψ < 50%, k 25 = 0.7. When 50% ≤ ψ < 75%, k 25 = 0.9. When 75% ≤ ψ < 90%, k 25 = 1.0. When ψ ≥ 90%, k 25 = 1.2;

[0028] S2.3 Calculate the sub - index K3 of the driving state of each tire according to the following formula

[0029]

[0030] where w5 and w6 represent the weight coefficients;

[0031] k 31 Represents the turning radius coefficient, whose value depends on the turning radius R corresponding to each wheel when the vehicle is driving on a curve. When k 31 = 0.9. When k 31 = 0.8. In other cases, k 31 = 1.0, where R max represents the maximum value of the turning radii corresponding to all wheels, and R min represents the minimum value of the turning radii corresponding to all wheels;

[0032] k 32 Represents the driving mode coefficient. When the driver selects the sport mode, k 32 = 1.2. When the driver selects the normal mode, k32 = 1.0. When the driver selects the comfort mode, k 32 = 0.8;

[0033] k 33 represents the accelerator pedal depression coefficient, whose value depends on the acceleration signal received by the drive motor. Among them, P1 represents the acceleration signal received by the accelerator pedal, and P j represents the acceleration signals received by each drive motor. The above formula ensures that the brake pedal has a 4% dead zone to prevent misoperation by the driver. At the same time, when the driver depresses the accelerator pedal to the limit, the acceleration signal received by the drive motor is 100%. When P ≤ 35%, k 33 = 0.8. When 35% < P ≤ 75%, k 33 = 1.0. When P > 75%, k 33 = 1.2;

[0034] k 34 represents the load distribution uniformity coefficient, whose value depends on the load distribution coefficient of each wheel. Among them, F Zmax represents the maximum value among the vertical ground forces of each tire, and F Zmin represents the minimum value among the vertical ground forces of each tire. represents the average value of the vertical ground forces of each tire. When φ < 0.01, k 34 = 1.4. When 0.01 ≤ φ < 0.05, k 34 = 1.1. When 0.05 ≤ φ < 0.1, k 34 = 0.8. When φ ≥ 0.1, k 34 = 0.6;

[0035] k 35 represents the tire slip coefficient, whose value depends on the slip ratio of each tire. Among them, w represents the angular velocity of tire rotation, r represents the rolling radius of the tire, and v represents the actual speed of the vehicle. When S ≤ 0.03, k 35 = 1.0. When 0.03 < S ≤ 0.10, k 35 = 0.8. When S > 0.10, k 35 = 0.6;

[0036] S2.4 Calculate the road condition sub-index K4 according to the following formula.

[0037]

[0038] Among them, w7, w8, and w9 represent the weight coefficients;

[0039] k 41Denotes the snow cover coefficient, whose value depends on the snow cover density Among them, S j Denotes the snow cover area within a section of road, and S all Denotes the total area of this section of road. When ρ < 0.5, k 41 = 1.2. When 0.5 ≤ ρ < 0.8, k 41 = 1.4. When ρ ≥ 0.8, k 41 = 1.6;

[0040] k 42 Denotes the snow depth coefficient, whose value depends on the snow depth H. When H ≤ 1 cm, k 42 = 0.8. When 1 cm < H ≤ 3 cm, k 42 = 1.0. When 3 cm < H ≤ 5 cm, k 42 = 1.3. When H > 5 cm, k 42 = 1.6;

[0041] k 43 Denotes the road surface adhesion coefficient, whose value depends on the road surface adhesion coefficient of the contact surface corresponding to each tire. Δφ = φ max - φ min Among them, φ max Denotes the maximum value of the road surface adhesion coefficients of the contact surfaces corresponding to each tire, and φ min Denotes the minimum value of the road surface adhesion coefficients of the contact surfaces corresponding to each tire. When Δφ < 0.05, k 43 = 0.8. When 0.05 ≤ Δφ < 0.15, k 43 = 1.0. When 0.15 ≤ Δφ < 0.3, k 43 = 1.1. When Δφ ≥ 0.3, k 43 = 1.3;

[0042] k 44 Denotes the road surface material coefficient, whose value depends on the road surface material. When the road surface material is asphalt, k 44 = 0.9. When the road surface material is concrete, k 44 = 1.1. When the road surface material is a gravel road, k 44 = 1.2. In other cases, k 44 = 1.0;

[0043] k 45 Denotes the road surface flatness coefficient, whose value depends on the flatness of the road. When there are obvious potholes, bumps and cracks on the road, k 45 = 1.1. In other cases, k 45 = 1.0;

[0044] k 46Indicates the coefficient of road icing condition, and its value depends on the water content of the snow cover where, m w represents the mass of water in the snow cover, m j represents the total mass of the snow cover. When ε ≤ 0.1, k 46 = 0.8. When 0.1 < ε ≤ 0.3, k 46 = 1.0. When ε > 0.3, k 46 = 1.2;

[0045] S3. Calculate the total index K of each wheel state according to the following formula

[0046]

[0047] where, α1, α2, α3, α4 are the weighted values for calculating the single index;

[0048] The driving force adjustment module is used to adjust the driving force of each distributed drive wheel according to the total index K of each wheel state;

[0049] The driving efficiency determination module is used to evaluate whether the adjustment of the driving force by the driving force adjustment module meets the driving requirements, including an objective evaluation index calculation module, a subjective evaluation index calculation module, and a comprehensive index judgment module;

[0050] The driving feedback module is used for the vehicle to exit the intelligent distributed drive system based on the snow-covered road.

[0051] The driving force adjustment module includes a mild driving force adjustment module, a moderate driving force adjustment module, and a deep driving force adjustment module. Among them, the mild driving force adjustment module has the smallest adjustment to the original driving force, the moderate driving force adjustment module has the second smallest adjustment to the original driving force, and the deep driving force adjustment module has the largest adjustment to the original driving force. The selection of the driving force adjustment module is described by introducing an initial judgment threshold ζ1 and a second judgment threshold ζ2, where 0 < ζ1 < ζ2 < 1;

[0052] When the total index K of the driving system state satisfies 0 < K ≤ ζ1, the driving force adjustment module will execute the mild driving force adjustment module, and the driving force F corresponding to each driving tire Xq satisfies the formula:

[0053]

[0054] where, m represents the vehicle mass, a represents the vehicle acceleration, F c the longitudinal ground force of the vehicle's driven wheels, F w represents the vehicle air resistance, F i represents the vehicle ramp resistance, and n represents the number of drive wheels;

[0055] When the total index K of the driving system state satisfies ζ1 < K ≤ ζ2, the driving force adjustment module will execute the moderate driving force adjustment module, and the driving force F corresponding to each driving tire Xq satisfies the formula:

[0056]

[0057] where, m represents the vehicle mass, a represents the vehicle acceleration, F c represents the longitudinal ground force of the vehicle's driven wheels, F w represents the vehicle air resistance, F i represents the vehicle ramp resistance, and n represents the number of driving wheels;

[0058] When the total index K of the driving system state satisfies ζ2 < K ≤ 1, the driving force adjustment module will execute the deep driving force adjustment module, and the driving force F corresponding to each driving tire Xq satisfies the formula:

[0059]

[0060] where, m represents the vehicle mass, a represents the vehicle acceleration, F c represents the longitudinal ground force of the vehicle's driven wheels, F w represents the vehicle air resistance, F i represents the vehicle ramp resistance, and n represents the number of driving wheels.

[0061] The objective evaluation index calculation module is used to calculate the objective evaluation index A obj , and the calculation formula of the objective evaluation index A obj is as follows:

[0062]

[0063] The following data are all measured under the same driving environment, where,

[0064] a represents the actual driving acceleration after being adjusted by the driving force adjustment module;

[0065] a0 represents the ideal driving acceleration that the vehicle can reach according to the driving conditions without using the intelligent distributed driving system based on snow-covered roads;

[0066] P represents the sum of the actual powers of the drive motors after being adjusted by the driving force adjustment module;

[0067] P0 represents the sum of the ideal powers of the drive motors that the vehicle can reach according to the driving conditions without using the intelligent distributed driving system based on snow-covered roads;

[0068] T Z represents the actual yaw moment of the vehicle after being adjusted by the driving force adjustment module

[0069] T Z0 This refers to the ideal yaw moment that the vehicle can achieve to maintain driving stability when the aforementioned intelligent distributed drive system based on snow-covered roads is not used, depending on the driving conditions.

[0070] The subjective evaluation index calculation module is used to calculate subjective evaluation index A. suj Subjective evaluation index A suj The calculation formula is as follows:

[0071]

[0072] The following data were all measured under the same driving conditions.

[0073] E1 represents the driver's ten-point evaluation score for driving comfort after adjustment by the drive force adjustment module;

[0074] E10 represents the driver's ten-point rating score for driving comfort when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0075] E2 represents the driver's ten-point evaluation score of the vehicle's dynamic performance after adjustment by the drive force adjustment module;

[0076] E20 represents the driver's ten-point rating of the vehicle's dynamics when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0077] E3 represents the driver's ten-point evaluation score of fuel economy after the driving force adjustment module has been adjusted.

[0078] E30 represents the driver's ten-point rating of the vehicle's fuel economy when the aforementioned intelligent distributed drive system based on snow-covered roads is not used.

[0079] The comprehensive index judgment module is used to calculate the comprehensive evaluation index A and judge the driving force adjustment effect. The calculation formula for the comprehensive evaluation index A is as follows:

[0080]

[0081] The values ​​of δ1 and δ2 can be determined autonomously by the driver and the system, provided that the above conditions are met.

[0082] The comprehensive index judgment module is used to calculate the comprehensive evaluation index A and judge the driving force adjustment effect;

[0083] When |A| < 0.05, the intelligent distributed drive system based on snow-covered roads exhibits excellent adjustment performance;

[0084] When 0.05≤|A|<0.15, the intelligent distributed drive system based on snow-covered roads exhibits good adjustment performance.

[0085] When 0.15≤|A|<0.30, the adjustment effect of the intelligent distributed drive system based on snow-covered roads is moderate;

[0086] When 0.30≤|A|<0.50, the adjustment effect of the intelligent distributed drive system based on snow-covered roads is not ideal;

[0087] When |A|≥0.50, the aforementioned intelligent distributed drive system based on snow-covered roads may malfunction.

[0088] The drive feedback module is used for the vehicle to exit an intelligent distributed drive system based on snow-covered roads. This module is executed when one of the following conditions occurs; otherwise, it is not executed:

[0089] The driver can choose to exit the intelligent distributed drive system based on snow-covered roads.

[0090] When A ≥ 0.50, it indicates that the intelligent distributed drive system based on snow-covered roads may malfunction.

[0091] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0092] 1. An intelligent distributed drive system based on snow-covered roads includes an on-board information acquisition module, a distributed drive index analysis module, a drive force adjustment module, a drive performance determination module, and a drive feedback module.

[0093] 2. The driving force adjustment module of the present invention includes a light adjustment driving force module, a medium adjustment driving force module, and a deep adjustment driving force module. The light adjustment driving force module has the smallest adjustment to the original driving force, the medium adjustment driving force module has the next smallest adjustment to the original driving force, and the deep adjustment driving force module has the largest adjustment to the original driving force. The selection of the driving force adjustment module is described by introducing an initial judgment threshold and a second judgment threshold.

[0094] 3. The driving performance determination module of the present invention is used to evaluate whether the driving force adjustment module's adjustment of driving force meets driving needs, including objective evaluation indicators and subjective evaluation indicators; Attached Figure Description

[0095] The present invention will be further described below with reference to the accompanying drawings:

[0096] Figure 1 This is a framework diagram of an intelligent distributed drive system based on snow-covered roads proposed in this invention. Detailed Implementation

[0097] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0098] like Figure 1 As shown, the present invention is an intelligent distributed drive system based on snow-covered roads, comprising: an on-board information acquisition module, a distributed drive index analysis module, a drive force adjustment module, a drive efficiency determination module, and a drive feedback module;

[0099] The vehicle information acquisition module is used to collect vehicle driving data, including: the vehicle's actual load mass m. e The vehicle's rated load capacity m a The vehicle's speed v, the tire's cross-sectional width Br, the original tread depth d0, and the depth of tread wear d. w The turning radius R corresponding to each wheel, the acceleration signal P1 received by the accelerator pedal, the acceleration signal P received by the drive motor, and the maximum value F of the vertical force on the ground for each tire. Zmax The minimum value F among the vertical forces on the ground for each tire Zmin The average vertical force on the ground for each tire Tire rotational angular velocity w, tire rolling radius r, and snow cover area S along a road section. j The total area of ​​this section of road is S all The snow depth H, and the maximum value φ of the road adhesion coefficient for each tire's corresponding contact surface. max The minimum value φ of the road adhesion coefficient of each tire's corresponding contact surface. min The mass of water in the snow m w ;

[0100] The distributed drive index analysis module is used to collect and calculate various index parameters for each wheel, including:

[0101] S1. Establish a driving force model for the vehicle during driving, including the driving force F of each wheel. Xq Satisfying the formula:

[0102]

[0103] Where m represents the vehicle mass, a represents the vehicle acceleration, and F... c F represents the longitudinal force on the ground applied to the driven wheels of the vehicle. w F represents the overall air resistance of the vehicle. i This represents the overall vehicle slope resistance, and n represents the number of drive wheels;

[0104] S2. Calculate the state score of each drive tire according to the following formula, including:

[0105] S2.1 Calculate the vehicle state sub-index K1 according to the following formula.

[0106]

[0107] Where w1 and w2 represent weighting coefficients;

[0108] k 11 k represents the drive mode coefficient; when the vehicle is a distributed rear-wheel drive system, k 11 =0.8, when the vehicle is a distributed front-wheel drive, k 11 =1.0, when the vehicle is a distributed four-wheel drive, k 11 =1.2, in other cases, k 11 =1.0;

[0109] k 12 This represents the drive motor type coefficient. When the drive wheel is an internal rotor hub motor, k 12 =1.2, when the drive wheel is an external rotor hub motor, k 12 =1.1, when the drive motor is a wheel-side motor, k 12 =1.0;

[0110] k 13 This represents the motor cooling coefficient, whose value depends on the cooling performance of each drive motor. When the motor cooling performance is poor, k... 13 =0.9, when the motor cooling performance is good, k 13 =1.0;

[0111] k 14 This represents the vehicle's remaining load capacity coefficient, the value of which depends on the proportion η that the vehicle can continue to load, where m e Indicates the actual loaded mass of the vehicle, m a k represents the vehicle's rated load capacity. When η≤30%, k 14 =1.2, when 30% < η ≤ 70%, k 14 =1.0, when η>70%, k 14 =0.8;

[0112] k 15 This represents the communication delay coefficient, which is equal to the time interval Δt between the drive motor that receives the control signal from the central controller earliest and the drive motor that receives the signal latest.

[0113] k 16 This represents the air deflector coefficient, the value of which depends on the vehicle's speed v and whether the vehicle has air deflectors. When the vehicle speed v is greater than or equal to 80 kilometers per hour and the vehicle is equipped with air deflectors, k... 16= 1.3, when the vehicle speed v is less than 80 kilometers per hour and the vehicle is equipped with an air deflector, k 16 = 1.1, when the vehicle speed v is greater than or equal to 80 kilometers per hour and the vehicle has no air deflector, k 16 = 0.8, when the vehicle speed v is less than 80 kilometers per hour and the vehicle has no air deflector, k 16 = 1.0;

[0114] S2.2 Calculate the tire performance sub-index K2 according to the following formula

[0115]

[0116] where, w3 and w4 represent the weight coefficients;

[0117] k 21 represents the tread rubber coefficient, whose value depends on the Shore A hardness measurement value L of the rubber of each tire. When L ≤ 60, k 21 = 1.2, when 60 < L ≤ 70, k 21 = 1.0, when L > 70, k 21 = 0.8;

[0118] k 22 represents the tire pressure coefficient. When the tire pressure is maintained within the manufacturer's recommended range, k 22 = 1.3, in other cases, k 22 = 1.0;

[0119] k 23 represents the tire type coefficient. When the drive wheel tire is an ordinary snow tire, k 23 = 1.2, when the drive wheel tire is a studded snow tire, k 23 = 1.4, in other cases, k 23 = 1.0;

[0120] k 24 represents the tire width coefficient, whose value depends on the section width Br of each tire. When Br ≤ 200 mm, k 24 = 0.8, when 200 mm < Br ≤ 250 mm, k 24 = 1.0, when Br > 250 mm, k 24 = 1.2;

[0121] k 25 represents the tire wear coefficient, which depends on the respective tread wear coefficients of the tires where, d0 represents the original depth of the tread of each tire, d w represents the depth by which the tread of each tire has been worn. When ψ < 25%, k 25= 0.5, when 25% ≤ ψ < 50%, k 25 = 0.7, when 50% ≤ ψ < 75%, k 25 = 0.9, when 75% ≤ ψ < 90%, k 25 = 1.0, when ψ ≥ 90%, k 25 = 1.2;

[0122] S2.3 Calculate the sub-index K3 of each tire driving state according to the following formula

[0123]

[0124] where, w5 and w6 represent the weight coefficients;

[0125] k 31 represents the turning radius coefficient, and its value depends on the turning radius R corresponding to each wheel when the vehicle is driving on a curve. When k 31 = 0.9, when k 31 = 0.8, in other cases, k 31 = 1.0, where R max represents the maximum value of the turning radii corresponding to all wheels, and R min represents the minimum value of the turning radii corresponding to all wheels;

[0126] k 32 represents the driving mode coefficient. When the driver selects the sport mode, k 32 = 1.2, when the driver selects the normal mode, k 32 = 1.0, when the driver selects the comfort mode, k 32 = 0.8;

[0127] k 33 represents the accelerator pedal depression coefficient, and its value depends on the acceleration signal received by the drive motor where, P1 represents the acceleration signal received by the accelerator pedal, and P j represents the acceleration signals received by each drive motor. The above formula ensures that the brake pedal has a 4% dead zone to prevent misoperation by the driver. At the same time, it ensures that when the driver depresses the accelerator pedal to the limit, the acceleration signal received by the drive motor is 100%. When P ≤ 35%, k 33 = 0.8, when 35% < P ≤ 75%, k 33 = 1.0, when P > 75%, k 33 = 1.2;

[0128] k 34 represents the load distribution uniformity coefficient, and its value depends on the load distribution coefficient of each wheel where, FZmax represents the maximum value among the vertical ground forces of each tire, F Zmin represents the minimum value among the vertical ground forces of each tire represents the average value of the vertical ground forces of each tire. When φ < 0.01, k 34 = 1.4. When 0.01 ≤ φ < 0.05, k 34 = 1.1. When 0.05 ≤ φ < 0.1, k 34 = 0.8. When φ ≥ 0.1, k 34 = 0.6;

[0129] k 35 represents the tire slip coefficient, and its value depends on the slip rate of each tire where, w represents the angular velocity of tire rotation, r represents the rolling radius of the tire, v represents the actual speed of the vehicle. When S ≤ 0.03, k 35 = 1.0. When 0.03 < S ≤ 0.10, k 35 = 0.8. When S > 0.10, k 35 = 0.6;

[0130] S2.4 calculates the road condition sub-index K4 according to the following formula

[0131]

[0132] where, w7, w8 and w9 represent the weight coefficients;

[0133] k 41 represents the snow cover coefficient, and its value depends on the snow cover density where, S j represents the snow cover area within a section of the road, S all represents the total area of this section of the road. When ρ < 0.5, k 41 = 1.2. When 0.5 ≤ ρ < 0.8, k 41 = 1.4. When ρ ≥ 0.8, k 41 = 1.6;

[0134] k 42 represents the snow depth coefficient, and its value depends on the snow depth H. When H ≤ 1 cm, k 42 = 0.8. When 1 cm < H ≤ 3 cm, k 42 = 1.0. When 3 cm < H ≤ 5 cm, k 42 = 1.3. When H > 5 cm, k 42 = 1.6;

[0135] k 43This represents the road surface adhesion coefficient, whose value depends on the road surface adhesion coefficient of the contact surface corresponding to each tire, Δφ = φ max -φ min , where φ max φ represents the maximum value of the road adhesion coefficient for each tire's corresponding contact surface. min This represents the minimum road adhesion coefficient among the contact surfaces of each tire. When Δφ < 0.05, k 43 =0.8, when 0.05≤Δφ<0.15, k 43 =1.0, when 0.15≤Δφ<0.3, k 43 =1.1, Δφ≥0.3, k 43 =1.3;

[0136] k 44 This represents the pavement material coefficient, the value of which depends on the road surface material. When the pavement surface material is asphalt, k... 44 =0.9, when the road surface material is concrete, k 44 =1.1, when the road surface material is gravel, k 44 =1.2, in other cases, k 44 =1.0;

[0137] k 45 k represents the road surface smoothness coefficient, and its value depends on the smoothness of the road. When the road has obvious potholes, bumps, and cracks, k... 45 =1.1, in other cases, k 45 =1.0;

[0138] k 46 This represents the road icing condition coefficient, the value of which depends on the water content of the snow. Where, m w The mass of water in snow is m. j Let k represent the total mass of snow cover. When ε≤0.1, k 46 =0.8, when 0.1 < ε ≤ 0.3, k 46 =1.0, when ε>0.3, k 46 =1.2;

[0139] S3. Calculate the overall index K of each wheel's condition according to the following formula.

[0140]

[0141] Among them, α1, α2, α3, and α4 are the weighted values ​​for individual indicators;

[0142] The driving force adjustment module is used to adjust the driving force of each distributed driving wheel according to the total index K of each wheel state.

[0143] The driving efficiency determination module is used to evaluate whether the driving force adjustment module's adjustment of the driving force meets the driving requirements, including an objective evaluation index calculation module, a subjective evaluation index calculation module, and a comprehensive index judgment module;

[0144] The driving feedback module is used for the vehicle to exit the intelligent distributed driving system based on a snow-covered road.

[0145] The driving force adjustment module includes a mild driving force adjustment module, a moderate driving force adjustment module, and a deep driving force adjustment module. Among them, the mild driving force adjustment module has the smallest adjustment to the original driving force, the moderate driving force adjustment module has the second smallest adjustment to the original driving force, and the deep driving force adjustment module has the largest adjustment to the original driving force. The selection of the driving force adjustment module is described by introducing an initial judgment threshold ζ1 and a second judgment threshold ζ2, where 0 < ζ1 < ζ2 < 1;

[0146] When the total driving system state index K satisfies 0 < K ≤ ζ1, the driving force adjustment module will execute the mild driving force adjustment module, and the driving force F corresponding to each driving tire Xq satisfies the formula:<00006​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

[0154] Where m represents the vehicle mass, a represents the vehicle acceleration, and F... c F represents the longitudinal force on the ground applied to the driven wheels of the vehicle. w F represents the overall air resistance of the vehicle. i This represents the vehicle's slope resistance, and n represents the number of drive wheels.

[0155] The objective evaluation index calculation module is used to calculate objective evaluation index A. obj Objective evaluation index A obj The calculation formula is as follows:

[0156]

[0157] The following data were all measured under the same driving conditions.

[0158] a represents the actual driving acceleration after adjustment by the driving force adjustment module;

[0159] a0 represents the ideal driving acceleration that the vehicle can achieve under driving conditions when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0160] P represents the sum of the actual power of the drive motor after adjustment by the drive force adjustment module;

[0161] P0 represents the sum of the ideal power of the drive motors that the vehicle can achieve under driving conditions when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0162] T Z This indicates the actual yaw torque of the vehicle after adjustment by the drive force adjustment module;

[0163] T Z0 This refers to the ideal yaw moment that the vehicle can achieve to maintain driving stability when the aforementioned intelligent distributed drive system based on snow-covered roads is not used, depending on the driving conditions.

[0164] The subjective evaluation index calculation module is used to calculate subjective evaluation index A. suj Subjective evaluation index A suj The calculation formula is as follows:

[0165]

[0166] The following data were all measured under the same driving conditions.

[0167] E1 represents the driver's ten-point evaluation score for driving comfort after adjustment by the drive force adjustment module;

[0168] E10 represents the driver's ten-point rating score for driving comfort when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0169] E2 represents the driver's ten-point evaluation score of the vehicle's dynamic performance after adjustment by the drive force adjustment module;

[0170] E20 represents the driver's ten-point rating of the vehicle's dynamics when the aforementioned intelligent distributed drive system based on snow-covered roads is not used;

[0171] E3 represents the driver's ten-point evaluation score of fuel economy after the driving force adjustment module has been adjusted.

[0172] E30 represents the driver's ten-point rating of the vehicle's fuel economy when the aforementioned intelligent distributed drive system based on snow-covered roads is not used.

[0173] The comprehensive index judgment module is used to calculate the comprehensive evaluation index A and judge the driving force adjustment effect. The calculation formula for the comprehensive evaluation index A is as follows:

[0174]

[0175] The values ​​of δ1 and δ2 can be determined autonomously by the driver and the system, provided that the above conditions are met.

[0176] The comprehensive index judgment module is used to calculate the comprehensive evaluation index A and judge the driving force adjustment effect;

[0177] When |A| < 0.05, the intelligent distributed drive system based on snow-covered roads exhibits excellent adjustment performance;

[0178] When 0.05≤|A|<0.15, the intelligent distributed drive system based on snow-covered roads exhibits good adjustment performance.

[0179] When 0.15≤|A|<0.30, the adjustment effect of the intelligent distributed drive system based on snow-covered roads is moderate;

[0180] When 0.30≤|A|<0.50, the adjustment effect of the intelligent distributed drive system based on snow-covered roads is not ideal;

[0181] When |A|≥0.50, the aforementioned intelligent distributed drive system based on snow-covered roads may malfunction.

[0182] The drive feedback module is used for the vehicle to exit an intelligent distributed drive system based on snow-covered roads. This module is executed when one of the following conditions occurs; otherwise, it is not executed:

[0183] The driver can choose to exit the intelligent distributed drive system based on snow-covered roads.

[0184] When A ≥ 0.50, it indicates that the intelligent distributed drive system based on snow-covered roads may malfunction.

[0185] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0186] 1. An intelligent distributed drive system based on snow-covered roads includes an on-board information acquisition module, a distributed drive index analysis module, a drive force adjustment module, a drive performance determination module, and a drive feedback module.

[0187] 2. The driving force adjustment module of the present invention includes a light adjustment driving force module, a medium adjustment driving force module, and a deep adjustment driving force module. The light adjustment driving force module has the smallest adjustment to the original driving force, the medium adjustment driving force module has the next smallest adjustment to the original driving force, and the deep adjustment driving force module has the largest adjustment to the original driving force. The selection of the driving force adjustment module is described by introducing an initial judgment threshold and a second judgment threshold.

[0188] 3. The driving performance determination module of the present invention is used to evaluate whether the driving force adjustment module's adjustment of driving force meets driving needs, including objective evaluation indicators and subjective evaluation indicators.

Claims

1. An intelligent distributed drive system based on snow-covered roads, characterized in that, Includes the following: Vehicle information acquisition module, distributed drive index analysis module, drive force adjustment module, drive efficiency judgment module, drive feedback module; The vehicle information acquisition module is used to collect vehicle driving data, including: the actual load mass of the vehicle. The vehicle's rated load capacity vehicle speed The tire's cross-sectional width Br and the original depth of the tire tread pattern. The depth of tire tread wear The turning radius R corresponding to each wheel, and the acceleration signal received by the accelerator pedal. The acceleration signal received by the drive motor The maximum value of the vertical force on the ground for each tire The minimum value of the vertical force on the ground for each tire The average vertical force on the ground for each tire Tire rotational angular velocity The radius of the tire rolling Snow cover area within a section of road The total area of ​​this section of road The snow depth H, and the maximum value of the road adhesion coefficient for each tire's corresponding contact surface. The minimum value of the road adhesion coefficient of each tire's corresponding contact surface. The mass of water in snow ; The distributed drive index analysis module is used to collect and calculate various index parameters for each wheel, including: S1. Establish a driving force model for the vehicle during driving, including the driving force of each wheel. Satisfying the formula: in, Indicates the overall vehicle weight. Indicates the acceleration of the entire vehicle. This represents the longitudinal force on the ground applied to the driven wheels of the vehicle. Indicates the overall air resistance of the vehicle. Indicates the vehicle's slope resistance. Indicates the number of drive wheels; S2. Calculate the state score of each drive tire according to the following formula, including: S2.1 Calculate the vehicle status sub-indicators according to the following formula. , in, , Indicates the weighting coefficient; This represents the drive mode coefficient; when the vehicle is a distributed rear-wheel drive system... When the vehicle is a distributed front-wheel drive, When the vehicle has a distributed four-wheel drive system, In other cases, ; This indicates the type coefficient of the drive motor. When the drive wheel is an internal rotor hub motor, When the drive wheel is an external rotor hub motor, When the drive motor is a wheel-side motor, ; This represents the motor cooling coefficient, and its value depends on the cooling performance of each drive motor. When the motor cooling performance is poor, When the motor cooling performance is good, ; This represents the vehicle's remaining load capacity coefficient, the value of which depends on the proportion of the vehicle that can continue to be loaded. ,in , This indicates the actual load capacity of the vehicle. Indicates the vehicle's rated load capacity, when hour, ,when hour, ,when , ; This represents the communication delay factor, which is equal to the time interval between the drive motor that receives the control signal from the central controller earliest and the drive motor that receives the signal latest. ; This indicates the air deflector coefficient, the value of which depends on the vehicle's speed. And whether the vehicle has air deflectors, at vehicle speed When the speed is greater than or equal to 80 kilometers per hour and the vehicle is equipped with an air deflector When the vehicle speed When the speed is less than 80 kilometers per hour and the vehicle is equipped with an air deflector... When the vehicle speed When the speed is greater than or equal to 80 kilometers per hour and the vehicle does not have an air deflector When the vehicle speed When the speed is less than 80 kilometers per hour and the vehicle does not have air deflectors ; S2.2 Calculate the performance sub-indicators of each tire according to the following formulas. , in, , Indicates the weighting coefficient; This represents the tread rubber coefficient, the value of which depends on the measurement value of each tire rubber using a Type A Shore hardness tester. ,when hour, ,when hour, ,when hour, ; This indicates the tire pressure coefficient, which is the value when the tire pressure is kept within the manufacturer's recommended range. In other cases, ; This indicates the tire type coefficient; when the drive wheel tires are ordinary snow tires... When the drive wheel tires are studded snow tires, In other cases, ; This represents the tire width factor, the value of which depends on the section width Br of each tire. At millimeters, ,when hour, ,when , ; The tire wear coefficient is indicated by the individual tire tread wear coefficient. ,in, This indicates the original depth of each tire tread pattern. This indicates the depth to which the tread pattern of each tire has been worn. , , hour, ,when hour, ,when hour, ,when hour, ; S2.3 Calculate the tire driving condition sub-indicators according to the following formula. , in, , Indicates the weighting coefficient; This represents the turning radius coefficient, the value of which depends on the turning radius R corresponding to each wheel when the vehicle is traveling on a curve. hour, ,when hour, In other cases, ,in This represents the maximum turning radius corresponding to all wheels. This represents the minimum turning radius corresponding to all wheels; This indicates the driving mode coefficient; when the driver selects Sport mode... When the driver selects normal mode, When the driver selects comfort mode, ; This represents the accelerator pedal depressor coefficient, the value of which depends on the acceleration signal received by the drive motor. ,in, This indicates the acceleration signal received by the accelerator pedal. This indicates the acceleration signal received by each drive motor. The above formula ensures a 4% free travel in the brake pedal to prevent driver misoperation, while simultaneously ensuring that when the driver depresses the accelerator pedal to its limit, the drive motor receives a 100% acceleration signal. hour, ,when hour, ,when hour, ; This represents the load distribution uniformity coefficient, the value of which depends on the load distribution coefficient of each wheel. ,in, This represents the maximum value of the vertical force exerted on the ground by each tire. This represents the minimum value among the vertical forces exerted on the ground by each tire. This represents the average value of the vertical force exerted on the ground by each tire. hour, ,when hour, ,when hour, ,when hour, ; This represents the tire slip coefficient, and its value depends on the slip ratio of each tire. ,in, Indicates the angular velocity of the tire rotation. Indicates the tire's rolling radius. Indicates the actual speed of the vehicle, when hour, ,when hour, ,when hour, ; S2.4 Calculate the road condition sub-indicators according to the following formulas. , in, , and Indicates the weighting coefficient; This represents the snow cover coefficient, whose value depends on the snow cover density. ,in, This indicates the area of ​​snow cover within a section of road. This represents the total area of ​​the road segment. hour, ,when hour, ,when hour, ; This represents the snow depth coefficient, whose value depends on the snow depth H. At centimeters, ,when hour, ,when hour, ,when 5 centimeters, ; This represents the road surface adhesion coefficient, and its value depends on the road surface adhesion coefficient of the contact surface corresponding to each tire. ,in, This represents the maximum value of the road adhesion coefficient for each tire's corresponding contact surface. This represents the minimum value of the road adhesion coefficient among the contact surfaces of each tire. hour, ,when hour, ,when hour, , , ; This represents the pavement material coefficient, the value of which depends on the road surface material. When the pavement surface material is asphalt... When the road surface material is concrete, When the road surface material is gravel, In other cases, ; This represents the road surface smoothness coefficient, whose value depends on the smoothness of the road. When the road has obvious potholes, bumps, and cracks, In other cases, ; This represents the road icing condition coefficient, the value of which depends on the water content of the snow. ,in, This indicates the mass of water in the snow. Represents the total mass of snow cover, when hour, ,when hour, ,when hour, ; S3. Calculate the overall condition index of each wheel according to the following formula. , in, Calculate the weighted value for each individual indicator; The drive force adjustment module is used to adjust the overall index of the condition of each wheel. To adjust the driving force of each distributed drive wheel; The driving performance determination module is used to evaluate whether the driving force adjustment module's adjustment of driving force meets driving needs, including an objective evaluation index calculation module, a subjective evaluation index calculation module, and a comprehensive index judgment module. The drive feedback module is used for the vehicle to exit the intelligent distributed drive system based on snow-covered roads.

2. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The driving force adjustment module includes a light adjustment module, a medium adjustment module, and a deep adjustment module. The light adjustment module provides the least adjustment to the original driving force, the medium adjustment module provides the next best adjustment, and the deep adjustment module provides the greatest adjustment. An initial judgment threshold is introduced. Second judgment threshold To describe the selection of the drive force adjustment module, where, ; When the overall state index of the drive system satisfy At that time, the drive force adjustment module will perform a slight adjustment of the drive force module, adjusting the drive force corresponding to each drive tire. Satisfying the formula: in, Indicates the overall vehicle weight. Indicates the acceleration of the entire vehicle. The longitudinal force on the ground of the driven wheels of the whole vehicle Indicates the overall air resistance of the vehicle. Indicates the vehicle's slope resistance. Indicates the number of drive wheels; When the overall state index of the drive system satisfy At that time, the drive force adjustment module will perform a moderate adjustment of the drive force module, adjusting the drive force corresponding to each drive tire. Satisfying the formula: in, Indicates the overall vehicle weight. Indicates the acceleration of the entire vehicle. This represents the longitudinal force on the ground applied to the driven wheels of the vehicle. Indicates the overall air resistance of the vehicle. Indicates the vehicle's slope resistance. Indicates the number of drive wheels; When the overall state index of the drive system satisfy At that time, the driving force adjustment module will perform a depth adjustment of the driving force module, adjusting the driving force corresponding to each driving tire. Satisfying the formula: in, Indicates the overall vehicle weight. Indicates the acceleration of the entire vehicle. This represents the longitudinal force on the ground applied to the driven wheels of the vehicle. Indicates the overall air resistance of the vehicle. Indicates the vehicle's slope resistance. Indicates the number of drive wheels.

3. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The objective evaluation index calculation module is used to calculate objective evaluation indicators. Objective evaluation indicators The calculation formula is as follows: The following data were all measured under the same driving conditions. This indicates the actual driving acceleration after adjustment by the drive force adjustment module; This indicates the ideal driving acceleration that the vehicle can achieve under driving conditions when the aforementioned intelligent distributed drive system based on snow-covered roads is not used; This represents the sum of the actual power of the drive motor after adjustment by the drive force adjustment module; This represents the sum of the ideal power of the drive motors that the vehicle can achieve under driving conditions when the aforementioned intelligent distributed drive system based on snow-covered roads is not used; This indicates the actual yaw torque of the vehicle after adjustment by the drive force adjustment module; This refers to the ideal yaw moment that the vehicle can achieve to maintain driving stability when the aforementioned intelligent distributed drive system based on snow-covered roads is not used, depending on the driving conditions.

4. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The subjective evaluation index calculation module is used to calculate subjective evaluation indicators. Subjective evaluation indicators The calculation formula is as follows: The following data were all measured under the same driving conditions. This represents a 10-point rating score for the driver's perception of driving comfort after adjustment by the drive force adjustment module. This indicates the driver's ten-point rating score for driving comfort when the aforementioned intelligent distributed drive system based on snow-covered roads is not used; This represents the driver's ten-point evaluation score of the vehicle's dynamic performance after adjustment by the drive force adjustment module; This indicates the driver's ten-point evaluation score for vehicle dynamics when the aforementioned intelligent distributed drive system based on snow-covered roads is not used; This represents a ten-point rating score from the driver regarding fuel economy after adjustment by the drive force adjustment module. This indicates the driver's ten-point rating of the vehicle's fuel economy when the aforementioned intelligent distributed drive system based on snow-covered roads is not used.

5. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The comprehensive index judgment module is used to calculate the comprehensive evaluation index. And judge the effect of driving force adjustment, and comprehensively evaluate the indicators. The calculation formula is as follows: in, and The value can be determined by the driver and the system themselves, provided that the above conditions are met.

6. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The comprehensive index judgment module is used to calculate the comprehensive evaluation index. And determine the effect of driving force adjustment; when At that time, the intelligent distributed drive system based on snow-covered roads showed excellent adjustment performance; when At that time, the intelligent distributed drive system based on snow-covered roads showed good adjustment performance; when At that time, the adjustment effect of the intelligent distributed drive system based on snow-covered roads was moderate. when At that time, the adjustment effect of the intelligent distributed drive system based on snow-covered roads was not ideal; when At that time, the intelligent distributed drive system based on snow-covered roads may malfunction.

7. The intelligent distributed drive system based on snow-covered roads according to claim 1, characterized in that: The drive feedback module is used for the vehicle to exit an intelligent distributed drive system based on snow-covered roads. This module is executed when one of the following conditions occurs; otherwise, it is not executed: ① The driver actively chooses to exit the aforementioned intelligent distributed drive system based on snow-covered roads; ② When This indicates that the intelligent distributed drive system based on snow-covered roads may malfunction.

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