A hydraulic brake-by-wire based pedal simulator mode selection system

Abstract

The application discloses a pedal simulator mode selection system based on hydraulic line control brake, which comprises a vehicle-mounted information acquisition module, a pedal simulator influence factor evaluation index calculation module, a brake pedal simulator mode selection module and a brake pedal simulator mode feedback module. The vehicle-mounted information acquisition module is used for acquiring various related data of a vehicle, a surrounding environment and a driver; the pedal simulator influence factor evaluation index calculation module is used for processing the acquired various data and calculating a total evaluation index of pedal simulator influence factors; the brake pedal simulator mode selection module is used for controlling the relationship between the force applied on the brake pedal and the brake master cylinder displacement according to the selected brake pedal simulator mode; and the brake pedal simulator mode feedback module is used for adjusting the brake pedal simulator mode according to the feedback of the driver.

Description

Technical Field

[0001] This invention relates to a pedal simulator mode selection system based on hydraulic brake-by-wire. Background Technology

[0002] The brake pedal is a crucial component of a car's braking system, and its design and performance play a vital role in driving safety and driver comfort. Researchers have largely focused on the shape, position, and force feedback of the brake pedal to improve braking system performance and user experience, but rarely considered continuously changing the pedal simulation mode based on the driver's braking style. Furthermore, the evaluation metrics for pedal simulator mode control are relatively singular. However, for vehicle braking performance and driver comfort, the pedal simulator needs to consider multiple factors such as brake pedal manufacturing processes, road conditions, and the driver's experience. Therefore, effectively ensuring the comfort of using the brake pedal simulator has become a pressing technical problem for the applicant. To address these issues, this invention proposes a pedal simulator mode selection system based on hydraulic brake-by-wire. Summary of the Invention

[0003] The purpose of this invention is to provide a pedal simulator mode selection system based on hydraulic brake-by-wire to solve the problems encountered in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a pedal simulator mode selection system based on hydraulic brake-by-wire includes an on-board information acquisition module, a pedal simulator influencing factor evaluation index calculation module, a brake pedal simulator mode selection module, and a brake pedal simulator mode feedback module.

[0005] The road traffic environment recognition module includes a vehicle information collection module, a surrounding environment detection module, and a driver status perception module.

[0006] The pedal simulator influencing factor evaluation index calculation module includes:

[0007] S1. Establish a pedal simulator model for a hydraulically controlled-by-wire vehicle. The force balance equation for the master cylinder piston is:

[0008] X1 = LX

[0009] Where X represents the brake pedal travel, X1 represents the brake master cylinder displacement, and L represents the brake pedal leverage ratio;

[0010] S2. Calculate the evaluation sub-indicators for the factors affecting the pedal simulator, including:

[0011] S2.1 Calculate the manufacturing process sub-index K1 of the brake pedal simulator according to the following formula.

[0012]

[0013] wherein w1, w2, w3 represent weighting factors, k 11 represents the dimensional accuracy factor of the brake pedal simulator, k 12 represents the geometric accuracy factor of the brake pedal simulator, k 13 represents the surface roughness factor of the brake pedal simulator, k 14 represents the positional accuracy factor of the brake pedal simulator, k 15 represents the repeatability factor of the brake pedal simulator, k 16 represents the process stability factor of the brake pedal simulator, k 17 represents the quality defect rate factor of the brake pedal simulator, wherein N D represents the number of defects of the brake pedal simulator found within a certain production batch, N A represents the number of products actually produced within this production batch; S2.2 calculates the brake pedal simulator variable performance sub-index K2 according to the following formula,

[0014]

[0015] wherein w4, w5, w6 represent weighting factors, k 21 represents the sensitivity factor of the brake pedal simulator pedal force sensor, whose value depends on the sampling frequency of the pedal force sensor, k 22 represents the sensitivity factor of the brake pedal simulator position sensor, whose value depends on the sampling frequency of the position sensor, k 23 represents the sensitivity factor of the brake pedal simulator travel sensor, whose value is equal to the pedal travel ratio ε of the pedal simulator P wherein X max represents the maximum travel of the brake pedal, k 24 represents the sensitivity factor of the brake pedal simulator speed sensor, whose value depends on the sampling frequency of the speed sensor;

[0016] S2.3 calculates the brake pedal simulator hydraulic oil state sub-index K3 according to the following formula,

[0017]

[0018] wherein w7 and w8 represent weighting factors, k 31 represents the hydraulic oil temperature sensitivity factor, k 31 = p0 * (1 + δ * (T - T0)), T represents the current temperature, p0 represents the viscosity at the reference temperature T0, and δ represents the brake fluid temperature coefficient, k 32 represents the hydraulic oil humidity sensitivity factor, k32 = Boil0- βH where H represents the current humidity, Boil represents the hydraulic oil boiling point at humidity H, Boil0 represents the reference boiling point of the hydraulic oil, β represents the humidity influence coefficient, k 33 represents the hydraulic oil replacement period coefficient, which takes a value equal to the hydraulic oil replacement period t ch , k 34 represents the hydraulic oil contaminant period coefficient, k 35 represents the hydraulic oil type coefficient, which takes a value depending on the type of hydraulic oil, k 35 = 0.9 when the hydraulic oil is mineral oil, k 35 = 1.0 when the hydraulic oil is synthetic oil, k 35 = 1.1 when the hydraulic oil is bio-based oil.

[0019] S2.4 Calculate the brake pedal simulator driver operation fraction index K4 according to the following formula,

[0020]

[0021] where w9, w 10 , w 11 and w 12 represent the weight coefficients, k 41 represents the driver pedal force application speed coefficient, which takes a value equal to the speed value v j when the driver applies action to the brake pedal, k 42 represents the driver driving age coefficient, which takes a value depending on the driving age Y j of the driver, k j = 1.3 when the driving age Y 42 of the driver is less than or equal to one year, k j = 1.0 when the driving age Y 42 of the driver is greater than one year and less than or equal to three years, k j = 0.8 when the driving age Y 42 of the driver is greater than three years and less than or equal to eight years, k j = 0.5 when the driving age Y 42 of the driver is greater than eight years and less than or equal to fifteen years, k j = 0.3 when the driving age Y 42 of the driver is greater than fifteen years, k 43 represents the driver's myoelectric activity coefficient, which takes a value depending on the myoelectric signal amplitude E max and the myoelectric signal frequency f of the driver, k 43 = 2.0 when the myoelectric signal amplitude and the myoelectric signal frequency of the driver show that the driver is nervous, k 43=1.0, k 44 k represents the driver's eye-tracking parameter coefficients. 45 This represents the driver's age coefficient, the value of which depends on the driver's age Y. n When the driver's age Y n Less than 25, k 45 =0.7, when the driver's age Y n When k is greater than or equal to 25 and less than 55 45 =1.2, when the driver's age Y n When k is greater than or equal to 55 and less than 65 45 =0.9, when the driver's age Y n When k is greater than or equal to sixty-five, 45 =0.5, k 46 This represents the driver's braking style coefficient, the value of which depends on the braking style selected by the driver based on their driving habits before driving the vehicle. When the driver uses a light braking style, k... 46 =0.4, when the driver is using a moderate braking style, k 46 =0.8, when the driver has a heavy braking style, k 46 =1.3, when the driver uses an emergency braking style, k 46 =1.5, k 47 This indicates the damage coefficient of the brake pedal simulator;

[0022] S2.5 Calculate the basic driving condition sub-index K5 according to the following formula.

[0023]

[0024] Among them, w 13 and w 14 It is the weighting coefficient, k 51 k represents the service braking deceleration coefficient. 52 k represents the vehicle speed coefficient. 53 This represents the road surface adhesion coefficient, and its value is equal to the road surface adhesion coefficient φ,k. 54 This represents the vehicle's load capacity coefficient, where m e The vehicle's payload capacity is represented by m0, and its curb weight is represented by k. 55 k represents the vehicle stability coefficient. 56 k represents the fuel economy coefficient of a vehicle. 57 The carbon emission coefficient of a vehicle is determined by the amount of carbon dioxide (G) per kilometer driven by the vehicle. L When G L When the value of k is less than or equal to 200, 57 =0.6, when G L When the value of k is greater than 200, 57= 0.8;

[0025] S3, according to the following formula calculates the brake pedal simulator impact factor total evaluation index K,

[0026]

[0027] Wherein, α1, α2, α3, α4, α5 is the single index calculation weighting value;

[0028] The brake pedal simulator mode selection module includes soft brake pedal simulator mode, moderate brake pedal simulator mode, hard brake pedal simulator mode, by introducing the first decision threshold ζ1, the second decision threshold ζ2 to determine the mode selection of the pedal simulation, wherein 0 < ζ1 < ζ2 < 1;

[0029] The brake pedal simulator mode feedback module includes: driver satisfaction feedback module, pedal simulator mode adjustment module, pedal simulator mode selection system forced stop module.

[0030] The road traffic environment recognition module includes vehicle information acquisition module, surrounding environment detection module, driver state perception module;

[0031] The vehicle information acquisition module is used for collecting various data of the vehicle, including: brake pedal stroke X, brake master cylinder displacement X1, size precision coefficient k of brake pedal simulator 11 , geometric precision coefficient k of brake pedal simulator 12 , surface roughness coefficient k of brake pedal simulator 13 , position accuracy coefficient k of brake pedal simulator 14 , repeatability coefficient k of brake pedal simulator 15 , process stability coefficient k of brake pedal simulator 16 , sensitivity coefficient k of brake pedal simulator pedal force sensor 21 , sensitivity coefficient k of brake pedal simulator position sensor 22 , maximum stroke X of brake pedal max , sensitivity coefficient k of brake pedal simulator speed sensor 24 , hydraulic oil pollutant periodic coefficient k 34 , type of hydraulic oil, driving brake deceleration coefficient k 51 , driving speed coefficient k 52 , load mass m of vehicle e , vehicle kerb mass m0, vehicle stability coefficient k 55 , fuel economy coefficient k of vehicle 56 , carbon dioxide mass G per kilometer of vehicle L , damage coefficient k of brake pedal simulator47 ;

[0032] The surrounding environment detection module is used to detect various data around the vehicle, including: the number of defects N of the brake pedal simulator found in a certain production batch D , the number of products actually produced in the production batch N A , the current temperature T, the viscosity ρ0 at the reference temperature T0, the brake fluid temperature coefficient δ, the current humidity H, the boiling point of the brake fluid at the humidity H Boil, the reference boiling point of the hydraulic oil Boil0, the humidity influence coefficient β, and the hydraulic oil replacement period t ch , the road adhesion coefficient φ;

[0033] The driver state perception module is used to collect information of the driver, including: the speed value v of the driver when applying force to the brake pedal j , the driving age Y of the driver j , the amplitude E of the electromyographic signal of the driver max , the frequency f of the electromyographic signal, and the eye movement parameter coefficient k of the driver 44 , the age Y of the driver n , and the braking style of the driver.

[0034] The pedal simulator influencing factor evaluation index calculation module includes:

[0035] First, a pedal simulator model of a hydraulic line control brake vehicle is established, and a force balance equation of a master cylinder piston is written, then each evaluation sub-index of the pedal simulator influencing factor is calculated, including: a brake pedal simulator manufacturing process sub-index K1, a brake pedal simulator variable performance sub-index K2, a brake pedal simulator hydraulic oil state sub-index K3, a brake pedal simulator driver operation sub-index K4, and a driving basic state sub-index K5. Finally, the total evaluation index K of the pedal simulator influencing factor is calculated according to each sub-index.

[0036] The brake pedal simulator manufacturing process sub-index K1 depends on the size accuracy coefficient k 11 of the brake pedal simulator, the geometric accuracy coefficient k 12 of the brake pedal simulator, the surface roughness coefficient k 13 of the brake pedal simulator, the position accuracy coefficient k 14 of the brake pedal simulator, the repeatability coefficient k 15 of the brake pedal simulator, the process stability coefficient k 16 of the brake pedal simulator, and the quality defect rate coefficient k 17 ;

[0037] The brake pedal simulator variable performance sub-index K2 depends on the sensitivity coefficient k 21The sensitivity coefficient k of the brake pedal simulator position sensor 22 The sensitivity coefficient k of the brake pedal simulator stroke sensor 23 The sensitivity coefficient k of the brake pedal simulator speed sensor 24 ;

[0038] The brake pedal simulator hydraulic oil state sub-index K3 depends on the hydraulic oil temperature sensitivity coefficient k 31 The hydraulic oil humidity sensitivity coefficient k 32 The hydraulic oil replacement period coefficient k 33 The hydraulic oil pollutant period coefficient k 34 The hydraulic oil type coefficient k 35 The brake pedal simulator driver operation sub-index K4 depends on the speed coefficient k of the driver's pedal force 41 The driver's driving age coefficient k 42 The driver's myoelectric activity coefficient k 43 The driver's eye movement parameter coefficient k 44 The driver's age coefficient k 45 The driver's braking style coefficient k 46 The brake pedal simulator damage coefficient k 47 ;

[0039] The driving basic state sub-index K5 depends on the driving brake deceleration coefficient k 51 The driving speed coefficient k 52 The road surface adhesion coefficient k 53 The driving load mass coefficient k 54 The vehicle stability coefficient k 55 The vehicle fuel economy coefficient k 56 The vehicle driving carbon emission coefficient k 57 .

[0040] The brake pedal simulator mode selection module includes three working modes of soft brake pedal simulator mode, medium brake pedal simulator mode, and hard brake pedal simulator mode, wherein when the three pedal modes reach the same brake master cylinder displacement, the driver's required brake pedal force of the soft brake pedal simulator mode is the smallest, the driver's required brake pedal force of the medium brake pedal simulator mode is the second, and the driver's required brake pedal force of the hard brake pedal simulator mode is the largest. The mode selection is determined by introducing the first determination threshold ζ1 and the second determination threshold ζ2, wherein 0<ζ1<ζ2<1. When the total evaluation index K of the pedal simulator influencing factors satisfies 0<K<ζ1, the brake pedal simulator mode selection module selects the soft brake pedal simulator mode, and the driver's required brake pedal force satisfies:

[0041]

[0042] wherein L represents a brake pedal leverage ratio, k1 represents a master cylinder return spring stiffness, k2 represents a wheel cylinder return spring stiffness, A1 represents a master cylinder piston area, A2 represents a wheel cylinder piston area, X represents a brake pedal stroke, C q represents an effective flow coefficient of a hydraulic pipeline.

[0043] When the total evaluation index K of the pedal simulator influencing factors satisfies ζ1≤K<ζ2, the brake pedal simulator mode selection module selects a soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies:

[0044]

[0045] wherein L represents a brake pedal leverage ratio, k1 represents a master cylinder return spring stiffness, k2 represents a wheel cylinder return spring stiffness, A1 represents a master cylinder piston area, A2 represents a wheel cylinder piston area, X represents a brake pedal stroke, C q represents an effective flow coefficient of a hydraulic pipeline.

[0046] When the total evaluation index K of the pedal simulator influencing factors satisfies ζ2≤K<1, the brake pedal simulator mode selection module selects a soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies:

[0047]

[0048] wherein L represents a brake pedal leverage ratio, k1 represents a master cylinder return spring stiffness, k2 represents a wheel cylinder return spring stiffness, A1 represents a master cylinder piston area, A2 represents a wheel cylinder piston area, X represents a brake pedal stroke, C q represents an effective flow coefficient of a hydraulic pipeline.

[0049] The brake pedal simulator mode feedback module comprises a driver satisfaction feedback module, a pedal simulator mode adjustment module, and a pedal simulator mode selection system forced stop module.

[0050] The driver satisfaction feedback module is used for feedback of the satisfaction of the driver to the current working mode of the pedal simulator, and the feedback includes two options of satisfaction and dissatisfaction. When the driver selects satisfaction, the pedal simulator continues to maintain the current working mode. When the driver selects dissatisfaction, the driver satisfaction feedback module drives the pedal simulator mode adjustment module to work. The pedal simulator mode adjustment module is used for adjusting the working mode of the brake pedal simulator according to the satisfaction of the driver. When the driver satisfaction feedback module outputs an unsatisfied result, the driver can adjust the working mode of the pedal simulator by changing the brake style selected according to the driving habit of the driver before the vehicle travels.

[0051] The pedal simulator mode selection system forced stop module is used to forcibly stop the operation of the pedal simulator mode selection system. Compared with the prior art, the advantages of this invention are:

[0052] 1. A mode selection system for a pedal simulator based on hydraulic brake-by-wire is provided. Based on the manufacturing process index, variable performance index, hydraulic oil status index, driver operation index, and basic driving status index of the brake pedal simulator, a total evaluation index of the influencing factors of the pedal simulator is obtained.

[0053] 2. The brake pedal simulator mode selection module includes three working modes: gentle brake pedal simulator mode, medium brake pedal simulator mode, and hard brake pedal simulator mode. When the three pedal modes reach the same brake master cylinder displacement, the gentle brake pedal simulator mode requires the least brake pedal force from the driver, the medium brake pedal simulator mode requires the next least, and the hard brake pedal simulator mode requires the most. The mode selection is determined by introducing a first judgment threshold and a second judgment threshold.

[0054] 3. Taking into account the influence of pedal manufacturing process, driver, and road environment, different brake pedal simulator modes are selected by introducing a total evaluation index of pedal simulator influencing factors. At the same time, the brake pedal simulator mode can be continuously adjusted based on driver feedback. Attached Figure Description

[0055] The present invention will be further described below with reference to the accompanying drawings:

[0056] Figure 1 This is a framework diagram of a pedal simulator mode selection system based on hydraulic brake-by-wire proposed in this invention. Detailed Implementation

[0057] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0058] like Figure 1 As shown, the present invention is a pedal simulator mode selection system based on hydraulic brake-by-wire, including an on-board information acquisition module, a pedal simulator influencing factor evaluation index calculation module, a brake pedal simulator mode selection module, and a brake pedal simulator mode feedback module.

[0059] The road traffic environment recognition module includes a vehicle information collection module, a surrounding environment detection module, and a driver status perception module.

[0060] The pedal simulator influencing factor evaluation index calculation module includes:

[0061] S1, establish a pedal simulator model of a hydraulic line control brake vehicle, the force balance equation of the master cylinder piston is:

[0062] X1=LX

[0063] Wherein X represents the brake pedal stroke, X1 represents the brake master cylinder displacement, L represents the brake pedal lever ratio;

[0064] S2, calculate the evaluation index of each factor of the pedal simulator, including:

[0065] S2.1, calculate the manufacturing process index K1 of the brake pedal simulator according to the following formula,

[0066]

[0067] Wherein w1, w2, w3 represent the weighting coefficient, k 11 represents the size accuracy coefficient of the brake pedal simulator, k 12 represents the geometric accuracy coefficient of the brake pedal simulator, k 13 represents the surface roughness coefficient of the brake pedal simulator, k 14 represents the position accuracy coefficient of the brake pedal simulator, k 15 represents the repeatability accuracy coefficient of the brake pedal simulator, k 16 represents the process stability coefficient of the brake pedal simulator, k 17 represents the quality defect rate coefficient of the brake pedal simulator, wherein N D represents the number of defects of the brake pedal simulator found in a certain production batch, N A represents the number of products actually produced in the production batch; S2.2, calculate the variable performance index K2 of the brake pedal simulator according to the following formula,

[0068]

[0069] Wherein w4, w5, w6 represent the weighting coefficient, k 21 represents the sensitivity coefficient of the brake pedal force sensor of the brake pedal simulator, which depends on the sampling frequency of the pedal force sensor, k 22 represents the sensitivity coefficient of the position sensor of the brake pedal simulator, which depends on the sampling frequency of the position sensor, k 23 represents the sensitivity coefficient of the stroke sensor of the brake pedal simulator, which is equal to the pedal stroke ratio ε of the pedal simulator P , wherein X max represents the maximum stroke of the brake pedal, k 24 represents the sensitivity coefficient of the speed sensor of the brake pedal simulator, which depends on the sampling frequency of the speed sensor;

[0070] S2.3 Calculate the brake pedal simulator hydraulic oil state sub-index K3 according to the following formula,

[0071]

[0072] wherein w7 and w8 represent weight coefficients, k 31 represents a hydraulic oil temperature sensitivity coefficient, k 31 = p0*(1+ d*(T-T0)), T represents a current temperature, p0 represents a viscosity at a reference temperature T0, d represents a brake fluid temperature coefficient, k 32 represents a hydraulic oil humidity sensitivity coefficient, k 32 = Boil0- bH, wherein H represents a current humidity, Boil represents a hydraulic oil boiling point at humidity H, Boil0 represents a reference boiling point of the hydraulic oil, b represents a humidity influence coefficient, k 33 represents a hydraulic oil replacement period coefficient, which takes a value equal to the hydraulic oil replacement period t ch , k 34 represents a hydraulic oil contaminant period coefficient, k 35 represents a hydraulic oil type coefficient, which takes a value depending on the type of the hydraulic oil, k 35 = 0.9 when the hydraulic oil is mineral oil, k 35 = 1.0 when the hydraulic oil is synthetic oil, k 35 = 1.1 when the hydraulic oil is bio-based oil.

[0073] S2.4 Calculate the brake pedal simulator driver operation sub-index K4 according to the following formula,

[0074]

[0075] wherein w9, w 10 , w 11 and w 12 represent weight coefficients, k 41 represents a driver applied pedal force speed coefficient, which takes a value equal to the speed value v j , k 42 represents a driver driving age coefficient, which takes a value depending on the driving age Y j of the driver, k j = 1.3 when the driving age Y 42 of the driver is less than or equal to one year, k j = 1.0 when the driving age Y 42 of the driver is greater than one year and less than or equal to three years, k j = 0.8 when the driving age Y 42= 0.8, when the driver's driving age Y j is greater than eight years and less than or equal to fifteen years, k 42 = 0.5, when the driver's driving age Y j is greater than fifteen years, k 42 = 0.3, k 43 represents the driver's myoelectric activity coefficient, whose value depends on the driver's myoelectric signal amplitude E max and the myoelectric signal frequency f, when the driver's myoelectric signal amplitude and the myoelectric signal frequency show that the driver is nervous, k 43 = 2.0, when the driver's myoelectric signal amplitude and the myoelectric signal frequency do not show that the driver is nervous, k 43 = 1.0, k 44 represents the driver's eye movement parameter coefficient, k 45 represents the driver's age coefficient, whose value depends on the driver's age Y n , when the driver's age Y n is less than twenty-five, k 45 = 0.7, when the driver's age Y n is greater than or equal to twenty-five and less than fifty-five, k 45 = 1.2, when the driver's age Y n is greater than or equal to fifty-five and less than sixty-five, k 45 = 0.9, when the driver's age Y n is greater than or equal to sixty-five, k 45 = 0.5, k 46 represents the driver's braking style coefficient, whose value depends on the braking style selected by the driver according to his / her driving habits before the vehicle is driven, when the driver is a light braking style, k 46 = 0.4, when the driver is a moderate braking style, k 46 = 0.8, when the driver is a heavy braking style, k 46 = 1.3, when the driver is a sudden stop braking style, k 46 = 1.5, k 47 represents the breaking of the brake pedal simulator coefficient;

[0076] S2.5 calculates the driving basic state sub-index K5 according to the following formula,

[0077]

[0078] where w 13 and w 14 are weight coefficients, k 51 represents the driving braking deceleration coefficient, k 52 represents the driving speed coefficient, k 53 represents the road adhesion coefficient, whose value is equal to the road adhesion coefficient φ, k54 represents the driving load quality coefficient of the vehicle, wherein m e represents the load quality of the vehicle, m0 represents the whole vehicle kerb mass, k 55 represents the vehicle stability coefficient, k 56 represents the fuel economy coefficient of the vehicle, k 57 represents the vehicle driving carbon emission coefficient, the value of which depends on the mass of carbon dioxide G L of the vehicle per kilometer, L when the value of G 57 is less than or equal to 200, k L = 0.6, when the value of G 57 is greater than 200, k

[0079] S3, calculating the total evaluation index K of the pedal simulator influencing factor according to the following formula,

[0080]

[0081] wherein, α1, α2, α3, α4, α5 are the weighted values calculated by the single index;

[0082] The brake pedal simulator mode selection module includes a soft brake pedal simulator mode, a medium brake pedal simulator mode, and a hard brake pedal simulator mode, and the mode selection of the pedal simulation is determined by introducing a first determination critical value ζ1 and a second determination critical value ζ2, wherein 0 < ζ1 < ζ2 < 1.

[0083] The brake pedal simulator mode feedback module includes a driver satisfaction feedback module, a pedal simulator mode adjustment module, and a pedal simulator mode selection system forced stop module.

[0084] The road traffic environment recognition module includes a vehicle information acquisition module, a surrounding environment detection module, and a driver state perception module.

[0085] The vehicle information acquisition module is used to acquire various data of the vehicle, including: brake pedal stroke X, brake master cylinder displacement X1, size accuracy coefficient k 11 of the brake pedal simulator, geometric accuracy coefficient k 12 of the brake pedal simulator, surface roughness coefficient k 13 of the brake pedal simulator, position accuracy coefficient k 14 of the brake pedal simulator, repeatability coefficient k 15 of the brake pedal simulator, process stability coefficient k 16 of the brake pedal simulator, sensitivity coefficient k 21 of the brake pedal simulator position sensor22 Maximum stroke of brake pedal X max Sensitivity coefficient k of brake pedal simulator speed sensor 24 Period coefficient k of hydraulic oil contamination 34 Type of hydraulic oil, braking deceleration coefficient k of service brake 51 Service speed coefficient k 52 Mass m of vehicle e Vehicle stability coefficient k of vehicle curb weight m0 55 Fuel economy coefficient k of vehicle 56 Mass G of carbon dioxide per kilometer of vehicle L Damage coefficient k of brake pedal simulator 47 The surrounding environment detection module is used to detect various data around the vehicle, including: the number N of defects of the brake pedal simulator found in a certain production batch D The number N of products actually produced in the production batch A Current temperature T, viscosity p0 at reference temperature T0, brake fluid temperature coefficient d, current humidity H, boiling point Boil of brake fluid at humidity H, reference boiling point Boil0 of hydraulic oil, humidity influence coefficient b, hydraulic oil replacement period t ch Road adhesion coefficient f

[0086] The driver state perception module is used to collect information of the driver, including: speed value v of the driver when applying force to the brake pedal j Driving age Y of the driver j Amplitude E of electromyographic signal of the driver max Frequency f of electromyographic signal, eye movement parameter coefficient k of the driver 44 Age Y of the driver n Braking style of the driver

[0087] The brake pedal simulator influencing factor evaluation index calculation module includes:

[0088] First, a brake pedal simulator model of a hydraulic line control brake vehicle is established, a force balance equation of a master cylinder piston is written, and then each evaluation sub-index of the brake pedal simulator influencing factor is calculated, including: brake pedal simulator manufacturing process sub-index K1, brake pedal simulator variable performance sub-index K2, brake pedal simulator hydraulic oil state sub-index K3, brake pedal simulator driver operation sub-index K4, and service basic state sub-index K5. Finally, the total evaluation index K of the brake pedal simulator influencing factor is calculated according to each sub-index;

[0089] The brake pedal simulator manufacturing process sub-index K1 depends on the size precision coefficient k of the brake pedal simulator 11 Geometric precision coefficient k of brake pedal simulator12 Surface roughness coefficient k of brake pedal simulator 13 Position accuracy coefficient k of brake pedal simulator 14 Repeatability coefficient k of brake pedal simulator 15 Process stability coefficient k of brake pedal simulator 16 Quality defect rate coefficient k of brake pedal simulator 17 ;

[0090] Variable performance sub-index K2 of brake pedal simulator depends on sensitivity coefficient k of brake pedal simulator pedal force sensor 21 Sensitivity coefficient k of brake pedal simulator position sensor 22 Sensitivity coefficient k of brake pedal simulator travel sensor 23 Sensitivity coefficient k of brake pedal simulator speed sensor 24 ;

[0091] Hydraulic oil status sub-index K3 of brake pedal simulator depends on hydraulic oil temperature sensitivity coefficient k 31 Hydraulic oil humidity sensitivity coefficient k 32 Hydraulic oil replacement period coefficient k 33 Hydraulic oil contamination period coefficient k 34 Hydraulic oil type coefficient k 35 Driver operation sub-index K4 of brake pedal simulator depends on speed coefficient k of driver applying pedal force 41 Driver driving age coefficient k 42 Electromyographic activity coefficient k of driver 43 Eye movement parameter coefficient k of driver 44 Driver age coefficient k 45 Driver braking style coefficient k 46 Damage coefficient k of brake pedal simulator 47 ;

[0092] Driving basic state sub-index K5 depends on driving brake deceleration coefficient k 51 Driving speed coefficient k 52 Road surface adhesion coefficient k 53 Driving loaded mass coefficient k 54 Vehicle stability coefficient k 55 Fuel economy coefficient k of vehicle 56 Vehicle travel carbon emission coefficient k 57 .

[0093] The brake pedal simulator mode selection module includes three working modes of soft brake pedal simulator mode, medium brake pedal simulator mode and hard brake pedal simulator mode, wherein when the three pedal modes reach the same brake master cylinder displacement, the brake pedal force required by the driver to apply in the soft brake pedal simulator mode is the smallest, the brake pedal force required by the driver to apply in the medium brake pedal simulator mode is the second, and the brake pedal force required by the driver to apply in the hard brake pedal simulator mode is the largest.

[0094] The mode selection is determined by introducing the first determination critical value ζ1 and the second determination critical value ζ2, wherein 0<ζ1<ζ2<1.

[0095] When the total evaluation index K of the pedal simulator influencing factors satisfies 0<K<ζ1, the brake pedal simulator mode selection module selects the soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies:

[0096]

[0097] Wherein, L represents the brake pedal lever ratio, k1 represents the master cylinder return spring stiffness, k2 represents the wheel cylinder return spring stiffness, A1 represents the master cylinder piston area, A2 represents the wheel cylinder piston area, X represents the brake pedal stroke, C q represents the effective flow coefficient of the hydraulic pipeline.

[0098] When the total evaluation index K of the pedal simulator influencing factors satisfies ζ1≤K<ζ2, the brake pedal simulator mode selection module selects the soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies:

[0099]

[0100] Wherein, L represents the brake pedal lever ratio, k1 represents the master cylinder return spring stiffness, k2 represents the wheel cylinder return spring stiffness, A1 represents the master cylinder piston area, A2 represents the wheel cylinder piston area, X represents the brake pedal stroke, C q represents the effective flow coefficient of the hydraulic pipeline.

[0101] When the total evaluation index K of the pedal simulator influencing factors satisfies ζ2≤K<1, the brake pedal simulator mode selection module selects the soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies:

[0102]

[0103] Wherein, L represents the brake pedal lever ratio, k1 represents the master cylinder return spring stiffness, k2 represents the wheel cylinder return spring stiffness, A1 represents the master cylinder piston area, A2 represents the wheel cylinder piston area, X represents the brake pedal stroke, C qEffective flow coefficient of a hydraulic line.

[0104] The brake pedal simulator mode feedback module comprises a driver satisfaction feedback module, a pedal simulator mode adjustment module, and a pedal simulator mode selection system forced stop module.

[0105] The driver satisfaction feedback module is used for the driver to feed back his satisfaction with the current working mode of the pedal simulator, and the satisfaction feedback comprises two options: satisfaction and dissatisfaction. When the driver selects satisfaction, the pedal simulator continues to maintain the current working mode. When the driver selects dissatisfaction, the driver satisfaction feedback module drives the pedal simulator mode adjustment module to work. The pedal simulator mode adjustment module is used for adjusting the working mode of the brake pedal simulator according to the satisfaction of the driver. When the driver satisfaction feedback module outputs the result of dissatisfaction, the driver can adjust the working mode of the pedal simulator by changing the brake style selected according to his driving habits before the vehicle travels.

[0106] The pedal simulator mode selection system forced stop module is used for forcibly stopping the working of the pedal simulator mode selection system.

Claims

1. A hydraulic line-based brake-by- pedal simulator mode selection system, characterized by, Comprise the following contents: It includes road traffic environment recognition module, pedal simulator influence factor evaluation index calculation module, brake pedal simulator mode selection module, brake pedal simulator mode feedback module; The road traffic environment recognition module comprises a vehicle-mounted information acquisition module, a surrounding environment detection module and a driver state perception module; The pedal simulator influence factor evaluation index calculation module comprises: S1, establish the pedal simulator model of hydraulic brake-by-wire vehicle, the force balance equation of master cylinder piston is: wherein X represents the brake pedal stroke, represents the brake master cylinder displacement, and L represents the brake pedal lever ratio; S2, calculate each evaluation index of pedal simulator influence factor, including: S2.1 Calculate the brake pedal simulator manufacturing process sub-index according to the following formula , wherein represents a weighting factor, represents a dimensional accuracy factor of the brake pedal simulator, represents a geometric accuracy factor of the brake pedal simulator, represents a surface roughness factor of the brake pedal simulator, represents a positional accuracy factor of the brake pedal simulator, represents a repeatability factor of the brake pedal simulator, represents a process stability factor of the brake pedal simulator, represents a quality defect rate factor of the brake pedal simulator, wherein , represents the number of defects of the brake pedal simulator found within a certain production lot, represents the number of products actually produced within this production lot; S2.2 Calculate the brake pedal simulator variable performance index according to the following formula , wherein represents a weighting factor, represents a sensitivity factor of the brake pedal simulator pedal force sensor, the value of which depends on the sampling frequency of the pedal force sensor, represents a sensitivity factor of the brake pedal simulator position sensor, the value of which depends on the sampling frequency of the position sensor, represents a sensitivity factor of the brake pedal simulator travel sensor, the value of which is equal to the pedal travel ratio of the brake pedal simulator wherein , represents the maximum travel of the brake pedal, represents a sensitivity factor of the brake pedal simulator speed sensor, the value of which depends on the sampling frequency of the speed sensor; S2.3 Calculate the brake pedal simulator hydraulic fluid condition sub-index according to the following formula , wherein, and represents a weight coefficient, represents a hydraulic oil temperature sensitivity coefficient, T represents the current temperature, represents the viscosity at the reference temperature , represents a brake fluid temperature coefficient, represents a hydraulic oil humidity sensitivity coefficient, wherein H represents the current humidity, represents the boiling point of the hydraulic oil at the humidity H, represents the reference boiling point of the hydraulic oil, represents a humidity influence coefficient, represents a hydraulic oil replacement period coefficient, whose value is equal to the hydraulic oil replacement period , represents a hydraulic oil contaminant period coefficient, represents a hydraulic oil type coefficient, whose value depends on the type of hydraulic oil, when the hydraulic oil is a mineral oil, when the hydraulic oil is a synthetic oil, when the hydraulic oil is a bio-based hydraulic oil, ; S2.4 Calculate a brake pedal simulator driver operation fraction index according to the following equation , wherein, represents a weight coefficient, represents a speed coefficient of the driver's applied pedal force, whose value is equal to the speed value when the driver exerts an action on the brake pedal , represents a driver's driving age coefficient, whose value depends on the driver's driving age , when the driver's driving age is less than or equal to one year, , when the driver's driving age is greater than one year and less than or equal to three years, , when the driver's driving age is greater than three years and less than or equal to eight years, , when the driver's driving age is greater than eight years and less than or equal to fifteen years, , when the driver's driving age is greater than fifteen years, , represents a driver's myoelectric activity coefficient, whose value depends on the driver's myoelectric signal amplitude and the frequency f of the myoelectric signal, when the driver's myoelectric signal amplitude and the frequency f of the myoelectric signal show that the driver is tense, , when the driver's myoelectric signal amplitude and the frequency f of the myoelectric signal do not show that the driver is tense, , represents a driver's eye movement parameter coefficient, represents a driver's age coefficient, whose value depends on the driver's age , when the driver's age is less than twenty-five, , when the driver's age is greater than or equal to twenty-five and less than fifty-five, , when the driver's age is greater than or equal to fifty-five and less than sixty-five, , when the driver's age is greater than or equal to sixty-five, , represents a driver's braking style coefficient, whose value depends on the braking style chosen by the driver according to his / her driving habits before the vehicle is driven, when the driver is a light braking style, , when the driver is a medium braking style, , when the driver is a heavy braking style, , when the driver is an emergency braking style, , represents a breaking of the brake pedal simulator coefficient; S2.5 Calculate the driving basic state sub-index according to the following formula , wherein, and are weight coefficients, denotes a coefficient of deceleration of service braking, denotes a coefficient of service speed, denotes a coefficient of road adhesion, the value of which is equal to the coefficient of road adhesion , denotes a coefficient of service load of the vehicle, wherein , denotes a load mass of the vehicle, denotes a total mass of the vehicle in a prepared state, denotes a coefficient of stability of the vehicle, denotes a coefficient of fuel economy of the vehicle, denotes a coefficient of carbon emissions of the vehicle, the value of which depends on the mass of carbon dioxide per kilometer , when the value of which is less than or equal to 200, , when the value of which is greater than 200, ; S3. Calculate the total evaluation index of the pedal simulator influencing factor according to the following formula , wherein, Weighted values are calculated for single indicators; The brake pedal simulator mode selection module includes a light brake pedal simulator mode, a medium brake pedal simulator mode, a hard brake pedal simulator mode, a mode selection of the pedal simulation is described by introducing a first decision threshold , a second decision threshold ; ; The brake pedal simulator mode feedback module comprises a driver satisfaction feedback module, a pedal simulator mode adjustment module and a pedal simulator mode selection system forced stop module.

2. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: The road traffic environment recognition module comprises a vehicle-mounted information acquisition module, a surrounding environment detection module and a driver state perception module; The vehicle information acquisition module is used for collecting various data of the vehicle, including: brake pedal stroke X, brake master cylinder displacement , size accuracy coefficient of brake pedal simulator , geometric accuracy coefficient of brake pedal simulator , surface roughness coefficient of brake pedal simulator , position accuracy coefficient of brake pedal simulator , repeatability coefficient of brake pedal simulator , process stability coefficient of brake pedal simulator , sensitivity coefficient of brake pedal simulator pedal force sensor , sensitivity coefficient of brake pedal simulator position sensor , maximum stroke of brake pedal , sensitivity coefficient of brake pedal simulator speed sensor , hydraulic oil pollutant cycle coefficient , type of hydraulic oil, driving brake deceleration coefficient , driving speed coefficient , load mass of vehicle , total mass of vehicle , vehicle stability coefficient , fuel economy coefficient of vehicle , mass of carbon dioxide per kilometer of vehicle , damage coefficient of brake pedal simulator ; The surrounding environment detection module is used to detect various data around the vehicle, including: the number of defects of the brake pedal simulator found in a certain production batch , the number of products actually produced in the production batch , the current temperature T, the reference temperature , the viscosity under the reference temperature , the brake fluid temperature coefficient , the current humidity H, the boiling point of the brake fluid under the humidity H , the reference boiling point of the hydraulic oil , the humidity influence coefficient , the hydraulic oil replacement period , the road adhesion coefficient ; The driver state perception module is used to collect information of the driver, including: speed value of the driver when applying force to the brake pedal , driving age of the driver , muscle electric signal amplitude value of the driver , frequency f of the muscle electric signal, eye movement parameter coefficient of the driver , age of the driver , braking style of the driver.

3. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: The pedal simulator influence factor evaluation index calculation module comprises: First, a pedal simulator model of a hydraulic brake-by-wire vehicle is established, a force balance equation of a master cylinder piston is written, and then evaluation sub-indexes of factors influencing the pedal simulator are calculated, including a manufacturing process index of the brake pedal simulator , a variable performance index of the brake pedal simulator , a hydraulic oil state index of the brake pedal simulator , a driver operation index of the brake pedal simulator , and a basic state index of driving Finally, a total evaluation index of the factors influencing the pedal simulator is calculated according to the sub-indexes ​ wherein the brake pedal simulator manufacturing process is divided into indicators a dimensional accuracy coefficient of the brake pedal simulator a geometric accuracy coefficient of the brake pedal simulator a surface roughness coefficient of the brake pedal simulator a position accuracy coefficient of the brake pedal simulator a repeatability accuracy coefficient of the brake pedal simulator a process stability coefficient of the brake pedal simulator a quality defect rate coefficient of the brake pedal simulator ; Brake pedal simulator variable performance index Sensitivity coefficient of the brake pedal simulator pedal force sensor Sensitivity coefficient of the brake pedal simulator position sensor Sensitivity coefficient of the brake pedal simulator travel sensor Sensitivity coefficient of the brake pedal simulator speed sensor ; Brake pedal simulator hydraulic fluid condition sub-index hydraulic oil temperature sensitivity coefficient hydraulic oil humidity sensitivity coefficient hydraulic oil replacement period coefficient hydraulic oil contamination period coefficient hydraulic oil type coefficient ; Driver operation sub-indexes of brake pedal simulator Speed coefficient depending on the driver's application of the pedal force Driver's driving age coefficient Electromyographic activity coefficient of the driver Eye movement parameter coefficient of the driver Driver's age coefficient Driver's braking style coefficient Brake pedal simulator's breakage coefficient ; driving basic state sub-indicators driving brake deceleration coefficient driving speed coefficient road adhesion coefficient driving load mass coefficient vehicle stability coefficient vehicle fuel economy coefficient vehicle driving carbon emission coefficient .

4. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: The brake pedal simulator mode selection module includes three working modes of soft brake pedal simulator mode, medium brake pedal simulator mode and hard brake pedal simulator mode, wherein, when the three pedal modes reach the same brake master cylinder displacement, the brake pedal force required by the driver to exert in the soft brake pedal simulator mode is the smallest, the brake pedal force required by the driver to exert in the medium brake pedal simulator mode is the second, and the brake pedal force required by the driver to exert in the hard brake pedal simulator mode is the largest, and the mode selection is determined by introducing a first determination critical value , a second determination critical value , wherein .

5. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: When the pedal simulator influencing factor total evaluation index satisfies , the brake pedal simulator mode selection module selects a soft brake pedal simulator mode, and the brake pedal force applied by the driver satisfies: wherein L represents a brake pedal lever ratio, represents a master cylinder return spring stiffness, represents a wheel cylinder return spring stiffness, represents a master cylinder piston area, represents a wheel cylinder piston area, and X represents a brake pedal stroke, represents an effective flow coefficient of a hydraulic line.

6. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: When the pedal simulator influencing factor total evaluation index Satisfies When the brake pedal force applied by the driver satisfies: wherein L represents a brake pedal lever ratio, represents a master cylinder return spring stiffness, represents a wheel cylinder return spring stiffness, represents a master cylinder piston area, represents a wheel cylinder piston area, and X represents a brake pedal stroke, represents an effective flow coefficient of a hydraulic line.

7. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: When the pedal simulator influencing factor total evaluation index satisfies When the brake pedal simulator mode selection module selects the soft brake pedal simulator mode, the brake pedal force applied by the driver satisfies: wherein L represents a brake pedal lever ratio, represents a master cylinder return spring stiffness, represents a wheel cylinder return spring stiffness, represents a master cylinder piston area, represents a wheel cylinder piston area, and X represents a brake pedal stroke, represents an effective flow coefficient of a hydraulic line.

8. The pedal simulator mode selection system based on hydraulic brake-by-wire according to claim 1, wherein: The brake pedal simulator mode feedback module comprises a driver satisfaction feedback module, a pedal simulator mode adjustment module and a pedal simulator mode selection system forced stop module; The driver satisfaction feedback module is used for the satisfaction feedback of driver to the current pedal simulator working mode, and the satisfaction feedback comprises two options of satisfaction and dissatisfaction. When the driver selects satisfaction, the pedal simulator continues to maintain the current working mode. When the driver selects dissatisfaction, the driver satisfaction feedback module drives the pedal simulator mode adjustment module to work; The pedal simulator mode adjustment module is used for adjusting the working mode of brake pedal simulator according to the satisfaction of driver. When the driver satisfaction feedback module outputs the result of dissatisfaction, the driver adjusts the working mode of pedal simulator by changing the brake style selected according to the driving habit before vehicle driving; The pedal simulator mode selection system forced stop module is used for forcibly stopping the working of the pedal simulator mode selection system.

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