An intelligent warning system based on brake system status

Abstract

The application discloses an intelligent warning system based on brake system state, which comprises a vehicle information sensing module, a brake system state index analysis module, a brake deceleration adjusting module, a brake efficiency determination index calculation module, an intelligent warning module and a driving feedback module. The vehicle information sensing module is used for collecting driving data of a vehicle during driving; the brake system state index analysis module is used for collecting and calculating various index parameters of the brake system state; the brake deceleration adjusting module is used for adjusting the brake deceleration of the vehicle; the brake efficiency determination index calculation module is used for recording some actual physical quantities and ideal physical quantities of the vehicle and calculating brake efficiency determination indexes; the intelligent warning module is used for warning the driver in different degrees according to the brake efficiency determination indexes; and the driving feedback module is used for making the vehicle exit the intelligent warning system based on brake system state.

Description

Technical Field

[0001] This invention relates to an intelligent warning system based on the status of the braking system. Background Technology

[0002] Brake warning systems are a vehicle safety technology designed to improve drivers' awareness of the vehicle's braking system status, thereby reducing accidents. By monitoring the braking system's condition, it enhances drivers' understanding of the vehicle's braking performance, helping to reduce the risk of brake-related accidents. This technology plays a crucial role in vehicle operation; however, current research largely focuses on brake force distribution and control, with limited research on warning and alerting systems regarding their status. Furthermore, the warning methods are relatively simple and fail to reflect the extent of brake system damage. As a key component ensuring driving safety, the vehicle's warning system is essential for safe driving. Therefore, to address the aforementioned issues, this invention proposes an intelligent warning system based on the braking system's status. Summary of the Invention

[0003] The purpose of this invention is to provide an intelligent warning system based on the status of the braking system 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 warning system based on the braking system status includes an on-board information perception module, a braking system status index analysis module, a braking deceleration adjustment module, a braking performance judgment index calculation module, an intelligent warning module, and a driving feedback module.

[0005] The vehicle information sensing module is used to collect driving data of the vehicle during driving, including: the vehicle mass m, and the longitudinal force F on the ground of the vehicle's drive wheels. X驱 The longitudinal force F on the ground of the driven wheel of the vehicle X从 The vehicle's air resistance F w The vehicle's gradient resistance F i The thickness d of the worn friction pad w ;

[0006] The braking system status index analysis module is used to collect and calculate various index parameters related to the braking system status, including:

[0007] S1. Establish a braking deceleration model for the vehicle during braking. The vehicle braking deceleration satisfies the following formula:

[0008]

[0009] Where m represents the total vehicle mass, F X驱 F represents the longitudinal force on the ground applied to the vehicle's drive wheels. X从 F represents the longitudinal force on the ground applied to the driven wheel of a vehicle.w F represents the air resistance of a vehicle. i Indicates the vehicle's slope resistance;

[0010] S2. Calculate the various state indicators of the braking system according to the following formulas, including:

[0011] S2.1 Calculate the friction plate condition index K1 according to the following formula.

[0012]

[0013] Where w1, w2, and w3 represent weighting coefficients, and k 11 This represents the driver's braking frequency coefficient, whose value is equal to the operating frequency of the friction pads, k. 12 k represents the impurity coefficient of the friction plate surface. When the friction plate surface is clean and free of impurities, k 12 =0.6, when there are a small amount of fine impurities on the surface of the friction plate, k 12 =1.0, when the friction plate surface has a lot of dirt and visible impurities, k 12 =1.5, when there is a large amount of obvious dirt and foreign matter embedded on the surface of the friction plate, k 12 =2.0, k 13 k represents the color change indicator coefficient. When the color indicator added to the friction pad material changes color due to overheating and excessive wear, k represents the color change coefficient. 13 =1.8, in other cases, k 13 =1.0, k 14 k represents the wear uniformity coefficient of the friction plate. When the friction plate produces abnormal noise and vibration during operation, it indicates that the wear of the friction plate is uneven. 14 =1.7, in other cases, k 14 =1.1, k 15 This represents the friction pad replacement frequency coefficient, whose value is equal to the frequency at which the driver replaces the friction pads, k. 16 This represents the friction pad usage time coefficient, whose value is equal to the current usage time of the friction pad, k. 17 This represents the coefficient for estimating the remaining life of the friction pad. Where d0 represents the initial thickness of the friction pad, d w d represents the thickness of the worn friction pad. min Indicates the minimum permissible thickness of the friction pad as specified by the manufacturer;

[0014] S2.2 Calculate the friction plate process performance index K2 according to the following formula.

[0015]

[0016] Where w4, w5, and w6 represent weighting coefficients, f represents the friction coefficient of the friction plate, and k 21k represents the wear resistance coefficient of the friction pad material. When the friction pad is an organic friction pad, k 21 =1.5, when the friction plate is a semi-metallic friction plate, k 21 =1.1, when the friction plates are ceramic friction plates and carbon fiber friction plates, k 21 =0.7, in other cases, k 21 =1.0, k 22 k represents the heat dissipation coefficient of the friction plate material. When the friction plate is an organic friction plate, k 22 =1.3, when the friction plate is a semi-metallic friction plate, k 22 =1.1, when the friction plate is a carbon fiber friction plate, k 22 =0.9, when the friction plate is a ceramic friction plate, k 22 =0.7, in other cases, k 22 =1.0, k 23 k represents the contact area coefficient of the friction pair, and its value is equal to the contact area of ​​the friction pair when the braking system is working. 24 k represents the coefficient of thermal degradation resistance of the friction pad. When the friction pad has good thermal degradation resistance, k 24 =0.5, otherwise, k 24 =1.1, k 25 k represents the water fading resistance coefficient of the friction pad. When the friction pad has good water fading resistance, k 25 =0.5, otherwise, k 25 =1.1, k 26 k represents the environmental friendliness coefficient of friction pads. When the friction pads are made of low-pollution, low-emission, and easily recyclable materials, k represents the coefficient. 26 =0.7, in other cases, k 26 =1.2, k 27 k represents the friction pair matching coefficient, the value of which depends on the degree of matching of the friction pair during operation. When the friction pair is well matched and the friction is uniform, k 27 =0.7, in other cases, k 27 =1.4;

[0017] S2.3 Calculate the brake fluid condition index K3 according to the following formula.

[0018]

[0019] Where w7 and w8 represent weighting coefficients, k 31 k represents the brake fluid level coefficient, which is used when the brake fluid level in the brake fluid reservoir is maintained within the appropriate range specified by the manufacturer. 31 =0.9, in other cases, k 31 =2.0, k 32 k represents the brake fluid type matching coefficient, which is used when the brake fluid type matches the vehicle type and braking system design.32 =1.0, otherwise, k 32 =1.5, k 33 This indicates the brake fluid moisture content coefficient. in k represents the water content value of the brake fluid. 34 This represents the brake fluid color coefficient; when the brake fluid color is transparent or pale yellow, k... 34 =0.8, when the brake fluid is cloudy, k 34 =1.2, k 35 This represents the boiling point coefficient of brake fluid. Where T b β represents the boiling point of brake fluid at a reference atmospheric pressure. b This represents the coefficient of variation of brake fluid boiling point with atmospheric pressure, expressed in Pa. b Pa represents the current atmospheric pressure, Pa0 represents the reference atmospheric pressure, and k represents the reference atmospheric pressure. 36 This represents the brake fluid corrosivity coefficient, whose value depends on the degree of corrosion the brake fluid causes to the brake lines. The specific value is determined by the actual situation. 37 Indicates the viscosity coefficient of brake fluid. Where η represents the viscosity of the brake fluid at the current temperature, η0 represents the viscosity of the brake fluid at 298.15 Kelvin, T represents the current temperature, and Q1 and Q2 are constants related to the properties of the brake fluid;

[0020] S2.4 Calculate the brake line condition index K4 according to the following formula.

[0021]

[0022] Among them, w9, w 10 k represents the weighting coefficient. 41 This represents the material coefficient of the brake line, and its value depends on the material of the brake line. When the brake line is made of stainless steel, k... 41 =0.8, when the brake line is made of copper-nickel alloy, k 41 =0.9, when the brake line is made of aluminum alloy, k 41 =1.1, in other cases, k 41 =1.0, k 42 This represents the brake circuit layout coefficient. When the brake circuit layout is a dual-half-shaft to dual-half-shaft type, k 42 =0.7, when the braking circuit layout is a one-and-a-half-to-one-half-shaft type and a one-and-a-half-wheel-to-one-and-a-half-shaft-to-one-wheel type, k 42 =0.9, when the braking circuit layout is cross-type and one-axle-to-one-axle type, k 42 =1.1, in other cases, k 42 =1.0, k 43k represents the brake line connection coefficient. When the brake line connection is a rigid pipe welded connection, k 43 =0.8, when the brake line is connected by a pressure flange, k 43 =0.9, when the brake line is connected by a threaded connection, k 43 =1.1, in other cases, k 43 =1.0, k 44 k represents the protection factor of the brake line. When the brake line has complete anti-corrosion coating and protective sleeve, k 44 =0.7, in other cases, k 44 =1.2, k 45 This represents the maintenance factor for the brake lines, and its value is equal to the frequency of inspecting and maintaining the brake lines and replacing worn parts.

[0023] S2.5 Calculate the brake pedal state sub-index K5 according to the following formula.

[0024]

[0025] Among them, w 11 w 12 w 13 k represents the weighting coefficient. 51 k represents the pedal travel coefficient. When the pedal travel is normal, k 51 =0.8, when the brake pedal travel is too long or too short, k 51 =1.2, k 52 k represents the pedal rebound coefficient; when the brake pedal is released, it quickly returns to its original position. 52 =0.9, in other cases, k 52 =1.0, k 53 k represents the brake pedal stability coefficient. When the brake pedal remains stable during operation without noticeable shaking or vibration, k represents this coefficient. 53 =0.7, in other cases, k 53 =1.0, k 54 k represents the pedal cleanliness and maintenance factor, which is the value when the brake pedal is clean and free of impurities and dirt. 54 =0.9, when impurities or dirt on the brake pedal affect the driver's operation, k 54 =1.1, k 55 This indicates the brake pedal force coefficient; k represents the braking force when the brake pedal is too heavy or too light. 55 =1.2, when the brake pedal force is within a reasonable range, k 55 =0.8, k 56 k represents the brake pedal noise coefficient, which is the value when there is abnormal noise from the brake pedal during operation. 56 =1.5, in other cases, k 56 =1.0;

[0026] S3. Calculate the total index K of the braking system state according to the following formula:

[0027]

[0028] where, α1, α2, α3, α4, α5 are the weighted values for calculating individual indexes.

[0029] The braking deceleration adjustment module is used to adjust the braking deceleration of the vehicle according to the total index K of the braking system state;

[0030] The braking deceleration adjustment module includes a slight braking deceleration adjustment module, a medium braking deceleration adjustment module, a forced braking deceleration adjustment module, and an extreme braking deceleration adjustment module. Among them, the slight braking deceleration adjustment module has the smallest adjustment to the original braking deceleration, the medium braking deceleration adjustment module has a smaller adjustment to the original braking deceleration, the forced braking deceleration adjustment module has a larger adjustment to the original braking deceleration, and the extreme braking deceleration adjustment module has the largest adjustment to the original braking deceleration. The selection of the braking deceleration adjustment module is described by introducing the first decision threshold ζ1, the second decision threshold ζ2, and the third decision threshold ζ3, where 0 < ζ1 < ζ2 < ζ3 < 1;

[0031] When the total index K of the braking system state satisfies 0 < K ≤ ζ1, the braking deceleration adjustment module will execute the slight braking deceleration adjustment module, and the braking deceleration of the vehicle satisfies:

[0032]

[0033] where, m represents the total vehicle mass, F X驱 represents the longitudinal ground force of the driving wheels of the vehicle, F X从 represents the longitudinal ground force of the driven wheels of the vehicle, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle;

[0034] When the total index K of the braking system state satisfies ζ1 < K ≤ ζ2, the braking deceleration adjustment module will execute the medium braking deceleration adjustment module, and the braking deceleration of the vehicle satisfies:

[0035]

[0036] where, m represents the total vehicle mass, F X驱 represents the longitudinal ground force of the driving wheels of the vehicle, F X从 represents the longitudinal ground force of the driven wheels of the vehicle, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle;

[0037] When the overall index K of the braking system state satisfies ζ2 < K ≤ ζ3, the braking deceleration adjustment module will execute the forced adjustment braking deceleration module, and the braking deceleration of the vehicle satisfies:

[0038]

[0039] where m represents the total vehicle mass, F X驱 represents the longitudinal ground force of the driving wheels of the vehicle, F X从 represents the longitudinal ground force of the driven wheels of the vehicle, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle; [[ID=1十七]]

[0040] When the overall index K of the braking system state satisfies ζ3 < K < 1, the braking deceleration adjustment module will execute the extreme adjustment braking deceleration module, and the braking deceleration of the vehicle satisfies:

[0041]

[0042] where m represents the total vehicle mass, F X驱 represents the longitudinal ground force of the driving wheels of the vehicle, F X从 [[ID=二八]]represents the longitudinal ground force of the driven wheels of the vehicle, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle.

[0043] The braking performance determination index calculation module is used to record the actual vehicle braking physical quantities obtained when the vehicle uses the intelligent warning system based on the braking system state and the best braking physical quantities that can be achieved when the vehicle does not use this system, and then calculate the braking performance determination index Ex according to the recorded physical quantities,

[0044]

[0045] where J represents the braking direction stability coefficient. When the vehicle maintains the expected driving path and direction during braking without deviation, side slip, and loss of steering ability, J = 1.0. In other cases, J = 2.0,

[0046] L0 represents the best braking distance that can be achieved when the vehicle does not use this system,

[0047] L represents the actual braking distance obtained when the vehicle uses the intelligent warning system based on the braking system state,

[0048] t0 represents the best braking time that can be achieved when the vehicle does not use this system,

[0049] t represents the actual braking time obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0050] a0 represents the optimal braking deceleration that the vehicle can achieve without using this system.

[0051] 'a' represents the actual braking deceleration obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0052] γ0 represents the optimal front-to-rear wheel braking force ratio that the vehicle can achieve when the system is not in use. F Xb10 F represents the sum of the optimal ground braking forces achieved by each front wheel when the system is not in use. Xb20 This represents the sum of the optimal ground braking forces that the vehicle can achieve with each rear wheel when the system is not in use.

[0053] γ represents the actual ratio of the front and rear wheel braking forces on the ground when the vehicle uses the aforementioned intelligent warning system based on the braking system status. F Xb1 F represents the sum of the actual ground braking forces of each front wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status. Xb2 This represents the sum of the actual ground braking forces of each rear wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0054] The intelligent warning module is used to select the working state according to the braking performance judgment index Ex, and to remind the driver of the status of the braking system to different degrees.

[0055] The intelligent warning module includes the following working states:

[0056] When 0≤Ex<0.01, the braking performance evaluation index calculation module outputs a "system normal" command to the intelligent warning module, and the intelligent warning module does not need to take warning measures.

[0057] When 0.01≤Ex<0.07, the braking performance judgment index calculation module outputs a "system prompt" command to the intelligent warning module. The intelligent warning module will display the K value and Δa value on the vehicle information display screen, where Δa=|a-a0|, and simultaneously display the black text "Please pay attention to potential problems, but no corresponding measures are needed for the time being". Here, a represents the actual braking deceleration obtained when the vehicle uses the intelligent warning system based on the braking system status, and a0 represents the optimal braking deceleration that the vehicle can achieve when the system is not used.

[0058] When 0.07≤Ex<0.15, the braking performance evaluation index calculation module outputs a "system warning" command to the intelligent warning module. The intelligent warning module illuminates the brake warning light on the vehicle's instrument panel and displays the words "There is a malfunction in the braking system. Please take repair and handling measures at an appropriate time" in black on the vehicle information display screen.

[0059] When 0.15≤Ex<0.20, the braking performance evaluation index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module commands the vehicle's buzzer to sound an alarm and displays the words "serious malfunction in the braking system, please take immediate repair and handling measures" in black on the vehicle information display screen.

[0060] When Ex≥0.20, the braking performance evaluation index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module commands the vehicle's buzzer to sound an alarm, and at the same time causes the brake pedal and driver's seat to vibrate slightly to attract the driver's attention. The vehicle information display screen shows the words "The braking system has a very serious malfunction. Please take immediate action" in red.

[0061] The driving feedback module is used to deactivate the intelligent warning system based on the braking system status. This module is executed when one of the following conditions occurs; otherwise, it is not executed:

[0062] A. When K≤0 and K≥1 occur, it is determined that the intelligent warning system based on the braking system status has malfunctioned.

[0063] B. When Γ>20%, the intelligent warning system based on the braking system status is determined to be malfunctioning. a represents the actual braking deceleration obtained when the vehicle uses the intelligent warning system based on the braking system status, and a0 represents the optimal braking deceleration that the vehicle can achieve when the system is not used.

[0064] C. The driver voluntarily exits the intelligent warning system based on the braking system status.

[0065] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0066] 1. An intelligent warning system based on braking system status includes an on-board information perception module, a braking system status index analysis module, a braking deceleration adjustment module, a braking performance judgment index calculation module, an intelligent warning module, and a driving feedback module.

[0067] 2. The braking deceleration adjustment module of the present invention includes a slight braking deceleration adjustment module, a medium braking deceleration adjustment module, a forced braking deceleration adjustment module, and an extreme braking deceleration adjustment module. Among them, the slight braking deceleration adjustment module has the smallest adjustment to the original braking deceleration, the medium braking deceleration adjustment module has a relatively small adjustment to the original braking deceleration, the forced braking deceleration adjustment module has a relatively large adjustment to the original braking deceleration, and the extreme braking deceleration adjustment module has the largest adjustment to the original braking deceleration. The selection of the braking deceleration adjustment module is described by introducing a first decision threshold ζ1, a second decision threshold ζ2, and a third decision threshold ζ3, wherein 0 < ζ1 < ζ2 < ζ3 < 1.

[0068] 3. The intelligent warning module of the present invention is used to select the working state according to the braking performance judgment index. Five working states are set for the module according to the braking effect of the system. Each working state has a different warning effect on the driver, ensuring driving safety. Attached Figure Description

[0069] The present invention will be further described below with reference to the accompanying drawings:

[0070] Figure 1 This is a framework diagram of an intelligent warning system based on the braking system status proposed in this invention. Detailed Implementation

[0071] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0072] like Figure 1 As shown, the present invention is an intelligent warning system based on the braking system status, including an on-board information perception module, a braking system status index analysis module, a braking deceleration adjustment module, a braking performance judgment index calculation module, an intelligent warning module, and a driving feedback module.

[0073] The vehicle information sensing module is used to collect driving data of the vehicle during driving, including: the vehicle mass m, and the longitudinal force F on the ground of the vehicle's drive wheels. X驱 The longitudinal force F on the ground of the driven wheel of the vehicle X从 The vehicle's air resistance F w The vehicle's gradient resistance F i The thickness d of the worn friction pad w ;

[0074] The braking system status index analysis module is used to collect and calculate various index parameters related to the braking system status, including:

[0075] S1. Establish a braking deceleration model for the vehicle during braking. The vehicle braking deceleration satisfies the following formula:

[0076]

[0077] Where m represents the total vehicle mass, F X驱 F represents the longitudinal force on the ground applied to the vehicle's drive wheels. X从 F represents the longitudinal force on the ground applied to the driven wheel of a vehicle. w F represents the air resistance of a vehicle. i Indicates the vehicle's slope resistance;

[0078] S2. Calculate the various state indicators of the braking system according to the following formulas, including:

[0079] S2.1 Calculate the friction plate condition index K1 according to the following formula.

[0080]

[0081] Where w1, w2, and w3 represent weighting coefficients, and k 11 This represents the driver's braking frequency coefficient, whose value is equal to the operating frequency of the friction pads, k. 12 k represents the impurity coefficient of the friction plate surface. When the friction plate surface is clean and free of impurities, k 12 =0.6, when there are a small amount of fine impurities on the surface of the friction plate, k 12 =1.0, when the friction plate surface has a lot of dirt and visible impurities, k 12 =1.5, when there is a large amount of obvious dirt and foreign matter embedded on the surface of the friction plate, k 12 =2.0, k 13 k represents the color change indicator coefficient. When the color indicator added to the friction pad material changes color due to overheating and excessive wear, k represents the color change coefficient. 13 =1.8, in other cases, k 13 =1.0, k 14 k represents the wear uniformity coefficient of the friction plate. When the friction plate produces abnormal noise and vibration during operation, it indicates that the wear of the friction plate is uneven. 14 =1.7, in other cases, k 14 =1.1, k 15 This represents the friction pad replacement frequency coefficient, whose value is equal to the frequency at which the driver replaces the friction pads, k. 16 This represents the friction pad usage time coefficient, whose value is equal to the current usage time of the friction pad, k. 17 This represents the coefficient for estimating the remaining life of the friction pad. Where d0 represents the initial thickness of the friction pad, d w d represents the thickness of the worn friction pad. min Indicates the minimum permissible thickness of the friction pad as specified by the manufacturer;

[0082] S2.2 Calculate the friction plate process performance index K2 according to the following formula.

[0083]

[0084] Where w4, w5, and w6 represent weighting coefficients, f represents the friction coefficient of the friction plate, and k 21 k represents the wear resistance coefficient of the friction pad material. When the friction pad is an organic friction pad, k 21 =1.5, when the friction plate is a semi-metallic friction plate, k 21 =1.1, when the friction plates are ceramic friction plates and carbon fiber friction plates, k 21 =0.7, in other cases, k 21 =1.0, k 22 k represents the heat dissipation coefficient of the friction plate material. When the friction plate is an organic friction plate, k 22 =1.3, when the friction plate is a semi-metallic friction plate, k 22 =1.1, when the friction plate is a carbon fiber friction plate, k 22 =0.9, when the friction plate is a ceramic friction plate, k 22 =0.7, in other cases, k 22 =1.0, k 23 k represents the contact area coefficient of the friction pair, and its value is equal to the contact area of ​​the friction pair when the braking system is working. 24 k represents the coefficient of thermal degradation resistance of the friction pad. When the friction pad has good thermal degradation resistance, k 24 =0.5, otherwise, k 24 =1.1, k 25 k represents the water fading resistance coefficient of the friction pad. When the friction pad has good water fading resistance, k 25 =0.5, otherwise, k 25 =1.1, k 26 k represents the environmental friendliness coefficient of friction pads. When the friction pads are made of low-pollution, low-emission, and easily recyclable materials, k represents the coefficient. 26 =0.7, in other cases, k 26 =1.2, k 27 k represents the friction pair matching coefficient, the value of which depends on the degree of matching of the friction pair during operation. When the friction pair is well matched and the friction is uniform, k 27 =0.7, in other cases, k 27 =1.4;

[0085] S2.3 Calculate the brake fluid condition index K3 according to the following formula.

[0086]

[0087] Where w7 and w8 represent weighting coefficients, k 31k represents the brake fluid level coefficient, which is used when the brake fluid level in the brake fluid reservoir is maintained within the appropriate range specified by the manufacturer. 31 =0.9, in other cases, k 31 =2.0, k 32 k represents the brake fluid type matching coefficient, which is used when the brake fluid type matches the vehicle type and braking system design. 32 =1.0, otherwise, k 32 =1.5, k 33 This indicates the brake fluid moisture content coefficient. in k represents the water content value of the brake fluid. 34 This represents the brake fluid color coefficient; when the brake fluid color is transparent or pale yellow, k... 34 =0.8, when the brake fluid is cloudy, k 34 =1.2, k 35 This represents the boiling point coefficient of brake fluid. Where T b β represents the boiling point of brake fluid at a reference atmospheric pressure. b This represents the coefficient of variation of brake fluid boiling point with atmospheric pressure, expressed in Pa. b Pa represents the current atmospheric pressure, Pa0 represents the reference atmospheric pressure, and k represents the reference atmospheric pressure. 36 This represents the brake fluid corrosivity coefficient, whose value depends on the degree of corrosion the brake fluid causes to the brake lines. The specific value is determined by the actual situation. 37 Indicates the viscosity coefficient of brake fluid. Where η represents the viscosity of the brake fluid at the current temperature, η0 represents the viscosity of the brake fluid at 298.15 Kelvin, T represents the current temperature, and Q1 and Q2 are constants related to the properties of the brake fluid;

[0088] S2.4 Calculate the brake line condition index K4 according to the following formula.

[0089]

[0090] Among them, w9, w 10 k represents the weighting coefficient. 41 This represents the material coefficient of the brake line, and its value depends on the material of the brake line. When the brake line is made of stainless steel, k... 41 =0.8, when the brake line is made of copper-nickel alloy, k 41 =0.9, when the brake line is made of aluminum alloy, k 41 =1.1, in other cases, k 41 =1.0, k 42 This represents the brake circuit layout coefficient. When the brake circuit layout is a dual-half-shaft to dual-half-shaft type, k 42=0.7, when the braking circuit layout is a one-and-a-half-to-one-half-shaft type and a one-and-a-half-wheel-to-one-and-a-half-shaft-to-one-wheel type, k 42 =0.9, when the braking circuit layout is cross-type and one-axle-to-one-axle type, k 42 =1.1, in other cases, k 42 =1.0, k 43 k represents the brake line connection coefficient. When the brake line connection is a rigid pipe welded connection, k 43 =0.8, when the brake line is connected by a pressure flange, k 43 =0.9, when the brake line is connected by a threaded connection, k 43 =1.1, in other cases, k 43 =1.0, k 44 k represents the protection factor of the brake line. When the brake line has complete anti-corrosion coating and protective sleeve, k 44 =0.7, in other cases, k 44 =1.2, k 45 This represents the maintenance factor for the brake lines, and its value is equal to the frequency of inspecting and maintaining the brake lines and replacing worn parts.

[0091] S2.5 Calculate the brake pedal state sub-index K5 according to the following formula.

[0092]

[0093] Among them, w 11 w 12 w 13 k represents the weighting coefficient. 51 k represents the pedal travel coefficient. When the pedal travel is normal, k 51 =0.8, when the brake pedal travel is too long or too short, k 51 =1.2, k 52 k represents the pedal rebound coefficient; when the brake pedal is released, it quickly returns to its original position. 52 =0.9, in other cases, k 52 =1.0, k 53 k represents the brake pedal stability coefficient. When the brake pedal remains stable during operation without noticeable shaking or vibration, k represents this coefficient. 53 =0.7, in other cases, k 53 =1.0, k 54 k represents the pedal cleanliness and maintenance factor, which is the value when the brake pedal is clean and free of impurities and dirt. 54 =0.9, when impurities or dirt on the brake pedal affect the driver's operation, k 54 =1.1, k 55 This indicates the brake pedal force coefficient; k represents the braking force when the brake pedal is too heavy or too light.55 = 1.2. When the braking pedal force is within a reasonable range, k 55 = 0.8, k 56 represents the braking pedal noise coefficient. When there is abnormal noise in the braking pedal during operation, k 56 = 1.5. In other cases, k 56 = 1.0;

[0094] S3. Calculate the total index K of the braking system state according to the following formula

[0095]

[0096] where α1, α2, α3, α4, α5 are the weighted values for calculating single-item indicators.

[0097] The braking deceleration adjustment module is used to adjust the braking deceleration of the vehicle according to the total index K of the braking system state;

[0098] The braking deceleration adjustment module includes a slight braking deceleration adjustment module, a medium braking deceleration adjustment module, a forced braking deceleration adjustment module, and an extreme braking deceleration adjustment module. Among them, the slight braking deceleration adjustment module has the smallest adjustment to the original braking deceleration, the medium braking deceleration adjustment module has a smaller adjustment to the original braking deceleration, the forced braking deceleration adjustment module has a larger adjustment to the original braking deceleration, and the extreme braking deceleration adjustment module has the largest adjustment to the original braking deceleration. The selection of the braking deceleration adjustment module is described by introducing the first decision threshold ζ1, the second decision threshold ζ2, and the third decision threshold ζ3, where 0 < ζ1 < ζ2 < ζ3 < 1;

[0099] When the total index K of the braking system state satisfies 0 < K ≤ ζ1, the braking deceleration adjustment module will execute the slight braking deceleration adjustment module, and the braking deceleration of the vehicle satisfies:

[0100]

[0101] where m represents the vehicle's total mass, F X驱 represents the longitudinal ground force of the vehicle's driving wheels, F X从 represents the longitudinal ground force of the vehicle's driven wheels, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle;

[0102] When the total index K of the braking system state satisfies ζ1 < K ≤ ζ2, the braking deceleration adjustment module will execute the medium braking deceleration adjustment module, and the braking deceleration of the vehicle satisfies:

[0103]

[0104] Among them, m represents the vehicle's total mass, F X驱 represents the longitudinal ground force of the vehicle's driving wheels, F X从 represents the longitudinal ground force of the vehicle's driven wheels, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle;

[0105] When the overall index K of the braking system state satisfies ζ2 < K ≤ ζ3, the braking deceleration adjustment module will execute the forced adjustment braking deceleration module, and the braking deceleration of the vehicle satisfies:

[0106]

[0107] Among them, m represents the vehicle's total mass, F X驱 represents the longitudinal ground force of the vehicle's driving wheels, F X从 represents the longitudinal ground force of the vehicle's driven wheels, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle;

[0108] When the overall index K of the braking system state satisfies ζ3 < K < 1, the braking deceleration adjustment module will execute the extreme adjustment braking deceleration module, and the braking deceleration of the vehicle satisfies:

[0109]

[0110] Among them, m represents the vehicle's total mass, F X驱 represents the longitudinal ground force of the vehicle's driving wheels, F X从 represents the longitudinal ground force of the vehicle's driven wheels, F w represents the air resistance of the vehicle, F i represents the ramp resistance of the vehicle.

[0111] The braking performance determination index calculation module is used to record the actual vehicle braking physical quantities obtained when the vehicle uses the intelligent warning system based on the braking system state and the best braking physical quantities that the vehicle can achieve when not using this system, and then calculate the braking performance determination index Ex according to the recorded physical quantities,

[0112]

[0113] Among them, J represents the braking direction stability coefficient. When the vehicle maintains the expected driving path and direction during braking without experiencing pulling to one side, sideslip, or loss of steering ability, J = 1.0. In other cases, J = 2.0,

[0114] L0 represents the best braking distance that the vehicle can achieve when not using this system,

[0115] L represents the actual braking distance obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0116] t0 represents the optimal braking time that the vehicle can achieve without using the system.

[0117] t represents the actual braking time obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0118] a0 represents the optimal braking deceleration that the vehicle can achieve without using this system.

[0119] 'a' represents the actual braking deceleration obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0120] γ0 represents the optimal front-to-rear wheel braking force ratio that the vehicle can achieve when the system is not in use. F Xb10 F represents the sum of the optimal ground braking forces achieved by each front wheel when the system is not in use. Xb20 This represents the sum of the optimal ground braking forces that the vehicle can achieve with each rear wheel when the system is not in use.

[0121] γ represents the actual ratio of the front and rear wheel braking forces on the ground when the vehicle uses the aforementioned intelligent warning system based on the braking system status. F Xb1 F represents the sum of the actual ground braking forces of each front wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status. Xb2 This represents the sum of the actual ground braking forces of each rear wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

[0122] The intelligent warning module is used to select the working state according to the braking performance judgment index Ex, and to remind the driver of the status of the braking system to different degrees.

[0123] The intelligent warning module includes the following working states:

[0124] When 0≤Ex<0.01, the braking performance evaluation index calculation module outputs a "system normal" command to the intelligent warning module, and the intelligent warning module does not need to take warning measures.

[0125] When 0.01≤Ex<0.07, the braking performance judgment index calculation module outputs a "system prompt" command to the intelligent warning module. The intelligent warning module will display the K value and Δa value on the vehicle information display screen, where Δa=|a-a0|, and simultaneously display the black text "Please pay attention to potential problems, but no corresponding measures are needed for the time being". Here, a represents the actual braking deceleration obtained when the vehicle uses the intelligent warning system based on the braking system status, and a0 represents the optimal braking deceleration that the vehicle can achieve when the system is not used.

[0126] When 0.07≤Ex<0.15, the braking performance evaluation index calculation module outputs a "system warning" command to the intelligent warning module. The intelligent warning module illuminates the brake warning light on the vehicle's instrument panel and displays the words "There is a malfunction in the braking system. Please take repair and handling measures at an appropriate time" in black on the vehicle information display screen.

[0127] When 0.15≤Ex<0.20, the braking performance evaluation index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module commands the vehicle's buzzer to sound an alarm and displays the words "serious malfunction in the braking system, please take immediate repair and handling measures" in black on the vehicle information display screen.

[0128] When Ex≥0.20, the braking performance evaluation index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module commands the vehicle's buzzer to sound an alarm, and at the same time causes the brake pedal and driver's seat to vibrate slightly to attract the driver's attention. The vehicle information display screen shows the words "The braking system has a very serious malfunction. Please take immediate action" in red.

[0129] The driving feedback module is used to deactivate the intelligent warning system based on the braking system status. This module is executed when one of the following conditions occurs; otherwise, it is not executed:

[0130] A. When K≤0 and K≥1 occur, it is determined that the intelligent warning system based on the braking system status has malfunctioned.

[0131] B. When Γ>20%, the intelligent warning system based on the braking system status is determined to be malfunctioning. a represents the actual braking deceleration obtained when the vehicle uses the intelligent warning system based on the braking system status, and a0 represents the optimal braking deceleration that the vehicle can achieve when the system is not used.

[0132] C. The driver voluntarily exits the intelligent warning system based on the braking system status.

Claims

1. An intelligent warning system based on the status of a braking system, characterized in that, Includes the following: Vehicle information perception module, braking system status index analysis module, braking deceleration adjustment module, braking performance judgment index calculation module, intelligent warning module, driving feedback module; The vehicle information sensing module is used to collect driving data during vehicle operation, including: vehicle mass. Longitudinal force on the ground of the vehicle's drive wheels The longitudinal force on the ground of the vehicle's driven wheels air resistance of vehicles vehicle slope resistance The thickness of the worn friction pad ; The braking system status index analysis module is used to collect and calculate various index parameters related to the braking system status, including: S1. Establish a braking deceleration model for the vehicle during braking. The vehicle braking deceleration satisfies the following formula: in, Indicates the overall vehicle weight. This represents the longitudinal force on the ground applied to the vehicle's drive wheels. This represents the longitudinal force on the ground applied to the driven wheels of a vehicle. Indicates the vehicle's air resistance. Indicates the vehicle's slope resistance; S2. Calculate the various state indicators of the braking system according to the following formulas, including: S2.1 Calculate the friction plate condition sub-index according to the following formula. , in, , , Indicates the weighting coefficient. This represents the driver's braking frequency coefficient, the value of which is equal to the operating frequency of the friction pads. This represents the impurity coefficient of the friction plate surface. When the friction plate surface is clean and free of impurities... When there are a few fine impurities on the surface of the friction plate, When the surface of the friction pad has a lot of dirt and visible impurities, When there is a large amount of obvious dirt and foreign matter embedded on the surface of the friction pad, , This indicates the color change indicator coefficient, which measures the color of the indicator added to the friction pad material when the friction pad changes color due to overheating and excessive wear. In other cases, , This represents the wear uniformity coefficient of the friction plate. Abnormal noise and vibration during friction plate operation indicate uneven wear. In other cases, , This represents the friction pad replacement frequency coefficient, whose value is equal to the frequency at which the driver replaces the friction pads. This represents the friction pad usage time coefficient, whose value is equal to the current usage time of the friction pad. This represents the coefficient for estimating the remaining life of the friction pad. ,in, This indicates the initial thickness of the friction pad. This indicates the thickness of the worn friction pad. Indicates the minimum permissible thickness of the friction pad as specified by the manufacturer; S2.2 Calculate the process performance sub-indicators of the friction plate according to the following formula. , in, , , Indicates the weighting coefficient. This indicates the coefficient of friction of the friction plate. This indicates the wear resistance coefficient of the friction pad material. When the friction pad is an organic friction pad, When the friction plate is a semi-metallic friction plate, When the friction plates are ceramic friction plates and carbon fiber friction plates, 7. Other cases, , This indicates the heat dissipation coefficient of the friction plate material. When the friction plate is an organic friction plate... When the friction plate is a semi-metallic friction plate, 1. When the friction pad is a carbon fiber friction pad, When the friction pad is a ceramic friction pad, In other cases, , This represents the contact area coefficient of the friction pair, and its value is equal to the contact area of ​​the friction pair when the braking system is working. This represents the coefficient of thermal degradation resistance of the friction pad. When the friction pad has good thermal degradation resistance, In other cases, , This represents the coefficient of water fading resistance of the friction pad. When the friction pad has good water fading resistance, In other cases, , This indicates the environmental friendliness coefficient of the friction pad. When the friction pad is made of low-pollution, low-emission, and easily recyclable materials, In other cases, , This represents the friction pair matching coefficient, the value of which depends on the degree of matching of the friction pair during operation. When the friction pair is well matched and the friction is uniform, In other cases, ; S2.3 Calculate the brake fluid condition index according to the following formula. , in, , Indicates the weighting coefficient. This indicates the brake fluid level coefficient, which is used when the brake fluid level in the brake fluid reservoir is maintained within the appropriate range specified by the manufacturer. In other cases, , This indicates the brake fluid type matching factor, which determines when the brake fluid type matches the vehicle type and braking system design. In other cases, , This indicates the brake fluid moisture content coefficient. ,in This indicates the water content value of the brake fluid. This indicates the brake fluid color factor. When the brake fluid color is transparent or pale yellow, When the brake fluid is cloudy, , This represents the boiling point coefficient of brake fluid. ,in This indicates the boiling point of the brake fluid at a reference atmospheric pressure. This represents the coefficient of variation of the brake fluid boiling point with atmospheric pressure. Indicates the current atmospheric pressure. Indicates reference atmospheric pressure. This indicates the corrosivity coefficient of the brake fluid. Its value depends on the degree of corrosion the brake fluid causes to the brake lines, and the specific value is determined by the actual situation. Indicates the viscosity coefficient of brake fluid. , ,in, This indicates the viscosity of the brake fluid at the current temperature. This indicates the viscosity of the brake fluid at 298.15 Kelvin, where T represents the current temperature. and These are constants related to the properties of the brake fluid; S2.4 Calculate the brake line condition sub-index according to the following formula. , in, , Indicates the weighting coefficient. This indicates the material coefficient of the brake line, and its value depends on the material of the brake line. When the brake line is made of stainless steel, When the brake lines are made of copper-nickel alloy, When the brake lines are made of aluminum alloy, In other cases, , This represents the brake circuit layout coefficient. When the brake circuit layout is a dual-half-shaft to dual-half-shaft type, When the braking circuit layout is a one-and-a-half to one-half-shaft type and a half-shaft-one-wheel to one-and-a-half-shaft-one-wheel type, When the braking circuit layout is a cross type or a one-axle-to-one type, In other cases, , This indicates the brake line connection coefficient. When the brake line is connected by rigid welded pipe connections... When the brake line is connected by a pressure flange, When the brake line is connected by a threaded connection, In other cases, , This indicates the protection factor of the brake lines. It is used when the brake lines have complete anti-corrosion coatings and protective sleeves / covers. In other cases, , This represents the maintenance factor for the brake lines, and its value is equal to the frequency of inspecting and maintaining the brake lines and replacing worn parts. S2.5 Calculate the brake pedal state sub-index according to the following formula. , in, , , Indicates the weighting coefficient. This represents the pedal travel coefficient; when the pedal travel is normal... When the brake pedal travel is too long or too short, , This indicates the pedal rebound coefficient; when the brake pedal is released, it should quickly return to its original position. In other cases, , This represents the brake pedal stability coefficient, indicating the stability of the brake pedal during operation without noticeable shaking or vibration. In other cases, , This indicates the pedal cleanliness and maintenance factor; when the brake pedal is clean and free of impurities and dirt, When impurities or dirt on the brake pedal affect the driver's operation, , This indicates the brake pedal force coefficient; it indicates whether the brake pedal is too heavy or too light. When the brake pedal force is within a reasonable range, , This represents the brake pedal noise factor; abnormal noise from the brake pedal during operation is indicated by this factor. In other cases, ; S3. Calculate the overall state index of the braking system according to the following formula. , in, Calculate the weighted value for each individual indicator.

2. The intelligent warning system based on the braking system status according to claim 1, characterized in that: The braking deceleration adjustment module is used to adjust the braking system status based on the overall index. To adjust the vehicle's braking deceleration; The braking deceleration adjustment module includes a slight braking deceleration adjustment module, a medium braking deceleration adjustment module, a forced braking deceleration adjustment module, and an extreme braking deceleration adjustment module. The slight braking deceleration adjustment module provides the smallest adjustment to the original braking deceleration, the medium adjustment module provides a relatively small adjustment, the forced adjustment module provides a relatively large adjustment, and the extreme adjustment module provides the largest adjustment. A first decision threshold is introduced. Second decision threshold Third decision threshold To describe the selection of the braking deceleration adjustment module, where, ; When the overall status index of the braking system satisfy At that time, the braking deceleration adjustment module will perform a slight adjustment to the braking deceleration module, and the vehicle's braking deceleration will meet the following requirements: in, Indicates the overall vehicle weight. This represents the longitudinal force on the ground applied to the vehicle's drive wheels. This represents the longitudinal force on the ground applied to the driven wheels of a vehicle. Indicates the vehicle's air resistance. Indicates the vehicle's slope resistance; When the overall status index of the braking system satisfy At that time, the braking deceleration adjustment module will perform medium-level braking deceleration adjustment, and the vehicle's braking deceleration will meet the following requirements: in, Indicates the overall vehicle weight. This represents the longitudinal force on the ground applied to the vehicle's drive wheels. This represents the longitudinal force on the ground applied to the driven wheels of a vehicle. Indicates the vehicle's air resistance. Indicates the vehicle's slope resistance; When the overall status index of the braking system satisfy At that time, the braking deceleration adjustment module will execute forced adjustment of the braking deceleration module, and the vehicle's braking deceleration will meet the following requirements: in, Indicates the overall vehicle weight. This represents the longitudinal force on the ground applied to the vehicle's drive wheels. This represents the longitudinal force on the ground applied to the driven wheels of a vehicle. Indicates the vehicle's air resistance. Indicates the vehicle's slope resistance; When the overall status index of the braking system satisfy At that time, the braking deceleration adjustment module will perform extreme adjustment of the braking deceleration module, and the vehicle's braking deceleration will meet the following requirements: in, Indicates the overall vehicle weight. This represents the longitudinal force on the ground applied to the vehicle's drive wheels. This represents the longitudinal force on the ground applied to the driven wheels of a vehicle. Indicates the vehicle's air resistance. This indicates the vehicle's gradient resistance.

3. The intelligent warning system based on the braking system status according to claim 1, characterized in that: The braking performance evaluation index calculation module records the actual vehicle braking physical quantities obtained when the vehicle uses the intelligent warning system based on the braking system status and the optimal braking physical quantities that the vehicle can achieve when the system is not used. Then, it calculates the braking performance evaluation index based on the recorded physical quantities. , in, This represents the braking directional stability coefficient, which is the coefficient of performance achieved when the vehicle maintains its intended path and direction during braking without veering, skidding, or losing steering ability. In other cases, , This indicates the optimal braking distance the vehicle can achieve without using the system. This indicates the actual braking distance obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This indicates the optimal braking time that the vehicle can achieve when the system is not in use. This indicates the actual braking time obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This indicates the optimal braking deceleration that the vehicle can achieve when the system is not in use. This indicates the actual braking deceleration obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This indicates the optimal front-to-rear wheel braking force ratio that the vehicle can achieve when the system is not in use. , This represents the sum of the optimal ground braking forces that the vehicle can achieve with each front wheel when the system is not in use. This represents the sum of the optimal ground braking forces that the vehicle can achieve with each rear wheel when the system is not in use. This indicates the actual ratio of front and rear wheel braking forces on the ground when the vehicle uses the aforementioned intelligent warning system based on braking system status. , This represents the sum of the actual ground braking forces of each front wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This represents the sum of the actual ground braking forces of each rear wheel when the vehicle uses the aforementioned intelligent warning system based on the braking system status.

4. The intelligent warning system based on the braking system status according to claim 1, characterized in that: The intelligent warning module is used to determine braking performance indicators. Select the operating status to provide the driver with varying degrees of alerts regarding the braking system's condition; The intelligent warning module includes the following working states: when When the braking performance assessment index calculation module outputs a "system normal" command to the intelligent warning module, the intelligent warning module does not need to take any warning measures. when At this time, the braking performance assessment indicator calculation module outputs a "system prompt" command to the intelligent warning module, which will then display a message on the vehicle information display screen. value, Value, of which At the same time, it displays the black text "Please be aware of potential problems, but no action is needed at this time." This indicates the actual braking deceleration obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This indicates the optimal braking deceleration that the vehicle can achieve when the system is not in use; when At this time, the braking performance assessment index calculation module outputs a "system warning" command to the intelligent warning module. The intelligent warning module illuminates the brake warning light on the vehicle's instrument panel and displays the words "There is a malfunction in the braking system. Please take repair and handling measures at an appropriate time" in black on the vehicle information display screen. when At that time, the braking performance assessment index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module then commands the vehicle's buzzer to sound an alarm and displays the message "Serious malfunction in the braking system, please take immediate repair and handling measures" in black on the vehicle information display screen. when At this time, the braking performance assessment index calculation module outputs a "serious system malfunction" command to the intelligent warning module. The intelligent warning module commands the vehicle's buzzer to sound an alarm, and at the same time causes the brake pedal and driver's seat to vibrate slightly to attract the driver's attention. The vehicle information display screen shows the words "The braking system has a very serious malfunction. Please take immediate action" in red.

5. The intelligent warning system based on the braking system status according to claim 1, characterized in that: The driving feedback module is used to deactivate the intelligent warning system based on the braking system status. This module is executed when one of the following conditions occurs; otherwise, it is not executed: A. When it occurs and When the system malfunctions, it is determined that the intelligent warning system based on the braking system status has malfunctioned. B, when When the intelligent warning system based on the braking system status is deemed to have malfunctioned, it is determined that such a system is in malfunction. , This indicates the actual braking deceleration obtained when the vehicle uses the aforementioned intelligent warning system based on the braking system status. This indicates the optimal braking deceleration that the vehicle can achieve when the system is not in use; C. The driver voluntarily exits the intelligent warning system based on the braking system status.

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