High-fidelity modeling method for motion intensity analysis of braking system

Abstract

The invention belongs to the technical field of automobiles, and particularly relates to a high-fidelity modeling method for brake system motion intensity analysis, which comprises a real vehicle road characteristic recognition module, a real vehicle brake parameter acquisition module, a brake intention calibration module, a brake deceleration calibration module and a brake control module. By designing the real vehicle road characteristic recognition module and the braking intention calibration module, the maximum braking speed of the ground where a real vehicle is located and the braking intention deceleration expected by a driver can be accurately recognized and controlled, and the problem that other braking system models cannot accurately express the braking strength actually expected by the driver is solved; high fidelity is achieved, and the braking strength consistent with that of a real vehicle can be obtained through simulation.

Description

Technical Field

[0001] The invention relates to the field of automobile technology, and in particular to a high-fidelity modeling method for analyzing the motion intensity of a braking system. Background Art

[0002] With the popularization of automobiles, their functions have been gradually improved, and they have gradually changed from production / transportation tools to consumer goods. People are also paying more and more attention to the sports quality of the car during driving. A good braking system can have better performance in terms of sensitivity, stability, accuracy and comfort when the driver brakes.

[0003] Invention patent CN118753247A discloses a magnetorheological intelligent pedal control system and method that integrates intention recognition and feedback control. The system includes a symmetrically arranged magnetorheological torque control device fixedly connected to both sides of the pedal base, a rotating shaft connected to the middle of the inner sides of the two support plates of the pedal base through a bearing, a brake pedal fixedly connected to the middle of the rotating shaft, and a torsion spring is also embedded on the rotating shaft, an angle sensor is connected to the upper end of the pedal, and a control unit for braking intention recognition and braking force feedback control is fixedly connected to the pedal, integrating pedal signal acquisition, braking intention recognition, and active pedal force feedback adjustment; However, you may encounter rainy or snowy weather while driving, and changes in ground conditions may cause the pedal control system designed based on intent recognition to be unable to respond.

[0004] Invention patent CN118790207A discloses a vehicle control method, device and vehicle. It includes: obtaining the current wheel speed of the wheel in the target vehicle under the current braking behavior, the current piston pressure of the brake piston and the current pedal stroke of the brake pedal; determining the current friction coefficient of the friction brake part in the target vehicle according to the current wheel speed and the current piston pressure; determining the target braking strength of the brake pedal in the target vehicle according to the current friction coefficient and the current pedal stroke when the current friction coefficient meets the braking force attenuation condition; and performing braking control on the target vehicle according to the target braking strength; However, during actual driving, when the driver operates the brake pedal to a small extent, it is difficult for the system designed by this invention to provide the driver with braking characteristics that meet his intentions.

[0005] Therefore, we propose a high-fidelity modeling method for braking system motion intensity analysis to solve the above problems. Summary of the invention

[0006] 1. Technical issues to be resolved In view of the deficiencies of the prior art, the present invention provides a high-fidelity modeling method for analyzing the motion intensity of a brake system, which solves the problems raised in the above-mentioned background technology.

[0007] (II) Technical solution In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions: A high-fidelity modeling method for analyzing the motion intensity of a braking system includes a real vehicle road characteristic recognition module, a real vehicle braking parameter acquisition module, a braking intention calibration module, a braking deceleration calibration module and a braking control module, and further includes the following steps: Step 1: Set the initial vehicle speed to 140km / h, considering that the maximum deceleration does not exceed 12m / s 2 , that is, when the pedal gradually increases its opening, it usually takes 5-8 seconds to stop completely. Here we take a 6-second incremental input of the pedal opening. Therefore, in actual vehicles, the brake pedal is input with a slope of 6 seconds at road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.95, and 1.0. For the convenience of data processing, the opening of the brake pedal in the actual vehicle test is 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90%, and 100%. When the braking force is greater than the adhesion force, the braking force will not continue to increase. At this time, it is the maximum value of the braking force, that is, the maximum value of the braking deceleration. The brake pedal input opening information under different road adhesion coefficients is collected; Step 2: Under the current road conditions, the driver is asked to brake three times with random pedal openings and then perform emergency braking, and the braking deceleration data of different longitudinal speeds and different braking inputs are collected to determine the braking deceleration slow-changing region threshold belonging to the current driver; Step 3: Process the experimental data under different working conditions obtained in steps 1 and 2, obtain the boundary curve of the braking characteristic field of the actual vehicle with the brake pedal as a slope input under different road adhesion coefficients and the braking deceleration curve under different pedal openings by interpolation, extract the braking decelerations of each point with the pedal opening of 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90% and 100% under the road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85 and 0.95, and obtain the braking deceleration characteristic field; Step 4: Take the characteristic field of braking deceleration changing with opening degree under different road adhesion coefficients of the actual vehicle as the control target to obtain a high-fidelity analytical model of braking system motion intensity.

[0008] Furthermore, the actual vehicle road characteristic identification module identifies the road adhesion conditions according to actual vehicle experimental data during actual vehicle testing.

[0009] Furthermore, the actual vehicle braking parameter acquisition module acquires the actual vehicle braking input of the driver, and the acquired data is the brake pedal opening.

[0010] Furthermore, the braking intention calibration module divides the braking deceleration intention into three segments, namely, the OP segment, the PQ segment and the RQ segment. The various threshold values ​​of the driver's expected braking deceleration versus pedal opening curve are calibrated according to actual vehicle experimental data. The OP segment is the slow-changing area of ​​braking deceleration, the PQ segment is the main action area of ​​the braking system, and the RQ segment is the braking saturation area.

[0011] Furthermore, the pedal opening, the maximum braking deceleration and the obtained braking threshold value are input into the braking deceleration calibration module to obtain the curve of the driver's expected braking deceleration changing with the pedal opening and then obtain the brake pedal-expected braking deceleration characteristic field.

[0012] Furthermore, the brake control module uses the identified brake pedal opening-brake deceleration characteristic field as a design basis for the control system's braking intention recognition module, so that the model's brake pedal-expected brake deceleration characteristic field has high fidelity with that of the actual vehicle.

[0013] (III) Beneficial effects Compared with the prior art, the present invention provides a high-fidelity modeling method for analyzing the motion intensity of a braking system, which has the following beneficial effects: The present invention can accurately identify and control the maximum braking speed of the ground on which the actual vehicle is located and the braking intention deceleration expected by the driver by designing a real vehicle road characteristic recognition module and a braking intention calibration module, thereby solving the problem that other braking system models cannot accurately express the braking intensity actually expected by the driver. The present invention has high fidelity, and the simulation can obtain a braking intensity consistent with the real vehicle. In addition, the present invention solves the problem that a single braking system model cannot model the brake pedal-expected braking deceleration characteristic field of any vehicle, reduces the dependence on product manufacturing accuracy, effectively improves mass production consistency and service performance, and can model the brake pedal-expected braking deceleration characteristic field of any vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the system principle of the present invention; Figure 2 It is a schematic diagram of a braking deceleration relationship curve based on the driver's braking intention of the present invention; Figure 3 It is a schematic diagram of the braking characteristic field of the present invention. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] Example like Figure 1-3 As shown, a high-fidelity modeling method for analyzing the motion intensity of a braking system proposed in one embodiment of the present invention is composed of a real vehicle road characteristic recognition module, a real vehicle braking parameter acquisition module, a braking intention calibration module, a braking deceleration calibration module, and a braking control module. The real vehicle road characteristic identification module is used to identify the road adhesion conditions according to the real vehicle experimental data in the real vehicle test; the real vehicle braking parameter acquisition module is used to collect the real vehicle braking input of the driver, and the collected data is the brake pedal opening; the braking intention calibration module divides the braking deceleration intention into 3 sections, namely the OP section (slow-changing braking deceleration area), the PQ section (the main action area of ​​the braking system, in accordance with the Weber-Fencher law), and the RQ section (braking saturation area), and calibrates the various thresholds of the driver's expected braking deceleration with the pedal opening curve according to the real vehicle experimental data; the pedal opening and the maximum braking deceleration and the obtained braking threshold value are input into the braking deceleration calibration module to obtain the driver's expected braking deceleration with the pedal opening curve and then obtain the brake pedal-expected braking deceleration characteristic field; the braking control module uses the identified brake pedal opening-brake deceleration characteristic field as the design basis of the control system braking intention recognition module, so that the model's brake pedal-expected braking deceleration characteristic field has high fidelity with the actual vehicle. The working process of the present invention applied to the ASCL driving simulator of Jilin University is as follows: Step 1: The initial vehicle speed in the experiment was 140 km / h, considering that the maximum deceleration did not exceed 12 m / s 2, that is, when the pedal gradually increases its opening, it usually takes 5-8 seconds to stop completely. Here we take a 6-second incremental input of the pedal opening. Therefore, in the actual vehicle, the brake pedal is inputted with a slope of 6 seconds at road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.95, and 1.0. For the convenience of data processing, the opening of the brake pedal in the actual vehicle test is 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90%, and 100%. When the braking force is greater than the adhesion force, the braking force will not continue to increase. At this time, it is the maximum value of the braking force, that is, the maximum value of the braking deceleration. The brake pedal input opening information under different road adhesion coefficients is collected (it is found through experiments that the curve relationship between the brake pedal opening and the braking deceleration is almost unaffected when the initial vehicle speed is any value).

[0017] Step 2: Under the current road conditions, the driver is asked to brake three times with random pedal openings and then perform emergency braking. The braking deceleration data of different longitudinal speeds and different braking inputs are collected to determine the slow-changing region threshold of braking deceleration belonging to the current driver.

[0018] Step 3: Data processing is performed on the experimental data under different working conditions obtained in steps 1 and 2, and the boundary curve of the braking characteristic field of the actual vehicle with the brake pedal as a slope input under different road adhesion coefficients and the braking deceleration curve under different pedal openings are obtained by interpolation. The braking decelerations at the points of 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90%, and 100% of the pedal opening under the road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, and 0.95 are extracted to obtain the braking deceleration characteristic field.

[0019] Step 4: In a high-fidelity modeling method for the analysis of the motion strength of the braking system, the characteristic field of the braking deceleration changing with the opening degree under different road adhesion coefficients of the real vehicle is used as the control target to obtain a high-fidelity analytical model of the motion strength of the braking system. The braking characteristics of the high-fidelity modeling of the analysis of the motion strength of the braking system are consistent with the braking characteristics of the real vehicle.

[0020] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-fidelity modeling method for analyzing the motion intensity of a braking system, comprising a real vehicle road characteristic recognition module, a real vehicle braking parameter acquisition module, a braking intention calibration module, a braking deceleration calibration module and a braking control module, characterized in that: The following steps are also included: Step 1: Set the initial vehicle speed to 140km / h, considering that the maximum deceleration does not exceed 12m / s 2 That is, when the pedal gradually increases its opening, it takes 5-8 seconds to stop completely. Here, we take a 6-second incremental input of the pedal opening. Therefore, in the actual vehicle, the brake pedal is input with a slope of 6 seconds at road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85, 0.95, and 1.

0. For the convenience of data processing, the opening of the brake pedal in the actual vehicle test is 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90%, and 100%. When the braking force is greater than the adhesion force, the braking force will not continue to increase. At this time, it is the maximum value of the braking force, that is, the maximum value of the braking deceleration. The brake pedal input opening information under different road adhesion coefficients is collected; Step 2: Under the current road conditions, the driver is asked to brake three times with random pedal openings and then perform emergency braking, and the braking deceleration data of different longitudinal speeds and different braking inputs are collected to determine the braking deceleration slow-changing region threshold belonging to the current driver; Step 3: Process the experimental data under different working conditions obtained in steps 1 and 2, obtain the boundary curve of the braking characteristic field of the actual vehicle with the brake pedal as a slope input under different road adhesion coefficients and the braking deceleration curve under different pedal openings by interpolation, extract the braking decelerations of each point with the pedal opening of 1%, 2.5%, 3.5%, 5%, 15%, 30%, 45%, 60%, 75%, 90% and 100% under the road adhesion coefficients of 0.05, 0.15, 0.25, 0.35, 0.45, 0.55, 0.65, 0.75, 0.85 and 0.95, and obtain the braking deceleration characteristic field; Step 4: Take the characteristic field of braking deceleration changing with opening degree under different road adhesion coefficients of the actual vehicle as the control target to obtain a high-fidelity analytical model of braking system motion intensity.

2. A high-fidelity modeling method for brake system motion intensity analysis according to claim 1, characterized in that: The real vehicle road characteristic identification module identifies the road adhesion conditions according to the real vehicle experimental data during the real vehicle test.

3. A high-fidelity modeling method for analyzing the motion intensity of a brake system according to claim 2, characterized in that: The actual vehicle braking parameter acquisition module is used to acquire the actual vehicle braking input of the driver, and the acquired data is the brake pedal opening.

4. A high-fidelity modeling method for analyzing the motion intensity of a brake system according to claim 3, characterized in that: The braking intention calibration module divides the braking deceleration intention into three sections, namely the OP section, the PQ section and the RQ section. The threshold values ​​of the driver's expected braking deceleration curve changing with the pedal opening are calibrated according to the actual vehicle experimental data. The OP section is the slow-changing area of ​​braking deceleration, the PQ section is the main action area of ​​the braking system, and the RQ section is the braking saturation area.

5. A high-fidelity modeling method for analyzing the motion intensity of a brake system according to claim 4, characterized in that: The pedal opening, the maximum braking deceleration and the obtained braking threshold value are input into the braking deceleration calibration module to obtain the curve of the driver's expected braking deceleration changing with the pedal opening, and then obtain the brake pedal-expected braking deceleration characteristic field.

6. A high-fidelity modeling method for analyzing the motion intensity of a brake system according to claim 5, characterized in that: The brake control module uses the identified brake pedal opening-brake deceleration characteristic field as the design basis of the control system braking intention recognition module, so that the model's brake pedal-expected brake deceleration characteristic field has high fidelity with the actual vehicle.

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