A Dynamic Adhesion Coefficient Correction Evaluation Method and System Based on Multi-Source Data Fusion

Abstract

This invention discloses a dynamic adhesion coefficient correction and evaluation method and system based on multi-source data fusion, belonging to the field of vehicle electronic control. The method includes the following steps: S1, multi-source sensor data acquisition; S2, calculating the slip ratio based on wheel speed sensor data, calculating the dynamic compensation factor based on suspension load sensor data, correcting the center of gravity offset error based on inertial sensor data, and triggering segmented compensation based on brake disc temperature sensor data; S3, calculating the base adhesion coefficient based on the slip ratio; S4, correcting the base adhesion coefficient based on the dynamic compensation factor and the corrected center of gravity offset; S5, correcting the base braking force and base torque allocated by the ESC system. By employing the above-mentioned dynamic adhesion coefficient correction and evaluation method and system based on multi-source data fusion and integrated design with the ESC system, high-precision correction of the dynamic adhesion coefficient and intelligent adjustment of the braking force are achieved.

Description

Technical Field

[0001] This invention relates to the field of vehicle electronic control technology, and in particular to a dynamic adhesion coefficient correction and evaluation method and system based on multi-source data fusion. Background Technology

[0002] In modern automotive active safety systems, Electronic Stability Control (ESC) is a core technology for ensuring vehicle stability and plays a crucial role in reducing traffic accidents and improving driving safety. However, traditional ESC systems still face many unresolved technical challenges that hinder further performance improvements.

[0003] From the perspective of vehicle state estimation, existing ESC systems mainly rely on wheel speed differences and inertial sensors to estimate the vehicle's motion state. However, this technical solution does not take into account the dynamic changes in suspension load. In actual driving scenarios, when the vehicle brakes suddenly, the front axle load changes drastically due to the axle load transfer effect. Simultaneously, tire adhesion is closely related to load. This neglect of suspension load changes makes it difficult for traditional ESC systems to accurately control the vehicle on low-traction surfaces, resulting in reduced safety control accuracy.

[0004] The existing ESC system has a significant deficiency in terms of temperature compensation mechanisms. The system lacks an integrated brake disc temperature sensor, making it unable to detect real-time changes in brake disc temperature. Under continuous braking conditions, the brake disc experiences thermal fade due to frictional heat generation. For example, with cast iron brake discs, the coefficient of friction decreases by 40% when the temperature exceeds 300℃. This leads to severe inaccuracies in the ESC system's calculation of braking torque, making it unable to provide reliable braking force to the vehicle in high-temperature braking scenarios, significantly impacting driving safety.

[0005] Furthermore, at the hardware architecture level, traditional adhesion coefficient correction systems often employ an independent control unit design. This design results in complex and intertwined system wiring harnesses, which not only increases the difficulty and complexity of vehicle wiring but also leads to high costs. Summary of the Invention

[0006] The purpose of this invention is to provide a dynamic attachment coefficient correction and evaluation method and system based on multi-source data fusion, thereby solving the above-mentioned technical problems.

[0007] To achieve the above objectives, this invention provides a dynamic attachment coefficient correction and evaluation method based on multi-source data fusion, comprising the following steps:

[0008] S1. Multi-source sensor data acquisition: Simultaneously acquire data from wheel speed sensor, suspension load sensor, inertial sensor and brake disc temperature sensor;

[0009] S2. Multi-source sensor data processing: Calculate slip ratio based on data collected by wheel speed sensor, calculate dynamic compensation factor based on data collected by suspension load sensor, correct centroid offset error based on data collected by inertial sensor, and trigger segmented compensation based on data collected by brake disc temperature sensor.

[0010] S3. Calculate the basic adhesion coefficient based on the slip ratio;

[0011] S4. Based on the dynamic compensation factor and the corrected centroid offset, the basic adhesion coefficient is corrected;

[0012] S5. Based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold, correct the base braking force and base torque allocated by the ESC system.

[0013] Preferably, in step S2, the slip ratio The calculation formula is as follows:

[0014] (1);

[0015] In the formula, Indicates wheel speed; Indicates the radius of the wheel; Indicates vehicle speed;

[0016] Dynamic compensation factor The calculation formula is as follows:

[0017] (2);

[0018] In the formula, and These represent the dynamic vertical load and static load of each wheel, respectively.

[0019] The expression for correcting centroid offset error is as follows:

[0020] (3);

[0021] In the formula, and These represent the corrected lateral and longitudinal accelerations, respectively. and These represent the lateral and longitudinal accelerations collected by the inertial sensor, respectively. , , These represent the pitch acceleration, roll acceleration, and yaw acceleration around the vehicle's axle, respectively. , , These represent the lateral, longitudinal, and vertical projections of the distance between the inertial sensor mounting point and the center of mass, respectively.

[0022] The following segmented compensation strategy is set based on the brake disc material:

[0023] Cast iron material: when hour, ;

[0024] Carbon ceramic materials: when , ;

[0025] In the formula, Indicates the temperature compensation coefficient; This indicates the brake disc temperature collected by the brake disc temperature sensor.

[0026] Preferably, step S3 involves calculating the basic adhesion coefficient based on the slip ratio. The expression is as follows:

[0027] (4);

[0028] In the formula, Indicates the maximum adhesion coefficient; Represents the shape factor; This represents the stiffness factor.

[0029] Preferably, the basic adhesion coefficient correction formula in step S4 is as follows:

[0030] (5);

[0031] In the formula, This represents the corrected base adhesion coefficient; It represents the acceleration due to gravity.

[0032] Preferably, step S5 specifically includes the following steps:

[0033] S51. Determine if the condition is met. If so, the basic braking force and basic torque are triggered, and step S52 is executed;

[0034] S52, Correcting the base braking force allocated by the ESC system. and base torque :

[0035] (6);

[0036] (7);

[0037] In the formula, and These represent the corrected braking force and torque, respectively. This represents the correction factor.

[0038] Preferably, in step S51, when the road surface is a dry asphalt road surface, ;

[0039] When driving on icy or snowy roads .

[0040] Preferably, in step S2, the dynamic vertical load of each wheel The expression is as follows:

[0041] (8);

[0042] in,

[0043] (9);

[0044] In the formula, Indicates the overall vehicle weight; Indicates the number of axles in a vehicle; This indicates the amount of load transfer caused by acceleration or gradient; This indicates the amount of error caused by the thermal expansion of the axle due to temperature. Indicates the axle thermal expansion-load conversion coefficient; Indicates ambient temperature; Indicates standard temperature; Indicates the coefficient of thermal expansion of the axle material; This indicates the axle length at standard temperature.

[0045] A system for performing a dynamic attachment coefficient correction evaluation method based on multi-source data fusion includes:

[0046] The multi-source sensor data acquisition module is used to simultaneously acquire data from wheel speed sensors, suspension load sensors, inertial sensors, and brake disc temperature sensors.

[0047] The multi-source sensor data processing module is used to calculate the slip ratio based on data collected by the wheel speed sensor, calculate the dynamic compensation factor based on data collected by the suspension load sensor, correct the center of gravity offset error based on data collected by the inertial sensor, and trigger segmented compensation based on data collected by the brake disc temperature sensor.

[0048] The basic adhesion coefficient calculation module is used to calculate the basic adhesion coefficient based on the slip ratio;

[0049] The base adhesion coefficient correction module is used to correct the base adhesion coefficient based on the dynamic compensation factor and the corrected centroid offset.

[0050] The braking force and torque correction module is used to correct the base braking force and base torque allocated by the ESC system based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold.

[0051] Preferably, the multi-source sensor data acquisition module includes a wheel speed sensor, a suspension load sensor, an inertial sensor, and a brake disc temperature sensor, all of which communicate with the ESC system.

[0052] Therefore, the present invention employs the above-mentioned dynamic adhesion coefficient correction and evaluation method and system based on multi-source data fusion, which has the following beneficial effects:

[0053] 1. Improved accuracy: By using suspension load sensors and dynamic load distribution models, the 20% axle load transfer error during emergency braking is corrected, improving the axle load calculation accuracy to over 95%; at the same time, based on the brake disc material (cast iron / carbon ceramic) trigger segment model, the accuracy of friction coefficient prediction in the high-temperature section is improved by 35%, solving the problem of inaccurate braking force caused by thermal fade in traditional solutions.

[0054] 2. Control Optimization: Adjust torque distribution based on the corrected adhesion coefficient, with a threshold of 0.7 for dry asphalt pavement and 0.3 for icy and snowy pavement, improving the control accuracy of low-adhesion pavement by 40%.

[0055] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0056] Figure 1 This is a flowchart of the dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion of the present invention. Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the embodiments of the present invention and are not intended to limit the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of this application. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout.

[0058] It should be noted that the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion, such as a process, method, system, product, or server that includes a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such process, method, product, or device.

[0059] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0060] like Figure 1 As shown, the dynamic attachment coefficient correction and evaluation method based on multi-source data fusion includes the following steps:

[0061] S1. Multi-source sensor data acquisition: Simultaneously acquire data from wheel speed sensor, suspension load sensor, inertial sensor and brake disc temperature sensor;

[0062] S2. Multi-source sensor data processing: Calculate slip ratio based on data collected by wheel speed sensor, calculate dynamic compensation factor based on data collected by suspension load sensor, correct centroid offset error based on data collected by inertial sensor, and trigger segmented compensation based on data collected by brake disc temperature sensor.

[0063] In step S2, slip ratio The calculation formula is as follows:

[0064] (1);

[0065] In the formula, Indicates wheel speed; Indicates the radius of the wheel; Indicates vehicle speed;

[0066] Dynamic compensation factor The calculation formula is as follows:

[0067] (2);

[0068] In the formula, and These represent the dynamic vertical load and static load of each wheel, respectively.

[0069] Dynamic vertical loads on each wheel The expression is as follows:

[0070] (8);

[0071] in,

[0072] (9);

[0073] In the formula, Indicates the overall vehicle weight; Indicates the number of axles in a vehicle; This indicates the amount of load transfer caused by acceleration or gradient; This indicates the amount of error caused by the thermal expansion of the axle due to temperature. Indicates the axle thermal expansion-load conversion coefficient; Indicates ambient temperature; Indicates standard temperature; Indicates the coefficient of thermal expansion of the axle material; This indicates the axle length at standard temperature.

[0074] The expression for the centroid offset error correction is as follows:

[0075] (3);

[0076] In the formula, and These represent the corrected lateral and longitudinal accelerations, respectively. and These represent the lateral and longitudinal accelerations collected by the inertial sensor, respectively. , , These represent the pitch acceleration, roll acceleration, and yaw acceleration around the vehicle's axle, respectively. , , These represent the lateral, longitudinal, and vertical projections of the distance between the inertial sensor mounting point and the center of mass, respectively.

[0077] The following segmented compensation strategy is set based on the brake disc material:

[0078] Cast iron material: when hour, ;

[0079] Carbon ceramic materials: when , ;

[0080] In the formula, Indicates the temperature compensation coefficient; This indicates the brake disc temperature collected by the brake disc temperature sensor.

[0081] S3. Calculate the basic adhesion coefficient based on the slip ratio;

[0082] Step S3 describes the calculation of the basic adhesion coefficient based on the slip ratio. The expression is as follows:

[0083] (4);

[0084] In the formula, Indicates the maximum adhesion coefficient; Represents the shape factor; This represents the stiffness factor.

[0085] S4. Based on the dynamic compensation factor and the corrected centroid offset, the basic adhesion coefficient is corrected;

[0086] The basic adhesion coefficient correction formula mentioned in step S4 is as follows:

[0087] (5);

[0088] In the formula, This represents the corrected base adhesion coefficient; It represents the acceleration due to gravity.

[0089] S5. Based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold, correct the base braking force and base torque allocated by the ESC system.

[0090] Step S5 specifically includes the following steps:

[0091] S51. Determine if the condition is met. If so, the basic braking force and basic torque are triggered, and step S52 is executed;

[0092] In step S51, when the road surface is a dry asphalt road surface, When driving on icy or snowy roads, .

[0093] S52, Correcting the base braking force allocated by the ESC system. and base torque :

[0094] (6);

[0095] (7);

[0096] In the formula, and These represent the corrected braking force and torque, respectively. This represents the correction factor.

[0097] In this embodiment, when the brake disc temperature > 250°C, the following coordinated control is triggered:

[0098] The torque limit threshold of the TCS (Traction Control System) is reduced by 15% to 25%; the pressure holding phase of the ABS (Anti-lock Braking System) is extended by 10ms to 20ms; and the instrument panel outputs a high-temperature adhesion coefficient warning signal.

[0099] Verification Example

[0100] To verify the effectiveness of the present invention, actual scenario tests were conducted using the transmission scheme (the scheme described in the background art) and the scheme described in the present invention, and the results are shown in Table 1.

[0101] Table 1. Comparison of traditional solutions and the solution described in this invention

[0102] ;

[0103] As shown in Table 1, the traditional solution, lacking integrated suspension load and temperature sensors, cannot correct for axle load transfer errors during emergency braking (front axle load error reaches 20%), resulting in large deviations in the adhesion coefficient calculation. In contrast, this invention, through multi-source data fusion and utilizing dynamic compensation factors and temperature segmentation compensation, reduces the adhesion coefficient error on dry asphalt pavements from 12% to below 6%, directly improving braking control accuracy.

[0104] Traditional ESC systems rely on wheel speed differences to estimate adhesion, resulting in high cross-system communication latency (>10ms) and delayed ABS intervention. This invention integrates a data fusion algorithm into the ESC main control chip, completing calculations within a 5ms control cycle. This reduces the ABS intervention delay on icy and snowy roads from 120ms to 75ms, allowing for earlier response to emergency braking needs and reducing the risk of skidding.

[0105] Traditional solutions lack brake disc temperature compensation. During continuous braking, the friction coefficient of cast iron discs above 300℃ decreases by 40%, and the braking distance increases by 22% on the fifth braking event. In contrast, this invention uses a temperature-segmented compensation model to control the increase in braking distance caused by thermal fade from 22% to 9%, ensuring braking reliability in conditions such as long downhill slopes.

[0106] In summary, the present invention surpasses traditional solutions in terms of accuracy, response speed, and resistance to attenuation, thus proving the effectiveness of the present invention.

[0107] A system for performing a dynamic attachment coefficient correction evaluation method based on multi-source data fusion includes:

[0108] The multi-source sensor data acquisition module is used to simultaneously acquire data from wheel speed sensors, suspension load sensors, inertial sensors, and brake disc temperature sensors.

[0109] The multi-source sensor data processing module is used to calculate the slip ratio based on data collected by the wheel speed sensor, calculate the dynamic compensation factor based on data collected by the suspension load sensor, correct the center of gravity offset error based on data collected by the inertial sensor, and trigger segmented compensation based on data collected by the brake disc temperature sensor.

[0110] The basic adhesion coefficient calculation module is used to calculate the basic adhesion coefficient based on the slip ratio;

[0111] The base adhesion coefficient correction module is used to correct the base adhesion coefficient based on the dynamic compensation factor and the corrected centroid offset.

[0112] The braking force and torque correction module is used to correct the base braking force and base torque allocated by the ESC system based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold.

[0113] The multi-source sensor data acquisition module includes wheel speed sensors, suspension load sensors, inertial sensors, and brake disc temperature sensors. All of these sensors communicate with the ESC system.

[0114] In this embodiment, the suspension load sensor is a strain gauge fixed on the suspension, and the strain gauge signal is connected to the ESC system through an unused pin; the SDA / SCL line of the brake disc temperature sensor (an MLX90614 infrared probe is used, installed inside the caliper and 10mm away from the brake disc) is connected in parallel with the wheel speed sensor harness of the ESC system (with a 10kΩ pull-up resistor added).

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion, characterized in that: Includes the following steps: S1. Multi-source sensor data acquisition: Simultaneously acquire data from wheel speed sensor, suspension load sensor, inertial sensor and brake disc temperature sensor; S2. Multi-source sensor data processing: Calculate slip ratio based on data collected by wheel speed sensor, calculate dynamic compensation factor based on data collected by suspension load sensor, correct centroid offset error based on data collected by inertial sensor, and trigger segmented compensation based on data collected by brake disc temperature sensor. In step S2, slip ratio The calculation formula is as follows: （1）； In the formula, Indicates wheel speed; Indicates the wheel radius; Indicates vehicle speed; Dynamic compensation factor The calculation formula is as follows: （2）； In the formula, and These represent the dynamic vertical load and static load of each wheel, respectively. The expression for correcting centroid offset error is as follows: （3）； In the formula, and These represent the corrected lateral and longitudinal accelerations, respectively. and These represent the lateral and longitudinal accelerations collected by the inertial sensor, respectively. , , These represent the pitch acceleration, roll acceleration, and yaw acceleration around the vehicle's axle, respectively. , , These represent the lateral, longitudinal, and vertical projections of the distance between the inertial sensor mounting point and the center of mass, respectively. The following segmented compensation strategy is set based on the brake disc material: Cast iron material: when hour, ; Carbon ceramic materials: when , ; In the formula, Indicates the temperature compensation coefficient; This indicates the brake disc temperature collected by the brake disc temperature sensor. S3. Calculate the basic adhesion coefficient based on the slip ratio; S4. Based on the dynamic compensation factor and the corrected centroid offset, the basic adhesion coefficient is corrected; S5. Based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold, correct the base braking force and base torque allocated by the ESC system.

2. The dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion according to claim 1, characterized in that: Step S3 describes the calculation of the basic adhesion coefficient based on the slip ratio. The expression is as follows: （4）； In the formula, Indicates the maximum adhesion coefficient; Represents the shape factor; This represents the stiffness factor.

3. The dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion according to claim 2, characterized in that: The basic adhesion coefficient correction formula mentioned in step S4 is as follows: （5）； In the formula, This represents the corrected base adhesion coefficient; It represents the acceleration due to gravity.

4. The dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion according to claim 3, characterized in that: Step S5 specifically includes the following steps: S51. Determine if the condition is met. If so, the basic braking force and basic torque are triggered, and step S52 is executed; S52, Correcting the base braking force allocated by the ESC system. and base torque : （6）； （7）； In the formula, and These represent the corrected braking force and torque, respectively. This represents the correction factor.

5. The dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion according to claim 4, characterized in that: In step S51, when the road surface is a dry asphalt road surface, ; When driving on icy or snowy roads .

6. The dynamic adhesion coefficient correction and evaluation method based on multi-source data fusion according to claim 2, characterized in that: In step S2, the dynamic vertical load of each wheel The expression is as follows: （8）； in, （9）； In the formula, Indicates the overall vehicle weight; Indicates the number of axles in a vehicle; This indicates the amount of load transfer caused by acceleration or gradient; This indicates the amount of error caused by the thermal expansion of the axle due to temperature. Indicates the axle thermal expansion-load conversion coefficient; Indicates ambient temperature; Indicates standard temperature; Indicates the coefficient of thermal expansion of the axle material; This indicates the axle length at standard temperature.

7. A system for performing the dynamic attachment coefficient correction evaluation method based on multi-source data fusion as described in any one of claims 1-6, characterized in that: include: The multi-source sensor data acquisition module is used to simultaneously acquire data from wheel speed sensors, suspension load sensors, inertial sensors, and brake disc temperature sensors. The multi-source sensor data processing module is used to calculate the slip ratio based on data collected by the wheel speed sensor, calculate the dynamic compensation factor based on data collected by the suspension load sensor, correct the center of gravity offset error based on data collected by the inertial sensor, and trigger segmented compensation based on data collected by the brake disc temperature sensor. The basic adhesion coefficient calculation module is used to calculate the basic adhesion coefficient based on the slip ratio; The base adhesion coefficient correction module is used to correct the base adhesion coefficient based on the dynamic compensation factor and the corrected centroid offset. The braking force and torque correction module is used to correct the base braking force and base torque allocated by the ESC system based on the comparison between the corrected base adhesion coefficient and the set adhesion coefficient threshold.

8. The system for performing a dynamic attachment coefficient correction evaluation method based on multi-source data fusion according to claim 7, characterized in that: The multi-source sensor data acquisition module includes wheel speed sensors, suspension load sensors, inertial sensors, and brake disc temperature sensors. All of these sensors communicate with the ESC system.

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