Detection system for braking force and speed of automobile

Abstract

The invention discloses an automobile braking force and speed detection system, and belongs to the field of automobile supervision. An automobile braking force and speed detection system comprises a data acquisition part, a data preprocessing part, an automobile ECU controller and a display part. The system is realized in the following mode: the compression amount of suspension at each wheel of an automobile, the wheel speed in the driving process, the distance between the automobile and a front object in the driving process, the position of the automobile and meteorological information of the position are acquired through a data acquisition part; compared with a traditional mode that only the pressure of a brake cylinder on a wheel disc is detected to reflect the vehicle power, the method combines the influence of the wheel load on the braking force, so that the braking force of the vehicle can be detected more accurately, and due to the fact that the braking force of each wheel is detected, the detection accuracy is improved. When the automobile distributes the braking force unevenly or the braking force is abnormal due to the fact that a wheel braking system is damaged, the situation can be found in time.

Description

Technical Field

[0001] The present invention relates to vehicle supervision, and particularly to a detection system for vehicle braking force and speed. Background Art

[0002] With the improvement of modern technology and living standards, automobiles have become an important means of transportation in people's daily lives. To ensure the safety of vehicles during driving, the braking force and speed of vehicles are usually detected in real time. During the detection of vehicle braking force and speed, the vehicle wheel speed is detected in real time through a wheel speed sensor, and through the analysis of the vehicle ECU, the real-time detection of vehicle speed can be achieved. For the detection of braking, an EMB force sensor is usually installed at the wheel to collect and detect the braking force. However, due to the relatively harsh operating environment at the wheel, the use accuracy of the EMB force sensor will decrease over time. And since the EMB force sensor is directly installed at the brake caliper, the detected braking force is only the pressure of the brake caliper on the brake disc, while the braking force of the wheel is not only from the pressure of the brake caliper on the brake disc, but also affected by the load on the wheel, the weight of the wheel itself, etc. Therefore, the traditional method of collecting and detecting the braking force through the EMB force sensor cannot accurately detect the braking force of the vehicle. In addition, the traditional vehicle braking force detection also includes detecting the braking force of the vehicle by measuring the pressure inside the master cylinder, but it is similar to the EMB force sensor, and only detects the braking force of the vehicle by measuring the squeezing force of the caliper on the brake disc. And as the vehicle is driving, the increase in the temperature of the hydraulic oil will lead to a decrease in the measurement accuracy. And the current detection methods of braking force and speed cannot integrate information such as braking force and speed to adjust the safety braking force of the vehicle in real time to detect whether the braking force of the vehicle is sufficient to meet the requirements. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a detection system for vehicle braking force and speed to solve the problems that the current detection methods for vehicle braking force and speed have low detection accuracy for braking force and cannot integrate braking force and speed to adjust the safety braking force of the vehicle in real time, so as to detect whether the braking force of the vehicle is sufficient to meet the requirements.

[0004] Technical solution: An automobile braking force and speed detection system includes a data acquisition part, a data preprocessing part, an automobile ECU controller, and a display part. This system is implemented in the following way: The data acquisition part collects the compression amount of the suspension at each wheel of the automobile, the wheel speed during driving, the distance from the vehicle to the object in front during driving, the vehicle position, and the meteorological information at the location. The collected information data is sent to the data preprocessing part for data preprocessing. The preprocessing part processes the wheel speed and the compression amount of the suspension at each wheel to obtain the deceleration of each wheel of the vehicle and the load of each wheel. Then, the deceleration of each wheel and the load of each wheel are handed over to the automobile ECU controller. The automobile ECU controller detects the braking force on each wheel according to the deceleration of each wheel and the load of each wheel, and then displays the detected braking force on each wheel through the display part;

[0005] The automobile ECU controller analyzes the wheel speed to obtain the current speed of the vehicle, and displays the real-time vehicle speed through the display part. At the same time, it dynamically adjusts the safe distance between the vehicle and the object in front after braking in combination with the meteorological information at the current position of the vehicle. Then, the automobile ECU controller monitors in real time whether the vehicle brakes. If it monitors that the vehicle brakes, it obtains the safe braking force of the vehicle according to the distance between the vehicle and the object in front, the current speed of the vehicle, and the safe distance between the vehicle and the object in front after braking, and compares the safe braking force of the vehicle with the detected real-time braking force of the vehicle.

[0006] Preferably, the system includes a wheel speed sensor, a suspension travel sensor, a radar sensor, a positioning module, and a meteorological module; the wheel speed sensor, the suspension travel sensor, the radar sensor, the positioning module, and the meteorological module all perform data interaction with the data acquisition part.

[0007] Preferably, when the preprocessing part processes the wheel speed and the compression amount of the suspension at each wheel, the deceleration of each wheel and the load of each wheel are obtained respectively through the following method:

[0008]

[0009] where a is the deceleration of each wheel, v i is the sampled wheel speed per second i, Δt is the sampling time interval, T is the total duration of the sampling period, M is the load of each wheel, k is the stiffness coefficient of the suspension spring of each wheel, x is the compression stroke of the spring, r is the suspension leverage ratio, and g is the acceleration due to gravity.

[0010] Preferably, the ECU controller detects the braking force on each wheel according to the deceleration of each wheel and the load of each wheel through the following method:

[0011] F = a·(m + M)

[0012] Among them, F is the braking force of each wheel, and m is the weight of each wheel.

[0013] Preferably, the safety distance between the vehicle and the object in front after the vehicle stops is obtained through a correspondence table preset in the system between the safety distance between the vehicle and the object in front after the vehicle stops and speed, visibility, and the friction coefficient between the tire and the ground under different weather conditions.

[0014] Preferably, the safety braking force of the vehicle is obtained by the following method:

[0015]

[0016] Among them, F safe is the safety braking force of the vehicle, M j is the load on each wheel j, L is the real-time distance between the vehicle and the object in front, V is the real-time speed of the vehicle, t is the reaction time of the driver, and D is the safety distance between the vehicle and the object in front after the vehicle stops.

[0017] Preferably, when it is determined that the total braking force of the vehicle is less than the safety braking force, at this time, it is detected by the pedal travel sensor whether the brake pedal is in the limit position. If so, it is determined that the braking is insufficient. Otherwise, it is determined that the brake pedal is not depressed enough and sufficient braking force is not generated; the generated detection result is sent to the supervision background; among them, the total braking force is the sum of the braking forces of each wheel.

[0018] Preferably, the system further includes a data storage module and a data sending module. The data storage module is used to store the detected real-time vehicle speed, the braking force on each wheel, and the generated detection result; the data sending module is used to send the detected real-time vehicle speed, the braking force on each wheel, and the generated detection result to the supervision background.

[0019] Advantageous effects: By the deceleration of the wheels and the wheel load conditions, the present invention can detect the braking force of each wheel in real time. Compared with the traditional method of only detecting the pressure of the brake caliper on the brake disc to reflect the vehicle braking force, the present invention combines the influence of the wheel load on the braking force, so as to be able to more accurately detect the braking force of the vehicle. And because the present invention detects the braking force of each wheel, it can be timely discovered when the braking force distribution of the vehicle is uneven or when the braking system of the wheel is damaged resulting in abnormal braking force. And the present invention obtains the dynamic safety braking force through the vehicle speed in combination with the real-time distance between the vehicle and the object in front, the vehicle mass, and the safe braking distance between the vehicle and the object in front after the vehicle stops, and compares the detected total braking force of the vehicle with the dynamic safety braking force to detect whether the braking is in place, so as to give an auxiliary basis for the division of responsibilities after a traffic accident. Description of the Drawings

[0020] Figure 1 is a system flow diagram;

[0021] Figure 2 is a system structure diagram;

[0022] Figure 3 is a graph showing the relationship between the braking force on the wheel, deceleration, and the total wheel load;

[0023] Figure 4 is a graph showing the relationship between the safety braking force, vehicle speed, and available distance. Specific implementation manner

[0024] To make the technical solution of the present invention clearer, the following further describes the present invention in detail with reference to the accompanying drawings and specific embodiments.

[0025] Embodiment

[0026] As Figure 1-2 shown, the data acquisition part, data preprocessing part, vehicle ECU controller, display part, data memory, and data sending part together constitute a detection system for the braking force and speed of an automobile. The data acquisition part interacts with the wheel speed sensor, suspension travel sensor, radar sensor, positioning module, and meteorological module deployed on the vehicle. Specifically, when the vehicle brakes each time, it respectively collects the real-time wheel speed during driving, the compression amount of the suspension at each wheel, the distance between the vehicle and the object in front during driving, the real-time position of the vehicle, and the meteorological information (including visibility and weather information) at the location where the vehicle is located. Then, the data preprocessing part obtains the deceleration and load of each wheel through the following method based on the collected real-time wheel speed and the suspension compression amount at each wheel:

[0027]

[0028] In the formula, a is the deceleration of each wheel, v i is the sampled wheel speed per second at i, Δt = 1 is the sampling time interval, T is the total duration of the sampling period, M is the load of each wheel, k is the stiffness coefficient of the suspension spring of each wheel, x is the compression stroke of the spring, r is the suspension lever ratio, and g is the gravitational acceleration.

[0029] Then, the deceleration of each wheel and the load of each wheel obtained are handed over to the vehicle ECU controller for processing, and the braking force of each wheel of the vehicle can be obtained through the following method:

[0030] F = a·ZM = a·(m + M)

[0031] In the formula, F is the braking force of each wheel, m is the weight of each wheel, and ZM is the total load of each wheel. As Figure 3As shown, when the total wheel load is constant, as the wheel deceleration increases, the braking force of each wheel also increases. And when the wheel deceleration is constant, as the total wheel load increases, the braking force of each wheel also increases, indicating that the braking force of each wheel has a positive linear correlation with the deceleration and the wheel load. Therefore, compared with the braking force detected only by the EMB force sensor and the master cylinder hydraulic sensor in the traditional way, this embodiment fully considers the influence of the wheel load on the braking force of the wheel, so that the detection of the braking force can be more accurate.

[0032] Thus, the braking force of each wheel detected during each vehicle braking can be displayed on the vehicle instrument through the display part. And the total braking force of the vehicle (the sum of the braking forces of each wheel) can be displayed on the vehicle instrument through the display part for the driver to observe in real time whether the braking force of the vehicle is within the range that meets the driving state.

[0033] At the same time, the vehicle ECU controller can process and analyze the real-time wheel speed monitored by the wheel speed sensor, so as to analyze the real-time speed of the vehicle and display the real-time speed of the vehicle on the vehicle instrument through the display part for the vehicle driver to observe. And the vehicle ECU controller can analyze the real-time distance between the vehicle and the object in front in real time according to the data monitored by the radar sensor. At the same time, according to the positioning module and the meteorological module, the visibility and weather information of the current location of the vehicle can be obtained, and according to the real-time speed, visibility and weather information of the vehicle, the safety distance between the vehicle and the object in front after braking can be dynamically adjusted according to the corresponding relationship table (safety distance dynamic adjustment table) of the safety distance, speed, visibility and the friction coefficient between the tire and the ground under different weather conditions preset in the system.

[0034] Table 1 Safety Distance Dynamic Adjustment Table

[0035]

[0036] Then the vehicle ECU controller monitors in real time whether the vehicle is braking. If it is detected that the vehicle is braking, the safe braking force of the vehicle is obtained according to the distance between the vehicle and the object in front, the current speed of the vehicle, and the safety distance between the vehicle and the object in front after braking:

[0037]

[0038] In the formula, F safe is the safe braking force of the vehicle, m car is the total vehicle weight, d u is the available distance, M jLet \(F_j\) be the load on each wheel \(j\), \(L\) be the real-time distance between the vehicle and the object in front, \(V\) be the real-time speed of the vehicle, \(t = 0.5s\) be the reaction time of the driver, and \(D\) be the safety distance between the vehicle and the object in front after braking. It follows that Figure 4 As can be seen, as the vehicle speed increases, in order to ensure no collision with the object in front, a greater safety braking force is required. At the same time, as the available distance decreases, a greater safety braking force is also needed to ensure no collision with the object in front. Also, according to inertia, as the vehicle weight increases, a greater safety braking force is required to ensure no collision with the object in front during vehicle operation. Therefore, when the speed increases and the weather conditions are poor, a greater safety braking force is needed to ensure no collision.

[0039] Then the vehicle ECU controller compares the safety braking force of the vehicle with the detected real-time braking force of the vehicle. When it is determined that the total braking force of the vehicle is less than the safety braking force, the brake pedal position sensor is used to detect whether the brake pedal is at the limit position at this time. If so, it is determined that there is a fault or abnormality in the braking system, resulting in insufficient braking force for braking. Otherwise, it is determined that the brake is not fully depressed. The generated detection results are sent to the supervision background through the data sending module using 4G / 5G communication technology. The above detection results (wheel braking force, total braking force, real-time vehicle speed, detection results, etc.) can be stored in the data memory. When a traffic accident occurs, the detection results and other data can be directly obtained from the vehicle's data memory or from the background supervision platform, thus providing an auxiliary basis for liability determination.

[0040] The above-described embodiments merely represent several implementation manners of the present invention. Their descriptions are relatively specific and detailed, but should not be construed as limiting the scope of the present invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. An automobile braking force and speed detection system, comprising a data acquisition part, a data preprocessing part, an automobile ECU controller and a display part, characterized in that, The system is implemented as follows: The compression amount suspended at each wheel of the vehicle, the wheel speed during driving, the distance from the vehicle to the object in front during driving, the vehicle position, and the meteorological information at the location are collected through the data acquisition part; The collected information data is sent to the data preprocessing part for data preprocessing. The preprocessing part processes the wheel speed and the compression amount suspended at each wheel, so as to obtain the deceleration of each wheel of the vehicle and the load of each wheel; then the deceleration of each wheel and the load of each wheel are handed over to the vehicle ECU controller. The vehicle ECU controller detects the braking force on each wheel according to the deceleration of each wheel and the load of each wheel, and then displays the detected braking force on each wheel through the display part; The vehicle ECU controller analyzes the wheel speed to obtain the current speed of the vehicle, and displays the real-time vehicle speed through the display part. At the same time, it dynamically adjusts the safety distance between the vehicle and the object in front after the vehicle stops in combination with the meteorological information at the current position of the vehicle; then the vehicle ECU controller monitors in real time whether the vehicle brakes. If it monitors that the vehicle brakes, it obtains the safety braking force of the vehicle according to the distance between the vehicle and the object in front, the current speed of the vehicle, and the safety distance between the vehicle and the object in front after the vehicle stops, and compares the safety braking force of the vehicle with the detected real-time braking force of the vehicle.

2. The vehicle braking force and speed detection system according to claim 1, wherein The system includes a wheel speed sensor, a suspension travel sensor, a radar sensor, a positioning module, and a meteorological module; the wheel speed sensor, the suspension travel sensor, the radar sensor, the positioning module, and the meteorological module all perform data interaction with the data acquisition part.

3. The detection system for the braking force and speed of an automobile according to claim 1, wherein, When the preprocessing part processes the wheel speed and the compression amount suspended at each wheel, the deceleration of each wheel and the load of each wheel are obtained respectively through the following methods: where a is the deceleration of each wheel, v i is the sampled wheel speed per second i, Δt is the sampling time interval, T is the total duration of the sampling period, M is the load of each wheel, k is the stiffness coefficient of the suspension spring of each wheel, x is the compression stroke of the spring, r is the suspension leverage ratio, and g is the acceleration due to gravity.

4. The detection system for the braking force and speed of an automobile according to claim 3, characterized in that, The ECU controller detects the braking force on each wheel according to the deceleration of each wheel and the load of each wheel through the following methods: F = a·(m + M) where F is the braking force of each wheel and m is the weight of each wheel.

5. The detection system for the braking force and speed of an automobile according to claim 1, wherein The safety distance between the vehicle and the object in front after the vehicle stops is obtained through the correspondence table preset in the system between the safety distance between the vehicle and the object in front after the vehicle stops and the speed, visibility, and friction coefficient between the tire and the ground under different weather conditions.

6. The detection system for vehicle braking force and speed according to claim 4, characterized in that, The safety braking force of the vehicle is obtained through the following method: Among them, F safe is the safety braking force of the vehicle, M j is the load on each wheel j, L is the real-time distance between the vehicle and the object in front, V is the real-time speed of the vehicle, t is the reaction time of the driver, and D is the safety distance between the vehicle and the object in front after braking to a stop.

7. The vehicle braking force and speed detection system according to claim 1, characterized in that When it is judged that the total braking force of the vehicle is less than the safety braking force, at this time, the pedal travel sensor is used to detect whether the brake pedal is in the limit position. If so, it is judged that the braking is insufficient, otherwise, it is judged that the brake pedal is not depressed enough and not enough braking force is generated; the generated detection result is sent to the supervision background; among them, the total braking force is the sum of the braking forces of each wheel.

8. The detection system for the braking force and speed of an automobile according to claim 7, characterized in that, The system also includes a data storage module and a data sending module. The data storage module is used to store the detected real-time vehicle speed, the braking force on each wheel, and the generated detection results; The data sending module is used to send the detected real-time vehicle speed, the braking force on each wheel, and the generated detection results to the supervision background.

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