CN118689190A - A self-learning calibration method and system for automatic emergency braking system - Google Patents

Abstract

The present invention relates to a self-learning calibration method and system for an automatic emergency braking system, comprising S1, activating the self-learning calibration, an AEBS controller acquiring and judging whether the braking data of a whole vehicle meets the calculation conditions of the braking force deceleration data of the whole vehicle, and if so, allowing the calculation of the braking force deceleration data of the whole vehicle; S2, judging the empty and full-load working conditions of the vehicle, and respectively calculating and storing the braking force deceleration data of the whole vehicle under different working conditions of the vehicle being empty and full; S3, judging the storage result status of the braking force deceleration data of the whole vehicle, and if the storage result fails, sending it to a combination instrument to display the storage failure status and reminding; if the storage result is valid, sending it to a combination instrument to display the storage success status and reminding; S4, acquiring and judging whether the braking force deceleration data of the whole vehicle under different working conditions of the vehicle being empty and full is written into the AEBS controller parameters, and if so, the vehicle is calibrated, and if not, step S1 is executed.

Description

A self-learning calibration method and system for automatic emergency braking system

Technical Field

The present invention relates to the technical field of automobile intelligent assisted driving, and in particular to a self-learning calibration method and system for an automatic emergency braking system.

Background Art

The automatic emergency braking system involves multiple execution systems of the vehicle, among which the calibration of the vehicle's braking force deceleration is the most important. Accurate braking force deceleration values can ensure that the vehicle triggers emergency braking at the optimal TTC time, so that the automatic emergency braking system meets and exceeds standard requirements while improving driving comfort. The vehicle's braking force deceleration of the current first model is completed through manual testing, calculation, writing, verification and other processes, and manual testing and calibration requires a lot of manpower, material resources and time costs, and manual calibration will cause larger errors due to human operation.

Summary of the invention

The purpose of the present invention is to provide a self-learning calibration method and system for an automatic emergency braking system in view of the deficiencies in the prior art.

The present invention is achieved by adopting the following technical solutions:

A self-learning calibration method for an automatic emergency braking system comprises the following steps:

S1. The self-learning calibration of the default automatic emergency braking system of the vehicle to be calibrated is activated, and the AEBS controller obtains and determines whether the vehicle braking data meets the vehicle braking force deceleration data calculation conditions. If so, the vehicle braking force deceleration data is allowed to be calculated;

S2, entering the whole vehicle braking force deceleration data calculation process, judging the vehicle empty and full-load working conditions, and respectively calculating and storing the whole vehicle braking force deceleration data under different working conditions of the vehicle empty and full-load;

S3, judging the state of the storage result of the braking force and deceleration data of the whole vehicle, and if the storage result is faulty, sending it to the instrument cluster to display the storage fault state and reminding; if the storage result is valid, sending it to the instrument cluster to display the storage success state and reminding;

S4. Obtain and determine whether the vehicle braking force deceleration data of the vehicle to be calibrated under different working conditions of empty and fully loaded is written into the AEBS controller parameters. If so, the vehicle is calibrated. If not, start executing step S1.

As a further illustration of the invention, before executing step S1, the following steps are also included:

The AEBS controller obtains and determines whether the vehicle braking-related CAN signals meet the self-learning calibration standby conditions. If the vehicle braking-related CAN signals are fault-free, it is allowed to enter the self-learning calibration pre-activation process;

Enter the process before self-learning calibration activation, obtain and judge whether the self-learning calibration activation conditions are met. If the vehicle speed is in the activation speed range, the brake pedal switch is on, the gear is in the forward gear, the load signal of the axle load sensor, and the lateral angular velocity are not greater than the set value, then self-learning calibration activation is allowed.

As a further illustration of the invention, executing step S1 specifically includes the following steps:

The vehicle brake switch is activated, and the first frame of the vehicle front axle speed message, the brake pedal position during braking, the braking time interval, and the lateral angular velocity during braking are obtained and recorded. If the first frame of the vehicle real-time axle speed message signal value is judged to be 0, the data recording is stopped;

When it is determined whether the recorded data simultaneously satisfies the following conditions: the brake pedal position during braking is not less than the set value, the braking time interval of the vehicle is not less than the set value, and the lateral angular velocity during braking is not greater than the set value, then the calculation of the braking force deceleration data of the vehicle is allowed.

As a further explanation of the invention, the vehicle braking force deceleration calculation formula is:

Wherein, a represents the deceleration of the vehicle braking force, v represents the real-time axle speed of the vehicle, t1 represents the time when the axle speed is v when the brake switch is first turned on, and t2 represents the time when the axle speed is zero for the first time after the brake switch is activated.

As a further illustration of the invention, executing step S2 specifically includes the following steps:

Determine whether the vehicle is in an empty or fully loaded state based on the load signal of the axle load sensor;

The vehicle speed is divided into intervals according to the empty and full-load conditions of the vehicle, and the vehicle braking force deceleration data in different speed intervals are calculated and stored.

As a further explanation of the invention, when executing step S3, if there is a storage result failure, sending it to the combination instrument to display the storage failure state and reminding specifically includes the following steps:

If one or more items of the vehicle braking deceleration data are missing, the instrument cluster displays the missing storage data and reminds you, and returns to re-execute step S1.

As a further explanation of the invention, after the vehicle braking force deceleration data is successfully calibrated, the following steps are also included:

According to the average value of the vehicle braking force deceleration data in different speed ranges under different working conditions of the vehicle being empty or fully loaded, the optimal collision time for vehicle collision warning and emergency braking triggering is calculated and stored respectively, and the optimal collision time is written into the AEBS controller parameters. When the vehicle triggers automatic emergency braking when driving under empty or fully loaded working conditions, the AEBS controller issues an emergency braking command according to the corresponding optimal collision time and sends an external braking request to the braking execution system. After receiving the braking request, the braking execution system executes emergency braking.

As a further explanation of the invention, according to the working condition classification corresponding to the front vehicle speed, the optimal collision time calculation formula for vehicle collision warning and emergency braking triggering under different front vehicle speed conditions is:

When the front vehicle is stationary, the calculation formula is:

When the front vehicle is at a constant speed or accelerating, the calculation formula is:

When the front vehicle is decelerating, the calculation formula is:

Among them, TTC represents the optimal collision time for vehicle collision warning and emergency braking triggering, a represents the braking force deceleration of the own vehicle, a1 represents the braking force deceleration of the front vehicle, v represents the real-time axle speed of the whole vehicle, v1 represents the real-time speed of the front vehicle, t1 represents the driver's reaction time, t2 represents the braking system reaction time, t3 represents the braking deceleration growth time, and S0 represents the distance between the own vehicle and the front vehicle after braking.

The calibration system of the self-learning calibration method of the automatic emergency braking system as described in any one of the above items comprises:

The AEBS controller is used to obtain and judge the vehicle braking-related CAN signals before braking and the braking-related CAN signals during braking, and is used to calculate, record and store the vehicle braking force deceleration data under different vehicle speed ranges under different working conditions of the vehicle being empty or fully loaded, as well as the corresponding vehicle collision warning and the optimal collision time data for emergency braking triggering; is used to send the storage result status of the vehicle braking force deceleration data to the instrument cluster; and is used to calibrate the default automatic emergency braking system of the vehicle to be calibrated;

The instrument cluster is used to receive the storage result status of the vehicle's braking force and deceleration data and display the fault status or success status, while giving reminders.

Compared with the prior art, the present invention has the following beneficial technical effects:

The present invention can solve the problem that manual calibration requires a large amount of manpower and material resources and the problem of calibration errors for different vehicle models. At the same time, since the emergency braking timing can be accurately controlled, driving comfort can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a self-learning calibration method for an automatic emergency braking system of the present invention.

DETAILED DESCRIPTION

As shown in FIG1 , a self-learning calibration method for an automatic emergency braking system includes the following steps:

SS1. The self-learning calibration of the default automatic emergency braking system of the vehicle to be calibrated is activated. The AEBS controller obtains and determines whether the vehicle braking data meets the vehicle braking force deceleration data calculation conditions. If so, the vehicle braking force deceleration data is allowed to be calculated;

S2, entering the whole vehicle braking force deceleration data calculation process, judging the vehicle empty and full-load working conditions, and respectively calculating and storing the whole vehicle braking force deceleration data under different working conditions of the vehicle empty and full-load;

S3, judging the state of the storage result of the braking force and deceleration data of the whole vehicle, and if the storage result is faulty, sending it to the instrument cluster to display the storage fault state and reminding; if the storage result is valid, sending it to the instrument cluster to display the storage success state and reminding;

S4. Obtain and determine whether the vehicle braking force deceleration data of the vehicle to be calibrated under different working conditions of empty and fully loaded is written into the AEBS controller parameters. If so, the vehicle is calibrated. If not, start executing step S1.

When the braking force of the default automatic braking system of the vehicle to be calibrated is self-learned and calibrated, before executing step S1, the following steps are also included:

The AEBS controller obtains and determines whether the vehicle braking-related CAN signals meet the self-learning calibration standby conditions. If the vehicle braking-related CAN signals are fault-free, it is allowed to enter the self-learning calibration pre-activation process; the vehicle braking-related CAN signals at least include the vehicle braking system's axle speed signal, brake pedal switch signal, brake pedal position signal, vehicle heading angle signal, engine controller's accelerator pedal signal, gear position signal of the transmission controller, instrument's AEB enable switch signal, axle load sensor's load signal and status information of other systems on the vehicle, etc. The CAN message signals of each system are in a valid state, and the automatic braking system enters standby mode by default;

Before entering the self-learning calibration activation process, obtain and determine whether the self-learning calibration activation conditions are met. If the vehicle speed is in the activation speed range, the brake pedal switch is on, the gear is in the forward gear, the load signal of the axle load sensor, and the lateral angular velocity are not greater than the set value, preferably 0.02Rad/s, then entering the self-learning calibration activation is allowed.

Executing step S1 specifically includes the following steps:

The vehicle brake switch is activated, and the first frame of the vehicle front axle speed message, the brake pedal position during braking, the braking time interval, and the lateral angular velocity during braking are obtained and recorded. If the first frame of the vehicle real-time axle speed message signal value is judged to be 0, the data recording is stopped;

Determine whether the recorded data simultaneously satisfies the following conditions: the brake pedal position during braking is not less than the set value, preferably the brake pedal position is ≥90%, the braking time interval of the whole vehicle is not less than the set value, preferably the braking time interval t≥2s, and the lateral angular velocity during braking is not greater than the set value, preferably 0.020.02Rad/s, then the calculation of the braking force deceleration data of the whole vehicle is allowed.

The calculation formula of vehicle braking force deceleration is:

Wherein, a represents the deceleration of the vehicle braking force, v represents the real-time axle speed of the vehicle, t1 represents the time when the axle speed is v when the brake switch is first turned on, and t2 represents the time when the axle speed is zero for the first time after the brake switch is activated.

Executing step S2 specifically includes the following steps:

Determine whether the vehicle is in an empty or fully loaded state based on the load signal of the axle load sensor;

According to the speed intervals corresponding to the vehicle's empty and full-load conditions, the vehicle braking force deceleration data in different speed intervals are calculated and stored. Preferably, in the empty or full-load condition, the speed intervals include 15-25km/h, 35-45km/h, 55-65km/h, and 75-85km/h.

When executing step S3, if the storage result fails, the calibration failure state is displayed and a reminder is given, which specifically includes the following steps:

If one or more items of the vehicle braking deceleration data are missing, the stored data is displayed as missing and a reminder is given, and the process returns to re-execute step S1; preferably, the stored data value occupies 1 byte in length, and each of the 8 states occupies 1 position. The data of no-load 15-25km/h occupies the first position, the data of no-load 35-45km/h occupies the second position, the data of no-load 55-65km/h occupies the third position, the data of no-load 75-85km/h occupies the fourth position, the data of full load 15-25km/h occupies the fifth position, the data of full load 35-45km/h occupies the sixth position, the data of full load 55-65km/h occupies the seventh position, and the data of full load 75-85km/h occupies the eighth position. When there is data in the position, the value is 1, and when there is no data, the value is 0. When all the stored data exist, the stored data value is FF, and the AEBS controller verifies the stored data value. When the data value is not FF, the AEBS controller sends the stored data value to the instrument. The instrument prompts which data is missing based on the corresponding value and prompts the operator to test again. The system jumps to the start state in 2 seconds. The system continues to store the vehicle braking force deceleration data when the self-learning calibration test conditions are met; when the stored data value is FF, the AEBS controller sends the stored data value to the instrument, and the instrument prompts that the data collection is completed.

After the vehicle braking force deceleration data is calibrated successfully, the following steps are also included:

According to the average value of the vehicle braking force deceleration data in different speed ranges under different working conditions of the vehicle being empty or fully loaded, the optimal collision time for vehicle collision warning and emergency braking triggering is calculated and stored respectively, and the optimal collision time is written into the AEBS controller parameters. When the vehicle triggers automatic emergency braking when driving under empty or fully loaded working conditions, the AEBS controller issues an emergency braking command according to the corresponding optimal collision time and sends an external braking request to the braking execution system. After receiving the braking request, the braking execution system executes emergency braking.

According to the working conditions corresponding to the front vehicle speed, the optimal collision time calculation formula for vehicle collision warning and emergency braking triggering under different front vehicle speed conditions is:

When the front vehicle is stationary, the calculation formula is:

When the front vehicle is at a constant speed or accelerating, the calculation formula is:

When the front vehicle is decelerating, the calculation formula is:

Among them, TTC represents the optimal collision time for vehicle collision warning and emergency braking triggering, a represents the braking force deceleration of the own vehicle, a1 represents the braking force deceleration of the front vehicle, v represents the real-time axle speed of the whole vehicle, v1 represents the real-time speed of the front vehicle, t1 represents the driver's reaction time, t2 represents the braking system reaction time, t3 represents the braking deceleration growth time, and S0 represents the distance between the own vehicle and the front vehicle after braking. It should be noted that the own vehicle represents the vehicle to be calibrated, and the front vehicle represents the target vehicle to be calibrated.

A calibration system for the self-learning calibration method of an automatic emergency braking system as described in any one of the above, characterized by comprising:

The AEBS controller has a built-in self-learning calibration program, which is used to obtain and judge the vehicle's braking-related CAN signals before braking and the braking-related CAN signals during braking, and is used to calculate, record, store and write the vehicle's braking force deceleration data under different vehicle speed ranges under different working conditions of the vehicle being empty or fully loaded, and is used to send the storage result status of the vehicle's braking force deceleration data to the instrument cluster; is used to calibrate the default automatic emergency braking system of the vehicle to be calibrated; is used to calculate, record, store and write the optimal collision time for the vehicle collision warning and emergency braking trigger under different vehicle speed conditions, and perform emergency braking;

The instrument cluster is used to receive the storage result status of the vehicle's braking force and deceleration data and display the fault status or success status, while giving reminders.

Claims (9)

1. The self-learning calibration method of the automatic emergency braking system is characterized by comprising the following steps of:

S1, self-learning calibration activation of a default automatic emergency braking system of a vehicle to be calibrated, wherein an AEBS controller acquires and judges whether whole vehicle braking data meets a whole vehicle braking force deceleration data calculation condition, and if so, calculation of whole vehicle braking force deceleration data is allowed;

s2, entering a whole vehicle braking force deceleration data calculation flow, judging the self-vehicle empty and full-load working conditions, and respectively calculating and storing whole vehicle braking force deceleration data under different self-vehicle empty and full-load working conditions;

S3, judging the storage result state of the braking force deceleration data of the whole vehicle, if the storage result is faulty, sending the storage result to a combination instrument to display the storage fault state and reminding; if the storage result is valid, sending the storage result to the combination instrument to display the successful storage state and reminding;

S4, acquiring and judging whether the braking force deceleration data of the whole vehicle is written into the AEBS controller parameters under different working conditions of empty and full vehicles of the vehicle to be calibrated, if so, completing the calibration of the own vehicle, and if not, starting to execute the step S1.

2. The self-learning calibration method of an automatic emergency braking system according to claim 1, characterized in that it further comprises the following steps, before executing step S1:

the AEBS controller acquires and judges whether the CAN signal related to the whole vehicle braking meets the self-learning calibration standby condition, and if the CAN signal related to the whole vehicle braking meets the self-learning calibration standby condition, the self-learning calibration standby condition is allowed to enter a pre-activation process;

And entering a self-learning calibration activation process, acquiring and judging whether the self-learning calibration activation condition is met, and allowing the self-learning calibration activation if the vehicle speed is in an activated vehicle speed interval, a brake pedal switch is started, a gear is in a forward gear, a load signal of an axle load sensor and the transverse angular speed are not greater than a set value.

3. The self-learning calibration method of an automatic emergency braking system according to claim 2, wherein the execution of step S1 comprises the steps of:

The whole vehicle brake switch is activated, a front axle shaft speed message of the first frame whole vehicle, a brake pedal position in a brake process, a brake time interval and a transverse angular speed in the brake process are obtained and recorded, and if the real-time axle shaft speed message signal value of the first frame whole vehicle is 0, the data recording is stopped;

And judging whether the recorded data simultaneously meet the conditions that the position of a brake pedal in the braking process is not smaller than a set value, the braking time interval of the whole vehicle is not smaller than the set value and the transverse angular speed in the braking process is not larger than the set value, and allowing calculation of the braking force deceleration data of the whole vehicle.

4. The self-learning calibration method of an automatic emergency brake system according to claim 3, wherein the whole vehicle braking force deceleration calculation formula is:

Wherein a represents the braking force deceleration of the vehicle, v represents the real-time axle speed of the whole vehicle, t1 represents the time when the axle speed of the first opening of the brake switch is v, and t2 represents the time when the axle speed of the first opening of the brake switch is zero.

5. The self-learning calibration method of an automatic emergency braking system according to claim 4, wherein the performing step S2 specifically includes the steps of:

judging whether the vehicle is in an empty state or a full state according to the load signal of the axle load sensor;

and calculating and storing the braking force deceleration data of the whole vehicle in different vehicle speed intervals according to the vehicle speed dividing intervals corresponding to the self-vehicle empty and full load working conditions.

6. The self-learning calibration method of an automatic emergency brake system according to claim 5, wherein when executing step S3, if the storage result fails, the method sends the storage result to the combination meter to display the storage failure state and reminds the combination meter of the storage failure state, and specifically comprises the following steps:

and if one or more items of storage data of the braking deceleration data of the whole vehicle are missing, the combination instrument displays the missing storage data and reminds, and the step S1 is executed again.

7. The self-learning calibration method of an automatic emergency brake system according to claim 6, further comprising the steps of, after successful calibration of the vehicle braking force deceleration data:

According to the average value of braking force deceleration data of the whole vehicle in different vehicle speed intervals under different working conditions of the empty and full load of the vehicle, respectively calculating and storing optimal collision time for vehicle collision early warning and emergency braking triggering, writing the optimal collision time into parameters of an AEBS controller, when the vehicle runs under the working condition of the empty and full load of the vehicle to trigger automatic emergency braking, issuing an emergency braking command by the AEBS controller according to the corresponding optimal collision time, sending an external braking request to a braking execution system, and executing emergency braking after the braking execution system receives the braking request.

8. The self-learning calibration method of an automatic emergency braking system according to claim 7, wherein the calculation formula of the optimal collision time for vehicle collision early warning and emergency braking triggering under different front vehicle speed working conditions is as follows:

under the static working condition of the front vehicle, the calculation formula is as follows:

under the working condition of uniform speed or acceleration of the front vehicle, the calculation formula is as follows:

under the front vehicle deceleration working condition, the calculation formula is as follows:

wherein, TTC represents the optimal collision time triggered by vehicle collision early warning and emergency braking, a represents the braking force deceleration of the own vehicle, a1 represents the braking force deceleration of the front vehicle, v represents the real-time axle speed of the whole vehicle, v1 represents the real-time speed of the front vehicle, t1 represents the response time of a driver, t2 represents the response time of a braking system, t3 represents the increasing time of the braking deceleration, and S0 represents the distance between the own vehicle and the front vehicle after the braking is finished.

9. Calibration system for a self-learning calibration method of an automatic emergency braking system according to any of claims 1 to 8, comprising:

The AEBS controller is used for acquiring and judging a whole vehicle braking related CAN signal before braking and a braking related CAN signal in the braking process, and calculating, recording and storing whole vehicle braking force deceleration data under different vehicle speed intervals under different working conditions of self-vehicle space full load and corresponding optimal collision time data of vehicle collision early warning and emergency braking triggering; the method comprises the steps of sending the storage result state of the braking force deceleration data of the whole vehicle to a combination instrument; the automatic emergency braking system calibration device is used for calibrating a default automatic emergency braking system of a vehicle to be calibrated;

And the combination instrument is used for receiving the storage result state of the braking force deceleration data of the whole vehicle, displaying the fault state or the success state and reminding.