CN116811876A - Vehicle braking method and device and vehicle-mounted terminal - Google Patents

Abstract

The embodiment of the application is suitable for the technical field of vehicles, and provides a vehicle braking method, a vehicle braking device and a vehicle-mounted terminal, wherein the method comprises the following steps: responding to a braking instruction of a vehicle, and acquiring scene information on a current running road of the vehicle, wherein the scene information is used for representing the complexity of a braking scene faced by the vehicle; determining a desired acceleration required for braking the vehicle, the desired acceleration being used to measure whether the vehicle can meet braking requirements solely by motor braking; determining a braking mode of the vehicle according to the scene information and the expected acceleration; and braking the vehicle according to the braking mode. By the method, the safe running of the vehicle can be ensured in the vehicle braking process.

Description

Vehicle braking method and device and vehicle-mounted terminal

Technical Field

The application belongs to the technical field of vehicles, and particularly relates to a vehicle braking method and device and a vehicle-mounted terminal.

Background

For a vehicle equipped with an intelligent driving system, braking energy recovery can be performed when the vehicle is braked and started more frequently. That is, the kinetic energy of the vehicle is converted into electric energy at the time of braking.

The current pure electric vehicle type braking energy recovery implementation mode can be as follows: conversion of electric vehicle kinetic and electrical energy is accomplished by a motor/generator having a reversible function. When the vehicle is decelerated or braked, the reversible motor works in a generator mode, and the kinetic energy of the vehicle driving drives the generator to convert the kinetic energy of the vehicle into electric energy and store the electric energy in the storage battery; when the vehicle starts or accelerates, the reversible electric machine works as a motor to convert the electric energy stored in the energy accumulator into mechanical energy for the vehicle.

However, when the reversible motor alone is used for braking during deceleration braking, there are cases where the deceleration provided by the reversible motor cannot meet the vehicle demand. When the deceleration provided by the reversible motor cannot meet the vehicle requirement, the reversible motor is used alone for braking, so that the vehicle has safety risks. For example, the acceleration of the vehicle braking is relatively low, resulting in the braking of the vehicle being too slow, resulting in the vehicle striking other vehicles or pedestrians in front.

Disclosure of Invention

In view of the above, the embodiments of the present application provide a vehicle braking method, device, and vehicle-mounted terminal, which are used for ensuring that a vehicle can provide sufficient acceleration when braking the vehicle, so as to ensure driving safety of the vehicle.

A first aspect of an embodiment of the present application provides a vehicle braking method, including:

responding to a braking instruction of a vehicle, and acquiring scene information on a current running road of the vehicle, wherein the scene information is used for representing the complexity of a braking scene faced by the vehicle;

determining a desired acceleration required for braking the vehicle, the desired acceleration being used to measure whether the vehicle can meet braking requirements solely by motor braking;

determining a braking mode of the vehicle according to the scene information and the expected acceleration;

and braking the vehicle according to the braking mode.

A second aspect of an embodiment of the present application provides a vehicle brake device including:

the system comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for responding to a braking instruction of a vehicle and acquiring scene information on the current running road of the vehicle, wherein the scene information is used for representing the complexity degree of a braking scene faced by the vehicle;

the expected acceleration determining module is used for determining expected acceleration required by braking of the vehicle, and the expected acceleration is used for measuring whether the vehicle can meet braking requirements only through motor braking;

the braking mode determining module is used for determining the braking mode of the vehicle according to the scene information and the expected acceleration;

And the braking module is used for braking the vehicle according to the braking mode.

A third aspect of an embodiment of the present application provides a vehicle-mounted terminal, including a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the method according to the first aspect when executing the computer program.

A fourth aspect of embodiments of the present application provides a computer readable storage medium storing a computer program which, when executed by a processor, implements a method as described in the first aspect above.

A fifth aspect of an embodiment of the application provides a vehicle which, when braked, performs a method as described in the first aspect above.

A sixth aspect of an embodiment of the present application provides a computer program product for causing an in-vehicle terminal to perform the method of the first aspect described above when the computer program product is run on the in-vehicle terminal.

Compared with the prior art, the embodiment of the application has the following advantages:

the vehicle braking method in the embodiment of the application can be applied to the scene where energy recovery is required. In response to a braking instruction of the vehicle, the vehicle-mounted terminal may acquire scene information on a current running road of the vehicle and determine a desired acceleration required for braking of the current vehicle. Based on the scene information and the desired acceleration, the in-vehicle terminal may determine a braking mode of the vehicle, thereby braking the vehicle based on the braking mode. When the vehicle is braked, the embodiment of the application can judge whether the braking scene faced by the vehicle is complex or not based on the scene information, and can measure whether the motor braking can meet the braking requirement or not based on the expected acceleration. Therefore, a braking mode is selected based on scene information and expected acceleration, on one hand, the braking mode is ensured to provide the expected acceleration required by braking for the vehicle, so that the vehicle can brake according to the expected, and the driving safety is ensured; on the other hand, the motor braking and the hydraulic braking are combined to brake based on a predetermined braking mode, so that sudden intervention of the hydraulic braking in the braking process is avoided, vehicle shake of a vehicle caused by the sudden intervention of the hydraulic braking is eliminated, and riding experience of a user is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings that are required to be used in the embodiments or the description of the prior art.

FIG. 1 is a schematic representation of energy conversion in a vehicle according to an embodiment of the present application;

FIG. 2 is a schematic diagram of a vehicle deceleration and acceleration link according to an embodiment of the present application;

FIG. 3 is a schematic diagram of a vehicle body with excessive hydraulic brake intervention slope provided by an embodiment of the application;

FIG. 4 is a flowchart illustrating steps of a method for braking a vehicle according to an embodiment of the present application;

FIG. 5 is a flowchart illustrating steps of another vehicle braking method according to an embodiment of the present application;

FIG. 6 is a schematic illustration of a vehicle braking process provided by an embodiment of the present application;

FIG. 7 is a schematic illustration of a vehicle braking device according to an embodiment of the present application;

fig. 8 is a schematic diagram of a vehicle-mounted terminal according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth such as the particular system architecture, techniques, etc., in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

Intelligent driving refers to that a vehicle can assist a driver to operate the vehicle through devices such as a carrying sensor, a controller, an actuator, a communication module and the like. Vehicles carrying intelligent driving systems are increasingly moving to the consumer market at present, and the intelligent driving scenes facing the vehicles are also various. For example, a vehicle carrying an intelligent driving system may operate in a complex urban scenario. The related researches show that under the urban working condition operation condition of more frequent braking and starting, the braking energy is effectively recovered, the energy consumption of the electric vehicle can be reduced by about 15 percent, and the running distance of the electric vehicle can be prolonged by 10 to 30 percent. Therefore, it is significant to recover braking energy of an electric vehicle equipped with an intelligent driving system.

Electric vehicles that may perform braking energy recovery may include all-electric vehicles. The current pure electric vehicle type vehicle braking energy recovery implementation mode is as follows: conversion of electric vehicle kinetic and electrical energy is accomplished by a motor/generator having a reversible function. When the vehicle is decelerated or braked, the reversible motor works in a generator mode, and the kinetic energy of the vehicle driving drives the generator to convert the kinetic energy of the vehicle into electric energy and store the electric energy in the storage battery; when the vehicle starts or accelerates, the reversible electric machine works as a motor to convert the electric energy stored in the energy accumulator into mechanical energy for the vehicle. Fig. 1 is a schematic diagram of energy conversion of a vehicle according to an embodiment of the present application. As shown in fig. 1, when the vehicle accelerates, a part of the battery power of the vehicle may be converted into running kinetic energy, and a part may be converted into resistance internal energy to be dissipated. When the vehicle is decelerating, the running kinetic energy can be converted into frictional internal energy and resistance internal energy to be dissipated, and meanwhile, a part of the running kinetic energy can be converted into battery electric energy, so that energy recovery is realized.

The acceleration required for braking can be provided by a brake controller and a power controller in the vehicle when the vehicle is braked. Wherein the brake controller may perform hydraulic braking so that braking force may be provided to the vehicle. When the power controller outputs positive torque, the vehicle can be accelerated; when the power controller outputs negative torque, the vehicle can be decelerated or braked. Because both the power controller and the brake controller can be used for decelerating or braking the vehicle, in the prior art, when decelerating or braking is performed, the brake system of the vehicle can judge the magnitude of deceleration sent by the intelligent driving system and simultaneously combine the negative torque range executable by the motor to mobilize different brake modules to perform braking actions.

Fig. 2 is a schematic diagram of a vehicle deceleration and acceleration link according to an embodiment of the present application. As shown in fig. 2, an intelligent driving awareness system and an intelligent driving planning system may be included in the vehicle. The intelligent driving perception system can perceive external environment information and send the perceived external environment information to the intelligent driving planning system, and the intelligent driving planning system can determine the torque required during acceleration and deceleration based on the external environment information. While accelerating, the intelligent drive planning system may send a positive torque request for the acceleration link to the power controller, causing the power controller to execute the positive torque request to accelerate the vehicle. The intelligent drive planning system may determine a deceleration request of a deceleration link based on external environment information and transmit the deceleration request to a brake controller, and the brake controller may transmit a negative torque request to the power controller according to the deceleration request, a vehicle speed, a wheel speed, a pulse, and related information of a whole vehicle inertia measurement unit ((Inertial Measurement Unit, IMU)) and the like.

In the braking process, the braking controller performs hydraulic braking based on negative torque feedback of the power controller, namely the hydraulic braking can be suddenly intervened in the motor braking process, so that the hydraulic braking intervention slope is overlarge. Too large a hydraulic brake intervention slope can cause uncomfortable vehicle vibration and body feel and can reduce the efficiency of energy recovery.

Fig. 3 is a schematic diagram of vehicle body shake caused by excessive hydraulic brake intervention slope provided by the embodiment of the application. The upper layer requested acceleration in fig. 3 is the acceleration that the intelligent driving system of the vehicle expects the vehicle to reach. As shown in fig. 3, after the vehicle is electrically braked for a while, the vehicle body acceleration cannot reach the upper layer request acceleration at all times, and at this time, the hydraulic brake can be used. When the hydraulic brake is added, the acceleration of the vehicle body can be quickly reduced to meet the vehicle requirement, but when the hydraulic brake is added, the vehicle can shake, and the shake of the vehicle can reach a body feeling shake point, so that the user experience is poor. The electric brake in fig. 3 is the motor brake in the present application.

Based on this, the present application provides a vehicle braking method. The vehicle braking method can be applied to vehicles with intelligent driving functions started, and the intervention mode of hydraulic braking is used for controlling, so that the problem of vehicle body shaking caused by the intervention of hydraulic braking when braking energy is recovered is eliminated or weakened, and the braking energy recovery efficiency is improved.

The technical scheme of the application is described below through specific examples.

Referring to fig. 4, a schematic step flow diagram of a vehicle braking method according to an embodiment of the present application is shown, which may specifically include the following steps:

s401, responding to a braking instruction of a vehicle, and acquiring scene information on the current running road of the vehicle, wherein the scene information is used for representing the complexity degree of a braking scene faced by the vehicle.

The method in the embodiment of the application can be applied to a vehicle, and the vehicle can comprise a power controller and a brake controller. The power controller may be used for motor braking of the vehicle and the brake controller may be used for hydraulic braking of the vehicle.

The execution subject of the method in the embodiment of the application can be a vehicle-mounted terminal in a vehicle. The vehicle-mounted terminal can be provided with an intelligent driving perception system and an intelligent driving planning system. The intelligent driving perception system can perceive the driving environment of the vehicle based on a sensor or other information acquisition equipment installed on the vehicle, and the intelligent driving planning system can issue control signals to each module in the vehicle according to the driving environment perceived by the intelligent driving perception system, so that the vehicle is controlled to carry out corresponding driving strategy adjustment based on the driving environment. For example, when braking, the intelligent driving perception system may perceive a braking scenario of the vehicle based on a sensor or other information acquisition device installed on the vehicle, and the intelligent driving planning system may send control signals to the power controller and the braking controller according to the braking scenario perceived by the intelligent driving perception system, so that the braking controller and the power controller may provide acceleration required for braking of the vehicle. The vehicle-mounted terminal can be a vehicle machine or a central electronic control module on a vehicle, and is not limited in the embodiment of the application.

Braking, commonly known as "braking", is an action that stops or slows down a locomotive, vehicle, other transportation means or machinery, etc. in operation. The braking of the vehicle may be triggered by the braking command described above. The braking instruction can be automatically generated by the vehicle according to the current driving environment or can be generated according to a user instruction. For example, when the intelligent driving perception system of the vehicle detects that an obstacle exists in front of the vehicle and a traffic light exists in front of the vehicle, the intelligent driving planning system can generate a braking instruction so as to trigger the vehicle to brake. In addition, when the user steps on the brake or presses a brake button, a brake command may also be generated, triggering braking of the vehicle.

After receiving the braking command, the vehicle-mounted terminal can reduce the speed of the vehicle or stop the vehicle according to the braking command. The deceleration or stop of the vehicle requires the participation of acceleration. In the embodiment of the application, the vehicle can be braked by providing acceleration through the power controller and the brake controller. Based on the power controller and the brake controller, the braking modes of the vehicle can include hydraulic braking, motor braking and combined braking. Wherein the hydraulic braking and the motor braking jointly perform braking is called joint braking. When braking, the vehicle-mounted terminal needs to select a braking mode.

When braking a vehicle, it is first necessary to ensure the driving safety of the vehicle. That is, it is necessary to ensure that the vehicle does not collide during braking. The risk of a collision of the vehicle during braking is related to the braking scenario in which the vehicle is located. For example, when the vehicle is braked, if no obstacle affecting the running of the vehicle exists in front of the vehicle, the safety risk of the vehicle in the braking process is low, and the corresponding braking scene belongs to a non-complex braking scene. When a vehicle is braked, if a plurality of running vehicles, pedestrians and the like exist in front of the vehicle, the probability of collision in the braking process of the vehicle is high, and the corresponding braking scene belongs to a complex braking scene. In order to ensure the driving safety of the vehicle, the braking scenario of the vehicle may be considered when selecting the braking mode.

Therefore, after receiving the braking instruction of the vehicle, the vehicle-mounted terminal can acquire scene information on the current running road of the vehicle. The context information may be used to characterize the complexity of the braking context faced by the vehicle and may also indicate the urgency of braking. For example, the scene information may be used to characterize the scene in which the vehicle is located as either the first scene or the second scene. The first scene is used for describing a complex braking scene, and the complex braking scene has high requirement on braking; the second scenario is used to describe a non-complex braking scenario, which requires less braking. In general, the degree of emergency in braking in complex scenes is relatively high, and the degree of emergency in braking in non-complex scenes is relatively low.

In one possible implementation, the above-described scenario information may be determined based on the number of targets in front of the vehicle. Based on the intelligent driving perception system, the vehicle-mounted terminal can identify an object existing in front of the vehicle, wherein the object refers to an obstacle which affects the vehicle to advance, such as other vehicles, pedestrians or fixed objects.

When the number of targets in front of the vehicle is large, for example, the number of targets is greater than or equal to a preset threshold, the vehicle may be considered to be in the first scene. In this case, since there are many targets in front of the vehicle, there are many factors to be considered when the vehicle is braked, that is, the braking scene to be processed is complicated.

When the number of targets in front of the vehicle is small, for example, the number of targets is smaller than a preset threshold, the vehicle may be considered to be in a second scene. At this time, since targets in front of the vehicle are fewer, the braking scenario of the vehicle process is simpler.

In another possible implementation, the above-mentioned scene information may also be determined by the intelligent perception system according to the user's settings. For example, the user may set that the vehicle is in a first scene when there is a pedestrian in front, and the vehicle is in a second scene when there is no pedestrian in front.

S402, determining the expected acceleration required by the vehicle braking, wherein the expected acceleration is used for measuring whether the vehicle can meet the braking requirement only through motor braking.

The desired acceleration may be an ideal acceleration to meet the braking demand of the vehicle. The vehicle braking demand may be a demand set by a user or a vehicle driving safety demand. When a desired acceleration is provided to the vehicle, the vehicle may complete the vehicle deceleration at the speed requested by the user; or the vehicle may not collide with other objects during deceleration. For energy recovery, it is of course preferable to choose to perform electric braking, but the acceleration provided by electric braking is limited, and comparing the desired acceleration with the acceleration that can be provided by electric braking, it can be determined whether the vehicle can meet the braking demand by electric motor braking alone.

In one possible implementation, the desired acceleration may be set by the driver of the vehicle.

In another possible implementation, the desired acceleration may be determined based on the driving safety requirements. The magnitude of the desired acceleration may affect the path length traveled by the vehicle during braking. In order to ensure driving safety, the path length of the vehicle traveling during braking needs to ensure that the vehicle does not collide with a target in front of the vehicle. Based on this, the in-vehicle terminal can determine the desired acceleration of the vehicle from the state information of the vehicle and the state information of the object located in front of the vehicle.

The vehicle-mounted terminal can identify whether an object exists in front of the vehicle, and when the object does not exist in front of the vehicle, that is, the vehicle does not encounter obstruction in the braking process, the vehicle generally does not collide in the braking process. In this case, the magnitude of the desired acceleration, which may be an acceleration that the motor can satisfy to perform the negative torque request, may not affect the driving safety, and may be an acceleration set in advance by the user.

When a target exists in front of the vehicle, the vehicle-mounted terminal can acquire state information of the vehicle and state information of the target, wherein the state information can comprise position information and speed information, and based on the state information of the vehicle and the state information of the target, the vehicle-mounted terminal can determine a path length that the vehicle can travel in a braking process, so that expected acceleration for guaranteeing driving safety can be determined based on the state information of the vehicle and the state information of the target. For example, the in-vehicle terminal may determine a distance between the target and the vehicle based on the position information of the target and the position information of the vehicle; determining the speed difference between the target and the vehicle according to the speed information of the target and the speed information of the vehicle; based on the speed difference and the distance, the vehicle-mounted terminal may determine a desired acceleration. Specifically, based on the speed difference and the distance, the in-vehicle terminal may determine a minimum acceleration absolute value such that the vehicle does not strike the target, and take the minimum acceleration absolute value as an absolute value of the desired acceleration.

For example, the target is 10 meters in front of the vehicle, the target speed is 0; the current speed of the vehicle is 5m/s, and then in order to ensure that the vehicle does not hit the target, the absolute value of the minimum acceleration of the vehicle is 1.25m/s2, at which time the acceleration may be expected to be 1.25m/s2.

S403, determining a braking mode of the vehicle according to the scene information and the expected acceleration.

The above scene information can be used to determine the degree of emergency of braking. When the vehicle is in the first scene, the vehicle is easy to collide due to the complex braking scene faced by the vehicle, and the emergency degree of braking is high at the moment. When the vehicle is in the second scene, the vehicle is not easy to collide due to the fact that the braking scene faced by the vehicle is simpler, and the emergency degree of braking at the moment is low. When braking, the accuracy of executing the hydraulic braking is higher, and a certain hysteresis or execution deviation may exist in motor braking, so that the selection of the braking mode of the vehicle needs to consider scene information.

In addition, the braking mode selected when the vehicle is braked needs to be capable of providing the desired acceleration to the vehicle, so as to ensure driving safety.

The braking method provided by the embodiment of the application is applied to the scene of energy recovery of the vehicle. Therefore, motor braking may be used preferentially for energy recovery. The combination brake may be used when the acceleration provided by the motor brake cannot meet the desired acceleration.

The motor has an executable negative torque range, based on which an ideal maximum acceleration absolute value that the motor can provide when braking can be determined. However, since there may be an execution deviation of the motor brake, the actual maximum acceleration that the motor brake can actually provide may be smaller than the ideal maximum acceleration absolute value. Thus, a threshold value can be determined that is less than the absolute value of the ideal maximum acceleration, which can be used to characterize the maximum acceleration that the motor can actually provide. When the vehicle is in the first scene, the degree of the emergency braking of the vehicle is higher, the allowable degree of the execution deviation of the motor braking is smaller, and at the moment, a first threshold value can be set as the maximum acceleration which can be provided by the motor braking, and the first threshold value can have a certain difference value with the absolute value of the ideal maximum acceleration. When the vehicle is in the second scene, the degree of the braking emergency of the vehicle is not high, the allowable degree of the execution deviation of the motor braking is relatively large, and at this time, a second threshold value can be set as the maximum acceleration which can be provided by the motor braking, and the second threshold value can be slightly smaller than the ideal maximum acceleration absolute value. The first threshold may be less than the second threshold. Of course, in another possible implementation, the first threshold value may also be equal to the second threshold value.

When the vehicle is in a first scene, if the absolute value of the expected acceleration is smaller than a first threshold value, the motor braking can meet the requirement of the expected acceleration, so that the braking mode can be determined to be motor braking; if the absolute value of the expected acceleration is greater than or equal to the first threshold value, the motor braking cannot meet the requirement of the expected acceleration, so that the braking mode can be determined to be combined braking.

When the vehicle is in the second scene, if the absolute value of the acceleration is smaller than the second threshold value, the motor braking can meet the requirement of the expected acceleration, so that the braking mode can be determined to be motor braking, and if the absolute value of the acceleration is larger than or equal to the second threshold value, the braking mode is determined to be combined braking.

In this step, based on different braking scenarios of the vehicle, different thresholds may be selected as the actual maximum acceleration that can be provided by the motor braking, so that the motor braking may have different execution errors in different braking scenarios. Based on different execution errors, the emergency braking requirement can be met in a complex braking scene, and more braking energy can be recovered in a non-complex braking scene.

And S404, braking the vehicle according to the braking mode.

If the braking mode is motor braking, a corresponding negative torque request can be sent to the power controller according to the expected acceleration, and the power controller can execute the negative torque request to enable the motor to output the corresponding negative torque, so that the vehicle is braked. When the motor outputs negative torque, the kinetic energy of the vehicle can be converted into electric energy, so that energy recovery is realized.

If the braking mode is combined braking, the vehicle can be braked by controlling the motor to output a desired negative torque and controlling the brake controller to output a desired braking force, wherein the desired negative torque and the desired braking force are used together to provide the desired acceleration to the vehicle.

When the combined braking is carried out, the vehicle-mounted terminal can determine the expected negative torque of the motor braking according to the executable negative torque range of the motor. Based on the desired acceleration and the negative torque request, the vehicle terminal may determine a desired braking force that needs to be provided by the hydraulic brake. For example, the in-vehicle terminal may determine the acceleration that the vehicle can be provided with a negative torque request; based on the desired acceleration and the acceleration that the negative torque request can provide to the vehicle, then the remaining acceleration that needs to be provided by the hydraulic brake can be determined; based on the remaining acceleration that the hydraulic braking is required to provide, the in-vehicle terminal may determine the desired braking force that the hydraulic braking is required to provide. The in-vehicle terminal may transmit the desired negative torque to the power controller and the desired braking force to the brake controller, thereby performing the joint braking.

According to the embodiment of the application, the braking mode of the vehicle can be determined based on the braking scene of the vehicle and the expected acceleration required by braking, so that the vehicle braking can be controlled finely, the vehicle shake caused by sudden addition of the hydraulic braking in the vehicle braking process is avoided, the vehicle using experience of a user is improved, and the energy recovery efficiency is improved, so that the comfort of the vehicle and the cruising performance of the whole vehicle in intelligent driving of the vehicle are improved.

Referring to fig. 5, a schematic step flow diagram of another vehicle braking method according to an embodiment of the present application is shown, which may specifically include the following steps:

s501, responding to a braking instruction of a vehicle, and acquiring scene information on a current running road of the vehicle, wherein the scene information is used for representing the complexity degree of a braking scene faced by the vehicle;

s502, determining the expected acceleration required by the vehicle braking, wherein the expected acceleration is used for measuring whether the vehicle can meet the braking requirement only through motor braking.

S503, determining a braking mode of the vehicle according to the scene information and the expected acceleration.

And S504, braking the vehicle according to the braking mode.

S501 to S504 of this embodiment are similar to S401 to S404 of the previous embodiment, and are referred to each other and are not described herein.

And S504, when the vehicle is in a first scene, or when the vehicle is in a second scene and the braking mode is combined braking, performing braking hydraulic pressure compensation on the vehicle.

There are conditions where motor braking is insensitive. For example, the motor brake outputs a lower negative torque or a lower speed of outputting a negative torque, and the braking effect of the motor brake may be less ideal at this time, and in order to achieve a better braking effect, the running safety of the vehicle is ensured, and the brake hydraulic compensation may be performed. The brake hydraulic pressure compensation is that the brake controller additionally performs hydraulic braking to compensate the execution deviation of the motor negative torque brake. That is, in the case where the negative torque actually performed by the power controller is insufficient, the hydraulic braking may be performed using the brake controller, thereby compensating for the lack of motor braking.

In order to ensure the safety in the driving process, whether the negative torque output by the motor of the vehicle in the vehicle braking process is smaller than the expected negative torque for motor braking or not can be monitored, and the expected negative torque is used for providing braking force for the motor for vehicle braking; if the negative torque output by the motor is lower than the desired negative torque, the speed of the vehicle decreases relatively slowly during the deceleration, and the distance traveled during the braking increases, thereby possibly causing a safety accident. Therefore, when the negative torque output by the motor is lower than the desired negative torque, the braking hydraulic pressure compensation can be performed, and the braking force required for braking is compensated by the braking controller of the vehicle, thereby ensuring the running safety of the vehicle.

In the embodiment of the application, in order to ensure the running safety of the vehicle, when the braking scene is complex or the combined braking is needed, the braking hydraulic pressure compensation can be performed, so that the vehicle can be decelerated according to the expected acceleration in the braking process, the collision can not occur in the braking process of the vehicle, and the running safety of the vehicle is ensured.

It should be noted that, the sequence number of each step in the above embodiment does not mean the sequence of execution sequence, and the execution sequence of each process should be determined by its function and internal logic, and should not limit the implementation process of the embodiment of the present application in any way.

In order to more clearly illustrate the present application, the present application will be described below with reference to a specific example.

Fig. 6 is a schematic diagram of a vehicle braking process according to an embodiment of the present application. As shown in fig. 6, a vehicle may include a vehicle-mounted terminal, which may deploy an intelligent driving perception system and an intelligent driving planning system. The intelligent driving perception system can perceive external environment information, so that scene information and a vehicle body state are obtained. Based on the scene information and the car body state acquired by the intelligent driving perception system, the intelligent driving planning system controls the vehicle to brake. The intelligent driving planning system can be respectively connected with a power controller and a brake controller of the vehicle. Motor braking may be performed based on the power controller, and hydraulic braking may be performed based on the brake controller. The intelligent driving planning system can distribute motor negative torque to be executed to the power controller according to the current executable negative torque range, scene information and vehicle body state of the power controller and distribute deceleration to be executed by the brake controller to the brake controller, so that the vehicle can be decelerated based on the power controller and the hydraulic controller.

In the embodiment of the application, an intelligent driving perception system deployed in a vehicle-mounted terminal can collect scene information and vehicle state information through a sensor and a perception fusion system installed in the vehicle, and output related target information to an intelligent driving planning system, wherein the output target information can comprise the relative speed and the relative distance between a target in front of the vehicle and the vehicle; the intelligent driving planning system receives the related target information sensed by the intelligent driving sensing system, can judge whether the vehicle is a complex braking scene according to the related target information, and combines the control result (expected vehicle speed setting) of a driver on a user interface (Human Machine Interaction, HMI) of the vehicle and the actual running state (speed and acceleration information) of the real vehicle to output the negative torque of motor braking and the deceleration of the braking controller braking. In addition, the intelligent driving planning system can also determine whether hydraulic compensation braking is needed according to the expected acceleration and whether the braking scene is complex.

For example, the in-vehicle terminal may determine the intelligent driving braking strategy according to table 1. The intelligent driving strategy may include a braking mode and whether braking hydraulic pressure compensation is required.

TABLE 1

The first scenario in table 1 is a complex braking scenario, and the second scenario is a non-complex braking scenario. The first and second thresholds in table 1 are each 0.3g.

The basis for the judgment of the complex braking scenario and the non-complex braking scenario may be the number of moving targets in front of the vehicle. The number of moving targets in front of the vehicle is more than or equal to 3, and the complex braking scene is obtained. If the number of moving targets in front of the vehicle is <3, a non-complex braking scenario is assumed.

The desired deceleration may be an absolute value of the desired acceleration. The desired deceleration may be determined based on the braking distance of the own vehicle and the preceding vehicle and the difference in speed between the front target and the own vehicle.

According to the embodiment of the application, a braking scene can be subdivided through an intelligent driving perception system and an intelligent driving planning system in the intelligent driving system, so that intervention of negative torque of a motor and hydraulic braking is requested according to the emergency degree of the braking scene on a deceleration requirement, the problem of shaking of a vehicle body caused by too urgent recovery of hydraulic braking intervention energy is slowed down or solved, and a vehicle is controlled to reduce collision risk more safely in an emergency.

Referring to fig. 7, a schematic diagram of a vehicle braking device according to an embodiment of the present application may specifically include an acquisition module 71, a desired acceleration determining module 72, a braking mode determining module 73, and a braking module 74, where:

An obtaining module 71, configured to obtain, in response to a braking instruction of a vehicle, scene information on a current road on which the vehicle is currently traveling, where the scene information is used to characterize a complexity degree of a braking scene faced by the vehicle;

a desired acceleration determination module 72 for determining a desired acceleration required for braking of the vehicle, the desired acceleration being used to measure whether the vehicle can meet braking requirements via motor braking alone;

a braking mode determining module 73 for determining a braking mode of the vehicle according to the scene information and the desired acceleration;

and a braking module 74 for braking the vehicle according to the braking mode.

In one possible implementation manner, the acquiring module 71 includes:

an identification sub-module for identifying an object located in front of the vehicle;

a determining submodule, configured to determine the scene information according to the number of the targets; when the number of targets is greater than or equal to a preset threshold, the scene information is the number of targets when the vehicle is in a first scene; and when the number of the targets is smaller than the preset threshold, the scene information is the number of the targets when the vehicle is in a second scene.

In one possible implementation, the desired acceleration determination module 72 includes:

a state information acquisition sub-module for respectively acquiring state information of the vehicle and a target located in front of the vehicle, the state information including position information and speed information;

a desired acceleration determination sub-module for determining the desired acceleration based on the state information of the vehicle and the state information of the target.

In one possible implementation manner, the expected acceleration determining submodule includes:

a distance determining unit configured to determine a distance between the target and the vehicle based on the position information of the target and the position information of the vehicle;

a speed difference determining unit configured to determine a speed difference between the target and the vehicle based on speed information of the target and speed information of the vehicle;

and the expected acceleration determining unit is used for determining the expected acceleration according to the speed difference and the distance.

In one possible implementation, the braking mode determining module 73 includes:

the first determining submodule is used for determining that the braking mode is motor braking if the absolute value of the expected acceleration is smaller than a first threshold value when the vehicle is in a first scene, and determining that the braking mode is combined braking if the absolute value of the expected acceleration is larger than or equal to the first threshold value, wherein the combined braking is braking through hydraulic braking and motor braking together;

And the second determining submodule is used for determining that the braking mode is motor braking if the absolute value of the acceleration is smaller than a second threshold value when the vehicle is in a second scene, and determining that the braking mode is combined braking if the absolute value of the acceleration is larger than or equal to the second threshold value.

In one possible implementation, the braking module 74 includes:

the first braking submodule is used for braking the vehicle by controlling the motor of the vehicle to output negative torque if the braking mode is motor braking;

and the second braking submodule is used for controlling the motor to output expected negative torque and controlling the braking controller to output expected braking force to brake the vehicle if the braking mode is the combined braking, wherein the expected negative torque and the expected braking force are used for providing the expected acceleration for the vehicle together.

In one possible implementation manner, the apparatus further includes:

and the braking hydraulic pressure compensation module is used for carrying out braking hydraulic pressure compensation on the vehicle when the vehicle is in a first scene or the vehicle is in a second scene and the braking mode is combined braking.

In one possible implementation, the brake hydraulic pressure compensation module described above:

the monitoring sub-module is used for monitoring whether the negative torque output by the motor of the vehicle in the vehicle braking process is smaller than the expected negative torque for motor braking by the motor, and the expected negative torque is used for providing braking force for the vehicle braking by the motor;

and the compensation sub-module is used for compensating braking force required by braking through a braking controller of the vehicle if the negative torque output by the motor is lower than the expected negative torque.

For the device embodiments, since they are substantially similar to the method embodiments, the description is relatively simple, and reference should be made to the description of the method embodiments.

Fig. 8 is a schematic structural diagram of a vehicle-mounted terminal according to an embodiment of the present application. As shown in fig. 8, the in-vehicle terminal 800 of this embodiment includes: at least one processor 80 (only one shown in fig. 8), a memory 81 and a computer program 82 stored in the memory 81 and executable on the at least one processor 80, the processor 80 implementing the steps in any of the various method embodiments described above when executing the computer program 82.

The in-vehicle terminal may include, but is not limited to, a processor 80, a memory 81. It will be appreciated by those skilled in the art that fig. 8 is merely an example of the in-vehicle terminal 800 and is not intended to limit the in-vehicle terminal 800, and may include more or less components than illustrated, or may combine certain components, or different components, such as may also include input-output devices, network access devices, etc.

The processor 80 may be a central processing unit (Central Processing Unit, CPU), the processor 80 may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), off-the-shelf programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 81 may in some embodiments be an internal storage unit of the in-vehicle terminal 800, such as a hard disk or a memory of the in-vehicle terminal 800. The memory 81 may also be an external storage device of the in-vehicle terminal 800 in other embodiments, for example, a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card) or the like, which are provided on the in-vehicle terminal 800. Further, the memory 81 may also include both an internal storage unit and an external storage device of the in-vehicle terminal 800. The memory 81 is used for storing an operating system, application programs, boot loader (BootLoader), data, other programs etc., such as program codes of the computer program etc. The memory 81 may also be used to temporarily store data that has been output or is to be output.

The embodiment of the application also provides a vehicle, and the steps in the method embodiments can be executed when the vehicle is braked.

Embodiments of the present application also provide a computer readable storage medium storing a computer program which, when executed by a processor, implements steps for implementing the various method embodiments described above.

Embodiments of the present application provide a computer program product that, when run on a vehicle-mounted terminal, enables the vehicle-mounted terminal to perform the steps of the method embodiments described above.

The above embodiments are only for illustrating the technical solution of the present application, and are not limited thereto. Although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims (10)

1. A vehicle braking method, characterized by comprising:

responding to a braking instruction of a vehicle, and acquiring scene information on a current running road of the vehicle, wherein the scene information is used for representing the complexity of a braking scene faced by the vehicle;

determining a desired acceleration required for braking the vehicle, the desired acceleration being used to measure whether the vehicle can meet braking requirements solely by motor braking;

determining a braking mode of the vehicle according to the scene information and the expected acceleration;

and braking the vehicle according to the braking mode.

2. The method of claim 1, wherein the obtaining the scene information corresponding to the vehicle comprises:

identifying an object located in front of the vehicle;

determining the scene information according to the number of targets; when the number of targets is greater than or equal to a preset threshold, the scene information is the number of targets when the vehicle is in a first scene; and when the number of the targets is smaller than the preset threshold, the scene information is the number of the targets when the vehicle is in a second scene.

3. The method of claim 1, wherein the determining the desired acceleration required for braking of the vehicle comprises:

Respectively acquiring state information of the vehicle and a target positioned in front of the vehicle, wherein the state information comprises position information and speed information;

the desired acceleration is determined based on the state information of the vehicle and the state information of the target.

4. The method of claim 3, wherein the determining the desired acceleration based on the state information of the vehicle and the state information of the target comprises:

determining a distance between the target and the vehicle according to the position information of the target and the position information of the vehicle;

determining a speed difference between the target and the vehicle according to the speed information of the target and the speed information of the vehicle;

and determining the expected acceleration according to the speed difference and the distance.

5. The method of claim 2, wherein said determining a braking mode of the vehicle based on the scene information and the desired acceleration comprises:

when the vehicle is in the first scene, if the absolute value of the expected acceleration is smaller than a first threshold value, determining that the braking mode is motor braking, and if the absolute value of the expected acceleration is larger than or equal to the first threshold value, determining that the braking mode is combined braking, wherein the combined braking is braking through hydraulic braking and motor braking together;

And when the vehicle is in the second scene, determining that the braking mode is motor braking if the absolute value of the acceleration is smaller than a second threshold value, and determining that the braking mode is combined braking if the absolute value of the acceleration is larger than or equal to the second threshold value.

6. The method of claim 5, wherein said braking said vehicle according to said braking mode comprises:

if the braking mode is the motor braking mode, the motor of the vehicle is controlled to output negative torque to brake the vehicle;

and if the braking mode is the combined braking mode, the vehicle is braked by controlling the motor to output expected negative torque and controlling the braking controller to output expected braking force, wherein the expected negative torque and the expected braking force are used for providing the expected acceleration to the vehicle together.

7. The method of any one of claims 1-6, wherein after determining a braking mode of the vehicle based on the scenario information and the desired acceleration, the method further comprises:

and when the vehicle is in a first scene or the braking mode is combined braking, performing braking hydraulic pressure compensation on the vehicle.

8. The method of claim 7, wherein said compensating for brake fluid pressure for said vehicle comprises:

monitoring whether the negative torque output by a motor of the vehicle in the vehicle braking process is smaller than the expected negative torque for motor braking by the motor, wherein the expected negative torque is used for providing braking force for the vehicle braking by the motor;

and if the negative torque output by the motor is lower than the expected negative torque, compensating braking force required by braking through a braking controller of the vehicle.

9. A vehicle brake device, characterized by comprising:

the system comprises an acquisition module, a control module and a control module, wherein the acquisition module is used for responding to a braking instruction of a vehicle and acquiring scene information on the current running road of the vehicle, wherein the scene information is used for representing the complexity degree of a braking scene faced by the vehicle;

the expected acceleration determining module is used for determining expected acceleration required by braking of the vehicle, and the expected acceleration is used for measuring whether the vehicle can meet braking requirements only through motor braking;

the braking mode determining module is used for determining the braking mode of the vehicle according to the scene information and the expected acceleration;

and the braking module is used for braking the vehicle according to the braking mode.

10. A vehicle terminal comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the method according to any of claims 1-8 when executing the computer program.