CN116691660A - Vehicle and curve braking control method and system thereof - Google Patents

Vehicle and curve braking control method and system thereof Download PDF

Info

Publication number
CN116691660A
CN116691660A CN202310687864.4A CN202310687864A CN116691660A CN 116691660 A CN116691660 A CN 116691660A CN 202310687864 A CN202310687864 A CN 202310687864A CN 116691660 A CN116691660 A CN 116691660A
Authority
CN
China
Prior art keywords
vehicle
distance
collision time
actual
vehicles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310687864.4A
Other languages
Chinese (zh)
Inventor
高建平
姚晨豪
吴延峰
李炫�
史振宁
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Henan University of Science and Technology
Original Assignee
Henan University of Science and Technology
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Henan University of Science and Technology filed Critical Henan University of Science and Technology
Priority to CN202310687864.4A priority Critical patent/CN116691660A/en
Publication of CN116691660A publication Critical patent/CN116691660A/en
Pending legal-status Critical Current

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/08—Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T7/00—Brake-action initiating means
    • B60T7/12—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger
    • B60T7/22—Brake-action initiating means for automatic initiation; for initiation not subject to will of driver or passenger initiated by contact of vehicle, e.g. bumper, with an external object, e.g. another vehicle, or by means of contactless obstacle detectors mounted on the vehicle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
    • B60T8/17—Using electrical or electronic regulation means to control braking
    • B60T8/1755—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve
    • B60T8/17558—Brake regulation specially adapted to control the stability of the vehicle, e.g. taking into account yaw rate or transverse acceleration in a curve specially adapted for collision avoidance or collision mitigation
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/08—Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
    • B60W30/095—Predicting travel path or likelihood of collision
    • B60W30/0953—Predicting travel path or likelihood of collision the prediction being responsive to vehicle dynamic parameters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/08—Active safety systems predicting or avoiding probable or impending collision or attempting to minimise its consequences
    • B60W30/095—Predicting travel path or likelihood of collision
    • B60W30/0956—Predicting travel path or likelihood of collision the prediction being responsive to traffic or environmental parameters
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T2201/00—Particular use of vehicle brake systems; Special systems using also the brakes; Special software modules within the brake system controller
    • B60T2201/02—Active or adaptive cruise control system; Distance control
    • B60T2201/022—Collision avoidance systems
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
    • B60T2201/00—Particular use of vehicle brake systems; Special systems using also the brakes; Special software modules within the brake system controller
    • B60T2201/16—Curve braking control, e.g. turn control within ABS control algorithm
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2554/00—Input parameters relating to objects
    • B60W2554/80—Spatial relation or speed relative to objects

Landscapes

  • Engineering & Computer Science (AREA)
  • Transportation (AREA)
  • Mechanical Engineering (AREA)
  • Automation & Control Theory (AREA)
  • Traffic Control Systems (AREA)

Abstract

The invention belongs to the technical field of automobile braking safety, and particularly relates to a vehicle and a curve braking control method and system thereof, wherein the method is used for calculating the actual distance between two vehicles in the direction of a self-vehicle driving path when the vehicle is in curve driving; according to the actual distance between two vehicles, the front vehicle operation information of the front vehicle and the own vehicle operation information of the own vehicle, acquiring the actual collision time between the own vehicle and the front vehicle by using a safe distance model; and if the actual distance between the two vehicles is smaller than the preset safety distance or the actual collision time is smaller than the preset second collision time, controlling the self-vehicle to actively brake. According to the invention, whether the vehicle reaches the condition requiring braking is judged by combining the collision time and the distance between the vehicle and the front vehicle, so that when the two vehicle speeds are close and the collision time cannot be accurately calculated, the accurate braking of the vehicle can be realized through the safety distance, and the early braking condition is avoided based on the collision time determining process of the actual arc distance compared with the straight line distance.

Description

Vehicle and curve braking control method and system thereof
Technical Field
The invention belongs to the technical field of automobile braking safety, and particularly relates to a vehicle and a method and a system for controlling braking of a curve of the vehicle.
Background
The automatic emergency braking control of the vehicle curve refers to the problem that when the vehicle encounters a collision risk between the vehicle and a target vehicle (namely a front vehicle) in a curve scene, braking is actively carried out to ensure the running safety of the vehicle. The existing method for judging the collision risk is generally determined based on a collision time model, i.e. the collision time model is used for predicting the collision time between the own vehicle and the target vehicle, and the vehicle is actively braked when the collision time is smaller (or not exceeding) a safety time threshold. The collision time model predicts the collision time of the own vehicle and the target vehicle by obtaining the distance between the own vehicle and the target vehicle and the speed difference between the own vehicle and the target vehicle, so when the speed of the own vehicle is the same as (or approaches to the same as) the speed of the target vehicle, the result obtained based on the collision model approaches infinity, and thus the emergency braking process is not actively triggered, but there is still a risk of collision of the two vehicles in this case, for example, if the speed of the own vehicle is always faster than the speed of the target vehicle and approaches to the same, the collision between the own vehicle and the target vehicle occurs, so the predicted collision time is difficult to calculate based on the ratio of the distance to the speed difference, and the obtained collision time is inaccurate. The distance between the self-vehicle and the target vehicle in the collision time model is usually the straight line distance between the two vehicles, and when the vehicle is in a curve, the straight line distance is smaller than the actual distance, so that the predicted collision time of the self-vehicle and the target vehicle is based on the ratio of the straight line distance to the speed difference, the predicted collision time is smaller than the actual collision time, and the false action condition of early braking of the emergency braking device is caused based on the predicted collision time.
Disclosure of Invention
The invention aims to provide a vehicle and a curve braking control method and system thereof, which are used for solving the problem that when the vehicle is braked based on a collision time model, the predicted collision time is inaccurate, so that the vehicle is braked in advance when the vehicle collides or the vehicle is braked in advance when the vehicle does not have collision risk.
In order to solve the technical problems, the invention provides a vehicle curve braking control method, which comprises the following steps:
1) When the vehicle runs on a curve, calculating according to the turning radius of the vehicle and the central angle between the vehicle and the front vehicle to obtain the actual distance between the two vehicles in the direction of the running path of the vehicle;
2) According to the actual distance between two vehicles, the front vehicle operation information of the front vehicle and the own vehicle operation information of the own vehicle, acquiring the actual collision time between the own vehicle and the front vehicle by using a safe distance model;
3) And if the actual distance between the two vehicles is smaller than the preset safety distance or the actual collision time is smaller than the preset second collision time, controlling the self-vehicle to actively brake.
The beneficial effects are as follows: according to the invention, not only is the collision time used for judging whether the vehicle reaches the condition of needing braking, but also the distance between the vehicle and the front vehicle is used for judging whether the vehicle reaches the condition of needing braking, so that even if the situation that the collision time cannot be accurately determined due to the fact that the speeds of the two vehicles are similar exists, the situation that the actual distance between the two vehicles is smaller than the preset safety distance is used for determining whether the vehicle needs to be braked urgently, and the collision time and the actual distance between the two vehicles are combined for judging whether the vehicle needs to enter an emergency braking process, so that the braking process of the vehicle can be realized according to the actual distance between the two vehicles even if the speeds of the two vehicles are the same (or approach to the same), and the problem that the collision risk exists and the vehicle does not have braking is avoided. In the invention, the actual distance between two vehicles is used as the basis of distance judgment and collision time calculation, and the actual distance is the distance between the vehicle and the front vehicle in the actual running direction of the vehicle, so that the distance is more accurate compared with the linear distance between the two vehicles, the actual distance between the two vehicles is more accurate, the collision time of the two vehicles obtained based on the actual distance is more accurate, and the problem of false braking when no collision risk exists due to inaccurate collision time obtained by adopting the linear distance is avoided. The actual distance between the two vehicles is obtained based on the acquired turning radius and the central angle, wherein the central angle between the vehicle and the front vehicle is the included angle between the turning radius at the position of the vehicle and the turning radius at the position of the front vehicle to date, and the arc distance (namely the actual distance) between the vehicle and the front vehicle can be accurately determined based on the included angle and the turning radius of the vehicle, so that the result of distance judgment or collision time calculation based on the accurately determined actual distance between the two vehicles is more accurate.
Further, in step 1), the turning radius of the own vehicle is obtained according to the ratio of the own vehicle speed to the yaw rate of the own vehicle.
In the invention, the turning radius of the self-vehicle can be accurately obtained by applying the data (namely, the self-vehicle speed and the self-vehicle yaw rate) which can be directly obtained and the corresponding relation between the data and the turning radius of the self-vehicle (namely, the turning radius = the self-vehicle speed/(the self-vehicle yaw rate), and the actual distance obtained based on the turning radius is more accurate.
Further, the yaw rate of the vehicle is directly obtained through the vehicle-mounted sensor, or the yaw rate of the vehicle is obtained through calculation through the speed of the vehicle obtained through the vehicle-mounted sensor and the acceleration of the vehicle.
In the invention, when the sensor capable of acquiring the yaw rate of the vehicle exists in the vehicle-mounted sensor, the yaw rate of the vehicle can be directly acquired through the vehicle-mounted sensor, and can also be obtained by calculation based on other data acquired by the vehicle-mounted sensor when the sensor capable of directly acquiring the yaw rate of the vehicle does not exist in the vehicle-mounted sensor, and the sensors capable of acquiring the yaw rate and the acceleration of the vehicle exist in the vehicle-mounted sensor, so that the corresponding relation between the yaw rate of the vehicle and the acceleration of the vehicle is obtained by calculation by the vehicle speed and the acceleration of the vehicle, and the yaw rate of the vehicle is as follows: since the vehicle yaw rate=vehicle acceleration/vehicle speed, the vehicle yaw rate can be accurately obtained based on the acquired vehicle acceleration and vehicle speed.
Further, in step 1), the calculation formula of the actual distance S between two vehicles in the direction of the travelling path of the vehicle is:wherein θ is the central angle between the vehicle and the front vehicle, R A Is the turning radius of the bicycle.
According to the invention, the actual distances of the two vehicles in the direction of the self-vehicle driving path are obtained by applying a calculation formula of the circular arc, namely, the turning radius of the self-vehicle is taken as the radius of the circular arc, and the central angle between the self-vehicle and the front vehicle is taken as the included angle corresponding to the circular arc, so that the circular arc length can be accurately obtained by applying the calculation formula of the circular arc based on the two data, and the circular arc length is the actual distance of the two vehicles in the direction of the self-vehicle driving path required by the invention.
Further, in step 3), the safe distance model is s=s ego +S stop -S traget Wherein S is the actual distance between two vehicles, S ego S is the running distance of the self-vehicle in a set time period traget For the running distance of the front vehicle in a set time period S stop The distance between the own vehicle and the front vehicle after the set time period; s is S ego According to the self-vehicle operation information of the vehicle, S traget And calculating according to the front vehicle operation information of the front vehicle.
The safe distance model comprises the actual distance S of two vehicles and the running distance S of the own vehicle in a set time period ego Distance S of travel of preceding vehicle in set time period traget Distance S between the own vehicle and the front vehicle after the set time period stop These four parameters, three of which (S ego 、S traget S) can be calculated before and after the set time period, so that the safe distance model can obtain the distance S between the front vehicles after the set time period stop Because the distance between two vehicles is from S to S stop Can be predicted by S stop Time to 0 (i.e., collision time).
Further, the actual collision time between the own vehicle and the front vehicle is calculated through a safe distance model to obtain the distance between the own vehicle and the front vehicle after a set time period, and the collision time between the own vehicle and the front vehicle is predicted and obtained according to the actual distance between the own vehicle and the front vehicle, the distance between the own vehicle and the front vehicle after the set time period, the running information of the own vehicle and the running information of the front vehicle.
The invention can obtain the distance S between the front vehicles after the set time period through the safe distance model stop Because the distance between two vehicles is from S to S stop And at an actual distance S between two vehicles stop The own vehicle operation information and the preceding vehicle operation information acquired under the condition can be predicted by S stop Time to 0 (i.e., collision time).
Further, the prediction formula of the actual collision time TTC between the own vehicle and the preceding vehicle includes:
if a is r When=0, ttc= (S-S) stop )v r -1 ；
If a is r When it is not equal to 0,
wherein a is r The acceleration difference between the own vehicle and the front vehicle, v r Is the speed difference between the own vehicle and the front vehicle.
I.e. the invention predicts that S stop The time to 0 (i.e., collision time) is as follows: the method comprises the steps of obtaining the acceleration difference between the own vehicle and the front vehicle by using the difference between the acceleration in the own vehicle operation information and the acceleration in the front vehicle operation information, obtaining the speed difference between the own vehicle and the front vehicle by using the difference between the speed in the own vehicle operation information and the speed in the front vehicle operation information, and obtaining the speed difference between the own vehicle and the front vehicle by using the formula based on the obtained actual distance between the own vehicle and the front vehicle and the distance between the own vehicle and the front vehicle after a set time period. The above formula considers that the speed of the own vehicle is equal to (or approaches to be equal to) the speed of the front vehicle (i.e. a) r In the case of 0), in this case, the collision time is predicted using another formula, thereby avoiding the situation that the own vehicle and the front vehicle are equal in speed (or approach to the phaseEtc.), the obtained collision time is inaccurate.
Further, in step 4), if the actual distance between the two vehicles is not less than the preset safe distance and the actual collision time is less than the preset first collision time, controlling the self-vehicle alarm; the preset first collision time is longer than the preset second collision time.
The control strategy of the invention not only has the process of emergency braking under the condition of influencing the safety of the vehicle, but also reminds a driver to make corresponding reaction in a warning mode to ensure the safety running process of the vehicle under the condition that the vehicle is predicted to be close to the collision risk.
In order to solve the technical problems, the invention also provides a vehicle curve brake control system which comprises a memory and a processor, wherein the processor is used for executing instructions to realize the steps of the vehicle curve brake control method and achieve the same beneficial effects as the method.
In order to solve the technical problems, the invention also provides a vehicle, which comprises a vehicle-mounted sensor and a control device, wherein the vehicle-mounted sensor is used for acquiring the self-vehicle running information of the vehicle and the front-vehicle running information of the front vehicle and transmitting the acquired self-vehicle running information and the front-vehicle running information to the control device, and the control device comprises a memory and a processor, and the processor is used for executing instructions to realize the steps of the vehicle curve braking control method and achieve the same beneficial effects as the method.
Drawings
FIG. 1 is a flow chart of a vehicle curve brake control method of the present invention;
FIG. 2 is a control strategy diagram of the vehicle curve brake control method of the present invention;
FIG. 3 is a schematic diagram of the real distance between two vehicles in a curve scene according to the present invention;
FIG. 4a is a schematic illustration of the distance between two vehicles during the two-vehicle operation of the present invention;
FIG. 4b is a schematic diagram of two vehicles when reaching a preset first collision time during the two-vehicle running process according to the present invention;
FIG. 4c is a schematic diagram of two vehicles when reaching a preset second collision time during the two-vehicle running process according to the present invention;
FIG. 4d is a schematic diagram of the two-vehicle situation at the end of the two-vehicle braking process during two-vehicle operation according to the present invention;
fig. 5 is a schematic view of a longitudinal safe distance model in a following scene of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent.
Vehicle embodiment:
in order to avoid the problem of braking in advance when no braking occurs or collision risk does not occur during automatic emergency braking control of a vehicle in a curve of the vehicle, the vehicle in this embodiment not only judges whether the vehicle reaches a condition requiring braking by applying the collision time, but also judges whether the condition requiring braking is achieved by the distance between the vehicle and the front vehicle, so that even if the two vehicles have similar vehicle speeds and the collision time cannot be accurately determined, whether the vehicle needs to be braked in an emergency manner can be determined by the fact that the actual distance between the two vehicles is smaller than the preset safety distance. In the invention, the actual distance between two vehicles is used as the basis of distance judgment and collision time calculation, and the actual distance is the distance between the vehicle and the front vehicle in the actual running direction of the vehicle, so that the distance is more accurate compared with the linear distance between the two vehicles, the actual distance between the two vehicles is more accurate, the collision time of the two vehicles obtained based on the actual distance is more accurate, and the problem of false braking when no collision risk exists due to inaccurate collision time obtained by adopting the linear distance is avoided.
Specifically, the vehicle of the embodiment includes a sensing module (i.e. a vehicle-mounted sensor) including a camera, a laser radar and a millimeter wave radar, for acquiring data such as speed, acceleration, distance, etc. of the vehicle and the target vehicle; comprises a decision module, mainly a vehicle-mounted ECU, which is used for determining the arc distance between the own vehicle and the target vehicle in a curve scene according to the detection data obtained by the perception module, judging whether the minimum safety distance is reached or not according to the longitudinal safety distance model, calculating a TTC value of pre-collision time, and sending an early warning and braking force control instruction to the vehicle according to the safety distance and a set TTC threshold value; the system comprises an execution module, wherein the execution module comprises an early warning system and a braking system, and is used for sending out early warning according to an early warning signal output by a decision module and braking according to a braking signal output by the decision module, and when the calculated TTC reaches the TTC 1 When the threshold value (namely the preset first collision time) is reached, the early warning system sends out early warning; when the calculated TTC value reaches TTC 2 At the threshold value (i.e., the preset second collision time), the vehicle speed is controlled by controlling the throttle opening degree and braking is performed by controlling the master cylinder pressure. I.e. in this embodiment by means of a perception module such as: the camera, the information (information such as position, speed and acceleration) of pedestrian or vehicle in front of the real-time detection of laser radar or millimeter wave radar, confirm early warning and AEB braking intervention's opportunity according to decision-making module (including safe distance model and collision time model), send early warning and brake through actuating mechanism.
The vehicle can only determine the straight line distance between the vehicle and the target vehicle through the sensing module, but the arc line distance between the vehicle and the target vehicle in a curve scene cannot be accurately and directly obtained, the emergency braking strategy based on the safety distance model can intervene and brake relatively early for the operation of a driver, the safety is relatively high compared with the collision time strategy, and compared with the braking strategy, the early warning based on the collision time is more flexible and can improve the comfort of the driver. The cooperative strategy combined with the two can simultaneously improve the comfort of driving the vehicle and the safety of running.
Specifically, the steps of the method for performing vehicle curve brake control by the vehicle of the present embodiment are shown in fig. 2:
1) And acquiring the speed, the position and the braking condition of the self-vehicle by using the vehicle-mounted information sensing module, and calculating the real distance and the collision time according to the speed of the self-vehicle and the distance between the speed of the target vehicle and the self-vehicle.
In this embodiment, the position, speed and acceleration of the own vehicle and the target vehicle are detected, the arc distance between the own vehicle and the target is calculated, and the safe distance between the two vehicles is determined and the collision time is calculated according to the detected information of the own vehicle and the target vehicle.
Specifically, the calculation of the arc distance between the vehicle and the target vehicle in the curve scene is as follows:
according to the vehicle driving in a curve: vt=rωt, and according to the circular motion centripetal force formula: f=ma y ＝mrω 2 Can obtain rω 2 ＝a y Further, itSubstituting this formula into vt=rωt gives +.>Where v is the vehicle speed, ω is the vehicle yaw rate, r is the vehicle turning radius, m is the vehicle mass, a y Since the above equation yields the vehicle turning radius calculation equation used in the present embodiment, the vehicle acceleration can be identified as: />Wherein R is n For turning radius of vehicle, V n Omega, the speed of the vehicle n The yaw rate of the vehicle in the present embodiment can be obtained by not only the above +.>Formula acquisition is also possible by havingThe vehicle-mounted sensor that acquires the yaw rate of the vehicle directly acquires.
Application of calculation formula based on turning radius of vehicleThe actual distance S between two vehicles (the vehicle and the front vehicle) in the running path direction of the vehicle can be calculated by the formula of (1), wherein theta is the central angle between the vehicle and the front vehicle, R A For turning radius of the vehicle (+)>V A For speed of the vehicle omega A Yaw rate of the own vehicle), and specifically a parameter diagram is shown in fig. 3. The central angle between the own vehicle and the front vehicle in the embodiment is that after the turning radius of the own vehicle and the target vehicle (i.e. the front vehicle) is determined, the two vehicles travel on the same curve lane, and R can be determined when the turning radius and the positions of the two vehicles are determined A R is as follows B (R B For the turning radius of the front vehicle +.>V B For speed of preceding vehicle omega B Yaw rate of the preceding vehicle) extends from the center of mass of the vehicle to the center of circle of the circular motion it is traveling, R A And R is R B Forming an intersection point, wherein the angle theta between the intersection points is the required central angle. The vehicle in the present stage can obtain the position information of the front vehicle and the vehicle by the vehicle-mounted sensor, and then the vehicle-mounted ECU processes the obtained data to determine the specific value of theta, namely, the central angle theta is calculated based on the position information of the front vehicle and the vehicle and then the geometric relationship is applied.
In this embodiment, the actual distances of the two vehicles in the direction of the travelling path of the vehicle are obtained by applying a calculation formula of the arc, that is, the radius of the arc is the turning radius of the vehicle, and the central angle between the vehicle and the front vehicle is the included angle corresponding to the arc.
The calculation formula for determining the collision time of two vehicles in this embodiment is obtained through the following process:
as shown in FIG. 5, due to the minimum safe distance S safe To meet S safe ≥S ego +S stop -S traget Wherein S is traget For the minimum braking distance of the target vehicle, S stop Is the distance between two vehicles after braking, S ego For the distance travelled by the vehicle during the whole emergency braking,and s=s ego +S stop -S traget Thus->Wherein v is 1 For the speed of the vehicle, v 2 For target vehicle speed, T 1 For braking time of bicycle, T 2 A is the braking time of the front vehicle 1 For self-vehicle acceleration, a 2 Is the target vehicle acceleration. Based on this->The calculation formula of the TTC value of the pre-collision time can be obtained, namely
If a is r =0, at which point:
TTC＝(S-S stop )v r -1 ；
if a is r Not equal to 0, at this time:
wherein v is r ＝v 1 -v 2 ，a r ＝a 1 -a 2 ，a r For the difference in acceleration (relative acceleration) between the host vehicle and the target vehicle, v r Is the speed difference (relative speed) between the host vehicle and the target vehicle. The minimum safe distance from the scene can be determined according to the speed of the own vehicle and the speed of the target vehicle. Self-propelled vehicle and targetThe vehicle speed difference is obtained by calculating the vehicle speed detected by the vehicle-mounted sensor through the vehicle-mounted ECU.
Namely, the manner in which the collision time is obtained in this embodiment is: the method comprises the steps of obtaining the acceleration difference between the own vehicle and the front vehicle by using the difference between the acceleration in the own vehicle operation information and the acceleration in the front vehicle operation information, obtaining the speed difference between the own vehicle and the front vehicle by using the difference between the speed in the own vehicle operation information and the speed in the front vehicle operation information, and obtaining the speed difference between the own vehicle and the front vehicle by using the formula based on the obtained actual distance between the own vehicle and the front vehicle and the distance between the own vehicle and the front vehicle after a set time period. The above formula considers that the speed of the own vehicle is equal to (or approaches to be equal to) the speed of the front vehicle (i.e. a) r In the case of 0), the collision time is predicted by applying another formula, and thus the problem of inaccurate collision time obtained when the own vehicle and the front vehicle are equal in speed (or approach to be equal) is avoided.
2) Based on the calculated collision time and the set TTC 1 Judging whether to send out early warning to remind a driver to brake or not by a threshold (namely presetting first collision time); according to minimum safety distance and time to collision TTC 2 The threshold (i.e., the preset second collision time) determines whether to control the AEB system to intervene in braking.
Fig. 4a, 4b, 4c and 4d are schematic views of two-vehicle positions at different periods during the running of the vehicle.
As shown in fig. 1, in this embodiment, when the distance between the own vehicle and the target vehicle reaches the minimum safe distance, a braking force control command is sent to the actuator by the decision module to implement braking.
When the calculated TTC value of the own vehicle and the target vehicle reaches TTC 1 At threshold (as in fig. 4 b), the host vehicle issues an alarm through the decision module, alerting the driver to apply the braking operation.
When the calculated TTC value of the own vehicle and the target vehicle reaches TTC 2 When the threshold value is reached (as shown in fig. 4 c), the decision module directly sends a braking force control command to the executing mechanism to brake.
And judging whether the driver takes braking measures after the early warning, if not, calculating collision time again to judge, and if so, judging whether the minimum safety distance is reached again based on the longitudinal safety distance model.
The control strategy of the invention not only has the process of emergency braking under the condition of influencing the safety of the vehicle, but also reminds a driver to make corresponding reaction in a warning mode to ensure the safety running process of the vehicle under the condition that the vehicle is predicted to be close to the collision risk.
According to the invention, not only is the collision time used for judging whether the vehicle reaches the condition of needing braking, but also the distance between the vehicle and the front vehicle is used for judging whether the vehicle reaches the condition of needing braking, so that even if the situation that the collision time cannot be accurately determined due to the fact that the speeds of the two vehicles are similar exists, the situation that the actual distance between the two vehicles is smaller than the preset safety distance is used for determining whether the vehicle needs to be braked urgently, and the collision time and the actual distance between the two vehicles are combined for judging whether the vehicle needs to enter an emergency braking process, so that the braking process of the vehicle can be realized according to the actual distance between the two vehicles even if the speeds of the two vehicles are the same (or approach to the same), and the problem that the collision risk exists and the vehicle does not have braking is avoided. In the invention, the actual distance between two vehicles is used as the basis of distance judgment and collision time calculation, and the actual distance is the distance between the vehicle and the front vehicle in the actual running direction of the vehicle, so that the distance is more accurate compared with the linear distance between the two vehicles, the actual distance between the two vehicles is more accurate, the collision time of the two vehicles obtained based on the actual distance is more accurate, and the problem of false braking when no collision risk exists due to inaccurate collision time obtained by adopting the linear distance is avoided. The invention obtains the actual distance between two vehicles based on the acquired turning radius and central angle, wherein the central angle between the vehicle and the front vehicle is the turning radius and the front vehicle at the position of the vehicleThe included angle between the turning radius of the vehicle and the turning radius of the vehicle can be accurately determined based on the included angle and the turning radius of the vehicle, so that the result of distance judgment or collision time calculation based on the accurately determined actual distance between the two vehicles is more accurate. The invention obtains the state information of the self-vehicle and the target vehicle through the sensing module by utilizing the method of combining the safe distance model and the collision time model, determines the execution strategy to be adopted through the processing judgment of the vehicle-mounted ECU on the information, and when the motor vehicle and the target vehicle reach the minimum safe distance, the AEB actively intervenes in braking, and when the collision time reaches the set TTC 1 With TTC 2 And when the threshold value is reached, the motor vehicle sends out early warning to remind the driver of braking and AEB active intervention, so that the reliability of emergency braking and the driving safety are improved.
Vehicle curve brake control method embodiment:
when the vehicle runs on a curve, the method of the embodiment calculates the actual distance between two vehicles in the running path direction of the vehicle according to the turning radius of the vehicle and the central angle between the vehicle and the front vehicle; according to the actual distance between two vehicles, the front vehicle operation information of the front vehicle and the own vehicle operation information of the own vehicle, acquiring the actual collision time between the own vehicle and the front vehicle by using a safe distance model; and if the actual distance between the two vehicles is smaller than the preset safety distance or the actual collision time is smaller than the preset second collision time, controlling the self-vehicle to actively brake.
The invention not only uses the collision time to judge whether the vehicle reaches the condition of needing braking, but also judges whether the vehicle reaches the condition of needing braking through the distance between the vehicle and the front vehicle, so even if the situation that the collision time cannot be accurately determined due to the fact that the speeds of the two vehicles are similar exists, the situation that the actual distance between the two vehicles is smaller than the preset safety distance can also be used for determining whether the vehicle needs to be braked urgently, and therefore, the invention combines the collision time and the actual distance between the two vehicles to judge whether the vehicle needs to enter the process of urgent braking, and ensures that the braking process of the vehicle can be realized by using the actual distance between the two vehicles as the basis even when the speeds of the two vehicles are the same (or approach to the same), thereby avoiding the problem that the collision risk exists and no braking exists. In the invention, the actual distance between two vehicles is used as the basis of distance judgment and collision time calculation, and the actual distance is the distance between the vehicle and the front vehicle in the actual running direction of the vehicle, so that the distance is more accurate compared with the linear distance between the two vehicles, the actual distance between the two vehicles is more accurate, the collision time of the two vehicles obtained based on the actual distance is more accurate, and the problem of false braking when no collision risk exists due to inaccurate collision time obtained by adopting the linear distance is avoided. And in particular the vehicle curve brake control method steps have been described in detail in the vehicle embodiments and will not be described in detail here.
Vehicle curve brake control system embodiment:
the system of the present embodiment includes a memory and a processor, where the processor is configured to execute instructions to implement the steps of the vehicle curve brake control method, and the steps of the vehicle curve brake control method are described in detail in the vehicle embodiment, which is not described herein.
The above description is only a preferred embodiment of the present invention, and the patent protection scope of the present invention is defined by the claims, and all equivalent structural changes made by the specification and the drawings of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A vehicle curve brake control method, characterized by comprising the steps of:
1) When the vehicle runs on a curve, calculating according to the turning radius of the vehicle and the central angle between the vehicle and the front vehicle to obtain the actual distance between the two vehicles in the direction of the running path of the vehicle;
2) According to the actual distance between two vehicles, the front vehicle operation information of the front vehicle and the own vehicle operation information of the own vehicle, acquiring the actual collision time between the own vehicle and the front vehicle by using a safe distance model;
3) And if the actual distance between the two vehicles is smaller than the preset safety distance or the actual collision time is smaller than the preset second collision time, controlling the self-vehicle to actively brake.
2. The vehicle curve brake control method according to claim 1, characterized in that in step 1), the turning radius of the own vehicle is obtained from a ratio of an own vehicle speed to an own vehicle yaw rate.
3. The vehicle curve brake control method according to claim 2, characterized in that the own vehicle yaw rate is obtained directly by an in-vehicle sensor or is calculated from the own vehicle speed obtained by the in-vehicle sensor and the own vehicle acceleration.
4. The vehicle curve brake control method according to claim 1, wherein in step 1), the calculation formula of the two-vehicle actual distance S in the direction of the own-vehicle travel path is:wherein θ is the central angle between the vehicle and the front vehicle, R A Is the turning radius of the bicycle.
5. The vehicle curve brake control method according to claim 1, characterized in that in step 3), the safe distance model is s=s ego +S stop -S traget Wherein g is the actual distance between two vehicles, S ego S is the running distance of the self-vehicle in a set time period traget For the running distance of the front vehicle in a set time period S stop The distance between the own vehicle and the front vehicle after the set time period; s is S ego According to the self-vehicle operation information of the vehicle, S traget And calculating according to the front vehicle operation information of the front vehicle.
6. The method according to claim 5, wherein the actual collision time between the host vehicle and the preceding vehicle is calculated by a safe distance model to obtain the distance between the host vehicle and the preceding vehicle after a set period of time, and the collision time between the host vehicle and the preceding vehicle is predicted based on the actual distance between the host vehicle and the preceding vehicle after the set period of time, the distance between the host vehicle and the preceding vehicle, the host vehicle running information, and the preceding vehicle running information.
7. The vehicle curve brake control method according to claim 6, wherein the prediction formula of the actual collision time TTC of the own vehicle with the preceding vehicle includes:
if a is r When=0, ttc= (S-S) stop )v r -1 ；
If a is r When it is not equal to 0,
wherein a is r The acceleration difference between the own vehicle and the front vehicle, v r Is the speed difference between the own vehicle and the front vehicle.
8. The method according to claim 1, wherein in step 4), if the actual distance between the two vehicles is not less than the preset safe distance and the actual collision time is less than the preset first collision time, the vehicle-by-vehicle warning is controlled; the preset first collision time is longer than the preset second collision time.
9. A vehicle curve brake control system comprising a memory and a processor, wherein the processor is adapted to execute instructions to implement the vehicle curve brake control method steps of any one of claims 1 to 8.
10. A vehicle comprising an in-vehicle sensor for acquiring own vehicle running information of the vehicle and front vehicle running information of a preceding vehicle and transmitting the acquired own vehicle running information and front vehicle running information to a control device comprising a memory and a processor, characterized in that the processor is adapted to execute instructions to implement the vehicle curve brake control method steps of any one of claims 1 to 8.
CN202310687864.4A 2023-06-09 2023-06-09 Vehicle and curve braking control method and system thereof Pending CN116691660A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310687864.4A CN116691660A (en) 2023-06-09 2023-06-09 Vehicle and curve braking control method and system thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310687864.4A CN116691660A (en) 2023-06-09 2023-06-09 Vehicle and curve braking control method and system thereof

Publications (1)

Publication Number Publication Date
CN116691660A true CN116691660A (en) 2023-09-05

Family

ID=87825246

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310687864.4A Pending CN116691660A (en) 2023-06-09 2023-06-09 Vehicle and curve braking control method and system thereof

Country Status (1)

Country Link
CN (1) CN116691660A (en)

Similar Documents

Publication Publication Date Title
US10864909B2 (en) Vehicle control method and vehicle control system
US10996672B2 (en) Driving control apparatus for vehicle
CN107415945B (en) Automatic driving system for evaluating lane change and using method thereof
US20200231152A1 (en) Vehicle driving support apparatus
US11938924B2 (en) Driving assistance control apparatus for vehicle, driving assistance control system for vehicle, and driving assistance control method for vehicle
US8548709B2 (en) Drive assisting device
JP7176415B2 (en) Pre-collision control device
CN113942499B (en) Collision avoidance aid
EP2799302A1 (en) Vehicle driving assistance device
JP7470588B2 (en) Collision avoidance support device
JP2008514937A (en) Vehicle start-up support system
US20210370924A1 (en) Driving assistance apparatus
JP2020097346A (en) Travel control device for vehicle
CN111645649A (en) Method for controlling a vehicle fleet during emergency braking
JP3602337B2 (en) Vehicle travel control device
EP4375155A2 (en) Collision avoidance support apparatus
CN114834444A (en) Vehicle control device
JP7140092B2 (en) Driving support device
JP7196448B2 (en) Collision control device
CN116691660A (en) Vehicle and curve braking control method and system thereof
JP5018411B2 (en) Vehicle tracking device
JP7433734B2 (en) Driving support device
CN111565961A (en) Method for controlling a vehicle
US20240140411A1 (en) Vehicle control apparatus
JP3951970B2 (en) Vehicle travel control device

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination