Detailed Description
In order to make the technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of exemplary embodiments of the present application is provided in conjunction with the accompanying drawings, and it is apparent that the described embodiments are only some embodiments of the present application and not exhaustive of all embodiments. It should be noted that, without conflict, the embodiments of the present application and features of the embodiments may be combined with each other.
Example 1
As shown in fig. 1, the present embodiment proposes a traffic light-free left-turn scene vehicle passing method, which includes:
s101, screening collision vehicles of the unprotected intersection in front of the running direction of the self vehicle, and obtaining collision track points where collision possibility exists between the self vehicle and the collision vehicles.
Specifically, an intersection is a road section with a relatively complex traffic condition. The vehicles come from four sides of the southeast and the northwest, and various crossing conditions are easy to generate. Particularly at intersections without traffic lights, accident-prone sections are common. The vehicle passing method provided by the embodiment is applicable to a left turn scene of a vehicle without a signal lamp.
In the present embodiment, as shown in fig. 2, the own vehicle 1 travels to the intersection, and will make a left turn without a signal lamp. At this time, another vehicle, i.e., the collision vehicle 2, appears in front of the own vehicle 1. If the collision vehicle 2 moves straight normally, it collides with the own vehicle 1 at a certain position at the intersection. Therefore, when the collision vehicle 2 is represented as another vehicle that may collide with the own vehicle 1 when the own vehicle 1 turns left at the unprotected intersection, the position where the two vehicles may collide is the collision trajectory point 3. The position where the collision trajectory point 3 occurs may be determined comprehensively according to the traveling route, traveling speed, vehicle size, and the like of the own vehicle 1 and the collision vehicle 2.
However, it is not necessarily possible to attribute all vehicles that appear in front of the own vehicle 1 to the collision vehicle 2. Only vehicles that present in front of the own vehicle 1 and present a risk of collision with the own vehicle 1 can be analyzed as collision vehicles 2. Therefore, it is necessary to screen out conflicting vehicles among all vehicles in front of the own vehicle 1. In order to screen the conflicting vehicles 2, first, the present embodiment acquires the motion states of all vehicles within the unprotected intersection area, including the current vehicle speed and acceleration information. Then, a period of time is taken to generate predicted motion trajectories of all vehicles through a traditional kinematic model. Next, an intersection point with the motion trajectory of the own vehicle 1, which is a trajectory point that is likely to collide with the own vehicle 1, i.e., a collision trajectory point 3, among all the predicted motion trajectories of the vehicles is selected. Finally, the vehicles with the conflict track points 3 are screened out to be the conflict vehicles 2, and the conflict vehicles can be represented by a vehicle setCo-ordination of->And (5) a vehicle.
S102, acquiring a motion state of the self vehicle and a motion state of the conflict vehicle, and determining the passing sequence of the self vehicle and the conflict vehicle according to the motion state of the self vehicle, the motion state of the conflict vehicle and the positions of the conflict track points.
In particular, currently, motor vehicles are classified into various categories such as class a, class B, sports cars, SUVs, etc. in different dimensions according to the driving style, size parameters, characteristics of the driving scene. In general, the most intuitive way to determine the class of motor vehicle is by vehicle size parameters. The difference in vehicle size parameters can cause the overall component layout, configuration parameters, etc. of the motor vehicle to be affected. For the present embodiment, the difference in physical dimensions of the vehicle may cause an expansion or contraction of the safety area thereof, and the safety threshold with the surrounding vehicle may also be affected. Because of this, due to the variability in physical dimensions (length, width, height, etc.) of the vehicles, if a collision of the vehicles occurs, it is inevitable that the position and time of the collision of the vehicles are also affected to some extent. For example, if two vehicles with a long length collide laterally, the collision position is the middle position (front-rear range of the B pillar) between the vehicle head and the vehicle, and if two vehicles with a short length collide laterally at the same speed under the same scene, the collision position may be the vehicle head and the vehicle tail. Moreover, there is a difference in the time of collision in the two scenes. Therefore, the present embodiment first determines the own-vehicle safety zone 5 and the conflicting-vehicle safety zone 6 according to the physical dimensions of the own vehicle 1 and the conflicting vehicle 2, the inter-vehicle distance requirement, and the compliance gimmick requirement, as shown in fig. 3. The safety area may be specifically expressed as:
wherein,for the safety zone boundary of the vehicle in the longitudinal direction, +.>For the length of the car, add>Is the minimum distance between vehicles>Gifting threshold value for length direction traffic rules, +.>Is the minimum distance between vehicles minimum threshold value, +.>For the vehicle model related constant coefficients +.>The vehicle speed is the vehicle speed, whereby the safety zone boundary of the vehicle in the longitudinal direction can be determined. In a similar manner, the safety zone boundary in the width direction can also be determined:
wherein,for the safety zone boundary of the vehicle in the width direction, +.>For the width of the vehicle>The threshold is gifted for the width direction traffic rules.
The own vehicle safety zone 5 and the collision vehicle safety zone 6 can be obtained by the above-described process. Dividing the own vehicle safety zone 5 and the collision vehicle safety zone 6 into a plurality of side lengthsFor ease of calculation, it is preferably divided into squares, as shown in fig. 3. The number of rectangular squares of the area 7 where the two-vehicle safety area overlaps is predicted when both the own vehicle 1 and the collision vehicle 2 reach the collision trajectory point 3. If and only if the number of overlapping holding blocks +.>Less than a preset overlap amountWhen the overlap occurs at the tail of the own vehicle 1, the own vehicle 1 passes through the collision vehicle 2 before the collision vehicle 2, and in other cases, the collision vehicle 2 passes through the collision vehicle. Of course, the present embodiment only adopts a rectangular square manner to exemplify the vehicle safety area, so that the figure is shown more clearly and the calculation process is simpler. In practical application, the shape of the region division can be set according to various factors such as road conditions, software algorithms and the like, triangle, diamond, circle and the like can be realized, and the embodiment is not particularly limited.
The passing sequence determining process of the embodiment does not depend on V2V communication, specifically corrects an iteration form, and can be suitable for a scene with collision risks with a plurality of slave vehicles and can be suitable for a mixed traffic scene.
In this embodiment, the requirements of the inter-vehicle distance and the compliance and legal requirements are set to strictly comply with the requirements of laws and regulations such as the road safety law, so as to ensure that the vehicle passing method provided by this embodiment ensures that the vehicle passes through the intersection without traffic lights safely on the premise of ensuring compliance with the discipline.
S103, generating a conflict relation between the self vehicle and the conflict vehicle according to the traffic sequence and correcting in real time.
Specifically, the collision relationship of the own vehicle 1 and the collision vehicle 2 may be generated according to the above-determined traffic sequence. In this embodiment, the collision relationship is represented by a travel time-boundary position-preceding vehicle sequence array:
wherein,representing predicted conflict occurrence time, +.>Represents boundary position +.>Representing conflicting vehicle sequence identifications.
Thus, it is possible to obtain the collision relationship of the own vehicle 1 for coping with each collision vehicle, that is. The numbering is carried out in such a way that the occurrence times of the predicted conflicts are ordered in the order of magnitude, i.e. +.>Representing that the own vehicle 1 first collides with the first colliding vehicle, and so on.
After determining the passing sequence of the self vehicle 1 and the first collision vehicle, the collision relation of the subsequent collision vehicles is corrected, and the correction method is that the boundary position of the second collision vehicle is taken as follows:
wherein,representing a second conflicting vehicle at +.>Predicting a time of dayBoundary position->Representing a first conflicting vehicle at +.>Boundary position of predicted time, +_>A constant for the desired traffic speed, thereby avoiding unnecessary acceleration and deceleration.
The embodiment introduces a running time-boundary position-front vehicle sequence array to describe the conflict relation between the vehicle and the conflict vehicle, and reduces the frequent acceleration and deceleration problem of the vehicle caused by conflict processing through correcting the array, thereby improving the running comfort.
Further, in the process of generating the collision relationship between the own vehicle 1 and the collision vehicle 2, the predicted collision time when the own vehicle 1 and the collision vehicle 2 collide at the collision track point 3 can be obtained according to the motion state of the own vehicle 1 and the motion state of the collision vehicle 2. If the own vehicle 1 passes before the collision vehicle 2, it is to be in +.>Time to reach the upper boundary of the boundary position of the own vehicle 1 +.>：
Wherein,for conflicting vehicles 2->Position of moment in own vehicle 1 coordinate system, own vehicleThe conflicting relation that the vehicle 1 generates for coping with the conflicting vehicle 2 can be expressed as +.>. If the collision vehicle 2 passes before the own vehicle 1, the own vehicle 1 is to be in +.>Time of arrival at the boundary position lower boundary +.>：
The collision relationship generated by the own vehicle 1 for coping with the collision vehicle 2 can be expressed as。
Repeating the above procedure for all the conflict track points 3 having the conflict for the conflict vehicle 2, if the conflict vehicle 2 has the conflict vehicle 1 let go at the conflict track point 3, thenTaking the smallest one of all lower boundaries; if not, then->The smallest one of all the upper boundaries is taken.
And S104, controlling the self vehicle to turn left to pass through the unprotected intersection at the front of the driving direction according to the conflict relation.
Specifically, first, the tracking error between the own vehicle 1 and the conflicting vehicle 2 is established according to the traffic sequence and the conflicting relationship. Assuming that the own vehicle 1 has advanced to the point where a collision with the conflicting vehicle 2 is imminent, the inter-vehicle distance error may be expressed as:
wherein,for time (I)>Is constant, indicating the desired inter-vehicle distance; />Representing the distance of the own vehicle 1 from the collision trajectory point 3; />Representing the distance of the collision vehicle 2 from the collision track point 3; />Representing the body length of the own vehicle 1; />Is the speed of the own vehicle 1; />As long as the own vehicle 1 adjusts the inter-vehicle distance to the desired inter-vehicle distance before the collision time predicted to occur with the collision vehicle 2, the own vehicle 1 can avoid collision with the collision vehicle 2, as a constant related to the convergence time. Similarly, the own vehicle 1 can avoid collision with each collision vehicle successively, and when the own vehicle 1 completes collision avoidance with one collision vehicle, the collision vehicle sequence identification is switched, and a tracking error is established with the collision vehicle which is about to collide next.
Then, a vehicle longitudinal dynamics model is established:
wherein,the vehicle speed is the vehicle speed; />Is a vehicle driving force or braking force; />Is the vehicle mass; />Is an air resistance item; />Is the rolling resistance and the ramp resistance term.
And finally, substituting the tracking error into the established longitudinal dynamics model of the vehicle to construct a nonlinear tracking error dynamics model.
According to the nonlinear tracking error dynamics model constructed above, the following vehicle driving force is designed:
wherein,is the vehicle spacing error; />Is a constant coefficient.
Under the action of the driving force of the vehicle, the vehicle distance errorAccording to differential equation->Convergence from initial error, pass->Time convergence to an acceptable error threshold +.>Within the range, thus can be adjusted->So that the time of convergence within the acceptable error range does not exceed the collision time, thereby ensuring the running safety.
The method can ensure convergence in limited time in the process of calculating the driving force, can strictly ensure collision avoidance of the vehicle and the collision vehicle by combining with prediction of collision occurrence time, and is a powerful support for deployment of the method in actual scenes.
The present embodiment can send the above-described driving force of the own vehicle 1 to the control unit of the power system through the controller, and this desired driving force of the own vehicle 1 is executed by the power system, thereby controlling the own vehicle 1 to turn left through the unprotected intersection.
In addition, the present embodiment can also acquire the current position of the own vehicle 1 before screening the conflicting vehicles at the unprotected intersection ahead of the own vehicle in the traveling direction. The current position of the own vehicle 1 can be acquired by recognition of an on-vehicle high-precision map and a positioning apparatus. The motion trajectory of the own vehicle 1 may be constructed by means of a conventional dynamics model, which is not described in detail in the present embodiment.
Further, during the traveling of the own vehicle 1, whether or not the protected intersection exists in a certain preset range in front of the traveling direction can be determined by the vehicle-mounted high-precision map and the positioning device. When an unprotected intersection exists, the own vehicle 1 may send a traffic request to the roadside management unit 4 through a vehicle-to-road (V2I) communication technology. The roadside management unit 4 returns an instruction of whether or not to pass. If the vehicle cannot pass, stopping the vehicle 1 at the entrance of the unprotected intersection; if the traffic is possible, the above steps are performed.
The implementation architecture of the traffic light-free left-turn scene vehicle passing method provided by the embodiment is mainly divided into a traffic decision layer, a sequence decision layer and a dynamics control layer. The traffic decision layer is used for determining whether the self vehicles pass from the top layer angle; the sequence decision layer is used for determining the passing sequence of the self vehicle and the conflict vehicle; the dynamics control layer is used for solving the expected driving force of the self vehicle from the perspective of distributed control and realizing the expected driving force through a power system. According to the method and the device for determining the traffic sequence, the traffic sequence is determined by combining the motion states of the self vehicle and the collision vehicle, and meanwhile, the collision relation between the self vehicle and the collision vehicle is established and corrected in real time, so that the frequent acceleration and deceleration conditions of the vehicle caused by collision processing can be reduced, and the travelling comfort is improved on the basis of smoothly solving the traffic problem of a left turn scene without a signal lamp. In addition, the embodiment adopts a nonlinear dynamics model to obtain the driving force of the vehicle, and the driving force is more in line with the characteristics of the vehicle compared with the traditional kinematics model, so that the safety of the vehicle in the left turning process is improved.
Example 2
Corresponding to embodiment 1, this embodiment proposes a traffic light-free left-turn scene vehicle passing system, as shown in fig. 4, comprising:
a collision vehicle screening unit for screening collision vehicles at unprotected intersections in front of the running direction of the own vehicle and obtaining collision track points where collision possibility exists between the own vehicle and the collision vehicles;
the passing sequence determining unit is used for obtaining the motion state of the self vehicle and the motion state of the conflict vehicle and determining the passing sequence of the self vehicle and the conflict vehicle according to the motion state of the self vehicle, the motion state of the conflict vehicle and the positions of the conflict track points;
the conflict relation generation and correction unit is used for generating the conflict relation between the self vehicle and the conflict vehicle according to the passing sequence and carrying out real-time correction;
and a control unit for controlling the left turn of the own vehicle to pass through the unprotected intersection in front of the driving direction according to the conflict relation.
Further, the system further comprises:
the self vehicle motion trail generation unit is used for acquiring the current position of the self vehicle and generating the motion trail of the self vehicle;
wherein, the control unit specifically still includes:
the dynamics model building unit is used for building a nonlinear tracking error dynamics model according to the conflict relation and the motion states of the self vehicle and the conflict vehicle;
a driving force determination unit configured to determine a driving force of the own vehicle based on the nonlinear tracking error dynamics model;
and a driving force control unit for controlling the left turn of the own vehicle to pass through the unprotected intersection at the front of the running direction according to the driving force of the own vehicle.
Specifically, the traffic light-free left-turn scene vehicle passing system provided by the embodiment is mainly divided into a traffic decision layer, a sequence decision layer and a dynamics control layer. The traffic decision layer is used for determining whether the self vehicle passes from the top layer angle and comprises a self vehicle motion track generating unit; the sequence decision layer is used for determining the passing sequence of the self vehicle and the conflict vehicle and comprises a conflict vehicle screening unit, a passing sequence determining unit and a conflict relation generating and correcting unit; the dynamics control layer is used for solving the expected driving force of the vehicle from the perspective of distributed control and realizing the expected driving force through a power system, and mainly comprises a dynamics model building unit, a driving force determining unit and a driving force control unit.
In this embodiment, the collision vehicle is represented as another vehicle that may collide with the own vehicle when the own vehicle turns left at the unprotected intersection, and the position where the two vehicles may collide is the collision track point. In order to screen conflicting vehicles, first, the present embodiment obtains the motion states of all vehicles in the unprotected intersection area range, including the current vehicle speed and acceleration information. Then, a period of time is taken to generate predicted motion trajectories of all vehicles through a traditional kinematic model. And then, selecting an intersection point with the motion track of the own vehicle in the predicted motion tracks of all vehicles, wherein the intersection point is a track point possibly colliding with the own vehicle, namely a collision track point. And finally, screening the vehicles with the conflict track points to obtain the conflict vehicles.
Due to the variability in physical dimensions (length, width, height, etc.) of vehicles, if a vehicle collides, it is inevitable that the position and time of the collision of the vehicle are also affected. Therefore, the present embodiment first determines the own-vehicle safety area and the conflicting-vehicle safety area according to the physical dimensions of the own vehicle and the conflicting vehicle, the inter-vehicle distance requirement, and the compliance gimmick requirement. And dividing the safety area of the vehicle and the safety area of the collision vehicle into a plurality of rectangular blocks. The number of rectangular squares of the area where the two-vehicle safety area overlaps when both the own vehicle and the collision vehicle reach the collision trajectory point is predicted. If and only if the number of overlapped holding blocks is smaller than the preset overlapped number, and the overlapped part occurs at the tail of the vehicle, the vehicle passes before the collision vehicle, and otherwise, the collision vehicle passes before the collision vehicle.
A collision relationship between the own vehicle and the collision vehicle can be generated according to the determined traffic sequence. In this embodiment, the collision relationship is represented by a travel time-boundary position-preceding vehicle sequence array. After the passing sequence of the self vehicle and the first collision vehicle is determined, the collision relation of the subsequent collision vehicles is corrected. In the process of generating the conflict relation between the self vehicle and the conflict vehicle, the predicted conflict moment of the collision of the self vehicle and the conflict vehicle at the conflict track point can be obtained according to the motion state of the self vehicle and the motion state of the conflict vehicle. If the own vehicle passes before the collision vehicle, the collision vehicle is to be inThe time reaches the upper boundary of the boundary position of the own vehicle. Repeating the steps for all the conflict track points with conflicts of the conflict vehicles, and if the conflict track points with conflicts are the vehicles to give way, taking the smallest one of all the lower boundaries; if not, the smallest of all upper boundaries is taken.
And establishing tracking errors between the self vehicles and the conflict vehicles according to the passing sequence and the conflict relation. Then, a vehicle longitudinal dynamics model is established. And finally, substituting the tracking error into the established longitudinal dynamics model of the vehicle to construct a nonlinear tracking error dynamics model. And designing the driving force of the vehicle according to the constructed nonlinear tracking error dynamics model. The present embodiment may send the above-described own vehicle driving force to the control unit of the power system through the controller, and the power system executes this desired own vehicle driving force, thereby controlling the own vehicle to turn left through the unprotected intersection.
The present embodiment corresponds to the embodiment of the traffic light-free left-turn scene vehicle passing method portion, so that the specific process of the traffic light-free left-turn scene vehicle passing system is referred to the description of the embodiment of the traffic light-free left-turn scene vehicle passing method portion, and is not repeated herein.
According to the method and the device for determining the traffic sequence, the traffic sequence is determined by combining the motion states of the self vehicle and the collision vehicle, and meanwhile, the collision relation between the self vehicle and the collision vehicle is established and corrected in real time, so that the frequent acceleration and deceleration conditions of the vehicle caused by collision processing can be reduced, and the travelling comfort is improved on the basis of smoothly solving the traffic problem of a left turn scene without a signal lamp. In addition, the embodiment of the application adopts the nonlinear dynamics model to obtain the driving force of the vehicle, and is more in line with the characteristics of the vehicle compared with the traditional kinematics model, thereby improving the safety of the vehicle in the left turning process.
Example 3
As shown in fig. 5, the present embodiment proposes an electronic device including: the system comprises a processor, a memory and a communication bus, wherein the memory stores machine-readable instructions executable by the processor, when the electronic device is running, the processor and the memory are communicated through the communication bus, and the processor executes the machine-readable instructions to execute the steps of the traffic light-free left-turn scene vehicle passing method.
Since the embodiment of the electronic device portion corresponds to the embodiment of the traffic light-free left-turn scene vehicle passing method portion, the embodiment of the electronic device portion is referred to the description of the embodiment of the traffic light-free left-turn scene vehicle passing method portion, and is not repeated herein.
According to the method and the device for determining the traffic sequence, the traffic sequence is determined by combining the motion states of the self vehicle and the collision vehicle, and meanwhile, the collision relation between the self vehicle and the collision vehicle is established and corrected in real time, so that the frequent acceleration and deceleration conditions of the vehicle caused by collision processing can be reduced, and the travelling comfort is improved on the basis of smoothly solving the traffic problem of a left turn scene without a signal lamp. In addition, the embodiment of the application adopts the nonlinear dynamics model to obtain the driving force of the vehicle, and is more in line with the characteristics of the vehicle compared with the traditional kinematics model, thereby improving the safety of the vehicle in the left turning process.
Example 4
The present embodiment provides a computer-readable storage medium having stored therein computer-executable instructions that, when loaded and executed by a processor, implement the traffic light-free left-turn scene vehicle passing method as described above.
Since the embodiments of the computer readable storage medium portion and the embodiments of the traffic signal-less left-turn scene vehicle passing method portion correspond to each other, the embodiments of the storage medium portion are referred to the description of the embodiments of the traffic signal-less left-turn scene vehicle passing method, and are not repeated herein.
According to the method and the device for determining the traffic sequence, the traffic sequence is determined by combining the motion states of the self vehicle and the collision vehicle, and meanwhile, the collision relation between the self vehicle and the collision vehicle is established and corrected in real time, so that the frequent acceleration and deceleration conditions of the vehicle caused by collision processing can be reduced, and the travelling comfort is improved on the basis of smoothly solving the traffic problem of a left turn scene without a signal lamp. In addition, the embodiment of the application adopts the nonlinear dynamics model to obtain the driving force of the vehicle, and is more in line with the characteristics of the vehicle compared with the traditional kinematics model, thereby improving the safety of the vehicle in the left turning process.
It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein. The scheme in the embodiment of the application can be realized by adopting various computer languages, such as object-oriented programming language Java, an transliteration script language JavaScript and the like.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present application without departing from the spirit or scope of the application. Thus, it is intended that the present application also include such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof.