Vehicle-road collaborative signal perception and attenuation simulation method, system, device and medium

Abstract

The present invention discloses a vehicle-road collaborative signal perception and attenuation simulation method, system, device and medium. The method includes: constructing a real-time virtual traffic simulation platform; constructing in-vehicle units and roadside units in the real-time virtual traffic simulation platform based on a physics engine; determining the receptive fields and bounding volumes of the in-vehicle units, and the receptive fields and bounding volumes of the roadside units to obtain a first receptive field, a first bounding volume, a second receptive field and a second bounding volume; judging whether a communication connection is established between two communication units based on the collision detection method of hierarchical bounding volumes according to the first receptive field, the first bounding volume, the second receptive field and the second bounding volume; if a communication connection is established between the two communication units, simulating the attenuation of the communication signals transmitted between the two communication units by setting rays. The present invention can improve the efficiency of vehicle-road collaborative simulation and the real-time performance of scenario operation.

Description

Technical Field

[0001] The present invention relates to the field of vehicle-road collaborative simulation testing, and particularly to a method, system, device and medium for vehicle-road collaborative signal perception and attenuation simulation. Background Art

[0002] Virtual reality technology is a technology that uses a computer system to build a virtual three-dimensional environment similar to the real world, realizing a digital twin of the real world. At the same time, it can manipulate and control objects in the virtual scene and interact to complete the required test simulation functions. Vehicle-road collaborative testing often requires building different traffic scenarios for multiple tests to cover as many real driving situations as possible. However, the actual construction of general test scenarios is difficult and expensive, so most vehicle-road collaborative tests are completed through simulation experiments. However, since pure virtual simulation cannot fully reproduce the real scene, there may be accuracy problems or model accuracy problems in some states through virtual simulation, so mixed reality simulation is particularly important.

[0003] In vehicle-road collaborative testing, a corresponding vehicle-road collaborative test environment needs to be built in the actual test field. At this time, an existing virtual reality platform is used to realize the digital twin of the real test field, constituting a mixed reality simulation test platform. The virtual traffic scene is digitally designed according to the real test field. When deploying roadside units, according to the real position of the device inside the real test field, the corresponding position in the three-dimensional virtual scene is determined to install the roadside unit. The virtual scene is consistent with the actual test field. The vehicles participating in the test can be either virtual vehicles or real vehicles; vehicle-road communication simulation can be between virtual vehicles and real vehicles, between virtual vehicles and virtual vehicles, between virtual vehicles and virtual roadside units, between virtual vehicles and real roadside units, and between real vehicles and virtual roadside units. When the vehicle is driving, it not only needs to know its own state information, but also needs to communicate with roadside units or surrounding vehicles to obtain information about nearby vehicles or other roadside messages.

[0004] The information exchange between connected vehicles and the roadside is the basis for building a three-dimensional real-time simulation platform for vehicle-road collaborative traffic scenarios. Connected vehicles widely communicate and exchange with surrounding vehicles or roadside sensing devices on the basis of obtaining their own vehicle passing data, so as to perceive the surrounding environment information of their own vehicle or the state of other connected vehicles, providing a decision-making basis for the next behavior. When carrying out vehicle-road collaborative simulation testing, it is necessary to simulate the communication between in-vehicle units and roadside units or between in-vehicle units. However, as the complexity of the three-dimensional test scenario increases, the efficiency of system simulation will decrease. When communication simulation is to be carried out, the situation will become even worse, the control complexity increases, and the real-time performance of the simulation decreases. Summary of the Invention

[0005] Based on this, the embodiments of the present invention provide a vehicle-road collaborative signal perception and attenuation simulation method, system, device and medium, which can improve the efficiency of vehicle-road collaborative simulation and the real-time performance of scenario operation.

[0006] To achieve the above object, the present invention provides the following solutions:

[0007] A vehicle-road collaborative signal perception and attenuation simulation method, including:

[0008] Construct a real-time virtual traffic simulation platform;

[0009] Based on a physics engine, construct an on-vehicle unit and a roadside unit in the real-time virtual traffic simulation platform; the on-vehicle unit is located at the center of the vehicle in the real-time virtual traffic simulation platform, and the roadside unit is located at a set position on the roadside in the real-time virtual traffic simulation platform;

[0010] Determine a first receptive field, a first bounding volume, a second receptive field and a second bounding volume; the first receptive field is the receptive field of the on-vehicle unit; the first bounding volume is the bounding volume of the on-vehicle unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the perception range of the internal sensor;

[0011] According to the first receptive field, the first bounding volume, the second receptive field and the second bounding volume, based on the hierarchical bounding volume collision detection method, determine whether a communication connection is established between two communication units; the two communication units include: one on-vehicle unit and one roadside unit, or, the two communication units include: two on-vehicle units;

[0012] If a communication connection is established between the two communication units, then simulate the attenuation of the communication signal transmitted between the two communication units through a set ray; the set ray is a ray emitted by the communication unit serving as the signal source to the communication unit serving as the signal receiver among the two communication units.

[0013] Optionally, the determining whether a communication connection is established between two communication units according to the first receptive field, the first bounding volume, the second receptive field and the second bounding volume, based on the hierarchical bounding volume collision detection method, specifically includes:

[0014] Calculate the center distance between the two communication units; if the two communication units include: one on-vehicle unit and one roadside unit, then the center distance is the distance between the center of the first bounding volume and the center of the second bounding volume; if the two communication units include: two on-vehicle units, then the center distance is the distance between the centers of the two first bounding volumes;

[0015] Determine whether a communication connection is established between the two communication units according to the center distance and the radii of the receptive fields of the two communication units.

[0016] Optionally, the attenuation of the communication signal transmitted between the two communication units is simulated by setting a ray, which specifically includes:

[0017] Determine the nearest intersection point of the communication unit serving as the signal source on the set ray;

[0018] Determine the nearest intersection point of the communication unit serving as the signal receiver on the set ray;

[0019] Calculate the distance between the two nearest intersection points to obtain the intersection point distance;

[0020] Calculate the packet loss probability of the communication signal transmitted between the two communication units according to the center distance, the intersection point distance, and the radii of the receptive fields of the two communication units; the packet loss probability is used to represent the attenuation situation of the communication signal.

[0021] Optionally, the determining whether a communication connection is established between the two communication units according to the center distance and the radii of the receptive fields of the two communication units specifically includes:

[0022] Determine the smaller one of the radii of the receptive fields of the two communication units as the target radius;

[0023] Judge whether the center distance is less than the target radius;

[0024] If so, determine that a communication connection is established between the two communication units.

[0025] Optionally, the calculation formula of the packet loss probability is:

[0026] P = 2 - 2 / [1 + (|O1 - O2| * |O1 - O2|) / (min(R1, R2) * min(R1, R2))] + k * |D1 - D2|;

[0027] Wherein, P represents the packet loss probability; |O1 - O2| represents the center distance, where O1 represents the center of one of the two communication units, and O2 represents the center of the other of the two communication units; |D1 - D2| represents the intersection distance, where D1 represents the nearest intersection point of one of the two communication units on the set ray, and D2 represents the nearest intersection point of the other of the two communication units on the set ray; min(R1, R2) represents the smaller of the radii of the receptive fields of the two communication units, where R1 represents the radius of the receptive field of one of the two communication units, and R2 represents the radius of the receptive field of the other of the two communication units; k represents the material attenuation coefficient.

[0028] Optionally, the construction of the real - time virtual traffic simulation platform specifically includes:

[0029] Constructing a three - dimensional traffic scene using a virtual reality platform;

[0030] Constructing a traffic flow using microscopic traffic simulation software;

[0031] Establishing a real - time virtual traffic simulation platform based on the three - dimensional traffic scene and the traffic flow.

[0032] The present invention also provides a vehicle - road collaborative signal perception and attenuation simulation system, including:

[0033] A platform construction module for constructing a real - time virtual traffic simulation platform;

[0034] A communication unit construction module for constructing in - vehicle units and roadside units in the real - time virtual traffic simulation platform based on a physics engine; the in - vehicle units are located at the centers of vehicles in the real - time virtual traffic simulation platform, and the roadside units are located at set positions on the roadside in the real - time virtual traffic simulation platform;

[0035] A receptive field determination module for determining a first receptive field, a first bounding volume, a second receptive field, and a second bounding volume; the first receptive field is the receptive field of the in - vehicle unit; the first bounding volume is the bounding volume of the in - vehicle unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the perception range of internal sensors;

[0036] A collision detection module for judging whether a communication connection is established between two communication units according to the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, based on the collision detection method of hierarchical bounding volumes; the two communication units include: one in - vehicle unit and one roadside unit, or, the two communication units include: two in - vehicle units;

[0037] An attenuation simulation module, configured to simulate the attenuation of a communication signal transmitted between two communication units by setting a ray if a communication connection is established between the two communication units; the set ray is a ray emitted from the communication unit serving as a signal transmitter to the communication unit serving as a signal receiver among the two communication units.

[0038] The present invention also provides an electronic device, including a memory and a processor, where the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the above-mentioned vehicle-road collaborative communication signal perception and attenuation simulation method.

[0039] The present invention also provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the above-mentioned vehicle-road collaborative communication signal perception and attenuation simulation method is implemented.

[0040] According to the specific embodiments provided by the present invention, the following technical effects are disclosed:

[0041] The embodiments of the present invention propose a vehicle-road collaborative signal perception and attenuation simulation method, system, device, and medium. The method includes: constructing a real-time virtual traffic simulation platform; constructing an on-vehicle unit and a roadside unit in the real-time virtual traffic simulation platform based on a physics engine; determining the receptive field and bounding volume of the on-vehicle unit, and the receptive field and bounding volume of the roadside unit, to obtain a first receptive field, a first bounding volume, a second receptive field, and a second bounding volume; based on the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, and using a hierarchical bounding volume-based collision detection method, determining whether a communication connection is established between two communication units; if a communication connection is established between two communication units, simulating the attenuation of a communication signal transmitted between the two communication units by setting a ray. The present invention uses a collision detection method and a ray detection method to implement signal perception and attenuation simulation, which can improve the efficiency of vehicle-road collaborative simulation and the real-time performance of scenario operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention, and those of ordinary skill in the art can also obtain other drawings without creative efforts.

[0043] Figure 1 It is a flowchart of the communication signal perception and attenuation simulation method provided by the embodiments of the present invention;

[0044] Figure 2It is the overall framework diagram of the communication signal perception and attenuation simulation method provided by the embodiment of the present invention;

[0045] Figure 3 It is the schematic diagram of the critical condition for establishing communication between the "RSU" provided by the embodiment of the present invention and the vehicle equipped with the "OBU";

[0046] Figure 4 It is the schematic diagram of the critical condition for establishing communication between the vehicle equipped with the "OBU" and the vehicle equipped with the "OBU" provided by the embodiment of the present invention;

[0047] Figure 5 It is the structural diagram of the communication signal perception and attenuation simulation system provided by the embodiment of the present invention. Detailed implementation manners

[0048] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0049] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the drawings and specific implementation manners.

[0050] Embodiment 1

[0051] The physical engine calculates the force or collision situation by endowing real physical properties to rigid body objects, so as to simulate their real motion states. The physical engine requires that objects in the three-dimensional virtual scene should follow physical laws to run, so as to make the virtual world as close as possible to the real world. Use the collision detection method based on bounding spheres of the physical engine to complete the modeling of the wireless communication capabilities of sensors, and simulate the communication process between the roadside unit and the vehicle in vehicle-road cooperation to complete signal perception. Mainly realize the simulation of the wireless communication capabilities of the roadside unit and in-vehicle equipment. This method does not consider the internal physical structure and specific functional principles of the equipment. When simulating, simplify the complex external shape and internal structure of the equipment, use a simple model to replace the external shape and ignore the internal structure, focus on function design and simulation, and finally improve the efficiency of vehicle-road cooperation simulation and the real-time performance of scene operation.

[0052] When performing signal perception and information transmission for vehicle-road cooperation in a hybrid scenario without the aid of an external network emulator, this embodiment proposes a signal perception and simulation method based on a physics engine. In the traffic simulation system used in the experiment, considering the real-time nature of scenario simulation and the focus of vehicle-road cooperation device simulation, the complex shapes of devices in the scenario are simplified, the concept of "receptive field" is derived, and the communication process between the driving vehicles, roadside units, and other vehicles in the scenario is simulated. The method in the physics engine is used to design the V2X communication process. Among them, whether to establish a connection between the roadside unit (RSU) and the on-board unit (OBU) mounted on the vehicle or the on-board unit (OBU) mounted on the vehicle is judged through their respective "receptive fields". After determining the connection, information perception and exchange are carried out between the devices to assist the vehicle in planning the next driving plan. And whether there are other obstacles between the signal emitter and the signal receiver is judged through virtual rays, so as to realize information perception and signal attenuation simulation between communication devices.

[0053] The embodiment of the present invention proposes a communication strategy for vehicle-road cooperation based on a physics engine, simulates the communication distance and signal attenuation through physical simulation, and uses the method of computer graphics to solve the process simulation of establishing communication and signal attenuation between the on-board unit and the roadside unit and between the on-board units.

[0054] See Figure 1 , the communication signal perception and attenuation simulation method of this embodiment specifically includes:

[0055] Step 101: Construct a real-time virtual traffic simulation platform.

[0056] Step 102: Based on the physics engine, construct on-board units and roadside units in the real-time virtual traffic simulation platform.

[0057] The on-board unit is located at the center of the vehicle in the real-time virtual traffic simulation platform, and the roadside unit is located at a set position on the roadside in the real-time virtual traffic simulation platform.

[0058] Step 103: Determine the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume.

[0059] The first receptive field is the receptive field of the on-board unit; the first bounding volume is the bounding volume of the on-board unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the perception range of the internal sensor.

[0060] Step 104: Based on the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, and using the collision detection method based on hierarchical bounding volumes, judge whether a communication connection is established between two communication units.

[0061] The two communication units include: one vehicle-mounted unit and one roadside unit, or, the two communication units include: two vehicle-mounted units;

[0062] Step 105: If a communication connection is established between the two communication units, simulate the attenuation of the communication signal transmitted between the two communication units by setting a ray.

[0063] The set ray is a ray emitted from the communication unit acting as the signal source to the communication unit acting as the signal receiver among the two communication units.

[0064] In one example, step 101 specifically includes:

[0065] Build a three-dimensional traffic scene using the virtual reality platform Unity; build a traffic flow using the microscopic traffic simulation software SUMO; establish a real-time virtual traffic simulation platform based on the three-dimensional traffic scene and the traffic flow.

[0066] In one example, step 104 specifically includes:

[0067] 1) Calculate the central distance between the two communication units; if the two communication units include: one vehicle-mounted unit and one roadside unit, then the central distance is the distance between the center of the first bounding volume and the center of the second bounding volume; if the two communication units include: two vehicle-mounted units, then the central distance is the distance between the centers of the two first bounding volumes.

[0068] 2) Determine whether a communication connection is established between the two communication units according to the central distance and the radii of the receptive fields of the two communication units.

[0069] In one example, step 105 specifically includes:

[0070] 1) Determine the nearest intersection point of the communication unit acting as the signal source on the set ray.

[0071] 2) Determine the nearest intersection point of the communication unit acting as the signal receiver on the set ray.

[0072] 3) Calculate the distance between the two nearest intersection points to obtain the intersection point distance.

[0073] 4) Calculate the packet loss probability of the communication signal transmitted between the two communication units according to the central distance, the intersection point distance, and the radii of the receptive fields of the two communication units; the packet loss probability is used to represent the attenuation situation of the communication signal. Specifically:

[0074] Determine the smaller of the radii of the receptive fields of the two communication units as the target radius; determine whether the center distance is less than the target radius; if so, determine that a communication connection is established between the two communication units. That is to say, if the distance between the centers of the two objects in the scenario is less than the minimum sensing range of the two communication units, i.e., D = |O1 - O2| < min(R1, R2), it can be determined that the wireless signals of the two communication units can cover each other, and thus a communication can be established. Here, |O1 - O2| represents the center distance; min(R1, R2) represents the smaller of the radii of the receptive fields of the two communication units, that is, the target radius.

[0075] The calculation formula for the packet loss probability is as follows:

[0076] P = min(2 - 2 / [1 + (|O1 - O2| * |O1 - O2|) / (min(R1, R2) * min(R1, R2))] + k * |D1 - D2|, 1);

[0077] Where, P represents the packet loss probability; |O1 - O2| represents the center distance, O1 represents the center of one of the two communication units, and O2 represents the center of the other of the two communication units; |D1 - D2| represents the intersection point distance, D1 represents the nearest intersection point of one of the two communication units on the set ray, and D2 represents the nearest intersection point of the other of the two communication units on the set ray; min(R1, R2) represents the smaller of the radii of the receptive fields of the two communication units, R1 represents the radius of the receptive field of one of the two communication units, and R2 represents the radius of the receptive field of the other of the two communication units; k represents the material attenuation coefficient.

[0078] In practical applications, a more specific implementation process of the above communication signal perception and attenuation simulation method is as follows:

[0079] The concept of this specific example is: simulating the perception of V2X signals through collision detection and bounding sphere methods in a physics engine; by equipping connected vehicles in a mixed reality scenario with on-board units (OBUs) and placing roadside units (RSUs) on the road, the concept of "receptive field" is introduced and the action space of perception is determined. Whether a connection is established between the roadside and the vehicle and between vehicles is judged by the coincidence of the receptive fields, and whether there are other obstacles between the signal transmitter and the signal receiver is judged by virtual rays, so as to realize information perception and signal attenuation simulation between communication devices. This specific example uses computer graphics methods to solve the V2X communication simulation problem in a virtual simulation environment without connecting an external network simulator, and efficiently solves the process simulation of establishing communication and signal attenuation between on-board units and roadside units and between on-board units and on-board units.

[0080] See Figure 2 , the communication signal perception and attenuation simulation method mainly includes: building a real-time mixed reality traffic simulation platform; modeling roadside units (RSUs) and on-board units (OBUs) in the scenario; and the process of signal perception and attenuation simulation.

[0081] Construction of the traffic simulation platform:

[0082] It is mainly to build a real vehicle-road collaboration test environment in an actual test field, and use a virtual reality platform (such as Unity3D) and microscopic traffic simulation software SUMO to complete the construction of a three-dimensional real-time virtual traffic simulation platform, realizing the digital twin of the actual test field and constituting a mixed reality simulation test platform. Among them, Unity is responsible for constructing a three-dimensional virtual traffic scene, rendering and presenting, and simulating, while SUMO provides traffic flow. The virtual traffic scene is digitally designed according to the test requirements of the actual test field. When arranging roadside units, based on the actual position of the device inside the actual test field, determine the corresponding position in the three-dimensional virtual scene to install the roadside unit.

[0083] During the scenario test, when a vehicle is driving, it not only needs to know its own status information but also needs to communicate with roadside devices or surrounding vehicles to obtain information about nearby vehicles or other roadside messages, providing a basis for subsequent driving behaviors. In the mixed reality scenario, vehicles equipped with communication modules exchange data with roadside units to complete data sharing, that is, after the simulation starts, the OBU and RSU or the OBU communicates with other OBUs to simulate the signal perception process and continuously exchange information.

[0084] In the mixed reality test scenario, the virtual scene is consistent with the actual test field. The vehicles participating in the test can be either virtual vehicles or real vehicles; vehicle-road communication simulation can be between virtual vehicles and real vehicles, between virtual vehicles and virtual vehicles, between virtual vehicles and virtual roadside units, between virtual vehicles and real roadside units, and between real vehicles and virtual roadside units. Real vehicles and real roadside devices access the virtual simulation platform through the network to form a mixed reality test scenario.

[0085] Modeling of on-board units (OBUs) and roadside units (RSUs) in the scenario:

[0086] The OBU is used to communicate with the roadside unit and complete information transmission. The on-vehicle unit is replaced by a simple geometric model because in the virtual scenario, the simulation of the wireless communication capabilities of the sensors in the OBU is emphasized, and the environmental perception of the on-vehicle unit mainly involves obtaining driving environment information related to the safe driving of the vehicle. Mainly considering the functional modeling of the on-vehicle unit, the specific physical structure and physical principles are not considered, and the complex shape of the OBU can also be ignored in the scenario to improve the rendering efficiency and real-time performance. Vehicles in the scenario can all be equipped with an OBU. The OBU and the vehicle use different geometric models. The OBU selects a simple geometric shape as its model, while the vehicle selects a geometric model that matches its shape. The OBU is placed at the center of the vehicle, and its position needs to change as the vehicle moves.

[0087] The RSU is used to communicate with the vehicles in the scenario and complete information transmission. In reality, the position of the RSU is fixed, so a specific position is selected in the virtual scenario to complete the layout of the RSU. Generally, the geometric shape of the roadside unit is complex, and the RSU also selects a simple geometric shape as its model to approximate the shape of the complex object in this way.

[0088] The method for simulating signal perception and attenuation is as follows:

[0089] First, the concept of the "receptive field" of the communication unit is proposed. Generally, the "receptive field" is mostly used in convolutional neural networks. It is the area in the image corresponding to the convolution required. This area must ensure that the model used can obtain sufficient image area information, which corresponds to a region in the specific convolutional neural network feature input space. Sufficient global information is obtained through the "receptive field". Generally, sensors have a sensing range, and each signal has its action space, which is called the visibility of the sensor. Now, in combination with the above concept, the "receptive field" is given to the RSU and the OBU. This area is the sensing space of the on-vehicle unit and the roadside unit, and it is the visible range of the internal sensors. This area is a circular area with the geometric center of the RSU and OBU models as the center and a set value R as the radius. When a target is in the "receptive field", first lock and obtain the target for analysis, and then judge whether the target is obtained and whether information exchange with the target is required.

[0090] Secondly, signal perception is completed by means of collision detection methods in the physical engine, and the specific geometric models of RSU and OBU are determined. The signal perception based on the physical engine mainly uses collision detection based on hierarchical bounding volumes. The bounding volumes are selected to simplify the devices with complex internal structures and shapes. Generally, the structure of the bounding volume has a great impact on the simulation. Typical bounding volumes include: bounding sphere, axis-aligned bounding box AABB, oriented bounding box OBB, K-DOP bounding box, etc. Considering the setting of the "receptive field" range proposed and the characteristics of signal propagation, the bounding sphere is selected as the bounding volume. In the scenario, the geometric shapes of RSU and OBU are both simplified to solid spheres.

[0091] In the physical engine, collision detection is often used to prevent penetration between objects. According to the shortest distance between two objects, it is calculated whether two moving objects will collide within a given time period. In this design, the above research direction of collision detection is used to simulate the signal perception and communication process in the virtual simulation system. Collision detection is also known as intersection testing or contact testing, which is used to judge the positional relationship between objects. When an object is in motion, it is necessary to judge whether there is an intersection area between objects and the timing of intersection, which can be achieved through collision detection. In this method, collision is mainly used to determine whether contact and position information occur between two or more objects. The designed analog signal perception method in this method, that is, the transmission of signals is simulated through this principle of the collision detection method. It realizes the exchange of information between vehicles and roadside units (V2I) through the method of the physical engine without connecting an external network simulator.

[0092] In the traffic simulation system used in the experiment, the "receptive fields" of roadside units (RSU) and on-board units (OBU) are mainly defined, and the complex shapes of the devices are simplified in the scenario, simulating the communication processes of vehicles and roadside units (V2I) and vehicles and vehicles (V2V) driving in the scenario. The signal perception in vehicle-road collaboration is simulated through the collision detection method. Among them, RSU and vehicles judge whether to establish a connection through their respective "receptive fields". After determining the connection, RUS exchanges information with the surrounding vehicles to assist the vehicle in planning the next driving plan.

[0093] Again, the simulation of signal attenuation is completed by means of the ray detection method in the physics engine. On the basis of the above collision detection, that is, when a connection is established between the signal transmitter and the signal receiver, the signal will attenuate during propagation in the air, and the signal may pass through buildings or other vehicles. These obstacles will block the wireless signal, resulting in the attenuation of the wireless signal and packet loss in message transmission. By emitting a ray from the signal transmitter to the signal receiver, that is, emitting a ray from the center of the sphere of the collision bounding volume representing the RSU or OBU to the center of the sphere of the collision bounding volume of another RSU or OBU, not only the distance between the signal transmitter and the signal receiver can be calculated through ray detection, but also the occlusion situation between this ray can be quickly detected, so as to attenuate the simulation signal according to the signal attenuation law.

[0094] Referring to the collision detection method in the physics engine, collision detection is often used to avoid penetration between objects. According to the shortest distance between two objects, it is calculated whether two moving objects will collide within a given time period. In this embodiment, the collision detection method is used to simulate the signal perception process in the virtual simulation system. Collision detection is also called intersection test or contact test, which is used to judge the positional relationship between objects. When an object is in motion, it is necessary to judge whether there is an intersection area between objects and the timing of intersection, which can be achieved through collision detection. In this embodiment, collision is mainly used to determine whether the intensity of two or more wireless signals can cover the corresponding range. The designed analog signal perception method in this embodiment, that is, the establishment of wireless signals is simulated through the collision detection method. Without connecting an external network simulator, the information exchange between connected vehicles and roadside equipment (V2I) or between connected vehicles and connected vehicles (V2V) is realized through the method of the physics engine.

[0095] In the traffic simulation system used in the experiment, the "receptive fields" of roadside units (RSUs) and on-vehicle units (OBUs) are mainly defined and virtual device deployment is carried out in the scenario, simulating the communication processes of connected vehicles and roadside equipment (V2I) and vehicles and vehicles (V2V) driving in the simulation scenario, and simulating signal perception in vehicle-road collaboration through the collision detection method. Among them, the RSU and the connected vehicle judge whether to establish a connection through their respective "receptive fields". After determining the connection, the RSU exchanges information with the surrounding connected vehicles or the connected vehicle exchanges information with other surrounding connected vehicles to assist the vehicle in planning the next driving plan.

[0096] Process of signal perception and attenuation simulation:

[0097] Step 1: Attribute setting of RSU and OBU;

[0098] In the virtual scenario, the OBU uses a different model from the vehicle. The OBU is placed at the center of the vehicle, and its position is continuously updated as the position of the moving vehicle changes. The RSU is placed at a specific location on the roadside, and its position remains fixed.

[0099] By means of the method of the physics engine (physical simulation in the Unity3D virtual reality platform), it is first necessary to add rigid body components to the RSU and OBU in the scenario, and then consider the collision detection method. Generally, there are two ways of collision detection: collider and trigger. The collider will have the effect of physical collision, and the trigger can make two objects penetrate without physical collision effect. Adding the rigid body property means that the RSU and OBU will be physically controlled during the simulation process and will participate in the physical simulation. At the same time, since the RSU and OBU do not participate in collision detection and make corresponding collision response actions like ordinary rigid bodies, the trigger mechanism is adopted in the collision detection method. That is, when it is detected that two objects collide, only the corresponding function is called to notify these two objects that a collision has occurred, without changing the actual motion states of the two objects. Considering that the designed signal perception method does not require the physical collision effect, but only detects whether two objects are close enough to establish communication, the trigger mode is used to notify the RSU and OBU, and the detection is realized through the Trigger trigger.

[0100] Step 2: Conditions for establishing communication;

[0101] Based on the physical properties of the RSU and OBU in Step 1, the communication conditions in the scenario are analyzed. By means of the concept in collision detection that determines whether a collision effect occurs by judging whether two objects intersect, it is set to judge whether to establish communication by detecting whether the bounding spheres of the objects in the scenario coincide, that is, the intersection test. That is to say, according to Step 1, bounding spheres are set for the RSU and OBU as collision bodies, and the centers of the spheres are the positions of these objects. At the same time, the radii of the bounding spheres are set according to their wireless coverage ranges, that is, the receptive fields of the communication units are defined. For example, if the wireless communication coverage range of an OBU is 200 meters, then the radius of the bounding sphere is 200 meters. In addition, since the bounding sphere only participates in collision detection and does not need to be rendered. By means of collision detection, when the bounding spheres representing the RSU or OBU collide, it means that communication may be established between these objects.

[0102] First, it is necessary to determine the center of the enclosing sphere. First, determine the center O of the enclosing sphere at the RSU and OBU respectively. The distance calculation radius is the radius R of the set "field of view". Since the range covered by the enclosing spheres representing these vehicle-mounted units or roadside units is the wireless coverage range of the communication unit, but both need to be within the field of view of each other to receive information from each other. Assuming that the centers of the enclosing spheres representing the RSU or OBU are O1 and O2 respectively, |O1 - O2| represents the distance between the signal source and the signal receiver, and the "field of view" ranges are R1 and R2 respectively. Therefore, if the distance between the centers of the two objects in the scenario is less than the minimum perception range of the two communication units, that is:

[0103] D = |O1 - O2| < min(R1, R2)

[0104] It can be determined that the wireless signals of the two communication units can cover each other, and thus communication can be established.

[0105] Step 3: Conduct signal attenuation simulation;

[0106] Based on Step 2, on the one hand, calculate the spatial loss of the signal according to |O1 - O2|. The greater the distance, the more the signal attenuates. If there are obstacles between the signal source and the signal receiver, there is a blocking loss. Moreover, different types of obstacles have different penetration depths and different attenuation degrees. Therefore, it is necessary to calculate the penetration distance. To accelerate the intersection calculation of the ray and the obstacle, a physical simulation based on the virtual reality platform emits a ray from the signal source and the signal receiver respectively, and at the same time limits the working range of the ray to |O1 - O2| to obtain the nearest intersection points D1 and D2. The distance between these two intersection points is the penetration distance |D1 - D2|. The greater the penetration distance, the more the signal attenuates. To simulate signal attenuation, a simple relationship between signal attenuation and packet loss is established to represent the signal problems in the simulation process.

[0107] P = min(2 - 2 / [1 + (|O1 - O2| * |O1 - O2|) / (min(R1, R2) * min(R1, R2))] + k * |D1 - D2|, 1)

[0108] Where P is the probability of packet loss, and k is the material attenuation coefficient used to simulate the attenuation of signals by obstacles of different materials.

[0109] Figure 3 Shows the critical conditions for establishing communication between the "RSU" and the vehicle equipped with the "OBU", where the dashed part is the "field of view"; Figure 4 Shows the critical conditions for establishing communication between the vehicle equipped with the "OBU" and the vehicle equipped with the "OBU", where the dashed part is the "field of view".

[0110] The communication signal perception and attenuation simulation method of this embodiment proposes a method for simulating V2X signal perception and simulation using a physical engine method. Based on the "receptive field" in a convolutional neural network and the perception range of sensors, the "receptive fields" of RSU and OBU are proposed. The collision detection method in the physical engine is extended to the conditions for establishing communication connections between devices, and ray detection is used to simulate signal attenuation, thus providing an efficient communication connection and attenuation method for large-scale scenario simulation, enabling multiple in-vehicle devices and roadside devices to be deployed in the vehicle-road cooperation simulation test scenario for simultaneous simulation implementation.

[0111] Embodiment 2

[0112] To execute the method corresponding to the above Embodiment 1 to achieve the corresponding functions and technical effects, the vehicle-road cooperation signal perception and attenuation simulation system is provided below. See Figure 5 , The system includes:

[0113] The platform construction module 501 is used to construct a real-time virtual traffic simulation platform.

[0114] The communication unit construction module 502 is used to construct in-vehicle units and roadside units in the real-time virtual traffic simulation platform based on a physical engine; the in-vehicle unit is located at the center of the vehicle in the real-time virtual traffic simulation platform, and the roadside unit is located at a set position on the roadside in the real-time virtual traffic simulation platform.

[0115] The receptive field determination module 503 is used to determine a first receptive field, a first bounding volume, a second receptive field, and a second bounding volume; the first receptive field is the receptive field of the in-vehicle unit; the first bounding volume is the bounding volume of the in-vehicle unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the perception range of internal sensors.

[0116] The collision detection module 504 is used to judge whether a communication connection is established between two communication units based on the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, using the collision detection method of hierarchical bounding volumes; the two communication units include: one in-vehicle unit and one roadside unit, or, the two communication units include: two in-vehicle units.

[0117] The attenuation simulation module 505 is used to simulate the attenuation of the communication signal transmitted between two communication units by setting a ray if a communication connection is established between the two communication units; the set ray is a ray emitted from the communication unit as the signal emitter to the communication unit as the signal receiver among the two communication units.

[0118] Embodiment 3

[0119] This embodiment provides an electronic device, including a memory and a processor. The memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the vehicle-road collaborative communication signal perception and attenuation simulation method of Embodiment 1.

[0120] Optionally, the above-mentioned electronic device may be a server.

[0121] In addition, an embodiment of the present invention also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the vehicle-road collaborative communication signal perception and attenuation simulation method of Embodiment 1.

[0122] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple, and reference can be made to the description of the method part for related parts.

[0123] In this article, specific examples are used to elaborate on the principles and implementation manners of the present invention. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A vehicle-road collaborative signal perception and attenuation simulation method, characterized in that Including: Construct a real-time virtual traffic simulation platform; Based on a physics engine, construct an on-vehicle unit and a roadside unit in the real-time virtual traffic simulation platform; the on-vehicle unit is located at the center of the vehicle in the real-time virtual traffic simulation platform, and the roadside unit is located at a set position on the roadside in the real-time virtual traffic simulation platform; Determine a first receptive field, a first bounding volume, a second receptive field, and a second bounding volume; the first receptive field is the receptive field of the on-vehicle unit; the first bounding volume is the bounding volume of the on-vehicle unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the sensing range of internal sensors; Based on the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, and based on a hierarchical bounding volume collision detection method, determine whether a communication connection is established between two communication units, specifically including: calculating the center distance between the two communication units; based on the center distance and the radii of the receptive fields of the two communication units, determine whether a communication connection is established between the two communication units; the two communication units include: one on-vehicle unit and one roadside unit, or, the two communication units include: two on-vehicle units; if the two communication units include: one on-vehicle unit and one roadside unit, then the center distance is the distance between the centers of the spheres of the first bounding volume and the second bounding volume; if the two communication units include: two on-vehicle units, then the center distance is the distance between the centers of the spheres of the two first bounding volumes; If a communication connection is established between the two communication units, then simulate the attenuation of the communication signal transmitted between the two communication units by a set ray, specifically including: determining the nearest intersection point of the communication unit as the signal transmitter on the set ray; determining the nearest intersection point of the communication unit as the signal receiver on the set ray; calculating the distance between the two nearest intersection points to obtain the intersection point distance; based on the center distance, the intersection point distance, and the radii of the receptive fields of the two communication units, calculate the packet loss probability of the communication signal transmitted between the two communication units; the packet loss probability is used to represent the attenuation situation of the communication signal; the set ray is a ray emitted from the communication unit as the signal transmitter to the communication unit as the signal receiver among the two communication units; the nearest intersection point is the intersection point of the set ray and the obstacle between the two communication units.

2. The vehicle-road collaborative signal perception and attenuation simulation method according to claim 1, wherein The determining whether a communication connection is established between the two communication units based on the center distance and the radii of the receptive fields of the two communication units specifically includes: Determine the smaller of the radii of the receptive fields of the two communication units as the target radius; Judge whether the center distance is less than the target radius; If so, determine that a communication connection is established between the two communication units.

3. The vehicle-road collaborative signal perception and attenuation simulation method according to claim 1, characterized in that The calculation formula for the packet loss probability is: P = min(2 - 2 / [1 + (|O1 - O2| * |O1 - O2|) / (min(R1, R2) * min(R1, R2))] + k * |D1 - D2|, 1); Wherein, P represents the packet loss probability; |O1 - O2| represents the center distance, O1 represents the center of the sphere of one of the two communication units, and O2 represents the center of the sphere of the other of the two communication units; |D1 - D2| represents the intersection distance, D1 represents the nearest intersection point of one of the two communication units on the set ray, and D2 represents the nearest intersection point of the other of the two communication units on the set ray; min(R1, R2) represents the smaller of the radii of the receptive fields of the two communication units, R1 represents the radius of the receptive field of one of the two communication units, and R2 represents the radius of the receptive field of the other of the two communication units; k represents the material attenuation coefficient.

4. The vehicle-road collaborative signal perception and attenuation simulation method according to claim 1, wherein The construction of the real-time virtual traffic simulation platform specifically includes: Using a virtual reality platform to construct a three-dimensional traffic scene; Using microscopic traffic simulation software to construct traffic flow; Establishing a real-time virtual traffic simulation platform according to the three-dimensional traffic scene and the traffic flow.

5. Vehicle-road collaborative signal perception and attenuation simulation system, characterized in that Including: A platform construction module for constructing a real-time virtual traffic simulation platform; A communication unit construction module for constructing an in-vehicle unit and a roadside unit in the real-time virtual traffic simulation platform based on a physics engine; the in-vehicle unit is located at the center of the vehicle in the real-time virtual traffic simulation platform, and the roadside unit is located at a set position on the roadside in the real-time virtual traffic simulation platform; A receptive field determination module for determining a first receptive field, a first bounding volume, a second receptive field, and a second bounding volume; the first receptive field is the receptive field of the in-vehicle unit; the first bounding volume is the bounding volume of the in-vehicle unit; the second receptive field is the receptive field of the roadside unit; the second bounding volume is the bounding volume of the roadside unit; the receptive field represents the perception range of the internal sensor; A collision detection module for judging whether a communication connection is established between two communication units based on the collision detection method of the hierarchical bounding volume according to the first receptive field, the first bounding volume, the second receptive field, and the second bounding volume, specifically including: calculating the center distance between the two communication units; judging whether a communication connection is established between the two communication units according to the center distance and the radii of the receptive fields of the two communication units; the two communication units include: one in-vehicle unit and one roadside unit, or, the two communication units include: two in-vehicle units; if the two communication units include: one in-vehicle unit and one roadside unit, then the center distance is the distance between the center of the sphere of the first bounding volume and the center of the sphere of the second bounding volume; if the two communication units include: two in-vehicle units, then the center distance is the distance between the centers of the spheres of the two first bounding volumes; An attenuation simulation module, which is used to simulate the attenuation of the communication signal transmitted between the two communication units by setting a ray if a communication connection is established between the two communication units. Specifically, it includes: determining the nearest intersection point of the communication unit serving as the signal transmitter on the set ray; determining the nearest intersection point of the communication unit serving as the signal receiver on the set ray; calculating the distance between the two nearest intersection points to obtain the intersection point distance; calculating the packet loss probability of the communication signal transmitted between the two communication units according to the central distance, the intersection point distance, and the radii of the receptive fields of the two communication units; the packet loss probability is used to represent the attenuation situation of the communication signal; the set ray is a ray emitted by the communication unit serving as the signal transmitter to the communication unit serving as the signal receiver among the two communication units; the nearest intersection point is the intersection point of the set ray and the obstacle between the two communication units.

6. An electronic device, characterized in that, It includes a memory and a processor. The memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the vehicle-road collaborative communication signal perception and attenuation simulation method according to any one of claims 1 to 4.

7. A computer-readable storage medium, characterized in that, It stores a computer program, and when the computer program is executed by a processor, it implements the vehicle-road collaborative communication signal perception and attenuation simulation method according to any one of claims 1 to 4.

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