An automatic precise lane-changing system and lane-changing method for a two-vehicle scenario

Abstract

The present application discloses an automatic precise lane-changing system and a lane-changing method for a two-vehicle scenario, which relates to the technical field of autonomous driving testing, and includes: a communication base station; two positioning antennas; two communication processing modules respectively arranged on the host vehicle and the target vehicle, each communication processing module is respectively connected to its own ADCU controller and positioning antenna, and the two communication processing modules can communicate with each other; the communication base station and the two positioning antennas reflect the positioning coordinates of the two vehicles to the two communication processing modules in real time, and the two communication processing modules jointly calculate the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and send it to the ADCU controller of the target vehicle, and the ADCU controller of the target vehicle triggers a steering lane change when the longitudinal distance is equal to the test distance. The automatic precise lane-changing system and lane-changing method of the present application can accurately trigger a steering lane-changing operation when the longitudinal distance is equal to the test distance, and accurately execute the lane-changing process according to a preset trajectory.

Description

Technical Field

[0001] The present application relates to the technical field of autonomous driving testing, and particularly to an automatic precise lane-changing system and a lane-changing method for a two-vehicle scenario. Background Art

[0002] During the design process of autonomous vehicles, it is necessary to conduct two-vehicle scenario tests on the vehicles. For the two-vehicle scenario test of autonomous driving, it is necessary to accurately master the longitudinal distance between the front and rear vehicles to meet the performance indicators in the test, so that the target vehicle can perform autonomous lane-changing at the accurate time and distance.

[0003] In the related art, in the industry, the safety distance for the front target vehicle to cut in mainly relies on the driver's experience. The driver judges the longitudinal distance between the front and rear vehicles through experience. After confirming safety, the driver manually operates the lane change. In the two-vehicle scenario field test, each of the host vehicle and the target vehicle requires a driver. The drivers communicate through a walkie-talkie. When the relative distance between the two vehicles observed by the test engineer on the host vehicle is equal to the test spacing, a lane-changing instruction is sent to the target vehicle through the walkie-talkie, and the target vehicle driver executes the lane-changing operation to complete the lane change.

[0004] However, the driver's experience can only redundantly expand the critical lane-changing longitudinal spacing in a low-speed environment, and meet the requirements of fuzzy testing under a roughly lane-changing spacing, but it can never meet the precise requirements of objective testing. Moreover, when steering to change lanes, the manually operated lane-changing trajectory will generate unnecessary errors relative to the preset trajectory.

[0005] With the development of autonomous driving technology, for the scenario layout of the target vehicle freely changing lanes relative to the host vehicle in the two-vehicle scenario test of autonomous driving, engineers need to calculate the accurate boundary values for the target vehicle of autonomous driving to safely change lanes relative to the host vehicle according to the longitudinal distances at different vehicle speeds. Therefore, it is necessary to very precisely trigger the lane-changing operation according to the test spacing during the test and precisely execute the lane-changing process according to the preset trajectory. Summary of the Invention

[0006] Aiming at the defects existing in the prior art, the purpose of the present application is to provide an automatic precise lane-changing system and a lane-changing method for a two-vehicle scenario, which can precisely trigger the steering lane-changing operation when the longitudinal spacing is equal to the test spacing and precisely execute the lane-changing process according to the preset trajectory.

[0007] To achieve the above object, the technical solution adopted is: An automatic precise lane-changing system for a two-vehicle scenario, comprising:

[0008] A communication base station whose signal covers the test area of the two-vehicle scenario;

[0009] Two positioning antennas, which are respectively installed on the roofs of the host vehicle and the target vehicle;

[0010] Two communication processing modules are respectively arranged on the host vehicle and the target vehicle. Each communication processing module is respectively connected to its own ADCU controller and positioning antenna, and the two communication processing modules can communicate with each other;

[0011] The communication base station and the two positioning antennas reflect the positioning coordinates of the two vehicles to the two communication processing modules in real time. The two communication processing modules jointly calculate the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and send it to the ADCU controller of the target vehicle. When the longitudinal distance is equal to the test distance, the ADCU controller of the target vehicle triggers a lane change.

[0012] On the basis of the above technical solution, the communication processing module performs RTK carrier phase differential processing on the positioning coordinates of the two vehicles to calculate the longitudinal distance between the two vehicles; when the target vehicle triggers a lane change, the communication processing module of the target vehicle sends a notification steering signal to the communication processing module of the host vehicle.

[0013] On the basis of the above technical solution, when the ADCU controller controls the steering gear controller to perform a lane change, the ADCU controller calculates the theoretical deflection angle of the target vehicle according to the lateral distance between the two vehicles, the set lane change time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel.

[0014] On the basis of the above technical solution, the theoretical deflection angle θ of the target vehicle is

[0015]

[0016] where L H is the known lateral distance between the two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time of the target vehicle during the steering process; where t0 = t - 2t c , t is the set lane change time of the target vehicle during the lane change process, and t c is the time taken for the steering gear controller to control the steering wheel to rotate and transmit to the wheels.

[0017] On the basis of the above technical solution, the set t needs to make t0 satisfy the condition:

[0018] d2 + v2t0sinθ - v1t0 > L

[0019] where d2 is the test distance between the host vehicle and the target vehicle, v1 is the speed of the host vehicle, and L is the vehicle body length.

[0020] On the basis of the above technical solution, the ADCU controller sends θ and t to the steering gear controller, and the steering gear controller converts θ into the steering angle w of the steering wheel and controls the steering wheel to perform a lane change through w and t.

[0021] The present application also discloses a lane-changing method based on the above automatic precise lane-changing device, which includes the following steps:

[0022] The communication base station and the positioning antenna collect the positioning coordinates of the two vehicles in real time and send them to the communication processing module;

[0023] The communication processing module calculates the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and sends it to the ADCU controller of the target vehicle;

[0024] The ADCU controller determines whether the longitudinal distance is equal to the test distance. If so, proceed to the next step; if not, return to continue collecting coordinates;

[0025] The ADCU controller controls the steering gear controller to start executing the steering lane change.

[0026] Based on the above technical solution, the ADCU controller controls the steering gear controller to start executing the steering lane change, including:

[0027] The ADCU controller calculates the theoretical deflection angle of the target vehicle according to the lateral distance between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel.

[0028] Based on the above technical solution, the calculation method of the theoretical deflection angle θ of the target vehicle is

[0029]

[0030] where L H is the known lateral distance between the two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time during the steering process of the target vehicle;

[0031] where t0 = t - 2t c , t is the set lane-changing time during the steering lane change process of the target vehicle, and t c is the time taken for the steering gear controller to transfer the rotation of the steering wheel to the wheels;

[0032] where the set t needs to make t0 satisfy the condition:

[0033] d2 + v2t0sinθ - v1t0 > L

[0034] where d2 is the test distance between the host vehicle and the target vehicle, v1 is the speed of the host vehicle, and L is the vehicle body length.

[0035] Based on the above technical solution, the ADCU controller sends θ and t to the steering gear controller, and the steering gear controller converts θ into the steering angle w of the steering wheel and controls the steering wheel to execute the steering lane change through w and t.

[0036] The beneficial effects brought by the technical solution provided in this application include:

[0037] 1. In the automatic precise lane-changing system of this application, by setting up a communication base station, two positioning antennas and two communication processing modules, the communication base station and the two positioning antennas cooperate with each other to reflect the positioning coordinates of the two vehicles to the communication processing modules in real time. The two communication processing modules work together to calculate the longitudinal distance between the two vehicles in real time based on the positioning coordinates of the two vehicles, and send the calculated longitudinal distance to the ADCU controller of the target vehicle; when the longitudinal distance is equal to the test distance, the ADCU controller triggers a steering lane change.

[0038] The automatic precise lane-changing system of this application can locate the position coordinates of the two vehicles in real time, and use the position coordinates of the two vehicles as the condition for controlling and triggering the steering. It accurately uses the longitudinal distance equal to the test distance as the starting point of the steering, and triggers the steering lane-changing operation; compared with the manual cooperation operation of two drivers in the prior art, it greatly improves the accuracy of the starting point of the steering lane change, which is beneficial to carrying out various tests related to the two-vehicle scenario, especially a test scenario where a target vehicle in front cuts into and out of this lane. Through this device, the longitudinal distance from the vehicle in front can be accurately identified, and in the test, the cut-in and cut-out distances and lane-changing time with different speed thresholds can be used to accurately realize the automatic lane-changing function of the target vehicle at different vehicle speeds.

[0039] 2. On the basis of accurately triggering the steering lane change, the automatic precise lane-changing system of this application can also achieve precise steering lane change. When the ADCU controller triggers the steering lane change, the ADCU controller calculates the theoretical deflection angle of the target vehicle based on the lateral distance between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering machine controller to control the steering angle of the steering wheel.

[0040] In addition to newly setting up a communication base station, positioning antennas and communication processing modules, the automatic precise lane-changing system of this application also optimizes the internal program logic of the ADCU controller, enabling the ADCU controller to calculate the theoretical deflection angle of the target vehicle based on the lateral distance between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and use the theoretical deflection angle to guide the steering machine controller to control the steering angle of the steering wheel, and perform a precise steering lane-changing process. The steering angle and lane-changing time can make the driving trajectory of the vehicle consistent with the preset lane-changing trajectory. Compared with the prior art where the driving trajectories of two drivers are prone to errors, the automatic precise lane-changing system of this application has a more precise driving trajectory, which is beneficial to the on-site test of the two-vehicle scenario.

[0041] 3. In the automatic precise lane-changing system of this application, the theoretical deflection angle θ of the target vehicle is based on L H, v2 and t0 are obtained through careful calculations in combination with right-angled trigonometric functions. After ensuring the theoretical deflection angle θ and the set lane-changing time t, it can ensure that the target vehicle steers and changes lanes precisely according to the preset trajectory, which is conducive to the process of the two-vehicle scenario test.

[0042] In the automatic precise lane-changing system of this application, the ADCU controller controls the steering angle of the steering wheel according to θ, and then controls the wheel deflection angle. At the same time, it controls the diagonal driving time according to t, and makes the wheels return to the straight position after steering at the appropriate time to complete the entire steering process, which can achieve complete coincidence with the preset trajectory, meet the starting point of precise commutation, and also meet the precise commutation trajectory.

[0043] 4. The lane-changing method of this application is jointly executed by adding a communication base station, two positioning antennas, two communication processing modules, and the ADCU controller of the vehicle; the communication processing module calculates the longitudinal distance between the two vehicles in real time according to the two-vehicle positioning coordinates, and sends the calculated longitudinal distance to the ADCU controller of the target vehicle; the ADCU controller judges whether the longitudinal distance is equal to the test distance, and when it is equal, it starts to trigger the lane-changing steering, that is, the ADCU controller controls the steering gear controller to start executing the lane-changing steering.

[0044] The lane-changing method of this application can real-time locate the position coordinates of the two vehicles, and use the two-vehicle position coordinates as the condition for controlling and triggering the steering. It accurately uses the longitudinal distance equal to the test distance as the starting point of the lane-changing steering to trigger the lane-changing operation; compared with the manual cooperation operation of two drivers in the prior art, it greatly improves the accuracy of the starting point of the lane-changing steering, which is conducive to carrying out various tests related to the two-vehicle scenario. Description of the Drawings

[0045] In order to more clearly illustrate the technical solutions in the embodiments of this application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of this application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0046] Figure 1 It is a schematic diagram of the positions of the host vehicle and the target vehicle before and after the target vehicle steers and changes lanes in the two-lane scenario provided by the embodiment of this application;

[0047] Figure 2 It is a schematic diagram of the lane-changing distance and the theoretical steering angle of the target vehicle provided by the embodiment of this application;

[0048] Figure 3 It is a schematic diagram of the sequence of the execution components of the automatic precise lane-changing system and the entire lane-changing steering of the vehicle provided by the embodiment of this application;

[0049] Figure 4It is a flowchart of the lane-changing method provided by the embodiment of the present application. Detailed implementation manners

[0050] In order to make the objectives, technical solutions and advantages of the present application more clear and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0051] As Figures 1 to 4 shown, the present application discloses an embodiment of an automatic precise lane-changing system for a two-vehicle scenario, which can accurately trigger a steering lane-changing operation when the longitudinal distance is equal to the test distance and accurately execute the lane-changing process according to a preset trajectory; the automatic precise lane-changing system of the present application greatly improves the accuracy of the steering lane-changing starting point and the steering lane-changing process compared with the cooperation operation of two drivers, which is beneficial to carrying out various tests related to the two-vehicle scenario.

[0052] The automatic precise lane-changing system includes a communication base station, two positioning antennas and two communication processing modules. Among them, the communication base station has its signal covering the test area of the two-vehicle scenario, providing a good communication environment. The two positioning antennas are respectively installed on the roofs of the host vehicle and the target vehicle. Specifically, the host vehicle and the target vehicle have the same vehicle model and the same body length; regarding the specific installation position of the positioning antenna, after the positioning antenna and the vehicle body are projected downward, the positioning antenna is exactly located at the center of the rectangular projection of the vehicle body.

[0053] The two communication processing modules are respectively arranged on the host vehicle and the target vehicle. Each communication processing module is respectively connected to the ADCU controller and the positioning antenna of its own vehicle. The communication processing module not only has the function of transitional communication, but also has the function of data processing. The two communication processing modules can communicate with each other to facilitate the joint calculation of the relative distance between the two vehicles.

[0054] The communication base station and the two positioning antennas work together to reflect the positioning coordinates of the two vehicles to the two communication processing modules in real time; the two communication processing modules work together to calculate the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and send it to the ADCU controller of the target vehicle. The ADCU controller of the target vehicle triggers the execution of steering lane-changing when the longitudinal distance is equal to the test distance.

[0055] Specifically, after the two communication processing modules work together to calculate the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles, the communication processing module of the target vehicle sends the longitudinal distance to the ADCU controller of the target vehicle. The ADCU controller of the target vehicle takes the moment when the longitudinal distance is equal to the test distance as the starting point of the steering lane-changing.

[0056] Specifically, in the double-vehicle scenario test, the initial distance between the target vehicle and the host vehicle is less than the test distance and gradually increases during driving.

[0057] The automatic precise lane-changing system of the present application sets up a communication base station, two positioning antennas and two communication processing modules. The communication base station and the two positioning antennas cooperate with each other to reflect the positioning coordinates of the double vehicles to the communication processing modules in real time. The two communication processing modules work together to calculate the longitudinal distance between the double vehicles in real time according to the positioning coordinates of the double vehicles, and send the calculated longitudinal distance to the ADCU controller of the target vehicle; the ADCU controller makes a basic judgment, and when the longitudinal distance is equal to the test distance, it triggers a steering lane change. Specifically, the ADCU controller controls the steering controller of the vehicle to perform a steering lane change; the automatic precise lane-changing system of the present application can locate the position coordinates of the double vehicles in real time, and uses the position coordinates of the double vehicles as the condition for controlling and triggering steering, and precisely uses the longitudinal distance equal to the test distance as the starting point of steering, triggering the steering lane-changing operation; compared with the prior art where two drivers cooperate manually, it greatly improves the accuracy of the starting point of the steering lane change, which is beneficial for conducting various tests related to the double-vehicle scenario.

[0058] Specifically, the ADCU controller (Automated Driving Control Unit, also known as the autonomous driving control unit), as an intelligent computing platform, is applied to driverless vehicles. It can integrate computationally intensive sensor data processing and sensor fusion work with control strategy development into one control unit, and helps to establish a structured and organized vehicle controller network.

[0059] Preferably, the signal coverage radius of the communication base station is 300m, and the surrounding area is wide and unobstructed to meet the best signal reception, providing a basis for precise lane-changing operations. Figure 1 and Figure 2 Lane 1 and Lane 2 in

[0060] In one embodiment, the communication processing module performs RTK carrier phase differential processing on the positioning coordinates of the double vehicles to calculate the longitudinal distance between the double vehicles, which can make the calculation result of the longitudinal distance more precise, and the accuracy of the calculated longitudinal distance reaches the centimeter level.

[0061] When the two mutually communicating communication processing modules trigger a steering lane change of the target vehicle, the communication processing module of the target vehicle sends a notification steering signal to the communication processing module of the host vehicle. This notification steering signal can let the host vehicle know that the target vehicle will perform a steering, which is convenient for conducting the remaining site tests of the double-vehicle scenario.

[0062] The automatic precise lane-changing system of the present application transmits the positioning coordinates to the communication processing module. After differential processing, the accuracy of the coordinate positions of the two vehicles is greatly improved. The centimeter-level accuracy range enables more precise determination of the starting point for triggering steering, and greatly improves the accuracy of the lane-changing process, enhancing the reliability of the two-vehicle scenario field test.

[0063] Specifically, RTK (Real Time Kinematic) is a carrier phase differential technology, also known as real-time kinematic positioning technology, which has the function of differential correction and can improve the positioning accuracy.

[0064] Specifically, the test scenarios that the automatic precise lane-changing system of the present application can be applied to include but are not limited to:

[0065] ① The host vehicle is driving in lane 1, and the target vehicle overtakes from lane 2. The two vehicles are driving at a uniform speed. When the longitudinal distance between the two vehicles reaches the test spacing, the target vehicle automatically cuts into lane 1, which can be used to test the critical collision distance when the host vehicle brakes.

[0066] ② The host vehicle is driving in lane 1, and the target vehicle is accelerating in lane 2. When the longitudinal distance between the two vehicles reaches the test spacing, the target vehicle automatically cuts into lane 1, which can be used to test the shortest overtaking distance for the target vehicle to overtake and change lanes at different relative speeds.

[0067] Furthermore, on the basis of precisely triggering the steering and lane-changing, the automatic precise lane-changing system of the present application can also achieve precise steering and lane-changing.

[0068] When the ADCU controller triggers the steering and lane-changing, the ADCU controller calculates the theoretical deflection angle of the target vehicle according to the lateral spacing between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel. The lane-changing time is preset in the ADCU controller, and the driving speed of the target vehicle can be obtained by the ADCU controller.

[0069] The automatic precise lane-changing system of the present application, in addition to newly setting up a communication base station, a positioning antenna, and a communication processing module, also optimizes the internal program logic of the ADCU controller, enabling the ADCU controller to calculate the theoretical deflection angle of the target vehicle according to the lateral spacing between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and using the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel to perform a precise steering and lane-changing process. The steering angle and the lane-changing time can make the driving trajectory of the vehicle consistent with the preset lane-changing trajectory. Compared with the prior art where the driving trajectories are prone to errors when operated by two drivers, the automatic precise lane-changing system of the present application has a more precise driving trajectory, which is beneficial to the field test of the two-vehicle scenario.

[0070] In one embodiment, the theoretical deflection angle θ of the target vehicle is calculated as follows:

[0071]

[0072] where L H is the known lateral spacing between the two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time during the steering process of the target vehicle.

[0073] where t0 = t - 2t c , t is the set lane-changing time during the steering and lane-changing process of the target vehicle, which is preset in the ADCU controller; t c is the time taken for the steering controller to transfer the rotation of the steering wheel to the wheels when controlling the steering wheel.

[0074] Specifically, through a large number of experimental tests, t c is obtained as 0.5 seconds.

[0075] Specifically, during the actual steering and lane-changing process, from the zero position of the steering wheel before steering to the zero position of the steering wheel after steering, it includes:

[0076] The steering controller controls the steering wheel at the initial zero position to turn left by the steering angle w, and after a certain transfer time t c it is transferred to the wheels and the steering wheel returns to the zero position;

[0077] The vehicle travels straight from point A to point B;

[0078] The steering controller controls the steering wheel to turn right by w, and after a certain transfer time t c it is transferred to the wheels and the steering wheel returns to the zero position.

[0079] Specifically, L H is a fixed constant of 3.75 m, which is the width of the highway lane line.

[0080] For the automatic precise lane-changing system of the present application, the theoretical deflection angle θ of the target vehicle is obtained through careful calculation based on L H , v2 and t0 in combination with right-angled trigonometric functions. After ensuring the theoretical deflection angle θ and the set lane-changing time t, it can ensure that the target vehicle performs precise steering and lane-changing according to the preset trajectory, which is beneficial for the process of the two-vehicle scenario test.

[0081] As Figure 1 shown, the preset t needs to satisfy that after the target vehicle completes the steering and lane-changing, the two vehicles will not collide, that is, it is necessary to make t0 satisfy the condition:

[0082] d2 + v2t0sinθ - v1t0 > L

[0083] Among them, d2 is the test spacing between the host vehicle and the target vehicle, which is preset in the ADCU controller of the target vehicle; v1 is the speed of the host vehicle; v2 is the speed of the target vehicle; θ is the theoretical deflection angle of the target vehicle; L is the vehicle body length; L H is the known lateral spacing between the two vehicles.

[0084] Specifically, the host vehicle and the target vehicle have the same model, that is, the vehicle body lengths are the same, both being L.

[0085] Specifically, the derivation process of the above formula is as follows:

[0086] d1 > L;

[0087] That is, d2 + s2 - s1 > L;

[0088] That is, d2 + L0sinθ - s1 > L;

[0089] That is, d2 + v2t0sinθ - s1 > L;

[0090] That is, d2 + v2t0sinθ - v1t0 > L;

[0091] The automatic precise lane-changing system of this application sets the lane-changing time t. After careful calculation and consideration, it ensures that the two vehicles will not collide during the set t, further ensuring the safety of the test.

[0092] Furthermore, the ADCU controller sends θ and t to the steering gear controller. The steering gear controller converts θ into the steering angle w of the steering wheel and controls the steering wheel to perform lane-changing steering through w and t. Specifically, the steering gear controller obtains the steering angle w of the steering wheel according to θ, and then controls the wheel deflection angle. At the same time, the steering gear controller controls the diagonal driving time according to t, and makes the wheels return to the straight position after turning at the appropriate time, completing the entire steering process, which can achieve complete coincidence with the preset trajectory, meet the starting point of precise lane-changing, and also meet the precise lane-changing trajectory.

[0093] When the error μ between θ and the actual heading angle hdg satisfies = |θ - hdg|, it is considered that

[0094] From A to B is the cut-in driving trajectory of the target vehicle. And the steering angle w of the steering wheel is strongly correlated with θ. When the error value μ between the theoretical deflection angle θ and the actual heading angle hdg of the controlled vehicle is 0, the steering gear controller converts the corresponding theoretical deflection angle θ into the steering angle w of the steering wheel. At this time, the steering angle w of the steering wheel can exactly make the vehicle travel along the preset trajectory. The steering gear controller performs the lane-changing operation according to the steering angle w of the steering wheel and the lane-changing time t0, realizing the lane-changing steering with the same preset trajectory.

[0095] The present application also discloses a lane-changing method based on the above automatic precise lane-changing device, which includes the following steps:

[0096] The communication base station and the positioning antenna jointly and real-time collect the positioning coordinates of the two vehicles and send them to the communication processing module;

[0097] The communication processing modules of the two vehicles calculate the longitudinal distance between the two vehicles in real-time according to the positioning coordinates of the two vehicles and send it to the ADCU controller of the target vehicle;

[0098] The ADCU controller determines whether the longitudinal distance is equal to the test distance. If so, proceed to the next step; if not, return to continue collecting coordinates; specifically, the communication base station and the positioning antenna jointly and real-time collect the positioning coordinates of the two vehicles.

[0099] The ADCU controller controls the steering gear controller to start executing the steering lane change.

[0100] The lane-changing method of the present application is jointly executed through the newly added communication base station, two positioning antennas, two communication processing modules, and the ADCU controller of the vehicle; the communication processing module calculates the longitudinal distance between the two vehicles in real-time according to the positioning coordinates of the two vehicles and sends the calculated longitudinal distance to the ADCU controller of the target vehicle; the ADCU controller determines whether the longitudinal distance is equal to the test distance, and when it is equal, it starts to trigger the steering lane change, that is, the ADCU controller controls the steering gear controller to start executing the steering lane change.

[0101] The lane-changing method of the present application can real-time locate the position coordinates of the two vehicles and use the position coordinates of the two vehicles as the condition for controlling and triggering the steering, accurately using the longitudinal distance equal to the test distance as the starting point of the steering, and triggering the steering lane change operation; compared with the prior art in which two drivers cooperate manually, it greatly improves the accuracy of the starting point of the steering lane change and is conducive to conducting various tests related to the two-vehicle scenario.

[0102] Regarding the lane-changing method, in one embodiment, the communication processing module performs RTK carrier phase differential processing on the positioning coordinates of the two vehicles to calculate the longitudinal distance between the two vehicles, which can make the calculation result of the longitudinal distance more accurate, and the accuracy of the calculated longitudinal distance reaches the centimeter level.

[0103] When the two communication processing modules communicate with each other and the target vehicle triggers the steering lane change, the communication processing module of the target vehicle sends a notification steering signal to the communication processing module of the host vehicle. This notification steering signal can let the host vehicle know that the target vehicle will perform a steering, which is convenient for conducting the remaining site tests of the two-vehicle scenario.

[0104] The lane-changing method of this application transmits the positioning coordinates to the communication processing module. After differential processing, the accuracy of the coordinate positions of the two vehicles is greatly improved. The centimeter-level accuracy range enables a more accurate judgment of the starting point for triggering a turn, and greatly improves the accuracy of the lane-changing process, enhancing the reliability of the two-vehicle scenario field test.

[0105] Regarding the lane-changing method, further, on the basis of accurately triggering a turn for lane change, the automatic and accurate lane-changing system of this application can also achieve accurate turning for lane change.

[0106] The ADCU controller controls the steering gear controller to start executing a turn for lane change, including:

[0107] The ADCU controller calculates the theoretical deflection angle of the target vehicle based on the lateral distance between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel. The lane-changing time is preset in the ADCU controller, and the driving speed of the target vehicle can be obtained by the ADCU controller.

[0108] The lane-changing method of this application, in addition to newly setting up a communication base station, positioning antenna, and communication processing module, also optimizes the internal program logic of the ADCU controller, enabling the ADCU controller to calculate the theoretical deflection angle of the target vehicle based on the lateral distance between the two vehicles, the set lane-changing time, and the known driving speed of the target vehicle, and using the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel to perform an accurate turning for lane change process. The steering angle and lane-changing time can make the driving trajectory of the vehicle consistent with the preset lane-changing trajectory. Compared with the prior art where the driving trajectories are prone to errors when operated by two drivers, the automatic and accurate lane-changing system of this application has a more accurate driving trajectory, which is beneficial to the field test of the two-vehicle scenario.

[0109] Regarding the lane-changing method, the theoretical deflection angle θ of the target vehicle, the specific calculation process is

[0110]

[0111] where L H is the known lateral distance between the two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time during the steering process of the target vehicle.

[0112] where t0 = t - 2t c , t is the set lane-changing time for the target vehicle to turn for lane change, which is preset in the ADCU controller; t c is the time it takes for the steering gear controller to control the steering wheel to rotate and transmit to the wheels.

[0113] The lane-changing method of this application, the theoretical deflection angle θ of the target vehicle is based on L H, v2 and t0 are obtained through careful calculations in combination with right-angled trigonometric functions. After ensuring the theoretical deflection angle θ and the set lane-changing time t, it can be guaranteed that the target vehicle can accurately steer and change lanes according to the preset trajectory, which is beneficial for the process of the two-vehicle scenario test.

[0114] Furthermore, as Figure 1 shown, the preset t needs to satisfy that after the target vehicle completes the lane change, the two vehicles will not collide, that is, it is necessary to make t0 satisfy the condition:

[0115] d2 + v2t0sinθ - v1t0 > L

[0116] where d2 is the test distance between the host vehicle and the target vehicle, which is preset in the ADCU controller of the target vehicle; v1 is the speed of the host vehicle; v2 is the speed of the target vehicle; θ is the theoretical deflection angle of the target vehicle; L is the vehicle body length; L H is the known lateral distance between the two vehicles.

[0117] Specifically, the host vehicle and the target vehicle have the same model, that is, the vehicle body lengths are the same, both are L.

[0118] Specifically, the derivation process of the above formula is as follows:

[0119] d1 > L;

[0120] That is, d2 + s2 - s1 > L;

[0121] That is, d2 + L0sinθ - s1 > L;

[0122] That is, d2 + v2t0sinθ - s1 > L;

[0123] That is, d2 + v2t0sinθ - v1t0 > L;

[0124] For the automatic precise lane-changing system of this application, the set lane-changing time t is also carefully calculated and considered to ensure that the two vehicles will not collide during the set t, further ensuring the safety of the test.

[0125] Regarding the lane-changing method, the ADCU controller sends θ and t to the steering gear controller, and the steering gear controller converts θ into the steering angle w of the steering wheel and controls the steering wheel to execute the lane change through w and t.

[0126] Specifically, the steering gear controller obtains the steering angle w for controlling the steering wheel according to θ, and then controls the wheel deflection angle. At the same time, the steering gear controller controls the time of diagonal driving according to t, and makes the wheels return to the straight position after turning at the appropriate time to complete the entire steering process, which can achieve complete coincidence with the preset trajectory, meet the starting point of precise lane change, and also meet the precise lane-changing trajectory.

[0127] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present application. Unless otherwise clearly specified and defined, the terms "installed", "connected" and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0128] It should be noted that in the present application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the existence of additional identical elements in the process, method, article or device including the said element.

[0129] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. An automatic and precise lane-changing system for a two-vehicle scenario, characterized in that, Including: A communication base station whose signal covers the test area of the two-vehicle scenario; Two positioning antennas respectively installed on the roofs of the host vehicle and the target vehicle; Two communication processing modules respectively set in the host vehicle and the target vehicle, each communication processing module is respectively connected to its own ADCU controller and positioning antenna, and the two communication processing modules can communicate with each other; The communication base station and the two positioning antennas reflect the positioning coordinates of the two vehicles to the two communication processing modules in real time. The two communication processing modules jointly calculate the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and send it to the ADCU controller of the target vehicle. The ADCU controller of the target vehicle triggers a steering lane change when the longitudinal distance is equal to the test distance; When the ADCU controller controls the steering gear controller to perform a steering lane change, the ADCU controller calculates the theoretical deflection angle of the target vehicle according to the lateral distance between the two vehicles, the set lane change time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel; The theoretical deflection angle θ of the target vehicle is Among them, L H is the known lateral spacing between two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time during the steering process of the target vehicle; among them, t0 = t - 2t c , t is the set lane-changing time during the lane-changing process of the target vehicle's steering, and t c is the time transferred to the wheels when the steering controller controls the steering wheel to turn; The set t needs to make t0 satisfy the condition: d2 + v2t0sinθ - v1t0 > L Where d2 is the test distance between the host vehicle and the target vehicle, v1 is the speed of the host vehicle, and L is the vehicle body length.

2. The automatic precise lane-changing system for a two-vehicle scenario according to claim 1, characterized in that: The communication processing module performs RTK carrier phase differential processing on the positioning coordinates of the two vehicles to calculate the longitudinal distance between the two vehicles; when the target vehicle triggers a steering lane change, the communication processing module of the target vehicle sends a steering notification signal to the communication processing module of the host vehicle.

3. The automatic precise lane-changing system for a two-vehicle scenario according to claim 1, characterized in that, The ADCU controller sends θ and t to the steering gear controller, and the steering gear controller converts θ into the steering angle w of the steering wheel, and controls the steering wheel to perform a steering lane change through w and t.

4. A lane-changing method for the automatic and precise lane-changing system according to claim 1, characterized in that, Including the following steps: The communication base station and the positioning antenna collect the positioning coordinates of the two vehicles in real time and send them to the communication processing module; The communication processing module calculates the longitudinal distance between the two vehicles in real time according to the positioning coordinates of the two vehicles and sends it to the ADCU controller of the target vehicle; The ADCU controller judges whether the longitudinal distance is equal to the test distance. If so, proceed to the next step; if not, return to continue collecting coordinates; The ADCU controller controls the steering gear controller to start performing a steering lane change; The ADCU controller controls the steering gear controller to start performing a steering lane change, including: The ADCU controller calculates the theoretical deflection angle of the target vehicle according to the lateral distance between the two vehicles, the set lane change time, and the known driving speed of the target vehicle, and uses the theoretical deflection angle to guide the steering gear controller to control the steering angle of the steering wheel.

5. The lane-changing method of the automatic precise lane-changing system according to claim 4, characterized in that, The calculation method of the theoretical deflection angle θ of the target vehicle is Among them, L H is the known lateral spacing between two vehicles, v2 is the speed of the target vehicle, and t0 is the actual driving time during the turning process of the target vehicle; where \(t_0 = t - 2t'\), \(t\) is the set lane-changing time during the target vehicle's steering and lane-changing process, and \(t'\) is the time taken for the steering controller to transfer the steering wheel rotation to the wheels when controlling the steering wheel; c , \(t\) is the set lane-changing time during the target vehicle's steering and lane-changing process, and \(t\) c is the time taken for the steering controller to transfer the steering wheel rotation to the wheels when controlling the steering wheel; Where the set t needs to make t0 satisfy the condition: d2 + v2t0sinθ - v1t0 > L Where d2 is the test distance between the host vehicle and the target vehicle, v1 is the speed of the host vehicle, and L is the vehicle body length.

6. The lane-changing method of the automatic precise lane-changing system according to claim 4, characterized in that, The ADCU controller sends θ and t to the steering gear controller, and the steering gear controller converts θ into the steering angle w of the steering wheel, and controls the steering wheel to perform a steering lane change through w and t.

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