A ramp driving assistance method for mixed traffic scenarios with autonomous truck fleets

Abstract

The present invention discloses a ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy, including: obtaining the current motion information of the main vehicle; calculating the two-dimensional collision time index SACT according to the collision distance between the main vehicle and the autonomous driving freight convoy and the speed difference along the collision distance; calculating the time required for the autonomous driving freight convoy to travel to the ramp; calculating the driving time for the main vehicle to reach the ramp after acceleration and deceleration from the current state; and providing auxiliary information prompts for the main vehicle to exit the highway ramp. Aiming at the complex traffic environment in the vicinity of the highway exit ramp, the present invention focuses on the mixed traffic scenario of the interaction between manually driven vehicles and autonomous driving freight convoys, fully considers the physical characteristics and behavioral characteristics of vehicle driving, makes recommendations on the driver's choice of entering the ramp, and provides auxiliary prompt information such as speed limit reminders, vehicle distance reminders, voice navigation, and remaining distance.

Description

Technical Field

[0001] The present invention belongs to the technical field of driving assistance, and specifically relates to a ramp driving assistance method in a mixed traffic scenario with an autonomous driving freight fleet. Background Art

[0002] With the continuous development of autonomous freight fleet technology and the continuous improvement of new technology infrastructure construction, it is very likely that there will be a certain number of autonomous freight fleets on my country's highways in the future. Since autonomous driving technology is still in the early stages of development in commercial applications, the number of autonomous driving vehicles is small and its scope of use is limited. In the future, it is very likely that autonomous freight fleets and manually driven vehicles will be mixed on my country's highways. For this mixed traffic scenario, for manually driven vehicles, there may be differences in the driving speeds of autonomous freight fleets and manually driven cars. The speed mismatch problem can easily lead to changes in the relative positions of vehicles, increase the proximity between vehicles, and increase the risk of collision. At the same time, trucks have the characteristics of large size, heavy weight, poor vision, difficult control, and serious consequences of loss of control. The danger area is wider, which will affect the safety of manual drivers in nearby areas to a greater extent.

[0003] In view of the above complex mixed traffic scenarios, the driving assistance system is expected to provide a feasible solution to the above problems. In recent years, with the continuous advancement of science and technology, driving assistance technology has also achieved rapid development. Driving assistance technology can improve the safety, comfort and driving efficiency of drivers through communication between vehicles, between vehicles and infrastructure, and between vehicles and in-vehicle equipment. On the highway, the driving assistance system can assist the driver in adjusting driving speed, changing lanes, following vehicles and other driving behaviors by communicating with the autonomous driving freight fleet and providing vehicle information to reduce the distance between the truck and the truck, thereby avoiding traffic congestion. In addition, the driving assistance system can also monitor the driver's fatigue level and provide reminders to ensure the driver's safe driving. In general, the driving assistance system is expected to help drivers make reasonable lane change decisions in advance based on the auxiliary information, reduce the negative effects of the autonomous driving freight fleet on the manually driven vehicles, such as visual obstruction and psychological pressure, thereby improving the traffic safety of manually driven vehicles and reducing traffic accidents. Therefore, it is necessary to explore the safety impact of the driving assistance system on the forced lane change behavior of manually driven vehicles in this mixed traffic scenario.

[0004] Based on this, prior art 1, a method and an assistance system for preparing and / or implementing a lane change: The method relates to a method for automatically preparing and / or implementing a possible lane change of an own vehicle and a driving assistance system for implementing the method, so as to enable the own vehicle to move from the first lane to the second lane of a multi-lane road in flowing traffic with the help of a driving assistance system. When a sufficiently large gap is detected in an adjacent lane in flowing traffic and the lane can be changed and merged into the gap by lateral driving of the own vehicle, the driving assistance system signals the optional lane change with the help of a signal device. Specifically, the following steps are included:

[0005] Step 1: Detect the gap between adjacent lanes. The driving assistance system detects the gap between the vehicle and the lane adjacent to the first lane. The gap is between two vehicles running in front and behind.

[0006] Step 2: Adjust the following distance and speed. The driving assistance system adjusts the following distance and / or following speed of the vehicle relative to the vehicle ahead based on the detected gap information.

[0007] Step 3: Execute lane change. The lane change is achieved by moving the vehicle sideways and merging the vehicle into the gap between adjacent lanes.

[0008] The shortcomings of the prior art are:

[0009] 1. In this method, the auxiliary information is presented in the form of "You can change lanes to the left (or right)", and does not include auxiliary information such as remaining distance and speed limit.

[0010] 2. This method adjusts the following distance or following speed of the own vehicle through the driving assistance system. It is suitable for autonomous driving vehicles, but not suitable for lane change assistance for manually driven vehicles in mixed traffic scenarios.

[0011] 3. In this method, only the gap between the vehicle and the adjacent lane is considered, without focusing on the forced lane change behavior of the off-ramp, nor the safety indicators between vehicles and the current distance of the manually driven vehicle from the ramp. Therefore, the overall stability and safety may be low. Summary of the invention

[0012] The purpose of the present invention is to address the above-mentioned deficiencies in the prior art and to provide a ramp driving assistance method for mixed traffic scenarios with autonomous driving freight fleets, so as to solve the problem that the existing driving assistance system is suitable for autonomous driving vehicles but not suitable for lane change assistance for manually driven vehicles in mixed traffic scenarios.

[0013] In order to achieve the above object, the technical solution adopted by the present invention is:

[0014] A ramp driving assistance method for a mixed traffic scenario with an autonomous driving freight convoy comprises the following steps:

[0015] S1. Obtain the current motion information of the main vehicle;

[0016] S2, calculating a two-dimensional collision time indicator SACT based on the collision distance between the host vehicle and the autonomous truck fleet and the speed difference along the collision distance;

[0017] S3. Calculate the time T required for the autonomous truck fleet to reach the ramp P ;

[0018] S4. Calculate the driving time T of the main vehicle from the current state after acceleration and deceleration to reach the ramp m ;

[0019] S5. Based on the two-dimensional collision time indicator SACT, the time T required for the autonomous truck fleet to reach the ramp P , the driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m , providing auxiliary information prompts for the main vehicle when exiting the highway ramp.

[0020] Furthermore, the current motion information of the host vehicle in step S1 includes:

[0021] The coordinates, speed, acceleration, and remaining distance to the ramp of the main vehicle, as well as the current coordinates, speed, and remaining distance of the first vehicle in the autonomous freight fleet.

[0022] Furthermore, the calculation of the two-dimensional collision time index SACT in step S2 includes:

[0023] If the main vehicle lags behind the front vehicle of the autonomous truck convoy, that is, L m >L p , then the two-dimensional collision time index SACT is:

[0024]

[0025]

[0026] If the main vehicle is ahead of the front of the autonomous driving freight convoy, that is, Lm≤Lp, the two-dimensional collision time index SACT is:

[0027]

[0028]

[0029] Among them, L m is the current remaining distance of the main vehicle, L p is the distance from the first vehicle in the autonomous driving freight fleet to the ramp; L disis the collision distance between the host vehicle and the autonomous driving freight convoy, D is the Cartesian distance between the midpoints of the rear axles of the host vehicle and the autonomous driving freight convoy; l m The main vehicle length, car P 、car m are the rear wheelbases of the autonomous truck fleet and the main vehicle; V m is the main vehicle speed; V P is the speed of the autonomous freight convoy; α and θ are the angles between the line connecting the rear of the main vehicle and the midpoint of the front of the autonomous freight convoy and the vertical and horizontal lines; Δv is the speed difference between the main vehicle and the autonomous freight convoy along the collision distance.

[0030] Furthermore, in step S3, the time T required for the autonomous driving freight convoy to travel to the ramp is calculated. P ,include:

[0031]

[0032] Among them, V P is the driving speed of the autonomous freight convoy.

[0033] Furthermore, in step S4, the driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration is calculated. m ,include:

[0034]

[0035] Among them, t ACC The acceleration time required for the main vehicle to accelerate from the current state to complete the lane change and overtaking; t DEC L is the deceleration time of the main vehicle during the deceleration phase; slow The deceleration distance required for the main vehicle to decelerate to the target speed when it completes the overtaking action and enters the rightmost lane; V r V is the speed of the main vehicle when it completes the lane change and reaches the right lane; obj is the target speed for deceleration; a Dec The deceleration rate of the main vehicle during deceleration.

[0036] Furthermore, in step S5, the auxiliary information prompt for the host vehicle to exit the highway ramp includes an exit ramp plan recommendation, and the exit ramp plan recommendation includes:

[0037] If condition one or condition two is met, the driver of the main vehicle is recommended to speed up and overtake, and the screen will display "Lane change allowed, speed up and overtake recommended";

[0038] If condition one and condition two are not met, the driver of the main vehicle is advised to slow down and give way, and the screen will display "Lane change allowed, recommended to slow down";

[0039] in:

[0040] Condition 1: The driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m <Time T required for the autonomous truck fleet to reach the ramp P ;

[0041] Condition 2: Distance L from the main vehicle to the ramp main ≥500 and the two-dimensional collision time index SACT≥5.

[0042] Furthermore, the auxiliary information prompt for the host vehicle when exiting the highway ramp also includes a speeding reminder, and the speeding reminder is specifically:

[0043] If the main vehicle speed is higher than 120Km / h, a speed limit reminder will be given and the speeding icon will be displayed at the top of the screen; if the speed returns to below the 120Km / h speed limit, the speed limit icon will disappear.

[0044] Furthermore, the auxiliary information prompt for the host vehicle when exiting the highway ramp also includes a vehicle distance display, and the vehicle distance display is specifically: before the front vehicle changes lanes, the distance to the front vehicle is displayed in real time.

[0045] Furthermore, the auxiliary information prompt for the host vehicle when exiting the highway ramp also includes a remaining distance prompt, which specifically displays the distance from the host vehicle to the ramp to reduce the impact of visual occlusion of the autonomous driving freight fleet on the driver.

[0046] Furthermore, the auxiliary information prompt for the host vehicle to exit the highway ramp also includes voice navigation, and the voice navigation includes:

[0047] (1) When the remaining distance of the main vehicle is 3050 m, the message “After three kilometers, drive to the right and take a certain exit” is played for 5 seconds;

[0048] (2) When the remaining distance of the main vehicle is 2050 m, the message “Two kilometers later, drive to the right and take a certain exit” is played for 5 seconds;

[0049] (3) When the remaining distance of the main vehicle is 1050 m, the message “After one kilometer, drive to the right and take an exit” is played for 5 seconds;

[0050] (4) When the remaining distance to the main vehicle is 550 m, the message “After 500 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane” is played for 9 seconds;

[0051] (5) When the remaining distance to the main vehicle is 350 m, the message “After 300 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane” is played for 9 seconds;

[0052] (6) After the main vehicle reaches the ramp, the video “Drive to the right, enter the ramp, and take the exit” is played for about 5 seconds.

[0053] The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy provided by the present invention has the following beneficial effects:

[0054] The present invention focuses on the mixed traffic scenarios when manually driven vehicles interact with self-driving freight fleets in the vicinity of highway off-ramp areas. Combining the behavioral characteristics and safety risks of manually driven vehicles during their movement, the present invention constructs a highway off-ramp driving assistance method. It recommends off-ramp driving plans based on the driver's choice of entering the ramp, and provides auxiliary prompt information such as speed limit reminders, vehicle distance reminders, voice navigation, and remaining distance, aiming to improve driving safety and efficiency and optimize the driver's decision-making process when dealing with off-ramp scenarios.

[0055] 2. The present invention targets the complex traffic environment near the off-ramp of the highway, focuses on the mixed traffic scenarios of manually driven vehicles and autonomous driving freight fleets, fully considers the physical characteristics and behavioral features of vehicle driving, and establishes a model framework for recommending off-ramp solutions based on conflict and driving time according to the principles of reliability and applicability.

[0056] 3. The present invention designs an off-ramp driving assistance system based on a safe lane-changing strategy according to the readability, consistency and rationality of the auxiliary information, recommends a method for the driver to enter the ramp, and provides auxiliary prompt information such as speed limit reminder, vehicle distance reminder, voice navigation and remaining distance.

[0057] 4. The present invention can provide support for relevant management departments to formulate more scientific traffic rules and management policies, thereby promoting the safe operation of highway freight fleets, and providing data support and verification for the research and development and application of driving assistance systems, thereby improving traffic safety performance and human-computer interaction experience.

[0058] 5. The present invention constructs a two-dimensional collision time index SACT to more effectively identify potential traffic conflicts in lateral movements such as lane changing; and for the traffic scenario where manually driven vehicles and self-driving freight convoys are mixed in the vicinity of the highway off-ramp, the present invention fully considers the safety impact of the freight convoy on manually driven vehicles and constructs a model framework for recommending off-ramp solutions based on conflicts and driving time; the present invention organizes driving simulation experiments to collect experimental data, and through data analysis and statistical modeling, it is found that the highway off-ramp driving assistance system can reduce the psychological pressure of the driver during driving and can reduce the risk of accidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic diagram of the driving process of Example 1 of the present invention.

[0060] Figure 2 This is a flowchart of the solution recommendation framework of Example 1 of the present invention.

[0061] Figure 3 The SACT-L of Example 2 of the present invention dis Schematic diagram of the calculation process.

[0062] Figure 4 Schematic diagram of the SACT-Δv calculation process of Example 2 of the present invention.

[0063] Figure 5 Schematic diagram of the distance difference calculation process of embodiment 2 of the present invention.

[0064] Figure 6 This is the off-ramp driving assistance system information of embodiment 2 of the present invention.

[0065] Figure 7 This is a flow chart of a ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to Example 2 of the present invention. DETAILED DESCRIPTION

[0066] The specific implementation modes of the present invention are described below so that those skilled in the art can understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific implementation modes. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations utilizing the concept of the present invention are protected.

[0067] Example 1

[0068] This embodiment sets the following research scenario for a traffic scenario where manually driven vehicles and autonomous driving freight convoys are mixed in the vicinity of the highway off-ramp:

[0069] A manually driven car is driving on the highway. This car is the main vehicle. When approaching the exit ramp, it encounters a convoy of self-driving cars in the right lane (outer lane) of the two cars. At this time, the driver needs to go to a certain place according to the signs and navigation, and choose the right time to overtake the convoy or slow down and give way and wait for the convoy to pass before entering the exit ramp.

[0070] Combined with the motion characteristics of the scene, it is assumed that the initial motion stage of the main vehicle includes the acceleration stage of catching up with the convoy, the overtaking stage of changing lanes, and the deceleration stage of entering the ramp after overtaking. The driving process is as follows Figure 1 As shown, the safe overtaking time from the current state of the vehicle to the completion of overtaking and entering the ramp can be calculated.

[0071] refer to Figure 2When the main vehicle is allowed to change lanes and there are currently no safe lane change conditions, the driver will be advised to speed up to overtake or slow down to give way by calculating key indicators such as traffic conflict value and driving time in real time. The purpose is to enable the main vehicle to adjust its speed in advance to respond to the need to avoid the convoy entering the ramp.

[0072] Figure 2 In, L main is the distance from the main vehicle to the ramp; SACT is the collision time between the rear of the main vehicle and the front of the convoy; T m T is the time required for the main vehicle to travel from the current state to the end of safe overtaking and decelerate to the target speed at a certain deceleration rate; P It is the time it takes for the fleet to travel from the current state to the ramp.

[0073] When the main vehicle meets condition 1(T m <T P ), or condition 2 (L main ≥500 and SACT≥5), the driver is advised to speed up and overtake the convoy to enter the ramp. If not, the driver is advised to slow down and give way to the convoy to enter the ramp.

[0074] Example 2

[0075] Based on the scenario in Example 1, this embodiment provides a ramp driving assistance method for a mixed driving scenario with an autonomous driving freight convoy, and constructs a highway off-ramp driving assistance method, which recommends a solution for the driver to choose to enter the ramp, and suggests the driver to speed up to overtake or slow down to give way, and provides auxiliary prompt information such as speed limit reminder, vehicle distance reminder, voice navigation, and remaining distance. Figure 7 , which specifically includes the following steps:

[0076] Step S1, obtaining the current motion information of the main vehicle, which specifically includes:

[0077] The coordinates, speed, acceleration, and remaining distance to the ramp of the main vehicle, as well as the current coordinates, speed, and remaining distance of the first vehicle in the autonomous freight convoy;

[0078] Step S2: Calculate a two-dimensional collision time index SACT according to the collision distance between the main vehicle and the autonomous driving freight convoy and the speed difference along the collision distance, which specifically includes the following contents:

[0079] When calculating the time to collision between vehicles, the traditional TTC (Time to Collision) index may not be fully suitable because the main vehicle and the freight convoy are traveling in different lanes and involve lane-changing interactions. In order to more effectively identify potential traffic conflicts in lateral movements such as lane changing, this embodiment constructs a two-dimensional collision time index SACT, which is the collision distance L between the two vehicles. dis With two cars along Ldis The ratio of the speed difference in the direction;

[0080] refer to Figure 3 and Figure 4 , assuming that the heading angle of the vehicle is 0 during driving, the calculation process diagram is as follows Figure 3 and Figure 4 As shown, the left car represents the main car, and the right car represents the first car in the autonomous driving freight team. The specific calculation is as follows:

[0081] If the main vehicle lags behind the front vehicle of the autonomous truck convoy, that is, L m >L p , then the two-dimensional collision time index SACT is:

[0082]

[0083]

[0084] If the main vehicle is ahead of the front of the autonomous driving freight convoy, that is, Lm≤Lp, the two-dimensional collision time index SACT is:

[0085]

[0086]

[0087] Among them, L m is the current remaining distance of the main vehicle, L p is the distance from the first vehicle in the autonomous driving freight fleet to the ramp; L dis is the collision distance between the host vehicle and the autonomous driving freight convoy, D is the Cartesian distance between the midpoints of the rear axles of the host vehicle and the autonomous driving freight convoy; l m The main vehicle length, car P 、car m are the rear wheelbases of the autonomous truck fleet and the main vehicle; V m is the main vehicle speed; V P is the speed of the autonomous freight convoy; α and θ are the angles between the line connecting the rear of the main vehicle and the midpoint of the front of the autonomous freight convoy and the vertical and horizontal lines; Δv is the speed difference between the main vehicle and the autonomous freight convoy along the collision distance.

[0088] Step S3: Calculate the time T required for the autonomous driving freight convoy to reach the ramp P ;

[0089]

[0090] Among them, V P is the driving speed of the autonomous truck fleet; L P It is the distance from the first vehicle in the convoy to the ramp.

[0091] Step S4: Calculate the driving time T of the main vehicle from the current state after acceleration and deceleration to reach the ramp m , which specifically includes the following:

[0092] Calculate the acceleration time t required for the host vehicle to accelerate from the current state to complete lane change and overtaking ACC , the specific calculation method is as follows:

[0093]

[0094] Among them, L m The remaining distance of the main vehicle; L slow The deceleration distance required for the main vehicle to decelerate to the target speed at a certain deceleration rate when the main vehicle completes the overtaking action and enters the rightmost lane; ΔL2 is the overtaking distance of the main vehicle. The specific calculation diagram is as follows: Figure 5 As shown, the overtaking distance l m A is the length of the main vehicle, after the main vehicle changes lanes to overtake, the safe overtaking distance between the main vehicle and the front of the convoy, l U is the driving distance of the main vehicle before it catches up with the convoy and starts the forced lane change action, so the driving time in the acceleration phase is t ACC It can be expressed as:

[0095]

[0096] Calculate the deceleration time t of the main vehicle during deceleration Dec , the formula is as follows:

[0097]

[0098] Among them, t Dec For the master car, follow V r Decelerate to target speed V obj Required deceleration time; V r The speed of the main vehicle when it completes the lane change and reaches the right lane; a Dec The deceleration rate of the main vehicle during deceleration.

[0099] Based on this, the driving time T of the main vehicle from the current state to the ramp at a certain speed after acceleration and deceleration is m for:

[0100]

[0101] Among them, t ACC The acceleration time required for the main vehicle to accelerate from the current state to complete the lane change and overtaking; t DEC L is the deceleration time of the main vehicle during the deceleration phase; slowThe deceleration distance required for the main vehicle to decelerate to the target speed when it completes the overtaking action and enters the rightmost lane; V r V is the speed of the main vehicle when it completes the lane change and reaches the right lane; obj is the target speed for deceleration; a Dec The deceleration rate of the main vehicle during deceleration.

[0102] Step S5: according to the two-dimensional collision time index SACT and the time T required for the autonomous driving freight convoy to travel to the ramp P , the driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m , to provide auxiliary information prompts for the main vehicle to exit the highway ramp, which specifically includes the following information prompts:

[0103] 1. Recommended off-ramp plan;

[0104] Based on real-time data, the system calculates conflicts and driving time to make acceleration and deceleration judgments, and recommends off-ramp options to drivers, that is, recommends drivers to accelerate to overtake or decelerate to enter the ramp, thereby helping drivers to adjust and control vehicle speed in advance. The specific prompt options are:

[0105] If condition one or condition two is met, the driver of the main vehicle is recommended to speed up and overtake, and the screen will display "Lane change allowed, speed up and overtake recommended";

[0106] If condition one and condition two are not met, the driver of the main vehicle is advised to slow down and give way, and the screen will display "Lane change allowed, recommended to slow down";

[0107] When the driver completes the lane change, the auxiliary information recommended for the off-ramp option will no longer be displayed.

[0108] in:

[0109] Condition 1: The driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m <Time T required for the autonomous truck fleet to reach the ramp P ;

[0110] Condition 2: Distance from the main vehicle to the ramp L main ≥500 and the two-dimensional collision time index SACT≥5.

[0111] 2. Speeding reminder;

[0112] Once the main vehicle speed exceeds 120Km / h, a speed limit reminder will be given, that is, the speeding icon will be displayed at the top of the screen. If the speed returns to below the speed limit of 120Km / h, the speed limit icon will disappear, thereby reducing the risk of speeding.

[0113] 3. Vehicle distance display;

[0114] Before the vehicle in front changes lanes, the distance to the vehicle in front is displayed in real time to help drivers avoid rear-end collisions.

[0115] 4. Remaining distance prompt;

[0116] The distance from the main vehicle to the ramp is displayed throughout the entire process to reduce the impact of visual obstruction by the truck convoy on the driver. This helps the driver make lane change decisions in advance and avoid sudden lane changes when the distance to the ramp is too close.

[0117] 5. Voice navigation;

[0118] In order to enhance the driver's sense of reality, a voice navigation prompt is set in the driving simulation software; in this embodiment, the announcement is made 50 meters in advance at different remaining distances of the main vehicle, and the announcement sentences are:

[0119] (1) When the remaining distance of the main vehicle is 3050 m, the message “After three kilometers, drive to the right and take a certain exit” is played for 5 seconds;

[0120] (2) When the remaining distance of the main vehicle is 2050 m, the message “Two kilometers later, drive to the right and take a certain exit” is played for 5 seconds;

[0121] (3) When the remaining distance of the main vehicle is 1050 m, the message “After one kilometer, drive to the right and take an exit” is played for 5 seconds;

[0122] (4) When the remaining distance to the main vehicle is 550 m, the message “After 500 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane” is played for 9 seconds;

[0123] (5) When the remaining distance to the main vehicle is 350 m, the message “After 300 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane” is played for 9 seconds;

[0124] (6) After the main vehicle reaches the ramp, the video “Drive to the right, enter the ramp, and take the exit” is played for about 5 seconds.

[0125] refer to Figure 6 The auxiliary method of this embodiment will obtain the vehicle's operating information in real time and cyclically update the auxiliary information until the driver enters the ramp.

[0126] This embodiment designs an off-ramp driving assistance system based on a safe lane-changing strategy according to the readability, consistency and rationality of the auxiliary information, recommends a plan for the driver to choose to enter the ramp, and provides auxiliary prompt information such as speed limit reminder, vehicle distance reminder, voice navigation and remaining distance. It can provide support for relevant management departments to formulate more scientific traffic rules and management policies, thereby promoting the safe operation of highway freight fleets, and providing data support and verification for the research and development and application of driving assistance systems, thereby improving traffic safety performance and human-computer interaction experience.

[0127] Although the specific implementation of the invention is described in detail in conjunction with the drawings, it should not be understood as limiting the scope of protection of this patent. Within the scope described in the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy, characterized in that: The following steps are involved: S1. Obtain the current motion information of the main vehicle; S2, calculating a two-dimensional collision time indicator SACT based on the collision distance between the host vehicle and the autonomous truck fleet and the speed difference along the collision distance; S3. Calculate the time T required for the autonomous truck fleet to reach the ramp P ; S4. Calculate the driving time T of the main vehicle from the current state after acceleration and deceleration to reach the ramp m ; S5. Based on the two-dimensional collision time indicator SACT, the time T required for the autonomous truck fleet to reach the ramp P , the driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m , provide auxiliary information prompts for the main vehicle to exit the highway ramp; The step S2 of calculating the two-dimensional collision time index SACT includes: If the main vehicle lags behind the front vehicle of the autonomous truck convoy, that is, L m >L p , then the two-dimensional collision time index SACT is: If the main vehicle is ahead of the front of the autonomous driving freight convoy, that is, Lm≤Lp, the two-dimensional collision time index SACT is: Among them, L m is the current remaining distance of the main vehicle, L p is the distance from the first vehicle of the autonomous driving freight fleet to the ramp; L dis is the collision distance between the host vehicle and the autonomous truck convoy, D is the Cartesian distance between the midpoints of the rear axles of the host vehicle and the autonomous truck convoy; l m The main vehicle length, car P 、car m are the rear wheelbases of the autonomous truck fleet and the main vehicle; V m is the main vehicle speed; V P is the speed of the autonomous freight convoy; α and θ are the angles between the line connecting the midpoints of the rear of the main vehicle and the front of the autonomous freight convoy and the vertical and horizontal lines; Δv is the speed difference between the main vehicle and the autonomous freight convoy along the collision distance; In step S4, the driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration is calculated. m ,include: Among them, t ACC The acceleration time required for the main vehicle to accelerate from the current state to complete the lane change and overtaking; t DEC L is the deceleration time of the main vehicle during the deceleration phase; slow The deceleration distance required for the main vehicle to decelerate to the target speed when it completes the overtaking action and enters the rightmost lane; V r V is the speed of the main vehicle when it completes the lane change and reaches the right lane; obj is the target speed for deceleration; a Dec The deceleration rate of the main vehicle during deceleration; The auxiliary information prompt for the host vehicle to exit the highway ramp in step S5 includes a recommendation for an exit ramp plan, and the recommendation for an exit ramp plan includes: If condition one or condition two is met, the driver of the main vehicle is recommended to speed up and overtake, and "Lane change allowed, speed up and overtake recommended" is displayed on the screen; If condition 1 and condition 2 are not met, the driver of the main vehicle is advised to slow down and give way, and the screen displays "Lane change allowed, recommended to slow down"; in: Condition 1: The driving time T of the main vehicle from the current state to the ramp after acceleration and deceleration m <Time T required for the autonomous truck fleet to reach the ramp P ; Condition 2: Distance from the main vehicle to the ramp L main ≥500 and the two-dimensional collision time index SACT≥5.

2. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1 is characterized in that: The current motion information of the host vehicle in step S1 includes: The coordinates, speed, acceleration, and remaining distance to the ramp of the main vehicle, as well as the current coordinates, speed, and remaining distance of the first vehicle in the autonomous freight fleet.

3. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1 is characterized in that: In step S3, the time T required for the autonomous driving freight convoy to travel to the ramp is calculated. P ,include: Among them, V P is the driving speed of the autonomous freight convoy.

4. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1, characterized in that: The auxiliary information prompt for the host vehicle on the highway off-ramp also includes a speeding reminder, and the speeding reminder is specifically: If the main vehicle speed is higher than 120Km / h, a speed limit reminder will be given and the speeding icon will be displayed at the top of the screen; if the speed returns to below the 120Km / h speed limit, the speed limit icon will disappear.

5. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1, characterized in that: The auxiliary information prompt for the host vehicle when exiting the highway ramp also includes a vehicle distance display, and the vehicle distance display specifically includes: displaying the distance to the leading vehicle in real time before the leading vehicle changes lanes.

6. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1, characterized in that: The auxiliary information prompt for the host vehicle when exiting the highway ramp also includes a remaining distance prompt, and the remaining distance prompt specifically displays the distance from the host vehicle to the ramp to reduce the impact of visual occlusion of the autonomous driving freight fleet on the driver.

7. The ramp driving assistance method for mixed traffic scenarios with an autonomous driving freight convoy according to claim 1, characterized in that: The auxiliary information prompt for the host vehicle to exit the highway ramp also includes voice navigation, and the voice navigation includes: (1) When the remaining distance of the main vehicle is 3050 m, the message "After three kilometers, drive to the right and take a certain exit" is played for 5 seconds; (2) When the remaining distance of the main vehicle is 2050 m, the message "After two kilometers, drive to the right and take a certain exit" is played for 5 seconds; (3) When the remaining distance of the main vehicle is 1050 m, the message "After one kilometer, drive to the right and take a certain exit" is played for 5 seconds; (4) When the remaining distance to the main vehicle is 550 m, the message "After 500 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane" is played for 9 seconds; (5) When the remaining distance to the main vehicle is 350 m, the message "After 300 m, drive to the right, enter the ramp, take an exit, and drive in the rightmost lane" is played for 9 seconds; (6) After the main vehicle reaches the ramp entrance, play "Drive to the right front, enter the ramp, and take the exit" for 5 seconds.

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