Vehicle-following driving method, system and equipment for heavy commercial child-mother vehicle based on inter-vehicle communication

Abstract

The invention provides a following driving method, system and equipment for a heavy commercial child-mother vehicle based on inter-vehicle communication, and belongs to the technical field of commercial child-mother vehicles, the mother vehicle starts a predictive self-adaptive cruise function, and the child vehicle starts a following mode. The mother vehicle obtains speed limit and curvature information through a map and carries out dynamic planning in combination with the state of the mother vehicle. The child car receives the operation information of the mother car in real time through the DSRC technology and corrects the air resistance coefficient of the child car according to the distance between the cars. The child car determines a safe car-following distance according to the car speed, the load difference and the ramp, and the torque demand of the child car is calculated through an inverse dynamics model based on the mother car state. The sensor is kept coincident with the longitudinal center line of the mother vehicle, and the steering angle is calculated when transverse deviation occurs. And the child vehicle also performs smooth processing on the deceleration of the mother vehicle, and sends torque, steering and deceleration requests to the execution unit. According to the invention, the driving safety is improved, the fatigue strength of a driver is reduced, and safe exit during communication interruption is ensured.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of commercial parent-child vehicles, and particularly relates to a platooning driving method, system and equipment based on inter-vehicle communication for heavy commercial parent-child vehicles. BACKGROUND

[0002] The heavy commercial parent-child vehicle industry focuses on scenarios such as logistics and energy transportation, and is also used in coal transportation and remote route freight transportation fields. In terms of technology, the platooning technology realizes real-time synchronization of vehicle speed and position through V2V communication, and improves control accuracy in combination with an ADAS system.

[0003] In the related art, the air resistance coefficient of the child vehicle is calibrated based on the no-load and high-speed state of the single vehicle, without considering the change of the platooning distance with the parent vehicle. Generally, the smaller the distance, the stronger the wind-breaking effect of the parent vehicle, and the lower the air resistance coefficient of the child vehicle. This leads to overestimation of wind resistance loss when calculating the engine torque, and the child vehicle may accelerate excessively or maintain a high speed, resulting in fuel waste.

[0004] The related art adopts a platooning distance of 50-60 meters, without considering factors such as load difference of the parent-child vehicles and slope angle. This easily leads to collision caused by the parent vehicle pushing the child vehicle due to too close following. The existing deviation correction of the parent-child vehicles calculates the steering wheel angle based on the lateral deviation value, and a larger deviation is allowed at high speed, and the following distance is large. At low speed, the deviation needs to be adjusted. If the deviation accumulates slowly at high speed but is not adjusted in time, the deviation is adjusted excessively at low speed, the steering is frequent, and the platooning smoothness is affected. If the parent vehicle deceleration signal is not adapted to the load of the child vehicle, brake problems are caused, resulting in insufficient braking of the heavy child vehicle, which cannot follow the parent vehicle, or the light child vehicle brakes suddenly, and the brake coordination is poor. SUMMARY

[0005] The application provides a platooning driving method based on inter-vehicle communication for heavy commercial parent-child vehicles, which can improve driving safety, reduce fuel consumption of heavy commercial vehicles, and improve transportation efficiency.

[0006] The method comprises the following steps: S101: When the parent and child vehicles travel along the same route at the same place and the same time, the parent vehicle starts the predictive adaptive cruise function, and the child vehicle follows behind the parent vehicle and starts the platooning mode; S102: The parent and child vehicles exchange information, and the child vehicle obtains the running information of the parent vehicle; S103: The child vehicle determines the platooning distance with the parent vehicle according to the current vehicle speed of the child vehicle, the load difference between the parent and child vehicles, and the slope angle of the travel slope; S104: The child vehicle corrects the air resistance coefficient of the child vehicle according to the distance between the child and parent vehicles; S105: The child vehicle calculates the acceleration of the parent vehicle according to the obtained vehicle speed of the parent vehicle, and calculates the required engine torque of the child vehicle through a vehicle inverse dynamics model in combination with the corrected air resistance coefficient in S104. S106: The child vehicle determines the longitudinal center line of the parent vehicle through sensing and judges the position deviation of itself, thereby providing a judgment standard for lateral path correction; S107: When it is judged through S106 that there is a lateral deviation between the child vehicle and the parent vehicle, the child vehicle calculates the required steering wheel turning angle through single-point preview optimal value calculation according to the vehicle center line deviation provided by the sensing fusion unit and in combination with the following distance determined in S103; S108: The child vehicle acquires the deceleration of the parent vehicle and smoothes the request value of its own deceleration, and sends the engine torque obtained in S105, the steering wheel turning angle obtained in S107 and the request value to the execution unit for execution.

[0007] According to still another embodiment of the present application, an electronic device is also provided, which comprises a memory, a processor and a computer program stored in the memory and executable on the processor, and the processor implements the steps of the platooning driving method based on inter-vehicle communication of the heavy commercial child-parent vehicle when executing the program.

[0008] As can be seen from the above technical solutions, the present application has the following advantages: In the platooning driving method based on inter-vehicle communication of the heavy commercial child-parent vehicle provided by the present application, the child vehicle reduces the air resistance coefficient with the decrease of the following distance, calculates the engine torque in combination with the inverse dynamics model, reduces the power loss and lowers the fuel consumption. The longitudinal center line of the parent vehicle is identified through multi-modal sensing fusion of the camera and the radar, the steering wheel turning angle is calculated in combination with the following distance and the center line deviation, the child vehicle is aligned behind the parent vehicle when driving in a straight line, the child vehicle drives along the path of the parent vehicle when driving in a curve, and the lateral deviation is controlled within a preset range.

[0009] The deceleration of the parent vehicle is smoothed and adapted to the load of the child vehicle in the present application, the required deceleration is matched with the braking capability of the child vehicle, and the disadvantages of not being able to stop or sudden braking are avoided. The following distance model of the present application comprehensively considers the vehicle speed, load difference and slope angle, increases the following distance when driving downhill to avoid the shortening of the safety distance due to the gravitational acceleration, and reduces the distance when driving uphill to utilize the wind breaking of the parent vehicle to reduce the wind resistance and the collision risk. The communication interruption is monitored and the platooning is automatically exited, the driver is supported to exit autonomously, and the risk of losing control due to communication failure is avoided. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical solutions of the present application, the drawings required to be used in the description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0011] Figure 1 The system communication platooning framework diagram; Figure 2 Flow chart of the car-following driving method based on inter-vehicle communication for heavy commercial parent-child vehicle; Figure 3 Car-following schematic diagram; Figure 4 Single-point preview schematic diagram of child vehicle; Figure 5 Schematic diagram of the car-following driving system based on inter-vehicle communication for heavy commercial parent-child vehicle; Figure 6 Electronic device schematic diagram. DETAILED DESCRIPTION

[0012] As Figure 1 shown, the system for implementing the car-following driving method based on inter-vehicle communication for heavy commercial parent-child vehicle includes a parent vehicle with a predictive cruise function, a car-following model, and a child vehicle executing the car-following model.

[0013] The parent vehicle predictive cruise vehicle includes a perception data fusion unit, a human-computer interaction unit, a communication unit, and a vehicle motion state module; the car-following model includes data processing, air resistance coefficient correction, variable following distance, vehicle inverse dynamics model, lateral positioning, and steering machine angle calculation; and the child vehicle car-following driving vehicle includes a perception data fusion unit, a human-computer interaction unit, a communication unit, and an execution unit.

[0014] The perception fusion unit includes a camera, a driving assistance map, a millimeter wave radar, and a laser radar; the human-computer interaction unit includes an instrument, a buzzer, a key, and the communication unit includes a vehicle-mounted OBU communication device; the vehicle motion state module includes vehicle speed, gear, engine speed, brake, torque, accelerator pedal position, and steering wheel angle; and the execution unit includes an engine, a retarder, a gearbox, an EBS, and a steering machine.

[0015] The car-following driving method based on inter-vehicle communication for heavy commercial parent-child vehicle involved in the present application will be described in detail below. For the purpose of illustration but not for the purpose of limitation, specific details such as specific system structures, technologies, and the like are presented in order to thoroughly understand the embodiments of the present application. However, it should be clear to those skilled in the art that the present application can also be implemented in other embodiments without these specific details.

[0016] It should be understood that when used in the specification of the present application, the term "comprising" indicates the presence of the described features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or sets thereof. The terms "comprising", "including", "having" and their variants mean "including but not limited to", unless otherwise specifically emphasized.

[0017] The terms "one embodiment" or "some embodiments" used in this application mean that one or more embodiments of this application include the specific features, structures, or characteristics described in that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this application do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized.

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 2 The diagram shows a flowchart of a method for driving a heavy-duty commercial vehicle based on inter-vehicle communication in a specific embodiment. The method includes: S101: When the mother and child vehicles are traveling along the same route at the same location and time, the mother vehicle activates the predictive adaptive cruise control function, and the child vehicle follows behind the mother vehicle and activates the follow mode.

[0020] In some embodiments, the same location is determined by the latitude and longitude coordinates obtained by the on-board positioning modules of the two vehicles. When the difference between the coordinates of the two vehicles is less than a preset distance, they are determined to be the same location. The same time is determined by the on-board clocks of the two vehicles. When the time difference is less than a preset time difference, they are determined to be the same time. The same route is determined by comparing the preset driving routes in the navigation systems of the two vehicles. The predictive adaptive cruise control function of the mother vehicle is activated by the driver pressing the ACC button on the steering wheel. After activation, the system automatically loads the preset cruise parameters.

[0021] The child vehicle following mode is activated by the driver pressing the following activation button. When activated, the child vehicle OBU automatically sends a following request to the parent vehicle OBU. After the parent vehicle OBU responds, the child vehicle enters the following ready state, and the initial following position of the child vehicle is kept in the same lane as the parent vehicle.

[0022] It should be noted that the mother vehicle uses the driving assistance map to obtain the speed limit information of the road ahead, processes the data sent by its perception module, converts it into the data information required by the intelligent driving dynamic planning controller, and sends the vehicle speed, engine speed, engine torque, transmission gear, and braking torque signals from its own motion state module, together with the maximum speed limit and minimum speed limit from the data processing module, to the intelligent driving dynamic planning controller.

[0023] In some embodiments, the driving assistance map stores road speed limit information within a preset range ahead, including section speed limits and fixed-point speed limits. The mother vehicle perception module includes a front-facing monocular camera, a front-facing millimeter-wave radar, and a lidar. The road markings and obstacle distances collected by the perception module are transmitted to the data processing module, which filters noise from the data and converts it into data that can be recognized by the intelligent driving dynamic planning controller.

[0024] The vehicle motion status module in this embodiment includes a vehicle speed sensor, an engine speed sensor, a torque sensor, a transmission gear position sensor, and a braking torque sensor. These signals are transmitted in real time to the data processing module via a CAN bus. The data processing module integrates the motion status signals with the maximum / minimum speed limits and sends them to the intelligent driving dynamic planning controller. Based on this data, the controller formulates a driving strategy that adjusts the vehicle speed according to the speed limit and the steering according to the curvature, achieving predictive driving control.

[0025] In some specific embodiments, the mother vehicle uses a driving assistance map to obtain speed limit information for the road ahead, such as section speed limits or fixed-point speed limits. It then processes the data sent by the perception module and converts it into the data information required by the intelligent driving dynamic planning controller. The vehicle's current position information is in three-dimensional coordinates. Speed ​​limit information is The road curvature is The radius of curvature is .

[0026] The vehicle speed, engine speed, engine torque, transmission gear, and braking torque signals from the vehicle's own motion state module, along with the maximum and minimum speed limits from the data processing module, are sent to the intelligent driving dynamic programming controller. Finally, a dynamic programming controller model is established.

[0027] The dynamic programming controller model established in this embodiment is software logic embedded in the intelligent driving dynamic programming controller of the mother vehicle. It discretizes a continuous driving process into multiple consecutive stages. In each stage, based on the current position, vehicle speed, speed limit, and curvature, it selects the action that minimizes the total cost from the current stage to the destination from a series of possible control actions such as accelerating, cruising, and coasting. This plans a driving trajectory with the best overall performance from the current position to a point ahead.

[0028] The overall multi-objective optimization objective function involved in this embodiment is:

[0029] in, These are the weight coefficients for the three optimization objectives. Let fuel consumption be the objective function. Let fuel consumption be the objective function. Let the objective function be the magnitude of the acceleration. The engine torque per unit distance. The engine speed per unit distance. This refers to the engine fuel consumption rate per unit distance. The vehicle speed per unit distance. and Let K and K+1 be the vehicle speeds. For reference target speed.

[0030] Parameter constraints include: engine speed constraints.

[0031] Speed ​​limits

[0032]

[0033] Engine torque constraint:

[0034] Speed ​​constraints:

[0035] in, These are the calibration values ​​for the control system.

[0036] To find the optimal value, i.e., to minimize the objective function value at each stage, based on the principle of inverse optimization and forward solution, the optimal control value for stage N can be obtained:

[0037] By analogy, the optimal control value for the first stage can be derived:

[0038] The overall optimal value is:

[0039] In the above embodiments, core environmental information of the road ahead is obtained through a driving assistance map. Simultaneously, real-time road condition data is collected through the mother vehicle's camera and radar. This perceived data is converted into the vehicle's current position represented by three-dimensional coordinates and quantified road curvature values, which can be recognized by the intelligent driving dynamic planning controller. Real-time operating speed, engine speed, engine torque, transmission gear, and braking torque collected by the mother vehicle's own motion state module are integrated with preprocessed road speed limit information and transmitted together to the intelligent driving dynamic planning controller. This ensures that the controller simultaneously grasps both the vehicle's own capabilities and external driving constraints, preventing the planning strategy from deviating from the vehicle's actual performance or road rules.

[0040] Based on the above input data, a dynamic programming controller model is constructed, a multi-objective optimization objective function is set, and vehicle physical and safety constraints are clearly defined to ensure that the planning strategy conforms to the vehicle's mechanical limits and driving safety. Finally, a dynamic programming method of inverse optimization and forward solution is adopted. The optimal control value of each stage is calculated backward from the last Nth stage, and then the optimal values ​​of each stage are accumulated forward to obtain the overall optimal control strategy for the entire driving process. Ultimately, this results in the driving commands output by the mother vehicle.

[0041] S102: The on-board unit (OBU) devices of the mother vehicle and the daughter vehicle interact with each other through DSRC technology, enabling the daughter vehicle to obtain the vehicle operation information of the mother vehicle in real time. The vehicle operation information includes vehicle speed, gear, engine speed, brake pedal position, torque, accelerator pedal position, and steering wheel angle.

[0042] In some embodiments, based on DSRC dedicated short-range communication technology, a high-frequency, low-latency operation information exchange between the parent and child vehicles is realized through an encrypted message transmission mechanism. The child vehicle obtains the real-time driving status by parsing the parent vehicle's messages, providing dynamic reference for the child vehicle's car-following control and ensuring that the child vehicle can respond to the parent vehicle's acceleration, braking, and steering in a timely manner.

[0043] S103: As Figure 3 As shown, the child vehicle determines its following distance from the mother vehicle based on its current speed, the load difference between the child and mother vehicles, and the slope angle of the driving slope.

[0044] In some embodiments, the current vehicle speed of the subsidiary vehicle is measured by fusion of wheel speed sensors and GPS. The load difference between the parent and subsidiary vehicles is measured by the onboard weighing sensors of both vehicles. The slope angle α of the driving gradient is measured by the MEMS slope sensor of the subsidiary vehicle. The load adjustment coefficient A = 0.5m / t ± 0.05m / t. The gradient adjustment coefficient B = 2m / ° ± 0.2m / °. The following distance calculation is performed by the subsidiary vehicle's VCU, and the calculation result must meet the lower and upper limits; if the calculated value exceeds the range, the lower limit is used.

[0045] It should be noted that although a smaller distance between the parent and child vehicles results in lower air resistance and higher fuel economy, there is a certain lag in the child vehicle's following distance due to a delay of approximately 50ms in DSRC communication. Furthermore, the loads of the parent and child vehicles differ, and braking distance is directly proportional to load. When the vehicle is going uphill, the following distance can be closer due to gravitational deceleration along the slope; conversely, when the vehicle is going downhill, the following distance needs to be greater due to gravitational acceleration along the slope. Therefore, the following distance model is related to vehicle speed, the load difference between the parent and child vehicles, and the slope size, as detailed below:

[0046] in, The current speed of the vehicle. For communication time delay, B is the load adjustment factor, and A is the ramp adjustment factor. For the load of the subcar, For the load of the mother car, The slope angle is denoted by .

[0047] The following distance in this embodiment simultaneously satisfies the requirements of response safety under communication delay, braking safety under load differences, and driving safety under gravity on slopes. The higher the vehicle speed, the longer the braking distance due to communication delay, requiring an increased following distance; the greater the load difference between the parent and child vehicles, the greater the difference in braking performance, requiring an increased distance; when going downhill, the vehicle accelerates due to gravity, increasing the braking distance, requiring an increased distance; when going uphill, gravity decelerates, shortening the braking distance, allowing for a shorter distance; through comprehensive quantitative calculations of these three factors, a safe and economical following distance is determined.

[0048] S104: The daughter car adjusts its own air resistance coefficient based on the distance between itself and the mother car.

[0049] In some embodiments, the distance between the subsidiary vehicle and the parent vehicle is measured by the subsidiary vehicle's front-mounted radar. The empirical drag coefficient is obtained through real-vehicle testing. The drag coefficient correction calculation is performed by the subsidiary vehicle's VCU (Vehicle Control Unit). The VCU receives the distance d measured by the radar and substitutes it into the correction formula to calculate the drag coefficient. The results are then sent to the vehicle's power control module.

[0050] It should be noted that since the subsidiary car follows the parent car and receives airflow from it, the air velocity and pressure changing as it passes through the subsidiary car cause a change in its air resistance coefficient. Therefore, a correction is needed for the air resistance coefficient. The specific relationship is as follows:

[0051] in, Distance between the child vehicle and the mother vehicle d air drag coefficient at that time This is the air resistance coefficient when the vehicle is moving alone. and This is an empirical coefficient for air resistance. d This refers to the distance between the mother and child vehicles.

[0052] It can be seen that when the child vehicle follows the mother vehicle, the "wind-breaking" effect of the mother vehicle on the airflow causes changes in the airflow field around the child vehicle, and the air resistance coefficient decreases as the distance between the two vehicles decreases. Based on the empirical coefficient calibrated on the actual vehicle and the real-time measured distance between the two vehicles, the air resistance coefficient of the child vehicle is dynamically corrected so that the coefficient value matches the air resistance situation in the actual following scenario, providing accurate parameters for power calculation.

[0053] S105: The child vehicle calculates the acceleration of the mother vehicle based on the obtained speed of the mother vehicle, and calculates the required engine torque by combining the air resistance coefficient corrected in S103 through the vehicle inverse dynamics model.

[0054] In some embodiments, the acceleration of the mother vehicle is calculated using the speed data received by the daughter vehicle, employing the differentiation between two consecutive speed samples. The input parameters for the vehicle inverse dynamics model, in addition to the mother vehicle acceleration and the S104 correction value, include the daughter vehicle rolling resistance coefficient f, transmission system efficiency, tire radius, rotational mass conversion factor, daughter vehicle mass, and gravitational acceleration. Engine torque calculation is performed by the daughter vehicle power control module; the calculation result must meet engine torque constraints, and if exceeded, the limit value is used.

[0055] It should be noted that the engine torque of this vehicle was calculated using a vehicle inverse dynamics model.

[0056] in: This refers to engine torque. This refers to the gear ratio of the transmission. The transmission ratio of the main reducer. The transmission efficiency of the transmission mechanism For the tire radius, For rolling friction resistance, For slope, air drag coefficient, For the windward cross-sectional area, air density, Current vehicle speed This is the rotational mass conversion factor.

[0057] The vehicle inverse dynamics model is based on the equation: power demand = driving resistance + inertial force. Driving resistance includes air resistance, rolling resistance, and gradient resistance. Inertial force is proportional to acceleration and the conversion factor of rotational mass. By inversely estimating the engine torque required to overcome these forces through the model, the power output of the subsidiary vehicle can match the acceleration of the parent vehicle, achieving speed synchronization during following, enabling the subsidiary vehicle to smoothly follow the speed changes of the parent vehicle and improving the smoothness of following.

[0058] S106: The subcar determines the longitudinal centerline of the mother car through its own camera and radar, and judges whether its own longitudinal centerline coincides with the longitudinal centerline of the mother car based on its own position, so as to ensure that it is directly behind the mother car when driving in a straight line and follows the path of the mother car when driving on a curve.

[0059] In some embodiments, the daughter vehicle camera is a front-facing camera, and the radar is a front-wave radar. The identification of the mother vehicle's longitudinal centerline involves capturing images of the rear of the mother vehicle using the camera, employing an image edge detection algorithm to identify the reflective strips on both sides of the rear of the mother vehicle, and taking the line connecting the midpoints of the two reflective strips as the longitudinal centerline of the mother vehicle. Radar-assisted verification involves measuring the distances between the two sides of the mother vehicle, taking the longitudinal line corresponding to the average distance as the centerline, and comparing it with the camera's identification result. The daughter vehicle's longitudinal centerline is the symmetrical centerline of the vehicle body. When driving in a straight line, if the lateral deviation of the two vehicle centerlines is less than the lateral deviation threshold, they are considered to coincide. When driving in a curve, the turning radius of the mother vehicle is calculated based on the steering wheel angle and vehicle speed, and the daughter vehicle plans a path with the same radius. If the centerline deviation is less than the turning deviation threshold, they are considered to coincide; if the deviation exceeds the limit, steering adjustment S108 is triggered.

[0060] S107: When it is determined through S106 that there is a lateral deviation between the slave vehicle and the parent vehicle, the slave vehicle, based on the vehicle centerline deviation provided by the perception fusion unit and combined with the following distance determined in S103, such as... Figure 4 As shown, the required steering wheel angle is calculated by using the optimal value of single-point pre-aiming.

[0061] In some embodiments, the perception fusion unit employs a Kalman filter algorithm to fuse deviation data from cameras, radar, and IMU, outputting the vehicle centerline deviation. The determined following distance d is the current real-time distance. The vehicle speed v is measured via GPS, the vehicle wheelbase L is the vehicle's factory calibration value, and the transmission ratio i is the steering system transmission ratio. The steering wheel angle calculation is performed by the vehicle's steering motor controller, with the calculation result ranging from -450° to +450°, and is then sent to the steering actuator.

[0062] In this embodiment, when it is determined that there is a lateral deviation between the child vehicle and the vehicle in front, the deviation of the vehicle centerline is obtained through the perception fusion unit. The required steering wheel angle for the vehicle is obtained by using the single-point pre-aiming optimal value calculation formula:

[0063]

[0064]

[0065]

[0066] By combining the above formulas, we can determine the steering wheel angle:

[0067] in, For steering wheel angle, This refers to the vehicle's wheelbase. The vehicle's lateral position. For the vehicle's lateral acceleration, For vehicle speed, The transmission ratio of the transmission system. Where is the turning radius, and T is the forward look-ahead time. For the following distance.

[0068] The vehicle anticipates future deviation changes over a preset time period based on the current lateral deviation and following distance. It calculates the required steering angle using geometric relationships; a longer following distance results in a smaller required steering angle for the same deviation. Higher vehicle speeds require longer anticipation times, leading to smoother steering adjustments. The steering wheel angle is determined through single-point anticipation calculations, driving the steering mechanism to correct the vehicle's direction and eliminate lateral deviation.

[0069] S108: The child vehicle obtains the deceleration of the parent vehicle and smooths it to obtain the requested value of its own deceleration. It then sends the engine torque obtained in S105, the steering wheel angle obtained in S107, and the requested value to the execution unit for execution.

[0070] In some embodiments, the smoothing process employs a weighted moving average algorithm, taking five consecutive deceleration sampling points with weighting coefficients of 0.1, 0.2, 0.4, 0.2, and 0.1 respectively. After smoothing, the deceleration fluctuation amplitude is reduced. In this embodiment, the controller is the vehicle control unit (VCU), and the control request priority is determined as follows: braking request > steering request > power request. The execution units include the engine control unit (ECU), the steering motor control unit (EPS), and the brake master cylinder control unit (EBCU).

[0071] S109: If communication between the parent and child vehicles is interrupted or packets are lost during the car-following process, the car-following function will be discontinued, the instrument display of the human-machine interface unit will display the discontinuation information, the buzzer will sound an alarm, and the vehicle will continue to drive in the state before the function was discontinued until the driver intervenes and stops control.

[0072] In some embodiments, the communication interruption determination condition is: the slave vehicle OBU fails to receive the master vehicle's heartbeat message three times consecutively, or receives two consecutive verification failure data messages. The car-following function exit is triggered by the slave vehicle VCU. After exiting, the VCU sends a command to the human-machine interface unit, the instrument panel displays a prompt message, and the reason for exiting is shown. The buzzer is an on-board audible and visual alarm that sounds continuously until the driver takes over. The vehicle maintains its speed, gear, and steering position as before exiting. Driver intervention is determined by the driver operating the brake pedal, accelerator pedal, or turning the steering wheel. After intervention, the VCU stops controlling the vehicle, improving the fault tolerance and safety of the car-following system.

[0073] S110: If the driver of the vehicle stops following the car during the following process, he / she can exit the following function by pressing a button in the human-machine interaction unit.

[0074] In some embodiments, a way is provided for the driver to manually intervene in the car-following function. The exit process is triggered by pressing a button. When exiting, the parent vehicle is notified first, and then the control authority is smoothly transferred. Multi-dimensional feedback is provided through lights, instruments, and sounds to ensure that the driver is clearly aware of the changes in the function status.

[0075] In one embodiment of the present invention, based on step S106, the following is a possible embodiment and its specific implementation will be described in a non-limiting manner. S106 further includes the following steps: S1061: The daughter vehicle collects data on the mother vehicle body and the surrounding environment.

[0076] In some embodiments, the sub-vehicle utilizes the complementary characteristics of different sensors to achieve timestamp alignment of multi-sensor data through a data synchronization triggering mechanism, and then performs interference suppression on the data of each sensor according to the environmental type to ensure the validity of the body data of the parent vehicle.

[0077] S1062: The slave vehicle receives the real-time operation information of the master vehicle and the road curvature information processed by the master vehicle. Based on the driving parameters of the master vehicle and the road characteristics, it generates the predicted trajectory of the longitudinal centerline of the master vehicle within a preset time period and determines the dynamic change trend of the centerline of the master vehicle.

[0078] In some embodiments, after the child vehicle receives the steering wheel angle, vehicle speed and road curvature of the mother vehicle, it divides the future time interval into a preset time interval with the current time as the starting point and a preset time step. Within each time interval, the change in the driving direction of the mother vehicle is determined according to the change rate of the steering wheel angle of the mother vehicle, the change rate of the vehicle speed and the change trend of the road curvature, and then the longitudinal centerline coordinates of the mother vehicle at each time node are generated.

[0079] S1063: The sub-vehicle collects its own body posture data through the on-board suspension displacement sensor and body tilt sensor. Based on the sub-vehicle load, the offset of the body posture from the sensor's perception angle is calculated, and the identification reference position of the longitudinal centerline of the mother vehicle is corrected to eliminate the identification deviation caused by the sub-vehicle's heavy load causing the body to sink or tilt when turning.

[0080] In some embodiments, when the sub-vehicle is heavily loaded, the vehicle body will sink by a preset size due to suspension compression, causing the viewing angle of the front sensor to shift downward. The viewing angle originally aimed at the center of the mother vehicle will shift to the rear of the mother vehicle, resulting in a lower centerline recognition. The viewing angle offset is calculated by the vehicle body attitude parameters, and the recognized centerline coordinates of the mother vehicle are corrected upward. At the same time, the lateral coordinates are corrected according to the lateral roll angle to ensure that the recognition reference is consistent with the actual centerline of the mother vehicle.

[0081] S1064: The child vehicle determines the traffic density of the current road segment through the environmental perception module. If the traffic density is higher than the preset traffic density threshold, the recognition area of ​​the longitudinal center line of the mother vehicle is limited to the preset high reflectivity mark at the rear of the mother vehicle. If the traffic density is lower than the preset threshold, the recognition area is extended to the outline of both sides of the mother vehicle to improve recognition stability.

[0082] In some embodiments, in congested road sections, surrounding vehicles are likely to enter the sensor detection range of the child vehicle. If the recognition area is too large, the outline of adjacent vehicles may be misjudged as the center line of the mother vehicle. By reducing the recognition area to the exclusive mark at the rear of the mother vehicle, interference from other vehicles can be eliminated. In open road sections without interference, expanding the recognition area to the entire vehicle body can improve the center line recognition accuracy by utilizing the symmetry of the outlines on both sides of the mother vehicle body.

[0083] S1065: The child vehicle retrieves the lane marking data of the current road segment from the driving assistance map at preset intervals, compares the longitudinal centerline of the mother vehicle identified and corrected by S1061-S1064 with the road centerline in the map, and updates the child vehicle's recognition benchmark for the longitudinal centerline of the mother vehicle at preset centerline deviation thresholds to eliminate the accumulation of deviations during long-term following.

[0084] In some embodiments, during car following, slight drift of the child vehicle's sensor can cause the centerline recognition deviation to gradually accumulate, while the road lane centerline is a fixed reference benchmark. By periodically comparing the parent vehicle's centerline with the lane centerline, the fixedness of the lane centerline is used to correct the recognition deviation and avoid the accumulation of deviations.

[0085] In one embodiment of the present invention, based on step S108, the following will provide a possible embodiment and its specific implementation will be described in a non-limiting manner. Step S108 further includes the following steps: Step S1081: The sub-vehicle receives a continuous speed data stream from the mother vehicle in real time through the on-board communication module.

[0086] In this embodiment, the on-board unit (OBU) of the child vehicle continuously receives vehicle operation information messages broadcast by the OBU of the parent vehicle at a preset time period, and parses the instantaneous speed value of the parent vehicle from the messages, ensuring that the status of the preceding vehicle on which the car-following system makes decisions is up-to-date and continuous.

[0087] Step S1082: The VCU of the subcar performs time difference calculation on the received continuous speed data of the mother car to obtain the original deceleration sequence of the mother car.

[0088] In this embodiment, the VCU of the slave vehicle records the speed values ​​of the parent vehicle and the corresponding timestamps received at the current and previous moments, and calculates the instantaneous raw deceleration of the parent vehicle. Using the basic physical definition of the rate of change of speed, the vehicle speed information is converted into deceleration information that can directly reflect the braking intention of the vehicle in front.

[0089] Step S1083: The VCU of the subcar uses a first-order low-pass filter to smooth the original deceleration sequence in order to suppress high-frequency jitter in the data.

[0090] In this embodiment, due to communication noise, sensor errors, and subtle fluctuations in the driver's operation, the calculated original deceleration sequence will exhibit high-frequency jitter. The VCU uses a calibrated low-pass filter with a cutoff frequency to process this sequence, filtering out unreasonable abrupt changes and outputting a smooth, gradual deceleration signal. This improves ride comfort and fuel economy, and reduces mechanical wear on the actuators.

[0091] Step S1084: The VCU of the subcar will map the smoothed deceleration of the mother car, combined with the preset safety distance model, to the target deceleration required by the subcar itself.

[0092] In this embodiment, the VCU receives the smoothed deceleration of the parent vehicle. It doesn't simply use this directly as the deceleration of the child vehicle, but rather combines it with a real-time safe distance model calculated from parameters such as vehicle speed, weight, and road conditions. For example, considering a predetermined following distance, when the actual distance between the two vehicles is much smaller than the safe distance, the child vehicle's calculated required deceleration will be appropriately greater than the parent vehicle's deceleration to increase the distance more quickly; conversely, it may be slightly smaller to ensure smooth following. In this way, by combining the preceding vehicle's intentions with its own safety boundaries, a final control target value is generated that both responds to the preceding vehicle's actions and conforms to its own safety strategy.

[0093] Step S1085: The VCU of the sub-vehicle encapsulates the target required deceleration, engine torque request value and steering wheel angle request value into a unified control command frame, and sends it to the corresponding actuator unit through the vehicle CAN bus.

[0094] In this embodiment, the VCU vehicle controller coordinates and encapsulates lateral and longitudinal control requests to form standardized data frames, which are then sent to the Electronic Power Steering (EPS), Engine Management System (EMS), and Electronic Braking System (EBS) via the CAN bus. This ensures the integrity and consistency of vehicle control and improves system integration and reliability.

[0095] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0096] The following are embodiments of a heavy-duty commercial vehicle following-drive system based on inter-vehicle communication provided in this disclosure. This system and the heavy-duty commercial vehicle following-drive method based on inter-vehicle communication in the above embodiments belong to the same inventive concept. For details not described in detail in the embodiments of the heavy-duty commercial vehicle following-drive system based on inter-vehicle communication, please refer to the embodiments of the heavy-duty commercial vehicle following-drive method based on inter-vehicle communication.

[0097] like Figure 5 As shown, the system includes: The follow-car mode activation module 201 is used when the mother car and the child car are traveling along the same route at the same location and at the same time, the mother car activates the predictive adaptive cruise control function, and the child car follows behind the mother car and activates the follow-car mode. Vehicle information interaction module 202 is used for information interaction between the mother and child vehicles, allowing the child vehicle to obtain the operating information of the mother vehicle; The following distance determination module 203 is used to enable the child vehicle to determine the following distance with the mother vehicle based on its current speed, the load difference between the child and mother vehicles, and the slope angle of the driving slope. The air resistance correction module 204 is used to correct the air resistance coefficient of the subcar based on the distance between it and the mother car. The torque calculation module 205 is used to enable the sub-vehicle to calculate the acceleration of the mother vehicle based on the acquired speed of the mother vehicle, and to calculate the required engine torque for itself through the vehicle inverse dynamics model after correcting the air resistance coefficient. The longitudinal detection module 206 is used to enable the subcar to determine the longitudinal centerline of the mother car through sensing and to judge its own position deviation, providing a judgment standard for lateral path correction; The steering wheel angle calculation module 207 is used to calculate the required steering wheel angle by using the single-point pre-aiming optimal value when it is determined that there is a lateral deviation between the child vehicle and the parent vehicle. The child vehicle determines the following distance based on the vehicle centerline deviation provided by the perception fusion unit. The execution module 208 is used to enable the child vehicle to obtain the deceleration of the mother vehicle and smooth it to obtain the requested value of its own deceleration, and send the obtained engine torque, the obtained steering wheel angle and the requested value to the execution unit for execution.

[0098] like Figure 6 As shown, this application also provides an electronic device, including a display module 103, a memory 102, a processor 101, and a computer program stored in the memory and executable on the processor 101. When the processor 101 executes the program, it implements the steps of a method for following a heavy commercial vehicle based on inter-vehicle communication.

[0099] In embodiments of the present invention, electronic devices include, but are not limited to, laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the embodiments described and / or claimed herein.

[0100] In this embodiment, processor 101 may be implemented using at least one of an application-specific integrated circuit, a programmable logic device, a field-programmable gate array, a processor, a controller, a microcontroller, a microprocessor, or an electronic unit designed to perform the functions described herein. In some cases, such an implementation may be implemented within a controller. For software implementation, implementations such as processes or functions may be implemented with separate software modules that allow the performance of at least one function or operation. Software code may be implemented by a software application (or program) written in any suitable programming language, and the software code may be stored in memory and executed by the controller.

[0101] The display module 103 is used to display information input by the user or information provided to the user. The display module 103 may include a display panel, which may be configured in the form of a liquid crystal display, an organic light-emitting diode, or the like.

[0102] The memory 102 can be used to store software programs and various data. The memory 102 may include high-speed random access memory, and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other volatile solid-state storage device.

[0103] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for car-following driving of heavy-duty commercial vehicles based on inter-vehicle communication, characterized in that, The methods include: S101: When the mother and child vehicles are traveling along the same route at the same location and time, the mother vehicle activates the predictive adaptive cruise control function, and the child vehicle follows behind the mother vehicle and activates the follow mode. S102: Information exchange between mother and daughter vehicles, where the daughter vehicle obtains operating information from the mother vehicle; S103: The slave vehicle determines the following distance from the mother vehicle based on its current speed, the load difference between the slave and mother vehicles, and the slope angle of the driving slope; S104: The daughter car adjusts its own air resistance coefficient based on the distance between it and the mother car; S105: The subcar calculates the acceleration of the mother car based on the obtained speed of the mother car, and calculates the required engine torque by combining the air drag coefficient corrected in S104 through the vehicle inverse dynamics model. S106: The subcar determines the longitudinal centerline of the mother car through sensing and judges its own positional deviation, providing a judgment standard for lateral path correction; S107: When it is determined through S106 that there is a lateral deviation between the child vehicle and the parent vehicle, the child vehicle calculates the required steering wheel angle based on the vehicle centerline deviation provided by the perception fusion unit and the following distance determined by S103 through the single-point pre-aiming optimal value. S108: The child vehicle obtains the deceleration of the parent vehicle and smooths it to obtain the requested value of its own deceleration. It then sends the engine torque obtained in S105, the steering wheel angle obtained in S107, and the requested value to the execution unit for execution.

2. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, Following S101, the system also includes: the mother vehicle using a driving assistance map to obtain speed limit information for the road ahead, and also obtaining the vehicle's current position information, defined as three-dimensional coordinates. Speed ​​limit information is The road curvature is The radius of curvature is ; The vehicle speed, engine speed, engine torque, transmission gear position, and braking torque signals, along with the maximum and minimum speed limits from the data processing module, are sent to the intelligent driving dynamic programming controller to establish a dynamic programming controller model. The overall multi-objective optimization objective function is: in, These are the weight coefficients for the three optimization objectives. Let fuel consumption be the objective function. Let fuel consumption be the objective function. Let the objective function be the magnitude of the acceleration. The engine torque per unit distance. The engine speed per unit distance. This refers to the engine fuel consumption rate per unit distance. The vehicle speed per unit distance. and Let K and K+1 be the vehicle speeds. For reference target speed; Parameter constraints include: Engine speed constraint: ; Speed ​​constraints: ; Engine torque constraint: Speed ​​constraints: in, These are the calibration values ​​for the control system; The optimal control value for stage N is: The optimal control value obtained in the first stage: The overall optimal value is: 。 3. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, In S104, the air drag coefficient is corrected, specifically as follows: in, Distance between the child vehicle and the mother vehicle d air drag coefficient at that time This is the air resistance coefficient when the vehicle is moving alone. and This is an empirical coefficient for air resistance. d This refers to the distance between the mother and child vehicles.

4. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, In S103, the following distance of the vehicle. It is related to vehicle speed, the load difference between the mother and child vehicles, and the gradient, with the specific relationships as follows: in, The current speed of the vehicle. For communication time delay, B is the load adjustment factor, and A is the ramp adjustment factor. For the load of the subcar, For the load of the mother car, The slope angle is denoted by .

5. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, In S105, the engine torque of this vehicle is calculated using the vehicle inverse dynamics model: in: This refers to engine torque. This refers to the gear ratio of the transmission. The transmission ratio of the main reducer. The transmission efficiency of the transmission mechanism. For the tire radius, For rolling friction resistance, For slope, air drag coefficient, For the windward cross-sectional area, air density, Current vehicle speed This is the rotational mass conversion factor.

6. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, In S107, when it is determined that there is a lateral deviation between the child vehicle and the vehicle in front, the deviation of the vehicle centerline is obtained through the perception fusion unit. The required steering wheel angle for the vehicle is obtained by using the single-point pre-aiming optimal value calculation formula: Combining the above formulas, we can obtain the steering wheel angle: in, For steering wheel angle, This refers to the vehicle's wheelbase. The vehicle's lateral position. For the vehicle's lateral acceleration, For vehicle speed, The transmission ratio of the transmission system. Where is the turning radius, and T is the forward look-ahead time. For the following distance.

7. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, S106 also includes the following steps: The subsidiary vehicle collects information on the operation of the parent vehicle ahead and the road curvature through onboard sensors; The subcar combines the received operating information of the parent car with the road curvature information to generate a predicted path for the parent car's longitudinal centerline over a future period of time; The sub-vehicle compensates and corrects the identification reference position of the longitudinal centerline of the mother vehicle based on its own body posture and load conditions; The subsidiary vehicle adjusts the detection area of ​​the sensor used to identify the longitudinal centerline of the parent vehicle based on the current traffic density; The child vehicle periodically compares the identified longitudinal centerline of the parent vehicle with the lane information on the map, and updates the identification benchmark when the deviation is too large.

8. The method for following and driving heavy-duty commercial vehicles based on inter-vehicle communication according to claim 1, characterized in that, Step S108 also includes the following steps: The subsidiary vehicle receives a continuous speed data stream from the parent vehicle in real time via its onboard communication module. The VCU of the subcar performs time difference calculation on the received continuous speed data of the mother car to obtain the original deceleration sequence of the mother car; a first-order low-pass filter is used to smooth the original deceleration sequence. The smoothed deceleration of the mother car, combined with a pre-set safety distance model, is mapped to the target deceleration required by the daughter car itself. The target required deceleration, engine torque request value, and steering wheel angle request value are encapsulated into a unified control command frame and sent to the corresponding actuator unit via the vehicle CAN bus.

9. A car-following driving system for inter-vehicle communication in heavy-duty commercial vehicles, characterized in that, The system is used to implement the car-following driving method for heavy commercial vehicles based on inter-vehicle communication as described in any one of claims 1 to 8; The system includes: The Follow-the-Car Mode Activation Module is used when the mother car activates the predictive adaptive cruise control function and the daughter car follows behind the mother car and activates Follow-the-Car Mode when the mother car and the daughter car are traveling along the same route at the same location and at the same time. The vehicle information interaction module is used for information exchange between the mother and child vehicles, allowing the child vehicle to obtain the operating information of the mother vehicle. The following distance determination module is used to enable the child vehicle to determine the following distance with the parent vehicle based on its current speed, the load difference between the child and parent vehicles, and the slope angle of the driving slope. The air resistance correction module is used to correct the drag coefficient of the subcar based on the distance between it and the parent car. The torque calculation module is used to enable the sub-vehicle to calculate the acceleration of the mother vehicle based on the acquired speed of the mother vehicle, and to calculate the required engine torque for itself through the vehicle inverse dynamics model after correcting the air drag coefficient. The longitudinal detection module enables the child vehicle to determine the longitudinal centerline of the parent vehicle through sensing and to judge its own positional deviation, providing a judgment standard for lateral path correction; The steering wheel angle calculation module is used to calculate the required steering wheel angle when it is determined that there is a lateral deviation between the child vehicle and the parent vehicle. The child vehicle determines the following distance based on the vehicle centerline deviation provided by the perception fusion unit and calculates the optimal value of single-point pre-aiming. The execution module is used to enable the child vehicle to obtain the deceleration of the parent vehicle and smoothly process it to obtain the requested value of its own deceleration. The obtained engine torque, the obtained steering wheel angle, and the requested value are sent to the execution unit for execution.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the following driving method for heavy commercial vehicle mother-daughter vehicles based on workshop communication as described in any one of claims 1 to 7.

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