Longitudinal and transverse cooperative control method for automatic driving vehicle under longitudinal section working condition

Abstract

The invention discloses a longitudinal and transverse cooperative control method for an automatic driving vehicle under a longitudinal section working condition, and relates to the technical field of automatic driving and intelligent network connection vehicle control. The method comprises the following steps: acquiring road vertical section gradient, lane geometry and front vehicle state information through a sensor system; a cruising or following mode is judged based on comparison of the front vehicle distance and double threshold values, and a hysteretic mechanism is introduced to avoid frequent switching; a longitudinal control instruction is generated according to the driving mode, the expected speed is used as a control target in the cruising mode, the target is calculated based on a safe distance model in the following mode, and a gravity feedforward compensation mechanism based on the road gradient is introduced; generating a transverse instruction through a transverse controller with adjustable parameters; and finally, carrying out cooperative constraint on the longitudinal and transverse instructions, including safety constraint and stability constraint, and outputting a final control instruction to an execution mechanism of the vehicle. According to the method, the problem of longitudinal and transverse control coupling is effectively solved, and the car-following safety and the track stability under the complex longitudinal section road are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of autonomous driving and intelligent connected vehicle control technology, specifically to a longitudinal and lateral coordinated control method for autonomous vehicles under longitudinal section conditions. Background Technology

[0002] With the advancement of autonomous driving technology, longitudinal speed control and lateral path tracking have become core functions. Existing systems mostly adopt a decoupled architecture, with the longitudinal module independently handling speed following and distance maintenance, and the lateral module focusing on lane keeping and deviation correction.

[0003] This design can basically meet the needs on flat roads, but it faces serious challenges on roads with complex longitudinal profiles, such as mountain slopes or urban vertical curves. Changes in longitudinal profile slope introduce nonlinear gravity component interference. Traditional feedback control such as PID relies on error adjustment, which is prone to response lag and speed overshoot on steep roads. For example, speed drops when going uphill and unexpected acceleration when going downhill, affecting the safety and comfort of following the car.

[0004] Meanwhile, longitudinal and lateral dynamics exhibit strong coupling characteristics: longitudinal velocity fluctuations reduce tire lateral stiffness, weakening lateral stability; while lateral steering actions consume adhesion, interfering with longitudinal acceleration execution. Independent control logic lacks a coordination mechanism, which may lead to sideslip due to unrestricted speed in scenarios such as high-speed downhill curves, or longitudinal velocity fluctuations caused by trajectory correction, reducing overall driving stability. Existing research, such as anticipation control, enhances single-loop robustness but does not address the systemic coupling problem, especially since sudden acceleration changes on vertical curves amplify interference.

[0005] Therefore, there is an urgent need for a longitudinal and transverse coordinated control method to improve control accuracy and safety under complex longitudinal profile conditions. Summary of the Invention

[0006] The purpose of this invention is to provide a longitudinal and lateral coordinated control method for autonomous vehicles under longitudinal profile conditions, so as to overcome the above-mentioned problems in the prior art. By introducing slope feedforward compensation and longitudinal and lateral state coupling constraints, stable operation of the vehicle on complex longitudinal profile roads can be achieved while keeping the basic structure of the longitudinal and lateral controllers unchanged.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A longitudinal and lateral cooperative control method for autonomous vehicles under longitudinal profile conditions includes the following steps: The sensor system acquires information such as road longitudinal profile slope, lane geometry, distance and speed of the vehicle in front relative to the vehicle, as well as the vehicle's longitudinal speed, lateral offset and heading angle. The driving mode of this vehicle is determined based on the comparison between the distance of the preceding vehicle relative to this vehicle and a preset threshold. The preset threshold includes an entry threshold and an exit threshold, and the exit threshold is greater than the entry threshold. When the distance is greater than the exit threshold, it is in cruise mode. When the distance is less than the entry threshold, it is in follow mode. When the distance is between the two thresholds, it maintains the original mode and introduces a hysteresis mechanism to avoid frequent mode switching. The longitudinal control command is generated according to the driving mode. In cruise mode, the preset desired speed is used as the longitudinal control target. In car-following mode, the longitudinal control target is calculated based on the safe distance model, and gravity feedforward compensation based on the road longitudinal profile slope information is introduced. Based on the lane geometry information, lateral offset, and heading angle, lateral control commands are generated by a lateral controller containing adjustable control parameters. The longitudinal control command and the lateral control command are subjected to coordinated constraints to generate the final control command. The coordinated constraints include safety constraints that limit the longitudinal control target based on the lateral offset and heading angle, and stability constraints that dynamically adjust the control parameters of the lateral controller based on the longitudinal speed. The final control command after coordination and constraint is output to the actuator of this vehicle.

[0008] Furthermore, the hysteresis mechanism also includes a time-continuous confirmation mechanism, which requires that the mode switching condition be continuously satisfied for a preset number of sampling periods before the mode switching is performed.

[0009] Furthermore, the gravity feedforward compensation is achieved in the following way: Based on the longitudinal slope angle of the road The formula for calculating slope resistance is: ; Where m is the mass of the vehicle and g is the acceleration due to gravity; The slope resistance is superimposed as a feedforward compensation term on the longitudinal control command.

[0010] Furthermore, the safety distance model adopts a constant target following distance strategy, which calculates the target following distance based on the vehicle's longitudinal speed and preset safety distance parameters, wherein the preset safety distance parameters are pre-set based on the vehicle's braking performance and road adhesion conditions.

[0011] Furthermore, the lateral controller generates steering control commands based on the lateral offset, heading angle error, and offset change rate, wherein the heading angle error is calculated based on the heading angle and lane geometry information, and the offset change rate is determined based on the lateral offset.

[0012] Furthermore, the stability constraint is achieved by dynamically adjusting the control parameters of the lateral controller based on the longitudinal speed of the vehicle. In low-speed driving conditions, the control parameters are increased to improve steering sensitivity, while in high-speed driving conditions, the control parameters are decreased to prevent overcorrection.

[0013] Furthermore, the safety constraint is implemented by: calculating a speed limit coefficient based on the lateral offset and road curvature, and correcting the longitudinal control target with the speed limit coefficient, wherein the speed limit coefficient decreases as the lateral offset or road curvature increases, and the road curvature is obtained from the lane geometry information.

[0014] Furthermore, the sensor system includes millimeter-wave radar, cameras, and vehicle status sensors, and acquires the road longitudinal profile slope information, lane geometry information, and the status information of the vehicle in front through multi-sensor fusion.

[0015] Another objective of this invention is to provide an autonomous driving control system, including a processor and a memory, wherein the memory stores a computer program, and when the program is executed by the processor, it implements the aforementioned method for longitudinal and lateral coordinated control of an autonomous vehicle under longitudinal profile conditions.

[0016] Another object of the present invention is to provide an autonomous driving vehicle equipped with the aforementioned autonomous driving control system.

[0017] Compared with the prior art, the present invention has the following beneficial effects: In terms of longitudinal control, the gravity feedforward compensation mechanism based on road slope information can actively predict and counteract the dynamic disturbances caused by changes in longitudinal profile. This mechanism enables the control system to make compensation adjustments in the early stages of slope changes, effectively improving the response lag problem of traditional feedback control and enabling vehicles to maintain more stable speed tracking performance on uphill, downhill, and vertical curve sections.

[0018] At the lateral control level, by combining a state feedback controller with a dynamic gain scheduling strategy, the system can adaptively adjust lateral control parameters based on real-time longitudinal speed. This design enables the vehicle to maintain high trajectory tracking accuracy at low speeds and automatically reduce control sensitivity at high speeds or on downhill conditions, avoiding the risk of lateral instability caused by oversteering.

[0019] The most innovative aspect is the dual-channel design of the longitudinal and lateral collaborative constraint mechanism: the safety channel constrains the longitudinal desired velocity in real time through lateral status, actively limiting the velocity when a large lateral deviation or complex alignment is detected, thus reserving a larger stability margin for lateral control; the stability channel dynamically optimizes the lateral control parameters based on the longitudinal velocity, forming a two-way coupled closed-loop optimization. This collaborative design fundamentally solves the problem of conflict between longitudinal and lateral control objectives.

[0020] In summary, this invention, through the organic combination of slope feedforward compensation and longitudinal and lateral coordinated constraints, enables vehicles to maintain more stable longitudinal distance control on road sections with changing longitudinal profiles, while keeping lateral offset within a reasonable range, significantly improving the system's anti-interference capability and adaptability to operating conditions. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method of the present invention. Figure 2 This is a system framework diagram of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0023] This embodiment provides a longitudinal and lateral cooperative control method for autonomous vehicles under longitudinal profile conditions, aiming to solve the problem of longitudinal and lateral control coupling interference under complex longitudinal profile road conditions (such as uphill, downhill, and vertical curves), and improve following safety and trajectory stability. The overall process of the method is as follows: Figure 1 As shown, the system framework is as follows: Figure 2 As shown in the diagram. The method uses multi-sensor fusion to perceive environmental information, generates longitudinal and lateral control commands based on driving mode determination, and introduces gravity feedforward compensation and longitudinal and lateral cooperative constraint mechanisms. Finally, it outputs cooperative control commands to the vehicle actuators (such as the drive system, braking system, and steering system). The following is a detailed explanation of each step.

[0024] Step 1: Environmental Perception and State Acquisition The sensor system acquires information such as road longitudinal profile slope, lane geometry, distance and speed of the vehicle ahead relative to the vehicle, as well as the vehicle's longitudinal speed, lateral offset, and heading angle. This step aims to obtain the environmental and state information required for vehicle operation. Specifically, the sensor system collects the following data in real time: Road longitudinal profile slope information: The longitudinal slope angle θ of the road is obtained through a high-precision map or an inertial measurement unit (IMU) for subsequent gravity compensation calculations.

[0025] Lane geometry information, including lane centerline position and road curvature ρ, is extracted using high-definition cameras to identify lane lines. After the cameras acquire images, computer vision algorithms (such as Hough transform or deep learning models) are used to detect lane boundaries and fit lane geometry parameters.

[0026] Forward vehicle status information: including the distance between the vehicle in front and the vehicle in front. Relative velocity is detected by millimeter-wave radar. Millimeter-wave radar transmits frequency-modulated continuous waves, and calculates distance and velocity based on the echo time difference and frequency shift.

[0027] Vehicle status information: including the vehicle's longitudinal speed. Horizontal offset Heading angle Longitudinal velocity, etc. Lateral offset can be obtained through wheel speed sensors or GPS / IMU fusion. and heading angle Calculated using cameras or positioning systems, among which ( This refers to the lateral position of the vehicle. (Lane centerline position), heading angle error ( This is the heading angle of the vehicle. (This refers to the lane direction angle).

[0028] Multi-sensor fusion ensures comprehensive and reliable information acquisition, providing accurate input for subsequent control. Millimeter-wave radar operates 24 / 7, cameras enhance lane perception, and combined with vehicle status sensors, a redundant design is formed to improve system robustness.

[0029] Step 2: Determining the Driving Mode The vehicle's driving mode is determined based on a comparison between the distance of the preceding vehicle relative to the current vehicle and a preset threshold. This preset threshold includes an entry threshold and an exit threshold, with the exit threshold being greater than the entry threshold. When the distance is greater than the exit threshold, it is in cruise mode; when the distance is less than the entry threshold, it is in follow-the-car mode; and when the distance is between the two thresholds, the original mode is maintained. A hysteresis mechanism is introduced to avoid frequent mode switching. This step is used to determine the current driving mode (cruise mode or follow-the-car mode) and avoid frequent mode switching. The specific implementation is as follows: Threshold setting: Preset entry threshold and exit threshold ,and (For example =50m, =60m). The threshold is adaptively adjusted based on vehicle braking performance and road conditions.

[0030] Pattern determination logic: based on distance to the vehicle in front Comparison with threshold: like It is determined to be in cruise mode; like It is determined to be in car-following mode; like Between and In between, maintain the current mode.

[0031] Hysteresis Mechanism and Time-Based Continuous Acknowledgment: To avoid mode jitter, a time-based continuous acknowledgment mechanism is introduced. For example, it requires mode switching conditions (such as...) Switching is only performed after five consecutive sampling periods (0.1s per period) are met. This is achieved through a counter: the counter increments when the condition is met and resets to zero otherwise; the mode is switched only when the counter reaches a threshold.

[0032] The dual-threshold hysteresis mechanism effectively prevents frequent mode switching, reduces control system oscillations, and improves ride comfort. The continuous time confirmation mechanism further enhances the stability of the judgment and avoids misjudgments caused by sensor noise.

[0033] Step 3: Generation of longitudinal control commands Based on the driving mode, longitudinal control commands are generated. In cruise mode, a preset desired speed is used as the longitudinal control target. In follow mode, the longitudinal control target is calculated based on a safe distance model, and gravity feedforward compensation based on the road longitudinal profile slope information is introduced. The specific implementation includes the following three key parts: 1. Defining control objectives (1) Cruise mode control target When the system determines that the vehicle is in cruise driving mode, the longitudinal controller moves at the preset desired speed. This serves as the control target. The preset value is set based on road grade, traffic regulations, and driver preferences, and is usually a fixed value, such as 100km / h in a highway scenario.

[0034] (2) Car-following mode control target The safe distance model (i.e., the following distance control model) adopts a constant target following distance strategy, where the target following distance is... Based on the longitudinal speed of this vehicle and preset safety distance parameters calculate: in For system response time, This is the minimum safety margin set based on vehicle braking distance and road adhesion conditions. Using this safety distance model, the system prioritizes fine-tuning speed within the safe following distance range, while quickly triggering distance intervention when the following distance is insufficient, ensuring both following safety and optimizing ride comfort.

[0035] 2. Gravity feedforward compensation mechanism To eliminate nonlinear interference caused by changes in longitudinal profile slope, this invention introduces gravity feedforward compensation based on feedback control. This mechanism, through slope resistance prediction and feedforward compensation, proactively adjusts the driving / braking force in the early stages of slope change, transforming the lag response of traditional feedback control into proactive control. The specific implementation is as follows: (1) Calculation of slope resistance The system acquires the longitudinal slope angle of the road in real time using high-precision maps or inertial measurement units. Calculate slope resistance based on vehicle dynamics model: Where m is the mass of the vehicle, which can be obtained through a load sensor or estimation algorithm; g is the acceleration due to gravity. The slope angle is positive for uphill and negative for downhill.

[0036] (2) Feedforward-feedback composite control The total output of the longitudinal controller consists of the superposition of feedback and feedforward terms: Among them, feedback items Used to eliminate velocity tracking errors. Feedforward term This mechanism is used to preemptively offset the gravitational component effect caused by the slope. Experiments show that this compensation mechanism can reduce the speed overshoot of vehicles on variable slope sections by about 30% and shorten the settling time by more than 25%.

[0037] Feedforward compensation and It is directly proportional, and dynamic compensation is achieved through the following rules: Uphill driving condition (θ>0): Increase driving force output to counteract the speed reduction caused by gravity; Downhill driving condition (θ<0): Increase braking force or reduce driving force to suppress the acceleration tendency caused by gravity.

[0038] The feedforward coefficient is calibrated based on the characteristics of the vehicle's powertrain system to ensure a balance between compensation accuracy and system response speed.

[0039] 3. Dual Closed-Loop PID Control Algorithm A hierarchical control structure is adopted, with an outer loop for distance control and an inner loop for speed control. This optimized structure ensures safe following distance control in the outer loop and optimizes ride comfort in the inner loop for speed control. The specific implementation is as follows: (1) Distance control loop (outer loop), based on real-time vehicle distance Following distance from the target vehicle Adjust the deviation: Distance error: PID control law: in This is a distance control signal; This represents the error between the actual distance and the set distance. , , These are the proportional, integral, and differential gains of the distance loop, which are tuned using the Ziegler-Nichols method or an optimization algorithm.

[0040] (2) Speed ​​control loop (inner loop), based on the vehicle speed With expected speed Adjust the deviation: Speed ​​error: PID control law: The speed loop output acts directly on the throttle / brake actuator. The feedback control item... That is, the output of the speed control loop. It is obtained through PID control law calculation.

[0041] (3) Output limiting and smoothing To suppress abrupt changes in control commands caused by changes in longitudinal profile, the total output is adjusted. Constrain the rate of change: in The output rate limit is set according to vehicle ride comfort requirements, typically 50%-70% of the maximum acceleration. This limit effectively suppresses abrupt changes in longitudinal acceleration common on vertical curves by constraining the rate of change of control commands, avoiding vehicle "nodding" or "tilting" phenomena and significantly improving ride comfort.

[0042] The aforementioned longitudinal control strategy enables autonomous vehicles to maintain stable speed tracking performance under complex longitudinal profile conditions, while ensuring that the longitudinal safety distance is maintained within a high reliability range.

[0043] Step 4: Generating Lateral Control Commands Based on the lane geometry information, lateral offset, and heading angle, a lateral controller with adjustable control parameters generates lateral control commands to achieve precise trajectory tracking and lane centering of the vehicle within the lane. The core task of the lateral control system is to maintain the vehicle near the center of the lane by adjusting the steering angle in real time during longitudinal travel, effectively suppressing lateral deviations that may be caused by changes in road alignment or longitudinal control adjustments. This invention deeply integrates Lane Centering Assist (LKA) and Lane Departure Warning (LDW) functions into lateral control, achieving precise monitoring and proactive intervention of the vehicle's lateral movement state through the coordinated operation of state feedback control and warning mechanisms.

[0044] 1. Lateral state calculation The input to the lateral controller is based on the vehicle status information obtained in step one, including the lateral offset. Heading angle error and the newly added rate of change of offset .in, and The calculation is as described in step one, the rate of change of offset. Based on the vehicle's longitudinal speed Calculation of heading angle error: Among the parameters mentioned above, Lane Offset refers to the lateral distance between the vehicle's current position and the lane centerline, which directly reflects the degree of deviation of the vehicle from the lane center; Heading Deviation refers to the angular error between the vehicle's current heading angle and the lane tangent direction, used to ensure that the vehicle's driving direction is consistent with the lane direction; Rate of Lateral Error refers to the rate of change of the lateral offset over time, reflecting the trend and speed of the vehicle's deviation from the lane center. This parameter provides forward-looking information to the control system, helping to suppress possible oscillations or overcorrections in advance.

[0045] The above three parameters are calculated in real time by a dedicated sub-module (corresponding to the "Lane Offset", "HeadingDeviation" and "Rate of Lateral Error" calculation modules in the simulation model) and serve as the input basis for the entire lateral control (including LKA) and lane departure warning (LDW) system.

[0046] 2. Horizontal Controller Design (LKA Module) The Lane Keeping Assist (LKA) controller employs a state feedback-based control architecture. This controller uses the calculated lateral offset... Heading angle error and the rate of change of offset As input, the desired steering wheel angle command is calculated using a defined gain matrix K. Its control law is defined by the following state feedback formula: in, The term is mainly used for lateral offset correction, and its gain This determines the strength of the system's response to positional deviations; This term is used for heading angle correction to ensure the vehicle points towards the center of the lane, and the gain is... It affects the convergence speed of the direction; The term provides damping suppression to attenuate the oscillating tendency of lateral motion, improve stability, and prevent overcorrection of the control system.

[0047] To ensure the smoothness of control commands and the adaptability of the actuator, the calculated steering wheel angle command is... Amplitude limiting and low-pass filtering were applied. The amplitude limiting function ensures that the command does not exceed the physical limits of the vehicle's steering system; the filtering effectively smooths out instantaneous changes in the command, avoiding impact on the electronic power steering system, thereby improving ride comfort and reducing actuator wear.

[0048] 3. Lane Departure Warning (LDW) and Cooperative Intervention The Lane Departure Warning (LDW) module serves as a safety redundancy mechanism for lateral control, assessing the risk of vehicle deviation based on preset thresholds. Its judgment logic comprises two conditions, and an AND operation ensures the reliability of the judgment, preventing false alarms caused by brief disturbances. Lateral offset threshold determination: When the absolute value of the detected lateral offset of the vehicle exceeds the set safety threshold, i.e. (For example, setting) (±0.4m), the system initially determined that the vehicle was trending towards deviating from the lane edge.

[0049] Offset Change Rate Threshold Determination: To further confirm the initiative and risk level of the deviation, the system simultaneously checks the lateral offset change rate. This indicates that the vehicle is deviating from the center of the lane at a relatively high speed.

[0050] The final deviation determination logic combines the above two conditions, as shown in the equation: When the LDW output is 1, it indicates that the vehicle has a clear and persistent risk of deviation. At this time, the system will not only issue a warning signal to the driver, but also trigger the LKA module to enter a higher gain deviation control mode, generating more intervention-oriented lateral correction commands to actively and reinforcely correct the vehicle's trajectory.

[0051] Step 5: Vertical and Horizontal Coordination Constraints The longitudinal and lateral control commands are subject to coordinated constraints to generate the final control command. These coordinated constraints include safety constraints that limit the longitudinal control target based on lateral offset and heading angle, and stability constraints that dynamically adjust the control parameters of the lateral controller based on longitudinal velocity. Specifically, this includes two channels: (1) Safety constraints: based on lateral offset The speed limit coefficient is calculated using the road curvature ρ (obtained from lane geometry information). (0< ≤1). Modify the longitudinal control target: Among them, the speed limit coefficient It is the lateral offset. It is a function of the road curvature ρ, and its value range is (0, 1). The rule for determining its value is: it varies with the horizontal offset. The absolute value of ρ increases and decreases, or decreases as the absolute value of road curvature ρ increases. This means that the further the vehicle deviates laterally from the center of the lane, or the greater the curvature of the road curve, the more the system... Longitudinal expected speed To impose more restrictions (i.e.) Approaching 0), prioritizing lateral stability and avoiding the risk of sideslip. The revised longitudinal control target... The above formula provides the answer.

[0052] (2) Stability constraints: based on the longitudinal speed of the vehicle Dynamically adjust the parameters of the lateral controller At low speeds (such as...) <30km / h), increase parameters to improve sensitivity; at high speeds (such as... (>80km / h), reduce parameters to prevent over-correction. The parameter adjustment rule can be expressed as: , where f is a decreasing function.

[0053] The final control command is generated after the coordination constraints are applied to ensure the coordination of the longitudinal and lateral control objectives.

[0054] The dual-channel collaborative constraint fundamentally solves the problem of longitudinal and lateral coupling. The safety channel prioritizes speed limiting to ensure lateral stability and avoid the risk of sideslip; the stability channel adaptively adjusts parameters to ensure lateral control performance across the entire speed range and improves overall driving stability.

[0055] Step Six: Output Control Commands The final control commands, after being coordinated and constrained, are output to the vehicle's actuators. Longitudinal control commands act on the drive / braking system, while lateral control commands act on the steering system. The actuators adjust the vehicle's state according to these commands to achieve stable following and trajectory maintenance.

[0056] This embodiment provides an autonomous driving control system, including a processor and a memory. The memory stores a computer program. When the program is executed by the processor, it implements the aforementioned method for longitudinal and lateral coordinated control of an autonomous vehicle under longitudinal section conditions.

[0057] This embodiment provides an autonomous driving vehicle equipped with the aforementioned autonomous driving control system.

[0058] Embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0059] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0060] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1The function specified in one or more boxes.

[0061] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0062] Contents not described in detail in this specification are prior art known to those skilled in the art. It is hereby indicated that the above description is intended to help those skilled in the art understand this invention, but does not limit the scope of protection of this invention. Any equivalent substitutions, modifications, improvements, or simplifications of the above descriptions that do not depart from the essential content of this invention fall within the scope of protection of this invention.

Claims

1. A longitudinal and lateral cooperative control method for automated vehicles under longitudinal profile conditions, characterized in that, Includes the following steps: The sensor system acquires information such as road longitudinal profile slope, lane geometry, distance and speed of the vehicle in front relative to the vehicle, as well as the vehicle's longitudinal speed, lateral offset and heading angle. The driving mode of this vehicle is determined based on the comparison between the distance of the preceding vehicle relative to this vehicle and a preset threshold. The preset threshold includes an entry threshold and an exit threshold, and the exit threshold is greater than the entry threshold. When the distance is greater than the exit threshold, it is in cruise mode. When the distance is less than the entry threshold, it is in follow mode. When the distance is between the two thresholds, it maintains the original mode and introduces a hysteresis mechanism to avoid frequent mode switching. Based on the driving mode, a longitudinal control command is generated. In cruise mode, the preset desired speed is used as the longitudinal control target. In follow mode, the longitudinal control target is calculated based on the safe distance model, and gravity feedforward compensation based on the road longitudinal profile slope information is introduced. Based on the lane geometry information, lateral offset, and heading angle, lateral control commands are generated by a lateral controller containing adjustable control parameters. The longitudinal control command and the lateral control command are subjected to coordinated constraints to generate the final control command. The coordinated constraints include safety constraints that limit the longitudinal control target based on the lateral offset and heading angle, and stability constraints that dynamically adjust the control parameters of the lateral controller based on the longitudinal speed. The final control command after coordination and constraint is output to the actuator of this vehicle.

2. The longitudinal and lateral coordinated control method for an automated driving vehicle under longitudinal profile conditions according to claim 1, characterized in that, The hysteresis mechanism also includes a time-continuous confirmation mechanism, which requires that the mode switching condition be continuously satisfied for a preset number of sampling periods before the mode switching is performed.

3. The longitudinal and lateral coordinated control method for an automated driving vehicle under longitudinal profile conditions according to claim 1, characterized in that, The gravity feedforward compensation is achieved in the following way: Based on the longitudinal slope angle of the road The formula for calculating slope resistance is: ； Where m is the mass of the vehicle and g is the acceleration due to gravity; The slope resistance is superimposed as a feedforward compensation term on the longitudinal control command.

4. The longitudinal and lateral cooperative control method for automated vehicles under longitudinal profile conditions according to claim 1, characterized in that, The safe distance model adopts a constant target following distance strategy, which calculates the target following distance based on the vehicle's longitudinal speed and preset safe distance parameters, wherein the preset safe distance parameters are pre-set based on the vehicle's braking performance and road adhesion conditions.

5. The longitudinal and lateral cooperative control method for automated vehicles under longitudinal profile conditions according to claim 1, characterized in that, The lateral controller generates steering control commands based on the lateral offset, heading angle error, and offset change rate, wherein the heading angle error is calculated based on the heading angle and lane geometry information, and the offset change rate is determined based on the lateral offset.

6. The longitudinal and lateral coordinated control method for an automated driving vehicle under longitudinal profile conditions according to claim 5, characterized in that, The stability constraint is achieved by dynamically adjusting the control parameters of the lateral controller based on the longitudinal speed of the vehicle. In low-speed driving conditions, the control parameters are increased to improve steering sensitivity, and in high-speed driving conditions, the control parameters are decreased to prevent overcorrection.

7. The longitudinal and lateral cooperative control method for an automated driving vehicle under longitudinal profile conditions according to claim 5, characterized in that, The safety constraints are implemented by calculating a speed limit coefficient based on the lateral offset and road curvature, and using the speed limit coefficient to correct the longitudinal control target, wherein the speed limit coefficient decreases as the lateral offset or road curvature increases, and the road curvature is obtained from the lane geometry information.

8. The longitudinal and lateral cooperative control method for an automated driving vehicle under longitudinal profile conditions according to claim 1, characterized in that, The sensor system includes millimeter-wave radar, cameras, and vehicle status sensors. It acquires road longitudinal profile slope information, lane geometry information, and forward vehicle status information through multi-sensor fusion.

9. An automatic driving control system, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, and when the program is executed by the processor, it implements a longitudinal and lateral cooperative control method for an autonomous vehicle under longitudinal section conditions as described in any one of claims 1-8.

10. An autonomous vehicle, characterized in that, It is equipped with an autonomous driving control system as described in claim 9.

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