A safety speed planning method for heterogeneous vehicles and electronic equipment

Abstract

The application provides a safety speed planning method and electronic equipment for heterogeneous vehicles, and belongs to the technical field of intelligent automobiles. The method solves the problem that front and rear vehicles lack effective heterogeneous coordination mechanisms and cannot provide more accurate, more forward-looking and more vehicle-specific front road capacity estimation for the rear vehicle. The method comprises the following steps: acquiring dynamic data of a front vehicle during driving; obtaining total confidence of prior estimation of road capacity according to the front vehicle data; performing time correction and heterogeneous re-interpretation to obtain a safety speed upper limit of the rear vehicle; judging the instability risk of the rear vehicle based on the prior road capacity; and executing safety speed planning and early deceleration control strategies according to the instability risk judgment result. The method completes heterogeneous re-interpretation by projecting the shared road capacity prior into the safety constraint set of the rear vehicle, and improves the safety and control robustness of the vehicle during cornering under complex working conditions.

Description

Technical Field

[0001] This invention relates to the field of intelligent vehicle technology, and in particular to a safe speed planning method for heterogeneous vehicles. Background Technology

[0002] Traditional vehicle active safety control systems typically rely on the vehicle's own sensors to estimate the current road conditions and make control decisions based on this. However, these methods still have limitations.

[0003] Vehicle sensors struggle to anticipate road conditions ahead, especially in obstructed curves, complex road conditions, and low-adhesion abrupt changes, limiting their warning and control capabilities. Furthermore, estimation lag exists; dynamic estimation relies on the vehicle's current state, resulting in a certain degree of delay and hindering feedforward control.

[0004] Traditional control methods lack effective heterogeneous collaboration mechanisms and fail to fully utilize the information exchange advantages between the preceding and following vehicles. They cannot provide the following vehicle with a more accurate, forward-looking, and characteristic estimate of the road ahead by fusing multi-source information such as the preceding vehicle's dynamic perception results, communication sharing information, and the reinterpretation of the following vehicle's own dynamic parameters, thereby improving the vehicle's safety and stability in high-risk curves and low-adhesion conditions.

[0005] Therefore, a new technical solution is urgently needed in the existing technology to solve the above problems. Summary of the Invention

[0006] To address the problem that the lack of an effective heterogeneous coordination mechanism between the front and rear vehicles makes it impossible to provide the rear vehicle with a more accurate, forward-looking, and characteristic-appropriate estimate of the road ahead, this invention provides a safe speed planning method and electronic device for heterogeneous vehicles.

[0007] To address the aforementioned technical problems, in a first aspect, according to some embodiments, the present invention provides a safe speed planning method for heterogeneous vehicles, comprising: Establish communication with the vehicle in front to obtain the dynamics data of the vehicle in front during its movement; Based on the longitudinal, lateral, and yaw excitations of the preceding vehicle, the total confidence level of the prior road capability estimate is obtained. Based on the total confidence level, following vehicle data, and road data, timeliness correction and heterogeneous reinterpretation are performed to obtain the safe speed limit of the following vehicle; The risk of instability of the following vehicle is determined based on prior assessment of road capabilities; Based on the instability risk assessment results, a safe speed planning and early deceleration control strategy is implemented. The control strategy includes: upper-level safe speed control based on prior reinterpretation of shared road capacity, and lower-level longitudinal deceleration control based on target deceleration solution.

[0008] Optionally, in some embodiments, acquiring the dynamics data of the preceding vehicle during its movement specifically includes: Dynamic data of the preceding vehicle during its movement were collected to establish a monorail lateral-yaw dynamic model of the preceding vehicle. This model yielded longitudinal acceleration, lateral acceleration, yaw rate of change, equivalent normal loads on the front and rear axles, and equivalent lateral forces. Longitudinal road capacity observations, lateral road capacity observations, and yaw channel road capacity observations were constructed. A single-state multi-observation Kalman filter algorithm was then used to obtain estimated prior values ​​of the preceding vehicle's road capacity. This includes: using accelerometers, gyroscopes, wheel speed sensors, and steering angle sensors to collect dynamic data of the vehicle in front during its driving process, including longitudinal speed, longitudinal acceleration, lateral acceleration, yaw rate, and steering angle; and performing noise removal and filtering preprocessing on the collected data.

[0009] Optionally, in some embodiments, obtaining the total confidence level of the prior road capability estimate based on the longitudinal, lateral, and yaw excitations of the preceding vehicle specifically includes: Based on the longitudinal, lateral, and yaw excitations of the preceding vehicle, the confidence scores for the longitudinal channel, lateral channel, and yaw channel are calculated respectively. The total confidence score for this prior estimation of road capability is obtained through confidence score fusion. .

[0010] Optionally, in some embodiments, the step of performing timeliness correction and heterogeneous reinterpretation based on the total confidence level, subsequent vehicle data, and road data specifically includes: Obtain the data from the following vehicle and construct a shared data packet: ; In the formula: Share data packets for prior road capabilities; The prior value of the road capability of the vehicle ahead; Estimate the total confidence level of the road capability prior for the vehicle ahead; Generate timestamps for the data; The spatial location corresponding to the data; The rear vehicle is marked with an "H"; After receiving the shared data packet, the following vehicle calculates the information age based on the current time and timestamp: ; In the formula: Information age; The current time of the following vehicle; Establish an information freshness decay factor based on information age: ; In the formula: Information freshness decay factor; This is the time-related decay coefficient; Calculate the effective confidence weights using the total confidence level and the information freshness decay factor: ; The following vehicle, based on the spatial location in the shared data packet and its own positioning result, projects the prior road capability of the preceding vehicle onto the arc-length coordinate system of the following vehicle's pre-aiming path to obtain the matching position: ; In the formula: The arc length coordinates of the prior road capability of the preceding vehicle projected onto the pre-aiming path of the following vehicle; For spatial projection mapping operators; The road capability function for safe speed planning of the following vehicle at arc length coordinate s is defined as follows: ; In the formula: Spatial matching tolerance threshold; This is the default value for the local road capability of the following vehicle or a conservative estimate for this vehicle. The parameter set for the rear vehicle is as follows: ; In the formula: For the overall vehicle weight of the following vehicle; This refers to the rear wheelbase; This is the distance from the rear vehicle's center of gravity to the front axle. This is the distance from the rear vehicle's center of gravity to the rear axle. The height of the rear vehicle's center of gravity; The moment of inertia of the rear vehicle about the vertical axis is the yaw motion. The equivalent lateral stiffness of the front axle of the rear vehicle; The equivalent lateral stiffness of the rear axle of the rear vehicle; This is the distance between the rear wheels.

[0011] Optionally, in some embodiments, the step of determining the risk of instability of the following vehicle based on prior road capability specifically includes: The following vehicle obtains the curvature of the path ahead through the path prediction module, and uses the road capability function at the arc length coordinate s of the following vehicle for safe speed planning. With the set of parameters of the following vehicle Solve for the upper limit of safe speed, which includes at least the friction circle constraint. Tire slip constraint, roll constraint Safe speed limit According to the aforementioned safe speed limit Assess the risk of instability of the rear vehicle; The friction circle constraint is as follows: Under combined braking-turning conditions, the following vehicle satisfies: ; In the formula: Let be the candidate speed of the following vehicle at the arc length coordinate s; Provide the longitudinal deceleration for the following vehicle; The arc length coordinates of the path ahead Curvature at that point; The road capability function for safe speed planning of the following vehicle at arc length coordinate S; Let be the acceleration due to gravity, and take . ; Determine the upper limit of the velocity of the rear vehicle at arc length coordinate s based on the friction circle constraint: ; In the formula, To prevent the unit of an extremely small positive number with a denominator of zero, and the curvature Consistent, take here ; The following vehicle is in the arc length coordinate. The upper limit of safe speed is further expressed as follows: ; In the formula: Speed ​​limits are imposed on roads or by external regulations. The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the friction circle constraint; The upper limit of the speed of the following vehicle at arc length coordinate s is obtained based on the front axle sideslip constraint; The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the rear axle sideslip constraint; This represents the upper limit of the speed of the following vehicle at the arc length coordinate s based on the roll constraint.

[0012] Optionally, in some embodiments, the tire lateral restraint includes: Under the steady-state small-angle monorail model, the rear vehicle satisfies: ; ; For the overall vehicle weight of the following vehicle; This is the distance from the rear vehicle's center of gravity to the front axle. This is the distance from the rear vehicle's center of gravity to the rear axle. therefore: ; ; This refers to the rear wheelbase, and ; In the formula: This is the equivalent lateral force on the front axle of the rear vehicle; This is the equivalent lateral force on the rear axle of the vehicle behind. The linear tire relationship is as follows: , ; In the formula: The side slip angle of the rear vehicle's front axle; The rear axle side slip angle of the rear vehicle; The equivalent lateral stiffness of the front axle of the rear vehicle; The equivalent lateral stiffness of the rear axle of the rear vehicle; Therefore: , ; If the front axle slip angle and rear axle slip angle of the rear vehicle are required to not exceed their respective maximum allowable slip angles. and Then the following condition is met: , ; Therefore, the upper limit of the lateral slip constraint speed of the rear axle can be obtained: ; The upper limit of the rear axle lateral slip constraint speed of the rear vehicle: ; In the formula: The upper limit of the speed of the following vehicle at arc length coordinate s is obtained based on the front axle sideslip constraint; The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the rear axle sideslip constraint; This is the maximum allowable sideslip angle for the front axle of the following vehicle; This is the maximum allowable sideslip angle for the rear axle of the following vehicle.

[0013] Optionally, in some embodiments, the roll constraint includes: To mitigate the roll risk of high-center-of-gravity vehicles in corners, roll constraints are established: ; In the formula: A preset roll safety threshold is used to limit the permissible degree of lateral load transfer from the following vehicle, and 0 < <1; The height of the rear vehicle's center of gravity; This refers to the rear wheel track. Therefore, the upper limit of the roll constraint speed is determined: ; In the formula: This represents the upper limit of the speed of the following vehicle at the arc length coordinate s based on the roll constraint.

[0014] Optionally, in some embodiments, determining the risk of the following vehicle becoming unstable based on the upper limit of safe speed specifically includes: The current speed of the following vehicle satisfies Then there must be: , , , , This represents the current longitudinal speed of the following vehicle; Therefore, the friction circle constraint Front axle lateral slip constraint Rear axle lateral slip constraint and roll restraint Established simultaneously; gather as follows: ; The set The following vehicle's road capability function constitutes the following vehicle's road capability function. The safe and feasible domain below.

[0015] Optionally, in some embodiments, the step of determining the risk of instability of the following vehicle based on prior road capability specifically includes: Define attached supply and demand margin: ; In the formula: This refers to the adhesion requirements of the following vehicle under its current operating conditions; This is the road capability function used for safe speed planning of the following vehicle at arc length coordinate s; The attachment requirement is expressed as: ; In the formula: This represents the current longitudinal acceleration of the following vehicle; This represents the current longitudinal speed of the following vehicle; It is the acceleration due to gravity; The arc length coordinates of the path ahead Curvature at that point; The following vehicle is deemed to be in danger of instability when any of the following conditions are met: ;or, ; In the formula: The adhesion supply and demand margin threshold is the minimum safety requirement used to characterize the remaining adhesion capability of the following vehicle. This represents the upper limit of the safe speed of the following vehicle at the arc length coordinate s.

[0016] In a second aspect, embodiments of the present invention also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the method described in any of the first aspects above.

[0017] Thirdly, embodiments of the present invention also provide a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method described in any of the above embodiments.

[0018] The above-described technical solution of the present invention has at least the following beneficial technical effects:

[0019] A road capability prior sharing and safe speed planning method for heterogeneous vehicles is proposed to address the problems of speed planning lag and increased instability risk in complex road environments, especially in high-risk curves, slippery curves, and low-adhesion abrupt road sections. This is because following vehicles cannot obtain timely and accurate information about the road capability ahead and perform safety reinterpretation based on their own heterogeneous characteristics. The method effectively improves the following vehicle's forward perception of risks ahead. By using a dual-output collaborative interface where the preceding vehicle outputs "road capability prior value + estimated confidence level", the interpretability of shared information is improved. Through time decay and spatial alignment mechanisms, control deviations caused by outdated and misaligned information are avoided. By projecting the shared road capability prior onto the following vehicle's own safety constraint set to complete heterogeneous reinterpretation, the lack of rigorous proof for empirical scaling formulas is avoided. Through advance deceleration control based on the safe speed upper limit, the safety and control robustness of vehicles cornering under complex conditions are improved. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or in the conventional art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart of a safe speed planning method for heterogeneous vehicles provided in an embodiment of the present invention.

[0022] Figure 2 This is a schematic diagram of an application scenario for road capability prior sharing and safe speed planning for heterogeneous vehicles provided by an embodiment of the present invention.

[0023] Figure 3 This is a flowchart of a priori estimation and confidence calculation process for the road capability of a preceding vehicle provided in an embodiment of the present invention.

[0024] Figure 4 This is a schematic diagram of a shared data packet construction and V2V communication structure for vehicles in front and rear, provided by an embodiment of the present invention.

[0025] Figure 5 This is a priori time-dependent modification diagram of shared road capability provided in an embodiment of the present invention.

[0026] Figure 6 This is a schematic diagram of a shared road capability space alignment method provided in an embodiment of the present invention.

[0027] Figure 7 This is a flowchart of a method for solving the safe speed limit based on a road capacity function and a set of parameters of the following vehicles, provided by an embodiment of the present invention.

[0028] Figure 8 This is a schematic diagram of an instability risk assessment and early deceleration control process provided by an embodiment of the present invention.

[0029] Figure 9 This is a schematic diagram of the speed-distance relationship for instability risk assessment provided by an embodiment of the present invention.

[0030] Figure 10 This is a schematic block diagram of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0031] 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.

[0032] Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the present invention.

[0033] It should be noted that the sequence number mentioned in this application does not necessarily mean that the execution must be strictly in the correct order in the actual implementation process. The sequence number is used to distinguish each step, facilitate explanation, and prevent confusion.

[0034] The accompanying drawings illustrate a layer structure according to an embodiment of the present invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0035] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0036] Currently, existing vehicle sensors struggle to anticipate road conditions ahead, especially in obstructed curves, complex road conditions, and low-adhesion abrupt changes, limiting their warning and control capabilities. Furthermore, estimation lag exists; dynamic estimation relies on the vehicle's current state, resulting in a certain degree of delay and hindering feedforward control.

[0037] This invention provides a method for prior sharing of road capabilities and safe speed planning for heterogeneous vehicles, which addresses the problem of speed planning lag and increased instability risk in complex road environments, especially in high-risk curves, slippery curves, and low-adhesion abrupt road sections. This is because following vehicles cannot timely and accurately obtain the road capabilities ahead and combine them with their own heterogeneous characteristics for safe reinterpretation.

[0038] This application presents a method for prior sharing of road capabilities and safe speed planning for heterogeneous vehicles, which is triggered in a specific scenario where the preceding vehicle enters a high-risk curve or low-adhesion road section before the following vehicle, and the following vehicle has not yet entered the risky road section.

[0039] To address the aforementioned problems, one embodiment of the present invention provides a safe speed planning method and electronic device for heterogeneous vehicles.

[0040] A safe speed planning method for heterogeneous vehicles, such as Figure 1 As shown, it includes:

[0041] S1. Establish communication with the vehicle in front and obtain the dynamic data of the vehicle in front during its movement;

[0042] S2. Based on the longitudinal excitation, lateral excitation and yaw excitation of the preceding vehicle, obtain the total confidence level of this prior road capability estimate;

[0043] S3. Based on the total confidence level, the following vehicle data, and the road data, perform timeliness correction and heterogeneous reinterpretation to obtain the safe speed limit of the following vehicle;

[0044] S4. Based on prior knowledge of road capabilities, determine the risk of instability of the following vehicle;

[0045] S5. Based on the instability risk assessment results, execute a safe speed planning and early deceleration control strategy. The control strategy includes: upper-level safe speed control based on prior reinterpretation of shared road capacity, and lower-level longitudinal deceleration control based on target deceleration solution.

[0046] The following provides a detailed explanation, and you can refer to the specific application scenarios. Figure 2 As shown.

[0047] Step 1: Obtain the prior value of the road capability of the vehicle ahead;

[0048] Step 2: Obtain the estimated confidence level of the road capability prior;

[0049] Step 3: Time-sensitive correction and heterogeneous reinterpretation of shared road capability priors;

[0050] Step 4: The vehicle in front establishes communication with the vehicle behind;

[0051] Step 5: Assess the current risk of instability based on prior knowledge of road capabilities;

[0052] Step Six: Based on the assessment of the danger, implement safe speed planning and early deceleration control strategies.

[0053] In step one, the method for calculating the prior value of the preceding vehicle's road capability is as follows: Dynamic data of the preceding vehicle during its movement is collected; a monorail lateral-yaw dynamic model of the preceding vehicle is established to obtain longitudinal acceleration, lateral acceleration, yaw rate of change, equivalent normal loads on the front and rear axles, and equivalent lateral forces; longitudinal road capability observations, lateral road capability observations, and yaw channel road capability observations are constructed respectively; and a one-state multi-observation Kalman filter algorithm is used to obtain the estimated prior value of the preceding vehicle's road capability. .

[0054] In step two, the method for calculating the confidence level of the road capacity prior estimate is as follows: based on the longitudinal excitation, lateral excitation, and yaw excitation of the preceding vehicle, the confidence levels for the longitudinal channel, lateral channel, and yaw channel are calculated respectively; the total confidence level of this road capacity prior estimate is obtained by fusing the confidence levels. .

[0055] The process for steps one and two is as follows: Figure 3 As shown.

[0056] The method for time-sensitive correction and heterogeneous reinterpretation of shared road capability priors described in step three is as follows:

[0057] Step 3.1: Calculate the information age based on the timestamp of the shared data packet. ;

[0058] Step 3.2: Establish an information freshness decay factor based on information age. ;

[0059] Step 3.3: Utilize the total confidence level Information freshness decay factor Calculate the effective confidence weights ;

[0060] The above process can be used as a reference. Figure 5 , Figure 6 As shown.

[0061] Step 3.4: Based on the spatial location in the shared data packet, spatially align the prior road capability of the preceding vehicle with the arc length coordinates of the following vehicle's projected path to obtain the matching position. and the road capability function distributed along the rear vehicle's aiming path. ;

[0062] Step 3.5: Based on the dynamic parameters of the rear vehicle itself, establish a set of feasible speeds for the rear vehicle with respect to friction circle constraints, tire slip constraints, and roll constraints;

[0063] Step 3.6: The road capacity function Projecting onto the set of feasible speeds, the upper limit of safe speed applicable to the following vehicle is obtained. This completes the heterogeneous reinterpretation.

[0064] The above process can be used as a reference. Figure 7 As shown.

[0065] In step four, the method for establishing communication between the preceding and following vehicles is as follows: the preceding vehicle sends a shared data packet to the following vehicle through its vehicle-to-vehicle communication module, including the preceding vehicle's prior road capability value. Total confidence level corresponding to prior values ​​of road capability Valid timestamp of data Corresponding road segment location information The system includes the status indicator of the preceding vehicle; the communication module of the following vehicle receives the shared data packet and transmits the shared data packet to the safe speed planning and control module of the following vehicle.

[0066] This process can be referenced. Figure 4 As shown.

[0067] In step five, the prior judgment of the current instability risk based on road capability includes whether the following vehicle exceeds the safe speed limit at the current speed, whether there is insufficient adhesion supply and demand margin, and whether it faces the risk of sideslip, understeering, oversteering or roll under combined braking-turning conditions.

[0068] In step six, the implementation of safe speed planning and early deceleration control strategies based on the assessment of danger includes upper-level safe speed planning design based on prior reinterpretation of shared road capacity, and lower-level longitudinal deceleration control method based on target deceleration solution.

[0069] Steps five and six of this application can be referenced. Figure 8 , Figure 9 As shown.

[0070] The upper-level safe speed planning method based on prior reinterpretation of shared road capacity is as follows:

[0071] By combining the curvature of the path ahead, friction circle constraints, tire side slip constraints, and roll constraints, the upper limit of the safe speed of the following vehicle is determined; if the current vehicle speed is higher than the upper limit of the safe speed, the target deceleration and the deceleration start time are generated.

[0072] For details, please refer to the following:

[0073] Step 1: Obtain the prior value of the road capability of the vehicle ahead.

[0074] Accelerometers, gyroscopes, wheel speed sensors, and steering angle sensors are used to collect dynamic data of the vehicle in front during its driving process, including longitudinal speed, longitudinal acceleration, lateral acceleration, yaw rate, and steering angle. The collected data is then preprocessed by removing noise and filtering.

[0075] Establish a lateral yaw dynamic model for the lead vehicle on a single rail. The lead vehicle is denoted as the guide vehicle, and its subscript is [insert subscript here]. .

[0076] The equation of motion for the vehicle in front is:

[0077] ;

[0078] The equation of motion for the yaw motion of the vehicle in front is:

[0079] ;

[0080] In the formula:

[0081] The total weight of the vehicle in front;

[0082] The rate of change of the lateral velocity of the center of gravity of the vehicle in front;

[0083] The longitudinal speed of the vehicle in front;

[0084] The yaw rate of the vehicle in front;

[0085] The moment of inertia of the preceding vehicle about the vertical axis is the yaw motion.

[0086] This is the distance from the center of gravity of the vehicle in front to the front axle.

[0087] This is the distance from the center of gravity of the front vehicle to the rear axle;

[0088] This is the equivalent lateral force on the front axle of the vehicle in front;

[0089] This is the equivalent lateral force on the rear axle of the front vehicle.

[0090] The front wheelbase is:

[0091] ;

[0092] In the formula:

[0093] This refers to the wheelbase of the front vehicle.

[0094] From the lateral motion relationship, we can obtain:

[0095] ;

[0096] In the formula:

[0097] This refers to the lateral acceleration of the vehicle in front.

[0098] Therefore:

[0099] ;

[0100] The meanings of the letters in the formula are the same as before.

[0101] It should be noted that this implementation uses a monorail model to perform lumped modeling of the preceding vehicle, and the subsequent calculations are... and The equivalent normal loads of the front and rear axles in the sense of the monorail model are represented by the lumped result of the normal loads of the left and right wheels, which are used to describe the influence of longitudinal load transfer on the adhesion utilization capability of the front and rear axles. The lateral load transfer between the left and right wheels caused by lateral acceleration is not discussed separately in this step, but is supplemented and characterized in the roll constraint in step five.

[0102] Constructing longitudinal road capacity observations:

[0103] ;

[0104] In the formula:

[0105] For the longitudinal lane capacity observation of the vehicle ahead;

[0106] This refers to the longitudinal acceleration of the vehicle in front.

[0107] This is the acceleration due to gravity.

[0108] Construction of lateral road capacity observations:

[0109] ;

[0110] In the formula:

[0111] For the observation of road capacity in the lateral passage of the vehicle in front.

[0112] Calculate the equivalent normal loads on the front and rear axles:

[0113] ;

[0114] In the formula:

[0115] The equivalent normal load on the front axle of the vehicle ahead;

[0116] The equivalent normal load on the rear axle of the front vehicle;

[0117] The height of the center of gravity of the vehicle in front.

[0118] Invert the equivalent lateral forces between the front and rear axles:

[0119] ;

[0120] The meanings of the letters in the formula are the same as before.

[0121] The rate of change of yaw angular velocity is obtained by discrete differentiation:

[0122] ;

[0123] In the formula:

[0124] For the first The rate of change of the yaw rate of the vehicle in front at each sampling time;

[0125] The sampling period.

[0126] Construction of front and rear axle attachment observations:

[0127] ;

[0128] In the formula:

[0129] For the observation of the adhesion of the front axle of the vehicle in front;

[0130] For the observation of the attachment of the rear axle of the front vehicle;

[0131] To prevent extremely small positive numbers with a denominator of zero.

[0132] Establish a yaw rate road capacity observation:

[0133] ;

[0134] In the formula:

[0135] The measurement is used to assess the road capacity of the lane ahead when the vehicle veers across.

[0136] Considering that longitudinal, lateral, and cross-traverse lanes, although originating from different sources, collectively reflect the comprehensive road capacity that the same road surface can provide to vehicles at the current moment, this implementation method uses road capacity state variables... It is set as a scalar, and a Kalman filter structure with one state and multiple observations is used to fuse and estimate the observations of the three channels.

[0137] The state equation is:

[0138] ;

[0139] In the formula:

[0140] For the first The comprehensive road capacity state variables at each sampling time;

[0141] This is process noise.

[0142] The observation equation is:

[0143] ;

[0144] In the formula:

[0145] For observation vectors;

[0146] The observation matrix;

[0147] To measure the noise vector.

[0148] The filter prediction steps are as follows:

[0149] ;

[0150] The filter update steps are as follows:

[0151] ;

[0152] ;

[0153] ;

[0154] In the formula:

[0155] This is a predicted value;

[0156] This is the updated estimate;

[0157] For the prediction error covariance;

[0158] To update the error covariance;

[0159] For process noise covariance;

[0160] To measure the noise covariance matrix;

[0161] Kalman gain;

[0162] It is an identity matrix.

[0163] The prior value of the road capability of the preceding vehicle is defined as:

[0164] ;

[0165] In the formula:

[0166] The prior value of road capability output for the vehicle ahead;

[0167] Lower bound for road capacity estimation;

[0168] This serves as an upper bound for road capacity estimation.

[0169] This is the amplitude limiting function.

[0170] Step 2: Obtain the estimated confidence level of the road capability prior.

[0171] Based on the longitudinal, lateral, and yaw excitations of the preceding vehicle, the confidence scores for the longitudinal channel, lateral channel, and yaw channel are constructed respectively:

[0172] ;

[0173] ;

[0174] ;

[0175] In the formula:

[0176] Confidence level of the longitudinal passage of the vehicle ahead;

[0177] Confidence level for the lateral passage of the vehicle in front;

[0178] Confidence level for the vehicle ahead swerving across the lane;

[0179] This refers to the longitudinal excitation threshold parameter;

[0180] This is the lateral excitation threshold parameter;

[0181] This is the yaw excitation threshold parameter.

[0182] The saturation function is:

[0183] ;

[0184] In the formula:

[0185] The variable to be normalized.

[0186] The confidence scores of the three channels are combined to obtain the total confidence score:

[0187] ;

[0188] In the formula:

[0189] The total confidence level is used to estimate the road capability of the preceding vehicle, with a value ranging from 0 to 1.

[0190] when In such cases, only the Kalman prediction can be retained as the prior output for the current time step to avoid noise dominating measurement updates under extremely weak excitation.

[0191] Step 3: Time-sensitive correction and heterogeneous reinterpretation of shared road capability priors.

[0192] The leading vehicle builds a shared data packet:

[0193] ;

[0194] In the formula:

[0195] Share data packets for prior road capabilities;

[0196] The prior value of the road capability of the vehicle ahead;

[0197] Generate timestamps for the data;

[0198] This refers to the spatial location corresponding to the data.

[0199] The following vehicle is designated as the target vehicle, and marked as such. After receiving the shared data packet, the following vehicle calculates its age based on the current time and timestamp:

[0200] ;

[0201] In the formula:

[0202] Information age;

[0203] This refers to the current moment of the car following behind.

[0204] Establish an information freshness decay factor based on information age:

[0205] ;

[0206] In the formula:

[0207] Information freshness decay factor;

[0208] This is the time-related decay coefficient.

[0209] Calculate the effective confidence weights using the total confidence level and the information freshness decay factor:

[0210] ;

[0211] In the formula:

[0212] Effective confidence weights are used to comprehensively consider both prior reliability and information timeliness.

[0213] The following vehicle uses the spatial location in the shared data packet. By projecting the prior road capability of the preceding vehicle onto the arc-length coordinate system of the following vehicle's target path using the self-localization result, the matching position is obtained:

[0214] ;

[0215] In the formula:

[0216] The matching arc length coordinates on the pre-aiming path of the following vehicle are based on the prior road capability of the preceding vehicle.

[0217] This is the spatial projection mapping operator.

[0218] The rear vehicle on the arc length coordinate The road capacity function used for safe speed planning is defined as follows:

[0219] ;

[0220] In the formula:

[0221] Spatial matching tolerance threshold;

[0222] This is the default value for the local road capability of the following vehicle or a conservative estimate for this vehicle.

[0223] The heterogeneous reinterpretation of the rear vehicle is not a correct answer. Instead of directly using empirical scaling factors to enlarge or reduce, the road capacity function is... Projecting this onto the following vehicle's own dynamic constraints, we solve for the upper bound of the following vehicle's feasible speed on this road segment. The following vehicle's parameter set is as follows:

[0224] ;

[0225] In the formula:

[0226] For the set of parameters of the following vehicle;

[0227] For the overall vehicle weight of the following vehicle;

[0228] This refers to the rear wheelbase;

[0229] This is the distance from the rear vehicle's center of gravity to the front axle.

[0230] This is the distance from the rear vehicle's center of gravity to the rear axle.

[0231] The height of the rear vehicle's center of gravity;

[0232] The moment of inertia of the rear vehicle about the vertical axis is the yaw motion.

[0233] The equivalent lateral stiffness of the front axle of the rear vehicle;

[0234] The equivalent lateral stiffness of the rear axle of the rear vehicle;

[0235] This is the distance between the rear wheels.

[0236] Define the rear vehicle's arc length coordinates The feasible velocity set at point is:

[0237]

[0238] In the formula:

[0239] For the rear vehicle in arc length coordinates The set of feasible velocities at a given location;

[0240] Here is the constraint function for the friction circle;

[0241] This is the front axle sideslip constraint function;

[0242] This is the rear axle lateral slip constraint function;

[0243] This is the roll constraint function.

[0244] Therefore, the safe speed limit applicable to following vehicles is defined as follows:

[0245] .

[0246] Step 4: Establish communication between the vehicle in front and the vehicle behind.

[0247] The vehicle in front sends a shared data packet to the vehicle behind via the vehicle-to-vehicle communication module. The communication is triggered when the relative distance between the two vehicles meets the following condition:

[0248] ;

[0249] In the formula:

[0250] The relative distance between the vehicle in front and the vehicle behind;

[0251] This is the communication trigger distance threshold.

[0252] When the vehicle in front detects a high-risk curve or low-friction road section ahead, the communication module of the vehicle in front broadcasts a shared data packet; the communication module of the vehicle behind receives the shared data packet and transmits the shared data packet to the safe speed planning and control module of the vehicle behind.

[0253] Step 5: Determine the current risk of instability based on prior knowledge of road capabilities.

[0254] The following vehicle obtains the curvature of the path ahead through the path prediction module. And based on the road capacity function With its own parameter set Solve for the safe speed limit.

[0255] I. Friction circle constraint.

[0256] Under combined braking-turning conditions, the following vehicle should meet the following requirements:

[0257] ;

[0258] In the formula:

[0259] Provide the longitudinal deceleration for the following vehicle;

[0260] To achieve the required safe speed;

[0261] The arc length coordinates of the path ahead The curvature at that point.

[0262] From the above formula, the upper limit of the friction circle constraint velocity can be obtained:

[0263] ;

[0264] In the formula:

[0265] The upper limit of velocity is based on the friction circle constraint;

[0266] To prevent extremely small positive numbers with a denominator of zero.

[0267] II. Tire lateral deviation constraint.

[0268] Under the steady-state small-angle monorail model, the following conditions are met:

[0269] ;

[0270] ;

[0271] It is important to understand that under steady-state or quasi-steady-state small-angle turning conditions, the yaw acceleration of the rear vehicle... We can approximate it as 0, therefore we have:

[0272] ;

[0273] therefore:

[0274] ;

[0275] Combining the above equations, we get:

[0276] ;

[0277] In the formula:

[0278] This is the equivalent lateral force on the front axle of the rear vehicle;

[0279] This is the equivalent lateral force on the rear axle of the vehicle.

[0280] Furthermore, the linear tire relationship is as follows:

[0281] ;

[0282] In the formula:

[0283] The side slip angle of the rear vehicle's front axle;

[0284] The rear axle side slip angle of the rear vehicle.

[0285] Therefore:

[0286] , ;

[0287] If the front and rear axle slip angles are required to not exceed their respective allowable thresholds. and Then the following must be satisfied:

[0288] , ;

[0289] Therefore, the upper limit of the front axle lateral slip constraint speed can be obtained:

[0290] ;

[0291] Rear axle lateral slip constraint speed limit:

[0292] ;

[0293] In the formula:

[0294] The upper limit of speed is based on the front axle sideslip constraint;

[0295] The upper limit of speed is based on the rear axle sideslip constraint;

[0296] This is the maximum allowable sideslip angle for the front axle of the following vehicle;

[0297] This is the maximum allowable sideslip angle for the rear axle of the following vehicle.

[0298] III. Roll restraint.

[0299] To mitigate the roll risk of high-center-of-gravity vehicles in corners, roll constraints are established:

[0300] ;

[0301] In the formula:

[0302] This is the roll safety factor.

[0303] Therefore, the upper limit of the roll constraint velocity can be obtained:

[0304] ;

[0305] In the formula:

[0306] This represents the upper limit of speed based on roll constraints.

[0307] IV. Ultimate safe speed limit.

[0308] The final safe speed limit for the following vehicle is set as follows:

[0309] ;

[0310] In the formula:

[0311] Speed ​​limits are imposed on roads or by external regulations.

[0312] As defined, as long as the current speed of the following vehicle satisfies Then there must be:

[0313]

[0314] ;

[0315] Therefore, the friction circle constraint, front axle sideslip constraint, rear axle sideslip constraint, and roll constraint all hold simultaneously. Thus, the set is:

[0316] ;

[0317] Constitutes the capability function of the following vehicle on a given road. The safe and feasible region is defined below. The above conclusion forms the basis for the rigorous mathematical logic of heterogeneous reinterpretation in this invention: the same shared road capability prior, mediated by different sets of subsequent vehicle parameters... After projection, different safe speed limits will be obtained. .

[0318] Further define the attached supply and demand margin:

[0319] ;

[0320] In the formula:

[0321] To accommodate supply and demand margins;

[0322] This is to meet the adhesion requirements of the following vehicle under the current operating conditions.

[0323] The attachment requirement is expressed as:

[0324] ;

[0325] In the formula:

[0326] This represents the current longitudinal acceleration of the following vehicle;

[0327] This represents the current longitudinal speed of the following vehicle.

[0328] The following vehicle is deemed to be at risk of instability when any of the following conditions are met:

[0329] one, ;

[0330] two, .

[0331] In the formula:

[0332] This is for attaching supply and demand margin thresholds.

[0333] Step 6: Based on the assessment of the danger, implement safe speed planning and early deceleration control strategies.

[0334] Let the remaining distance from the current position of the following vehicle to the target position where deceleration is completed be... The current speed is The target safe speed is According to the kinematic relations of uniform deceleration:

[0335] ;

[0336] The theoretical deceleration required to reduce speed to the upper limit of safety over the remaining distance can be obtained as follows:

[0337] ;

[0338] In the formula:

[0339] The theoretical deceleration required to achieve the target safe speed;

[0340] This represents the remaining distance from the current position of the following vehicle to the target position where deceleration is complete.

[0341] To prevent extremely small positive numbers with a denominator of zero.

[0342] when Sometimes, This indicates that the vehicle behind needs to slow down; when At that time, it can be made .

[0343] Construct longitudinal deceleration control commands:

[0344] ;

[0345] In the formula:

[0346] This is the final longitudinal deceleration control command for the following vehicle;

[0347] For speed error feedback gain;

[0348] This is the theoretical deceleration compensation gain;

[0349] This represents the negative boundary of the maximum permissible braking deceleration.

[0350] Calculate the required total braking force based on the longitudinal deceleration control command:

[0351] ;

[0352] In the formula:

[0353] This is the total braking force required for the following vehicle.

[0354] If front and rear axle braking force distribution is required, it should be distributed according to the normal load ratio as follows:

[0355] ;

[0356] In the formula:

[0357] To provide braking force to the front axle of the following vehicle;

[0358] For braking force on the rear axle of the following vehicle;

[0359] For the normal load on the front axle of the rear vehicle;

[0360] This is the normal load on the rear axle of the rear vehicle.

[0361] This invention does not simply pass the estimation results of the preceding vehicle directly to the following vehicle. Instead, it uses a complete chain of "precedence estimation of the preceding vehicle's road capability, calculation of estimation confidence, construction of shared data packets, timeliness correction, spatial alignment, heterogeneous reinterpretation, instability risk judgment, safe speed planning, and early deceleration control" to enable the following vehicle to construct a safety boundary and perform feedforward deceleration control before entering the risk area, based on the prior knowledge of the preceding vehicle and its own heterogeneous dynamic characteristics. This significantly improves the safety and robustness of vehicle cooperative cornering in complex road scenarios.

[0362] This invention also provides an electronic device 800, such as... Figure 10As shown, it includes a memory 801, a processor 802, and a computer program stored in the memory 801 and executable on the processor. When the processor 802 executes the program, it implements the steps of the method described in any of the above embodiments.

[0363] According to embodiments of the present invention, a computer-readable storage medium is also provided, on which a computer program is stored, wherein the computer program, when executed by a processor, implements the steps of the method described in any of the above embodiments.

[0364] This invention also provides a computer program product, including a computer program stored in a computer-readable storage medium; when a processor of an electronic device reads the computer program from the computer-readable storage medium, the processor executes the computer program, causing the electronic device to perform the steps of any of the methods described in the above embodiments.

[0365] Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0366] It should be understood that the specific embodiments described above are merely illustrative or explanatory of the principles of the invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the invention should be included within the protection scope of the invention. Furthermore, the appended claims are intended to cover all variations and modifications falling within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A safe speed planning method for heterogeneous vehicles, characterized in that, include: Establish communication with the vehicle in front to obtain the dynamics data of the vehicle in front during its movement; Based on the longitudinal, lateral, and yaw excitations of the preceding vehicle, the total confidence level of the prior road capability estimate is obtained. Based on the total confidence level, following vehicle data, and road data, timeliness correction and heterogeneous reinterpretation are performed to obtain the safe speed limit of the following vehicle; The risk of instability of the following vehicle is determined based on prior assessment of road capabilities; Based on the instability risk assessment results, a safe speed planning and early deceleration control strategy is implemented. The control strategy includes: upper-level safe speed control based on prior reinterpretation of shared road capacity, and lower-level longitudinal deceleration control based on target deceleration solution.

2. The safety speed planning method for heterogeneous vehicles according to claim 1, characterized in that, The acquisition of the dynamics data of the preceding vehicle during its movement specifically includes: Dynamic data of the preceding vehicle during its movement were collected to establish a monorail lateral-yaw dynamic model of the preceding vehicle. This model yielded longitudinal acceleration, lateral acceleration, yaw rate of change, equivalent normal loads on the front and rear axles, and equivalent lateral forces. Longitudinal road capacity observations, lateral road capacity observations, and yaw channel road capacity observations were constructed. A single-state multi-observation Kalman filter algorithm was then used to obtain estimated prior values ​​of the preceding vehicle's road capacity. This includes: using accelerometers, gyroscopes, wheel speed sensors, and steering angle sensors to collect dynamic data of the vehicle in front during its driving process, including longitudinal speed, longitudinal acceleration, lateral acceleration, yaw rate, and steering angle; and performing noise removal and filtering preprocessing on the collected data.

3. The safety speed planning method for heterogeneous vehicles according to claim 1, characterized in that, The process of obtaining the total confidence level of the prior road capability estimate based on the longitudinal, lateral, and yaw excitations of the preceding vehicle specifically includes: Based on the longitudinal, lateral, and yaw excitations of the preceding vehicle, the confidence scores for the longitudinal channel, lateral channel, and yaw channel are calculated respectively. The total confidence score for this prior estimation of road capability is obtained through confidence score fusion. .

4. The safety speed planning method for heterogeneous vehicles according to claim 1, characterized in that, The step of performing timeliness correction and heterogeneous reinterpretation based on the total confidence level, subsequent vehicle data, and road data specifically includes: Obtain the data from the following vehicle and construct a shared data packet: ； In the formula: Share data packets for prior knowledge of road capabilities; The prior value of the road capability of the vehicle ahead; Estimate the total confidence level of the road capability prior for the vehicle ahead; Generate timestamps for the data; The spatial location corresponding to the data; The rear vehicle is marked with an "H"; After receiving the shared data packet, the following vehicle calculates the information age based on the current time and timestamp: ； In the formula: Information age; The current time of the following vehicle; Establish an information freshness decay factor based on information age: ； In the formula: Information freshness decay factor; This is the time-related decay coefficient; Calculate the effective confidence weights using the total confidence level and the information freshness decay factor: ； The following vehicle, based on the spatial location in the shared data packet and its own positioning result, projects the prior road capability of the preceding vehicle onto the arc-length coordinate system of the following vehicle's pre-aiming path to obtain the matching position: ； In the formula: The arc length coordinates of the prior road capability of the preceding vehicle projected onto the pre-aiming path of the following vehicle; For spatial projection mapping operators; The road capability function for safe speed planning of the following vehicle at arc length coordinate s is defined as follows: ； In the formula: Spatial matching tolerance threshold; This is the default value for the local road capability of the following vehicle or a conservative estimate for this vehicle. The parameter set for the rear vehicle is as follows: ； In the formula: For the overall vehicle weight of the following vehicle; This refers to the rear wheelbase. This is the distance from the rear vehicle's center of gravity to the front axle. This is the distance from the rear vehicle's center of gravity to the rear axle. The height of the rear vehicle's center of gravity; The moment of inertia of the rear vehicle about the vertical axis is the yaw motion. The equivalent lateral stiffness of the front axle of the rear vehicle; The equivalent lateral stiffness of the rear axle of the rear vehicle; This is the distance between the rear wheels.

5. The safety speed planning method for heterogeneous vehicles according to claim 1, characterized in that, The prior assessment of the risk of vehicle instability based on road capability specifically includes: The following vehicle obtains the curvature of the path ahead through the path prediction module, and uses the road capability function at the arc length coordinate s of the following vehicle for safe speed planning. With the set of parameters of the following vehicle Solve for the upper limit of safe speed, which includes at least the friction circle constraint. Tire slip constraint, roll constraint Safe speed limit According to the aforementioned safe speed limit Assess the risk of instability of the rear vehicle; The friction circle constraint is as follows: Under combined braking-turning conditions, the following vehicle satisfies: ； In the formula: Let be the candidate speed of the following vehicle at the arc length coordinate s; Provide the longitudinal deceleration for the following vehicle; The arc length coordinates of the path ahead Curvature at that point; The road capability function for safe speed planning of the following vehicle at arc length coordinate S; Let be the acceleration due to gravity, and take . ; Determine the upper limit of the velocity of the rear vehicle at arc length coordinate s based on the friction circle constraint: ； In the formula, To prevent the unit of an extremely small positive number with a denominator of zero, and the curvature Consistent, take here ; The following vehicle is in the arc length coordinate. The upper limit of safe speed is further expressed as follows: ； In the formula: Speed ​​limits are imposed on roads or by external regulations. The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the friction circle constraint; The upper limit of the speed of the following vehicle at arc length coordinate s is obtained based on the front axle sideslip constraint; The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the rear axle sideslip constraint; This represents the upper limit of the speed of the following vehicle at the arc length coordinate s based on the roll constraint.

6. The safety speed planning method for heterogeneous vehicles according to claim 5, characterized in that, The tire lateral restraint includes: Under the steady-state small-angle monorail model, the rear vehicle satisfies: ； ； For the overall vehicle weight of the following vehicle; This is the distance from the rear vehicle's center of gravity to the front axle. This is the distance from the rear vehicle's center of gravity to the rear axle. therefore: ； ； This refers to the rear wheelbase, and ; In the formula: This is the equivalent lateral force on the front axle of the rear vehicle; This is the equivalent lateral force on the rear axle of the vehicle behind. The linear tire relationship is as follows: ， ； In the formula: The side slip angle of the rear vehicle's front axle; The rear axle side slip angle of the rear vehicle; The equivalent lateral stiffness of the front axle of the rear vehicle; The equivalent lateral stiffness of the rear axle of the rear vehicle; Therefore: ， ； If the front axle slip angle and rear axle slip angle of the rear vehicle are required to not exceed their respective maximum allowable slip angles. and Then the following condition is met: ， ； Therefore, the upper limit of the lateral slip constraint speed of the rear axle can be obtained: ； The upper limit of the rear axle lateral slip constraint speed of the rear vehicle: ； In the formula: The upper limit of the speed of the following vehicle at arc length coordinate s is obtained based on the front axle sideslip constraint; The upper limit of the speed of the following vehicle at the arc length coordinate s is obtained based on the rear axle sideslip constraint; This is the maximum allowable sideslip angle for the front axle of the following vehicle; This is the maximum allowable sideslip angle for the rear axle of the following vehicle.

7. A safe speed planning method for heterogeneous vehicles according to claim 5, characterized in that, The roll constraint includes: To mitigate the roll risk of high-center-of-gravity vehicles in corners, roll constraints are established: ； In the formula: A preset roll safety threshold is used to limit the permissible degree of lateral load transfer from the following vehicle, and 0 < <1; The height of the rear vehicle's center of gravity; This refers to the rear wheel track. Therefore, the upper limit of the roll constraint speed is determined: ； In the formula: This represents the upper limit of the speed of the following vehicle at the arc length coordinate s based on the roll constraint.

8. A safe speed planning method for heterogeneous vehicles according to claim 5, characterized in that, The step of determining the risk of the following vehicle becoming unstable based on the upper limit of safe speed specifically includes: The current speed of the following vehicle satisfies Then there must be: ， ， ， ， This represents the current longitudinal speed of the following vehicle; Therefore, the friction circle constraint Front axle lateral slip constraint Rear axle lateral slip constraint and roll restraint Established simultaneously; gather as follows: ； The set The following vehicle's road capability function constitutes the following vehicle's road capability function. The safe and feasible domain below.

9. The safety speed planning method for heterogeneous vehicles according to claim 1, characterized in that, The prior assessment of the risk of vehicle instability based on road capability specifically includes: Define attached supply and demand margin: ； In the formula: This refers to the adhesion requirements of the following vehicle under its current operating conditions; This is the road capability function used for safe speed planning of the following vehicle at arc length coordinate s; The attachment requirement is expressed as: ； In the formula: This represents the current longitudinal acceleration of the following vehicle; This represents the current longitudinal speed of the following vehicle; It is the acceleration due to gravity; The arc length coordinates of the path ahead Curvature at that point; The following vehicle is deemed to be in danger of instability when any of the following conditions are met: ;or, ； In the formula: The adhesion supply and demand margin threshold is the minimum safety requirement used to characterize the remaining adhesion capability of the following vehicle. This represents the upper limit of the safe speed of the following vehicle at the arc length coordinate s.

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 method according to any one of claims 1-9.

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