Method, device, equipment and medium for warning the reversing folding of a semi-trailer train

Abstract

The disclosed embodiments disclose a method, device, equipment, and medium for a semi-trailer train reversing folding warning. The method includes: determining a reversing folding time corresponding to the current driving state based on a controllable range of the articulation angle of the semi-trailer train when reversing; performing a reversing folding warning based on the reversing folding time and a time threshold; the articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer trailer; during reversing, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the tractor's front wheel deflection angle; the reversing folding time is the time required for the articulation angle to change outside the controllable range while maintaining the tractor's current speed and front wheel deflection angle unchanged during the reversing process of the semi-trailer train. The disclosed method improves the reversing stability, accuracy, and safety of the semi-trailer train.

Description

Technical Field

[0001] The present disclosure relates to the technical field of semi-trailer vehicle trains, and in particular to a method, device, equipment and medium for providing a warning of a semi-trailer vehicle train reversing and folding. Background Art

[0002] A semi-trailer train, consisting of a tractor and a semi-trailer trailer secured by a tow pin, boasts advantages such as high load capacity, high transport efficiency, and low costs. It is widely used in numerous transport scenarios, including ports, mines, and logistics parks. In practice, reversing a semi-trailer train at a specific articulation angle is a common operation, such as reversing into a cargo hold or docking at a docking platform. However, maneuvering a semi-trailer train in reverse is challenging and typically requires highly experienced drivers. The primary challenge lies in the fact that, due to factors such as the semi-trailer train's nonlinearity, instability, and uncertainty, its dynamic state during reversing is open-loop unstable, prone to unstable states such as folding and collision. Furthermore, due to the semi-trailer train's long body and large blind spots, visibility during reversing is even poorer, making it difficult for the driver to judge the semi-trailer train's instantaneous articulation angle.

[0003] In recent years, with advances in computer information processing and sensor technology, advanced vehicle-assisted driving and autonomous driving technologies have made significant progress in the commercial vehicle sector. This has provided strong support for real-time acquisition of the articulation angle of semi-trailer trains and, based on this, for reverse folding warnings. Developing a warning method for reverse folding semi-trailer trains can facilitate the development of reverse assistance systems for these trains, effectively reducing the difficulty of reverse driving and improving reverse efficiency, thereby alleviating driver workload and lowering the incidence of traffic accidents. Furthermore, research on warning methods for reverse folding semi-trailer trains also provides technical support for trajectory planning and motion control for autonomous reverse operations.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] In order to solve the above technical problems or at least partially solve the above technical problems, the embodiments of the present disclosure provide a method, device, equipment and medium for warning the reversing folding of a semi-trailer train, which improves the reversing stability, accuracy and safety of the semi-trailer train, effectively reduces the difficulty of reversing driving of the semi-trailer train, improves the reversing efficiency of the semi-trailer train, thereby reducing the driver's workload and reducing the incidence of traffic accidents. It can also provide technical support for realizing trajectory planning and motion control of autonomous reversing of the semi-trailer train.

[0006] In a first aspect, an embodiment of the present disclosure provides a method for early warning of a semi-trailer train reversing and folding, the method comprising:

[0007] Determine the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing;

[0008] Performing a reverse folding warning according to the reverse folding time and the time threshold;

[0009] The articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer; during reversing, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the front wheel deflection angle of the tractor; the current driving state includes the current speed of the tractor and the current front wheel deflection angle of the tractor, and the reversing folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current speed of the tractor and the current front wheel deflection angle of the tractor unchanged during the reversing of the semi-trailer train.

[0010] In a second aspect, the embodiments of the present disclosure further provide a semi-trailer train reversing folding warning device, the device comprising:

[0011] The first determining module is used to determine the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing;

[0012] An early warning module is used to issue an early warning for reversing folding according to the reversing folding time and the time threshold;

[0013] The articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer trailer; during reversing, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the front wheel deflection angle of the tractor; the current driving state includes the current vehicle speed and the current front wheel deflection angle, and the reversing folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current vehicle speed and the current front wheel deflection angle of the semi-trailer train unchanged during the reversing process.

[0014] In a third aspect, an embodiment of the present disclosure further provides an electronic device, comprising: one or more processors; a storage device for storing one or more programs; and when the one or more programs are executed by the one or more processors, the one or more processors implement the semi-trailer train reversing folding warning method as described above.

[0015] In a fourth aspect, an embodiment of the present disclosure further provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the above-mentioned method for warning the reversing and folding of a semi-trailer train.

[0016] A method for providing a reverse folding warning for a semi-trailer train is provided in an embodiment of the present disclosure. The method determines a reverse folding time corresponding to a current driving state based on a controllable range of an articulation angle of the semi-trailer train when reversing. During the reversing process, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the tractor's front wheel deflection angle. The reverse folding time is the time required for the articulation angle to change outside the controllable range while maintaining the tractor's current speed and front wheel deflection angle unchanged during the reversing process of the semi-trailer train. The technical means of providing a reverse folding warning based on the reverse folding time and a time threshold improves the reversing stability, accuracy, and safety of the semi-trailer train, effectively reduces the difficulty of reversing driving of the semi-trailer train, improves the reversing efficiency of the semi-trailer train, thereby reducing the driver's workload and the incidence of traffic accidents. The method also provides technical support for trajectory planning and motion control for autonomous reversing of the semi-trailer train. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other features, advantages, and aspects of the various embodiments of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals represent the same or similar elements. It should be understood that the drawings are schematic and that the originals and elements are not necessarily drawn to scale.

[0018] Figure 1 This is a flow chart of a method for early warning of a semi-trailer train reversing and folding according to an embodiment of the present disclosure;

[0019] Figure 2 Schematic diagram of a semi-trailer vehicle train according to an embodiment of the present disclosure;

[0020] Figure 3 Schematic diagram of a train in which a traction pin (point H0) is located behind the center of the rear axle of the tractor according to an embodiment of the present disclosure;

[0021] Figure 4 Schematic diagram of a train in which a traction pin (point H0) is located at the center of the rear axle of the tractor according to an embodiment of the present disclosure;

[0022] Figure 5 Schematic diagram of a train in which a traction pin (point H0) is located in front of the center of the rear axle of the tractor according to an embodiment of the present disclosure;

[0023] Figure 6Schematic diagram of a tracking deviation of a semi-trailer vehicle train relative to a reference track in an embodiment of the present disclosure;

[0024] Figure 7 Schematic diagram of the coupling relationship of state transfer during a reversing process in an embodiment of the present disclosure;

[0025] Figure 8 This is a schematic structural diagram of a semi-trailer train reversing folding warning device according to an embodiment of the present disclosure;

[0026] Figure 9 Schematic diagram of the structure of an electronic device in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0027] The following describes embodiments of the present disclosure in more detail with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of protection of the present disclosure.

[0028] It should be noted that the concepts of "first" and "second" mentioned in this disclosure are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0029] The names of the messages or information exchanged between multiple devices in the embodiments of the present disclosure are only used for illustrative purposes and are not used to limit the scope of these messages or information.

[0030] Figure 1 This is a flow chart of a method for warning the reversing folding of a semi-trailer train in an embodiment of the present disclosure. The method can be executed by a device for warning the reversing folding of a semi-trailer train, which can be implemented in software and / or hardware and can be configured in an electronic device. Figure 1 As shown, the method may specifically include the following steps:

[0031] S110: Determine a reversing folding time corresponding to a current driving state based on a controllable range of an articulation angle of the semi-trailer train when the semi-trailer train is reversing.

[0032] S120: Perform a reverse folding warning according to the reverse folding time and the time threshold.

[0033] The articulation angle is the difference between the heading angle of the tractor and the heading angle of the trailer. Figure 2Schematic diagram of a semi-trailer vehicle train is shown, which includes a tractor 210 and a semi-trailer trailer 220, wherein the articulation angle β1=θ0-θ1, θ0 is the heading angle of the tractor 210, and θ1 is the heading angle of the semi-trailer trailer 220.

[0034] During reversing, if the articulation angle is within the controllable range, the articulation angle can be varied toward 0 by controlling the deflection angle of the tractor's front wheels. In other words, if the articulation angle is within the controllable range, the folding between the tractor and the semi-trailer can be prevented by controlling the deflection angle of the tractor's front wheels, or the degree of folding between the tractor and the semi-trailer can be reduced, that is, the articulation angle can be varied toward 0 by control. The closer the articulation angle is to 0, the less folding between the tractor and the semi-trailer is considered to be.

[0035] The current driving state includes the current speed of the tractor and the current front wheel deflection angle of the tractor. The reverse folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current speed of the tractor and the current front wheel deflection angle of the tractor unchanged during the reverse movement of the semi-trailer train.

[0036] In summary, the size of the articulation angle is closely related to the motion state of the semi-trailer train. Therefore, in the embodiment of the present application, the articulation angle is analyzed based on the kinematic model of the semi-trailer train when reversing.

[0037] First, the reversing kinematic model of the semi-trailer train is established: the semi-trailer train can be simplified into a tractor and a semi-trailer trailer constrained by a traction pin, such as Figure 2 As shown, in the Cartesian coordinate system represented by XOY, (x0, y0) is the coordinate of the center of the rear axle of the tractor, v0 is the speed of the center of the rear axle of the tractor, and when the semi-trailer train is reversed, v0 < 0. (x1, y1) is the coordinate of the center of the rear axle of the semi-trailer, and v1 is the speed of the center of the rear axle of the tractor. θ0 is the heading angle of the tractor, θ1 is the heading angle of the semi-trailer, and the articulation angle between the tractor and the semi-trailer is β1 = θ0 - θ1. L0 is the wheelbase of the tractor, H0 represents the position of the traction pin between the tractor and the semi-trailer, then L h0 is the distance from the rear axle center of the tractor to the traction pin (point H0), and L1 is the distance from the rear axle center of the semi-trailer to the traction pin (point H0). The reverse movement of the semi-trailer train is controlled by controlling the front wheel deflection angle δ of the tractor. f Finish.

[0038] Based on the above notation, the differential equation describing the motion of the tractor can be written as:

[0039]

[0040] The differential equation describing the motion of the semi-trailer can be written as:

[0041]

[0042] Where, is the speed at the center of the rear axle of the semi-trailer.

[0043] The rate of change of the articulation angle β1 between the tractor and the semi-trailer You can write:

[0044]

[0045] Figure 2 The middle traction pin (H0 point) is located behind the center of the rear axle of the tractor. Figure 3 The structure of the semi-trailer train supported by this case is not limited to this form, and can also support an articulated structure in which the traction pin (H0 point) is located at the center of the rear axle of the tractor, such as Figure 4 Or the traction pin (H0 point) is located in the hinged structure in front of the center of the tractor rear axle, such as Figure 5 shown.

[0046] In order to maintain the consistency of formula (2) and formula (3) for semi-trailer trains with different articulation forms, Figure 2 The L of the articulated semi-trailer train shown h0 Take it as a positive value, for Figure 4 The hinge type L shown h0 The value is zero, for Figure 5 The hinge type L shown h0 Take a negative value.

[0047] The tracking deviation of the semi-trailer train relative to the reference trajectory is as follows: Figure 6 In this case, the reference trajectory of the reverse motion is represented by the symbol γ. The projection point of the semi-trailer on the reference trajectory is denoted as P, and the arc length between the projection point P and the starting point of the reference trajectory is denoted as s. The reference heading θ of the semi-trailer at point P can be obtained from the reference trajectory. 1r (s) and the reference articulation angle β 1r (s). The lateral deviation of the semi-trailer relative to the reference trajectory e d is the distance between the center of the rear axle of the semi-trailer and the projection point P, and the heading deviation e of the semi-trailer relative to the reference trajectory θ The heading θ1 of the semi-trailer and the reference heading θ at the projection point P 1r (s), denoted as e θ =θ1-θ 1r (s).

[0048] The differential equations for the lateral deviation and heading deviation of the semi-trailer relative to the reference trajectory during reversing can be written as:

[0049]

[0050] Where, It represents the actual turning curvature of the semi-trailer when the articulation angle is β1, It represents the reference turning curvature of the semi-trailer at the projection point P.

[0051] Based on the above-mentioned reversing kinematic model of the semi-trailer vehicle train, in some embodiments, the controllable region is determined based on the following method:

[0052] First, the definition of the controllable domain is clarified. The controllable domain is defined as follows: during the reversing process of the semi-trailer train, there is a certain range of thresholds for the articulation angle β1. When the articulation angle β1 exceeds this range threshold, no matter how the front wheel deflection angle is changed, the articulation angle of the semi-trailer train cannot approach 0 again, and the absolute value of the articulation angle keeps increasing, causing the semi-trailer train to enter a dangerous and unstable reversing folding condition. In other words, when the articulation angle β1 is within the range threshold of the controllable domain, the purpose of making the articulation angle of the semi-trailer train approach 0 can be achieved by changing the front wheel deflection angle. The range threshold of the articulation angle β1 is called the controllable domain β of the articulation angle. w .make Represents the lower limit threshold of the controllable range of the articulation angle during reversing, represents the upper threshold of the controllable range of the articulation angle during reversing, then the controllable range of the articulation angle β w It can be expressed as

[0053] According to the definition of the controllable range of the articulation angle, when the articulation angle When there is a front wheel deflection angle δ f The articulation angle β1 keeps decreasing, and when the front wheel deflection angle reaches the maximum value δ f,max When the hinge angle β1 decreases, the trend is the largest, that is, at this time Similarly, if Then if and only if δ f =δ f,min When the hinge angle β1 increases, the trend of increase is the largest, that is, at this time According to the above conclusions, when When and only when δ f =δ f,max When the hinge angle β1 remains unchanged, that is, Similarly, when When and only when δ f =δ f,min When the hinge angle β1 remains unchanged, that is, Therefore, get and That is to seek When δ f =δ f,min and δ f =δ f,max The value of the articulation angle β1 of the working condition.

[0054] According to the above inference, for any β1 in the controllable domain of the articulation angle, there is a corresponding δ f Make Define the stable solution β s During reversing The instantaneous hinge angle corresponding to the time, then β s Can be written as:

[0055]

[0056] Among them, sgn(δ f ) represents the front wheel deflection angle δ f From the above formula, we can see that the stable solution of the hinge angle β s is about the front wheel deflection angle δ f function, the front wheel deflection angle δ f The positive limit value δ f,max and the negative limit value δ f,min Substituting into, we can get the controllable range of the hinge angle β w The upper and lower thresholds are:

[0057]

[0058]

[0059] in, represents the first lower limit threshold, L1 represents the distance from the center of the rear axle of the semi-trailer to the traction pin, L0 represents the wheelbase of the tractor, L h0 Indicates the distance from the center of the tractor's rear axle to the traction pin, β f,min Indicates the negative limit value, sgn(δ f,min ) represents the negative limit value δ f,min The sign of δ f,max Indicates the positive limit value, sgn(δ f,max ) represents the positive limit value δ f,max The positive and negative signs.

[0060] The negative limit value and positive limit value of the tractor's front wheel deflection angle represent the maximum angles that the tractor's front wheels can deflect to the left and right. Assuming that the corresponding angle when the tractor's front wheels deflect to the left is a negative angle, the maximum angle that can be deflected to the left is the negative limit value, and the maximum angle that can be deflected to the right is the positive limit value.

[0061] It is understandable that the negative limit value and the positive limit value are determined according to the mechanical structure of the tractor steering system and the size of the semi-trailer train, such as Figure 2 As shown, the dimensions of the semi-trailer train include the distance L1 from the center of the rear axle of the semi-trailer to the traction pin H0, the wheelbase L0 of the tractor, and the distance L1 from the center of the rear axle of the tractor to the traction pin H0. h0 Assuming that the front wheel deflection angle δ is constrained by the mechanical structure of the tractor steering system, f The maximum value of δ M This value is determined when the vehicle leaves the factory. The front wheel deflection angle δ is constrained by the size of the semi-trailer train. f The maximum value of can be expressed as:

[0062]

[0063] The maximum value of the front wheel deflection angle under the two constraints is the intersection, which is the negative limit value of the tractor's front wheel deflection angle δ f,min and the positive limit value δ f,max , which can be expressed as: f,max =min(δ C ,δ M ), δ f,min =max(-δ C ,-δ M ).

[0064] In summary, before determining the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing, the method further includes:

[0065] determining a first lower threshold and a first upper threshold;

[0066] The controllable range is determined according to the first lower threshold and the first upper threshold.

[0067] Furthermore, in some embodiments, determining the first lower threshold and the first upper threshold includes:

[0068] The first lower threshold is determined based on the negative limit value of the tractor's front wheel deflection angle, and the first upper threshold is determined based on the positive limit value of the tractor's front wheel deflection angle. Specifically, the first lower threshold is determined using equation (6), and the first upper threshold is determined using equation (7). The first lower threshold is determined as the lower threshold of the controllable domain, and the first upper threshold is determined as the upper threshold of the controllable domain.

[0069] Optionally, based on the above embodiment, the controllable domain can also be determined based on the following method: the articulation angle threshold of the semi-trailer train in reverse motion (i.e., the limit threshold of the controllable domain, or the upper and lower thresholds of the controllable domain) also needs to consider the cumulative deviation of state transfer. The motion state of the semi-trailer train in reverse motion can be determined by the articulation angle β1, the heading deviation e θ and lateral deviation e d The relationships between them are given by the above equations (3) and (4). It can be found that the influences between these three are mutually coupled and progressive.

[0070] Take the reverse tracking straight line reference trajectory as an example for analysis:

[0071] When the hinge angle β1>0, That is, the heading deviation of the semi-trailer relative to the reference trajectory gradually decreases. θ >0, That is, the lateral deviation of the semi-trailer relative to the reference trajectory gradually decreases.

[0072] The schematic diagram of the coupling relationship of state transfer during reversing is as follows: Figure 7 Among them, there are two special conditions in working conditions 2 and 3 that easily cause the reversing trajectory to deviate from the reference trajectory.

[0073] Special case 1: articulation angle β1 approach And the heading deviation e θ <0, lateral deviation e d >0.

[0074] Special case 2: articulation angle β1 approach And the heading deviation e θ >0, lateral deviation e d <0.

[0075] For special case 1, when the articulation angle β1 approaches Although the front wheel deflection angle δ of the tractor can be adjusted f tends to the positive limit δ f,max The way makes But it still exists at the beginning At this time Then the heading deviation eθ The course deviation e continues to descend when it is already negative. θ The accumulation of lateral deviation will also cause d The absolute value of continues to increase, causing the semi-trailer train to deviate further from the reference trajectory during the reversing process.

[0076] Similarly, for special working condition 2, when the articulation angle β1 approaches Although the front wheel deflection angle δ of the tractor can be adjusted f Tends to the negative limit value δ f,min The way makes But it still exists at the beginning At this time Then the heading deviation e θ The course deviation e continues to rise when it is already positive. θ The accumulation of lateral deviation will also cause d The absolute value of the lateral deviation e continues to increase (for example, when the lateral deviation e d When it is a negative value, the lateral deviation e d will continue to decline), causing the semi-trailer train to deviate further from the reference trajectory during the reversing process.

[0077] From the above analysis, we can see that during the reversing process of the semi-trailer train, if the articulation angle β1 is too close to the controllable range β w The limit value will cause the front wheel deflection angle δ to be f , the articulation angle β1 is also difficult to adjust in time, resulting in a heading deviation e θ and lateral deviation e d The accumulated deviations cause the semi-trailer train to deviate further from the reference trajectory.

[0078] In order to reduce the cumulative error of each state and reduce the deviation caused by it to the subsequent state, this case not only considers the articulation angle β1, but also the intermediate state heading deviation e θ When reversing, the speed v1 at the center of the rear axle of the semi-trailer can be decomposed into the speed along e θ Directional component v 1p , and perpendicular to e θ Directional component v 1t Among them, v 1p It can be expressed as the ability of the semi-trailer train to travel along the reference trajectory, v 1t It can be expressed as the ability to change the lateral deviation. θ In the control of v 1p With v 1t The direction is the same and |v 1p |=|v 1t | is the critical condition.

[0079] Taking into account the different initial working conditions of the semi-trailer train when reversing, in order to eliminate the interference of other factors, this case defines the articulation angle β1, the semi-trailer trailer heading deviation e when determining the controllable range of the articulation angle. θ and lateral deviation e d The working condition where both are 0 is the initial working condition. Under the initial working condition, the front wheel deflection angle δ of the tractor is f =δ f,min Then start reversing until the critical condition is reached. The articulation angle β1 at this time is the upper limit threshold of the controllable range.

[0080] Similarly, the front wheel deflection angle δ of the tractor is f =δ f,max Then start reversing until the critical condition is reached. The articulation angle β1 at this time is the lower limit threshold of the controllable range. In summary, the controllable range of the articulation angle can be determined as

[0081] In summary, determining the first lower threshold and the first upper threshold includes:

[0082] Under an initial operating condition, the tractor is controlled to reverse with the front wheel deflection angle being the negative limit value until a critical condition is reached, and the magnitude of the articulation angle when the critical condition is reached is determined as the first upper limit threshold. The initial operating condition is a condition in which the articulation angle of the semi-trailer train, the heading deviation of the semi-trailer trailer relative to a reference trajectory, and the lateral deviation of the semi-trailer trailer relative to the reference trajectory are all zero. The heading deviation is the angle between the heading of the semi-trailer trailer and the reference heading at a projection point of the semi-trailer trailer on the reference trajectory. The lateral deviation is the distance between the center of the rear axle of the semi-trailer trailer and the projection point. The critical condition is that the first vector and the second vector have the same direction and the same length as the second vector. The first vector is the component of the velocity at the center of the rear axle of the semi-trailer trailer along the heading deviation, and the second vector is the component of the velocity at the center of the rear axle of the semi-trailer trailer perpendicular to the heading deviation.

[0083] Under the initial operating condition, the tractor is controlled to reverse with the front wheel deflection angle at the positive limit value until the critical condition is reached, and the magnitude of the articulation angle when the critical condition is reached is determined as the first lower threshold. The first lower threshold is determined as the lower threshold of the controllable range, and the first upper threshold is determined as the upper threshold of the controllable range.

[0084] In other embodiments, the intersection of the controllable regions determined by the above-mentioned different methods can be used as the final controllable region, thereby improving the accuracy of the controllable region. That is, the maximum value among the multiple first lower thresholds is determined as the lower threshold of the controllable region, and the minimum value among the multiple first upper thresholds is determined as the upper threshold of the controllable region.

[0085] Specifically, the controllable range of the articulation angle can be expressed as:

[0086] When the articulation angle β1 is within the controllable domain, the entire reversing process is stable and feasible. However, when the articulation angle β1 is outside the controllable domain, the reversing process is either unstable, infeasible, or both.

[0087] In some embodiments, determining the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing includes:

[0088] Determining a predicted value of the articulation angle in a future time from a current moment in an iterative manner according to an expression for a rate of change of the articulation angle in a reversing kinematic model of the semi-trailer train;

[0089] When the number of iterations does not reach the number threshold, if the predicted value exceeds the controllable domain, or the predicted value is the same as the limit threshold of the controllable domain, the iteration is stopped and the reverse folding time is determined to be k×T s , T s represents the iteration step, k represents the number of iterations, and the limit threshold includes an upper threshold and a lower threshold;

[0090] When the number of iterations reaches the threshold, if the predicted values ​​are all within the controllable range, the reverse folding time is determined to be N p ×T s , where N p Represents the number threshold, N p =T j / T s , T j It represents the time threshold, which can be set manually based on actual driving experience.

[0091] In summary, based on the current driving state (i.e., keeping the current vehicle speed and the current front wheel deflection angle of the tractor unchanged), the articulation angle in the future time domain is iteratively predicted according to the expression of the change rate of the articulation angle. Assume that the iteration step is T s , the artificially given time threshold is T j , then the total number of iterations (i.e., the number threshold) is N p =T j / Ts Assuming that the current vehicle speed and the current front wheel deflection angle of the tractor remain unchanged, the state of the articulation angle is iteratively updated according to the expression of the rate of change of the articulation angle. If the predicted value of the articulation angle is within the controllable range during the entire iterative process, the reverse folding time TTJ of the current driving state is considered to be N p ×T s , and terminate this calculation, and output TTJ=T j Otherwise, once the predicted value of the articulation angle reaches or exceeds the controllable range, the output is TTJ = k × T s For example, when the predicted value is the same as the limit threshold of the controllable domain at the fifth iteration, the iteration is stopped and k=5.

[0092] According to TTJ and the artificially given time threshold T j Perform reverse folding warning. If TTJ=T j , it means that the vehicle can reverse normally and will not fold or deviate from the reference trajectory within a given time threshold. <T j , it means that if the control input remains unchanged, the vehicle will enter an unstable or infeasible state after the TTJ moment, requiring early intervention and issuing warning signals such as lights and voice.

[0093] The semi-trailer train reversing folding warning method and the reversing feasibility determination method based on the feasible region of articulation angles provided in the embodiments of the present disclosure can be used in the development of a reversing assistance system for a semi-trailer train, effectively reducing the difficulty of reversing and improving the efficiency of semi-trailer train reversing, thereby alleviating the driver's workload and lowering the incidence of traffic accidents. The semi-trailer train reversing folding warning method proposed in the present invention can also provide technical support for trajectory planning and motion control for autonomous reversing of semi-trailer trains.

[0094] Figure 8 This is a schematic diagram of a structure of a semi-trailer train reversing folding warning device provided by an embodiment of the present disclosure. The device includes: a first determination module 810, configured to determine a reversing folding time corresponding to a current driving state based on a controllable range of an articulation angle of the semi-trailer train when reversing;

[0095] The warning module 820 is configured to provide a reverse folding warning based on the reverse folding time and the time threshold; wherein the articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer; during the reverse process, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the tractor's front wheel deflection angle; the current driving state includes the current vehicle speed and the current front wheel deflection angle, and the reverse folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current vehicle speed and the current front wheel deflection angle of the semi-trailer train during the reverse process.

[0096] The semi-trailer vehicle train reversing folding warning device provided in the embodiment of the present disclosure can execute the steps in the semi-trailer vehicle train reversing folding warning method provided in the method embodiment of the present disclosure, and can achieve the same beneficial effects, which will not be repeated here.

[0097] Figure 9 This is a schematic diagram of the structure of an electronic device in the embodiment of the present disclosure. Figure 9 , which shows a structural diagram of an electronic device 500 suitable for implementing the embodiments of the present disclosure. Figure 9 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present disclosure.

[0098] like Figure 9 As shown, the electronic device 500 may include a processing device (e.g., a central processing unit, a graphics processing unit, etc.) 501, which can perform various appropriate actions and processes to implement the methods of the embodiments described in the present disclosure according to the program stored in the read-only memory (ROM) 502 or the program loaded from the storage device 508 into the random access memory (RAM) 503. Various programs and data required for the operation of the electronic device 500 are also stored in the RAM 503. The processing device 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0099] In particular, according to an embodiment of the present disclosure, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program carried on a non-transitory computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart, thereby implementing the semi-trailer car train reversing folding warning method as described above. In such an embodiment, the computer program can be downloaded and installed from the network through the communication device 509, or installed from the storage device 508, or installed from the ROM 502. When the computer program is executed by the processing device 501, the above-mentioned functions defined in the method of the embodiment of the present disclosure are performed.

[0100] It should be noted that the computer-readable medium mentioned above in the present disclosure may be a computer-readable signal medium or a computer-readable storage medium, or any combination of the two. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or component, or any combination of the above. More specific examples of computer-readable storage media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device, or component. In the present disclosure, a computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted using any suitable medium, including but not limited to wires, optical cables, RF (radio frequency), etc., or any suitable combination thereof.

[0101] The computer-readable medium may be included in the electronic device, or may exist independently without being incorporated into the electronic device. The computer-readable medium carries one or more programs. When the one or more programs are executed by the electronic device, the electronic device: obtains a perception result output by a 3D perception algorithm that corresponds one-to-one to each frame of data to be perceived, wherein the perception result includes a tracking number of a target perceived by the 3D perception algorithm; arranges the perception results of targets with the same tracking number in chronological order to obtain a target tracking list; determines a quality assessment indicator for characterizing the stability of the perception result based on the target tracking list; and evaluates the quality of the perception result according to the quality assessment indicator.

[0102] Optionally, when the above one or more programs are executed by the electronic device, the electronic device may also execute other steps described in the above embodiments.

[0103] In the context of the present disclosure, a machine-readable medium can be a tangible medium that can contain or store a program for use by or in conjunction with an instruction execution system, device or equipment. A machine-readable medium can be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium can include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium can include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0104] The above description is merely a preferred embodiment of the present disclosure and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of disclosure involved in the present disclosure is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also includes other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the above-mentioned disclosed concepts. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this disclosure.

Claims

1. A method for early warning of a semi-trailer train reversing and folding, characterized in that: The method includes: determining a first lower threshold and a first upper threshold; Determining a controllable range based on the articulation angle of the semi-trailer train when reversing according to the first lower threshold and the first upper threshold; Determine the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing; Performing a reverse folding warning according to the reverse folding time and the time threshold; The articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer; during reversing, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the front wheel deflection angle of the tractor; the current driving state includes the current speed of the tractor and the current front wheel deflection angle of the tractor, and the reversing folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current speed of the tractor and the current front wheel deflection angle of the tractor unchanged during the reversing of the semi-trailer train.

2. The method according to claim 1, characterized in that The method of determining the reversing folding time corresponding to the current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing includes: Determining a predicted value of the articulation angle in a future time from a current moment in an iterative manner according to an expression for a rate of change of the articulation angle in a reversing kinematic model of the semi-trailer train; When the number of iterations does not reach the number threshold, if the predicted value exceeds the controllable domain, or the predicted value is the same as the limit threshold of the controllable domain, the iteration is stopped and the reverse folding time is determined to be k×T s , T s represents the iteration step, k represents the number of iterations, and the limit threshold includes an upper threshold and a lower threshold; When the number of iterations reaches the threshold, if the predicted values ​​are all within the controllable range, the reverse folding time is determined to be N p ×T s , where N p Represents the number threshold, N p =T j / T s , T j Indicates the time threshold.

3. The method according to claim 1, characterized in that The determining of the first lower threshold and the first upper threshold includes: The first lower limit threshold is determined according to the negative limit value of the tractor's front wheel deflection angle, and the first upper limit threshold is determined according to the positive limit value of the tractor's front wheel deflection angle, wherein the negative limit value and the positive limit value are determined according to the mechanical structure of the tractor's steering system and the size of the semi-trailer vehicle train, wherein the size of the semi-trailer vehicle train includes the distance from the center of the rear axle of the semi-trailer trailer to the traction pin, the wheelbase of the tractor, and the distance from the center of the rear axle of the tractor to the traction pin.

4. The method according to claim 3, characterized in that The step of determining the first lower threshold value according to the negative limit value of the front wheel deflection angle of the tractor, and determining the first upper threshold value according to the positive limit value of the front wheel deflection angle of the tractor, comprises: The first lower threshold is determined based on the following expression: The first upper threshold is determined based on the following expression: ； in, represents the first lower threshold, L1 represents the distance from the center of the rear axle of the semi-trailer to the traction pin, L0 represents the wheelbase of the tractor, L h0 Indicates the distance from the center of the tractor's rear axle to the traction pin. represents the negative limit value, Indicates negative limit value The positive and negative signs of represents the positive limit value, Indicates positive limit value The positive and negative signs.

5. The method according to claim 3, characterized in that The step of determining the first lower threshold value according to the negative limit value of the front wheel deflection angle of the tractor, and determining the first upper threshold value according to the positive limit value of the front wheel deflection angle of the tractor, comprises: Under an initial operating condition, the tractor is controlled to reverse with the front wheel deflection angle being the negative limit value until a critical condition is reached, and the magnitude of the articulation angle when the critical condition is reached is determined as the first lower threshold value. The initial operating condition is a condition in which the articulation angle of the semi-trailer train, the heading deviation of the semi-trailer trailer relative to a reference trajectory, and the lateral deviation of the semi-trailer trailer relative to the reference trajectory are all zero. The heading deviation is the angle between the heading of the semi-trailer trailer and the reference heading at a projection point of the semi-trailer trailer on the reference trajectory. The lateral deviation is the distance between the center of the rear axle of the semi-trailer trailer and the projection point. The critical condition is that the first vector and the second vector have the same direction and the same length as the second vector. The first vector is the component of the velocity at the center of the rear axle of the semi-trailer trailer along the heading deviation, and the second vector is the component of the velocity at the center of the rear axle of the semi-trailer trailer perpendicular to the heading deviation. Under the initial working condition, the tractor is controlled to reverse with the front wheel deflection angle being the positive limit value until the critical condition is reached, and the magnitude of the articulation angle when the critical condition is reached is determined as the first upper limit threshold.

6. The method according to claim 3 or 5, characterized in that Determining the controllable domain according to the first lower threshold and the first upper threshold includes: Determine the first lower threshold as the lower threshold of the controllable domain, and determine the first upper threshold as the upper threshold of the controllable domain; Alternatively, the maximum value among the plurality of first lower thresholds is determined as the lower threshold of the controllable domain, and the minimum value among the plurality of first upper thresholds is determined as the upper threshold of the controllable domain.

7. A semi-trailer train reversing folding warning device, characterized in that: include: A first determining module, configured to determine a first lower threshold and a first upper threshold; Determining a controllable range of the articulation angle of the semi-trailer train when reversing based on the first lower threshold and the first upper threshold, and determining a reversing folding time corresponding to a current driving state based on the controllable range of the articulation angle of the semi-trailer train when reversing; An early warning module is used to issue an early warning for reversing folding according to the reversing folding time and the time threshold; The articulation angle is the difference between the heading angle of the tractor and the heading angle of the semi-trailer trailer; during reversing, if the articulation angle is within the controllable range, the articulation angle can be changed toward zero by controlling the front wheel deflection angle of the tractor; the current driving state includes the current vehicle speed and the current front wheel deflection angle, and the reversing folding time is the time required for the articulation angle to change to outside the controllable range while maintaining the current vehicle speed and the current front wheel deflection angle of the semi-trailer train unchanged during the reversing process.

8. An electronic device, characterized in that: The electronic device comprises: one or more processors; a storage device for storing one or more programs; When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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