CN117104231A

CN117104231A - Reversing method and device for semi-trailer train, electronic equipment and storage medium

Info

Publication number: CN117104231A
Application number: CN202311146046.XA
Authority: CN
Inventors: 曹世卓; 刘凯; 牛弼陛; 周小成
Original assignee: Uisee Technologies Beijing Co Ltd
Current assignee: Uisee Technologies Beijing Co Ltd
Priority date: 2023-09-06
Filing date: 2023-09-06
Publication date: 2023-11-24

Abstract

The embodiment of the disclosure discloses a reversing method, a device, electronic equipment and a storage medium for a semi-trailer train, wherein the method is characterized in that a cascading model corresponding to a target automobile train and reversing constraints comprising folding prevention constraints are constructed, so that a final reversing reference track of a tractor in the target automobile train is determined according to an initial control quantity sequence of a last trailer, a pose of the last trailer at a first moment, an initial hinging angle of each vehicle at the first moment, the cascading model and the reversing constraints, so that the track is tracked, reversing control of the target automobile train is realized, and the reversing reference track is solved through the constructed folding prevention constraints and the cascading model to take the folding phenomenon in the reversing process into consideration, so that the folding phenomenon of the semi-trailer train in the reversing process is actively avoided, the semi-trailer train is prevented from entering an uncontrollable state, the reversing safety of the reversing reference track is improved, and the reversing safety of the semi-trailer train is ensured.

Description

Reversing method and device for semi-trailer train, electronic equipment and storage medium

Technical Field

The disclosure relates to the technical field of automatic driving, in particular to a reversing method and device for a semi-trailer train, electronic equipment and a storage medium.

Background

Automotive trains are typically composed of a tractor and one or more trailers restrained by kingpins. If a semitrailer is mounted, it is called a semitrailer train, and if a full trailer is mounted, it is called a full trailer train. In logistics scenes such as ports, airports and factories, unmanned closed-loop flow of semi-trailer trains is widely applied, automatic cargo transportation is realized in a set area, and transportation efficiency is improved. Typical tasks include: dispatch order reception, automatic hooking of vehicles, traction operation with hanging, automatic back-up warehouse entry with hanging, automatic unhooking, automatic return to a dispatch area and the like.

Similar to the automatic parking technology, the terminal scene with the function of hanging and backing the warehouse as the factory is a key ring of the unmanned operation of the whole scene. The reverse is hung in the area, namely: in the reversing process, the mounted trailer runs according to the expected track by continuously adjusting the control quantity of the tractor.

However, in the prior art, track planning with trailer backing is only discussed for a single trailer, backing track planning under a plurality of trailers cannot be realized, and in terms of backing track tracking, unstable running is easy to occur, namely, a folding phenomenon (jack-knife phenomenon) occurs, once the state is entered, the tractor control amount is adjusted anyway (the trailer is still kept backing), and the hinging angle between the trailer and the tractor is always continuously increased until parking or mechanical folding collision occurs.

Disclosure of Invention

In order to solve the technical problems or at least partially solve the technical problems, the disclosed embodiments provide a reversing method, device, electronic device and storage medium for a semi-trailer train, which solve the problem that the prior art cannot realize reversing track planning under a plurality of trailers, avoid folding phenomenon, and ensure reversing safety of the semi-trailer train.

In a first aspect, an embodiment of the present disclosure provides a reversing method for a semi-trailer train, where the method includes:

constructing a cascading model corresponding to a target automobile train and a reversing constraint, wherein the cascading model comprises a motion inverse model, a motion positive model, a hinge angle change model and a pose change model, and the reversing constraint comprises an anti-folding constraint;

determining a final reversing reference track of a tractor in a target automobile train based on an initial control quantity sequence of a last trailer in the target automobile train, a pose of the last trailer at a first moment, an initial hinging angle of each vehicle in the target automobile train at the first moment, the cascading model and the reversing constraint, wherein the final reversing reference track comprises a final control quantity sequence, a final hinging angle sequence and a final pose sequence;

And tracking the final reversing reference track of the tractor to control the reversing of the target automobile train.

In a second aspect, an embodiment of the present disclosure further provides a reversing device for a semi-trailer train, including:

the construction module is used for constructing a cascading model corresponding to the target automobile train and a reversing constraint, wherein the cascading model comprises a motion inverse model, a motion positive model, a hinge angle change model and a pose change model, and the reversing constraint comprises an anti-folding constraint;

the determining module is used for determining a final reversing reference track of a tractor in the target automobile train based on an initial control quantity sequence of a last trailer in the target automobile train, a pose of the last trailer at a first moment, an initial hinging angle of each vehicle in the target automobile train at the first moment, the cascading model and the reversing constraint, wherein the final reversing reference track comprises a final control quantity sequence, a final hinging angle sequence and a final pose sequence;

and the tracking module is used for tracking the final reversing reference track of the tractor so as to control the reversing of the target automobile train.

In a third aspect, embodiments of the present disclosure further provide an electronic device, including: one or more processors; a storage means for storing one or more programs; the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the semi-trailer train reversing method as described above.

In a fourth aspect, the disclosed embodiments also provide a computer readable storage medium having stored thereon a computer program which when executed by a processor implements a method of reversing a semi-trailer train as described above.

According to the reversing method of the semi-trailer train, the cascade model corresponding to the target automobile train and the reversing constraint comprising the folding prevention constraint are constructed, so that the final reversing reference track of the tractor in the target automobile train is determined according to the initial control quantity sequence of the last trailer in the target automobile train, the pose of the last trailer at the first moment, the initial hinging angle of each vehicle in the target automobile train at the first moment, the cascade model and the reversing constraint, and accordingly the track is tracked, reversing control of the target automobile train is achieved, the reversing reference track is solved through the constructed folding prevention constraint and the cascade model, the folding phenomenon of the semi-trailer train in the reversing process is actively avoided, the semi-trailer train is prevented from entering an uncontrollable state, the reversing safety of the semi-trailer train is improved, and the reversing safety of the semi-trailer train is guaranteed.

Drawings

The above and other features, advantages, and aspects of embodiments of the present disclosure will become more apparent by reference to the following detailed description when taken in conjunction with the accompanying drawings. The same or similar reference numbers will be used throughout the drawings to refer to the same or like elements. It should be understood that the figures are schematic and that elements and components are not necessarily drawn to scale.

FIG. 1 is a flow chart of a method of reversing a semi-trailer train in an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of a turning motion of a semi-trailer train in an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of turning critical points of a semi-trailer train movement model in an embodiment of the present disclosure;

FIG. 4 is a schematic illustration of a geometric collision of a semi-trailer train in an embodiment of the present disclosure;

FIG. 5 is a schematic diagram of a reverse re-plan of a semi-trailer train in an embodiment of the present disclosure;

FIG. 6 is a schematic structural diagram of a reversing device for a semi-trailer train in an embodiment of the disclosure;

fig. 7 is a schematic structural diagram of an electronic device in an embodiment of the disclosure.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure have been shown in the accompanying drawings, it is to be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein, but 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 illustration purposes only and are not intended to limit the scope of the present disclosure.

It should be noted that the terms "first," "second," and the like in this disclosure are merely used to distinguish between different devices, modules, or units and are not used to define an order or interdependence of functions performed by the devices, modules, or units.

The names of messages or information interacted between the various devices in the embodiments of the present disclosure are for illustrative purposes only and are not intended to limit the scope of such messages or information.

Before describing the method provided by the embodiment of the present disclosure in detail, an exemplary description is given of a technical problem solved by the method.

Patent 1 (CN 111071338A, a method for predicting folding angle of semi-trailer train and storage medium) discloses a method for determining the hinge angle of straight stable reversing of semi-trailer train, according to the division of the hinge angle into stable domain and feasible domain, driving prompt can be given, in the scheme, the straight stable reversing is mainly aimed at, and the feasible domain and stable domain of reversing hinge angle of semi-trailer train of single trailer are given.

Patent 2 (CN 113696970A, semi-trailer train, reverse control method, device, apparatus and medium) discloses a semi-trailer train, reverse control method, device, apparatus and medium, and mainly relates to a feasible reverse control method for a single semi-trailer train.

In patent 1, only a single trailer is discussed for reversing, and warning information is provided to a driving system based on the constraint condition, so that the problem of a complete unmanned reversing flow cannot be solved. In patent 2, the disclosed reversing control method is suitable for some paths with smooth track and smaller fluctuation, and in the track generation part, folding constraint in the reversing process is not considered, meanwhile, in the reversing track tracking aspect, folding phenomenon which is easy to occur is not considered, and the reversing cannot be actively prevented from entering an uncontrollable state in the reversing process.

Therefore, the above-mentioned patent does not consider the folding phenomenon in the reversing process, in order to solve the problem, the embodiment of the disclosure provides a reversing method for a semi-trailer train, and by introducing folding constraint and cascading model, the folding phenomenon in the reversing process can be considered, so that the folding phenomenon is avoided, the vehicle is actively prevented from entering an uncontrollable state in the reversing process, and the rationality of the reference track is improved.

Fig. 1 is a flowchart of a method for reversing a semi-trailer train in an embodiment of the present disclosure. The method provided by the embodiment of the disclosure can be suitable for the situation that the semi-trailer train carries out the belt-trailer reversing. The method can be executed by a reversing device of the semi-trailer train, the device can be realized in a software and/or hardware mode, and the device can be configured in electronic equipment. As shown in fig. 1, the method specifically may include the following steps:

S110, constructing a cascading model corresponding to a target automobile train and a reversing constraint, wherein the cascading model comprises a motion inverse model, a motion positive model, a hinge angle change model and a pose change model, and the reversing constraint comprises an anti-folding constraint.

The target car train may include one tractor and one or more semitrailers constrained by kingpins, among other things. In particular, the hinge point between the tractor and the trailer, or the hinge point between the trailer and the trailer, may be located in a position offset rearward of the center of the rear axle of the tractor or trailer.

For example, fig. 2 is a schematic diagram of a turning motion of a semi-trailer train in an embodiment of the disclosure, as shown in fig. 2, a target car train may be composed of a tractor and at least one trailer (i.e., trailer), the target car train moves in a plane in a horizontal plane, and a ground coordinate system is OXY, where an X-axis is directed in the forward direction and a Y-axis is directed in the forward direction, and for simplifying motion analysis, a single-axis bicycle model is used (X ₀ ,y ₀ ) Is the coordinates of the center of the rear axle of the tractor, theta ₀ Beta is the course angle of the tractor in the geodetic coordinate system ₀ Is the front wheel deflection angle of the vehicle.

Considering that N (N is greater than or equal to 1) trailers are mounted on the tractor, wherein the hanging point of the tractor is H ₀ Which is positioned right behind the center of the rear axle of the tractor and has a distance L with the center of the rear axle of the tractor _h0 . For the ith trailer, 1.ltoreq.i.ltoreq.N, the heading angle is recorded as θ _i ，(x ₁ ,y ₁ ) The absolute position coordinate of the center of the rear axle of the 1 st trailer in the geodetic coordinate system is that the distance between the suspension point of the i-th trailer and the center of the rear axle of the trailer is L _hi The wheelbase is marked as L _i And defines the hinge angle as beta _i ＝θ _i-1 -θ _i . In addition, the tractor and the trailer only do two-dimensional plane movement, the control quantity of each vehicle (tractor or trailer) in the target automobile train can be recorded as [ omega ] without considering the problem of vertical movement _i ,v _i ]，ω _i For the yaw rate of the ith vehicle, v _i Is the speed of the ith vehicle.

In the disclosed embodiments, the cascade model may be composed of a motion inverse model, a motion positive model, a hinge angle variation model, and a pose variation model. The motion inverse model can determine the control quantity of the previous vehicle according to the control quantity of the next vehicle in the two adjacent vehicles, for example, the motion inverse model can be used for deducing the control quantity of the tractor according to the control quantity of the last trailer; the motion positive model can determine the control quantity of the next vehicle according to the control quantity of the previous vehicle in the two adjacent vehicles, for example, the motion positive model can be used for deducing the control quantity of the last trailer according to the control quantity of the tractor; the hinge angle change model can determine the hinge angle of the vehicle at the next moment according to the hinge angle of the vehicle at the previous moment; the pose change model can determine the pose of the vehicle at the next moment according to the pose of the vehicle at the previous moment.

In particular, [ omega ] for a trailer _i ,v _i ]Can be used as an intermediate variable for establishing a cascade connection, and the control quantity of the whole target automobile train is provided by the tractor, namely the control quantity [ omega ] of the tractor ₀ ,v ₀ ]As a control input to the tracking system of the target car train. In general, it can be assumed that the tractor is reversing for uniform motion, i.e.:v ₀ (t)>0, the steering input of the tractor can be calculated by the ackerman steering model:

in embodiments of the present disclosure, [ omega ] can be employed directly ₀ ,v ₀ ]As the control input of the tracking system, the control input is derived through a cascading model, and the control input can also be compatible with a semi-trailer train of a differential steering system.

In the embodiment of the disclosure, according to the connection relation between the monorail kinematic model of the vehicle and the tractor trailer, the motion model of the ith vehicle can be obtained:

v _i ＝L _hi-1 sinβ _i ω _i-1 +cosβ _i v _i-1 (3)；

wherein L is _hi-1 The distance between the suspension point of the ith-1 vehicle and the center of the rear axle of the ith-1 vehicle is the suspension point distance of the ith-1 vehicle; l (L) _i For the wheelbase of the ith vehicle, beta _i Is the articulation angle of the ith vehicle.

Specifically, for the 1 st trailer, the motion model is:

further, the above formula may be expressed in terms of a positive motion model that may be:

u _i ＝J(β _i )u _i-1 (6)；

Wherein u is _i ＝[ω _i v _i ]I=1, 2,..n, represents the i-th trailer,

in the disclosed embodiments, the change in articulation angle between the trailer and the tractor, or the change in articulation angle between the trailer and the trailer, may be expressed by the following formula:

specifically, for the 1 st trailer, its articulation angle varies as:

further, the formula (7) can be sorted to obtain a hinge angle change model:

wherein,the variation of the articulation angle for the ith vehicle, c ^T ＝[1,0]，Γ _i (β _i )＝I _2×2 -J(β _i ) The method comprises the steps of carrying out a first treatment on the surface of the By means of->And integrating to obtain the articulation angle of the ith vehicle at the next moment.

In the presently disclosed embodiments, it is assumed thatAnd->J(β _i ) Is reversible, then a motion inverse model can be obtained:

u _i-1 ＝J ^-1 (β _i )u _i (10)；

wherein u is _i-1 Control amount for the i-1 th vehicle, u _i As the control amount of the i-th vehicle,

in the embodiment of the disclosure, considering that the tractor and the trailer both perform two-dimensional plane motion, the pose change model may be:

in the method, in the process of the invention,the pose q of the ith vehicle is the pose change quantity of the ith vehicle _i Can be expressed as [ theta ] _i x _i y _i ]The method comprises the steps of carrying out a first treatment on the surface of the By means of->And integrating to obtain the pose of the ith vehicle at the next moment.

By constructing a cascade model, a transfer relationship from the control input of the tracking system to the positions of the trailers and the traction vehicles and a cascade control quantity transfer relationship between the vehicles can be established. Based on the cascade model, the control quantity and the hinge angle of the adjacent vehicles can be used for pushing the control quantity of other vehicles, namely, the control quantity and the hinge angle of the ith vehicle can be used for only pushing the control quantity of other i-1 vehicles; and the change rate of the articulation angle of the current vehicle can be deduced through the control quantity of the previous vehicle and the articulation angle of the current vehicle, and then the articulation angle at the future moment can be obtained through integration.

In the embodiment of the disclosure, the reversing constraint may be formed by an anti-folding constraint, wherein the anti-folding constraint is used for limiting the hinge angle of each vehicle in the target automobile train so as to avoid the folding phenomenon of the vehicle.

In a specific embodiment, constructing a reversing constraint corresponding to a target car train includes: determining a first critical articulation angle of the trailer for each trailer in the target car train based on the wheelbase of the trailer, and the hitch point distance and the maximum turning radius of a previous vehicle of the trailer, and constructing an anti-fold constraint of the trailer according to the first critical articulation angle of the trailer; constructing anti-folding constraints of the target automobile train based on the anti-folding constraints of all trailers in the target automobile train; the distance between the hanging points is the distance between the corresponding hanging points and the center of the rear axle.

For example, fig. 3 is a schematic diagram of turning critical points of a motion model of a semi-trailer train in an embodiment of the disclosure, and it can be seen from fig. 3 that when the turning radius of the trailer itself is smaller than the maximum turning radius of the semi-trailer train, the tracking system will generate a fold-back (jack-knife) phenomenon. Therefore, when the turning center of the trailer is coincident with the maximum turning center of the previous vehicle, the articulation angle between the two can be used as a critical value to construct a boundary range, and further the folding prevention constraint of the articulation angle can be obtained.

Specifically, for each trailer, a corresponding first critical articulation angle may be calculated using the wheelbase of the trailer, the hitch point distance of the previous vehicle of the trailer, and the maximum turning radius; the following formula is shown:

wherein phi is _mi For the first critical angle of articulation, L, of the ith vehicle _i For the wheelbase of the i-th trailer,a hitch point distance for the i-1 th vehicle (trailer/tractor); />For the maximum turning radius of the preceding vehicle, it can be calculated based on a kinematic model, e.g. < +.>Or can be obtained through actual turning condition calibration.

After the first critical hinge angle of each trailer is calculated, further, an anti-folding constraint of the corresponding hinge angle may be constructed according to the first critical hinge angle of each trailer, where:

[Φ _mimin ，Φ _mimax ]＝[-Φ _mi ,Φ _mi ] (13)；

further, according to the anti-folding constraints of all trailers, the anti-folding constraints of the whole target automobile train can be constructed. Through the embodiment, the anti-folding constraint is constructed, the hinge angle is limited, the folding phenomenon of the vehicle can be avoided, and further, the parking or mechanical collision of the semi-trailer train in the reversing process is avoided.

Optionally, the reversing constraint further includes a geometric collision constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes: determining, for each trailer in the target automotive train, a second critical articulation angle for the trailer based on the trailing edge distance of the trailer and the hitch point distance and width of a preceding vehicle of the trailer; for each trailer in the target automobile train, determining a third critical articulation angle of the trailer based on the hitch point distance of the previous vehicle of the trailer, the width of the trailer and the hitch front distance, and constructing a geometric collision constraint of the trailer according to the second critical articulation angle and the third critical articulation angle of the trailer; constructing geometric collision constraints of the target automobile train based on the geometric collision constraints of all trailers in the target automobile train; the distance between the hanging front edge and the vehicle body front edge is the distance between the corresponding traction point and the vehicle body front edge.

Considering that there is a possibility of a geometric collision between two adjacent vehicles in a semi-trailer train, as shown in fig. 4, fig. 4 is a geometric collision schematic diagram of a semi-trailer train in an embodiment of the disclosure, and fig. 4 shows two collision situations respectively. Specifically, for the first collision situation, the corresponding second critical hinge angle may be calculated by the traction point distance of the trailer, the hitch point distance and the width of the previous vehicle of the trailer, as shown in the following formula:

wherein beta is _il For the second critical articulation angle of the ith vehicle,the hitching front distance of the ith vehicle, i.e., the distance from the traction point (which can be understood as the hitching point of the previous vehicle) to the body front of that vehicle; />The suspension point distance of the ith-1 vehicle; w (w) _i-1 Is the width of the i-1 th vehicle.

For the second collision, a corresponding third critical articulation angle may be calculated from the hitch point distance of the preceding vehicle of the trailer, and the width of the trailer and the hitch point distance, as shown in the following equation:

wherein beta' _il A third critical articulation angle, w, for the ith vehicle _i Is the width of the ith vehicle. Further, for each trailer, a geometric collision constraint may be constructed based on the second and third critical articulation angles, such as:

[Φ _limin ，Φ _limax ]＝[-min(β _il ，β′ _il )，min(β _il ，β′ _il )] (16)；

Further, the geometric collision constraints of the whole target automobile train can be constructed according to the geometric collision constraints of all trailers. It should be noted that the geometric collision constraint may be determined by the geometric shapes of two adjacent vehicles, and may not be calculated in real time. By the embodiment, the construction of geometric collision constraint is realized, and geometric collision of the vehicle can be avoided by limiting the hinge angle.

Optionally, the reversing constraint further includes a stability domain constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes: determining a fourth critical articulation angle of the trailer for each trailer in the target automobile train based on the wheelbase of the trailer and the sampled travel distance, the articulation angle maximum value and the wheelbase of a previous vehicle of the trailer, and constructing a stability domain constraint of the trailer according to the fourth critical articulation angle of the trailer; constructing the stability domain constraint of the target automobile train based on the stability domain constraint of all trailers in the target automobile train; the sampling driving distance is the distance that the previous vehicle drives in the sampling step length.

Specifically, it can be found from the calculation process of the anti-folding constraint and the geometric collision constraint that when the relative sizes of the trailers meet certain conditions, the expected upper and lower boundaries cannot be obtained, and at this time, the anti-folding constraint and the geometric collision constraint can be automatically reduced to

Further, the articulation angle change delta beta can be obtained by combining the motion relationship between the tractor/the previous trailer and the next trailer _i Relationship with hinge angle:

wherein Deltax is _i-1 For the i-1 th vehicle's sampled travel distance (i.e., distance traveled within the sampling step), β _i For the articulation angle of the ith vehicle, L _i-1 Is the wheelbase of the i-1 vehicle. With respect to the variation of the articulation angle of the trailer, without physical limitation, the variation of the articulation angle of the current trailer is maximum only when the front wheel slip angle of the tractor (which can be considered as the articulation angle of the preceding trailer for the preceding trailer) reaches a maximum value. When the front wheel slip angle of the tractor reaches the maximum value, the following relationship can be established according to the stable state at the moment:

wherein,is the fourth critical articulation angle for the ith vehicle. Further, a stability domain constraint may be constructed:

further, the stability domain constraints for the entire target automotive train may be constructed from the stability domain constraints for all trailers. Through the implementation mode, the construction of the stability domain constraint is realized, and the hinge angle of the vehicle can be ensured to be stable within a certain range through limiting the hinge angle.

Optionally, the reversing constraint further includes a feasible region constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes: determining, for each trailer in the target vehicle train, a articulation angle that makes the transverse speed of the trailer equal to the longitudinal speed during reversing of a preceding vehicle of the trailer at a critical steering angle as a fifth critical articulation angle, and constructing a feasible region constraint of the trailer according to the fifth critical articulation angle of the trailer; and constructing the feasible region constraint of the target automobile train based on the feasible region constraint of all trailers in the target automobile train.

In particular, in the case of straight-line reversing, for each trailer, it can be considered that during reversing, in which the steering angle of the preceding trailer is kept at a critical value, the articulation angle is such that its lateral speed is equal to the longitudinal speedIs a viable zone boundary for the trailer, which can be determined by the calibration process for the front of the trailer. That is, the articulation angle that makes the lateral speed of the trailer equal to the longitudinal speed during the reverse of the preceding trailer or tractor of the trailer at the critical steering angle may be determined as the fifth critical articulation angle of the trailer. For example:

further, the feasible region constraints of the entire target automobile train can be constructed according to the feasible region constraints of all trailers. Through the implementation mode, the construction of the feasible region constraint is realized, and the feasibility of the vehicle hinge angle can be ensured through limiting the hinge angle.

It should be noted that, if the reversing constraint is formed by at least one constraint, for example, at least two of an anti-folding constraint, a geometric collision constraint, a stability domain constraint and a feasible domain constraint, in the boundary range of the reversing constraint, the lower boundary limit may be the maximum value of the lower boundaries of all the constraints, and the upper boundary limit may be the minimum value of the upper boundaries of all the constraints. For example, the lower boundary of the reverse constraint may be: The boundary upper limit may be taken as: />The boundary range of the reversing constraint is as follows: [ phi ] _imin ,Φ _imax ]Reversing constraint is used to limit the articulation angle beta of the trailer _i ∈[Φ _imin ,Φ _imax ]。

In the embodiment of the disclosure, geometric collision constraint, folding prevention constraint, stability domain constraint and feasibility domain constraint of reversing of a semi-trailer train are considered, and the constructed constraint is used for reversing reference track planning, so that the rationality of reversing reference tracks is improved.

S120, determining a final reversing reference track of a tractor in the target automobile train based on an initial control quantity sequence of the last trailer in the target automobile train, the pose of the last trailer at the first moment, the initial hinging angle of each vehicle in the target automobile train at the first moment, a cascading model and reversing constraint.

The final reversing reference track comprises a final control quantity sequence, a final hinge angle sequence and a final pose sequence. The final control amount sequence may be constituted by final control amounts at respective times, the final articulation angle sequence may be constituted by final articulation angles at respective times, and the final pose sequence may be constituted by final poses at respective times.

In embodiments of the present disclosure, the desire of the last trailer in the target car train may be determined first And the driving route is taken as a basic reference path. Furthermore, based on the basic reference path, the initial reversing reference track of the last trailer can be obtained through a tracking algorithm facing the road point, such as a pure tracking algorithm, etc., namely, the initial reference path is discretized according to time. Based on the initial reversing reference track of the last trailer, the initial control quantity sequence of the last trailer can be obtainedAnd the pose of the last trailer at the first moment +.>

In addition, considering that a plurality of trailers are included in the target automobile train, the hinging angle of each vehicle in the initial reversing reference track at the first moment can be assumed to be equal to the hinging angle of each vehicle in the target automobile train at the current moment, so as to obtain the initial hinging angle of each vehicle at the first moment, namely:

further, based onq _rN (0)、β _r (0) And combining the cascade model and the reversing constraint, a final control quantity sequence, a final hinge angle sequence and a final pose sequence of the tractor can be obtained, and then the final control quantity sequence, the final hinge angle sequence and the final pose sequence are used as a final reversing reference track of the tractor.

In a specific embodiment, determining a final reversing reference track of a tractor in a target car train based on an initial control quantity sequence of a last trailer in the target car train, a pose of the last trailer at a first moment, an initial articulation angle of each vehicle in the target car train at the first moment, a cascading model and a reversing constraint, comprises the following steps:

Step 11, under the condition that a target automobile train comprises a tractor and a single trailer, taking the first moment as the current moment, and determining the initial control quantity of the tractor at the current moment according to the motion inverse model, the initial control quantity of the current moment in the initial control quantity sequence of the trailer and the initial hinging angle of the trailer at the current moment;

step 12, determining the initial articulation angle of the trailer at the next moment according to the articulation angle change model, the initial articulation angle of the trailer at the current moment and the initial control quantity of the tractor at the current moment;

step 13, taking the next moment as a new current moment, and returning to execute the step of determining the initial control quantity of the tractor at the current moment according to the motion inverse model, the initial control quantity of the trailer at the current moment in the initial control quantity sequence and the initial hinging angle of the trailer at the current moment until the current moment is the last moment to obtain the initial control quantity sequence of the tractor and the initial hinging angle sequence of the trailer;

step 14, updating an initial hinging angle sequence of the trailer based on reversing constraint, and determining a final control quantity sequence of the trailer according to the updated initial hinging angle sequence of the trailer;

Step 15, determining a final control quantity sequence of the tractor based on the final control quantity sequence of the trailer and the motion positive model, and determining a final articulation angle sequence of the tractor according to an initial articulation angle of the tractor at the first moment, the final control quantity sequence of the tractor and the articulation angle change model;

and step 16, determining the final pose sequence of the tractor according to the initial pose of the tractor at the first moment, the final control quantity sequence of the tractor and the pose change model.

In the embodiment of the disclosure, under the condition that the number of the trailers in the target automobile train is 1, the final reversing reference track of the tractor can be deduced through a motion inverse model, a hinge angle change model and a pose change model in the cascade model.

Specifically, the first moment is taken as the current moment, and the initial control quantity of the trailer at the current moment and the initial hinging angle of the trailer at the current moment in the initial control quantity sequence of the trailer are substituted into the motion inverse model to obtain the initial control quantity of the tractor at the current moment. For example, the initial control amount of the tractor at the current time can be calculated by the formula:

wherein u is _r (0) The initial control amount of each vehicle at the first moment, For the initial control quantity of the 0 th vehicle (i.e. the tractor) at the first moment +.>For the initial control quantity of the nth vehicle at the first moment,/for the first time>Is the initial articulation angle of the jth vehicle at the first moment.

Furthermore, the initial control quantity of the tractor at the current moment and the initial articulation angle of the trailer at the current moment can be substituted into the articulation angle change model to obtain the initial articulation angle of the trailer at the next moment. For example, in combination with the euler method, the hinge angle change model may be discretized to obtain:

wherein Δt is a discrete step length, that is, a time difference between two adjacent moments, and further, an initial articulation angle of the trailer at a next moment can be obtained through a discretized articulation angle change model:

further, the next moment can be used as a new current moment, and the steps 11-12 are returned to obtain the initial control quantity of the tractor at the new current moment, and the like until the initial control quantity of the tractor at all moments, namely the initial control quantity sequence of the tractor, is obtained, and the initial articulation angle of the trailer at all moments, namely the initial articulation angle sequence of the trailer, is obtained.

Further, the initial sequence of articulation angles of the trailer may be updated by the reverse constraint such that each initial articulation angle in the initial sequence of articulation angles of the trailer satisfies the reverse constraint, i.e., is within the boundary of the reverse constraint.

For the step 14, optionally, the initial articulation angle sequence of the trailer is updated based on the reversing constraint, and the final control quantity sequence of the trailer is determined according to the updated initial articulation angle sequence of the trailer, including the following steps:

step 21, judging whether the corresponding initial hinge angle violating the reversing constraint time exists in the initial hinge angle sequence of the trailer;

step 22, aiming at the moment of violating the reversing constraint, updating an initial hinge angle at the moment based on a critical hinge angle in the reversing constraint, determining a hinge angle change value at the moment based on the updated initial hinge angle and a hinge angle change model, and determining the yaw rate of the tractor at the moment before the moment according to the hinge angle change value at the moment;

step 23, determining the final control quantity of the tractor at the previous moment based on the yaw rate of the tractor at the previous moment, and determining the final control quantity of the trailer at the previous moment based on the final control quantity of the tractor at the previous moment;

and step 24, updating the initial control quantity sequence of the trailer based on the final control quantity of the trailer at the previous moment to obtain the final control quantity sequence of the trailer.

Specifically, whether each initial hinge angle of the trailer violates the reversing constraint can be judged first, if the initial hinge angle violating the reversing constraint exists, the initial hinge angle is updated based on the critical hinge angle in the reversing constraint, for example, the critical hinge angle closest to the initial hinge angle in the boundary range of the reversing constraint is used for updating the initial hinge angle.

Further, according to the updated initial hinge angle and the hinge angle change model, the hinge angle change value at the moment can be calculated:

wherein v is given by the fact that the speed of the tractor is low and the fluctuation is small during reversing ₀ (k)≈v ₀ (k-1)≈v ₀ (0). Further, the yaw rate of the tractor at a time immediately before the time may be determined based on the articulation angle change value at the time:

further, the final control amount of the tractor at the previous moment is calculated according to the yaw rate of the tractor at the moment before the moment:

further, based on the final control amount of the tractor at the previous time, the final control amount of the trailer at the previous time is calculated:

furthermore, the initial control quantity sequence of the trailer can be updated according to the final control quantity of the trailer at the previous moment, so as to obtain the final control quantity sequence of the trailer. For example, the final control quantity sequence of the trailer isBy the embodiment, the control quantity of the trailer is corrected according to the reversing constraint, and the vehicle entersAnd the safety of the finally planned track is ensured.

With respect to the above step 24, in one example, updating the initial control amount sequence of the trailer based on the final control amount of the trailer at the previous moment to obtain the final control amount sequence of the trailer includes: adopting the final control quantity of the trailer at the previous moment to replace the initial control quantity of the trailer at the previous moment in the initial control quantity sequence; and determining the final control quantity of the trailer at each moment based on the final control quantity of the trailer at the previous moment, the motion positive model and the hinge angle change model for each moment after the previous moment, and obtaining a final control quantity sequence of the trailer.

Specifically, the final control quantity of the trailer at the previous moment can be used to replace the initial control quantity at the previous moment in the initial control quantity sequence of the trailer, so as to obtain the final control quantity sequence of the trailer.

Or, the previous moment is further taken as the initial moment, the final control quantity of each moment after the previous moment is solved based on the motion positive model and the hinge angle change model, and the initial control quantity of each moment before the previous moment, the final control quantity of the previous moment and the final control quantity of each moment after the previous moment are combined to construct the final control quantity sequence of the trailer. By the method, the corrected track is more close to the original target place, and the reliability of the track is ensured.

After obtaining the final control quantity sequence of the trailer based on the reversing constraint, further, the final control quantity sequence of the trailer and the updated initial hinging angle sequence of the trailer can be substituted into the motion positive model, and the final control quantity of the tractor at each moment can be deduced, so that the final control quantity sequence is obtained. Further, the final articulation angle sequence of the tractor can be deduced from the initial articulation angle of the tractor at the first moment, the final control quantity sequence of the tractor and the articulation angle change model. And substituting the initial pose of the tractor at the first moment and the final control quantity sequence of the tractor into a pose change model to deduce the final pose of the tractor at each moment and obtain the final pose sequence of the tractor.

Through the embodiment, the solution of the final reversing reference track of the tractor under the single trailer is realized, and the final reversing reference track of the trailer which does not violate reversing constraint is obtained Reference track for final reversing of a tractor>

In the disclosed embodiments, in addition to the implementations described above, the final reversing reference trajectory may also be solved for multiple trailers or a single trailer based on an optimization problem.

In another specific embodiment, determining a final reversing reference track of a tractor in a target car train based on an initial control quantity sequence of a last trailer in the target car train, a pose of the last trailer at a first moment, an initial articulation angle of each vehicle in the target car train at the first moment, a cascading model and a reversing constraint, comprises the following steps:

step 31, constructing a target optimization problem by taking the minimum control quantity deviation of the last trailer and the minimum hinge angle deviation of each vehicle at each moment as targets and taking a reversing constraint, a motion positive model and a hinge angle change model as constraint conditions;

step 32, solving a target optimization problem based on an initial control quantity sequence of a last trailer in a target automobile train, the pose of the last trailer at the first moment and the initial hinging angle of each vehicle at the first moment to obtain a final reversing reference track of the last trailer;

And step 33, determining the final reversing reference track of the tractor based on the final reversing reference track of the last trailer, the hinge angle change model and the motion reverse model.

The control amount deviation may be a difference between an initial control amount and a final control amount, and the hinge angle deviation may be a difference between an initial hinge angle and a final hinge angle. Illustratively, the objective optimization problem may be:

wherein Q is _s And Q is equal to _u The weight coefficients of the hinge angle deviation and the control quantity deviation are respectively.For the final control of the last trailer at k-time,/or->For initial control of last trailer at time k, beta _r (k) For the initial articulation angle of the respective vehicle at time k, +.>Is the final articulation angle of each vehicle at time k.

Specifically, the initial control quantity sequence of the last trailer, the pose of the last trailer at the first moment and the initial hinging angle of each vehicle at the first moment are taken as known quantities, the target optimization problem is solved, the final control quantity sequence and the final hinging angle sequence of the last trailer are obtained, the final pose sequence of the last trailer can be further obtained by combining the pose change model, and the final reversing reference track of the last trailer is generated. Further, a final reversing reference track of the tractor can be derived.

By taking the minimum control quantity deviation of the last trailer and the minimum hinge angle deviation of each vehicle at each moment as targets and combining a reversing constraint, a motion positive model and a hinge angle change model to construct a target optimization problem, the track obtained by solving can not violate the anti-folding constraint, the rationality and the safety of the track are ensured, and the folding phenomenon in the actual driving process is prevented.

And S130, tracking the final reversing reference track of the tractor to control the reversing of the target automobile train.

Specifically, after the final reversing reference track of the tractor is obtained, the final reversing reference track can be used as input of a tracking system of the target automobile train to track the final reversing reference track, so that reversing control of the target automobile train is realized.

In consideration of the fact that the folding constraint is not violated in the reversing process in the process of tracking the final reversing reference track of the tractor, the final reversing reference track can be optimized and solved in the reversing tracking process.

Optionally, tracking a final reversing reference track of the tractor to control reversing of the target automobile train includes: taking the final control quantity sequence of the tractor as the input of a tracking system of the target automobile train so as to track the final reversing reference track of the tractor through the tracking system; in the process of tracking the final reversing reference track of the tractor by the tracking system, the final reversing reference track of the tractor is updated by taking the calculated result of the pre-constructed cost function as a target and reversing constraint as a constraint condition; the cost function is used for calculating the cost according to the control quantity deviation and the pose deviation.

The pose deviation may include a lateral displacement deviation, a longitudinal displacement deviation, and a heading angle deviation, among others. For example, the cost function may be:

wherein,representing the final pose, x, of the tractor at the kth moment ₀ (k)、y ₀ (k)、θ ₀ (k)、u ₀ (k) Representing the pose of the tractor solved by the cost function at the kth moment, Q _x 、Q _y 、Q _θ 、Q _u The weight corresponding to the lateral displacement deviation, the longitudinal displacement deviation, the course angle deviation and the control quantity deviation is respectively obtained.

Specifically, the calculation result of the cost function can be minimized as a target, the reversing constraint is taken as a constraint condition to solve, and the final reversing reference track of the tractor is updated according to the solved result. By the mode, the phenomenon of folding in the track tracking process can be further guaranteed, and the reversing safety of the semi-trailer train is further improved.

Considering that in the actual application process, the actual reverse parking position of the trailer at the initial moment can be influenced by manual influence or external factors, the trailer is in a reverse unstable state or a critical stable state, namelyAt this time, it may be impossible to directly start a stable reverse operation with a belt due to the limitation of the road boundary or the surrounding environment. Therefore, in the embodiment of the present disclosure, the starting point may also be reselected to perform the planning of the reversing reference trajectory.

Optionally, before determining the final reversing reference track of the tractor in the target automobile train based on the initial control quantity sequence of the last trailer in the target automobile train, the pose of the last trailer at the first moment, the initial hinging angle of each vehicle in the target automobile train at the first moment, the cascading model and the reversing constraint, the method further comprises:

judging whether a vehicle violating the reversing constraint exists in the target automobile train at the first moment, if so, switching the target automobile train to a forward mode for running until a preset stopping running condition is met, so as to update the pose of the last trailer at the first moment, the initial hinging angle of each vehicle at the first moment and the initial control quantity sequence of the last trailer.

The first time may be the current time, that is, it may be determined, before the track planning is performed, whether a vehicle that violates a reversing constraint exists in the target automobile train. If so, switching the target automobile train to a forward mode for running until a preset stop running condition is met, so as to update the pose of the last trailer at the first moment, the initial hinging angle of each vehicle at the first moment and the initial control quantity sequence of the last trailer.

Specifically, the preset stop running condition may be to run to a preset distance, or the preset stop running condition may be to run to a vehicle in which no reversing constraint violation exists in the target automobile train, or the like. By the embodiment, the feasibility of practical application and the integrity of unmanned operation can be improved.

Fig. 5 is a schematic diagram illustrating a reverse re-planning of a semi-trailer train according to an embodiment of the present disclosure. As shown in fig. 5, the target car train is already in an unstable state in backing at the position B, at this time, the re-planning function may be triggered, the target car train may switch to the forward mode to travel for a certain distance, a new position point, such as point a in fig. 5, is selected, the pose is adjusted after the target car train travels to the point a, and then the planning of the backing reference track is performed to the target point C with the point a as the starting point.

According to the reversing method of the semi-trailer train, the cascade model corresponding to the target automobile train and the reversing constraint comprising the anti-folding constraint are constructed, and then the final reversing reference track of the tractor in the target automobile train is determined according to the initial control quantity sequence of the last trailer in the target automobile train, the pose of the last trailer at the first moment, the initial hinging angle of each vehicle in the target automobile train at the first moment, the cascade model and the reversing constraint, so that the track is tracked, the reversing control of the target automobile train is realized, and the reversing reference track is solved through the constructed anti-folding constraint and the cascade model, so that the folding phenomenon of the semi-trailer train in the reversing process is actively avoided, the semi-trailer train is prevented from entering an uncontrollable state, the reversing safety of the reversing reference track is improved, and the reversing safety of the semi-trailer train is ensured.

Fig. 6 is a schematic structural diagram of a reversing device for a semi-trailer train in an embodiment of the disclosure. As shown in fig. 6: the device comprises: a construction module 610, a determination module 620, and a tracking module 630.

A building module 610, configured to build a cascade model corresponding to a target car train and a reversing constraint, where the cascade model includes a motion inverse model, a motion positive model, a hinge angle change model, and a pose change model, and the reversing constraint includes an anti-folding constraint;

a determining module 620, configured to determine a final reversing reference track of a tractor in a target automobile train based on an initial control amount sequence of a last trailer in the target automobile train, a pose of the last trailer at a first moment, an initial articulation angle of each vehicle in the target automobile train at the first moment, the cascading model, and the reversing constraint, where the final reversing reference track includes a final control amount sequence, a final articulation angle sequence, and a final pose sequence;

and the tracking module 630 is configured to track the final reversing reference track of the tractor, so as to control reversing of the target automobile train.

The reversing device for the semi-trailer train provided by the embodiment of the disclosure can execute steps in the reversing method for the semi-trailer train provided by the embodiment of the disclosure, and has the execution steps and beneficial effects, which are not described herein.

Fig. 7 is a schematic structural diagram of an electronic device in an embodiment of the disclosure. Referring now in particular to fig. 7, a schematic diagram of an electronic device 500 suitable for use in implementing embodiments of the present disclosure is shown. The electronic device shown in fig. 7 is merely an example and should not be construed to limit the functionality and scope of use of the disclosed embodiments.

As shown in fig. 7, an electronic device 500 may include a processing means (e.g., a central processor, a graphics processor, etc.) 501 that may perform various suitable actions and processes to implement the methods of embodiments as described in the present disclosure according to a program stored in a Read Only Memory (ROM) 502 or a program loaded from a storage means 508 into a Random Access Memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the electronic apparatus 500 are also stored. 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 bus 504.

In particular, according to embodiments of the present disclosure, the processes described above with reference to flowcharts may be implemented as computer software programs. For example, embodiments of the present disclosure include a computer program product comprising a computer program embodied on a non-transitory computer readable medium, the computer program containing program code for performing the method shown in the flowchart, thereby implementing the semi-trailer train reversing method as described above. In such an embodiment, the computer program may be downloaded and installed from a network via the communication means 509, or from the storage means 508, or from the ROM 502. The above-described functions defined in the methods of the embodiments of the present disclosure are performed when the computer program is executed by the processing device 501.

It should be noted that the computer readable medium described in the present disclosure may be a computer readable signal medium or a computer readable storage medium, or any combination of the two. The computer readable storage medium can be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or a combination of any of the foregoing. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer diskette, 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 disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this disclosure, a computer-readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. In the present disclosure, however, the computer-readable signal medium may include a data signal propagated in baseband or as part of a carrier wave, with the computer-readable program code embodied therein. Such a propagated data signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination of the foregoing. A computer readable signal medium may also be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to: electrical wires, fiber optic cables, RF (radio frequency), and the like, or any suitable combination of the foregoing.

The computer readable medium may be contained in the electronic device; or may exist alone without being incorporated into the electronic device. The computer readable medium carries one or more programs which, when executed by the electronic device, cause the electronic device to:

Alternatively, the electronic device may perform other steps described in the above embodiments when the above one or more programs are executed by the electronic device.

In the context of this disclosure, a machine-readable medium may be a tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. The machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, 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 disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Scheme 1, a semi-trailer train reversing method, the method includes:

Scheme 2, according to the method of scheme 1, build the constraint of backing a car corresponding to the target car train, comprising:

determining, for each trailer in the target automotive train, a first critical articulation angle of the trailer based on the wheelbase of the trailer and a hitch point distance and a maximum turning radius of a preceding vehicle of the trailer, and constructing an anti-fold constraint of the trailer according to the first critical articulation angle of the trailer;

Constructing anti-folding constraints of the target automobile train based on the anti-folding constraints of all trailers in the target automobile train;

the distance between the corresponding hanging point and the center of the rear axle is equal to the distance between the corresponding hanging point and the center of the rear axle.

The method according to claim 3, wherein the reversing constraint further includes a geometric collision constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes:

determining, for each trailer in the target automotive train, a second critical articulation angle for the trailer based on a hitch front distance of the trailer and a hitch point distance and width of a preceding vehicle of the trailer;

for each trailer in the target car train, determining a third critical articulation angle of the trailer based on a hitch point distance of a preceding vehicle of the trailer, and a width and a hitch front distance of the trailer, and constructing a geometric collision constraint of the trailer according to the second and third critical articulation angles of the trailer;

constructing geometric collision constraints of the target automobile train based on the geometric collision constraints of all trailers in the target automobile train;

the distance from the hitching front edge to the front edge of the vehicle body is the distance from the corresponding traction point to the front edge of the vehicle body.

The method according to claim 4, wherein the reversing constraint further includes a stability domain constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes:

determining, for each trailer in the target automotive train, a fourth critical articulation angle of the trailer based on the wheelbase of the trailer and a sampled travel distance, articulation angle maximum value, and wheelbase of a previous vehicle of the trailer, and constructing a stability domain constraint of the trailer according to the fourth critical articulation angle of the trailer;

constructing a stability domain constraint of the target automobile train based on the stability domain constraints of all trailers in the target automobile train;

the sampling driving distance is the distance that the previous vehicle drives in the sampling step length.

The method according to claim 5, wherein the reversing constraint further includes a feasible region constraint, and the constructing a reversing constraint corresponding to the target automobile train further includes:

determining, for each trailer in the target car train, a articulation angle that causes a lateral speed of the trailer to be equal to a longitudinal speed during a reverse of a preceding vehicle of the trailer at a critical steering angle as a fifth critical articulation angle, and constructing a feasibility domain constraint of the trailer according to the fifth critical articulation angle of the trailer;

And constructing the feasible region constraint of the target automobile train based on the feasible region constraint of all trailers in the target automobile train.

Scheme 6, the method according to scheme 1, wherein determining the final reversing reference track of the tractor in the target car train based on the initial control amount sequence of the last trailer in the target car train, the pose of the last trailer at the first moment, the initial articulation angle of each vehicle in the target car train at the first moment, the cascading model and the reversing constraint comprises:

when the target automobile train comprises a tractor and a single trailer, taking the first moment as the current moment, and determining the initial control quantity of the tractor at the current moment according to the motion inverse model, the initial control quantity of the current moment in the initial control quantity sequence of the trailer and the initial hinging angle of the trailer at the current moment;

determining an initial articulation angle of the trailer at the next moment according to the articulation angle change model, the initial articulation angle of the trailer at the current moment and the initial control quantity of the tractor at the current moment;

returning to the next moment serving as a new current moment, and executing the step of determining the initial control quantity of the tractor at the current moment according to the motion inverse model, the initial control quantity of the trailer at the current moment in the initial control quantity sequence and the initial hinging angle of the trailer at the current moment until the current moment is the last moment to obtain the initial control quantity sequence of the tractor and the initial hinging angle sequence of the trailer;

Updating the initial hinging angle sequence of the trailer based on the reversing constraint, and determining a final control quantity sequence of the trailer according to the updated initial hinging angle sequence of the trailer;

determining a final control quantity sequence of the tractor based on the final control quantity sequence of the trailer and the motion positive model, and determining a final articulation angle sequence of the tractor according to an initial articulation angle of the tractor at a first moment, the final control quantity sequence of the tractor and the articulation angle change model;

and determining the final pose sequence of the tractor according to the initial pose of the tractor at the first moment, the final control quantity sequence of the tractor and the pose change model.

Scheme 7, the method according to scheme 6, wherein updating the initial articulation angle sequence of the trailer based on the reversing constraint, determining the final control amount sequence of the trailer according to the updated initial articulation angle sequence of the trailer, includes:

judging whether the corresponding initial hinge angle violating the reversing constraint time exists in the initial hinge angle sequence of the trailer or not;

updating an initial hinge angle at the moment based on a critical hinge angle in the reversing constraint aiming at the moment of violating the reversing constraint, determining a hinge angle change value at the moment based on the updated initial hinge angle and the hinge angle change model, and determining the yaw rate of the tractor at the moment before the moment according to the hinge angle change value at the moment;

Determining a final control amount of the tractor at the previous moment based on a yaw rate of the tractor at the previous moment, and determining a final control amount of the trailer at the previous moment based on the final control amount of the tractor at the previous moment;

and updating the initial control quantity sequence of the trailer based on the final control quantity of the trailer at the previous moment to obtain the final control quantity sequence of the trailer.

The method according to claim 8, wherein updating the initial control amount sequence of the trailer based on the final control amount of the trailer at the previous time to obtain the final control amount sequence of the trailer includes:

replacing the initial control quantity of the previous moment in the initial control quantity sequence of the trailer by adopting the final control quantity of the trailer at the previous moment;

and determining the final control quantity of the trailer at each moment based on the final control quantity of the trailer at the previous moment, the positive movement model and the hinge angle change model, and obtaining a final control quantity sequence of the trailer.

The method according to claim 9, wherein the determining the final reversing reference track of the tractor in the target car train based on the initial control amount sequence of the last trailer in the target car train, the pose of the last trailer at the first moment, the initial articulation angle of each vehicle in the target car train at the first moment, the cascading model, and the reversing constraint includes:

the control quantity deviation of the last trailer and the hinging angle deviation of each vehicle at each moment are taken as targets, and the reversing constraint, the motion positive model and the hinging angle change model are taken as constraint conditions, so that a target optimization problem is established;

solving the target optimization problem based on an initial control quantity sequence of a last trailer in the target automobile train, the pose of the last trailer at the first moment and the initial hinging angle of each vehicle at the first moment to obtain a final reversing reference track of the last trailer;

and determining the final reversing reference track of the tractor based on the final reversing reference track of the last trailer, the hinge angle change model and the motion inverse model.

Solution 10, the method according to solution 1, wherein the tracking the final reversing reference track of the tractor to control the reversing of the target car train includes:

taking the final control quantity sequence of the tractor as the input of a tracking system of the target automobile train so as to track a final reversing reference track of the tractor through the tracking system;

in the process of tracking the final reversing reference track of the tractor by the tracking system, updating the final reversing reference track of the tractor by taking the reversing constraint as a constraint condition with the minimum calculation result of a pre-constructed cost function as a target;

the cost function is used for calculating the cost according to the control quantity deviation and the pose deviation.

The method according to claim 11, according to claim 1, further comprising, before determining the final reversing reference trajectory of the tractor in the target car train based on the initial control amount sequence of the last trailer in the target car train, the pose of the last trailer at the first time, the initial articulation angle of each vehicle in the target car train at the first time, the cascading model, and the reversing constraint:

Judging whether vehicles violating the reversing constraint exist in the target automobile train at the first moment, if yes, switching the target automobile train to a forward mode for running until a preset stopping running condition is met, so as to update the pose of the last trailer at the first moment, the initial hinging angle of each vehicle at the first moment and the initial control quantity sequence of the last trailer.

Scheme 12, a semi-trailer train reversing device, comprising:

the first determining module is used for determining at least one pose of the vehicle in a set time window through at least one positioning mode when the vehicle is in a running state, wherein the poses determined through different positioning modes are different;

the first correction module is used for carrying out first correction on the initial pose obtained through the wheel speed odometer based on the target pose in the at least one pose to obtain a first correction result;

the second correction module is used for continuously correcting the first correction result based on the road information acquired in the set time window to acquire a second correction result, wherein the road information comprises a road mark, three-dimensional points forming the road mark and an acquisition time stamp of the three-dimensional points;

And the second determining module is used for obtaining a final positioning result of the vehicle based on the second correction result.

Scheme 13, an electronic device, the electronic device comprising:

one or more processors;

a storage means for storing one or more programs;

the one or more programs, when executed by the one or more processors, cause the one or more processors to implement the methods of any of aspects 1-11.

Scheme 14, a computer readable storage medium having stored thereon a computer program which when executed by a processor implements the method of any of the schemes 1-11.

The foregoing description is only of the preferred embodiments of the present disclosure and description of the principles of the technology being employed. It will be appreciated by persons skilled in the art that the scope of the disclosure referred to in this disclosure is not limited to the specific combinations of features described above, but also covers other embodiments which may be formed by any combination of features described above or equivalents thereof without departing from the spirit of the disclosure. Such as those described above, are mutually substituted with the technical features having similar functions disclosed in the present disclosure (but not limited thereto).

Claims

1. A method for reversing a semi-trailer train, the method comprising:

2. The method of claim 1, wherein constructing a reverse constraint corresponding to a target car train comprises:

3. The method of claim 2, wherein the reversing constraints further comprise geometric collision constraints, the constructing reversing constraints corresponding to a target car train further comprising:

4. The method of claim 2, wherein the reversing constraint further comprises a stability domain constraint, the constructing a reversing constraint corresponding to a target car train further comprising:

5. The method of claim 2, wherein the reversing constraints further comprise a feasible region constraint, the constructing reversing constraints corresponding to a target car train further comprising:

6. The method of claim 1, wherein determining the final reversing reference trajectory of the tractor in the target car train based on the initial control volume sequence of the last trailer in the target car train, the pose of the last trailer at the first time, the initial articulation angle of each vehicle in the target car train at the first time, the cascading model, and the reversing constraint comprises:

7. The method of claim 6, wherein updating the initial sequence of articulation angles for the trailer based on the reverse constraints, and determining the final sequence of control amounts for the trailer based on the updated initial sequence of articulation angles for the trailer, comprises:

8. A reversing device for a semi-trailer train, comprising:

9. An electronic device, the electronic device comprising:

one or more processors;

a storage means for storing one or more programs;

The one or more programs, when executed by the one or more processors, cause the one or more processors to implement the method of any of claims 1-7.

10. A computer readable storage medium, on which a computer program is stored, characterized in that the program, when being executed by a processor, implements the method according to any of claims 1-7.