Path smoothing method and device, electronic equipment and storage medium

Abstract

The invention discloses a path smoothing method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a preview distance and a global expected path of a current vehicle, and a corresponding relation between a turning radius and a front wheel deflection angle of the current vehicle; determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path; calculating a target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relation; extending one preset step length in a target direction corresponding to the target front wheel deflection angle to obtain a target position, and planning the target position into a target track; and updating the target position to the current position, and returning to execute the operation of determining the current turning radius until a new target position is obtained, and planning the new target position into the target track. According to the technical scheme, the travelable track of the vehicle can be smoothed, so that a user has good driving comfort when driving the vehicle.

Description

Technical Field

[0001] The present application relates to the field of smart vehicle technology, and in particular to a path smoothing method, device, electronic device and storage medium. Background Art

[0002] With the promotion and popularization of different degrees of assisted driving functions in today's vehicles, more and more vehicles are equipped with assisted driving capabilities, thereby helping users perform some driving tasks such as following vehicles, changing lanes, and parking.

[0003] Among them, in order to realize the functions of the vehicle automatically merging into the main road, automatically entering and exiting ramps, automatically merging lanes or road bifurcations, it is necessary to use the global expected path as a reference line and track and execute the reference line. However, the map reference line often does not meet the curvature continuity. Tracking and executing such a path can easily cause oscillation of the vehicle control system, easily cause accidents, and bring safety risks. Therefore, how to make the vehicle path smoother has become one of the research focuses of technicians in related fields. Summary of the invention

[0004] The present application provides a path smoothing method, device, electronic device and storage medium to improve the smoothness of path planning.

[0005] According to one aspect of the present application, a path smoothing method is provided, the method comprising:

[0006] Obtain the preview distance of the current vehicle, the global expected path, and the corresponding relationship between the turning radius and the front wheel deflection angle of the current vehicle;

[0007] Determine the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path;

[0008] According to the current turning radius and the corresponding relationship, the target front wheel deflection angle of the current vehicle is calculated;

[0009] Extend a preset step length in the target direction corresponding to the target front wheel deflection angle to obtain the target position, and plan the target position into the target trajectory;

[0010] Update the target position to the current position, and return to perform the operation of determining the current turning radius of the current vehicle based on the current position of the current vehicle, the preview distance, and the global expected path, until a new target position is obtained, and the new target position is planned into the target trajectory.

[0011] According to another aspect of the present application, a path smoothing device includes:

[0012] The vehicle information acquisition module is used to obtain the preview distance of the current vehicle, the global expected path, and the corresponding relationship between the turning radius and the front wheel deflection angle of the current vehicle;

[0013] A turning radius determination module, used to determine a current turning radius of the current vehicle according to a current position of the current vehicle, a preview distance and a global expected path;

[0014] A front wheel deflection angle determination module is used to calculate the target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relationship;

[0015] A target trajectory planning module is used to extend a preset step length toward the target direction corresponding to the target front wheel deflection angle to obtain the target position and plan the target position into the target trajectory;

[0016] The path smoothing processing module is used to update the target position to the current position, and return to perform the operation of determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path, until the new target position is obtained, and the new target position is planned into the target trajectory.

[0017] According to another aspect of the present application, an electronic device is provided, the electronic device comprising:

[0018] at least one processor; and

[0019] a memory communicatively connected to the at least one processor; wherein,

[0020] The memory stores a computer program that can be executed by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can execute the path smoothing method described in any embodiment of the present application.

[0021] According to another aspect of the present application, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the path smoothing method described in any embodiment of the present application when executed.

[0022] According to another aspect of the present application, a computer program product is provided, the computer program product comprising a computer program, and the computer program, when executed by a processor, implements the path smoothing method according to any embodiment of the present application.

[0023] In the technical solution of the embodiment of the present application, the correspondence between the turning radius and the front wheel angle is obtained, which provides an accurate calculation basis for the subsequent calculation of the front wheel angle; then the current turning radius of the vehicle is obtained according to the preview distance and the global expected path, and the target front wheel angle of the current vehicle is obtained in combination with the correspondence, thereby determining the steering direction of the vehicle when planning a smooth path; planning the target trajectory based on the target front wheel angle and the preset step size can save the current vehicle from calling a third-party algorithm library, save a lot of computing resources, and improve computing efficiency, thereby helping the vehicle to determine the smooth path faster, successfully smooth out the vehicle's drivable trajectory, avoid path mutations and oscillations, and allow users to have good driving comfort when driving the vehicle.

[0024] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present application, nor is it intended to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1A is a flow chart of a path smoothing method provided according to Embodiment 1 of the present application;

[0027] Figure 1B is a schematic diagram of vehicle kinematic modeling provided according to Embodiment 1 of the present application;

[0028] Figure 1C is a schematic diagram of another vehicle kinematic modeling provided according to the first embodiment of the present application;

[0029] Figure 1D is a schematic diagram of calculating the front wheel deflection angle provided according to the first embodiment of the present application;

[0030] Figure 1E is a schematic diagram of a path smoothing process provided according to Embodiment 1 of the present application;

[0031] Figure 1F is a schematic diagram of the comparison of the path before and after smoothing provided according to the first embodiment of the present application;

[0032] Figure 2 is a structural schematic diagram of a path smoothing device provided according to Embodiment 2 of the present application;

[0033] Figure 3 It is a structural schematic diagram of an electronic device for implementing the path smoothing method of an embodiment of the present application. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0035] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] Embodiment 1

[0037] Figure 1A A flow chart of a path smoothing method is provided for the first embodiment of the present application. This embodiment is applicable to the case of performing path smoothing processing on a smart vehicle. The method can be executed by a path smoothing device. The path smoothing device can be implemented in the form of hardware and / or software. The path smoothing device can be configured in an electronic device. Figure 1A As shown, the method includes:

[0038] S110, obtaining the current vehicle preview distance, the global expected path, and the corresponding relationship between the turning radius of the current vehicle and the front wheel deflection angle.

[0039] Among them, the current vehicle can be any vehicle that is being path-planned and driven through the automatic driving / assisted driving function. The front wheel deflection angle is the angle at which the front wheel of the current vehicle deviates from the straight line when turning (changing direction, turning around, etc.). It can be understood that in the case of non-intelligent driving / assisted driving, the driver holds the steering wheel to change direction, and the steering wheel determines the size of the front wheel deflection angle. In the case of intelligent driving / assisted driving, the control system of the current vehicle can actively determine the size of the front wheel deflection angle. The turning radius has a theoretical relationship with both the linear velocity and the angular velocity, and the vehicle's heading and the front wheel deflection angle also have a theoretical relationship. Obtaining the corresponding relationship between the turning radius and the front wheel deflection angle helps the vehicle plan the path during the turning process. The preview distance can be the driving observation distance extended from the direction of the driver's eyes when driving the current vehicle. The preview distance can not only reflect the expected direction of vehicle driving (that is, the direction of vehicle driving that the driver wants), but also reflect the approximate position of the vehicle in the future, and can also be used as a reaction distance before an accident occurs to a certain extent. The preview distance may be pre-set by the driver when using the vehicle's automatic driving / assisted driving function, and thus may be directly obtained by the current vehicle. The specific value of the preview distance may be set by relevant technicians based on experiments, or may be set by the driver based on experience, and the present application embodiment does not limit this.

[0040] In an optional implementation, the preview distance is determined by: obtaining a preset preview time from an adaptive cruise control system of the current vehicle; and calculating the preview distance according to the preview time and the current speed of the current vehicle.

[0041] Among them, the adaptive cruise control system (ACC) is a new system that adds a control function for maintaining a reasonable distance from the vehicle in front to the system that performs cruise control according to a set speed. The preview time gear can be pre-set in ACC, and different gears represent different degrees of preview. Generally, three gears can be set. The current vehicle can obtain the preview time gear from ACC, multiply the preview time corresponding to the gear by the real-time speed of the current vehicle, and calculate the preview distance. Of course, the preview time of different gears can also be set by relevant technical personnel based on experiments, or by the driver based on experience, and the embodiments of the present application are not limited to this.

[0042] In addition, the global expected path can be the planned route obtained by the current vehicle from the map software, for example, the global path planned in the map by the navigation function after the destination has been confirmed.

[0043] In an optional embodiment, obtaining the correspondence between the turning radius and the front wheel angle of the current vehicle in S110 may include: obtaining a kinematic model of the current vehicle; obtaining a first calculation relationship between the front wheel angle and the yaw angular velocity, and a second calculation relationship between the yaw angular velocity and the turning radius according to the kinematic model; and determining the correspondence between the turning radius and the front wheel angle according to the first calculation relationship and the second calculation relationship.

[0044] The kinematic model may be a model constructed based on the inherent characteristics of the current vehicle and the physical properties of the current vehicle itself, and the model is used to reflect the kinematic constraints of the current vehicle itself. For example, Figure 1B and Figure 1C As shown, Oxy is the global coordinate system, (x f ,y f ) is the center position of the front axle of the vehicle, v f is the front axle speed, (x, y) is the center position of the rear axle of the vehicle, v is the rear axle speed, l is the wheelbase, δ is the front wheel deflection angle, and θ is the vehicle heading angle.

[0045] When turning, the speed at the center of the rear axle is:

[0046]

[0047] Since the front and rear wheels have a normal velocity of 0, the following constraints can be obtained:

[0048]

[0049]

[0050] According to formula (1) and formula (3), we can get:

[0051]

[0052] Again, there is a geometric relationship between the front and rear wheels:

[0053]

[0054] Derivative of formula (5):

[0055]

[0056] Substituting equations (4) and (6) into equation (2), we obtain:

[0057]

[0058] The kinematic model is obtained from (4)(7):

[0059]

[0060] The rate of change of the front wheel deflection angle is also added to the model to obtain the state equation based on kinematics:

[0061]

[0062] That is, after the linear velocity and angular velocity are input as control quantities into the kinematic model, the continuous change of the vehicle's position and heading can be obtained. Since the kinematic model of the current vehicle is obtained, the kinematic model constrains the relationship between the linear velocity, angular velocity, and the vehicle's position and heading during the movement of the current vehicle. The turning radius has a theoretical relationship with both the linear velocity and angular velocity, and the vehicle's heading has a theoretical relationship with the front wheel angle. Therefore, based on the kinematic model of the current vehicle, the corresponding relationship between the turning radius and the front wheel angle is determined.

[0063] The yaw rate is also one of the inherent properties of the vehicle. Continuing with the previous example, the front wheel deflection angle δ and the yaw rate The first calculation relationship between can be the above formula (4):

[0064]

[0065] Based on the theorem that linear velocity equals radius times angular velocity, turning radius and yaw angular velocity The second calculation relationship between can be:

[0066]

[0067] According to the above formula (4) and formula (8), the relationship between the turning radius and the front wheel deflection angle is derived:

[0068] δ=arctan(l / R)(9)

[0069] In the above implementation, based on the kinematic model of the current vehicle, the relationship between the front wheel deflection angle and the yaw angular velocity, and the relationship between the yaw angular velocity and the turning radius are obtained respectively, so as to calculate and derive the relationship between the turning radius and the front wheel deflection angle, thereby providing a basis for the subsequent calculation of the turning radius of the current vehicle during the path smoothing process, helping to improve the efficiency of the current vehicle calculation, and further helping to improve the efficiency of the current vehicle in processing the path smoothing process.

[0070] S120: Determine a current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance, and the global expected path.

[0071] Among them, the current position can be the position of the current vehicle. Of course, since the global expected path is only based on the navigation map route, not the actual driving trajectory, the current position is not necessarily on the global expected path. Since the driver theoretically hopes that the driving path of the current vehicle will not deviate too far from the global expected path, the global expected path can be used as a basis for path planning and smoothing in the process of path smoothing. The existence of the preview distance can help the current vehicle to move closer to the global expected path based on the current position, that is, the preview direction corresponding to the preview distance can always move closer to the global expected path. For example, the current position can be used as a reference point to find a target point that can meet the preview distance on the expected path to settle down. When planning a path from the reference point to the target point, the turning radius required in this process, that is, the current turning radius, can be calculated. Of course, a machine learning model can also be pre-trained, the input of which is the current position of the current vehicle, the preview distance and the global expected path, and the model outputs the current turning radius of the current vehicle in the process of planning the path. Of course, the machine learning model can be pre-trained by relevant technical personnel, such as using a convolutional neural network, etc., and the embodiment of the present application is not limited to this.

[0072] In an optional implementation, S120 determines the current turning radius of the current vehicle based on the current position, preview distance and global expected path of the current vehicle, which may include: determining the current expected position in the global expected path based on the current position and the preview distance; taking the current position as the starting point and the preview distance as the length to intercept the current expected position in the global expected path; determining the current turning radius of the current vehicle based on the current position, the current expected position and the preview distance.

[0073] The current expected position may be a position that is expected to be regressed to the global expected path (but in fact it is not necessarily possible to regress to the global expected path at this position, and the current expected position may be used as a target point for path planning and smoothing).

[0074] It should be noted that in path planning, when the vehicle turns and moves from its current position to its current desired position, the turning radius is fixed. The preview distance and the turning radius form a geometric relationship, so the current turning radius can be calculated based on the preview distance.

[0075] In a further optional embodiment, determining the current turning radius of the current vehicle based on the current position, the current expected position and the preview distance may include: calculating the deviation angle between the heading of the current vehicle and the direction corresponding to the current expected position based on the current position and the current expected position; and calculating the current turning radius based on the deviation angle and the preview distance.

[0076] Among them, the heading of the current vehicle can be the driving direction that the current vehicle is maintaining. It can be understood that there is a deviation angle between the direction formed between the current expected position and the current position and the heading of the current vehicle. Since the turning radius is constant, an arc trajectory can be planned from the current position to the current expected position, then the heading of the current vehicle is exactly the tangent direction of the arc trajectory, and the line formed by the preview distance between the current position and the current expected position happens to be the chord of the arc trajectory of the Requiem. Then, through geometric operations, the current turning radius can be calculated based on the deviation angle and the preview distance.

[0077] Specifically, Figure 1D As shown, point S(x v ,y v ) is the current position of the current vehicle (for example, the center position of the rear axle of the vehicle can be used as the standard), L is the preview distance, and the current expected position G(x) can be intercepted on the global expected path according to the preview distance. G ,y G ).Depend on Figure 1D It can be seen that the two current turning radii R and the preview distance L form an isosceles triangle, and the deviation angle between the heading and the target position is:

[0078]

[0079] Since L is the chord corresponding to ∠GOS, the central angle corresponding to the desired arc path shown in FIG. D1 is: 2α.

[0080] In the triangle GOS there exists:

[0081]

[0082] The current turning radius R can be deduced from equations (10) and (11):

[0083]

[0084] In the above implementation, based on the preview distance, a method for calculating the current turning radius of the vehicle is provided for the embodiment of the present application, which can intercept the current expected position on the global expected path only by the preview distance, and perform geometric operations based on this information, so as to efficiently obtain the size of the current turning radius, and provide a basis for the current vehicle to turn and change direction. It also reduces the dependence on third-party algorithm libraries to a certain extent, reduces the computing power required for operations, and can be directly run on the vehicle's SOC (System on Chips) and MCU (Microcontroller Unit), which improves the efficiency of calculation to a certain extent.

[0085] S130: Calculate the target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relationship.

[0086] Based on the corresponding relationship between the turning radius and the front wheel deflection angle of the current vehicle in S110 and the current turning radius determined in S120, the target front wheel deflection angle required for the current vehicle to smoothly approach the global desired path is calculated.

[0087] Specifically, continuing the previous example, based on the above equations (9) and (12), the target front wheel deflection angle δ can be obtained as:

[0088]

[0089] S140, extending a preset step length toward a target direction corresponding to the target front wheel deflection angle to obtain a target position, and planning the target position into a target trajectory.

[0090] The preset step length is the forward step length in the path planning process, which can be set by relevant technical personnel according to experiments or actual conditions, for example, 1 meter or 2 meters, and the embodiment of the present application does not limit this. The target trajectory can be a relatively smooth trajectory planned to get closer to the global expected path, and it is also the trajectory that the current vehicle needs to execute.

[0091] It can be understood that the target front wheel deflection angle represents the degree to which the current vehicle is about to turn, that is, the direction of the future deflection, and the preset step size represents each step in the process of planning the target trajectory. Therefore, according to the direction of the target front wheel deflection angle, the preset step size is used to move forward, and the resulting trajectory can be planned into the target trajectory.

[0092] Among them, the target direction corresponding to the target front wheel deflection angle can be the driving direction that the current vehicle is about to change. Based on this direction, a preset step length is planned in this direction to obtain the target position. This is equivalent to the current vehicle taking a step towards the target direction of the target front wheel deflection angle at the current position and reaching the target position in the process of path planning, and this target position is planned into the target trajectory.

[0093] The above implementation method provides a practical path exploration scheme for the embodiment of the present application. Based on the target front wheel angle calculated in the aforementioned implementation method, the path is explored and planned in the target direction corresponding to the target front wheel angle at the current position of the current vehicle, and the new step length and the obtained target position point are planned into the target trajectory. It not only provides trajectory planning for the current vehicle to approach the global expected path; because the target trajectory is based on the exploration of the vehicle's front wheel angle, the target trajectory is relatively smooth, and the shorter the step length, the smoother the trajectory. Therefore, the scheme also completes the smoothing of the global expected path at the same time, so that the current vehicle maintains smooth steering while driving according to the navigation route, thereby improving the stability and safety of the vehicle.

[0094] S150, updating the target position to the current position, and returning to perform the operation of determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path, until a new target position is obtained, and the new target position is planned into the target trajectory.

[0095] The target position determined in the above steps can be used as the starting point of the next path exploration, that is, the target position is updated to the current position of the next time, and the above steps S120-S140 are re-executed with this position as the starting point of path planning to achieve loop execution, and the target trajectory is obtained by accumulating step lengths until the target trajectory meets the preset trajectory length, then the loop is exited and the current vehicle is controlled to execute the target trajectory. Through the iterative process of the loop, the step length is accumulated, so that a trajectory that is close to the global expected path but smoother is planned for the current vehicle, which helps to improve the stability of vehicle driving.

[0096] In an optional implementation, the target position is updated to the current position in S150; accordingly, after the new target position is planned into the target trajectory, the method further includes: in response to the target trajectory satisfying the trajectory length, determining that the target trajectory is the current smooth path, and controlling the current vehicle to execute the target trajectory.

[0097] Among them, the preset trajectory length can be the basis for judging whether the target trajectory can be executed. It should be noted that since the current vehicle must have a certain speed during driving, if the planned smooth trajectory is too short, it is not easy to be directly executed by the current vehicle that already has a certain speed; therefore, a longer smooth path needs to be planned before it can be provided to the current vehicle as an executable path. The trajectory length can be set by relevant technical personnel based on experiments or actual conditions, for example, it can be 20 meters or 30 meters, etc., and this embodiment of the application does not limit this.

[0098] Then it can be understood that when the target trajectory does not meet the preset trajectory length requirement, the step length iteration continues. In order to avoid oscillation of the vehicle control system, the current vehicle cannot be directly controlled to execute the target trajectory that does not meet the trajectory length requirement. Therefore, the target position determined in the above steps can be used as the starting point of the next path exploration, that is, the target position is updated to the current position of the next time, and the steps of S130-S160 are re-executed with this position as the starting point of path planning, so as to achieve cyclic execution, and the target trajectory is obtained by accumulating step lengths, until the target trajectory meets the preset trajectory length, the cycle is exited, and the current vehicle is controlled to execute the target trajectory. Through the iterative process of the cycle, the step length is accumulated, so as to plan a trajectory that is similar to the global desired path but smoother for the current vehicle, which helps to improve the stability of vehicle driving. When the length of the planned target trajectory exceeds the preset trajectory length, the current vehicle can be controlled to execute the target trajectory, so that the current vehicle completes the navigation route corresponding to the global desired path with a smoother path, and the smooth path can ensure the safety and stability of vehicle driving.

[0099] For example, Figure 1E As shown in (where the solid line is the global expected path and the dotted line is the smooth path), assuming that the current position of the current vehicle is P n After the path exploration in the above manner, a preset step length is extended in the target direction corresponding to the target front wheel deflection angle to obtain the target position P n+1 , and combine this step length with P n+1 At this time, it is determined whether the target trajectory meets the preset trajectory length. If so, the vehicle can be controlled to execute the target trajectory; if not, P n+1 As a new starting point for iteration, the method in the above embodiment is reused to obtain P n+1 Based on the point, a desired position is determined in the global desired path using the preview distance, and the turning radius of the current vehicle is calculated based on this, and then the front wheel angle of the current vehicle is calculated, and the preset step length is extended again in the direction of the front wheel angle at this time to perform path smoothing exploration until the target trajectory meets the preset trajectory length. It should be noted that in each cycle, a new desired position on the global desired path needs to be re-determined based on the current position. The technical solution of the embodiment of the present application can effectively smooth the global desired path, such as Figure 1F As shown in the figure, from A to B to C and then to D, the global path given by the navigation software ( Figure 1F The solid line part in the figure is relatively stiff. After being processed by the method provided in the embodiment of the present application, the vehicle can travel along a smooth path ( Figure 1F The dotted part in the figure ensures the safety and stability of the vehicle.

[0100] In the technical solution of the embodiment of the present application, the correspondence between the turning radius and the front wheel angle is obtained, which provides an accurate calculation basis for the subsequent calculation of the front wheel angle; then the current turning radius of the vehicle is obtained according to the preview distance and the global expected path, and the target front wheel angle of the current vehicle is obtained in combination with the correspondence, thereby determining the steering direction of the vehicle when planning a smooth path; planning the target trajectory based on the target front wheel angle and the preset step size can save the current vehicle from calling a third-party algorithm library, save a lot of computing resources, and improve computing efficiency, thereby helping the vehicle to determine the smooth path faster, successfully smooth out the vehicle's drivable trajectory, avoid path mutations and oscillations, and allow users to have good driving comfort when driving the vehicle.

[0101] Embodiment 2

[0102] Figure 2 This is a schematic diagram of the structure of a path smoothing device provided in Example 2 of the present application. Figure 2 As shown, the device 200 includes:

[0103] The vehicle information acquisition module 210 is used to acquire the preview distance of the current vehicle, the global expected path, and the corresponding relationship between the turning radius and the front wheel deflection angle of the current vehicle;

[0104] A turning radius determination module 220, for determining a current turning radius of the current vehicle according to a current position of the current vehicle, a preview distance and a global desired path;

[0105] A front wheel deflection angle determination module 230 is used to calculate a target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relationship;

[0106] A target trajectory planning module 240 is used to extend a preset step length toward a target direction corresponding to a target front wheel deflection angle, obtain a target position, and plan the target position into a target trajectory;

[0107] The path smoothing processing module 250 is used to update the target position to the current position, and return to perform the operation of determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path, until a new target position is obtained, and the new target position is planned into the target trajectory.

[0108] In the technical solution of the embodiment of the present application, the correspondence between the turning radius and the front wheel angle is obtained, which provides an accurate calculation basis for the subsequent calculation of the front wheel angle; then the current turning radius of the vehicle is obtained according to the preview distance and the global expected path, and the target front wheel angle of the current vehicle is obtained in combination with the correspondence, thereby determining the steering direction of the vehicle when planning a smooth path; planning the target trajectory based on the target front wheel angle and the preset step size can save the current vehicle from calling a third-party algorithm library, save a lot of computing resources, and improve computing efficiency, thereby helping the vehicle to determine the smooth path faster, successfully smooth out the vehicle's drivable trajectory, avoid path mutations and oscillations, and allow users to have good driving comfort when driving the vehicle.

[0109] In an optional implementation, the target trajectory planning module 240 may be specifically used to:

[0110] In response to the target trajectory not satisfying a preset trajectory length, updating the target position to the current position;

[0111] Accordingly, the target trajectory planning module 240 may also be specifically used for:

[0112] In response to the target trajectory satisfying the trajectory length, the target trajectory is determined to be a current smooth path, and the current vehicle is controlled to execute the target trajectory.

[0113] In an optional implementation, the turning radius determination module 220 may include:

[0114] An expected position determination unit, used to determine a current expected position in a global expected path according to a current position and a preview distance;

[0115] The radius determination unit is used to determine the current turning radius of the current vehicle according to the current position, the current expected position and the preview distance.

[0116] In an optional implementation, the radius determination unit may include:

[0117] The deviation angle determination subunit is used to calculate the deviation angle between the current vehicle heading and the direction corresponding to the current expected position according to the current position and the current expected position;

[0118] The radius calculation subunit is used to calculate the current turning radius according to the deviation angle and the preview distance.

[0119] In an optional implementation, the correspondence determination module 210 may include:

[0120] A kinematic model acquisition unit, used to acquire a kinematic model of the current vehicle;

[0121] Two calculation relationship determination units, used to obtain a first calculation relationship between the front wheel deflection angle and the yaw rate, and a second calculation relationship between the yaw rate and the turning radius according to the kinematic model;

[0122] The radius and deflection angle correspondence determination unit is used to determine the correspondence between the turning radius and the front wheel deflection angle according to the first calculation relationship and the second calculation relationship.

[0123] In an optional implementation, the apparatus 200 further includes a preview distance determination module, and the preview distance determination module may include:

[0124] A preview time acquisition unit, used to acquire a preset preview time from an adaptive cruise control system of the current vehicle;

[0125] The preview distance calculation unit is used to calculate the preview distance according to the preview time and the current speed of the current vehicle.

[0126] The path smoothing device provided in the embodiment of the present application can execute the path smoothing method provided in any embodiment of the present application, and has the corresponding functional modules and beneficial effects for executing each path smoothing method.

[0127] Embodiment 3

[0128] Figure 3 A schematic diagram of the structure of an electronic device 10 that can be used to implement an embodiment of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices (such as helmets, glasses, watches, etc.) and other similar computing devices. The components shown herein, their connections and relationships, and

[0129] Their functions are merely exemplary and are not intended to limit the implementation of the present application described and / or claimed herein.

[0130] like Figure 3As shown, the electronic device 10 includes at least one processor 11, and a memory connected to the at least one processor 11, such as a read-only memory (ROM) 12, a random access memory (RAM) 13, etc., wherein the memory stores a computer program that can be executed by at least one processor, and the processor 11 can perform various appropriate actions and processes according to the computer program stored in the read-only memory (ROM) 12 or the computer program loaded from the storage unit 18 to the random access memory (RAM) 13. In the RAM 13, various programs and data required for the operation of the electronic device 10 can also be stored. The processor 11, the ROM 12, and the RAM 13 are connected to each other through a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0131] A number of components in the electronic device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, a mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, an optical disk, etc.; and a communication unit 19, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 19 allows the electronic device 10 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0132] The processor 11 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The processor 11 executes the various methods and processes described above, such as a path smoothing method.

[0133] An embodiment of the present application also provides a vehicle, which may be provided with the above-mentioned electronic device for implementing a path smoothing method provided by any embodiment of the present application.

[0134] In some embodiments, the path smoothing method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit 18. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via the ROM 12 and / or the communication unit 19. When the computer program is loaded into the RAM 13 and executed by the processor 11, one or more steps of the path smoothing method described above may be performed. Alternatively, in other embodiments, the processor 11 may be configured to perform the path smoothing method in any other appropriate manner (e.g., by means of firmware).

[0135] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0136] The computer programs for implementing the methods of the present application may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer programs are executed by the processor, the functions / operations specified in the flow charts and / or block diagrams are implemented. The computer programs may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0137] In the context of the present application, a computer readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, device or equipment. A computer readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer readable storage medium may be a machine readable signal medium. A more specific example of a machine readable storage medium may 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.

[0138] To provide interaction with a user, the systems and techniques described herein may be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and a pointing device (e.g., a mouse or trackball) through which the user can provide input to the electronic device. Other types of devices may also be used to provide interaction with the user; for example, the feedback provided to the user may be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user may be received in any form (including acoustic input, voice input, or tactile input).

[0139] The systems and techniques described herein may be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), a blockchain network, and the Internet.

[0140] A computing system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The client and server relationship is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services.

[0141] The present application also discloses a computer program product, which includes a computer program, and when the computer program is executed by a processor, implements the path smoothing method provided in any embodiment of the present application. The program product and the path smoothing method disclosed in each embodiment of the present application belong to the same inventive concept, so they are not described here.

[0142] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0143] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A path smoothing method, characterized in that: The method comprises: Obtaining a preview distance of the current vehicle, a global expected path, and a corresponding relationship between a turning radius and a front wheel deflection angle of the current vehicle; Determining a current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance, and the global desired path; Calculating a target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relationship; Extending a preset step length in the target direction corresponding to the target front wheel deflection angle to obtain a target position, and planning the target position into a target trajectory; The target position is updated to the current position, and the operation of determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path is returned until a new target position is obtained, and the new target position is planned into the target trajectory.

2. The method according to claim 1, characterized in that The updating of the target position to the current position comprises: In response to the target trajectory not satisfying a preset trajectory length, updating the target position to the current position; Accordingly, after planning the new target position into the target trajectory, the method further includes: In response to the target trajectory satisfying the trajectory length, determining the target trajectory as a current smooth path, and controlling the current vehicle to execute the target trajectory.

3. The method according to claim 1, wherein determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global desired path comprises: Determining a current desired position in the global desired path according to the current position and the preview distance; A current turning radius of the current vehicle is determined according to the current position, the current expected position and the preview distance.

4. The method according to claim 3, characterized in that The step of determining a current turning radius of the current vehicle according to the current position, the current expected position and the preview distance includes: Calculating a deviation angle between the current vehicle heading and a direction corresponding to the current expected position according to the current position and the current expected position; The current turning radius is calculated according to the deviation angle and the preview distance.

5. The method according to claim 1, characterized in that The obtaining of the corresponding relationship between the turning radius of the current vehicle and the front wheel deflection angle includes: Acquire the kinematic model of the current vehicle; According to the kinematic model, a first calculation relationship between the front wheel deflection angle and the yaw angular velocity and a second calculation relationship between the yaw angular velocity and the turning radius are obtained; The corresponding relationship between the turning radius and the front wheel deflection angle is determined according to the first calculation relationship and the second calculation relationship.

6. The method according to claim 1, characterized in that The preview distance is determined by: Obtaining a preset preview time from an adaptive cruise control system of the current vehicle; The preview distance is calculated according to the preview time and the current speed of the current vehicle.

7. A path smoothing device, characterized in that: The device comprises: A vehicle information acquisition module, used to acquire the preview distance and global expected path of the current vehicle, and the corresponding relationship between the turning radius and the front wheel deflection angle of the current vehicle; A turning radius determination module, configured to determine a current turning radius of the current vehicle according to a current position of the current vehicle, the preview distance and the global expected path; A front wheel deflection angle determination module, used for calculating a target front wheel deflection angle of the current vehicle according to the current turning radius and the corresponding relationship; A target trajectory planning module, used to extend a preset step length toward a target direction corresponding to the target front wheel deflection angle to obtain a target position, and plan the target position into a target trajectory; A path smoothing processing module is used to update the target position to the current position, and return to perform the operation of determining the current turning radius of the current vehicle according to the current position of the current vehicle, the preview distance and the global expected path until a new target position is obtained, and the new target position is planned into the target trajectory.

8. The device according to claim 7, characterized in that The target trajectory planning module can be specifically used for: In response to the target trajectory not satisfying a preset trajectory length, updating the target position to the current position; Accordingly, the target trajectory planning module can also be specifically used for: In response to the target trajectory satisfying the trajectory length, determining the target trajectory as a current smooth path, and controlling the current vehicle to execute the target trajectory.

9. An electronic device, characterized in that: The electronic device comprises: at least one processor; and a memory communicatively connected to the at least one processor; wherein, The memory stores a computer program executable by the at least one processor, and the computer program is executed by the at least one processor so that the at least one processor can perform the path smoothing method according to any one of claims 1 to 6.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a processor to implement the path smoothing method according to any one of claims 1 to 6 when executed.

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