Ramp entry method, computer program product and control device

Abstract

The invention provides a ramp driving-in method for an automatic driving vehicle. The ramp driving-in method comprises the following steps that S1, road information related to roads around the vehicle and motion information of the vehicle are obtained; s2, identifying whether the vehicle is in a ramp driving-in area or not; s3, under the condition that the vehicle is located in the ramp driving-in area, whether the ramp is a rapid opening type ramp or not is judged according to preset judgment conditions based on the road information and / or the motion information; s4, if the ramp is a rapid opening type ramp, a first upper limit and a second upper limit larger than the first upper limit are set for the transverse acceleration of the first side and the transverse acceleration of the second side which are opposite to each other respectively; and S5, determining a lateral acceleration of the vehicle, in which a first upper limit and a second upper limit are applied for lateral accelerations to the first side and to the second side, respectively. The invention also relates to a corresponding computer program product and a control device. By means of the ramp, the safety and comfort of the vehicle in the process of driving into the ramp can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of automatic driving of vehicles, and in particular to a ramp entry method, a computer program product, and a control device. Background Art

[0002] In recent years, the vehicle's autonomous driving technology has developed rapidly. Autonomous vehicles can automatically drive on the road according to the planned path without relying on the driver's manual operation.

[0003] When a vehicle is driving autonomously, it needs to face complex road conditions. This poses a challenge to autonomous driving technology. For example, according to the planned path, a vehicle traveling on a highway needs to enter a ramp. In this case, the autonomous driving vehicle can, for example, plan a driving trajectory curve for entering the ramp based on the vehicle's location information and map information when approaching the ramp entrance to guide the vehicle into the ramp.

[0004] Existing autonomous vehicles do not perform well when entering ramps. In practice, ramps have different designs. On some ramps, the autonomous vehicles may cause discomfort to passengers due to their abrupt movements. In addition, there is a possibility that the vehicle may run over the road boundary line.

[0005] Therefore, the existing technology still has shortcomings in autonomous driving when the vehicle enters the ramp. Summary of the invention

[0006] The purpose of the present application is to provide an improved ramp entry method and a corresponding computer program product and control device, so as to at least partially overcome the deficiencies of the prior art. In particular, it is possible to improve the lateral control of a vehicle when entering a ramp, and to improve the safety and comfort of the vehicle during the process of entering the ramp.

[0007] According to a first aspect of the present application, a ramp entry method for an autonomous driving vehicle is provided. The ramp entry method comprises the following steps: S1: acquiring road information related to the road around the vehicle and the motion information of the vehicle; S2: identifying whether the vehicle is in a ramp entry area, in which the vehicle travels from the original lane to the ramp located on the first side; S3: when the vehicle is in the ramp entry area, judging whether the ramp is a rapid opening type ramp based on the road information and / or motion information and a predetermined judgment condition; S4: if the ramp is a rapid opening type ramp, setting a first upper limit and a second upper limit greater than the first upper limit for the lateral acceleration to the first side and the second side opposite to each other, respectively; and S5: determining the lateral acceleration of the vehicle, wherein the first upper limit and the second upper limit are applied to the lateral acceleration to the first side and the lateral acceleration to the second side, respectively.

[0008] It should be understood that in the present application, "first side" and "second side" are intended to distinguish two lateral directions. "First side" and "second side" can be the left side and the right side, respectively, or the right side and the left side, respectively.

[0009] By identifying fast-opening ramps and applying inconsistent upper limits to the right lateral acceleration and the left lateral acceleration, the lateral control of the vehicle when entering the ramp can be improved, and the safety and comfort of the vehicle when entering the ramp can be improved. Facing various types of ramps, the vehicle can be ensured to travel more smoothly. Utilizing this asymmetric setting, the vehicle's driving direction can be prevented from changing abruptly to the first side (i.e., the vehicle swerves), while allowing a larger reverse change (i.e., the vehicle swerves), thereby allowing the vehicle to correct its driving direction more quickly. As a result, discomfort to passengers caused by rapid speed changes can be prevented, thereby improving the comfort of passengers in the vehicle. At the same time, the vehicle can be prevented from pressing against the road boundary line, and safety can be ensured.

[0010] The first upper limit is, for example, 0.5 m / s 2 Up to 1m / s 2 The first upper limit can be set to 0.75 m / s 2 .

[0011] The second upper limit is, for example, 1.25 m / s 2 Up to 1.75m / s 2 The second upper limit can be set to 1.5 m / s 2 .

[0012] In an exemplary embodiment, the second upper limit is more than twice the first upper limit. Optionally, the second upper limit is 0.5 m / s greater than the first upper limit. 2 above.

[0013] In an exemplary embodiment, in step S3, when the following judgment conditions are met, it is judged that the ramp is a rapid opening ramp:

[0014] - a first condition: a lateral distance change rate between the lateral distance between the vehicle and a road boundary line connected to the original lane on the first side is greater than a first change rate threshold; and / or

[0015] - Second condition: the angle change rate between the road boundary line connected to the original lane on the first side and the vehicle head direction is greater than a second change rate threshold.

[0016] The first condition and / or the second condition can be used to accurately identify a fast-opening ramp that may cause abrupt movement of the vehicle.

[0017] In particular, compared with the solution of judging the rapid opening ramp only based on the shape, direction and / or curvature of the road boundary line itself, the present application uses the lateral distance change rate to judge the rapid opening ramp, so as to more accurately identify the rapid opening ramp that may cause the vehicle to move rapidly. In this way, it is possible to prevent the first upper limit and the second upper limit from being redundantly set when it is not necessary. This may cause the lateral acceleration of the vehicle to be low, which in turn causes the vehicle to be unable to safely and smoothly enter the ramp.

[0018] The second condition can also be used to identify the fast opening ramp based not only on the shape of the road itself but also on the real-time state of the vehicle. This helps to prevent the first upper limit and the second upper limit from being set redundantly when not needed. The inventors realized in research and practice that at the entrance of the ramp, the angle change rate is associated with the rapid movement of the vehicle. Using the angle change rate, it is possible to more accurately identify the fast opening ramp that may cause the vehicle to move rapidly.

[0019] In an exemplary embodiment, the first change rate threshold is between 0.8 and 0.9, and is specifically set to 0.875.

[0020] In an exemplary embodiment, the second change rate threshold is between 0.11 and 0.13, and is specifically set to 0.123.

[0021] In an exemplary embodiment, in step S5, the lateral acceleration is determined according to the following calculation model: ay=a1+a2+a3, wherein a1 represents a first acceleration component associated with a rate of change of a lateral distance between a road boundary line connected to the original lane on a first side and the vehicle; a2 represents a second acceleration component associated with a rate of change of an angle between a road boundary line connected to the original lane on a first side and the direction of the vehicle head; and a3 represents a third acceleration component associated with a curvature of a road boundary line connected to the original lane on a first side.

[0022] According to the above calculation model, the lateral acceleration includes three acceleration components respectively associated with the lateral distance change rate, the angle change rate and the curvature. This helps the vehicle to travel with a suitable lateral acceleration when facing various road shapes at the ramp entrance, thereby improving safety and comfort. These three acceleration components can be determined and adjusted relatively independently. Therefore, the lateral acceleration of the vehicle can be better adapted to the changing road conditions. In addition, it also helps to adapt the lateral acceleration of the vehicle to the desired driving style of the vehicle.

[0023] In an exemplary embodiment, in step S5, the first upper limit and the second upper limit are used to limit the second acceleration component toward the first side and the second acceleration component toward the second side, respectively, so that the second acceleration component toward the first side does not exceed the first upper limit, and the second acceleration component toward the second side does not exceed the second upper limit.

[0024] The inventors have found in research and practice that at a fast open ramp, the second acceleration component is strongly associated with the rapid movement of the vehicle. By limiting the second acceleration component associated with the angle change rate, the safety and stability of the vehicle when passing through a fast open ramp can be effectively improved. At the same time, for other acceleration components (such as the first acceleration component and the third acceleration component), restrictions associated with the fast open ramp may not be imposed. Thus, unnecessary intervention in the lateral control of the vehicle can be avoided. Such unnecessary intervention may instead result in the vehicle being unable to safely and smoothly enter the ramp.

[0025] In an exemplary embodiment, the first acceleration component, the second acceleration component and / or the second acceleration component are determined using the following method:

[0026] a1=K_dy*dy, where dy is the lateral distance between the road boundary and the vehicle, and K_dy is a coefficient; and / or

[0027] a2=K_dψ*v*dψ, where dψ is the rate of change of the angle ψ between the road boundary line and the vehicle head direction, K_dψ is a coefficient, and v is the speed of the vehicle; and / or

[0028] a3=K_c*c*v 2 , where c is the curvature of the road boundary line, K_c is the coefficient, and v is the speed of the vehicle.

[0029] This helps the vehicle better adapt to various ramp forms so that it can enter the ramp smoothly and safely.

[0030] In an exemplary embodiment, the ramp entry method further includes step S6. In step S6, if the total lateral acceleration of the vehicle is continuously greater than the first threshold value within a predetermined time period, the total lateral acceleration is adjusted to be less than a third upper limit. In this way, a balance can be achieved between lane change efficiency and preventing oversteering.

[0031] The predetermined time length is, for example, between 400 ms and 600 ms, in particular, 500 ms. The first threshold is, for example, 1.2 m / s 2 Up to 1.5m / s 2 Between, especially 1.35m / s 2 The third upper limit is, for example, 0.8 m / s 2 Up to 1m / s2 Between, especially 0.9m / s 2 .

[0032] It is particularly advantageous that, in a preferred embodiment according to the present application, in step S5, the first upper limit and the second upper limit are used to limit the second acceleration component to the first side and the second acceleration component to the second side, respectively, in which case the additional execution of step S6 can achieve two-stage regulation of the lateral acceleration. At the fast open ramp, the second acceleration component is first limited by the first upper limit and the second upper limit to achieve local primary regulation of the lateral acceleration. Here, no restriction is imposed on other acceleration components, thereby avoiding unnecessary intervention in the lateral control of the vehicle. Executing step S6 in combination with the restriction of the second acceleration component can further regulate the total lateral acceleration when only limiting the second acceleration component by the first upper limit and the second upper limit is not enough to ensure the stability of the vehicle movement. Thus, the overall secondary regulation of the lateral acceleration is achieved. Thus, it can be ensured that the vehicle enters the ramp in a smooth manner and in accordance with the road shape when facing a fast open ramp.

[0033] In an exemplary embodiment, in step S2, whether the vehicle is in the ramp entry area is identified by at least one of the following methods: by identifying that the vehicle will enter the ramp located on the first side based on navigation information; by detecting, with the aid of a detection device of the vehicle, that the lane line of the original lane located on the first side changes from a solid line to a dashed line and detecting a road boundary line connected to the original lane at the junction of the dashed line and the solid line.

[0034] According to a second aspect of the present application, a computer program product is provided, comprising computer program instructions, wherein when the computer program instructions are executed by one or more processors, the one or more processors are enabled to execute the ramp entry method according to the present application.

[0035] According to a third aspect of the present application, a control device for an autonomous driving vehicle is provided, wherein the control device comprises a memory and a processor, the memory storing computer program instructions, and when the computer program instructions are executed by the processor, the processor is capable of executing the ramp entry method according to the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The present application will be described in more detail below with reference to the accompanying drawings, so that the principles, features and advantages of the present application can be better understood. The accompanying drawings include:

[0037] Figure 1 A flowchart of a ramp entry method for an autonomous driving vehicle according to an exemplary embodiment of the present application is schematically shown;

[0038] Figure 2Schematically showing that a vehicle is executing the ramp entry method according to an exemplary embodiment of the present application;

[0039] Figure 3 It schematically shows that the vehicle is in the ramp entry area;

[0040] Figure 4 A flowchart schematically shows a ramp entry method according to an exemplary embodiment of the present application; and

[0041] Figure 5 A vehicle capable of executing a ramp entry method according to an exemplary embodiment of the present application is schematically shown.

[0042] Reference numerals list

[0043] 1 Vehicle

[0044] 11 Control Device

[0045] 12 Detection device

[0046] 13 Positioning device

[0047] 14 Navigation Device

[0048] 15 Driving Execution System

[0049] 2 Original lane

[0050] 3 Ramp

[0051] 4 Road Boundaries DETAILED DESCRIPTION

[0052] In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the scope of protection of the present application.

[0053] Figure 1 A flowchart of a ramp entry method for an autonomous driving vehicle according to an exemplary embodiment of the present application is schematically shown. Figure 2 The vehicle 1 is schematically shown to be executing the ramp entry method.

[0054] like Figure 1 As shown, the ramp entry method may include steps S1, S2, S3, S4 and S5.

[0055] In step S1 , road information related to the road around the vehicle 1 and movement information of the vehicle 1 are acquired.

[0056] In step S2 , it is identified whether the vehicle 1 is in a ramp entry area, in which the vehicle 1 enters the ramp 3 located on the first side from the original lane 2 . Figure 2 The diagram schematically shows that the vehicle 1 is in the ramp entry area. Figure 2 As shown, the vehicle 1 is about to enter the ramp 3 located on the right from the rightmost lane of the road.

[0057] If it is identified that the vehicle 1 is in the ramp entry area, step S3 may be executed. In step S3, when the vehicle 1 is in the ramp entry area, based on the road information and / or the motion information, according to the predetermined judgment condition, it is determined whether the ramp 3 is a rapid opening ramp. A rapid opening ramp may refer to a type of ramp in which the road expands in a relatively rapid manner at the ramp entrance. In contrast, a normal opening ramp may refer to a type of ramp in which the road expands in a relatively gentle manner at the ramp entrance. Figure 2 A fast opening ramp is schematically shown. It can be seen that at the ramp entrance, the road boundary line 4 on the right side changes sharply.

[0058] If the ramp 3 is a fast opening ramp, step S4 may be performed. In step S4, a first upper limit is set for the lateral acceleration to the first side, and a second upper limit greater than the first upper limit is set for the lateral acceleration to the second side. The second side is opposite to the first side.

[0059] exist Figure 2 In the illustrated case, the first side is the right side, and the second side is the left side. Therefore, the first upper limit is a smaller upper limit of the lateral acceleration to the right, and the second upper limit is a larger upper limit of the lateral acceleration to the left.

[0060] In other examples, such as in countries or regions that enforce keep-left driving rules, the first side may be the left side and the second side may be the right side.

[0061] In step S5 , the lateral acceleration of the vehicle 1 is determined, wherein a first upper limit and a second upper limit are applied to the lateral acceleration to the first side and to the second side, respectively.

[0062] As a result, the lateral control of the vehicle 1 when entering the ramp 3 can be improved, and the safety and comfort of the vehicle 1 when entering the ramp 3 can be improved. Facing various types of ramps 3, the vehicle 1 can be ensured to travel relatively smoothly. As a result, the discomfort of passengers caused by rapid speed changes can be prevented, thereby improving the comfort of passengers in the vehicle 1. At the same time, the vehicle 1 can be prevented from pressing against the road boundary line 4.

[0063] See also Figure 2For such a fast opening ramp, a relatively low upper limit can be set for the right lateral acceleration, and a relatively high upper limit can be set for the left lateral acceleration. With this asymmetric setting, the driving direction of the vehicle 1 can be prevented from changing abruptly to the right (i.e., the vehicle swerves to the right), while allowing a large reverse change (i.e., the vehicle swerves in the opposite direction), thereby allowing the vehicle 1 to correct the driving direction more quickly.

[0064] The road information may include in particular information related to lane lines of the road, such as the position and / or line type of the lane lines, etc. The motion information may include, for example, the position of the vehicle 1, the front direction of the vehicle 1, the speed of the vehicle 1 and / or the acceleration of the vehicle 1, etc.

[0065] According to an exemplary embodiment of the present application, in step S2, it is possible to identify whether the vehicle 1 is in the ramp entry area by identifying that the vehicle 1 will enter the ramp 3 located on the first side based on the navigation information and the positioning information. For example, by using the positioning device of the vehicle 1 (such as a GNSS device), the current position of the vehicle 1 can be located, and the positioning information of the vehicle 1 can be obtained. By using the electronic map and the navigation path, it can be determined whether the vehicle 1 is close to the ramp entrance and whether it is about to enter the ramp 3. In particular, a high-precision map can be used to obtain more accurate lane information, including the specific location of the ramp 3, the number of lanes, the separation between lanes, etc. As a result, it is possible to more accurately identify whether the vehicle 1 is in the ramp entry area.

[0066] Alternatively or additionally, in step S2, the detection device 12 of the vehicle 1 (see Figure 5 ) detects that the lane line of the original lane 2 located on the first side changes from a solid line to a dotted line and detects the road boundary line 4 connected to the original lane 2 at the junction of the dotted line and the solid line to identify whether the vehicle 1 is in the ramp entry area.

[0067] The detection device 12 may include, for example, a camera device configured to capture an image of the exterior of the vehicle 1, in particular a road image. By extracting lane line features from the road image, it is possible to detect whether the lane line of the original lane 2 located on the first side changes from a solid line to a dashed line, and to detect whether a road boundary line 4 connected to the original lane 2 at the junction of the dashed line and the solid line exists. The road boundary line 4 is usually a solid line.

[0068] Optionally, if the lane line of the original lane 2 on the first side is detected to change from a solid line to a dashed line and a road boundary line 4 connected to the original lane 2 at the junction of the dashed line and the solid line is detected, it can be determined that the vehicle 1 is in the ramp entry area.

[0069] In an exemplary embodiment according to the present application, the above two methods can be combined to identify whether the vehicle 1 is in the ramp entry area, thereby improving accuracy. For example, the area within a predetermined distance threshold (e.g., 30 meters) adjacent to the ramp entrance can be set as the approaching area. When the vehicle 1 is identified to enter the approaching area based on the navigation information and positioning information, it can be further identified whether the vehicle 1 enters the ramp entry area based on the information collected by the detection device 12, especially the road image.

[0070] Optionally, after recognizing that the vehicle 1 enters the ramp entry area, the vehicle 1 may switch to the ramp entry mode. In the ramp entry mode, the control strategy of the vehicle 1, in particular the lateral control strategy, may be different from other modes, for example, different from the control strategy adopted when the vehicle 1 is driving on a highway or following a preceding vehicle.

[0071] For example, after switching to the ramp entry mode, step S3 may be performed. Figure 2 If, in step S2, it is identified that the vehicle 1 is not in the ramp entry area, step S3 is not executed.

[0072] It is particularly advantageous that, in step S3, in combination with the road information and the motion information, it is determined whether the ramp 3 is a rapid opening ramp according to predetermined judgment conditions. Therefore, the identification of the rapid opening ramp is not based solely on the shape of the road itself, but is also associated with the real-time state of the vehicle 1. As described above, a rapid opening ramp may represent a type of ramp in which the road expands in a relatively sharp manner at the entrance of the ramp. When judging whether the road "expands in a relatively sharp manner", it is not limited to the judgment criteria determined by the shape of the road itself, but a judgment criteria associated with the motion characteristics of the vehicle can be established. In other words, when the motion characteristics of the vehicle are difficult to adapt to the expansion speed of the road at the entrance of the ramp, it can be judged that this is a rapid opening ramp.

[0073] According to an exemplary embodiment of the present application, in step S3, the ramp 3 can be judged as a fast opening ramp when the following first condition is met: the lateral distance change rate of the lateral distance between the road boundary line 4 connected to the original lane 2 on the first side and the vehicle 1 is greater than the first change rate threshold.

[0074] exist Figure 2 In FIG. 1 , the lateral distance y between the right road boundary line 4 and the vehicle 1 is schematically marked. Based on the lateral distance y, the lateral distance change rate dy can be further determined. The lateral distance change rate is, for example, the change rate of the lateral distance (for example, in meters) relative to time (for example, in seconds).

[0075] Compared with the solution of judging the rapid opening ramp only based on the shape, direction and / or curvature of the road boundary line 4 itself, the present application uses the lateral distance change rate to judge the rapid opening ramp, so as to more accurately identify the rapid opening ramp that may cause the vehicle 1 to move rapidly. In this way, it is possible to prevent the first upper limit and the second upper limit from being set redundantly when it is not necessary. This may cause the lateral acceleration of the vehicle 1 to be low, which in turn causes the vehicle 1 to be unable to safely and smoothly enter the ramp 3.

[0076] The first rate of change threshold is, for example, between 0.8 and 0.9. The first rate of change threshold can be particularly set to 0.875. The first rate of change threshold set in this way is particularly conducive to accurately identifying a fast opening ramp.

[0077] Alternatively or additionally, in step S3, the ramp 3 may be judged to be a rapid opening ramp when the following second condition is met: the angle change rate of the angle between the road boundary line 4 connected to the original lane 2 on the first side and the direction of the vehicle head is greater than the second change rate threshold. The second condition involves both road information and the motion information of the vehicle 1. Therefore, the second condition can also be used to realize that the identification of the rapid opening ramp is not only based on the shape of the road itself but also associated with the real-time state of the vehicle 1. This helps to prevent the first upper limit and the second upper limit from being set redundantly when not needed. This may cause the lateral acceleration of the vehicle 1 to be low, which in turn causes the vehicle 1 to be unable to safely and smoothly enter the ramp 3.

[0078] The inventors have found in research and practice that at the ramp entrance, the angle change rate is associated with the rapid movement of the vehicle 1. By using the angle change rate, a fast opening ramp that may cause the vehicle 1 to move rapidly can be more accurately identified.

[0079] exist Figure 2 , the direction Db of the right road boundary line 4 and the front direction Dv of the vehicle 1 are schematically marked. The direction Db of the right road boundary line 4 may represent the tangential direction of the right road boundary line 4 at a position opposite to the vehicle 1 in the lateral direction (the lateral direction of the vehicle 1). The angle between the direction Db of the right road boundary line 4 and the front direction Dv is ψ. Based on the angle ψ, the angle change rate dψ may be further determined. The angle change rate is, for example, the rate of change of the angle (e.g., in radians) relative to time (e.g., in seconds).

[0080] The second rate of change threshold is, for example, between 0.11 and 0.13. The second rate of change threshold can be particularly set to 0.123. The second rate of change threshold set in this way is particularly conducive to accurately identifying a fast opening ramp.

[0081] According to an exemplary embodiment of the present application, the ramp 3 is determined to be a rapid opening ramp only when both the first condition and the second condition are satisfied, which is particularly helpful for accurately identifying the rapid opening ramp.

[0082] For example, in Figure 2 In the case shown, it can be determined that the ramp 3 is a rapid opening ramp based on the lateral distance change rate and the angle change rate.

[0083] Then, a first, smaller upper limit may be set for the rightward lateral acceleration, and a second, larger upper limit may be set for the leftward lateral acceleration.

[0084] Optionally, the second upper limit is more than twice the first upper limit. Alternatively or additionally, the second upper limit is 0.5 m / s greater than the first upper limit. 2 This obviously asymmetric arrangement is beneficial to improving the safety and comfort of the vehicle 1 when it enters the ramp 3 .

[0085] The first upper limit is, for example, 0.5 m / s 2 Up to 1m / s 2 The first upper limit is particularly set to 0.75 m / s 2 .

[0086] The second upper limit is, for example, 1.25 m / s 2 Up to 1.75m / s 2 The second upper limit is particularly set to 1.5 m / s 2 .

[0087] In an exemplary embodiment of the present application, the first upper limit and the second upper limit may be directly used to limit the total lateral acceleration.

[0088] According to a preferred embodiment of the present application, the first upper limit and the second upper limit are used to limit the lateral acceleration portion generated by the angle ψ channel. In other words, the first upper limit and the second upper limit are used to limit the lateral acceleration portion associated with the angle ψ (which will be further described below in conjunction with examples). By limiting the lateral acceleration portion associated with the angle ψ, the value of the total lateral acceleration can be indirectly affected.

[0089] According to an exemplary embodiment of the present application, in step S5, the lateral acceleration is determined according to the following calculation model: ay=a1+a2+a3, wherein a1 represents a first acceleration component associated with a lateral distance change rate of a lateral distance between a road boundary line 4 connected to the original lane 2 on a first side and the vehicle 1; a2 represents a second acceleration component associated with an angle change rate of an angle ψ between a road boundary line 4 connected to the original lane 2 on a first side and the vehicle front direction; a3 represents a third acceleration component associated with a curvature of a road boundary line 4 connected to the original lane 2 on a first side.

[0090] It can be seen that the lateral acceleration includes three acceleration components respectively associated with the lateral distance change rate, the angle change rate and the curvature. This helps the vehicle 1 to travel with a suitable lateral acceleration when facing various road shapes at the ramp entrance, thereby improving safety and comfort. These three acceleration components can be determined and adjusted relatively independently. Therefore, the lateral acceleration of the vehicle 1 can be better adapted to the changing road conditions. In addition, it also helps to adapt the lateral acceleration of the vehicle 1 to the desired driving style of the vehicle 1.

[0091] In step S5 , a first upper limit and a second upper limit are applied to the second acceleration component so that the second acceleration component toward the first side and toward the second side are respectively smaller than the first upper limit and the second upper limit.

[0092] Optionally, the first acceleration component may be determined using the following formula: a1=K_dy*dy, wherein dy is the lateral distance between the road boundary line 4 and the vehicle 1, and K_dy is a coefficient set for the lateral distance. The coefficient K_dy may be pre-calibrated.

[0093] The second acceleration component can be determined by the following formula: a2=K_dψ*v*dψ, where dψ is the angle change rate of the angle ψ between the road boundary line 4 and the vehicle head direction, K_dψ is a coefficient set for the angle change rate, and v is the speed of the vehicle 1. The coefficient K_dψ can be calibrated in advance. The speed of the vehicle 1 can be detected, for example, by means of a speed sensor of the vehicle 1.

[0094] The third acceleration component can be determined using the following formula: a3 = K_c*c*v 2 , where c is the curvature of the road boundary line 4, K_c is a coefficient set for the curvature, and v is the speed of the vehicle 1. The coefficient K_c can be pre-calibrated. The curvature of the road boundary line 4 can represent the curvature of the road boundary line 4 at a position opposite to the vehicle 1 in the transverse direction.

[0095] As an example, by setting the coefficients K_dy, K_dψ and / or K_c in different ways, the vehicle can perform automatic driving in a desired driving style.

[0096] In a preferred embodiment of the present application, in step S5, the first upper limit and the second upper limit are respectively used to limit the second acceleration component toward the first side and the second acceleration component toward the second side, so that the second acceleration component toward the first side does not exceed the first upper limit, and the second acceleration component toward the second side does not exceed the second upper limit.

[0097] At the fast opening ramp, the second acceleration component is strongly associated with the rapid movement of the vehicle 1. By limiting the second acceleration component associated with the angle change rate of the angle ψ, the safety and stability of the vehicle 1 when passing through the fast opening ramp can be effectively improved. At the same time, for other acceleration components (such as the first acceleration component and the third acceleration component), restrictions associated with the fast opening ramp may not be performed. In this way, unnecessary intervention in the lateral control of the vehicle 1 can be avoided. Such unnecessary intervention will instead result in the vehicle 1 being unable to safely and smoothly enter the ramp 3.

[0098] According to an exemplary embodiment of the present application, if the ramp 3 is a fast open ramp, the coefficient K_dψ set for the angle change rate is adjusted according to the angle change rate dψ of the angle ψ between the road boundary line 4 connected to the original lane 2 on the first side and the vehicle head direction. In particular, the coefficient K_dψ can be made negatively correlated with the angle change rate dψ.

[0099] For example, the coefficient K_dψ can be adjusted according to the following formula: K_dψ=-k1*dψ 2 +k2, where k1 and k2 are predetermined coefficients.

[0100] By dynamically adjusting the coefficient K_dψ according to the angle change rate, it is possible to effectively prevent a large and sudden lateral acceleration component from being generated due to a large angle change rate. At the same time, it is possible to adjust independently of the lateral distance and curvature, thereby not interfering with the influence of the lateral distance and curvature on the total lateral acceleration.

[0101] Figure 3 It is schematically shown that the vehicle 1 is in the ramp entry area.

[0102] The vehicle 1 may execute a ramp entry method according to an exemplary embodiment of the present application.

[0103] First, in step S1 , road information related to roads around the vehicle 1 and movement information of the vehicle 1 may be acquired.

[0104] In step S2, it can be identified whether the vehicle 1 is in the ramp entry area. Figure 3 As shown, the vehicle 1 is traveling in the rightmost lane of the road (ie, the original lane 2 ), and is about to enter the ramp 3 located on the right side from the rightmost lane of the road.

[0105] When it is identified that the vehicle 1 is in the ramp entry area, step S3 may be executed. In step S3, based on the road information and / or the motion information, according to a predetermined judgment condition, it is determined whether the ramp 3 is a rapid opening ramp.

[0106] exist Figure 3In FIG. 1 , the lateral distance y between the right road boundary line 4 and the vehicle 1 is schematically marked. Based on the lateral distance y, the lateral distance change rate dy can be further determined.

[0107] exist Figure 3 In FIG. 1 , the direction Db of the right road boundary line 4 and the front direction Dv of the vehicle 1 are also schematically marked. The angle between the direction Db of the right road boundary line 4 and the front direction Dv is ψ. Based on the angle ψ, the angle change rate dψ can be further determined.

[0108] For example, based on the road information and / or the motion information, according to the first condition and / or the second condition described above, it can be determined that the ramp 3 is not a rapid opening ramp.

[0109] Since it is determined in step S3 that the ramp 3 is not a rapid opening ramp, steps S4 and S5 are not performed. Alternatively, step S5' may be performed. In step S5', the lateral acceleration of the vehicle 1 is determined without applying the first upper limit and the second upper limit.

[0110] For example, in step S5 ′, the lateral acceleration may be determined according to the following calculation model: ay=K_dy*dy+K_dψ*v*dψ+K_c*c*v 2 , where dy is the lateral distance between the road boundary line 4 connected to the original lane 2 on the first side and the vehicle 1, dψ is the angle change rate of the angle ψ between the road boundary line 4 and the vehicle head direction, c is the curvature of the road boundary line 4, K_dy, K_dψ and K_c are coefficients, and v is the speed of the vehicle 1.

[0111] Figure 4 The flowchart of the ramp entry method according to an exemplary embodiment of the present application is schematically shown. Figure 1 Similar to the embodiment shown, in this embodiment, the ramp entry method may include at least steps S1, S2, S3, S4, S5 and S5'. Steps S1, S2, S3, S4, S5 and S5' may be performed as described above and will not be repeated here.

[0112] exist Figure 4 In the illustrated embodiment, the ramp entry method may further include step S6. In step S6, if the total lateral acceleration of the vehicle 1 is continuously greater than the first threshold value within a predetermined time period, the total lateral acceleration is adjusted to be less than the third upper limit. In this way, a balance can be achieved between lane change efficiency and preventing oversteering.

[0113] The predetermined time length is, for example, between 400 ms and 600 ms, in particular, 500 ms. The first threshold is, for example, 1.2 m / s 2 Up to 1.5m / s 2Between, especially 1.35m / s 2 The third upper limit is, for example, 0.8 m / s 2 Up to 1m / s 2 Between, especially 0.9m / s 2 .

[0114] According to an exemplary embodiment of the present application, step S6 is performed only when it is determined in step S3 that the ramp 3 is a rapid opening ramp. Step S6 may be performed after step S5, for example.

[0115] It is particularly advantageous that, in a preferred embodiment according to the present application, in step S5, the first upper limit and the second upper limit are used to limit the second acceleration component to the first side and the second acceleration component to the second side, respectively, in which case the additional execution of step S6 can achieve two-stage regulation of the lateral acceleration. At the fast open ramp, the second acceleration component is first limited by the first upper limit and the second upper limit to achieve primary regulation. Here, no restriction is imposed on other acceleration components, thereby avoiding unnecessary intervention in the lateral control of the vehicle 1. Executing step S6 in combination with the restriction of the second acceleration component can further adjust the total lateral acceleration when only limiting the second acceleration component by the first upper limit and the second upper limit is insufficient to ensure the smoothness of the movement of the vehicle 1. Thereby, it can be ensured that the vehicle 1 enters the ramp 3 in a smooth manner and in accordance with the road shape when facing a fast open ramp.

[0116] Figure 5 A vehicle 1 according to an exemplary embodiment of the present application is schematically shown. The vehicle 1 is, for example, a vehicle with an automatic driving function or an assisted driving function.

[0117] like Figure 5 As shown, the vehicle 1 may include a control device 11. The control device 11 may be configured to be able to implement a ramp entry method according to an exemplary embodiment of the present application. It should be understood that the features and advantages described herein for the ramp entry method are also applicable to the control device 11, and vice versa.

[0118] The control device 11 is implemented as an electronic control unit (ECU) of the vehicle 1, for example. The control device 11 may include a memory and a processor, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the processor is capable of executing, for example, a ramp entry method for the vehicle 1. The computer program product may be stored in a computer-readable storage medium. The computer-readable storage medium may include, for example, a high-speed random access memory, and may also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card, a secure digital card, a flash memory card, at least one disk storage device, a flash memory device, or other volatile solid-state storage devices. The processor may be a central processing unit, or may be other general-purpose processors, digital signal processors, application-specific integrated circuits, off-the-shelf programmable gate arrays or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0119] The vehicle 1 may further include at least one detection device 12 for detecting the surrounding environment of the vehicle 1. The detection device 12 may be configured to detect the road around the vehicle 1 during the driving of the vehicle 1 so as to obtain road information. The detection device 12 may be communicatively connected with the control device 11 so that the control device 11 may obtain information from the detection device 12. Optionally, the control device 11 may send a control instruction to the detection device 12 so as to control the detection device 12 to perform a detection operation.

[0120] The detection device 12 may include a camera device. The camera device may capture images of the road around the vehicle 1. Lane line features may be extracted from the images captured by the camera device, for example. The detection device 12 may also include multiple sensors such as radar and / or laser radar. Through multi-sensor fusion, the accuracy of detection can be improved.

[0121] The vehicle 1 may further include a positioning device 13 and a navigation device 14. The positioning device 13 may be configured to determine the position of the vehicle 1. The positioning device 13 may include, for example, a GNSS device and / or an inertial measurement unit. The navigation device 14 may be configured to provide map information and a navigation path. The navigation device 14 may be equipped with map information including road information, geographic information, etc. According to the destination of the vehicle 1, the navigation device 14 may plan the driving path of the vehicle 1 using the map information. The positioning device 13 and the navigation device 14 may be communicatively connected to the control device 11 so that the control device 11 may obtain information from the positioning device 13 and the navigation device 14.

[0122] The vehicle 1 may further include a driving execution system 15, which may be configured to at least be capable of executing lateral control of the vehicle 1. The driving execution system 15 may include, for example, a power unit, a transmission, a steering device, and / or tires. The driving execution system 15 may be communicatively connected to the control device 11, so that the driving execution system 15 may perform corresponding driving operations in response to the instructions of the control device 11. For example, after the control device 11 determines the lateral acceleration of the vehicle 1, the driving execution system 15 performs the driving operation accordingly so that the vehicle 1 travels at the determined lateral acceleration.

[0123] Although the specific embodiments of the present application are described in detail herein, they are provided for the purpose of explanation only and should not be considered to limit the scope of the present application. Various substitutions, changes and modifications may be conceived without departing from the spirit and scope of the present application.

Claims

1. A ramp entry method for an autonomous driving vehicle, wherein: The ramp entry method comprises the following steps: S1: Acquiring road information related to roads around the vehicle (1) and movement information of the vehicle (1); S2: Identifying whether the vehicle (1) is in a ramp entry area, in which the vehicle (1) moves from an original lane (2) to a ramp (3) located on a first side; S3: when the vehicle (1) is in the ramp entry area, judging whether the ramp (3) is a rapid opening ramp based on road information and / or movement information and according to a predetermined judgment condition; S4: if the ramp (3) is a rapid opening ramp, setting a first upper limit and a second upper limit greater than the first upper limit for lateral accelerations to a first side and a second side opposite to each other, respectively; as well as S5: Determine a lateral acceleration of the vehicle (1), wherein a first upper limit and a second upper limit are applied to the lateral acceleration to the first side and to the second side, respectively.

2. The ramp entry method according to claim 1, wherein: In step S3, when the following judgment conditions are met, it is judged that the ramp (3) is a rapid opening ramp: - a first condition: a lateral distance change rate of a lateral distance between a road boundary line (4) connected to the original lane (2) on the first side and the vehicle (1) is greater than a first change rate threshold; and / or - Second condition: the angle change rate between the road boundary line (4) connected to the original lane (2) on the first side and the vehicle head direction is greater than a second change rate threshold.

3. The ramp entry method according to claim 2, wherein: The first change rate threshold is between 0.8 and 0.9, and is particularly set to 0.875; and / or The second change rate threshold is between 0.11 and 0.13, and is specifically set to 0.

123.

4. The ramp entry method according to any one of claims 1 to 3, wherein: In step S5, the lateral acceleration is determined according to the following calculation model: ay=a1+a2+a3, wherein a1 represents a first acceleration component associated with a rate of change of a lateral distance between a road boundary line (4) connected to the original lane (2) on a first side and the vehicle (1); a2 represents a second acceleration component associated with a rate of change of an angle between a road boundary line (4) connected to the original lane (2) on the first side and the direction of the vehicle head; a3 represents a third acceleration component associated with the curvature of a road boundary line (4) connected to the original lane (2) on a first side.

5. The ramp entry method according to claim 4, wherein: In step S5, the first upper limit and the second upper limit are used to limit the second acceleration component toward the first side and the second acceleration component toward the second side, respectively, so that the second acceleration component toward the first side does not exceed the first upper limit, and the second acceleration component toward the second side does not exceed the second upper limit.

6. The ramp entry method according to claim 4 or 5, wherein: The first acceleration component, the second acceleration component and / or the second acceleration component are determined in the following manner: a1=K_dy*dy, wherein dy is the lateral distance between the road boundary line (4) and the vehicle (1), and K_dy is a coefficient; and / or a2=K_dψ*v*dψ, wherein dψ is the rate of change of the angle ψ between the road boundary line (4) and the direction of the vehicle head, K_dψ is a coefficient, and v is the speed of the vehicle (1); and / or a3=K_c*c*v 2 , wherein c is the curvature of the road boundary line (4), K_c is the coefficient, and v is the speed of the vehicle (1).

7. The ramp entry method according to any one of claims 1 to 6, wherein: The second upper limit is more than 2 times the first upper limit; and / or The second upper limit is 0.5 m / s greater than the first upper limit 2 above; and / or The first upper limit is 0.5m / s 2 Up to 1m / s 2 Between, especially 0.75m / s 2 ; and / or The second upper limit is 1.25m / s 2 Up to 1.75m / s 2 Between, especially 1.5m / s 2 .

8. The ramp entry method according to any one of claims 1 to 7, wherein: The ramp entry method further comprises step S6, in which if the total lateral acceleration of the vehicle (1) is continuously greater than the first threshold value within a predetermined time period, the total lateral acceleration is adjusted to be less than a third upper limit.

9. The ramp entry method according to claim 8, wherein: The predetermined duration is between 400ms and 600ms, especially 500ms; The first threshold is 1.2m / s 2 Up to 1.5m / s 2 Between, especially 1.35m / s 2 ; The third upper limit is 0.8m / s 2 Up to 1m / s 2 Between, especially 0.9m / s 2 .

10. The ramp entry method according to any one of claims 1 to 9, wherein: In step S2, whether the vehicle (1) is in the ramp entry area is identified by at least one of the following methods: By recognizing, based on the navigation information, that the vehicle (1) will enter a ramp (3) located on the first side; By using a detection device (12) of the vehicle (1), it is detected that the lane line of the original lane (2) located on the first side changes from a solid line to a dotted line, and a road boundary line (4) connected to the original lane (2) at the junction of the dotted line and the solid line is detected.

11. A computer program product comprising computer program instructions, wherein: When the computer program instructions are executed by one or more processors, the one or more processors are enabled to perform the ramp entry method according to any one of claims 1-10.

12. A control device for an autonomous driving vehicle, wherein: The control device (11) comprises a memory and a processor, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the processor is capable of executing the ramp entry method according to any one of claims 1 to 10.

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