Vehicle speed control method and system based on adaptive cruise control

Abstract

The present invention relates to a vehicle speed control method and system based on adaptive cruise control. The vehicle speed control method first divides lanes into categories and regions in sequence, and determines the lane in which the vehicle is located. When the vehicle is in the turning area of ​​the turning lane, the vehicle is controlled to travel at a preset speed, and the vehicle is controlled to start turning at the end of the turning area. When the vehicle is traveling in a straight lane, or after turning, it enters the straight area of ​​the next lane, the speed of the vehicle is adaptively regulated according to the logic of adaptive cruise control, and the following distance is maintained. The vehicle speed control method uses the identification of the turning area of ​​the turning lane as a basis, and actively controls the driving speed of the vehicle to be maintained at a safe threshold, thereby avoiding the vehicle in the traditional lane from losing the target when the front vehicle turns, causing the vehicle to accelerate, reducing the risk of collision with the vehicle in the opposite lane, and effectively improving the safety factor of vehicle assisted driving.

Description

Technical Field

[0001] The present invention relates to the technical field of assisted driving, and in particular to a vehicle speed control method and system based on adaptive cruise control. Background Art

[0002] With the development of intelligent driving technology, assisted driving systems have gradually begun to be applied to automotive products. Among them, the adaptive cruise control (ACC) function is the core function of longitudinal control. The basic working principle of the adaptive cruise control function is to increase the state of tracking the target ahead on the basis of constant speed cruise, and make adaptive adjustments to the vehicle speed according to the working conditions of different target states in front of the vehicle.

[0003] In traditional assisted driving systems with adaptive cruise control, a forward-looking camera and millimeter-wave radar are usually fused to determine the target vehicle in front of the lane and the motion state of the target, and then control the vehicle according to the set single-lane cruise logic. This method can achieve a high level of target recognition in the distant area in front of the lane or the adjacent lane. However, there are also inherent defects. Due to the limitation of the field of view, it cannot respond to close-range cut-in scenes. In addition, since the target is easily lost when the vehicle turns, according to the control logic of the adaptive cruise control function, the vehicle is prone to the risk of collision with vehicles in the opposite lane or the straight lane, and the safety factor of the assisted driving system needs to be improved.

[0004] In order to overcome the above shortcomings, technicians turned their attention to the perception solution that combines LiDAR with a front-view camera. In terms of performance, this solution can certainly meet certain performance requirements. However, LiDAR is expensive, and processing the point cloud data of LiDAR requires a lot of computing power, which further increases the actual application cost of such solutions, thus limiting their application in assisted driving systems. Summary of the invention

[0005] Based on this, it is necessary to address the technical problem of low safety factor of auxiliary driving systems in the prior art. The present invention provides a vehicle speed control method and system based on adaptive cruise control.

[0006] The present invention discloses a vehicle speed control method based on adaptive cruise control, which comprises the following steps:

[0007] S1: Set the cruising speed of the vehicle, collect the location information of the vehicle in real time, and classify each lane of the road section where the vehicle is currently located into a straight lane or a turning lane according to the lane category. Analyze the category of the lane the vehicle is traveling in based on the location information of the vehicle. When the vehicle is traveling in the straight lane, execute S5.

[0008] S2: When the vehicle is traveling in a turning lane, the turning lane is divided into a straight area and a turning area that are interconnected, and the area where the vehicle is located in the turning lane is analyzed based on the location information of the vehicle. When the vehicle is located in the straight area of ​​the turning lane, S5 is executed.

[0009] S3: When the vehicle is located in a turning area on a turning lane, the vehicle is controlled to travel at a preset speed, and the vehicle is controlled to start turning at the end of the turning area, and then S4 is executed.

[0010] S4: By analyzing the real-time turning angle of the front wheels of the vehicle, it is determined in real time whether the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane. When the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane, S5 is executed. When the vehicle has not completed the turn or has not entered the straight-ahead area of ​​the next lane, the process returns to S3.

[0011] S5: Real-time acquisition of the target state information ahead of the vehicle, and judging whether there is a target vehicle 1 that is the first vehicle ahead of the vehicle within a preset range 1 ahead of the current lane of the vehicle according to the target state information ahead. When the target vehicle 1 exists within the preset range 1, the speed of the target vehicle 1 is acquired in real time, and S6 is executed. When the target vehicle 1 does not exist within the preset range 1, S8 is executed.

[0012] S6: According to the speed of the target vehicle 1, determine whether the speed of the target vehicle 1 is higher than the cruising speed of the vehicle. When the speed of the target vehicle 1 is not higher than the cruising speed of the vehicle, execute S7. When the speed of the target vehicle 1 is higher than the cruising speed of the vehicle, execute S8.

[0013] S7: Control the vehicle to maintain the same speed as the first vehicle in front of the vehicle, and control the vehicle to maintain a distance from the vehicle in front that is not less than a preset following distance.

[0014] S8: Control the vehicle to travel at the set cruising speed.

[0015] As a further improvement of the present invention, in S1, the state information of the side target of the vehicle is also collected in real time.

[0016] The state information of the front target includes: the speed, direction, and distance between the vehicle and the vehicle in the preset range in front of the lane and the adjacent lane, as well as the type and position of the lane line. The state information of the side target includes: the speed, direction, and distance between the vehicle and the vehicle in the preset range on the side of the lane and the adjacent lane, as well as the type and position of the lane line and curb.

[0017] As a further improvement of the present invention, the positions and motion states of the vehicles around the vehicle in their respective lanes are obtained according to the front target state information and the side target state information.

[0018] As a further improvement of the present invention, the cruise speed of the vehicle is set within a range of (30, 60) km / h. In S3, the preset speed of the vehicle when turning is not higher than 30 km / h.

[0019] As a further improvement of the present invention, in S4, the driving state of the vehicle during the turning process is judged by analyzing the relationship between the real-time turning angle of the front wheel of the vehicle and a preset angle value interval (a, b):

[0020] 1. When the real-time turning angle increases from a state less than a preset angle value a to a state greater than a preset angle value b, and maintains this state for more than a preset time period one, it is determined that the vehicle is in a turning state.

[0021] 2. When the real-time turning angle decreases from a state greater than the preset angle value b to a state less than the preset angle value a, it is determined that the vehicle has completed the turn.

[0022] 3. When the real-time turning angle decreases from a state greater than the preset angle value b to a state less than the preset angle value a, and maintains this state for more than a preset time period 2, it is determined that the vehicle has completed the turn and has entered the next lane straight driving area.

[0023] As a further improvement of the present invention, after S7, the following steps are further performed:

[0024] S9: Determine whether the target vehicle 1 has driven out of the lane and there is no vehicle within the preset range 1 after the vehicle has driven out. If yes, execute S8. If no, return to S7.

[0025] As a further improvement of the present invention, after S7 and / or S8, the following steps are further performed:

[0026] S10: Determine whether there is a target vehicle 2 entering the lane in a preset range 2 of the adjacent lane, and the target vehicle 2 meets the following conditions: it enters the preset range 1 of the lane at a speed lower than the current speed of the vehicle and becomes the first vehicle in front of the vehicle after entering. If the target vehicle 2 exists in the adjacent lane, execute S7. If the target vehicle 2 does not exist in the adjacent lane, return to S5.

[0027] The present invention also discloses a vehicle speed control system based on adaptive cruise control, which comprises: a front acquisition module, a side acquisition module, a fusion module, a perception module and a controller.

[0028] The front acquisition module includes a front camera and a front millimeter-wave radar. The front camera is used to collect image 1 within a preset range in front of the lane and the adjacent lane. The targets in image 1 include: vehicles and lane lines within a preset range in front of the lane and the adjacent lane. The front target status information includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range in front of the lane and the adjacent lane, as well as the type and position of the lane line.

[0029] The side acquisition module includes multiple matching side-view cameras and side millimeter-wave radars. Multiple cameras are respectively arranged on both sides of the vehicle with their corresponding side millimeter-wave radars. The side-view camera located on the same side of the vehicle is used to collect image 2 within a preset range on the side of the lane and the adjacent lane. The targets in image 2 include: vehicles, lane lines and curbs within the preset range on the side of the lane and the adjacent lane. The side target status information includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range on the side of the lane and the adjacent lane, as well as the type and position of lane lines and curbs.

[0030] The fusion module is used to identify the targets in image one and image two through image recognition technology, and use the fusion algorithm to fuse the targets in image one and image two into the detection data of the corresponding millimeter-wave radar, and then identify the target status information in image one and each image two, that is, the front target status information and the side target status information.

[0031] The perception module is used to obtain the position and motion status of surrounding vehicles in their respective lanes based on the state information of the front target and the state information of the side target.

[0032] The controller is used to control the speed of the vehicle according to the position and movement status of the vehicle and surrounding vehicles in their respective lanes.

[0033] The controller controls the speed of the vehicle using any of the above-mentioned vehicle speed control methods based on adaptive cruise control.

[0034] As a further improvement of the present invention, at least four side-view cameras and side millimeter-wave radars are provided, corresponding one to one, and are respectively installed at the four corners of the vehicle.

[0035] As a further improvement of the present invention, the target in the image 1 also includes: a guide arrow in the lane; the type characteristics of the guide arrow include: left turn, left turn and go straight, go straight, right turn, right turn and go straight.

[0036] Compared with the prior art, the technical solution of the present invention has the following beneficial effects:

[0037] 1. This vehicle speed control method is based on the adaptive cruise function. It uses the identification of the turning area of ​​the turning lane as a basis to actively control the vehicle's driving speed to maintain a safe threshold, thereby avoiding the traditional lane adaptive cruise system from losing the target when the front vehicle turns and causing the vehicle to accelerate, reducing the risk of collision with vehicles in the opposite lane, and effectively improving the safety factor of vehicle assisted driving. In addition, this vehicle speed control method also sets two prerequisites: "completing the turn" and "entering the straight area of ​​the next lane". Only when these two conditions are met at the same time can the vehicle be judged to carry out the traditional ACC cruise condition, thereby further improving the safety and reliability of this vehicle speed control method.

[0038] 2. The vehicle speed control system collects images of the front and sides of the vehicle and detects the distance by respectively setting a front acquisition module and a side acquisition module at the front and both sides of the vehicle, and then fuses the collected images and detection data through a fusion module to obtain the front target state information and side target state information of the vehicle, and then can implement different control strategies for the vehicle speed according to different lane conditions or the motion state of the target vehicle, effectively improving the safety factor of the vehicle's automatic assisted driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Schematic diagram of the process of the vehicle speed control method based on adaptive cruise control in Embodiment 1 of the present invention;

[0040] Figure 2 is a logic block diagram of a vehicle speed control method based on adaptive cruise control in Embodiment 1 of the present invention;

[0041] Figure 3 A schematic diagram of classifying lanes in the current road section in Embodiment 1 of the present invention;

[0042] Figure 4 for Figure 3 Schematic diagram of the area demarcation of the turning lane;

[0043] Figure 5 This is a schematic diagram of the range in which the vehicle obtains the front and side lane lines and the vehicle status in Example 1 of the present invention. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0047] See also Figure 1 and Figure 2 This embodiment provides a vehicle speed control method based on adaptive cruise control, which includes steps S1 to S8.

[0048] S1: Set the cruising speed of the vehicle, collect the location information of the vehicle in real time, and classify each lane of the road section where the vehicle is currently located into a straight lane or a turning lane according to the lane category. Analyze the category of the lane the vehicle is traveling in based on the location information of the vehicle. When the vehicle is traveling in the straight lane, execute S5.

[0049] In step S1, the state information of the side target of the vehicle can also be collected in real time. The setting interval of the cruising speed can be (30, 60) km / h.

[0050] In this embodiment, the front target state information includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range in front of the lane and the adjacent lane, as well as the type and position of the lane line. The side target state information includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range on the side of the lane and the adjacent lane, as well as the type and position of the lane line and the curb.

[0051] It should be noted that the types of lane lines can include dotted lines and solid lines. The types of curbs can include guardrails, green belts, shoulders, curbstones, etc. According to the type of curb and its position, the type of lane the vehicle is in can be identified. For example, when the right curb of the vehicle is identified as a guardrail and the left is a lane line, it can be determined that the lane the vehicle is in is a right turn lane.

[0052] See also Figure 3 , Figure 3 The vehicle is shown on a four-lane road section. According to the lane type, the four lanes on the road section can be divided into two straight lanes in the middle (LS , Lane straight), and two turning lanes at the edge (L T , Lane turn).

[0053] In some other embodiments, the vehicle can also be directly positioned through the Beidou satellite navigation system or GPS. After obtaining the positioning information of the vehicle, the current lane of the vehicle can be directly determined according to the satellite map. This technology is similar to the technology used in existing taxi-hailing software to determine the lane of the passenger or driver's vehicle, and will not be repeated here. For some lanes that can go straight and turn (turn left / turn right), you can first determine whether you need to turn or go straight at the next intersection based on the planned driving route of the vehicle. If you need to turn, then the lane is a turning lane; if you need to go straight, then the lane is a straight lane.

[0054] S2: When the vehicle is traveling in a turning lane, the turning lane is divided into a straight area and a turning area that are interconnected, and the area where the vehicle is located in the turning lane is analyzed based on the location information of the vehicle. When the vehicle is located in the straight area of ​​the turning lane, S5 is executed.

[0055] See also Figure 4 , Figure 4 The A area in the figure is the straight-through area of ​​the turning lane, and the B area is the turning area of ​​the turning lane. It should be noted that the so-called turning area does not mean that you need to turn as soon as you enter the area. Instead, in order to improve driving safety, a turning area is demarcated within a preset distance at one end before entering the intersection, and the vehicle starts turning only when it drives to the end of the turning area. Generally speaking, in road traffic, in order to prevent vehicles on the road from changing lanes at will before entering the intersection and affecting traffic safety, the different positions of a lane line are different. For example, some lane lines are solid lines 50 to 100 meters before entering the intersection, and dotted lines more than 100 meters away. Therefore, this embodiment can determine whether the corresponding position is in the turning area by identifying the virtual and real lane lines on both sides of a certain position on the lane. If the lane line is a dotted line, it means that you can change lanes here, and you can determine that the place is a straight-through area; if the lane line is a solid line, it means that you are about to enter the vicinity of the intersection, and you can determine that the place is a turning area. Of course, similar to the above technology, after determining the position of the vehicle on the satellite map, the regional attributes of the turning lane where the vehicle is located can be directly obtained.

[0056] S3: When the vehicle is located in a turning area on a turning lane, the vehicle is controlled to travel at a preset speed, and the vehicle is controlled to start turning at the end of the turning area, and then S4 is executed.

[0057] In this embodiment, the preset speed of the vehicle when turning is not higher than 30km / h. By identifying the turning area of ​​the turning lane as a basis, the vehicle's speed is actively controlled to be maintained at a safe threshold, thereby avoiding the risk of the traditional lane adaptive cruise system losing the target when the front vehicle turns, causing the vehicle to accelerate and collide with the vehicle in the opposite lane, thereby effectively improving the safety factor of vehicle assisted driving on the basis of the traditional lane adaptive cruise system.

[0058] S4: By analyzing the real-time turning angle of the front wheels of the vehicle, it is determined in real time whether the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane. When the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane, S5 is executed. When the vehicle has not completed the turn or has not entered the straight-ahead area of ​​the next lane, the process returns to S3.

[0059] In this embodiment, in S4, the driving state of the vehicle during the turning process can be judged by analyzing the relationship between the real-time turning angle of the front wheel of the vehicle and a preset angle value interval (a, b):

[0060] 1. When the real-time turning angle increases from a state less than the preset angle value a to a state greater than the preset angle value b, and maintains this state for more than a preset time period one, it is judged that the vehicle is in a turning state. In this link, considering that the vehicle cannot absolutely maintain zero degrees when driving straight, the real-time turning angle will inevitably change dynamically. However, the law of such changes can be summarized through experimental tests. The analysis and judgment here uses the two conditions of "real-time turning angle" and "state holding time". When both conditions are met, it is judged that the vehicle is in a turning state, thereby reducing the probability of misjudgment and making the vehicle speed control method more accurate.

[0061] 2. When the real-time turning angle decreases from a state greater than the preset angle value b to less than the preset angle value a, it is determined that the vehicle has completed the turn. In this link, according to the steering wheel control logic of the normal driving process, when just turning to the next lane, the real-time turning angle of the steering wheel gradually returns to zero from the original "maximum state", that is, the direction returns to the positive state. The analysis and judgment here uses the trigger point of "decreasing to less than the preset angle value a" to determine that the vehicle has completed the turn.

[0062] 3. When the real-time turning angle decreases from a state greater than the preset angle value b to a state less than the preset angle value a, and maintains this state for more than a preset time period two, it is judged that the vehicle has completed the turn and has entered the straight-ahead area of ​​the next lane. In this link, it is considered that the vehicle may have returned to the correct direction in advance, that is, the steering wheel has returned to the correct direction before leaving the current intersection, but if it accelerates to the cruising speed mentioned later at this time, there will be a high traffic risk. Therefore, a preset time period two with a similar principle to the above is also set in this analysis link. By adding this condition, only when the real-time turning angle is small enough and this state is maintained for more than a certain period of time, can it be judged that the vehicle has truly completed the "turn" and entered the straight-ahead area of ​​the next lane, that is, leaving the current intersection, and then the cruising speed process mentioned later can be carried out.

[0063] In addition, the parameters of the preset angle value range (a, b), preset time period one and preset time period two can be adaptively adjusted in combination with one or more of the road width, road congestion level, vehicle speed and turning angle (90° right angle, 180° U-turn).

[0064] In summary, step S4 sets the two prerequisites of "completing the turn" and "entering the straight-ahead area of ​​the next lane". Only when these two conditions are met at the same time can the vehicle be determined to be able to carry out traditional ACC cruise conditions, thereby further improving the safety and reliability of the vehicle speed control method.

[0065] S5: Real-time acquisition of the target state information ahead of the vehicle, and judging whether there is a target vehicle 1 that is the first vehicle ahead of the vehicle within a preset range 1 ahead of the current lane of the vehicle according to the target state information ahead. When the target vehicle 1 exists within the preset range 1, the speed of the target vehicle 1 is acquired in real time, and S6 is executed. When the target vehicle 1 does not exist within the preset range 1, S8 is executed.

[0066] In this embodiment, the position and motion state of the vehicles around the vehicle in their respective lanes can be obtained according to the front target state information and the side target state information. The front target state information and the side target state information can be collected by using the existing vehicle-mounted camera and millimeter wave radar fusion technology.

[0067] See also Figure 5 , Figure 5 R F Represents the viewing and detection range of the front camera and front millimeter-wave radar, R FThe corresponding framing and detection range of the side-view camera and the side millimeter-wave radar. In this embodiment, a front-view camera and a front-view millimeter-wave radar can be installed at the front end of the vehicle. The front-view camera collects image information in front of the vehicle, and uses image recognition technology to identify the target vehicle in front and the target farther in front of the adjacent lane. At the same time, the targets identified by the front millimeter-wave radar are integrated to determine the lane line in front of the vehicle and the vehicle status. At the same time, four side-view cameras and four side millimeter-wave radars that match each other can be set on both sides of the vehicle (near the four corners). Similarly, the target information in the adjacent lanes collected by the four side millimeter-wave radars can be integrated to determine the lane line on the side of the vehicle and the vehicle status.

[0068] In this embodiment, for the image feature recognition of the camera: first, the lane line features in the image can be identified and located through a deep learning algorithm, and marked with a frame, and then the features in the frame are further identified, and the lane line width, virtual and real line type, and data on the distance from the vehicle are marked; secondly, the image of the guide arrow in the lane in the image can also be identified through a deep learning algorithm, and the type features of left turn / left turn and straight / straight go / right turn / right turn and straight go as well as the distance from the vehicle are output.

[0069] In addition, for the identification of curbs and guardrails: the side millimeter-wave radar can be used to perform feature clustering on the differences in the reflected waveforms of the curb and guardrail features, and output the curb / guardrail features and the distance from the vehicle (with an emphasis on the lateral distance); secondly, the curb / guardrail and the distance from the vehicle can be identified through images captured by the side-view camera.

[0070] In this embodiment, a fusion algorithm can also be used: first, the lane line is used to determine whether the vehicle is traveling inside the lane line, and the lane in which the vehicle is traveling is determined by combining the curb / guardrail feature recognition and the distance from the vehicle. Secondly, the feature recognition results of the guide arrows in the lane also assist in determining whether the vehicle is traveling in a straight lane or a turning lane.

[0071] For the identification of turning areas: first, the lane line type can be used as an auxiliary judgment basis, and the solid lane line can be used as an auxiliary judgment basis. Secondly, the distance between the vehicle and the guide arrow mark in the lane it is traveling in is integrated and considered (this distance can be designed through calibration). Finally, the lateral distance between the curb and guardrail and the vehicle is less than the calibration value (in principle, this value is the lane width value, and the specific setting is determined by calibration based on the measured data), to assist in determining that the vehicle is in the edge lane. When it is determined that there is a curb and guardrail on the side of the lane where the vehicle is traveling, the lane line is realized, and there is a turning or straight turning mark in the lane and the distance from the mark is less than the calibration value, then the vehicle is judged to be within the turning area.

[0072] It should be added that the above solution can also realize the perception of close-range cut-in scenarios. For close-range cut-in: the side-view camera and side millimeter-wave radar of the vehicle can identify vehicles in adjacent lanes and output the distance / speed / acceleration and other parameters of the vehicle. Combined with the width of the lane in which the vehicle is traveling and the parameters of the vehicle's speed / direction / acceleration, the prediction calculation is performed. When the calculation result shows that the vehicle in the adjacent lane will collide with the vehicle or the distance is less than the set value, the vehicle will be controlled to slow down in advance; when the calculation result shows that there is no risk, the vehicle's driving state is maintained.

[0073] S6: According to the speed of the target vehicle 1, determine whether the speed of the target vehicle 1 is higher than the cruising speed of the vehicle. When the speed of the target vehicle 1 is not higher than the cruising speed of the vehicle, execute S7. When the speed of the target vehicle 1 is higher than the cruising speed of the vehicle, execute S8.

[0074] S7: Control the vehicle to maintain the same speed as the first vehicle in front of the vehicle, and control the vehicle to maintain a distance from the vehicle in front that is not less than a preset following distance.

[0075] In this embodiment, after step S7, step S9 may be further executed, i.e., determining whether the target vehicle 1 has driven out of the lane and there is no vehicle within the preset range 1 after the vehicle has driven out. If yes, step S8 may be executed. If no, the process may return to step S7. This is conducive to restoring the cruising speed and improving driving efficiency when there is no low-speed vehicle blocking the front of the vehicle.

[0076] S8: Control the vehicle to travel at the set cruising speed.

[0077] In this embodiment, after S7 and / or S8, step S10 may be further executed, i.e., determining whether there is a target vehicle 2 entering the lane in a preset range 2 of the adjacent lane, and the target vehicle 2 meets the following requirements: entering the preset range 1 of the lane at a speed lower than the current speed of the vehicle and becoming the first vehicle in front of the vehicle after entering. When the target vehicle 2 exists in the adjacent lane, S7 may be executed. When the target vehicle 2 does not exist in the adjacent lane, the process may return to S5. Thus, when there is an external low-speed vehicle cutting in or overtaking in the adjacent lane in front of the vehicle, the vehicle speed may be adjusted to avoid the risk of collision with the vehicle in front.

[0078] Example 2

[0079] This embodiment provides a vehicle speed control system based on adaptive cruise control, which includes: a front acquisition module, a side acquisition module, a fusion module, a perception module and a controller.

[0080] The front acquisition module may include a front camera and a front millimeter-wave radar. The front camera is used to collect image 1 within a preset range in front of the lane and the adjacent lane. The targets in image 1 include: vehicles and lane lines within a preset range in front of the lane and the adjacent lane, and may also include: guide arrows in the lane. The type characteristics of the guide arrows include: left turn, left turn and go straight, go straight, right turn, right turn and go straight. . The front target status information includes: the movement speed, direction, and distance between the vehicles and the vehicle within the preset range in front of the lane and the adjacent lane, and the type and position of the lane line.

[0081] The side acquisition module may include a plurality of mutually matching side-view cameras and side millimeter-wave radars. The plurality of cameras are respectively arranged on both sides of the vehicle with the corresponding side millimeter-wave radars. The side-view camera located on the same side of the vehicle is used to collect image 2 within a preset range on the side of the lane and the adjacent lane. The targets in image 2 include: vehicles, lane lines and curbs within the preset range on the side of the lane and the adjacent lane. The side target status information includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range on the side of the lane and the adjacent lane, as well as the type and position of lane lines and curbs.

[0082] In this embodiment, four side-view cameras and side millimeter-wave radars can be provided, and they correspond one to one, and can be installed at the four corners of the vehicle respectively. The front-view camera and the front millimeter-wave radar can be arranged at the center of the front end of the vehicle. The installation point of each camera and the corresponding millimeter-wave radar can be the same, and the camera's viewing range can also correspond to the radar's detection range.

[0083] The fusion module is used to identify the targets in image one and image two through image recognition technology, and use the fusion algorithm to fuse the targets in image one and image two into the detection data of the corresponding millimeter-wave radar, and then identify the target status information in image one and each image two, that is, the front target status information and the side target status information.

[0084] The perception module is used to obtain the position and motion status of surrounding vehicles in their respective lanes based on the state information of the front target and the state information of the side target.

[0085] The controller is used to control the speed of the vehicle according to the position and movement status of the vehicle and surrounding vehicles in their respective lanes.

[0086] The controller may apply the vehicle speed control method based on adaptive cruise control in Example 1 to control the vehicle speed.

[0087] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0088] The above-mentioned embodiments only express several implementation modes of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A vehicle speed control method based on adaptive cruise control, characterized in that: It includes the following steps: S1: Set the cruising speed of the vehicle, collect the location information of the vehicle in real time, and classify each lane of the road section where the vehicle is currently located into a straight lane or a turning lane according to the lane category; analyze the category of the lane where the vehicle is traveling based on the location information of the vehicle; When the vehicle is traveling in the straight lane, execute S5; S2: When the vehicle is traveling in a turning lane, the turning lane is divided into a straight area and a turning area that are interconnected, and the area where the vehicle is located in the turning lane is analyzed based on the location information of the vehicle; When the vehicle is in the straight-ahead area of ​​the turning lane, execute S5; S3: when the vehicle is located in a turning area on a turning lane, controlling the vehicle to travel at a preset speed, and controlling the vehicle to start turning at the end of the turning area, and then executing S4; S4: By analyzing the real-time turning angle of the front wheel of the vehicle, it is determined in real time whether the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane; when the vehicle has completed the turn and entered the straight-ahead area of ​​the next lane, S5 is executed; when the vehicle has not completed the turn or has not entered the straight-ahead area of ​​the next lane, the process returns to S3; S5: collecting the target state information in front of the vehicle in real time, and judging whether there is a target vehicle 1 which is the first vehicle in front of the vehicle in a preset range 1 in front of the current lane of the vehicle according to the target state information in front; when the target vehicle 1 is in the preset range 1, obtaining the speed of the target vehicle 1 in real time, and executing S6; when the target vehicle 1 does not exist in the preset range 1, executing S8; S6: judging whether the speed of the target vehicle 1 is higher than the cruising speed of the vehicle according to the speed of the target vehicle 1; when the speed of the target vehicle 1 is not higher than the cruising speed of the vehicle, executing S7; when the speed of the target vehicle 1 is higher than the cruising speed of the vehicle, executing S8; S7: Control the vehicle to keep the same speed as the first vehicle in front of the vehicle, and control the vehicle to keep the distance between the vehicle and the front vehicle not less than a preset following distance; S8: Control the vehicle to travel at the set cruising speed.

2. The vehicle speed control method based on adaptive cruise control according to claim 1, characterized in that: In S1, the status information of the side targets of the vehicle is also collected in real time; Among them, the front target status information includes: the movement speed, direction, distance between the vehicle and the vehicle within the preset range in front of the lane and the adjacent lane, and the type and position of the lane line; the side target status information includes: the movement speed, direction, distance between the vehicle and the vehicle within the preset range on the side of the lane and the adjacent lane, and the type and position of the lane line and curb.

3. The vehicle speed control method based on adaptive cruise control according to claim 2, characterized in that: According to the front target state information and the side target state information, the positions and motion states of the vehicles around the vehicle in their respective lanes are obtained.

4. The vehicle speed control method based on adaptive cruise control according to claim 1, characterized in that: The setting range of the cruising speed of the vehicle is (30, 60) km / h. In S3, the preset speed of the vehicle when turning is not higher than 30 km / h.

5. The vehicle speed control method based on adaptive cruise control according to claim 1, characterized in that: In S4, by analyzing the relationship between the real-time turning angle of the front wheel of the vehicle and a preset angle value interval (a, b), the driving state of the vehicle during the turning process is judged:

1. When the real-time turning angle increases from a state less than a preset angle value a to a state greater than a preset angle value b, and maintains this state for more than a preset time period a, it is determined that the vehicle is in a turning state; 2. When the real-time turning angle decreases from a state greater than a preset angle value b to a state less than a preset angle value a, it is determined that the vehicle has completed the turn; 3. When the real-time turning angle decreases from a state greater than the preset angle value b to a state less than the preset angle value a, and maintains this state for more than a preset time period 2, it is determined that the vehicle has completed the turn and has entered the next lane straight driving area.

6. The vehicle speed control method based on adaptive cruise control according to claim 1, characterized in that: After S7, also execute: S9: Determine whether the target vehicle 1 drives out of the lane and there is no vehicle within the preset range 1 after the target vehicle drives out; If yes, execute S8; if no, return to S7.

7. The vehicle speed control method based on adaptive cruise control according to claim 1, characterized in that: After S7 and / or S8, the following is also executed: S10: Determine whether there is a target vehicle 2 entering the lane within a preset range 2 of the adjacent lane, and the target vehicle 2 meets the following requirements: entering the preset range 1 of the lane at a speed lower than the current speed of the vehicle and becoming the first vehicle in front of the vehicle after entering; when the target vehicle 2 exists in the adjacent lane, execute S7; when the target vehicle 2 does not exist in the adjacent lane, return to S5.

8. A vehicle speed control system based on adaptive cruise control, characterized in that: It includes: The front acquisition module includes a front-view camera and a front millimeter-wave radar; The front-view camera is used to collect images within a preset range in front of the lane and the adjacent lane; The targets in the first image include: vehicles and lane lines within a preset range in front of the lane and adjacent lanes; the front target state information in the first image includes: the moving speed, direction, and distance between the vehicles and the vehicle within a preset range in front of the lane and adjacent lanes, and the type and position of the lane lines; A side acquisition module, comprising a plurality of mutually matched side view cameras and side millimeter wave radars; the plurality of cameras are respectively arranged on both sides of the vehicle with the corresponding side millimeter wave radars; the side view camera located on the same side of the vehicle is used to acquire a second image within a preset range of the side of the lane and the adjacent lane; the targets in the second image include: vehicles, lane lines and curbs within the preset range of the side of the lane and the adjacent lane; the side target status information in the second image includes: the movement speed, direction, and distance between the vehicle and the vehicle within the preset range of the side of the lane and the adjacent lane, as well as the type and position of the lane lines and curbs; A fusion module, which is used to identify the targets in the image one and the image two by using an image recognition technology, and to fuse the targets in the image one and the image two into the detection data of the corresponding millimeter-wave radar by using a fusion algorithm, thereby respectively identifying the target state information in the image one and each of the images two, that is, the front target state information and the side target state information; A perception module, which is used to obtain the position and motion status of surrounding vehicles in their respective lanes according to the front target state information and the side target state information; and A controller for controlling the speed of the vehicle according to the position and motion state of the vehicle and surrounding vehicles in their respective lanes; Wherein, the controller controls the speed of the vehicle using the vehicle speed control method based on adaptive cruise as described in any one of claims 1 to 7.

9. The vehicle speed control system based on adaptive cruise control according to claim 8, characterized in that: There are at least four side-view cameras and side millimeter-wave radars, which correspond to each other one by one and are installed at the four corners of the vehicle respectively.

10. The vehicle speed control system based on adaptive cruise control according to claim 8, characterized in that: The target in the image 1 also includes: a guide arrow in the lane; the type characteristics of the guide arrow include: left turn, left turn and go straight, go straight, right turn, right turn and go straight.

Images