An adaptive cruise control method and system

Abstract

The application provides a kind of adaptive cruise control method, it includes: step S10, real-time obtains the current vehicle speed of the vehicle and front vehicle information;Step S11, according to the current vehicle speed of the vehicle and front vehicle information, it is judged to obtain the following state desired by the vehicle at current time;Step S12, according to the current vehicle speed of the vehicle and front vehicle information, it is calculated to obtain the confidence degree of the transition of the following state;Step S13, the confidence degree calculated is compared with the confidence degree threshold value preset, if the confidence degree is higher than the confidence degree threshold value, then the following state of the vehicle is switched to the following state desired by the vehicle at current time;Otherwise, maintain the previous following state of the vehicle.The application also provides a corresponding system.Implementation of the application can make the vehicle realize smooth switching between various following states, to achieve a balance between the safety and comfort of driving, improve the driving experience, and the scheme is easy to implement.

Description

Technical Field

[0001] This invention relates to the field of adaptive cruise control technology for vehicles, and in particular to an adaptive cruise control method and system. Background Technology

[0002] With the development of autonomous driving technology, more and more mid-to-high-end models now have varying degrees of autonomous driving capabilities, among which adaptive cruise control is the most frequently used function.

[0003] While adaptive cruise control effectively reduces driver workload on highways, its performance in urban areas falls short. For most people, commuting primarily occurs in city driving, making existing adaptive cruise control insufficient for most drivers' needs. The biggest challenge in urban driving is the heavy traffic and the unpredictable and sudden actions of other vehicles. Adaptive cruise control needs to adjust the vehicle's speed in real-time to maintain a safe distance from the vehicle ahead while also providing sufficient comfort. Frequent switching of cruise control modes, especially at low speeds, often results in a poor following experience. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an adaptive cruise control method and system that enables the vehicle to smoothly switch between various following states, so as to achieve a balance between driving safety and comfort and improve the driving experience.

[0005] To address the aforementioned technical problems, as one aspect of the present invention, an adaptive cruise control method is provided, comprising the following steps:

[0006] Step S10: Obtain the current speed of the vehicle and the information of the vehicle in front in real time. The information of the vehicle in front includes: whether there is a vehicle in front, the speed of the vehicle in front, and the distance between the vehicle and the vehicle in front.

[0007] Step S11: Based on the current speed of the vehicle and the information of the vehicle in front, determine the desired following state of the vehicle at the current moment.

[0008] Step S12: Calculate the confidence level of the current car-following state transition based on the vehicle's current speed and the information of the vehicle in front.

[0009] Step S13: Compare the calculated confidence level with a preset confidence threshold. If the confidence level is higher than the confidence threshold, switch the following state of the vehicle to the following state desired by the vehicle at the current moment; otherwise, maintain the previous following state of the vehicle.

[0010] Step S11 further includes:

[0011] If there are vehicles ahead, determine the safe distance between the vehicle ahead and your vehicle based on the speed of the vehicle ahead.

[0012] Based on the vehicle's current speed, information about vehicles ahead, and the safe distance between the vehicle ahead and the vehicle in front, the system is matched with several pre-determined following states. The matched following state is then taken as the vehicle's desired following state at the current moment. These various following states include:

[0013] No cars ahead;

[0014] The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance.

[0015] The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance;

[0016] The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance.

[0017] The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and

[0018] The vehicle in front is stationary.

[0019] The step of determining the safe distance between the vehicle in front and the vehicle itself based on the speed of the vehicle in front specifically involves:

[0020] When the vehicle in front is stationary, a predetermined safe distance value is used as the safe distance from the vehicle in front.

[0021] When the vehicle in front moves, the initial safe following distance S_safe is calculated according to the following formula. The initial safe following distance is compared with a preset minimum value S_min, and the smaller of the two is determined as the safe following distance of the vehicle in front:

[0022] S_safe = k * V_obs;

[0023] Where V_obs is the speed of the vehicle in front, and k is an adjustable parameter.

[0024] Step S12 further includes:

[0025] When the desired car-following state is that there are no vehicles ahead, the confidence level at which the car-following state transitions is determined as the first confidence level value.

[0026] When the expected following state is another following state, the confidence level p of the current following state transition is calculated according to the following formula:

[0027] p=exp(-sigma*((norm_delta_v) 2+(norm_delta_s) 2 )

[0028] norm_delta_v=delta_v / delta_v_threshold

[0029] norm_delta_s=delta_s / delta_s_threshold

[0030] Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is the preset first threshold, delta_s_threshold is the preset second threshold, sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

[0031] Step S13 further includes:

[0032] When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows:

[0033] When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed.

[0034] When the speed of the vehicle in front is greater than that of your vehicle and the distance between the vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping;

[0035] When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit.

[0036] When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front.

[0037] When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, and set the target speed to 80% of the speed of the vehicle in front.

[0038] When the vehicle in front is stationary, control this vehicle to slow down and stop.

[0039] Accordingly, as another aspect of the present invention, an adaptive cruise control system is also provided, comprising:

[0040] The information collection unit is used to obtain the current speed of the vehicle and the information of the vehicles ahead in real time. The information of the vehicles ahead includes: whether there is a vehicle ahead, the speed of the vehicle ahead, and the distance between the vehicle ahead and the vehicle.

[0041] The expected car-following state acquisition unit is used to determine and obtain the expected car-following state of the vehicle at the current moment based on the current speed of the vehicle and the information of the vehicle in front.

[0042] The confidence level acquisition unit is used to calculate the confidence level of the current car-following state transition based on the current vehicle speed and the information of the vehicle in front.

[0043] The switching processing unit is used to compare the calculated confidence level with a preset confidence level threshold. If the confidence level is higher than the confidence level threshold, the following state of the vehicle is switched to the following state that the vehicle expects at the current moment; otherwise, the previous following state of the vehicle is maintained.

[0044] The desired car-following state acquisition unit further includes:

[0045] The safe distance determination unit is used to determine the safe distance between the vehicle in front and the vehicle itself based on the speed of the vehicle in front when there is a vehicle in front.

[0046] The matching processing unit is used to match the vehicle's current speed, information about the vehicle ahead, and the safe distance between the vehicle ahead and the vehicle with a variety of pre-determined following states, and to take the matched following state as the following state that the vehicle expects at the current moment. The various following states include:

[0047] No cars ahead;

[0048] The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance.

[0049] The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance;

[0050] The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance.

[0051] The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and

[0052] The vehicle in front is stationary.

[0053] The safe distance determination unit includes:

[0054] The first determining unit is used to determine a predetermined safe distance value as the safe distance between the vehicle in front and the vehicle in front when the vehicle in front is stationary.

[0055] The second determining unit is used to calculate the initial safe following distance S_safe of the preceding vehicle according to the following formula when the preceding vehicle is moving, compare the initial safe following distance with a preset minimum value S_min, and determine the smaller of the two as the safe following distance of the preceding vehicle:

[0056] S_safe = k * V_obs;

[0057] Where V_obs is the speed of the vehicle in front, and k is an adjustable parameter.

[0058] The confidence level acquisition unit further includes:

[0059] The first obtaining unit is used to determine the confidence level of the current car-following state transition as the first confidence level value when the desired car-following state is no vehicle ahead.

[0060] The second acquisition unit is used to calculate the confidence level p of the current car-following state transition according to the following formula when the desired car-following state is another car-following state:

[0061] p=exp(-sigma*((norm_delta_v) 2 +(norm_delta_s) 2 )

[0062] norm_delta_v=delta_v / delta_v_threshold

[0063] norm_delta_s=delta_s / delta_s_threshold

[0064] Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is the preset first threshold, delta_s_threshold is the preset second threshold, sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

[0065] The switching processing unit is further configured to:

[0066] When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows:

[0067] When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed.

[0068] When the speed of the vehicle in front is greater than that of your vehicle and the distance between the vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping;

[0069] When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit.

[0070] When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front.

[0071] When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, and set the target speed to 80% of the speed of the vehicle in front.

[0072] When the vehicle in front is stationary, control this vehicle to slow down and stop.

[0073] Implementing the embodiments of the present invention has the following beneficial effects:

[0074] This invention provides an adaptive cruise control method and system that subdivides the following process on urban roads into multiple following states and implements a state machine to manage these multiple following states. In this invention, based on information such as the current vehicle speed, the speed of the vehicle in front, and the distance between vehicles, the desired following state for the next moment can be determined. If the calculated state transition confidence exceeds a preset confidence threshold, a transition from the current following state to the desired following state is allowed; otherwise, the current following state is maintained. This process smoothly transitions between these six following states. Implementing this invention allows the vehicle to smoothly switch between various following states, achieving a balance between driving safety and comfort, and improving the driving experience.

[0075] Furthermore, in this invention, a corresponding car-following strategy is designed for each car-following state. Since the problem domain to be solved by each car-following strategy is narrowed, the design difficulty of the car-following strategy can be reduced, as can the model mismatch risk and optimization difficulty faced by the car-following strategy. This makes the solution of this invention easy to implement and low in cost. Attached Figure Description

[0076] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.

[0077] Figure 1 This is a schematic diagram of the main flow of an embodiment of the adaptive cruise control method provided by the present invention;

[0078] Figure 2 This is a schematic diagram of a structure of an embodiment of an adaptive cruise control system provided by the present invention;

[0079] Figure 3 for Figure 2 A schematic diagram of the structure of the unit that obtains the expected catapult state;

[0080] Figure 4 for Figure 3 Schematic diagram of the structure of the safe distance determination unit;

[0081] Figure 5 for Figure 2 A schematic diagram of the structure of the unit that obtains medium confidence. Detailed Implementation

[0082] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings.

[0083] like Figure 1 The diagram shows a main flowchart of an embodiment of an adaptive cruise control method provided by the present invention; in this embodiment, the adaptive cruise control method includes at least the following steps:

[0084] Step S10: Obtain the current speed of the vehicle and the information of the vehicle in front in real time. The information of the vehicle in front includes: whether there is a vehicle in front, the speed of the vehicle in front, and the distance between the vehicle and the vehicle in front.

[0085] Specifically, the vehicle speed can be obtained through the vehicle's built-in speed sensor, and information about vehicles ahead can be obtained by monitoring and analyzing the data through radar or camera equipment.

[0086] Step S11: Based on the current speed of the vehicle and the information of the vehicle in front, determine the desired following state of the vehicle at the current moment.

[0087] In one example of the present invention, step S11 further includes:

[0088] Step S110: If there is a vehicle ahead, determine the safe distance between the vehicle ahead and the vehicle ahead based on the speed of the vehicle ahead.

[0089] Specifically, the step of determining the safe distance between the vehicle in front and the vehicle itself based on the speed of the vehicle in front is as follows:

[0090] When the vehicle in front is stationary, a predetermined safe distance value (e.g., 5 meters) is used as the safe distance from the vehicle in front.

[0091] When the vehicle in front moves, the initial safe following distance S_safe is calculated according to the following formula. The initial safe following distance is compared with a preset minimum value S_min, and the smaller of the two is determined as the safe following distance of the vehicle in front:

[0092] S_safe = k * V_obs;

[0093] Where V_obs is the speed of the vehicle in front, k is an adjustable parameter, and in one example, K can be 2, and the minimum value S_min can be 5 meters.

[0094] Step S111: Based on the vehicle's current speed, information about the vehicle ahead, and the safe distance between the vehicle ahead and the vehicle in front, perform matching processing with a variety of pre-determined following states, and take the matched following state as the following state desired by the vehicle at the current moment. The various following states include:

[0095] No cars ahead;

[0096] The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance.

[0097] The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance;

[0098] The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance.

[0099] The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and

[0100] The vehicle in front is stationary.

[0101] It is understood that the following process on urban roads in this invention is subdivided into the above six types, which can basically cover all following states.

[0102] Step S12: Calculate the confidence level of the current car-following state transition based on the vehicle's current speed and the information of the vehicle in front.

[0103] In a specific example, step S12 further includes:

[0104] When the desired car-following state is that there are no vehicles ahead, the confidence level at which the car-following state transitions is determined as the first confidence level value (e.g., a value of 1).

[0105] When the expected following state is another following state, the confidence level p of the current following state transition is calculated according to the following formula:

[0106] p=exp(-sigma*((norm_delta_v) 2 +(norm_delta_s) 2 )

[0107] norm_delta_v=delta_v / delta_v_threshold

[0108] norm_delta_s=delta_s / delta_s_threshold

[0109] Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is a preset first threshold (for example, it can be 2.0), delta_s_threshold is a preset second threshold (for example, it can be 3.0), sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

[0110] Step S13: Compare the calculated confidence level with a preset confidence threshold (e.g., a value of 0.5). If the confidence level is higher than the confidence threshold, switch the following state of the vehicle to the following state desired by the vehicle at the current moment; otherwise, maintain the previous following state of the vehicle.

[0111] In a specific example, step S13 further includes:

[0112] When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows:

[0113] When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed.

[0114] When the speed of the vehicle in front is greater than that of your vehicle and the distance between the vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping;

[0115] When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit.

[0116] When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front.

[0117] When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, and set the target speed to 80% of the speed of the vehicle in front.

[0118] When the vehicle in front is stationary, control this vehicle to slow down and stop.

[0119] It is understood that by using the method of the present invention, the following process involved in urban roads can be subdivided, and a smoothing mechanism for the transition of following state can be achieved by comparing confidence levels.

[0120] Meanwhile, the values ​​of each parameter involved in the above embodiments of the present invention are merely examples. These data can be calibrated in advance, and different parameter values ​​can achieve different sensitivities.

[0121] like Figure 2 The diagram shown illustrates a structural schematic of an embodiment of an adaptive cruise control system provided by the present invention. (In conjunction with...) Figures 3 to 5 As shown, in this embodiment, the adaptive cruise control system 1 includes at least:

[0122] The information collection unit 10 is used to obtain the current speed of the vehicle and the information of the vehicle in front in real time. The information of the vehicle in front includes: whether there is a vehicle in front, the speed of the vehicle in front, and the distance between the vehicle and the vehicle.

[0123] The expected following state acquisition unit 11 is used to determine and obtain the expected following state of the vehicle at the current moment based on the current speed of the vehicle and the information of the vehicle in front.

[0124] The confidence level acquisition unit 12 is used to calculate the confidence level of the current car-following state transition based on the current vehicle speed and the information of the vehicle in front.

[0125] The switching processing unit 13 is used to compare the calculated confidence level with a preset confidence level threshold. If the confidence level is higher than the confidence level threshold, the following state of the vehicle is switched to the following state that the vehicle expects at the current moment; otherwise, the previous following state of the vehicle is maintained.

[0126] Specifically, the expected car-following state acquisition unit 11 further includes:

[0127] The safe distance determination unit 110 is used to determine the safe distance between the vehicle in front and the vehicle itself based on the speed of the vehicle in front when there is a vehicle in front.

[0128] Matching processing unit 111 is used to match the current vehicle speed, information of the vehicle in front, and the safe distance between the vehicle in front and the vehicle with a variety of pre-determined following states, and to take the matched following state as the following state desired by the vehicle at the current moment. The various following states include:

[0129] No cars ahead;

[0130] The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance.

[0131] The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance;

[0132] The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance.

[0133] The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and

[0134] The vehicle in front is stationary.

[0135] In one example, the safe distance determination unit 110 includes:

[0136] The first determining unit 1100 is used to determine a predetermined safe distance value as the safe distance between the vehicle in front and the vehicle in front when the vehicle in front is stationary.

[0137] The second determining unit 1101 is used to calculate the initial safe distance S_safe of the vehicle in front according to the following formula when the vehicle in front is moving, compare the initial safe distance with a preset minimum value S_min, and determine the smaller of the two as the safe distance of the vehicle in front:

[0138] S_safe = k * V_obs;

[0139] Where V_obs is the speed of the vehicle in front, and k is an adjustable parameter.

[0140] More specifically, the confidence level obtaining unit 12 further includes:

[0141] The first obtaining unit 120 is used to determine the confidence level of the current car-following state transition as the first confidence level value when the desired car-following state is no vehicle ahead.

[0142] The second acquisition unit 121 is used to calculate the confidence level p of the current car-following state transition according to the following formula when the desired car-following state is another car-following state:

[0143] p=exp(-sigma*((norm_delta_v) 2 +(norm_delta_s) 2 )

[0144] norm_delta_v=delta_v / delta_v_threshold

[0145] norm_delta_s=delta_s / delta_s_threshold

[0146] Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is the preset first threshold, delta_s_threshold is the preset second threshold, sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

[0147] More specifically, the switching processing unit 13 is further configured to:

[0148] When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows:

[0149] When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed.

[0150] When the speed of the vehicle in front is greater than that of your vehicle and the distance between the vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping;

[0151] When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit.

[0152] When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front.

[0153] When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, and set the target speed to 80% of the speed of the vehicle in front.

[0154] When the vehicle in front is stationary, control this vehicle to slow down and stop.

[0155] For more details, please refer to and combine with the above. Figure 1 The description of that will not be repeated here.

[0156] Implementing the embodiments of the present invention has the following beneficial effects:

[0157] This invention provides an adaptive cruise control method and system that subdivides the following process on urban roads into multiple following states and implements a state machine to manage these multiple following states. In this invention, based on information such as the current vehicle speed, the speed of the vehicle in front, and the distance between vehicles, the desired following state for the next moment can be determined. If the calculated state transition confidence exceeds a preset confidence threshold, a transition from the current following state to the desired following state is allowed; otherwise, the current following state is maintained. This process smoothly transitions between these six following states. Implementing this invention allows the vehicle to smoothly switch between various following states, achieving a balance between driving safety and comfort, and improving the driving experience.

[0158] Furthermore, in this invention, a corresponding car-following strategy is designed for each car-following state. Since the problem domain to be solved by each car-following strategy is narrowed, the design difficulty of the car-following strategy is reduced, as is the risk of model mismatch and the optimization difficulty. This makes the solution of this invention easy to implement and low in cost.

[0159] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, apparatus, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0160] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0161] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.

Claims

1. An adaptive cruise control method, characterized in that, Includes the following steps: Step S10: Obtain the current speed of the vehicle and the information of the vehicle in front in real time. The information of the vehicle in front includes: whether there is a vehicle in front, the speed of the vehicle in front, and the distance between the vehicle and the vehicle in front. Step S11: Based on the current speed of the vehicle and the information of the vehicle in front, determine the desired following state of the vehicle at the current moment. Step S12: Calculate the confidence level of the current car-following state transition based on the vehicle's current speed and the information of the vehicle in front. Step S13: Compare the calculated confidence level with a preset confidence threshold. If the confidence level is higher than the confidence threshold, switch the following state of the vehicle to the following state that the vehicle expects at the current moment. Otherwise, maintain the previous following position of this vehicle; Step S12 further includes: When the desired car-following state is that there are no vehicles ahead, the confidence level at which the car-following state transitions is determined as the first confidence level value. When the expected following state is another following state, the confidence level p of the current following state transition is calculated according to the following formula: p=exp(-sigma ((norm_delta_v) 2 +(norm_delta_s) 2 ) norm_delta_v=delta_v / delta_v_threshold norm_delta_s=delta_s / delta_s_threshold Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is the preset first threshold, delta_s_threshold is the preset second threshold, sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

2. The method as described in claim 1, characterized in that, Step S11 further includes: If there are vehicles ahead, determine the safe distance between the vehicle ahead and your vehicle based on the speed of the vehicle ahead. Based on the vehicle's current speed, information about vehicles ahead, and the safe distance between the vehicle ahead and the vehicle in front, the system is matched with several pre-determined following states. The matched following state is then taken as the vehicle's desired following state at the current moment. These various following states include: No cars ahead; The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance. The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance; The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance. The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and The vehicle in front is stationary.

3. The method as described in claim 2, characterized in that, The specific steps for determining the safe distance between the vehicle in front and the vehicle ahead based on the speed of the vehicle in front are as follows: When the vehicle in front is stationary, a predetermined safe distance value is used as the safe distance from the vehicle in front. When the vehicle in front moves, the initial safe following distance S_safe is calculated according to the following formula. The initial safe following distance is compared with a preset minimum safe distance, and the smaller of the two is determined as the safe following distance of the vehicle in front: S_safe=k V_obs; Where V_obs is the speed of the vehicle in front, and k is an adjustable parameter.

4. The method according to any one of claims 1 to 3, characterized in that, Step S13 further includes: When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows: When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed. When the speed of the vehicle in front is greater than that of your vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping; When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit. When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front. When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, with the target speed set at 80% of the speed of the vehicle in front; When the vehicle in front is stationary, control this vehicle to slow down and stop.

5. An adaptive cruise control system, characterized in that, include: The information collection unit is used to obtain the current speed of the vehicle and the information of the vehicles ahead in real time. The information of the vehicles ahead includes: whether there is a vehicle ahead, the speed of the vehicle ahead, and the distance between the vehicle ahead and the vehicle. The desired following state acquisition unit is used to determine and obtain the desired following state of the vehicle at the current moment based on the current speed of the vehicle and the information of the vehicle in front. The confidence level acquisition unit is used to calculate the confidence level of the current car-following state transition based on the current speed of the vehicle and the information of the vehicle in front. The switching processing unit is used to compare the calculated confidence level with a preset confidence level threshold. If the confidence level is higher than the confidence level threshold, the following state of the vehicle is switched to the following state that the vehicle expects at the current moment. Otherwise, maintain the previous following position of this vehicle; The confidence level acquisition unit further includes: The first obtaining unit is used to determine the confidence level of the current car-following state transition as the first confidence level value when the desired car-following state is no vehicle ahead. The second acquisition unit is used to calculate the confidence level p of the current car-following state transition according to the following formula when the desired car-following state is another car-following state: p=exp(-sigma ((norm_delta_v) 2 +(norm_delta_s) 2 ) norm_delta_v=delta_v / delta_v_threshold norm_delta_s=delta_s / delta_s_threshold Where delta_v is the speed difference between the current vehicle speed and the speed of the vehicle in front, delta_s is the difference between the distance between the vehicles in front and behind and the safe distance S_safe; delta_v_threshold is the preset first threshold, delta_s_threshold is the preset second threshold, sigma is an adjustable parameter; exp() is an exponential function with the natural constant e as the base.

6. The system as described in claim 5, characterized in that, The desired car-following state acquisition unit further includes: The safe distance determination unit is used to determine the safe distance between the vehicle in front and the vehicle itself based on the speed of the vehicle in front when there is a vehicle in front. The matching processing unit is used to match the vehicle's current speed, information about the vehicle ahead, and the safe distance between the vehicle ahead and the vehicle with a variety of pre-determined following states, and to take the matched following state as the following state that the vehicle expects at the current moment. The various following states include: No cars ahead; The vehicle ahead is traveling faster than your vehicle and the following distance is greater than or equal to the safe following distance. The vehicle in front is traveling faster than your vehicle and the following distance is less than the safe following distance; The vehicle ahead is traveling at a speed less than or equal to your vehicle's speed, and the following distance is greater than or equal to a safe following distance. The vehicle ahead is traveling at a speed less than or equal to yours, and the following distance is less than a safe following distance; and The vehicle in front is stationary.

7. The system as described in claim 6, characterized in that, The safe distance determination unit includes: The first determining unit is used to determine a predetermined safe distance value as the safe distance between the vehicle in front and the vehicle in front when the vehicle in front is stationary. The second determining unit is used to calculate the initial safe distance S_safe of the preceding vehicle according to the following formula when the preceding vehicle is moving, compare the initial safe distance with a preset minimum safe distance, and determine the smaller of the two as the safe distance of the preceding vehicle: S_safe=k V_obs; Where V_obs is the speed of the vehicle in front, and k is an adjustable parameter.

8. The system according to any one of claims 5 to 7, characterized in that, The switching processing unit is further used for: When switching the vehicle's car-following mode to the desired car-following mode at the current moment, the vehicle is controlled to perform adaptive cruise control using the strategy corresponding to the desired car-following mode. The specific strategy corresponding to the car-following mode is as follows: When there are no vehicles ahead, control the vehicle to maintain a constant speed in the lane, using the current road speed limit as the target speed. When the speed of the vehicle in front is greater than that of your vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control your vehicle to maintain the original speed and implement lane keeping; When the speed of the vehicle in front is greater than that of this vehicle and the distance between the two vehicles is less than the safe distance, control this vehicle to decelerate. The target speed is the smaller of 80% of the speed of the vehicle in front and the local speed limit. When the speed of the vehicle in front is less than the speed of this vehicle and the distance between the two vehicles is greater than or equal to the safe distance, control this vehicle to decelerate, and the target speed is the speed of the vehicle in front. When the speed of the vehicle in front is less than or equal to that of this vehicle and the distance between them is less than the safe distance, control this vehicle to decelerate, with the target speed set at 80% of the speed of the vehicle in front; When the vehicle in front is stationary, control this vehicle to slow down and stop.

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