Vehicle cruise control method and device, electronic equipment and storage medium

Abstract

The application discloses a vehicle cruise control method and device, an electronic device and a storage medium, wherein the method comprises the following steps: acquiring a front vehicle distance and / or a vehicle speed of a host vehicle; and controlling a cruise acceleration of the host vehicle based on the front vehicle distance and / or the vehicle speed of the host vehicle. Thus, the demand of ACC algorithm on cruise control under various working conditions can be met.

Description

Technical Field

[0001] This application belongs to the field of computer data processing technology, specifically relating to a vehicle cruise control method and device, electronic equipment and storage medium. Background Technology

[0002] Advanced Driver Assistance Systems (ADAS) have become a hot topic in the autonomous driving industry. Among them, Adaptive Cruise Control (ACC), which takes into account factors such as following distance, following time, and fuel economy, has been developed. As a basic and most widely used function in ADAS, it controls the longitudinal movement of the vehicle by controlling the acceleration of the vehicle chassis under permissible conditions, replacing the driver's continuous operation of the accelerator or brake pedals and effectively reducing the driver's burden. However, the current ACC system control algorithm is simple and cannot meet the cruise control needs under various conditions.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of this application and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] The purpose of this application is to provide a vehicle cruise control method that solves the problem that the current ACC system control algorithm cannot meet the cruise control requirements.

[0005] To achieve the above objectives, this application provides a vehicle cruise control method, the method comprising:

[0006] Get the distance to the vehicle in front and / or the speed of this vehicle;

[0007] Based on the distance to the vehicle ahead and / or the vehicle speed, control the vehicle's cruise acceleration.

[0008] In one embodiment, when the distance to the vehicle ahead is greater than a set distance threshold, the method specifically includes:

[0009] Discretize the vehicle speed difference between the expected vehicle speed at the current step length and the set vehicle speed at the previous step length to determine the set vehicle speed at the current step length;

[0010] Based on the vehicle speed and the set speed of the current step length, determine the first control quantity;

[0011] The initial acceleration limit is corrected using the first control quantity to determine the cruise acceleration at the current step size.

[0012] In one embodiment, when the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is greater than a set speed threshold, the method specifically includes:

[0013] Discretize the vehicle speed difference between the expected vehicle speed at the current step length and the set vehicle speed at the previous step length to determine the set vehicle speed at the current step length;

[0014] Based on the vehicle speed and the set speed of the current step length, determine the first control quantity;

[0015] Based on the current expected following distance and the distance to the vehicle in front, determine the second control variable;

[0016] The initial acceleration limit is corrected using the first and second control variables to determine the cruise acceleration at the current step size.

[0017] In one embodiment, when the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is less than or equal to a set speed threshold, the method specifically includes:

[0018] The third control variable is determined based on the acceleration of the vehicle in front;

[0019] A fourth control quantity is determined based on the reference speed difference and the vehicle speed of the current vehicle, wherein the reference speed difference is the speed difference between the speed of the preceding vehicle and the speed of the current vehicle.

[0020] Based on the current expected following distance, the distance to the vehicle ahead, and the absolute following distance, determine the distance control amount;

[0021] The initial acceleration limit is corrected using the third control quantity, the fourth control quantity, and the distance control quantity to determine the cruise acceleration at the current step size.

[0022] In one embodiment, the method further includes:

[0023] Based on the current step length expected following distance and the distance to the vehicle in front, determine the fifth control quantity;

[0024] Based on the distance difference between the distance to the vehicle ahead and the absolute following distance, the sixth control quantity is determined;

[0025] The distance control quantity is determined based on the fifth and sixth control quantities.

[0026] In one embodiment, the method further includes:

[0027] Based on the vehicle speed, the speed of the vehicle in front, and the reference weighting coefficient, the current step-length following control distance is determined, wherein the reference weighting coefficient includes the weighting coefficients of the headway and vehicle speed using the driver model.

[0028] Based on the current step length following distance, the current step length set following distance, and the absolute following distance, the expected following distance for the current step length is determined.

[0029] In one embodiment, the method further includes:

[0030] Based on the speed difference between the current vehicle and the vehicle in front, as well as the acceleration of the vehicle in front, the expected following distance at the current step length is adjusted to obtain the current step length set following distance.

[0031] The current step length is used to set the following distance.

[0032] In one embodiment, when the rate of reduction in the distance to the vehicle ahead exceeds a set threshold, the method further includes:

[0033] Based on the vehicle speed, the speed of the vehicle in front, and the reference weighting coefficient, the current step-length following control distance is determined, wherein the reference weighting coefficient includes the weighting coefficients of the headway and vehicle speed using the driver model.

[0034] Based on the current step length following distance, the current step length set following distance, the absolute following distance, and the previous step length expected following distance, the current step length expected following distance is determined.

[0035] In one embodiment, the expected following distance for the current step length is determined based on the current step length following control distance, the current step length set following distance, the absolute following distance, and the expected following distance for the previous step length, specifically including:

[0036] Based on the current step length following distance, the current step length set following distance, and the absolute following distance, a baseline expected following distance is determined.

[0037] Based on the distance difference between the baseline expected following distance and the expected following distance of the previous step, and the baseline expected following distance, the current step length expected following distance is determined.

[0038] In one embodiment, the method further includes:

[0039] Based on the speed difference between the current vehicle and the vehicle in front, as well as the acceleration of the vehicle in front, the expected following distance at the current step length is adjusted to obtain the current step length set following distance.

[0040] The current step length is used to set the following distance.

[0041] In one embodiment, the method further includes:

[0042] Based on the acceleration difference between the current step-length cruise acceleration and the previous step-length cruise acceleration, an impact control amount is determined, wherein the previous step-length cruise acceleration is corrected based on the impact control amount and is limited by an acceleration threshold.

[0043] The rate of change of the current step-length cruise acceleration is corrected by the impact control amount.

[0044] This application also provides a vehicle cruise control device, including:

[0045] The determination module is used to obtain the distance to the vehicle in front and / or the vehicle speed;

[0046] The control module is used to control the vehicle's cruise acceleration based on the distance to the vehicle ahead and / or the vehicle's speed.

[0047] This application also provides an electronic device, including:

[0048] At least one processor; and

[0049] A memory that stores instructions that, when executed by the at least one processor, cause the at least one processor to perform the vehicle cruise control method as described above.

[0050] This application also provides a machine-readable storage medium storing executable instructions that, when executed, cause the machine to perform the vehicle cruise control method described above.

[0051] Compared with the prior art, the vehicle cruise control method according to this application can divide the vehicle's cruise mode based on the distance to the vehicle in front and / or the vehicle speed, thereby controlling the vehicle's cruise acceleration, which can meet the cruise control requirements of the ACC algorithm under various working conditions. Attached Figure Description

[0052] Figure 1 This is a schematic diagram of the principle framework of the vehicle cruise control method of this application;

[0053] Figure 2 This is an application scenario diagram of a vehicle cruise control method according to an embodiment of this application;

[0054] Figure 3 This is a flowchart of a vehicle cruise control method according to an embodiment of this application;

[0055] Figure 4 This is a vehicle ID index diagram in a vehicle cruise control method according to an embodiment of this application;

[0056] Figure 5 This is a state machine switching logic diagram of a vehicle cruise control method according to an embodiment of this application;

[0057] Figures 6 to 9 These are control flowcharts for cruise control mode, high-speed following mode, low-speed following mode, and side vehicle cut-in mode in a vehicle cruise control method according to one or more embodiments of this application.

[0058] Figure 10A block diagram of a vehicle cruise control device according to an embodiment of this application;

[0059] Figure 11 This is a hardware structure diagram of an electronic device according to an embodiment of this application. Detailed Implementation

[0060] The present application will now be described in detail with reference to the embodiments shown in the accompanying drawings. However, these embodiments do not limit the present application, and any structural, methodological, or functional modifications made by those skilled in the art based on these embodiments are included within the protection scope of the present application.

[0061] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “corresponding to,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0062] Before introducing the embodiments of this application, the basic technologies and some technical terms involved in the embodiments of this application will be explained illustratively:

[0063] Intelligent Traffic Systems (ITS), also known as Intelligent Transportation Systems, effectively integrate advanced science and technology (information technology, computer technology, data communication technology, sensor technology, electronic control technology, automatic control theory, operations research, and artificial intelligence) into transportation, service control, and vehicle manufacturing. This strengthens the connection between vehicles, roads, and users, thereby forming a comprehensive transportation system that ensures safety, improves efficiency, enhances the environment, and conserves energy.

[0064] The Intelligent Vehicle Infrastructure Cooperative Systems (IVICS), also known as the vehicle-road collaborative system, is a development direction of intelligent transportation systems. The vehicle-road collaborative system uses advanced wireless communication and new-generation Internet technologies to comprehensively implement dynamic real-time information interaction between vehicles and vehicles, and between vehicles and roads. Based on the collection and fusion of dynamic traffic information in all time and space, it conducts active safety control of vehicles and collaborative management of roads, fully realizing the effective collaboration of people, vehicles and roads, ensuring traffic safety, improving traffic efficiency, and thus forming a safe, efficient and environmentally friendly road traffic system.

[0065] ACC: Adaptive Cruise Control. It is a function provided by the autonomous driving system that dynamically adjusts the speed of the vehicle according to the cruising speed set by the user and the safe distance from the vehicle ahead. When the vehicle ahead accelerates, the vehicle will also accelerate to the set speed. When the vehicle ahead decelerates, the vehicle will decelerate to maintain a safe distance from the vehicle ahead.

[0066] Adaptive cruise control includes traditional cruise control and adaptive tracking control of the desired distance from the vehicle ahead. According to the motion relationship of the vehicle and the motion state of the vehicle ahead, by controlling the acceleration of the vehicle, the longitudinal distance between the vehicle ahead and the vehicle is always maintained near the desired distance, completing vehicle adaptive following. When following a vehicle, the user adjusts the desired distance between the two vehicles by setting the following time interval. The common definitions of the following time interval are as follows:

[0067]

[0068] where c is the longitudinal distance between the two vehicles, v0 is the speed of the vehicle, and τ is the following time interval.

[0069] See Figure 1 , which introduces a basic framework of the vehicle adaptive cruise control method, mainly including the perception fusion layer, the upper control layer and the lower-by-wire chassis execution layer. Using the relative motion state information of the vehicle ahead and the vehicle itself and the vehicle motion state information sent by the perception fusion layer and the chassis execution layer, the current vehicle condition is judged by the working condition decision layer (such as based on a state machine) using the above information. The acceleration planning layer uses a discrete longitudinal control algorithm for the corresponding working condition through a control model to obtain the longitudinal desired acceleration of the vehicle, and sends it to the chassis execution layer. The chassis execution layer can use algorithms such as PID, relying on the vehicle dynamics characteristics, to adjust the brake master cylinder pressure and throttle opening, quickly making the vehicle reach the desired acceleration. At the same time, the vehicle's own motion state is fed back to the acceleration planning layer for closed-loop control, thus realizing the adaptive cruise function.

[0070] See Figure 2, taking an application scenario of the vehicle cruise control method provided in the embodiments of the present application as an example. The user can drive the vehicle manually or use the intelligent driving system of the vehicle for autonomous driving. During either manual driving or autonomous driving, the terminal can collect environmental information based on sensors (such as those belonging to the perception fusion layer) and provide some decision-making basis information for vehicle cruise control.

[0071] Exemplarily, the sensors may include vision sensors, long-range radars (frontward) and short-range radars (corner radars) to provide information perception in multiple directions of the front, rear, left and right of the vehicle. The vision sensor can use a 360-degree panoramic camera to collect image information around the vehicle body, and the long-range radar and short-range radar can be used to collect the distance information of the obstacle in front of the vehicle and the running information of the obstacle in front of the vehicle, etc. The terminal realizes the cruise control of the vehicle by running the vehicle cruise control method provided in the embodiments of the present application.

[0072] Refer Figure 3 , an embodiment of the vehicle cruise control method of the present application will be introduced. In this embodiment, the method includes:

[0073] S11. Obtain the front vehicle distance and / or the vehicle speed of the vehicle itself.

[0074] S12. Control the cruise acceleration of the vehicle itself based on the front vehicle distance and / or the vehicle speed of the vehicle itself. [[ID=第十六条]]

[0075] [[ID=第十七条]]In the various embodiments of the present application, based on information such as the front vehicle distance and the vehicle speed of the vehicle itself, the current driving environment of the vehicle itself can be classified into at least four types. Specifically, to adapt to different driving environments, the embodiments of the present application provide a constant speed cruise mode, a high-speed following mode, a low-speed following mode, and a side vehicle cut-in mode to realize the cruise control of the vehicle itself.

[0076] It should be noted that the "mode" mentioned in the embodiments of the present application does not mean that it is necessary to first judge the specific cruise mode of the vehicle itself based on the front vehicle distance and / or the vehicle speed of the vehicle itself. For example, when the front vehicle distance and / or the vehicle speed of the vehicle itself meet various preset conditions, the cruise acceleration of the vehicle itself can also be directly controlled for the vehicle chassis execution layer to execute. In the following embodiments, the solution of the present application is described in the form of mode division only for the sake of simplicity of description.

[0077] Specifically, the above four driving environments and the corresponding cruise control modes are as follows:

[0078] Constant speed cruise mode: when the front vehicle distance is greater than the set vehicle distance threshold (for example, 120 meters) or there is no target vehicle in front;

[0079] High-speed following mode: The distance to the vehicle in front is less than or equal to the set distance threshold (e.g., 120 meters), and the vehicle speed is greater than the set speed threshold (e.g., 36 km / h).

[0080] Low-speed following mode: The distance to the vehicle in front is less than or equal to the set distance threshold (e.g., 120 meters), and the vehicle speed is less than or equal to the set speed threshold (e.g., 36 km / h).

[0081] Side vehicle cut-in mode: The rate of change in the distance to the vehicle in front exceeds the set change threshold.

[0082] Coordination Figure 4 It should be noted that in adaptive cruise control, the goal is to track the vehicle ahead within the current lane, so lane lines are used to define the tracking target. Considering that there may be multiple targets within the same lane, only the nearest obstacle vehicle is used as the tracking target. Figure 4 For the vehicle ID index map in the post-processing perception, vehicles numbered 1 and 6 are in the same lane as this vehicle, while the first and last rows of vehicles are divided by the positions of the front and rear bumpers. Accordingly, in the embodiments of this application, the forward distance mentioned refers to the distance between vehicle number 1 and this vehicle.

[0083] Coordination Figure 5 The diagram illustrates the state machine switching logic for the four cruise control modes described above. In one scenario, when the user activates the vehicle's adaptive cruise control, the terminal detects the distance to the vehicle ahead and, based on the presence of a vehicle in front, switches to either cruise control mode or following mode. Further, in following mode, the vehicle is controlled to travel at either high speed or low speed based on its own speed. If, while traveling in high speed or low speed following mode, the rate of change in the distance to the vehicle ahead exceeds a set threshold, it indicates a possible vehicle cutting in from the side, and the vehicle is then switched to following vehicle intrusion mode. In following vehicle intrusion mode, the terminal adjusts some control parameters from the previous high speed or low speed following mode. After adjustment, the vehicle can continue in high speed or low speed following mode, and the vehicle will determine the current step's cruise acceleration based on the adjusted control parameters.

[0084] In various embodiments of this application, the state machine can update the data stream information at each step, thereby controlling the vehicle to switch between various cruise control modes and simultaneously operate at an appropriate acceleration in the corresponding cruise control mode. The "step" mentioned in this application can be the time step of the state machine updating the data stream information, such as 25ms, 75ms, 100ms, etc.

[0085] The following combination Figures 6 to 9 The vehicle cruise control method provided in this application embodiment is described in detail under four cruise control modes.

[0086] ① Cruise Control Mode

[0087] S111: Discretize the speed difference between the expected speed of the current step and the set speed of the previous step to determine the set speed of the current step.

[0088] In various embodiments of this application, the desired vehicle speed can be the speed that the user driving the vehicle expects to travel at, and can be read by the upper control layer. The set vehicle speed can be the control speed issued by the upper control layer to the vehicle's drive-by-wire chassis execution layer.

[0089] The user-defined desired speed for the current step may differ significantly from the previously set speed. In this scenario, to achieve the user's desired speed for the current step, the vehicle may adjust its cruise acceleration step by step, resulting in a significant impact and affecting the smoothness of the cruise.

[0090] This embodiment proposes discretizing the speed difference between the desired speed of the current step and the set speed of the previous step. This allows for control over the achievement of the desired speed of the current step, dispersing it across more subsequent steps, thereby smoothing the impact force and intensity. In one embodiment, the set speed of the current step is expressed as:

[0091] V_desire t =V_desire t-1 +δ v_set

[0092] δ v_set =P v_set ×(V set -V_desire t-1 )

[0093] Among them, V set V_desire represents the desired speed at the current step size. t-1 To set the vehicle speed for the previous step, P v_set The preset adjustment coefficient can take any value between 0 and 1, such as 0.1, 0.2, 0.5, etc., δ v_set The speed difference is the vehicle speed difference between the expected vehicle speed at the current step size and the vehicle speed set at the previous step size after discretization.

[0094] In subsequent steps following the current step, the set speed for the corresponding step can be determined based on the speed calculation method described above. It can be seen that as the vehicle speed gradually approaches the desired speed, the speed difference at each step also decreases accordingly, further increasing the smoothness of vehicle operation.

[0095] Of course, in some alternative embodiments, the speed difference between the expected vehicle speed at the current step and the set vehicle speed at the previous step can be equally distributed across the next few step sizes, that is, the aforementioned δ v_set The vehicle speed will not be updated based on the setting of the previous step in the next few steps.

[0096] S112. Based on the vehicle speed and the set speed of the current step length, determine the first control quantity.

[0097] S113. The initial acceleration limit is corrected using the first control quantity to determine the cruise acceleration of the current step size.

[0098] In one embodiment, the cruising acceleration of the current step size is expressed as:

[0099]

[0100] Among them, a max Set a preset initial acceleration limit, for example, 1.4 m / s². 2 1.6m / s 2 wait, V0 is the vehicle speed, and V_desire is the first control variable. t Set the vehicle speed for the current step length.

[0101] It can be seen that in high-speed following mode, the correction of the first control quantity is aimed at the following: 1) If the vehicle speed is greater than the set speed of the current step length, the greater the speed difference between the two, the greater the negative gain of the first control quantity in the initial acceleration limit; 2) If the vehicle speed is less than the set speed of the current step length, the greater the speed difference between the two, the smaller the positive gain of the first control quantity in the initial acceleration limit.

[0102] Set the vehicle speed V_desire t Taking a speed greater than the vehicle's current speed V0 as an example, the vehicle needs to perform positive acceleration. Set the vehicle speed V_desire. t The larger the vehicle speed V0, the smaller the value of the first control variable, and correspondingly the preset initial acceleration limit a. max The smaller the reduction, the greater the cruising acceleration of the vehicle at its current step.

[0103] It is understood that, in different embodiments, the first control quantity may also be set, for example, based on the difference between the vehicle speed and the set speed of the current step, or the ratio of the vehicle speed to the set speed of the current step.

[0104] ②High-speed following mode

[0105] S121. Discretize the speed difference between the expected speed of the current step and the set speed of the previous step to determine the set speed of the current step.

[0106] S122. Based on the vehicle speed and the set speed of the current step length, determine the first control quantity.

[0107] The specific method for determining the current step size setting speed by the discrete vehicle speed difference in steps S121 and S122, and then determining the first control quantity, can refer in part or in whole to the cruise control mode. This will not be elaborated further in this embodiment.

[0108] S123. Based on the current step size, expected following distance, and distance to the vehicle in front, determine the second control variable.

[0109] S124. The initial acceleration limit is corrected using the first control quantity and the second control quantity to determine the cruise acceleration of the current step size.

[0110] In various embodiments of this application, the desired following distance can be determined based on the aforementioned following distance τ. For example, the value of τ can be between 1.5s and 2.2s. The following distance τ can be set based on a fixed-time strategy and a variable-time strategy. In actual road testing, the fixed-time strategy is more sensitive to drastic changes in the distance to the vehicle ahead. For example, when the vehicle ahead suddenly accelerates or decelerates, the vehicle's acceleration decreases or increases dramatically, and the sudden change in the input to the control system results in a larger step value for the current cruising acceleration compared to the previous step.

[0111] Adaptively, this embodiment provides a variable-time strategy for following distance. Specifically, the expected following distance at the current step size can be adjusted based on the speed difference between the current vehicle and the vehicle in front, as well as the acceleration of the vehicle in front. The adjusted expected following distance at the current step size is expressed as:

[0112]

[0113] Where τ0 is the expected following distance before correction, and τ0 can be set by the user according to their driving style; V0 is the speed of the current vehicle; V1 is the speed of the vehicle in front; header_a is the acceleration of the vehicle in front; and τ min τ is the minimum saturation limit for following distance. max The maximum saturation limit for following distance is given by denoted as 'a', which is an adjustment coefficient that takes into account the relative speed changes between the preceding vehicle and the current vehicle, and 'b' is an adjustment coefficient that takes into account the acceleration changes of the preceding vehicle.

[0114] The current step length expected following distance can be calculated using the traditional adaptive cruise control method and set to a constant value. From the user's perspective, they can still set a "constant" current step length expected following distance according to their driving style. However, the correction of the current step length expected following distance provided in this application embodiment can be automatically executed by the acceleration planning layer and directly sent to the chassis execution layer; that is, the corrected current step length expected following distance may not be "perceived" by the user.

[0115] As can be seen, the goal of correcting the expected following distance at the current step length in this embodiment is to reduce the sensitivity of the vehicle to the distance to the vehicle in front by using the speed difference between the vehicle and the vehicle in front, as well as the acceleration of the vehicle in front; at the same time, the corrected expected following distance at the current step length is subject to maximum and minimum saturation limits.

[0116] In the above-mentioned adjustment strategy for expected following distance, if the acceleration of the vehicle in front is positive, the response is to decrease the expected following distance; if the speed of the vehicle in front is greater than the speed of the vehicle in front, the response is to increase the expected following distance, and vice versa.

[0117] In various embodiments of this application, the acceleration of the vehicle in front can be calculated based on Kalman filtering. The acceleration of the vehicle in front is expressed as:

[0118] header_a=(v1-last_header_speed)×(1000 / τ)

[0119] header_min≤header_a≤header_max

[0120] Where last_header_speed is the speed of the vehicle ahead in the previous step. Considering the speed fluctuations of the vehicle ahead monitored by the vehicle radar, even small speed jumps within a step can cause the calculated acceleration of the vehicle ahead, header_a, to be too large. Therefore, the calculated acceleration of the vehicle ahead is limited by header_min and header_max.

[0121] After determining the expected following distance after the current step length correction, the current step length following control distance can be further determined based on the vehicle's speed, the speed of the vehicle in front, and the reference weight coefficient. Then, based on the current step length following control distance, the current step length set following distance, and the absolute following distance, the current step length expected following distance is determined. The current step length expected following distance is expressed as:

[0122]

[0123] Where τ×v0 is the current step length setting for following distance; d0 is the absolute following distance, which can be the minimum longitudinal distance from the center point of the rear axle of this vehicle to the center point of the rear bumper of the vehicle in front (i.e., the minimum protection distance). The current step size is the following distance control distance, with reference weighting coefficients including desire. max(a) and desire max(b) , which are the preset weighting coefficients for the headway and speed difference using the driver model.

[0124] In this embodiment, under high-speed following mode, it is desirable to use the expected following distance at the current step length and the distance to the vehicle ahead to weight the calculation of the cruise acceleration at the current step length in cruise control mode. Correspondingly, the cruise acceleration at the current step length is expressed as:

[0125]

[0126] in, d1 is the distance to the vehicle in front, which is the second control variable.

[0127] It can be seen that in high-speed following mode, the weighted correction of the second control variable aims at the following: 1) If the expected following distance of the current step size is greater than the distance to the vehicle in front, the greater the difference between the two distances, the greater the negative gain provided by the second control variable in the initial acceleration limit; 2) If the expected following distance of the current step size is less than the distance to the vehicle in front, the greater the difference between the two distances, the smaller the positive gain provided by the second control variable in the initial acceleration limit.

[0128] Similarly, in different embodiments, the second control quantity can also be set based on the difference between the current step length expected following distance and the distance to the vehicle in front, the ratio of the current step length expected following distance to the distance to the vehicle in front, etc.

[0129] ⑧ Low-speed following mode

[0130] S131. Determine the third control variable based on the acceleration of the preceding vehicle.

[0131] S132. Based on the reference speed difference and the vehicle speed, determine the fourth control quantity.

[0132] S133. Based on the current step length expected following distance, the distance to the vehicle in front, and the absolute following distance, determine the distance control amount.

[0133] S134. The initial acceleration limit is corrected using the third control quantity, the fourth control quantity, and the distance control quantity to determine the cruise acceleration at the current step size.

[0134] Among them, the reference speed difference is the speed difference between the speed of the vehicle in front and the speed of the current vehicle. Specifically, the fifth control quantity can be determined based on the current step length expected following distance and the distance to the vehicle in front; the sixth control quantity can be determined based on the distance difference between the distance to the vehicle in front and the absolute following distance; and the aforementioned distance control quantity can be determined based on the fifth control quantity and the sixth control quantity.

[0135] Similarly, the calculation of the expected following distance in this embodiment can be partially or entirely based on the high-speed following mode, which will not be elaborated further in this embodiment.

[0136] In some scenarios, such as at intersections or in traffic jams on urban roads, vehicles repeatedly start and stop. If the vehicle in front does not follow the vehicle in front promptly after it starts moving, the relative distance between the two vehicles will temporarily increase, which may cause other vehicles to cut in, reduce traffic flow efficiency, and increase the risk of rear-end collisions. Furthermore, if the vehicle in front suddenly decelerates, it may reduce the distance to the vehicle in front and the expected following distance, increasing the risk that the vehicle in front may not brake in time or the braking deceleration may not be sufficient to ensure a safe distance.

[0137] Correspondingly, in the current step-length cruise acceleration calculation of this embodiment, rapid tracking of the expected following distance for the preceding vehicle's start-up and braking is considered simultaneously; to prevent delays in closing the expected following distance after reaching it, the weight of the preceding vehicle's acceleration is increased; due to repeated start-stop cycles, the vehicle's acceleration is at 0 m / s². 2 Factors causing driver discomfort include vibrations. The current cruising acceleration is expressed as:

[0138]

[0139] Where, k q To account for the adjustment coefficient of the acceleration of the vehicle in front, k p To take into account the adjustment coefficients for distance to the vehicle ahead and absolute following distance, the header a 3 As the third control variable, This is the fourth control variable. This is the fifth control variable. The sixth control variable is k1, k2, and k3, which are preset adjustment coefficients.

[0140] It can be seen that in low-speed following mode, the correction of the third control variable is aimed at the following: 1) When the acceleration of the preceding vehicle is positive, the greater the acceleration of the preceding vehicle, the greater the positive gain provided by the third control variable in the initial acceleration limit; 2) When the acceleration of the preceding vehicle is negative, the greater the negative acceleration of the preceding vehicle, the greater the negative gain provided by the third control variable in the initial acceleration limit.

[0141] The correction of the fourth control variable aims to achieve the following: 1) When the speed of the preceding vehicle is greater than the speed of the current vehicle, the greater the speed difference, the greater the positive gain provided by the fourth control variable in terms of initial acceleration limit; 2) When the speed of the preceding vehicle is less than the speed of the current vehicle, the greater the speed difference, the greater the negative gain provided by the fourth control variable in terms of initial acceleration limit.

[0142] The fifth control variable is corrected with the following objectives: 1) When the expected following distance of the current step is greater than the distance to the vehicle in front, the greater the difference between the two distances, the greater the negative gain provided by the fifth control variable in the initial acceleration limit; 2) When the expected following distance of the current step is less than the distance to the vehicle in front, the greater the difference between the two distances, the smaller the positive gain provided by the fifth control variable in the initial acceleration limit.

[0143] The sixth control variable is corrected with the following objectives: 1) When the distance to the vehicle in front is greater than the absolute following distance, the greater the distance difference between the two, the greater the positive gain provided by the sixth control variable in the initial acceleration limit; 2) When the distance to the vehicle in front is less than the absolute following distance, the greater the distance difference between the two, the greater the negative gain provided by the sixth control variable in the initial acceleration limit.

[0144] ④ Side vehicle entry mode

[0145] S141. Based on the vehicle speed, the speed of the preceding vehicle, and the reference weighting coefficient, determine the current step length following distance.

[0146] S142. Based on the current step length following distance, the current step length set following distance, the absolute following distance, and the previous step length expected following distance, determine the current step length expected following distance.

[0147] In scenarios where a vehicle cuts in from the side, the distance to the vehicle in front will suddenly decrease. The acceleration (negative, i.e., deceleration) calculated using the above-mentioned cruise acceleration calculation methods for high-speed or low-speed following may be too large, resulting in a significant impact and threatening the safe driving of the vehicle behind. Therefore, this embodiment proposes to provide a more forgiving method for calculating the expected following distance in the side-vehicle cutting-in mode compared to high-speed or low-speed following.

[0148] In this embodiment, the calculation of the current step length following distance can be partially or entirely based on the high-speed following mode or the low-speed following mode, which will not be elaborated further in this embodiment. The difference is that in this embodiment, when calculating the expected following distance for the current step length, the expected following distance for the previous step length is further considered.

[0149] Specifically, the baseline expected following distance can be determined based on the current step length following distance control distance, the current step length set following distance, and the absolute following distance; then, the current step length expected following distance is determined based on the difference between the baseline expected following distance and the expected following distance of the previous step length, as well as the baseline expected following distance. The current step length expected following distance is expressed as:

[0150]

[0151]

[0152] in, The expected following distance is the current step length. Let t be the baseline expected following distance (current step size). Let P be the baseline expected following distance at time t-1 (the previous step length). s This is the preset gain coefficient.

[0153] As can be seen, the baseline expected following distance at time t in this embodiment can be partially or entirely referenced from the calculation of the expected following distance for the current step length in either high-speed or low-speed following mode. From another perspective, the "expected following distance for the current step length" in this embodiment can be seen as a correction to the calculation result of the expected following distance for the current step length in either high-speed or low-speed following mode. The goal of the correction is to increase the expected following distance within the current step length.

[0154] For the four modes mentioned above, the calculated current step-length cruise acceleration, if directly sent to the chassis execution layer, may cause a significant step change in vehicle acceleration. In this embodiment, since the cruise state does not need to consider the risk of rear-end collision with the vehicle in front (which has already been constrained by the vehicle cruise control method described above), the impact (the first derivative of acceleration, i.e., jerk) is considered from the perspective of the comfort of the user in the vehicle to determine whether it meets the driver's comfort requirements.

[0155] Specifically, the impact control quantity can be determined based on the acceleration difference between the current step-length cruise acceleration and the previous step-length cruise acceleration, and this impact control quantity can be used to correct the rate of change of the current step-length cruise acceleration. The previous step-length cruise acceleration is corrected based on this impact control quantity and is subject to an acceleration threshold limit. This is specifically expressed as follows:

[0156] δ a =P_×(a_cmd-a_cmd) t-1 )

[0157] a_cmd t =δ a +a_cmd t-1

[0158] |a_cmd t-1 |≤a wmax

[0159] where, δ a is the impact degree control quantity, P_ is the preset gain coefficient (such as the P gain coefficient in PID), a wmax is the set acceleration threshold, a_cmd t is the current step cruise acceleration, and a_cmd t-1 is the previous step cruise acceleration.

[0160] P_ can take a suitable value between 0 and 1, such as 0.1, 0.2, etc. In this way, it is equivalent to weakening the acceleration change speed of the current step and the previous step. The limit constraint on the previous step cruise acceleration (i.e., a wmax ) can be reasonably set considering the fuel economy of the vehicle, the sensitivity of the user to the acceleration change, and the maximum acceleration that can be tolerated.

[0161] Refer to Figure 10 for an embodiment of the vehicle cruise control device of the present application. In this embodiment, the vehicle cruise control device includes a determination module 21 and a control module 22.

[0162] The determination module 21 is used to obtain the front vehicle distance and / or the vehicle speed of the vehicle itself; the control module 22 is used to control the cruise acceleration of the vehicle itself based on the front vehicle distance and / or the vehicle speed of the vehicle itself.

[0163] In one embodiment, when the front vehicle distance is greater than the set vehicle distance threshold, the control module 22 is used to discretize the vehicle speed difference between the current step expected vehicle speed and the previous step set vehicle speed to determine the set vehicle speed of the current step; based on the vehicle speed of the vehicle itself and the set vehicle speed of the current step, determine a first control quantity; and correct the initial acceleration limit with the first control quantity to determine the cruise acceleration of the current step.

[0164] In one embodiment, when the front vehicle distance is less than or equal to the set vehicle distance threshold and the vehicle speed of the vehicle itself is greater than the set vehicle speed threshold, the control module 22 is used to discretize the vehicle speed difference between the current step expected vehicle speed and the previous step set vehicle speed to determine the set vehicle speed of the current step; based on the vehicle speed of the vehicle itself and the set vehicle speed of the current step, determine a first control quantity; based on the current step expected following distance and the front vehicle distance, determine a second control quantity; and correct the initial acceleration limit with the first control quantity and the second control quantity to determine the cruise acceleration of the current step.

[0165] In one embodiment, when the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is less than or equal to a set speed threshold, the control module 22 is used to determine a third control quantity based on the acceleration of the vehicle ahead; determine a fourth control quantity based on a reference speed difference and the vehicle speed, wherein the reference speed difference is the speed difference between the speed of the vehicle ahead and the speed of the vehicle; determine a distance control quantity based on the expected following distance at the current step length, the distance to the vehicle ahead, and the absolute following distance; and correct the initial acceleration limit using the third control quantity, the fourth control quantity, and the distance control quantity to determine the cruising acceleration at the current step length.

[0166] In one embodiment, the control module 22 is further configured to determine a fifth control quantity based on the current step length expected following distance and the distance to the vehicle ahead; determine a sixth control quantity based on the distance difference between the distance to the vehicle ahead and the absolute following distance; and determine the distance control quantity based on the fifth control quantity and the sixth control quantity.

[0167] In one embodiment, the control module 22 is further configured to determine the current step length following distance based on the vehicle speed, the speed of the preceding vehicle, and a reference weighting coefficient, wherein the reference weighting coefficient includes a weighting coefficient for the headway and vehicle speed using a driver model; and to determine the current step length expected following distance based on the current step length following distance, the current step length set following distance, and the absolute following distance.

[0168] In one embodiment, the control module 22 is further configured to correct the current step length expected following distance based on the speed difference between the vehicle speed and the speed of the preceding vehicle, and the acceleration of the preceding vehicle, so as to obtain the current step length set following distance; and determine the current step length set following distance based on the current step length set following distance.

[0169] In one embodiment, when the rate of reduction in the distance to the preceding vehicle exceeds a set change threshold, the control module 22 is further configured to determine the current step-length following control distance based on the vehicle speed, the speed of the preceding vehicle, and a reference weighting coefficient, wherein the reference weighting coefficient includes a weighting coefficient for the headway and vehicle speed using a driver model; and to determine the current step-length expected following distance based on the current step-length following control distance, the current step-length set following distance, the absolute following distance, and the expected following distance of the previous step.

[0170] In one embodiment, the control module 22 is specifically used to determine the baseline expected following distance based on the current step length following distance control distance, the current step length set following distance, and the absolute following distance; and to determine the current step length expected following distance based on the distance difference between the baseline expected following distance and the expected following distance of the previous step length, and the baseline expected following distance.

[0171] In one embodiment, the control module 22 is further configured to correct the current step length expected following distance based on the speed difference between the vehicle speed and the speed of the preceding vehicle, and the acceleration of the preceding vehicle, so as to obtain the current step length set following distance; and determine the current step length set following distance based on the current step length set following distance.

[0172] In one embodiment, the control module 22 is further configured to determine an impact control amount based on the acceleration difference between the current step-length cruise acceleration and the previous step-length cruise acceleration, wherein the previous step-length cruise acceleration is corrected based on the impact control amount and is limited by an acceleration threshold; and the change rate of the current step-length cruise acceleration is corrected by the impact control amount.

[0173] As per the above reference Figures 1 to 9 This specification describes a vehicle cruise control method according to embodiments thereof. The details mentioned in the above description of the method embodiments also apply to the vehicle cruise control device according to embodiments thereof. The above-described vehicle cruise control device can be implemented in hardware, software, or a combination of hardware and software.

[0174] Figure 11 A hardware structure diagram of an electronic device according to an embodiment of this specification is shown. Figure 11 As shown, the electronic device 30 may include at least one processor 31, a memory 32 (e.g., non-volatile memory), a memory 33, and a communication interface 34, and the at least one processor 31, memory 32, memory 33, and communication interface 34 are connected together via an internal bus 35. The at least one processor 31 executes at least one computer-readable instruction stored or encoded in the memory 32.

[0175] It should be understood that the computer-executable instructions stored in memory 32, when executed, cause at least one processor 31 to perform the above-described combinations in the various embodiments of this specification. Figures 1 to 9 The description includes various operations and functions.

[0176] In the embodiments of this specification, electronic device 30 may include, but is not limited to: personal computer, server computer, workstation, desktop computer, laptop computer, notebook computer, mobile electronic device, smartphone, tablet computer, cellular phone, personal digital assistant (PDA), handheld device, messaging device, wearable electronic device, consumer electronic device, etc.

[0177] According to one embodiment, a program product, such as a machine-readable medium, is provided. The machine-readable medium may have instructions (i.e., the elements implemented in software as described above), which, when executed by a machine, cause the machine to perform the above-described combinations of the various embodiments of this specification. Figures 1-7The various operations and functions described. Specifically, a system or apparatus equipped with a readable storage medium storing software program code that implements the functions of any of the embodiments described above, and enabling the computer or processor of the system or apparatus to read and execute the instructions stored in the readable storage medium.

[0178] In this case, the program code read from the readable medium itself can perform the functions of any of the above embodiments, and therefore the machine-readable code and the readable storage medium storing the machine-readable code constitute a part of this specification.

[0179] Examples of readable storage media include floppy disks, hard disks, magneto-optical disks, optical disks (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD-RW), magnetic tapes, non-volatile memory cards, and ROMs. Alternatively, program code can be downloaded from a server computer or the cloud via a communication network.

[0180] Those skilled in the art will understand that the various embodiments disclosed above can be modified and varied without departing from the spirit of the invention. Therefore, the scope of protection of this specification should be defined by the appended claims.

[0181] It should be noted that not all steps and units in the above process and system structure diagrams are mandatory; some steps or units can be omitted according to actual needs. The execution order of each step is not fixed and can be determined as needed. The device structure described in the above embodiments can be a physical structure or a logical structure. That is, some units may be implemented by the same physical client, or some units may be implemented by multiple physical clients, or they may be jointly implemented by certain components in multiple independent devices.

[0182] In the above embodiments, the hardware units or modules can be implemented mechanically or electrically. For example, a hardware unit, module, or processor may include permanent dedicated circuitry or logic (such as a dedicated processor, FPGA, or ASIC) to perform the corresponding operation. The hardware unit or processor may also include programmable logic or circuitry (such as a general-purpose processor or other programmable processor), which can be temporarily configured by software to perform the corresponding operation. The specific implementation method (mechanical, dedicated permanent circuitry, or temporarily configured circuitry) can be determined based on cost and time considerations.

[0183] The specific embodiments described above with reference to the accompanying drawings are exemplary embodiments, but do not represent all embodiments that can be implemented or fall within the scope of the claims. The term "exemplary" as used throughout this specification means "serving as an example, instance, or illustration" and does not imply that it is "preferred" or "advantageous" compared to other embodiments. Specific details are included to provide an understanding of the described techniques. However, these techniques can be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form to avoid obscuring the concepts of the described embodiments.

[0184] The foregoing description of this disclosure is provided to enable any person skilled in the art to implement or use this disclosure. Various modifications to this disclosure will be apparent to those skilled in the art, and the general principles applicable herein can be applied to other variations without departing from the scope of this disclosure. Therefore, this disclosure is not limited to the examples and designs described herein, but is consistent with the widest scope of the principles and novel features disclosed herein.

Claims

1. A vehicle cruise control method, characterized in that, The method includes: Get the distance to the vehicle in front and / or the speed of this vehicle; Based on the distance to the vehicle ahead and / or the vehicle speed, control the vehicle's cruise acceleration; When the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle's speed is greater than a set speed threshold, the method specifically includes: Discretize the vehicle speed difference between the current step length expected vehicle speed and the previous step length set vehicle speed to determine the current step length set vehicle speed; determine a first control quantity based on the vehicle speed and the current step length set vehicle speed; determine a second control quantity based on the current step length expected following distance and the distance to the vehicle in front; correct the initial acceleration limit with the first control quantity and the second control quantity to determine the current step length cruise acceleration; When the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is less than or equal to a set speed threshold, the method specifically includes: Based on the acceleration of the vehicle in front, a third control variable is determined; based on the reference speed difference and the current vehicle speed, a fourth control variable is determined, wherein the reference speed difference is the speed difference between the vehicle in front and the current vehicle speed; based on the expected following distance at the current step length, the distance to the vehicle in front, and the absolute following distance, a distance control variable is determined; the initial acceleration limit is corrected using the third control variable, the fourth control variable, and the distance control variable to determine the cruise acceleration at the current step length; The method further includes: determining the current step length following distance control distance based on the vehicle speed, the speed of the preceding vehicle, and a reference weighting coefficient, wherein the reference weighting coefficient includes a weighting coefficient for the headway and vehicle speed using a driver model; and determining the current step length expected following distance based on the current step length following distance control distance, the current step length set following distance, and the absolute following distance.

2. The vehicle cruise control method according to claim 1, characterized in that, When the distance to the vehicle ahead is greater than a set distance threshold, the method specifically includes: Discretize the vehicle speed difference between the expected vehicle speed at the current step length and the set vehicle speed at the previous step length to determine the set vehicle speed at the current step length; Based on the vehicle speed and the set speed of the current step length, determine the first control quantity; The initial acceleration limit is corrected using the first control quantity to determine the cruise acceleration at the current step size.

3. The vehicle cruise control method according to claim 1, characterized in that, When the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is less than or equal to a set speed threshold, the method further includes: Based on the current step length expected following distance and the distance to the vehicle in front, determine the fifth control quantity; Based on the distance difference between the distance to the vehicle ahead and the absolute following distance, the sixth control quantity is determined; The distance control quantity is determined based on the fifth and sixth control quantities.

4. The vehicle cruise control method according to claim 1, characterized in that, The method further includes: Based on the speed difference between the current vehicle and the vehicle in front, as well as the acceleration of the vehicle in front, the expected following distance at the current step length is adjusted to obtain the current step length set following distance. The current step length is used to set the following distance.

5. The vehicle cruise control method according to claim 1 or 3, characterized in that, When the rate of reduction in the distance to the vehicle ahead exceeds a set threshold, the method further includes: Based on the vehicle speed, the speed of the vehicle in front, and the reference weighting coefficient, the current step-length following control distance is determined, wherein the reference weighting coefficient includes the weighting coefficients of the headway and vehicle speed using the driver model. Based on the current step length following distance, the current step length set following distance, the absolute following distance, and the previous step length expected following distance, the current step length expected following distance is determined.

6. The vehicle cruise control method according to claim 5, characterized in that, Based on the current step length following distance, the current step length set following distance, the absolute following distance, and the expected following distance of the previous step length, the expected following distance for the current step length is determined, specifically including: Based on the current step length following distance, the current step length set following distance, and the absolute following distance, a baseline expected following distance is determined. Based on the distance difference between the baseline expected following distance and the expected following distance of the previous step, and the baseline expected following distance, the current step length expected following distance is determined.

7. The vehicle cruise control method according to claim 5, characterized in that, The method further includes: Based on the speed difference between the current vehicle and the vehicle in front, as well as the acceleration of the vehicle in front, the expected following distance at the current step length is adjusted to obtain the current step length set following distance. The current step length is used to set the following distance.

8. The vehicle cruise control method according to any one of claims 1 to 3, characterized in that, The method further includes: Based on the acceleration difference between the current step-length cruise acceleration and the previous step-length cruise acceleration, an impact control amount is determined, wherein the previous step-length cruise acceleration is corrected based on the impact control amount and is limited by an acceleration threshold. The rate of change of the current step-length cruise acceleration is corrected by the impact control amount.

9. A vehicle cruise control device, characterized in that, include: The determination module is used to obtain the distance to the vehicle in front and / or the vehicle speed; The control module is used to control the vehicle's cruise acceleration based on the distance to the vehicle ahead and / or the vehicle's speed; wherein, When the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is greater than a set speed threshold, the control module is specifically used to: discretize the speed difference between the expected speed of the current step and the set speed of the previous step to determine the set speed of the current step; determine a first control quantity based on the vehicle speed and the set speed of the current step; determine a second control quantity based on the expected following distance of the current step and the distance to the vehicle ahead; and correct the initial acceleration limit with the first and second control quantities to determine the cruise acceleration of the current step. When the distance to the vehicle ahead is less than or equal to a set distance threshold and the vehicle speed is less than or equal to a set speed threshold, the control module is specifically used to: determine a third control quantity based on the acceleration of the vehicle ahead; determine a fourth control quantity based on a reference speed difference and the vehicle speed, wherein the reference speed difference is the speed difference between the vehicle speed of the vehicle ahead and the vehicle speed of the vehicle; determine a distance control quantity based on the expected following distance at the current step length, the distance to the vehicle ahead, and the absolute following distance; and correct the initial acceleration limit using the third control quantity, the fourth control quantity, and the distance control quantity to determine the cruising acceleration at the current step length. The control module is also used to: determine the current step length following distance based on the vehicle speed, the speed of the vehicle in front, and a reference weighting coefficient, wherein the reference weighting coefficient includes a weighting coefficient for the headway and vehicle speed using a driver model; and determine the current step length expected following distance based on the current step length following distance, the current step length set following distance, and the absolute following distance.

10. An electronic device, comprising: At least one processor; as well as A memory that stores instructions that, when executed by the at least one processor, cause the at least one processor to perform the vehicle cruise control method as described in any one of claims 1 to 8.

11. A machine-readable storage medium storing executable instructions that, when executed, cause the machine to perform the vehicle cruise control method as described in any one of claims 1 to 8.

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