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

Abstract

The present invention provides a vehicle cruise control method, device, equipment and readable storage medium. The vehicle cruise control method includes: when the vehicle is in cruise mode, detecting whether the rainfall condition is met; if so, judging whether there is a risk of hydroplaning according to the current driving road conditions; if so, calculating the critical vehicle speed according to the preset water film thickness and the vehicle tire pressure; when the vehicle speed exceeds the product of the preset percentage and the critical vehicle speed, reducing the vehicle speed to a safe speed; judging whether there is a risk of hydroplaning by monitoring the wheel speed, and if so, outputting a speed reduction reminder. Through the present invention, when the vehicle is driving in cruise mode, the risk of hydroplaning is timely identified and monitored in real time, and by reducing the vehicle speed and providing reminders and warnings, the occurrence of vehicle hydroplaning is reduced, thereby improving the safety of the vehicle when driving in cruise mode.

Description

Technical Field

[0001] The present invention relates to the field of assisted driving technology, and in particular to a vehicle cruise control method, device, equipment and readable storage medium. Background Art

[0002] Existing cruise technologies include cruise control, adaptive cruise control and predictive cruise control. Cruise control takes vehicle speed as the target; adaptive cruise control considers the distance to the vehicle in front as one of the control targets based on cruise control; predictive cruise control considers the slope, length and curvature of the road ahead as one of the control targets based on cruise control. Existing cruise technologies have the following disadvantages: they are mainly based on controlling vehicle speed, and fail to consider the impact of traffic environment on cruise control, resulting in low safety; existing adaptive cruise technology mainly realizes cruise control based on the speed and distance of the vehicle in front, and considers the safety factor of the vehicle in front of the single lane compared to cruise control, but fails to consider the road conditions. For different road conditions, its driving safety needs to rely on the vehicle in front, which poses a greater safety risk; whether the vehicle is in cruise control or adaptive cruising, only when the wheel slip rate does not meet the requirements, the active safety configurations such as the relevant vehicle electronic stability control system will intervene, and for some risk situations, it is impossible to intervene in advance. Summary of the invention

[0003] The main purpose of the present invention is to provide a vehicle cruise control method, device, equipment and readable storage medium, aiming to solve the technical problem that when a vehicle encounters hydroplaning when using a cruise mode, it will cause driving risks.

[0004] In a first aspect, the present invention provides a vehicle cruise control method, the vehicle cruise control method comprising:

[0005] When the vehicle is in cruise mode, detect whether the rainfall condition is met;

[0006] If yes, determine whether there is a risk of hydroplaning based on the current driving conditions;

[0007] If yes, the critical vehicle speed is calculated based on the preset water film thickness and the vehicle tire pressure;

[0008] When the speed of the vehicle exceeds the product of the preset percentage and the critical speed, the speed of the vehicle is reduced to a safe speed;

[0009] By monitoring the wheel speed, it is determined whether there is a risk of hydroplaning. If so, a speed reduction reminder is output.

[0010] Optionally, the detecting whether the rainfall condition is met includes:

[0011] When the rainfall sensor detects that the rainfall is stable, and the weather forecast indicates that the current weather is heavy rain or rainstorm, and the difference between the current time and the rain start time in the weather forecast is greater than a preset difference, it is detected that the rainfall condition is met.

[0012] Optionally, judging whether there is a risk of hydroplaning according to the current driving road condition includes:

[0013] According to the current driving road conditions, detect whether the preset conditions are met, and the preset conditions include:

[0014] A curve appears at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature;

[0015] An uphill slope appears at a preset distance in front of the vehicle, and the uphill slope is greater than the preset slope;

[0016] A downhill slope appears at a preset distance in front of the vehicle, and the slope of the downhill slope is greater than the preset slope;

[0017] If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

[0018] Optionally, the calculating the critical vehicle speed according to the preset water film thickness and the vehicle tire pressure includes:

[0019] Obtain preset water film thickness and vehicle tire pressure;

[0020] According to the preset water film thickness and vehicle tire pressure, the critical vehicle speed is calculated by the formula:

[0021]

[0022] Where V is the critical speed, P max is the maximum pressure at the center of the vehicle tire contact surface, which is 1.55 times the vehicle tire pressure, ρ is the density of water, R is the wheel radius, and H is the preset water film thickness.

[0023] Optionally, when the vehicle speed exceeds the product of a preset percentage and a critical speed, reducing the vehicle speed to a safe speed includes:

[0024] When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling on a flat road, the vehicle power output is controlled to reduce the vehicle speed to a safe speed;

[0025] When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling downhill and the downhill slope is greater than the preset slope, the vehicle's power output is controlled and a speed reduction reminder is output to reduce the vehicle's speed to a safe speed.

[0026] Optionally, the determining whether there is a risk of hydroplaning by monitoring the wheel speed includes:

[0027] In a continuous time period, a first wheel speed is calculated by using the current vehicle speed and the tire circumference, and a second wheel speed is obtained by using a sensor;

[0028] Obtaining a first wheel speed and a second wheel speed for a preset number of times;

[0029] Calculating the ratio between the first wheel speed and the second wheel speed for a preset number of times respectively, and taking an average value of the calculated ratios to obtain an average value of the ratio for each cycle;

[0030] Subtract the average value of the ratio of the previous period from the average value of the ratio of the current period to get the difference;

[0031] If the difference decreases continuously, and the number of consecutive decreases reaches a preset number of decreases, it is determined that there is a risk of hydroplaning.

[0032] In a second aspect, the present invention further provides a vehicle cruise control device, the vehicle cruise control device comprising:

[0033] A detection module, used to detect whether a rainfall condition is met when the vehicle is in a cruise mode;

[0034] A judgment module, for judging whether there is a risk of hydroplaning according to the current driving conditions if yes;

[0035] a calculation module, for calculating the critical vehicle speed according to a preset water film thickness and a vehicle tire pressure;

[0036] A speed reduction module, used for reducing the speed of the vehicle to a safe speed when the speed of the vehicle exceeds the product of a preset percentage and a critical speed;

[0037] The monitoring module is used to determine whether there is a risk of hydroplaning by monitoring the wheel speed. If so, it outputs a speed reduction reminder.

[0038] Optionally, the judging module is used to:

[0039] According to the current driving road conditions, detect whether the preset conditions are met, and the preset conditions include:

[0040] A curve appears at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature;

[0041] An uphill slope appears at a preset distance in front of the vehicle, and the uphill slope is greater than the preset slope;

[0042] A downhill slope appears at a preset distance in front of the vehicle, and the slope of the downhill slope is greater than the preset slope;

[0043] If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

[0044] In a third aspect, the present invention also provides a vehicle cruise control device, comprising a processor, a memory, and a vehicle cruise control program stored in the memory and executable by the processor, wherein when the vehicle cruise control program is executed by the processor, the steps of the vehicle cruise control method described above are implemented.

[0045] In a fourth aspect, the present invention further provides a readable storage medium, on which a vehicle cruise control program is stored, wherein when the vehicle cruise control program is executed by a processor, the steps of the vehicle cruise control method as described above are implemented.

[0046] In the present invention, when the vehicle is in cruise mode, it is detected whether the rainfall condition is met; if so, it is determined whether there is a risk of hydroplaning based on the current driving conditions; if so, the critical vehicle speed is calculated based on the preset water film thickness and the vehicle tire pressure; when the vehicle speed exceeds the product of the preset percentage and the critical vehicle speed, the vehicle speed is reduced to a safe speed; by monitoring the wheel speed, it is determined whether there is a risk of hydroplaning, and if so, a speed reduction reminder is output. The present invention determines whether the vehicle has the risk of hydroplaning by combining whether the current driving road conditions are prone to water accumulation when the vehicle is in the cruise mode, and if the vehicle has the risk of hydroplaning, the critical speed is calculated according to the preset water film thickness and the tire pressure of the vehicle. The critical speed is the critical speed at which the vehicle is prone to hydroplaning. When the vehicle speed exceeds a certain preset percentage of the critical speed, it means that the speed is too high and the risk of hydroplaning is high. The vehicle speed is reduced to a safe speed to ensure driving safety. Moreover, by continuously monitoring the rotation speed of the wheels, it is observed whether the wheels have the phenomenon or trend of idling and slipping, and it is determined whether there is still the risk of hydroplaning. If there is, the driver is reminded to slow down through sound and light or the instrument screen to ensure driving safety. Through the present invention, when the vehicle is driving in the cruise mode, the risk of hydroplaning is timely identified and monitored in real time. By reducing the speed and giving warnings, the occurrence of the vehicle hydroplaning is reduced, and the safety of the vehicle when driving in the cruise mode is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic diagram of the hardware structure of an embodiment of a vehicle cruise control device of the present invention;

[0048] Figure 2 A schematic diagram of a flow chart of an embodiment of a vehicle cruise control method of the present invention;

[0049] Figure 3 for Figure 2A detailed flow chart of step S40;

[0050] Figure 4 for Figure 2 A detailed flow chart of step S50;

[0051] Figure 5 FIG. 1 is a schematic diagram of functional modules of an embodiment of a vehicle cruise control device of the present invention.

[0052] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0053] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0054] In a first aspect, an embodiment of the present invention provides a vehicle cruise control device.

[0055] Reference Figure 1 , Figure 1 The hardware structure diagram of an embodiment of a vehicle cruise control device of the present invention. In the embodiment of the present invention, the vehicle cruise control device may include a processor 1001 (e.g., a central processing unit, CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components; the user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard); the network interface 1004 may optionally include a standard wired interface, a wireless interface (such as a wireless fidelity WIreless-FIdelity, WI-FI interface); the memory 1005 may be a high-speed random access memory (random access memory, RAM), or a stable memory (non-volatile memory), such as a disk storage, and the memory 1005 may optionally be a storage device independent of the aforementioned processor 1001. Those skilled in the art will understand that Figure 1 The hardware structure shown in the figure does not constitute a limitation of the present invention, and may include more or less components than those shown in the figure, or combine certain components, or arrange the components differently.

[0056] Continue to refer to Figure 1 , Figure 1The memory 1005 as a computer storage medium may include an operating system, a network communication module, a user interface module, and a vehicle cruise control program. The processor 1001 may call the vehicle cruise control program stored in the memory 1005 and execute the vehicle cruise control method provided in the embodiment of the present invention.

[0057] In a second aspect, an embodiment of the present invention provides a vehicle cruise control method.

[0058] In order to more clearly demonstrate the vehicle cruise control method provided in the embodiment of the present application, the application scenario of the vehicle cruise control method provided in the embodiment of the present application is first introduced.

[0059] The vehicle cruise control method provided in the embodiment of the present application is applied when the vehicle is driving in cruise mode. The existing cruise technology does not fully consider the environment and road conditions and cannot fully guarantee the safety of driving. Therefore, it is very necessary to monitor the weather conditions, road conditions and the vehicle conditions when the vehicle is driving in cruise mode, especially for rainy days and waterlogged roads, when the vehicle is prone to hydroplaning, to identify and control risks.

[0060] In one embodiment, referring to Figure 2 , Figure 2 FIG. 1 is a flow chart of an embodiment of a vehicle cruise control method of the present invention. Figure 2 As shown, the vehicle cruise control method includes:

[0061] Step S10, when the vehicle is in the cruise mode, detecting whether the rainfall condition is met.

[0062] In this embodiment, the cruise mode is also called automatic cruise. Automobile cruise means that the automobile travels at a constant speed, so the automobile cruise control system is also called a constant speed control system, which is derived from the aircraft cruise control system. Once the automobile is set to the cruise state, the fuel supply of the engine is controlled by the computer. The computer will continuously adjust the fuel supply according to the road conditions and the driving resistance of the automobile, so that the automobile always maintains the set speed without operating the accelerator. When the vehicle uses the cruise mode, the detection of whether the rainfall condition is met is mainly to determine whether the rainfall under the current weather conditions may cause the risk of vehicle hydroplaning.

[0063] Step S20: If yes, determine whether there is a risk of hydroplaning based on the current driving conditions.

[0064] In this embodiment, under the premise that the weather conditions meet the rainfall conditions, the current driving road conditions are used to determine whether water is likely to accumulate, thereby determining whether the vehicle has a risk of hydroplaning. For example, water is likely to accumulate on curved sections and uphill and downhill sections, which may lead to the risk of hydroplaning. Hydroplaning refers to a situation where a rolling tire completely loses contact or is incompletely in contact with its load-bearing surface due to a slippery road surface such as accumulated water or snow, thereby reducing the braking effect of the tire and making it impossible to effectively slow down the wheel or control the direction. At a certain vehicle speed, when the lift of the dynamic water pressure under the tread is equal to the vertical load, the tire will completely float on the water film without any contact with the road surface. This is called hydroplaning.

[0065] Step S30: If yes, the critical vehicle speed is calculated based on the preset water film thickness and the vehicle tire pressure.

[0066] In this embodiment, the water film effect refers to a thin layer of water on the road when it rains, which sticks to the road surface like a water film. This "film" greatly reduces the friction coefficient between the tire and the road surface. When the vehicle speed is too fast, it is easy to "drift on water". The critical speed refers to the critical speed at which the vehicle is prone to hydroplaning. If there is a risk of hydroplaning, at this time, it is necessary to calculate the critical speed based on the preset water film thickness and the vehicle tire pressure to control the driving speed.

[0067] Step S40, when the vehicle speed exceeds the product of the preset percentage and the critical speed, the vehicle speed is reduced to a safe speed.

[0068] In this embodiment, the preset percentage can be set as needed, for example, a value of 95%. If the calculated critical speed is 100 km / h, then when the vehicle speed exceeds 95% × 100 km / h = 95 km / h, the vehicle speed will be reduced to a safe speed to ensure driving safety. The safe speed refers to a lower driving speed. When the vehicle travels at the safe speed, the risk of hydroplaning is low or there is no risk of hydroplaning.

[0069] Step S50, by monitoring the wheel speed, determine whether there is a risk of hydroplaning, and if so, output a speed reduction reminder.

[0070] In this embodiment, in step S30, the critical vehicle speed is calculated as the calculated value based on the preset water film thickness and the vehicle tire pressure. In order to ensure sufficient driving safety, it is also necessary to continuously monitor the wheel speed to observe whether the wheel has any phenomenon or trend of idling and slipping, and determine whether there is still a risk of hydroplaning. If there is still a risk of hydroplaning, the driver is further reminded to slow down through sound and light or the instrument screen to ensure driving safety.

[0071] In this embodiment, when the vehicle is driving in cruise mode, it detects the weather rainfall conditions and whether the road environment is prone to waterlogging, timely identifies the hydroplaning risk, real-time monitors the rotational speed of the wheels, observes whether there is a phenomenon or trend of wheel spin, and reduces the occurrence of vehicle hydroplaning by reducing the vehicle speed and giving warning, thereby improving the safety of the vehicle when driving in cruise mode.

[0072] Further, in one embodiment, step S10 includes:

[0073] When it is detected by the rain sensor that the rainfall is stable, and the current weather in the weather forecast is heavy rain or rainstorm, and the difference between the current time and the starting time of rainfall in the weather forecast is greater than a preset difference, it is detected that the rainfall condition is satisfied.

[0074] In this embodiment, the rainfall is detected by the in-vehicle rain sensor, and the stability of the rainfall can be detected by the formula (1 - λ AVR / λ min <n%), where λ is the infrared wavelength measured by the rain sensor, λ AVR is the average value of each infrared wavelength within the collected time period, λ min is the minimum value of each infrared wavelength within the collected time period, and n% represents the difference between the average value and the minimum value of the infrared wavelength, which can take values from 3% to 5%. When (1 - λ AVR / λ min <n% within the collected time period, it is detected that the rainfall is stable. To avoid errors that may be caused by other factors such as sprinkler trucks and to consider the rainfall situation in the weather forecast to ensure the accuracy of the rainfall condition detection, it is required that the current weather in the weather forecast is heavy rain or rainstorm, and the difference between the current time and the starting time of rainfall in the weather forecast is greater than a preset difference. For example, if the weather forecast from 3 o'clock to 3:30 is heavy rain or rainstorm, when the current time is 3:10, it can be determined that the rainfall condition of the weather forecast is satisfied. At this time, if it is detected by the rain sensor that the rainfall is stable, it is detected that the rainfall condition is satisfied.

[0075] Further, in one embodiment, step S20 includes:

[0076] According to the current driving road conditions, it is detected whether the preset conditions are satisfied. The preset conditions include:

[0077] There is a curve at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature;

[0078] There is an uphill at a preset distance in front of the vehicle, and the slope of the uphill is greater than the preset slope;

[0079] There is a downhill at a preset distance in front of the vehicle, and the slope of the downhill is greater than the preset slope;

[0080] If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

[0081] In this embodiment, in order to determine whether there is a risk of hydroplaning, in addition to satisfying the rainfall condition in step S10, it is also necessary to determine whether the road condition is prone to water accumulation. Road conditions that are prone to water accumulation are mainly divided into three types: curves with a small curvature, uphill with a large slope, and downhill with a large slope.

[0082] Furthermore, in one embodiment, step S30 includes:

[0083] Obtain preset water film thickness and vehicle tire pressure;

[0084] According to the preset water film thickness and vehicle tire pressure, the critical vehicle speed is calculated by the formula:

[0085]

[0086] Where V is the critical speed, P max is the maximum pressure at the center of the vehicle tire contact surface, which is 1.55 times the vehicle tire pressure, ρ is the density of water, R is the wheel radius, and H is the preset water film thickness.

[0087] In this embodiment, when it is determined that there is a risk of hydroplaning, the rainfall is heavy, and there is water on the road, the water film thickness can be set, for example, to 30 mm, and the vehicle tire pressure can be obtained through the tire pressure sensor.

[0088] Further, in one embodiment, referring to Figure 3 , Figure 3 for Figure 2 The detailed flow chart of step S40 is as follows: Figure 3 As shown, step S40 includes:

[0089] Step S401, when the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling on a flat road, the power output of the vehicle is controlled to reduce the vehicle speed to a safe speed;

[0090] Step S402, when the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling downhill and the downhill slope is greater than the preset slope, the vehicle power output is controlled and a speed reduction reminder is output to reduce the vehicle speed to a safe speed.

[0091] In this embodiment, when the vehicle speed exceeds the product of the preset percentage and the critical speed, there are three situations. The first is that when the vehicle is traveling uphill, the vehicle speed will automatically decrease due to resistance, so it is not considered in this embodiment. The second is that the vehicle is currently traveling on a flat road, so the power output of the vehicle is controlled. For example, the vehicle throttle can be controlled to achieve deceleration and reduce the vehicle speed to a safe speed. The third is that the vehicle is currently traveling downhill, and the slope of the downhill slope is greater than the preset slope. In this case, the vehicle speed is likely to increase too quickly. It is not enough to just control the power output of the vehicle. It is also necessary to remind the driver through sound and light or instrument screen, and take active braking through human intervention to reduce the vehicle speed to a safe speed to better ensure driving safety.

[0092] Further, in one embodiment, referring to Figure 4 , Figure 4 for Figure 2 The detailed flow chart of step S50 is as follows: Figure 4 As shown, step S50 includes:

[0093] Step S501, in a continuous time period, calculating a first wheel speed by using the current vehicle speed and the tire circumference, and obtaining a second wheel speed by using a sensor;

[0094] Step S502, collecting the first wheel speed and the second wheel speed for a preset number of consecutive times;

[0095] Step S503, respectively calculating the ratio between the first wheel speed and the second wheel speed to obtain the speed ratio of a preset number of times, and taking an average value of the speed ratio of the preset number of times to obtain the average value of the ratio of a single cycle;

[0096] Step S504, obtaining the average value of the ratio of each cycle;

[0097] Step S505, subtracting the average value of the ratio of the previous cycle from the average value of the ratio of the current cycle to obtain a difference;

[0098] Step S506: If the difference value decreases continuously, and the number of consecutive decreases reaches a preset number of decreases, it is determined that there is a risk of hydroplaning.

[0099] In this embodiment, in step S30, the critical vehicle speed calculated according to the preset water film thickness and the vehicle tire pressure is a calculated value. In order to ensure sufficient driving safety, it is also necessary to continuously monitor the wheel speed to observe whether the wheel has a phenomenon or tendency of idling and slipping, and determine whether there is still a risk of hydroplaning. The second wheel speed is obtained through a sensor. Specifically, the second wheel speed can be directly read through an anti-lock braking system (ABS) or an electronic stability control system (ESC). The second wheel speed is the actual wheel speed. The first wheel speed and the second wheel speed are continuously monitored and calculated. When driving under normal road conditions, the ratio of the first wheel speed to the second wheel speed is generally a fixed value or presents a small fluctuation state. If the difference finally calculated in this embodiment decreases continuously, and the number of continuous decreases reaches a preset number of decreases, such as 3-5 times, it means that the ground contact state of the wheel tire is unstable, and the wheel has a phenomenon or tendency of idling and slipping, and it is determined that there is a risk of hydroplaning.

[0100] In a third aspect, an embodiment of the present invention further provides a vehicle cruise control device.

[0101] Reference Figure 5 , Figure 5 FIG. 1 is a schematic diagram of functional modules of an embodiment of a vehicle cruise control device of the present invention.

[0102] In this embodiment, the vehicle cruise control device includes:

[0103] The detection module 10 is used to detect whether the rainfall condition is met when the vehicle is in the cruise mode;

[0104] A judgment module 20 is used to judge whether there is a risk of hydroplaning according to the current driving road conditions if yes;

[0105] A calculation module 30, for calculating a critical vehicle speed according to a preset water film thickness and a vehicle tire pressure;

[0106] The speed reduction module 40 is used to reduce the speed of the vehicle to a safe speed when the speed of the vehicle exceeds the product of a preset percentage and a critical speed;

[0107] The monitoring module 50 is used to determine whether there is a risk of hydroplaning by monitoring the wheel speed, and if so, output a speed reduction reminder.

[0108] Furthermore, in one embodiment, the detection module 10 is used to:

[0109] When the rainfall sensor detects that the rainfall is stable, and the weather forecast indicates that the current weather is heavy rain or rainstorm, and the difference between the current time and the rain start time in the weather forecast is greater than a preset difference, it is detected that the rainfall condition is met.

[0110] Furthermore, in one embodiment, the determination module 20 is used to:

[0111] According to the current driving road conditions, detect whether the preset conditions are met, and the preset conditions include:

[0112] A curve appears at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature;

[0113] An uphill slope appears at a preset distance in front of the vehicle, and the uphill slope is greater than the preset slope;

[0114] A downhill slope appears at a preset distance in front of the vehicle, and the slope of the downhill slope is greater than the preset slope;

[0115] If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

[0116] Furthermore, in one embodiment, the calculation module 30 is used to:

[0117] Obtain preset water film thickness and vehicle tire pressure;

[0118] According to the preset water film thickness and vehicle tire pressure, the critical vehicle speed is calculated by the formula:

[0119]

[0120] Where V is the critical speed, P max is the maximum pressure at the center of the vehicle tire contact surface, which is 1.55 times the vehicle tire pressure, ρ is the density of water, R is the wheel radius, and H is the preset water film thickness.

[0121] Furthermore, in one embodiment, the speed reduction module 40 is used to:

[0122] When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling on a flat road, the vehicle power output is controlled to reduce the vehicle speed to a safe speed;

[0123] When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling downhill and the downhill slope is greater than the preset slope, the vehicle's power output is controlled and a speed reduction reminder is output to reduce the vehicle's speed to a safe speed.

[0124] Furthermore, in one embodiment, the monitoring module 50 is used to:

[0125] In a continuous time period, a first wheel speed is calculated by using the current vehicle speed and the tire circumference, and a second wheel speed is obtained by using a sensor;

[0126] collecting the first wheel speed and the second wheel speed for a preset number of consecutive times;

[0127] Calculating the ratio between the first wheel speed and the second wheel speed respectively to obtain the speed ratio of a preset number of times, and taking an average value of the speed ratio of the preset number of times to obtain the average value of the ratio of a single cycle;

[0128] Get the average value of the ratio for each cycle;

[0129] Subtract the average value of the ratio of the previous period from the average value of the ratio of the current period to get the difference;

[0130] If the difference decreases continuously, and the number of consecutive decreases reaches a preset number of decreases, it is determined that there is a risk of hydroplaning.

[0131] Among them, the functional implementation of each module in the above-mentioned vehicle cruise control device corresponds to each step in the above-mentioned vehicle cruise control method embodiment, and its functions and implementation processes are no longer repeated here.

[0132] In a fourth aspect, an embodiment of the present invention further provides a readable storage medium.

[0133] The vehicle cruise control program is stored on the readable storage medium of the present invention, wherein when the vehicle cruise control program is executed by the processor, the steps of the vehicle cruise control method as described above are implemented.

[0134] The method implemented when the vehicle cruise control program is executed can refer to the various embodiments of the vehicle cruise control method of the present invention, and will not be described in detail here.

[0135] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or system. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or system including the element.

[0136] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0137] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus a necessary general hardware platform, and of course by hardware, but in many cases the former is a better implementation method. Based on such an understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for a terminal device to execute the methods described in each embodiment of the present invention.

[0138] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A vehicle cruise control method, characterized in that: The vehicle cruise control method comprises: When the vehicle is in cruise mode, detect whether the rainfall condition is met; If yes, determine whether there is a risk of hydroplaning based on the current driving conditions; If yes, the critical vehicle speed is calculated based on the preset water film thickness and the vehicle tire pressure; When the speed of the vehicle exceeds the product of the preset percentage and the critical speed, the speed of the vehicle is reduced to a safe speed; By monitoring the wheel speed, it determines whether there is a risk of hydroplaning. If so, a speed reduction reminder is output; Determining whether there is a risk of hydroplaning by monitoring the wheel speed includes: In a continuous time period, a first wheel speed is calculated by using the current vehicle speed and the tire circumference, and a second wheel speed is obtained by using a sensor; collecting the first wheel speed and the second wheel speed for a preset number of consecutive times; Calculating the ratio between the first wheel speed and the second wheel speed respectively to obtain the speed ratio of a preset number of times, and taking an average value of the speed ratio of the preset number of times to obtain the average value of the ratio of a single cycle; Get the average value of the ratio for each cycle; Subtract the average value of the ratio of the previous period from the average value of the ratio of the current period to get the difference; If the difference decreases continuously, and the number of consecutive decreases reaches a preset number of decreases, it is determined that there is a risk of hydroplaning.

2. The vehicle cruise control method according to claim 1, characterized in that: The detection of whether the rainfall condition is met includes: When the rainfall sensor detects that the rainfall is stable, and the weather forecast indicates that the current weather is heavy rain or rainstorm, and the difference between the current time and the rain start time in the weather forecast is greater than a preset difference, it is detected that the rainfall condition is met.

3. The vehicle cruise control method according to claim 1, characterized in that: The determining whether there is a risk of hydroplaning according to the current driving road condition includes: According to the current driving road conditions, detect whether the preset conditions are met, and the preset conditions include: A curve appears at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature; An uphill slope appears at a preset distance in front of the vehicle, and the uphill slope is greater than the preset slope; A downhill slope appears at a preset distance in front of the vehicle, and the slope of the downhill slope is greater than the preset slope; If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

4. The vehicle cruise control method according to claim 1, characterized in that: The calculating of the critical vehicle speed according to the preset water film thickness and the vehicle tire pressure includes: Obtain preset water film thickness and vehicle tire pressure; According to the preset water film thickness and vehicle tire pressure, the critical vehicle speed is calculated by the formula: Where V is the critical speed, P max is the maximum pressure at the center of the vehicle tire contact surface, which is 1.55 times the vehicle tire pressure, ρ is the density of water, R is the wheel radius, and H is the preset water film thickness.

5. The vehicle cruise control method according to claim 1, characterized in that: When the vehicle speed exceeds the product of the preset percentage and the critical speed, reducing the vehicle speed to a safe speed includes: When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling on a flat road, the vehicle power output is controlled to reduce the vehicle speed to a safe speed; When the vehicle speed exceeds the product of the preset percentage and the critical speed, if the vehicle is currently traveling downhill and the downhill slope is greater than the preset slope, the vehicle's power output is controlled and a speed reduction reminder is output to reduce the vehicle's speed to a safe speed.

6. A vehicle cruise control device, characterized in that: The vehicle cruise control device comprises: A detection module, used to detect whether a rainfall condition is met when the vehicle is in a cruise mode; A judgment module, for judging whether there is a risk of hydroplaning according to the current driving conditions if yes; a calculation module, for calculating the critical vehicle speed according to a preset water film thickness and a vehicle tire pressure; A speed reduction module, used for reducing the speed of the vehicle to a safe speed when the speed of the vehicle exceeds the product of a preset percentage and a critical speed; The monitoring module is used to determine whether there is a risk of hydroplaning by monitoring the wheel speed. If so, it outputs a speed reduction reminder; Monitoring module for: In a continuous time period, a first wheel speed is calculated by using the current vehicle speed and the tire circumference, and a second wheel speed is obtained by using a sensor; collecting the first wheel speed and the second wheel speed for a preset number of consecutive times; Calculating the ratio between the first wheel speed and the second wheel speed respectively to obtain the speed ratio of a preset number of times, and taking an average value of the speed ratio of the preset number of times to obtain the average value of the ratio of a single cycle; Get the average value of the ratio for each cycle; Subtract the average value of the ratio of the previous period from the average value of the ratio of the current period to get the difference; If the difference decreases continuously, and the number of consecutive decreases reaches a preset number of decreases, it is determined that there is a risk of hydroplaning.

7. The vehicle cruise control device according to claim 6, characterized in that: The judging module is used for: According to the current driving road conditions, detect whether the preset conditions are met, and the preset conditions include: A curve appears at a preset distance in front of the vehicle, and the curvature of the curve is less than the preset curvature; An uphill slope appears at a preset distance in front of the vehicle, and the uphill slope is greater than the preset slope; A downhill slope appears at a preset distance in front of the vehicle, and the slope of the downhill slope is greater than the preset slope; If at least one of the above preset conditions is met, it is determined that there is a risk of hydroplaning.

8. A vehicle cruise control device, characterized in that: The vehicle cruise control device includes a processor, a memory, and a vehicle cruise control program stored in the memory and executable by the processor, wherein when the vehicle cruise control program is executed by the processor, the steps of the vehicle cruise control method as described in any one of claims 1 to 5 are implemented.

9. A readable storage medium, characterized in that: The readable storage medium stores a vehicle cruise control program, wherein when the vehicle cruise control program is executed by a processor, the steps of the vehicle cruise control method according to any one of claims 1 to 5 are implemented.

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