A rear-end collision prevention backward warning method and system thereof

Abstract

The present invention relates to a rearward warning method and system for preventing rear-end collisions. The method includes the following steps: Step 1: Calculate the average deceleration value of the vehicle within a preset time period; Step 2: Determine whether the average deceleration value is greater than a preset threshold. If it is less than the threshold, inhibit the activation of the rearward warning function; if it is greater than the threshold, proceed to the next step; Step 3: Determine whether there is a vehicle coming from behind. If there is no vehicle coming from behind, inhibit the activation of the rearward warning function; if there is a vehicle coming from behind, proceed to the next step; Step 4: Determine whether the accelerator pedal is depressed. If it is depressed, inhibit the activation of the rearward warning function; if the accelerator pedal is not depressed, trigger the rearward warning function. It also includes a system for implementing the above method. The rearward warning function will only be activated in necessary and emergency situations to alert the vehicle behind of the danger ahead, thereby achieving the effect of reminding the vehicle behind to pay attention to decelerating or avoiding. The warning effect is better than that of frequently activating the warning.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle control methods, and particularly relates to a rearward warning method for preventing rear-end collisions and its system. Background Art

[0002] The "hazard warning flashers" function of a vehicle refers to a lighting warning function that makes the left and right turn signals flash simultaneously when the vehicle is in an abnormal state or in certain special driving situations. This function has obvious warning signals and is convenient to operate, which can well remind passing vehicles and pedestrians and reduce traffic accidents. On highways or in urban roads, the most common traffic accident is a rear-end collision. The main reason for rear-end collisions is that the driver's judgment of the driving state of the vehicle ahead is inaccurate and it is impossible to decelerate sufficiently in advance. Generally, when a vehicle decelerates, the "brake light" (also known as the "stop light") lights up. However, whether it is a slight brake or an emergency brake, the same brake light lights up, which cannot play an adequate warning role. Therefore, if the hazard warning flashers are used as a supplementary reminder, it can play a better warning role.

[0003] In the prior art, a motor vehicle automatic double-flash deceleration warning device with the publication number "CN205468757U" discloses a solution to control the on-off of the double-flash lights through the driver's operation of the accelerator. Specifically, when the driver releases the accelerator, the double-flash warning lights are automatically turned on, and when the driver steps on the accelerator to accelerate, the double-flash lights are turned off. In addition, there is also a motor vehicle brake reminder device with the publication number "CN203832339U" that discloses a solution to control the on-off of the double-flash lights through the driver's operation of the brake pedal. Specifically, when the brake pedal is depressed, the double-flash lights of the motor vehicle are turned on, and when the brake of the motor vehicle is cancelled, the double-flash lights of the motor vehicle are automatically turned off. This solution only replaces the brake lights with double-flash lights or makes the double-flash lights have the same starting mechanism as the brake lights.

[0004] In the above two technical solutions, the double-flash lights will be frequently turned on, which cannot play a warning effect in an emergency. Summary of the Invention

[0005] One object of the present invention is to provide a rearward warning method for preventing rear-end collisions to solve the problem of poor warning effect caused by the frequent turning on of the double-flash lights in the prior art; the second object is to provide a rearward warning system for preventing rear-end collisions.

[0006] To achieve the above objects, the technical solutions adopted by the present invention are as follows:

[0007] A rearward warning method for preventing rear-end collisions includes the following steps:

[0008] Step 1: Calculate the average deceleration value of the vehicle within a preset time period;

[0009] Step 2: Determine whether the average deceleration value is greater than a preset threshold; if it is less than the threshold, the rear warning function is inhibited from being turned on; if it is greater than the threshold, proceed to the next step;

[0010] Step 3: Determine whether there is a vehicle approaching from behind; if there is no vehicle approaching, the rear warning function is inhibited from being turned on; if there is a vehicle approaching, proceed to the next step;

[0011] Step 4: Determine whether the accelerator pedal is depressed; if it is depressed, the rear warning function is inhibited from being turned on; if the accelerator pedal is not depressed, the rear warning function is triggered.

[0012] According to the above technical means, the activation of the rear warning function is based on whether the average deceleration value is greater than a preset threshold, which can be set by the vehicle manufacturer through on-road tests. It can be obtained by summarizing the speed change situations that are prone to rear-end collisions. When the average deceleration value is greater than the preset threshold, it can be initially judged that regardless of the reason of the driver, in terms of vehicle speed, emergency braking is being taken to quickly reduce the vehicle speed. The preset threshold can exclude misjudgments caused by slight decelerations resulting from gently stepping on the pedal or releasing the accelerator. After judging that it is greater than the threshold, in order to prevent the following vehicle from continuing to approach at a relatively high speed, it is necessary to consider triggering the rear warning function to give a reminder. In order to further prevent the rear warning function from being triggered frequently, it is necessary to judge whether there is a vehicle approaching from behind and whether the accelerator pedal is depressed. If the accelerator pedal is depressed, it means that the vehicle speed has started to increase again and the state of emergency braking has ended, and the activation of the rear warning function can be inhibited. On the contrary, it means that the vehicle is still in a low-speed state, and the rear warning function is triggered to send a warning to the following vehicle.

[0013] Further, in Step 1, the average deceleration value is calculated by collecting the vehicle speed signal of the vehicle, specifically as follows:

[0014] d = (Vn - V) / N

[0015] In the formula, d is the average deceleration value; Vn is the vehicle speed at the initial moment within a preset time period; V is the vehicle speed at the last moment within a preset time period; N is the length of the preset time period.

[0016] According to the above technical means, the length of the time period is also set by the vehicle manufacturer through on-road tests. Since the changes in the vehicle often occur within a few seconds, the length of the time period is also in seconds and should not be too long. If the length of the time period is 2 seconds, there are a total of three moments, and the time interval between adjacent two moments is 1 second. If the time length is 3 seconds, there are a total of four moments, and the time interval between adjacent two moments is 1 second.

[0017] Further, the preset time period has the current moment of the vehicle as the last moment of the time period, Vn is the vehicle speed N seconds before the vehicle, and V is the current vehicle speed.

[0018] According to the above technical means, the average deceleration value is judged by comparing the current vehicle speed with the vehicle speed N seconds ago. In this way, it is possible to more quickly determine from the vehicle speed whether the rear warning function needs to be triggered, with the effects of fast response speed and good safety.

[0019] Furthermore, the preset time period is the previous time period of length N at the current moment of the vehicle. Vn is the vehicle speed N + 1 seconds ago, and V is the vehicle speed 1 second ago.

[0020] According to the above technical means, the average deceleration value is judged based on a time period before the current moment of the vehicle. Such a judgment will be more accurate. In actual operation, since there is a certain operation time for human operation, if the driver wants to step on the accelerator pedal to accelerate at the current moment, due to factors such as reaction time, body movement time, data transmission time, and time to trigger the accelerator pedal, it is possible that it is not judged as stepping on the accelerator pedal at the current moment and is delayed to the next moment. Therefore, by judging whether the average deceleration value of the time period before the current moment of the vehicle is greater than the threshold value, if it is greater than the threshold value, it indicates an emergency brake. Then, it is further judged whether the accelerator pedal is stepped on at the current moment. If the accelerator pedal is stepped on, it means that the emergency brake state has passed and the vehicle speed is increasing. If the accelerator pedal is not stepped on, it means that the emergency brake is still in progress.

[0021] Furthermore, in step four, it is judged whether the accelerator pedal is stepped on by obtaining the travel signal of the accelerator pedal.

[0022] According to the above technical means, the travel signal of the accelerator pedal indicates that the accelerator pedal has a certain travel movement. At this time, judging whether the accelerator pedal is stepped on can be more accurate, avoiding misjudgment caused by the driver simply placing the foot on the accelerator pedal.

[0023] Furthermore, the rear warning function includes the turning on and off of the hazard lights.

[0024] According to the above technical means, suppressing the activation of the rear warning function is to keep the hazard lights in the off state, while triggering the rear warning function is to keep the hazard lights in the on state. Since the vehicle performs the judgment of the above steps at each moment, the hazard lights at that moment will remain in the on or off state. The states of the hazard lights at all moments are connected together, and the external display effect is that the hazard lights can be continuously off, continuously on, or briefly on for a period of time.

[0025] A rear warning system for implementing the above-mentioned rear-end collision prevention rear warning method, comprising a controller, an accelerator pedal, a vehicle speed sensor, a hazard warning flasher installed at the rear of the vehicle, and a rear sensor installed at the rear of the vehicle; the accelerator pedal, the hazard warning flasher, the vehicle speed sensor, and the rear sensor are all electrically connected to the controller, and the controller includes an acquisition unit for acquiring vehicle speed signals, accelerator pedal travel signals, and rear sensor signals, and an operation unit for calculating the average deceleration value and performing numerical comparison.

[0026] According to the above technical means, the vehicle speed signal can be acquired at the vehicle speed sensor of the vehicle. After the acquisition unit acquires the vehicle speed signal, the operation unit performs operations based on the vehicle speed signal. The acquisition unit acquires the accelerator pedal travel signal and the rear sensor signal for conditional judgment, where the accelerator pedal travel signal and the rear sensor signal can be digital signals or high and low level signals. After the operation unit performs vehicle speed calculation, it compares the calculated average deceleration value with a preset threshold, and outputs a high and low level result to the controller. If it is greater than the threshold, it is a high level, and if it is lower than the threshold, it is a low level. The controller delivers a working signal to the hazard warning flasher according to the output result of the operation unit and the signals acquired by the acquisition unit, and this working signal is a signal to turn the hazard warning flasher on or off.

[0027] Further, the rear sensor can be any device for obtaining whether there is a target object behind, such as a radar, a camera, or an infrared sensor, where the radar can be a millimeter wave radar or a lidar, etc.

[0028] According to the above technical means, the radar and the infrared sensor can judge whether there is an object within a certain distance behind. If there is an object, it means there is a vehicle coming from behind. The camera takes pictures or videos and identifies whether there is a vehicle coming from behind through the image or video data.

[0029] Further, the rear sensor is installed at the center of the rear of the vehicle.

[0030] According to the above technical means, the rear sensor being located at the center of the vehicle can avoid misjudgment of the detection result caused by a vehicle coming from the side.

[0031] Further, it further includes a display, the controller is electrically connected to the display, and the display is used to display the working information of the hazard warning flasher after the hazard warning flasher is triggered.

[0032] According to the above technical means, when the hazard warning flasher is turned on because the average deceleration value is greater than the preset threshold, the display shows the working information of the hazard warning flasher being turned on to remind the driver to also pay attention to the vehicle coming from behind. In this way, it can not only remind the following vehicle, but also remind the driver, further preventing the occurrence of rear-end collision accidents.

[0033] Advantages of the present invention: By setting a threshold value for the average deceleration value, the rearward warning function is considered to be activated only when the average deceleration value is greater than the threshold, avoiding the activation of the rearward warning function due to light pedal pressing or throttle release. After considering whether to activate the rearward warning function, judgments are made on whether there is a following vehicle and whether to accelerate again. Finally, the rearward warning function will be activated only in necessary and urgent situations to remind the following vehicle of the danger ahead, thereby achieving the effect of reminding the following vehicle to pay attention to decelerating or avoiding. The warning effect is better than that of frequently activating the warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a flowchart of a rearward warning method for preventing rear-end collisions according to the present invention;

[0035] Figure 2 is a logic flowchart of a rearward warning method for preventing rear-end collisions according to the present invention;

[0036] Figure 3 is a schematic diagram of modules of a rearward warning system for preventing rear-end collisions according to the present invention;

[0037] Figure 4 is a schematic diagram of the working state of a rearward warning system for preventing rear-end collisions according to the present invention.

[0038] Among them, 1 - vehicle; 2 - hazard warning lights; 3 - rearward sensor; 4 - following vehicle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following will describe the embodiments of the present invention with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for explaining the present invention, rather than for limiting the protection scope of the present invention.

[0040] It should be noted that the diagrams provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner. Therefore, only the components related to the present invention are shown in the diagrams, rather than being drawn according to the number, shape, and size of the components in actual implementation. The types, numbers, and proportions of the components in actual implementation can be arbitrarily changed, and the component layout type may also be more complex.

[0041] This embodiment proposes a rearward warning method for preventing rear-end collisions as shown in Figure 1 and includes the following steps:

[0042] Step 1: Calculate the average deceleration value of the vehicle within a preset time period by collecting the vehicle speed signal, specifically as follows:

[0043] d = (Vn - V) / N

[0044] Wherein, d is the average deceleration value; Vn is the vehicle speed at the initial moment within a preset time period; V is the vehicle speed at the last moment within a preset time period; N is the length of the preset time period.

[0045] Step Two: Determine whether the average deceleration value is greater than a preset threshold; if it is less than the threshold, inhibit the activation of the rear warning function; if it is greater than the threshold, proceed to the next step;

[0046] Step Three: Determine whether there is a vehicle coming from behind; if there is no vehicle coming from behind, inhibit the activation of the rear warning function; if there is a vehicle coming from behind, proceed to the next step;

[0047] Step Four: Determine whether the accelerator pedal is depressed; if it is depressed, inhibit the activation of the rear warning function; if the accelerator pedal is not depressed, trigger the rear warning function.

[0048] In this embodiment, the rear warning function includes the turning on and off of the hazard lights. Inhibiting the activation of the rear warning function means turning off the hazard lights or keeping them off, while triggering the rear warning function means turning on the hazard lights or keeping them on. Since the vehicle performs the judgment of the above steps at each moment, the hazard lights at that moment will remain on or off. The states of the hazard lights at all moments are connected together, and the external display effect is that the hazard lights can be continuously off, continuously on, or briefly on within a time period.

[0049] The activation of the rear warning function is based on whether the average deceleration value is greater than a preset threshold. Both the threshold and the length of the time period can be set by the vehicle manufacturer through in-vehicle tests, and it can be obtained by summarizing the vehicle speed change situations that are prone to rear-end collisions. When the average deceleration value is greater than the preset threshold, it can be preliminarily judged that regardless of the reason of the driver, in terms of vehicle speed performance, it is to take emergency braking to quickly reduce the vehicle speed. The preset threshold can exclude misjudgments caused by slight deceleration due to gently stepping on the pedal or releasing the accelerator. The preset threshold is preferably greater than 6 m / s 2 , and the time period is preferably between 2 - 4 seconds. In this embodiment, the preset time period is 2 seconds, and the preset threshold is 8 m / s 2 .

[0050] After determining that the speed is greater than the threshold value, in order to prevent the following vehicle from approaching at a relatively high speed, it is necessary to consider triggering the activation of the hazard lights for warning. To further prevent the hazard lights from being frequently triggered, it is necessary to first determine whether there is a vehicle approaching from behind and whether the accelerator pedal has been depressed. If the accelerator pedal has been depressed, it indicates that the vehicle speed has started to increase again and the emergency braking state has ended, which can inhibit the activation of the hazard lights, that is, turn off the hazard lights or maintain the hazard lights in the off state. Otherwise, it indicates that the vehicle is still in a low-speed state, and the hazard lights will be triggered or maintained in the on state to issue a warning to the following vehicle. The logical control flow of this embodiment is as follows Figure 2 shown

[0051] In this embodiment, the preset time period has the current moment of the vehicle as the last moment of the time period. Vn is the vehicle speed N seconds ago, and V is the current vehicle speed. The determination of the average deceleration value is based on the comparison between the current vehicle speed and the vehicle speed N seconds ago. This can more quickly reflect from the vehicle speed whether the rearward warning function should be triggered, and has the effects of fast response speed and good safety. Taking the above-mentioned preset time period of 2 seconds and the preset threshold value of 8 m / s 2 as an example. The vehicle speed at the current moment is 50 km / h, approximately 13.9 m / s, and the vehicle speed 2 seconds ago was 110 km / h, approximately 30.65 m / s. Then the average deceleration value is approximately 8.4 m / s 2 , which is greater than the preset threshold value. At this time, it is also detected that there is a vehicle approaching from behind at the current moment and the accelerator pedal has not been depressed, so the hazard lights are turned on. In a similar situation, the difference is that if the accelerator pedal has been depressed at the current moment or there is no vehicle approaching from behind, the hazard lights are turned off.

[0052] In this embodiment, in step four, it is determined whether the accelerator pedal has been depressed by obtaining the travel signal of the accelerator pedal. The travel signal of the accelerator pedal indicates that the accelerator pedal has a certain amount of travel movement. At this time, determining whether the accelerator pedal has been depressed can be more accurate and avoid misjudgment caused by the driver simply placing their foot on the accelerator pedal.

[0053] Another calculation method for the average deceleration value is also provided, specifically: the preset time period is the previous time period of length N at the current moment of the vehicle, Vn is the vehicle speed N + 1 seconds ago, and V is the vehicle speed 1 second ago. Since in actual operation, people's operations all have a certain operation time, so if the driver wants to step on the accelerator pedal to accelerate at the current moment, but due to factors such as reaction time, body movement time, data transmission time, and trigger time of the accelerator pedal, it may not be judged as stepping on the accelerator pedal at the current moment and be delayed to the next moment. Therefore, by judging whether the average deceleration value of the time period before the current moment of the vehicle is greater than the threshold value, if it is greater than the threshold value, it indicates emergency braking. Then, it is judged whether the accelerator pedal is stepped on at the current moment. If the accelerator pedal is stepped on, it means that the emergency braking state has passed and the vehicle speed is already increasing. If the accelerator pedal is not stepped on, it means that the emergency braking is still in progress. The judgment of the average deceleration value is made according to a time period before the current moment of the vehicle, and such judgment accuracy will be better. Taking the above preset time period of 2 seconds and the preset threshold value of 8m / s 2 as an example. The speed of the vehicle at the current moment is 50, the vehicle speed 1 second before the current moment is 49km / h, approximately 13.6m / s, and the vehicle speed 3 seconds ago is 110, approximately 30.65m / s. Then the average deceleration value is 8.5m / s 2 , which is greater than the preset threshold value. At this time, it is also detected that there is a vehicle coming from behind and the accelerator pedal has been stepped on, so the hazard warning lights are turned off.

[0054] This embodiment also proposes a rear warning system for implementing the above rear-end collision prevention warning method, as shown in Figure 3 and Figure 4 , including a controller, an accelerator pedal, a vehicle speed sensor, a hazard warning light 2 installed at the rear of vehicle 1, and a rear sensor 3 installed at the rear of vehicle 1; the accelerator pedal, the hazard warning light 2, the vehicle speed sensor, and the rear sensor 3 are all electrically connected to the controller. The controller includes an acquisition unit for acquiring vehicle speed signals, accelerator pedal travel signals, and signals of the rear sensor 3, and an operation unit for calculating the average deceleration value and performing numerical comparison.

[0055] In this embodiment, the rear sensor 3 is a camera and is installed at the center of the rear of vehicle 1. The camera takes pictures or videos to identify whether there is a vehicle coming from behind in the image or video data.

[0056] In this embodiment, it further includes a display. The controller is electrically connected to the display, and the display is used to display the working information of the double flash lamp 2 after the double flash lamp 2 is triggered. The display can be a human-machine interactive screen. When the double flash lamp 2 is turned on because the average deceleration value is greater than the preset threshold, the display shows the working information that the double flash lamp 2 is turned on and displays the image captured by the camera on the display screen to remind the driver to also pay attention to the vehicle 4 behind. In this way, it can not only remind the vehicle 4 behind, but also remind the driver, further preventing the occurrence of rear-end collisions.

[0057] In the above technical solution, the vehicle speed signal can be collected at the vehicle speed sensor of the vehicle 1. After the vehicle speed signal is collected by the collection unit, the operation unit performs operations according to the vehicle speed signal. The throttle pedal travel signal and the rearward sensor 3 signal collected by the collection unit are used for conditional judgment. The throttle pedal travel signal and the rearward sensor 3 signal can be digital signals or high and low level signals. After the operation unit performs vehicle speed calculation, it compares the calculated average deceleration value with the preset threshold and outputs a high and low level result to the controller. For example, if it is greater than the threshold, it is a high level, and if it is lower than the threshold, it is a low level. The controller delivers the working signal to the double flash lamp 2 according to the output result of the operation unit and the signals collected by the collection unit. This working signal is a signal to turn the double flash lamp 2 on or off.

[0058] In the above-mentioned rearward warning method and rearward warning system for preventing rear-end collisions, by setting the threshold of the average deceleration value, the double flash lamp is only considered to be turned on when the average deceleration value is greater than the threshold, avoiding starting the double flash lamp due to light pedal stepping or releasing the accelerator and other situations. After considering whether to turn on the flash, etc., it then judges whether there is an oncoming vehicle and whether to accelerate again. Finally, the double flash lamp will only be started in necessary and urgent situations to remind the vehicle behind of the danger ahead, thereby achieving the effect of reminding the vehicle behind to pay attention to decelerating or avoiding, making the warning effect of starting the double flash lamp better than the effect of frequently starting the double flash lamp in the prior art.

[0059] The above embodiments are only preferred embodiments given to fully illustrate the present invention, and the protection scope of the present invention is not limited thereto. Equivalent substitutions or transformations made by those skilled in the art on the basis of the present invention are all within the protection scope of the present invention.

Claims

1. A rear - end collision prevention backward warning method, comprising the following steps: Step 1: Calculate the average deceleration value of the vehicle within a preset time period; Step 2: Determine whether the average deceleration value is greater than a preset threshold; if it is less than the threshold, inhibit the activation of the backward warning function; if it is greater than the threshold, proceed to the next step; Step 3: Determine whether there is a vehicle coming from behind the vehicle; if there is no vehicle coming from behind, inhibit the activation of the backward warning function; if there is a vehicle coming from behind, proceed to the next step; Step 4: Determine whether the accelerator pedal is depressed; if it is depressed, inhibit the activation of the backward warning function; if the accelerator pedal is not depressed, trigger the backward warning function.

2. The rear-end collision prevention backward warning method according to claim 1, characterized in that: In Step 1, the average deceleration value is calculated by collecting the vehicle speed signal of the vehicle, specifically as follows: d = (Vn - V) / N In the formula, d is the average deceleration value; Vn is the vehicle speed at the initial moment within the preset time period; V is the vehicle speed at the last moment within the preset time period; N is the length of the preset time period.

3. The rear-end collision prevention backward warning method according to claim 2, characterized in that: The preset time period takes the current moment of the vehicle as the last moment of the time period, Vn is the vehicle speed N seconds ago of the vehicle, and V is the current vehicle speed of the vehicle.

4. The rear-end collision prevention backward warning method according to claim 2, characterized in that: The preset time period is the previous time period of length N of the current moment of the vehicle, Vn is the vehicle speed N + 1 seconds ago of the vehicle, and V is the vehicle speed 1 second ago of the vehicle.

5. The rearward warning method for preventing rear-end collision according to claim 1, characterized in that: In Step 4, it is determined whether the accelerator pedal is depressed by obtaining the travel signal of the accelerator pedal.

6. The rear warning method for preventing rear-end collision according to any one of claims 1-5, characterized in that: The backward warning function includes the turning on and off of the hazard lights.

7. A rear-end collision prevention backward warning system for implementing the rear-end collision prevention backward warning method according to any one of claims 1-6, comprising a controller, an accelerator pedal, a vehicle speed sensor, a hazard warning flasher (2) installed at the rear of the vehicle (1), and a rearward sensor (3) installed at the rear of the vehicle (1); the accelerator pedal, the hazard warning flasher (2), the vehicle speed sensor, and the rearward sensor (3) are all electrically connected to the controller, and are characterized in that: The controller includes a collection unit for collecting the vehicle speed signal, the accelerator pedal travel signal, and the signal of the rearward sensor (3), and an arithmetic unit for calculating the average deceleration value and performing numerical comparison.

8. The rear warning system for preventing rear-end collisions according to claim 7, characterized in that: The rearward sensor (3) is a radar, a camera, or an infrared sensor.

9. The rear warning system for preventing rear-end collisions according to claim 7, characterized in that: The rearward sensor (3) is installed at the center of the rear of the vehicle (1).

10. The rear warning system for preventing rear-end collisions according to claim 7, characterized in that: It further includes a display, the controller is electrically connected to the display, and the display is used to display the working information of the hazard lights after the hazard lights are triggered.

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