TWI573713B - Indicating device and method for driving distance with vehicles - Google Patents

Description

Driving distance prompting device and method thereof

The present invention relates to a cueing device, and more particularly to a cueing device for a driving distance and a method thereof.

In general, the vehicle can determine the distance between the vehicle and other vehicles through the sensing device installed in the vehicle during driving. The aforementioned sensing device may be, for example, a microwave radar sensing system, an infrared photoelectric radar sensing system, or an ultrasonic radar sensing system. However, in the case of a microwave radar sensing system, there is a problem that the volume is too large, the installation is difficult, and the price is expensive. The infrared photoelectric radar sensing system or the ultrasonic radar sensing system has a short sensing distance, so it is not suitable for the vehicle to travel at a high speed and requires a long safe distance.

In view of the above, the present invention discloses a driving distance prompting device and a method thereof, which are used as a basis for judging whether a driving distance is safe or not by capturing a vehicle image.

Embodiments of the present invention provide a driving distance prompting device, which is applicable to a first vehicle. The device can calculate the distance traveled between the first vehicle and the second vehicle. The device comprises an image capturing module, a prompting module and a processing module. The image capturing module is used to obtain a vehicle image of the second vehicle. The processing module is coupled to the image capturing module and the prompting module. When the first vehicle is traveling on the road, the processing module first captures the license plate image in the vehicle image of the second vehicle, and according to the image characteristics of the license plate image. A driving distance between the first vehicle and the second vehicle is calculated. And, when the processing module calculates the safety distance according to the driving speed and the image feature of the first vehicle, it is determined whether the driving distance is greater than the safety distance. When the processing module determines that it is YES, the control prompt module correspondingly outputs a prompt message.

Embodiments of the present invention provide a driving distance prompting method, which is applicable to a first vehicle. This method calculates the distance traveled between the first vehicle and the second vehicle. This method first acquires the vehicle image of the second vehicle and captures the license plate image in the vehicle image. When the license plate image is obtained, the driving distance between the first vehicle and the second vehicle is calculated according to the image characteristics of the license plate image. And calculating a safety distance according to the driving speed and image characteristics of the first vehicle. Next, it is determined whether the driving distance is greater than the safety distance. When it is determined that the driving distance is greater than the safety distance, it is determined according to the determination result that the prompt message is output correspondingly to notify the driver of the first vehicle.

Based on the above, the driving distance prompting device and the method thereof according to the embodiment of the present invention use the image capturing means to obtain the vehicle image of the second vehicle and analyze the obtained license plate image, thereby converting the driving between the first vehicle and the second vehicle. distance. Moreover, the safety distance that the first vehicle and the second vehicle should be maintained may also be calculated according to the driving speed of the first vehicle and the image features in the license plate image of the second vehicle. Thereby, the present invention can quickly and accurately determine whether the driving distance is safe through a simple hardware structure.

In order to further understand the technology, method and function of the present invention in order to achieve the intended purpose, reference should be made to the detailed description and drawings of the invention. The drawings and the annexed drawings are to be considered as illustrative and not restrictive.

1, 3‧‧‧ first vehicle

2, 4‧‧‧ second vehicle

5‧‧‧ Third vehicle

12, 20‧‧‧ Driving distance indicating device

201, 32, 34‧‧‧ image capture module

203‧‧‧Processing module

205‧‧‧ prompt module

207‧‧‧ Warning Module

209‧‧‧Video Module

211‧‧‧Communication Module

213‧‧‧Speed signal input interface

215‧‧‧ storage module

217‧‧‧protection module

42a, 42b, 42c‧‧‧ Vehicle imagery

44a, 44b, 44c‧‧‧ license plate image

Steps S701, S703, S705, S707, S709, S711, S713‧‧

FIG. 1 is a side elevational view of a vehicle for setting a driving distance indicating device according to an embodiment of the present invention.

FIG. 2 is a functional block diagram of a driving distance prompting device according to an embodiment of the present invention.

FIG. 3 is a rear view of the vehicle for setting the driving distance prompting device on the road according to an embodiment of the present invention.

4A-4C are schematic diagrams of vehicle images acquired by an image capturing module according to an embodiment of the present invention.

5A-5B are a comparison table of determining a driving distance by using a preset license plate size according to an embodiment of the present invention.

FIG. 6 is a comparison table of the license plate size and the license plate image percentage to determine the driving distance according to an embodiment of the present invention.

FIG. 7 is a schematic flow chart of a driving distance prompting method according to an embodiment of the present invention.

FIG. 8 is a side elevational view of a vehicle for setting a driving distance prompting device according to another embodiment of the present invention.

The present invention provides a driving distance prompting device and method thereof for determining a safe distance between a vehicle in a driving vehicle and a front and/or rear vehicle by capturing front and/or rear vehicle image data. More specifically, the foregoing vehicle image includes a license plate image, and the present invention determines the driving between the currently traveling vehicle and the front and/or rear vehicles through the related image features of the license plate image and the combined driving speed. Whether the distance meets the distance.

[Driving distance indicating device embodiment]

FIG. 1 is a side elevational view of a vehicle for setting a driving distance indicating device according to an embodiment of the present invention. Referring to FIG. 1 , the first vehicle 1 and the second vehicle 2 travel on a road, and the first vehicle 1 is located behind the second vehicle 2 in the traveling direction. As shown in FIG. 1 , the driving distance indicating device 12 is disposed in the first vehicle 1 In front of the vehicle. In general, the driving distance indicating device 12 is disposed on the windshield, for example, similarly to the bracket using a common driving recorder, so that the driving distance indicating device 12 can perform its function normally through the windshield of the first vehicle 1, and The second vehicle 2 facing the front can be seen in the field of view. The present invention does not limit the specific installation position of the driving distance indicating device 12, and any place where the driving distance indicating device 12 can be disposed in front of the first vehicle 1 without being obscured by other objects of the first vehicle 1 can be realized. The present invention provides a means for setting the driving distance indicating device 12 on the first vehicle 1.

FIG. 2 is a functional block diagram of a driving distance prompting device according to an embodiment of the present invention. Referring to FIG. 1 and FIG. 2 simultaneously, the driving distance indicating device 20 is applied to the first vehicle 1 for calculating the driving distance between the first vehicle 1 and the second vehicle 2. The driving distance prompting device 20 includes an image capturing module 201, a processing module 203, a prompting module 205, a warning module 207, a video module 209, a communication module 211, a speed signal input interface 213, and a storage module 215. The detailed components of the driving distance indicating device 20 will be further described below.

Referring to FIG. 1 and FIG. 2 simultaneously, the image capturing module 201 is configured to capture a vehicle image of the second vehicle 2 . In this example, the first vehicle 1 trails to the second vehicle 2, and the driving distance indicating device 20 is disposed in front of the vehicle of the first vehicle 1, and the image capturing module 201 acquires the vehicle image behind the second vehicle 2. . In another example, the first vehicle 1 travels in front of the second vehicle 2 and the driving distance indicating device 20 is disposed behind the vehicle of the first vehicle 1 (not shown), and the image capturing module 201 obtains the second vehicle. Vehicle image in front of 2. It should be noted that, when the driving distance indicating device 20 is disposed on the first vehicle 1, the field of view of the image capturing module 201 is a means for facing the front license plate and/or the rear license plate of the second vehicle 2, so that the second The front license plate and/or the rear license plate of the vehicle 2 may be included in the vehicle image captured by the image capture module 201. The image capturing module 201 can implement the image capturing module 201 of the present invention by any device having a photographic lens, such as a camera, a digital camera, or a mobile phone.

Please refer to FIG. 1 and FIG. 2 simultaneously, the processing module 203 is coupled to the image capturing module. 201. Process the vehicle image and calculate the driving distance between the first vehicle 1 and the second vehicle 2 from the vehicle image. In the embodiment, the processing module 203 analyzes the vehicle image acquired by the image capturing module 201 to obtain the license plate image of the second vehicle 2 . The processing module 203 further analyzes the image features in the vehicle image, for example, using image processing technology to analyze the license plate frame in the vehicle image to obtain the range of the license plate image in the vehicle image, or analyze the license plate number in the license plate image and / or license plate color. The processing module 203 is, for example, an image processing chip or an image processor. The present invention is not limited by such means, and those skilled in the art to which the present invention pertains can be implemented using any image analysis means. The image features in the vehicle image can provide a processing module 203 to calculate the distance traveled. The method by which the processing module 203 calculates the driving distance based on the image features will be described in the following embodiments.

Referring to FIG. 1 and FIG. 2 simultaneously, the speed signal input interface 213 can obtain the driving speed of the first vehicle 1. The driving distance indicating device 20 can be connected to the driving computer of the first vehicle, the main control system or the GPS system (not shown) through the circuit and the speed signal input interface 213 to obtain the driving speed or other related information of the first vehicle 1. The prompt module 205 is coupled to the processing module 203 and can output a prompt message for alerting the driver or a nearby driver. Specifically, the processing module 203 further includes calculating a safety distance that the first vehicle 1 should maintain with the second vehicle 2 according to the driving speed and image characteristics of the first vehicle 1. The method of calculating the safety distance will be explained in the following embodiments. After calculating the safety distance, the processing module 203 determines whether the driving distance between the first vehicle 1 and the second vehicle 2 is greater than the safety distance between the first vehicle 1 and the second vehicle 2 . When the processing module 203 determines that the driving distance is less than the safety distance, the processing module 203 controls the prompting module 205 to output a prompt message. The prompt module 205 is, for example, a display panel or a speaker. The prompt message output by the prompt module 205 is, for example, a vehicle deceleration prompt message when the first vehicle 1 travels behind the second vehicle 2 and the driving distance is less than a safe distance, or is the first The vehicle acceleration prompt message when the vehicle 1 travels in front of the second vehicle 2 and the driving distance is less than the safety distance.

Referring to FIG. 1 and FIG. 2 simultaneously, the storage module 215 is used for storing vehicle images. The image features and a comparison table that can provide the processing module 203 to convert the driving distance. A detailed description of the comparison table will be presented in the following schema. The warning module 207 is coupled to the processing module 203 for outputting an alert message. After calculating the safety distance, the processing module 203 processes, in addition to determining whether the driving distance between the first vehicle 1 and the second vehicle 2 is greater than the safety distance between the first vehicle 1 and the second vehicle 2, The module 203 also determines whether the driving distance is less than the warning distance. When the processing module 203 determines that the driving distance is less than the warning distance, the processing module 203 controls the warning module 207 to output an alert message. The warning distance is another criterion for determining the safety distance, such as a preset value set by the user. When the processing module 203 determines that the driving distance is less than the warning distance, since the warning distance is less than the safety distance, it indicates that the driving distance between the first vehicle 1 and the second vehicle 2 is too small, thereby causing an increased risk of collision of the vehicles, and More urgent messages to prompt the user. The alert module 207 is, for example, a display panel or a speaker. In this example, the warning message is, for example, a light number message for controlling the headlights of the first vehicle 1, or a sound message for controlling the horn of the first vehicle 1, a combination of the two, or one of them.

Referring to FIG. 1 and FIG. 2 simultaneously, the video module 209 is coupled to the processing module 203 and controlled by the processing module 203. In this example, when the processing module 203 determines that the driving distance between the first vehicle 1 and the second vehicle 2 is less than the safety distance between the first vehicle 1 and the second vehicle 2, the processing module The 203 control video module 209 stores the vehicle image captured by the image capturing module 201. The communication module 211 is coupled to the processing module 203 and controlled by the processing module 203. In this example, when the processing module 203 determines that the driving distance between the first vehicle 1 and the second vehicle 2 is smaller than the warning distance between the first vehicle 1 and the second vehicle 2, the processing is processed. The module 203 controls the communication module 211 to output the vehicle image stored by the video module 209 to the remote network server for backup storage through the communication network. The protection module 217 is coupled to the processing module 203. When detecting that the distance between the first vehicle 1 and the second vehicle 2 is less than the warning distance, the protection module 217 starts a protection program to control the driving of the first vehicle 1, for example, control interruption. The first vehicle continues to approach the second vehicle 2. The protection module 217 is for example protected ABS (Anti-Lock Brake System) or other control system that controls the vehicle protection of the first vehicle 1 such as the tracking brake system and the stability control system. In an embodiment, the warning module 207 issues a warning light or a warning sound to the second vehicle 2 while the protection module 217 of the first vehicle 1 initiates the distance between the protection program control and the second vehicle 2. In another embodiment, the protection module 217 can be activated when the warning module 207 sends an alert message. For example, the protection module 217 is activated when the driver makes an emergency brake under any circumstances. The present invention is directed to the warning module 207. And the protection module 217 will be started at the same time as an exemplary description, and is not intended to be a limitation of the present invention. In addition, when the processing module 203 determines that the driving distance is less than the warning distance or the safety distance, the embodiment of the present invention provides that both the warning module 207 and the protection module 217 are activated, for example, only the warning module 207 sends a warning message. The protection module 217 is activated and can be set according to actual use conditions.

FIG. 3 is a rear view of the vehicle for setting the driving distance prompting device on the road according to an embodiment of the present invention. Referring to FIG. 3, the first vehicle 1 is traveling in the second vehicle 2, and the driving distance indicating device 12 is disposed in front of the vehicle of the first vehicle 1. In the present example, the field of view of the driving distance indicating device 12 can acquire the license plate AB-1234 behind the vehicle of the second vehicle 2, as shown by the dashed line in FIG.

4A-4C are schematic diagrams of vehicle images acquired by an image capturing module according to an embodiment of the present invention.

Referring to FIG. 2, FIG. 3 and FIG. 4A simultaneously, the vehicle image 42a is an image obtained by the image capturing module 201 when the first vehicle 1 and the second vehicle 2 are at the first driving distance. After the image capturing module 201 obtains the vehicle image 42a, the processing module 203 analyzes the vehicle image 42a by the image processing method to acquire the license plate image 44a. In this example, the first distance traveled between the first vehicle 1 and the second vehicle is kept outside the safe distance.

Referring to FIG. 2, FIG. 3 and FIG. 4B simultaneously, the vehicle image 42b is an image obtained by the image capturing module 201 when the first vehicle 1 and the second vehicle 2 are at the second driving distance. After the image capturing module 201 obtains the vehicle image 42b, the processing module 203 analyzes the vehicle image 42b by an image processing method to acquire the license plate image 44b. In this example, the second distance between the first vehicle 1 and the second vehicle is kept within a safe distance and outside of the warning distance.

Referring to FIG. 2, FIG. 3 and FIG. 4C simultaneously, the vehicle image 42c is an image obtained by the image capturing module 201 when the first vehicle 1 and the second vehicle 2 are at a third driving distance. After the image capturing module 201 obtains the vehicle image 42c, the processing module 203 analyzes the vehicle image 42c by the image processing method to obtain the license plate image 44c. In this example, the third distance between the first vehicle 1 and the second vehicle is maintained within the warning distance.

Referring to FIG. 3 and FIG. 4A to FIG. 4C simultaneously, the first driving distance is greater than the second driving distance, and the second driving distance is greater than the third driving distance. In other words, the driving distance indicating means 12 captures the vehicle images 42a, 42b, 42c at different points in time, and obtains the license plate images 44a, 44b, 44c, respectively. The method of calculating the distance between the first vehicle 1 and the second vehicle 2 based on the image characteristics in the license plate images 44a, 44b, and 44c by the driving distance indicating device 12 of the present invention will be described later.

[Example of calculation method of driving distance]

5A-5B are a comparison table of determining a driving distance by using a preset license plate size according to an embodiment of the present invention.

Referring to FIG. 2 and FIG. 5A, the comparison table is recorded in the storage module 215 of the driving distance presentation device 20. It should be noted that, in this embodiment, the preset license plate size and font size are, for example, the license plate specifications formulated by government agencies or other national laws of the world, and further correspond to the driving distance. Referring to FIG. 2 and FIG. 3 , after the image capturing module 201 disposed on the first vehicle 1 acquires the vehicle image of the second vehicle 2 , the processing module 203 processes and analyzes the license plate image in the vehicle image. Thus, the processing module 203 can acquire image features in the license plate image by the image processing means.

In this example, the image features such as the license plate size in the license plate image are shown in Figure 5A. The comparison table is shown. After the processing module 203 obtains the license plate size, the query comparison table is used to obtain the driving distance corresponding to the license plate size. For example, if the size of the license plate is 190 cm x 80 cm, the processing module 203 can obtain a driving distance of 10 meters between the first vehicle 1 and the second vehicle 2 in the comparison table of FIG. 5A.

In another example, image features such as font size in a license plate image are shown in the look-up table of Figure 5B. After the processing module 203 obtains the license plate image, the image processing analysis means further calculates the license plate number in the license plate image, and calculates the font size in the license plate number. For example, if the size of the font size in the license plate number is 36 cm x 72 cm, the processing module 203 can obtain the driving distance between the first vehicle 1 and the second vehicle 2 in the comparison table of FIG. 5B. ruler.

FIG. 6 is a comparison table of the license plate size and the license plate image percentage to determine the driving distance according to an embodiment of the present invention.

In contrast to the look-up tables of Figures 5A and 5B, another way to calculate the driving distance is used in the embodiment of Figure 6. In this example, the processing module 203 compares the license plate size of the license plate image with the size of the vehicle image, and calculates the driving distance from the comparison result. Referring to FIG. 2, after the processing module 203 processes and analyzes the license plate image in the vehicle image, the processing module 203 can obtain the pixel value of the license plate image and the pixel value of the vehicle image. Here, the processing module 203 does not need to analyze and calculate the license plate number in the license plate image. The processing module 203 calculates the distance of the pixel value of the license plate image in the pixel value of the vehicle image to calculate the driving distance. As shown in FIG. 6, if the license plate size and the percentage of the vehicle image in the pixel value are 80%, the processing module 203 can query the comparison table to obtain the driving distance of 2 meters. It should be noted that the data in the look-up tables disclosed in FIGS. 5A, 5B, and 6 of the present invention are presented only as an embodiment, and are not intended to limit the only method by which the driving distance indicating device of the present invention calculates the driving distance.

[Safety distance calculation method embodiment]

The method of safe distance calculation is explained in this embodiment. Please refer to Figure 2 and Figure 3. The processing module 203 calculates the safety distance based on the driving speed of the first vehicle 1 and the vehicle type information in the image feature. Incidentally, image features such as license plate numbers or license plate colors in license plate images, and vehicle type information such as large vehicles, small vehicles, locomotives, or the like, may be obtained according to license plate specifications established by government agencies or other national laws of the world. Other types of vehicles.

Specifically, for the method of calculating the safety distance, if the driving speed of the first vehicle 1 is larger, the braking distance required by the vehicle is larger. Moreover, the required braking distances for different types of vehicles are also different. In the following example, the processing module 203 recognizes that the second vehicle 2 is a large vehicle or a small vehicle based on the license plate color or the license plate number of the license plate image, and calculates the safety distance with respect to the calculation formula of the large vehicle or the small vehicle.

In the first example, the safety distance calculation method of the processing module 203 for the first vehicle 1 is a small vehicle: the safety distance is twice the vehicle speed (safe distance (meter) = vehicle speed (meters / second) × 2) . For example, if the driving speed of a small vehicle is 60 km/h (ie, 16.6 m/s), the safety distance is 33.2 meters. In another example, the safety distance calculation method of the processing module 203 for the first vehicle 1 is a large vehicle with a safety distance of three times the vehicle speed (safe distance = vehicle speed (meters / second) × 3). For example, if the speed of a large vehicle is 90 km/h (ie 25 m/s), the safety distance is 75 meters.

In the second example, the safety distance calculation method of the processing module 203 for the first vehicle 1 is a small vehicle: the safety distance is half of the vehicle speed data (safe distance (meter), vehicle speed (km/h) ÷ 2). For example, if the driving speed of a small vehicle is 60 km/h, the safety distance is 30 meters. In another example, the safety distance calculation method of the processing module 203 for the first vehicle 1 is a large vehicle: the safety distance is two-thirds of the vehicle speed data (safe distance ≡ vehicle speed (km / hour) × 2 / 3) . For example, if the speed of a large vehicle is 60 km/h, the safety distance is 40 meters.

In the third example, the processing module 203 can also determine the safety distance by determining the vehicle type of the second vehicle 2 through the vehicle type information in the image feature. Processing module 203 The safety distance calculation method for the second vehicle 2 to be a small vehicle is that the safety distance is the magnification of the driving speed of the first vehicle 1 multiplied by the vehicle length of the second vehicle 2 (safety distance = first vehicle speed / 10 × second vehicle) Vehicle length). For example, a general small vehicle has a length of about 5 meters, so when the processing module 203 determines that the second vehicle 2 is a small vehicle and the first vehicle 1 has a vehicle speed of 60 km/h, the safety distance is six times the length of the vehicle. That is 30 meters. In another example, the safety distance calculation method of the processing module 203 for the second vehicle 2 is a large vehicle: the safety distance is the second rate of the driving speed of the first vehicle 1 multiplied by the vehicle length of the second vehicle 2 (safe distance) = first vehicle speed / 10 × vehicle length of the second vehicle). For example, a typical large vehicle has a length of about 10 meters, so when the processing module 203 determines that the second vehicle 2 is a large vehicle and the first vehicle has a vehicle speed of 90 km/h, the safety distance is 90 meters.

It should be noted that the data in the above embodiment of calculating the safety distance is only an example for illustration. The ratio of the length of the vehicle to the speed of the driving speed may be different from the actual situation, and the present invention is not limited by such data.

[Example of driving distance prompting method]

FIG. 7 is a schematic flow chart of a driving distance prompting method according to an embodiment of the present invention.

Referring to FIG. 3 and FIG. 7 simultaneously, the method is applicable to the first vehicle 1 to calculate the driving distance between the first vehicle 1 and the second vehicle 2. The flow of the method embodiment is as follows.

In step S701, the image capturing module acquires the vehicle image of the second vehicle and captures the license plate image in the vehicle image. After the driving distance prompting device obtains the license plate image of the second vehicle, the processing module calculates the driving distance between the first vehicle and the second vehicle according to the image features in the license plate image in step S703. The method of calculating the driving distance has been explained in the above embodiment, and will not be repeated. Next, in step S705, the processing module calculates the safety distance according to the driving speed and image features of the first vehicle. The method of calculating the safety distance has been explained in the above embodiment, and will not be repeated. After obtaining the safety distance, in step S707, the processing module further determines the first car. Whether the distance between the vehicle and the second vehicle is less than the safety distance. If yes, in step S709, the processing module controls the prompting module to output a prompt message. If not, it returns to step S705 of calculating the safety distance. After the prompt message is output in step S709, the processing module further determines whether the driving distance is less than the warning distance, as in step S711. If yes, in step S713, the processing module controls the warning module to output an alert message and the protection module can simultaneously initiate the execution of the protection program. It is worth noting that the protection module can be operated simultaneously with the warning module, or can be selectively activated according to the actual driving condition. In this way, the level and flexibility of the protection module startup protection program can be improved. On the other hand, the present invention does not limit the operation of the protection module in conjunction with the activation of the warning module. For example, only one of the protection module and the warning module is activated. In the specific implementation, the protection module can set the starting condition according to the actual use condition, and the invention does not limit the warning module and the protection module to be simultaneously activated. If the answer of the step S711 is NO, the process returns to the step S705 of calculating the safety distance.

In another embodiment of the present invention, the image capturing module of the driving distance prompting device on the same vehicle further includes at least one image capturing device. FIG. 8 is a side elevational view of a vehicle for setting a driving distance prompting device according to another embodiment of the present invention. As shown in FIG. 8, the first vehicle 3 travels behind the second vehicle 4 and travels in front of the third vehicle 5. In this example, the second vehicle 4 is a small vehicle, and the third vehicle 5 is a large vehicle. A driving distance indicating device (not shown) is disposed on the first vehicle 3, and two image first image capturing devices 32 and second image capturing devices 34 are connected to the driving distance indicating device. The first image capturing device 32 is disposed at the front end of the first vehicle 3, and can capture the license plate image of the rear end of the vehicle of the second vehicle 4. The image capturing module 34 is disposed at the rear end of the first vehicle 3, and can capture the license plate image of the front end of the vehicle of the third vehicle 5. For example, the calculation of the driving distance, the safety distance, and the output of the prompt message and the warning message have been specifically described in the above embodiments, and will not be repeated herein. Therefore, the embodiment of the present invention provides an image capturing device that can be connected to at least one driving distance indicating device, and elastically provides a direction in which the first vehicle 3 can select the image of the vehicle, and increases the direction that the first vehicle 1 can monitor. First The safety of a vehicle 3 traveling on a driveway.

It should be noted that, after the image capturing module 32 of the present example acquires the vehicle image of the second vehicle 4, when the driving distance indicating device determines that the driving distance between the first vehicle 3 and the second vehicle 4 is too small, The prompting module of the driving distance prompting device outputs a prompt message prompting the user to decelerate the vehicle. On the other hand, after the image capturing module 34 of the present example acquires the vehicle image of the third vehicle 5, when the driving distance indicating device determines that the driving distance between the first vehicle 3 and the third vehicle 5 is too small, driving The prompting module of the distance prompting device outputs a prompt message prompting the user to accelerate the vehicle. In addition, when the processing module of the driving distance indicating device of the example determines that the driving distance with the second vehicle 4 is too small and the driving distance with the third vehicle 5 is too small, the prompting module outputs a reminder to the first vehicle 3 at this time. The prompt message of the driver switching the lane allows the driver to obtain the warning in advance and obtain the buffer time of leaving the lane to prevent the first vehicle 3 from being caught by the collision of the second vehicle 4 with the third vehicle 5.

In summary, the driving distance prompting device and the method thereof according to the present invention use the image recognition method to calculate the driving distance, and obtain the vehicle type information of the adjacent vehicle according to the identification of the license plate image in the vehicle image, so as to be more flexible. The driving distance that the driver should maintain to increase the safety of the vehicle in maintaining the distance. In addition, the driving distance indicating device and the method thereof of the present invention use the image recognition method to more accurately and instantaneously determine whether the driving distance is safe, in addition to reducing the cost of setting the hardware.

The above description is only a possible embodiment of the present invention, and all the equivalent changes and modifications made by the scope of the present invention should be within the scope of the following patent application.

20‧‧‧Driving distance indicating device

201‧‧‧Image capture module

203‧‧‧Processing module

205‧‧‧ prompt module

207‧‧‧ Warning Module

209‧‧‧Video Module

211‧‧‧Communication Module

213‧‧‧Speed signal input interface

215‧‧‧ storage module

217‧‧‧protection module

Claims (10)

A driving distance prompting device is applicable to a first vehicle and calculates a distance between the first vehicle and a second vehicle. The device comprises: an image capturing module, and obtaining one of the second vehicles a vehicle image; a prompting module; a processing module coupled to the image capturing module and the prompting module; and a speed signal input interface coupled to the processing module; wherein the processing module captures the vehicle a license plate image in the image, and calculating a driving distance between the first vehicle and the second vehicle according to an image feature of the license plate image, wherein the image feature includes a license plate size of the license plate image, and the processing The module calculates the driving distance according to the license plate size; wherein the processing module calculates a safety distance according to the line speed of the first vehicle and the image feature, and determines whether the driving distance is greater than the safety distance, and according to Controlling the prompting module to output a prompt message; wherein the image feature further includes a vehicle type information of the license plate image, and the processing module inputs the speed signal according to the speed signal Calculating the safety distance by the driving speed and the vehicle type information obtained by the interface; wherein the vehicle type information is at least one of a license plate color and a license plate number of the license plate image; wherein the processing module is based on the license plate color of the license plate image or The license plate number identifies that the second vehicle is a large vehicle or a small vehicle, and calculates the safety distance in a calculation formula relative to a large vehicle or a small vehicle. The driving distance prompting device of claim 1, further comprising a storage module for storing the image feature and a comparison table, wherein the processing module is configured to size the license plate in the comparison table with at least one preset license plate size Compare and calculate the driving distance based on the comparison result. The driving distance prompting device of claim 1, wherein the processing module compares the license plate size with the size of the vehicle image, and calculates according to the comparison result. Out of the driving distance. The driving distance prompting device of claim 1, wherein the prompting module outputs the prompting message when the driving distance is less than the safe distance, wherein the prompting message is a vehicle acceleration prompt message or a vehicle deceleration prompt message. The driving distance prompting device of claim 1, further comprising: a warning module coupled to the processing module and controlled by the processing module, and outputting a warning message when the driving distance is less than a warning distance The warning message is at least one of a light signal for controlling a light of the first vehicle and a sound message for controlling a speaker of the first vehicle; a video module coupled to the The processing module is controlled by the processing module, and stores the image captured by the image capturing module when the driving distance is less than the safe distance; a communication module coupled to the processing module is controlled by The processing module, when the driving distance is less than the warning distance, outputting the image stored by the video module to a network server backup storage through a communication network; and a protection module coupled to the processing module, And controlling the processing module, when the driving distance is less than the warning distance, the protection module starts a protection program to control the driving distance between the first vehicle and the second vehicle; wherein the image is The module includes a first image capturing device and a second image capturing device. The first image capturing device is disposed at a front end of the first vehicle, and captures the vehicle image when the second vehicle is located in front of the first vehicle. The second image capturing device is disposed at a rear end of the first vehicle, and captures the image of the vehicle when the second vehicle is located behind the first vehicle, and the warning module is configured when the protection module starts the protection program The warning message is output to the second vehicle. A method for prompting a driving distance is applicable to a first vehicle, and calculating a distance between the first vehicle and a second vehicle, the method comprising: obtaining a vehicle image of the second vehicle; Obtaining a license plate image in the image of the vehicle; calculating a driving distance between the first vehicle and the second vehicle according to an image feature of the license plate image, wherein the image feature includes a license plate size of the license plate image And the driving distance is calculated according to the license plate size; calculating a safety distance according to the traveling speed of the first vehicle and the image feature, wherein the image feature further includes a vehicle type information of the license plate image, and the safety The distance is calculated according to the driving speed and the vehicle type information; wherein the vehicle type information is at least one of a license plate color and a license plate number of the license plate image; wherein the safety distance is determined according to the license plate color or the license plate number of the license plate image The second vehicle is a large vehicle or a small vehicle, and is calculated according to a calculation formula of the large vehicle or the small vehicle; determining whether the driving distance is greater than the safety distance; and determining whether to output a prompt message according to the determination result. The driving distance prompting method according to claim 6, wherein the driving distance is compared with the at least one preset license plate size, and is calculated according to the comparison result. The driving distance prompting method according to claim 6, wherein the driving distance is compared with the size of the vehicle image, and is calculated according to the comparison result. The driving distance prompting method according to claim 6, when the driving distance is less than the safety distance, the prompt message is output, wherein the prompt message is a vehicle acceleration prompt message or a vehicle deceleration prompt message. The method for prompting the driving distance according to claim 6, further comprising: outputting a warning message when the driving distance is less than a warning distance, wherein the warning distance is less than the safety distance, the warning message is a light signal for controlling the light and Controlling at least one of the sound messages of the vehicle horn; storing the vehicle image in a video module when the driving distance is less than the safe distance; When the driving distance is less than the warning distance, the vehicle image stored by the video module is outputted to a network server backup storage through a communication network; wherein a vehicle image of the second vehicle is obtained through an image capturing module The image capturing module includes a first image capturing device and a second image capturing device. The first image capturing device is disposed at a front end of the first vehicle, and the second vehicle is located in front of the first vehicle. The vehicle image is taken at a rear end of the first vehicle, and the vehicle image is taken when the second vehicle is behind the first vehicle.