TWI493514B - Vehicle front-end collision warning method - Google Patents

Description

Vehicle front end collision warning method

The invention relates to an anti-collision warning method, in particular to a vehicle front-end anti-collision warning method capable of adjusting for slope adaptability.

The car front-end collision warning system is a system for detecting whether a vehicle is too close in front and gives a warning. The minimum standard to be alerted is that the position at which the front brake is stopped is equal to the position at which the rear brake is stopped.

Therefore, the formula for warning distance D is , where V ₁ is the initial vehicle speed of the rear vehicle, and T represents the preset reaction time for the user to step on the brake after seeing the warning, V ₁ . T is the idling distance, which is the distance traveled by the vehicle after the reaction time, and a ₁ is the average deceleration of the brakes of the rear vehicle. It is the rear brake distance, V ₂ and a ₂ are the initial vehicle speed and the average brake deceleration of the preceding vehicle. It is the front brake distance. In the case of braking, the above-mentioned average brake deceleration is positive.

The derivation method is: when the warning is issued, the position of the rear vehicle is taken as the origin, and the rear vehicle is separated from the preceding vehicle by the warning distance D. At this time, the front vehicle is braking and will walk again. Stopped afterwards, so the position when the front brake is stopped is And the rear car walks V ₁ during the reaction time before the user presses the brake after seeing the warning. T, walk after starting the brakes After stopping, the position when the rear brake is stopped is . The position when the front brake is stopped is equal to the position when the rear brake is stopped. The shifting term can obtain the aforementioned warning distance D.

However, the warning distance calculated in the above manner, on the sloped road, due to the relationship of gravity acceleration, will cause premature or late warning. Therefore, how to calculate the warning distance more accurately becomes a subject worthy of study.

Accordingly, it is an object of the present invention to provide a vehicle front end collision warning method that is adaptable to slope adaptation.

Therefore, the vehicle front end collision warning method of the present invention is executed by a warning system, the warning system includes a slope detector, a front vehicle detector, a memory storing a warning distance calculation program code, and a a processor connected to the component, the method includes the following steps: the slope detector detects and outputs a tilt angle value representing a tilt angle of the vehicle, and when the vehicle is uphill, the tilt angle value is greater than 0, when the The tilt angle value is less than 0 when the vehicle is going downhill.

The processor executes the code and receives the tilt angle value, and according to the tilt angle value, a gravity acceleration value, and a first vehicle speed value and a first subtraction respectively representing the initial vehicle speed and the brake average deceleration of the vehicle. The speed value calculates a warning distance value, and the warning distance value is at the inclination angle In the case where the degree value is increased, it is decreased, and in the case where the inclination angle value is decreased, it is increased.

The front vehicle detector detects and outputs a preceding vehicle distance value representing the distance between the vehicle and a preceding vehicle located in front of the vehicle.

The processor determines whether the preceding vehicle distance value is less than or equal to the warning distance value according to the warning distance value and the preceding vehicle distance value, and if yes, sends a warning signal.

Preferably, wherein the manner of calculating the warning distance value comprises Where α is the value of the tilt angle, g is the value of the gravitational acceleration, and g is the value of the gravitational acceleration, g. Sin(α) represents the magnitude of the component of the gravitational acceleration on the slope, V _{1 is} the first vehicle speed value, and a _{1 is} the first deceleration value.

Preferably, the warning distance value is represented by D, which is equal to a idling distance value plus a braking distance difference, and the idling distance value is represented by T _d , and represents a reaction of the user pressing the brake after receiving the warning signal. The distance traveled by the vehicle during the time, the brake distance difference is expressed by B _d , which is equal to the braking distance of the vehicle minus the braking distance of the preceding vehicle, and the equation is D=T _d +B _d , and Where T is the reaction time value representing the reaction time, V _{1 is} the first vehicle speed value, a _{1 is} the first deceleration value, and V ₂ and a ₂ are respectively representing the initial vehicle speed and the brake average of the preceding vehicle. a second vehicle speed value and a second deceleration value of the deceleration.

Preferably, the first deceleration value includes a fixed value of a vehicle type or a vehicle model built in the memory to represent the vehicle, or includes a plurality of vehicle types stored according to the user's selection of the memory. Or a value corresponding to one of the models.

Preferably, the first deceleration value is further related to at least one of: a vehicle condition parameter representing a vehicle state, and an environmental parameter representing a driving environment.

Preferably, the vehicle condition parameter includes a tire pressure parameter representing a tire pressure; the environmental parameter includes a rainy day parameter representing a weather as a rainy day, and the first deceleration value is when the tire pressure of the vehicle decreases or the weather is rainy. Reduce and increase the warning distance value.

Preferably, the front vehicle detector is a camera, and after continuously obtaining images of the preceding vehicle, calculating a rate of change of the pixels occupied by the preceding vehicle in the images to obtain a preceding vehicle relative to the vehicle. The relative speed of the vehicle, the processor adds the relative vehicle speed to the first vehicle speed of the host vehicle, and the vehicle speed of the preceding vehicle, that is, the second vehicle speed value; and the function of the front vehicle detecting device image recognition, identifying the After the vehicle type or the vehicle type of the vehicle in front, the identification result is output to the processor, and the processor further queries the corresponding second deceleration value from the memory.

Preferably, the alert system further includes a control interface for a user to operate, and the processor receives the input of the user via the control interface to adjust the magnitude of the alert distance within an allowable range, thereby adjusting The alert system sends the sensitivity of the alert signal.

Preferably, the manner of adjusting the magnitude of the warning distance value is to adjust the warning distance value by a first predetermined value or by multiplying a first predetermined magnification.

Preferably, the alert system further includes a control interface for a user to operate, and the processor receives the input of the user via the control interface to adjust the magnitude of the alert distance within an allowable range, thereby adjusting The alert system sends the sensitivity of the alert signal, wherein the magnitude of the alert distance value is adjusted by increasing or decreasing the reaction time value by a second predetermined value or by multiplying a second predetermined ratio to indirectly adjust the calculated The warning distance value.

Preferably, the warning system further comprises a warning device, the processor sends the warning signal to the warning device to cause the warning device to emit a light or a sound.

The effect of the present invention is that by calculating the acceleration caused by the gravitational acceleration at the time of tilting, the calculated warning distance value can be reduced in the case where the inclination angle value is increased, and in the case where the inclination angle value is decreased, In order to increase, it is compared with the distance of the preceding vehicle to determine whether to issue a warning signal, and an alert can be issued for the tilt angle adjustment of the vehicle traveling.

1‧‧‧ Warning System

11‧‧‧Slope detector

12‧‧‧Car detector

13‧‧‧ memory

14‧‧‧Control interface

15‧‧‧ Alerts

16‧‧‧Network Transmission Module

100‧‧‧ processor

2‧‧‧Driving computer system

21‧‧‧ tire pressure detector

22‧‧‧Speed detector

S1-S5‧‧‧ steps

The other features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments of the accompanying drawings. FIG. 1 is a system block diagram illustrating a preferred embodiment of the vehicle front end collision warning method of the present invention. Example; and Figure 2 is a flow diagram illustrating the preferred embodiment.

Referring to FIG. 1 and FIG. 2, a preferred embodiment of the vehicle front end collision warning method of the present invention is executed by a warning system 1 in conjunction with the line computer system 2. The warning system 1 is, for example, disposed in a navigation device or built in the vehicle when the vehicle is shipped from the factory. The warning system 1 includes a slope detector 11 and a front vehicle detector 12, and a warning distance is stored. The memory 13 of the code is calculated, a control interface 14, a warning device 15, a network transmission module 16, and a processor 100 connected to the aforementioned components. The slope detector 11 is, for example, a vertical gyroscope or the like that can sense its own angular change and generate an inclination angle value. The driving computer system 2 detects, records and manages various parameters related to driving, and includes a tire pressure detector 21 and a vehicle speed detector 22. The vehicle front end collision warning method includes the following steps S1 to S5.

Step S1 detects the tilt angle. The slope detector 11 detects and outputs the tilt angle value, which represents the tilt angle of the vehicle. When the vehicle is on an uphill slope, the tilt angle value is greater than 0. When the vehicle is downhill, the tilt angle value is less than 0.

Step S2 calculates the warning distance value. The processor 100 executes the code to receive the tilt angle value, and according to the tilt angle value, a gravity acceleration value, and a first vehicle speed value representing the initial vehicle speed and the brake average deceleration of the vehicle and a first The deceleration value calculates a warning distance value which is reduced in the case where the inclination angle value is increased, and is increased in the case where the inclination angle value is decreased.

In detail, the calculation formula of the warning distance value core is as follows. Where α is the angle of inclination value, and in the present invention is the angle between the horizontal line and the direction in which the vehicle travels. When the vehicle is on an uphill slope, α is greater than 0. When the vehicle is downhill, α is less than 0, the possible value range is less than 90 degrees and greater than minus 90 degrees, and g is the gravitational acceleration value, usually 9.8 m/s ² Substitute, g. Sin(α) represents the magnitude of the component of the gravitational acceleration on the slope, V _{1 is} the first vehicle speed value, and a _{1 is} the first deceleration value. In this formula, the first deceleration value is added to the component of the gravitational acceleration, and when the upslope is up, the component of the gravitational acceleration is in the same direction as the deceleration of the brake, and the gravitational acceleration helps the brake, so the first step is increased. The value of the deceleration value indicates that the vehicle can stop faster, only the lower warning distance value is required; when going downhill, sin(α) is a negative value, the component of gravity acceleration is opposite to the brake deceleration, and the gravity acceleration is The brake capacity is reduced, so the value of the first deceleration value is reduced, indicating that the vehicle will need a longer distance to stop, and a higher warning distance value is required. As such, the calculated warning distance value can be adjusted for slope adaptation.

To further illustrate, the more complete calculation of the warning distance value is based on the overall adjustment of the acceleration in the prior art formula based on the gravitational acceleration component on the slope. The warning distance value is represented by D, which is equal to a idling distance value plus a braking distance difference, and the idling distance value is represented by T _d , which represents the vehicle walking during the reaction time when the user receives the warning signal and then depresses the brake. The distance of the brake distance is expressed by B _d , which is equal to the braking distance of the vehicle minus the braking distance of a preceding vehicle (not shown) located in front of the vehicle, and the equation is D=T _d +B _d , and Wherein, T is a reaction time value representing the reaction time, and is usually set to 0.7 to 1.2 seconds, and V ₂ and a ₂ are respectively a second vehicle speed value representing an initial vehicle speed and a brake average deceleration of the preceding vehicle and a first Two deceleration values.

In addition, according to the more complete calculation method, the calculation formula of the foregoing core can be regarded as a simplified state in which the front vehicle is stationary and the user momentarily presses the brake.

In the actual use situation, the results obtained by the above complete calculation method may not be completely ideal and need to be adjusted. For example, to increase security, the warning distance value plus the preset distance value can be used to provide early warning. In addition, the control interface 14 is, for example, a set of buttons (not shown) for the user to set the sensitivity. The processor 100 receives the input of the user through the control interface 14 to adjust the magnitude of the warning distance value, and thus adjusts appropriately. The warning system 1 sends the sensitivity of the warning signal. The adjustment method is, for example, adjusting the warning distance value by a first predetermined value or multiplying the first predetermined value, or increasing or decreasing the reaction time value by a second predetermined value or multiplying a second predetermined number. The calculated warning distance value is indirectly adjusted by the magnification, but is not limited to the above.

The manner in which the other values are obtained will be described below. The first deceleration value required for the calculation is that the processor 100 reads from the memory 13, and the memory 13 stores a deceleration value corresponding to a plurality of vehicle types or vehicle models, if the warning system 1 Is installed in the navigation device, the memory 13 The stored vehicle type or vehicle type is for the user to select one of the vehicle types or models and set the corresponding deceleration value to the first deceleration value. If the warning system 1 is built in the vehicle when the vehicle is shipped, the The first deceleration value is built in the memory 13.

The first deceleration value is further related to at least one correction parameter, such as a tire pressure parameter representing a tire pressure or a rainy day parameter indicating that the weather is rainy, when the tire pressure of the vehicle is lowered or the weather is rainy. The first deceleration value is reduced and the warning distance value is increased. The rainy day parameter can be obtained by the network transmission module 16 connecting the internet data to the weather data, and the tire pressure parameter is connected with the driving computer system 2 to obtain the detected by the tire pressure detector 21. Related parameters. However, not limited to the above, various driving parameters such as mileage, maintenance status, and the like can be added, and if the vehicle manufacturer has support, the above parameters can be accessed through the Internet transmission module 16 to access the Internet. The equation for this part can be expressed as a ₁ = w ₁ . a ₁₁ -w ₂ . a ₁₂ -..., where a ₁₁ in the first term is the first deceleration value under normal conditions, and a _{12 is} followed by a correction term of the pre-stored first deceleration value associated with each of the above-mentioned correction parameters, and w ₁ , w ₂ ... is the weight that can be adjusted for mobility based on the aforementioned parameters. For example, when it rains, the weight of the item related to the rain increases, so the last deceleration value obtained is reduced, and the warning distance value is increased.

In this embodiment, the first vehicle speed value is that the processor 100 is connected to the driving computer system 2 to obtain the vehicle speed detected by the vehicle speed detector 22, but not limited thereto, and may be, for example, based on Global satellite positioning The number is measured by the speed of the car.

Regarding the second vehicle speed value, it should be noted that in the embodiment, the front vehicle detector 12 is a camera, and the distance of the preceding vehicle is detected in step S3, and the description is performed later, and the front vehicle detection is performed in this step. After continuously obtaining the image of the vehicle in front, the detector 12 calculates the rate of change of the pixels occupied by the preceding vehicle in the images, and obtains the relative vehicle speed of the preceding vehicle with respect to the host vehicle. The processor 100 then compares the relative vehicle speed. In addition, the first vehicle speed of the host vehicle is worth the speed of the preceding vehicle, that is, the second vehicle speed value. However, it is not limited to the above, and the Doppler effect may be used to detect the frequency change of the radar or the ultrasonic wave, or other methods to measure the relative speed of the preceding vehicle relative to the host vehicle.

As for the second deceleration value, the front vehicle detector 12 has an image recognition function, and identifies the vehicle type or vehicle type of the preceding vehicle, and outputs an identification result to the processor 100, and the processor 100 is further from the memory 13 The query obtains the corresponding second deceleration value. However, not limited to the above, the image of the preceding vehicle can be taken from an external driving recorder or other camera.

The above is the more accurate calculation method of the warning distance value proposed by the present invention.

Step S3 detects the distance of the preceding vehicle. The front vehicle detector 12 detects and outputs a preceding vehicle distance value representing the distance between the vehicle and the preceding vehicle. The front vehicle detector 12 is the camera, and detects the amount of pixels occupied by the preceding vehicle according to the captured image and calculates the distance of the preceding vehicle. However, it is not limited thereto, and the reflection time of the radar or the ultrasonic wave may be detected to estimate the distance of the preceding vehicle, or the distance of the preceding vehicle may be measured by other means.

It should be noted that the step S3 is not limited to being executed after the step S2, and may be performed at any time before the step S4. Since the acquisition of the second vehicle speed value in the foregoing step S2 requires the front vehicle detector 12, this step S3 can also be performed before the step S2. However, strictly speaking, the preceding vehicle distance value is not required in step S2, so this step may be performed before step S4 at the latest. The manner in which the speed and distance of the object are judged by the number of image pixels is not the focus of the present invention and will not be described herein.

Step S4: The processor 100 determines, according to the warning distance value and the preceding vehicle distance value, whether the preceding vehicle distance value is less than or equal to the warning distance value. If yes, an alert signal is sent to the alerter 15 (step S5). The alerter 15 is, for example, an LED or a speaker, and emits a warning such as a light or a sound after receiving the alert signal. Finally, whether the processor 100 issues a warning signal or not, it returns to step S1 for the next process.

In summary, by calculating the acceleration caused by the gravitational acceleration at the time of tilting, the calculated warning distance value can be reduced in the case where the inclination angle value is increased, and in the case where the inclination angle value is decreased, Increase, and then cooperate with other driving parameters and manual settings to adjust the warning distance value, and finally compare with the preceding vehicle distance value to determine whether to issue a warning signal, which can issue a warning more accurately, so it can achieve the purpose of the present invention.

However, the above is only the preferred embodiment of the present invention, and the scope of the present invention cannot be limited thereto, that is, the simple equivalent change and repair according to the scope of the patent application and the patent specification of the present invention. Decorations are still within the scope of the invention patent.

S1-S5‧‧‧ steps

Claims (11)

A vehicle front end collision warning method is implemented by a warning system, the warning system includes a slope detector, a front vehicle detector, a memory storing a warning distance calculation code, and a connection with the foregoing component. The processor includes the following steps: the slope detector detects and outputs a tilt angle value representative of a tilt angle of the vehicle, and when the vehicle is on an uphill slope, the tilt angle value is greater than 0 when the vehicle is downhill The tilt angle value is less than 0; the processor executes the warning distance calculation code to receive the tilt angle value, and according to the tilt angle value, a gravity acceleration value, and the initial vehicle speed and the brake average reduction respectively representing the vehicle Calculating a warning distance value for a first vehicle speed value and a first deceleration value of the speed, wherein the warning distance value is decreased when the inclination angle value is increased, and when the inclination angle value is decreased, Adding; the front vehicle detector detects and outputs a preceding vehicle distance value representing a distance between the vehicle and a preceding vehicle located in front of the vehicle; and the processor According to the warning value and distance value is determined from the preceding vehicle from the preceding vehicle is less than or equal to the warning value is a distance value, if yes, issuing a warning signal. The anti-collision warning method of claim 1, wherein the method for calculating the warning distance value includes Where α is the value of the tilt angle, g is the value of the gravitational acceleration, and g is the value of the gravitational acceleration, g. Sin(α) represents the magnitude of the component of the gravitational acceleration on the slope, V _{1 is} the first vehicle speed value, and a _{1 is} the first deceleration value. The anti-collision warning method of claim 2, wherein the warning distance value is represented by D, which is equal to a idling distance value plus a braking distance difference, and the idling distance value is represented by T _d , and the user receives the warning on behalf of the user. The distance traveled by the vehicle during the reaction time after the signal is pressed. The brake distance difference is expressed by B _d , which is equal to the braking distance of the vehicle minus the braking distance of the preceding vehicle. The equation is D=T _d +B _d ,and Where T is the reaction time value representing the reaction time, V _{1 is} the first vehicle speed value, a _{1 is} the first deceleration value, and V ₂ and a ₂ are respectively representing the initial vehicle speed and the brake average of the preceding vehicle. a second vehicle speed value and a second deceleration value of the deceleration. The vehicle front end collision warning method according to claim 1 or 2 or 3, wherein the first deceleration value includes a value of a vehicle type or a vehicle type built in the memory to represent the vehicle in which the memory is located; or includes one The value corresponding to one of the plurality of vehicle types or models stored in the memory is selected by the user. The vehicle front end collision avoidance warning method of claim 4, wherein the first deceleration value is further related to at least one of: a vehicle condition parameter representing a vehicle state, and an environmental parameter representing a driving environment. The vehicle front end collision warning method according to claim 5, wherein the vehicle condition The parameter includes a tire pressure parameter representing a tire pressure; the environmental parameter includes a rainy day parameter representing a weather as a rainy day, and the first deceleration value is decreased when the tire pressure of the vehicle is lowered or the weather is rainy, and the warning distance value is increase. The vehicle front end collision avoidance warning method according to claim 3, wherein the front vehicle detector is a camera, and after continuously obtaining images of the preceding vehicle, calculating a change in the number of pixels occupied by the preceding vehicle in the images. Rate the relative vehicle speed of the preceding vehicle relative to the host vehicle, and the processor adds the relative vehicle speed to the first vehicle speed of the host vehicle to derive the second vehicle speed value; and the front vehicle detector identifies the preceding vehicle After the vehicle type or vehicle type, the identification result is output to the processor, and the processor further queries the corresponding second deceleration value from the memory. The vehicle front end collision warning method of claim 1 or 2 or 3, wherein the warning system further comprises a control interface for a user operation, the processor receiving the user input through the control interface Adjust the size of the warning distance value within the allowable range. The vehicle front end collision avoidance warning method of claim 8, wherein the manner of adjusting the warning distance value is adjusted by increasing or decreasing the warning distance value by a first predetermined value or by multiplying a first predetermined magnification. The method of claim 3, wherein the warning system further comprises a control interface for a user to operate, and the processor receives the user input through the control interface to adjust within an allowable range. The magnitude of the warning distance value, thereby adjusting the sensitivity of the warning system to issue the warning signal, wherein the manner of adjusting the magnitude of the warning distance value is The warning distance value is indirectly adjusted by increasing or decreasing the reaction time value by a second predetermined value or by multiplying a second predetermined magnification. The vehicle front end collision avoidance warning method of claim 1 or 2 or 3, wherein the warning system further comprises a warning device, the processor sends the warning signal to the warning device to cause the warning device to emit a light or a sound ring.