WO2008146304A2

WO2008146304A2 - A forward brake indicate device and method thereof

Info

Publication number: WO2008146304A2
Application number: PCT/IN2008/000329
Authority: WO
Inventors: Ramalingam Krishnamurthi
Original assignee: Ananya Innovations Limited
Priority date: 2007-05-25
Filing date: 2008-05-26
Publication date: 2008-12-04
Also published as: WO2008146304A3

Abstract

The present invention relates to a Forward Brake Indicator device used in the automobiles, preferably, relates to a method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2).

Description

FIELD OF THE INVENTION The present invention relates to a Forward Brake Indicator device used in the automobiles, preferably, relates to a method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2).

BACKGROUND OF THE INVENTION AND PRIOR ART

Vehicles such as automobiles move independently from each other on a road. Therefore, there might be an accident such as bumping of vehicles. On a congested city traffic, in particular, the frequency of rear-end collisions is higher and a high vehicle speed is liable to invite serious results.

The major cause of collision is distance between vehicles being short. Under these circumstances, apparatuses have been conventionally proposed for preventing an accident between a subject vehicle and a preceding vehicle by using various devices like a device for measuring distance, brake indicators etc.

Prior art devices use technology like radar and laser to sense the distance between the subject vehicle and vehicle in surrounding and thus avoid collision.

Systems for warning other road users include vehicle-mounted devices such as brake lights, which signal a slowing down to following traffic. The brake lights are activated as soon as the driver operates the brake pedal. Another known means for providing optical information to road users is a traffic light, which regulates traffic using a light signal and which informs road users regarding an actual traffic situation.

Above all, with respect to brake lights and their control, various modifications have been proposed for increasing traffic safety. These modifications are on the one hand concerned with the geometric design or more specifically the dynamic change of the image of the brake lights, for example by blinking signals, and on the other hand are concerned with an advancement of the time point at which the brake lights are activated in response to a rapid removal of the foot from the gas pedal.

Prior art also discloses an accessory brake light system for an automobile is located on the grill. This is to provide an accessory brake light system for automobiles that can provide various kinds of warning signals to point out the braking conditions of the automobile for vehicles or pedestrians positioned in front of the vehicle. The device as disclosed comprises specific warning signals when the automobile is braking to slow down or fully stop in order to enable other vehicles or pedestrians that are positioned in front of the vehicle to be clearly aware of whether the driver of that vehicle is prepared to stop or not and hence reduce the chance of an accident from happening.

Another prior art device discloses a lighting system which is on the back of the vehicle but it has a sequence of lights with various logical steps so that cars following the vehicle can know exactly the nature of the way the vehicle is braking. The vehicle signaling display device is mounted on an automotive vehicle, so that signaling lights of the device are visible for drivers of following vehicles. They include orange or amber, red and green lights and includes a system specifically designed to count speed sensor pulses for measuring speed of any vehicle of any make and model on which the device is installed for controlling the signaling lights in accordance with the speed of the vehicle so that the device turns certain sequence colors to tell following drivers how fast the vehicle is going and whether it is slowing down.

It is also described in prior art a concept of having different lighting sequences to illustrate different speeds of the vehicle and what the driver is doing. The brake lights are in the back of the vehicle and not the front. The progressive vehicle brake light system consists of a brake sensor arranged to sense the travel of a brake pedal and the brake light display arrangement to illuminate or extinguish in sequence or progressively in response to the travel of the brake pedal. The brake light display consists of a row of light emitting diodes, which are arranged to illuminate from the opposite ends toward the middle as the brake pedal is depressed and to extinguish in reverse sequence when the brake pedal is released.

Prior art discloses warning systems to advise other drivers of what a driver of a vehicle is doing have been developed. Most of these systems involve the use of warning lights to signal what a driver is about to do or has just done.

While the prior art discloses warning systems, which include a sequence of lights, there is a significant need for an improved advisory system to advise drivers of other vehicles and passengers within the vehicle being driven as to the moving or stopping condition of the vehicle at any given time.

Whereby, it is desirable to provide a brake indicator for automobiles, which will avoid the problems/disadvantages, noted above and overcome other problems encountered in conventional methods. The objects, advantages and novel features of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the detailed description when taken in conjunction with the accompanying drawings.

OBJECTS OF THE INVENTION

One or more of the problems of the conventional prior art may be overcome by various embodiments of the present invention. The present invention relates to a Forward Brake Indicator device used in the automobiles, which will indicate brake status of the vehicle ahead to avoid rear end collision due to sudden braking of vehicle.

Accordingly, it is an object of the present invention is to provide a forward brake indicator device that overcomes many of the disadvantages of the prior art devices. Yet another object of the present invention is to provide for a forward brake indicator that detects the brake status of the vehicle. Still another object of the present invention is to provide for a forward brake indicator wherein sensors and image processing techniques are used to detect the brake status of the front vehicle.

Still another object of the present invention is to provide for a forward brake indicator wherein using DSP processors does the image processing technique.

Still another object of the present invention to provide for a forward brake indicator wherein Image Processing algorithms are developed and implemented using DSP processors.

Still object of the present invention is to provide for a forward brake indicator wherein a camera is placed at the rear view mirror of the vehicle to take the images and these images would be fed into the DSP Processor.

STATEMENT OF THE INVENTION Accordingly, the present invention provides for a method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said method comprising acts of capturing rear- view video signal of on-going vehicle (1) and thereafter segmenting the captured signal to detect brake light region of the vehicle (1); monitoring intensity of the brake light region continuously to identify intensity changes in that region; detecting glowing of light by processing the identified intensity changes to obtain status of the brake lights of the vehicle (1); and triggering a signal to a visual alert based on status of brake lights for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), and also provides for a forward brake indicator system to indicate brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said device comprises acquisition unit comprising camera to capture images of rear end of the on-going vehicle (1); processing unit configured to obtain status of brake lights of the on-going vehicle (1) and to trigger a visual alert to the vehicles (2) that follow; and alerting system comprising brake lights mounted at rear end of the following vehicle (2) to indicate brake status of the on-going vehicle (1) before applying brakes of vehicle (2).

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

The features described in this disclosure are set forth with particularity in the appended claims. These features and attendant advantages will become apparent from consideration of the following detailed description, taken in conjunction with the accompanying drawings. One or more embodiments are now described, by way of example only, with reference to the accompanying drawings wherein like reference numerals represent like elements and in which:

Figure 1 shows flow chart of entire process used in forward brake indicator device

Figure 2 shows flow chart of logic used in the image processing.

Figure 3 illustrates the working of the instant disclosure Figure 4 shows block diagram of forward brake indicator system

DETAILED DESCRIPTION OF THE INVENTION

So that the manner in which the features, advantages and objects of the invention, as well as others which will become apparent, may be understood in more detail, more particular description of the invention briefly summarized above may be had by reference to the embodiment thereof which is illustrated in the appended drawings, which form a part of this specification.

The primary embodiment of the present invention is a method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said method comprising acts of capturing rear- view video signal of on-going vehicle (1) and thereafter segmenting the captured signal to detect brake light region of the vehicle (1); monitoring intensity of the brake light region continuously to identify intensity changes in that region; detecting glowing of light by processing the identified intensity changes to obtain status of the brake lights of the vehicle (1); and triggering a signal to a visual alert based on status of brake lights for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2).

In yet another embodiment of the present invention the captured video signal is sampled using video decoder to generate digital video in predetermined format.

In still another embodiment of the present invention the predetermined format is preferably BT656 format comprising Luminance (Y), Chrominance (CbCr) signals in the 4:2:2 ratios.

In still another embodiment of the present invention the Y₅ Cb, Cr signals are fed into image processing unit to detect brake light of the vehicle (1).

In still another embodiment of the present invention the brake light detection process comprises acts of; storing two consecutive YCbCr frames and converting the stored frames into RGB frames; performing pixel- wise comparison between the corresponding

R, G and B frames to store difference data in predetermined number of buffers; obtaining binary image and comparing the obtained image with one of the predetermined buffer to highlight red region; and detecting turning ON/OFF of brake light based on the number of pixel count in the region.

In still another embodiment of the present invention the predetermined number of buffer is 3.

In still another embodiment of the present invention the buffers are (R1-R2) buffer, (Gl- G2) buffer, and (B1-B2) buffer.

In still another embodiment of the present invention the binary image is a non-zero R component, G component, and B component, and is obtained by performing pixel wise logical AND on data stored in the buffers. In still another embodiment of the present invention the red light region is highlighted by performing difference between the binary image and the (R1-R2) buffer.

Another embodiment of the present invention is a forward brake indicator system to indicate brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said device comprises acquisition unit comprising camera to capture images of rear end of the on-going vehicle (1); processing unit configured to obtain status of brake lights of the on-going vehicle (1) and to trigger a visual alert to the vehicles (2) that follow; and alerting system comprising brake lights mounted at rear end of the following vehicle (2) to indicate brake status of the on-going vehicle (1) before applying brakes of vehicle (2).

In still another embodiment of the present invention the processing unit comprises a video decoder adopted to generate digital video, DSP processor configured to process the images captured to determine change in intensity of color at indicators of the on-going vehicle (1) and OFF-chip memory to store YCbCr frames.

The forward brake indicator system is placed in vehicle 2. The camera fixed in the system captures the video and sends to the image processor. When the brake light of the vehicle 1 glows, the brake light of vehicle 2 indicator is triggered. This alerts vehicle 3, about the brake status of the vehicle 1. This alert instantaneous that it is triggered before the driver of the vehicle 2 applies brake.

Model of the system:

The method for detecting brake light is framed in divide and conquer manner. This approach first segments the vehicle in the front and then gets on brake light region of the vehicle. Then segmenting the brake light is done. Each segmentation process is a combination of detection and recognition of the particular region of interest in the image. Constrains are framed and implemented for detection and recognition.

Once the brake light region is detected and confirmed, the intensity of that region is observed. Based on the intensity changes, the glowing of the brake light is detected and a trigger signal is given to the visual alert. The above description is diagrammatically represented in figure 1. The figure 4 shows the setup of the forward brake indicator system.

Image Capturing:

The forward vehicle brake indicator system has an IR-CCD camera placed behind the rearview mirror of the vehicle. The rear view video of the on-going vehicles is captured using this IR-CCD camera. This video signal of the camera is fed into the video decoder. The video decoder samples the signal and outputs digital video in BT656 format. The BT656 format has Y, Cb, Cr samples in the 4:2:2 ratios. This Y, Cb, Cr signal is fed into the processing unit, which is a Digital Signal Processor. The video port in the processor facilitates storing the whole frame, which is the Image.

The frame data is in the YCbCr 4: 2: 2 formats. Y data, Cb data, Cr data are stored separately in three buffers Y buffer, Cb buffer, Cr buffer respectively.

Image Processing

The logic used in processing of images captured is illustrated in figure 2. This stored image is passed on to the processor sequentially. Image processing algorithms ported into the processor gets the status of the Brake lights of the vehicle ahead and triggers a visual alert to the vehicles that follow.

Image processing involves the filtering stage, brake light detection stage.

Filtering:

Noises in the image are removed in this stage. A normal median filtering in this stage removes the noise and smoothen the image.

Brake light detection stage:

Image is processed in such a way that the red region in the image is highlighted. This involves the following processes.

1. Storing 2 consecutive frame (Frame 1 & Frame 2). 2. YCbCr - RGB conversion on two frames.

3. Values stored in separate buffers (6 Buffers for two frames)

4. Pixel wise comparison between the corresponding buffers. 5. Logical AND ing.

6. Difference between the output of 5 & R component of step 3.

In the image processing part two consecutive frames are stored. The Frames in the YCbCr format is converted into the RGB format. Then a pixel-wise comparison is made between the corresponding R, G and B buffers. The differences are stored in 3 buffers (R1-R2) buffer, (G1-G2) buffer, (B1-B2) buffer. Then the data in these buffer are pixel wise logical ANDed. This produces a binary image, which non-zero R component, G component, B component. The difference between this binary image and the (R1-R2) buffer will highlight the red region, along with few scattered pixels.

Based on the number of pixel count in a region decision is made on the turning ON/OFF the brake light. Once the ON of the brake light is detected, that particular region is tracked to get the information of turning OFF the brake light. .

Alerting system:

Based on the Vehicle 1 's brake status, Vehicle2's brake lights are controlled.

The Illustration of working of instant disclosure is shown in figure 3, wherein when the vehicle 1 applies brakes, the brake lights of vehicle 1 appear at its rear end. The camera of vehicle 2 at its rear view mirror captures the images of vehicle l's rear end brake light and processes them using Image Processing Algorithms with the help of DSP circuitry and puts on the additional lights of vehicle 2 at its rear end before applying the brakes, indicating that the vehicle 1 has applied the brakes and vehicle2 is going to apply the brakes. As a result the driver of vehicle3 can apply the brakes by visualizing the additional lights at the rear end of vehicle 2. ANNEXURE

YCbCr - Y -> Luminance, CbCr - > Chrominance

RGB - Red Green Blue

IR CCD - Infra Red Charge Coupled Device

DSP - Digital Signal Processing

Claims

We Claim:

1. A method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said method comprising acts of: i. capturing rear- view video signal of on-going vehicle (1) and thereafter segmenting the captured signal to detect brake light region of the vehicle

(D; ii. monitoring intensity of the brake light region continuously to identify intensity changes in that region; iii. detecting glowing of light by processing the identified intensity changes to obtain status of the brake lights of the vehicle (1); and iv. triggering a signal to a visual alert based on status of brake lights for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2).

2. The method as claimed in claim I₅ wherein the captured video signal is sampled using video decoder to generate digital video in predetermined format.

3. The method as claimed- in claim 2, wherein the predetermined format is preferably BT656 format comprising Luminance (Y), Chrominance (CbCr) signals in the 4:2:2 ratios.

4. The method as claimed in claim 2, wherein the Y, Cb, Cr signals are fed into image processing unit to detect brake light of the vehicle (1).

5. The method as claimed in claim 1 and 4, wherein the brake light detection piuucao comprises acts of; a. storing two consecutive YCbCr frames and converting the stored frames into

RGB frames; b. performing pixel-wise comparison between the corresponding R, G and B frames to store difference data in predetermined number of buffers; c. obtaining binary image and comparing the obtained image with one of the predetermined buffer to highlight red region; and d. detecting turning ON/OFF of brake light based on the number of pixel count in the region.

6. The method as claimed in claim 5, wherein the predetermined number of buffer is 3.

7. The method as claimed in claim 6, wherein the buffers are (R1-R2) buffer, (G1-G2) buffer, and (B 1 -B2) buffer. .

8. The method as claimed in claim 5 and 7, wherein the binary image is a non-zero R component, G component, and B component, and is obtained by performing pixel wise logical AND on data stored in the buffers.

9. The method as claimed in claim 5 and 7, wherein the red light region is highlighted by performing difference between the binary image and the (R1-R2) buffer.

10. A forward brake indicator system to indicate brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2), said device comprises; i. acquisition unit comprising camera to capture images of rear end of the on-going vehicle (1); ii. processing unit configured to obtain status of brake lights of the on-going vehicle (1) and to trigger a visual alert to the vehicles (2) that follow; and iii. alerting system comprising brake lights mounted at rear end of the following vehicle (2) to indicate brake status of the on-going vehicle (1) before applying brakes of vehicle (2).

11. The system as claimed in claim 10, wherein the processing unit comprises a video decoder adopted to generate digital video, DSP processor configured to process the images captured to determine change in intensity of color at indicators of the on- going vehicle (1) and OFF-chip memory to store YCbCr frames.

12. A method for indicating brake status of on-going vehicle (1) to following vehicle(s) (3) to avoid rear end collision due to sudden braking of vehicle (2) is substantially as herein above described in the specification with respect to accompanying drawings and examples.