KR102259603B1 - Apparatus for calculating distance between vehicles and method thereof - Google Patents

Abstract

The present invention relates to an apparatus and method for calculating an inter-vehicle distance, wherein lane width information is obtained based on a camera sensor that captures a front image of an own vehicle, and lanes detected from a front image photographed through the camera sensor, and is provided to the own vehicle. and a distance calculator for calculating the inter-vehicle distance from the own vehicle to the vehicle in front by applying the location information of the installed camera sensor and the obtained lane width information to a predefined geometric model.

Description

Apparatus and method for calculating distance between vehicles {APPARATUS FOR CALCULATING DISTANCE BETWEEN VEHICLES AND METHOD THEREOF}

The present invention relates to an apparatus and method for calculating a distance between vehicles, and more particularly, to an apparatus and method for calculating a distance to a vehicle in front by using a camera sensor mounted on the vehicle.

An autonomous vehicle refers to a vehicle that autonomously determines a driving route by recognizing the surrounding environment through external information sensing and processing functions while driving, and driving independently using its own power. An autonomous vehicle can drive itself to its destination by preventing collisions with obstacles on the driving path and adjusting the vehicle speed and driving direction according to the shape of the road without the driver operating the steering wheel, accelerator pedal, or brake. have. For example, acceleration may be performed on a straight road, and deceleration may be performed on a curved road while changing a driving direction in response to the curvature of the road.

A plurality of advanced driver assistance systems (ADAS) are applied to these autonomous vehicles to assist drivers in driving, and driver assistance systems include ACC (Adaptive Cruise Control), LDWS (Lane Departure Warning System), There are Lane Keeping Assist System (LKAS), High Beam Assist (HBA) and Autonomous Emergency Braking (AEB).

Meanwhile, sensors used in autonomous driving technology include a camera sensor, a radar sensor, a lidar sensor, and the like. Among them, as the camera sensor is easy to process data, detects an object, and has a low price, prior studies for calculating the inter-vehicle distance based on the camera sensor are in progress. However, it is difficult to extract an accurate inter-vehicle distance using only the camera sensor, and has a limit in which the accuracy is greatly reduced. In addition, research on finding the position and distance of a front object using stereo vision technology using two cameras or fusion with other sensors is active, but research on finding the distance to a front object with a single camera sensor or monocular camera sensor is insufficient. the current situation.

Background art of the present invention is disclosed in Korean Patent Publication No. 10-2017-0117855 (published on October 24, 2017).

An object according to an aspect of the present invention is to obtain a lane width in an image based on a lane and a vanishing point detected from a front image of a monocular camera sensor, and calculate the inter-vehicle distance from the own vehicle to the front vehicle based on geometric information, An object of the present invention is to provide an apparatus and method for calculating a distance between vehicles capable of improving distance accuracy even when a monocular camera sensor is used.

An apparatus for calculating an inter-vehicle distance according to an aspect of the present invention obtains lane width information based on a camera sensor for photographing a front image of an own vehicle, and a lane detected from a front image photographed through the camera sensor, and and a distance calculator configured to calculate an inter-vehicle distance from the host vehicle to the vehicle in front by applying the location information of the camera sensor installed in the vehicle and the obtained lane width information to a predefined geometric model.

In the present invention, the lane width information includes a first lane width (L1) based on the wheels of the front vehicle and a second lane width (L2) based on the bonnet of the host vehicle do.

In the present invention, the position information of the camera sensor includes a first height h1 of the camera sensor with respect to the ground, a second height h2 of the camera sensor with respect to the bonnet of the own vehicle, and the ground A first distance (b) from the bonnet to the camera sensor in a parallel direction, and a second distance (c) from the front end of the own vehicle to the camera sensor in a direction parallel to the ground characterized in that

In the present invention, the distance calculating unit, the distance from the front end of the own vehicle to the end point of the blind spot of the camera sensor formed by the bonnet of the own vehicle based on the longitudinal direction of the own vehicle (a) _{and, after calculating the distance (d image} ) from the end point to the wheel of the front vehicle based on the geometric model, the distance _{between the vehicles using the calculated distance (a, d image} ) and the specification information of the front vehicle It is characterized in that the distance from the front end of the host vehicle to the rearmost end of the front vehicle is calculated as the distance d _{real .}

In the present invention, the distance calculator calculates the distance a using the first and second heights h1 and h2 and the first and second distances b and c based on the geometric model. characterized in that

In the present invention, the distance calculating unit connects the camera sensor and the wheel of the front vehicle from the ground at the end point using the first and second lane widths L1 and L2 based on the geometric model. A second second connecting the camera sensor and the end point by calculating the height l to the first straight line, and using the distance a, the second distance c, and the first height h1 A first angle (θ) formed by a straight line with a straight line perpendicular to the ground is calculated, and the first angle (θ), the distance (a), the second distance (c), and the first height (h1) are used. to calculate the second angle α formed by the first straight line and the second straight line, and then use the height l, the first angle θ, and the second angle α to calculate the distance It is characterized in that (d _{image) is calculated.}

In the present invention, the distance calculator may be configured _{to subtract a rear overhang length d OH} as the specification information of the front vehicle from the sum of _{the distance a and the distance d image} to obtain the inter-vehicle distance. It is characterized in that (d _{real ) is calculated.}

In the present invention, the camera sensor is a monocular camera sensor.

The present invention may further include a controller for controlling an operation of a driver assistance system (DAS) applied to the own vehicle based on the inter-vehicle distance calculated through the distance calculator.

A method for calculating a distance between vehicles according to an aspect of the present invention includes the steps of: obtaining, by a distance calculating unit, a front image through a camera sensor that captures a front image of the own vehicle; and, by the distance calculating unit, based on a lane detected from the front image obtaining lane width information; and, by the distance calculating unit, the inter-vehicle distance from the own vehicle to the vehicle in front by applying the position information of the camera sensor installed in the own vehicle and the obtained lane width information to a predefined geometric model It characterized in that it comprises the step of calculating.

According to one aspect of the present invention, the present invention obtains a lane width in an image based on a lane and a vanishing point detected from a front image of a camera sensor, and determines the inter-vehicle distance from the own vehicle to the front vehicle based on a predetermined geometric model By calculating, the distance accuracy can be improved even when the monocular camera sensor is used, and the accuracy of autonomous driving control can be improved by utilizing the calculated inter-vehicle distance for autonomous driving control.

1 is a block diagram illustrating an apparatus for calculating a distance between vehicles according to an embodiment of the present invention.
2 and 3 are exemplary views for explaining a process of calculating the inter-vehicle distance in the inter-vehicle distance calculating apparatus according to an embodiment of the present invention.
4 is a flowchart illustrating a method for calculating a distance between vehicles according to an embodiment of the present invention.

Hereinafter, an embodiment of an apparatus and method for calculating a distance between vehicles according to the present invention will be described with reference to the accompanying drawings. In this process, the thickness of the lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of description. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of users or operators. Therefore, definitions of these terms should be made based on the contents throughout the present specification.

1 is a block diagram illustrating an apparatus for calculating an inter-vehicle distance according to an embodiment of the present invention, and FIGS. 2 and 3 are diagrams for calculating an inter-vehicle distance in the apparatus for calculating an inter-vehicle distance according to an embodiment of the present invention. It is an example diagram to explain the process.

Referring to FIG. 1 , an apparatus for calculating a distance between vehicles according to an embodiment of the present invention may include a camera sensor 100 , a distance calculator 200 , and a controller 300 .

The camera sensor 100 may capture a front image of the own vehicle and transmit it to the distance calculating unit 200 to be described later. The camera sensor 100 may be a front camera sensor that is installed on the top of the windshield inside the own vehicle to photograph a front image of the own vehicle, or may be a monocular camera sensor.

The distance calculator 200 may calculate the inter-vehicle distance to the vehicle in front based on the front image captured by the camera sensor 100 . Although the distance calculator 200 and the controller 300 to be described later are described as separate components to help understand the embodiment, the function of the distance calculator 200 of the present embodiment may be integrated into the controller 300 and implemented. . The distance calculator 200 and the controller 300 may be implemented as a processor or system on chip (SoC) that processes and calculates various data, and receives instructions or data received from other components. It may be designed to process by loading it into a memory, and to store various data in the memory.

A process in which the distance calculating unit 200 calculates the inter-vehicle distance from the host vehicle to the vehicle in front will be described in detail.

In this embodiment, the distance calculator 200 obtains lane width information based on a lane detected from a front image captured by the camera sensor 100 , and obtains location information and the location information of the camera sensor 100 installed in the own vehicle. By applying the obtained lane width information to a predefined geometric model, the inter-vehicle distance from the own vehicle to the vehicle in front can be calculated. Here, the lane width information may include a first lane width L1 based on a wheel of the front vehicle and a second lane width L2 based on a bonnet of the own vehicle.

FIG. 2 shows an example of a process of obtaining lane width information from a front image captured by the camera sensor 100 . A left lane and a right lane are detected from the forward image, and a point where the detected left and right lanes meet forms a vanishing point.

In the front image, the first lane width L1 means the distance between the left and right lanes based on the point where the wheels (rear wheels) of the front vehicle and the ground contact, and the second lane width L2 is the bonnet of the own vehicle. It means the distance between the left and right lanes based on (B, eg: the top of the bonnet in the front image). Since the first lane width L1 and the second lane width L2 have distance values in the front image, the value of the first lane width L1 is smaller than the value of the second lane width L2. . In FIG. 2 , the height H1 means the vertical distance between the first lane width L1 and the second lane width L2 , and the height H2 is the distance from the vanishing point to the straight line formed by the first lane width L1 . vertical distance. An image processing algorithm for calculating the lane widths L1 and L2 and the heights H1 and H2 from the front image captured by the camera sensor 100 may be predefined in the distance calculator 200 ( _{In addition, a rear overhang length (d OH} ) of a front vehicle, which will be described later, may also be obtained through the above image processing algorithm).

When the lane width information is obtained through the above process, the distance calculating unit 200 applies the location information and the lane width information of the camera sensor 100 installed in the own vehicle to a predefined geometric model from the own vehicle to the vehicle in front. can calculate the inter-vehicle distance. 3 schematically shows a geometric model to help understanding of the present embodiment, and specific equations follow Equations 2 to 6 to be described later. Referring to FIG. 3 , location information of the camera sensor 100 considered in the geometric model includes a first height h1 of the camera sensor 100 with respect to the ground and a camera sensor based on the bonnet of the own vehicle. The second height (h2) of (100), the first distance (b) from the bonnet to the camera sensor 100 based on the direction parallel to the ground, and the front end of the own vehicle based on the direction parallel to the ground The second distance c to the camera sensor 100 may be included.

As shown in Figure 3, the inter-vehicle distance (d _real ) finally calculated in this embodiment is the distance from the front end (eg, front bumper) of the own vehicle to the rearmost end (eg, rear bumper) of the front vehicle, In order to calculate such an inter-vehicle distance (d _real ), in the present embodiment, three distance parameters, that is, a distance (a), a distance (d _image ), and a rear overhang length (d _{OH) as specification information of the vehicle in front} ) is employed.

The distance (a) is from the front end of the own vehicle, the terminal point of the blind spot of the camera sensor 100 formed by the bonnet of the own vehicle based on the longitudinal direction of the own vehicle (P in FIG. 3, the longitudinal direction of the own vehicle) refers to the distance to the front end point of the blind spot of the camera sensor 100). The distance d _image means a distance from the aforementioned termination point to a wheel (rear wheel) of the front vehicle. When following the definition of the distance (a) and the distance (d _image) as described above, in this embodiment the inter-vehicle distance is the distance (a) and the distance (d _image) the rear overhang of the front vehicle at a value adding (rear overhang) length ( d _OH ) can be calculated by subtracting. If this is expressed as an equation, it is as shown in Equation 1 below.

[ Equation 1 ]

Now, the process of calculating the distance (a) and the distance (d _image ), which are factors of Equation 1, will be described in detail.

First, the distance calculator 200 may calculate the distance a using the first and second heights h1 and h2 and the first and second distances b and c based on the geometric model. The location information of the camera sensor 100 currently installed in the own vehicle may be previously stored in the distance calculating unit 200 . Using the proportional expression with reference to FIG. 3 , the distance a may be calculated according to Equation 2 below.

[ Equation 2 ]

Next, _{the process of calculating the distance d image} is a process of calculating the height l in FIG. 3 based on the geometric model, the process of calculating the first angle θ, and calculating the second angle α and a process of calculating a _{distance (d image).}

Specifically, the distance calculating unit 200 uses the first and second lane widths L1 and L2, and the height from the ground point to the first straight line connecting the camera sensor 100 and the wheel of the vehicle in front. (l) can be calculated. The second lane width L2 obtained from the front image corresponds to the first height h1, and the difference between the second lane width L2 and the first lane width L1 corresponds to the height l. Considering the proportional relationship, the height l may be calculated according to Equation 3 below.

[ Equation 3 ]

Then, the distance calculator 200 uses the distance (a), the second distance (c), and the first height (h1) so that the second straight line connecting the camera sensor 100 and the end point is perpendicular to the ground. The first angle θ formed with the straight line may be calculated. Referring to FIG. 3 , the first angle θ may be calculated according to Equation 4 below.

[ Equation 4 ]

Then, the distance calculator 200 uses the first angle θ, the distance a, the second distance c, and the first height h1, and the second angle formed by the first straight line and the second straight line. (α) can be calculated. Referring to FIG. 3 , the second angle α may be calculated according to Equation 5 below.

[ Equation 5 ]

_{Finally, the distance calculator 200 may calculate the distance d image} by using the height l, the first angle θ, and the second angle α. Referring to FIG. 3 , the distance d _image may be calculated according to Equation 6 below.

[ Equation 6 ]

When the distance a and the distance d _image are calculated through the above-described process, the final inter-vehicle distance d _real may be calculated according to Equation 1 described above.

Tables 1 and 2 below are experimental data showing the values obtained from the front image captured by the camera sensor 100 and the error rates from the measured values, respectively. From Tables 1 and 2, it can be seen that the error rate of the inter-vehicle distance detection method according to the present embodiment has high reliability in the range of 0% to 5%.

[ Table 1 ]

[ Table 2 ]

Meanwhile, in the present embodiment, as shown in FIG. 1 , the controller 300 controls the operation of a driver assistance system (DAS) applied to the own vehicle based on the inter-vehicle distance calculated through the distance calculator 200 . ) may be further included. The driving assistance system may refer to various systems that use the inter-vehicle distance as a control factor thereof, such as ACC (Adaptive Cruise Control), AEB (Autonomous Emergency Braking), LKAS (Lane Keeping Assist System), and HDA (Highway Driving Assist). may include.

4 is a flowchart illustrating a method for calculating a distance between vehicles according to an embodiment of the present invention. The method of calculating the distance between vehicles according to the present embodiment will be described with reference to FIG. 4 , and the content overlapping with the previously described content will be omitted and the time series configuration will be mainly described.

First, the distance calculating unit 200 acquires a front image through the camera sensor 100 that captures an image of the front of the own vehicle (S100).

Next, the distance calculator 200 acquires lane width information based on the lane detected from the front image ( S200 ).

Next, the distance calculating unit 200 calculates the inter-vehicle distance from the own vehicle to the vehicle in front by applying the location information and the lane width information of the camera sensor 100 installed in the own vehicle to a predefined geometric model ( S300 ).

The above-described lane width information may include a first lane width L1 based on a wheel of the front vehicle and a second lane width L2 based on a bonnet of the own vehicle. In addition, the position information of the camera sensor 100 includes a first height h1 of the camera sensor 100 with respect to the ground, a second height h2 of the camera sensor 100 with respect to the bonnet of the own vehicle, A first distance (b) from the bonnet to the camera sensor 100 based on a direction parallel to the ground, and a second distance from the front end of the own vehicle to the camera sensor 100 based on a direction parallel to the ground ( c) may be included.

Accordingly, in step S300, the distance calculating unit 200 is the distance from the front end of the own vehicle to the end point of the blind spot of the camera sensor 100 formed by the bonnet of the own vehicle based on the longitudinal direction of the own vehicle. _{After calculating (a) and the distance (d image} ) from the end point to the wheel of the front vehicle based on the geometric model, using the calculated distance (a, d _image ) and the specification information of the vehicle in front, it is calculated as the inter-vehicle distance. The distance from the front end of the vehicle to the rearmost end of the vehicle in front is calculated.

To describe step S300 in more detail, the distance calculator 200 uses the first and second heights h1 and h2 and the first and second distances b and c based on the geometric model to determine the distance a ) is calculated.

In addition, in step S300, the distance calculator 200 connects the camera sensor 100 and the wheel of the vehicle in front from the ground at the end point using the first and second lane widths L1 and L2 based on the geometric model Calculates the height l to the first straight line, and uses the distance (a), the second distance (c), and the first height (h1), a second straight line connecting the camera sensor 100 and the end point The first angle θ formed with the straight line perpendicular to the ground is calculated, and the first straight line is calculated using the first angle θ, the distance a, the second distance c, and the first height h1. And after calculating the second angle α formed by the second straight line, the distance d _image is calculated using the height l, the first angle θ, and the second angle α.

In step S300 , the distance calculating unit 200 finally _{subtracts the rear overhang length d OH} as specification information of the front vehicle from the sum of the _{distance a and the distance d image} to obtain the inter-vehicle distance. to calculate

After step S300 , as shown in FIG. 4 , step S400 in which the controller 300 controls the operation of the driving assistance system applied to the own vehicle based on the inter-vehicle distance may be further performed.

As such, in this embodiment, the lane width in the image is obtained based on the detected lane and vanishing point detected from the front image of the camera sensor 100, and the inter-vehicle distance from the own vehicle to the vehicle in front is calculated based on a predetermined geometric model. By calculating, even when the monocular camera sensor 100 is used, the distance accuracy may be improved, and the calculated inter-vehicle distance may be used for autonomous driving control, thereby improving the accuracy of autonomous driving control.

Implementations described herein may be implemented in, for example, a method or process, an apparatus, a software program, a data stream, or a signal. Although discussed only in the context of a single form of implementation (eg, only as a method), implementations of the discussed features may also be implemented in other forms (eg, in an apparatus or a program). The apparatus may be implemented in suitable hardware, software and firmware, and the like. A method may be implemented in an apparatus such as, for example, a processor, which generally refers to a computer, a microprocessor, a processing device, including an integrated circuit or programmable logic device, or the like. Processors also include communication devices such as computers, cell phones, portable/personal digital assistants (“PDAs”) and other devices that facilitate communication of information between end-users.

Although the present invention has been described with reference to the embodiment shown in the drawings, this is merely exemplary, and it is understood that various modifications and equivalent other embodiments are possible by those skilled in the art to which the art pertains. will understand Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

100: camera sensor
200: distance calculator
300: control unit

Claims (17)

A camera sensor for photographing a front image of the own vehicle; and
Obtaining lane width information based on the lane detected from the front image captured by the camera sensor, and using the position information of the camera sensor installed on the windshield inside the own vehicle and the obtained lane width information in a predefined geometric model a distance calculating unit for calculating an inter-vehicle distance from the host vehicle to a vehicle ahead by applying to ;
Including,
The lane width information includes a first lane width L1 based on a wheel of the front vehicle and a second lane width L2 based on a bonnet of the host vehicle,
The location information of the camera sensor includes a first height h1 of the camera sensor with respect to the ground, a second height h2 of the camera sensor with respect to the bonnet of the own vehicle, and a direction parallel to the ground. a first distance (b) from the bonnet to the camera sensor as a reference, and a second distance (c) from the front end of the own vehicle to the camera sensor in a direction parallel to the ground,
The distance calculator,
The distance (a) from the front end of the own vehicle to the end point of the blind spot of the camera sensor formed by the bonnet of the own vehicle based on the longitudinal direction of the own vehicle, and from the end point to the front vehicle After calculating the distance (d _image ) to the wheel of the vehicle based on the geometric model, the host vehicle as the inter-vehicle distance (d _real ) using the calculated distance (a, d _{image ) and the specification information of the front vehicle} Inter-vehicle distance calculating device, characterized in that for calculating the distance from the front end of the front end of the vehicle.
delete delete delete The method of claim 1,
The distance calculation unit, based on the geometric model,
and calculating the distance a using the first and second heights h1 and h2 and the first and second distances b and c.
The method of claim 5,
The distance calculation unit, based on the geometric model,
Using the first and second lane widths L1 and L2, a height l from the ground to a first straight line connecting the camera sensor and the wheel of the front vehicle is calculated from the terminal point,
Using the distance (a), the second distance (c), and the first height (h1), a first angle formed by a second straight line connecting the camera sensor and the end point with a straight line perpendicular to the ground ( θ) is calculated,
A second angle α formed by the first straight line and the second straight line using the first angle θ, the distance a, the second distance c, and the first height h1 After calculating
and calculating _{the distance d image} using the height l, the first angle θ, and the second angle α.
The method of claim 6,
The distance calculator,
and calculating the inter-vehicle distance d _{real by subtracting a rear overhang length d OH} as the specification information of the front vehicle from the sum of the distance a and the distance d _image A device for calculating the distance between vehicles.
The method of claim 1,
The camera sensor is a distance calculating device between vehicles, characterized in that the monocular camera sensor.
The method of claim 1,
and a controller for controlling an operation of a driver assistance system (DAS) applied to the own vehicle based on the inter-vehicle distance calculated through the distance calculator.
obtaining, by the distance calculator, a front image through a camera sensor that captures an image of the front of the own vehicle;
obtaining, by the distance calculator, lane width information based on a lane detected from the front image; and
Calculating, by the distance calculator, the inter-vehicle distance from the own vehicle to the vehicle in front by applying the position information of the camera sensor installed on the windshield inside the host vehicle and the obtained lane width information to a predefined geometric model ;
Including,
The lane width information includes a first lane width L1 based on a wheel of the front vehicle and a second lane width L2 based on a bonnet of the host vehicle,
The location information of the camera sensor includes a first height h1 of the camera sensor with respect to the ground, a second height h2 of the camera sensor with respect to the bonnet of the own vehicle, and a direction parallel to the ground. a first distance (b) from the bonnet to the camera sensor as a reference, and a second distance (c) from the front end of the own vehicle to the camera sensor in a direction parallel to the ground,
In the calculating step, the distance calculating unit,
The distance (a) from the front end of the own vehicle to the end point of the blind spot of the camera sensor formed by the bonnet of the own vehicle based on the longitudinal direction of the own vehicle, and from the end point to the front vehicle After calculating the distance (d _image ) to the wheel of the vehicle based on the geometric model, the host vehicle as the inter-vehicle distance (d _real ) using the calculated distance (a, d _{image ) and the specification information of the front vehicle} An inter-vehicle distance calculation method, characterized in that the distance from the frontmost end of the to the rearmost end of the front vehicle is calculated.
delete delete delete The method of claim 10,
In the calculating step, the distance calculating unit, based on the geometric model,
and calculating the distance a using the first and second heights h1 and h2 and the first and second distances b and c.
The method of claim 14,
In the calculating step, the distance calculating unit, based on the geometric model,
Using the first and second lane widths L1 and L2, a height l from the ground to a first straight line connecting the camera sensor and the wheel of the front vehicle is calculated from the terminal point,
Using the distance (a), the second distance (c), and the first height (h1), a first angle formed by a second straight line connecting the camera sensor and the end point with a straight line perpendicular to the ground ( θ) is calculated,
A second angle α formed by the first straight line and the second straight line using the first angle θ, the distance a, the second distance c, and the first height h1 After calculating
The distance calculating method between vehicles, characterized in that _{the distance (d image} ) is calculated using the height (l), the first angle (θ), and the second angle (α).
The method of claim 15,
In the calculating step, the distance calculating unit,
and calculating the inter-vehicle distance d _{real by subtracting a rear overhang length d OH} as the specification information of the front vehicle from the sum of the distance a and the distance d _image A method of calculating the distance between vehicles.
The method of claim 10,
and controlling, by a controller, an operation of a driver assistance system (DAS) applied to the own vehicle based on the calculated inter-vehicle distance.

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