JP5537348B2 - Object position estimation device - Google Patents

Description

  The present invention relates to an object position estimation apparatus.

Conventionally, this type of infrared guidance device acquires image data with a sensor that captures a medium-wavelength infrared image, and detects and guides a target flying object based on the magnitude of luminance. However, in this method, when excessive light such as laser light is irradiated from the target flying object, luminance information is saturated and erroneous guidance is performed.

In such a case, in order to prevent erroneous induction, a method of switching the processing system when excessive light occurs, or dimming on hardware to detect an object has been proposed. The size of itself increases (see, for example, Patent Document 1 and Patent Document 2).

JP-A-10-185498 JP-A-11-295408

There have been problems such as the need for hardware changes such as the need to add a new sensor mechanism to the device itself, and the size of the device itself becoming larger.

For example, the flying object seeker disclosed in Patent Document 1 is provided with a laser light detector, and the processing system is switched depending on the intensity of the laser light, thereby controlling the attitude of the flying object even when excessive laser light is emitted from the object. It is an invention that maintains the above. However, it is necessary to change the hardware, such as attaching an extra laser detector, which increases the overall size of the device.

Further, the object tracking device disclosed in Patent Document 2 controls the neutral density filter and the bandpass filter according to the intensity of received light, thereby preventing excessive light from entering the sensor and maintaining and tracking the processing target image. It is an invention that continues the process. This device also requires the insertion of the filter and the addition of a filter control mechanism, and increases the overall size of the device.

The present invention is for solving the above-described problem, and is an object position estimation device that reduces erroneous induction due to the influence of excessive light. In the present invention, when excessive light is emitted, the position of the object is estimated by using the shape and orientation information of the saturated region appearing on the imaging. Compared to conventional brightness threshold processing alone, even if excessive light is emitted and the brightness information of most of the image is saturated, the position of the object can be estimated accurately, and accurate guidance is possible. . Further, even when the apparatus is configured, it is not necessary to add an extra sensor, and an increase in the apparatus size can be prevented.

In order to achieve the above object, an object position estimation apparatus of the present invention extracts image data acquisition means for acquiring electromagnetic wave image data, and a region that exceeds a predetermined threshold with respect to luminance information of the electromagnetic wave image data as a saturated region. And when the coordinate data in the orthogonal image coordinate system of each pixel in each saturation region obtained by the saturation region extraction means is projected onto the one-dimensional space, Area inclination calculating means for calculating an axial direction of the one-dimensional space in which the variance of coordinate data is maximized as an inclination vector of each of the saturated areas in the orthogonal image coordinate system; and in each of the saturated areas in the orthogonal image coordinate system A straight line is drawn in the direction of the inclination vector that passes through the center of gravity and corresponds to each saturation region, and the point where these drawn straight lines intersect is determined as the position of the object. , A position estimation means for estimating Te and having a.

ADVANTAGE OF THE INVENTION According to this invention, the target object position estimation apparatus which can reduce the misleading by the influence of excessive light can be provided.

The figure which shows the structure of the target object position estimation apparatus which concerns on Embodiment 1 of this invention. The flowchart which shows the operation | movement process of the target object position estimation apparatus which concerns on Embodiment 1 of this invention. The figure which shows an example of the electromagnetic wave image data which concerns on Embodiment 1 of this invention. The figure for demonstrating the flatness of the saturation area | region which concerns on Embodiment 1 of this invention. The figure for demonstrating the inclination vector of the saturation area | region which concerns on Embodiment 1 of this invention. The figure explaining estimation of the position of the target object concerning Embodiment 1 of this invention. The figure explaining estimation of the position of the target object concerning Embodiment 1 of this invention. The figure which shows the structure of the target object position estimation apparatus which concerns on Embodiment 2 of this invention. The figure which shows the structure of the target object position estimation apparatus which concerns on Embodiment 3 of this invention. The figure for demonstrating the area division which concerns on Embodiment 3 of this invention. The figure which shows the structure of the target object position estimation apparatus which concerns on Embodiment 4 of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a block diagram showing a configuration of an object position estimation apparatus according to Embodiment 1 of the present invention. The object position estimation apparatus includes an image data acquisition unit 100 that acquires electromagnetic wave image data, and a saturation region that extracts, as a saturation region, a region that exceeds a luminance threshold with respect to luminance information of the electromagnetic wave image data acquired by the image data acquisition unit 100 Extraction unit 101, region inclination calculation unit 102 that calculates the inclination of the saturation region with respect to the image coordinate system in each saturation region extracted by saturation region extraction unit 101, and the target from the inclination of the saturation region calculated by region inclination calculation unit 102 It is comprised from the position estimation part 103 which estimates the position of an object.

Subsequently, an operation process of the object position estimation apparatus according to Embodiment 1 of the present invention will be described with reference to FIG.

FIG. 2 is a flowchart showing operation processing of the object position estimation apparatus according to Embodiment 1 of the present invention.

The electromagnetic wave image data is acquired by the image data acquisition unit 100 (S1). FIG. 3 shows an example of infrared image data obtained as electromagnetic wave image data by the image data acquisition unit 100.

Here, when an excessive infrared laser beam is emitted from the object, the imaging result differs depending on the position of the object image 301 in the infrared image, and the imaging result when the object image 301 is near the center of the image is It becomes like FIG. 3 (a), (b).

In addition, when excessive infrared laser light is emitted from the object, most of the luminance information including the center of the image is saturated, and a saturated region 302 appears as a small arc-shaped region in the peripheral portion of the image.

On the other hand, the imaging when the object image 301 is captured near the edge of the image is shown in FIGS.
)become that way.

In this case, the saturation region 302 tends to expand radially from the position of the object image 301.
These events are generally caused by the mechanism and optical properties of the imaging system.

Next, the infrared image data acquired by the image data acquisition unit 100 is the saturated region extraction unit 1.
In 01, a saturated region 302 is extracted (S2).

Here, in the extraction of the saturated region 302, an arbitrary luminance threshold is set, and a pixel portion having a luminance value higher than the luminance threshold is extracted as the saturated region 302.

Further, in the extraction of the saturated region 302, it is possible to remove random noise or the like by extracting only the region larger than the area threshold with respect to the arbitrarily set area threshold and excluding the small region.

Further, the flattening rate f of each saturated region 302 is calculated, and by extracting only the saturated region 302 having a flatness higher than the flattening rate threshold with respect to the arbitrarily set flattening rate threshold, an inclination vector 303 described later (see FIG. 5, 6, and 7) can be improved.

The flatness ratio f can be calculated by the following equation (1).

Here, as shown in FIG. 4, a represents the length of the major axis of the saturated region 302, and b represents the length of the minor axis.

The saturation region 302 extracted by the saturation region extraction unit 101 is input to the region inclination calculation unit 102, and the inclination of each saturation region 302 in the image coordinate system is calculated as an inclination vector 303 (S3).

As shown in FIG. 5, the inclination vector 303 is the coordinate data 30 of each pixel in the saturation region 302.
When 4 is projected onto the one-dimensional space, the axis direction that maximizes the data dispersion in the same dimensional space is determined as the inclination vector 303.

The gradient vector 303 calculated by the region gradient calculation unit 102 is input to the position estimation unit 103, and the object position 306 is estimated (S4).

Here, as shown in FIG. 6, the inclination vector 3 passes through the center of gravity 305 in each saturation region 302.
The intersection when the straight line is extended in the direction of 03 is estimated as the object position 306.

Further, the position estimation unit 103 estimates the position by selecting either the direction of the inclination vector 303 or the direction orthogonal to the inclination vector 303 according to the center of gravity position of the saturation area having the maximum area among the plurality of saturation areas 302. It is also possible to have a function to perform.

That is, when the center of gravity appears near the edge of the image as shown in FIGS. 3C and 3D, the object position 306 is determined by using the direction of the inclination vector 303 as shown in FIG. Can be sought.

Further, when the center of gravity appears in the vicinity of the center of the image as shown in FIGS. 3A and 3B, the intersection when the straight line is extended in the normal direction 307 with respect to the direction of the inclination vector 303 as shown in FIG. Can be obtained as the object position 306.

As described above, according to the first embodiment, it is possible to accurately estimate the position of the object even if excessive infrared laser light is emitted from the object and the luminance information of most of the image is saturated. And accurate guidance is possible. Moreover, it is not necessary to add an extra sensor, and the enlargement of the apparatus size can be prevented.

(Embodiment 2)
Next, a second embodiment of the present invention will be described. In the second embodiment of the present invention, the image data acquisition unit 100 is provided with a function of acquiring long-wavelength infrared image data and medium-wavelength infrared image data in the same field of view, thereby observing data in a wide range of different bands. I can do it.

As a configuration of an object position estimation apparatus that acquires image data of two wavelength bands with the same field of view, for example, the configuration shown in FIG. 8 is conceivable. The image data acquisition unit 100 oriented in the direction in which the object is supposed to exist, displays the image of the object as a lens 200 and a dichroic mirror 201.
To the long wavelength infrared sensor 202 and the medium wavelength infrared sensor 203. Lens 2
A dichroic mirror 201 is disposed at the rear of 00, and the dichroic mirror 201 transmits long-wavelength infrared light and reflects medium-wavelength infrared light.

A long wavelength infrared sensor 202 is disposed in the transmission direction, and a medium wavelength infrared sensor 203 is disposed in the reflection direction. A multifocal lens may be used as a method for guiding the object image to both sensors.

By observing images in two or more wavelength bands, if there is excessive light only in a certain wavelength band, erroneous induction can be achieved by selecting and processing an image in a wavelength band that is not affected by excessive light. It can be avoided. Further, even when excessive light over both wavelength bands is emitted, the amount of information is statistically increased, so that the position estimation performance is improved.

(Embodiment 3)
Subsequently, Embodiment 3 of the present invention will be described. The third embodiment will be described with reference to FIGS. 9 and 10.

FIG. 9 shows the configuration of the object position estimation apparatus according to Embodiment 3 of the present invention. In the present embodiment, a luminance gradient calculation unit 104 and a region division unit 105 are added to the object position estimation apparatus according to the first embodiment.

  The same components as those in the first embodiment are denoted by the same reference numerals, and redundant description is omitted.

  Next, operation processing of the object position estimation apparatus according to Embodiment 3 of the present invention will be described.

The image data obtained by the image data acquisition unit 100 is input to the luminance gradient calculation unit 104, and a luminance gradient vector is calculated for each pixel. Here, the calculation of the luminance gradient vector is performed by the following equation (2).

Here, I (i, j) indicates the luminance at the coordinates (i, j).

The luminance gradient vector calculated by the luminance gradient calculating unit 104 is input to the region dividing unit 105 as luminance gradient information, and the entire image is divided into regions based on the input luminance gradient information.

Here, a vector orthogonal to the luminance gradient vector shown in the above equation (2) (hereinafter referred to as a rotation vector r (i, j). The following equation (3)) is considered.

As shown in FIG. 10, on the image data 400, an edge exists at a portion where the size of the rotation vector 401 is large, and the direction of the rotation vector 401 is along the edge.

Using the information of the rotation vector 401, it is possible to draw a dividing line 402 that divides the region by selecting a local maximum in size and following the direction.

The region information divided by the region dividing unit 105 is input to the saturated region extracting unit 101, and it is determined whether each divided region is a saturated region. Subsequent operation processing is the same as that of the first embodiment, and thus description thereof is omitted.

According to the third embodiment of the present invention, since the region extraction is performed from the absolute value evaluation to the relative value evaluation by using the luminance gradient vector, the region is robust against fluctuations in luminance intensity. Estimation can be performed and guidance performance can be improved.

(Embodiment 4)
Next, a fourth embodiment of the present invention will be described. FIG. 11 shows the configuration of the object position estimation apparatus according to Embodiment 4 of the present invention. In the present embodiment, an estimated position storage unit 106 is added to the configuration of the object position estimating apparatus according to the first embodiment. Embodiment 1
The same components are denoted by the same reference numerals and redundant description is omitted.

  Next, operation processing of the object position estimation apparatus according to Embodiment 4 of the present invention will be described.

First, as in Embodiment 1, the position estimation unit 103 estimates the object position.
The estimated position information of the object is input to the estimated position storage unit 106 and recorded. Here, the recording amount can be arbitrarily set by the user. For example, if recording for M frames is set, a history of estimated positions of the object for the immediately preceding M frames can be accumulated. . Then, the position estimation unit 103 estimates the object position by combining the temporal changes in the estimation results for M frames recorded in the estimated position storage unit 106.

According to the fourth embodiment, by observing the estimation result for a certain period of time, the temporal change can be evaluated as one feature amount, and erroneous estimation due to the influence of white random noise or the like can be reduced. Actually, when excessive light is emitted from the target flying object, imaging is not stable, and thus the estimated value is stabilized by estimating the position temporally and statistically.

Note that the present invention is not limited to the above-described embodiment, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some constituent elements may be deleted from all the constituent elements shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 100 Image data part 101 Saturation area extraction part 102 Area inclination calculation part 103 Position estimation part 104 Luminance gradient calculation part 105 Area division part 106 Estimated position memory | storage part 202 Long wavelength infrared sensor 203 Medium wavelength infrared sensor

Claims (6)

Image data acquisition means for acquiring electromagnetic wave image data;
A saturation region extraction means for extracting a region exceeding a predetermined threshold with respect to the luminance information of the electromagnetic wave image data as a saturation region;
When the coordinate data in the orthogonal image coordinate system of each pixel in each saturated region obtained by the saturated region extracting means is projected onto a one-dimensional space, the variance of each coordinate data in the one-dimensional space after projection is maximum. An area inclination calculating means for calculating an axial direction of the one-dimensional space as an inclination vector of each of the saturated areas in the orthogonal image coordinate system ;
In the orthogonal image coordinate system, a position where a straight line is drawn in the direction of an inclination vector corresponding to each saturated area passing through the center of gravity of each saturated area, and a point where these drawn straight lines intersect is estimated as the position of the object An estimation means;
The object position estimation apparatus characterized by having. The saturated region extracting means includes
2. The object position estimation apparatus according to claim 1, wherein only a saturated region having an area larger than a predetermined threshold is extracted from the saturated regions. The saturation region calculation means includes
Of the saturated regions, extracting only a saturated region in which the flatness calculated by dividing the difference between the length of the major axis and the length of the minor axis by the length of the major axis is higher than a predetermined threshold value. The object position estimation apparatus according to claim 1, wherein the object position estimation apparatus is characterized. The position estimating means includes
When the gravity center position of the saturation region having the maximum area among the saturation regions appears near the end of the electromagnetic wave image data, the direction of the inclination vector corresponding to each saturation region through the gravity center of each saturation region Draw a straight line at the point where the point where these drawn straight lines intersect is the object position,
When the gravity center position of the saturation region having the maximum area appears near the center of the electromagnetic wave image data, a straight line is drawn in a direction orthogonal to the inclination vector corresponding to each saturation region through the gravity center of each saturation region. The object position estimation apparatus according to claim 1, wherein a point where these drawn straight lines intersect is estimated as the position of the object. For each coordinate position of each pixel from the electromagnetic wave image data, luminance gradient information calculating means for calculating a luminance gradient vector as luminance gradient information based on the difference in luminance information between both pixels adjacent to this pixel ;
A vector orthogonal to the brightness gradient vector is calculated as a rotation vector for each, and based on a dividing line drawn by following a gradient inflection position that is a position where the size of the calculated rotation vector is locally maximum. Region dividing means for dividing the electromagnetic wave image data into regions,
Further comprising
The saturated region extracting means includes
5. The object position estimation apparatus according to claim 1, wherein it is determined whether or not each region divided by the region dividing unit is a saturated region . The position estimating means includes
An estimated value of the position of the object for a plurality of frames within a preset time is accumulated, and the position of the object is estimated based on a temporal change amount of the accumulated estimated value. The object position estimation apparatus according to any one of claims 1 to 5.