KR20150106241A

KR20150106241A - Apparatus and method for controling direction error of gimbal apparatus using image processing

Info

Publication number: KR20150106241A
Application number: KR1020140028504A
Authority: KR
Inventors: 남병욱; 이호정; 조시훈; 조성훈
Original assignee: 국방과학연구소
Priority date: 2014-03-11
Filing date: 2014-03-11
Publication date: 2015-09-21
Also published as: KR101560578B1

Abstract

The present invention relates to an apparatus and a method for controlling direction error of a gimbal apparatus for measuring and controlling direction accuracy of a final load end by using image processing in the gimbal apparatus. The apparatus for controlling direction error of a gimbal apparatus comprises an image obtaining device coaxially installed with a load end of a gimbal apparatus, and obtaining image information of a direction point directed by the load end from image information of a target; an image processing device part processing the obtained image information, and calculating a distance between a target point of the load end and the direction point of the load end; and a gimbal control device calculating direction error in azimuth and elevation based on the load end of the gimbal apparatus by using the distance between the image obtaining device and the target, and the distance between the target point and the direction point of the load end, and then changing direction of the load end by controlling operation of the gimbal apparatus upon the calculated direction error.

Description

[0001] APPARATUS AND METHOD FOR CONTROLLING DIRECTION ERROR OF GIMBAL APPARATUS USING IMAGE PROCESSING [0002]

The present invention relates to an apparatus and method for controlling a directional error of a Kimball apparatus for measuring and controlling a directivity accuracy of a final load by using image processing in a Kimball apparatus.

A typical gimbal device may be mounted on a platform, such as a stationary platform or a moving vehicle, an aircraft and a trap. The Gimbal device mounted on the fixed platform must be oriented in a certain direction or point and the Gimbal device mounted on the moving platform is also operated in a disturbance environment applied to the Gimbal device during the movement, The final end of the antenna, such as the antenna, must maintain its initial direction of orientation.

Generally, a conventional Gimbal device which generates a rotational motion at a final stage with a rotational torque generated from a motor and drives the motor at a specific speed or position is provided with a speed reducer for increasing a small torque generated in the motor. However, a general Gear-reducer-based Gimbal device that uses motor position information to control the position of the final part under the influence of the backlash existing in the reducer and the deformation caused by the finite stiffness of the structure Is difficult to measure.

On the other hand, the Gimbal device mounted on the mobile platform is equipped with an Inertial Navigation System (INS) for measuring the disturbance information applied to the platform to measure the directional accuracy. By using the attitude information of the platform measured by the inertial navigation system and the elevation angle and azimuth information of the gimbal device, it is possible to calculate the direction that the bottom end of the current gimbal device is oriented to and by deriving the angle difference from the target direction value, Can be calculated.

However, this method is problematic in that the inertial navigation device for measuring the disturbance angle applied to the platform must have a high performance in order to measure precise level of directivity accuracy, and the cost increases.

Second, in consideration of the suitability of the cost, when the inertial navigation system is installed, the accuracy of the output signal is degraded and the accuracy of the directivity is inaccurate.

Thirdly, since the influence of the assembly error due to the position sensor and the mechanical deformation due to the stiffness, etc., which are used as the feedback signal, is eliminated in the above method, there is a problem that the directivity accuracy value at the final stage can not be measured.

It is an object of the present invention to provide an apparatus and method for controlling a directional error of a gimbal device which can precisely measure and control a directional error between a point at a bottom of a final part compared with a target point by acquiring and processing image information of a point, have.

In order to achieve the above object, the apparatus for controlling directional error of a Gimun device according to an embodiment of the present invention includes: a Gimbal device that is mounted coaxially with a load end of a Gimbal device and acquires image information of a target point toward a lower end from image information of the target An image acquisition device; An image processing unit for processing the acquired image information and calculating a distance between the image acquisition device and the target and a distance between the target point and the target point at the bottom; And a distance between the image acquiring device and the target distance and a distance between the target point and the target point at the lower end to calculate the lower reference azimuth and the elevation angle error of the gimbal device and control the driving of the gimbal device according to the directional error, And a gimbal control device for changing the orientation direction.

The lower end includes a GUN or an antenna reflector.

The image acquisition device acquires a target image within a predetermined image acquisition range including a fixed range in the horizontal direction and a fixed range in the vertical direction around the orientation point toward which the lower end is directed.

The image acquiring apparatus acquires a target image in which a target point indicating the center of the target and a target point at the bottom are simultaneously present.

The image processing unit calculates the distance between the target point and the target point on the basis of the number of pixels in the azimuth direction and the number of pixels in the high-angle direction of the obtained image information after identifying the target point on the target ground by extracting a specific point.

According to an aspect of the present invention, there is provided a method of controlling a steering error of a Gimg-foot device, the method comprising: driving a Gimbal device to control a load end toward an initial direction; Acquiring a target image within a predetermined image acquisition range centered on an orientation point at which a lower end is directed via an image acquisition device; Processing the obtained image information to calculate a distance between the image acquisition device and the target and a distance between the target point and the target point at the bottom; Calculating a lower-limit reference azimuth and an elevation-orientation error of the gimbal using the calculated distance between the image acquisition device and the target, and the distance between the target point and the lower-end target point; And controlling the driving direction of the gimbal device according to the calculated directional error to change the initial orientation direction.

Wherein the acquiring of the target image includes acquiring a target image within a predetermined image acquisition range including a fixed range in the horizontal direction and a fixed range in the vertical direction around the orientation point toward which the target is directed, And the target point at the lower end exists at the same time.

The distance between the target point and the target point on the lower end can be obtained by using the number of pixels in the azimuth direction and the number of pixels in the high-angle direction of the acquired image information after identifying the target point on the target ground by the specific point extraction.

The present invention relates to a gimbal device for guiding a final target lower end of a gimbal device to a characteristic target point on a target through a high angle / azimuth drive of a gimbal device mounted on a fixed or moving platform, And obtaining and processing image information of a point at which the lower end is directed, thereby achieving an effect of measuring and controlling a directional error between a point at which the lower end of the final part is directed with respect to the target point.

In addition, the present invention has an effect of measuring and controlling the final system-directed error including both the mechanical error and the deformation existing in the inside of the device, as well as the control error and the sensor error.

Brief Description of the Drawings Fig. 1 is a configuration diagram of a steering error control device of a Kimbal device according to the present invention; Fig.
FIG. 2 is an embodiment of a gimbal device. FIG.
FIG. 3 is a flowchart illustrating an operation of a directional error control apparatus for a device according to an embodiment of the present invention; FIG.
4 is a view showing a moving image acquisition range in which a target point at a lower end and an orientation point at a lower end exist at the same time.
5 is a view showing coordinate definitions for calculating a distance from an image acquisition device to a target point;

The present invention relates to a gimbal device in which a final lower end of a gimbal device is directed to a characteristic target point on a target ground through a high angle / azimuth drive of a gimbal device (two-axis drive system) mounted on a fixed or moving platform, It is possible to measure and control the directional error between the target point and the target point at the lower end of the target point.

Since the embodiment of the present invention includes the contents of the device of the present invention mounted on a fixed platform, only the former is described.

FIG. 1 is a configuration diagram of a steering error control device of a Kimbal device according to the present invention, and FIG. 2 is an embodiment of a Kimbal device.

1, the apparatus for measuring a directional error of a gimbal apparatus comprises a six-axis motion simulator 1, a gimbal apparatus 2 (two-axis gimbal apparatus), an image acquisition apparatus 4, an image processing apparatus 5, A control device 6 and a target 7 as shown in FIG.

The six-axis motion simulator 1 is a device that simulates the behavior of a moving platform, and performs a function of applying a three-axis angular disturbance of roll, pitch, and yaw and a three-axis translational disturbance of X, Y, and Z directions to the Gimbal device 2 . The posture of the six-axis motion simulator 1 can be measured by the inertial navigation apparatus 8.

The gimbal device 2 is mounted on a six-axis motion simulator 1 and is driven by a two-axis or three-axis drive stabilization function under a disturbance environment applied from the six-axis motion simulator 1, Ensure that the bottom end of the final section maintains the initial orientation direction.

Basically, the Gimbal control device 6 generates a control signal for driving the gimbal device 2 at a high angle and an azimuth angle using the attitude information of the platform measured by the inertial navigation device 8, And the control is performed so that the direction of the target is continuously directed to the target point P1 located at the center of the target 7. [ The detailed control algorithm will be omitted since the present invention is focused on a method for measuring the final directional accuracy rather than a control algorithm mounted on the gimbal control device 6.

Therefore, in the above-described configuration, the present invention can be said to be a directional accuracy measurement through the image acquisition device 4 and the image processing device 5.

In other words, in case of disturbance, the control device 6 applies a rotation torque to the high angle and azimuth driving motor through the implementation of an appropriate control algorithm to generate the high angle and azimuth driving of the device 2 as shown in FIG. 2, And controls the antenna (GUN) or the antenna reflector to be oriented in a specific direction. At this time, the image acquisition device 4 is mounted at the end of the gun (GUN), which is a representative embodiment of the loading stage 3, and the center of the acquired image is the orientation point at which the gun is finally oriented. The target point located at the center of the target 7 becomes the target point to which the gun should aim and the angular error between the point at which the end of the gun GUN obtained through the image processing apparatus 5 is directed is the final system .

The finally measured directional error means the system-oriented accuracy including error information such as the control error of the gimbal device 2, the measurement error of the inertial navigation device 8, and the mechanical error and deformation in the gimbal device. The measured directional error information may be fed back to the gimbal controller 6 for position control.

In addition, through the present invention, it is possible to measure not only the mechanical error and strain existing in the device but also the final system-oriented error including the control error and the sensor error.

Hereinafter, an operation of a directional error control apparatus for a device according to an embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 3 is a flowchart illustrating an operation of a directional error control apparatus for a device according to an embodiment of the present invention, and FIG. 4 shows an image acquisition range.

First, the (six-axis) motion simulator 1 applies a three-axis disturbance of roll, pitch, and yaw and a three-axis disturbance of X-axis and Z-axis directions to the gimbal device 2 (S100) 20 drives a high angle and an azimuth angle by applying a rotation torque to the high angle and azimuth driving motor so that the GUN or the antenna reflector of the final stage 3 is directed to a specific direction (initial direction) (S120) . The above operation is the same as the conventional one.

In this state, the image acquiring device 4 mounted coaxially to the final lower end 3 of the gimbal device 2 acquires the target image information (S120). That is, as shown in FIGS. 1 and 4, the image acquiring device 4 acquires the image of the target 7 centered on the point (the aiming point) P2 at which the lower end 3 is oriented. In detail, the image acquiring device 4 acquires an image pickup range (FOV: Field) consisting of a fixed range D1 in the horizontal direction and a fixed range D2 in the vertical direction at the center of the image, (N1, N2) of the image data (e.g.

The image processing device 5 processes the image acquired by the image acquisition device 4 to identify a target point P1 located at the center of the target 7. That is, the image processing apparatus 5 identifies the target point P1 of the black circle on the white target subject 7 by extracting a specific point.

Subsequently, the image processing apparatus 5 calculates the distance (horizontal and vertical directions) between the identified target point P1 and the orientation point P2 of the lower stage 3 (S130). At this time, the target point P1 located at the center of the target 70 and the center P2 of the acquired image screen (the target point at the lower end) must exist simultaneously in the image screen obtained by the image acquisition device 4. [ The distance (x, y) between the tea target point P1 and the center P2 of the image screen (the point at the lower end) is determined by the number of detected pixels nx in the azimuth direction and the number ny of detected pixels in the high- .

Subsequently, the image processing apparatus 5 calculates a distance L between the image capturing apparatus 4 and the target (S140).

5 shows a distance calculation operation from the image acquisition device to the target point.

As shown in Fig. 5, the vector from the center of the floor of the motion simulator to the center of the upper plate

, The vector from the center of the top plate of the motion simulation to the center of the turret azimuth axis

, The vector from the azimuth rotation axis to the high-angle rotation axis center point

, The vector from the elevation axis to the image acquisition device

, The vector to the target

Can be represented by the following equation (1). The sum of the vectors is the vector from the center of the bottom of the motion simulator to the target

.

[Equation 1]

Where each vector is defined as: " (2) "

&Quot; (2) "

When the relationship between the above vectors is expressed by using the Roll / Pitch / Yaw transformation matrix [4 × 1] of the motion simulator and the azimuth / elevation transformation matrix [4 × 1] of the turret system, the following relational expression Respectively. Here, the motion simulator is a Yaw (

) -Pitch (

) -Roll (

), And the turret system considers the conversion to the azimuth-elevation order.

&Quot; (3) "

here,

Is defined as Equation (4), where s and c denote sin and cos, respectively. Also, ao denotes the center of the fixed turret azimuth rotation axis, and a denotes the new azimuth rotation axis center after rotating the turret.

&Quot; (4) "

Equation (3) can be expressed by the following Equation (5).

&Quot; (5) "

here

Is defined by the following equation (6).

&Quot; (6) "

When the azimuth angle / high angle driving command for the target orientation is obtained using Equation (6), the following Equations (7) and (8) can be obtained.

&Quot; (7) "

&Quot; (8) "

Therefore, the distance L from the image acquiring device to the target point is expressed by the following equation (9).

&Quot; (9) "

1, the image processing apparatus 5 includes a distance L between a line of sight LOS between the image capturing apparatus 4 and the target 7 and a distance L between a target point P1 and an orientation point P2 at a lower end Using the distance, the azimuth and elevation angle error (q1, q2) of the final sub-step reference of the gimbal device is calculated as shown in Equation (10) below (S150).

&Quot; (10) "

Azimuthal directional directional error (q1) = atan ((nx x D1) / N1 / L)

(Q2) = atan ((ny x D2) / N2 / L)

Therefore, the gimbal control device 6 generates control signals corresponding to the azimuth and elevation-directional errors output from the image processing device 5 to control the high angle and azimuth angle drive of the gimbal device 2, So that the lower end 4 is continuously directed to the target point P1 located at the center of the target 7 at step S160.

As described above, according to the present invention, the image acquiring apparatus is mounted on the bottom end of the final part, and the image information of the point where the bottom end is directed is obtained and processed to measure a directional error between points (orientation points) Based on this, it is possible to control the high angle and azimuth driving of the gimbal device so that the subordinate is always aimed at the target point located at the center of the target area at all times.

It will be appreciated that the configurations and methods of the embodiments described above are not to be limited and that the embodiments may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, it should be understood that the above-described embodiments are to be considered in all respects as illustrative and not restrictive.

1: 6 axis motion simulator 2: Gimbal device (drive system)
3: subordinate stage 4: image acquisition device
5: Image processing device 6: Gimbal control device
7: Targets

Claims

An image acquiring device which is installed coaxially with a load end of the Kimgye device and acquires image information of an orientation point at which a lower end is directed from image information of a target;
An image processing unit for processing the acquired image information and calculating a distance between the image acquisition device and the target and a distance between the target point and the target point at the bottom; And
The distance between the image acquisition device and the target and the distance between the target point and the target point at the lower end are used to calculate the lower and upper angle azimuths of the gimbal device to control the driving of the gimbal device according to the directional errors, And a gimbal control device for changing a direction of the gimbal.

The apparatus of claim 1, wherein the sub-
Wherein the antenna is a GUN or an antenna reflector.

2. The image capturing apparatus according to claim 1,
And a target image within a predetermined image acquisition range composed of a fixed range in the horizontal direction and a fixed range in the vertical direction is obtained centering on the orientation point toward which the lower end is directed.

2. The image capturing apparatus according to claim 1,
And a target point image in which a target point indicating the center of the target and a target point in the lower end coexist are obtained.

2. The image processing apparatus according to claim 1,
And calculates the distance between the target point and the orientation point at the lower end based on the number of pixels in the azimuth direction of the obtained image information and the number of pixels in the high-angle direction after identifying the target point on the target ground by extracting a specific point. Directional error measuring device.

2. The image processing apparatus according to claim 1,
Wherein the azimuth angle and the elevation angle error of the final sub-stage reference of the gimbal device are calculated by the following equations.
Azimuthal directional directional error (q1) = atan ((nx x D1) / N1 / L)
(Q2) = atan ((ny x D2) / N2 / L)
Where nx is the number of detected pixels in the azimuth direction, ny is the number of detected pixels in the elevation direction, and D1 and D2 are the fixed ranges in the horizontal and vertical directions of the acquired target image.

Driving the gimbal device so as to direct the loading end toward the initial direction;
Acquiring a target image within a predetermined image acquisition range centered on an orientation point at which a lower end is directed via an image acquisition device;
Processing the obtained image information to calculate a distance between the image acquisition device and the target and a distance between the target point and the target point at the bottom;
Calculating a lower-end reference azimuth and an elevation-orientation error of the gimbal using the calculated distance between the image acquisition device and the target, the distance between the target point and the orientation point at the lower end; And
And controlling the driving of the gimbal device according to the calculated directional error to change an initial direction of the gimbal device.

8. The method of claim 7, wherein acquiring the target image comprises:
Acquiring a target image within a predetermined image acquisition range including a fixed range in a horizontal direction and a fixed range in a vertical direction around an orientation point at which a lower end is directed,
Wherein the acquired target image includes a target point at the lower end and a target point at the lower end that both represent the center of the target and exist at the same time.

8. The method of claim 7, wherein the distance between the target point and the orientation point of the sub-
Wherein a target point on the target ground is identified by a specific point extraction, and then the number of pixels in the azimuth direction and the number of pixels in the high-angle direction of the obtained image information are used.

8. The method of claim 7, wherein the azimuth and elevation direction error of the final sub-stage reference of the gimbal device is calculated by the following equation.
Azimuthal directional directional error (q1) = atan ((nx x D1) / N1 / L)
(Q2) = atan ((ny x D2) / N2 / L)
Where nx is the number of detected pixels in the azimuth direction, ny is the number of detected pixels in the elevation direction, and D1 and D2 are the fixed ranges in the horizontal and vertical directions of the acquired target image.