JP5998881B2 - TRACKING DEVICE AND TRACKING METHOD - Google Patents

Description

  The present invention relates to a tracking device and a tracking method for a moving object that moves at high speed, and in particular, tracking that tracks a moving object based on position information and image information of the moving object such as a spacecraft, a flying object, an aircraft, and an automatic vehicle. The present invention relates to an apparatus and a tracking method.

  As a target tracking device that tracks a moving body that moves at high speed, such as an aircraft, a measurement tracking system that uses monopulse radio waves, GPS (Global Positioning System) positioning data, etc. and an image tracking system that uses a camera tracking function There is. For example, Patent Document 1 discloses an imaging control that acquires a position and a moving state of an aircraft using a radar device, calculates an estimated position of the aircraft when actually imaging the aircraft, and images the calculated estimated position of the aircraft. An apparatus is disclosed.

  The imaging control device of Patent Literature 1 acquires aircraft position information and movement information using a radar, and controls the shooting direction of the camera based on the acquired aircraft position information and movement information. Furthermore, Embodiment 4 of Patent Document 1 discloses that a GPS receiver is mounted on an aircraft instead of using a radar, and aircraft position information and movement information are acquired based on the positioning results of the GPS receiver. ing.

JP 2006-270404 A

  However, when acquiring position information and movement information of an aircraft using a radar device, if the aircraft is located far away, it may be difficult to perform highly accurate measurement, and necessary information may not be acquired. On the other hand, when the position and movement state of an aircraft are acquired using a GPS receiver, a signal may not be received from the GPS receiver due to the influence of radio wave shielding or the like.

  Therefore, it is desirable to use both the positioning by the radar device and the positioning by the GPS receiver. However, when there is a gap in the positioning result when switching from the radar device to the GPS receiver, the shooting direction of the camera cannot be controlled smoothly. .

  The object of the present invention has been made in view of the above problems, and even when a plurality of tracking methods are used in combination, the tracking target behavior can be continuously tracked without abrupt changes, and the tracking target can be imaged. It is an object of the present invention to provide a tracking device and a tracking method that can smoothly control the imaging direction of an imaging device.

  In order to achieve the above object, a tracking device according to the present invention includes an imaging unit that images a tracking target and outputs it as image information, and controls the imaging direction of the imaging unit based on a drive signal and the driving state at that time A camera gimbal that is fed back as information, a GPS receiver that is arranged on the tracking target, acquires position information of the tracking target by the GPS function, and transmits it as an acquired position signal, acquires a planned trajectory of the tracking target, and acquires the planned trajectory The position information of the tracking target is calculated using the trajectory predicting means for identifying the position information of the tracking target using the and the position information of the tracking target that is output as a specific position signal, and sequentially acquiring the position information of the tracking target in the tracking process and performing a predetermined calculation. And selecting one of the sequential calculation means for outputting as the calculation position signal, the acquisition position signal, the specific position signal, and the calculation position signal. Reference position output means for outputting as a position signal, distance measurement means for measuring the distance between the imaging means and the tracking target, and output as distance information, and error extraction means for extracting and outputting the position error of the tracking target from the image information And control means for generating and outputting a drive signal based on the reference position signal, the distance information, the position error, and the state information.

  In order to achieve the above object, a tracking method according to the present invention includes: an imaging unit that captures a tracking target and outputs the image information as image information; As a tracking method using a camera gimbal that feeds back as follows, the tracking target position information is acquired by the GPS function, transmitted as an acquisition position signal, the tracking target planned trajectory is acquired, and the tracking is performed using the acquired planned trajectory The position information of the target is identified and output as a specific position signal, and the position information of the tracking target is calculated by sequentially acquiring the position information of the tracking target and performing a predetermined calculation in the tracking process, and output as a calculated position signal Select any one of the acquisition position signal, the specific position signal, and the calculation position signal, and output as a reference position signal. Distance was measured, and output as distance information from the image information by extracting the position error of the tracking target output, the reference position signal, the distance information, and generates and outputs a drive signal based on the position error and status information.

  The tracking device and the tracking method according to the present invention can continuously track the behavior of the tracking target without sudden change even when a plurality of tracking methods are used together, and smoothly control the imaging direction of the tracking target. Can do.

1 is a block configuration diagram of a tracking device 10 according to a first embodiment of the present invention. It is a block block diagram of the image guidance tracking device 100 which concerns on the 2nd Embodiment of this invention. It is the figure which showed the relationship between the gimbal coordinate system (SIGMA) b and the inertial coordinate system (SIGMA) i.

(First embodiment)
A tracking device according to the first embodiment will be described. FIG. 1 shows a block diagram of the tracking device according to the present embodiment. In FIG. 1, the tracking device 10 includes an imaging unit 20, a camera gimbal 30, an error extraction unit 40, a reference position output unit 50, a distance measurement unit 60, and a control unit 70.

  The imaging unit 20 images a tracking target that moves at high speed, such as a spacecraft, flying object, aircraft, or automobile, and outputs image information of the tracking target to the error extraction unit 60.

  The camera gimbal 30 controls the imaging direction of the imaging unit 20 based on the drive signal input from the control unit 70. Further, the camera gimbal 30 grasps the driving state of the imaging unit 20 and periodically feeds it back to the control unit 70 as state information.

  The error extraction means 40 extracts the tracking target image data from the image information input from the imaging means 20, measures the shift amount between the center position of the image information and the tracking target image data, and controls it as a position error. It outputs to the means 70.

  The reference position output unit 50 includes a GPS receiver 51, a trajectory prediction unit 52, and a sequential calculation unit 53. The acquired position signal generated by the GPS receiver 51, the specific position signal generated by the trajectory prediction unit 52, and the sequential calculation. One signal is selected from the calculated position signals generated by the means 53 and output to the control means 70 as a reference position signal.

  Here, the GPS receiver 51 is arranged as a tracking target, acquires position information of the tracking target by a GPS function, and outputs the acquired position information as a acquired position signal. The trajectory predicting unit 52 acquires a planned trajectory to be tracked, specifies position information of the tracking target by using the acquired planned trajectory and time information, and outputs it as a specific position signal. The sequential calculation means 53 sequentially acquires the position information of the tracking target in the tracking process, calculates the position information of the tracking target by performing a predetermined calculation on the sequentially acquired position information, and outputs it as a calculated position signal.

  In this embodiment, the reference position output means 50 selects the acquisition position signal generated in the GPS receiver 51 and outputs it as a reference position signal during normal times. When the reference position output means 50 cannot receive the acquired position signal from the GPS receiver 51 due to the influence of radio wave shielding or the like, the reference position signal generated by the trajectory prediction means 52 and the calculated position signal generated by the sequential calculation means 53 Are compared, the signal for which the tracking target position information is generated more continuously is selected and output as a reference position signal.

  The distance measuring means 60 measures the distance between the imaging means 20 and the tracking target and outputs it as distance information. For the distance measuring means 60, for example, a laser range finder (LRF) can be applied. In this case, the LRF is arranged in the vicinity of the imaging unit 20, the laser is irradiated from the LRF toward the imaging direction of the imaging unit 20, and the laser reflected by the tracking target is measured, thereby measuring the imaging unit 20 and the tracking target. Measure the distance between.

  The control means 70 is based on the state information fed back from the camera gimbal 30, the position error input from the error extraction means 40, the reference position signal input from the reference position output means 50, and the distance information input from the distance measurement means 60. Then, a drive signal for making the imaging direction of the imaging means 20 coincide with the direction of the tracking target is generated and output to the camera gimbal 30.

  In the present embodiment, the control means 70 corrects the reference position signal using position error (image tracking information), distance information (actual measurement value), and state information (feedback information). In this case, any position signal selected from the acquired position signal from the GPS receiver 51, the specific position signal from the trajectory prediction means 52, or the calculated position signal from the sequential calculation means 53 is selected as the reference position signal. The corrected position signal is corrected to be continuous with the previously selected position signal. Therefore, the tracking target behavior is continuously tracked without abrupt changes, and the imaging direction of the imaging means 20 can be controlled smoothly.

  Furthermore, the tracking device 10 according to the present embodiment selects the acquisition position signal from the GPS receiver 51 in the normal state and specifies only when the acquisition position signal cannot be received from the GPS receiver 51 due to the influence of radio wave shielding or the like. Of the position signal and the calculated position signal, the signal on which the tracking target position information is generated more continuously is selected. In this case, the imaging direction of the imaging unit 20 can be controlled more smoothly.

(Second Embodiment)
A second embodiment will be described. FIG. 2 shows a block configuration diagram of the image guidance tracking device according to the present embodiment. An image guidance tracking device 100 according to the present embodiment includes a position information acquisition unit 200, a laser range finder (LRF) 300, a tracking error acquisition unit 400, a target position estimator 500, a camera gimbal control unit 600, and a camera gimbal. 700.

  The position information acquisition unit 200 includes a GPS receiver 210, an orbital position profile model 220, a sequential position predictor 230, and a target position information generator 240, calculates a position vector of a target such as an unmanned aircraft, and serves as a reference position signal a. Output to the target position estimator 500.

The GPS receiver 210 is mounted on the target, calculates a position vector P = [x, y, z] ^T at the time of measurement of the target based on time information acquired from a GPS satellite, and sets the target position as a target position detection signal a1. Transmit to the information generator 240.

  The trajectory position profile model 220 generates a trajectory position profile by predicting the navigation trajectory of the target from the trajectory of the target, specifies the target position vector using the generated trajectory position profile, and uses the specified result as the target position estimation signal. It outputs to the target position information generator 240 as a2. For example, the trajectory position profile model 220 generates a trajectory position profile using a target flight plan obtained in advance, and specifies a position vector corresponding to the current time information in the generated trajectory position profile based on the kinematic model. And the target position estimation signal a2.

  The sequential position predictor 230 periodically acquires a target position vector in the target tracking process, and holds the latest position vector as a reference position vector. The sequential position predictor 230 sequentially estimates the target position vector after moving by applying the target dynamic model to the held reference position vector of the target, and uses the estimation result as the target position prediction signal a3 as a target. The information is output to the position information generator 240. In the present embodiment, the sequential position predictor 230 sequentially estimates a target position vector after movement by applying a target dynamics such as a simple equation of motion or a Kalman filter to the reference position vector of the target.

The target position information generator 240 normally estimates the position vector P ′ = [x ′, y ′, z ′] ^T after the movement of the target based on the target position detection signal a1 input from the GPS receiver 210. The reference position signal a is output to the target position estimator 500. When the target position information generator 240 cannot acquire the target position detection signal a1 from the GPS receiver 210 due to the influence of radio wave shielding or the like, the target position information generator 240 receives the target position estimation signal a2 input from the orbital position profile model 220 and the sequential position prediction. The target position prediction signal a3 input from the generator 230 is compared, a signal on which the target position vector is continuously generated is selected, and the position vector P ′ after movement of the target estimated based on the selected signal is selected. Is output to the target position estimator 500 as the reference position signal a.

  A laser range finder (LRF) 300 is installed on the camera gimbal 700 and irradiates an infrared laser toward the target and measures the infrared laser reflected from the target, thereby obtaining an instantaneous distance L ′ from the installation position to the target. Measure and output to the target position estimator 500 as a distance signal b.

  The tracking error acquisition unit 400 includes a gimbal-mounted camera 410, a camera image acquisition unit 420, and a target image information generator 430, calculates a target tracking error, and outputs the calculation result as a tracking error signal c to the target position estimator 500. To do.

  The gimbal-equipped camera 410 has its imaging direction controlled by a camera gimbal 700 described later, images the controlled direction, and outputs imaging data to the camera image acquisition unit 420. The camera image acquisition unit 420 performs predetermined processing on the imaging data input from the gimbal-equipped camera 410 and outputs the image data to the target image information generator 430 as image data. The target image information generator 430 extracts a target image from the image data input from the camera image acquirer 420, calculates a shift amount between the center position coordinates of the extracted target image and the center coordinates of the image data, and a tracking error signal c is output to the target position estimator 500.

  Here, the coordinate axis on the image data is defined by the gimbal coordinate system Σb, and the coordinate axis of the real space where the target navigates is defined by the inertial coordinate system Σi. In FIG. 3, the gimbal coordinate system Σb is defined as the origin of the plane (imaging plane) of the image data captured by the mounted camera 410, the horizontal direction h as the horizontal axis h, and the vertical direction as the vertical axis v. On the other hand, the inertial coordinate system Σi drives the camera gimbal 700 so that the direction in which the imaging surface is moved along the horizontal axis h and the rotational direction ψ (azimuth (AZ) angle) around the z axis coincide. It is defined so that the direction in which the surface is moved along the vertical axis v coincides with the rotation direction φ (elevation (EL) angle) around the x axis.

  In the present embodiment, the target image information generator 430 measures, on the gimbal coordinate axis, a deviation amount (Δh, Δv) between the center position coordinates of the extracted target image and the center coordinates of the image data on the image data. The tracking error (αh · Δh, αv · Δv) in the real space is calculated using the horizontal pixel size αh and the vertical pixel size αv of the image data, and is output to the target position estimator 500 as a tracking error signal c.

The target position estimator 500 uses the gimbal angle signal f input from the camera gimbal 700 to calculate the target position vector P = [x, y, z] ^T at the time of measurement. Then, the target position estimator 500 includes the reference position signal a (position vector P ′ = [x ′, y ′, z ′] ^T ) input from the position information acquisition unit 200 and the distance signal b (instantaneous) input from the LRF 300. The distance L ′), the tracking error signal c (tracking error (αh · Δh, αv · Δv)) input from the tracking error acquisition unit 400, and the calculated target position vector (P = [x, y, z] ^T ) And a camera gimbal target estimation signal (φr, ψr) d, which is a set target value of the camera gimbal 700, is calculated and output to the camera gimbal control unit 600. Here, the target position estimator 500 corresponds to the correcting means in the claims. The camera gimbal target estimation signal d will be described later.

  The camera gimbal control unit 600 includes a camera gimbal angle error signal generator 610 and a camera gimbal controller 620, and receives a camera gimbal target estimation signal (φr, ψr) d input from the target position estimator 500 and feedback from the camera gimbal 700. A camera gimbal control signal e for driving the camera gimbal 700 is generated from the received gimbal angle signal (φ, ψ) f and output to the camera gimbal 700. Here, the camera gimbal control unit 600 corresponds to the driving means in the claims.

  Specifically, the camera gimbal angle error signal generator 610 includes a camera gimbal target estimation signal d that is a set target value for making the imaging direction coincide with the target direction after movement, and the currently set gimbal angle signal f. The difference (Δφ, Δψ) is calculated, converted into values corresponding to the AZ axis and the EL axis (converted from the inertial coordinate system to the gimbal coordinate system), and output to the camera gimbal controller 620. The camera gimbal controller 620 is composed of a general-purpose stabilization controller such as a PID (Proportional Integral Derivative Controller) controller, for example, and AZ for setting the difference calculated by the camera gimbal angle error signal generator 610 to zero. The rotation angles of the axis and the EL axis are calculated and output as a camera gimbal control signal e.

  The camera gimbal 700 includes a camera gimbal driving unit 710, a camera gimbal dynamics 720, and a camera gimbal angle sensor 730, and controls the imaging direction of the gimbal mounted camera 410. The camera gimbal driving unit 710 drives the AZ axis and the EL axis of the camera gimbal dynamics 720 based on the camera gimbal control signal e input from the camera gimbal control unit 600. When the camera gimbal dynamics 720 is driven based on the camera gimbal control signal e, the imaging direction of the gimbal mounted camera 410 is controlled to coincide with the target direction.

  The camera gimbal angle sensor 730 outputs the set values (φ, ψ) set in the camera gimbal dynamics 720 at that time to the target position estimator 500 and the camera gimbal control unit 600 as the gimbal angle signal f.

Next, a method for generating the camera gimbal target estimation signal d in the target position estimator 500 will be described. The position information acquisition unit 200 generates a position vector P ′ = [x ′, y ′, z ′] ^T (inertial coordinate system) after movement of the target as the reference position signal a, and the LRF 300 transmits the distance signal b to the target. Consider the case where the instantaneous distance L ′ is measured and the tracking error acquisition unit 400 calculates the tracking error (αh · Δh, αv · Δv) as the tracking error signal c.

The position vector P = [x, y, z] ^T at the time of measurement of the target unmanned aerial vehicle (flying object) uses the EL angle φ, the AZ angle ψ of the camera gimbal 700, and the distance L to the target at the time of measurement. It is described as (1).

At this time, the position vector P ′ = [x ′, y ′, z ′] ^T (true value) after the movement of the target is described as the equation (2) using the instantaneous distance L ′.

In the equation (2), Δφ and Δψ are control error angles with respect to the EL angle φ and the AZ angle ψ of the camera gimbal 700, respectively. In the expressions (1) and (2), the difference in position derived for the x-axis and the z-axis is equal to the tracking error signal c (αh · Δh, αv · Δv) calculated on the gimbal coordinate axis. , (3) is established.

Therefore, the following relational expression is established from the expression (3).

と仮定すれば、（４）式よりΔφ、Δψが決定できる。従って、カメラジンバル目標推定信号（φｒ、ψｒ）ｄは（６）式のように生成される。

here,

Assuming that, Δφ and Δψ can be determined from equation (4). Therefore, the camera gimbal target estimation signal (φr, ψr) d is generated as shown in Equation (6).

  By driving the camera gimbal 700 based on the camera gimbal target estimation signal (φr, ψr) d calculated from the equation (6), the imaging direction of the gimbal-equipped camera 410 and the target direction (true value) after the movement are obtained. Match.

  Next, an operation procedure of the image guidance tracking device 100 according to the present embodiment will be described. In this embodiment, a GPS receiver 210 is mounted on an unmanned aerial vehicle (flying object) as a target, and the flying object is tracked with high accuracy by a two-axis drive type camera gimbal 700 and an LRF 300 installed in a ground station.

  In the present embodiment, the camera gimbal 700 measures the gimbal angle signal (φ, ψ) f at the time of target imaging and feeds it back to the target position estimator 500 and the camera gimbal control unit 600.

  The target position estimator 500 is fed back from the reference position signal a input from the position information acquisition unit 200, the distance signal b input from the LRF 300, the tracking error signal c input from the tracking error acquisition unit 400, and the camera gimbal 700. Based on the gimbal angle signal f, the camera gimbal target estimation signal (φr, ψr) d shown in the above equation (6) is generated and output to the camera gimbal control unit 600.

  Based on the camera gimbal target estimation signal (φr, ψr) d input from the target position estimator 500 and the gimbal angle signal (φ, ψ) f fed back from the camera gimbal 700, the camera gimbal control unit 600 A camera gimbal control signal e for adjusting the direction of the gimbal 700 is generated, and the camera gimbal 700 is controlled. When the camera gimbal 700 is controlled by the camera gimbal control signal e, the imaging direction of the gimbal mounted camera 410 matches the target direction after movement.

  As described above, the image guidance and tracking apparatus 100 according to the present embodiment generates the distance signal b detected by the LRF 300 and the target image information from the pointing direction error of the camera gimbal 700 whose direction is controlled based on the reference position signal a. Correction is performed in real time using the tracking error signal c generated by the device 430.

  As described above, the image guidance tracking device 100 according to the present embodiment receives the distance signal b measured by the LRF 300, the tracking error signal c calculated by the tracking error acquisition unit 400, and the camera gimbal 700 in the target position estimator 500. Using the position information of the target at the time of measurement calculated from the gimbal angle signal f, the reference position signal a input from the position information acquisition unit 200 is corrected in real time. In this case, the error included in the reference position signal a is corrected appropriately, and the target position does not change abruptly. Therefore, the target can be tracked continuously, and the camera gimbal 700 can be controlled smoothly.

  In the image guidance tracking device 100 according to the present embodiment, the target position information generator 240 normally generates the reference position signal a using the target position detection signal a1 input from the GPS receiver 210, and generates radio waves. When the target position detection signal a1 cannot be obtained due to the influence of shielding or the like, the target position estimation signal a2 input from the trajectory position profile model 220 and the target position prediction signal a3 input from the sequential position predictor 230 are compared, and the target The reference position signal a is generated by selecting the signal for which the position vector is continuously generated. In this case, a highly accurate and continuous reference position signal a can be generated, the tracking accuracy of the target can be improved, and the camera gimbal 700 can be controlled more smoothly.

  Furthermore, the image guidance tracking device 100 according to the present embodiment uses a distance signal b (measured value of the distance between the gimbal-mounted camera 410 and the target detected by the LRF 300 for the calculation of the camera gimbal target estimation signal (φr, ψr) d. The instantaneous distance L ′) is used. In this case, the tracking accuracy of the target can be further improved.

  The present invention is not limited to the above-described embodiment, and can be applied to control of a camera that tracks an unmanned aerial vehicle (flying object), control of a camera that tracks various moving objects, an antenna, and the like. Further, design changes and the like within a range not departing from the gist of the present invention are also included in the present invention.

DESCRIPTION OF SYMBOLS 10 Tracking apparatus 20 Imaging means 30 Camera gimbal 40 Error extraction means 50 Reference position output means 51 GPS receiver 52 Orbit prediction means 53 Successive calculation means 60 Distance measurement means 70 Control means 100 Image guidance tracking apparatus 200 Position information acquisition part 210 GPS reception Machine 220 Orbital position profile model 230 Sequential position predictor 240 Target position information generator 300 LRF
400 Tracking error acquisition unit 410 Gimbal mounted camera 420 Camera image acquisition unit 430 Target image information generator 500 Target position estimator 600 Camera gimbal control unit 610 Camera gimbal angle error signal generator 620 Camera gimbal controller 700 Camera gimbal 710 Camera gimbal drive 720 Camera Gimbal Dynamics 730 Camera Gimbal Angle Sensor

Claims (6)

Imaging means for imaging a tracking target and outputting it as image information;
A camera gimbal for controlling the imaging direction of the imaging means based on a drive signal and feeding back the driving state at that time as state information;
A GPS receiver that is arranged in a tracking target, acquires position information of the tracking target by a GPS function, and transmits it as an acquired position signal;
A trajectory prediction means for acquiring a planned trajectory of a tracking target, specifying position information of the tracking target using the acquired planned trajectory, and outputting the specific position signal;
Sequential calculation means for calculating the position information of the tracking target by sequentially acquiring the position information of the tracking target in the tracking process and performing a predetermined calculation, and outputting the calculation position signal;
Reference position output means for selecting any one of the acquisition position signal, the specific position signal and the calculation position signal and outputting as a reference position signal;
Distance measuring means for measuring the distance between the imaging means and the tracking target and outputting the distance information;
Error extraction means for extracting and outputting a position error of the tracking target from the image information;
Control means for generating and outputting the drive signal based on the reference position signal, distance information, position error and state information;
A tracking device comprising: The control means includes
Correction means for correcting the reference position signal using the distance information, position error and state information, and outputting the correction position as a correction position;
Drive means for generating and outputting a drive signal for making the imaging direction of the imaging means coincide with the correction position;
A tracking device according to claim 1. The reference position signal, distance information, position error and state information are represented in a coordinate system in real space,
The correction means outputs a correction position expressed in a coordinate system in real space,
The drive means converts a drive signal generated in a coordinate system in real space into a drive signal expressed in a coordinate system on the imaging surface, and outputs the drive signal.
The tracking device according to claim 2. The reference position output means normally selects an acquisition position signal, and when the acquisition position signal cannot be received, selects a signal having a larger continuity with the reference position signal output last time from the specific position signal or the calculation position signal. The tracking device according to any one of claims 1 to 3. The trajectory prediction means identifies the position corresponding to the current time on the planned trajectory as position information of the tracking target,
The sequential calculation means calculates the tracking target position information by applying an equation of motion or a Kalman filter to the tracking target position information acquired sequentially,
The tracking device according to any one of claims 1 to 4. An imaging unit that images a tracking target and outputs it as image information, and a tracking method using a camera gimbal that controls the imaging direction of the imaging unit based on a drive signal and feeds back a driving state at that time as state information,
The position information of the tracking target is acquired by the GPS function and transmitted as an acquisition position signal.
Acquire the planned track of the tracking target, specify the position information of the tracking target using the acquired planned track, and output it as a specific position signal,
In the tracking process, the position information of the tracking target is sequentially obtained and the position information of the tracking target is calculated by performing a predetermined calculation, and output as a calculated position signal,
Select one of the acquisition position signal, the specific position signal and the calculation position signal, and output as a reference position signal,
Measure the distance between the imaging means and the tracking target, and output as distance information,
Extract and output the tracking target position error from the image information,
Generating and outputting the drive signal based on the reference position signal, distance information, position error and state information;
Tracking method.

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