CN102143324A - Method for automatically and smoothly tracking target by cradle head - Google Patents

Abstract

The invention relates to a method for automatically and smoothly tracking a target by a cradle head, which comprises the following steps of: (1) acquiring target position information and cradle head state information and updating in real time; (2) calculating actual rotating speed and direction of a cradle head tracked moving target according to the target position information and cradle head state information, wherein the calculation method comprises the following steps of: calculating the angular speed and direction of the target moving relative to the cradle head, and correcting the angular speed and direction of the target moving relative to the cradle head according to deviation between the current actual rotating angle of the cradle head and a theoretical rotating angle of the target in the center of an image so as to obtain the actual rotating speed and direction of the cradle head tracked moving target; and (3) controlling the rotation of the cradle head to track the moving target according to the actual rotating speed and direction of the cradle head tracked moving target. The method is reasonable in design, realizes intelligent monitoring function of the moving target so as to position the moving target in a central range of a monitored picture, and has the characteristics of simple implementation, fast tracking, high accuracy, high real-time property and the like.

Description

A kind of method of The Cloud Terrace automatic smoothing tracking target

Technical field

The invention belongs to protection and monitor field, especially a kind of method of The Cloud Terrace automatic smoothing tracking target.

Background technology

At present, monopod video camera is to use one of the most general monitoring frontend in the monitoring field.The monitor staff can control manually that monopod video camera is rotated and convergent-divergent, to realize the observation to monitoring scenery and monitored object.Development along with the intelligent video analysis technology, watch-dog with intelligent function more and more is subjected to liking of user, for example, the watch-dog that has the automatically track target function can carry out intelligent video analysis by the video image that video camera is absorbed into, find and find the position at moving target place, rotation of control watch-dog and convergent-divergent are to realize the automatic following function to moving target.This autotrack mode can be realized the shooting of moving target in the active situation of whole monitoring scene, manually tracking mode has higher accuracy, and can remove monitor staff's worry constantly on duty, be one of the important development trend in following monitoring market.

Realize that The Cloud Terrace to the conventional method that moving target carries out automatic following function is: at first obtain the position at moving target place, control then monopod video camera be rotated with convergent-divergent realize to target from motion tracking.At present, more for the method for obtaining the moving target position, for example can realize by video analysis or by methods such as moving target carry satellite fix tracing equipment passback positional informations, but, how to control monopod video camera be rotated with convergent-divergent to realize that the automatic following function to moving target is a key technology, control method is improper will directly to cause the Automatic Target Tracking failure.At present, realize that the method for control The Cloud Terrace automatically track target can directly turn to the method realization of target position by the control The Cloud Terrace, treat to control again when target will break away from monitoring visual field the The Cloud Terrace rotation and make target occupy picture centre, to guarantee that moving target is all the time in the monitoring visual field scope.But this method can not guarantee moving target all the time in the center range of monitoring visual field, and need whether will break away from the monitoring visual field accuracy of judgement to moving target, otherwise lose objects easily; When the target rapid movement, need under the less time interval, rotate by the continuous control The Cloud Terrace, make monitored picture one moving quiet, visual effect is bad, also is unfavorable for the good observation to moving target.

Summary of the invention

The objective of the invention is to overcome the deficiencies in the prior art, a kind of tracking accuracy height is provided, follows the tracks of the method for rapid and real-time a kind of The Cloud Terrace automatic smoothing tracking target.

The present invention solves its technical problem and takes following technical scheme to realize:

A kind of method of The Cloud Terrace automatic smoothing tracking target may further comprise the steps:

(1) obtains target position information and The Cloud Terrace state information, and carry out real-time update;

(2), calculate the actual speed and the direction of The Cloud Terrace pursuit movement target according to target position information and The Cloud Terrace state information;

(3) according to the actual speed and the direction of The Cloud Terrace pursuit movement target, the rotation of control The Cloud Terrace is with the pursuit movement target;

Step (2) is calculated the actual speed of The Cloud Terrace pursuit movement target and the method for direction is: at first calculate angular speed and the direction of target with respect to the The Cloud Terrace motion, then according to the anglec of rotation of the current reality of The Cloud Terrace with make target occupy the deviation of the theoretical anglec of rotation of picture centre, target is revised with respect to the angular speed and the direction of The Cloud Terrace motion, obtained the actual speed and the direction of The Cloud Terrace pursuit movement target.

And described moving target positional information is obtained by methods of video analyses or is obtained by moving target carry Satellite Tracking positioning equipment passback positional information method.

And described calculating target is to obtain according to the different target position informations that get access to constantly with respect to the angular speed of The Cloud Terrace motion with direction, and its computing formula is:

Horizontal direction angular speed w1:

Vertical direction angular speed w2:

In the formula: what α 1 and β 1 represented previous moment t1 respectively horizontally rotates the angle and the vertical anglec of rotation, α 2 and β 2 respectively current time t2 horizontally rotate the angle and the vertical anglec of rotation, Δ t1 representative is carved into the time that t2 is experienced constantly during from t1.

And the described method that target is revised with respect to the angular speed and the direction of The Cloud Terrace motion is: when The Cloud Terrace was ahead of object run, the angular speed and the adjustment in direction of The Cloud Terrace motion are: the angular speed of horizontal direction was

The angular speed of vertical direction is

When The Cloud Terrace lagged behind object run, the angular speed and the adjustment in direction of The Cloud Terrace motion are: the angular speed of horizontal direction was

The angular speed of vertical direction is

In the formula: w1 and w2 be respectively target with respect to The Cloud Terrace in the horizontal direction with the angular speed of movement in vertical direction,With

Represent respectively The Cloud Terrace angular speed in the horizontal direction with the variable quantity of vertical direction.

And, described The Cloud Terrace angular speed in the horizontal direction with the variable quantity of vertical direction

With

Computing formula be:

In the formula:

What γ 1 and θ 1 represented The Cloud Terrace reality respectively horizontally rotates the angle and the vertical anglec of rotation, and γ 2 represents the The Cloud Terrace theoretical level anglec of rotation and the vertical anglec of rotation respectively with θ 2, and Δ t2 representative pulls up to the time interval of moving target.

And, obtaining of the described theoretical anglec of rotation comprises following method: the method that (1) adopts wide-angle imaging machine and monopod video camera to cooperate, absorbing image with the wide-angle imaging machine carries out intelligent video analysis and gets access to the definite position of target on image, according to the relative position relation of monopod video camera and wide-angle imaging machine, get access to the theoretical anglec of rotation of The Cloud Terrace; (2) with moving target carry mobile satellite location equipment, by the geographic information data of wireless network transmissions moving target, calculating of the relative position by target and The Cloud Terrace makes target occupy the theoretical anglec of rotation of The Cloud Terrace of picture centre; The theoretical anglec of rotation of The Cloud Terrace when (3) position by current The Cloud Terrace and the position of target on the image that monopod video camera absorbed obtain making target occupy picture centre.

And the anglec of rotation of the current reality of described The Cloud Terrace obtains by The Cloud Terrace system queries or feedback.

And described step (3) is after the actual speed and direction that obtain The Cloud Terrace pursuit movement target, by selecting to control the The Cloud Terrace rotation with the immediate speed step of actual speed in each speed step of The Cloud Terrace.

Advantage of the present invention and good effect are:

1, this method can guarantee that by the actual speed and the automatically continuous rotation of direction method control The Cloud Terrace of calculating The Cloud Terrace pursuit movement target moving target is all the time in the center range of monitored picture, help observation, have characteristics such as implementation method is simple, tracking is rapid, precision is high, real-time simultaneously moving target.

2, this method adopts methods of video analyses or obtains the moving target positional information by moving target carry Satellite Tracking positioning equipment passback positional information method, has increased the flexibility that system expands.

3, the present invention is reasonable in design, has realized the intelligent monitoring function to moving target, makes moving target be positioned at the center range of monitored picture all the time, has reduced professional monitor staff's labour intensity, has strengthened the robustness of target tracking algorism simultaneously again.

Description of drawings

Fig. 1 is a flow chart of the present invention;

Fig. 2 is the flow chart of the embodiment of the invention;

Fig. 3 is that the embodiment of the invention is calculated the principle schematic of target with respect to the The Cloud Terrace movement velocity;

Fig. 4 is the principle schematic that the embodiment of the invention is calculated the velocity variable of The Cloud Terrace tracking target.

Embodiment

Below in conjunction with accompanying drawing the embodiment of the invention is further described:

A kind of method of The Cloud Terrace automatic smoothing tracking target is rotated to keep moving target all the time in the center range of monitored picture continuously by the control The Cloud Terrace.The Cloud Terrace carrying video camera can make monopod video camera realize horizontal direction 360 degree rotations, vertical direction 90 degree rotations, when target is in a certain position of monitoring range, under unscreened situation, make target be in the center of monitored picture by The Cloud Terrace being rotated in the horizontal and vertical directions certain angle.When target is moved in monitoring range, we can control The Cloud Terrace and rotate to and make target keep the center of monitored picture under a certain angle, we are referred to as the theoretical anglec of rotation of The Cloud Terrace this anglec of rotation, promptly no matter The Cloud Terrace is current is under for which kind of anglec of rotation, just can make target be in the center of monitored picture under this theoretical anglec of rotation as long as the control The Cloud Terrace rotates to, we can represent the positional information of target with this theoretical anglec of rotation.Want to realize The Cloud Terrace to moving target next step is exactly how to control the The Cloud Terrace rotation to keep target in monitored picture from motion tracking.Method provided by the invention is the rotation continuously along with the motion of moving target of control The Cloud Terrace, makes monitored picture seem more level and smooth, and we are referred to as a kind of method of The Cloud Terrace automatic smoothing tracking target.Below this method is elaborated.

As shown in Figure 1, a kind of method of The Cloud Terrace automatic smoothing tracking target may further comprise the steps:

Step 1: obtain target position information and The Cloud Terrace state information, and carry out real-time update.

In this step, the moving target positional information is to adopt methods of video analyses to obtain, and also can obtain by moving target carry Satellite Tracking positioning equipment passback positional information method.

Step 2:, calculate the actual speed and the direction of The Cloud Terrace pursuit movement target according to target position information and The Cloud Terrace state information.

This step is the key content of invention, and the actual speed of The Cloud Terrace pursuit movement target and the accuracy of direction calculating will directly have influence on the effect of The Cloud Terrace automatically track target.Its concrete computational methods are: calculate angular speed and the direction of target with respect to the The Cloud Terrace motion according to the target position information that gets access to constantly in difference; According to the anglec of rotation of the current reality of The Cloud Terrace with make target occupy the deviation of the theoretical anglec of rotation of picture centre, target is revised (quickening or deceleration) with respect to the angular speed and the direction of The Cloud Terrace motion, thereby determine the actual speed and the direction of The Cloud Terrace pursuit movement target.

The above-mentioned theory anglec of rotation obtain following method: the method that (1) adopts wide-angle imaging machine and monopod video camera to cooperate, absorbing image with the wide-angle imaging machine carries out intelligent video analysis and gets access to the definite position of target on image, relative position relation according to monopod video camera and wide-angle imaging machine, just can get access to the theoretical anglec of rotation of The Cloud Terrace, when The Cloud Terrace drives video camera and rotates to this angle, just can make target be in the center of the image that monopod video camera absorbs; (2) with moving target carry mobile satellite location equipment, by the geographic information data of wireless network transmissions moving target, the calculating of the relative position by target and The Cloud Terrace also can obtain the theoretical anglec of rotation of The Cloud Terrace that makes target occupy picture centre; The theoretical anglec of rotation of The Cloud Terrace when (3) position by current The Cloud Terrace and the position of target on the image that monopod video camera absorbed obtain making target occupy picture centre.

The anglec of rotation of the current reality of above-mentioned The Cloud Terrace obtains by The Cloud Terrace system queries or feedback.

Step 3: according to the actual speed and the direction of The Cloud Terrace pursuit movement target, the rotation of control The Cloud Terrace is with the pursuit movement target.

This step is after the actual speed and direction that obtain The Cloud Terrace pursuit movement target, by selecting to control the The Cloud Terrace rotation with the immediate speed step of actual speed in each speed step of The Cloud Terrace.

The present invention is described further with specific embodiment shown in Figure 2 below.

When receiving tracking target information, we judge at first whether target is new tracking target (being whether target is to occur for the first time).When target occurs for the first time, no matter which kind of position The Cloud Terrace is at this moment, we can rotate to The Cloud Terrace under the theoretical anglec of rotation with prestissimo earlier, so that target appears in the monitored picture center range, at this moment the physical location of The Cloud Terrace and target is immediate, and this will be very beneficial for follow-up tracking.After just judgement was the tracking target that occurs for the first time, we got access to the theoretical anglec of rotation of The Cloud Terrace, directly with prestissimo The Cloud Terrace are rotated to this theoretical anglec of rotation then.

When target is not when occurring for the first time, we will controls The Cloud Terrace with certain speed and direction rotation, and the maintenance moving target is in the center range of image.Owing to be not fresh target, thereby the positional information that the target front arranged as a reference, so can judge whether target position information is unusual: when the position of the position of target and front is too wide in the gap, can think invalid target information, not process; When the positional information of target just often can be participated in the processing of The Cloud Terrace pursuit movement target as effective target position information.Its processing method is:

Calculate the movement velocity and the direction of the relative The Cloud Terrace of moving target.Moving target can obtain by calculating in the theoretical anglec of rotation of the different The Cloud Terraces that obtain constantly with direction with respect to the movement velocity of The Cloud Terrace.As shown in Figure 3, in the target travel process, we have obtained the theoretical anglec of rotation of The Cloud Terrace that The Cloud Terrace is inscribed when difference, horizontally rotate angle α 1 and vertical anglec of rotation β 1 when being previous moment t1, horizontally rotate angle α 2 and vertical anglec of rotation β 2 during current time t2, being carved into the time that t2 experienced constantly during from t1 is Δ t1.When too little or too big, statistics speed can be too inaccurate as Δ t1, and general Δ t1 gets 120 milliseconds to 600 milliseconds, and representative value can be got 280 milliseconds.We obtain the theoretical anglec of rotation of The Cloud Terrace every the Δ t1 time exactly, and the angular speed that moves in the horizontal direction with respect to The Cloud Terrace of target and the angular speed of movement in vertical direction can calculate so:

Horizontal direction angular speed:

Vertical direction angular speed:

If moving target, is commanded The Cloud Terrace to follow the tracks of with this speed so and just can be kept target all the time in the picture centre scope with constant angular speed motion with respect to The Cloud Terrace.Because the speed statistics is controlled the hysteresis quality of The Cloud Terrace, when target occurs quickening in motion process or slows down, The Cloud Terrace target will occur falling behind or being ahead of with speed motion before, if do not adjust rapidly and just may make target slip chart inconocenter, even run out of monitoring visual field, at this moment we just must adjust the speed of The Cloud Terrace.With the target acceleration is example, and when target was quickened, The Cloud Terrace can lag behind target, as shown in Figure 4.The current residing physical location of The Cloud Terrace can be represented with vertical anglec of rotation θ 1 with horizontal anglec of rotation γ 1, but, because target is quickened, target has departed from the center of image, just according to the current physical location of target obtain to make target occupy the theoretical anglec of rotation γ 2 of The Cloud Terrace and the θ 2 (level and vertical direction) of picture centre unequal with actual anglec of rotation γ 1 of The Cloud Terrace and θ 1 (level and vertical direction), at this moment must make target come back to the center of image to the quickening of The Cloud Terrace.If we require to pull up to moving target in the Δ t2 at certain time intervals, so The Cloud Terrace just need be in the Δ t2 time on original basis level rotate more

Angle, vertical direction is rotated more

Angle, the variable quantity of the angular speed of The Cloud Terrace so

Horizontal direction:

Vertical direction:

If we control The Cloud Terrace with horizontal direction

Vertical direction

Angular speed operation just can after the Δ t2 time, catch up with moving target, Δ t2 has influenced The Cloud Terrace and has caught up with the speed of target, generally Δ t2 can get 500ms.The rotary speed of common The Cloud Terrace has certain limit, general The Cloud Terrace can not rotate with arbitrary speed in this scope, but speed is divided into some grades, the certain angular velocity of rotation of each grade representative can only be with the angular speed control The Cloud Terrace rotation of these grades.Thereby can not be with the horizontal direction angular velocity of rotation that calculates at us

With the vertical direction angular velocity of rotationControl The Cloud Terrace rotation, we can select the speed class control The Cloud Terrace rotation of the angular speed of the most approaching calculating gained according to the angular speed of each speed class correspondence of The Cloud Terrace.

Owing to can only select the rotation of immediate speed class control The Cloud Terrace to cause the The Cloud Terrace may be leading in the process of pursuit movement target or lag behind target when target speed changeable and the rotation of control The Cloud Terrace.When The Cloud Terrace was ahead of object run, The Cloud Terrace should slow down on the basis of target with respect to the movement velocity of The Cloud Terrace, promptly horizontal direction should withAngular speed, vertical direction should with

Angular speed select the operation of The Cloud Terrace proper speed grade.When The Cloud Terrace lagged behind object run, The Cloud Terrace should quicken operation on respect to the basis of The Cloud Terrace motion in target, promptly level should withAngular speed, vertically should with

Angular speed select the operation of The Cloud Terrace proper speed grade.Target can be passed through formula (1) and (2) acquisition with respect to the movement velocity w1 and the w2 of The Cloud Terrace.The Cloud Terrace is in the angular velocity varies amount of level and vertical direction

With

Can pass through formula (3) and (4) obtains.Sum up the situation that The Cloud Terrace may occur in the pursuit movement object procedure, the direction of our controlled The Cloud Terrace rotation and the judgement and the computational methods of the anglec of rotation, with the horizontal direction is example, and the rotational angular velocity of control The Cloud Terrace pursuit movement target and the computational methods of direction are as shown in the table.

Table 1

The vertical direction situation is with β 1, and β 2, and θ 1, and θ 2, w2 and

Judge and calculating that method is identical with horizontal direction.Show us thus and calculate the angular velocity of rotation and the direction of The Cloud Terrace pursuit movement, just can reach the purpose of controlling The Cloud Terrace automatic smoothing pursuit movement target according to this angular speed and the rotation of direction control The Cloud Terrace.

When the information obtained less than tracking target, two kinds of situations may take place: a kind of is that target is run out of monitoring range, and this is normal track rejection; Another kind is exactly that target is blocked or is obtained less than, Here it is improper track rejection by the target information that the reason of message transmission problem causes.Can judge that from the position of track rejection any reason causes obtaining less than tracking target information: when target is run out of monitoring range, be judged as target for losing normally, this moment, the may command The Cloud Terrace was out of service, waited for that new target occurs proceeding to follow the tracks of again; When target is improper when losing, the position of measurable target, for example can adopt the position of Kalman's forecast method target of prediction, continue the rotation of control The Cloud Terrace with the pursuit movement target, continuation pursuit movement target that can be timely, level and smooth when guaranteeing that target occurs with prediction result.

It is emphasized that; embodiment of the present invention is illustrative; rather than it is determinate; therefore the present invention is not limited to the embodiment described in the embodiment; every other execution modes that drawn by those skilled in the art's technical scheme according to the present invention belong to the scope of protection of the invention equally.

Claims (8)

1. the method for a The Cloud Terrace automatic smoothing tracking target may further comprise the steps:

(1) obtains target position information and The Cloud Terrace state information, and carry out real-time update;

(2), calculate the actual speed and the direction of The Cloud Terrace pursuit movement target according to target position information and The Cloud Terrace state information;

(3) according to the actual speed and the direction of The Cloud Terrace pursuit movement target, the rotation of control The Cloud Terrace is with the pursuit movement target;

It is characterized in that: step (2) is calculated the actual speed of The Cloud Terrace pursuit movement target and the method for direction is: at first calculate angular speed and the direction of target with respect to the The Cloud Terrace motion, then according to the anglec of rotation of the current reality of The Cloud Terrace with make target occupy the deviation of the theoretical anglec of rotation of picture centre, target is revised with respect to the angular speed and the direction of The Cloud Terrace motion, obtained the actual speed and the direction of The Cloud Terrace pursuit movement target.

2. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1 is characterized in that: described moving target positional information is obtained by methods of video analyses or is obtained by moving target carry Satellite Tracking positioning equipment passback positional information method.

3. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1 is characterized in that: described calculating target is to obtain according to the different target position informations that get access to constantly with respect to the angular speed of The Cloud Terrace motion with direction, and its computing formula is:

Horizontal direction angular speed w1:

$w1=\frac{|\mathrm{\α}1-\mathrm{\α}2|}{\mathrm{\Δt}1}$

Vertical direction angular speed w2:

$w2=\frac{|\mathrm{\β}1-\mathrm{\β}2|}{\mathrm{\Δt}1}$

In the formula: what α 1 and β 1 represented previous moment t1 respectively horizontally rotates the angle and the vertical anglec of rotation, α 2 and β 2 respectively current time t2 horizontally rotate the angle and the vertical anglec of rotation, Δ t1 representative is carved into the time that t2 is experienced constantly during from t1.

4. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1, it is characterized in that: the described method that target is revised with respect to the angular speed and the direction of The Cloud Terrace motion is: when The Cloud Terrace is ahead of object run, the angular speed and the adjustment in direction of The Cloud Terrace motion are: the angular speed of horizontal direction is | w1-Δ w1|, the angular speed of vertical direction be | and w2-Δ w2|; When The Cloud Terrace lags behind object run, the angular speed and the adjustment in direction of The Cloud Terrace motion are: the angular speed of horizontal direction is (w1+ Δ w1), the angular speed of vertical direction is (w2+ Δ w2), in the formula: w1 and w2 be respectively target with respect to The Cloud Terrace in the horizontal direction with the angular speed of movement in vertical direction, Δ w1 and Δ w2 represent respectively The Cloud Terrace angular speed in the horizontal direction with the variable quantity of vertical direction.

5. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 4 is characterized in that: described The Cloud Terrace angular speed with the variation delta w1 of vertical direction and the computing formula of Δ w2 be in the horizontal direction:

$\mathrm{\Δw}1=\frac{|\mathrm{\γ}1-\mathrm{\γ}2|}{\mathrm{\Δt}2}$

$\mathrm{\Δw}2=\frac{|\mathrm{\θ}1-\mathrm{\θ}2|}{\mathrm{\Δt}2}$

In the formula:

What γ 1 and θ 1 represented The Cloud Terrace reality respectively horizontally rotates the angle and the vertical anglec of rotation, and γ 2 represents the The Cloud Terrace theoretical level anglec of rotation and the vertical anglec of rotation respectively with θ 2, and Δ t2 representative pulls up to the time interval of moving target.

6. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1, it is characterized in that: obtaining of the described theoretical anglec of rotation comprises following method: the method that (1) adopts wide-angle imaging machine and monopod video camera to cooperate, absorbing image with the wide-angle imaging machine carries out intelligent video analysis and gets access to the definite position of target on image, according to the relative position relation of monopod video camera and wide-angle imaging machine, get access to the theoretical anglec of rotation of The Cloud Terrace; (2) with moving target carry mobile satellite location equipment, by the geographic information data of wireless network transmissions moving target, calculating of the relative position by target and The Cloud Terrace makes target occupy the theoretical anglec of rotation of The Cloud Terrace of picture centre; The theoretical anglec of rotation of The Cloud Terrace when (3) position by current The Cloud Terrace and the position of target on the image that monopod video camera absorbed obtain making target occupy picture centre.

7. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1 is characterized in that: the anglec of rotation of the current reality of described The Cloud Terrace obtains by The Cloud Terrace system queries or feedback.

8. the method for a kind of The Cloud Terrace automatic smoothing tracking target according to claim 1, it is characterized in that: described step (3) is after the actual speed and direction that obtain The Cloud Terrace pursuit movement target, by selecting to control the The Cloud Terrace rotation with the immediate speed step of actual speed in each speed step of The Cloud Terrace.

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