CN108596941B - Prediction method and system of target body motion trajectory based on depth image - Google Patents

Abstract

The invention relates to the technical field of image processing, and specifically provides a method and system for predicting the motion trajectory of a target body based on a depth image, aiming at solving the technical problem of how to conveniently obtain a target body trajectory with high precision. For this purpose, the method for predicting the motion trajectory of the target body in the present invention can predict a plurality of motion trajectories in segments based on the target body trajectory points in the depth image of the target body, and then according to the spatial distance between the target body trajectory points and the motion trajectory, select Motion trajectories with high accuracy, so that the best target motion trajectories can be obtained according to these motion trajectories. Meanwhile, the target body motion trajectory prediction system in the present invention can execute and realize the above method.

Description

Prediction method and system of target body motion trajectory based on depth image

technical field

The invention relates to the technical field of image processing, in particular to a method and system for predicting the motion trajectory of a target body based on a depth image.

Background technique

Badminton robot is an intelligent control system based on technologies such as computer and visual tracking, which can simulate human badminton. Among them, badminton trajectory prediction is an important factor affecting the accuracy of badminton robot movements. Currently, badminton trajectories can be predicted using a badminton physical model or a neural network-based computational model. Among them, using the badminton physical model to predict the trajectory of the badminton is simple and easy to implement, but the prediction accuracy is low. Using a neural network-based computational model to predict the trajectory of badminton has high prediction accuracy, but requires orders of magnitude larger training samples to obtain a predicted trajectory with high accuracy.

SUMMARY OF THE INVENTION

In order to solve the above-mentioned problem in the prior art, that is, to solve the technical problem of how to conveniently obtain a target body trajectory with high precision. For this purpose, the present invention provides a method and system for predicting the motion trajectory of a target body based on a depth image.

In a first aspect, the method for predicting the motion trajectory of a target body based on a depth image in the present invention includes:

According to the pre-acquired depth image of the target body, obtain a plurality of continuous target body trajectory points;

Based on a preset trajectory prediction method, and according to the 1st to 3rd consecutive trajectory points of the target body, a first motion trajectory is obtained;

Based on the preset trajectory prediction method, and according to the 2nd to 4th consecutive trajectory points of the target body, a second motion trajectory is obtained;

Based on the preset trajectory prediction method, and according to the 3rd to 5th consecutive trajectory points of the target body, a third motion trajectory is obtained;

The first motion trajectory, the second motion trajectory and the third motion trajectory are corrected to obtain the target body motion trajectory.

Further, a preferred technical solution provided by the present invention is:

The preset trajectory prediction method specifically includes:

Obtain the spatial positions of three consecutive target body trajectory points, and calculate the initial movement speed and initial movement direction of the target body according to the obtained spatial positions;

The second target body trajectory point in the three continuous target body trajectory points is used as the initial position point; according to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in the following formula, calculate the current movement Target body trajectory points in the trajectory:

Wherein, (x _i , y _i , y _i ) are the spatial position coordinates of the i-th target body trajectory point in the current motion trajectory; (v _0x , v _0y , v _0z ) are the spatial position of the initial position point Coordinates; Described v _i is the movement speed of the target body at the i-th target body track point; Described α _i is the movement direction of the target body at the _i -th target body track point; The sampling interval at which the camera device acquires the depth image of the target body.

Further, a preferred technical solution provided by the present invention is:

The movement speed v _i and movement direction α _i of the target body at the i-th target body trajectory point are as follows:

Wherein, the v _i-1 is the movement speed of the target body at the i-1th target body trajectory point; the α _i-1 is the movement direction of the target body at the i-1th target body trajectory point; the k is the coefficient of air resistance; the g is the acceleration of gravity.

Further, a preferred technical solution provided by the present invention is:

The step of "correcting the first motion trajectory, the second motion trajectory and the third motion trajectory to obtain the target body motion trajectory" specifically includes:

In the case that neither the fourth motion trajectory point nor the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point does not deviate from the second motion trajectory, according to The method shown in the following formula obtains the target body motion trajectory T _m :

When the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point does not deviate from the second motion trajectory, the following formula The shown method obtains the target body motion trajectory T _m :

When the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point deviates from the second motion trajectory, the target body motion trajectory T _m =T ₃ ;

Wherein, the T ₁ , T ₂ and T ₃ are the first motion trajectory, the second motion trajectory and the third motion trajectory, respectively.

Further, a preferred technical solution provided by the present invention is:

The step of "correcting the first motion trajectory, the second motion trajectory and the third motion trajectory to obtain the target body motion trajectory" includes:

Calculate the spatial distance W _{n+1_1} between the fourth motion trajectory point and the first motion trajectory, and calculate the spatial distance W between the fifth motion trajectory point and the first motion trajectory and the second motion trajectory, respectively _{n+2_1} and W _{n+2_2} ;

According to the spatial distance W _{n+1_1} and the preset threshold e, it is determined whether the fourth motion trajectory point deviates from the first motion trajectory: if W _{n+1_1} >e, the fourth motion trajectory point Deviating from the first motion trajectory;

According to the spatial distance W _{n+2_1} and the preset threshold e, determine whether the fifth motion trajectory point deviates from the first motion trajectory: if W _{n+2_1} >e, the fifth motion trajectory The trajectory point deviates from the first motion trajectory;

According to the spatial distance W _{n+2_2} and the preset threshold e, determine whether the fifth motion trajectory point deviates from the second motion trajectory: if W _{n+2_2} >e, the fifth motion trajectory The trajectory point deviates from the second motion trajectory.

In the second aspect, the target body motion trajectory prediction system based on the depth image in the present invention includes:

The target body trajectory point acquisition module is configured to obtain a plurality of continuous target body trajectory points according to the pre-acquired target body depth image;

a first motion trajectory acquisition module, configured to obtain a first motion trajectory based on a preset trajectory prediction method and according to the first to third target body trajectory points;

The second motion trajectory acquisition module is configured to obtain a second motion trajectory based on the preset trajectory prediction method and according to the second to fourth consecutive trajectory points of the target body;

a third motion trajectory acquisition module, configured to obtain a third motion trajectory based on the preset trajectory prediction method and according to the 3rd to 5th consecutive trajectory points of the target body;

A target body motion trajectory acquisition module, configured to acquire the first motion trajectory acquired by the first motion trajectory acquisition module, the second motion trajectory acquired by the second motion trajectory acquisition module, and the third motion trajectory acquisition module The acquired third motion trajectory is corrected to obtain the target body motion trajectory.

Further, a preferred technical solution provided by the present invention is:

The system also includes a trajectory prediction module configured to perform the following operations to enable the system to obtain the first motion trajectory, the second motion trajectory, and the third motion trajectory:

Obtain the spatial positions of three consecutive target body trajectory points, and calculate the initial movement speed and initial movement direction of the target body according to the obtained spatial positions;

The second target body trajectory point in the three continuous target body trajectory points is used as the initial position point; according to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in the following formula, calculate the current movement Target body trajectory points in the trajectory:

Wherein, (x _i , y _i , y _i ) are the spatial position coordinates of the i-th target body trajectory point in the current motion trajectory; (v _0x , v _0y , v _0z ) are the spatial position of the initial position point Coordinates; Described v _i is the movement speed of the target body at the i-th target body track point; Described α _i is the movement direction of the target body at the _i -th target body track point; The sampling interval at which the camera system obtains the depth image of the target body.

Further, a preferred technical solution provided by the present invention is:

The trajectory prediction module includes a target body motion speed/direction calculation unit, which is configured to perform the following operations:

Calculate the movement speed v _i and movement direction α _i of the target body at the i-th target body trajectory point according to the method shown in the following formula:

Wherein, the v _i-1 is the movement speed of the target body at the i-1th target body trajectory point; the α _i-1 is the movement direction of the target body at the i-1th target body trajectory point; the k is the coefficient of air resistance; the g is the acceleration of gravity.

Further, a preferred technical solution provided by the present invention is:

The target body motion trajectory acquisition module includes a first trajectory correction unit, a second trajectory correction unit and a third trajectory correction unit;

The first trajectory correction unit is configured so that neither the fourth movement trajectory point nor the fifth movement trajectory point deviates from the first movement trajectory, and the fifth movement trajectory point does not deviate from all the points. In the case of the second motion trajectory described above, obtain the target body motion trajectory T _m according to the method shown in the following formula:

Wherein, the T ₁ , T ₂ and T ₃ are respectively the first motion track, the second motion track and the third motion track;

The second trajectory correction unit is configured to deviate from the first motion trajectory at the fourth motion trajectory point or the fifth motion trajectory point, and the fifth motion trajectory point does not deviate from the first motion trajectory point. In the case of two motion trajectories, obtain the target body motion trajectory T _m according to the method shown in the following formula:

The third trajectory correction unit is configured to deviate from the first motion trajectory at the fourth motion trajectory point or the fifth motion trajectory point, and the fifth motion trajectory point deviates from the second motion trajectory point In the case of a motion trajectory, the target body motion trajectory T _m =T ₃ .

Further, a preferred technical solution provided by the present invention is:

The target body movement trajectory acquisition module further includes a target body deviation calculation unit, a first target body deviation judgment unit, a second target body deviation judgment unit, and a third target body deviation judgment unit;

The target body deviation calculation unit is configured to calculate the spatial distance W _{n+1_1} between the fourth motion trajectory point and the first motion trajectory, and calculate the fifth motion trajectory point and the first motion trajectory respectively. the spatial distances W _{n+2_1} and W _{n+2_2} of the trajectory and the second motion trajectory;

The first target body deviation judgment unit is configured to judge whether the fourth motion trajectory point deviates from the first motion trajectory according to the spatial distance W _{n+1_1} and a preset threshold e: if W _{n+1_1} >e, the fourth motion trajectory point deviates from the first motion trajectory;

The second target body deviation judgment unit is configured to judge whether the fifth motion trajectory point deviates from the first motion trajectory according to the spatial distance W _{n+2_1} and the preset threshold e: if W _{n +2_1} >e, then the fifth motion trajectory point deviates from the first motion trajectory;

The third target body deviation judgment unit is configured to judge whether the fifth motion trajectory point deviates from the second motion trajectory according to the spatial distance W _{n+2_2} and the preset threshold e: if W _{n +2_2} >e, the fifth motion trajectory point deviates from the second motion trajectory.

Compared with the closest prior art, the above technical solution at least has the following beneficial effects:

1. The method for predicting the motion trajectory of a target body based on a depth image in the present invention can predict a plurality of motion trajectories in segments based on the target body trajectory points in the depth image of the target body, and then can be based on the spatial distance between the target body trajectory points and the motion trajectory. , and select motion trajectories with higher accuracy, so that the best target motion trajectories can be obtained according to these motion trajectories.

2. In the method for predicting the motion trajectory of a target body based on a depth image in the present invention, the threshold value of the spatial distance is set according to the accuracy of the camera device, so that it can accurately judge whether the trajectory point in the current trajectory deviates from the previous trajectory.

3. The method for predicting the motion trajectory of the target body based on the depth image in the present invention adopts three consecutive target body trajectory points to predict a motion trajectory, and according to the three continuous motion trajectories, the optimal target body motion trajectory and The target body's landing location.

Description of drawings

1 is a schematic diagram of the main steps of a method for predicting the motion trajectory of a target body based on a depth image in an embodiment of the present invention;

2 is a schematic diagram of the main steps of another depth image-based target body motion trajectory prediction system in an embodiment of the present invention;

3 is a schematic diagram of the main structure of a system for predicting the motion trajectory of a target body based on a depth image according to an embodiment of the present invention.

Detailed ways

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principle of the present invention, and are not intended to limit the protection scope of the present invention.

Referring to FIG. 1 , FIG. 1 exemplarily shows the main steps of a method for predicting a motion trajectory of a target body based on a depth image in this embodiment. As shown in Figure 1, in this embodiment, the motion trajectory of the target body can be predicted according to the following steps:

Step S101: Acquire a plurality of continuous target body track points according to the pre-acquired depth image of the target body. Specifically, in this embodiment, a camera device, such as a depth camera, may be used to acquire a depth image during the movement of the target body, and a conventional depth image processing method may be used to obtain the target body track point. For example, in this embodiment, the Depth Basics-D2D program disclosed by the Kinect for Windows v2.0 SDK may be used to acquire the target body trajectory points.

Step S102: Based on the preset trajectory prediction method, and according to the 1st to 3rd target body trajectory points, obtain a first motion trajectory.

Specifically, the preset trajectory prediction method in this embodiment includes the following steps:

First, the spatial positions of three consecutive target body track points are obtained, and according to the obtained spatial positions, the initial movement speed and initial movement direction of the target body are calculated.

Secondly, the second target body trajectory point in the three continuous target body trajectory points is used as the initial position point; according to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in the following formula (1), Calculate the target body trajectory points in the current motion trajectory:

The meaning of each parameter in formula (1) is:

(x _i , y _i , y _i ) are the spatial position coordinates of the i-th target body track point in the current motion track. (v _0x , v _0y , v _0z ) are the spatial position coordinates of the initial position point. v _i is the movement speed of the target body at the i-th target body trajectory point. α _i is the moving direction of the target body at the i-th target body trajectory point. t _s is the sampling interval at which the depth image of the target body is acquired by the camera device.

In this embodiment, the movement speed v _i and movement direction α _i of the target body at the i-th target body trajectory point are shown in the following formula (2):

The meaning of each parameter in formula (2) is:

v _i-1 is the movement speed of the target body at the i-1th target body trajectory point. α _i-1 is the movement direction of the target body at the i-1th target body trajectory point. k is the air resistance coefficient. g is the acceleration of gravity.

Further, based on the above-mentioned preset trajectory prediction method, the target body motion trajectory prediction method shown in FIG. 1 can obtain the first motion trajectory according to the following steps:

和

Step S1021: Obtain the spatial positions of the 1st to 3rd continuous target body trajectory points P ₁ , P ₂ and P ₃ , that is,

and

Step S1022: The target body trajectory point P ₂ is used as the initial position point, and the initial motion speed (v _0x , v _0y , v _0z of the target body in the first motion trajectory can be calculated according to the following formulas (3) and (4) ) and the initial motion direction α ₀ :

Step S1023: According to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in formula (1), calculate other target body trajectory points in the first movement trajectory, and then obtain the first movement trajectory.

Step S103: Based on the preset trajectory prediction method, and according to the 2nd to 4th consecutive target body trajectory points, a second motion trajectory is obtained. The method for acquiring the second motion trajectory in this embodiment is the same as the method for acquiring the first motion trajectory, and may specifically include the following steps:

和

Step S1031: Obtain the spatial positions of the _2nd to _4th continuous target body trajectory points P2, _P3 and P4, namely

and

Step S1032: take the target body trajectory point P ₃ as the initial position point, and calculate the initial motion speed (v _0x , v _0y of the target body in the second motion trajectory according to the methods described in formulas (3) and (4) , v _0z ) and the initial motion direction α ₀ .

Step S1033: According to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in formula (1), calculate other target body trajectory points in the second movement trajectory, and then obtain the second movement trajectory.

Step S104: Based on the preset trajectory prediction method, and according to the 3rd to 5th consecutive target body trajectory points, a third motion trajectory is obtained.

和

Step S1041: Obtain the 3rd to 5th continuous target body trajectory points P ₃ , P ₄ and P ₅ spatial positions, namely

and

Step S1032: Taking the target body trajectory point P4 as the initial position point, and according to the methods described in formulas (3) and ( ₄ ), calculate the initial movement speed (v _0x , v _0y of the target body in the third movement trajectory) , v _0z ) and the initial motion direction α ₀ .

Step S1033: According to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in formula (1), calculate other target body trajectory points in the third movement trajectory, and then obtain the third movement trajectory.

Step S105: Correct the first motion trajectory, the second motion trajectory and the third motion trajectory to obtain the target body motion trajectory. Specifically, in this embodiment, the motion trajectory of the target body can be obtained according to the following method:

Step S1051: Determine whether the target body trajectory point deviates from the motion trajectory:

First, calculate the spatial distance W _{n+1_1} between the fourth motion trajectory point and the first motion trajectory, and calculate the spatial distances W _{n+2_1} and W _n between the fifth motion trajectory point and the first motion trajectory and the second motion trajectory, respectively _{+2_2} .

Secondly, according to the spatial distance W _{n+1_1} and the preset threshold e, it is judged whether the fourth motion trajectory point deviates from the first motion trajectory; according to the spatial distance W _{n+2_1} and the preset threshold e, it is judged whether the fifth motion trajectory point deviates from the first motion trajectory Deviating from the first motion trajectory; according to the spatial distance W _{n+2_2} and the preset threshold e, determine whether the fifth motion trajectory point deviates from the second motion trajectory.

If W _{n+1_1} > e, the fourth motion trajectory point deviates from the first motion trajectory;

If W _{n+2_1} > e, the fifth motion trajectory point deviates from the first motion trajectory;

If W _{n+2_2} >e, the fifth motion trajectory point deviates from the second motion trajectory.

Step S1052: According to the above judgment result, obtain the motion trajectory T _m of the target body:

1. In the case that neither the fourth motion trajectory point nor the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point does not deviate from the second motion trajectory, it can be shown in the following formula (5). The method of obtaining the target body motion trajectory T _m :

The meaning of each parameter in formula (5) is: T ₁ , T ₂ and T ₃ are the first motion track, the second motion track and the third motion track, respectively.

2. When the fourth motion track point or the fifth motion track point deviates from the first motion track, and the fifth motion track point does not deviate from the second motion track, obtain it according to the method shown in the following formula (6). Target body motion trajectory T _m :

3. When the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point deviates from the second motion trajectory, the target body motion trajectory T _m =T ₃ .

Referring to FIG. 2 , FIG. 2 exemplarily shows the main steps of another method for predicting the motion trajectory of a target body based on a depth image in this embodiment. As shown in Figure 2, in this embodiment, the motion trajectory of the target body can be predicted according to the following steps:

Step S201: Acquire a depth image of the target body.

Step S202: Acquire the spatial positions of the 1st to 3rd consecutive target body trajectory points.

Step S203: Calculate the initial movement speed and initial speed direction of the target body in the current movement track. Specifically, in this embodiment, the initial motion speed (v _0x , v _0y , v _0z ) and the initial motion direction α of the target body in the current motion trajectory can be calculated according to the methods shown in formulas (3) and (4). ₀ .

Step S204: Calculate other target body track points in the current motion track according to the initial position point, the initial motion speed and the initial speed direction. Specifically, in this embodiment, other target body track points in the current motion track can be calculated according to the method shown in formula (1).

Step S205 : forming a first motion trajectory according to the 1st to 3rd consecutive target body trajectory points and their corresponding other target body trajectory points.

Step S206: Acquire the spatial position of the fourth target body trajectory point, and repeat steps S203-S204 to obtain a second motion trajectory.

Step S207: Obtain the spatial position of the fifth target body trajectory point, and repeat steps S203-S204 to obtain a third motion trajectory.

Step S208: Determine whether the fourth target body trajectory point or the fifth target body trajectory point deviates from the first motion trajectory. Specifically, if the fourth target body trajectory point or the fifth target body trajectory point deviates from the first motion trajectory, go to step S209. If neither the fourth target body trajectory point nor the fifth target body trajectory point deviates from the first motion trajectory, go to step S213.

Step S209: Abandon the first motion track.

Step S210: Determine whether the fifth target body trajectory point deviates from the second motion trajectory. Specifically, if the fifth target body trajectory point does not deviate from the second motion trajectory, go to step S211. If the fifth target body trajectory point deviates from the second motion trajectory, the second motion trajectory is abandoned, and the process goes to step S212.

Step S211: Obtain the target body motion trajectory according to the second and third motion trajectories. Specifically, in this embodiment, the movement trajectory of the target body can be obtained according to the method shown in formula (6).

Step S212 : obtaining the movement trajectory of the target body according to the third movement trajectory. Specifically, in this embodiment, the movement trajectory of the target body is the third movement trajectory.

Step S213: Determine whether the fifth target body trajectory point deviates from the second motion trajectory. Specifically, if the fifth target body trajectory point deviates from the second motion trajectory, go to step S214. If the fifth target body trajectory point does not deviate from the second motion trajectory, go to step S215.

Step S214: Abandon the second motion trajectory.

Step S215: Obtain the motion trajectory of the target body according to the first, second and third motion trajectories. Specifically, in this embodiment, the movement trajectory of the target body can be obtained according to the method shown in formula (5).

In the above-mentioned embodiment, although each step is described according to the above-mentioned order, those skilled in the art can understand that, in order to realize the effect of this embodiment, different steps need not be performed in this order, and it can be performed simultaneously ( parallel) or in reverse order, simple variations of these are within the scope of the present invention.

Based on the same technical concept as the method embodiment, the embodiment of the present invention also provides a depth image-based target body motion trajectory prediction system. The system for predicting the motion trajectory of a target body based on a depth image will be described in detail below with reference to the accompanying drawings.

Referring to FIG. 2, FIG. 2 exemplarily shows the main structure of a system for predicting the motion trajectory of a target body based on a depth image in this embodiment. As shown in FIG. 2 , the target body motion trajectory prediction system based on the depth image in this embodiment may include a target body trajectory point acquisition module 11 , a first motion trajectory acquisition module 12 , a second motion trajectory acquisition module 13 , and a third motion trajectory The acquisition module 14 and the target body motion trajectory acquisition module 15 . Specifically, in this embodiment, the target body trajectory point acquiring module 11 may be configured to acquire a plurality of continuous target body trajectory points according to a pre-acquired target body depth image. The first motion trajectory obtaining module 12 may be configured to obtain the first motion trajectory based on the preset trajectory prediction method and according to the first to third target body trajectory points. The second motion trajectory obtaining module 13 may be configured to obtain the second motion trajectory based on the preset trajectory prediction method and according to the 2nd to 4th consecutive target body trajectory points. The third motion trajectory obtaining module 14 may be configured to obtain the third motion trajectory based on the preset trajectory prediction method and according to the 3rd to 5th consecutive target body trajectory points. The target body motion trajectory acquisition module 15 may be configured to obtain the first motion trajectory acquired by the first motion trajectory acquisition module 12 , the second motion trajectory acquired by the second motion trajectory acquisition module 13 , and the third motion trajectory acquisition module 13 . The third motion trajectory of the target body is corrected to obtain the target body motion trajectory.

Further, in the present embodiment, the target body trajectory prediction system shown in FIG. 2 may further include a trajectory prediction module, which is configured to perform the following operations, so that the system can obtain the first motion trajectory, the second motion trajectory and the third motion trajectory. :

First, the spatial positions of three consecutive target body track points are obtained, and according to the obtained spatial positions, the initial movement speed and initial movement direction of the target body are calculated.

Secondly, the second target body trajectory point in the three continuous target body trajectory points is used as the initial position point; according to the initial position point, the initial movement speed and the initial movement direction, and according to the method shown in formula (1), calculate The target body track point in the current motion track.

Further, in the present embodiment, the trajectory prediction module may include a target body motion speed/direction calculation unit, which is configured to calculate the motion speed v _i and Movement direction α _i .

Further, in this embodiment, the target body motion trajectory acquisition module 15 may include a first trajectory correction unit, a second trajectory correction unit, and a third trajectory correction unit.

Specifically, the first trajectory correction unit may be configured to, when the fourth motion trajectory point and the fifth motion trajectory point do not deviate from the first motion trajectory, and the fifth motion trajectory point does not deviate from the second motion trajectory, according to The method shown in formula (5) obtains the motion trajectory T _m of the target body. The second trajectory correction unit may be configured to, when the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point does not deviate from the second motion trajectory, according to formula (6) The shown method obtains the target body motion trajectory T _m . The third trajectory correction unit may be configured to, when the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point deviates from the second motion trajectory, the target body motion trajectory T _m =T ₃ .

Further, in this embodiment, the target body motion trajectory acquisition module 15 may further include a target body deviation calculation unit, a first target body deviation judgment unit, a second target body deviation judgment unit, and a third target body deviation judgment unit.

Specifically, the target body deviation calculation unit may be configured to calculate the spatial distance W _{n+1_1} between the fourth motion trajectory point and the first motion trajectory, and calculate the difference between the fifth motion trajectory point and the first motion trajectory and the second motion trajectory, respectively. Spatial distances W _{n+2_1} and W _{n+2_2} . The first target body deviation judgment unit may be configured to judge whether the fourth motion trajectory point deviates from the first motion trajectory according to the spatial distance W _{n+1_1} and the preset threshold e: if W _{n+1_1} >e, the fourth motion trajectory point The trajectory point deviates from the first motion trajectory. The second target body deviation judgment unit may be configured to judge whether the fifth motion trajectory point deviates from the first motion trajectory according to the spatial distance W _{n+2_1} and the preset threshold e: if W _{n+2_1} >e, then the fifth motion trajectory point deviates from the first motion trajectory. The trajectory point deviates from the first motion trajectory. The third target body deviation judgment unit may be configured to judge whether the fifth motion trajectory point deviates from the second motion trajectory according to the spatial distance W _{n+2_2} and the preset threshold e: if W _{n+2_2} >e, then the fifth motion trajectory point deviates from the second motion trajectory. The trajectory point deviates from the second motion trajectory.

The above-mentioned embodiments of the system for predicting the motion trajectory of a target body based on a depth image can be used to execute the above-mentioned embodiments of the method for predicting the motion trajectory of a target body based on a depth image. Those skilled in The corresponding process in the embodiment is not repeated here.

Those skilled in the art can understand that the above-mentioned depth image-based target body motion trajectory prediction system also includes some other well-known structures, such as processors, memories, etc., wherein the memories include but are not limited to random access memory, flash memory, read-only memory, programmable Read-only memory, volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc., processors including but not limited to CPLD/FPGA, DSP, ARM processors, MIPS processors, etc., in order to unnecessarily To obscure embodiments of the present disclosure, these well-known structures are not shown in FIG. 2 .

It should be understood that the number of the various modules in FIG. 2 is merely illustrative. Each module can have any number according to actual needs.

Those skilled in the art will understand that the modules in the system in the embodiment can be adaptively changed and placed in one or more systems different from the embodiment. The modules or units in the embodiments may be combined into one module or unit, and further they may be divided into multiple sub-modules or sub-units. All features disclosed in this specification (including accompanying claims, abstract and drawings) and any method so disclosed may be employed in any combination, unless at least some of such features and/or procedures or elements are mutually exclusive. All processes or units of equipment are combined. Each feature disclosed in this specification (including accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise.

It should be noted that the above-described embodiments illustrate rather than limit the invention, and that alternative embodiments may be devised by those skilled in the art without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

Furthermore, it will be understood by those skilled in the art that although some of the embodiments described herein include certain features, but not others, included in other embodiments, that combinations of features of different embodiments are intended to be within the scope of the invention within and form different embodiments. For example, in the claims of this invention, any of the claimed embodiments may be used in any combination.

So far, the technical solutions of the present invention have been described with reference to the preferred embodiments shown in the accompanying drawings, however, those skilled in the art can easily understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims (8)

1. A target body motion track prediction method based on a depth image is characterized by comprising the following steps:

acquiring a plurality of continuous target body track points according to a target body depth image acquired in advance;

based on a preset track prediction method, obtaining a first motion track according to 1 st to 3 rd continuous target body track points;

based on the preset track prediction method, obtaining a second motion track according to 2 nd to 4 th continuous target body track points;

based on the preset track prediction method, obtaining a third motion track according to 3 rd to 5 th continuous target body track points;

correcting the first motion track, the second motion track and the third motion track to obtain a motion track of a target body;

the preset trajectory prediction method specifically includes:

acquiring the spatial positions of three continuous target body track points, and calculating the initial movement speed and the initial movement direction of a target body according to the acquired spatial positions;

taking a second target body track point of the three continuous target body track points as an initial position point; calculating a target body track point in the current motion track according to the initial position point, the initial motion speed and the initial motion direction and according to a method shown in the following formula:

wherein (x)_i,y_i,y_i) The spatial position coordinates of the ith target body track point in the current motion track are obtained; (v)_0x,v_0y,v_0z) The space position coordinates of the initial position point are obtained; v is_iThe motion speed of the object at the ith object track point is α_iThe motion direction of the object body at the ith object body track point is taken as the motion direction of the object body; said t is_sThe sampling interval for acquiring the depth image of the target body by the camera device.

2. The depth image-based target motion trail prediction method according to claim 1, wherein the motion velocity v of the target at the ith target track point_iAnd direction of motion α_iAs shown in the following formula:

wherein, v is_i-1The motion speed of the object at the i-1 th object track point is shown as α_i-1The motion direction of the object body at the ith-1 th object body track point is taken as the motion direction of the object body; k is an air resistance coefficient; the g is the acceleration of gravity.

3. The depth-image-based target body motion trajectory prediction method according to claim 1 or 2, wherein the step of modifying the first motion trajectory, the second motion trajectory, and the third motion trajectory to obtain the target body motion trajectory specifically includes:

under the condition that the fourth motion track point and the fifth motion track point do not deviate from the first motion track and the fifth motion track point does not deviate from the second motion track, the motion track T of the target body is obtained according to the method shown in the following formula_m：

Under the condition that the fourth motion track point or the fifth motion track point deviates from the first motion track and the fifth motion track point does not deviate from the second motion track, obtaining a target body motion track T according to a method shown in the following formula_m：

In the case where the fourth motion trajectory point or the fifth motion trajectory point deviates from the first motion trajectory, and the fifth motion trajectory point deviates from the second motion trajectory, the target body motion trajectory T_m＝T₃；

Wherein, T is₁、T₂And T₃Respectively a first motion trail, a second motion trail and a third motion trail.

4. The method for predicting the target body motion trail based on the depth image according to claim 3, wherein the step of modifying the first motion trail, the second motion trail and the third motion trail to obtain the target body motion trail comprises:

calculating the space distance W between the fourth motion track point and the first motion track_{n+1_1}Calculating the space distance W between the fifth motion track point and the first motion track and the space distance W between the fifth motion track point and the second motion track_{n+2_1}And W_{n+2_2}；

According to the space distance W_{n+1_1}And a preset threshold value e, judging whether the fourth motion track point deviates from the first motion track: if W_{n+1_1}If the position is more than e, the fourth motion track point deviates from the first motion track;

according to the space distance W_{n+2_1}And the preset threshold value e is used for judging whether the fifth motion track point deviates from the first motion track: if W_{n+2_1}If the position is more than e, the fifth motion track point deviates from the first motion track;

according to the space distance W_{n+2_2}And the preset threshold value e is used for judging whether the fifth motion track point deviates from the second motion track: if W_{n+2_2}And if the second motion track point is larger than e, the fifth motion track point deviates from the second motion track.

5. A depth image-based target body motion trajectory prediction system, comprising:

the target body track point acquisition module is configured to acquire a plurality of continuous target body track points according to a pre-acquired target body depth image;

the first motion track acquisition module is configured to obtain a first motion track based on a preset track prediction method according to 1 st to 3 rd target body track points;

the second motion track acquisition module is configured to obtain a second motion track according to 2 nd to 4 th continuous target body track points based on the preset track prediction method;

the third motion track acquisition module is configured to obtain a third motion track according to 3 rd to 5 th continuous target body track points based on the preset track prediction method;

a target body movement track acquisition module configured to correct the first movement track acquired by the first movement track acquisition module, the second movement track acquired by the second movement track acquisition module, and the third movement track acquired by the third movement track acquisition module to obtain a target body movement track;

the system further includes a trajectory prediction module configured to perform operations to enable the system to acquire the first, second, and third motion trajectories:

acquiring the spatial positions of three continuous target body track points, and calculating the initial movement speed and the initial movement direction of a target body according to the acquired spatial positions;

taking a second target body track point of the three continuous target body track points as an initial position point; calculating a target body track point in the current motion track according to the initial position point, the initial motion speed and the initial motion direction and according to a method shown in the following formula:

wherein (x)_i,y_i,y_i) The spatial position coordinates of the ith target body track point in the current motion track are obtained; (v)_0x,v_0y,v_0z) The space position coordinates of the initial position point are obtained; v is_iThe motion speed of the object at the ith object track point is α_iThe motion direction of the object body at the ith object body track point is taken as the motion direction of the object body; said t is_sFor obtaining purpose by camera systemSampling interval of the object depth image.

6. The depth-image-based target body movement trajectory prediction system according to claim 5, wherein the trajectory prediction module includes a target body movement speed/direction calculation unit configured to perform operations of:

calculating the motion speed v of the target body at the ith target body track point according to the method shown in the following formula_iAnd direction of motion α_i：

Wherein, v is_i-1The motion speed of the object at the i-1 th object track point is shown as α_i-1The motion direction of the object body at the ith-1 th object body track point is taken as the motion direction of the object body; k is an air resistance coefficient; the g is the acceleration of gravity.

7. The depth-image-based target motion trajectory prediction system according to claim 5 or 6, wherein the target motion trajectory acquisition module includes a first trajectory correction unit, a second trajectory correction unit, and a third trajectory correction unit;

the first trajectory correction unit is configured to acquire the target body movement trajectory T according to a method shown in the following formula under the condition that the fourth movement trajectory point and the fifth movement trajectory point do not deviate from the first movement trajectory and the fifth movement trajectory point does not deviate from the second movement trajectory_m：

Wherein, T is₁、T₂And T₃Respectively a first motion track, a second motion track and a third motion track;

the second track correction unit is configured to correct the fourth motion trackAnd under the condition that the point or the fifth motion track point deviates from the first motion track and the fifth motion track point does not deviate from the second motion track, acquiring a target body motion track T according to a method shown in the following formula_m：

The third trajectory correction unit is configured to correct the target body movement trajectory T when the fourth movement trajectory point or the fifth movement trajectory point deviates from the first movement trajectory and the fifth movement trajectory point deviates from the second movement trajectory_m＝T₃。

8. The depth-image-based target body movement track prediction system according to claim 7, wherein the target body movement track acquisition module further includes a target body deviation calculation unit, a first target body deviation determination unit, a second target body deviation determination unit, and a third target body deviation determination unit;

the target body deviation calculation unit is configured to calculate a spatial distance W between the fourth motion trajectory point and the first motion trajectory_{n+1_1}Calculating the space distance W between the fifth motion track point and the first motion track and the space distance W between the fifth motion track point and the second motion track_{n+2_1}And W_{n+2_2}；

The first target body deviation determination unit is configured to determine the first target body deviation according to the spatial distance W_{n+1_1}And a preset threshold value e, judging whether the fourth motion track point deviates from the first motion track: if W_{n+1_1}If the position is more than e, the fourth motion track point deviates from the first motion track;

the second target body deviation determination unit is configured to determine the second target body deviation based on the spatial distance W_{n+2_1}And the preset threshold value e is used for judging whether the fifth motion track point deviates from the first motion track: if W_{n+2_1}If the position is more than e, the fifth motion track point deviates from the first motion track;

the third target body deviation determination unit is configured to determine the spatial distance W_{n+2_2}And the preset threshold value e is used for judging whether the fifth motion track point deviates from the second motion track: if W_{n+2_2}And if the second motion track point is larger than e, the fifth motion track point deviates from the second motion track.

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