CN212256370U - Optical motion capture system - Google Patents

Abstract

The utility model provides an optical type motion capture system, include: a motion capture device comprising a plurality of optical identification points and a plurality of motion capture cameras, each motion capture camera acquiring target motion video information through each optical identification point; each identification point is arranged on different target parts and is an active signal transmitting device; the active signal transmitting apparatus includes: the LED lamp comprises an LED lamp bead, a power supply module, a light homogenizing cover and a substrate; the power supply module supplies power to the LED lamp beads, the light homogenizing cover is buckled on the LED lamp beads, and the substrate is used for installing the LED lamp beads on a target part; the three-dimensional reconstruction unit is used for acquiring target motion video information and motion capture camera calibration information, and performing three-dimensional reconstruction processing on the target motion video information according to the motion capture camera calibration information to obtain a space coordinate of the identification point; the motion capture camera calibration information includes: lens focal length, imaging center, tilt factor, and distortion parameter.

Description

Optical motion capture system

Technical Field

The utility model belongs to the technical field of the motion is caught, concretely relates to optics formula motion capture system.

Background

The optical motion capture technology is a technology which acquires through an optical sensor and calculates spatial information such as motion trail, posture and the like of an object by adopting a computer vision principle. Optical motion capture technologies can be divided into two broad categories, labeled point and unlabeled point, according to different principles. The marked point type motion capture technology has the characteristics of high speed, high precision and high reliability, and has wide application space in the fields of CG manufacture, industrial measurement, surgical navigation, virtual reality, physical training, medical rehabilitation, robots and the like.

The optical marking point is an important component in the hardware of the marking point type motion capture system, and is used for marking a target object, and acquiring motion information of the object through acquisition and calculation of the mark.

The optical mark points commonly used for mark point type motion capture at present are divided into two-dimensional marks and three-dimensional marks according to different forms. The former is a plane mark point, such as a circular mark, a two-dimensional code mark and the like, and has the defects of small space visible angle and inconvenience for space omnibearing observation; the latter is a three-dimensional mark point, usually a spherical mark, and is characterized by a large visual angle, which is convenient for all-around observation in space, and thus is widely used in the motion capture technology. The space spherical mark is usually a reflective ball, does not emit light, enters a camera for imaging through light of a reflected light supplementing light source, and is recorded as a highlight light spot on an image, so that identification and detection and subsequent calculation of a mark point are facilitated.

The plane optical mark has small visual angle and many space observation blind areas, so the plane optical mark has low practicability for the motion capture technology.

The common spherical reflective marker solves the problem of visual angle, but is limited by the reflective principle, the luminous brightness is limited, and the brightness of the marker is not enough to be obviously distinguished from the background brightness on the occasion of strong ambient light, so that the marker detection is invalid. This is also a major reason why this type of motion capture system is not suitable for outdoor scenarios, limiting the applicability of the system. On the other hand, the reflecting ball needs to be covered with a reflecting material on the surface of the ball body, so that good sphericity and stability are required to be maintained, the process difficulty is high, the problems of poor spherical roundness, uneven surface or uneven reflecting brightness and the like generally exist in the common marking points at present, and the defects cause that the technology is difficult to meet the application in the high-precision measurement field, such as industrial measurement, surgical navigation and the like.

SUMMERY OF THE UTILITY MODEL

The utility model aims at adopting an active optical capturing mark point of an active light-emitting device to replace a passive light-reflecting ball.

The utility model discloses a following technical scheme realizes:

an optical motion capture system, the system comprising: a motion capture device comprising a plurality of optical identification points and a plurality of motion capture cameras, each motion capture camera acquiring target motion video information through each optical identification point; each identification point is arranged on different target parts and is an active signal transmitting device; the active signal transmitting apparatus includes: the LED lamp comprises an LED lamp bead, a power supply module, a light homogenizing cover and a substrate; the power supply module supplies power to the LED lamp beads, the light homogenizing cover is buckled on the LED lamp beads, and the substrate is used for installing the LED lamp beads on a target part; the three-dimensional reconstruction unit is used for acquiring target motion video information and motion capture camera calibration information, and performing three-dimensional reconstruction processing on the target motion video information according to the motion capture camera calibration information to obtain the space coordinates of the identification points; wherein the motion capture camera calibration information comprises: lens focal length, imaging center, tilt factor, and distortion parameter.

Preferably, the power module supplies power for one or more LED lamp beads.

The utility model discloses an optical type motion capture system adopts the active optics of initiative illuminator replacement passive reflection of light ball to catch the identification point, makes traditional optics capture system can also accurate perception mark point in outdoor environment to because the perception distance of the adjustable multiplicable traditional optics capture system of luminance of infrared identification point. Effectively improve the identification precision, accuracy and application range of the action failure system.

The technical solution of the present invention will be described in detail with reference to the accompanying drawings and specific embodiments.

Drawings

FIG. 1 is a flow chart of the steps of the optical motion capture method of the present invention;

FIG. 2 is a block diagram of the optical motion capture system of the present invention;

fig. 3 is a schematic structural diagram of the active signal emitting device of the present invention.

Detailed Description

Fig. 1 is a flowchart illustrating the steps of the optical motion capture method of the present invention. As shown in fig. 1, the present invention provides an optical motion capture method, comprising the steps of:

acquiring motion capture camera calibration information, comprising: lens focal length, imaging center, tilt factor and distortion parameter;

acquiring target motion video information, comprising: the motion conditions of the target part marked by the optical identification points acquired by the plurality of motion capture cameras;

and performing three-dimensional reconstruction processing on the target motion video information according to the motion capture camera calibration information to obtain the space coordinates of the identification points.

Fig. 2 is a block diagram of the structure of the optical motion capture system of the present invention, and fig. 3 is a schematic structural diagram of the active signal transmitter of the present invention. As shown in fig. 2 and with reference to fig. 3, the present invention provides an optical motion capture system, the system comprising:

the motion capture device comprises a plurality of optical identification points 1 and a plurality of motion capture cameras 2, wherein each motion capture camera acquires target motion video information through each optical identification point;

each identification point is arranged on different target parts and is an active signal transmitting device; as shown in fig. 3, the active signal transmitting apparatus includes: LED lamp pearl 12, power module 13, dodging cover 11 and base 14. The power module 13 supplies power to one or more LED lamp beads 11. The substrate 14 is used for arranging/mounting the LED lamp beads 11 on a target portion surface, such as a magic tape.

The three-dimensional reconstruction unit 3 is used for acquiring target motion video information and motion capture camera calibration information, and performing three-dimensional reconstruction processing on the target motion video information according to the motion capture camera calibration information to obtain the space coordinates of the identification points;

wherein the motion capture camera calibration information comprises: lens focal length, imaging center, tilt factor, and distortion parameter.

It should be noted that the LED lamp bead is a high-power LED lamp bead, for example, the power is 3 w. The higher the power is, the higher the brightness of the mark point is, the higher the separability in the light environment is, and on the premise that the imaging of the mark point in the camera reaches a certain brightness threshold, the imaging brightness of the background can be reduced by reducing the aperture or reducing the shutter, so that the recognition degree of the optical mark in the image is enhanced.

The power module can adapt to input voltage within a certain range, such as 5-32 v, and can adjust output voltage (such as 0.8-30 v) and current (such as 0-5A) within a certain range. The power module is a small/micro portable power supply, can be a button cell and used for supplying power to the single LED lamp beads, and can also be a high-capacity mobile power supply and used for supplying power to a plurality of LED lamp beads simultaneously.

The specific working principle is as follows:

the active signal transmitting device arranged on the target transmits visible light, and the plurality of motion capture cameras capture the visible light to acquire target motion video information and transmit the target motion video information to the three-dimensional reconstruction unit. The three-dimensional reconstruction unit processes a target motion video according to the calibration information (including a lens focal length, an imaging center, a tilt factor and a distortion parameter) of the motion capture cameras, when at least two motion capture cameras observe the same identification point from different visual angles, the identification point is represented as a highlight circular spot in an image, the center of the circular spot is extracted, and the spatial coordinate of the center of the identification point can be obtained by utilizing a stereoscopic vision triangulation principle; when there are multiple identified points in the image, according to the epipolar constraint principle, for example: the homonymous point of the marked point a in the image A in the image B is necessarily on the epipolar line of the marked point a, and the point which is closest to the epipolar line and meets a given distance threshold is the homonymous point of the marked point a in the image B, so that homonymous marked point pairs in different images are obtained.

After the space coordinates of each identification point on the target object are obtained, the space coordinates can be output to various animation production software (such as Motionbuilder) to bind the animation character model to realize action driving.

The present invention also provides a storage medium including a stored program, wherein the program executes an optical motion capture method.

The utility model also provides a processor, processor is used for the operation procedure, wherein, execute optics formula motion capture method when the procedure operation.

It should be noted that the steps illustrated in the flowcharts of the figures may be performed in a computer system such as a set of computer-executable instructions and that, although a logical order is illustrated in the flowcharts, in some cases, the steps illustrated or described may be performed in an order different than presented herein.

Claims (2)

1. An optical motion capture system, the system comprising:

a motion capture device comprising a plurality of optical identification points and a plurality of motion capture cameras, each motion capture camera acquiring target motion video information through each optical identification point;

each identification point is arranged on different target parts and is an active signal transmitting device; the active signal transmitting apparatus includes: the LED lamp comprises an LED lamp bead, a power supply module, a light homogenizing cover and a substrate; the power supply module supplies power to the LED lamp beads, the light homogenizing cover is buckled on the LED lamp beads, and the substrate is used for installing the LED lamp beads on a target part;

the three-dimensional reconstruction unit is used for acquiring target motion video information and motion capture camera calibration information, and performing three-dimensional reconstruction processing on the target motion video information according to the motion capture camera calibration information to obtain a space coordinate of the motion capture identification point;

wherein the motion capture camera calibration information comprises: lens focal length, imaging center, tilt factor, and distortion parameter.

2. The optical motion capture system of claim 1 wherein the power module powers one or more LED light beads.

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