CN105928457A - Omnidirectional three-dimensional laser color scanning system and method thereof - Google Patents

Abstract

The invention relates to the technical field of three-dimensional color point cloud data processing and three-dimensional scene reconstruction, in particular to an omnidirectional three-dimensional laser color scanning system and a method thereof, wherein the system comprises a laser scanner, a high-speed camera, an electric control rotating platform, a conductive slip ring, an encoder, a data acquisition module, a switch, a servo driver, a computer and an equipment support, and the method comprises the following steps: 1. and controlling the electric control rotating platform to rotate at a constant speed, synchronizing the composite data of software and hardware, and fusing the synchronously acquired data. The method has the advantages that firstly, a software and hardware composite data synchronization method is utilized to synchronously acquire the laser line point cloud, the two-dimensional image and the rotation angle in real time, and the synchronization precision is high; secondly, data fusion is carried out by using the laser line point cloud and the two-dimensional image at each synchronous moment, three-dimensional color point cloud data of a scene are obtained in real time, and data acquisition real-time performance is good; and thirdly, the two-dimensional images at each synchronous moment are used for data fusion, so that the image information quantity is large, and the fusion quality is high.

Description

An omnidirectional three-dimensional laser color scanning system and method thereof

technical field

The invention relates to an omnidirectional three-dimensional laser color scanning system and a method thereof, belonging to the technical fields of three-dimensional color point cloud data processing and three-dimensional scene reconstruction.

Background technique

In the process of digitizing the real world, the 3D point cloud data records the geometric properties and position information of the object surface, and the 2D image records the color information and texture information of the object surface. The deep fusion of the two will form an emerging digital Media, that is, 3D color point cloud data, 3D color point cloud data is a further development of 3D point cloud data, which can more accurately describe the real world. In order to obtain the 3D color point cloud data of the scene, it is necessary to build a 3D laser color scanning system, which is mainly composed of a laser scanner, a digital camera, and a computer. The laser scanner obtains the 3D point cloud data of the scene, the digital camera obtains the 2D image data of the scene, the computer fuses the 3D point cloud data with the 2D image data, and finally obtains the 3D color point cloud data of the scene. 3D laser color scanning technology has strong theoretical significance and application value, and has been used more and more in the fields of industrial inspection, autonomous navigation, reverse engineering, virtual reality and military defense.

According to different geometric structures, 3D point cloud data can be divided into two categories: line point cloud and surface point cloud. At present, the working mode of laser scanners is generally line scanning. Each scan can obtain a discrete curve composed of a series of discrete points, that is, the line point cloud. The discrete curve (line point cloud) is located in the actual scene and the laser scanning plane intersection. In order to obtain the surface point cloud of the entire scene, it is necessary to add a translation and rotation device to the laser scanner. During the translation and rotation process, the laser scanner scans in real time to obtain multiple line point clouds, and converts these line point clouds according to the translation position and rotation angle. The surface point cloud of the entire scene is combined, that is, the three-dimensional point cloud data of the scene, so as to realize a comprehensive scan of the entire scene.

At present, the existing three-dimensional laser color scanning system is mainly composed of a laser scanner, a digital camera, a translation and rotation table, and a computer. Its working method is as follows: 1) The translation and rotation table drives the laser scanning device to translate and rotate, and combine the multiple line point clouds acquired by the laser scanner during the translation and rotation process into the surface point cloud of the entire scene through the translation position and rotation angle, namely 3D point cloud of the scene; 2) a two-dimensional image of the scene taken by a digital camera; 3) the computer fuses the three-dimensional point cloud and the two-dimensional image of the scene to form a three-dimensional color point cloud of the entire scene. The above three-dimensional laser color scanning device has the following problems: 1) It is necessary to first complete the three-dimensional laser scanning of the entire scene to obtain the three-dimensional point cloud of the entire scene, and then it can be fused with the two-dimensional image of the scene, and the three-dimensional image of the scene cannot be obtained in real time during the scanning process. Color point cloud, 3D color point cloud data acquisition is not real-time; 2) The 3D point cloud of the whole scene is only fused with one or a few 2D images, with little image information and low fusion quality.

Contents of the invention

In order to solve the above-mentioned problems in the prior art, the object of the present invention is to provide an omnidirectional three-dimensional laser color scanning system and its method with simple structure and high work efficiency. The system and its method first use the software and hardware composite data synchronization method to collect laser line point cloud, two-dimensional image and rotation angle in real time synchronously, with high synchronization accuracy; the second is to use the laser line point cloud and two-dimensional image at each synchronization moment Data fusion is carried out to obtain the 3D color point cloud data of the scene in real time, and the data collection is good in real time; the third is to use the 2D images at each synchronization moment for data fusion, which has a large amount of image information and high fusion quality.

In order to achieve the purpose of the above invention and solve the problems existing in the prior art, the technical solution adopted by the present invention is: an omnidirectional three-dimensional laser color scanning system, including a laser scanner, a high-speed camera, an electronically controlled rotary table, and a conductive slip ring , an encoder, a data acquisition module, a switch, a servo drive, a computer and an equipment support, the bottom of the equipment support is fixed on the electric control rotary table by screws, the high-speed camera is fixed on the top of the equipment support by screws, and the laser scanner It is installed in the middle part of the equipment bracket through screws, and the optical center of the laser scanner, the optical center of the high-speed camera lens and the rotation center of the electric control rotary table are vertically downwardly overlapped, and the scanning plane of the laser scanner is perpendicular to the imaging plane of the high-speed camera. The slip ring and the encoder are installed on the central shaft of the electric control rotary table; the network communication interfaces of the high-speed camera and the laser scanner are respectively connected to the switch through the gigabit network cable of the conductive slip ring, and the switch is connected to the computer through the gigabit network cable connected; the power supply interface of the high-speed camera and the laser scanner is connected with the power supply through the power line of the conductive slip ring respectively; the wiring port of the encoder is directly connected with the data acquisition module, and the data acquisition module is connected with the The computer is connected; the electric control rotary table also includes a mechanical rotary table and a servo motor, the servo motor is connected with the servo driver, and the servo driver is connected with the computer through the RS-485 communication line; the data acquisition module, the switch, the servo driver, and the computer are respectively Connect to the power supply through the power line; the switch output port of the laser scanner is connected to the switch input port of the high-speed camera, and the switch output port of the laser scanner is also connected to the data acquisition module through the signal line of the conductive slip ring Digital input port.

The three-dimensional color point cloud data acquisition method of the omnidirectional three-dimensional laser color scanning system comprises the following steps:

Step 1. Control the electric control rotary table to rotate at a constant speed. The computer controls the electric control rotary table to rotate at a constant speed through the servo driver. At the same time, the laser scanner and high-speed camera installed on the electric control rotary table also rotate at a constant speed with the electric control rotary table;

Step 2. Software and hardware composite data synchronization. During the rotation process, the computer software sends data acquisition commands to the laser scanner at a certain main frequency through the gigabit network. After receiving the data acquisition commands, the laser scanner starts to scan the scene to obtain laser line points Cloud, and send a high-level hardware synchronous acquisition signal to the high-speed camera and the digital input port of the data acquisition module through its switch output port. After receiving the hardware synchronization signal, the high-speed camera immediately shoots the scene to obtain a two-dimensional image, and the data acquisition module After the hardware synchronization signal is received, the encoder value is immediately stored to obtain the current rotation angle, so as to realize the real-time synchronization of the laser line point cloud, the two-dimensional image and the rotation angle. Then, the computer software sends the data to the laser scanner, high-speed camera, and data acquisition module Data reading command to obtain the laser line point cloud, 2D image and rotation angle at that moment;

Step 3. Synchronous collection of data fusion. After the computer obtains the laser line point cloud, two-dimensional image and rotation angle, it uses the camera imaging principle to solve the homography matrix between the camera imaging plane and the laser scanning plane, and obtain the spatial coordinates and The mapping relationship between its pixel coordinates, and use the mapping relationship to fuse the laser line point cloud and the two-dimensional image at each synchronization moment in real time to obtain the color line point cloud at the synchronization moment; on this basis, use the laser line point cloud at each synchronization moment The rotation angle combines the color line point cloud into the color surface point cloud of the whole scene, and then the 3D color point cloud data of the whole scene can be obtained.

The beneficial effect of the present invention is: a method for collecting three-dimensional color point cloud data of an omnidirectional three-dimensional laser color scanning system, comprising the following steps: 1. The electronically controlled rotary table rotates at a uniform speed; 2. Synchronization of software and hardware composite data; fusion. Compared with the prior art, the present invention first uses the software and hardware composite data synchronization method to collect laser line point clouds, two-dimensional images and rotation angles synchronously in real time, with high synchronization accuracy; the second is to use the laser line point clouds at each synchronization moment Data fusion with two-dimensional images, real-time acquisition of three-dimensional color point cloud data of the scene, and good real-time data acquisition; third, data fusion is performed using two-dimensional images at each synchronization moment, which has a large amount of image information and high fusion quality.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the present invention.

Fig. 2 is a system block diagram of the present invention.

Fig. 3 is a flowchart of the method steps of the present invention.

Figure 4 is the result map of the 3D color point cloud of the scene.

In the figure: 1. High-speed camera, 2. Laser scanner, 3. Equipment support, 4. Electric control rotary table.

detailed description

The present invention will be further described below in conjunction with accompanying drawing.

As shown in Figures 1 and 2, an omnidirectional three-dimensional laser color scanning system includes a laser scanner 2, a high-speed camera 1, an electronically controlled rotary table 4, a conductive slip ring, an encoder, a data acquisition module, a switch, a servo driver, Computer and equipment support 3, the bottom of the equipment support 3 is fixed on the electric control rotary table 4 by screws, the high-speed camera 1 is fixed on the top of the equipment support 3 by screws, and the laser scanner 2 is installed on the equipment support 3 by screws The middle part, and the optical center of the laser scanner 2, the optical center of the lens of the high-speed camera 1 and the rotation center of the electric control rotary table 4 are vertically downwardly overlapped, the scanning plane of the laser scanner 2 is perpendicular to the imaging plane of the high-speed camera 1, and the conductive slide The ring and the encoder are installed on the central shaft of the electric control rotary table 4; the network communication interfaces of the high-speed camera 1 and the laser scanner 2 are respectively connected to the switch through the gigabit network cable of the conductive slip ring, and the switch is connected to the switch through the gigabit network cable Connected to the computer; the power supply interface of the high-speed camera 1 and the laser scanner 2 is connected to the power supply through the power line of the conductive slip ring; The 485 communication line is connected with the computer; the electric control rotary table 4 also includes a mechanical rotary table and a servo motor, the servo motor is connected with the servo driver, and the servo driver is connected with the computer through the RS-485 communication line; the data acquisition module, switch, The servo drive and the computer are respectively connected to the power supply through the power cord; the switching output port of the laser scanner 2 is connected to the switching input port of the high-speed camera 1, and the switching output port of the laser scanner 2 is also connected to the conductive slip ring. The signal line is connected to the digital input port of the data acquisition module.

As shown in Figure 3, a method for collecting three-dimensional color point cloud data of an omnidirectional three-dimensional laser color scanning system includes the following steps:

Step 1. Control the electric control rotary table to rotate at a constant speed. The computer controls the electric control rotary table to rotate at a constant speed through the servo driver. At the same time, the laser scanner and high-speed camera installed on the electric control rotary table also rotate at a constant speed with the electric control rotary table;

Step 2. Software and hardware composite data synchronization. During the rotation process, the computer software sends data acquisition commands to the laser scanner at a certain main frequency through the gigabit network. After receiving the data acquisition commands, the laser scanner starts to scan the scene to obtain laser line points Cloud, and send a high-level hardware synchronous acquisition signal to the high-speed camera and the digital input port of the data acquisition module through its switch output port. After receiving the hardware synchronization signal, the high-speed camera immediately shoots the scene to obtain a two-dimensional image, and the data acquisition module After the hardware synchronization signal is received, the encoder value is immediately stored to obtain the current rotation angle, so as to realize the real-time synchronization of the laser line point cloud, the two-dimensional image and the rotation angle. Then, the computer software sends the data to the laser scanner, high-speed camera, and data acquisition module Data reading command to obtain the laser line point cloud, 2D image and rotation angle at that moment;

Step 3. Synchronous collection of data fusion. After the computer obtains the laser line point cloud, two-dimensional image and rotation angle, it uses the camera imaging principle to solve the homography matrix between the camera imaging plane and the laser scanning plane, and obtain the spatial coordinates and The mapping relationship between its pixel coordinates, and use the mapping relationship to fuse the laser line point cloud and the two-dimensional image at each synchronization moment in real time to obtain the color line point cloud at the synchronization moment; on this basis, use the laser line point cloud at each synchronization moment The rotation angle combines the color line point cloud into the color surface point cloud of the whole scene, and then the 3D color point cloud data of the whole scene can be obtained.

The advantages of the present invention are: an omnidirectional three-dimensional laser color scanning system and its method, one is to use the software and hardware composite data synchronization method to synchronously collect laser line point clouds, two-dimensional images and rotation angles in real time, and the synchronization accuracy is high; the other is to use Data fusion of laser line point cloud and 2D image at each synchronization moment, real-time acquisition of 3D color point cloud data of the scene, and good real-time data collection; third, use 2D image at each synchronization moment for data fusion, image information High volume, high quality fusion.

Claims (2)

1. omnidirectional's Three Dimensional Laser Color Scanning System, including laser scanner, high speed camera, automatically controlled Turntable, conducting slip ring, encoder, data acquisition module, switch, servo-driver, computer and Equipment supporter, it is characterised in that: it is screwed in bottom described equipment supporter on automatically controlled turntable, institute Stating high speed camera and be screwed in equipment supporter top, described laser scanner is arranged on by screw and sets In standby support mid portion, and laser scanner photocentre, high speed camera camera lens photocentre and the rotation of automatically controlled turntable The heart three overlap vertically downward, and laser scanner scans plane is perpendicular to high speed camera imaging plane, described in lead Electric slip ring and encoder are arranged on the central rotating shaft of automatically controlled turntable；Described high speed camera and laser scanner Network communication interface be connected with switch by the gigabit network cable of conducting slip ring respectively, described switch passes through Gigabit network cable is connected with computer；The power supply power supply interface of described high speed camera and laser scanner passes through respectively The power line of conducting slip ring is connected with power supply；Described encoder wiring port is directly and data acquisition module Being connected, data acquisition module is connected with computer by RS-485 order wire；Described automatically controlled turntable also wraps Including mechanical rotary stage and servomotor, servomotor is connected with servo-driver, and servo-driver passes through RS-485 order wire is connected with computer；Described data acquisition module, switch, servo-driver, calculating Machine is connected with power supply by power line respectively；The output switch parameter port of described laser scanner connects To the On-off signal port of high speed camera, the output switch parameter port of laser scanner is also by conducting slip ring Holding wire be connected to the On-off signal port of data acquisition module.

A kind of three-dimensional colour point clouds of omnidirectional Three Dimensional Laser Color Scanning System Collecting method, it is characterised in that comprise the following steps:

Step 1, controlling automatically controlled turntable and at the uniform velocity rotate, computer controls automatically controlled rotation by servo-driver Platform at the uniform velocity rotates, and is simultaneously attached to the laser scanner on automatically controlled turntable and high speed camera also with automatically controlled rotation Platform at the uniform velocity rotates；

Step 2, software and hardware complex data synchronize, and in rotary course, computer software passes through gigabit networking Sending data acquisition command with certain basic frequency to laser scanner, laser scanner receives data acquisition Start to scan scene after order and obtain laser rays point cloud, and by its output switch parameter port to high speed camera and The On-off signal port of data acquisition module sends high level hardware synchronization and gathers signal, and high speed camera receives After hardware synchronization signal, photographed scene obtains two dimensional image at once, and data acquisition module receives hardware synchronization Store encoder numerical value after signal at once and obtain present rotation angel degree, to realize laser rays point cloud, two dimensional image With the real-time synchronization of anglec of rotation three, then, computer software is to laser scanner, high speed camera, number Send data read command according to acquisition module, obtain this moment laser rays point cloud, two dimensional image and the anglec of rotation；

Step 3, synchronous acquisition merge, and computer obtains laser rays point cloud, two dimensional image and the anglec of rotation After degree, utilize camera imaging principle, solve the homography matrix between camera imaging plane and laser scanning plane, Obtain the mapping relations between laser scanning point space coordinates and its pixel coordinate, and utilize these mapping relations real The laser rays point cloud of each synchronization point of Shi Ronghe and two dimensional image, obtain the multi-color cord point of synchronization point Cloud；On this basis, multi-color cord point cloud is combined into whole field by the anglec of rotation utilizing each synchronization point The colored millet cake cloud of scape, can obtain the three-dimensional colour point clouds data of whole scene.