KR100901311B1 - Autonomous platform - Google Patents

Abstract

The present invention and the main body having a wheel to move the ground; A first scanner configured to generate first information by scanning to a predetermined distance in front of the main body; A camera for photographing the front image of the main body to generate second information; A mount configured to mount the first scanner and the camera and to rotate the first scanner and the camera so as to adjust a direction in which the first scanner and the camera are directed; And a controller for controlling autonomous movement of the main body based on the first and second information.

Description

Autonomous Mobile Platform {AUTONOMOUS MOBILE PLATFORM}

The present invention relates to an autonomous platform and a movement control method thereof that can recognize and determine the surrounding situation by itself using a plurality of sensors.

Due to the development and development of advanced science and technology, various technologies have been applied to the military field, and in particular, the development of sensors and computer hardware makes the combat system unmanned.

Developed countries already have great interest in the development of military robots, and the United States, in particular, is conducting research on the unmanned military sector in order to deploy unmanned vehicles in the Future Combat System. Unmanned vehicles are being actively researched in Korea, and various unmanned systems are being developed in the defense sector.

When looking at the direction of technology development in the unmanned field, unmanned vehicles, or autonomous mobile platforms, perform mission functions such as surveillance, reconnaissance, hitting, command control, and explosive detection / removal. Platforms will be able to perform systematic tasks in the line of sight / non-visible environment.

Autonomous movement refers to the movement of the computer and the eyes, which act as the human brain and humans, using sensors to recognize and judge the surrounding environment without human intervention. In order to enable such autonomous movement, an accurate sensing means capable of recognizing the terrain and the situation of the movement path of the autonomous platform is needed. Various kinds of sensors are used as the sensing means, and various studies have been made on the adoption, combination, and placement of sensors capable of optimizing autonomous movement.

The present invention provides an autonomous platform capable of optimal 3D space modeling by arranging as few sensors with different characteristics as possible, and also controls to efficiently control movement of the autonomous platform based on 3D space modeling. It is to provide a method.

In order to achieve the above object, the present invention includes a main body having a wheel to move the ground; A first scanner configured to generate first information by scanning to a predetermined distance in front of the main body; A camera for photographing the front image of the main body to generate second information; A mount configured to mount the first scanner and the camera and to rotate the first scanner and the camera so as to adjust a direction in which the first scanner and the camera are directed; And a controller for controlling autonomous movement of the main body based on the first and second information.

The first scanner is a 2D laser scanner for irradiating a laser beam toward the front of the main body, and the first information may include distance information to a target that the laser beam reaches.

The camera is a stereo camera having a first and a second recording unit, wherein the second information is the first and second recording unit for the same object to be estimated so as to estimate the position information of the object to be photographed through stereo matching Each photographed pair may be image information.

The control unit comprises a world modeling unit for generating a three-dimensional world model by fusing the first and second information; And it may include a route plan generation unit for forming a route plan for the autonomous movement of the main body based on the world model.

The main body may further include a second scanner that scans the front in a direction parallel to the ground to generate third information. The main body may further include a third scanner that generates fourth information by scanning farther than the scanning distance of the first scanner.

On the other hand, the present invention includes the steps of generating a first information by scanning a distance from the autonomous platform, and generating a second information by photographing the front image of the autonomous platform; Fusing the first and second information to generate a three-dimensional world model; Generating a route plan for autonomous movement of the autonomous platform based on the world model; And controlling the autonomous movement of the autonomous platform in accordance with the route plan.

The generating of the world model may include: generating a point distribution map by combining position information obtained by the navigation sensor with the first and second information; And connecting the points of the point distribution map to represent a plurality of grids.

The path plan may include a far path plan generated based on information obtained by the 3D laser scanner, and a near path plan generated based on the first and second information.

According to the present invention, the first scanner and the camera are mounted on the same mount, and the first scanner and the camera are rotated to achieve the same effect as applying a large number of sensors with a small number of sensors. This provides a viable autonomous platform.

In addition, the present invention provides an arrangement structure of the sensor that can sense the entire area in front of the autonomous mobile platform without blind spots so that the autonomous mobile platform can quickly avoid moving obstacles that suddenly appear when moving quickly to the field and rough terrain. do.

In addition, the present invention provides an efficient method for controlling an autonomous mobile platform for generating a world model based on the data obtained from the sensors and controlling the movement of the autonomous mobile platform according to a route plan based on the same.

Hereinafter, the autonomous platform and the movement control method thereof according to the present invention will be described in more detail with reference to the accompanying drawings.

1 and 2 are a perspective view and a front view of the autonomous platform according to an embodiment of the present invention.

The autonomous platform associated with the present invention includes a main body 110, a first scanner 120, a camera 130, a mount 140, and a controller 150 (see FIG. 5).

The main body 110 includes a plurality of wheels 111 so that the autonomous platform can move the ground. The wheels 111 may be connected to an arm rotatably connected to the main body 110 to allow the autonomous platform to travel in the field and the hum.

The main body 110 includes a controller 150 for controlling autonomous movement of the autonomous mobile platform and a wireless communication module for wireless communication in the form of electronic components.

The first scanner 120 scans to a predetermined distance in front of the main body to generate first information. The first scanner 120 may be implemented in the form of a 2D laser scanner that receives a laser beam reflected from an object by irradiating a laser beam toward the front of the main body 110. In this case, the first information has a form of distance information to the object to which the laser beam arrives.

The 2D laser scanner applied to the present embodiment shows the distance from the object to the front 200m distance in two-dimensional information. When the mounting position of the 2D laser scanner is centered in the width direction of the main body, four scanning lines at an angle of 0.8 ° in the vertical direction are equally forward to obtain distance data with the target object.

The camera 130 is for generating the second information by photographing the front image of the main body 110. The camera 130 may have a form of a stereo camera having a plurality of CCD cameras fixed to one mount.

The camera 130 according to the present embodiment may be implemented in the form of a stereo camera having the first and second photographing units 131 and 132. In this case, the second information may be a pair of image information captured by the first and second photographing units 131 and 132, respectively, with respect to the same photographing target, and the image information may be stereoscopic matching. Used to estimate

The stereo camera may estimate the disparity of the acquired left and right images, and measure the distance between the main body 110 and the target object and three-dimensional distance data of the terrain information through a triangulation method. When the 3D distance data is projected based on the ground, an altitude map of the terrain is generated, and the altitude map is fused with the 2D data (first information) of the first scanner 120 and used for 3D spatial modeling in front. do.

The mount 140 is a structure for mounting the first scanner 120 and the camera 130 together, and is fixed to the front of the main body 110. The first scanner 120 and the camera 130 are rotatably mounted to the mount 140 to adjust the direction in which the first scanner 120 and the camera 130 are directed. According to the present exemplary embodiment, the first and second photographing units 131 and 132 are positioned at both ends of the first scanner 120.

3 and 4 are conceptual diagrams illustrating sensing ranges of a first scanner and a camera.

The mount 140 may be configured to adjust the rotation direction and speed of the first scanner 120 and the camera 130 according to various situations, for example, the purpose of the autonomous platform, whether it is moving, and the driving environment. have.

The mount 140 applied to the present embodiment is configured to rotate the first scanner 120 and the camera 130 to -30 ° in the horizontal direction and to + 10 ° in the upward direction.

The mount 140 may repeatedly drive the first scanner 120 and the camera 130 within the rotation range as described above. The mount 140 may acquire distance data of an object within a range of a predetermined period by adjusting the direction of the first scanner 120 and the camera 130. Here, the rotation speed of the first scanner 120 and the camera 130 may be adjusted according to the moving speed of the main body 110. For example, the mount may increase the rotational speed of the first scanner 120 and the camera 130 in proportion to the moving speed of the main body.

In addition, when the main body 110 moves up or down the slope while moving up the rough ground, the front of the main body 110 is lifted or lowered so that the directing direction of the first scanner 120 and the camera 130 faces the air. 140 may adjust the directing directions of the first scanner 120 and the camera 130 according to the inclination of the ground.

According to the present exemplary embodiment, the mount 140 drives the first scanner 120 and the camera 130 in the up and down direction of the main body 110, but the mount 140 is connected to the first scanner 120. It is also possible to be configured to drive the camera 130 in the horizontal direction of the main body 110 as well as the vertical direction.

For example, the autonomous platform receives position data from the navigation sensor mounted on the main body 110. When the position data is lost due to the failure and shadow area of the navigation sensor, it is purely dead-reckoning (several other low cost). It may be necessary to find and move its own location only with dead reckoning, which estimates the position information of the starting point using the auxiliary sensor and the filter.

In this case, the autonomous platform is searched based on the pre-stored image DB (the location data and the image feature information are stored together through pre-driving) and the feature points extracted from the left and right scanned image data to find its location. It finds its own position, and in this case, the mount 140 may be selectively driven left and right to obtain the surrounding image information as much as possible, thereby increasing the probability of success of the search.

In this way, the sensor can be operated such that a plurality of sensors are arranged by driving the mount 140.

The controller 150 controls the autonomous movement of the main body 110 based on the first and second information generated by the first scanner 120 and the camera 130. The controller 150 generates 3D data by combining the altitude values provided from the navigation sensor mounted on the main body 110 with the distance data generated by the first scanner 120 and the camera 130. The controller 150 controls the movement of the autonomous platform based on the 3D data. A detailed process of controlling the movement of the autonomous platform will be described later.

On the other hand, the main body 110 may be additionally equipped with a second scanner 160 for generating the third information by scanning the front in a direction parallel to the ground. When the mount 140 is located above the main body 110 as in the present embodiment, the sensing range of the first scanner 120 is within a predetermined angle range in the vertical direction based on the horizontal direction of the main body. Accordingly, as shown in FIG. 3, a blind spot outside the sensing range of the first scanner 120 occurs around the lower portion of the main body 110. Therefore, the second scanner 160 is additionally mounted at a position spaced apart by a predetermined interval in the downward direction from the mounting position of the mount 140 of the main body 110, and measures the distance information of the object in the blind area.

Like the first scanner 120, a 2D laser scanner may be used as the second scanner 160, and the third information may be distance information about terrain, obstacles, and the like located in a direction parallel to the ground.

The second scanner 160 is disposed so as to be oriented in the horizontal direction with respect to the ground, and obtains distance and width information about obstacles having a predetermined height or more in front of the body 110 when the main body 110 moves. Such information may be converted into an obstacle map composed of two-dimensional data when a request for obstacle recognition is received. Moving obstacles require fast responsiveness to obstacle recognition, so two-dimensional data is used instead of computational and complex three-dimensional data. The main body 110 may accurately determine the short distance obstacle and the driving path based on the third information provided from the second scanner 160, and recognize the moving obstacle suddenly appearing at the short distance, and quickly avoid it.

The second scanner 160 may be located at a height corresponding to the radius R of the wheel 111 from the ground. The autonomous platform according to the present embodiment is designed to overcome obstacles of a height lower than the radius R of the wheel 111. In this case, the distance information provided by the second scanner 160 located at a height corresponding to the radius R may be used as a basis for determining whether the autonomous platform moves over an obstacle or moves to avoid an obstacle. have.

In more detail, the two-dimensional distance data obtained from the first and second scanners 120 and 160 having the difference in the direction of orientation are used to distinguish whether the front object is the ground or an obstacle by using the difference in the mutual orientation angles. do. That is, the inclination of the object is calculated by using the distance information obtained from the first and second scanners 120 and 160 having different viewing angles, and the object in front of the object is a steep ground or avoided according to the degree of inclination. You can tell if it is an obstacle to do.

1 and 2, a third scanner 170 for generating fourth information by scanning farther than the scanning distance of the first scanner 120 may be further disposed on one surface of the main body 110.

The third scanner 170 may be installed to protrude on the upper surface of the main body 110 to be rotated 360 degrees, the distance information of the object that is farther than the 2D laser scanner as the third scanner 170 (fourth information) A 3D laser scanner capable of obtaining can be used.

The 3D laser scanner may acquire more accurate 3D coordinate values than 3D data generated from the first scanner 120 (2D laser scanner) and the navigation sensor. The 3D laser scanner used in the present embodiment performs forward scanning at the same time zone in the laser generator arranged in the vertical direction, and also generates three-dimensional data for the azimuth direction while rotating at 360 °.

Although the 3D laser scanner lacks a unit scan speed or spatial resolution than a 2D laser scanner that scans left and right at a high speed in a single direction, the 3D laser scanner can directly and sufficiently acquire 3D data in all directions. This three-dimensional data can be used for route planning and driving judgment in large areas that have not been planned in advance. In addition, the 3D data obtained by the 3D laser scanner is compared and fused with the 3D data generated from the 2D laser scanner 120 and the navigation sensor, thereby verifying or improving the accuracy and reliability of the data.

Hereinafter, a description will be given of the movement control method of the autonomous platform associated with the present invention based on the foregoing description.

5 is a block diagram of an autonomous platform according to an embodiment of the present invention.

Referring to FIG. 5, the controller 150 includes a world modeling unit 151, a route plan generation unit 152, and a control signal generator 153.

The world modeling unit 151 may generate three-dimensional data (point distribution map, point cloud) by combining the elevation data obtained from the navigation sensor with the distance data generated by the first scanner 120 (2D laser scanner). . 6 illustrates a point distribution map generated based on distance data obtained from the first scanner 120 (2D laser scanner).

The world modeling unit 151 generates a world model based on the point distribution map. Here, the world model means that the ground is represented in a grid form by connecting the point distribution map in a mesh form. 8 shows an example of such world model data.

As described above, an altitude map of the terrain may be generated using distance data measured by the camera 130, and the altitude map may be fused with data of the first scanner 120 to form a point distribution map. Can be. The point distribution map is represented by the final integrated world model through space-time accumulation.

The second scanner 160 generates distance data of a distance of about 50m ahead, that is, distance data about bending and obstacles of the front terrain. The data generated by the second scatter can be used to more precisely generate the world model. Accordingly, the autonomous platform can accurately determine near obstacles and driving paths, and can quickly avoid them by recognizing moving obstacles suddenly appearing at near distance.

Third scanner 170. That is, as described above, the 3D laser scanner acquires distance information of a farther distance than the first scanner 120, and the received distance information on the omnidirectional space is converted into a three-dimensional point cloud. FIG. 7 illustrates an example of a point cloud generated based on distance data acquired by a 3D laser scanner, and a world model of a grid structure may be generated therefrom.

The final world model data may be generated using all of the 3D data generated by the first to third scanners 120, 160 and 170 and the camera 130 described above. That is, the final integrated world model data is generated through the space-time accumulation of the previous frame and the next frame of the point distribution map. FIG. 8 illustrates that the three-dimensional data generated by the scanners and the camera are fused to generate the final world model data.

The route plan generation unit 152 generates a route plan for autonomous movement of the autonomous platform on the basis of a predetermined start point and end point and the generated world model data. That is, the route plan generation unit 152 sets the movement route to which the autonomous platform is to travel, and generates a final mobility map for the autonomous platform to overcome or avoid obstacles.

Such a route plan may include a near route plan and a far route plan. The route plan generator 152 may generate a near route plan based on the first and second information of the first scanner 120 and the camera 130, the third information of the second scanner 160, and the like. In addition, the route plan generator 152 may generate a far route plan based on the fourth information of the third scanner 170.

The short-range route plan refers to a set of short-range (eg, within 50m) driving route points that detects an object in an area detected by the first scanner 120 and the camera 130 and generates a route to travel. it means.

These driving paths have a cycle in which the autonomous platform is updated again with new paths to avoid sudden obstacles to movement.

The far path plan refers to a set of driving path points of a relatively far distance (within 50 to 120 m) than the near path plan considered in the area sensed by the third scanner 170.

FIG. 9 is a conceptual diagram illustrating an effective range of a scanning range and measurement of data of the first to third scanners described above.

The outer solid line shown in the outermost part of FIG. 9 represents a data sensing area that is effectively measured by the third scanner 170, that is, the 3D laser scanner.

The dotted line in the middle indicates a data sensing area effectively measured by the first scanner 120 and the camera 130 disposed in the center, and is used for near path planning.

The last inner dashed line indicates an effective measured data sensing area of the second scanner 160 disposed for short-range obstacle avoidance.

Areas detected by the ultrasonic sensors are displayed on the left and right and rear sides of the front surface of the autonomous platform. Ultrasonic sensors may be additionally installed on the left and right and rear sides of the front surface of the autonomous platform in order to detect moving objects appearing in proximity to the autonomous platform.

On the other hand, the remote route plan can be re-modified by updating the near route plan with a relatively high update period.

For example, if a moving object is detected in the front area during the operation of the autonomous platform, the moving object is avoided by the near path plan. If the moving path of the autonomous platform is far from the far path plan, the far path plan may be modified. Can be.

In remote path planning, tracking and collision avoidance by moving object detection and recognition information are not considered. That is, the movement of the remote object or the determination of the stationary object is not required. This is because the accuracy of the remote data has a lot of errors due to the characteristics of the laser scanner, and the update rate and accuracy of the data need to be increased for tracking the moving object, which requires expensive and high-performance equipment. Therefore, obstacle avoidance is only considered in the near path planning.

The 3D laser scanner, i.e., the third scanner 170, has a lower data update rate (15 Hz level) than the 2D laser scanner, and provides the far-field data that is the basis for changing the originally planned far path plan.

The control signal generator 152 generates a control signal for moving the autonomous platform based on the path plan as described above. Accordingly, the autonomous platform will perform autonomous movement according to the route plan.

In the above described with reference to the accompanying drawings, the autonomous mobile platform and the movement control method related to the present invention, the present invention is not limited by the embodiments and drawings disclosed herein, it is within the scope of the technical idea of the present invention Various modifications can be made by those skilled in the art.

1 is a perspective view of an autonomous platform associated with an embodiment of the present invention.

FIG. 2 is a front view of the autonomous platform shown in FIG. 1. FIG.

3 and 4 are conceptual views illustrating a sensing range of a first scanner and a camera.

Figure 5 is a block diagram of an autonomous platform associated with one embodiment of the present invention.

6 is a point distribution map generated based on distance data obtained from a first scanner.

7 is a point distribution map generated based on distance data obtained from a third scanner.

8 is world model data generated from the point distribution maps of FIGS. 6 and 7;

9 is a conceptual diagram showing an effective range of the scanning range of the first to third scanners and measurement of data;

Claims (24)

In the autonomous mobile platform that can recognize, determine and move the surrounding situation using a plurality of sensors, A main body having wheels to move the ground; A first laser scanner mounted on a front surface of the main body and generating two-dimensional first information including distance information to a target to which the laser beam reaches by irradiating a laser beam toward the front of the main body; A first and second photographing units disposed at both ends of the first laser scanner, and generating second information including a pair of stereo images photographed through the first and second photographing units for the same photographing target; Stereo cameras; The first laser scanner and the stereo camera are mounted to rotate the first laser scanner and the stereo camera within a predetermined rotation range so that the direction and the rotation speed of the first laser scanner and the stereo camera are adjusted when the main body is driven. Mount; And A control unit for controlling the autonomous movement of the main body based on the first and second information, The mount rotates the first laser scanner and the stereo camera so that the direction of orientation of the first laser scanner and the stereo camera is adjusted according to the inclination of the ground on which the main body travels. The control unit, After generating the 3D distance data of the distance between the main body and the target object and the topographical information from the stereo images of the second information and the terrain information, and projecting the 3D distance data on the ground basis to generate an altitude map A world modeling unit for generating a three-dimensional world model by fusing an elevation map with the first information; And An autonomous platform comprising a route plan generator for forming a route plan for movement of the main body based on the world model. The method of claim 1, And the mount is configured to rotate the first laser scanner and the stereo camera in a vertical direction with respect to a horizontal direction with respect to the ground. The method of claim 1, And the mount is configured to repeatedly drive the first laser scanner within a range of rotation. The method of claim 3, The rotation speed of the first laser scanner is adjusted according to the moving speed of the main body. The method of claim 1, And a second laser scanner mounted on the main body, the third laser scanner generating a third information including distance information about a terrain and an obstacle located in a non-detection area of the first laser scanner by scanning the front in a direction parallel to the ground. Autonomous platform, characterized in that. The method of claim 5, And the second laser scanner is mounted at a position spaced apart by a predetermined interval in a downward direction from a mounting position of the mount. The method of claim 6, The second laser scanner is located at a height corresponding to the radius of the wheel from the ground, The distance information provided by the second laser scanner is used as a basis for determining whether the main body moves over an obstacle or moves to avoid an obstacle. The method of claim 1, And a third laser scanner mounted to the main body, the third laser scanner generating fourth information by scanning farther than the scanning distance of the first laser scanner. The method of claim 8, The third laser scanner is a 3D laser scanner rotatably installed on the upper surface of the main body, And the fourth information is distance information corresponding to a distance from the scanning distance of the first laser scanner. The method of claim 9, And the fourth information is generated at a lower update rate than the first and second information. The method of claim 9, The controller generates a distance route plan based on the fourth information, and generates a near route plan based on the first and second information. The method of claim 11, The near path plan is updated with a certain period as the main body moves, And the remote route plan is re-modified by updating the short range route plan. delete delete delete delete delete delete delete delete delete delete delete delete

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