The present invention generally relates to electronic mapping of a surrounding environment, and more particularly relates to apparatus, systems, and methods for rotating a two-dimensional light detection and ranging (LIDAR) device to map objects in an environment in three dimensions.
Developing autonomous vehicles that are capable of safely navigating through an environment has been a subject of research for several years. One difficulty encountered with many previous autonomous vehicles has been the ability to accurately detect objects in three dimensions while the vehicle is in motion with sufficient detail that those objects can be identified as an obstacle, a landmark (for use in navigation), or as inconsequential. Without this information an autonomous vehicle is unlikely to avoid such obstacles while traveling through an environment, whether the obstacles are on and/or above ground-level, or are in the form of potholes, runouts, and ditches (so-called negative obstacles). Furthermore, without the ability to identify landmarks, the position and orientation of an autonomous vehicle is difficult for the autonomous vehicle to determine.
Accordingly, it is desirable to provide perception apparatus, systems, and methods that are capable of detecting objects in three dimensions so that a vehicle may be autonomously navigated through an environment. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.
Various embodiments of the invention provide perception apparatus for a vehicle. One perception and navigation apparatus comprises a turntable capable of being coupled to the vehicle and a light detection and ranging (LIDAR) device mounted on the turntable.
Perception and navigation systems are also provided. A perception and navigation system comprises a vehicle and a turntable coupled to the vehicle. The perception and navigation system further comprises a LIDAR device mounted on the turntable.
Various embodiments of the invention also provide object perception methods for a vehicle in an environment having a ground. One object perception method comprises the steps of rotating a two-dimensional LIDAR device along an axis of rotation that is substantially normal to a ground plane beneath the vehicle, capturing data points of objects within the environment surrounding the LIDAR device, and generating a three-dimensional representation of the objects based on the data points.
The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and
The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention.
Various embodiments of the invention provide perception and navigation apparatus, systems, and methods. One perception and navigation apparatus comprises a turntable capable of being coupled to the vehicle and a light detection and ranging (LIDAR) device mounted on the turntable. A perception and navigation system comprises a vehicle with a turntable coupled to the vehicle and a LIDAR device mounted on the turntable. One perception and navigation method comprises the steps of rotating a LIDAR device along an axis of rotation that is substantially normal to a ground plane beneath the vehicle and capturing 3-dimensional images of objects within the environment surrounding the LIDAR device.
Turning now to the figures,
Perception apparatus 110 comprises one or more LIDAR devices 1110 (e.g., two LIDAR devices, three LIDAR devices, four LIDAR devices, etc.) mounted on a turntable 1120. Each LIDAR device 1110 may be any LIDAR device known in the art or developed in the future. In one embodiment, LIDAR device 1110 is a LIDAR device manufactured by SICK, Inc. of Waldkirch, Germany, which includes among other models, model number LMS221-30206. In another embodiment, LIDAR device 1110 is a Spinning Line Laser Rangefinder (SPLINE) manufactured by RedZone Robotics, Inc. of Pittsburg, Pa. Other embodiments may use a LIDAR device 1110 manufactured by another entity. LIDAR device 1110 may be adjustably mounted on turntable 1120 via any adjustable means known in the art or mounted to turntable 1120 in a fixed position.
Turntable 1120 may be any system, device, or combinations thereof including a platform that is capable of rotating 360 degrees and is capable of having LIDAR device 1110 mounted thereon. That is, turntable 1120 includes a suitable structure so that when LIDAR device 1110 is mounted on turntable 1120, LIDAR device 1110 rotates along an axis of rotation created by the rotation of turntable 1120.
In the illustrated embodiment, LIDAR device 1110 is mounted on the perimeter of turntable 1120. In another embodiment, LIDAR device 1110 is mounted to turntable 1120 at a position between the center and the perimeter of turntable 1120. In these embodiments, turntable 1120 is configured to rotate at a rate of speed based on the type of LIDAR device 1110 used such that LIDAR device 1110 is capable of detecting the maximum number of objects per revolution. In one embodiment, LIDAR device 1110 is rotated at a rate of about 1.1 Hz, although other rates greater than or less than 1.1 Hz may be used. In another embodiment, the rate at which LIDAR device 1110 scans and the rate at which turntable 1120 rotates may be, individually or collectively, adjustable based on the rate of speed at which vehicle 120 is traveling.
In one embodiment, LIDAR device 1110 is mounted on turntable 1120 such that LIDAR device 1110 is tilted at an angle that is below or at horizontal (i.e., 0-90 degrees) with respect to the axis of rotation created by LIDAR device 1110. That is, turntable 1120 is configured such that the axis of rotation of turntable 1120 is normal with respect to the ground (or ground plane) and LIDAR device 1110 is aimed at the ground or ground plane a predetermined distance away from turntable 1120 to create an angle between LIDAR device 1110 and the ground plane. In this embodiment, because the laser inside LIDAR device 1110 rotates the angle at which LIDAR device 1110 is pointed at the ground plane enables LIDAR device 1110 to detect objects (or obstacles) on or near the ground plane and landmarks to the sides of vehicle 120 in, for example, the x and z planes. Specifically, and with reference to
Furthermore, the rotation of LIDAR device 1110 enables LIDAR device 1110 to detect objects (both obstacles and landmarks) that are located in the y plane. As such, while LIDAR device 1110 is rotating, LIDAR device 1110 is able to detect obstacles and landmarks in the x, y, and z planes.
The distance an obstacle or landmark is away from LIDAR device 1110 may be calculated using simple geometry and/or other mathematical algorithms. In one embodiment and with reference to
Furthermore, LIDAR device 1110 includes a laser point at, for example, 0.5 degree increments from 0° to 180° for a total of 360 laser points. That is, the above discussion regarding determining h and d may be applied to each laser point such that data points for obstacles and landmarks may be generated by a plurality of laser points. As such, perception apparatus 110 may include processing and storage means for collecting and storing the data points detected by LIDAR device 1110.
In addition, the rotation of LIDAR device 1110 on the axis of rotation created by turntable 1120 enables LIDAR device 1110 to detect objects in the, for example, y plane. That is, when LIDAR device 1110 is rotating via turntable 1120, LIDAR device 1110 is capable of detecting objects in the x, y, and z axes surrounding vehicle 120. In other words, LIDAR device 1110 is capable of generating a 3-dimensional (3D) image of the environment surrounding vehicle 120 based on data points gathered during each revolution since LIDAR device 1110 is a two-dimensional LIDAR device generating data points in the x and z planes, and the rotation of LIDAR device 1110 enables data points in the y plane to be detected. That is, perception apparatus 110 is capable of generating a 3D map (or volume equivalent) of a particular environment surrounding vehicle 120 while vehicle 120 is operating.
In generating the 3D map, the position of LIDAR device 1110 along the axis of rotation is tracked. To do such, various embodiments of perception apparatus 110 may include a sensor axle or encoder (each not shown) that records the position of LIDAR device 1110 or where in terms of time in the rotation cycle LIDAR device 1110 is, respectively, when each data point is collected.
In another embodiment, LIDAR device 1110 is mounted on turntable 1120 such that LIDAR device 1110 is tilted at an angle that is above horizontal (e.g., 91-180 degrees) with respect to the axis of rotation created by LIDAR device 1110. For example, the axis of rotation of turntable 1120 is normal with respect to the ground and LIDAR device 1110 aimed at the sky (or a plane above turntable 11120) a predetermined distance away from turntable 1120 such that LIDAR device 1110 is capable of detecting objects above and to the sides of vehicle 120 when turntable 1120 is rotating.
In summary, the angle at which LIDAR device 1110 is directed dictates the range at which objects may be detected and the height of LIDAR device 1110 is mounted to vehicle 120 determines the distance at which landmarks may be detected. In any case, LIDAR device 1110 should be pointed such that occlusion of the light beams from LIDAR device 1110 by portions of vehicle 120 (which in essence creates a shadow) is minimized.
In the illustrated embodiment, vehicle 120 is a lawnmower. In other embodiments, vehicle 120 may be a motor vehicle (e.g., an automobile, truck, etc.), an aircraft, a spacecraft, a watercraft, or other similar vehicle. In one embodiment, vehicle 120 includes navigation apparatus and/or systems (not shown) that are capable of autonomously navigating vehicle 120 in an environment based on any objects (e.g., obstacles and/or landmarks) detected by perception apparatus 110. In other words, vehicle 120 may be an unmanned vehicle.
The following example may be helpful in better understanding the operations of system 100. As vehicle 120 travels, perception apparatus 110 detects the objects (e.g., obstacles and/or landmarks) in the environment surrounding vehicle 120 and is also capable of determining the translation characteristics of the environment surrounding vehicle 120. That is, perception apparatus 110 is capable of generating a 3D map (or volume equivalent) of a particular environment surrounding vehicle 120 while vehicle 120 is operating. The navigation apparatus/systems then control the movement of vehicle 120 through the environment based on the objects detected by perception apparatus 110. That is, vehicle 120 is capable of autonomously traveling through the environment using detected landmarks and avoiding detected obstacles (including negative obstacles) detected by perception apparatus 110.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.