Patent Application
20150192677
The present invention relates generally to the field of vehicle-based three-dimensional mapping, and more particularly to the use of distributed time-of-flight lidar sensing systems for real-time wide-field-of-view three-dimensional mapping of the space surrounding a vehicle.
A lidar sensor is a light detection and ranging sensor. It is an optical remote sensing module that can measure the distance to a target or objects in a landscape, by irradiating the target or landscape with light, using pulses from a laser, and measuring the time it takes photons to travel to said target or landscape and return after reflection to a receiver in the lidar module. In the field of lidar mapping, the three-dimensional rendering of a landscape and the recognition of objects are traditionally achieved through the use of a single lidar sensor with a large number of transmitter-receiver pairs (per cited Hall references), or the use of a large number of sensors having a single transmitter-receiver pair (per cited Wetteborn and Ray references). These traditional approaches are prohibitively expensive. High cost has been one of the main reasons behind the lack of broadly-deployed commercial lidar solutions for consumers.
A three-dimensional mapping system comprising a moderate number (typically 2 to 4) of moderate-beam-count (typically 8-beam to 16-beam) lidar sensors is proposed to achieve low cost systems with wide fields of view. Secondary advantages include compact sensors and a small minimum range (possible by optimal placement of each of a plurality of sensors).
The following drawings are illustrative of embodiments of the present invention and are not intended to limit the invention as encompassed by the claims forming part of the application.
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The proposed apparatus and related method are used for real-time wide-field-of-view three-dimensional mapping using a moderate number (typically 2 to 6) time-of-flight lidar sensors, each containing a moderate number of transmitter-receiver pairs (typically 4 to 16) and a mechanism to scan each laser beam of each transmitter horizontally and vertically, as well as central data processing electronics.
Primary advantages of these systems include low cost and wide field of view. Secondary advantages include compact sensors and a small minimum range made possible by optimal placement of each of a plurality of sensors.
Each sensor features multi-dimensional scanning and a high sampling rate, enabling the collection of rich data capable of supporting high-resolution three-dimensional mapping and object recognition.
The present invention also includes mutual calibration of the plurality of time-of-flight lidar sensors, arbitrary mounting angle, automated leveling of the sensors, ranging in different planes, as well as the flexibility of unique mounting positions when installed (e.g., in a vehicle, the mounting can be done on the side view mirror fixtures, between the rear view mirror and the windshield, on the headlight fixtures, on the bumpers, in front of or behind the grill, on the hood, on the trunk and/or on the roof).
The present application claims the benefit of priority from U.S. Provisional Application Ser. No. 61/748,748, filed Jan. 3, 2013. Other related U.S. application is U.S. Provisional Application Ser. No. 61/726,538, filed Nov. 14, 2012.
