Silicon lidar chip brings accuracy at low cost to autonomous vehicles
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A compact 3D lidar imaging system has been developed that its creators say can match the performance and accuracy of most advanced, mechanical systems currently used.
Lidar (light and radar) uses the precision of lasers to sense an environment by emitting them into the nearby environment and measuring the time taken for them to be reflected from objects and returned to the sensor. This provides the distances from various objects and allows a three-dimensional map of the environment to be built up quickly
They are often used as the 'eyes' for autonomous cars but are also used in facial recognition software and by autonomous robots and drones.
Accurate imaging is essential for machines to map and interact with the physical world, but the size and costs of the technology currently needed has limited lidar’s use in commercial applications.
Researchers from San Francisco start-up Pointcloud and the University of Southampton have developed a new, integrated system, which uses silicon photonic components and CMOS electronic circuits in the same microchip.
They believe their prototype is a low-cost solution and could pave the way to large volume production of cheap, compact and high-performance 3D imaging cameras for use in robotics, autonomous navigation systems, mapping of building sites to increase safety and in healthcare.
“Lidar has been promising a lot but has not always delivered on its potential in recent years because, although experts have recognised that integrated versions can scale down costs, the necessary performance has not been there - until now,” said Graham Reed at the University of Southampton.
“The silicon photonics system we have developed provides much higher accuracy at distance compared to other chip-based lidar systems to date, and most mechanical versions, showing that the much sought-after integrated system for lidar is viable.”
Remus Nicolaescu, CEO of Pointcloud Inc, added: “The combination of high performance and low-cost manufacturing, will accelerate existing applications in autonomy and augmented reality, as well as open new directions, such as industrial and consumer digital twin applications requiring high depth accuracy, or preventive healthcare through remote behavioural and vital signs monitoring requiring high velocity accuracy.
The latest tests of the prototype show that it has an accuracy of 3.1mm at a distance of 75m.
Amongst the problems faced by previous integrated systems are the difficulties in providing a dense array of pixels that can be easily addressed; this has restricted them to fewer than 20 pixels whereas this new system is the first large-scale 2D coherent detector array consisting of 512 pixels.
The research teams are now working to extend the pixels arrays and the beam-steering technology to make the system even better suited to real-world applications and further improve performance.
In November, another start-up, Velodyne Lidar, announced it had made a $500 (£364) lidar array with no moving parts, significantly cheaper than earlier units which could cost well over $10,000.
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