Constant innovation is what drives us. From sci-fi to reality, self-driving cars are a great example. From large manufacturers, such as Tesla, to new start-ups, lidars have been an essential part in creating this new industry. To simplify, a lidar works by rapidly sending out laser lights and measuring the time it takes for each pulse to bounce back. By doing so, it can map out the nearby surfaces, an important aspect for autonomous .
Sense Photonics
This new lidar, being created by Sense Photonics, will contain 11,000 lasers, an unheard of feat in this industry. Most typically have between 1 and 128 while other ones are currently being developed to a similar stature. This type, called vertical-cavity surface-emitting laser (VCSEL), is low cost and can be made with conventional methods. The main element that allows this to be possible, however, is called micro-transfer printing, a technique that allows for the lasers to be spread out. To do this, Sense puts these VCSELs on a gallium arsenide wafer, often used for various electrical components, and then moved to a ceramic substrate, another important component. Then, micro printing uses a rubber stamp with tiny bumps to pick up VCSEL chips.
Issues
All of this, however, isn’t always easy. Lidars like this often have poor range because capturing the whole area causes some light to get wasted. This capture also creates lots of heat and could potentially harm someone’s vision. Fortunately, spreading out the lasers solves these issues, except three major drawback. Currently, Sense’s lidar has shorter range than most others, uses significantly more energy, and doesn’t have the 360-degree coverage of other competitors. These will likely be the key factors in the lidar’s success or downfall.
SPADs
Another important addition to this development is the use of Single-Photon Avalanche Diodes (SPADs). These are being used to detect laser lights in Sense’s next generation lidar sensor and work by sending out currents to pick up photons. Like VCSELs, they are cheap and will solve a current problem, range. This technology may prove useful, especially in competitors’ product.
Use In Cars
But how does all of this relate to cars? Ibeo, a leader in automotive lidar sensors, has also been working on using SPADs. A few years, Ibeo secured a contract with Audi, making it the first time lidars were installed in production cars. Recently, Ibeo’s Operations Director, Mario Brumm, told Ars that they are developing a lidar with a modular design of VCSELs and SPADs, allowing it to be configured to the needs of a variety of vehicles. The next challenge is to manufacture these lidars cheap enough for automakers and avoid heat and eye-safety issues. While Sense can avoid the last two issues with micro-printing, Ibeo does not have a similar technique available. With that being said, we are left to wonder. Will we see a collaboration with lidar producers, or do we wait until one company has figured it out. Or will lidars become obsolete, as Elon Musk as been saying. In early 2019, he told Tesla investors that, “Lidar is a fool’s errand. Anyone who relies on it is doomed.” Whatever the current position is, it’s safe to say that autonomous vehicles still have a long way from becoming mainstream.
Sources:
- https://arstechnica.com/cars/2020/01/most-lidars-today-has-between-1-and-128-lasers-this-one-has-11000/
- https://heraldwriter.com/2020/01/16/maximum-lidars-these-days-have-between-1-and-128-lasers-this-one-has-11000/
- https://sensephotonics.com/automotive/
- https://www.laserfocusworld.com/lasers-sources/article/16548308/lasers-for-lidar-application-parameters-dictate-laser-source-selection-in-lidar-systems
- http://forbes.com/sites/edgarsten/2019/08/05/startups-answer-to-elon-musks-aversion-to-lidar/#83a74717a5c7
