A New Approach to New Markets
Mirada was launched by industry veterans who have created a new approach to precision optics. The need for a new approach is driven by the emerging automotive LiDAR and industrial LiDAR markets. This approach enables low cost manufacturing of precision optical components, as well as a new method of enabling rotating optical systems survive the shock and vibration on the road.
High performance polygon optics, and similar complex optical elements are often manufactured by single point diamond turning / diamond machining. For optics that need a higher level of smoothness, often they are subsequently polished. This type of processing can produce incredible products, but with incredible prices. The machines that produce this class of optics operate on one face at a time, one part at a time. There is no way that this technology can scale to the cost and production volume needs of the growing LiDAR market.
Mirada has created another way. We invert the manufacturing process, and form optical surfaces with ultra high flatness and low roughness. Then, these surfaces are assembled and aligns in a novel, patent pending process to create complex, yet low cost polygon optics, in a method that scales to high volume.
LiDAR beam steering technologies in the past have been highly suseptable to shock and vibration. In the short term, speedbumps and potholes on the road can displace beam scanners, resulting in unctolled motion that results in erronious image date, risking safety. In the long term, month after month of wear and tear from road vibrations destroy most LiDAR scanning technologies in a few short years.
Mirada addresses these challenges with fluidic stabilization. The scanner is comprised of a cavity which contains a fully liquid immersed rotating polygon and its drive motor. This scanner architecture enables resistance to vibration, as well as other benefits:
- The buoyant forces of the fluid act to reduce the transmission of external forces to the scanner that originate from shock and vibration. For complete neutral buoyancy, external accelerations are entirely suppressed and the reflector moves in perfect coordination with the scanner body, rigidly attached to the vehicle/robot frame. In practice, density is temperature dependent, and thus so are buoyant forces, but the substantial reduction in external acceleration act to retard image distortion caused by scanner pointing errors and reduce wear mechanisms, increasing long term reliability.
- Rotating a mirror inside a non-unity refractive index medium increases the ratio between mechanical and optical deflection (scan magnification factor) above two to approximately three. This increases the azimuthal scan range for a given polygon, increases the refresh rate for a given azimuthal span, or increases elevation resolution for a given azimuthal span.
- The lubricating and heat transfer properties of the fluid reduce and dissipate heat at the bearings, increasing long term reliability.
Fluids are selected for LiDAR scanner applications based upon several properties, including viscosity across automotive temperature ranges. The viscosities of the fluids are substantially higher than air, which increases drive motor torque requirements, increasing electrical power consumption. But unlike point to point scanners which are speed limited by different physics, continuously rotating polygon reflectors are practically limited by the system power budget. In practice, power consumption in LiDAR applications are roughly 90% lower from fluid immersed polygon scanners compared to galvanometer scanners at similar refresh rates and the increased power requirements are acceptable.
LiDAR stands for Light Detection and Ranging, and is a family of many variants of methods that use light to determine the distance of an object. Two main families of LiDAR that are most relevant to automotive LiDAR are:
- Time Of Flight (TOF) LiDAR
- Coherent LiDAR
Mirada’s products are used to enable breakthrough LiDAR systems based on both types of LiDAR. TOF LiDAR sends out a pulse of light, and the time it takes for faint reflections off of objects to return to the LiDAR sensor are measured, yielding the distance of the objects. TOF LiDAR can use a single point measurement from a single channel, and scan this point distant measurement around (using our products) to create a LiDAR point cloud. TOF LiDAR can also illuminate a larger scene with a single flash, and measure many spatially separate reflections at the same time using a sensor array, in a variant known as flash LiDAR.
Coherent LiDAR operates differently. A beam of light is split into two beams, a source beam and a reference beam. The source beam is sent out into the scene in front of the LiDAR, and the reflected beam that returns is captured and mixed with the reference beam. Information in the resulting optical interference patterns can yield distance of objects, as well as their velocity towards or away from the LiDAR system.
Mirada’s scanning technology is compatible with all the aforementioned LiDAR technologies, enabling high performance, automotive grade LiDAR systems to be deployed widely in the industry.
LiDAR is a technology that has impacted many industries and markets, from space travel, mapping, archaeology, construction, mining, and transportation. The automotive industry is rapidly adopting LiDAR technology to enable future safer vehicles in features known as Advanced Driver Assistance Systems (ADAS). Also, there is much work on more advanced automotive features that can be termed as Autonomous Driving, where LiDAR plays a critical role. LiDAR, radar, camera systems, ultrasonic sensors, and other technologies work together to make drivers and passengers safer.
Polygon scanners can be single line (regular polygons) or multi-line (multiple lines). As a single line polygon scanner rotates it will reflect light repeatedly in a single horizontal line. By directing a LiDAR channel on that rotating polygon, one can create a single line of LiDAR data (A 2-D point cloud including azimuthal angle and distance). Similarly, by illuminating a multi-line polygon with a LiDAR channel one can create multiple horizontal lines of LiDAR data (a 3-D point cloud, azimuthal angle, elevation angle, and distance). For example, an eighth sided, multi-line scanner with one LiDAR channel can create a 3D point cloud with eight distinct horizontal lines of data. Couple that same scanner to eight LiDAR channels, and you have a point cloud with 64 horizontal lines of data.
There many alternative configurations, some of which include a second scanner. Contact us to see what product and configuration is right for you.
Mirada offers several things that make us different:
- Responsiveness: Stock products in days, Back order units in a few weeks, Customer systems in a month or so.
- Multi-line polygon scanners: We deliver single line and multi-line scanners, however, a responsive, custom provider of low cost, volume scalable multi-line scanners is hard to find (but you have found it in Mirada). See our product selector for more.
- Fluid stabilized scanners: Our fluid stabilized scanners are a unique breakthrough in rotational optics. See XXX
It is Spanish for “a look, gaze, or glance”. We enable LiDAR that will look out and deliver unprecedented performance and scalability.
Mirada offers traditional air scanners as well as fluid scanners. Our fluid stabilized scanners offer several unique advantages:
- The fluid expands the scan angle, acting like an expansion lens. This gives you up to 50% larger scan angle than any air scanner, or you can use this advantage to give you 50% more scan lines at the same scan angle.
- The fluid puts the large rotating optic in neutral buoyancy, enabling breakthrough shock and vibration resistance. You may have noticed how, when you walk into a swimming pool you feel lighter. This is the effect of buoyancy, where the mass of the water you displace effectively reduces your weight. When a scuba diver is properly weighted, they will neither float nor sink, and are immune from the effects of external forces, like gravity. In the same way, our fluid scanners are neutrally buoyant in the fluid, and as such, immune from shock and vibration from the road. This gives them breakthrough shock and reliability resistance, key to many applications for scanning solutions.
- The fluid cools and lubricates the system, adding to our reliability.