Inside Unmanned Systems

DEC 2018 - JAN 2019

Inside Unmanned Systems provides actionable business intelligence to decision-makers and influencers operating within the global UAS community. Features include analysis of key technologies, policy/regulatory developments and new product design.

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38  December 2018/January 2019 unmanned systems inside Cameras also require proper illumination and lane markings must be high-quality or it will be difficult to model lanes. Thermal imaging will be used in parallel with physical cameras, Lamprecht said, making it possible to extend ranges in adverse weather conditions such as fog. PARALLEL/CENTRALIZED PROCESSING. This enables easier sen- sor fusion, offers a lower cost at high volumes and enables application specific processing. ULTRASONIC. Ultrasonics offer low cost sensing that is ro- bust and reliable. They work well for short range applica- tions, such as parking. Lamprecht ended his portion of the webinar with an overview of the pros and cons of GNSS Ground Truth Systems, like those NovAtel offers. Though complex and in some cases expensive, these systems are extremely ac- curate and provide adequate positioning in a variety of scenarios. PRECISE POSITIONING FOR AUTOMOTIVE WITH MASS MARKET GNSS CHIPSETS The webinar moved along with the next presenter, de Groot from NovAtel, focusing on production systems for production automotive. GNSS systems in production au- tomotive today tend to be L1 only receivers that provide a pseudo range only positon solution with an accuracy on the order of several meters. While this works for onboard navigation or localization for emergency services, emerg- ing ADAS applications demand much higher accuracy. While the industry is still settling on how much accuracy is required, it's expected to be less than 1 meter for true autonomous driving applications. There are two ways to meet these new requirements, de Groot said. The first is the arrival of multi-frequency mass market chipsets. Three of these chipsets were an- nounced in the last year, and he expects more to hit the scene in 2019. "They will allow us to use dual frequency measure- ments, which means we can correct for the atmospheric delay. We get more observables," he said. "We're seeing more constellations coming in with these new receivers, so that will definitely help." The other part, which is where corrections come in, is high precision carrier phase position algorithms, he said. These al- gorithms, traditionally used in survey and precision agricul- ture, can be used in automotive to reach higher accuracies. This typically involves two techniques: Real-time ki- nematic positioning (RTK) and Precise Point Positioning (PPP). RTK works by differencing measurements between rover and base to remove errors. It's a regional solution that typically covers the size of a U.S. state or a small coun- try. It requires about 20-50 km station spacing. PPP, on the other hand, provides corrections for all errors a user will experience. Users can apply corrections to their so- lution for higher accuracy. PPP is global but can be en- hanced with regional networks to provide corrections for regional errors. Regional PPP networks require about 100-300 km station spacing. "At NovAtel and Hexagon we believe that the right ap- proach for automotive is PPP," de Groot said. "And there's a few reasons for that. One is that there's one-way data trans- fer of the corrections to the user whereas with network RTK the user has to occasionally send their position back to the network for them to generate a new virtual base station. Because it's one way it's automatically more scalable and also you eliminate any privacy concerns with having to transmit the positon of your users back to the service." The wider spaced base stations also mean less infra- structure, de Groot said, and generating corrections in one place with a global solution is important to safety of life concerns. The ability to analyze the integrity of correc- tions that are all coming from one source is an advantage. The company is focusing on using the new mass market chipsets with their PPP algorithms to achieve the require- ments demanded by autonomous driving and ADAS ap- plications, de Groot said. The team recently tested four chipsets in different environments. He went over those results during the webinar as well as the challenges with mass market chipsets and how the future TerraStar-X ser- vice can enhance convergence performance to reach sub- meter levels in 30 seconds. Without the service, it takes nine minutes to reach 1 meter for dual frequency and more than 20 minutes using single frequency. Mass market chipsets also need mass market dual fre- quency antennas, he said. "Using new mass market chipsets with NovAtel's high pre- cision algorithms and TerraStar corrections is a viable solu- tion for bringing GNSS into autonomous driving," he said. "To get the convergence performance we believe the indus- try will demand, ionospheric corrections are necessary. And lastly, antenna performance is going to be very important WEBINAR RECAP » ROAD TO AUTONOMY

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