Chipset aid to safer autonomous driving
Assisting safer autonomous driving, STMicroelectronics has introduced the multi-frequency satellite-navigation receiver chipset suitable for safety-critical automotive applications and high accuracy positioning at the decimeter and centimeter-level for PPP and RTK applications.
Traditional in-car navigation systems help drivers reach their destinations using receivers and commercial satellite services that allow positioning accurate to within a few metres. With increasing use of autonomous systems such as lane-departure warning adaptive cruise control valet parking, and auto-pilot, greater accuracy is needed to ensure safety and reliability, in combination with proximity sensors such as cameras, radar, lidar, and others, to monitor the driving environment automatically. Fully self-driving vehicles of the future will also demand high-accuracy positioning.
By tracking satellites of all global navigation satellite system (GNSS) constellations GPS, GLONASS, Galileo, BeiDou, QZSS, and IRNSS simultaneously on at least two of the frequencies used by each system (instead of one in other products), ST’s automotive-quality Teseo automotive precise positioning receiver (APP) provides high-quality raw GNSS data for precise point positioning (PPP) and real time kinematic (RTK) algorithm, which allows accurate positioning and rapid convergence time worldwide.
In addition to its high accuracy, the industry-unique receiver monitors the integrity of the satellite data to alert the system if accuracy is degraded for any reason. This permits Tier-1 manufacturers to certify safety-critical systems in accordance with the automotive industry functional-safety standard, ISO 26262, up to the highest automotive safety integrity level (ASIL). Teseo APP also integrates a secure microcontroller for secure system boot and data-output authentication to keep sensitive data safe from attack.
Launched alongside Teseo APP, ST’s Teseo V chip provides equivalent multi-frequency precise positioning in a simplified device for non-safety-critical applications where integrity assurance is not required.
“High-accuracy satellite positioning makes autonomous driving safer, smoother, and more reliable,” said Antonio Radaelli, director, infotainment business unit, STMicroelectronics. “Our newest Teseo APP GNSS chip combines extreme accuracy and precision with industry-unique integrity assurance for use in safety-critical applications.”
ST is now supplying product samples to lead customers who are developing autonomous-driving systems expected to appear first in high-end vehicles launched in 2020/2021.
Conventional GNSS-based automotive positioning and navigation systems use only single-frequency GNSS receivers that operate in the L1 frequency bands available for consumer use, and are subject to environmentally related errors such as multipath and ionospheric phase delays that impair positional accuracy.
Teseo APP eliminates these errors by tracking all available GNSS signals in multiple frequency bands, such as the GPS and GLONASS, Galielo, BeiDou, QZSS, and IRNSS L1, L2, and L5 frequency bands, and the Galileo E6 signal that contains PPP correction data to allow worldwide decimeter-level accuracy.
Until now, GNSS signals containing precise-positioning information have been reserved for commercial and government organisations. Other techniques for enhancing accuracy have included expensive differential systems reliant on a combination of ground base-station signals as well as satellite signals, or techniques such as RTK, which generally require a denser reference station network.
The new Teseo chips make high accuracy affordable for autonomous driving through an ingenious combination of tracking up to three constellations simultaneously over two frequency domains. These multi-frequency combinations bring reliable GNSS ionospheric and multipath modeling in most environments.
