Allegro is leading the way with high-resolution GMR wheel speed and range sensors for ADAS applications

     Allegro MicroSystems has announced the launch of its new A19360 wheel speed and range sensor, ideal for emerging applications such as advanced driver assistance systems (ADAS). The technology-leading giant Magnetic resistance (GMR) sensor can provide automakers with the high signal resolution and reliability required for high-level autonomous driving in passenger cars and other mobility services (mobility-as-a-service).

     According to a recent report by Strategy consulting firm Strategy&, the first passenger cars with L3 level autonomous driving (conditional autonomous driving) capability will generally be available by the end of 2022. By 2025, vehicles with L4 (highly automated) capabilities will be available for manned applications. By 2030, vehicles with L3, L4 and L5 (fully automated) capabilities are expected to account for 20 percent of the European market, 12 percent of the U.S. market and 11 percent of the Chinese market. Allegro's new A19360 sensor is a component of the software and hardware that automakers are working to develop despite the coronavirus pandemic and government regulations that have delayed the development of autonomous driving technology.

     Peter Wells, Allegro's Speed and Sensor interface business director, said: "Our new A19360 sensor is a game changer for autonomous vehicle manufacturers. Designed for the L3, L4, and L5 levels of the SAE J3016, it delivers a four-fold improvement in position measurement accuracy, "It helps to safely enable features such as parking assistance, fully automated valet parking, and congestion assistance, and it can even improve autonomous driving capabilities and low-speed control in congested traffic environments."

     Self-driving cars need excellent wheel rotation information to achieve accurate low-speed control. By using a special protocol compatible with the Electronic Control Unit (ECU), the A19360 is able to generate additional output events per magnetic cycle to provide higher resolution data for the vehicle control system. This includes 8 event patterns per magnetic cycle for ADAS applications, providing approximately every 5 mm incremental resolution for tire rolling. The A19360 also includes a 4 event mode per magnetic cycle, which doubles the number of outputs per magnetic cycle compared to a normal wheel speed sensor. This allows the designer to halve the number of poles on the inner ring magnet in the hub, thereby drastically saving costs, or increasing air gaps, and still get the same amount of incremental change per revolution.

     The A19360 is based on Allegro's monolithic GMR technology, developed specifically for the ISO 26262 ASIL B(D) standard, with ultra-low jitter and relatively high atmospheric gap capabilities. The A19360 is also integrated with Allegro's SolidSpeed Digital Architecture™, which provides a wider dynamic range of operating air gaps and height adaptation to eliminate system failures due to thermal drift and system dynamics.