High-resolution GMR wheel speed and distance sensor for ADAS applications

24-01-2022 | Allegro | Automotive & Transport

Allegro MicroSystems, Inc. offers its new A19360 wheel speed and distance sensor for usage in emerging applications in ADAS. The cutting-edge GMR sensor offers automakers with the signal resolution and reliability needed for advanced levels of automation in passenger vehicles and mobility-as-a-service applications.

"Our new A19360 sensor is a game changer for automakers working on autonomous vehicles,” says Peter Wells, business line director for Speed and Sensor Interfaces at Allegro. “It’s designed for SAE J3016 levels of automation 3, 4 and 5, and helps to safely enable features such as park assist, fully autonomous valet parking and traffic jam assistance with 4x better positional measurement where the tires hit the road. It can even improve autopilot functionality and low-speed control in dense environments.”

Automated and autonomous vehicles need superior wheel rotation information for accurate low-speed control. The device offers high-resolution information to automotive systems by creating extra output events per magnetic cycle with a special protocol that’s compatible with ECUs. It includes an eight-event-per-magnetic-cycle mode targeted at ADAS applications, providing an increment for every ~5 mm of tyre roll. It also includes a four-event-per-magnetic-cycle mode that doubles the amount of outputs per magnetic cycle (compared to a normal wheel speed sensor). This enables designers to halve the poles on in-wheel ring magnets to save costs, or increase the air gap and still get the same number of increments per revolution.

The device was developed for ISO 26262 ASIL B(D), and is constructed on the company's monolithic GMR technology with ultra-low jitter and large air gap abilities. The company’s SolidSpeed Digital Architecture offers the widest dynamic range of operating air gap and highly adaptive performance that removes flatlining due to thermal drift and system dynamics.

By Natasha Shek