In autonomous vehicles, it is important to know not only what is around the vehicle, but also the accurate position on the road. GPS can be used for localization, but it has certain limitations. At slow speeds, the heading determination is challenging, and in an urban environment, the GPS signal can be blocked or have interference from buildings.
Autonomous vehicles must rely on an inertial measurement unit (IMU). The IMU provides a continuous stream of data related to the vehicle’s linear acceleration on three principle axes and rotation parameters – pitch, roll and heading. When this data is fused with the GPS signal, localization accuracy and robustness against external disturbance can be improved significantly.
While most autonomous concept cars today use expensive fiber-optic gyro (FOG) technology, Murata – as a performance leader in MEMS sensors – has the technology to bring the cost of high-performance IMUs down to an acceptable level so that it can be used in the mass production of autonomous vehicles.
Murata’s inertial sensor products are qualified to be used in safety-critical applications. Murata’s gyro and accelerometer technology, based on 3D MEMS, feature:
- Excellent performance, even in harsh and vibrating environments;
- Superior performance over wide temperature range;
- Advanced failure diagnostics, digitally activated self-test, memory parity or checksum check, and continuous connection failure detection; and
- Can support any mounting orientation.
Over the past few years, combo sensors are gaining traction. Just as MEMS technology reduces costs of high-performance sensors dramatically, combo sensors could further lower the cost and footprint by combining the two sensors into one package with a single ASIC. Typically, combos are being used in electronic stability control but can be used also to support autonomous driving.
Murata is a global market leader in inertial sensors for ADAS applications. The company’s sensor offerings will continue to evolve in the marketplace — from road safety improvement to user interface applications that will further take advantage of its vast expertise in high-performance inertial sensor technology.