TDK, through its InvenSense subsidiary, unveils a new family of automotive sensors and inertial-aided positioning software for autonomous vehicles

By Gina Roos, editor-in-chief

TDK Corp., through its InvenSense subsidiary,
rolled out a new line of automotive high-accuracy MEMS motion sensors at CES
2019. These include the “MotionTracking” automotive-qualified IAM-20680
and IAM-20680HP

six-axis inertial measurement units (IMUs), which expand TDK’s existing line of
automotive sensors that include the IAM-20380

and IAM-20381
three-axis accelerometer
. The automotive MEMS sensors can help
improve the absolute position of a vehicle in GNSS- and GPS-poor environments,
such as tunnels, parking garages, and urban canyons.

Here’s the automotive sensor lineup:

  • Touted
    as the smallest six-axis automotive-qualified sensor (combining a
    three-axis gyroscope and a three-axis accelerometer), the IAM-20680 is claimed
    as the industry’s only device featuring 16-bit accelerometers
    and 16-bit gyroscopes in a series production car today. The operating
    temperature range is –40°C to 85°C.
  • If
    you’re looking for a beefier and higher-temperature-range IMU, the IAM-20680HP,
    a high-performance version of the IAM-20680, offers an extended operating temperature
    range of –40°C to 105°C and high gyroscope and offset thermal stability.
    It is pin-, package-, and register-compatible with the IAM-20680.
  • The
    IAM-20380, with an operating temperature range of –40°C to 85°C, is
    claimed as the only automotive-qualified gyroscope fully compatible (pin,
    package, register, and software) with a three-axis automotive
    accelerometer (IAM-20381) and an automotive-qualified six-axis device
  • Similarly,
    the IAM-20381, with an operating temperature range of –40°C to 85°C, is
    touted as the only automotive-qualified three-axis accelerometer fully
    compatible (pin, package, register, and software) with a three-axis
    automotive gyroscope (IAM-20380) and an automotive-qualified six-axis
    device (IAM-20680).

Key specs include:

  • Gyroscope
    full-scale: ±250°/s, ±500°/s, ±1,000°/s, ±2,000°/s
  • Accelerometer
    full-scale: ±2g, ±4g, ±8g, ±16g
  • Embedded
    temperature sensor
  • 16-bit
    output for accelerometer, gyroscope, and temperature sensor
  • SPI
    and I²C serial interface
  • 512-bit
  • 16-pin
    LGA package (3 × 3 × 0.75 mm)

Specifically, the six-axis IAM-20680HP or the
IAM-20680 can be used to improve the estimate of the position, direction,
and speed of a vehicle when the satellite signal is poor or non-existent as
well as improve the quality of the position estimation when the satellite
signal is strong, said TDK. Other key features include excellent temperature
stability that enables navigational driving through challenging environments
and low sensitivity error that keeps the car turning correctly. The sensors
measure up to 16g acceleration and up to 2,000 degrees per second.

Primary applications for the new sensors
include navigation system aids for dead reckoning, automotive lift gate motion
detection, accurate location for vehicle-to-vehicle and infrastructure, 360°
view camera stabilization, car alarms, telematics, and insurance vehicle

In addition, the IAM-20680 and
IAM-20680HP are designed into the new InvenSense Coursa Drive software
solution, claimed as the first inertial-aided positioning software for
autonomous vehicle (AV) platform developers. The Coursa Drive is a
high-performance extension of the InvenSense
Positioning Library

(IPL) and improves inertial-only vehicle positioning to

TDK said that the Coursa Drive “delivers a
cost-effective, vehicle-dead-reckoning accuracy software solution equivalent to
high-end systems costing tens of thousands of dollars.” Primary applications
include Level 2 to Level 5 advanced driver-assistance systems (ADAS),
robotaxis, trucking, and precision agriculture.

How it works: The inertial navigation system
calibrates using the absolute position inputs from high-accuracy GNSS receivers
or perception-based systems such as cameras, radar, or LiDAR with high-definition
(HD) maps. In real time, the software provides high-rate, 100-Hz delta
positions and orientation to the AV systems. In offline mode, it improves
accuracy for HD map building and maintenance applications.

Coursa Drive is available to select early
partners and customers. Contact the company for more information.

TDK and its group companies will showcase the
automotive sensor solutions, along with other sensor products, at CES 2019, in Booth #30306, Las Vegas Convention Center,
South Hall 3.