Epson Toyocom Develops Inertial Measurement Unit with Quartz Gyro-Sensors

Miniature IMU with high accuracy & stability for wide use in industrial applications

TOKYO, Japan - Epson Toyocom Corporation, the leader in crystal devices, today announced that it has begun commercial development of a highly compact, accurate, and stable inertial measurement unit (IMU)*1. The IMU employs technology the company has accumulated in the development of QMEMS*2 quartz gyro-sensors. Epson Toyocom plans to make engineering samples available in April 2011.

Epson Toyocom already provides its customers around the world with a variety of sensing products, including six-axis sensors for motion sensing and gyro-sensors for use in camera-shake correction and high-accuracy navigation systems. The company has also been providing customers with support and system solution support for its sensing devices. Epson Toyocom launched the IMU development project with the aim of using the know-how accumulated in the course of providing customer service to provide efficient and high-performance inertia measurement.

The IMU currently under development is a compact device that employs ±300 degrees per second triple gyroscopes on three axes and three ±3-G tri-axis accelerometers. It exhibits excellent angular rate characteristics, with gyro bias instability*3 less than 6 degrees per hour and angle random walk*4 performance less than 0.24 degrees per √hr. The new IMU’s instability and accuracy parameters, respectively, are approximately 25% and 12.5% better than comparable IMUs available in the market. Technology for adding highly accurate compensations enables the IMU to show excellent bias-temperature stability (instability less than 0.005 degree per second /°C) across the operating temperature range. This represents an approximately 50% improvement in bias-temperature stability compared to comparable IMUs.

Sensor stability and miniaturization are generally mutually opposing. However, Epson Toyocom has fine-tuned its QMEMS technology to enable it to downsize the device package for easy assembly in lightweight applications and mobile systems without sacrificing stability characteristics. The ease with which the IMU can be handled will help lower the technical barriers for customers wanting to offer inertial measurement and allow them to provide on-board inertial motion analysis or control to applications with minimal time and engineering expense.

The IMU is being developed for a wide variety of applications in areas such as industrial system motion analysis and control, moving object control, and vibration control and stabilization. Excellent stability, accuracy, and other characteristics, combined with a compact form factor, will make it easy for customers to use the IMU in new industrial applications or differentiate existing applications, accelerating the spread of inertial measurement in these markets.
Target Applications

* Motion analysis and control
* Control of moving objects
* Navigation systems
* Platform stabilization and control
* Movement analysis

General Specifications of the Inertial Measurement Unit (compared to comparable IMU)

1. Accuracy and stability
Gyroscope bias stability*3: ˜6 degrees per hour (approx. 25%)
Angle random walk*4: ˜0.24 degrees per √hr (approx. 12.5%)
2. Bias-temperature stability: ˜0.005 degrees per second /°C (approx. 50%)
3. Six-degree of freedom: Triple gyroscopes, ±300 degrees per second 3-axis accelerometer, ±3-G
4. Digital serial interface: SPI/UART

Glossary

*1 inertial measurement unit (IMU)
A device that detects and measures inertial motion, which is made up of angular velocity on three axes and acceleration in three directions.
*2 QMEMS
QMEMS is a combination of “Quartz,” a crystalline material with excellent characteristics such as excellent frequency stability and high precision, and “MEMS” (micro electro mechanical system). QMEMS devices, produced via a microfabrication process on a quartz material instead of on a semiconductor material like MEMS, offer high performance in a compact package. QMEMS is a registered trademark of Epson Toyocom.
*3 gyro bias instability
The random variations having 1/f noise density characteristics of gyro output bias calculated by averaging a specified finite length of sampling times and time intervals
*4 angle random walk
The angular error buildup with time that is due to white noise in angular rate

About Epson
Epson is a global imaging and innovation leader that is dedicated to exceeding the vision of customers worldwide through its compact, energy-saving, high-precision technologies, with a product lineup ranging from printers and 3LCD projectors for business and the home, to electronic and crystal devices.

Led by the Japan-based Seiko Epson Corporation, the Epson Group comprises over 70,000 employees in 106 companies around the world, and is proud of its ongoing contributions to the global environment and the communities in which it operates.
http://global.epson.com/

About Epson Toyocom
Epson Toyocom Corporation is the global leader in crystal devices, which serve as the heart and pulse for a wide range of electronic products for consumers and industry. Utilizing its innovative hybrid quartz microfabrication technology, QMEMS, Epson Toyocom offers technological expertise in timing, sensing, and optical devices, and maintains its leadership position by providing customer-specific combinations and solutions.
http://www.epsontoyocom.co.jp/english/