Epson Develops the Ideal IMU for Attitude and Vibration Control

Seiko Epson Corporation ("Epson," TSE: 6724) has developed and is now shipping samples of the M-G370PDS0, a new inertial measurement unit (IMU)1 equipped with a high-performance six-axis sensor. Volume production of the new product is scheduled for the spring of 2022.

Epson's IMUs, first launched in 2011, have been used in an array of customer applications, earning an excellent reputation for outstanding performance and quality. In recent years, IMU use has expanded into fields such as surveying and aerial and underwater video photography by unmanned systems, creating a growing need for more accurate position and attitude control. Accordingly, demand is rising for IMUs that offer greater precision, which is crucial in attitude control, and especially noise performance. The M-G370PDS0 has an angle random walk2 (short-term variation in output) of 0.03 ° / √h, which is half that of its predecessor, and can more accurately detect very slight changes in the attitude of equipment and systems, since they do not get lost in sensor noise. The small size, light weight, and low power consumption of this IMU will help customers make their own products smaller and lighter.
The new IMU maintains compatibility with earlier products (the M-G370/365/364/354), making performance upgrades easy.

• Equipped with a low-noise, high-performance sensor that maintains the high stability of Epson's previous IMUs
  Angle random walk of 0.03 °/√h
  Noise density: 2.5 (°/h)/√Hz
• Outstanding dynamic performance (scale factor non-linearity) for high-precision measurement, from static states to high-speed motion
• Maintains compatibility with earlier IMUs (the M-G370/365/364/354), sharply reducing customer development costs and evaluation time
• Low current consumption: 16 mA

• Unmanned vehicles (industrial drones, terrestrial vehicles, sea probes, etc.)
• Vibration damping for cameras, antennas, etc.
• Vibration, angle, trajectory measurement of industrial equipment, etc.
• Navigation systems (GNSS3, INS4, high-precision locators), etc.

• Product specifications

Allan variance
An indicator of sensor performance, the Allan variance indicates the stability of the static output. The horizontal axis shows the averaging time of data, and the vertical axis shows the distribution of the average value when separated by the average time. It is known that the slopes of the characteristics appearing in the Allan variance are -1, -1/2, 0, 1/2, and 1st power slopes, the Allan variance correlates with the noise density, and the noise density is the frequency. Allan variance is an indicator expressed in time. The smaller the value, the higher the stability and the better the performance.

1 Inertial measurement unit (IMU)
An IMU is a device that is used for sensing inertial motion. It is comprised of triaxial angular rate sensors and triaxial accelerometers.
2 Angle random walk
The part of the Allan variance with a slope of -1/2 is called the angle random walk. Since there is a correlation with white noise, increasing the average time decreases the value at -1/2 of the average time.
3 A global navigation satellite system (GNSS)
A satellite system that is used to pinpoint a geographic location anywhere in the world
4 Inertial navigation system (INS)
5 Gyroscopic sensor (angular rate sensor)
Measures the rotation angle (angular rate) of an object versus a reference axis per unit of time.
6 Bias instability
The part of the Allan variance that represents the horizontal (zero power) characteristic is called bias instability. It correlates with 1/f noise and is one of the important indicators of sensor potential.