DMU41評価キット (DMU41 EVK) はIMUから出力される評価や開発テストに必要なデータを視覚化し、記録することができます。 DMU41 EVKは、ユーザーがDMU41インターフェースパラメータをホストシステムの要件に合わせて容易に再設定できる機能もございます。 DMU41EVKにIMU本体は含まれていません。別途購入いただく必要がございます。


Please explain DMU41's Delta Theta and Delta Velocity outputs

The basic inertial data output from DMU41 is angular rate (deg/s) and acceleration (g). Delta Theta and Delta Velocity outputs can be considered as a re-scaling of these basic data outputs. Provision and use of these values is an industry standard expected and used by many of our customers.

Delta Theta is in degrees and represents the degrees rotated over the sampling time of 5.0ms (or 1/200th of a second). For example, if the IMU axis is rotating at 200deg/s, Delta Theta will be 1 deg.

Similarly, Delta Velocity is a re-scaling from g to m/s, representing the change in velocity change over the same 5ms. The output in m/s is equal to the acceleration in g multiplied by 0.04903325 (divide by 200 and multiply by 9.80665, the latter being a universal measure of g).

What is the resolution of sensor data inside DMU41?

24-bit sigma delta analogue to digital convertors are used within DMU41. Compensation is carried out using single precision floating point mathematics. The DMU41 output message is also output as single precision floating point numbers. So, the mathematical resolution is very small indeed.

In practical terms, the minimum resolvable change is dominated by the sensor noise. With averaging, this can be improved to a point where the minimum resolvable change is dictated by the bias instability derived from Allan Deviation plots. For the gyro channels this is below 0.1 deg/hr and for the accelerometers, around 10μg.