Monthly Archives: March 2016

Estimating Gyro Bias – Calculating Orientation pt5

Estimating Gyroscope Bias MEMs gyroscopes never read zero when they are stationary. There is always a small measurement offset. This gyro bias is often related to temperature, so warming up the gyro with a heat gun will cause the bias to change – sometimes quite dramatically. The most common way to remove gyro bias is… Read More »

Modelling Acceleration – Calculating Orientation pt4

Modelling Acceleration Dynamics The accuracy of an orientation sensing system can generally be improved if the acceleration dynamics of the system can be estimated. Accelerometers are commonly used in orientation sensing systems because they can sense gravity (the down vector). They also measure acceleration due to changes in motion – of course. Modelling acceleration dynamics… Read More »

Magnetometer Calibration – Calculating Orientation pt3

Magnetometer Calibration Calibrating magnetometers is critically important. Without a good mag cal, you’ll get rubbish out of your magnetometers. Fortunately it isn’t that hard to do a basic calibration. If you were to create a scatter plot of your magnetometer readings, it would probably show both hard iron and soft iron errors. An ideal plot… Read More »