According to a IHS iSuppli report, sensor fusion will eventually power the next generation of iPhone and iPad devices. A fused signal combines the outputs of three types of Microelectromechanical system (MEMS) motion sensors (gyroscopes, accelerometers and compasses) to improve the motion-based interface. Sensor fusion could enhance interfaces of any tablet or smartphone that uses a combination of a 3-axis accelerometer, 3-axis compass and 3-axis gyroscope to provide 9-axis sensor fusion.
Gyroscopes, accelerometers and compasses each provide a different form of motion sensing. However, each sensor type has its own limitations. The gyroscope suffers a strong drift over time, the compass is sensitive to electromagnetic interference and the accelerometer works better for slow movement than for fast motions. When the signals of the three sensors are fused together, each sensor function can compensate for the others’ inherent limitations. This will result in a motion sensing experience that is much faster, smoother and more accurate than is possible with each sensor used individually.
STMicroelectronics and InvenSense have already developed 9-axis sensor fusion engines that will enable original equipment manufacturers to implement the next-generation of motion-based interfaces in handset and tablets very soon. InvenSense’s combo sensor with embedded 9-axis sensor fusion now is in mass production for handsets and tablets. Handsets featuring STMicroelectronics’ iNEMO 9-axis sensor fusion engine will be available before the end of the year. Microsoft recently announced that it uses ST sensor fusion solution in Windows 8.
The Apple iOS and Android operating systems currently do not support full 9-axis integration from either a hardware or software perspective. On iOS, the output signal of the gyroscope is combined with that of the accelerometer to provide 6-axis fusion. On Android handsets and tablets that already have a gyroscope, only the raw data of the gyroscope is made available, with no combination with the accelerometer signal.