Miniaturised inertial measurement units (IMU) for wireless sensor networks and novel display interfaces

This paper presents the work done in designing and fabricating miniaturised inertial measurement units (IMU´s) for 2 distinct applications: a 25mm form factor wireless sensor network platform and a novel display interface. The 2 IMU´s developed for the novel display interface are a low-dynamics sensor module that includes a 3-axis magnetometer and a 2-axis inclinometer and high-dynamics sensing module, which consists of a complete strapdown inertial measurement system and a compass module. The IMU designed for the wireless sensor network platform is based on the high-dynamics sensing module but realised in a 25mm times 25mm panel. This panel increases the sensory capabilities of each network node allowing the orientation of each node to be completely realized. As part of the NMRC´s technology development there is a drive towards wireless nodes for sensor networks of volume in the sub 5mm region. As a stepping stone towards this goal, the target objectives for the development of a 25mm cube module were to develop, a low volume prototyping and experimentation platform. This is for use as a platform for sensing and actuating through various parameters, for use in scalable, reconfigurable distributed autonomous sensing networks in a number of research projects currently underway in the NMRC. This paper outlines the development of the system with particular emphasis on the IMU layer. The total system is packaged in a modular 25mm cubed form factor which gives the capability for the module to be utilised in a wide variety of projects incorporating a multitude of actuators/sensors in miniaturised, mobile, autonomous systems.