Shigemi Kurashima

Impulse Radio UWB Positioning System

We developed a positioning system using impulse radio UWB. The system consists of tags equipped only with transmitters and nodes provided with both transmitters and receivers. The system calculates the position of the tags using the TDOA method, whereby some nodes receive the UWB pulses sent from a tag. The tag is operated with a coin battery, and sends UWB pulses intermittently. The node sends the receiving time data to a PC via an Ethernet network for position calculation. We developed a time clock correction method, which is also required for the TDOA method. We will further evaluate positioning accuracy etc. in the future

A new electric power sensor module using magnetoresistive thin film

The authors describe an electric power sensor module using Ni-Fe magnetoresistive thin film. It is compact and microprocessor-interfaceable. The module is constructed of five components: a bridge-type magnetoresistive element used as a multiplier, a permanent magnet to provide some magnetic bias, a Permalloy case for a magnetic shield, an isolation transformer, and an amplifier. The thin-film element has good offset voltage/temperature characteristics and linearity. >