Study of Vehicle Vibration for High-Performance Land Mobile Satellite Tracking System for Telemedicine

The land mobile satellite service (LMSS) is a key component of telemedicine and an important technology for grasping the status of a patient in an ambulance. However, rough road surfaces can destabilize satellite tracking and disturb data communications with the ambulance carrying the patient. Nevertheless, accurate estimates of the location of the vehicle at any given time and rapid reconfiguration of the tracking antenna based on past data can allow stable and effective data communications. This study examined positions characterized by large vibration amplitudes from past data on vehicle vibrations due to rough road surfaces as feature points to provide the vehicle system in advance with reference pitch angle vibration data. Drawing on reference vibration data for convolution and a cost function, The authors synchronized past data with real-time vibration data and accurately estimated the point at which the ambulance or other vehicle passes on the road. They also discuss limits on the range of vibrations that can be used for data synchronization. This study demonstrates that the present method enables high-precision estimates of vehicle location.