Aaron Ault

Recommended Tolerances for Magnetometer Orientation and Field Calibration Procedure

Magnetometers are increasingly being deployed for traffic detection in both fixed wired and wireless installations around the United States. Magnetometers respond to local magnetic field disturbances from the ambient magnetic field of the earth, and this response may be expected to depend on the relative orientation of the magnetometer axis and the direction of the earths magnetic field lines at the point of deployment. As documented by U.S. Geological Survey (USGS) maps, the declination and inclination of the earths magnetic field vary significantly over the continental United States, yet there is no traffic engineering design literature characterizing the effect of geographic magnetic field variation on magnetometer detection performance. This study briefly reviews the scientific theory, identifies the magnetometer installation parameters of most importance, and characterizes their impact on performance. In addition, recommendations are based on USGS data, which can be used to develop specifications for installation, testing, and acceptance of magnetometer-based detection technology. Finally, a simple procedure for field calibration of sensor orientation in a conduit to near-optimal rotation angle is presented.

Rich Immersive Sports Experience: A Hybrid Multimedia System for Content Consumption

Recent widespread use of multimedia-enabled devices has prompted the industry to look at systems which can provide a distributed, synchronized content consumption experience. Motorola has partnered with Purdue Universitys eStadium project to create the Rich Immersive Sports Experience (RISE) project. RISE is an attempt to design and develop such a system geared toward use in suites in Purdues Ross-Ade football stadium. The core of the system is Motorolas Media Bundle technology that represents content and timing information for the TV screens and smart phones used in the system. This paper discusses the design process for the RISE system, how Media Bundles are used, and our solutions to issues of synchronization, speed, reliability, and scalability.

Wireless Load Weight Monitoring Via a Mobile Device Based on Air Suspension Pressure

A system was designed and tested to measure pressure in the airbag suspension components of an over-the-road tractor trailer and use those signals to wirelessly display load weight. Three subcomponents (a HID -- human interface device and two DPUs -- digital processing units) were required and communicated using Zigbee wireless devices. Except for a region directly in front of the cab, the unit transmitted weights up to 45 m. Effect of number of calibration points on system accuracy was evaluated.