Todd Petersen

Planar Compliances of Symmetric Notch Flexure Hinges: The Right Circularly Corner-Filleted Parabolic Design

This study proposes a general analytical compliance model for symmetric notch flexure hinges composed of segments with constant width and analytically defined variable thicknesses. Applying serial combination and longitudinal/transverse mirroring of base segments, the in-plane compliances of the full flexure are obtained as functions of one quarter-flexure compliances. The new right circularly corner-filleted parabolic flexure hinge is introduced as an illustration of the general analytical modeling algorithm. Experimental testing and finite element simulation confirm the analytical model predictions for an aluminum flexure prototype. The planar compliances sensitivity to the relevant geometric parameters is also studied.

Comparison of Experimental Measurements of Current Distribution in a Flat Conductor With Simulated Results From the Partial Inductance Method

The current distribution in a stripline is calculated by using a partial inductance formulation to produce a circuit model that is evaluated with the SPICE program. The program also simulates the signals produced in a recently invented magnetic current probe. Measurements using the current probe have been made over a wide range of frequencies and compared to the calculations. Agreement is achieved within the measurement accuracy. This technique can be used directly to find current distributions with pulse excitations.

907-Plow - Anchorage's approach to real-time snowplow tracking

We present a novel approach to tracking heavy machinery used as snowplows for the improvement of commuter safety. We have developed hardware designed for universal installation in snowplows that relay location and plow position data without human interaction over a cellular network to the real-time traffic simulator FreeSim [1-3]. FreeSim analyzes the data and overlays it onto Google Maps [4] by color-coded lines displaying the time elapsed since the roadway was last plowed. The plow position is determined utilizing magnetic fields between the plow blade and a stationary mount on the snowplow. By publicly displaying this information we aim to educate the end user with the current reported road conditions.

Imaging sonar tracking of salmon for size and tail beat frequency

In order to set sustainable harvest limits on anadro-mous fish, fishery managers require a method for estimating return numbers of individual species. As seasonal migration times of several returning species may overlap, simple fish counts are insufficient. This paper presents an algorithm for tracking fish crossing an insonified area using an extended Gaussian mixture probability hypothesis density filter as well as analyzing both their lengths and the frequency of their tail beats. The combination of the two provides a useful estimate of the return size of a given fish species when combined with seasonal return timing. The algorithm is tested against data collected using a dual frequency imaging sonar on the Kenai River in Alaska and compares favorably to estimates made by manual inspection and sub-sampling.