The next general meeting of the ION North Star Section will be Tuesday, Oct 3th in Mechanical Engineering Building Room 1130 at the University of Minnesota (http://campusmaps.umn.edu/tc/map.php?building=265), starting at 6:00 PM. Tom Jakel of the University of Minnesota will be the keynote speakers. Tom will give a presentation entitled “Use of Trunk Roll Constraint to Improve Heading Estimation in Pedestrian Dead Reckoning Navigation Systems.” This presentation is co-authored with Demoz Gebre-Egziabher of the University of Minnesota Sandwiches and beverages will be served during the Meet and Greet portion of the meeting. Please email us at firstname.lastname@example.org, if you plan to attend. Agenda: 6:00 Meet and Greet 6:30 Keynote Speaker 7:45 Section Business 8:00 Final remarks Keynote presentation: Title: Use of Trunk Roll Constraint to Improve Heading Estimation in Pedestrian Dead Reckoning Navigation Systems: Authors: T. Jakel ,Honeywell; D. Gebre-Egziabher, University of Minnesota, Twin Cities Abstract: A method for increasing the accuracy of the heading estimate in IMU-based personal navigation system will be discussed. Heading estimation without use or emittance of any external electromagnetic signals for reference is a critical but challenging component of pedestrian dead reckoning navigation systems. In the environments where these systems are normally used, electromagnetic signals may be unavailable. custodia iphone outlet Even when available, these signals may be intentionally or inadvertently corrupted for an extended period of time. custodia samsung s8 In such environments, the navigation system must determine initial heading through gyro-compassing or using information from other sensors such as magnetometers or radio frequency multilateration systems. iphone 7 custodia outlet Subsequently, these external measurements may be used periodically to arrest the heading drift when signal conditions and trajectory allow it. Due to the size, weight, power, and cost constraints imposed on a pedestrian navigation systems as well as current IMU performance limitations, the gyroscopes used to determine heading have significant drift. To deal with this drift problem without having to rely on information external to the navigator, the use of human motion models as constraints has been proposed. cover samsung custodia For example, one such motion model used as a constraint predicts the onset of turning motion of the pedestrian by thresholding the outputs of the yaw gyroscope. For example, unless a significant yaw rate is detected, the user is assumed to be moving in a straight line. samsung custodia outlet This gyroscope is also integrated to determine the change in angle over the period of turning, such constraints delay the open loop gyro integration time onset which increases the accumulated drift, especially for sudden turns, which can occur during indoor navigation. The use of the trunk roll angle and angular rate are presented as additional signals used to predict the onset of pedestrian turning motion. The signature of the trunk roll motion relative to foot and body reorientation is described. Integration of the trunk roll motion based turning prediction method with existing yaw threshold methods is described and analyzed. Experimental data from ten subjects was captured in a gait laboratory, where a Vicon motion tracking unit is used for validation. In these experiments the subjects were instrumented with five low cost IMU units; one on the right foot, one on the right ankle, one on the right thigh, one on the lower back and one on the chest. The outputs of the foot-mounted IMUs are used with Zero Velocity Updates (ZUPTs) to determine the subject’s gross body motion. The torso mounted IMUs are used to sense upper body motion and this information is used in activating the trunk-roll constraint. The analysis of experimental data demonstrates that trunk rolling motion precedes heading change and can be used together with yaw rate threshold methods to predict the onset of a turning motion.