Research Online: Integer ambiguity resolution in GPS/INS, UAV multiple laser-inertial nav

Illustration of the contemplative real-time (CRT) window measurement timeline. The window contains a prior for the initial state, K GPS measurements, and many IMU measurements between each pair of GPS measurements. IMU measurement times are indicated as dots on the timeline. All of these items yield constraints on the estimated trajectory ˆX during the CRT window.

Integer ambiguity resolution in multi-epoch GPS/INS

A novel integer ambiguity resolution approach over a time window of GPS/IMU data enhances the reliability of obtaining high-accuracy position estimation, using carrier phase measurements, even in challenging environments. The method focuses on reducing computational cost. The achievable savings should be on the order of 104, while 600 has been demonstrated. The theoretical approach shows that the cost function can be decomposed into one part that determines the shape and vicinity of the trajectory, but is insensitive to the carrier phase integers and a position shift vector, and a second part that is sensitive to the carrier phase integer and can be solved to determine the required position shift so that the location of the trajectory is accurately known.

By Yiming Chen, Sheng Zhao, and Jay A. Farrell, University of California, Riverside.

Presented at IEEE Transactions on Control Systems Technology 2015.

UAV multiple laser-inertial nav

Indoor Flight Demonstration Results of an Autonomous Multi-copter Using Multiple Laser Inertial Navigation, by Adam Schultz, Russell Gilabert, and Maarten Uijt de Haag, Ohio University.

This paper discusses aspects of autonomy on a small-size multi-copter UAS for challenging environments, addresses in detail the modified proposed navigation algorithm, its integration with the flight controller for autonomous flight and the actual implementation on the multi-copter platform. The paper includes flight test results of a multi-copter UAS operating in an outdoor/indoor environment and shows some navigation and mapping performance results.

Presented at ION-ITM 2016.