Inertial reference unit

About: Inertial reference unit is a research topic. Over the lifetime, 1306 publications have been published within this topic receiving 22068 citations. The topic is also known as: IRU.

Initial Alignment for a Doppler Velocity Log-Aided Strapdown Inertial Navigation System With Limited Information

Abstract: This paper proposes an ingenious alignment scheme for a Doppler velocity log-aided strapdown inertial navigation system with only the initial velocity and position information. The proposed scheme decomposes the task into two tightly coupled subproblems. First, an optimization-based coarse alignment (OBCA) method is developed to derive the constant attitude at the very start of the alignment. During the OBCA process, the required velocity and position are all approximated using their initial values. Second, a nonlinear-filtering-based fine alignment (NFFA) is developed to refine the attitude and calculate the real-time velocity and position. In an NFFA, the standard inertial navigation equations are used directly as the process model, which, therefore, can track the vehicle maneuverability during the alignment period. The NFFA is carried out again from the very start, initialized with the roughly known attitude by OBCA and the known initial velocity and position information. This scheme necessitates the recording of the sensor data during the OBCA. The experimental results show that the proposed method can not only align the attitude to high precision within very short time, but also determine the velocity and position with satisfied accuracy.

Rapid Fine Strapdown INS Alignment Method under Marine Mooring Condition

Abstract: In order to solve the strapdown inertial navigation system (INS) alignment problem under the marine mooring condition, the rapid strapdown INS fine alignment method is proposed. This method uses the gravity in the inertial frame to deal with the lineal and angular disturbances. Also the forward and backward processes for strapdown INS calculation and filter estimation are designed. Making use of the forward and backward processes to repeatedly process the saved inertial measurement unit (IMU) data sequence could quickly obtain the initial strapdown attitude matrix. Simulation and trial test validate the performance of the proposed rapid fine strapdown INS alignment.

Modeling and Calibration of Inertial and Vision Sensors

Abstract: This paper is concerned with the problem of estimating the relative translation and orientation of an inertial measurement unit and a camera, which are rigidly connected. The key is to realize that this problem is in fact an instance of a standard problem within the area of system identification, referred to as a gray-box problem. We propose a new algorithm for estimating the relative translation and orientation, which does not require any additional hardware, except a piece of paper with a checkerboard pattern on it. The method is based on a physical model which can also be used in solving, for example, sensor fusion problems. The experimental results show that the method works well in practice, both for perspective and spherical cameras.

Vision-aided inertial navigation for flight control

Abstract: Published in the Journal of Aerospace Computing, Information, and Communication, Vol. 2, September 2005

Augmented reality computing with inertial sensors

Abstract: Example embodiments of the present disclosure provide techniques for receiving measurements from one or more inertial sensors (i.e. accelerometer and angular rate gyros) attached to a device with a camera or other environment capture capability. In one embodiment, the inertial measurements may be combined with pose estimates obtained from computer vision algorithms executing with real time camera images. Using such inertial measurements, a system may more quickly and efficiently obtain higher accuracy orientation estimates of the device with respect to an object known to be stationary in the environment.