Improving MEMS-IMU/GPS integrated systems for land vehicle navigation applications

Abstract

The cost of inertial navigation systems (INS) has decreased significantly during recent years using micro-electro-mechanical system technology in production of inertial measurement units (IMUs). However, these IMUs do not provide the accuracy and stability of their classical mechanical counterparts which limit their applications. Hence, the error control of such systems is of the great importance which is achievable using external information via an appropriate fusion algorithm. Traditionally, this external information can be derived from global positioning system (GPS). But it is well known that GPS data availability and accuracy are vulnerable to signal-degrading circumstances and satellite visibility. We introduce a standalone attitude and heading reference system (AHRS) algorithm which employs the IMU and magnetometers data in an averaging manner. The averaging method is different from a simple smoothing procedure, since it takes the rotations of the platform (during the averaging interval) into account. The proposed AHRS solution is further used to provide additional attitude updates with adaptive noise variances for the integrated INS/GPS system during GPS outages via a refined loosely coupled filtering procedure, making the error growth well restrained. Functionality of the algorithm has been assessed via a field test. The results indicate that the proposed procedure outperforms the traditional integration scheme in different situations, while the latter almost loses track of the movements of the vehicle after 60-second GPS outages.

3D Digitisation of Large-Scale Unstructured Great Wall Heritage Sites by a Small Unmanned Helicopter

“…where R wb and t are the rotation matrix and translation matrix from the GPS/IMU/altimeter integrated system, using a similar technique presented in [25].  is the rotation angle of the pan-tilt (3D scanning using a 2D laser range scanner and a pan-tilt).…”

“…where wb R and t are the rotation matrix and translation matrix from the GPS/IMU/altimeter integrated system, using a similar technique presented in [25]. ) for a Great Wall segment are matched and fused together using an ICP algorithm [26] based on the sequential and lateral constraints among the laser scans shown in Figure 2a.…”

A MEMS-IMU Assisted BDS Triple-Frequency Ambiguity Resolution Method in Complex Environments

“…In fact, the original carrier wavelength of GNSS is about 20cm, while the prediction error of some low-cost Microelectromechanical System-Inertial Measurement Unit (MEMS-IMU) in within 1 epoch (1s) of GNSS for geometric distance is more than half of the original carrier wavelength [27]. Obviously, the accuracy of the low-cost MEMS-IMU does not meet the requirement to fix the original carrier ambiguity by rounding.…”

Concept of AHRS Algorithm Designed for Platform Independent Imu Attitude Alignment

“…Micro systems are used in a variety of fields to increase productivity, improve functionality and reduce their operating costs. Attitude heading reference system (AHRS) build on MEMS IMU (Inertial Measurement Unit) is one of mentioned features used in applications such as underwater navigation (Emami & Taban, 2017), motion capture (Sasani, 2016), augmented reality (Yang Ling, 2016) and aircraft guidance (Tang Daquan, 2016). As well as a support for obtaining the initial orientation of IMU for the purpose of IMU/GPS integrated navigation.…”