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.

Gyroscope Free Strapdown Inertial Navigation System Using rotation modulation

Abstract: In order to improve precision of Gyroscope FreeStrapdown Inertial Navigation System (GFINS), the idea of rotation modulation is adopted. And a new scheme of GFINS using 10 accelerometers is proposed, which is convenient for modulation all of the accelerometers. Through rotating around three orthogonal axes respectively, biases of all 10 accelerometers in the GFINS can be modulated by sinusoid and cosine functions. Procedures of both navigation calculation and rotation modulation in the 10-accelerometer based GFINS are derived. The scheme of GFINS and the rotation modulation method are simulated and verified. Simulation results show that precision of GFINS has been improved by more than 50% after rotation modulation.

Motion alignment method of inertial navigation system

Abstract: The present invention relates to the technical field of inertial navigation system, and in particular, to a motion alignment method of an inertial navigation system. The inertial navigation system is mounted on a motion carrier, and the method comprises: the inertial navigation system measuring rotation information and linear acceleration information of the inertial navigation system; the inertial navigation system synchronously receiving reference speed and location information of the inertial navigation system in a reference coordinate system provided by an external auxiliary information source; and the inertial navigation system performing data process on the rotation information and linear acceleration information as well as the reference speed and the location information, so as to obtain an attitude of the inertial navigation system in a body coordinate system of the current moment relative to the reference coordinate system. By means of the present invention, a motion alignment problem of the inertial navigation system in speed/location assistance of the reference coordinate system is effectively solved, and rapid attitude alignment is implemented without any attitude priori initial value.

A miniature, low-cost MEMS AHRS with application to posture control of robotic fish

Abstract: Inertial sensing is of paramount importance for a wide variety of navigation, guidance and control tasks. Historically, application of inertial sensing was limited to high-performance, high-cost aerospace and military fields. Recent MEMS technology has enabled miniaturization, mass production, and cost reduction of inertial sensors. This paper presents the development and robotic application of a miniature, low-cost AHRS unit based on MEMS technology. The sensor suite includes a tri-axis gyroscope, a tri-axis accelerometer and a tri-axis magnetometer. Fusion of the sensor measurements is achieved with a quaternion-based EKF algorithm. The performance of the AHRS unit is evaluated with a rotating platform and the results suggest numerous application possibilities. As an application case, the AHRS unit is employed for posture measurement of a robotic fish. By adjusting the lift forces produced by pectoral fins on both sides, the robotic fish can maintain desired posture during highspeed swimming.

Acceleration measurement improvement by application of novel frequency measurement technique for FDS based INS

Abstract: Inertial navigation systems have as sensing elements gyroscopes and accelerometers. The accelerometers with a frequency output domain have some outstanding characteristics like output of quasi-digital signals, high sensitivity, high resolution, wide dynamic range, anti-interference capacity and good stability. This work explains how this sensor works inside an inertial navigation unit and how the measurement of acceleration can be improved through a novel frequency measurement principle. Also it is examined how in a common accelerometer the frequency measurement by principle of rational approximation can be easily implemented with low cost-affordable components. The error analysis in the measurement process is introduced.

Fluidic inertial platform

Abstract: An improved gyro stabilized inertial platform is provided which employs fluidic concepts in the entirety of its operation. The inertial platform to be described may serve as a mounting base for accelerometers, distance measuring devices, and the like. It may also provide angular read-out signals for pitch, roll and yaw of the vehicle in which it is installed. The fluidic controlled inertial platform of the invention operates at all attitudes, and it is particularly useful in aircraft, missiles and other space vehicles which are subject to abrupt flight maneuvers.