In General Relativity the Principle of General Covariance allows one to describe phenomena by means of any convenient choice of coordinate system. In this paper it is shown that the geodetic precession of a gyroscope orbiting a spherically symmetric, nonrotating mass can be recast as a Lense-Thirring frame-dragging effect, in an appropriately chosen coordinate frame whose origin falls freely al...

Owing to the imposed coupling accelerations such as quadrature error and cross-axis perturbation, the micro-machined gyroscope could not be unconditionally retained at resonant mode. Once the preset resonance is not sustained, the performance of the micro-gyroscope is accordingly degraded. In this paper, a direct model reference adaptive control loop which is integrated with a modified disturba...

In this paper, the adverse effects of variation in operating temperature, on the performance of PM sensors and actuators used in aerospace and military applications, and methods to provide inherent temperature compensation by design, are presented. Unlike the conventional shunt compensation, the proposed method uses the direct leakage path between two neighboring permanent magnets. This novel m...

Activity Recognition based on the sensors available on a smartphone is becoming a widely researched area. Smartphones are capable of collecting vital data from the sensors. These sensors include acceleration sensors, position sensors, vision sensors, audio sensors, temperature sensors and direction sensors. In this paper we propose a filter based sensor fusion system that uses smartphones accel...

We calculate the precession of a gyroscope at rest in a Bondi spacetime. It is shown that, far from the source, the leading term in the rate of precession of the gyroscope is simply expressed through the news function of the system, and vanishes if and only if there is no news. Rough estimates are presented, illustrating the order of magnitude of the expected effect for different scenarios. It ...

Obtaining the approximation of rotation rate form a Z-Axis MEMS gyroscope is a challenging problem. Currently, most commercially available MEMS gyroscopes are operating in an open-loop for purposes of simplicity and cost reduction. However, MEMS gyroscopes are still fairly expensive and are not robust during operation. The purpose of this research was to develop a high-performance and low-cost ...

In this paper, one dimensional drift free attitude estimation system using accelerometer and gyroscope was studied. The proposed system fuses data from accelerometers and gyroscopes by means of a Kalman filter. A PIC microcontroller is used for estimating the angle value in the proposed system. Moreover, this controller does all data acquisition and interfacing tasks. The experimental results a...

This paper introduces the working principle of the two-stage decoupled micro-machined gyroscope, and establishes the vibration equation of the driving mode. By solving the differential equation, the analytical solution and the amplitude-frequency characteristics of the driving mode are obtained. By the visual measurement based on high-speed photography and the post image processing, it measures...

Driving mode of MEMS (Micro-Electro-Mechanical Systems) Vibratory Gyroscope is discussed in the paper. We analyze the closed-loop circuit of MEMS gyroscope from two aspects of amplitude fixed and frequency locking. In the amplitude fixed circuit, Automatic Gain Control (AGC) circuit is employed to update the amplitude of the driving force, together with a PI controller to improve the accuracy a...

Forces due to propulsion should approximate forces due to hydrodynamic drag for animals horizontally swimming at a constant speed with negligible buoyancy forces. Propulsive forces should also correlate with energy expenditures associated with locomotion-an important cost of foraging. As such, biologging tags containing accelerometers are being used to generate proxies for animal energy expendi...