Gotowa bibliografia na temat „Electromagnetic ring gyroscope”

Presented is a control system that is designed for an electromagnetic vibrating ring gyroscope. Three functions are realized in this control system. First, fixed amplitude of the drive-mode is guaranteed by using a variable gain control (VGC). Test result shows that the stability of the drive-mode amplitude is about 0.4% in the range of-40°C~80°C. Second, suitable drive-frequency is set up. And experimental result indicates that the suitable drive-frequency should be set between the drive-and sense-mode resonance frequencies, which results in a superior sensitivity. Third, regulation module is employed to further improve the performance.

This paper presents the design, fabrication and tests of an electro-magnetic vibrating ring gyroscope based on a control system and SOI-MEMS technology. The control system, including variable gain control (VGC), drive-frequency control and regulation module, is designed to improve mode matching. In device fabrication, and buffered hydrofluoric acid (BHF) solution is used to remove the buried oxide layer and release the suspended spring. Meanwhile, a compensate disk and negative photo resist (AZ303) coated on the backside of the wafer are employed to weaken the Lag and Footing effects during through-wafer etching process. The design of the gyroscope is optimized by FEA simulation and the fabricated devices show a rather good performance.

This study presented an overview of current developments in optical micro-electromechanical systems in biomedical applications. Optical micro-electromechanical system (MEMS) is a particular class of MEMS technology. It combines micro-optics, mechanical elements, and electronics, called the micro-opto electromechanical system (MOEMS). Optical MEMS comprises sensing and influencing optical signals on micron-level by incorporating mechanical, electrical, and optical systems. Optical MEMS devices are widely used in inertial navigation, accelerometers, gyroscope application, and many industrial and biomedical applications. Due to its miniaturised size, insensitivity to electromagnetic interference, affordability, and lightweight characteristic, it can be easily integrated into the human body with a suitable design. This study presented a comprehensive review of 140 research articles published on photonic MEMS in biomedical applications that used the qualitative method to find the recent advancement, challenges, and issues. The paper also identified the critical success factors applied to design the optimum photonic MEMS devices in biomedical applications. With the systematic literature review approach, the results showed that the key design factors could significantly impact design, application, and future scope of work. The literature of this paper suggested that due to the flexibility, accuracy, design factors efficiency of the Fibre Bragg Grating (FBG) sensors, the demand has been increasing for various photonic devices. Except for FBG sensing devices, other sensing systems such as optical ring resonator, Mach-Zehnder interferometer (MZI), and photonic crystals are used, which still show experimental stages in the application of biosensing. Due to the requirement of sophisticated fabrication facilities and integrated systems, it is a tough choice to consider the other photonic system. Miniaturisation of complete FBG device for biomedical applications is the future scope of work. Even though there is a lot of experimental work considered with an FBG sensing system, commercialisation of the final FBG device for a specific application has not been seen noticeable progress in the past.

This paper investigates the dynamic behaviour of a rotating ring that forms an essential element in ring-based vibratory gyroscopes that utilize oscillatory electromagnetic forces. Understanding the effects of nonlinear actuator dynamics is considered important for characterizing the dynamic behavior of such devices. A suitable theoretical model to generate nonlinear electromagnetic force that acts on the ring structure is formulated. In order to predict the dynamic behaviour of a ring system subjected to external excitation and body rotation, discretized equations obtained via Galerkin’s procedure is employed to investigate the time as well as frequency response behavior. Dynamic response in the driving and the sensing directions are examined via time responses, phase diagram, Poincare’ map and bifurcation plots when the input angular motion and the nonlinear electromagnetic force are considered simultaneously. The analysis is envisaged to aid ongoing experimental research as well as for providing design improvements in Ring-based Gyroscopes.

The successful industrial application of flexible rotors supported on active magnetic bearings (AMBs) requires careful attention not only to rotordynamic design aspects, but also to electromagnetic and feedback control design aspects. This paper describes the design, construction and modeling process for an AMB test rig which contains a 1.23m long flexible steel rotor, with a mass of 44.9 kg and two gyroscopic disks. The rotor typifies a small industrial centrifugal compressor designed to operate above 12,000 rpm and the first bending natural frequency. There are four AMBs — two AMBs at the shaft ends to support the shaft with a combined load capacity of 2600N and two additional AMBs at the mid and quarter spans to allow for the application of simulated destabilizing fluid or electromagnetic forces to the rotor. Simulated aerodynamic cross coupling stiffness values are to be applied to the rotor through these two internal AMBs with the goal of developing stabilizing robust controllers. The unique design allows multiple support and disturbance locations providing the ability to represent a variety of machine configurations, e.g., between bearing and overhung designs. The shaft transfer function in lateral movement has been developed with finite element model and then verified by experimental frequency response measurements. Models for the power amplifiers, position sensors, signal conditioning and data converter hardware were developed, verified experimentally and included in the overall system model. A PID controller was developed and tuned to levitate the rotor and enable further system characterization.

Abstract Borehole survey is a very crucial element in drilling a well. The data will be utilized during all phases of drilling campaign – planning, execution, and post drilling. During planning, borehole survey data are critical to avoid well collision with nearby well. It is done through correct survey of offset data and correct toolcode assigned to the survey program together with database QAQC. While actual drilling itself, the survey will be closely monitored to ensure that the well is clear from any collision risk. The survey will guide the directional driller to steer to the geological objectives and hit the geological target with high confidence. Finally, once drilling has been completed, the survey data will be tied in to geological and reservoir models and to be used for planning of future campaign. Since the last forty years, measurement while drilling (MWD) surveys have been the backbone for the borehole surveying. MWD surveys are in fact a measurement/surveying while static condition not during online drilling itself. Industry has experienced multiple evolution of MWD surveys, but none of the evolutions lead to the survey in dynamic conditions. Realizing the true potentials of getting the survey data in dynamic condition, it will help the rigsite operation to minimize the risk associated with longer stationary time. With this definitive dynamic survey while drilling can accurately be taken while drilling, moving, rotating and sliding, it had proven to eliminate the survey-related rig time per survey and reduced associated drilling risks, therefore improves the overall drilling efficiency. The service incorporates the new telemetry innovations that enables up to 20bps and the advance drilling dynamics design includes three-axis shock and vibration and turbine power. Additionally, geological accuracy is refined using gamma ray and electromagnetic resistivity in combination with continuous six-axis direction and inclination sensors. The deployment of this dynamic-survey-while drilling service had enable the operator to acquire precise BHA location data at a higher frequency during drilling for improved decision making, eleiminating up to 15 min of survey-related rig time per survey. This also eliminated the need for additional pump cycles along with their associated washouts, stuck pipe risks and other directional drilling difficulties. The ultimate yield is definitive dynamic surveys, delivering real-time borehole conditions that reduce time to TD. This paper also covers the advance procedure of taking definitive non-static survey. The challenge is to ensure the non-static data to be sent continuously and meet survey acceptance criteria. Hence, the continuous survey data can be qualified as definitive survey and assigned a proper toolcode. To validate this continuous survey measurements, the author analyses the survey comparison with conventional static survey and gyroscopic survey results in the field test runs. The author will then present the conclusions, further work recommendations in which this wellbore surveying advancement can transform the well construction process with great impact in drilling efficiency, as well as minimizing the stuck pipe risk and wellbore uncertainty.