Papers by Keyword: Gyroscope

Abstract: Because of the imperfections of the manufacture, the quadrature and offset error become the major concerns in Micro-gyroscopes for high performance. So in order to eliminate and minimize quadrature and offset error, various methods employing improvement of manufacture and suppression circuitry have been put forward to improve the performance. And this paper summarize most of the suppression methods those who have better performance.

Abstract: To enhance the accuracy of stabilization, this paper presents a design of two-axis horizontal stabilization platform system, which is based on the combination of gyroscope and inclinometer sensors. The self-correction control method is put forward to solve the system error caused by gyroscope zero drift in traditional gyro stabilized platform, which works in the way of revising the gyroscope zero coefficient, according to the real-time attitude information feed backed by inclinometer sensors fixed in objective platform.

Abstract: Walking is one of the basic human activities. Several well-defined, motion tracking systems have been used for gait analysis. However, these systems such as the optical motion tracking system are very expensive and limited to laboratory usage. Recently, microelectromechanical systems (MEMS)-based inertial sensors have made it possible to overcome these disadvantages. The aim of this study was to identify gait events and the supporting leg by measuring the mediolateral swing angle. An inertial sensor unit with a 3-axis accelerometer and 2-axis gyroscope was attached to the subject’s lower trunk using an elastic band. Five, healthy and young (20–29 yrs.) subjects participated in this experiment. Each walked twice along a straight, 25-m path at three different speeds. During each trial, the sensor transmitted signals to a PC via Bluetooth technology. In this study, gait events and the supporting leg were identified using the peak and sign of the mediolateral swing angle. The mediolateral swing angle was calculated using the integrated gyroscope signal. For comparison, a well-defined spatiotemporal gait analysis technique was also applied. In this reference method, the gait event was identified with the last peak of the vertical acceleration before the sign change from positive to negative. The supporting leg was identified using the sign of the mediolateral acceleration double integration. Identification of the supporting leg was difficult in the reference method because of the offset and gravity components in the mediolateral acceleration. However, the proposed method reported here, showed stable identification of gait events and the supporting leg. This study could be expanded to more detailed gait analysis with the additional fusion of a 3-axis acceleration, gyroscope and magnetometer.

Abstract: 3-D Imaging refers to a technique for creating or enhancing the illusion of depth in an image by presenting two offset images separately to the left and right eye of the viewer. Anaglyph generation is one of the most cost effective methods of spectroscopic 3D imaging. Almost all human activities are related to some motion. In this paper we discuss about a method to control realtime anaglyph images based on the movement of MEMS inertial sensors. The aim is to track the movements of the sensor and accordingly build a system that controls anaglyph images simultaneously. A system to control anaglyph images using MEMS was developed at the end of experiment successfully. This can be further enhanced to develop various systems based on motion tracking and image creation, like human body modeling and gesture recognition and also to other 3D imaging techniques.

Abstract: Human fall in the elderly population is one of the major causes of injury or bone fracture: it can be a cause of various injuries (e.g., fracture, concussion, and joint inflammation). It also could be a possible cause of death in a severe case. To detect human fall, various fall detection algorithms have been devised. Most fall detection algorithms rely on signals from a single accelerometer or gyroscope and use a threshold-based method to detect the human fall. However, these algorithms need careful adjustment of a threshold for each subject and cannot detect the direction of falls. In this study, we propose a novel fall recognition algorithm using a pair of a tri-axial accelerometer and a tri-axial gyroscope. Our fall recognition algorithm utilizes a set of augmented features including autoregressive (AR) modeling coefficients of signals, signal magnitude area (SMA), and gradients of angles from the sensors. After Linear Discriminant Analysis (LDA) of the augmented features, an Artificial Neural Nets (ANNs) is utilized to recognize four directional human falls: namely forward fall, backward fall, right-side fall, and left-side fall. Our recognition results show the mean recognition rate of 95.8%. Our proposed fall recognition technique should be useful in the investigation of fall-related injuries and possibly in the prevention of falls for the elderly.

Abstract: Micromachined modal gyroscope based on elastic body (MMGEB) is a novel kind of rotating rate sensor, which has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. In this paper, the model and working mechanism of MMGEB are proposed first. The modal analysis, the harmonic analysis and Coriolis analysis for the model by the finite element method (FEM) have been conducted. The research in the paper provides theoretical foundation for realizing this micromachined gyroscope.

Abstract: This paper reports a novel kind of solid micro-gyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG). PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. A set of quantitative indicators were developed to optimize the operation mode and corresponding device size was obtained. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operation mode needed. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition.

Abstract: When the power transmission line is covered with ice and snow in the winter, the galloping of power line often happens. A new type of damper used for preventing galloping of the electric power transmission line has been put forward and received patent license of China. The damper like fan blades, which can rotate about the axes of the power line at 360°, is fixed on the overhead power line. It hangs on the line when there is no wind. The blade rotates at high speed in the plane vertical to wind when there is wind, which results in a gyroscope. The theorem of angular momentum of a gyroscope is used in the design of the damper. Model tests of this kind of damper have been carried out and the results show that it is successful in preventing galloping of the cable model.

Abstract: In this paper, design, analysis and simulation of microelectromechanical system (MEMS) based inertial sensor type of tuning fork micro gyroscope have been presented. CoventorWare has been used for design and simulation. The proposed design has improved the performances and structure for small vibration amplitude to minimize the mechanical crosstalk. Simulation results show that the capacitance in sense mode, which is detected by variable-gap capacitors, is equal to 2.68 pF in each side of sense mode. Oscillations in drive and sense electrodes with 1-DOF and proof mass with 2-DOF ensure that the proposed model has no common mode that causes mechanical crosstalk.

Abstract: Based on the principle of tracking inversion points method for north-finding, the tracking inversion points method without torque is presented with a tracking and controlling system. According to the gyroscope’s cursor signal captured in real time, the theodolite can be turned round by the electric turntable to follow the swing of the main axis of gyroscope. After simple calculating, the coarse north can be obtained. The influence of changed torque of hang spring is reduced and the measurement precision is improved. It has been proved through experiments that the coarse north can be obtained in a large range by the tracking inversion points method without torque. The experiment shows that the measurement precision is superior to 30′ and it costs no more than 7minutes to obtain the coarse north-finding.