Showing 4 results for Gyroscope
Ali Reza Rarivar, Mohammad Reza Zakerzadeh,
Volume 15, Issue 7 (9-2015)
Abstract
The purpose of this paper is design, construction and the control of a two-wheel self-balancing robot. For this purpose firstly, a literature study is carried out on the history of manufactured self-balancing robots and the researches which have been done so far in this area are reported. In addition, the robot chassis with consideration of the size and material is analyzed; and the dynamic equations of the robot are computed according to the designed chassis. Then, the robot inertial parameters are measured through different experimental tests and these parameters are used in the equations. Also, the derived equations are simplified and the transfer functions are evaluated for considering the stability of the robot. In this self-balancing robot, the simplified Kalman and complementary filters are used for identifying of the bias angle from the vertical position by combination of data obtained from accelerometer and gyroscope sensors. The PID controller and the robot transfer functions are simulated in MATLAB software. Then, the controller gains are obtained for the stability of the constructed robot. These gains are computed by PID tuning toolbox of MATLAB software as well as theoretically, and the results in each method have been compared with each other. Finally, the robot control electronic circuit is designed for analyzing the results through AVR microcontroller, while angle identification sensor is used.
Sayed Bagher Fazeli Asl, Seyyed Sajjad Moosapour,
Volume 17, Issue 5 (7-2017)
Abstract
In this paper, a fractional order backstepping type of fast terminal sliding mode controller is proposed for controlling a micro-electro-mechanical triaxial gyroscope with parameter uncertainty and internal and external disturbances. To compensate uncertainties and also incoming disturbances to the system used combination of sliding mode and backstepping robust nonlinear controllers. In the proposed approach, the sliding surface is selected in the form of fractional order. To increase the speed of convergence the system states to equilibrium points or the error to zero, the fast terminal sliding mode controller is used. The globally stability of the closed loop system will prove by Lyapunov stability theorem. Also in addition to the above proposal controller, a fractional order backstepping sliding mode controller designed and implemented for the gyroscope system. In order to evaluate the performance of designed controllers, these controllers compared with backstepping sliding mode controller and the backstepping fast terminal sliding mode controller. The results shown that the proposed controller has a faster transient response than the other controllers. Another advantage of the proposed controller is simplicity designed and implemented, increase system stability and acceptable tracking than the other controllers. Also unlike the other two controllers the chattering phenomenon completely removed in the fractional order designed controllers.
Mohammad Ali Mokhtari Amir Majdi, Masoud Tahani,
Volume 18, Issue 1 (3-2018)
Abstract
The aim of the proposed study is to investigate the size dependent behavior of the micro-bridge gyroscopes under the combined effects of instantaneous DC voltage and harmonic base excitation. To do so, modified couple stress theory is utilized to model the size-dependent behavior of the micro-gyroscope. To avoid resonance, viscous damping is used. Hamilton’s principle is then employed to derive the governing equations of motion. Afterwards, to convert the partial differential equations of motion to ordinary differential equations of motion, a Galerkin based single mode approximation is made. Then fourth-order Range-Kutta method is used to solve the governing equations of motion. To check the accuracy of the present model, the results are then validated through comparison with the available results in the literature and the comparison shows good agreements. In addition to the previous comparison, the present results are the validated through comparison with the results of COMSOL simulation. Furthermore, the effects of different parameters on the dynamic pull-in instability and amplitude of the vibrations are investigated. The observation shows that for the case of the harmonic base excitation, the system will be excited on two frequencies.
M. Mirzaei, I. Hosseini,
Volume 20, Issue 7 (6-2020)
Abstract
Initial bias is a random parameter in micro-electro-mechanical rate gyroscopes that changes with each turn on and turn off. The bias can be estimated by averaging in static condition or by extended Kalman filter in other conditions. In addition, this parameter is affected by temperature or linear acceleration. Curve fitting on the bias variation of micro-electro-mechanical rate gyroscopes due to thermal effects is a usual method for thermal compensation of these sensors. However, these approximate curves cannot completely compensate the effect of the thermal bias in long-time applications. In this study, it is tried to improve the calculating accuracy by a combination of extended Kalman filter and the results of these curves and using advantages of both methods. Also bias estimation is improved using the switching algorithm in accelerated motions by avoiding improper data in the estimation process. Experimental tests show the effectiveness of this method especially in long-time accelerated motions.
