The Design of a New Biaxial Decoupled Resonant Micro-Accelerometer

2013 ◽  
Vol 744 ◽  
pp. 466-469 ◽  
Author(s):  
Bo Yang ◽  
Hui Zhao ◽  
Bo Dai

A new biaxial decoupled resonant micro-accelerometer is researched. The new biaxial resonant micro-accelerometer consists of four same tuning forking resonators, four pair of decoupled beams, four lever mechanisms and a proof mass. The decoupling between two orthogonal axes is realized by the decoupling beams, which will benefit to isolate two axes acceleration detection. The simulation is implemented to verify the basic principle by the Ansys. The simulation results prove that the effective frequencies of two acceleration sensitive modes are 3.699 kHz and 3.718 kHz separately. Two pair of resonator modes which are 23.893 kHz, 23.946 kHz, 26.974 kHz and 26.999 kHz separately have about 3kHz difference in frequency in order to prevent the mutual interference. And the interference modes are isolated with effective mode apparently. The input-output characteristic simulation results indicate the y-axis scale factor is 57.1Hz/g and the coupling output in the x-axis is 0.0148Hz/g, while the x-axis scale factor is 56.1Hz/g and the coupling output in the y-axis is 0.0073Hz/g, which proves that the new biaxial resonant micro-accelerometer is practicable and has an excellent decoupled performance.

2013 ◽  
Vol 744 ◽  
pp. 478-483
Author(s):  
Bo Yang ◽  
Bo Dai ◽  
Hui Zhao

Resonant micro-accelerometers have good properties such as the large dynamic range, the high sensitivity, the strong anti-interference ability as well as the direct digital output. A new z-axis resonant micro-accelerometer based on electrostatic stiffness is researched. The new z-axis resonant micro-accelerometer consists of a torsional accelerometer and two plane resonators. The sensing movement of the accelerometer is decoupled with oscillation of the plane resonators by electrostatic stiffness, which will benefit to improve the performance of the new z-axis resonant micro-accelerometer. The new structure is designed. The sensitive theory of the acceleration is investigated and the equation of scale factor is deduced under ideal conditions. The simulation is implemented to verify the basic principle by the Ansys and Matlab. The structure simulation results prove that the effective frequency of the torsional accelerometer and the resonator are 0.66kHz and 13.3kHz separately. And the interference modes are isolated with the effective mode apparently. The system simulation results indicate that the scale factor is 37Hz/g and the system has excellent capabilities in locking and tracking natural frequency of resonators, which proves that the basic theory is feasible.


Micromachines ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 38
Author(s):  
Libin Huang ◽  
Qike Li ◽  
Yan Qin ◽  
Xukai Ding ◽  
Meimei Zhang ◽  
...  

This study designed an in-plane resonant micro-accelerometer based on electrostatic stiffness. The accelerometer adopts a one-piece proof mass structure; two double-folded beam resonators are symmetrically distributed inside the proof mass, and only one displacement is introduced under the action of acceleration, which reduces the influence of processing errors on the performance of the accelerometer. The two resonators form a differential structure that can diminish the impact of common-mode errors. This accelerometer realizes the separation of the introduction of electrostatic stiffness and the detection of resonant frequency, which is conducive to the decoupling of accelerometer signals. An improved differential evolution algorithm was developed to optimize the scale factor of the accelerometer. Through the final elimination principle, excellent individuals are preserved, and the most suitable parameters are allocated to the surviving individuals to stimulate the offspring to find the globally optimal ability. The algorithm not only maintains the global optimality but also reduces the computational complexity of the algorithm and deterministically realizes the optimization of the accelerometer scale factor. The electrostatic stiffness resonant micro-accelerometer was fabricated by deep dry silicon-on-glass (DDSOG) technology. The unloaded resonant frequency of the accelerometer resonant beam was between 24 and 26 kHz, and the scale factor of the packaged accelerometer was between 54 and 59 Hz/g. The average error between the optimization result and the actual scale factor was 7.03%. The experimental results verified the rationality of the structural design.


2021 ◽  
Vol 30 (1) ◽  
pp. 19-27
Author(s):  
Kumar Gomathi ◽  
Arunachalam Balaji ◽  
Thangaraj Mrunalini

Abstract This paper deals with the design and optimization of a differential capacitive micro accelerometer for better displacement since other types of micro accelerometer lags in sensitivity and linearity. To overcome this problem, a capacitive area-changed technique is adopted to improve the sensitivity even in a wide acceleration range (0–100 g). The linearity is improved by designing a U-folded suspension. The movable mass of the accelerometer is designed with many fingers connected in parallel and suspended over the stationary electrodes. This arrangement gives the differential comb-type capacitive accelerometer. The area changed capacitive accelerometer is designed using Intellisuite 8.6 Software. Design parameters such as spring width and radius, length, and width of the proof mass are optimized using Minitab 17 software. Mechanical sensitivity of 0.3506 μm/g and Electrical sensitivity of 4.706 μF/g are achieved. The highest displacement of 7.899 μm is obtained with a cross-axis sensitivity of 0.47%.


2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Mohammadreza Kasaei ◽  
Ali Ahmadi ◽  
Nuno Lau ◽  
Artur Pereira

AbstractBiped robots are inherently unstable because of their complex kinematics as well as dynamics. Despite many research efforts in developing biped locomotion, the performance of biped locomotion is still far from the expectations. This paper proposes a model-based framework to generate stable biped locomotion. The core of this framework is an abstract dynamics model which is composed of three masses to consider the dynamics of stance leg, torso, and swing leg for minimizing the tracking problems. According to this dynamics model, we propose a modular walking reference trajectories planner which takes into account obstacles to plan all the references. Moreover, this dynamics model is used to formulate the controller as a Model Predictive Control (MPC) scheme which can consider some constraints in the states of the system, inputs, outputs, and also mixed input-output. The performance and the robustness of the proposed framework are validated by performing several numerical simulations using MATLAB. Moreover, the framework is deployed on a simulated torque-controlled humanoid to verify its performance and robustness. The simulation results show that the proposed framework is capable of generating biped locomotion robustly.


2018 ◽  
Vol 41 (5) ◽  
pp. 1323-1330 ◽  
Author(s):  
Milad Malekzadeh ◽  
Alireza Khosravi ◽  
Mehdi Tavan

This paper addresses the problem of state and parameter estimation for a class of uncertain DC-DC such converters as DC–DC boost, buck and buck-boost converters. Using the advantages of Immersion and Invariance technique with input-output filtered transformation, a proper immersion and auxiliary dynamic filter is constructed in the proposed estimator. Uniform global asymptotic convergence of the estimator is proven for the system with parametric uncertainties. In the presence of both output and state dynamics perturbations, the performance of the proposed estimator has been theoretically analyzed and verified by means of simulation results. In addition, the effectiveness of this scheme is validated via experimental test for DC-DC boost converter.


2019 ◽  
Vol 69 (1) ◽  
pp. 69-84
Author(s):  
Veldurthi Naresh ◽  
D. Bodas ◽  
Chandel Sunil ◽  
Bhave Tejashree

AbstractIn the present work, two geometrically similar passive geometries with dumbbell shape were designed to perturb the dominating viscous forces in the low Reynolds number (Re) flows of the fluids. The geometries were designated as PDM-I and PDM-II, in which all the linear dimensions were related by a constant scale factor of two. Mixing efficiencies and pressure drops of the species at various Reynolds number (Re) were calculated to estimate the scaling effect validations. Finally, the geometrically similar PDM geometries were fabricated in Polydimethylsiloxane (PDMS) polymer to evaluate the scaling effect on the mixing efficiencies of the dyes and validated with the simulation results of species mixing.


2010 ◽  
Vol 36 ◽  
pp. 243-252 ◽  
Author(s):  
Yoshinori Ando ◽  
Tatsuya Sakanushi ◽  
Kou Yamada ◽  
Iwanori Murakami ◽  
Takaaki Hagiwara ◽  
...  

The multi-period repetitive (MPR) control system is a type of servomechanism for periodic reference inputs. Using MPR controllers, transfer functions from the reference input to the output and from the disturbance to the output of the MPR control system have infinite numbers of poles. To specify the input-output characteristic and the disturbance attenuation characteristic easily, Yamada and Takenaga proposed MPR control systems, named simple multi-period repetitive (simple MPR) control systems, where these transfer functions have finite numbers of poles. In addition, Yamada and Takenaga clarified the parameterization of all stabilizing simple MPR controllers. However, using the simple MPR repetitive controller by Yamada and Takenaga, we cannot specify the input-output characteristic and the disturbance attenuation characteristic separately. From the practical point of view, it is desirable to specify the input-output characteristic and the disturbance attenuation characteristic separately. The purpose of this paper is to propose the parameterization of all stabilizing two-degree-of-freedom (TDOF) simple MPR controllers that can specify the input-output characteristic and the disturbance attenuation characteristic separately.


2011 ◽  
Vol 55-57 ◽  
pp. 648-653
Author(s):  
Lian Qing Fu ◽  
Li Sheng Yang ◽  
Tao Wang ◽  
Qing Le Zhang

In this paper, a novel netted radar system is designed to reduce the influence of mutual interference between signals. The emission signals of all stations are assigned the orthogonal PN codes. Because of the good autocorrelation and cross-correlation properties, mutual interference becomes weaker and signals from different stations could be separated by the preassigned PN codes. At the same time, the spectrum of the emission signal is spreaded, the peak-to-mean envelope power ratio (PMEPR) and the intercepted probability of the signals descend therefore. Simulation results show the good performance of the proposed approach.


Author(s):  
Chidentree Treesatayapun

Purpose The purpose of this paper is to design an online-data driven adaptive control scheme based on fuzzy rules emulated network (FREN) for a class of unknown nonlinear discrete-time systems. Design/methodology/approach By using the input-output characteristic curve of controlled plant and the set of IF-THEN rules based on human knowledge inspiration, the adaptive controller is established by an adaptive FREN. The learning algorithm is established with convergence proof of the closed-loop system and controller’s parameters are directly designed by experimental data. Findings The convergence of tracking error is verified by the theoretical results and the experimental systems. The experimental systems and comparison results show that the proposed controller and its design procedure based on input-output data can achieve superior performance. Practical implications The theoretical aspect and experimental systems with the light-emitting diode (LED) current control and the robotic system prove that the proposed controller can be designed by using only input-output data of the controlled plants when the tracking error can be affirmed the convergence. Originality/value The proposed controller has been theoretically developed and used through experimental systems by using only input-output data of the controlled plant. The novel design procedure has been proposed by using the input-output characteristic curve for both positive and negative control directions.


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