A Small Range Six-Axis Accelerometer Designed with High Sensitivity DCB Elastic Element

Abstract

This paper describes a small range six-axis accelerometer (the measurement range of the sensor is ±g) with high sensitivity DCB (Double Cantilever Beam) elastic element. This sensor is developed based on a parallel mechanism because of the reliability. The accuracy of sensors is affected by its sensitivity characteristics. To improve the sensitivity, a DCB structure is applied as the elastic element. Through dynamic analysis, the dynamic model of the accelerometer is established using the Lagrange equation, and the mass matrix and stiffness matrix are obtained by a partial derivative calculation and a conservative congruence transformation, respectively. By simplifying the structure of the accelerometer, a model of the free vibration is achieved, and the parameters of the sensor are designed based on the model. Through stiffness analysis of the DCB structure, the deflection curve of the beam is calculated. Compared with the result obtained using a finite element analysis simulation in ANSYS Workbench, the coincidence rate of the maximum deflection is 89.0% along the x-axis, 88.3% along the y-axis and 87.5% along the z-axis. Through strain analysis of the DCB elastic element, the sensitivity of the beam is obtained. According to the experimental result, the accuracy of the theoretical analysis is found to be 90.4% along the x-axis, 74.9% along the y-axis and 78.9% along the z-axis. The measurement errors of linear accelerations ax, ay and az in the experiments are 2.6%, 0.6% and 1.31%, respectively. The experiments prove that accelerometer with DCB elastic element performs great sensitive and precision characteristics.

Forward and Inverse Dynamics of a Six-Axis Accelerometer Based on a Parallel Mechanism

“…Therefore, all flexible spherical joints are assumed to be ideal without friction and creep. For a six-axis accelerometer system, the damping force can be ignored due to the greater stiffness of the system [ 12 , 28 ]. …”

“…For a six-axis accelerometer system, the damping force can be ignored due to the greater stiffness of the system [ 12 , 28 ].…”

“…The six-axis force sensor based on the Stewart platform generally has the characteristics of high stiffness and load capacity through distributing the loading axially over the six legs [ 25 ]. Inspired by the design scheme of the six-axis force sensor based on the Stewart platform, some scholars proposed and studied the six-axis acceleration measurement scheme that only contained one inertial unit by using the Stewart platform as the elastic body of the sensor [ 26 , 27 , 28 , 29 , 30 ]. Therefore, this article will take the six-axis accelerometer proposed in Reference [ 31 ] as the research object.…”

An isogeometric analysis based design of highly sensitive and precise omnidirectional piezoelectric-fiber accelerometer

“…The structures and transduction schemes of multi-axis accelerometers are mainly divided into the following types: (1) in-plane four orthogonal cantilevers connected with single proof mass (piezoresistive or piezoelectric) (Amarasinghe et al, 2006; Kunz et al, 2001; Zhu et al, 2018), (2) fully decoupled structure (triboelectric, piezoelectric or piezoresistive) (Gao and Zhang, 2010; Jin et al, 2018; Pang et al, 2015), (3) parallel mechanism (piezoresistive) (Gao and Zhang, 2010; Sun et al, 2016), (4) in-plane orthogonal comb-finger structure (capacitive) (Qu et al, 2004; Tavakoli et al, 2017; Yin et al, 2016), (5) spherical structure (capacitive) (Toda et al, 2002). Table 1 shows the advantages and disadvantages of various transduction schemes.…”

A Generic Compliance Modeling Method for Two-Axis Elliptical-Arc-Filleted Flexure Hinges

“…Flexure hinges can utilize their slender portions to produce relative motion between two adjacent rigid links in flexure-based compliant mechanism. In many high precision and micro-operation applications such as micro/nano-positioning platforms [ 1 , 2 , 3 ], displacement amplifiers [ 4 , 5 , 6 , 7 ], sensors [ 8 , 9 , 10 ], elliptical-vibration texturing device [ 11 ], micro-grippers, bionics, and micro-electromechanical systems [ 12 , 13 , 14 , 15 ], flexure hinges also play a very important role as alternative solutions to traditional rigid joints due to their positive features of not requiring assembly, compactness, zero friction and high resolution, etc.…”