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Design And Application Of Three-dimensional Force Sensor

Posted on:2019-09-24Degree:MasterType:Thesis
Country:ChinaCandidate:C ZhangFull Text:PDF
GTID:2428330545990091Subject:Mechanical engineering
Abstract/Summary:PDF Full Text Request
The multidimensional force sensor is a sensor that can measure two or more directional forces/moments at the same time.It has been widely used and studied because of its abundant measurement information.Due to the coupling between dimensions,measuring precision is difficult to improve,the technical difficulty is how to design decoupling elastomer and decouple the coupling output signal.This paper was based on the small wind tunnel test application of the flapping wing flight robot and designed a novel smooth sensitive mechanism according to the double holes parallel cantilever beam and redundant drive restraint planar parallel mechanism,which used to measure the lift of vehicles,traction,and upsetting force.In addition,a new decoupling optimization method which used redundant and sensitive signal null space was proposed.Firstly introducing the elastomer design of three dimension force sensor,which included the basic deformation unit,the transmission mechanism of three forces-redundant drive restraint planar parallel mechanism and the configuration process;On this basis,the kinematics model of the mechanism was established and kinematics equation was derived.The inverse analysis concluded the inverse solution formula of the mechanism and a set of inverse solutions were obtained according to the continuity of motion.In addition,by regarding the global condition number of Jacobi matrix as evaluation index of mechanism isotropic,structure parameters was optimized by using MATLAB genetic algorithm toolbox and then obtained a group of optimal objective function value.Based on the kinematics conclusion,the static equation of mechanism was established,and the mapping matrix of sensor input and output was obtained.Secondly,the 3d force sensor was modeled and analyzed in four aspects by finite element simulation analysis.The results of static analysis showed that the nonlinear error of the sensor is small and the sensitivity of each direction is high and consistent.The zero space inverse solution optimization of the mapping matrix reduced the dimensional coupling and resulted in the maximum coupling error less than 2%.The rigidity analysis verified that the mechanism had good isotropic performance.Modal analysis got the first six order displacement nephogram and inherent frequency value of the three dimension force sensor and calculated working bandwidth of the sensor according to the first order natural frequency,which met small flapping wing flight vehicle flapping frequency requirements;The response time of sensor under dynamic load was obtained by transient analysis,which provided reference for data acquisition time of upper computer.Finally,designing the three dimension force sensor signal acquisition system,which included the design of overall system,the writing of the lower machine driver and the design of PC interface,RS232 serial port is used for real-time communication between MCU and PC;In addition,the paper set up the experimental platform and did the static test experiment of three dimension force sensor using the weight loading method,and then got some important static performance indicators under the actual working condition,which shows that the designed three dimension force sensor has good static performance.
Keywords/Search Tags:three-dimensional force sensor, hybrid mechanism, optimization toolbox, finite element analysis, signal acquisition
PDF Full Text Request
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