TY - GEN

T1 - Pseudo-elastic flexure-hinges in robots for micro assembly

AU - Hesselbach, Jürgen

AU - Raatz, Annika

PY - 2000/10/11

Y1 - 2000/10/11

N2 - The increasing tendency of products towards miniaturization makes the substitution of conventional hinges to flexure hinges necessary, since they can be manufactured almost arbitrarily small. On account of their multiple advantages like no backlash, no slip-stick-effects and no friction, their application is especially reasonable in high-precision robots for micro assembly. Particular pseudo-elastic shape memory alloys offer themselves as material for flexure hinges. Since flexible joints gain their mobility exclusively via the elastic deformation of matter, the attainable angle of rotation is strongly limited when using conventional metallic materials with approximately 0.4% maximal elastic strain. Using pseudo-elastic materials, with up to 15% elastic strain, this serious disadvantage of flexure hinges can be avoided. A further problem of flexible joints is their kinematic behavior since they do not behave exactly like conventional rotational joints. In order to examine the kinematics of the hinges an experimental set-up was developed whereby good compliance with theoretical computed values could be achieved. A three (+1) degree of freedom parallel robot with integrated flexure hinges is investigated showing its kinematic deviations to its rigid body model. The data of the kinematic model of the flexible joint can then be implemented into the control of this compliant mechanism in order to gain not only a higher repeatability but also a good absolute accuracy over the entire working space.

AB - The increasing tendency of products towards miniaturization makes the substitution of conventional hinges to flexure hinges necessary, since they can be manufactured almost arbitrarily small. On account of their multiple advantages like no backlash, no slip-stick-effects and no friction, their application is especially reasonable in high-precision robots for micro assembly. Particular pseudo-elastic shape memory alloys offer themselves as material for flexure hinges. Since flexible joints gain their mobility exclusively via the elastic deformation of matter, the attainable angle of rotation is strongly limited when using conventional metallic materials with approximately 0.4% maximal elastic strain. Using pseudo-elastic materials, with up to 15% elastic strain, this serious disadvantage of flexure hinges can be avoided. A further problem of flexible joints is their kinematic behavior since they do not behave exactly like conventional rotational joints. In order to examine the kinematics of the hinges an experimental set-up was developed whereby good compliance with theoretical computed values could be achieved. A three (+1) degree of freedom parallel robot with integrated flexure hinges is investigated showing its kinematic deviations to its rigid body model. The data of the kinematic model of the flexible joint can then be implemented into the control of this compliant mechanism in order to gain not only a higher repeatability but also a good absolute accuracy over the entire working space.

UR - http://www.scopus.com/inward/record.url?scp=0034508324&partnerID=8YFLogxK

U2 - 10.1117/12.403696

DO - 10.1117/12.403696

M3 - Conference contribution

AN - SCOPUS:0034508324

SN - 0-8194-3859-6

T3 - Proceedings of SPIE - The International Society for Optical Engineering

SP - 157

EP - 167

BT - Microrobotics and microassembly II

PB - SPIE

CY - Bellingham

T2 - Microrobotics and Microassembly II

Y2 - 5 November 2000 through 6 November 2000

ER -