TY - JOUR
T1 - Instantaneous Center of Rotation of Flexure Joints and Velocity Kinematic Analysis of Microhexapod Using Screw Theory
TT - محور آنی دوران مفصلهای خمشی و تحلیل سینماتیک سرعت میکروهگزاپاد با استفاده از تئوری پیچواره
JF - mdrsjrns
JO - mdrsjrns
VL - 15
IS - 3
UR - http://mme.modares.ac.ir/article-15-4818-en.html
Y1 - 2015
SP - 173
EP - 180
KW - Microhexapod
KW - Flexure Joint
KW - Instantaneous Center of Rotation
KW - Velocity Kinematics
N2 - In this article microhexapod robot is introduced as a micromanipulator. First hexapod which is a parallel mechanism is investigated and also modifications that is needed for the improvement of positioning accuracy and eliminating factors such as clearance and friction in the conventional joints. Doing this, spherical and universal joints are replaced with flexural beam type joints after scaling down the hexapod. Then the degrees of freedom of flexure joints are achieved and after that the instantaneous center of rotation of flexure joints is derived for every finite twist of moving platform and it is shown that the kinematic chain of each pod of microhexapod consists of two spherical joints and a prismatic actuator; but it differs from hexapod in a way the location of the instantaneous center changes with the change of the finite twist of moving platform. Thereafter the velocity kinematics of microhexapod is solved using screw theory. In addition, using the analytical formula, the velocity of actuators was calculated for some case studies; linear motion of moving platform with constant velocity and also constant acceleration and also movement with constant velocity in a circular path. The results are verified with the finite element analysis and shown good agreement.
M3
ER -