1 Copyright © 2015 by ASME
DRAFT PAPER
Proceedings of the International Mechanical Engineering Congress & Exposition
IMECE2015
November 13-19, 2015, Houston, Texas, USA
IMECE2015-53306
Modeling, System Identification and Experimental Investigation of Double
Parallelogram Flexural Manipulator for Precision Scanning
Sharad Mulik
Research Scholar,
Satyabhama University,
Chennai, Tamilnadu, India
sharadmulik@gmail.com
Suhas P. Deshmukh
Professor,
Sinhgad Academy of Engineering,
Pune, Maharashtra, India
suhas.deshmukh@gmail.com
Hrishikesh Zambare
Research Scholar,
Purdue School of
Engineering & Technology, IUPUI,
Indianapolis, Indiana, USA
hrishi.zambare18@gmail.com
Mahesh S. Shewale
Student,
Sinhgad Academy of Engineering,
Pune, Maharashtra, India,
mshewale802@gmail.com
ABSTRACT
Double Parallelogram Flexural Manipulator (DFM) is
basic building block of planar type flexural mechanism used for
precision scanning application. DFM offers better performance
as building block for planar type flexural mechanism due to its
zero parasitic error motion and very less amount of rotation of
motion stage. Static and dynamic model of double
parallelogram flexural manipulator (DFM) is presented. Static
model and dynamic model is derived from basic classical
mechanics theory. Forth order vibration wave equation is used
for mathematical modeling of DFM. Differential equation is
solved using assumed modes method and its performance is
determined for step input and sinusoidal forced input. Results
of simulation are investigated and it is observed that natural
frequency of DFM is 4.95Hz. DFM model is further
experimental investigated. Different components of DFM is
manufactured and assembled to achieve a desired motion
objective. Here, Voice Coil Motor is used as Actuator and
optical encoder is used for positioning sensing of motion stage.
DFM module with actuator and sensor is interfaced to PC using
dSPACE DS1104 microcontroller with ControlDesk software
module. DFM is characterized in two different domains (1)
Static characterization is carried out to determine its stiffness
and force deflection characteristics over the entire motion
range; (2) Dynamic characteristics is carried out using
Transient response and Frequency response. Transient response
is determined using step input to DFM which gives system
properties such as damping, rise time and settling time. These
parameters are further compared with theoretical model
presented previously. It is observed that theoretical model is
having close agreement with experimental results within 5 %
accuracy. Frequency response of DFM system gives
characteristics of system with different frequency inputs. This
frequency response is further used for experimental modeling
of DFM device. Experimental model (transfer function of DFM
with input: voltage signal output: displacement of motion stage)
using frequency response is determined using constrained
minimization approach. Experimental model is further
compared with theoretical model developed using fourth order
wave equation and it is observed that results of simulations and
experiments are in good agreements. Developed experimental
model is further used for PID control implementation. PID
parameters (i.e. proportional gain, derivative gain and integral
gains) are tuned using Zeigler Nichols Method. Experimental
model was initially tested offline and accuracy of less than 1
micron is achieved. PID control is implemented experimentally
using dSPACE DS1104 microcontroller and Control Desk
software. There is slight deviation from theoretical results is
due to assumptions made during modeling process. During
modeling noise is not taken into consideration. Experimentally
positioning accuracy of less than 5 microns is achieved.
INTRODUCTION
The progress in the fields of electronics, material
science and advanced manufacturing demands ultra-precision
scanning and positioning technology [1,3,5,6]. Various XY
scanning mechanisms are developed which range from screw
type to high precision recirculation ball mechanisms. Micro and
nano-positioning stages play a very important role in modern
technology. It finds application in many fields, such as