AEROSPACE MECHANISMS

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EURON07 WINTER SCHOOL PARALLEL ROBOTS Theory
and Applications 2nd International UMH Robotics
Winter School Flamingo Oasis Hotel, Benidorm,
Spain March 26 - 30, 2007
Aerospace applications of PKM
Prof. Rosario Sinatra
Dipartimento di Ingegneria Industriale e
Meccanica Università degli Studi di Catania
March 30, 2007
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AEROSPACE MECHANISMS

• POINTING SYSTEMS FOR SATELLITE ANTENNAS

Sinatra Rosario Pirrotta Simone
THE SATELLITE COMMUNICATIONS REQUIRES A VERY
ACCURATE POINTING SYSTEM, COMPOSED BY DIFFERENT
ELECTRO-MECHANICAL DEVICES
CONTROL SYSTEM SCHEME FOR POINTING ERROR
COMPENSATION
RESEARCH PROJECTS IN WITH PARTNERSHIP WITH
ANTENNA MECHANICAL and MECHANISM DESIGN SECTION,
ING. ABERTO MESCHINI
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AEROSPACE MECHANISMS

• POINTING SYSTEM FOR DOUBLE REFLECTOR ANTENNA

SUBREFLECTOR
W24
PARABOLIC REFLECTOR
FEED
OLD PONTING CONCEPT
NEW PONTING CONCEPT
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AEROSPACE MECHANISMS

• POINTING SYSTEM FOR DOUBLE REFLECTOR ANTENNA

RE-POINTING BY SUBREFLECTOR DYNAMIC POSITIONING
RADIATION DIAGRAM
ORBITAL RE-POINTING
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AEROSPACE MECHANISMS

• POINTING SYSTEM FOR DOUBLE REFLECTOR ANTENNA

MOBILE PLATFORM
LEGS
FIXED PLATFORM
KINEMATIC EQUATION
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AEROSPACE MECHANISMS

• POINTING SYSTEM FOR DOUBLE REFLECTOR ANTENNA

ORBITAL DISTURBANCE SIGNAL (STATION KEEPING)
SUBREFLECTORS CENTRE 3D-PATH
DISPLACEMENT
VELOCITY
ACCELERATION
KINEMATICS VARIABLES OF THE ACTUATED PRISMATIC
JOINTS
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AEROSPACE MECHANISMS

• 2 DOF POINTING SYSTEM

MOBILE PLATFORM
LINEAR ACTUATOR
FIXED PLATFORM
POINTING CONTROL RELATIONS
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AEROSPACE MECHANISMS

• 2 DOF POINTING SYSTEM

MATLAB GUI FOR DIRECT AND INVERSE KINEMATICS
MATLAB GRAPHICS OUTPUT
POINTING SURFACE j1 f(s1, s2)
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AEROSPACE MECHANISMS

• 2 DOF POINTING SYSTEM

RESIDUALS MAP AND DISTRIBUTION WITH RESPETC TO
ANALYTIC POINTING RELATIONS
COMPARISON WITH CAD EUCLID KINEMATIC RESULTS
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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

STATOR
ROTORS
PIEZOELECTRICS
ELECTRICAL
STATOR
Flexural vibration 2 waves with time phase of 90
2 Supply Channels
Travelling wave
Equal amplitude VmaxAVmaxB Opposite phase (90)
ROTORS
Rotational motion around vertical axes
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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

MULTIBODY SYSTEM
PRELOAD FORCE
NORMAL AND TANGENTIAL FORCES FROM ROTOR TO STATOR

NORMAL AND TANGENTIAL FORCES FROM STATOR TO ROTOR

EXTERNAL TORQUE
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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

EQUATIONS OF MOTION
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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

AREA-FORCE RELATIONSHIP
TORQUE CALCULATION
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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

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AEROSPACE MECHANISMS

• ULTRASONIC MOTOR

TORQUE-SPEED CURVES PARAMETRIZED WITH RESPECT
TO 1-MAXIMUM VOLTAGE AMPLITUDE (CASE a and
b) 2-FRICTION COEFFICIENT
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References
A. Meschini, R. Sinatra and S. Pirrotta,
2002. A Parallel Mechanism for a Gregorian offset
Satellitare Antenna with double
reflector, Proceedings of the WORKSHOP on
Fundamental Issues and Future Research
Directions for Parallel Mechanisms and
Manipulators, October 34, Quebec City, Quebec.
A. Cammarata and R. Sinatra, 2005, Dynamics
of a two-dof parallel pointing mechanism,
Fifth ASME International Conference on Multibody
Systems, Nonlinear Dynamics and Control,
Sept. 24-28, 2005, Long Beach, California, USA.
R. Di Gregorio, A. Cammarata and R.
Sinatra, 2005, On The Dynamic Isotropy Of 2-Dof
Mechanisms, Fifth ASME International
Conference on Multibody Systems, Nonlinear
Dynamics and Control, Sept. 24-28, 2005,
Long Beach, California, USA. R. Sinatra,
D. Scalora and A. Meschini, 2004, Direct
Kinematics of a Parallel Pointing Mechanism
Configuration, Proceedings of the WSEAS
Conferences, August 17-19, 2004, Corfu, Greece.
S. Pirrotta, R. Sinatra, A. Meschini, 2006.
Evaluation of the Effect of Preaload Force on
Resonance Frequencies for a Traveling Wave
Ultrasonic Motor, IEEE Transactions on
ultrasonics, ferroelectrics, and frequency
control, Vol. 53, n.4, pp. 746-753. S.
Pirrotta, R. Sinatra and A. Meschini, 2007. A
novel simulation model for ring type ultrasonic
motor, Meccanica International Journal, Vol.
42, n.2, pp. 127-139.