Smart Materials for Advanced Robotic Space Applications Space Engineering Research Center Texas Engineering Experiment Station, Texas A&M University Space Engineering Institute Team Members Richard Colunga Shane Davis Jimmy Espitia Tim Guenthner Brian Kuehner Chris Mahaney Lora Palacios Dr. Ron Diftler NASA Mentor Dr. James Boyd TAMU Mentor Reid Zevenbergen Graduate Mentor
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Smart Materials for Advanced Robotic Space Applications Space Engineering Research Center Texas Engineering Experiment Station, Texas A&M University Space.
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Smart Materials for Advanced Robotic Space Applications
Space Engineering Research CenterTexas Engineering Experiment Station, Texas A&M University
Space Engineering InstituteTeam MembersRichard Colunga
• Can be scaled to Tendril prototype (>1cm) or to manufacture (5mm).
• Two hinges interface between each link.
• Tools and instruments can be included.
• Allows for bi-directional actuation per link.
• Utilizes linear and angular actuation provided by Squiggle motors.
• Four hinges interface each link with three forces and two moments each (assuming no friction at hinges).
• Kinetics can be solved using N2L and E2L.• Forward and Inverse Kinetic Problem
– Forward: Given the orientation of each link, what is the position of the tip?
– Inverse: Given the position of the tip, what are the orientations of the links?
Kinetics
0 0.2 0.4 0.6 0.8 1 1.2 1.4-0.1
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
Initial CoordinatesAngle 1 rotation
Transformation 1
Angle 2 rotation
Angle 3 rotation
Transformation 3
Final State
][c1 -s1 0s1 c1 00 0 1
c2 0 s20 1 0-s2 0 c2][
1 0 00 c3 -s30 s3 c3][
keyC = cosineS = sine
Kinematics• Forward kinematics of a 3-2-1Euler rotation of 60°, 240° and 240° at Joint 1, 2 and 3 respectively.
• Given equal lengths of three rigid joints, solution to forward kinematic problem puts the position of the tip back at the origin.
• A code was written to calculate the position of various joints in a collection of linkages assuming each linkage consists of straight segments connected to joints that can rotate on all 3 axes.
Wiring Must be Small• Constraint of 5x5mm cross section dictates the need for a small wiring harness.• The size of an electrical wire depends on the applied current and length of the wire. • How small can our wires be?
Wire Choice:Templfex Micro-miniature flat and wire CableTempflex cables are used extensively in the medical field. The outer wall coating is a Teflon alternative.
AWG(Stranded) Minimum wall thickness(mils)
Resistance (Ω/km)
36 to 50 .5 N/A
Minimum wirecross-sectionalarea.
V= Applied voltage L = Length of wireA = cross sectional area
𝜎 = conductivity of material
Potentially Useful Hardware
• Motion Sensor: MEMS 3-axis - ± 2g/± 8g
Smart Digital Output “Piccolo” Accelerometer– This is a 3-axis digital accelerometer that is 3x5x0.9mm. It operates with
2.16 V to 3.6 V and the temperature range is -40°C to 85°C
• Position Sensor: TRACKER NSE-5310– This position sensor is 8.5x11.5x1.61mm and can
operate over -40°C to 125°C. It uses a magnet and
requires 3 V to 3.6 V and is made by the same company
as the Squiggle motor.
• Optics: Fiber Lens Scope Viewer– This lens viewer is has a 2mm diameter tube and is 1 meter long.
• Pressure Sensor: TouchMicro-3 v1.0– This pressure sensor is 3mm in diameter and it uses 5 V. It can handle up
to 39N of force and the operating temperature is -20°C to 100 °C.
Spring 2010 Future Work
• Kinematics and Dynamics– Add external forces and moments to FBD calculations.
– Verify kinematic calculations with addition of translation to rotation.
• Prototype– Design, build, verify couple to join Squiggle to hinge.
– Addition of rotational Squiggle motor to linkage design.
– Fabricate and build links; Assemble links into linkage.