Research Papers

Design and Implementation of a Binary Redundant Manipulator With Cascaded Modules1

[+] Author and Article Information
Emmanouil Tzorakoleftherakis

Department of Mechanical Engineering,
Northwestern University,
Evanston, IL 60208-3111
e-mail: man7therakis@gmail.com

Anastasia Mavrommati

Department of Mechanical Engineering,
Northwestern University,
Evanston, IL 60208-3111

Anthony Tzes

Department of Electrical and Computer Engineering,
University of Patras,
Rio 26500, Greece

2Corresponding author.

Manuscript received July 5, 2014; final manuscript received April 7, 2015; published online August 18, 2015. Assoc. Editor: Satyandra K. Gupta.

J. Mechanisms Robotics 8(1), 011002 (Aug 18, 2015) (10 pages) Paper No: JMR-14-1157; doi: 10.1115/1.4030372 History: Received July 05, 2014

The subject of this paper is the design and implementation of a prototype snakelike redundant manipulator. The manipulator consists of cascaded modules eventually forming a macroscopically serial robot and is powered by shape memory alloy (SMA) wires. The SMAs (NiTi) act as binary actuators with two stable states and as a result, the repeatability of the manipulator's movement is ensured, alleviating the need for complex feedback sensing. Each module is composed of a customized spring and three SMA wires which form a tripod with three degrees of freedom (DOFs). Embedded microcontrollers networked with the I2C protocol activate the actuators of each module individually. In addition, we discuss certain design aspects and propose a solution that deals with the limited absolute stroke achieved by SMA wires. The forward and inverse kinematics of the binary manipulator are also presented and the tradeoff between maneuverability and computational complexity is specifically addressed. Finally, the functionality and maneuverability of this design are verified in simulation and experimentally.

Copyright © 2016 by ASME
Your Session has timed out. Please sign back in to continue.



Grahic Jump Location
Fig. 1

(a) The 3DOF spatial tripod, (b) the implemented SMA-based tripod, (c) link design, and (d) IC slot

Grahic Jump Location
Fig. 2

(a) Simplified model of a bending module, (b) SMA arrangement, and (c) worst case configuration

Grahic Jump Location
Fig. 3

(a) Electronics architecture ((b) and (c)) forward kinematics parameters

Grahic Jump Location
Fig. 4

(a) Tripod discrete states, with the activated SMAs drawn with dashes and (b) macroscopically serial robot

Grahic Jump Location
Fig. 5

Workspace of the manipulator for all 88 possible configurations. One can see that despite the binary nature of actuation, the discrete positions of the end-effector essentially form a continuous workspace due to the large number of discrete states. Different levels indicate the vertical distance from the robot base.

Grahic Jump Location
Fig. 6

(a) Snapshots of the robot movement, (b) state variations, (c) actual robot path, and (d) position error

Grahic Jump Location
Fig. 7

Parametric evaluation of angle θ

Grahic Jump Location
Fig. 8

(a) Manufactured link, (b) slave IC, and (c) assembly details

Grahic Jump Location
Fig. 9

Experimental results

Grahic Jump Location
Fig. 10

Demonstration of repeatability

Grahic Jump Location
Fig. 11

Additional configurations




Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In