Fully-compliant statically-balanced mechanisms without prestressing assembly: concepts and case studies

Abstract. The purpose of this paper is to present new concepts for designing fully-compliant statically-balanced mechanisms without prestressing assembly. A statically-balanced compliant mechanism can ideally provide zero stiffness and energy free motion like a traditional rigid-body mechanism. These characteristics are important in design of compliant mechanisms where low actuation force, accurate force transmission or high-fidelity force feedback are primary concerns. Typically, static balancing of compliant mechanisms has been achieved by means of prestressing assembly. However, this can often lead to creep and stress relaxation arising in the flexible members. In this paper two concepts are presented which eliminate the need for prestressing assembly of compliant mechanisms: (1) a weight compensator which employs a constant-force compliant mechanism, (2) a near-zero-stiffness mechanism which combines two multistable mechanisms. In addition to the advantages provided by statically-balanced compliant mechanisms, two other notable features of these statically-balanced mechanisms are their ability to be monolithically fabricated and to return to their as-fabricated position without any disassembly when not in use.

[1]  Guimin Chen,et al.  Finding the optimal characteristic parameters for 3R pseudo-rigid-body model using an improved particle swarm optimizer , 2011 .

[2]  Pablo Estevez,et al.  Collinear-Type Statically Balanced Compliant Micro Mechanism (SB-CMM): Experimental Comparison Between Pre-Curved and Straight Beams , 2011 .

[3]  Multistable Compliant Mechanisms : The State of the Art , 2022 .

[4]  Yong Mo Moon,et al.  DESIGN OF LARGE-DISPLACEMENT COMPLIANT JOINTS , 2005 .

[5]  Just L. Herder,et al.  Feasibility Study of a Fully Compliant Statically Balanced Laparoscopic Grasper , 2004 .

[6]  Larry L. Howell,et al.  Fully compliant double tensural tristable micromechanisms (DTTM) , 2009 .

[7]  Chao-Chieh Lan,et al.  A compliant constant-force mechanism for adaptive robot end-effector operations , 2010, 2010 IEEE International Conference on Robotics and Automation.

[8]  Jeong Sam Han,et al.  Design, Simulation, and Fabrication of a Quadstable Monolithic Mechanism With X- and Y-Directional Bistable Curved Beams , 2007 .

[9]  Just L. Herder,et al.  DESIGN OF A GENERIC ZERO STIFFNESS COMPLIANT JOINT , 2010 .

[10]  Just L. Herder,et al.  CRITERIA FOR THE STATIC BALANCING OF COMPLIANT MECHANISMS , 2010 .

[11]  Mary Frecker,et al.  Method for Optimization of a Nonlinear Static Balance Mechanism With Application to Ophthalmic Surgical Forceps , 2005 .

[12]  Thomas Sugar,et al.  Compliant constant-force mechanism with a variable output for micro/macro applications , 2003, 2003 IEEE International Conference on Robotics and Automation (Cat. No.03CH37422).

[13]  Guimin Chen,et al.  Synthesis of Compliant Multistable Mechanisms Through Use of a Single Bistable Mechanism , 2011 .

[14]  Sridhar Kota,et al.  Design of Nonlinear Springs for Prescribed Load-Displacement , 2008 .

[15]  Just L. Herder,et al.  Statically Balanced Compliant Micro Mechanisms (SB-MEMS): Concepts and Simulation , 2010 .

[16]  Guimin Chen,et al.  A Tristable Mechanism Configuration Employing Orthogonal Compliant Mechanisms , 2010 .

[17]  Giuseppe Radaelli,et al.  An Energy Approach to Static Balancing of Systems With Torsion Stiffness , 2010 .

[18]  B. Ilic,et al.  Large displacement low voltage multistable micro actuator , 2008, 2008 IEEE 21st International Conference on Micro Electro Mechanical Systems.

[19]  Just L. Herder,et al.  A Building Block Approach for the Design of Statically Balanced Compliant Mechanisms , 2009 .

[20]  S. Kota,et al.  Synthesis of Multistable Equilibrium Compliant Mechanisms Using Combinations of Bistable Mechanisms , 2009 .

[21]  Giuseppe Radaelli,et al.  An Energy Approach to a 2DOF Compliant Parallel Mechanism With Self-Guiding Statically-Balanced Straight-Line Behavior , 2010 .

[22]  Larry L. Howell,et al.  Evaluating three-dimensional effects on the behavior of compliant bistable micromechanisms , 2008 .

[23]  Matthew O. T. Cole,et al.  Analysis of a Gravity Compensated Four-Bar Linkage Mechanism With Linear Spring Suspension , 2008 .