Static balancing of an inverted pendulum with prestressed torsion bars. (February 2017)

• Record Type: Journal Article
• Authors: Radaelli, G.; Buskermolen, R.; Barents, R.; Herder, J.L.
• Is Part Of: Mechanism and machine theory. Volume 108(2017:Feb.)
• Page Start: 14
• Page End: 26
• Publication Date: 2017-02
• Subjects: Static balancing -- Torsion springs -- Torsion bars -- Series spring -- Parallel springs; Machine theory -- Periodicals; Machinery -- Periodicals; Machines -- Périodiques; Génie mécanique -- Périodiques; Machine theory; Machinery; Periodicals; 621.81
• DOI: 10.1016/j.mechmachtheory.2016.10.005
• Languages: English
• ISSNs: 0094-114X

Abstract

Abstract: This paper presents a method for the design of a statically balanced inverted pendulum. The non-linear moment-rotation characteristic of the pendulum's weight is approximated by a piecewise linear characteristic. Each transition is realized by engaging or disengaging one or more torsion bars, by means of mechanical stops. The whole set of torsion bars is located along the hinge axis of the pendulum. A prototype with three parallel torsion bars was built. Experimental evaluation of the prototype revealed a 99% work reduction of the balanced pendulum with respect to the unbalanced one. Abstract : Graphical abstract: Abstract : Highlights: A method for static balancing of a pendulum with torsion springs is presented. A nonlinear moment characteristic is approximated by a piecewise linear function. Degressive stiffness can be accomplished by deactivating prestressed torsion springs. A trilinear fit of a sine gives a factor 100 error reduction w.r.t. a linear one. A physical demonstrator shows a work reduction of 99% w.r.t. the unbalanced pendulum.