We propose a reduced-model-based analytic approach to active shock absorption by a falling humanoid robot at impact. We model the segment between the contact point at impact and the impacting limb extremity attached to the torso or waist of the humanoid robot as a one degree-offreedom linear mass-spring-damper system. By mapping the joint angle limits and torque limits of the joints in the impa...

Vibrations of a nonlinear oscillator with an attached pendulum, excited by movement of its point of suspension, have been analysed in the paper. The derived differential equations of motion show that the system is strongly nonlinear and the motions of both subsystems, the pendulum and the oscillator, are strongly coupled by inertial terms, leading to the so-called autoparametric vibrations. It ...

The aim of this paper is to study the energy pumping (the irreversible energy transfer from one structure, linear, to another structure, nonlinear) robustness considering the uncertainties of the parameters of a two DOF mass-springdamper, composed of two subsystems, coupled by a linear spring: one linear subsystem, the primary structure, and one nonlinear subsystem, the so-called NES (non-linea...

A method for computing nonlinear soft–tissue deformation caused by simulated surgical procedures is presented. A mass–spring system is used to model patient individual soft–tissue. Instead of simulating dynamic behaviour, the introduced approach directly estimates the rest position of the system. Very fast and robust nonlinear soft–tissue deformation is computed using an optimization approach. ...

The nonlinear corrections for a Helmholtz resonator type impedance based on systematic asymptotic solution of the pertaining equations has been formulated in [1]. The length of the cavity considered was much smaller compared to the typical acoustic wavelength of interest so that the pressure inside could be assumed to be uniform. This way, the cavity worked as a spring to the external excitatio...

In this paper, the robust design with an uncertain model of a vibro-impact electro-mechanical system is done. The electro-mechanical system is composed of a cart, whose motion is excited by a DC motor (motor with continuous current), and an embarked hammer into this cart. The hammer is connected to the cart by a nonlinear spring component and by a linear damper, so that a relative motion exists...

81st (Spring) Meeting of Ulster Society of Internal Medicine, Friday 15th May 2009 Medical Education Centre, Craigavon Hospital, Portadown

We describe the locomotion dynamics of a biomimetic robot and compare them with those of its exemplar: the cockroach. The robot is a small (0.275kg) hexapod created using a layered manufacturing technique that allows us to tailor the compliance and damping of the limbs to achieve passive stabilization similar to that observed in insects. The robot runs at over 3 body-lengths per second (55 cm/s...

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