Investigation of Soft Impacts in Elements of Pipe Robots

Abstract

Vibrators with deformable impact support under harmonic excitation are especially useful in the case when their stationary regimes of motion are stable. This is useful in practice by applying those vibrators to single direction manipulators and various robots of space type.
 For practical application it is necessary to reveal dynamical qualities of the system from where it would be possible to determine optimal regimes. For this purpose investigations of dynamics of the system by numerical methods were performed.
 Investigation of dynamics of impact interactions in elements of robots is an important engineering problem. Dynamics of soft impacts in elements of manipulators and robots is investigated. The model of the investigated system is described. Numerical investigations for various parameters of the system are performed. Free and forced vibrations are investigated.
 From the presented results it can be noted that for the smaller values of the coefficient of stiffness of the support period of steady state motion coincides with the period of the exciting force, while for the higher values of the coefficient of stiffness of the support period of steady state motion is equal to two periods of the exciting force. Thus it is concluded that with the increase of the coefficient of stiffness of the support behavior of the investigated vibro impact system with soft impacts experiences essential changes.
 Main characteristics of steady state motion as functions of frequency of excitation are investigated. From the presented results the minimum and maximum inter impact intervals as functions of frequency of excitation, minimum and maximum velocities before impact as functions of frequency of excitation, minimum and maximum minimum displacements in inter impact intervals as functions of frequency of excitation are seen. Three resonant zones of expected single valued motions are observed in the presented results. They correspond to optimal regions of operation of the vibro impact system with soft impacts.
 Results of the performed analysis of dynamic interactions with soft impacts in the elements of manipulators and robots are used in the process of design of pipe robots of advanced type.