Paweł Chodkiewicz

• MS
• Research Assistant at Warsaw University of Technology

We present a distributed framework for predicting whether a planned reconfiguration step of a modular robot will mechanically overload the structure, causing it to break or lose stability under its own weight. The algorithm is designed to be executed by the modular robot itself and is based on an distributed iterative solution of mechanical equilib...

We present a distributed framework for predicting whether a planned reconfiguration step of a modular robot will mechanically overload the structure, causing it to break or lose stability under its own weight. The algorithm is executed by the modular robot itself and based on a distributed iterative solution of mechanical equilibrium equations deri...

This paper investigates cylindrical samples made of vacuum packed particles. Such structures are composed of granular media placed in a hermetic encapsulation where, in the final stage, a partial vacuum is generated. The main advantage of such a structure is that the underpressure value makes it possible to control the global physical properties of...

We present a method based on Discrete Element Method (DEM) to modeling the Vacuum Packed Particles(VPP)—a class of smart materials/smart structures. Mechanical properties of VPP can be simply adjusted bycontrolling the underpressure, which makes the structures very interesting from practical point of view, givingraise to numerous applications, incl...

In this paper, we present a novel approach to modeling and analysis of Vacuum Packed Particle dampers (VPP dampers) with the use of Discrete Element Method (DEM). VPP dampers are composed of loose granular medium encapsulated in a hermetic envelope, with controlled pressure inside the envelope. By changing the level of underpressure inside the enve...

Module localization is an important aspect of the operation of self-reconfigurable robots. The knowledge of spatial positions of modules, or at least of the overall shape which the modules form, is the usual prerequisite for reconfiguration planning. We present a general, decentralized algorithm for determining the positions of modules placed on a...

The control of vibrations of a mass-spring system with a damper made of granular material is modeled, numerically simulated and experimentally verified. The damper consists of a hermetically closed flexible sleeve filled with granular material. Pumping air out of or into the sleeve increases or decreases the under-pressure, which increases or decre...

In this paper, the authors focus on the proposition of an innovative semi-active linear damper prototype working on the basis of granularmaterials. Vacuum Packed Particles (VPP) belong to the class of materials whose mechanical (rheological, dissipative) propertiesmay be quickly changed by applying a partial vacuum inside the system. The concept of...

In this paper authors would like to introduce a new controllable structure, in some aspects similar to MR fluids, which is composed on the basis of granular material. Loose material is initially placed in a deformable hermetic encapsulation (basically made of soft polymer), equipped in a special valve. In the next step, an internal pressure is pump...

A conglomerate, composed of granular materials encapsulated in a tight, flexible envelope, and submitted to an internal underpressure, changes its properties in the function of the vacuum range. The underpressure level, controlled by a vacuum pump, enables controlling the behavior of such a medium. This particular ability could be useful in some sp...

The work is related to the numerical modeling of Vacuum Packed Particles (VPP)-structures composed of grains enclosed in an elastic envelope and submitted to internal underpressure. The behavior of the material is modeled using viscoplastic law of Bodner-Partom. The inverse problem of constitutive model parameter identification is solved using the...

The present work mainly focuses on modeling of the mechanical properties of the vacuum packed particles. Such structures are composed on the basis of loose granular materials encapsulated in a hermetic space. Initially granular system behaves like a classical plastic mass. When the internal pressure is pumped out of the system, what was baggy bulk...