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1

Effectiveness of the active pneumatic suspension of the operator’s seat of the mobile machine in depend of the vibration reduction strategies

Chwastek S., Pobędza J.

Journal of KONES

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2018

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Vol. 25, No. 4

43--48

EN

Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.

2

Effectiveness of the active pneumatic suspension of the operator’s seat of the mobile machine in depend of the vibration reduction strategies

Chwastek S., Pobędza J.

Journal of KONES

|

2018

|

Vol. 25, No. 3

93--98

EN

Low speeds of heavy mobile machines combined with large inertia result in the excitation of low frequency vibrations. Dissipation of vibration energy in the case of unsprung machines is performed only through tires, which slightly reduces the intensity of vibrations. Effective reduction of vibrations of mobile machines is possible only with active or semi-active methods. In unsprung mobile machines, on the way of propagation of vibrations between the source of vibrations and the protected object (machine operator), are vibroisolation systems located. These are most often controlled seat suspensions. In the case of the active suspensions, it is necessary to provide external energy, e.g. in the form of compressed air. The compressed air has the advantage that it is generally available in working machines as the working fluid and has its environmentally friendly properties (leaks do not contaminate the environment). This article is the result of the continuation of work on active methods of vibro-activity lowering in mobile machines, which resulted in, among others, elaboration of simulation model of the active operator’s seat suspension with controlled pneumatic actuator and its experimental identification. In particular, it was verifying the effectiveness of the adopted solution made the identification the friction model and thermodynamic phenomena in the controlled pneumatic cylinder. The aim of this work is parametric optimization of the suspension system and searching for the optimal control strategy. Experimental tests were carried out under conditions of harmonic excitations, coming from the electromechanical vibration exciter with controllable pitch and frequency. Data acquisition system and control circuit of the proportional directional control valve, supplying compressed air to the actuator were implemented using MATLAB-Simulink Real-Time software.

3

Redukcja obciążeń dynamicznych nieresorowanych maszyn na podwoziach kołowych

Chwastek S., Michałowski S.

Czasopismo Techniczne. Mechanika

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2006

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R. 103, z. 1-M

71-80

PL

Maszyny robocze na podwoziach kołowych podlegają podczas jazdy złożonym oddziaływaniom dynamicznym. W pewnych warunkach może dochodzić do wpadania w drgania samowzbudne lub stan zwany "galopowaniem". W pracy przedstawiono model fizyczny i matematyczny maszyny roboczej z uwzględnieniem zmienności momentu napędowego oraz obciążeń dynamicznych pochodzących od osprzętu.

EN

Heavy machines on wheeled chassis are subject to complex dynamic excitations during the ride. In certain conditions these give rise to self-excited vibrations or most unfavourable ride conditions, referred to as "galloping". The study gives a physical and mathematical model of a heavy machine taking into account the fluctuations of the driving moment and dynamic loads due to the working equipment.