Annals of Warsaw University of Life Sciences - SGGW.

14 G. Viselga, J.R. KamińskiEXPERIMENTAL OBJECTIVETo identify possibilities to reducedeviations of straight-line coursemovement and positioning in relation tothe effect of micro and macro unevennessof the field, by choosing chassis type,control methods and parameters, andto estimate technological and energeticefficiency of the model.EXPERIMENTAL METHODSThe course of the positioned gantrymodule (PGM) is maintained by alaser instrument UKL – 1 (УКЛ – 1).A laser beam generator emitting avertical beam is placed at the end of theexperimental field. A laser beam catcherwith photo diodes is mounted on a PGMreplaceable support (Fig. 1). When themodule deviates from the course, laserbeam is passed into one of the marginalphotodiodes and a signal is formed, whichis passed into the control panel. Thecontrol panel switches off transmitter ofone or the other chassis and when PGMspar turns perpendicularly to the straightlinecourse, the transmitter of the chassisis turned on again.PGM is positioned by a specialpositioning trundle. It is run by a 12 Velectric motor through a worm self--braking reduction gear.When positioning trundle is running,a horizontal round tube inertly joinedwith it, moves along the bracket withterminal switches. When running, PGMbracket with terminal switches movesalong the tube of stopped positioningtrundle. Having moved on motionlimiters, the terminal switch of theFIGURE 1. Technological scheme of PGM: 1 – spar; 2 – chassis; 3 – working parts stretcher; 4 – ropeof working parts stretcher; 5 – working parts; 6 – working parts fixing carriage; 7 –axis of turning ofworking parts; 8 – back disconnectors with the switchover contact; 9 – flexible cable; 10 – cable drum;11 – horizontal tube with motion limiters; 12 – laser catcher with photodiodes; 13 – positioning trundle;14 – motor of working parts stretcher; A – distance between centres of photodiodes; B – distance ofcatcher’s photodiodes to the spar (B = 1 m); C – catcher’s distance from a wheel positioned the chassis;l s – spar length (l s = 18 m)