Laitserallyparki Liikluslinnaku Lastesõiduki Juhtseadiste Arendusprojekt

Töö eesmärk projekteerida sobiv rooli- ja pidurisüsteem täideti rahuldavalt. Projekteerimisega jõuti piisavalt kaugele, et oleks võimalik alustada algse prototüübi loomist. Baaslahenduseks roolisüsteemi puhul võeti kasutusele hobikardi roolisüsteem, millele tuli lisada juurde reduktor. Reduktori ainuke ülesanne oli muuta rooli pöörete arvu ning sobiv reduktori ülekandearv oli ligikaudu 9:1. Sobilikuks reduktoriks osutus planetaarülekanne elektrimootorilt ülekandega 10,5625:1. Lisaks loodi vajalikud kinnitused roolisüsteemi komponentidele, et need oleks võimalik uue raamiga kinnitada. Olulistele detailidele tehti ka tugevusanalüüsid, et veenduda roolisüsteemi töökindluses. Pidurisüsteem ehitati jalgratta pidurisadula Shimano BR-M375 ümber, kohandades selle antud sõidukiga. Pidurikettaid ostutootena kasutada polnud võimalik, sest nõutud mõõtmetele ja tingimustele vastavaid pidurikettaid ei leitud ja seega otsustati need ise luua. Samuti loodi piduripedaal koos kinnitusega. Kokku kogu pidurisüsteem arvutuste põhjal tagas selle, et laps reaalselt suudaks ka sõiduki mõistliku aeglustusega seisma saada. Lisaks kontrolliti analüüside põhjal, kas pidurisüsteemi komponendid peavad vastu neile avalduvatele jõududele. Antud lahendusi tuleks kindlasti prototüübi peab katsetada, et kas projekteeritud süsteemid vastavad soovitud tingimustele. Et saada parim lahendus roolisüsteemile tuleks põhjalikumalt üle kaaluda roolilatti kasutav roolisüsteem. Algselt plaanitud hobikardi roolisüsteemi lihtsus kaob lisades juurde reduktori ja vajalikud kinnitused. Samuti võtab planetaarülekanne palju ruumi jalgade piirkonnast ning võib raskendada sõidukisse sisse istumist. Pidurite poole pealt on oluline testida töökindlust ja piduriklotside puhul kestvust, sellega veendudes, et jalgratta pidurisadul koos klotsidega tasub materiaalselt ära.

The topic of this thesis was LaitseRallyPark Traffic Town Children's Vehicle Control Systems Development Project. This topic is currently relevant because this project is for LaitseRallyPark who are in need of a miniature vehicle for their traffic town. The traffic town is meant to be a fun way for children to learn traffic and driving. The goal of this thesis was to design working control systems for this vehicle specifically the braking system and steering system so that a prototype could be made and tested. The base vehicle used for the project was an electric mobility scooter. Since its steering system didn’t mimic a real car’s steering system well enough it had to change. The changed steering system consisted of a go-kart’s steering system since it was cheaper than other options and a planetary gear so that the steering wheel would turn at least two full turns. It was also important to find suitable wheelbase and trackwidth since the original wasn’t suitable for the needs of this car. The trackwidth was derived from the width of the traffic town and the final result was 0,71 meters. The general size of the wheelbase had to be calculated from the minimal radius of a turn from the track. The final number was 1,13 meters and was chosen so that the car wouldn’t look too long. The original brakes on the mobility scooter were also electric and so that the car would feel like a real car there was a need for mechanical brakes that would work from pushing a pedal. The brake calipers were chosen from a bicycle with disc brakes because there wasn’t much space to add anything bigger and they were also quite cheap. The chosen brake caliper was Shimano BR-M375. Since the brake discs from bicycles wouldn’t fit our vehicle, it was decided that the brake discs would be made from sheet metal with the help of laser cutting technology. The necessary mounting brackets for the brake caliper and discs were designed by the author. The brakes were designed so that a child pushing on the pedal with a force of 120 N could stop the wheels of the moving vehicle. Future improvements and corrections could be made after the testing of the prototype but at this moment the prototype isn’t made yet.