Auto mootori ja jõuülekande juhtimine sõiduauto Lexus baasil

Õppestend, mis on loodud kaasaegse sõiduauto Lexus GS300 baasil, kus on kasutusel mootor, automaatkäigukast ja kogu juhtimissüsteem, on mõeldud eelkõige õppeotstarbel süsteemi tööpõhimõte tutvustamiseks ning diagnostika ja elektrooniliste rikete defekteerimise õpetamiseks, kus saab jälgida erinevaid parameetreid ning andurite ja täiturite tööd. Selleks on loodud keskkond, mis on lähedane sõiduauto reaalsetele tingimustele. Erinevalt Eestis enim levinud mootori õppestendidest, antud stendil on mootori ja jõuülekande koormamiseks kasutusel veoauto hüdropidur ZF-retarder, millega on võimalik kogu mootori võimsuse ulatuses anda koormust. Selline lahendus ei ole mitte ainult uudne, vaid ka palju odavam, kui võtta kasutusele müügil olevaid spetsiaalseid mootori koormamiseks mõeldud pidureid. Õppestend on oma olemuselt lihtsa ehitusega, mis tagab hea juurdepääsu erinevatele mootori sõlmedele. Juhtmestik on väljaehitatud sarnaselt sõiduauto paigutusega. Tänu sellele, erinevalt komplektsest sõiduautost, on kogu juhtimissüsteem silmnähtavale välja toodud, sellega on kohe aru saada, kui keeruliseks on läinud tänapäeva sõiduauto. Keskkond on väljatöötatud nii, et oleks võimalik simuleerida elus esinevaid kaabelduse ja anduririkeid, kus on võimalik jälgida reaalajas ja reaalsete tingimustega, andurite signaale muutes, kuidas käitub mootor ja automaatkäigukast. Selleks on konstrueeritud rikete boks, mis on juhtimisüsteemi kaabelduses vahele lülitatud ja võimaldab täpselt mõjutada mootori juhtplokkidesse anduritelt edastavaid signaale. Õppimise eesmärgil saab näidata mootori ja automaatkäigukasti halva töö erinevaid sümptomeid, esinevate elektroonika rikete puhul. Õppur saab tutvuda kogu juhtimissüsteemi ülesehitusega ja õppida diagnostiku tööd, kus ta ülesandeks on leida vastavalt tootja juhenditele, miks mootor töötab halvasti, millised parameetrid on muutunud ja defekteerima, mis on riket põhjustanud. Samas saab antud õppestendi kasutada ka keerulisteks mootori ja jõuülekande testideks, kus tulevane insener õpib kuidas ja milliseid katseid tuleb teha mootori projekteerimise käigus.

Nowadays car technology develops rapidly and their structure is becoming increasingly complicated. Whilst car demand has grown, car manufacturers are forced to create high technology vehicles to get low fuel consumption and long-lasting durability by high efficiency. Thereby, a demand for technicians with a very good education starts to also grow, because while cars are being in exploitation different electronical breakdowns may occur. There is a big demand in high technology cars in Estonia, but there are few equivalent means of instruction which could be used to educate technicians. Hence, an idea came up to create teaching stand based on Lexus car, where high technology solutions are used. My aim was to construct the control panel of the teaching stand and develop an environment, which is meant to above all teach diagnostics of motor and automatic transmission and also defecting of electronical breakdowns. It should be possible to observe different parameters and also work of sensors and actuators, at the same time simulate wiring and sensor breakdowns which appear in the electronical managing system of the motor and automatic transmission of the car. An environement should give a possibility to observe behaviour of engine and automatic transmission’s managing systems and how their work changes in real-time and real conditions. For creating real conditions it is decided to take into use a hydraulic brake, which provides load to the extent of whole capacity of power source. This kind of solution is not only novel, but also cheaper than buying special breaks for motor load brakes. For simulating wiring and sensors’ breakdowns, a breakdown box should be constructed and switched in wiring of the more important managing systems, in the box there are installed several potentiometers to change different parameters simultaneously if needed. To compose various diagnostic tasks, firstly it is needed to accurately study the database of Lexus’s factory to identify how the managing of engine and automatic transmission works, what are the components and work principles. It is important to understand how different electronical breakdowns affect work of managing systems, which parameters change, how it is reflected on work of engine and automatic transmission and what are the symptoms of breakdowns. Secondly factory’s instructional material should be studied to understand how various electronical breakdowns should be diagnosed. When whole managing system is studied, it is possible to begin to construct the managing of the teaching stand. This teaching stand has a simple construction, which provides a good access to different engine assemblies. Wiring is constructed similarly to the placement of a car. Due to that, unlike complex car whole managing system is revealed, it gives an immediate idea how complicated is a nowadays car. For teaching purpose it is possible to show different symptoms of engine and automatic transmission’s bad work while electronical breakdowns occur. A student can study the construction of the managing system and study work of diagnostics, where his task is to find why the engine works poorly, which parameters have changed and defect the reason of breakdown all based on manufacturer’s instructions. The teaching stand could be also used for complicated motor and power transmission tests, where future engineer studies how and what kind of tests should be done while developing the engine.