motor and throttle body synchronization unit

Since a small DC motor is used to work as an engine, a special designed DC motor and throttle body synchronization unit must be used. When the throttle is closed, the DC motor runs at idle at the speed of 800 rpm. With gradually opened throttle body, the DC motor speed increases correspondingly until reaches to top speed at 4000 rpm when the throttle is fully open. The following picture shows the DC motor and throttle body synchronization unit. It looks like just the same with the unit we have used for the MAP sensor, but the program and is totally different.

The programming of the DC motor and throttle body synchronization unit is the biggest problem we have ever encountered in the project as well as how to wire the unit into the EFI system. The following two pictures show the programs we wrote for the unit but the DC motor did not synchronize well with the throttle. We wrote over 10 programmes from the unit and tried again and again until it really works well.

Electromagnetic Interference

When electric devices are close or interconnected to each other, electromagnetic interference interacts among all these devices. As for our project, the primary source of interference is caused by the secondary ignition cables. When current stops and starts it creates a strong electromagnetic signal wave which interferes with other electronic systems such as crankshaft position sensor, camshaft position sensor and ignitor. The undesirable side-effect of the phenomenon of interference we encounter is that the louder electronic device operating noise and sometimes malfunctions of the electronic devices.  and when we perform scope test, the interference is especially appeared on the waveforms

temperature sensor simulation

there are engine coolant temperature sensor and air temperature sensor included in this project. we thought of two ways to test these two sensors by using a heat gun. and also for the convenience of testing these two sensors, we decided to use a potential meter to simulate the temperature changing. As the potential meter is adjusted the resistance value changes correspondingly which changes the signal voltage to the ECU. howevery, the resistance of engine coolant temperatue sensor can goes from 10,000 ohms when it is cold and drops to a few hundred ohms when it is hot. the potential meter we used can only adjust from 1000 ohms to 3000 ohms, this is why when we use scope to test the sensor there is not much change.