loumstar / dmt-control-system

A repo of the software for a control system that will allow a motorcycle engine to run on bioethanol through controlling the spark and ignition timings

DMT Biofuel Engine Control System

This is the repository for the software used for the DMT Biofuel Engine Sensors & Control Team. The Sensors & Control team are developing a control system that will allow a motorcycle engine to run on E85 fuel using an Arduino Micro to control the fuel injection and spark timings of the engine.

This is based off camshaft and crankshaft encoders from the engine to determine the precise angle of the shafts. By modelling the engine using 1D analysis, the optimal shaft angles for charging/discharging the ignition coils or opening/closing the fuel injectors can be found. When the shaft positions reach these optimal angles, the program will open or close the appropriate circuit controlling one of the ignition coils or fuel injectors.

The software has not yet been fully refactored or commented. This will be completed in the next few weeks.

Pre-requisites

For testing prerequisites, go to the readme within the relevant test folder.

In order to run this software, you must have:

• Arduino Micro.
• Arduino IDE.
• arduino-cli (optional).
• GitHub Desktop (optional).

You can install the Arduino IDE from here. Make sure you have the latest versions of all libraries, especially SoftwareSerial. These come as part of the IDE when it is first downloaded.

You can install arduino-cli from here or use Homebrew:

brew install arduino-cli

Also make sure you have installed the latest core libraries, which can be done using the following commands:

arduino-cli core install arduino:avr
arduino-cli upgrade

You can download and install GitHub Desktop from here.

Installation & Board Uploading

This repository can be downloaded using:

git clone [email protected]:Loumstar/DMT-Control-System.git

Alternatively, you can download this repository by clicking the code button on the repository homepage and selecting either Open with GitHub Desktop or Download ZIP.

Open bioengine.ino on the Arduino IDE. Connect your computer to the Arduino via USB. From the Tools dropdown menu, set the board type to Arduino Micro and select the relevant Port. The port is often selected automatically.

To upload the program to the arduino, click Upload on the Arduino IDE. Alternatively, you can use arduino-cli for more information on the process.

Within bioengine/ use the following commands:

arduino-cli compile bioengine -v --fqbn arduino:avr:micro
arduino-cli upload bioengine -v --port [PORT_NAME] --fqbn arduino:avr:micro

Usage

When the program has been uploaded, Click on the Serial Monitor from the Tools dropdown menu. This will allow you to communicate and instruct the Arduino to open/close different circuits.

Set the baud rate to 9600 Bd. Ensure that the Serial messages are sent with a newline at the end. This is how the Arduino knows a message is available. This can be selected from the dropdown menu at the bottom of the serial monitor.

The instructions passed to the Arduino have a bash-style syntax:

command [--RPM target_speed ]

There are four commands available:

• START, which starts the engine by allowing the control system to control the injector and ignition coil circuits.
• STOP, which shuts down the engine.
• SET, which allows you to configure parts of the control system. So far, only the target engine speed can be configured but this will be expanded soon.
• STATUS, which details information about the control system and its latest estimations of the timings, speed and temperature.

--RPM is a flag used with the SET command to select the target engine speed while the control system is running.

The speed value is given in RPM, and will cause the circuit to pulse at the same rate as if the engine had that RPM.

Testing

PCB Test

The PCB test is a test script that is run on the Arduino while it is housed in the PCB of the control system.

This test is necessary for checking all the transistors function as they should, by producing a square wave for a particular injector or coil circuit, at a particular engine speed.

For more information, go to the readme within pcb_test/ and refer to the PCB Test Specification in the Testing Report.

Engine Simulation (integration) test

The engine simulator test is a script for modelling engine signals that are used in the control system. This is includes the CPG, IPG and the analog signal from the thermistor.

This test is used to determine the speed and resilience of the constrol system software when loaded onto the Arduino Micro.

For more information, go to the readme within engine_simulator/ and refer to the Engine Simulator Test Specification in the Testing Report.

Repository structure

DMT-Control-System/
    readme.md  
    bioengine/
        bioengine.ino
        src/
            control_system/
                control_system.h
                control_system.c 
            engine_map/
                engine_map.h
                engine_map.c
            messages/
                messages.h
                messages.c
    tests/
        pcb_test/
            readme.md
            pcb_test.ino
            src/
                control_system/
                    control_system.h
                    control_system.c
                messages/
                    messages.h
                    messages.c
        engine_simulator/
            engine_simulator.ino
            src/
                messages/
                    messages.h
                    messages.c

Note some of these libraries are copied over to the test folders. This is due to a quirk of Arduino when compiling, where local libraries can only be found if they are in a src/ folder within the Arduino sketch.

Contact

If you need any information or help, please email me at [email protected].