Assignment 1

Reading: Find material on Dijstra's Algorithm and read through carefully at least once. For example: Module 8 of the Algorithms course.

In this exercise, you will write a controller for the Dubin car (non-accelerative model) to perform a single task.

But first, let's see how a car simulator can be used without the GUI. Suppose you have written a controller. There are two ways you can test your controller:

Load your controller into the GUI and run the GUI. This has the advantage that you can see what's going on, but has the disadvantage of being slow. For example, if you were seeking to optimize a parameter and wanted to try a thousand values - it could take a lot of time.
Alternatively, you can create an instance of the appropriate simulator and use it directly.

Here's an example of using an instance of SimpleCarSimulator (for the unicycle, say):

public class SimpleCarControlTest {
    public static void main (String[] argv) 
    {
        // Build an instance of the simulator. Note: no obstacles in this example.
        // The constructor: isAccel=false, isUnicycle=true
        SimpleCarSimulator simulator = new SimpleCarSimulator (false, true);
        simulator.init (50, 50, 0, null);

        // This example moves the unicycle from (50,50) to (550,50).
        double x = 50;

        while (x < 550) {

            // Pass the controls (v=10, theta=0) to the simulator. DeltaT=0.1.
            simulator.nextStep (10, 0, 0.1);

            // Now extract the new location and other info.
            double t = simulator.getTime ();
            x = simulator.getX ();
            double y = simulator.getY ();

            // Display.
            System.out.println ("t=" + t + " x=" + x + " y=" + y);

            // The CarGUI merely adds an animation delay and drawing here.

        } //end-while
        
    }
}

To use the DubinCarSimulator, your code would be similar:

public class DubinCarControlTest {
    public static void main (String[] argv) 
    {
        // Build an instance of the simulator. Note: no obstacles in this example.
        // The constructor: isAccel=false
        DubinCarSimulator simulator = new DubinCarSimulator (false);
        simulator.init (50, 50, 0, null);

        // This example moves the car from (50,50) to (550,50).
        double x = 50;

        while (x < 550) {

            // Pass the controls (v1=10, v2=10) to the simulator. DeltaT=0.1.
            simulator.nextStep (10, 10, 0.1);

            // Now extract the new location and other info.
            double t = simulator.getTime ();
            x = simulator.getX ();
            double y = simulator.getY ();

            // Display.
            System.out.println ("t=" + t + " x=" + x + " y=" + y);

        } //end-while
        
    }
}

You are to use the configuration in Scene-3:

The car starts at (50, 50) and pointing right (theta=0).
There is an obstacle - a rectangle with top-left corner at (150,100) and width=100, height=100.
The target is at (500,50).

Thus, the initial position is:

The ultimate goal is to reach the target quickly and in the orientation facing rightwards. However, you are to do this in four discrete phases:

Phase 1: Rotate the car so that it points at an angle of A degrees (for example A = 45 degrees).
Phase 2: Then adjust the two wheel velocities (v1=right-wheel-velocity, v2=left-wheel-velocity) so that they are at a fixed ratio. If the ratio is selected appropriately, the car will turn in an arc all the way around the obstacle to "hit" the target. If it doesn't hit the target, it will at least hit the horizontal line y=50.
Phase 3: Turn the car so that it is facing right.
Phase 4: If needed, move the car rightwards until it reaches the target.

You should experiment with various values of A, v1 and v2 to see which values get you to the target (and facing rightwards) the soonest. Write code to systematically try different values of A, v1 and v2. This latter program is different than the controller that uses the best values.

Guidelines:

Your code should be also written in the move() method of your controller so that, we can see your controller at work using the GUI, and with your best values of A, v1 and v2.
To have your controller run in the GUI, your controller needs to implement the CarController interface.
The GUI has two levels of accuracy. You can use the lower one, which results in termination if the distance to the target is within 25 pixels.

Submission:

Make sure all your Java classes are named such have your username is embedded in each class name. This is to avoid name clashes with other students. Thus, if your username is karel, you can call your controller KarelCarController.java.
Use this submission procedure.
Name your jar file karel1.jar (for username karel).