Launch Interceptor Program

Siyao Liu, Edwin So, Filip Bäck, Tobias Gabi Goobar

Assignment 1 in course DD2480, Spring 2022, KTH

Overview

This project models an hypothetical anti-ballistic missile system based on the specification by J. C. Knight and N. G. Leveson.

The main function is the Decide() function. This function decides whether or not an interceptor should be launced based on planar data points representing radar echoes.

Inputs

• A set of planar data points.
• LCM (Logical Connector Matrix) which is a 15 x 15 symmetric matrix where the elements are have values ANDD, ORR, NOTUSED.
• PUV (Preliminary Unlocking Vector) is a 15 x 1 boolean vector, explained below.

Outputs

• A boolean (TRUE/FALSE) indicating if an interceptor should be launced.

Functionality

The decision is made based on 15 different LICs (Launch Interceptor Conditions).

These 15 LICs have a one-to-one correspondance with the corresponding element in the CMV (Conditions Met Vector).

Each element LCM[i,j] defines what logical operator should be used for the pair CMV[i], CMV[j] to create the corresponding element PUM[i,j] (Preliminary Unlocking Matrix), which is a symmetric boolean matrix.

For example, let's say that element LCM[i,j] is ANDD, LIC[i] = TRUE and LIC[i] = TRUE then element PUM[i,j] will be TRUE ANDD TRUE which evaluates to TRUE.

The FUV (Final Unlocking Vector) is a 15 x 1 boolean vector where each element FUV[i] is TRUE either if all elements in row i of the PUM is true or if PUV[i] is FALSE indicating that this condition should not be used.

Finally, the function Decide() returns true if and only if all elements in the FUV are TRUE.

How to use

Our project uses Maven as the build tool, so it is essential that it is installed before attempting to run the program. To run the program, change the inputs in src/main/java/Main.java as you like and type the following in the terminal:

mvn clean install
mvn exec:java

You can also modify the tests contained in src/test/java correspondingly. To run the tests, type:

mvn test

Way of Working

Currently, we are in the stage of In Place. This is because we have already established a bunch of principles and agreed on the tools that we use for the work, and they are being used by the whole team to perform the work. We would regularly inspect if the rules or principles are followed and if not, we would make changes and make sure we abide by them.

But we are still not in the stage of Working well since we cannot naturally apply the practices without thinking about them.

We think the obstacles to reaching the next stage is time because it has not been a long time since the group was formed and principles were established.

Contributions

Tobias Gabi Goobar:

Implemented

• LIC0
• LIC2
• LIC6
• LIC7
• LIC12

along with corresponding unit tests.

Filip Bäck

Implemented

• LIC3
• LIC5
• LIC8
• LIC10
• LIC14

along with corresponding unit tests.

Siyao Liu

Implemented

• LIC1
• LIC4
• LIC9
• LIC11
• LIC13

along with corresponding unit tests.

Edwin So

Designed

• Code structure and code skeleton

Implemented

• Decide class
• FUV logics
• Launch logics
• Preliminary Unlocking Matrix logics
• (along with corresponding unit tests.)

Enabled

• GitGub Actions (CI for checking if code compiles and if tests are passed or not)

Note to the grader(s):

• Basically 99% of the commits are linked to a valid issue with description. If it is not the case at the first glance, please check the comment area or the corresponding pull requests, and you will see the linked issue.
• Possible ambiguity: the way we interpret the requirements of the parameters is that the input of must fulfill them, otherwise we directly throw assertion errors and abort the program.