Project specification

Team: Make HOOKE great again

Team members: Adam Torkkeli-Johansson (adamjoha@kth.se), Ramtin Erfani (ramtin1995@gmail.com), Gabriel Gessle (gessle@kth.se)

Project: Rope Bridge Simulation

The simulation that we would like to do is a simulation of a classic rope bridge. To do this we plan on using spring forces between certain points on the rope bride to simulate a “hanging/bouncing” behavior. This project is inspired by a previous project in the Models and Simulation course called “Epic Rope Bridge”.

We plan on using Unity to make this a real time simulation and like stated above we intend to use spring forces between points on the bridge to simulate the bridges behavior. Although there is built in support for spring systems in Unity we plan on implementing our own versions of spring behaviour using Hooke’s law. As a start we plan on implementing either Euler or Runge-Kutta (RK4) integration methods for location approximations. If we have enough time we will also implement the wooden planks breaking if under a large enough force, this should be using predefined thresholds where the planks are supposed to break.

The final system will include a rope bridge that is affected by wind (we will either use build in wind features in Unity or custom wind forces that we make ourselves) and several weights that can be dropped on the bridge to simulate its behaviour. We believe that the structure of the rope bridge will look something like this:

We are fairly certain that we can program the functionality of a spring force between objects, however there are potential risks for the project regarding the implementation of wind forces on the bridge and predefined breaking points on the planks. We are not quite sure how to make these work together with our spring simulation to create a realistic environment. To minimize the risk, we are also okay with the possibility to create some sort of “fake wind” that will just push the bridge in a certain direction without using a proper wind simulation. The breaking points on the planks is primarily a nice touch if we have time and not vital for the simulation to work properly.

The physics simulations that we will create ourselves:

- Hooke´s law, spring force between objects

- Wind force (maybe)

- Pressure force (when objects are dropped on the bridge, deciding if the planks break or not)

The preexisting physics simulations that are present in Unity that we will use:

- Gravitational force

- Wind force (maybe)