at University of California, Irvine

The Falling Ball Example

 

In the current phase of the project, we work with small examples for CPSs to test and understand models and design methods.

One example developed, modeled and implemented in our group is the Falling Ball Example. The Falling Ball example has the objective to take a picture exactly at the moment a falling ball passes a camera. The approaching time is predicted based on information from motion sensors mounted above the camera.

This simple example has some interesting properties of CPSs. The example needs exact timing and it requires modeling of physical phenomena. In spite of the example’s simplicity, a designer has to cope with deviations between model and real physical world as well as with timing uncertainties on the cyber part.

Setup of the Falling Ball example: (A) as schematics, (B) in practice.
Setup of the Falling Ball example: (A) as schematics, (B) in practice.

The application of the Falling Ball example as part of an educational program is described in our paper A Ball Goes to School - Our Experiences from a CPS Design Experiment

 

Simulations of the Falling Ball Example

Simulink - version 1

simulink1

source: simulink.1

 

Simulink - version 2

This is a less elaborated version of the simulation that embeds the grabber functions into the ball model.

simulink2

source simulink.2

 

Modelica

modelica

source: modelica_catch

SystemC

source: ball.tar