SIM_bounce

Overview

This is a project I've worked on to learn the basics of NASA/Trick. As of now it is a simple ball bouncing with no forces other than gravity acting on the ball. I've used matplotlib & python to make a real time plot showing the ball position over time by connecting to the trick server that can be run from the "clients/vs_plot.py" script. I will add more features over time to continue learning trick simulation tools.

Trick Concepts Demonstrated

• Job scheduling
• Job ordering
• Regula falsi event detection
• IntegLoop
• DRAscii data recording
• Variable server client (TCP socket connection)
• S_define
• LIBRARY_DEPENDENCY
• Real time data visualization
• subprocess sim lifecycle management (launching and terminating the sim from the client)

Project structure

SIM_bounce/
├── S_define          - sim entry point, job scheduling
├── S_overrides.mk    - build configuration
├── RUN_test/         - test run configuration and output
├── Modified_data/    - data recording configuration
├── clients/
│   └── vs_plot.py    - live variable server plot client
└── models/ball/
    ├── include/ball.h         - struct definition and function declarations
    └── src/
        ├── ball_default_data.c
        ├── ball_init.c
        ├── ball_force.c
        ├── ball_integrate.c
        └── ball_impact.c

Building

Requires NASA Trick installed and TRICK_CFLAGS configured via S_overrides.mk.

trick-CP

Running

Run just the simulation:

./S_main_*.exe RUN_test/input.py

Run the live variable server plot (starts sim automatically):

python3 clients/vs_plot.py

Requires matplotlib: pip3 install matplotlib

Initial conditions can be modified in RUN_test/input.py.

Screenshot

Output

Simulation data is logged to RUN_test/log_ball.csv containing time, position, and velocity. Impact events are printed to stderr with exact impact time.