MSE_lab

MATLAB software for 24-452 Mechanical Systems Experimentation at CMU. Students drive an EMB spring–mass–damper (SMD) kit from ROBOTS5 through Simulink Desktop Real-Time.

Highlights

• Plant — MSE_PLANT.slx runs in Desktop Real-Time (external) mode and reads force, stiffness, and damping from the MATLAB base workspace.
• Forcing function builder — SignalBuilderApp stacks sine, step, ramp, swept sine, band-limited noise, custom (F(t)), and zero-output, then returns a timeseries. With the controller on, the same builder is a reference trajectory in mm. The main app writes that to sim_input.
• Student app — src/App/ is an MVC window with time/frequency tabs and a sidebar. Start Simulation compiles and connects Desktop Real-Time; Create Forcing Function opens the builder and plots the result as the reference.
• Labs — Live scripts (Lab_1.mlx, lab_3.m, …) build the same sim_input by hand and start the plant. Five labs; each has or will have the minimum code to run the kit.
• Same contract everywhere — Labs, AppModel.setForcingInput, and the lab scripts all write sim_input, k_sim, and b_sim into the base workspace for MSE_PLANT.

Quickstart

From the repo root in MATLAB:

addpath(genpath('src/App'));
addpath('src');

genpath('src/App') also puts src/App/components/Images on the path so sidebar icons resolve.

1. Launch the student app

main

That opens a 1900×900 figure, loads MSE_PLANT, and wires the sidebar. Create Forcing Function runs SignalBuilderApp in force mode; Enable Controller switches that button to Create Reference Trajectory (mm). Start Simulation builds/connects Desktop Real-Time (hardware must be attached).

2. Build a forcing function alone

tsData = SignalBuilderApp;   % blocks until Finish or the window is closed
tsData = SignalBuilderApp("Mode", "reference");   % mm + travel limit

Add waveforms, preview Single vs Overall, then Finish Signal Building. That returns a timeseries. Closing without Finish returns an empty timeseries (Length == 0).

3. Build a forcing function (no UI)

model = SignalBuilderModel;
model.addSignal(StepSignal(2, 5, 5));     % magnitude [N], on [s], off [s]
model.addSignal(SineSignal(1, 2, 0, 5));  % A [N], f [Hz], phase [deg], duration [s]
[t, y] = model.compileCompositeSignal;    % superposition from t = 0
plot(t, y);

Signals overlay on one time axis; they are not played back-to-back. See docs/signals.md.

4. Run the plant from a timeseries

appModel = AppModel;
appModel.setForcingInput(tsData);   % writes sim_input, k_sim, b_sim; sets StopTime
appModel.startSimulation;          % external (SLDRT) mode

Lab 1 is src/Lab_1.mlx; Lab 3 sine-sweep is src/lab_3.m. Those scripts assign sim_input themselves, then set_param('MSE_PLANT', ...).

Layout

src/
  MSE_PLANT.slx              % Desktop Real-Time plant
  Lab_1.mlx, lab_1.m, lab_3.m
  App/
    main.m                   % app entry (MVC)
    AppModel.m, AppView.m, AppController.m
    components/
      forcing_builder/       % standalone forcing-function UI
      main_panels/           % Time, Frequency, Sidebar
      Images/
docs/                        % developer guides

Documentation

Changing code? Start at docs/README.md.

Guide	When to open it
architecture.md	How the app, builder, plant, and labs fit together
app.md	Main window, sidebar, Simulink wiring
signal-builder.md	Forcing-function UI, or adding a new waveform type
signals.md	How each *Signal is computed
labs-and-plant.md	MSE_PLANT, hardware parameters, lab scripts

MATLAB classes use the SignalBuilderModel header style: a short description plus an Example usage block you can paste into the Command Window.