Quanser QUBE-Servo

This repository contains the C code required to generate the experimental dataset used in Closed-Loop Koopman Operator Approximation, which can be found in the companion repository.

This dataset uses the Quanser QUBE-Servo (version 1), but makes use of the Quanser HIL SDK to use the device, rather than Simulink.

Requirements

This software has only been tested with the Windows version of the Quanser HIL SDK, though a Linux version does exist that should be compatible with the QUBE-Servo.

First, install the Quanser HIL SDK and ensure that the environment variable %HIL_DIR% is set to the appropriate location. This should be C:\Program Files\Quanser\HIL SDK.

Next, install Microsoft Visual Studio Community, as the HIL SDK only supports the msvc compiler.

Finally, install CMake, which will be used to build the project.

Optionally, to run the unit tests, install Catch2 with CMake integration via vcpkg. To do so, follow these instructions in the x86 Native Tools terminal. However, be sure to install the 64-bit version of Catch2 instead, by running vcpkg.exe install catch2:x64-windows.

Usage

To compile the project, first create a directory called build/ inside the root of the repository, navigate to it, and run CMake to generate the required Visual Studio projects:

> mkdir build
> cd build
> cmake ..

Then run

cmake --build .

from within build/ to compile the project.

The main executable is build/src/Debug/QubeBalance.exe, which can be run as-is, or with seeds for the pseudorandom binary sequences as arguments:

> QubeBalance.exe 123 456 789

If the QUBE-Servo is connected, it will wait for the user to position the pendulum upright before running the controller. After execution, the program will save a CSV file containing the results wherever the program was run from. It will have a name like qube_<TIMESTAMP>_<THETA_SEED>_<ALPHA_SEED>_<FEEDFORWARD_SEED>.csv

Optionally, to run all the unit tests, run

> ctest -C Debug

Outputs

The CSV output has the following columns

Column	Description
t	Timestamp (s)
target_theta	Target motor angle (rad)
target_alpha	Target pendulum angle (rad)
theta	Measured motor angle (rad)
alpha	Measured pendulum angle (rad)
control_output	Control signal calculated by the controller (V)
feedforward	Feedforward signal to be added to control_output (V)
plant_input	control_output summed with feedforward (V), saturated between -10V and 10V
saturation	Signal indicating if saturation is active (i.e., -1 if saturating in the negative direction, +1 if saturating in the positive direction)