This is a simple implementation of a simulated cartpole in javascript where the user battles an LQR controller.
Try the game here
The challenge is to keep the pole upright, and keep close to the target x-coordinate. The further away from the target, the lower score you get each step.
The LQR controller is synthesized using ModelingToolkit.jl for implementing and linearizing the model, and ControlSystems.jl to solve the Riccati equation.
To run the script, install Julia and add the Pluto.jl package. Run Pluto and open the notebook src/lqr_tuning.jl, it might take a while the first time since it installs and precompiles the dependencies.