A recent paper by members of the DCIST alliance develops the use of reinforcement learning techniques to train policies in simulation that transfer remarkably well to multiple different physical quadrotors. Quadrotor stabilizing controllers often require careful, model-specific tuning for safe operation. The policies developed are low-level, i.e., they map the rotorcrafts’ state directly to the motor outputs. The trained control policies are very robust to external disturbances and can withstand harsh initial conditions such as throws. The work shows how different training methodologies (change of the cost function, modeling of noise, use of domain randomization) might affect flight performance. The is the first work that demonstrates that a simple neural network can learn a robust stabilizing low-level quadrotor controller (without the use of a stabilizing PD controller) that is shown to generalize to multiple quadrotors.
Sim-to-(Multi)-Real: Transfer of Low-Level Robust Control Policies to Multiple Quadrotors
A.Molchanov, T. Chen, W. Hönig, J. A.Preiss, N. Ayanian, G. S. Sukhatme
IEEE/RSJ International Conference on Robots and Systems (IROS) 2019