L1 adaptive controller with additional uncertainty bias estimation

This paper presents an L₁ adaptive controller with an additional approximator in the adaptive law. The new approximator is used to estimate biases in system uncertainties. The benefit of this approach is the ability to maintain performance with increased integration step-size. This is an important improvement because hardware sampling time is a limitation in any real-world application. The improvements of this design are verified in simulation using two different step-sizes, and comparing the results to the traditional L₁ controller.