Projections or dead-zones: A non-singular performance comparison in robust adaptive control

We consider robust adaptive control designs for relative degree one, minimum phase linear systems of known high frequency gain. The designs are based on the dead-zone and projection modifications, and we compare their performance w.r.t. a worst case transient cost functional penalising the L^∞ norm of the output, control and control derivative. If a bound on the L^∞ norm of the disturbance is known, it is shown that the dead-zone controller outperforms the projection controller when the a-priori information on the unknown system parameter is sufficiently conservative.