Abstract
Many stability proofs have been already presented both for continuous and discrete time model reference adaptive control (MRAC) systems. However, these are all for the direct MRAC scheme where the controller-parameters are directly adjutsted by the adaptive law, except for the one by Sastry and Bodson. This paper presents a simple stability proof for the continuous time indirect MRAC scheme where the controller-parameters are determined from the plant-parameter estimates via design calculation. In this method, the system is analyzed by using the relation between control error and identification error and the properties guaranteed by the adaptive law, and then the stability is proved by applying Gronwall's lemma as in the ones by Morse and Goodwin et al.. The proposed method is easier to understand than the one by Sastry and Bodson based on the regularity of the signals.
