Dual control for an unstable mechanical plant

The problem of applying direct dual control for positioning of a laboratory pilot-plant for the roll angle control of a vertical takeoff airplane by means of two propellers is described in the article. The bicriterial approach is applied for the synthesis of dual controllers, where two criteria are used which correspond to the two goals of dual control: control of the system output and exciting the system for speeding up the parameter estimation. The control law is derived after compromised optimization of two cost functions. The basic theory needed for synthesis of a direct dual control for linear single-input, single-output plants is discussed. After describing the experimental setup, the results of adaptive control of a mechanical laboratory pilot-plant are presented. It is pointed out that adaptive control is necessary and is the most suitable approach for this kind of plant. The new direct dual control algorithm is compared with indirect and direct adaptive control strategies based on the standard CE assumption