L1 adaptive control design for the rigid body launch vehicle

Abstract

This paper investigates the use of an L1-adaptive controller to improve the performance of the Vega launch vehicle because the classical controller does not guarantee stability and tracking of the system in the transient. The L1-AC ensures uniformly bounded transient and steady-state tracking for both systems’ signals, input, and output. In this paper, we used the equations of the adaptation and the L1-norm with two filters, the first one is first-order order and the second filter is third-order, we used the large adaptive gain with the first filter, also used the low adaptive gain with the second filter, and after the analysis the result numerically we found the lambda with the first filter less than 1 and the lambda with second filter larger than lambda with the first filter. The L1 adaptive controller can generate a stable system response to track the control input and the system output, both in transient and steady-state because we selected the adaptive gain large with minimize lambda. It is noted that the system response for the L1 adaptive control configuration with the first filter, as compared with the system response with the second filter, has much better performances, both from the point of view of the overshoot and rise time.

Keywords

• l1 adaptive controller
• vega launch vehicle
• performance and stability
• smooth transient tracking
• pd controller