Abstract:

The problem of disturbance attenuation by output feedback was investigated for a class of nonlinear systems with an uncertain control coefficient and unmeasured states dependent growth. This problem could not be solved by the existing methods because of the uncertainty of the control coefficient. In order to realize disturbance attenuation by the control, highgain Kfilters were first introduced and an appropriate state observer was constructed based on the K-filters. Then, a linear output feedback controller was designed using the backstepping technique. By choosing appropriate design parameters, disturbance attenuation was achieved in the sense of L₂-gain.

Key words: nonlinear systems; uncertain control coefficient; disturbance attenuation; high-gain K-filters; output feedback