On the Jitter Sensitivity of an Adaptive Digital Controller: A Computational Simulation Study

In many real
-
time control applications, the ability to accurately track a reference trajectory with stable, pre
-
specified
closed
-
loop dynamics is highly desirable. For fixed gain control systems, the detrimental impact of jitter
on performance has been relatively well studied. However, research that quantifies the possible impact of jitter on
the performance and relative stab
ility of adaptive control schemes is comparatively much rarer. With technology
advances now making real
-
time adaptive control a viable option for high
-
speed applications, this situation requires
further investigation. In this paper, the jitter sensitivity
of a digital parameter adaptive tracking control system is
studied using precise software
-
in
-
the
-
loop computational simulations. The results obtained indicated that the
adaptive controller was significantly susceptible to jitter. In particular, key metrics
such as the phase margin, gain
margin, settling time, overshoot and root mean square parameter and tracking errors were all significantly
impacted following the introduction of 5% jitter in the controller. The obtained data are thought to be the first
det
ailed results of this kind and present useful insights into the practical complexities when innovating adaptive
real
-
time tracking control systems and indicate that specialized controller implementations that minimize jitter
should be employed and that fur
ther analysis is warranted
.