Abstract

Nulling-type tilt control in tilting railway vehicles, i.e. SISO (Single-Input-Single-Output) control us-
ing non-precedent sensor information for lateral acceleration and tilt angle, suffers from performance
limitations due to the system’s non-minimum phase characteristics Zolotas & Goodall (2000). From a
engineering point of view this is due to the suspension’s dynamic interactions and the sensor information
used for feedback control. This paper revisits SISO PID-based nulling-type tilt control design (hereby
referred to as “economical tilt control”) and rigorously studies its design via optimization to improve
system performance. The strong coupling between the roll and lateral dynamic modes of the vehicle body
is shown and the performance limitations using conventional control highlighted. PID controllers are de-
signed to illustrate different levels of tilt performance regarding the deterministic (curving acceleration
response) and stochastic (ride quality) with the latter being a bounded constraint. With novel contri-
bution to use of PID control in the tilt control application with rational transfer functions, particular
emphasis is placed on the practical aspects of the tilt dynamics within the design framework via detailed
simulation results.