Worse-case Methodology---Example Applications
on Truck Rollover, VSC and Rollover Warning
Active safety technologies (AST) define a group of technologies
for vehicle safety enhancement and crash avoidance. AST product
development is accelerating rapidly in Europe and Japan, but proceeds at
a much slower pace in the U.S. This difference is partly due to
business strategy and perceptions of market readiness. A major
contributing factor, however, is litigations/liability concerns. To
speed up the AST product development, it is necessary to develop an
effective evaluation methodology for guaranteed AST system performance
under the worst possible scenarios. The worst-case scenario generator
algorithm should identify the weak links of the vehicle/control systems
and generate worst-case evaluation maneuver in an intelligent manner. A
carefully designed test procedure that combines traditional testing and
the worst-case testing methods can systematically identify AST
performance under common as well as worst-case scenarios, which will
accelerate the overall products development cycles of AST techniques.
Given the above motivation, it is clear that a worst-case
disturbance generator needs to be developed. The worst-case
disturbances will first be generated by linear optimal control and game
theories. Depending on the existence, information structre, and goals
of the control algorithms, we formulated 4 different linear cases. The
linear solutions than serve as initial guess, base on which the final
worst-case disturbances are obtained numerically.
Finally, two example vehicle applications will be demonstrated.
The first is the rollover and jackknife of articulated vehicles (a one-player
example). The second one is the evaluation of an interactive vehicle
dynamic system (a two-player example). Application of the worst-case
methodology on improved vehicle control and warning systems will be
given.