Since there is complex dependence between total autonomous flight performance cost index and the constraints on the optimization variables (3 P-I-D gains for longitudinal controller
, 3 P-I-D gains for lateral controller, and 2 passive morphing parameters of TUAV and 2 active morphing parameters of TUAV, entire of 10 parameters), computation of cost function derivatives with respect to these parameters is not analytically possible.
The output variable of the longitudinal controller is the actual signal u; it represents the throttle opening or the braking pedal travel.
There are two inputs variables RD and RV into the fuzzy longitudinal controller. The output variable u of the longitudinal controller is the throttle opening or the braking pedal travel.
In this paper, the braking pedal travel S is one of the output variables of the longitudinal controller. So, it will need to convert the pedal force [P.sub.b] into pedal travel S.
Nouveliere and Mammar  proposed an experimental implementation of a shared vehicle longitudinal controller
based on a second-order sliding mode technique, which was tested under usual traffic conditions such as stop-and-go, stopping at obstacles, and car-following in a number of scenarios, but it mainly concentrated on the low velocity.