Take a look at
Membership Functions

4 Inputs
Input	Symbol
Distance from robot to the waypoint	$d_{wpt}$
Distance from robot to the closest obstacle	$d_{obs}$
Angle between robot and obstacle	$\delta_{obs}$
Angle between waypoint and obstacle	$\delta_{wpt-obs}$

4 Outputs
Output	Symbol
Behavior coefficient of FIS for go_to_waypoint behavior	$\beta_{wpt}$
Behavior coefficient of FIS for avoid_obstacle behavior	$\beta_{o}$
Behavior coefficient of FIS for wall_follow behavior	$\beta_{w}$
Behavior coefficient of FIS for wander behavior	$\beta_{wd}$

$d_{wpt}$

$d_{obs}$

$\delta_{obs}$

$\delta_{wpt-obs}$

$\beta_{o}$

$\beta_{t}$ , $\beta_{w}$ and $\beta_{wd}$