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intention levels by breaking down the starting of the vehicle into four phases for
which the information given to the driver can be different (Figure 7.12):
- stop: the driver is not doing anything to indicate a maneuver;
- selection of the direction of the maneuver: the driver shows his intention to
initiate a maneuver;
- starting: the driver initiates a maneuver; and
- moving forward: the driver carried out a maneuver.
(1)
Stop
(2)
Selection backward
Selection Turn Right Forward
Selection forward
(3)
StartingTurn Right Forward
Starting backward
Starting forward
(4)
Moving forward
Moving Turn Right Forward
Moving backward
Figure 7.12.
Driver intention model for the activation of the system
The model retained comprises three intention levels that are involved during the
realization of three maneuvers identified in the scenarios described in Table 7.1
(“moving forward”, “reversing” and “turn right while moving forward”). Nine states
therefore combine these two criteria (situation to be covered and activity phases of
the driver) and the tenth corresponds to “stop” (see Figure 7.12).
As the assistance strategies during the forward maneuvers are different
depending on whether the driver turns right (consideration of the vulnerable users
coming along the right-hand side of the vehicle) or not (consideration of the
vulnerable user in front of the vehicle only), the states are duplicated. Moreover,
these states are connected as the evolution of “moving forward” to “turn right” can
occur without going via the “stop” stage, which is not the case for the change
between “going forward” and “reversing”.
The advantage of this type of model is twofold. First, it takes into account the
intentions of the driver that are inferred based on his behavior in real time, for
example, when the driver shifts into reverse, the speed is lower than a given
threshold and the accelerator is greater than a given threshold, the intention is “back
selection”.
This requires the different states of the driver to be defined and then the
objective measures which could differentiate them to be searched for. Second, this
model provides a semantic of the activity that can be understood whatever the
discipline: the ergonomics will be able to validate the functioning of the HMI
