Driving assistance method for a public transport vehicle
The method comprises, for a given route between a starting point and a destination, and for an arrival at the destination at a given desired time: a preliminary step of determining and recording a plurality of vehicle mission profiles, at least a first instant during the journey, a step of determining an instantaneous position of the vehicle at this first instant and a desired time remaining to reach the destination, a step of identifying, among the mission profiles, the mission profile(s) whose curves are closest to the desired time remaining at the instantaneous position of the vehicle, and a step of determining new driving parameters to follow a new mission profile, the new mission profile being determined on the basis of the determined mission profiles.
1. A device for assisting in driving a public transport vehicle, for a given journey between a starting point and a destination, and for an arrival at the destination at a given desired time, said device comprising a driving assistance device wherein:
said driving assistance device is configured to determine and record a plurality of mission profiles of the vehicle, each profile being formed by a curve of time remaining to reach the destination as a function of a position of the vehicle on the route according to driving data parameters associated with this profile,
said driving assistance device is configured so that at a first instant during the journey, said driving assistance device determines an instantaneous position of the vehicle at this first instant and a desired time remaining to reach the destination, the desired time remaining being obtained by the difference between the desired time given to arrive at the destination and the first time,
said driving assistance device is configured to identify a mission profile from said plurality of mission profiles whose curves are closest to the desired time remaining at the instantaneous position of the vehicle,
said driving assistance device is configured to compare the desired time remaining with the lowest time remaining at the instantaneous position among all of said plurality of mission profiles,
said driving assistance device is configured so that when the desired time remaining is less than the lowest time remaining at the instantaneous position among all of said plurality of mission profiles, said driving assistance device determines new driving parameters to follow a new mission profile, the new mission profile being the profile whose time remaining is the lowest at the instantaneous position among all the determined new mission profiles,
said driving assistance device is configured so that when the desired time remaining is greater than the highest time remaining at the instantaneous position among all the profiles but below a predetermined value, determining new driving parameters to follow a new mission profile, the new mission profile being the profile with the highest time remaining at the instantaneous position among all the determined new mission profiles,
said driving assistance device is configured so that when the desired time remaining is, at the instantaneous position, between the time remaining of two profiles comprising an upper framing profile whose time remaining at the instantaneous position is immediately greater than the desired time remaining and a framing profile less than the time remaining at the instantaneous position is immediately less than the desired time remaining,
said driving assistance device is configured so that weightings are calculated from the desired time remaining at the instantaneous position and the time remaining at said instantaneous position for each framing mission profile, the weightings comprising a first weighting and a second weighting and being calculated as follows:
W
1
=
(
RT
2
-
RT
)
(
RT
2
-
RT
1
)
and
W
2
=
(
RT
-
RT
1
)
(
RT
2
-
RT
1
)
,
where W1 is the first weighting, applied to the lower profile,
W2 is the second weighting, applied to the upper profile,
RT is the desired time remaining at the instantaneous position,
RT1 is the time remaining at the instantaneous position for the lower framing profile, and
RT2 is the time remaining at the instantaneous position for the upper framing profile; and
said driving assistance device is configured so that new driving parameters are determined to follow a new mission profile, the new mission profile being an intermediate weighted profile between the surrounding mission profiles as a function of the results obtained in the weighting calculation; and
W
1
=
(
RT
2
-
R
T
)
(
R
T
2
-
RT
1
)
W
2
=
(
RT
-
RT
1
)
(
RT
2
-
RT
1
)
,
wherein said deriving assisting device is configured for transmitting the new driving parameters to traction and braking devices of said public transport vehicle, said traction and braking devices being configured to apply the new driving parameters based on the determined mission profile.
2. The device for assisting in driving according to claim 1 , wherein the driving parameters comprise at least one parameter selected from the group consisting of an instantaneous speed, a position of a driving lever, and a tractive effort of the vehicle.
3. The device for assisting in driving according to claim 1 , wherein determining new driving parameters comprises:
determining a target speed to be reached within a predetermined time frame to follow the new mission profile,
determining an instantaneous speed of the vehicle, and
indicating driving instructions to a driver of the public transport vehicle, said driving instructions comprising instructions for modifying the instantaneous speed in order to approach the target speed.
4. The device for assisting in driving according to claim 3 , wherein the new driving parameters are determined by calculating the target speed as follows:
if
W 1 *S 2 +W 2 *S 1≠0,
TS =(( S 2* S 1))/(( W 1* S 2+ W 2* S 1))
where TS is the target speed profile to be reached within a predetermined time frame,
W1 is the first weighting,
W2 is the second weighting,
S1 is the speed profile at the instantaneous position for the lower framing profile, and
S2 is the speed profile at the instantaneous position for the upper framing profile, and in cases where
W 1* S 2+ W 2* S 1=0,
the target speed is 0.
5. The device for assisting in driving according to claim 1 , wherein determining new driving parameters comprises:
determining a target speed to be reached within a predetermined time frame to follow the new mission profile,
determining an instantaneous speed of the vehicle, and
automatically modifying the instantaneous speed in order to approach the target speed.
6. The device for assisting in driving according to claim 1 , wherein the vehicle comprises a satellite guidance device for determining the instantaneous position of the vehicle and the desired time remaining.
7. The device for assisting in driving according to claim 1 , wherein when the vehicle performs at least one trip between a first starting point and a first destination, then a journey between this first destination becoming a second departure point, and a second destination, said vehicle performs two distinct missions.
8. The device for assisting in driving according to claim 1 , wherein the starting point and the destination of each mission are stops or passage points on the route.
9. A public transport vehicle comprising a device for assisting the driving according to claim 1 .
10. The device for assisting in driving according to claim 1 , wherein the new driving parameters are applied automatically.