Method for estimating and displaying range of a vehicle
Estimating a vehicle's driving range by combined processing of measured and calculated range data. A measured range it is adjusted to account for processes not included in the original measurements. These adjustments may include changes in road surface, terrain elevation, aerodynamic drag, or other losses. The resulting model is thus relative to the conditions used in quantifying vehicle range by calculating contributions that either penalize or enhance the measured range. This method is implemented in a software system that can also provide real-time display of the range for both a single trip or a contour that illustrates what the range is for all directions.
1. A method for estimating a range of a vehicle to follow along a projected route comprising:
within a computerized apparatus:
determining a set of N road segments that comprise the route;
receiving information concerning a measured maximum range, D max ;
determining an energy spent to travel along each such road segment, k, from
∑
k
n
≤
N
α
k
d
k
=
D
max
where
d k =s k cos(θ k )
is a projection of the k-th segment s k on a ground reference; and
α
k
=
1
(
1
+
Γ
)
(
1
+
Δ
)
[
(
μ
k
μ
ave
)
+
(
tan
(
θ
k
)
μ
ave
)
+
Γsec
(
θ
k
)
(
v
k
v
ave
)
2
+
Δ
(
1
+
Γ
)
sec
(
θ
k
)
(
G
k
+
H
k
G
ave
+
H
ave
)
]
is a coefficient that weighs contributions for one or more current conditions that depend on one or more aspects of road slope angle θ k , rolling resistance μ k , velocity v k , driver behavior G k , and/or accessory energy H k for each road segment, k, relative to one or more aspects of measured values including a ratio of aerodynamic force to rolling resistance force Γ, and other forces including effective vehicle accessory forces Δ, average rolling resistance μ ave , average velocity v ave , average driver behavior G ave , and average accessory energy H ave ; and
adjusting the measured range according to the energy spent to follow the projected route for each of the road segments; and
on a display device located in the vehicle,
displaying a representation of a result of adjusting the measured range.
2. The method of claim 1 further comprising:
on the display device located in the vehicle,
displaying information representing a location along the route where remaining energy available for the vehicle to follow the route would reach a predetermined energy level.
3. The method of claim 1 further comprising, on the display device located in the vehicle:
displaying information representing the route with color or gray scale coding to indicate locations along the route where remaining energy available for the vehicle to follow the route reaches two or more predetermined levels.
4. The method of claim 1 further comprising, on the display device located in the vehicle:
displaying the result of adjusting the measured range as a contour line of multiple compass points referenced to a current location of the vehicle.
5. The method of claim 1 further comprising:
within the display device located in the vehicle:
(d) displaying a map; and
(e) overlaying on the map the result of adjusting the measured range.
6. The method of claim 5 , further comprising, within the display device located in the vehicle,
displaying range contour lines with color or gray scale coding to indicate two or more predetermined range contours with reference to a starting location of the route.