Systems and methods for vehicle cruise control
View Patent ↗An exemplary cruise control system includes an application that integrates curvature speed control, speed limit control, and adaptive speed control and generates an optimized speed profile that is used to control the vehicle.
1. A cruise control system, comprising:
a positioning sensor configured to obtain a set of locations along a road;
a distance sensor configured to measure a distance to a proximate vehicle from a controlled vehicle;
a speed sensor configured to measure a speed of a proximate vehicle;
a processor; and
a memory having stored thereon computer-executable instructions comprising:
a speed optimization application that, when executed by the processor, causes the processor to determine a speed profile, the speed profile comprising a set of speeds corresponding to the set of locations, wherein the speed profile is determined as a minimum of:
a first sub-expression representing a time to move through the set of locations;
a second sub-expression representing a longitudinal acceleration of the controlled vehicle at the set of locations;
a third sub-expression representing a lateral acceleration of the controlled vehicle at the set of locations; and
a fourth sub-expression representing an accumulated deviation from a traffic flow velocity.
2. The cruise control system of claim 1 , wherein the cruise control system is configured to control the speed of the controlled vehicle according to the speed profile.
3. The cruise control system of claim 2 , the memory further comprising an adaptive cruise control application configured to generate a control speed as a function of the speed of a proximate vehicle measured by the speed sensor; wherein the cruise control system is configured to control the speed of the controlled vehicle according to the control speed.
4. The cruise control system of claim 3 , wherein the cruise control system is configured to control the speed of the controlled vehicle according to the control speed if a distance measured by the distance sensor is less than a threshold distance.
5. The cruise control system of claim 3 , wherein the adaptive cruise control application is configured to generate the control speed as approximately the speed of the proximate vehicle measured by the speed sensor.
6. The cruise control system of claim 3 , further comprising a selecting application comprising computer executable instructions that, when executed by the processor, cause the processor to:
indicate a presence of a closest-in-path proximate vehicle if a distance to a proximate vehicle measured with the distance sensor is less than a threshold distance; and
otherwise, indicate an absence of a closest-in-path proximate vehicle.
7. The cruise control system of claim 6 , the selecting application further comprising computer executable instructions that, when executed by the processor, cause the processor to:
determine the indication;
control the speed of the controlled vehicle according to the control speed if the presence of a closest-in-path vehicle is indicated; and
otherwise, control the speed of the controlled vehicle according to the speed profile.
8. The cruise control system of claim 2 , wherein the cruise control system is configured to control a throttle.
9. The cruise control system of claim 1 , wherein the first sub-expression is a function of an inverse of the speed.
10. The cruise control system of claim 1 , wherein the first sub-expression is
∫
0
S
1
v
(
s
)
ⅆ
s
where s is location, S is arclength, and v(s) is the speed profile.
11. The cruise control system of claim 1 , wherein the second sub-expression is a function of a derivative of speed with respect to location.
12. The cruise control system of claim 1 , wherein the second sub-expression
∫
0
S
v
(
s
)
ⅆ
v
(
s
)
ⅆ
s
ⅆ
s
where s is location, S is arclength, and v(s) is the speed profile.
13. The cruise control system of claim 1 , wherein the third sub-expression is a function of a derivative of heading with respect to location and a difference between a square of the velocity and a square of a speed limit.
14. The cruise control system of claim 1 , wherein the third sub-expression is
∫
0
S
k
(
s
)
(
v
(
s
)
2
-
v
L
(
s
)
2
)
ⅆ
s
where s is location, S is arclength, and v(s) is the speed profile, v L (s) is speed limit at location, and k(s) is curvature given by
k
(
s
)
=
ⅆ
θ
(
s
)
ⅆ
s
where θ(s) is heading angle.
15. The cruise control system of claim 1 , wherein the fourth sub-expression is a function of a difference between the traffic flow velocity and a speed of the controlled vehicle.
16. The cruise control system of claim 1 , wherein the fourth sub-expression is
∫
0
S
H
(
s
)
ⅆ
s
where H(s) is given by
H ( s )=| v ( s ) v t ( s )|
where v(s) is speed profile and v t (s) is the traffic flow velocity.
17. The cruise control system of claim 16 , wherein the traffic flow velocity is an interpolation of speeds of a plurality of proximate vehicles.
18. The cruise control system of claim 1 , where the speed profile is determined by minimizing a cost path through a Trellis graph, the Trellis graph including a range of speeds associated with each location.
19. The cruise control system of claim 18 , wherein the path through the Trellis Graph includes nodes connected by edges.
20. The cruise control system of claim 1 , wherein the cruise control system is configured to control a braking system.