REAL-TIME ANTICIPATORY SPEED CONTROL

• US 20160318513A1
• Filed: 04/30/2015
• Published: 11/03/2016
• Est. Priority Date: 04/30/2015
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: LEE, JIN-WOO
• Granted Patent: US 9,650,043 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60W 10/20 including control of steering systems
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2552/30 Road curve radius
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/12 Lateral speed
• CPC Class Codes: B60W 30/0956 the prediction being responsive to traffic or environmental parameters
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 40/072 Curvature of the road
• CPC Class Codes: B60W 40/109 Lateral acceleration
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 19/393 Trajectory determination or predictive tracking, e.g. Kalman filtering
• CPC Class Codes: G01S 19/49 whereby the further system is an inertial position system, e.g. loosely-coupled
• CPC Class Codes: G06F 18/25 Fusion techniques
• CPC Class Codes: G06V 20/56 exterior to a vehicle by using sensors mounted on the vehicle

Abstract

An anticipatory speed-control system and method for generating a speed profile in real time by iteratively calculating proposed reduced speeds associated with an electronically identified target curve until the proposed speed is compliant with a lateral-acceleration-based comfort metric and a steering-angle-based safety metric and implementing the speed profile in accordance with a longitudinal comfort metric and providing a user with override options.

Claims

1. A vehicular, anticipatory speed-control system comprising:

a vehicular speed-profile generator configured to generate a speed profile in accordance with predicted lateral acceleration of a target curve identified at least partly from map data; and

a speed controller configured to actuate vehicle deceleration in accordance with the speed profile,

wherein the predicted lateral acceleration is calculated in accordance with

2. The vehicular, anticipatory speed-control system of claim 1, wherein the vehicular speed-profile generator is further configured to generate the speed profile in accordance with predicted lateral acceleration at the target curve.

3. The vehicular, anticipatory speed-control system of claim 2, wherein the vehicular speed-profile generator is further configured to generate the speed profile in accordance with a change in steering angle.

4. The vehicular, anticipatory speed-control system of claim 1, wherein the vehicular speed-profile generator is further configured to model a travel path as a Vehicle Centered Path (VCP) in accordance with a 5th order polynomial equation.

5. The vehicular, anticipatory speed-control system of claim 2, wherein the speed-profile generator is further configured to calculate a deceleration location “

s_curve”

in accordance with “

s_curve”

=(v_x,pred²−

v_x,current²)/2a_x,lim, wherein “

s_curve”

is a distance spanning a current vehicle location and the target curve and “

a_x,lim”

is a longitudinal deceleration limit, “

v_x,pred”

is predicted longitudinal velocity, and “

v_x,current²”

is current longitudinal velocity.

6. The vehicular, anticipatory speed-control system of claim 5, wherein the position-tracking unit includes a Global Positioning System (GPS) receiver.

7. The vehicular, anticipatory speed-control system of claim 5, wherein the position tracking unit is configured to track the vehicle position in accordance with a dead reckoning algorithm responsively to loss of a GPS signal, the dead reckoning algorithm including Kalman filtering.

8. The vehicular, anticipatory speed-control system of claim 2, further comprising a Human Machine Interface (HMI) configured to inform a driver of a planned deceleration.

9. The vehicular, anticipatory speed-control system of claim 8, wherein the HMI is further configured to prompt a driver to override the planned deceleration.

10. A method for anticipatory speed-control comprising:

providing a vehicular speed-command generator configured to generate a speed profile in accordance with predicted lateral acceleration through a target curve identified at least partly from map data; and

decelerate the vehicle responsively deceleration in accordance with the speed profile,

wherein the predicted lateral acceleration {dot over (v)}i_{y pred} is calculated in accordance with

11. The method of claim 10, wherein the speed-profile generator is further configured to calculate a deceleration location “

s_curve”

in accordance with “

s_curve”

=(v_x,pred²−

v_x,current²)/2a_x,lim, wherein “

s_curve”

is a distance spanning a current vehicle location and the target curve and “

a_x,lim”

is a longitudinal deceleration limit, “

v_x,pred”

is predicted longitudinal velocity, and “

v_x,current²”

is current longitudinal velocity.

12. The method of claim 10, wherein the longitudinal deceleration limit “

ax,lim”

is implemented at a value less than or equal to 0.15 g.

13. The method of claim 10, wherein the vehicular speed-command generator is further configured to generate the speed profile in accordance with predicted steering angle associated with the target curve.

14. The method of claim 13, wherein the vehicular speed-command generator is further configured to generate the speed profile in accordance with predicted change in steering angle associated with the target curve.

15. The method of claim 14, wherein the speed-profile generator includes a position-tracking unit configured to track vehicle position.

16. The method of claim 15, wherein the position-tracking unit includes a Global Positioning System (GPS) receiver.

17. The method of claim 15, wherein the tracking module is configured to track vehicle position in accordance with a dead reckoning algorithm responsively to loss of a GPS signal, the dead reckoning algorithm including Kalman filtering.

18. The method of claim 10, further comprising informing a driver of a proposed deceleration.

19. The method of claim 10, further comprising providing a prompt requesting driver override of the proposed deceleration.

20. The method of claim 18, further comprising providing a prompt requesting driver override of the proposed deceleration.