Third-order polynomial-based course prediction for driver assistance functions

• US 9,045,144 B2
• Filed: 01/31/2014
• Issued: 06/02/2015
• Est. Priority Date: 05/09/2013
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schwindt, Oliver F., Gulati, Shilpa, Chakraborty, Bhavana
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): Lee, Tyler J
• Application Number:
  US14/169,958
• Publication Number:
  US 20140336844A1
• Time in Patent Office: 487 Days
• Field of Search: 701/1, 701/36, 701 41- 44, 701/58, 701/70, 701 93- 98, 701/301, 180/280, 340/435
• US Class Current: 1/1
• CPC Class Codes: B60K 31/0008 including means for detecting potential obstacles in vehicle path
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 2520/14 Yaw
• CPC Class Codes: B60W 2520/20 Sideslip angle
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2554/00 Input parameters relating to objects
• CPC Class Codes: B60W 2554/80 Spatial relation or speed relative to objects
• CPC Class Codes: B60W 2554/801 Lateral distance
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• CPC Class Codes: B60W 30/0953 the prediction being responsive to vehicle dynamic parameters
• CPC Class Codes: B60W 30/10 Path keeping cruise control for automatically following a preceding vehicle B60W30/165
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 30/16 Control of distance between vehicles, e.g. keeping a distance to preceding vehicle
• CPC Class Codes: B60W 30/18163 Lane change; Overtaking manoeuvres
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B62D 15/025 Active steering aids, e.g. helping the driver by actively influencing the steering system after environment evaluation B62D1/28 takes precedence
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G05D 1/00 Control of position, course, altitude or attitude of land, water, air or space vehicles, e.g. using automatic pilots drive control systems specially adapted for autonomous road vehicles B60W60/00
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: Y02T 10/84 : Data processing systems or methods, management, administration

Abstract

Methods and systems for performing vehicle driver assistance. One method includes determining, at a controller, whether the vehicle is steering toward a drive-straight state and when the vehicle is steering toward the drive-straight state, calculating, at the controller, a predicted course trajectory using a third order polynomial. The method also includes calculating, at the controller, the predicted course trajectory using a non-third-order function when the vehicle is not steering toward the drive-straight state. In addition, the method includes performing the driver assistance based on the predicted course trajectory.

Claims

1. A method of performing driver assistance for a vehicle, the method comprising:

receiving a state signal from at least one dynamic state sensor,

determining, at a controller, whether the vehicle is steering toward a drive-straight state, based on the state signal;

calculating, at the controller, a predicted course trajectory using a third order polynomial in response to a determination that the vehicle is steering toward the drive-straight state;

calculating, at the controller, the predicted course trajectory using a non-third-order function in response to a determination that the vehicle is not steering toward the drive-straight state; and

performing the driver assistance based on the predicted course trajectory.

2. The method of claim 1, wherein determining whether the vehicle is driving toward the drive-straight state includes determining whether a steering angle of the vehicle is greater than zero and a steering angle velocity of the vehicle is less than zero.

3. The method of claim 1, wherein determining whether the vehicle is driving toward the drive-straight state includes determining whether a steering angle of the vehicle is less than zero and a steering angle velocity of the vehicle is greater than zero.

4. The method of claim 1, wherein calculating the predicted course trajectory using a third order polynomial includes calculating a first portion of the predicted course trajectory using the third order polynomial, the first portion extending from the vehicle in a driving direction of the vehicle, and calculating a second portion of the predicted course trajectory using a non-third-order function, the second portion extending from an end of the first portion in the driving direction of the vehicle.

5. The method of claim 4, wherein calculating the first portion of the predicted course trajectory includes determining a distance along the first portion where the vehicle reaches a zero-curvature point, the zero-curvature point defining the end of the first portion.

6. The method of claim 5, wherein determining the distance includes calculating the zero-curvature point in a longitudinal direction based on a tangent of a steering angle of the vehicle divided by a distance between a front axle and a rear axle of the vehicle.

7. The method of claim 4, wherein determining the distance includes calculating the zero-curvature point in a longitudinal direction based on a yaw rate of the vehicle divided by a velocity of the vehicle.

8. The method of claim 4, wherein calculating the second portion of the predicted course trajectory includes calculating the second portion using a linear model.

9. The method of claim 1, further comprising, when a velocity of the vehicle is less than approximately 1.0 meters per second, calculating the predicted course trajectory using a non-third-order function.

10. The method of claim 1, wherein calculating the predicted course trajectory using the third order polynomial includes combining the predicted course trajectory calculated using the third order polynomial and the predicted course trajectory calculated using the non-third-order function.

11. A driver assistance system for a vehicle, the system including:

a vehicle dynamic state sensor; and

a controller configured to;

receive a signal from the vehicle dynamic state sensor,

determine whether the vehicle is steering toward a drive-straight state based on the signal from the vehicle dynamic state sensor,

calculate a predicted course trajectory using a third order polynomial in response to a determination that the vehicle is steering toward the drive-straight state,

calculate the predicted course trajectory using a non-third-order function in response to a determination that the vehicle is not steering toward the drive-straight state, and

perform a driver assistance function based on the predicted course trajectory.

12. The system of claim 11, wherein the signal indicates at least one selected from the group comprising (i) a steering angle of the vehicle, (ii) a steering angle velocity of the vehicle, (iii) a yaw rate of the vehicle, and (iv) a velocity of the vehicle.

13. The system of claim 11, wherein the controller determines whether the vehicle is driving toward the drive-straight state based on whether a steering angle of the vehicle is less than zero and a steering angle velocity of the vehicle is greater than zero.

14. The system of claim 11, wherein the controller is configured to calculate the predicted course trajectory using the third order polynomial by calculating a first portion of the predicted course trajectory using the third order polynomial, the first portion extending from the vehicle in a driving direction of the vehicle, and calculating a second portion of the predicted course trajectory using a non-third-order function, the second portion extending from an end of the first portion in the driving direction of the vehicle.

15. The system of claim 14, wherein the controller is configured to determine a distance along the first portion where the vehicle reaches a zero-curvature point, the zero-curvature point defining the end of the first portion.

16. The system of claim 15, wherein the controller is configured to calculate the zero-curvature point in a longitudinal direction based on a tangent of a steering angle of the vehicle divided by a distance between a front axle and a rear axle of the vehicle.

17. The system of claim 15, wherein the controller is configured to calculate the zero-curvature point in a longitudinal direction based on a yaw rate of the vehicle divided by a velocity of the vehicle.

18. The system of claim 14, wherein the controller is configured to calculate the second portion of the predicted course trajectory using a linear model.

19. The system of claim 11, wherein the controller calculates the predicted course trajectory based on combining a predicted course trajectory using the third order polynomial and the predicted course trajectory using the non-third-order function.

20. The system of claim 11, wherein the controller determines whether the vehicle is driving toward the drive-straight state based on whether a steering angle of the vehicle is greater than zero and a steering angle velocity of the vehicle is less than zero.