TRAVEL DIRECTION DETERMINATION METHOD AND SYSTEM

• US 20130231820A1
• Filed: 03/01/2013
• Published: 09/05/2013
• Est. Priority Date: 03/05/2012
• Status: Active Grant

• Current Assignee: Volvo Car Corporation (AB Volvo)
• Original Assignee: Volvo Car Corporation (AB Volvo)
• Inventors: Solyom, Stefan, Nordvall, Martin
• Granted Patent: US 9,020,680 B2
• Time in Patent Office: Days
• US Class Current: 701/23
• CPC Class Codes: B62D 15/02 Steering position indicators ; Steering position determination; Steering aids
• CPC Class Codes: B62D 15/026 combined with automatic distance control, i.e. electronic tow bar
• CPC Class Codes: G05D 1/0293 Convoy travelling
• CPC Class Codes: G08G 1/00 Traffic control systems for road vehicles arrangement of road signs or traffic signals E01F9/00 ; automatic vehicle control B62D
• CPC Class Codes: G08G 1/22 Platooning, i.e. convoy of communicating vehicles

Abstract

A method for determining a direction of travel for a following vehicle ensures that the following vehicle follows a path indicative of that of a target vehicle. The target vehicle extends in longitudinal (X) and lateral (Y) directions, the longitudinal direction (X) corresponding to an intended direction of travel of the following vehicle. The method may include determining a measured lateral offset (ΔY_measure) between the following and target vehicles. The method may also include measuring a lateral position change parameter corresponding to an actual performed, ongoing and/or impending lateral position change of the following vehicle, an actual performed, ongoing and/or impending lateral position change of the target vehicle, or a combination thereof. The method may further include determining a lateral offset modification measure (O_Y) using the lateral position change parameter, and using the measured lateral offset (ΔY_measure) and lateral offset modification measure (O_Y) when determining the direction of travel.

Claims

1. A method for determining a direction of travel for a following vehicle in order to ensure that said following vehicle follows a path that is indicative of a vehicle path of a target vehicle, said target vehicle extending in a longitudinal direction (X) and a lateral direction (Y), wherein said longitudinal direction (X) corresponds to an intended direction of travel of said following vehicle, said method comprising:

determining a measured lateral offset (Δ

Y_measure) between said following vehicle and said target vehicle;

measuring at least one lateral position change parameter corresponding to an actual performed and/or ongoing and/or impending lateral position change of said following vehicle, an actual performed and/or ongoing and/or impending lateral position change of said target vehicle, or a combination thereof;

determining a lateral offset modification measure (O_Y) using said at least one lateral position change parameter; and

using said measured lateral offset (Δ

Y_measure) and said lateral offset modification measure (O_Y) when determining said direction of travel.

2. The method according to claim 1 further comprising:

determining a first portion (O_Y,1) of said lateral offset modification measure (O_Y), which first portion (O_Y,1) is indicative of a slip value comprising a slip angle of the following vehicle, a slip angle of the target vehicle, or a combination thereof.

3. The method according to claim 2 further comprising:

determining a longitudinal distance (Δ

X) between said following vehicle and said target vehicle;

determining a longitudinal velocity value (v_x) comprising a longitudinal velocity of said following vehicle, a longitudinal velocity of said target vehicle or a combination thereof;

determining a lateral velocity value (v_y) comprising a lateral velocity of said following vehicle, a lateral velocity of said target vehicle or a combination thereof; and

determining a first portion (O_Y,1) of said lateral offset modification measure (O_Y) by using a first modification relation comprising the following parameters;

said longitudinal distance (Δ

X), said longitudinal velocity value (v_x) and said lateral velocity value (v_y).

4. The method according to claim 3 further comprising:

determining said first portion of said lateral offset modification measure by using the following formula;

5. The method according to claim 1 further comprising:

determining a second portion (O_Y,2) of said lateral offset modification measure (O_Y) which second portion (O_Y,2) is indicative of a curve radius (R) of a curve which at least one of the following vehicle and the target vehicle follows.

6. The method according to claim 5 further comprising:

determining a yaw rate value ({dot over (ψ

)}) comprising a yaw rate of said following vehicle, a yaw rate of said target vehicle or a combination thereof; and

determining a second portion (O_Y,2) of said lateral offset modification measure by using a second modification relation comprising the following parameters;

said yaw rate value ({dot over (ψ

)}), said longitudinal distance (Δ

X) and said longitudinal velocity value (v_y).

7. The method according to claim 6 further comprising:

determining said second portion of said lateral offset modification measure by using the following formula;

8. The method according to claim 6, wherein said target vehicle comprises means for transmitting a yaw rate signal ({dot over (ψ

)}) indicative of said yaw rate of said target vehicle to one or more receivers located outside said target vehicle, the method further comprising;

receiving said yaw rate signal to thereby determine said yaw rate ({dot over (ψ

)}) of said target vehicle.

9. The method according to claim 1 further comprising:

determining a modified lateral offset (Δ

Y_mod) by modifying said measured lateral offset (Δ

Y_measure) by said lateral offset modification measure (O_Y); and

automatically adjusting said direction of travel for said following vehicle in order to ensure that said modified lateral offset is reduced.

10. The method according to claim 9 further comprising:

automatically adjusting said direction of travel for said following vehicle in order to ensure that said modified lateral offset is reduced to a value below a predetermined threshold value.

11. The method according to claim 9 further comprising:

automatically adjusting a steering angle of said following vehicle.

12. A non-transitory storage medium having computer readable instructions stored thereon for determining a direction of travel for a following vehicle in order to ensure that said following vehicle follows a path that is indicative of a vehicle path of a target vehicle, said target vehicle extending in a longitudinal direction (X) and a lateral direction (Y), wherein said longitudinal direction (X) corresponds to an intended direction of travel of said following vehicle, said instructions comprising instructions for:

determining a lateral offset (Δ

Y_measure) between said following vehicle and said target vehicle;

determining at least one lateral position change parameter corresponding to at least one of i) one of a performed, ongoing and impending lateral position change of said following vehicle, and ii) one of a performed, ongoing and impending lateral position change of said target vehicle;

determining a lateral offset modification (O_Y) using said at least one lateral position change parameter; and

using said lateral offset (Δ

Y_measure) and said lateral offset modification (O_Y) when determining said direction of travel.

13. The storage medium of claim 12, wherein said instructions further comprise instructions for:

determining a first portion (O_Y,1) of said lateral offset modification (O_Y), which first portion (O_Y,1) is indicative of a slip value comprising at least one of a slip angle of the following vehicle and a slip angle of the target vehicle.

14. The storage medium of claim 13, wherein said instructions further comprise instructions for:

determining a longitudinal distance (Δ

X) between said following vehicle and said target vehicle;

determining a longitudinal velocity value (v_x) comprising a longitudinal at least one of a velocity of said following vehicle and a longitudinal velocity of said target vehicle;

determining a lateral velocity value (v_y) comprising at least one of a lateral velocity of said following vehicle and a lateral velocity of said target vehicle; and

determining a first portion (O_Y,1) of said lateral offset modification (O_Y) by using a first modification relation based on said longitudinal distance (Δ

X), said longitudinal velocity value (v_x) and said lateral velocity value (v_y).

15. The storage medium of claim 14 wherein said instructions further comprise instructions for:

determining said first portion of said lateral offset modification using the formula;

16. A system for determining a direction of travel for a following vehicle in order to ensure that said following vehicle follows a path that is indicative of a vehicle path of a target vehicle, said target vehicle extending in a longitudinal direction (X) and a lateral direction (Y), wherein said longitudinal direction (X) corresponds to an intended direction of travel of said following vehicle, said system comprising a controller configured to:

determine a lateral offset (Δ

Y_measure) between said following vehicle and said target vehicle;

determine at least one lateral position change parameter corresponding to at least one of i) one of a performed, ongoing and impending lateral position change of said following vehicle, and ii) one of a performed, ongoing and impending lateral position change of said target vehicle;

determine a lateral offset modification (O_Y) using said at least one lateral position change parameter; and

use said lateral offset (Δ

Y_measure) and said lateral offset modification (O_Y) to determine said direction of travel.

17. The system of claim 16, wherein said controller is further configured to:

determine a first portion (OY,1) of said lateral offset modification (OY), which first portion (OY,1) is indicative of a slip value comprising at least one of a slip angle of the following vehicle and a slip angle of the target vehicle.

18. The system of claim 17, wherein said controller is further configured to:

determine a longitudinal distance (Δ

X) between said following vehicle and said target vehicle;

determine a longitudinal velocity value (v_x) comprising a longitudinal at least one of a velocity of said following vehicle and a longitudinal velocity of said target vehicle;

determine a lateral velocity value (v_y) comprising at least one of a lateral velocity of said following vehicle and a lateral velocity of said target vehicle; and

determine a first portion (O_Y,1) of said lateral offset modification (O_Y) by using a first modification relation based on said longitudinal distance (Δ

X), said longitudinal velocity value (v_x) and said lateral velocity value (v_y).

19. The system of claim 18 wherein said controller is further configured to:

determine said first portion of said lateral offset modification using the formula;

20. The system of claim 16 wherein said controller is further configured to:

determine a modified lateral offset (Δ

Y_mod) by modifying said lateral offset (Δ

Y_measure) by said lateral offset modification (O_Y); and

automatically adjust said direction of travel for said following vehicle in order to ensure that said modified lateral offset is reduced.