System and method for timing of target speed for cooperative speed control system

• US 7,296,646 B2
• Filed: 03/31/2005
• Issued: 11/20/2007
• Est. Priority Date: 03/31/2005
• Status: Expired due to Fees

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Technical Center North America Incorporated (Nissan Motor Co., Ltd.)
• Inventors: Tsuda, Hiroshi, Kawazoe, Hiroshi
• Primary Examiner(s): PHAN, HAU VAN
• Application Number:
  US11/094,844
• Publication Number:
  US 20060225936A1
• Time in Patent Office: 964 Days
• Field of Search: 180/167, 180/168, 180/169, 180/170, 180/197, 701/121, 701/93, 701/19, 701/20, 246/122.R, 246/182.R, 318/139, 318/258, 318/138, 74/3
• US Class Current: 180/179
• CPC Class Codes: B60T 7/16 operated by remote control, i.e. initiating means not mounted on vehicle

Abstract

A device for automatically controlling vehicle speed, including a processor that receives at least (i) a first signal indicative of a first local required speed, (ii) a second signal indicative of a second local required speed received after the first signal, and (iii) a third signal indicative of a value of a current vehicle speed, wherein the processor includes logic to automatically determine a new set vehicle speed based at least on the first local required speed, the second local required speed, and the current vehicle speed and to automatically initiate output of a signal to a vehicle speed controller to change vehicle speed to a new set vehicle speed.

Claims

1. A device adapted to automatically control vehicle speed, comprising:

a processor adapted to receive at least a first signal indicative of a first local required speed, a second signal indicative of a second local required speed received after the first signal, and a third signal indicative of a value of a current vehicle speed;

wherein the processor includes logic to;

automatically determine a new set vehicle speed based at least on the first local required speed, the second local required speed, and the current vehicle speed; and

automatically initiate output of a signal to a vehicle speed controller to change vehicle speed to the new set vehicle speed.

2. The device according to claim 1, wherein the logic to automatically determine a new set vehicle speed includes logic to:

automatically identify a vehicle acceleration rate value based on a current vehicle component status, wherein the vehicle acceleration rate value is an effective constant.

3. The device according to claim 2, further comprising a device adapted to automatically change the vehicle speed to the new set vehicle speed based on the vehicle acceleration rate value.

4. The device according to claim 2, wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is indicative of a distance between a current vehicle position and a position where the first local required speed will change to the second local required speed; and

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value for the current vehicle speed.

5. The device according to claim 4, wherein the processor further includes logic to:

automatically determine a value for a time Δ

t which is equivalent to a value obtained by;

subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the vehicle acceleration rate value; and

automatically initiate output of the signal to the vehicle speed controller to change the vehicle speed to the new set vehicle speed if the value of the times T and Δ

t are substantially equal to each other.

6. The device according to claim 5, wherein the logic to automatically initiate output of the signal to the vehicle speed controller to change the vehicle speed to the new set vehicle speed if the value of the times T and Δ

t are substantially equal to each other includes logic to automatically initiate output of a signal to the vehicle speed controller to at least one of;

(a) gradually reduce the speed to the new set vehicle speed substantially in accordance with the acceleration rate value; and

(b) gradually increase the speed to the new set vehicle speed substantially in accordance with the acceleration rate value.

7. The device according to claim 1, wherein the processor further includes logic to:

automatically determine a value for a distance which is indicative of a distance between a caution zone and a location where the first local required speed changes to the second local required speed and using this determined value to control approach speed to the caution zone.

8. The device according to claim 1, wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is less than the new set vehicle speed;

automatically determine a value for a distance Lr which is indicative of a distance between a caution zone and a location where the first local required speed changes to the second local required speed;

automatically determine a value for a time Δ

t based on a predetermined relationship between predetermined values of Δ

t and Lr;

automatically determine a value for an acceleration rate, which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the time Δ

t;

automatically determine whether the time T and the time Δ

t are substantially equal to each other; and

if the time T and the time Δ

t are substantially equal to each other, and if the current vehicle speed has been determined to be less than the new set vehicle speed, automatically initiate output of a signal to the vehicle speed controller to increase the speed to the new set vehicle speed substantially in accordance with the value for the acceleration rate.

9. The device according to claim 8, wherein the predetermined values for Δ

t increase as the value of Lr increases to a first value of Lr and Δ

t is constant for values of Lr greater than the first value of Lr.

10. The device according to claim 1, wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is less than the new set vehicle speed;

automatically receive a fourth signal indicative of a local traffic density;

automatically determine a value for a time Δ

t based on a predetermined relationship between Δ

t and traffic density;

automatically determine a value for an acceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the time Δ

t;

automatically determine whether the time T and the time Δ

t are substantially equal to each other; and

if the time T and the time Δ

t are substantially equal to each other, and

if the current vehicle speed has been determined to be less than the new set vehicle speed, automatically initiate output of a signal to the vehicle speed controller to increase the speed to the new set vehicle speed substantially in accordance with the acceleration rate value.

11. The device according to claim 10, wherein in the predetermined relationship, Δ

t is a first constant for a first traffic density range of values, Δ

t decreases from the first constant with increasing traffic density values in between the first traffic density range and a second traffic density range, and Δ

t is a second constant for the second traffic density range of values, the second constant being less than the first constant.

12. The device according to claim 1, wherein the processor further includes logic to:

automatically analyze a fourth signal indicative of at least one of a driver'"'"'s desired deceleration rate and a driver'"'"'s desired acceleration rate and to use this analysis to control approach speed to a caution zone.

13. A device adapted to automatically control vehicle speed, comprising:

a processor adapted to receive at least a first signal indicative of a first local required speed, a second signal indicative of a second local required speed received after the first signal, and a third signal indicative of a value of a current vehicle speed;

wherein the processor includes logic to;

automatically determine a new set vehicle speed based at least on the first local required speed, the second local required speed, and the current vehicle speed; and

automatically initiate output of a signal to a vehicle speed controller to change vehicle speed to the new set vehicle speed,

wherein the processor is adapted to receive information that will enable the processor to determine whether the vehicle is approaching a caution zone, and wherein the processor further includes logic to;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically determine a value for a first time Δ

t based on predetermined values of the first time Δ

t, wherein the predetermined values of first time Δ

t vary with respect to at least a value which is indicative of a distance between a caution zone and a location where the first required speed changes to the second required speed;

automatically determine whether the first time Δ

t substantially equals a time for the vehicle to reach the location where the first local required speed changes to the second local required speed at the current vehicle speed; and

if the current vehicle speed is determined to be greater than the new set vehicle speed, and if the vehicle is determined to be approaching a caution zone, and if the first time Δ

t substantially equals a time for the vehicle to reach the location where the first local required speed changes to the second local required speed at the current vehicle speed, automatically initiate output of a signal to the vehicle speed controller to reduce vehicle speed to the new set vehicle speed.

14. The device according to claim 13, wherein the processor is adapted to receive information related to at least one of (i) a type of caution zone that the vehicle is approaching and (ii) a condition of the caution zone that the vehicle is approaching, and wherein the predetermined values of the first time Δ

t vary with respect to at least one of the type of caution zone that the vehicle is approaching and the condition of the caution zone that the vehicle is approaching.

15. The device according to claim 13, wherein the processor is adapted to receive information that will enable the processor to determine whether the vehicle is approaching a red traffic light, and wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed; and

if the current vehicle speed is determined to be greater than the new set vehicle speed and the vehicle is determined to be approaching a red traffic light;

automatically determine a value for a second time Δ

t based on a predetermined system deceleration value for vehicle approach of a red traffic light; and

automatically determine whether the time T and the second time Δ

t are substantially equal to each other; and

if the time T and the second time Δ

t are substantially equal to each other, automatically initiate output of a signal to the vehicle speed controller to reduce vehicle speed to the new set vehicle speed.

16. The device according to claim 15, wherein the processor further includes logic to:

reduce vehicle speed to the new set vehicle speed substantially in accordance with a variable acceleration rate value that varies with time based on finite periods of time t within second time Δ

t.

17. The device according to claim 13, wherein the processor is adapted to receive information that will enable the processor to determine that the vehicle is approaching a red traffic light, and wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is indicative of the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically determine a value for a distance Lf which is indicative of a distance between a caution zone and a location where the first local required speed changes to the second local required speed;

automatically determine a value for a second time Δ

t based on a predetermined relationship between the second time Δ

t and Lf,

automatically determine a value for a deceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the second time Δ

t;

automatically determine whether the time T and the second time Δ

t are substantially equal to each other; and

if the current vehicle speed has been determined to be greater than the new set vehicle speed, and if the processor has not determined that the vehicle is approaching a red traffic light and if the time T and the second time Δ

t are substantially equal to each other, automatically initiate output of a signal to the vehicle speed controller to reduce the speed to the new set vehicle speed substantially in accordance with the value of the deceleration rate.

18. The device according to claim 17, wherein, in the predetermined relationship, the second time Δ

t decreases as the value of Lf increases to a first value of Lf and the second time Δ

t is constant for values of Lf greater than the first value of Lf.

19. The device according to claim 13, wherein the processor is adapted to receive information that will enable the processor to determine whether the vehicle is traveling away from a caution zone, and wherein the processor further includes logic to:

automatically determine whether the current vehicle speed is less than the new set vehicle speed; and

if the current vehicle speed is determined to be less than the new set vehicle speed, and if the vehicle is determined to be traveling away from a caution zone, and if the first time Δ

t substantially equals the time for the vehicle to reach the location where the first local required speed changes to the second local required speed at the current vehicle speed, automatically initiate output of a signal to the vehicle speed controller to increase vehicle speed to the new set vehicle speed.

20. The device according to claim 13, wherein the processor further includes logic to:

automatically analyze received information indicative of a local traffic density and using this analysis to control approach speed to the caution zone.

21. The device according to claim 13, wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically receive information indicative of a local traffic density;

automatically determine a value for a second time Δ

t based on a predetermined relationship between the second time Δ

t and traffic density;

automatically determine a value for a deceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the second time Δ

t;

automatically determine whether the time T and the second time Δ

t are substantially equal to each other; and

if the time T and the second time Δ

t are substantially equal to each other, and if the current vehicle speed has been determined to be greater than the new set vehicle speed, automatically initiate output of a signal to the vehicle speed controller to reduce the speed to the new set vehicle speed substantially in accordance with the value for the deceleration rate.

22. The device according to claim 21, wherein in the predetermined relationship, the second time Δ

t is a first constant for a first traffic density range of values, the second time Δ

t increases from the first constant with increasing traffic density values in between the first traffic density range and a second traffic density range, and the second time Δ

t is a second constant for the second traffic density range of values, the second constant being greater than the first constant.

23. The device according to claim 13, wherein the processor further includes logic to:

automatically analyze a fourth signal indicative of a local road surface coefficient of friction and to use this analysis to control approach speed to the caution zone.

24. The device according to claim 13, wherein the processor is adapted to receive a fourth signal indicative of a local road surface coefficient of friction, and wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine a value for a second time Δ

t based on a predetermined relationship between the second time Δ

t and a value indicative of a road surface coefficient of friction;

automatically determine a value for a deceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the second time Δ

t; and

automatically determine whether the time T and the second time Δ

t are substantially equal to each other and if the time T and the second time Δ

t are substantially equal to each other, automatically initiate output of a signal to the vehicle speed controller to reduce the speed to the new set vehicle speed substantially in accordance with the deceleration rate value.

25. The device according to claim 24, wherein in the predetermined relationship, the second time Δ

t is a first constant for a first range of values indicative of road surface coefficients of friction, the second time Δ

t decreases from the first constant in a range of increasing road surface coefficients of friction between the first range and a second range of values related to road surface coefficient of friction, and the second time Δ

t is a second constant for the second range of values, the second constant being lower than the first constant.

26. A device adapted to automatically control vehicle speed, comprising:

a processor adapted to receive at least a first signal indicative of a first local required speed, a second signal indicative of a second local required speed received after the first signal, and a third signal indicative of a value of a current vehicle speed;

wherein the processor includes logic to;

automatically determine a new set vehicle speed based at least on the first local required speed, the second local required speed, and the current vehicle speed; and

automatically initiate output of a signal to a vehicle speed controller to chance vehicle speed to the new set vehicle speed,

wherein the processor is adapted to receive a fourth signal indicative of at least one of a driver'"'"'s desired deceleration rate and a driver'"'"'s desired acceleration rate, and wherein the processor further includes logic to;

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local required speed will change to the second local required speed;

determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically determine a value for a first time Δ

t based on a predetermined relationship between the first time Δ

t and the driver'"'"'s desired deceleration rate;

automatically determine a value for a deceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the first time Δ

t;

automatically determine whether the time T and the first time Δ

t are substantially equal to each other; and

if the time T and the first time Δ

t are substantially equal to each other, and if the current vehicle speed has been determined to be greater than the new set vehicle speed, automatically initiate output of a signal to the vehicle speed controller to reduce the speed to the new set vehicle speed substantially in accordance with the deceleration rate value.

27. The device according to claim 26, wherein the processor further includes logic to:

automatically determine whether the current vehicle speed is less than the new set vehicle speed;

automatically determine a value for a second time Δ

t based on a predetermined relationship where the second time Δ

t varies with the driver'"'"'s desired acceleration rate;

automatically determine a value for an acceleration rate, which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the second time Δ

t;

determine whether the time T and the second time Δ

t are substantially equal to each other; and

if the time T and the second time Δ

t are substantially equal to each other, and if the current vehicle speed has been determined to be less than the new set vehicle speed;

automatically initiate output of a signal to the vehicle speed controller to increase the speed to the new set vehicle speed substantially in accordance with the acceleration rate value.

28. A device adapted to automatically control vehicle speed, comprising:

a processor adapted to receive at least a first signal indicative of a first local maximum speed limit, the first signal being initiated remotely from the vehicle, a second signal indicative of a second local maximum speed limit received after the first signal, the second signal also being initiated remotely from the vehicle, and a third signal indicative of a value of a current vehicle speed;

wherein the processor includes logic to;

automatically determine a new set vehicle speed based at least on the first local maximum speed limit, the second local maximum speed limit, and the current vehicle speed; and

automatically initiate output of a signal to a vehicle speed controller to change vehicle speed to the new set vehicle speed.

29. The device of claim 28, wherein the second local maximum speed limit is a current maximum speed limit communicated to the vehicle by an infrastructure communication device, and wherein the current maximum speed limit is the maximum speed limit for a zone in which the vehicle is currently traveling.

30. The device according to claim 28, wherein the logic to automatically determine a new set vehicle speed includes logic to automatically identify a vehicle acceleration rate value based on a current vehicle component status, wherein the vehicle acceleration rate value is an effective constant,

the device adapted to automatically control vehicle speed further comprising a device adapted to automatically change the vehicle speed to the new set vehicle speed based on the vehicle acceleration rate value.

31. The device according to claim 30, wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is indicative of a distance between a current vehicle position and a position where the first local maximum speed limit will change to the second local maximum speed limit; and

automatically determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value for the current vehicle speed.

32. The device according to claim 31, wherein the processor further includes logic to:

automatically determine a value for a time Δ

t which is equivalent to a value obtained by;

subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the vehicle acceleration rate value; and

automatically initiate output of the signal to the vehicle speed controller to change the vehicle speed to the new set vehicle speed if the value of the times T and Δ

t are substantially equal to each other.

33. The device according to claim 28, wherein the processor is adapted to receive information that will enable the processor to determine whether the vehicle is approaching a caution zone, and wherein the processor further includes logic to:

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically determine a value for a time Δ

t based on predetermined values of Δ

t, wherein the predetermined values of Δ

t vary with respect to at least a value which is indicative of a distance between a caution zone and a location where the first local maximum speed limit changes to the second local maximum speed limit;

automatically determine whether the time Δ

t substantially equals a time for the vehicle to reach the location where the first local maximum speed limit changes to the second local maximum speed limit at the current vehicle speed; and

if the current vehicle speed is determined to be greater than the new set vehicle speed, and if the vehicle is determined to be approaching a caution zone, and if the time Δ

t substantially equals a time for the vehicle to reach the location where the first local maximum speed limit changes to the second local maximum speed limit at the current vehicle speed, automatically initiate output of a signal to the vehicle speed controller to reduce vehicle speed to the new set vehicle.

34. The device according to claim 28, wherein the processor is adapted to receive a fourth signal indicative of at least one of a driver'"'"'s desired deceleration rate and a driver'"'"'s desired acceleration rate, and wherein the processor further includes logic to:

automatically determine a value for a distance L, wherein the distance L is the distance between a current vehicle position and a position where the first local maximum speed limit will change to the second local maximum speed limit;

determine a value for a time T which is equivalent to a value obtained by dividing the value for the distance L by the value indicative of the current vehicle speed;

automatically determine whether the current vehicle speed is greater than the new set vehicle speed;

automatically determine a value for a time Δ

t based on a predetermined relationship between Δ

t and the driver'"'"'s desired deceleration rate;

automatically determine a value for a deceleration rate which is indicative of a value obtained by subtracting the value of the current vehicle speed from the new set vehicle speed to obtain a resulting value, and dividing the resulting value by the value of the time Δ

t;

automatically determine whether the time T and the time Δ

t are substantially equal to each other; and

if the time T and the time Δ

t are substantially equal to each other, and if the current vehicle speed has been determined to be greater than the new set vehicle speed, automatically initiate output of a signal to the vehicle speed controller to reduce the speed to the new set vehicle speed substantially in accordance with the deceleration rate value.

35. The device of claim 28, wherein the first local maximum speed limit is a current maximum speed limit communicated to the vehicle by an infrastructure communication device, and wherein the current maximum speed limit is the maximum speed limit for a zone in which the vehicle is currently traveling.