Method and module for controlling a vehicle's speed

• US 8,972,138 B2
• Filed: 06/21/2011
• Issued: 03/03/2015
• Est. Priority Date: 06/23/2010
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Johansson, Oskar, Sdergren, Maria, Roos, Fredrik
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): PIPALA, EDWARD J
• Application Number:
  US13/703,176
• Publication Number:
  US 20130085651A1
• Time in Patent Office: 1,351 Days
• Field of Search: 701/36, 701/70, 701/91, 701/93, 701/94, 701/123, 701/32.1, 701/32.3, 701/32.4, 701/32.5, 701/32.9, 701/33.4, 701/400, 701/408, 701/409, 701/423, 701/424, 701/425, 701/532, 701/83, 701/84, 340/988, 340/989, 340/995.14, 340/995.27, 180/170, 180/197, 180/271, 180/282
• US Class Current: 701/70
• CPC Class Codes: B60K 31/00 Vehicle fittings, acting on a single sub-unit only, for automatically controlling vehicle speed, i.e. preventing speed from exceeding an arbitrarily established velocity or maintaining speed at a particular velocity, as selected by the vehicle operator fittings acting on two or more sub-units B60W30/14; speedometers G01P; systems or devices for controlling speed in general G05D13/00 ; in traffic anti-collision system for road vehicles G08G1/16
• CPC Class Codes: B60W 2552/20 Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 2720/103 Speed profile
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: B60W 50/087 where the control system corrects or modifies a request from the driver
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

A method for controlling a vehicle'"'"'s speed by adopting a desired speed v_set for the vehicle; determining a horizon for the intended itinerary made up of route segments, effecting the following during each of a number of simulation cycles (s) each comprising a number N of simulation steps conducted at a predetermined frequency f: first predicting the vehicle'"'"'s speed v_pred—cc along the horizon with conventional cruise control when v_set is presented as reference speed, comparing the predicted vehicle speed v_pred—cc in a range v_min to v_max, making a second prediction of the vehicle'"'"'s speed v_pred—Tnew along the horizon based on the vehicle'"'"'s engine torque T; determining a reference value for how the vehicle'"'"'s speed is to be influenced on the basis of at least one of the comparisons and the predicted vehicle speed v_pred—Tnew; controlling the vehicle by the reference value. A module for the foregoing controls a vehicle'"'"'s speed.

Claims

1. A method for controlling a vehicle'"'"'s speed which comprises:

receiving a desired speed v_set for the vehicle;

determining by means of map data and location data a horizon for the intended itinerary which is made up of route segments with at least one characteristic for each segment;

effecting the following during each of a number of simulation cycles (s) each simulation cycle comprising a number N of simulation steps conducted at a predetermined frequency f;

in a first prediction, calculating a first predicted vehicle speed v<sub>pred—

cc</sub> along the horizon with conventional cruise control using v_set as reference speed, and based on the characteristics of a segment;

comparing the first predicted vehicle speed v<sub>pred—

cc</sub> with a minimum speed value v_min and a maximum speed value v_max, which demarcate an intended range for the vehicle'"'"'s speed;

in a second prediction, calculating a second predicted vehicle speed v<sub>pred—

Tnew</sub> along the horizon using a torque value T when first predicted vehicle speed v<sub>pred—

cc</sub> is higher than the maximum speed v_max or less than the minimum speed value v_min, the torque value T being selected based on the comparison resulting from comparing in a latest preceding simulation cycle (s−

1);

determining at least one reference value which indicates how the vehicle'"'"'s speed is to be influenced based on at least one of the comparison in simulation cycle (s) and the predicted vehicle speed v<sub>pred—

Tnew</sub>; and

sending to a control system in the vehicle the at least one reference value based on which the vehicle is thereupon regulated.

2. A method according to claim 1, further comprising performing a series of N of the simulation steps to define a cycle of the simulation steps, and the simulation steps during a simulation cycle of N said simulation steps have a constant step length which depends on the vehicle'"'"'s speed.

3. A method according to claim 1, wherein the reference value is selected from among a reference vehicle speed v_ref, a reference torque T_ref or a reference engine speed ω

_ref.

4. A method according to claim 1, further comprising performing a series of N of the simulation steps to define a cycle of the simulation steps, and wherein if v_pred—

_cc is higher than v_max, the torque value T in the second prediction is taken as a minimum torque in subsequent simulation cycles.

5. A method according to claim 4, further comprising detecting the highest speed v_pred—

_cc,max during the second prediction of the vehicle'"'"'s speed v<sub>pred—

cc</sub> with ordinary cruise control and then using v<sub>pred—

cc,max</sub> in the comparison with v_max and v_min to determine the torque value T in the second prediction.

6. A method according to claim 1, further comprising performing a series of N of the simulation steps to define a cycle of the simulation steps, and wherein if v_pred—

_cc is lower than v_min the torque value T in the second prediction, that torque is taken as a maximum torque in subsequent simulation cycles.

7. A method according to claim 6, further comprising detecting the highest speed v_pred—

_cc,min during the second prediction of the vehicle'"'"'s speed v<sub>pred—

cc</sub> with ordinary cruise control and then using v<sub>pred—

cc,min</sub> in the comparison with v_max and v_min to determine the torque value T in the second prediction.

8. A method according to claim 1, further comprising adding a hysteresis to v_ref.

9. A method according to claim 1, further comprising applying rules to determine the reference value with respect to which the vehicle is to be regulated.

10. A method according to claim 9, comprising a rule wherein the vehicle speed v_pred—

_Tnew in the second prediction is compared with v_min and v_max, to demarcate a range for the vehicle'"'"'s speed.

11. A method according to claim 10, comprising a rule wherein if v_pred—

_Tnew in the second prediction is higher than v_max or lower than v_min, the vehicle'"'"'s reference value is determined as a value which represents v_set.

12. A method according to claim 10, comprising a rule wherein if v_pred—

_Tnew in the second prediction is between v_min and v_max or equal to v_min or v_max, the vehicle'"'"'s reference value is determined as a value which represents the predicted speed v<sub>pred—

Tnew</sub>.

13. A computer program product comprising non-transitory program instructions for causing a computer system in a vehicle to perform steps according to the method of claim 1 when the instructions are run on said computer system.

14. A computer program product according to claim 13, in which the program instructions are stored on a non-transitory computer-readable medium which can be read by a computer system.

15. A module for controlling a vehicle'"'"'s speed, which comprises:

an input unit configured for receiving a desired speed v_set for the vehicle;

a horizon unit configured for determining by means of map data and location data a horizon for an intended itinerary which is comprised of route segments with at least one characteristic for each segment;

a calculation unit configured for effecting the following during each of a number of simulation cycles (s) wherein each cycle comprises a number N of simulation steps conducted at a predetermined frequency f, the steps each comprising;

calculating to make a first prediction of vehicle speed v<sub>pred—

cc</sub> along a horizon with a conventional cruise control using v_set as a reference speed, wherein the first prediction depends on the characteristics of the segment;

comparing vehicle speed v<sub>pred—

cc</sub> with a minimum speed value v_min and a maximum speed value v_max, which demarcate a range of the vehicle'"'"'s intended speed;

calculating to make a second prediction of vehicle speed v<sub>pred—

Tnew</sub> along the horizon using torque value T when the first predicted value speed v<sub>pred—

cc</sub> is higher than the maximum speed value v_max or less than the minimum speed value v_min, the torque value T being selected based on comparison resulting from comparing in the latest preceding simulation cycle (s−

1);

determining at least one reference value which indicates how the vehicle'"'"'s speed is to be influenced based at least one of the comparison in simulation cycle (s) and the predicted vehicle speed v<sub>pred—

Tnew</sub>; and

the module is further configured for sending to a control system in the vehicle said at least one reference value based on which the vehicle is thereupon regulated.

16. A module according to claim 15, wherein the simulation steps during a simulation cycle of N simulation steps have a constant step length which depends on the vehicle'"'"'s speed, and the calculation unit is configured for adjusting the step length according to the vehicle'"'"'s speed.

17. A method according to claim 15, wherein the reference value is selected from among a reference vehicle speed v_ref, a reference torque T_ref or a reference engine speed ω

_ref.

18. A module according to claim 15, wherein the calculation unit is configured for calculating if v_pred—

_cc is higher than v_max, and then is configured for taking the torque value T in the second prediction as a minimum torque in subsequent simulation cycles.

19. A module according to claim 18, wherein the calculation unit is configured for determining the highest speeds v_pred—

_cc,max during the second prediction of the vehicle'"'"'s speed v<sub>pred—

cc</sub> with ordinary cruise control, and to using the v<sub>pred—

cc,max</sub> in the comparison with v_max and v_min to determine the torque value T in the second prediction.

20. A module according to claim 15, wherein the calculation unit is configured for calculating if v_pred—

_cc is lower than v_min and is configured for taking the torque value T in the second prediction as a maximum torque in subsequent simulation cycles.

21. A module according to claim 20, wherein the calculation unit is configured for determining the lowest speeds v_pred—

_cc,min during the second prediction of the vehicle'"'"'s speed v<sub>pred—

cc</sub> with ordinary cruise control, and to using the v<sub>pred—

cc,min</sub> in the comparison with v_max and v_min to determine the torque value T in the second prediction.

22. A module according to claim 15, wherein the calculation unit is configured for adding a hysteresis to v_ref.

23. A module according to claim 15, wherein the calculation unit is configured for applying rules for determining the reference value with respect to which the vehicle is to be regulated.

24. A module according to claim 23, comprising a rule wherein the vehicle speed v_pred—

_Tnew in the second prediction is compared with v_min and v_max, to demarcate a range for v<sub>pred—

Tnew</sub>.

25. A module according to claim 24, comprising a rule wherein if v_pred—

_Tnew in the second prediction is higher than v_max or lower than v_min, the vehicle'"'"'s reference value is determined as a value which represents v_set.

26. A module according to claim 24, comprising a rule wherein if v_pred—

_Tnew in the second prediction is between v_min and v_max or equal to v_min or v_max, the vehicle'"'"'s reference value is determined as a value which represents the predicted speed v<sub>pred—

Tnew</sub>.