METHOD AND MODULE FOR DETERMINING OF REFERENCE VALUES FOR A VEHICLE CONTROL SYSTEM

• US 20140350819A1
• Filed: 12/22/2011
• Published: 11/27/2014
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Maria Sodergren
• Inventors: Johansson, Oskar, Sdergren, Maria, Roos, Fredrik
• Granted Patent: US 9,114,708 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• CPC Class Codes: B60K 2310/244 changing target speed or setting a new target speed, e.g. changing algorithms
• 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 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: G05B 13/026 using a predictor
• CPC Class Codes: G05B 13/048 using a predictor
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

Reference speed values for a vehicle'"'"'s control system are determined by: determining, using map and location data, route segments, each with route characteristics; performing, simulation cycles, each comprising simulation steps of: predicting the speed when the set speed is imparted as the reference speed; comparing with first lower and upper limit values, which define an engine torque, for use in the next simulation cycle; making a second prediction of the speed when the engine torque is a value that depends on the result of said first comparison in the immediately preceding simulation cycle; comparing the second predicted vehicle speed with second lower and upper limit values, which delineate a range within which the speed is maintained, with an offset added if the vehicle is in a route segment with a steep hill; and determining the reference value based on the second comparison and/or the second predicted vehicle speed.

Claims

1. A method for determination of at least one reference value for a control system of a vehicle, the method comprising:

acquiring a set speed v_set for the vehicle;

determining a horizon for the itinerary by reference to map data and location data, which horizon comprises one or more route segments, each route segment having at least one route characteristic;

performing, by a module including an automated processor, a number of simulation cycles, wherein each simulation cycle s_j includes a number N of simulation steps conducted at a predetermined rate f, the simulation steps comprising;

making a first prediction of the speed v<sub>pred—

cc</sub> of the vehicle along the horizon according to a conventional cruise control when the set speed v_set is imparted as a reference speed v_ref, wherein the first prediction depends on the route characteristic of said route segment;

comparing, as a first comparison, the first predicted vehicle speed v<sub>pred—

cc</sub> with at least one of first lower and upper limit values v_lim1 and v_lim2, wherein the first lower and upper limit values v_lim1 and v_lim2 define an engine torque T for use in an immediately following simulation cycle s_j+1;

making a second prediction of the speed v<sub>pred—

Tnew</sub> of the vehicle along the horizon when the engine torque T is a value which depends on the result of said first comparison in an immediately preceding simulation cycle s<sub>j−

1</sub>;

comparing, as a second comparison, the second predicted vehicle speed v<sub>pred—

Tnew</sub> with at least one of second lower and upper limit values v_min and v_max, wherein the second lower and upper limit values v_min and v_max delineate a range within which the speed of the vehicle is maintained, and adding an offset v_offset to at least one of said second lower and upper limit values v_min and v_max when the at least one route characteristic of the route segment in which the vehicle is located indicates a steep hill;

determining the at least one reference value along the horizon based on the said second comparison and/or the second predicted vehicle speed v<sub>pred—

Tnew</sub> in this simulation cycle s_j; and

controlling, by the control system of the vehicle, the speed of the vehicle according to the at least one reference value.

2. A method according to claim 1, wherein said offset v_offset is positive when the vehicle is in a route segment with a route characteristic indicating a steep upgrade.

3. A method according to claim 1, wherein said offset v_offset is negative when the vehicle is in a route segment with a route characteristic indicating a steep downgrade.

4. A method according to claim 1, wherein the value of said offset v_offset varies over time.

5. A method according to claim 1, wherein the value of said offset v_offset is at least partly based on a driving mode applied by the vehicle.

6. A method according to claim 5, wherein said driving mode is chosen by a driver of the vehicle.

7. A method according to claim 1, wherein only one out of acceleration and retardation is allowed within a section L where a steep upgrade is followed by a steep downgrade within the length of section L from said steep upgrade.

8. A method according to claim 1, wherein only one out of acceleration and retardation is allowed within a section L where a steep downgrade is followed by a steep upgrade within the length of section L from said steep downgrade.

9. A method according to claim 7, wherein the length of section L depends on

the speed of the vehicle, and/or

a driving mode applied.

10. A method according to claim 1, wherein an offset on the respective second lower and upper limit values v_min and v_max is allowed when the current speed of the vehicle is outside the range bounded by the second lower and upper limit values v_min and v_max and when the second prediction v_pred—

_Tnew of the speed of the vehicle indicates that the set speed v_set will be reached by imparting the reference value which resulted in the second prediction v<sub>pred—

Tnew</sub> of the speed of the vehicle.

23. A non-transitory computer-readable medium product incorporating instructions for enabling a computer of a vehicle to perform steps according to the method of claim 1 when the instructions are run on said computer.

11. A module configured to control a speed of a vehicle, the module comprising:

an input unit configured to receive a set speed v_set for the vehicle;

a horizon unit configured to determine a horizon for an itinerary of the vehicle, by reference to map data and location data which comprise route segments, each route segment having at least one route characteristic;

a calculation unit configured to perform a number of simulation cycles, wherein each simulation cycle s_j comprises a number N of simulation steps conducted at a predetermined rate f, the simulation steps comprising;

making a first prediction of the speed v<sub>pred—

cc</sub> of the vehicle along the horizon according to a conventional cruise control when the set speed v_set is imparted as a reference speed v_ref, which first prediction depends on the at least one route characteristic of said route segment;

comparing, as a first comparison, the first predicted vehicle speed v<sub>pred—

cc</sub> with at least one of first lower and upper limit values v_lim1 and v_lim2, wherein the first lower and upper limit values v_lim1 and v_lim2 define an engine torque T for use in an immediately following simulation cycle s_j+1;

making a second prediction of the speed v<sub>pred—

Tnew</sub> of the vehicle along the horizon when the engine torque T is a value which depends on a result of said first comparison in an immediately preceding simulation cycle s<sub>j−

1</sub>;

comparing, as a second comparison, the second predicted vehicle speed v<sub>pred—

Tnew</sub> with at least one of second lower and upper limit values v_min and v_max wherein the second lower and upper limit values v_min and v_max delineate a range within which the speed of the vehicle is maintained, and adding an offset v_offset to at least one of said second lower and upper limit values v_min and v_max when the vehicle is in a route segment with a route characteristic indicating a steep hill; and

determining the at least one reference value along the horizon based on the second comparison and/or the second predicted vehicle speed v<sub>pred—

Tnew</sub> in this simulation cycle s_j; and

a providing unit configured to supply a control system of the vehicle with the at least one reference value for regulating the speed of the vehicle.

12. A module according to claim 11, wherein said offset v_offset is positive when the vehicle is in a route segment with a route characteristic indicating a steep upgrade.

13. A module according to claim 11, wherein said offset v_offset is negative when the vehicle is in a route segment with a route characteristic indicating a steep downgrade.

14. A module according to claim 11, wherein the value of said offset v_offset varies over time.

15. A module according to claim 11, wherein the value of said offset v_offset is at least partly based on a driving mode applied by the vehicle.

16. A module according to claim 15, wherein said driving mode is chosen by a driver of the vehicle.

17. A module according to claim 11, wherein the calculation unit is configured to allow only one of acceleration and retardation within a section L where a steep upgrade is followed by a steep downgrade within the length of section L from said steep upgrade.

18. A module according to claim 11, wherein the calculation unit is configured to allow only one of acceleration and retardation within a section L where a steep downgrade is followed by a steep upgrade within the length of section L from said steep downgrade.

19. A module according to claim 17, wherein the length of section L depends on

the vehicle'"'"'s speed, and/or

a driving mode applied.

20. A module according to claim 11, wherein the calculation unit is configured to determine threshold values used to control the speed of the vehicle, based on at least one from among a current transmission ratio, a current vehicle weight, a maximum torque curve for the engine of the vehicle, a mechanical friction, and a running resistance at current speed of the vehicle.

21. A module according to claim 11, wherein the calculation unit is configured to calculate threshold values in the form of gradient threshold values l_min and l_max.

22. A module according to claim 11, wherein an offset on the respective second lower and upper limit values v_min and v_max is allowed when the current speed of the vehicle is outside the range bounded by the second lower and upper limit values v_min and v_max, and when the second prediction v_pred—

_Tnew of the speed of the vehicle indicates that the set speed v_set will be reached by imparting the reference value which resulted in the second prediction v<sub>pred—

Tnew</sub> of the speed of the vehicle.

25. A vehicle comprising the module of claim 11.

24. (canceled)