MODULE AND METHOD PERTAINING TO MODE CHOICE WHEN DETERMINING REFERENCE VALUES

• US 20140330503A1
• Filed: 12/22/2011
• Published: 11/06/2014
• Est. Priority Date: 12/22/2011
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Johansson, Oskar, Sdergren, Maria, Roos, Fredrik
• Granted Patent: US 9,376,109 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• 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 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/11 Stepped gearings
• CPC Class Codes: B60W 2540/215 Selection or confirmation of options
• 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 2710/0666 Engine torque
• CPC Class Codes: B60W 2720/10 Longitudinal speed
• 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 50/08 Interaction between the driver and the control system
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

Described is a method for determining a reference value for a vehicle. The method includes: performing a number of simulation cycles S_j each comprising simulation steps: making a first prediction of the vehicle'"'"'s speed v_pred—cc along the determined horizon with a conventional cruise control; comparing, in a first comparison, the predicted vehicle speed v_pred—cc with v_lim1 and v_lim2, which define a motor torque used in a subsequent simulation cycle; making a second prediction of the speed when the engine torque is a value that depends on the result of said comparison in the latest preceding simulation cycle; comparing, in a second comparison, the predicted vehicle speed v_pred—Tnew with v_min, and v_max1 which demarcate a range within which the speed is maintained; determining the reference value based on the second comparison and/or the second predicted speed in that simulation cycle S_j; and controlling the vehicle according to the reference value.

Claims

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

an input unit configured to receive at least one set speed v_set for the vehicle;

a mode choice unit configured to receive a choice from at least two selectable driving modes, each driving mode comprising a setting which influences the determination of the at least one reference value;

a horizon unit configured to determine an itinerary by reference to map data and location data, the horizon made up of at least one route segment with at least one characteristic;

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

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

cc</sub> of the vehicle along the horizon such that the set speed v_set is taken as a reference speed v_ref, the first prediction made based on the characteristic of said route segment;

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

cc</sub> with first lower and upper limit values v_lim1 and v_lim2 to define an engine torque T, the engine torque T used 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, the engine torque T being a value defined in said first comparison in an immediately preceding simulation cycle s<sub>j−

1</sub>; and

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 v_min, and v_max delineate a range within which the speed of the vehicle is maintained; and

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

Tnew</sub> in this simulation cycle s_j, so that the at least one reference value is within the range bounded by the second lower and upper limit values v_min and v_max; and

a providing unit configured to output to a control system of the vehicle said at least one reference value based on which the speed of the vehicle is then regulated.

2. A module according to claim 1, wherein the second lower and upper limit values v_min and v_max are defined on the basis of the choice of driving mode.

3. A module according to claim 1, wherein a further lower limit value v_min2 and upper limit value v_max2 are defined based on the choice of driving mode and are related to the at least one set speed v_set.

4. A module according to claim 1, wherein the choice of driving mode decides how said at least one reference value is determined.

5. A module according to claim 1, wherein said at least one reference value is a reference speed v_ref, and the mode choice defines a permissible acceleration and/or retardation of the vehicle.

6. A module according to claim 1, wherein the mode choice defines a weighting parameter β

, which is used in evaluation of one or more cost functions when determining said at least one reference value.

7. A module according to claim 6, wherein the calculation unit is configured to perform the simulations by calculating the cost for the second predicted vehicle speed v_pred—

_Tnew and/or a third predicted vehicle speed v<sub>pred—

Tk+new</sub> by use of at least one cost function J_Tnew, J_Tk+new.

8. A module according to claim 7, wherein the calculation unit is configured to determine the cost functions J_Tnew and J_Tk+new for the second predicted vehicle speed v_pred—

_Tnew and a third predicted vehicle speed v<sub>pred—

Tk+new</sub> by weighting with the weighting parameter β

, respectively, their energy reductions and journey time reductions relative to the first predicted vehicle speed v<sub>pred—

cc</sub>.

9. A module according to claim 8, wherein the calculation unit is configured to compare, as a fourth comparison, the cost functions J_Tnew and J_Tk+new for the second predicted vehicle speed v_pred—

_Tnew and for a third predicted vehicle speed v<sub>pred—

Tk+new</sub>,

wherein the determination of the at least one is based on said fourth comparison.

21. A vehicle comprising the module of claim 1.

10. A method for determination of at least one reference value for a control system of a vehicle, wherein the method comprises:

acquiring a set speed v_set for the vehicle;

receiving a choice from at least two selectable driving modes, each driving mode comprising a setting which influences the determination of the at least one reference value;

determining for the itinerary, by reference to map data and location data, a horizon made up of at least one route segment with at least one characteristic;

performing, by a module incorporating an automated processor, a number of simulation cycles, each simulation cycle s_j, comprising 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, the first prediction depending on the at least one characteristic of the 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 vehicle'"'"'s speed v<sub>pred—

Tnew</sub> along the horizon when the vehicle'"'"'s 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;

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

Tnew</sub> in this simulation cycle s_j, such that the at least one reference value is within a range bounded by the second lower and upper limit values v_min, and v_max; and

regulating, by a control system of the vehicle, based on said at least one reference value, the speed of the vehicle.

11. A method according to claim 10, wherein the second lower and upper limit values v_min and v_max are defined based on the choice of driving mode.

12. A method according to claim 10, wherein a further lower limit value v_min2 and upper limit value v_max2 are defined based on the choice of driving mode and based on the set speed v_set.

13. A method according to claim 10, wherein the choice of driving mode decides how said at least one reference value is determined.

14. A method according to claim 10, wherein, when said at least one reference value is a reference speed v_ref, the mode choice defines a permissible acceleration and/or retardation of the vehicle.

15. A method according to claim 10, wherein the mode choice defines a weighting parameter β

, the weighting parameter β

used in evaluation of one or more cost functions when determining said at least one reference value.

16. A method according to claim 15, wherein the simulations are performed by calculating the cost for the second predicted vehicle speed v_pred—

_Tnew and/or a third predicted vehicle speed v<sub>pred—

Tk+new</sub> by use of at least one cost function J_Tnew, J_Tk+new.

17. A method according to claim 16, wherein the respective cost functions J_Tnew and J_Tk+new are determined for the second predicted vehicle speed v_pred—

_Tnew and a third predicted vehicle speed v<sub>pred—

Tk+new</sub> by weighting with the weighting parameter β

, respectively, energy reductions and journey time reductions relative to the first predicted vehicle speed v<sub>pred—

cc</sub>.

18. A method according to claim 17, further comprising, comparing, as a fourth comparison, the cost functions J_Tnew and J_Tk+new for the second predicted vehicle speed v_pred—

_Tnew and for a third predicted vehicle speed v<sub>pred—

Tk+new</sub>,

wherein the at least one reference value is determined based on said fourth comparison.

19. A non-transitory computer-readable medium product instructions configured to enable a computer of a vehicle to perform steps according to the method of claim 10 when the instructions are run on said computer.

20. (canceled)