Module and method pertaining to mode choice when determining reference values

Patent metadata

Field	Value
Publication number	US-9376109-B2
Application number	US-201114364817-A
Country	US
Kind code	B2
Filing date	Dec 22, 2011
Priority date	Dec 22, 2011
Publication date	Jun 28, 2016
Grant date	Jun 28, 2016

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.

First claim

The invention claimed is:

1. A control system configured to determine at least one reference value for controlling a speed of a vehicle, the control system comprising:
a set speed input unit configured to receive at least one set speed v set for the vehicle;
a mode choice receiving 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 map data and location data-based 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 simulation cycle 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 pred _ cc 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 pred _ cc 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 pred _ Tnew 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 j−1 ; and
comparing, as a second comparison, the second predicted vehicle speed v pred _ Tnew 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 pred _ Tnew 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

the control system configured to regulate the speed of the vehicle according to said at least one reference value.

2. The control system 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. The control system according to claim 1 , wherein a further lower limit value v min 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. The control system according to claim 1 , wherein the choice of driving mode decides how said at least one reference value is determined.

5. The control system 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. The control system 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. The control system 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 pred _ Tk+new by use of at least one cost function J Tnew , J Tk+new .

8. The control system 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 pred _ Tk+new by weighting with the weighting parameter β, respectively, their energy reductions and journey time reductions relative to the first predicted vehicle speed V pred _ cc .

9. The control system 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 pred _ Tk+new ,
wherein the determination of the at least one is based on said fourth comparison.

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 pred _ cc 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 pred _ cc 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 pred _ Tnew 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 j−1 ;
comparing, as a second comparison, the second predicted vehicle speed V pred _ Tnew 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 pred _ Tnew 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.

Assignees

• Johansson Oskar
• Södergren Maria
• Roos Fredrik
• Scania Cv Ab

Inventors

• Johansson Oskar
• Södergren Maria
• Roos Fredrik

Classifications

• B60W50/082 Primary

  Selecting or switching between different modes of propelling · CPC title

• B60W30/14

  {Adaptive} cruise control · CPC title

• G05B13/04

  involving the use of models or simulators · CPC title

• B60W2552/20

  Road profile, i.e. the change in elevation or curvature of a plurality of continuous road segments · CPC title

• B60W2552/15

  Road slope, i.e. the inclination of a road segment in the longitudinal direction · CPC title