METHOD AND MODULE FOR CONTROLLING A VELOCITY OF A VEHICLE

• US 20120083985A1
• Filed: 05/31/2010
• Published: 04/05/2012
• Est. Priority Date: 06/10/2009
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Johansson, Oskar, Hansson, Jörgen, Pettersson, Henrik, Södergren, Maria
• Granted Patent: US 8,620,558 B2
• Time in Patent Office: Days
• US Class Current: 701/93
• CPC Class Codes: B60W 2552/15 Road slope, i.e. the inclination of a road segment in the longitudinal direction
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60W 30/143 Speed control B60W30/16 takes precedence
• CPC Class Codes: B60W 40/06 Road conditions
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: Y02T 10/40 Engine management systems
• CPC Class Codes: Y02T 10/84 Data processing systems or methods, management, administration

Abstract

A method for regulating a vehicle'"'"'s speed including the steps of: determining a horizon by means of position data and map data of an itinerary made up of route segments with length and gradient characteristics for each segment; calculating threshold values for the gradient of segments according to one or more vehicle-specific values, which threshold values serve as boundaries for assigning segments to various categories; comparing the gradient of each segment with the threshold values and placing each segment within the horizon in a category according to the results of the comparisons; and, for each segment within the horizon which is in a category indicating a steep upgrade or a steep downgrade, calculating the vehicle'"'"'s final speed v_end after the end of the segment, based inter alia on the entry speed v_i to the segment; and determining the entry speed v_i for said segment based on the calculated final speed vend for the segment, which determination is defined by rules for said segment'"'"'s category, so that the vehicle'"'"'s final speed V_end is within the range defined by v_max and v_min for the vehicle'"'"'s current reference speed v_set, on the supposition that v_i is determined within the same range; and regulating the vehicle'"'"'s speed according to speed set-point values v_ref based on the entry speeds v_i to each segment.

Claims

1. A method for regulating a vehicle'"'"'s speed comprising:

A) determining a horizon from position data and map data of an itinerary made up of route segments with length and gradient characteristics for each segment;

B) calculating threshold values for the gradient of segments according to one or more vehicle-specific values, wherein the threshold values serve as boundaries for assigning segments to various categories;

C) comparing the gradient of each segment with the threshold values and placing each segment within the horizon in a category according to the results of the comparisons;

for each segment within the horizon which is in a category indicating a steep upgrade or a steep downgrade, the method comprises;

D) calculating the vehicle'"'"'s final speed v_end after the end of the segment, based inter alia on the entry speed v_i to the segment; and

if the calculated final speed v_end is outside the range for the vehicle'"'"'s current reference speed v_set defined by v_max and v_min, the method performs the step of

E) correcting the entry speed v_i for the segment on the basis of the calculated final speed v_end for the segment, wherein the correction is defined by rules for the segment'"'"'s category, so that v_min≦

v_end≦

v_max, on the supposition that v_i is corrected within the same range;

F) regulating the vehicle'"'"'s speed according to speed set-point values v_ref based on the entry speeds v_i to each segment.

2. A method according to claim 1, in which vehicle-specific values are determined by current transmission ratio, current vehicle weight, the engine'"'"'s maximum torque curve, mechanical friction and/or the vehicle'"'"'s running resistance at current speed.

3. A method according to claim 1, further comprising calculating the vehicle'"'"'s final speed v_end after the end of the segment based also on the force F_track acting from the engine torque in the vehicle'"'"'s direction of movement, the force F_roll which is the rolling resistance acting upon the vehicle'"'"'s wheels, the force F_α

acting upon the vehicle because of the gradient a of the segment, and the running resistance.

4. A method according to claim 1, further comprising wherein step E) also comprises determining the entry speed v_i to the segment according to the length of the segment, whereby the maximum correction of the entry speed v_i is determined by a calculated maximum acceleration or retardation according to rules for the segment categories.

5. A method according to claim 1, further comprising ramping a requested speed change between two consecutive entry speeds v_i to provide the control system with gradually increasing or decreasing speed set-values V_ref.

6. A method according to claim 4, wherein the determination of the entry speed v_i involves entry speeds which occur in earlier segments being determined according to the rules for the segment classes so that said entry speed v_i can be fulfilled.

7. A method according to claim 1, further comprising when a first steep upgrade or a first steep downgrade is followed by a steep upgrade or a steep downgrade within a certain distance L, preventing both acceleration and retardation of the vehicle within the section L.

15. A computer program product comprising computer program instructions for enabling a computer system in a vehicle to perform the steps according to the method according to claim 1 when the computer program instructions are run on the computer system.

16. A computer program product according to claim 15, further comprising the computer program instructions are stored on a medium which is readable by a computer system.

8. A module for regulating a vehicle'"'"'s speed, comprising:

a horizon unit configured and operable to determine a horizon based on received position data and map data of an itinerary made up of route segments with length and gradient characteristics for each segment;

a processor unit configured and operable to

calculate threshold values for the gradient of segments according to one or more vehicle-specific values, wherein the threshold values serve as boundaries for assigning segments to various categories;

comparing the gradient of each segment with the threshold values and placing each segment within the horizon in a category according to the results of the comparisons; and

;

for each segment within the horizon which is in a category indicating a steep upgrade or a steep downgrade, the processor unit is configured and operable to;

calculating the vehicle'"'"'s final speed v_end after the end of the segment, based inter alia on the entry speed v_i to the segment; and

correcting the entry speed v_i for the segment based on the calculated final speed v_end for the segment, wherein the correction is defined by rules for the segment'"'"'s category, so that v_min≦

v_end≦

v_max, on the supposition that v_i is corrected within the same range; and

a control system configured and operable to regulate the vehicle'"'"'s speed according to speed set-point values v_ref based on the entry speeds v_i to each segment.

9. A module according to claim 8, further comprising determining vehicle-specific values by current transmission ratio, current vehicle weight, the engine'"'"'s maximum torque curve, mechanical friction and/or the vehicle'"'"'s running resistance at current speed.

11. A module according to claim 8, wherein the processor unit is configured and operable to determine the entry speed v_i to the segment according to the length of the segment, wherein a maximum correction of the entry speed v_i is determined by a calculated maximum acceleration or retardation according to rules for the segment categories.

12. A module according to claim 8, wherein the processor unit is configured and operable to ramp a requested speed change between two consecutive entry speeds v_i in order to provide the control system with gradually increasing or decreasing speed set-values v_ref.

13. A module according to claim 8, wherein when the processor unit is determining an entry speed v_i, the processor unit is also configured and operable to determine entry speeds which occur in earlier segments according to the rules for the segment classes so that the entry speed v_i can be fulfilled.

14. A module according to claim 8, wherein when a first steep upgrade or a first steep downgrade is followed by a steep upgrade or a steep downgrade within a certain distance L, the processor unit is configured and operable to not allowing both acceleration and retardation of the vehicle within the section L.

10. A module according to wherein the processor unit is configured and operable to calculate the vehicle'"'"'s final speed v_end after the end of the segment based also on a force F_track acting from engine torque in the vehicle'"'"'s direction of movement, a force F_roll which is the rolling resistance acting upon the vehicle'"'"'s wheels, a force Fα

acting upon the vehicle because of the gradient a of the segment, and running resistance.