Method and module for controlling a velocity of a vehicle

1. A method performed by a control system incorporating a computer for regulating a vehicle's speed, the method comprising:

determining a horizon from position data and map data of an itinerary including route segments, each route segment having a with length, an end, and gradient characteristics;

calculating threshold values according to one or more vehicle-specific values;

comparing the gradient characteristics of each segment with the threshold values and assigning each segment within the horizon to a respective category according to the results of the comparisons, wherein the threshold values serve as boundaries for assigning the segments to the respective categories;

for each segment within the horizon assigned to a category indicating a steep upgrade or a steep downgrade, the method comprises:

calculating the vehicle's final speed V end , the final speed V end being a speed immediately after the end of the segment, based inter alia on an entry speed v i to the segment; and

when the calculated final speed V end is outside a range for the vehicle's current reference speed v set defined by V max and V min , the method comprises:

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 assigned category, so that V min ≦V end ≦V max , on the supposition that v i is corrected within the same range; and

regulating the vehicle's speed according to speed set-point values V ref based on a respective entry speed v i for each segment.

2. A method according to claim 1 , wherein the vehicle-values are determined by current transmission ratio, current vehicle weight, a maximum torque curve of an engine of the vehicle, 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 based also on a force F track acting from an engine torque in the vehicle's direction of movement, a force F roll which is a rolling resistance acting upon the vehicle's wheels, a force F α acting upon the vehicle because of a gradient α of the segment, and a running resistance.

4. A method according to claim 1 , wherein the correcting of the entry speed v i for the segment further comprises: determining the entry speed v i to the segment according to the length of the segment, whereby 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.

5. 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 categories so that said entry speed v i can be fulfilled.

6. 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 .

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 section. L, preventing both acceleration and retardation of the vehicle within the section L.

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

a horizon unit configured and operable to determine a horizon based on received position data and map data of an itinerary including route segments, each route segment having a length, an end, and a gradient characteristic;

a processor unit that includes a data processor, the processor unit configured and operable:

to calculate threshold values according to one or more vehicle-specific values;

to compare the gradient characteristic of each segment with the threshold values and to assign each segment within the horizon to a respective category according to the results of the comparisons, wherein the threshold values serve as boundaries for assigning the segments to the respective categories; and

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

calculate the vehicle's final speed V end , the final speed being a speed immediately after the end of the segment, based inter alia on the entry speed v i to the segment; and

correct 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 assigned 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 a respective entry speed v i for each segment.

9. A module according to claim 8 , wherein vehicle-specific values are determined by current transmission ratio, current vehicle weight, a maximum torque curve of an engine of the vehicle, mechanical friction and/or the vehicle's running resistance at current speed.

10. A module according to claim 8 , wherein the processor unit is configured and operable to calculate the vehicle's final speed V end based also on a force F track acting from engine torque in the vehicle's direction of movement, a force F roll which is a rolling resistance acting upon the vehicle's wheels, a force F α acting upon the vehicle because of a gradient a of the segment, and running resistance.

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 % the processor unit is also configured and operable to determine entry speeds which occur in earlier segments according to the rules for the segment categories 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 section L, the processor unit is configured and operable to not allowing both acceleration and retardation of the vehicle within the section L.

15. A computer-readable medium incorporating a non-transitory program product comprising computer program of instructions for enabling a computer system in a vehicle to perform the steps of:

determining a horizon from position data and map data of an itinerary

including route segments, each route segment having a with length, an end, and gradient characteristics;

calculating threshold values according to one or more vehicle-specific values;

comparing the gradient characteristics of each segment with the threshold values and assigning each segment within the horizon to a respective category according to the results of the comparisons, wherein the threshold values serve as boundaries for assigning the segments to the respective categories;

for each segment within the horizon assigned to a category indicating a steep upgrade or a steep downgrade, the method comprises:

calculating the vehicle's final seed V end , the final seed V end being a speed immediately after the end of the segment, based inter alia on an entry speed v i to the segment; and

when the calculated final speed Vend is outside a range for the vehicle's current reference seed v set defined by V max and V min , the method comprises:

correcting the entry seed 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 assigned category, so that V min ≦V end ≦V max , on the supposition that v i is corrected within the same range; and

regulating the vehicle's speed according to speed set-point values V ref based on a respective entry seed v i for each segment

when the computer program of instructions is run on the computer system.

16. A computer-readable medium program product according to claim 15 , wherein the computer system is on-board the vehicle.