Method and device for controlling the reference speed of a down-hill speed controller

• US 9,493,161 B2
• Filed: 05/28/2013
• Issued: 11/15/2016
• Est. Priority Date: 06/19/2012
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: Johansson, Oskar, gren, Mikael, Swartling, Fredrik
• Primary Examiner(s): CHEUNG, CALVIN K
• Application Number:
  US14/409,057
• Publication Number:
  US 20150191170A1
• Time in Patent Office: 1,267 Days
• US Class Current: 1/1
• 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: B60T 1/062 acting on transmission parts
• CPC Class Codes: B60T 10/00 Control or regulation for continuous braking making use of fluid or powdered medium, e.g. for use when descending a long slope
• CPC Class Codes: B60T 7/12 for automatic initiation; for initiation not subject to will of driver or passenger limiting speed of vehicles other than rail vehicles B60K31/00
• CPC Class Codes: B60T 7/18 operated by wayside apparatus
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/105 Longitudinal acceleration
• 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 2720/10 Longitudinal speed
• CPC Class Codes: B60W 2720/106 Longitudinal acceleration
• CPC Class Codes: B60W 30/146 Speed limiting
• CPC Class Codes: B60W 30/18072 Coasting
• CPC Class Codes: B60W 50/0097 Predicting future conditions
• CPC Class Codes: G07C 5/002 Analysing tachograph charts arrangements for graph-reading in general G06K11/00
• CPC Class Codes: G07C 5/08 Registering or indicating performance data other than driving, working, idle, or waiting time, with or without registering driving, working, idle or waiting time

Abstract

A system for governing a reference speed v_{ref_dhsc} for a downhill speed control system in a vehicle in connection with a downhill gradient. A simulation unit simulates at least one future speed profile v_sim for an actual vehicle speed over a section of road in front of the vehicle, based on topographic information. An establishing unit establishes whether the reference speed v_{ref_dhsc} is to be allocated an increased reference speed v_{ref_dhsc_schwung}. This establishing is based on a comparison of the simulated future speed profile v_sim with a permitted magnitude of the increased reference speed v_{ref_dhsc_schwung} and/or with an infringement speed v_sl. An allocation unit allocates the value of the increased reference speed v_{ref_dhsc_schwung} to the reference speed v_{ref_dhsc} if this has been established.

Claims

1. A method for governing a reference speed v_{ref_dhsc} for a downhill speed control system in a vehicle in connection with vehicle travel on a downhill gradient, which enables an increased reference speed v_{ref_dhsc_schwung} of the vehicle in a final part of said gradient,

the method comprises:

simulating at least one future speed profile v_sim for an actual speed for said vehicle on a section of road in front of said vehicle, wherein said simulation is based on topographic information;

establishing whether said reference speed v_{ref_dhsc} is to be allocated said increased reference speed v_{ref_dhsc_schwung}, wherein said establishing is based on a comparison of said simulated future speed profile v_sim with at least one of a permitted magnitude for said increased reference speed v_{ref_dhsc_schwung} and an infringement speed v_sl;

allocating said increased reference speed v_{ref_dhsc_schwung} to said reference speed v_{ref_dhsc}; and

after said allocating, changing said actual speed for said vehicle on said section of road in front of said vehicle with said speed control system in said vehicle in connection with vehicle travel on a downhill gradient.

2. The method according to claim 1, wherein said establishing is also calculated based on a rule for giving infringements related to speeding violations.

3. The method according to claim 2, wherein said rule for giving infringements puts an infringement into a tachograph in said vehicle if an actual vehicle speed v_act exceeds an infringement speed v_sl for a predetermined infringement period T_sl.

4. The method according to claim 2, further comprising giving a warning to a driver of said vehicle of an actual vehicle speed v_act exceeding an infringement speed v_sl for a predetermined infringement period T_sl.

5. The method according to claim 1, further comprising governing said reference speed v_{ref_dhsc} for said downhill speed control system based on a selected set speed v_{set_dhsc} for said downhill speed control system.

6. The method according to claim 5, further comprising prior to said allocating of said increased reference speed v_{ref_dhsc_schwung} reducing said reference speed v_{ref_dhsc} for said downhill speed control system below said set speed v_{set_dhsc} for said downhill speed control system, if said simulated future speed profile v_sim indicates that an actual vehicle speed v_act will exceed an infringement speed v_sl for at least a predetermined infringement period T_sl in connection with said downhill gradient.

7. The method according to claim 6, further comprising establishing a magnitude of said increased reference speed v_{ref_dhsc_schwung} for said downhill speed control system as being essentially the same as said set speed v_{set_dhsc} for said downhill speed control system.

8. The method according to claim 1, further comprising establishing a magnitude of said increased reference speed v_{ref_dhsc_schwung} for said downhill speed control system as being essentially the same as an actual vehicle speed v_act which can be permitted without infringing a rule for giving infringements related to speed violations.

9. The method according to claim 1, further comprising allocating said increased reference speed v_{ref_dhsc_schwung} to said reference speed v_{ref_dhsc} when said simulated future speed profile v_sim according to the simulation will be less than said infringement speed v_sl.

10. The method according to claim 9, further comprising said allocating comprising at least once comparing at least one point in time and a current point in time of an infringement time T_t, during which said simulated future speed profile v_sim according to said simulating will exceed said infringement speed v_sl, for a predetermined infringement period T_sl.

11. The method according to claim 1, wherein said establishing of a second point in time T₂ when said allocating of said increased reference speed v_{ref_dhsc_schwung} to said reference speed v_{ref_dhsc} takes place comprises comparing an infringement time T_t, during which said simulated future speed profile v_sim according to the simulation will exceed said infringement speed v_sl, for a predetermined infringement period T_sl.

12. The method according to claim 11, wherein said establishing of said second point in time T₂ comprises the steps of:

simulating a first future speed profile v_{sim_t0} for said vehicle;

at a current point in time t₀ for said vehicle,

comparing a first infringement time T_t0 with said infringement period T_sl, wherein said first infringement time T_t0 corresponds to a time when said first future speed profile v_{sim_t0} is simulated to exceed said infringement speed v_sl, wherein;

if said first infringement time T_t0 is shorter than said infringement period T_sl, T_t0<

T_sl,

setting said second point in time T₂ to said current position, T₂=t₀;

if said first infringement time T_t0 is equal to or longer than said infringement period T_sl, T_t0>

T_sl, leaving said reference speed v_{ref_dhsc} unchanged and further simulating at least one future speed profile v_{sim_t1}, v_{sim_t2} for said vehicle, based on a further current point in time t₁, t₂ to which said vehicle has moved since said current position t₀;

comparing at least one further infringement time T_t1, T_t2 with said infringement period T_sl, where said at least one further infringement time T_t1, T_t2 corresponds to a time when said first future speed profile v_{sim_t0} is simulated to exceed said infringement speed v_sl, wherein;

if said at least one further infringement time T_t1, T_t2 is shorter than said infringement period T_sl, T_t1<

T_sl, or T_t2<

T_sl, setting said second point in time T₂ to said current point in time position, T₂=t₁ or T₂=t₂ and

if said at least one further infringement time T_t1, T_t2 is equal to or longer than said infringement period T_sl, T_t1>

T_sl, or T_t2>

T_sl, leaving said reference speed v_{ref_dhsc} unchanged and performing at least one further simulation of a future speed profile.

13. The method according to claim 1, further comprising performing said allocating of said reference speed V_{ref_dhsc} to said increased reference speed v_{ref_dhsc_schwung} if said simulated future speed profile v_sim remains less than said increased reference speed v_{ref_dhsc_schwung}.

14. The method according to claim 1, further comprising coordinating said control of said reference speed v_{ref_dhsc} with a control carried out by a cruise control system for setting said reference speed v_{ref_dhsc} to a value corresponding to a set speed v_{set_cc} for said cruise control system.

15. The method according to claim 1, further comprising coordinating said control of said reference speed v_{ref_dhsc} for said downhill speed control system with a function for a reference speed governing cruise control system for maximizing said magnitude of said increased reference speed v_{ref_dhsc_schwung}.

16. The method according to claim 15, further comprising controlling said reference speed v_{ref_dhsc} for said downhill speed control system taking account of a reduction of said reference speed v_{ref_cc} for said reference speed governing cruise control system prior to said downhill gradient.

17. The method according to claim 16, further comprising temporarily reducing said reference speed v_{ref_dhsc} for said downhill speed control system to an initial level v_{ref_dhsc_initial} for said reference speed, if said simulated future speed profile v_sim indicates that an actual vehicle speed v_act will exceed an infringement speed v_sl for at least a predetermined infringement period T_sl in connection with said downhill gradient.

18. The method according to claim 16, further comprising temporarily reducing said reference speed v_{ref_dhsc} for said downhill speed control to an initial level v_{ref_dhsc_initial} for said reference speed if said simulated future speed profile v_sim is at least partially greater than or equal to said increased reference speed v_{ref_dhsc_schwung}.

19. The method according to claim 18, wherein said increased reference speed v_{ref_dhsc_schwung} has a level which, with an excess speed_vschwung, exceeds an initial level v_{ref_dhsc_initial} of said reference speed at a first section of said downhill gradient.

20. The method according to claim 19, further comprising permitting said reference speed v_{ref_dhsc} to retain its increased value v_{ref_dhsc_schwung} until an actual vehicle speed v_act is less than a set speed v_{set_dhsc} for said downhill speed control system.

21. The method according to claim 20, wherein said increased reference speed v_{ref_dhsc_schwung} for said downhill speed control system causes at least one action in a group consisting of:

reducing a magnitude of a braking force acting in said vehicle;

performing a gear change in said vehicle into a higher gear;

performing a gear change in said vehicle to neutral gear; and

performing a transition to engine braking of said vehicle.

22. The method according to claim 18, wherein said increased reference speed v_{ref_dhsc_schwung} causes an increased actual vehicle speed at the final section of said downhill gradient, compared with an actual vehicle speed v_act which had resulted in said initial reference speed v_{ref_dhsc_initial} for said downhill speed control system, wherein said increased actual vehicle speed means that said vehicle leaves said downhill slope with increased kinetic energy W_k.

23. The method according to claim 1, wherein said simulation of said at least one future speed profile v_sim is based on ignoring the effect of said downhill speed control system.

24. A system for governing a reference speed v_{ref_dhsc} for a downhill speed control system in a vehicle, in connection with a downhill gradient, wherein said system is configured and operable to provide an increased reference speed v_{ref_dhsc_schwung} in a final part of said gradient, said system comprising:

a simulation unit configured to simulate at least one future speed profile v_sim for an actual speed for said vehicle on a section of road in front of said vehicle, where said simulation is based on topographic information;

an establishment unit configured to establish whether said reference speed v_{ref_dhsc} is to be allocated said increased reference speed v_{ref_dhsc_schwung},

wherein said establishment unit is configured to compare said simulated future speed profile v_sim with at least one of a permitted magnitude for said increased reference speed v_{ref_dhsc_schwung} and an infringement speed v_sl, and

an allocation unit configured to allocate said increased reference speed v_{ref_dhsc_schwung} to said reference speed v_{ref_dhsc},

wherein said downhill speed control system is configured to change said actual speed, for said vehicle on said section of road in front of said vehicle in connection with vehicle travel on a downhill gradient.