METHOD AND SYSTEM FOR CONTROL OF A COOLING SYSTEM

• US 20160061093A1
• Filed: 04/23/2014
• Published: 03/03/2016
• Est. Priority Date: 04/25/2013
• Status: Active Grant

• Current Assignee: Scania CV AB (Volkswagen AG)
• Original Assignee: Scania CV AB (Volkswagen AG)
• Inventors: WIKSTRM, Hans, JOHANSSON, Svante, JARELIUS, Sofie, ERIKSSON, Rickard
• Granted Patent: US 9,822,691 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F01P 11/14 Indicating devices; Other safety devices
• CPC Class Codes: F01P 2025/60 Operating parameters
• CPC Class Codes: F01P 2025/62 Load
• CPC Class Codes: F01P 2025/66 Vehicle speed
• CPC Class Codes: F01P 2037/00 Controlling
• CPC Class Codes: F01P 7/04 by varying pump speed, e.g. by changing pump-drive gear ratio
• CPC Class Codes: F01P 7/10 by throttling amount of air flowing through liquid-to-air heat exchangers
• CPC Class Codes: F01P 7/16 by thermostatic control
• CPC Class Codes: F01P 7/167 by adjusting the pre-set temperature according to engine parameters, e.g. engine load, engine speed

Abstract

A method and a system for controlling a vehicle cooling system includes: a velocity prediction unit makes a prediction of at least one future velocity profile v_pred for the vehicle; a temperature prediction unit predicts at least one future temperature profile T_pred for at least one component in the vehicle, based on at least tonnage for the vehicle; information related to a section of road ahead of the vehicle and on the at least one future velocity profile v_pred. A cooling system control unit controls the cooling system based on the at least one future temperature profile T_pred and on a limit value temperature T_comp—lim for the respective at least one component in the vehicle so that a number of fluctuations of an inlet temperature T_{comp—fluid—in—radiator} for the cooling fluid flow into the radiator is reduced and/or so that a magnitude of the flow into the radiator is reduced when a temperature derivative dT/dt for the inlet temperature T_{comp—fluid—in—radiator} exceeds a limit value dT/dt_lim for the temperature derivative.

Claims

1. A method for controlling a cooling system in a motor vehicle, wherein said cooling system regulates a temperature T_comp for at least one component in said vehicle and said cooling system contains a radiator connected to a thermostat, wherein said thermostat controls a flow of cooling fluid through said radiator by said thermostat being in an open or closed state;

wherein said method comprises;

predicting at least one future velocity profile v_pred for a velocity of said vehicle along a section of road ahead of said vehicle;

predicting at least one future temperature profile T_pred for a temperature of said at least one component along said section of road, wherein said prediction of said at least one future temperature profile T_pred is based on at least a tonnage of said vehicle, on information related to said section of road, and on said at least one future velocity profile v_pred;

carrying out said control of said cooling system based on said at least one future temperature profile T_pred and on a limit value temperature T<sub>comp—

lim</sub> for said at least one component in said vehicle;

wherein if a temperature derivative dT/dt for an inlet temperature T<sub>comp—

fluid—

in—

radiator</sub> for said cooling fluid in said radiator exceeds a limit value dT/dt_lim for said temperature derivative dT/dt, carrying out said control of said cooling system so that a reduction is achieved in at least one of

a number of fluctuations in said inlet temperature T<sub>comp—

fluid—

in—

radiator</sub>; and

a size of a flow into said radiator.

2. A method according to claim 1, wherein a cooling power P_cooling of said radiator exceeds a cooling power limit value P_cooling—

_thres and a cooling fluid temperature T<sub>comp—

fluid—

radiator</sub> in said radiator is lower than a low cooling fluid limit value T<sub>comp—

fluid—

radiator—

thres—

cold</sub> of said cooling fluid in said radiator.

3. A method according to claim 2, wherein said cooling power limit value P_cooling—

_thres corresponds to 100 kW and said cooling fluid limit value T<sub>comp—

fluid—

radiator—

thres—

cold</sub> corresponds to a temperature in the range from 0°

C. to −

10°

C.

4. A method according to claim 2 wherein, when said thermostat is closed, assigning a reference temperature T_ref, which indicates when said thermostat is to switch from a closed to an open state based on said future temperature profile T_pred, assigning a maximum permissible value T_ref—

_max if said future temperature profile T_pred indicates that said temperature T<sub>comp—

fluid</sub> for said cooling fluid for at least one component will be lower than said limit value temperature T<sub>comp—

lim</sub> for the respective component if a limited cooling by means of said radiator is applied, whereby a prolonged time t_closed with a closed thermostat is obtained before said thermostat is opened.

5. A method according to claim 4 wherein, when said thermostat has opened, assigning said reference temperature T_ref a minimum permissible value T_ref—

_min and using said limited cooling during the time in which said temperature T<sub>comp—

fluid</sub> for said cooling fluid is decreasing toward said minimum permissible value T<sub>ref—

min</sub>, result in a prolonged time t_open with said thermostat open is obtained before said thermostat is closed.

6. A method according to claim 5, wherein said prolonged time t_closed with said thermostat closed and said prolonged time t_open with said thermostat open collectively result in a prolonged period of time between two consecutive openings of said thermostat.

7. A method according to claim 5, wherein said maximum permissible value T_ref—

_max corresponds to about 105°

C. and said minimum permissible value T<sub>ref—

min</sub> corresponds to about 70°

C.

8. A method according to claim 4, wherein said limited cooling is defined by at least one of the group consisting of:

a flow of less than 5 liters per minute through said radiator;

a passive airflow through said radiator; and

actively controlling said limited cooling so that a cooling fluid temperature T<sub>pred—

fluid</sub> is controlled toward a predefined relatively low reference temperature T_ref.

9. A method according to claim 1, further comprising preheating of said cooling fluid if a predicted inflow Q into said radiator, which is determined based on said future temperature profile T_pred, exceeds a limit value Q_lim, and when a cooling power P_cooling for said radiator exceeds a cooling power limit value P_cooling—

_thres, and a cooling fluid temperature T<sub>comp—

fluid—

radiator</sub> in said radiator is lower than a low cooling fluid limit value T<sub>comp—

fluid—

radiator—

thres—

cold</sub> for said cooling fluid in said radiator.

10. A method according to claim 9, wherein said preheating is achieved by gradually increasing a flow Q into said radiator, whereby said cooling fluid temperature T_comp—

<sub>fluid—

radiator</sub> is increased.

11. A method according to claim 10, further comprising:

said gradual increasing of said flow Q into said radiator is in combination with at least one measure in the group consisting of;

closing of a radiator blind; and

controlling a cooling fluid flow Q into said radiator by an adjustable cooling water pump.

12. A method according to claim 9, further comprising when said preheating of said cooling fluid is performed, applying limited cooling by said radiator if a temperature derivative dT/dt for a temperature T_comp—

_fluid for said cooling fluid for said at least one component is predicted to exceed a limit value for the temperature derivative (dT/dt)<sub>lim—

cold</sub>.

13. A method according to claim 12, wherein said limited cooling comprises limiting an opening of said thermostat so that said future temperature profile T_pred indicates that, for every said at least one component, said future temperature profile is lower than said limit value temperature T_comp—

_lim for the respective component.

14. A method according to claim 13, wherein said limiting of said opening results in said thermostat being closed.

15. A method according to claim 1, further comprising arranging pre-cooling of said cooling fluid if said future temperature profile T_pred indicates that a temperature derivative dT/dt for an actual temperature T_comp for any of said at least one components is greater than a high limit value for the temperature derivative (dT/dt)_lim—

_warm when a cooling fluid temperature T<sub>comp—

fluid—

radiator</sub> in said radiator is higher than a high cooling fluid limit value T<sub>comp—

fluid—

radiator—

thres—

warm</sub> for said cooling fluid in said radiator.

16. A method according to claim 15, wherein said high cooling fluid limit value T_comp—

<sub>fluid—

radiator—

thres—

warm</sub> for said cooling fluid corresponds to about 60°

C.

17. A method according to claim 15, wherein said pre-cooling is achieved by opening of said thermostat followed by passive cooling of said cooling fluid.

18. A method according to claim 15, wherein said pre-cooling continues until at least one occurrence in the group consisting of:

said cooling fluid temperature T<sub>comp—

fluid</sub> reaches a temperature limit value T<sub>comp—

fluid—

lim</sub>; and

said cooling fluid temperature T<sub>comp—

fluid</sub> reaches said limit value temperature T<sub>comp—

lim</sub> for said cooling fluid; and

said future temperature profile T_pred indicates that a temperature T_comp for any of said at least one components does not exceed said limit value temperature T<sub>comp—

lim</sub>.

19. A method according to claim 15, further comprising determining said future temperature profile T_pred based on said temperature derivative dT/dt for said temperature T_comp—

_fluid for said cooling fluid exceeding a high limit value for said temperature derivative (dT/dt)<sub>lim—

warm</sub>, and wherein limited cooling by said radiator is applied after said pre-cooling of said cooling fluid.

20. A method according to claim 15, wherein said limited cooling is obtained when said temperature derivative T/dt for said temperature T_comp—

_fluid for said cooling fluid exceeds a high limit value for the temperature derivative (dT/dt)<sub>lim—

warm</sub>, and wherein an opening of said thermostat is limited so that said future temperature profile T_pred indicates that a temperature T_comp for said at least one component is lower than said limit value temperature T<sub>comp—

lim</sub> for said at least one component.

21. A method according to claim 20, wherein said limitation of said opening results in said thermostat being closed.

22. A method according to claim 1, further comprising causing an inlet temperature T_comp—

<sub>fluid—

in—

radiator</sub> for said radiator to be essentially constant if a cooling fluid temperature T<sub>comp—

fluid—

radiator</sub> in said radiator is higher than a high cooling fluid limit value T<sub>comp—

fluid—

radiator—

thres—

warm</sub> for said cooling fluid in said radiator, and if said future temperature profile T_pred indicates a future temperature imbalance in said cooling system.

23. A method according to claim 22, wherein said high cooling fluid limit value T_comp—

<sub>fluid—

radiator—

thres—

warm</sub> has a value corresponding to about 90°

C.

24. A method according to claim 22, further comprising achieving said essentially constant inlet temperature T_comp—

<sub>fluid—

in—

radiator</sub> by pre-controlling said cooling system to meet a predicted cooling demand, wherein said predicted cooling demand is determined based on said future temperature profile T_pred.

25. A method according to claim 1, wherein said at least one component comprises at least one of the group consisting of:

said cooling fluid;

a motor oil;

a retarder device;

a cylinder material in an engine;

an exhaust recirculation device;

a turbocharger;

a dual turbocharger;

a transmission;

a compressor for a brake system;

exhaust from an engine;

a post-processing device for exhaust; and

an air-conditioning system.

26. A method according to claim 1, wherein said information related to said section of road includes a road gradient.

27. A method according to claim 26, wherein said information relating to said section of road includes said road gradient that is determined based on information selected from the group consisting of:

radar-based information;

camera-based information;

information obtained from a vehicle other than said vehicle;

road gradient information and positioning information previously stored in said vehicle; and

information obtained from a traffic system related to said section of road.

28. A method according to claim 1, wherein said information related to said section of road includes at least one selected from the group consisting of:

a driving resistance acting upon said vehicle;

a speed limit for said section of road;

a velocity history for said section of road; and

traffic information.

29. A method according to claim 1, wherein said prediction of said at least one future temperature profile T_pred is also based on at least one from the group consisting of:

a predicted torque delivered by said engine;

an rpm for said engine;

a gear selection for a transmission in said vehicle;

a component use in said vehicle;

an airflow through said radiator;

an ambient air pressure; and

an ambient temperature.

31. A computer program product comprising a non-transitory computer-readable medium and a computer program comprising program code contained in the computer-readable medium, and which when the program code is executed in a computer, causes the computer to cause performance of the method according to claim 1.

30. (canceled)

32. A system arranged for controlling a cooling system in a motor vehicle, wherein said cooling system is configured to regulate a temperature T_comp for at least one component in said vehicle;

said cooling system comprises a radiator connected to a thermostat, wherein said thermostat controls a flow of cooling fluid through said radiator;

said system comprising;

a velocity prediction unit configured to predict at least one future velocity profile v_pred for a velocity of said vehicle over a section of road ahead of said vehicle;

a temperature prediction unit, configured to predict at least one future temperature profile T_pred for a temperature for said at least one component over said section of road, wherein said prediction of at least one future temperature profile T_pred is based on at least a tonnage for said vehicle, on information related to said section of road and on said at least one future velocity profile v_pred;

a cooling system control unit configured and operable to perform control of said cooling system based on said at least one future temperature profile T_pred and on a limit value temperature T<sub>comp—

lim</sub> of said at least one component in said vehicle;

wherein, if a temperature derivative dT/dt for an inlet temperature T<sub>comp—

fluid—

in—

radiator</sub> for said cooling fluid into said radiator exceeds a limit value dT/dt_lim for said temperature derivative, said control unit of said cooling system is configured to control said cooling system to achieve a reduction of at least one of;

a number of fluctuations in an inlet temperature T<sub>comp—

fluid—

in—

radiator</sub> for said cooling fluid into said radiator; and

a magnitude of a flow into said radiator.