Automated vehicle battery protection with programmable load shedding and engine speed control

• US 20060253237A1
• Filed: 05/03/2005
• Published: 11/09/2006
• Est. Priority Date: 05/03/2005
• Status: Active Grant

• Current Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Original Assignee: International Truck Intellectual Property Co. LLC (Volkswagen AG)
• Inventors: Lovell, Steven R., Dannenberg, Robert D.
• Granted Patent: US 7,421,323 B2
• Time in Patent Office: Days
• US Class Current: 701/36
• CPC Class Codes: F02D 2200/503 Battery correction, i.e. corrections as a function of the state of the battery, its output or its type
• CPC Class Codes: F02D 31/001 Electric control of rotation speed
• CPC Class Codes: F02D 41/021 Introducing corrections for particular conditions exterior to the engine conjoint control of vehicle sub-units for propelling the vehicle B60W30/18

Abstract

Automated motor vehicle battery voltage protection is provided by setting voltage trip points for increasing engine speed and for shedding selected electrical loads. The system is effected by programming a vehicle body computer which communicates with, and exerts control over, various vehicle system controllers over one or more controller area networks. The body computer is programmed to monitor battery voltage and initiates an increase in engine speed first, and if that fails to restore a minimum battery voltage level, begins shedding loads in a predetermined order.

Claims

12. A battery state of charge protection system comprising:

an electricity generating source with a rotating element;

an engine coupled to rotate the rotating element;

an engine controller for controlling the rotational speed of the engine;

a battery connected to the electricity generating source for charging;

a plurality of power consuming systems coupled to the battery for selective energization;

a programmable data processing element connected for controlling the energization state of each of the plurality of power consuming systems and further connected for communication with the engine controller;

means for supplying battery voltage measurements to the programmable data processing element;

at least first and second voltage trip levels programmed in the programmable data processing element, the first voltage trip level being of a lesser absolute magnitude than the second voltage trip level;

the programmable data element being responsive to absolute battery voltage measurement excursions below the first voltage trip level for issuing instructions for the engine controller to increase engine output and to excursions in the absolute battery voltage measurements above the second voltage trip level for issuing instructions for the engine controller to decrease engine output.

13. A battery state of charge protection system as claimed in claim 12, further comprising:

the programmable data element including a delay means operative after an initial detection of a absolute battery voltage measurement excursion below the first trip point for executing a delay and requiring a second, consecutive absolute battery voltage measurement below the first voltage trip level before issuing instructions for the engine controller to increase speed.

14. A battery state of charge protection system as claimed in claim 13, further comprising:

the programmable data element including a second delay element operative after issuance of the instruction for the engine controller to increase engine output before execution of a post engine ramp up battery voltage measurement.

15. A battery state of charge protection system as claimed in claim 14, further comprising:

the programmable data element including programming means executable on the programmable data element for comparing the post engine ramp up battery voltage measurement to the second voltage trip level and responsive to voltage measurements taken after engine ramp up which exceed the second voltage trip level for causing issuance of a reduce engine output instruction for the engine controller.

16. A battery state of charge protection system as claimed in claim 15, further comprising:

the programmable data element including programming means for comparing the absolute post engine ramp up battery voltage measurement to a load shed trigger voltage level and operative responsive to the absolute post engine ramp up battery voltage measurement being less than the load shed trigger voltage level for causing deenergization of a power consuming system.

17. A battery state of charge protection system as claimed in claim 16, further comprising:

the programmable data element being further programmed to sequentially shed power consuming systems as long as repeated post engine ramp up battery voltage measurement continue to be less than the load shed trigger level; and

the programmable data element being still further programmed to sequentially restore energization to power consuming systems responsive to post engine ramp battery voltage measurements exceeding a load restore trigger level until each selected power consuming systems is reenergized and then causing an instruction for the engine controller to be generated for reducing engine output.

18. A battery state of charge protection system as claimed in claim 17, further comprising:

a controller area network providing data communication between the engine controller and the programmable data element.

19. A battery state of charge protection system as claimed in claim 18, further comprising:

a plurality of interlocks for testing by the programmable data element before execution of battery protection operations.

20. A battery state of charge protection system as claimed in claim 19, further comprising:

providing an on/off select means for an operator for turning the battery state of charge protection system on and off.

21. A battery state of charge protection system as claimed in claim 12, further comprising:

program means for enabling engine speed control responsive to battery voltage falling below the first voltage trip level.

22. A battery state of charge protection system as claimed in claim 21, further comprising:

program means responsive to enablement of engine speed control, battery voltage remaining below the first voltage trip level continuously for a minimum period and engine speed less than a predetermined maximum for increasing engine speed; and

program means responsive to enablement of engine speed control and battery voltage above the second voltage trip level continuously for reducing engine speed.

23. A method of protecting the state of charge of a motor vehicle battery, comprising the steps of:

(a) running a motor vehicle engine at idle;

(b) providing a first and a second, higher, voltage level triggers;

(c) measuring the voltage of the motor vehicle battery;

(d) comparing the measured voltage against the first voltage level trigger;

(e) if the comparison fails low executing a delay and remeasuring the voltage of the motor vehicle battery;

(f) comparing the remeasured voltage against the first voltage level trigger; and

(g) if the comparison of the remeasured voltage also fails ramping up the speed of the engine.

1. A motor vehicle comprising:

an engine;

a controller area network;

a plurality of vocational controllers including an engine controller connected to at least a first controller area network for the exchange of data, the vocational controllers each having at least a one vehicle subsystem associated therewith;

a vehicle battery;

means for providing vehicle battery voltage measurements to at least a first of the plurality of vocational controllers; and

a battery monitor program stored on the first vocational controller for execution, the battery monitor program being responsive upon execution to at least two battery voltage trip points, including a first greater magnitude voltage trip point to which the programmed vocational controller is responsive for directing the engine controller to increase engine speed, and a second, greater magnitude voltage trip point to which the programmed vocational controller is responsive for directing the engine controller to reduce engine speed.

2. A motor vehicle as claimed in claim 1, wherein the specially programmed vocational controller is an electrical system controller and the vehicle battery voltage measurements are coupled directly to the electrical system controller.

3. A motor vehicle as claimed in claim 1, further comprising:

at least first and second controller area networks including a power train controller area network and a body controller area network;

the first and second controller area networks each being connected to the electrical system controller; and

a vocational controller for a power takeoff application, the vocational controller for the power takeoff application being connected to the second controller area network.

4. A motor vehicle as set forth in claim 3, further comprising:

an interlock responsive to one or more motor vehicle conditions for preventing execution of the battery monitor program.

5. A motor vehicle as set forth in claim 4, further comprising:

a load shed trip point to which the programmed vocational controller is responsive for causing a vehicle subsystem to be turned off.

a power takeoff application installed on the motor vehicle; and

the interlock is responsive to the state of the power takeoff application.

6. A motor vehicle as set forth in claim 4, further comprising:

the interlock is responsive to the states of a combination of motor vehicle conditions.

7. A motor vehicle as set forth in claim 4, the battery monitor program further comprising:

means for comparing the measured battery voltage against a first voltage trip level and initiating a delay if the magnitude of the measured battery voltage is less than the first voltage trip level; and

means responsive to occurrence of the delay for comparing an updated measured battery voltage against the first voltage trip level and triggering an increase in engine speed if the updated measured battery voltage remains at a lesser magnitude than the first voltage trip level.

8. A motor vehicle as set forth in claim 7, the battery monitor program further comprising:

means for executing a delay after a triggered increase in engine speed;

means responsive to execution of the delay after a triggered increase in engine speed for comparing yet another updated measurement of battery voltage against a idle return trigger level and, responsive to a measured battery voltage being of greater magnitude than the trigger level, for further causing the engine to return to an idle level.

9. A motor vehicle as set forth in claim 8, the battery monitor program further comprising:

means responsive to the measured battery voltage being of a smaller magnitude than the idle return trigger level for comparing the measured battery voltage against a load shedding trigger level and if the measured battery voltage is of greater magnitude than the load shedding trigger level, causing the program to loop through cycles of measurements of battery voltage and comparison of the battery voltage measurements with the idle return trigger level and the load shedding trigger level; and

means responsive to a battery voltage measurement less than the load shedding trigger level for cutting power to a vehicle subsystem by issuance of a instruction on one of the vehicle controller area networks for operation on by a vocational controller connected to the vehicle controller area network.

10. A motor vehicle as set forth in claim 9, further comprising:

means responsive to cutting power to a vehicle subsystem for executing a program delay; and

means responsive to execution of a program delay after a power cut to at vehicle subsystem for comparing a new measurement of vehicle battery voltage to a load restore trigger and responsive to the new measurement being larger in magnitude than the load restore trigger returning power to a vehicle subsystem previously cut, responsive to the new measurement being smaller in magnitude than the load shedding trigger cutting power to another vehicle subsystem, and responsive to the new measurement being of a magnitude between the load shedding trigger and the load restore trigger cycling delays, vehicle battery voltage remeasurements and comparisons of each new measurement of battery voltage to the trigger levels.

11. A motor vehicle as set forth in claim 1, further comprising:

the battery monitoring program being responsive to the first and second trip points for ramping up and ramping down engine speed, respectively.

24. A method of protecting the state of charge of a motor vehicle battery as set forth in claim 23, comprising the additional steps of:

(h) after ramp up in engine speed and a delay following ramp up measuring the battery voltage;

(i) comparing the battery voltage measured at step (h) with the first or the second higher voltage trip level; and

(j) if in the comparison of step (i) the measured battery voltage at least exceeds the first or higher voltage trip level reducing engine output.

25. A method of protecting the state of charge of a motor vehicle battery as set forth in claim 24, comprising the additional steps of:

(m) following step (l) continuing measurements and comparisons of battery voltage against the two differentiated voltage trigger levels, and restoring motor vehicle electrical subsystems previously deenergized whenever the measured battery voltage recovers above the higher of the thresholds and deenergizing motor vehicle electrical subsystems whenever the measured battery voltage falls below the second lower threshold.

26. A method of protecting the state of charge of a motor vehicle battery as set forth in claim 25, comprising the additional steps of:

(n) following step (m), returning the engine to idle if the measured battery voltage recovers above the higher threshold and no electrical subsystems remain deenergized.

24-1. A method of protecting the state of charge of a motor vehicle battery as set forth in claim 23, comprising the additional steps of:

(k) if the comparison of step (i) is not met comparing the voltage measurement of step (h) with a third voltage trigger level;

(l) if the comparison of step (k) results in the voltage measurement not meeting the second lower voltage trigger level, deenergizing a motor vehicle electrical subsystem.