Battery parameter-based power management for suppressing power spikes

• US 9,696,782 B2
• Filed: 02/09/2015
• Issued: 07/04/2017
• Est. Priority Date: 02/09/2015
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Inventors: Moscibroda, Thomas, Chandra, Ranveer, Hodges, Stephen E., Hu, Pan, Ferrese, Anthony John, Skiani, Evangelia, Meinershagen, Julia L., Priyantha, Nissanka Arachchige Bodhi, Badam, Anirudh
• Primary Examiner(s): Cao, Chun
• Application Number:
  US14/617,719
• Publication Number:
  US 20160231801A1
• Time in Patent Office: 876 Days
• Field of Search: 713340, 713300
• CPC Class Codes: G01R 31/3647 for determining the ability of a battery to perform a critical function, e.g. cranking
• CPC Class Codes: G06F 1/3206 Monitoring of events, devices or parameters that trigger a change in power modality
• CPC Class Codes: G06F 1/3212 Monitoring battery levels, e.g. power saving mode being initiated when battery voltage goes below a certain level
• CPC Class Codes: G06F 1/3287 by switching off individual functional units in the computer system
• CPC Class Codes: G06F 1/329 by task scheduling
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

This document describes techniques and apparatuses for suppressing power spikes. In some embodiments, these techniques and apparatuses determine an available amount of power that a battery is capable of providing while maintaining a particular voltage level and a requisite amount of power that components will consume to perform a task. When the requisite amount of power exceeds the available amount of power, power states of the components are altered effective to enable the battery to maintain the particular voltage level.

Claims

1. A computer-implemented method comprising:

determining, for an upcoming point in time, an available amount of power that a battery of a computing device is capable of providing while maintaining a predefined voltage level, the available amount of power determined based on an open circuit potential, internal resistance, and load current of the battery, the predefined voltage level being a voltage level at or above a hard cutoff voltage level or a soft cutoff voltage level at which the computing device ceases to operate from battery power;

determining, for the upcoming point in time, a requisite amount of power that components of the computing device will consume to perform at least a portion of a task at their respective power states; and

altering, responsive to determining that the requisite amount of power exceeds the available amount of power, respective power states of one or more of the components at the upcoming point in time effective to enable the battery to maintain the predefined voltage level and the computing device to continue operate while the components consume the requisite amount of power from the battery.

2. The computer-implemented method as described in claim 1, wherein altering the respective power states of the one or more components comprises altering a sequence in which the task or other tasks of the device are performed effective to reduce, at the upcoming point in time, a respective power state of at least one of the components involved in performing the tasks.

3. The computer-implemented method as described in claim 1, wherein altering the respective power states of the one or more components comprises reducing a respective power state of at least one of the components.

4. The computer-implemented method as described in claim 3, wherein reducing the respective power states of the one or more components negatively effects performance of the task and the method further comprises increasing, at another point in time, the respective power states of the one or more components to mitigate the effects on performance of the task.

5. The computer-implemented method as described in claim 4, wherein the other point in time occurs before or after the upcoming point in time at which the requisite amount of power exceeds the available amount of power.

6. The computer-implemented method as described in claim 1, wherein determining the available amount of power that the battery is capable of providing further comprises determining a state-of-charge of the battery and determining, based on the state-of-charge, the open circuit potential of the battery or the internal resistance of the battery.

7. The computer-implemented method as described in claim 6, wherein determining the open circuit potential of the battery based on the state-of-charge comprises accessing, based on the state-of-charge, predetermined information that describes a relationship between the state-of-charge and the open circuit potential of the battery.

8. The computer-implemented method as described in claim 1, further comprising selecting which of the respective power states of the one or more components to alter based on component interdependencies associated with performing the task.

9. The computer-implemented method as described in claim 1, further comprising selecting a degree by which to alter the respective power states of the one or more components based on a minimum power state of a respective component at which performance of the task is enabled.

10. A computer-implemented method comprising:

receiving a request for a device to perform, in addition to other tasks being performed by the device, an additional task having a particular priority level;

determining an available amount of power that a battery of the device can provide while maintaining a predefined voltage level, the available amount of power determined based on an open circuit potential of the battery, internal resistance of the battery, and load current of the battery, the predefined voltage level being a voltage level at or above a hard cutoff voltage level or a soft cutoff voltage level at which the device ceases to operate from battery power;

determining that a requisite amount of power that resources of the device will consume to perform the additional task and other tasks exceeds the available amount of power that a battery of the device can provide while maintaining the predefined voltage level;

determining which ones of the other tasks have respective priority levels that are lower than the particular priority level of the additional task;

identifying which ones of the resources are involved in performing the other tasks having the lower respective priority levels; and

altering respective power states of at least some of the resources involved in performing the other tasks having the lower respective priority levels effective to enable the battery to maintain the predefined voltage level and the device to continue to operate while the resources of the device consume the requisite amount of power from the battery to perform the additional task.

11. The computer-implemented method as described in claim 10, further comprising altering respective power states of resources involved with performing the additional task such that the requisite power does not exceed the available amount of power when the additional task is performed.

12. The computer-implemented method as described in claim 10, further comprising, prior to altering the respective power states, identifying interdependencies between the resources involved with performing the other tasks having the lower respective priority levels and resources involved with performing the additional task, and wherein altering the respective power states of at least some of the resources alters respective power states of the resources involved in performing the other tasks that are not interdependent with resources involved with performing the additional task.

13. The computer-implemented method as described in claim 10, wherein altering respective power states of at least some of the resources includes shutting down or idling the resources involved in performing the other tasks having the lower respective priority levels.

14. The computer-implemented method as described in claim 10, wherein the other tasks having the lower respective priority levels are background tasks of an operating system or application.

15. A system comprising:

a battery from which the system draws power to operate;

hardware-based resources by which the system performs tasks;

a power manager configured to perform operations comprising;

determining, for an upcoming point in time, an available amount of power that the battery is capable of providing while maintaining a predefined voltage level, the available amount of power determined based on an open circuit potential of the battery, internal resistance of the battery, and load current of the battery, the predefined voltage being a voltage level at or above a hard cutoff voltage level or a soft cutoff voltage level at which the system ceases to operate from the battery;

determining, for the upcoming point in time, a requisite amount of power that the hardware-based resources will consume to perform one of the tasks at the hardware-based resources'"'"' respective power states; and

altering, responsive to determining that the requisite amount of power exceeds the available amount of power, respective power states of one or more of the hardware-based resources at the upcoming point in time effective to enable the battery to maintain the predefined voltage level and the system to continue to operate while the hardware-based resources consume the requisite amount of power from the battery to perform the task.

16. The system as described in claim 15, wherein altering the respective power states of the one or more of the hardware-based resources negatively effects performance of the task and the power manager is further configured to restore, at another point in time, the respective power states of the one or more of the hardware-based resources to mitigate the negative effects on performance of the task.

17. The system as described in claim 15, wherein the hardware-based resources of the system comprise at least one of a processing resource, memory resource, display resource, graphics processing resource, communication resource, or mass storage resource.

18. The system as described in claim 15, wherein to determine the available amount of power that the battery is capable of providing the power manager is further configured to perform operations comprising determining a state-of-charge of the battery and determining, based on the state-of-charge, the open circuit potential of the battery or the internal resistance of the battery.

19. The system as described in claim 15, wherein the power manager is further configured to select which of the respective power states of one or more of the hardware-based resources to alter based on component interdependencies associated with performing the task.

20. The system as described in claim 15, wherein the power manager is further configured to select a degree by which to alter the respective power states of the one or more of the hardware-based resources based on a minimum power state of a respective hardware-based resource at which performance of the task is enabled.