Patent Application
20080024007
In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.
The functions or algorithms described herein are implemented in software or a combination of software and human implemented procedures in one embodiment. The software may consist of computer executable instructions stored on computer readable media such as memory or other type of storage devices. The term “computer readable media” is also used to represent any means by which the computer readable instructions may be received by the computer, such as by different forms of wireless transmissions as well as different memory devices that can store code. Further, such functions correspond to modules, which are software, hardware, firmware or any combination thereof. Multiple functions are performed in one or more modules as desired, and the embodiments described are merely examples. The software is executed on a digital signal processor, ASIC, microprocessor, or other type of processor operating on a computer system, such as a personal computer, server or other computer system.
A supply-load multiplexer is described that has multiple power inputs for coupling to multiple power supplies and multiple power outputs for coupling to multiple loads. The multiplexer dynamically and selectively couples the power inputs to the power outputs. A controller is coupled to the supply-load multiplexer and controls the selective coupling of power inputs to power outputs as a function of load power requirements and/or power supply characteristics. Several embodiments will be described showing different examples of operation of the present invention.
In one embodiment of the invention a hybrid power supply is shown generally at 100 in
A more detailed block diagram of an alternative hybrid power supply is shown generally at 200 in
A controller, sometimes referred to as a decision engine 250 is coupled to the supply-load multiplexer 210 and controls the selective coupling of power inputs to power outputs as a function of load power requirements determined at a power requirement estimator 255 and/or power availability calculated at a power supply manager 260. In further embodiments, the number of inputs and outputs may be varied, and need not be equal. Different types of power supplies and different types of loads may be used. Further, the decision engine 250, power requirement estimator 255 and power supply manager may be at least partially implemented in software executing on one or more computers.
The power supply manager 260 may measured power supply characteristics through the use of power level sensors 262. Consumption of power from the various power supplies may be measured by consumption rate sensors 264. The power supplies may also have pre-programmed current levels that they can provide as indicated at 266. A power availability calculator 268 receives information from the power level sensors 262, consumption rate sensors 264 and the current level information from 266, and provides indications of available power from each supply to the decision engine 250. The sensors may take any form now known or developed in the future, and may be hardwired or wireless, battery operated or line powered.
The power requirement estimator 255 receives current load activity information from an activity-load cognitive map 270 in one embodiment. The cognitive map may measure the actual current load consumption characteristics for different statuses of the loads, such as active, idle, sleeping, or in various different forms of operation. The power requirements of such different statuses may also be provided. A precognitive activity table 272 provides information about the expected power use of the loads. This information may take different forms, such as whether a load is actually active, or times during which a load may become active and for how long such activity may occur. The power requirement estimator 255 receives information from the map 270 and table 272 and calculates the power needs, such as how many mAHrs are needed and for how long. It provides this information to the decision engine 255.
Decision engine 255 receives the availability information and the power requirements information from the power supply manager 260 and power requirement estimator 255, and decides how to connect power supplies to loads to provide desired use of the various power supplies to adequately power the loads. In one embodiment, the connections may be provided to optimally use the various power supplies to provide power to the multiple loads.
A block diagram of an example hybrid power supply coupled to identified components, and illustrating connections between components is shown generally at 300 in
The multiplexer 310 selectively couples the power inputs to the power outputs. In one embodiment, AAA battery 322 is not providing power to any load. Radio module 342, which may currently be in sleep mode, but is known to be switching from sleep to transmit mode in 2 us and stay in transmit mode for 1 ms, is currently powered by the fuel cell 323. Solar cell 324 is coupled via multiplexer 310 to occupancy sensor 333 which may be in an active mode. Micro fuel cell 323 may also be coupled to temperature sensor 344, which is idle.
A controller, sometimes referred to as a decision engine 350 is coupled to the supply-load multiplexer 310 and controls the selective coupling of power inputs to power outputs as a function of load power requirements determined at a power requirement estimator 355 and/or power availability calculated at a power supply manager 360. In further embodiments, the number of inputs and outputs may be varied, and need not be equal. Different types of power supplies and different types of loads may be used. Further, the decision engine 350, power requirement estimator 355 and power supply manager may be at least partially implemented in software executing on one or more computers.
The power supply manager 360 may measured power supply characteristics through the use of power level sensors 362. In this embodiment, example readings determine that the AAA battery 322 has medium power level, fuel cell 323 has high power and solar cell 324 has medium power. Consumption of power from the various power supplies may be measured by consumption rate sensors 364. Current consumptions are 0 mA/ns for the AAA pattery 322, 5 uA/ns for the fuel cell 323 and 1 mA/ns for the solar cell 324. The power supplies may also have pre-programmed current and/or voltage levels that they can provide as indicated at 366. An example of such a current level is 0 to 5 uA for the fuel cell 323.
A power availability calculator 368 receives information from the power level sensors 362, consumption rate sensors 364 and the current level information from 366, and provides indications of available power from each supply to the decision engine 350. For this example, the power consumption for AAA battery 322 is 50 mAHr left for 60 hrs, the fuel cell 323 has 100 AHr left for 20 yrs, and the solar cell has 20 mAHr left for 4 hours.
The power requirement estimator 355 receives current load activity information from an activity-load cognitive map 370 in one embodiment. The cognitive map may measure the actual current load consumption characteristics for different statuses of the loads, such as active, idle, sleeping, or in various different forms of operation. The power requirements of such different statuses may also be provided. In this example, the radio 342 in transmit mode, TX, requires 100 mA, in receive mode, RX, 50 mA, and 5 uA in sleep mode. The Occupancy sensor 343 requires 1 mA in active mode and 5 uA in idle mode. The temperature sensor 344 utilizes 1 mA in active mode and 5 uA in idle mode.
A precognitive activity table 372 provides information about the expected power use of the loads. This information may take different forms, such as whether a load is actually active, or times during which a load may become active and for how long such activity may occur. In this example, the radio is known to be in transmit mode in 2 us for a duration of 1 ms. The occupancy sensor 343 is currently active, and the temperature sensor 344 is idle. The power requirement estimator 355 receives this information from the map 370 and table 372 and calculates the power needs, such as how many mAHrs are needed and for how long. It provides this information to the decision engine 355. In this example, since it is known that the radio 342 will begin transmitting in 2 us, the AAA battery 322 is changed by the decision engine 350 to begin providing power to the radio 342. The fuel cell 323 continues providing power to the temperature sensor 344 and the solar cell 324 continues providing power to the occupancy sensor 343.
Power requirement calculator 375 determines that the radio 342 needs 100 mA for 1 ms, in 2 us. The occupancy sensor 343 will continue needing 1 mA for 1 minute, and the temperature sensor will continue needing 5 uA for 10 seconds. It also calculates how may mAHrs will be needed and for how long for each load. The above calculations are for one example period of time. Conditions will vary as loads are predicted to transition to different modes at different times. The calculations may be done continuously or at various intervals as desired.
The decision to switch the radio 342 to AAA battery 322 power is a function of the expected amount of power required by the various loads, and the abilities of the power supplies to provide the power. The AAA battery 322 has the ability to provide from 0 to 100 mA, while the fuel cell may only provide from 0 to 5 uA as indicated by 366. Thus, the AAA battery 322 is better suited to provide the 100 mA that the radio 342 will need during transmission beginning in 2 μsec. 366, which may be a table or other form of data providing device also indicates a pre-programmed current level of 0 to 75 mA for the solar cell 324. These are just example current levels for example power supplies. The current levels for the supplies may vary, as may the number and type of power supplies which may be utilized. Some loads may be following predetermined schedules and some may react to the environment in which they are located. The precognitive power requirement estimator 355 may take such schedules into account, and may also monitor conditions to predict mode changes of the loads. In further embodiments, the loads may provide the estimator 355 with mode switching information to assist with power supply multiplexing management.
Decision engine 355 receives the availability information and the power requirements information from the power supply manager 360 and power requirement estimator 355, and decides how to connect power supplies to loads to provide desired use of the various power supplies to adequately power the loads. In one embodiment, the connections may be provided to optimally use the various power supplies to provide power to the multiple loads.
Certain power supplies, sensors and loads have been described with reference to an example embodiment. It should be noted that many different power supplies may be used, such as larger or different types of batteries, thermal power supplies, wind power supplies, and many others. Some sensors which may be used to monitor the power supplies include temperature, lux level, vibration, acoustic, ambient, voltage, power level and others. The loads may additionally includes actuators, display devices and many other types of sensors or other devices.
A flow chart illustrating functions of a hybrid power supply in multiplexing supplies and loads is shown generally at 400 in
Controller 150, also referred to as a decision engine, along with the power supply manager and power requirement estimator may be implemented via a general purpose or special purpose computer system or systems in various embodiments. A block diagram of such a computer system that executes programming for performing the above algorithm is shown in
Computer-readable instructions stored on a computer-readable medium are executable by the processing unit 602 of the computer 610. A hard drive, CD-ROM, and RAM are some examples of articles including a computer-readable medium. For example, a computer program 625 capable of providing a generic technique to perform access control check for data access and/or for doing an operation on one of the servers in a component object model (COM) based system according to the teachings of the present invention may be included on a CD-ROM and loaded from the CD-ROM to a hard drive. The computer-readable instructions allow computer 610 to provide generic access controls in a COM based computer network system having multiple users and servers.
The Abstract is provided to comply with 37 C.F.R. §1.72(b) to allow the reader to quickly ascertain the nature and gist of the technical disclosure. The Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.
