1. Field of the Invention
The invention relates to energy management and, more particularly, to a method for radio-based activation and deactivation of zero-energy standby operation of automation components, and to electrical automation components.
2. Description of the Related Art
Automation systems have widely differing automation components for performing automation tasks such as sensors, actuators, or controllers or drives. Like all electrical or electronic appliances, the automation components must be supplied with power to perform their task. With a few exceptions, the power supply for this purpose is generally ensured by cables, radio or batteries. It is desirable for two reasons to reduce the power consumption of the electrical and electronic appliances. On the one hand, increasing energy costs are necessitating more economic electricity consumption and, on the other hand, the maintenance effort for battery-powered components should be kept as low as possible.
In particular, radio-based system components, which are supplied with electricity by a battery, often have only a very restricted duration of operation. Sensor/actuator networks in automation systems are one such radio-based system components.
These comprise a multiplicity of small, intelligent sensor/actuator nodes which are networked with one another, perform complex tasks as a group, and can communicate with one another over a radio link. These components consume energy all the time, except when they are explicitly (manually) deactivated by a switch.
In conventional systems, active radio-based components are generally supplied with electricity through a switch by connection to the power source (i.e., by inserted batteries). Various mechanisms exist for saving energy depending on the connection quality or load level. No standby mode which requires no energy exists for radio-based appliances, such as for appliances which can be controlled remotely by radio, infrared or similar techniques. If the elements are not disconnected from the power source, such as by a switch or the removal of the power source, this results in energy being consumed continuously.
US Publication No. 2007/0205873 A1 describes a method for activation of an RFID tag. Here, a passive RFID tag is activated with the aid of the energy in the radio signal that is sent to the RFID tag. The RFID tag then activates a circuit that can supply power autonomously from a battery. However, the described method allows only the activation of the RFID tag itself.
It is therefore an object of the present invention to switch automation components to zero-energy standby operation by radio, and to activate automation components again by radio from zero-energy standby operation.
This and other object and advantages are achieved by a method for radio-based activation and deactivation of zero-energy standby operation of automation components, wherein a passive unit of the automation component receives a radio signal, energy which is transmitted with the radio signal is used to operate an electronic switch, and a power supply to a functional unit of the automation component is interrupted or recreated by the operation of the electronic switch, such that the functional unit of the automation component is activated or deactivated.
The invention is based on the discovery that a passive unit or a passive element, such as an RFID tag, can be addressed by radio and that, in doing so, sufficient energy is transmitted with the radio signal to operate an electronic switch that is coupled to the passive unit. In accordance with the invention, the switch is inserted into a circuit by which a functional unit, which acts as a load, is connected to a power supply such as a battery.
When the switch is now operated by the radio signal, for example, the circuit can be closed or opened, and the power supply from the electricity source, e.g., the battery, for the functional unit of an automation component is interrupted (when the switch is open) or is recreated (when the switch is closed). The functional unit of the automation component can therefore be switched to the standby mode, or can be reactivated again from the standby mode, in a simple manner by transmission of a radio signal. Here, since the switch disconnects the functional unit from the power supply in the standby mode, it is possible to switch to a standby mode in which no energy at all is consumed by the functional unit. Here, the passive unit itself does not require a power supply, as a result of which the entire automation component, with the functional unit and the passive unit, does not consume any energy at all when in the standby mode. The energy required for reactivation can be transmitted exclusively by the radio signal. The actual functional unit is therefore supplied with the energy source after the activation of the passive element and the operation of the switch.
The energy saving in this case is particularly advantageous because no energy at all is consumed any longer by the functional unit during standby operation. Furthermore, this results in an increase in the operating duration when using an internal energy source. The energy of a battery is not consumed as quickly as in the normal case, when an automation component or an electrical appliance in the standby mode nevertheless consumes energy. Furthermore, no manual action is required by a user, since the system can itself specifically switch individual components which are not-in-use to the zero-energy state, and can reactivate the individual components. The automation components are therefore autonomous, and can be installed without the use of cables.
In a further advantageous embodiment of the invention, the power supply is interrupted or recreated by a CMOS switch. A CMOS switch is a semiconductor element which has a particularly low energy threshold to perform switching. The switching process is performed electronically. As a result, there is no mechanical wear.
In a further advantageous embodiment of the invention, the radio signal is received by an RFID tag. Here, it is advantageous that a single standard component, which is provided in any case for reception of radio signals, can be used for wire-free activation and deactivation of the automation components.
In a further advantageous embodiment of the invention, the sensor/actuator nodes of a sensor network are activated and deactivated. Particularly in automation systems in which a large number of sensors are distributed within the installation, and are once again combined to form networks, wiring for the electrical power supply is extremely complex. Sensors such as these are therefore frequently supplied by an autonomous energy source. In order to ensure that the sensors and actuators in the installation have a long life in this case, it is particularly advantageous for it to be possible to switch these automation components to zero-energy standby operation, thus providing a capability to save energy from the power supply, thus leading to the already mentioned advantages of long life, energy saving and little maintenance effort.
In yet a further advantageous embodiment of the invention, a specific signal for activation and deactivation of the functional unit is transmitted with the radio signal. In the present advantageous embodiment, in order to activate and deactivate the automation component, i.e., the functional unit of the automation component, not only must the energy be sufficient to operate the switch, but it is necessary to send a further signal which indicates that a reaction is expected from the automation component, i.e., the functional unit. This ensures that the automation component is not deactivated or activated when power is merely flowing and there is no intention at all for activation or deactivation.
In still a further advantageous embodiment of the invention, an ID is transmitted with the radio signal, and the functional unit is activated or deactivated when the transmitted ID matches an ID of the automation component. This ensures in a simple manner that, in an automation system in which a large number of automation components are activated and deactivated with the aid of the method and a large number of automation components themselves transmit radio signals again, the only automation components which are activated are those which receive a corresponding identification signal or a tag which matches their own. This ensures that automation components can be addressed and activated individually, and that automation components which are not intended to react remain appropriately passive.
In another advantageous embodiment of the invention, the automation component sends and receives data by radio, as soon as the functional unit is active. Consequently, the automation component is activated and deactivated not only by radio signals and the energy transmitted in them, but also uses the radio capability for general communication with other automation components, or with the central controller for the automation system, thus allowing general communication which is based on the same infrastructure as the method for activation and deactivation of the automation component. This minimizes the infrastructure complexity to the greatest possible extent.
In another advantageous embodiment of the invention, a plurality of automation components communicate with one another by radio signals, and the automation components activate and deactivate one another by the radio signals. Activation and deactivation therefore need not be performed from a central point. When the automation components are distributed over a relatively large area within the installation, the automation components autonomously ensure activation and deactivation of adjacent automation components, provided that they are within range of one another for the radio signals.
In yet a further advantageous embodiment of the invention, a plurality of sensor/actuator nodes form a sensor/actuator network. The formation of these networks allows entire groups of automation components in these sensor/actuator nodes of a network to be activated and deactivated in a cascaded form by their adjacent components.
In a further advantageous embodiment of the invention, at least two sensor/actuator networks have different automation tasks, and the functional unit of at least one automation component in the second sensor/actuator network is activated by the reception of a radio signal from an automation component in the first sensor/actuator network. This results in the capability to successively activate different sensor/actuator networks which, for example, have different tasks in a manufacturing installation. For example, one specific automation task can be performed completely first in a sensor network, and the second sensor network will be activated by an automation component, which is located within the first sensor network and receives the information in this sensor network. As a result, the second sensor network can now be activated by the transmission of an appropriate radio signal in an automation component of the second sensor/actuator network. The activation of only one automation component in the second network is then sufficient to once again initiate a chain reaction in the second network, and to activate all of the automation components involved in the network.
The object of the invention is also achieved by an electrical automation component having a passive unit which is intended to receive a radio signal, a functional unit for performing automation functionality, a local power source for supplying the functional unit and an electronic switch, which is arranged between the power source and the functional unit, where the electronic switch is coupled to the passive unit such that energy received by the passive unit with the radio signal leads to operation of the electrical switch, by which the functional unit of the automation component can be activated and deactivated.
The object is also achieved by a system comprising a plurality of sensor/actuator networks, consisting of electrical automation components, where the automation components are intended to communicate with one another by radio signals, and where radio signals are intended for mutual activation and deactivation of the automation components.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention, for which reference should be made to the appended claims. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
The invention will be described and explained in more detail in the following text with reference to the figures, in which:
In addition to the energy, the radio signal also transmits data to the automation component 1. Here, useful data can be transmitted, or else signals which, in addition to the energy, contain, for example, activation and/or deactivation information, or an identification, for example a tag or a specific automation component, as a result of which the automation component reacts only if its own tag matches the transmitted tag.
The operation of the electronic switch interrupts or recreates a power supplied to a functional unit of the automation component such that the functional unit of the automation component is one of activated and deactivated, as indicated in step 430.
Thus, while there are shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the illustrated apparatus, and in its operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it should be recognized that structures shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.
This is a U.S. national stage of International Application No. PCT/EP2008/006323, filed on 31 Jul. 2008.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/006323 | 7/31/2008 | WO | 00 | 1/31/2011 |