WO2015059625A1

WO2015059625A1 - Energy-collecting wireless command device, and related system and method

Info

Publication number: WO2015059625A1
Application number: PCT/IB2014/065474
Authority: WO
Inventors: Pietro Porzio Giusto; Antonio Caramelli
Original assignee: Sisvel Technology S.R.L.; 3D Switch S.R.L.
Priority date: 2013-10-24
Filing date: 2014-10-20
Publication date: 2015-04-30
Also published as: ITTO20130860A1

Abstract

A wireless command device adapted to cooperate with a command regenerator device is described, said command device comprising: - a command transmitter adapted to issue a command signal receivable by the command regenerator device; - an activation transmitter adapted to send an activation signal for activating the command regenerator device; - energy collecting means arranged to collect energy from electromagnetic waves picked up by a main antenna connected thereto; - processing means configured for determining if said command device has sufficient energy to issue the command signal; said activation signal being adapted to activate energy irradiating means included in the command regenerator device, said energy irradiating means being adapted to irradiate electromagnetic waves with at least a first power value Pc capable of powering the command device for the purpose of issuing the command signal.

Description

ENERGY-COLLECTING WIRELESS COMMAND DEVICE, AND RELATED SYSTEM AND METHOD

DESCRIPTION

The present invention relates to an electronic device configured for issuing command signals adapted to control electronic apparatuses. More in detail, it relates to the particular configuration of the device, aimed at supplying energy for the latter^*s operation.

It is known that many apparatuses exist which require commands from a user. The most common one is the television set. possibly equipped with a set-top box. a video recorder, an Internet connection, etc. However, also other apparatuses require interaction with their users, such as computers, music players, video players, climate control apparatuses, door/w indow/curtain closing systems, and the like.

For these purposes, wireless remote controls are now largely in use. which are typically powered by batteries and have a certain number of buttons, or small keypads, for entering commands to be transmitted to the apparatuses to be controlled. For more comfort of use. ideas have recently been proposed that relate to v ery small remote controls that can be contained in a ring that can be worn on a finger, so that the user can easily operate it at any time. With such a small size, only a minimal number of manually operated buttons and sensors can be accommodated, and therefore sensors of different kinds have been proposed, especially for detecting movements of the remote control from which the commands to be transmitted can be deriv ed.

Patent application US 2012/2 181 84 A l describes a ring that can be used as a remote control for several apparatuses, in particular for computers. The ring contains some buttons and an accelerometer for detecting three-dimensional mov ements to be interpreted as command gestures. Commands are transmitted v ia radio, typically through a Bluetooth system. With Bluetooth, the remote control can also receive signals for activating vibrators and heaters useful for warning or providing information to the user in particular situations. Power can be supplied to the electric circuits from different sources, such as batteries, piezoelectric microgenerators. and inductors for collecting energy from magnetic fields. The latter, however, can only be used at very short distances from the magnetic field generator; therefore, they are not suited for use in remote controls for many types of apparatuses, including, in particular, television sets. Patent application US 201 1 /007035 A l describes various embodiments of a ring that can contain a generic radio transceiver for communicating with other devices. The main peculiarity of these embodiments is the mechanical combination, w ithin the ring, of a fixed pail and one or more parts that can rotate about it. The positions of the rotary parts with respect to the fixed part are associated with commands to be transmitted. Energy can be supplied from different sources, including batteries, piezoelectric devices, and systems exploiting the mechanical energy used for moving the rotary parts.

Patent application US 5832296 A describes a device, preferably in the form of a ring, that allows the user to control electronic apparatuses by acting with his/her fingers upon buttons, temperature sensors and force detectors. Reception/transmission can be implemented through radio waves, infrared light, acoustic waves and other similar means. Energy can be supplied by a battery or. if the user stays at a short distance from an electromagnetic wave generator, it may be collected from radio waves. In the description it is assumed that the device will be used for controlling an ambient temperature thermostat, the doors of a room, a television set. a music player, etc. However, commands are issued by manually operating buttons and exerting pressure on force sensors, which operations are not very comfortable.

Patent application US 2009/25 1407 A l describes a device that can be worn on a finger of a hand or a foot or around a leg or the waist, or as a bracelet or a necklace, etc. The description covers a wide range of mechanical, transmissive and functional features, stating that the device can be used either alone or in combination with other devices in order to interpret complex gestures or quantities detected by various sensors, and can communicate with other devices by means of various transceiving systems and by using techniques ranging from simple RFID ("Radio Frequency IDenti fication^*') passive tags to neural networks and detection of the user^'s emotions. For very simple functions and short distances, the device can operate as a passive element much like RFID tags, whereas for the functions of a normal remote control for television sets it relies on traditional power supply sources, such as batteries.

Patent application US 2009/295616 A l describes a transmission system that can be used for transmitting stimuli to animals (typically dogs ) being trained. It comprises a ring to be w orn on a finger, a remote control that must remain in proximity to the ring, and a receiver, which is typically fastened to the animal ^'s collar. The ring transmits signals to the remote control within a range of a few meters. The remote control processes the information receiv ed from the ring and transmits commands to the animal's collar within distances of the order of kilometers. The ring^'s transmission system is typically implemented via radio (w ith "ZigBee^" or "Bluetooth^" protocols), but may also be based on infrared light or ultrasound. The circuits of the ring receiv e power from a battery. Patent application US 2007/ 1 75321 A l describes a ring-shaped remote control that can be used for controlling special effects of musical instruments (typically rev erb, echo, tremolo, etc. of a guitar). The ring is worn on the middle finger and. through a capacitive sensor, detects whether the middle finger is extended or bent. Power is supplied by a rechargeable battery.

Therefore, the prior art describes remote controls having some features that improve traditional techniques, but it does not completely solve the problem of providing a remote control that is suitable for television sets and several other apparatuses, w hile also not requiring batteries to be replaced or recharged beforehand. This necessity considerably limits the portability and availability of the command device, since the user still has to worry about the exhaustion of its power source.

It is therefore one object of the present invention to provide an energy-collecting wireless command device, as well as the related system and method, which allow a user to control an apparatus without worrying about the exhaustion of the power source of the command device itself.

It is a second object of the present invention to provide an energy-collecting wireless command device, as well as the related system and method, which avoid the use of traditional batteries, which normally contain polluting heavy metals.

It is a third object of the present inv ention to provide an energy-collecting wireless command device and the related system and method, which are environmentally sustainable.

These and other objects of the invention are achieved by an energy-collecting wireless command device and the related system and method as claimed in the appended claims. which are intended to be an integral part of the present description.

In brief, the invention describes an energy-collecting wireless command device and the related system and method, wherein the command device, or remote control, has the energy necessary for its operation without requiring batteries or other power supply means to be replaced or recharged beforehand. Said remote control is configured for cooperating with an electronic command regenerator apparatus, which regenerates the signals that cany the commands transmitted by the remote control and forwards them to the apparatuses (w hether one or more) for w hich they are intended (e.g. a television set, a DVD player, a Blu-Ray player, or the like).

The command regenerator can supply energy to the remote control by electromagnetic wave energy irradiation. The system of the present invention, comprising the remote control and the command regenerator, and the related method allow said means for irradiating electromagnetic wave energy to be set into a low -power state and then reactivated into the normal state, or full operation state, through the remote control itself, i.e. via an activation signal.

The above objects will become more apparent from the follow ing detailed description of an energy-collecting wireless command device and the related system and method according to the present invention, with particular reference to the annexed drawings, wherein:

- Figure 1 shows an example of a shape of a command device in accordance with the present invention;

- Figure 2 shows an example of a system according to the present invention;

- Figure 3 show s an example of a block diagram of the command device in accordance w ith the present invention;

- Figure 4 shows an example of an operating logic of the command device according to the present invention;

- Figure 5 shows a further example of a system according to the present invention.

With reference to Figure 1 . there is show n an example of a w ireless command device 201 , or remote control 201 ; more in detail, there is shown one embodiment of the design of the latter. In fact, the remote control 201 is implemented as a compact device that may. for example, be shaped like a ring to be worn on a finger of a user^'s hand. It is clear that also other shapes may be adopted for the remote control 201 ; for example, it may be provided in the form of a bracelet or a watch to be worn on a person's wrist. Preferably, the remote control 201 is a wearable electronic device, but such an embodiment is not binding for the purposes of the present invention; in fact, it may be provided as a traditional compact remote control known in the art.

With reference to Fig, 2. there is shown an example of a command transmission system 10 according to the present invention. The system 10 comprises a command device 201 . or remote control 201 . and a command regenerator device 202, or regenerator 202. The regenerator 202 comprises a command receiver 207 which, together with a command transmitter 309 (Fig. 3 ) included in a first command subsystem 203 (Fig. 2) of the remote control 201 . constitutes a communication channel for the commands that the remote control 201 is adapted to transmit.

The commands transmitted by the remote control 201 are received and decoded by the regenerator 202 and are then forwarded by the latter to an apparatus to be controlled 217. which is not an object of the present invention.

The regenerator 202 further comprises energy irradiating means 2 1 1 . or. more simply, irradiator 21 1 . arranged to irradiate an electromagnetic wave with a first power value P_c. sufficient to allow the remote control 201 to obtain therefrom the energy required for powering the circuits of the remote control 201 . In fact, the remote control 201 picks up the electromagnetic waves irradiated by the regenerator 202 through the energy irradiating means 21 1 and an irradiation antenna 209 connected thereto. More in detail, the first power value P is sufficient to allow the remote control 201 to obtain the energy necessary for emitting a signal, hereafter referred to. for simplicity, as command signal, which carries a piece of numerical information that the regenerator 202 will regenerate by receiving and demodulating the command signal issued by the remote control 201 .

Said numerical information can be interpreted as a command by the apparatus to be controlled 21 7. to which it is forwarded via the connection 2 14. More precisely, the command signal is receivable by the regenerator 202.

With the above-described components, the remote control 201 can transmit commands to the regenerator 202 without needing batteries or energy accumulators to be recharged beforehand. Fig. 3 shows an example of a block diagram of the command device 201 in accordance with the present invention. The command device 201 . or remote control 201 , comprises the first command subsystem 203 and a second auxiliary activation subsystem 204. The first command subsystem 203 comprises a set of elements for command production, referred to as command originator 307. a command transmitter 309, and energy collecting means 3 12, such as those used in RFID systems, which are well known to those skilled in the art. e.g. a capacitor and a diode. The command originator 307 comprises buttons and sensors, which allow reception of the user's instances and production of the commands to be sent. The sensors may be motion sensors, which detect the gestures of a user^'s hand, wherein each gesture is associated with a command to be sent by means of the same remote control 201 . Preferably, the sensors comprise at least one three-axis accelerometer. through which the movements of the remote control 201 can be determined in the three spatial dimensions. There may also be at least one button for defining the start instants, and possibly also the end instants, of a gesture to be interpreted as a command. The sensors and buttons for command production will not be discussed herein any further, since they belong to the prior art. It must only be pointed out that the sensors, during the activity steps, normally require a significant quantity of electric energy, typically greater than required by the other circuits of the remote control 201 , and in particular much greater than required by the command transmitter 309 and by an auxiliary transmitter 320. the use and operation of w hich will be described below. This implies that the transmission of simple command codes is much less costly, in terms of energy, than the production and transmission of a command determined by a user^'s gesture.

The command transmitter 309 is connected to a main antenna 205. The energy collecting means 3 12 are configured for obtaining sufficient energy from the electromagnetic waves emitted by the regenerator 202 for supplying power to the electric circuits of the remote control 201 .

The remote control 201 further comprises memory means 3 10. processing means 3 14. and an energy management module 3 1 5. The general control and governing operations of the remote control 201 are executed by the processing means 3 14, with the aid of the memory means 3 10, which contain the software code of the procedures to be carried out. with the data necessary for such procedures, the identification codes of the remote control 201 , and any other information useful for the operation of the same. In particular, the processing means 3 14 are configured for determining if the remote control 201 has sufficient energy to issue a command signal.

The energy management module 3 1 5, instead, takes care of optimizing the accumulation and utilization of the energy within the remote control 201 . To the energy management module 3 1 5 an energy accumulator 3 1 7 is connected, which is adapted to store backup electric energy. In many conditions, the energy consumed by the remote control 201 is. in fact, less than is collected from the electromagnetic waves, so that a part thereof can be stored into the energy accumulator 3 1 7 and can contribute to powering the circuits of the remote control 201 . particularly of its second auxiliary activ ation subsystem 204.

The second auxiliary activation subsystem 204 is preferably of a different type than the first command subsystem 203. It may use transmission techniques such as Bluetooth, ZigBee or Wi-Fi. or techniques based on infrared light or acoustic waves. These techniques are well suited for obtaining very low-consumption receivers and transmitters, in particular expressly prean-anged for the occasional transmission of a single activ ation signal, characterized by requiring a minimal quantity of energy. This quantity of energy can be produced by an energy generator 3 1 8. e.g. a piezoelectric one. comprised in the remote control 201 , as will be further explained below . The acti ation signals are transmitted by an activation transmitter 320 connected to a radiating element 206.

Some transmission techniques that can be used for the second auxiliary activation subsystem 204. i.e. those using an electromagnetic wave as a carrier, will allow the radiating element 206. which in this case will be an electromagnetic antenna, to be shared with the main antenna 205 of the first command subsystem 203 ; in this case, both the command transmitter 309 and the auxiliary transmitter 320 will be connected to the same main antenna 205, whether directly or through an adder or mixer device, as known to those skilled in the art. In other cases, e.g. when infrared light or acoustic waves are used for the transmission of the activation signals, sharing will not be possible. The radiating element 206 should not. therefore, be strictly considered as an antenna for electromagnetic wav es, but more generally as an element capable of emitting signals of any physical nature. For example, in the case of infrared transmission, the radiating element 206 w ill be a photodiode that can emit light in the infrared range, w hereas in the case of transmission based on acoustic waves, the radiating element 206 w ill be a passband acoustic device comprising the acoustic frequencies chosen for the transmission system.

Furthermore, the energy obtained from electromagnetic waves is distributed from the energy management module 3 1 5 to the components of the remote control 201 . as necessary, via a multiwire connection 308. also referred to as ^"'bus^" 308.

Again with reference to Fig. 2, in order to minimize total energy consumption, for some periods of time (e.g. in the night hours) the regenerator 202 can be placed into an idle state, wherein at least the energy irradiating means 21 1 are off. and consequently the command transmitter 309 cannot transmit command signals.

In order to reactivate the energy irradiating means 21 1 through the remote control 201 , as aforementioned, the remote control 201 includes the second auxiliary activ ation subsystem 204 that can communicate w ith an activ ation receiver 21 3, included in the command regenerator device 202. through the radiating element 206 and a pick-up device 2 1 2 connected to said activation receiver 2 1 3. These devices, since they have to deal with simple information to be sent only occasionally, can use a technique requiring just a minimal quantity of energy for transmitting an activ ation signal. Therefore, the activation receiver 213 is preferably a very low-consumption unit and stays always on. The same considerations just made for the radiating element 206 also apply to the pickup element 2 12, i.e. it must be consistent with the transmission technique adopted for the second auxiliary activation subsystem 204 (antenna for electromagnetic waves, photodiode for infrared light, ultrasound detector, etc.).

The activation receiver 2 1 3. which receives the signals transmitted by the activ ation transmitter 320, consumes very little energy and. since it is preferably included in a constantly powered apparatus (e.g. a television set in stand-by mode or turned on. constantly connected to the electric mains of a building), it can stay always on. When the activation receiver 2 1 3 recognizes the activation signal, it sends to the other circuits of the regenerator 202 a signal that will cause them to switch into the active state, if they are not already in such a state.

Therefore, once the regenerator 202 has received the activation signal (e.g. a single impulse) from the remote control 201 , the regenerator 202 will enter a normal state, or operating state, or it will stay in such a state, w ithout the remote control 201 requiring any batteries or accumulators to be recharged.

In normal conditions, the energy required by the command transmitter 309 for transmitting a command signal is supplied in real time by the energy collecting means 3 12. w hile the energy required by the activation transmitter 320 for transmitting an activation signal or code is supplied in real time by the energy generator 3 1 8. In this embodiment of the invention, in fact, it is not strictly necessary that electromagnetic waves be continuously or periodically emitted by the regenerator 202: the energy generator 3 1 8 will ensure the necessary energy supply to the remote control 201 for sending the activation code in the event that the regenerator 202 is in a low- consumption operating state, wherein the energy irradiating means 21 1 do not emit energy that can be used by the remote control 201 . and that the energy accumulator 3 1 7 is completely discharged, e.g. due to the well-know n self-discharge phenomenon that is found in every power accumulation dev ice. The on state of the regenerator 202, whether in normal or low -consumption mode, is ensured by the fact that the regenerator 202 is turned on together with the apparatus to be controlled 2 1 7. e.g. because it is included in the same apparatus 2 1 7 or anyway it is powered together with it.

When the energy collected by the energy collecting means 3 12 and the energy produced by the energy generator 3 1 8 exceed the energy consumed by the circuits of the remote control 201 (typically, when the energy irradiating means 21 1 are active, the energy collecting means 3 12 w ill continuously collect the energy picked up by the antenna. while the remote control 201 w ill consume it only at intervals ), the energy management module 3 15 stores the excess energy into the energy accumulator 3 1 7. Therefore, also the energy generator 3 1 8 can contribute to energy accumulation.

The energy accumulator 3 1 7 preferably comprises a first section "c^" and a second section "a". The second section "a" can accumulate energy sufficient for the transmission of a few activation signals by the activation transmitter 320. whereas the first section "c can accumulate energy for the transmission of more command signals. This implies that the capacity of the first section "c^" is greater, or much greater, than the capacity of the second section "a ; as a consequence, the recharging time of the second section "a^" will be shorter. This division ensures optimum energy accumulation and distribution in any circumstances, e.g. based on the following criteria:

- the second section "a" has recharging priority, i.e. energy will only be accumulated into the first section "c^" when the second section "a^" is fully charged;

- the activation transmitter 320 has priority for the use of the energy (when the activation transmitter 320 needs to be activated, the energy it requires will be taken from any source, including the first section "c^" of the energy accumulator 3 1 7, w ith priority over any other use);

- the energy accumulated in the second section "a^" of the energy accumulator 3 1 7 is exclusively reserv ed for the needs of the activation transmitter 320 (in particular, it cannot be used for command transmission).

In order to adv antageously make energy storage and use more flexible, in one variant the energy accumulator 3 17 has a number of sections greater than two. without however departing from the basic inventive idea and from the above-described management criteria.

As aforesaid, the remote control 201 transmits command signals that are representative of command codes and data; the regenerator 202 receives such command signals. decodes them, and conv erts them into control signals, which are outputted over a connection 214 (e.g. a simple conducting wire) for the apparatuses to be controlled 2 1 7 for which they are intended, such as telev ision sets, set-top boxes, music players, image and video players, and other electronic apparatuses. Preferably, the regenerator 202 is included in the apparatus to be controlled 217. e.g. included in a television set.

One example of a command signal is the signal for turning off a television set. which signal may simply consist of a short code, w hereas the command for moving a pointer on a screen may comprise a more articulated code including data such as the direction and speed of movement, the acceleration components of the movement, the increments of the position coordinates, and other data.

In some circumstances, said circuits of the regenerator 202 may be in a low- consumption state, typically for energy saving purposes. Their condition of normal activity or idle state is indicated by signalling means 21 5, in particular a warning lamp 2 1 5 that can preferably take three states:

- off, indicating that all circuits of the regenerator 202 are off;

- on in a first colour, indicating that all circuits of the regenerator 202 are on:

- on in a second colour, indicating the idle state, wherein all circuits of the regenerator 202 are off except those which allow reception of the activation signal, i.e. the activation receiv er 2 13.

The deactivation of the circuits of the regenerator 202. and the corresponding determination of the state thereof through the w arning lamp 2 1 5. can occur upon an action carried out by the user of the remote control 201 or according to an automatic procedure, e.g. after a predefined inactivity time interv al. In practice, the regenerator 202 will have a simple governing logic that drives its circuits from one operating state to another upon reception of a deactivation command from the remote control 201 . or after the expiry of a timer, or in the absence of power.

When said circuits are off. the command communication channel w ill not be operativ e. In order to allow full reactiv ation of the system 1 0 by means of the remote control 201 , as aforesaid, the remote control 201 can issue an activation signal.

The command transmitter 309 can be implemented by using any technique known to those skilled in the art. Howev er, considering that a fundamental requisite of the remote control 201 is energy consumption minimization, as an example of a command transmission technique reference w ill be made herein to the radio technique employed in RFID tags. According to this technique, transmission via the command transmitter 309 occurs by ^''modulating^", in relation to the data to be transmitted, the impedance of the remote control 201 (also called "load^" in technical jargon ) to which the main antenna 205 is connected. This impedance v ariation causes a modulation of the electromagnetic wave that, arriving at the remote control 201 from the regenerator 202 (in practice, from the energy irradiating means 21 1 and from an irradiating antenna 209 connected thereto), is reflected by the main antenna 205. In other w ords, the command signal is a reflection of a modulated electromagnetic wave, obtained through a variation of the impedance of the circuit to which the main antenna 205 is connected. It is known. in fact, that the energy of an electromagnetic wav e picked up by an antenna will be wholly absorbed by the device to w hich the antenna is connected only if said load device has an impedance "adapted'^' to the impedance of the antenna. If. on the contrary, there is no adaptation between the antenna and its load, only a part of the energy picked up w ill be transferred to the load, w hile the remaining energy w ill be reflected and re- irradiated in the space. In the RFID technique, the impedance of the load to which the antenna is connected is deliberately varied, typically from the adapted condition (null reflection) to a greatly non-adapted condition (significant reflection), so as to determine the reflection of an electromagnetic wave having v ariable characteristics, i.e. modulated. The "modulator^" of this reflected electromagnetic wave can thus be a simple switch that connects or does not connect a passiv e element that will cause the load of the antenna to become non-adapted. The energy used by the "transmitter-modulator^'* circuit of the remote control 201 is therefore minimal.

The electromagnetic wave modulated and reflected by the remote control 201 is received by a command antenna 208 of the regenerator 202. and its command signal arrives at the command receiver 207. The latter demodulates the command signal, extracts therefrom and decodes the data of the transmitted command, and forwards the decoded command to the apparatus to be controlled 2 1 7, v ia the connection 214.

The electromagnetic wave that reaches the remote control 201 from the regenerator 202 is produced by the energy irradiating means 21 1 . which typically may be of the continuous w ave type, e.g. a sinusoidal wave with adequate frequency and power for the desired transmission range, within the limits imposed by the law. Should one need to make the regenerator 202 identifiable, e.g. in order to be able to discern it from other similar devices in the vicinity, the electromagnetic w av e generated by the energy irradiating means 21 1 could be modulated by using one of the modulation methods known in the art. so as to associate a distinctive code w ith the regenerator 202 w ith which the remote control 201 has been paired. This distinctive code of the regenerator 202 can be kept recognizable in the electromagnetic w ave reflected by the remote control 201 . so that the regenerator 202 can distinguish between the reflections of its own signals and other signals. Moreover, the command receiver 207 can discriminate the origin of the command signals by entering, into the command signals issued by the remote control 201 . appropriate codes identifying the remote control 201 . With these measures, the probability that signals coming from foreign sources will be mistaken for commands is reduced.

In particular, by entering a code identifying the remote control 201 into the command signals transmitted by the remote control 201 itself it is possible to associate one or more remote controls 201 with the regenerator 202, thus avoiding that the regenerator 202 might forw ard to the apparatus to be controlled 21 7. via the connection 214. commands coming from unauthorized apparatuses, and allow ing it to resolve any conflicts between commands coming from authorized remote controls. Entering identification codes and associating apparatuses authorized to communicate is a known common practice in the field of electric communications.

As is commonly done in practice, the regenerator 202 comprises a local oscillator 2 10. known in the art. from w hich both the command receiver 207 and the energy irradiating means 2 1 1 derive a radio frequency reference which is necessary for their proper operation.

It is apparent that the scheme of the regenerator 202 illustrated so far represents just one example of embodiment, and that the man skilled in the art may conceive other w ays of implementing the above-described functionalities without departing from the inventive idea of the present invention. In particular, as will be further explained below, the command receiver 207 and the energy irradiating means 2 1 1 may be caused to share one same antenna.

The method for transmitting commands according to the present invention comprises the following main steps:

- determining, through the processing means 3 14, if the remote control 201 has sufficient energy to issue a command signal;

- if the remote control 201 does not have sufficient energy to issue a command signal. sending, through the activation transmitter 320, the activation signal to the command regenerator device 202;

- activating, through the activation signal, the energy irradiating means 2 1 1 of the command regenerator device 202;

- irradiating, through the energy irradiating means 21 1 , electromagnetic w aves with a first power value P_c. which w ill allow the remote control 201 to obtain the energy required for issuing a command signal .

With reference to Fig. 4. there is shown one example of the operating logic of the command device 201 in accordance with the present invention. More in detail. Fig. 4 shows a command transmission procedure according to the invention, whereb the remote control 201 sends commands to the regenerator 202; after the start at step 401 . the procedure comprises the following steps:

- a wait step 402. wherein a command transmission instance is expected from the set of elements prearranged for command reception and production, i.e. the command originator 307;

- a first determination step 403, wherein it is determined if the remote control 201 is constantly receiving at least one electromagnetic w ave from which energy can be obtained : if one such electromagnetic wav e is not receiv ed, the process will continue with a first evaluation step 408, otherwise it w ill continue w ith a second evaluation step 404;

- a first evaluation step 408. wherein the quantity of energy available for issuing a signal for activating all circuits of the regenerator 202 is evaluated;

- a second determination step 409, wherein, based on the result of the first evaluation step 408. it is determined if there is sufficient energy to issue said activation signal : if the energy is not sufficient, the process will go back to the wait step 402. otherwise it will continue with an activation step 410;

- an activation step 410. wherein a signal for activating all circuits of the regenerator 202 is issued through the activation transmitter 320:

- a delay step 4 1 1 . wherein a delay is interposed prior to switching to the next step, in order to allow the circuits being activated sufficient time to reach a condition of normal operation; typically, the circuits that need some time to reach their condition of normal operation are all those of the regenerator 202, except those of the activation receiver 21 3. Also, after the energy irradiating means 21 1 have reached their normal operation condition it may be necessary to provide a short settling time for the energy collecting means 3 12 and some sensors of the remote control 201 ;

- a second evaluation step 404. wherein the quantity of energy available for producing a command signal and transmitting it to the regenerator apparatus 202 is evaluated; - a third determination step 405, wherein, based on the result of the second evaluation step 404. it is determined if there is sufficient energy to produce a command signal and transmit it to the regenerator 202 : if the energy is not sufficient, the process will go back to the wait step 402. otherwise it w ill continue with the sensor data collection step 406; - a sensor data collection step 406. related to the command transmission instance that caused the exit from the wait step 402; it is assumed that the collection of the data provided by the sensors (e.g. the data of an accelerometer) cannot always occur in concomitance with step 402 w hen the remote control 201 is not constantly receiving electromagnetic energy, since the energy available might not suffice for the operation of the sensors. Instead, the energy required by the sensors is always available upon a positive outcome of the third determination step 405 ;

- a command production step 407. w herein the command signal to be transmitted is prepared;

- a transmission step 412, w herein the command signal is transmitted to the regenerator 202 through the command transmitter 309; the process w ill then go back to the wait step

402.

In order to exit from the wait step 402, the remote control 201 must have a minimum quantity of energy. This can be supplied by the energy collecting means 3 1 2, by the energy accumulator 3 1 7. and by the energy generator 3 1 8. When available, the latter can be activated when a button is pressed for issuing a command, so that the exit from the wait step 402 can occur in any condition.

In the first determination step 403. it may be found out that the electromagnetic wave emitted by the energy irradiating means 2 1 1 is not being constantly received by the remote control 201 for two reasons;

a) the energy irradiating means 2 1 1 are off or in the idle state:

b) the remote control 201 is out of the transmission range.

In the former case, the w arning lamp 21 5 w ill indicate the idle state wherein all circuits of the regenerator 202 are inactive, and, in particular, the state wherein the energy irradiating means 2 1 1 are inactive. The user of the remote control 201 can take into account the indication of said warning lamp 21 and act accordingly: if the warning lamp 21 5 indicates that the energy irradiating means 21 1 are not active, then the user will issue the signal for activating the energy irradiating means 2 1 1 ; otherwise, he/she w ill try to move into a position with better reception of the electromagnetic waves that are constantly or periodically emitted by the energy irradiating means 2 1 1 . Generally, said energy irradiating means 2 1 1 are already on and active w hen the apparatus to be controlled 2 1 7 is in a fully operational state, wherein it can receiv e and execute any command (on off. channel switching, v olume adjustment, etc.) that may be issued by the user via the remote control 201 . Every time the apparatus to be controlled 2 1 7 is put by the user into a condition w herein it can receive commands from the remote control 201 (sw itching from the off state, i.e. absence of power supply, to the stand-by or on state), the energy irradiating means 2 1 1 w ill sw itch into the active state and emit electromagnetic waves. This w ill ensure that a remote control w ithin the range of the energy irradiating means 21 1 , with or w ithout local energy reserves, will be able to acquire in real time. i.e. after a transient that cannot be perceived by the user, the energy required for operating and issuing commands. The regenerator 202 can be integrated into a controlled device, so that it will enter the active state w hen the remote control 201 needs to be able to issue commands towards said device.

In the second determination step 409, if during the activation request energy is being produced by the energy generator 3 1 8 and any energy accumulated in the energy accumulator 3 1 7 is being used, it is likely that there w ill be sufficient energy to transmit an activation command. It may however also happen that the quantity of energy w ill not be sufficient and that the user will have to reiterate his/her instance. The necessity for a reiteration will be indicated by the w arning lamp 2 1 5. which, if no activation signal is received, will continue to indicate inactivity of the energy irradiating means 2 1 1 .

After the activation signal has been sent and the delay applied at step 441 has elapsed. the second evaluation step 404 is carried out. wherein it is evaluated if the remote control 201 has sufficient energy to send the set command signal. It should be noted that, if the activation signal is not transmitted due to lack of energy (negative result of the second determination step 409). production and transmission of the command signal will not even be attempted, because such operations would require more energy than is needed for the transmission of the activation signal.

In the case that, during the first determination step 403. the remote control 201 is out of the range of the energy irradiating means 21 1 . the user will not be explicitly informed about it. nor the remote control 201 will be able to discern it from the preceding case. The user may deduce it from the failure of his/her attempts to send commands to the addressed apparatus, or from the combination of the indication of the warning lamp 2 1 5 and a "no signal^" indication that the remote control 201 may give through an indicator of its own (not shown in the drawings).

Furthermore, if there is sufficient energy in the energy accumulator 3 1 7, the set command signal may also be transmitted with an electromagnetic wave that is not sufficient for the energy collecting means 3 12. since the transmission range of the channel formed by the command transmitter 309 and command receiver 207 is generally greater than the range within which the energy irradiating means 21 1 can deliver sufficient energy to the energy collecting means 3 12.

This remark highlights the usefulness of having an energy backup in the energy accumulator 3 1 7. to be used for transmitting a command even in situations wherein the electromagnetic wave received by the remote control 201 from the regenerator 202 has insufficient power for the energy collecting means 3 12, but sufficient to reflect towards the regenerator 202 an electromagnetic wave that is powerful enough to allow the receiver 207 of the command regenerator 202 to decode the information content that it carries. In this case, a greater transmission range is advantageously obtained for the command signals than is av ailable when power to the circuits of the remote control 201 can only be supplied in real time by the energy collecting means 3 12.

With reference to Fig. 5. there is show n a further example of a system 1 0 in accordance with the present invention; more in detail, it shows a variant of the regenerator 202. In this variant, the regenerator 202 no longer includes the irradiation antenna 209. but comprises the device 5 16, which allows using a single antenna for picking up the signals to be conveyed towards the receiv er 207 and for emitting the signals produced by the energy radiator 2 1 1 . As the man skilled in the art will know, the dev ice 5 16 can be implemented by means of filters and circulators, which can separate and decouple the two signal types. The advantage of using a single antenna for both functions is apparent. According to a second variant of the invention, the range of the activ ation transmitter

320 is made dependent on the quantity of energy stored in the energy accumulator 3 1 7. or. more in general, on the quantity of energy available to it. For example, the activation transmitter 320 may use a minimal transmission power as long as the energy available for it will stay below a predetermined threshold, while it w ill be allowed to use a higher transmission power when more energy becomes available. This measure advantageously allows increasing the transmission range within which the full functionality of the system 10. in particular of the regenerator 202. can be activated.

In a third variant, command signals are transmitted through the activation transmitter 320 when the energy stored in the energy accumulator 3 1 7 exceeds a predetermined limit value. In this case, the receiver 2 1 3 w ill recognize the codes of the command signals and, just like the receiver 207. will take care of decoding the commands and forwarding them to the addressed apparatuses. This possibility advantageously allows transmitting command signals without first having to activate the energy irradiating means 21 1 ; moreover, all circuits of the regenerator 202 can be activated upon receiving a command signal through the activation receiver 21 3, as if an activation signal had also been received. Furthermore, in combination w ith a possible increase in the range of the activation transmitter 320 that could be provided by the above-described second variant, the range for transmitting commands through the activation transmitter 320 could advantageously be greater than that which would be obtained by transmitting the commands through the command transmitter 309.

In a second embodiment of the invention, the energy generator 3 1 8 has significantly lower requirements or is not used at all. In this embodiment it is assumed, in fact, that the energy irradiating means 21 1 are not completely deactivated and put into the idle state of the preceding embodiment; instead, their power is reduced, so that they w ill only emit electromagnetic w av es at (preferably short) time intervals hav ing a first duration T_a, w hich are repeated w ith a cyclic period T_c. The T_a/T_c ratio must be sufficiently low to keep the consumption of the regenerator 202 within limits compatible with the low-power specifications, and sufficiently high to allow the accumulation of sufficient energy, possibly w ithin the span of multiple intervals w ith a cy clic period T_c, for the emission of an activation signal within an acceptable time. In this operating mode, the power of the irradiated electromagnetic waves is equal to a second pow er value P_a. smaller than said first value P_c. theoretically in accordance with the formula:

T

p a = p c

The cyclic period T_c must be longer than the time required for the emission of an activation signal (thus reasonably excluding the option of dividing the activation signal into multiple emissions) and shorter than the maximum acceptable wait time that may elapse between a command instance and the emission of the respective command signal . The values of the first duration T_a and of the cyclic period T_c are. therefore, the result of a compromise that the man skilled in the art will be able to determine.

On the other hand, during the time interv als of duration Ta the electromagnetic w aves are emitted w ith the same (or only slightly different) power as those emitted during the normal operation when the radiator 2 1 1 is fully active; therefore, in such intervals the energy collecting means 3 12 can collect energy from the emissions of the regenerator 202, which the energy management module 3 1 5 can store into the energy accumulator 3 1 7.

This low-power state of the energy irradiating means 2 1 1 can be signalled by a blinking warning lamp 21 5, or by the same lamp turning on in a particular colour, or otherw ise. In this second embodiment of the present invention, the operation of the sy stem 1 0 and of the remote control 201 is similar to that of the first embodiment, with the following specifications and assumptions:

- when the user wants to use the remote control 201 , and the warning lamp 21 5 indicates that the energy irradiating means 2 1 1 are in low-power state, he/she will set the instance for sending an activation signal for the puipose of fully activating the energy irradiating means 21 1 ;

- it is assumed that, in such a circumstance, the energy collected from the low-pow er electromagnetic wave, possibly added to that generated by the energy generator 3 1 8. if present, is sufficient to cause the transmission process show n in Fig. 4 to exit from the wait step 402; should such energy be insufficient, from step 409 (Fig. 4 ). w hich is arrived at from the determination step 403 , as stated below, the process w ill repeatedly go back to step 402 until the accumulated energy obtained from the low-power electromagnetic wave will suffice; - during the first determination step 403, it is determined again if the remote control 201 is regularly receiv ing an electromagnetic wav e from which energy can be obtained; however, it is to be understood that reception is not constant, and therefore step 408 and then step 409 will be executed if the electromagnetic wave is received as impulses repeated with a period approximately equal to the cyclic period T . This determination can be made by using a simple filter know n in the art, distinguishing betw een an average power value and a peak power value of the electromagnetic w ave;

- the first duration T_a of the time interval of the impulses generated by the energy irradiating means 21 1 and the cyclic period T_c are sized in a manner such as to take into account the energy required for emitting an activ ation signal through the activation transmitter 320, the time period required for the transmission of the command signal, and, as aforesaid, the limits within which the power absorption of the energy irradiating means 2 1 1 must be kept, as well as the maximum acceptable wait time that may elapse between a command instance and the emission of the respective signal.

With these specifications, the process shown in Fig. 4 is also applicable to the second embodiment of the invention.

In this second embodiment, the reception of the activ ation signals produced by the activation transmitter 320 can advantageously exploit the cadence at which the energy irradiating means 21 1 emit the impulses of electromagnetic waves w hen they are in the low-power state. In fact, if the transmission of the activ ation signals produced by the activ ation transmitter 320 is synchronized with the impulses of the electromagnetic waves that the remote control 201 receiv es from the regenerator 202, the search for and reception of the activation signals of the activ ation transmitter 320 can be confined within a short periodic time window comprising the time intervals in which such activation signals are expected. For example, by starting the transmission of an activation signal, generated by the activation transmitter 320, at the end of an impulse of an electromagnetic wave emitted by the energy irradiating means 21 1 . i.e. at the end of a time interval hav ing a first duration T_a. on the reception side it is possible to confine the search for and reception of the activation signal within a time interval that starts at the end of the interval having a first duration T_a and lasts for a time equal to the time necessary for the transmission of said activation signal . The activation receiver 21 3 can thus be activated only within said time window, thereby reducing energy consumption and facilitating the search for activation signals to be identified and decoded, especially in the presence of interferences. In general, the emission of the activation signals and the periodic opening of the corresponding observation window for detecting the presence thereof can be prearranged at any instant within the cyclic period T_c. as the man skilled in the art will know.

Furthermore, considering that the T_a/T_c ratio is especially important for establishing the durations of the impulses of the electromagnetic waves generated by the energy irradiating means 21 1 , one can distinguish between a certain number of different regenerators 202 by setting therein different values of the cyclic period T_c, without altering the optimal T_a/T_c ratio.

According to a variant of this second embodiment, the remote control 201 still has the possibility of generating energy through the energy generator 3 1 8. considering that small quantities of energy can be obtained in various ways, as taught by the above- mentioned patent application US 201 1 /007035 A l . A ty pical example illustrated therein concerns buttons that produce energy when pressed for entering data or issuing commands. The use of one such energy generator 3 1 8 can advantageously increase the range of the activation transmitter 320 and reduce the time required for emitting its signals, as previously mentioned.

As regards the transmission technique that can be used by the second auxiliary activation subsystem 204, several variants are available as in the case of the first embodiment of the invention (infrared light, acoustic waves, radio systems such as Bluetooth. ZigBee, WiFi, or sy stems specifically designed for this particular application). Considering the presence, in this second embodiment of the invention, of an electromagnetic w ave emitted by the regenerator 202 also in circumstances wherein an activation signal needs to be transmitted, though in pulsed form, there is also the possibility of using transmission techniques similar to the RFID ones. i.e. a technique similar to the one used for transmitting command signals by the command transmitter 309. In this case, the command transmitter 309 and the activation transmitter 320 can advantageously share the antenna (the single main antenna 205) and possibly also the modulator that modulates the impedance of the load to w hich the antenna is connected, as previously explained with reference to the first embodiment of the invention. The modulating signal of the activation transmitter 320 will have a very simple form known in the art (just a few bits), because it has to carry very simple information.

As regards the way in w hich the user can set, by means of buttons and sensors, the commands to be transmitted to the regenerator 202. it can be found in the prior art. In particular, the prior art includes many examples of methods based on movements and gestures, even sophisticated ones, for use in electronic games. However, the following will illustrate some devices that could be taken into account for a particular application of the present inv ention.

As a reference hypothesis, it will be assumed that the remote control 201 is shaped as a ring that can be worn on a finger of a hand, and that commands are essentially defined through gestures made w ith said hand. One important constraint is given by energy consumption minimization because, depending on the transmission range to be obtained, energy consumption also dictates the size of the antenna that must intercept the electromagnetic wave from which energy will be collected, and hence also the physical dimensions of the remote control 201 . One possible basic solution is the use of a three-axis accelerometer, which provides the three spatial acceleration components dependent on the movements made by the remote control 201 in space. By integrating the acceleration components, one obtains the respectiv e speed components; by integrating the speed components, one obtains the respective displacement components. With these parameters, the man skilled in the art will be able to define the various commands according to the movement of the remote control 201 (i.e. the movement of the hand holding it). The use of an accelerometer appears to be particularly suitable for the present invention, because accelerator models exist which only require a few microwatts and have adequate sensitivity and resolution for detecting hand gestures.

With these assumptions, a ring-shaped remote control 201 with adequate performance for use in household environments can be implemented in forms like, for example, the one show n in Fig. 1 . Preferably, the main antenna 205, to which the energy collecting means 3 12 are connected, occupies an area slightly smaller than the frontally exposed surface of the ring. By reducing the energy consumption or the transmission range, the dimensions of said surface can be reduced as well . In order to make movement interpretation independent of the particular position and orientation of the remote control 201 with respect to the position of the regenerator 202, the position and orientation of the remote control 201 is defined prior to the start of a gesture to be interpreted as a command. This can be achieved through a button to be pressed by the user before starting the gesture. This button action is also necessary to indicate when the user wants to use a gesture as a command, so as to avoid that gestures commonly made in everyday life w ill be interpreted as commands.

In order to avoid the issue of wrong commands, it is also necessary to define the end of the gesture to be interpreted as a command. The end indication could be determined automatically by establ ishing a time interval within which the gesture w ill have to be considered as a command, or by defining a movement with which each command will be terminated, or by pressing a button again. One option that seems particularly practical may be to hold dow n the button to indicate the start of the command gesture until the gesture itself has been completed.

Pressing a button at every gesture appears, in any case, to be advantageous. Since, as aforesaid, there are buttons that can produce electric energy at each actuation, it is anyway conceivable to provide an energy generator inside the remote control 201 . like the generator 3 1 8 shown in Fig. 3. which can convert the mechanical energy produced by said actuation into electric energy.

The remote control 201 described in the present invention allows, therefore, addressing commands to various apparatuses by means of gestures made ith just one hand, without previously hav ing to verify if batteries need to be replaced or recharged.

The system 10 described herein adv antageously allows placing the regenerator 202. w hich receives command signals from the remote control 201 . into a low-power state. and then reactiv ating it by means of the remote control 201 itself.

Thanks to the various possible embodiments and variants thereof, the present invention can be sized for offering different levels of performance and can be adapted for fulfilling different needs.

The method according to the invention can be implemented by means of a computer product which can be loaded into a memory of said command device 201 and/or into said command regenerator device 202, and which comprises software code portions adapted to implement said method.

The features of the present invention, as well as the adv antages thereof, are apparent from the abov e description.

A first advantage of the energy-collecting wireless command device and of the related system and method is that they allow a user to control an apparatus without hav ing to worry about the exhaustion of the power source of the command device itself.

A second advantage of the command dev ice, system and method according to the invention is that the use of traditional batteries is av oided, which generally contain polluting heavy metals.

A third advantage of the command device, system and method according to the invention is that they have an environmentally sustainable character.

The energy-collecting w ireless command system and the related system and method according to the present inv ention may be subject to many possible v ariations without departing from the nov elty spirit of the inventiv e idea; it is also clear that in the practical implementation of the invention the illustrated details may have different shapes or be replaced with other technically equiv alent elements.

It can therefore be easily understood that the present invention is not limited to an energy-collecting wireless command device and the related system and method as described herein, but may be subject to many modifications, improvements or replacements of equivalent parts and elements without departing from the novelty spirit of the inventive idea, as clearly specified in the following claims.

Claims

1 . A wireless command device (201 ) adapted to cooperate with a command regenerator dev ice (202), said command device (201 ) comprising:

- a command transmitter (309) adapted to issue a command signal receivable by said command regenerator device (202);

- an activation transmitter (320) adapted to send an activation signal for activating said command regenerator device (202);

- energy collecting means (3 12) arranged to collect energy from electromagnetic waves picked up by a main antenna (205 ) connected thereto:

- processing means (3 14) configured for determining if said command device (201 ) has sufficient energy to issue said command signal;

said activ ation signal being adapted to activate energy irradiating means (2 1 1 ) included in said command regenerator device (202), said energy irradiating means (21 1 ) being adapted to irradiate said electromagnetic wav es with a first power value (P ) capable of powering said command device (201 ) for the purpose of issuing said command signal.

2. A command device (201 ) according to claim 1 , wherein said command transmitter (309) uses said energy collected by said energy collecting means (3 12).

3. A command device (201 ) according to claim 1 or 2. wherein said command device (201 ) comprises an energy accumulator (3 1 7) configured for accumulating said energy from said electromagnetic waves.

4. A command device (201 ) according to claim 3, wherein said energy accumulator (3 1 7) comprises a first section (c ) and a second section (a), said first section (c ) being adapted to accumulate energy for the transmission of said command signals, said second section (a) being adapted to accumulate energy for the transmission of said activation signals.

5. A command device (201 ) according to claim 4, wherein said first section (c) has a higher capacity than said second section (a).

6. A command device (201 ) according to one or more of claims 3 to 5. wherein said second section (a) has recharging priority over said first section (c).

7. A command device (201 ) according to one or more of the preceding claims, wherein said activ ation transmitter (320) has priority for the use of the energy stored in said energy accumulator (3 1 7).

8. A command device (201 ) according to one or more of the preceding claims, wherein said command device (201 ) comprises an energy management module (3 1 5) adapted to optimize the accumulation and use of said energy.

9. A command device (201 ) according to one or more of the preceding claims, w herein said command signal is a reflection of said electromagnetic waves irradiated by said energy irradiating means (21 1 ). obtained by varying an impedance of said command device (201 ).

1 0. A command device (201 ) according to one or more of the preceding claims, wherein said command device (201 ) comprises an energy generator (3 1 8) adapted to supply energy for said activation signal.

1 1 . A command device (201 ) according to claim 10. wherein said energy generator (3 1 8) is of the piezoelectric type.

12. A command device (201 ) according to claim 10 or 1 1 , wherein said energy generator (3 1 8) contributes to energy accumulation.

1 3. A command dev ice (201 ) according to one or more of the preceding claims, wherein said command dev ice (201 ) is a wearable device, in particular a ring.

14. A command transmission system ( 10). said system ( 10) comprising a wireless command device (201 ) according to one or more of claims 1 to 13. and a command regenerator device (202) comprising energy irradiating means (2 1 1 ) adapted to irradiate electromagnetic waves with at least a first power value (P_c) upon receiving an activation signal issued by said command device (201 ). said electromagnetic waves being capable of powering said command device (201 ) for the purpose of issuing a command signal.

15. A command transmission system ( 10) according to claim 14. wherein, in the absence of said activation signal, said energy irradiating means (21 1 ) are off. i .e. in an idle state.

16. A command transmission system ( 10) according to claim 14. wherein, in the absence of said activation signal, said energy irradiating means (21 1 ) are in a low-power state in which they only emit electromagnetic waves at time intervals having a first duration (T_a). which are repeated with a cyclic period (T_c).

1 7. A command transmission system ( 10) according to claim 16. wherein the av erage power of said electromagnetic waves corresponds to a second power value (P_a) which is lower than said first power value (P_c), said second power value (P_a) being sufficient to supply energy to said command device (201 ) for the purpose of issuing said activation signal .

1 8. A command transmission system ( 10) according to claim 16 or 1 7, wherein said command device (201 ) issues said activation signal synchronously with said cyclic duration period (T_c).

19. A command transmission system ( 10) according to one or more of claims 14 to 1 8, wherein said command regenerator device (202) comprises signalling means (21 5 ) adapted to signal its own operating state.

20. A method for transmitting commands, said method comprising the steps of:

- determining, through processing means (3 14), if a command device (201 ) has sufficient energy to issue a command signal:

- sending, through an activ ation transmitter (320), an activ ation signal to a command regenerator device (202) if said command device (201 ) does not receive sufficient energy to issue said command signal;

- activating, through said activation signal, energy irradiating means (21 1 ) included in said command regenerator device (202 );

- irradiating, through said energy irradiating means (2 1 1 ). said electromagnetic waves with at least a first power value (P_c) capable of powering said command dev ice (201 ) for the purpose of issuing said command signal.

2 1 . A method according to claim 20. wherein said method comprises the step of collecting energy, through energy collecting means (3 12 ) of said command device (201 ). from said electromagnetic waves picked up by a main antenna (205) connected thereto.

22. A method according to claim 20 or 21 . wherein said method comprises the steps of:

- waiting for a command start instance from a command originator (307) of said command device (201 );

- determining, through said command device (201 ). if it receives at least one electromagnetic wave;

- evaluating, through said command device (201 ), if the quantity of energy available in said command device (201 ) is sufficient for said command device (201 ) to issue said activation signal;

- evaluating, through said command device (201 ). if the quantity of energy available in said command device (201 ) is sufficient for said command device (201 ) to issue said command signal.

23. A method according to one or more of claims 20 to 22. wherein said method comprises the step of:

- collecting data from said command originator (307), in particular from sensors and buttons:

- producing said command signal;

- transmitting said command signal to said command regenerator device (202) through a command transmitter (309) of said command device (201 ).

24. A method according to one or more of claims 20 to 23. wherein said method provides for transmitting said command signals through said activation transmitter (320) w hen the energy available in said command device (201 ). or stored in an energy accumulator (3 17). exceeds a predetermined limit value.

25. A method according to one or more of claims 20 to 24, wherein the transmission range of said activation transmitter (320) depends on the quantity of avai lable energy stored in said energy accumulator ( 3 1 7).

26. A computer product which can be loaded into a memory of said command device (201 ) and/or into said command regenerator device (202). comprising portions of software code adapted to implement the method according to one or more of claims 20 to 25.