EP1397576A1

EP1397576A1 - Device for radio-frequency controlled drive

Info

Publication number: EP1397576A1
Application number: EP02738219A
Authority: EP
Inventors: Michel Ramus
Original assignee: Somfy SA
Current assignee: Somfy SA
Priority date: 2001-06-01
Filing date: 2002-05-07
Publication date: 2004-03-17
Anticipated expiration: 2022-05-07
Also published as: US20040162040A1; WO2002097230A1; EP2345789A1; FR2825498A1; ATE548537T1; ES2381661T3; EP1397576B1; JP2004527200A; CN1225593C; JP4112487B2; US7151464B2; ES2567035T3; EP2345789B1; CN1463320A; FR2825498B1

Abstract

The drive (2) has a motor (10) controlled by a radio frequency circuit (12). Conductors (14) supply electricity to the motor and to the radio frequency circuit. The drive circuit can transmit or receive radio frequency signals directly through an antenna (16), or from the electric power supply conductors through an isolating coupling.

Description

RADIO FREQUENCY DRIVE DEVICE

The present invention relates to radio frequency controlled drive devices, and more specifically to the drive devices used for winding blinds and roller shutters.

In the housing or building sector in general, radio transmission is used more and more frequently to remotely control elements electrically supplied by the low voltage network (typically 230 V AC 50 Hz or 120 V AC 60 Hz), or sector.

The applicant markets under the reference SLT and IPSO a motor for driving blinds or roller shutters, with radio remote control. This motor has a tubular shape and is placed inside a steel winding tube, on which the product to be rolled up is arranged. Under these conditions, the radio integrated into the motor has an antenna in the form of a semi-rigid strand of wire, leaving the tubular motor and also leaving the winding tube over an appropriate distance, for example λ / 4 (a quarter of wavelength), i.e. 17 cm for a frequency of 433 MHz or approximately 8 cm for a frequency of 868 MHz. This type of antenna has a disadvantage of fragility, relative to the mass of the engine, which imposes special precautions for handling and packaging. In addition, the housing of the blind or roller shutter winding tube often consists of a steel or even aluminum box. In this unfavorable environment, the range of the antenna may be considerably reduced. In addition, as long as the device is mounted externally, on a reinforced concrete wall, this reduction is accentuated.

It should be noted that various solutions have been proposed to facilitate the integration of a radio receiver to such an engine. Thus EP-0-921 266-A2 proposes the direct installation of the radio receiver inside the engine tube. There is no explicit mention of the antenna layout. In the product marketed by the company TOPELECTRO International, in Spain, under the reference TOPELECTRO JUNIOR, the quarter wave antenna is arranged completely independently of the sector wire, partially wound on itself so as to take up less space. This provision explains an extremely limited scope.

In patent FR-2 743 390, the radio receiver is arranged in a control box independent of the motor tube, but easy to integrate into the roller shutter box or to a blind fixing. There is no mention of any particular arrangement of the antenna within this box.

It has also been proposed, in separate applications, to use the mains supply cable as the mechanical support for an antenna. Examples of devices ordered by radio, having an antenna extending along the mains supply cable but without coupling to the mains, are proposed in US-A-2,218,830, GB-A-340,389, US-A-6,104

920, US-A-5,351,284 or even US-A-3,863,157. US-A-2,218,830 proposes an antenna for radio or television receiver, having an antenna formed by a wire associated with the power cable; the antenna is associated with this cable so as to minimize the coupling between the antenna and the mains wire. The advantage is then to have a non-directional antenna of length well calibrated by the manufacturer: thus the adjustment of the HF circuit does not depend on variable parameters, as is the case with an outdoor antenna left at the installer initiative.

GB-A-340 389 proposes, for such receivers, to use directly as the antenna a portion of the mains cable, isolated upstream and downstream by two plug circuits. At the frequency of the signal, everything happens as if the cable were a single wire serving as an aerial strand. The two plugs provide insulation between the signals received by the antenna cable and the sector signals. Figure 4 of US-A-6 104 920 proposes a device of the same kind as this English patent. GB-A-702 525 offers a similar solution for television receivers. The signal received on the part of the antenna supply conductors is coupled into the receiver using a coupling coil and a coaxial cable.

US-A-5,351,284 relates to the base of a cordless telephone; the telescopic antenna is replaced by a wire coupled either to the telephone line or to the power cord; it is expressly stated that the telephone line or the power cord does not contribute to the reception of the antenna. US-A-3,863,157 proposes a device of the same kind, in which the connecting wires between the amplifier of a stereo receiver and the loudspeakers are also used as antenna wires; provision is also made for a separation of the two functions. In all these documents, the objective pursued is to replace a fragile or unsightly aerial with a portion of a cable accepted for other reasons. These documents therefore specify that it is important to isolate the signals received on the aerial cable from the signals transmitted on the cable in its usual use.

US-A-4,032,723 shows a duplex cordless telephone system; one of the elements of a dipole antenna consists of a conductor of the power cable. The teaching of this document is similar to that of the previous documents - the antenna being however of another type.

It has also been proposed to use the sector as a receiving antenna. The company BUBENDORFF markets under the reference 'id' a motor for roller shutters with integrated radio without specific antenna, for which the sector is generally used as receiving antenna, and using an electrical connection by capacitor between the terminal of arrival of a wire sector and the RF input point of the receiver circuit. It should be noted that such an arrangement makes the electronic card particularly sensitive to attacks by energy parasites carried by the sector. For other fields of technology, a similar teaching appears in the documents US-A2 581 983, US-A-3 290 601, US-A-2 915 627 or even US-A-4 507 646.

US-A2 581 983 proposes to couple a radio frequency reception circuit to the mains supply cable of a radio receiver. The coupling point is a quarter or an eighth of a wavelength away from the receiver chassis, which is grounded. US-A-3,290,601 is an improvement on this patent, and simply proposes to form a doublet antenna by associating with the preceding device a monopoly antenna. US-A-2 915 627 proposes an antenna for radio receiver. A cylindrical conductor with a length between a quarter and a half of the wavelength of the radiofrequency signals surrounds the power cable; the cylindrical conductor allows to transmit to a radiofrequency receiver the radiofrequency signals received by the sector, which acts as an antenna. US-A-4 507 646 proposes to use for a calling system ("paging" in English) the wires of the sector as antenna of the transmitter or the receiver; the nature of the coupling circuit of the radio frequency receiver or transmitter to the mains is not specified. The devices described in these various documents have the objective of avoiding the use of a dedicated antenna, by using the sector conductors as an antenna. This solution involves precisely controlling the point of coupling of the radio frequency receiver or transmitter to the sector conductors; in the absence of such control over the coupling point, this solution in fact presents serious drawbacks in terms of selectivity and of susceptibility to broadband energy parasites carried by the sector. In addition, galvanic isolation may require the use of particularly protected capacitors.

The invention proposes, in the specific case of tubular motors, a solution which makes it possible to control a motor by radio, with good reliability. The solution applies to all the environments in which these engines are used; it is simple to implement. More specifically, the invention provides a drive device having a motor, a radiofrequency circuit for controlling the motor, electrical supply conductors for the motor and the radiofrequency circuit and an antenna connected to the radiofrequency circuit and electrically coupled for the radiofrequencies to at least one of the conductors by a non-galvanic coupling. Advantageously, the power received or transmitted partly directly through the antenna represents more than 5%, or even 10% of the power received or transmitted by the radiofrequency circuit.

Preferably, the power received or emitted in part directly through the antenna represents less than 50%, even less than 40% of the power received or emitted by the radiofrequency circuit. In one embodiment, the antenna is mechanically coupled to the conductors.

The antenna can be a monopoly antenna, and in this case, it can have a length close to a quarter of the wavelength of the radiofrequency signals received or emitted by the radiofrequency circuit. In another embodiment, the device has a motor tube in which the motor, the radio frequency circuit and the antenna are arranged. This tube is for example a metal tube.

It is also possible to provide that the antenna is formed of a printed circuit track. In this case, it is advantageous that at least one conductor has a printed circuit track extending parallel to the track forming the antenna.

Other characteristics and advantages of the invention will appear on reading the following description of embodiments of the invention, given by way of example and with reference to the appended drawings which show: - Figure 1 a schematic view in section of a drive device according to the invention;

- Figure 2 a partial schematic view of another embodiment of a drive device.

The invention proposes, for the radio control of an engine, to use a monopole antenna and to couple this antenna to the electrical supply conductors of the engine, by a non-galvanic coupling; the antenna is thus coupled to the conductors for the radio frequencies, but is isolated from these at the frequency of the supply currents. In this way, the radiofrequency power transmitted or received is:

- partly by the antenna, which acts like a conventional antenna; - partly through the sector, which acts as an antenna.

The invention differs from the prior art solution described in US-A-2,218,830 or in similar documents. Indeed, the antenna is electrically coupled to the power supply conductors, so that the radiofrequency signals are at least partly received or transmitted through the sector supply conductors. This configuration is particularly advantageous when the motor is in a steel or aluminum box, which can limit the propagation of electromagnetic waves.

The invention also differs from the prior art solution proposed in US-A2

581 983 or in similar documents; in fact, in these documents, there is no provision for an antenna directly receiving or emitting part of the radiated or emitted power. As the invention is not based solely on the sector, it ensures more efficient reception or transmission.

The solution of the invention makes it possible to solve the problems of the motors of the state of the art. As the antenna is electrically coupled to the mains wires, it is possible to place the antenna inside a metal tube containing the motor and its control circuit. The antenna therefore does not protrude from the tube, and does not risk being damaged during transport or assembly.

Figure 1 shows a schematic sectional view of a drive device according to a first embodiment of the invention. The device 2 has a tube 4, or tube of engine. The engine tube is typically cylindrical in shape. It is often made of metal, which provides the necessary mechanical rigidity; it can also be made of plastic. Around the engine tube is provided a winding tube 9, most often made of metal. This winding tube is mounted on two supports 6 and 8, the support 6 being at one end of the tube 4. The two supports include a bearing facilitating the rotation of the winding tube. This tube 9 receives the end of the shutter or blind to be rolled up.

Inside the motor tube 4 is provided an electric motor 10, which is capable of rotating the winding tube 9, relative to the motor tube 4, using a drive wheel 11. The device further comprises, still inside the motor tube 4, a radio frequency circuit 12 for controlling the motor. This circuit is capable of receiving or transmitting radio frequency signals, as explained below. The term "radiofrequency" is understood here to mean the frequency ranges between 100 and 1000 MHz, with transmission through the air over short distances - of the order of 10 to 1000 m in free field. The circuit 12 controls the motor as a function of the signals received and / or the signals transmitted.

The motor and the radio frequency circuit are supplied with power by conductors 14 intended to be connected to the electrical network.

The device also has an antenna 16. This antenna is firstly connected to the radio frequency circuit, so that the radio frequency signals received by the antenna. are applied to the circuit and / or so that the radio frequency signals supplied by the circuit are radiated by the antenna. The antenna is typically a quarter-wave antenna, formed of an elongated conductor having a length of the order of a quarter of the wavelength of the frequency used for controlling the motor; the current frequency ranges for home automation applications are 433 MHz or 868 MHz, which leads to an antenna length of approximately 17 or 8 cm. In the simplest version, the antenna will be a monopoly. As shown in the figure, the antenna extends entirely into the motor tube 4; this has the advantage that the antenna is thus protected by the tube. The problems of fragility of the antenna or installation thereof therefore no longer arise.

The antenna 16 is also electrically coupled to at least one of the electrical supply conductors 14 of the motor and the power circuit. The electrical coupling between the conductor (s) 14 and the antenna 16 allows the radio frequency circuit to receive, through the antenna, radio frequency signals picked up by the electrical network; the network can therefore serve as an antenna for receiving radiofrequency signals intended for the engine control circuit. Conversely, the electrical coupling between the conductor (s) 14 and the antenna 16 allows the radio frequency circuit to transmit through the antenna 16 radio frequency signals to the electrical network; the electrical network can therefore serve as a transmitting antenna for radiofrequency signals emitted by the engine control circuit. The coupling between the antenna and the conductor (s) 14 is both non-galvanic and selective coupling; in other words, the antenna and the conductor are electrically coupled for signals in radio frequency ranges used for controlling the motor; however, at the motor power frequency, the antenna and the conductors are isolated. This non-galvanic coupling can be carried out in various ways; the simplest is, as shown in Figure 1, that the antenna extends in the vicinity of the conductors; the distance between the conductor (s) and the antenna can be as small as possible and simply correspond to the thickness of the insulation surrounding the conductors; this configuration has the advantage of maximizing the coupling between the antenna and the conductors for the radio frequencies.

It is also possible to mechanically couple the antenna to the conductors; this facilitates the mounting of the drive device. A simple method consists in passing the conductors and the antenna strand in the same insulating sheath, possibly heat-shrinkable; such mechanical coupling ensures good proximity of the conductors and the antenna strand, and therefore good electrical coupling.

Figure 1 also shows in dotted lines the limits of a box 18 in which is placed the drive device; this box is often a metal box made of steel or aluminum; it receives the winding tube as well as the blind or the roller shutter when the latter is in a folded position. The box can then be fully closed; this is particularly the case for the boxes of external blinds, which are closed when the blind is folded. In such a configuration, the antenna 16 is surrounded first by the motor tube 4, then by the winding tube 9, then by the box; the conductors 14, on the other hand, exit from the motor tube as from the box, so that they can be connected to the sector. It is however obvious that the exact position of the connection between the conductors 14 and the electrical network has no effect on the operation of the device.

The device of Figure 1 works as explained now. It can operate on the one hand in reception, for example to transmit to the drive device an operating order - in the case of a blind or a rolling shutter, an order to roll up or unwind the blind, or another order to stop the winding or unwinding. It can also function in transmission, to transmit information relating to the state of the drive device - for example an acknowledgment of receipt of a command, or even information on the position of the drive device or its speed; in this case, it is of course improper to qualify the circuit 12 as a "control" circuit, since the control of the motor can be carried out by other means; this term is nevertheless used for simplicity in the present description. The operation in transmission and the operation in reception are similar, and only the operation in reception is described in detail. On reception, radio frequency signals are transmitted by a transmitter - for example a portable transmitter - to the drive device. These signals are firstly received directly by the antenna 16, and are therefore applied to the control circuit, to be decoded and executed there. On the other hand, the signals are also received by the conductors of the sector - which act as antenna. Due to the electrical coupling in the radiofrequency field between the conductors 14 and the antenna, the radiofrequency signals received by the conductors are transmitted to the antenna 16 and therefore applied to the control circuit. The latter therefore receives:

- the signals directly received by the antenna 16, and - the signals received by the supply conductors and coupled to the antenna 16.

The commands applied to the control circuit are transmitted by the latter to the motor, so as to cause the winding tube to rotate in one direction or the other, or to interrupt its rotation.

The Applicant has carried out acceptance tests of a drive device according to the invention, with respect to a device without electrical coupling of the antenna and of the supply conductor (s); coupling during the tests was obtained by placing the antenna in the vicinity of the conductors, at a distance of 2 mm, over almost the entire length (14 cm) of the antenna (17 cm); for a frequency of 433 MHz. The tests were carried out in a semi anechoic chamber. They demonstrated that the proportion of signals received directly by the antenna or through the supply conductors depended on the orientation of the drive device. This proportion between:

- signals received directly by the antenna; and

- the total power received by the radiofrequency circuit varied between 3 and 40% with an average of 21%. It is therefore preferable that this proportion is greater than 5%, or even greater than 10%; this is ensured by the mere presence of the antenna. It is also preferable that this proportion is less than 50%, even 40%; this is ensured by the non-galvanic coupling between the antenna and the conductor (s). The proportion decreases all the more as the winding tube limits the propagation of the radiofrequency waves; it also decreases if the winding device is in a metal box. The proposed terminals ensure correct operation in all the circumstances usually encountered in buildings.

For comparison, when we compare single, identical motors but one (MA) with the antenna outside the steel tube 4, as already marketed by the applicant, and the other (MB) with the antenna according to the invention, the radiofrequency signals at the input of the control circuit have in the second case a power 10 dB lower than the corresponding power in the first case; this weakening is representative of the weakening caused by the engine tube - the antenna being placed in the engine tube. The invention therefore has the effect of deteriorating the performance of an engine not yet installed. On the other hand, when the MB device is inside a winding tube and a metal box, corresponding to typical conditions of use, the radio frequency signals at the input of the control circuit have a higher power of 3 dB the corresponding power in an MA device also placed in a winding tube and a box; this increase in power is representative of the effect of the non-galvanic coupling between the supply conductors and the antenna in the device of the invention.

Figure 2 shows a schematic partial view of another embodiment. In the embodiment of FIG. 2, the antenna has the form of a track 22 of a printed circuit 24. The coupling can then be simply carried out using for the conductor (s) one or two neighboring tracks 26 or 28 of the track materializing the antenna.

The device of the invention is remarkable in that it avoids problems during assembly of the device, during its installation, as during its current use.

Of course, the present invention is not limited to the examples and embodiments described and shown, but it is susceptible of numerous variants accessible to those skilled in the art. We could thus use configurations different from those of the figures, provided for example that the engine is delivered with the power cord, which is not always the case. In such a situation, the cord would be produced specifically, and would contain, at the end to be connected to the motor, the antenna strand or a portion thereof. Such an arrangement would make it possible, at least partially, to have the antenna outside the motor tube and / or the winding tube, and therefore to better distribute the control signal powers transmitted directly or by the wires d 'food. It is also possible that the antenna extends outside the motor tube, even in the case where the power cord is delivered with the motor. It is also clear that the invention is not limited to the preferred embodiment of the roller shutters or blinds. It more generally applies to all drive devices, such as those of garage doors, armchairs or articulated beds, or the like.

Claims

1. A drive device (2) having: - a motor (10);

- a radiofrequency circuit (12) for controlling the motor;

- electrical supply conductors (14) for the motor and the radio frequency circuit;

- An antenna (16) connected to the radio frequency circuit and electrically coupled for the radio frequencies to at least one of the conductors by a non-galvanic coupling.

2. The device of claim 1, characterized in that the power received or transmitted partly directly through the antenna (16) represents more than 5%, even 10% of the power received or transmitted by the radio frequency circuit (12 ).

3. The device of claim 1 or 2, characterized in that the power received or transmitted partly directly through the antenna (16) represents less than 50%, or even less than 40% of the power received or transmitted by the radio frequency circuit (12).

4. The device of claim 1, 2 or 3, characterized in that the antenna (16) is mechanically coupled to the conductors (14).

5. The device of one of claims 1 to 4, characterized in that the antenna (16) is a monopoly antenna.

6. The device of claim 5, characterized in that the antenna (16) has a length close to a quarter of the wavelength of the radiofrequency signals received or emitted by the radiofrequency circuit.

7. The device of one of claims 1 to 4, characterized in that it has a motor tube (4) in which are arranged the motor, the radio frequency circuit and the antenna.

8. The device of claim 7, characterized in that the tube (4) is metallic.

9. The device of one of claims 1 to 8, characterized in that the antenna is formed of a track (22) of printed circuit (24).

10. The device of claim 9, characterized in that at least one conductor (14) has a printed circuit track (26, 28) extending parallel to the track forming the antenna.