EP0288791A2 - Wireless transmission method for power and data transmission, and mechanically and electronically coded lock - Google Patents

Abstract

A wireless transmission method for power and data transmission, especially for a combined mechanically and electronically coded lock, uses power-supplied main electronics and part electronics with no power supply and with an energy storage circuit. Data and power transmission takes place respectively via coupling elements connected to the main electronics and part electronics. The power and data exchange is controlled by a microcontroller in the main unit in such a way that - power or data are transmitted alternately via the coupling elements, - the transmitted power is matched automatically to the consumption of the part electronics, including the transmission losses, by a variation of the power pulse length, - the starting times of the data sequences in the part electronics are synchronised with the cycles in the main electronics. <IMAGE>

Description

The invention relates to a method for contactless energy and data transmission according to the preamble of the main claim, in particular for a combined mechanical-electronic coded lock according to claim 5.

A device for the inductive identification of information in access controls, in particular in an inductive electronic lock and key part, is known from DE-PS 31 49 789. When the key part approaches the lock part, an oscillator of the lock part vibrates at high frequency, these vibrations being picked up by the key part and modulated back to the lock part with a frequency or pulse pattern serving as a key identifier are transmitted and processed there with a lock-side electronics. The key part has an energy storage device which receives the energy received via an HF resonant circuit. In such a device, the data and energy transmission take place simultaneously with the same RF signal.

From DE-OS 35 00 353 a mechanically and electronically coded key with a lock to be actuated thereby is known. Such a key has a conventional mechanical coding and an electronic coding present in its casing, while the corresponding lock contains a mechanical locking device and an electronic storage and control system provided with a decoding or reading device and energy supply. The lock is provided with a detector which can interact with a counter detector present on the key and transmitting a non-mechanical coding in a contact-free exchange of energy and data. The detector is housed on the front side of the lock cylinder and the counter detector in the front side of the key lock facing the lock cylinder. A module with a microprocessor, a data memory and a short-term energy store is accommodated in the key box, the key coding being programmed in the module. The detectors can consist of RF transmitters or RF receivers. When the counter detector present on the key approaches the detector of the lock cylinder, there is a corresponding excitation in the oscillating circuit of the key and thus energy supply, which is required for data transmission or data comparison between the lock and key electronics is. With this mechanically and non-mechanically coded key / lock combination, no adaptation of the energy transmission to the energy consumption of the key electronics and the transmission path is provided.

Another device for contactless coupling of the control and power currents between lock electronics and key electronics in an electronic / mechanical locking device is known from DE-OS 35 01 482. The communication between the key and the lock takes place via a bidirectional, serial inductive interface, whereby both the key and the lock electronics can be equipped with a microcontroller and an erasable PROM. With such a mechanical / electronic lock, no adaptation to the actual energy consumption of the key electronics and the transmission link is provided, so that the main electronics have a significantly higher energy consumption, which excludes battery or accumulator operation. Furthermore, the transmission of the data is susceptible to faults, which in the event of a fault means that the lock cannot be unlocked.

The invention has for its object to provide a method for contactless energy and data transmission, in particular for a combined mechanically / electronically coded lock, which ensures the energy transmission and the transmission security with respect to the coded data even under different transmission conditions and enables low energy consumption.

To achieve this object, the invention provides

- That energy or data are alternately transmitted via the coupling elements and

that the transmitted energy is automatically adapted to the energy consumption of the partial electronics, which is dependent on varying transmission losses, by varying the length of the energy pulse,

- In that after the main electronics have been switched on, energy pulses of a predetermined length of time are transmitted repeatedly until a reset acknowledgment signal of the sub-electronics is present and by energy pulses with a length depending on the energy consumption are transmitted after the presence of a reset acknowledgment signal.

The method according to the invention enables high transmission security even in the event of transmission losses or disruptive influences in the transmission link. The transmitted energy automatically adapts to the power consumption of the sub-electronics including the losses in the transmission path. This automatic adaptation of the transmitted power to the changing influences on the transmission line in practical operation allows adaptation to different doors and fittings made of different materials that have a more or less dampening effect on high-frequency energy, as well as to different geometrical characteristics of doors and fittings also dampens just like an inaccurate alignment of receiver and transmitter part RF transmission and thus the key's wireless power supply can be interrupted. Operation would then not be possible without adaptation or - in a preliminary stage of the business interruption - the data codes would be falsified, with the result that the lock operation would not be possible. As a side advantage there is low power consumption with high transmission security, which allows battery or accumulator operation.

After switching on the main electronics, energy pulses of a specified length of time are transmitted repeatedly until a reset acknowledgment signal of the sub-electronics is present and that after the presence of a reset acknowledgment signal, energy pulses (energy bursts) with a length determined by the actual energy consumption are transmitted. This enables the required supply voltage in the partial electronics to be reached as quickly as possible with small amounts of energy, ensuring that not too much energy is transmitted.

Furthermore, the transmission security is increased in that the data are binary coded, so that there is a large signal-to-noise ratio.

A mechanically / electronically coded lock, in particular for using the method according to the invention, is characterized in that the lock cylinder is enclosed by a plug-in, integral, non-metallic lock interface module of a certain length, which has a key detection switch, an electronically controllable locking mechanism and the lock-side Coupling element takes.

Such an interface module can be used in conjunction with an unmodified conventional lock, the interface module being seated only on the part of the lock cylinder protruding from the lock case. The use of a non-metallic material, e.g. Zirconium oxide, enables the transmission losses to be reduced and thus contributes to the battery operation of the mechanically / electronically coded lock. The key detection switch allows the device to be switched off when not in use, which enables a further increase in the number of lock actuations per battery set when operated on batteries.

In a preferred embodiment, the electronic coding of the key is provided in a serial EEPROM via an n-fold connector, which after programming and encapsulation is no longer accessible without being destroyed. The encapsulation of the key electronics with the plug makes unauthorized key programming impossible. The use of a serial code memory allows the number of pins on the programming connector to be kept small.

The lock-side coupling element can be isolated from metallic objects, e.g. of door panels, be arranged above the lock cylinder in the interface module. The arrangement of the coupling element in non-metallic material of the lock interface module enables the transmission losses to be minimized, the influence of metal behind the lock interface being slight.

In the following an embodiment of the invention will be explained with reference to the drawings.

• Fig. 1 ein Blockschaltbild der für das erfindungs­gemäße Verfahren verwendeten Elektronik,
• Fig. 2 ein Blockschaltbild der Hauptelektronik,
• Fig. 3 ein Blockschaltbild der Schlüsselelektronik,
• Fig. 4 ein Zeitdiagramm mit der Ablaufsteuerung der Energie- und Datenübertragung,
• Fig. 5 ein Zeitdiagramm gemäß Fig. 4 in der Anlauf­phase,
• Fig. 6 eine Frontansicht eines mechanisch/elektro­nisch kodierten Schlosses,
• Fig. 7 ein Schlüssel des mechanisch/elektronisch kodierten Schlosses und
• Fig. 8 eine Seitenansicht des vorderen Teils des Schloßzylinders mit eingestecktem Schlüssel.

Show it:

• 1 is a block diagram of the electronics used for the method according to the invention,
• 2 is a block diagram of the main electronics,
• 3 is a block diagram of the key electronics,
• 4 shows a time diagram with the sequence control of the energy and data transmission,
• 5 shows a time diagram according to FIG. 4 in the start-up phase,
• 6 is a front view of a mechanically / electronically coded lock,
• Fig. 7 a key of the mechanically / electronically coded lock and
• Fig. 8 is a side view of the front part of the lock cylinder with the key inserted.

1 shows a block diagram of the electronics required for the method for contactless energy and data transmission. The main electronics 1 are suitably supplied with energy via a power supply unit 3, which can be transmitted from the main electronics 1 to a sub-electronics 2 via contactless coupling elements 4, 5. Data can also be transmitted in both directions via the same contactless coupling elements 4, 5.

Fig. 2 shows a block diagram of the main electronics with a microcontroller 8 including software. The microcontroller 8 controls a switch S1 via a data direction signal, which switches the data transmitted by the primary coupling element 4 from the sub-electronics 2 to a demodulator 9 or, in the other switching position, the data output by the microcontroller 8 via a modulator 7 with a power stage transmits the primary coupling element 4. The power supply unit 3 must apply the energy for the main electronics 1, the sub-electronics 2 and the losses in the transmission link. A high-frequency coupling element is used as the primary coupling element 4. An RF oscillator 6 supplies the carrier oscillation for the energy and the data to the modulator 7 with the power stage.

In the reception phase, the microcontroller 8 of the main electronics 1 switches the switch S1 to the demodulator 9. The data energy coupled in by the sub-electronics 2 via the primary coupling element 4 is converted into a binary signal in the demodulator 9 and then evaluated by the microcontroller 8.

3 shows the block diagram of the partial electronics 2. The energy fed in periodically by the main electronics 1 via the secondary coupling element 5 is rectified in the energy recovery unit 11 and smoothed and stored in a capacitor. The energy supply of the partial electronics 2 takes place from this capacitor.

The data / energy control signal recovery unit 12 is constructed similarly to the energy store of the energy recovery unit 11, except that the time constant of the smoothing is considerably shorter in order to quickly detect changes in the energy / data signal. The generated control signal notifies a sequence controller 18 of the end of the energy phase.

The sequence controller 18 then starts a data direction changeover cycle or a useful data cycle. A switch S3 controlled by the sequence controller 18 enables the realization of the time windows belonging to the phases, in which a switch is made to a memory logic 17, while the data direction is determined by the switch S2 likewise controlled by the sequence controller 18.

The memory logic 17 has the task of transporting data from or to a data memory 16 at the appropriate times while evaluating the read / write signal from the sequence controller 18.

The clock for the sequence control 18 and the carrier oscillation for the data information running to the main electronics 1 via a modulator 13 are derived from a quartz-controlled RF oscillator 13 of the sub-electronics 2 or synchronized by the main electronics 1. When sent to the main electronics 1, the modulator 13 links the data binary signal from the memory logic 17 to the RF carrier.

Fig. 4 shows the transmission protocol of the energy and data transmission. The sequence controller 18 starts a switchover or data phase after the energy has been switched off. Common to both is the decay phase t _a . If the main electronics sends t _u energy in the following switchover phase, the data direction for all subsequent data phases is switched in the subelectronics (key) and the cycle is ended. If the main electronics does not transmit any energy in the switchover phase, a user data phase td _is started after the switchover phase t _u . In this phase, data is transferred from or to the partial electronics.

In the case of the transmission of data from the sub-electronics to the main electronics, the signal has a lower amplitude in order to keep the energy consumption of the sub-electronics low.

Each cycle ends with an energy refresh phase in which the main electronics again transmit energy to compensate for the energy consumed. The course of the supply voltage of the partial electronics can be seen in the lower diagram in FIG. 4. After the end of the energy phase, namely, the supply voltage V _cc decreases continuously until the end of the data transmission in the fifth section, in order then to rise again during the energy pulse in the energy refresh phase.

· (t_ges (I_verl + I_TE) + t_d · I_DTE )

wobei I_g der Effektivstrom am primären Koppelelement 4, t_ges die Gesamtzeit der Daten- und Energie-Phase, I_verl der Verluststrom in der Übertragungsstrecke, I_TE der Stromverbrauch des Schaltungsteiles der Teilelektronik, der über den gesamten Zeitraum aktiv ist, und I_DTE der Stromverbrauch des Schaltungsteiles der Teilelektronik, der nur während der Datenphase aktiv ist (t_d = Dauer Datenphase).The length of the energy pulse t _e should be set so that the following approximation applies:
t _e ≈

· (T _ges (I _ET + I _TE) + t _d · I _DTE)

where I _g the effective current at the primary coupling element 4, t _tot the total time of the data and energy phase, I _lose the leakage current in the transmission path, I _TE the current consumption of the circuit part of the sub-electronics that is active over the entire period, and I _DTE the current consumption of the circuit part of the sub-electronics that is only active during the data phase (t _d = duration of the data phase).

Fig. 5 shows the start-up phase after switching on the main electronics. This begins with the transmission of energy pulses with a fixed time period T _er . A time window T _{r is} provided between the energy pulses, in which the main electronics scans the coupling point after a reset acknowledgment of the partial electronics. If the partial electronics does not send a reset acknowledgment, energy pulses of length T _{er are} transmitted until the partial electronics sends a reset acknowledgment. A reset acknowledgment is issued by the sub-electronics when the supply voltage has reached the value sufficient for normal operation. The required energy pulse time t _e is then calculated by the microcontroller 8.

During the delivery of the energy pulses of constant length (T _er ), the supply voltage in the subelectronics rises continuously, whereby it drops slightly in the interim time windows T _r . When the required voltage level in the sub-electronics has been reached, the reset acknowledgment signal is used to switch to energy pulses of the length calculated by the microcontroller, which are virtually infinitely variable depending on the energy consumption of the sub-electronics and the efficiency of the adapted contactless coupling. The efficiency depends, for example, on the quality of the resonant circuit, the eddy current losses in the metal and / or the transmission distance. The proposed circuit achieves a large signal-to-noise ratio for the transmitted signals, since the binary-coded data are represented either by an existing energy signal (HIGH) or a missing energy signal (LOW). The signal-to-noise ratio and functional reliability are further increased by adapting the energy pulse length to changing transmission conditions at the beginning of a closing process. The transmission conditions can change in practice, for example due to misalignment between the coupling elements, due to a different sized air gap between the coupling elements and due to contamination between the coupling elements, as well as due to different materials and geometries in the lock, door and fittings.

The circuit enables information to be transmitted bidirectionally without the circuit complexity being significantly increased. The quartz clock-controlled microcontroller 8 enables synchronization and control of the transmission through the energy phase that takes place after each transmission. This means that there are practically no synchronization problems. Finally, only one coupling element is required for the energy and data transmission.

The figures 6 to 8 show an exemplary embodiment of a combined mechanically-electronically coded lock with a lock cylinder 10 which is connected to the main electronics 1 and with a mechanically coded key 23, in the key box 24 of which the Part electronics 2 is housed. The lock cylinder 10 is surrounded by a non-metallic lock interface module 20 which is pushed onto the lock cylinder over part of its length. The lock interface module 20 is seated only on the part of the lock cylinder 20 protruding from the lock case and thereby enables installation in an unmodified, conventional lock. The lock interface module is in one piece and has a key recognition switch 21 arranged in its upper part, an electrically controllable locking mechanism 22 arranged laterally on the lock interface module 20, and the lock-side primary coupling element 4 in the vicinity of the end face of the lock, which ends with the lock cylinder 10 Interface module 20. The lock-side coupling element 4 consists of a coil which has a ferrite core running parallel to the key insertion direction, the coupling element being provided above the lock cylinder. The ferrite cores of the coils are used for field focusing.

The lock-side coupling element 4 is isolated on the one hand from a possible metallic cover and, on the other hand, is brought as close as possible to the secondary key-side coupling element 5 located in the key ring 24.

Due to the optimal placement of the electronic coupling elements 4, 5 and the use of non-metallic material, the transmission losses are minimized.

The mechanical key recognition switch allows the device to be switched off when not in use, which enables a further increase in the number of locks per battery when operated on batteries. The positive engagement of the lock cylinder 10 by the lock interface module 20 makes complicated adjustment of the lock interface module unnecessary. The lock interface module 20 is fixed with a single screw.

The mechanically coded key 23 has the sequence control 18, the memory logic 17 and a serial EEPROM 25 in its casing 24. This contains the data memory 16 and can be programmed with the electronic coding via an n-fold connector 26. The use of a serial EEPROM 25 enables the number of pins of the programming connector 26 to be kept small.

The secondary coupling element 5 also consists of a coil which surrounds a ferrite core which, when the key 23 is inserted, runs coaxially to the ferrite core of the primary coupling element 4, a narrow air gap remaining between the coupling elements 4, 5 when the key 23 is inserted.

After programming the serial EEPROM 25 via the n-fold connector 26, the sub-electronics 2 contained in the key lock 24 are encapsulated together with the other components so that the cover 24 can no longer be opened without being destroyed. This makes unauthorized key programming impossible.

Claims (5)

1. Method for contactless energy and data transmission, in particular for a mechanically / electronically coded lock, between a power-supplied main electronics and a non-power-supplied partial electronics with an energy storage circuit via coupling elements each connected to the main or partial electronics,
characterized,

- That energy or data are alternately transmitted via the coupling elements and

that the transmitted energy is automatically adapted to the energy consumption of the partial electronics, which is dependent on varying transmission losses, by varying the length of the energy pulse,

- In that after the main electronics have been switched on, energy pulses of a predetermined length of time are transmitted repeatedly until a reset acknowledgment signal of the sub-electronics is present and by energy pulses with a length depending on the energy consumption are transmitted after the presence of a reset acknowledgment signal. 2. The method according to claim 1, characterized in that the data flow direction in the sub-electronics is determined by the main electronics and that the data transmission takes place bidirectionally, the starting times of the data sequences in the sub-electronics being synchronized with the processes in the main electronics. 3. The method according to any one of claims 1 or 2, characterized in that the data are binary coded according to the ASK method (amplitude shift keying). 4. Mechanically and electronically coded lock, with a lock cylinder, with main electronics, and with a key, which has both a mechanical and an electronic coding, which is programmed in a sub-electronics arranged in the key box, whereby data and energy transfers without contact Coupling elements take place which are arranged on the one hand on the end face of the lock cylinder facing the key and on the other hand on the key in such a way that the coupling elements face each other when the key is inserted, in particular for using the method according to one of claims 1 to 3,
characterized,
that the lock cylinder (10) is enclosed by an attachable, integral, non-metallic lock interface module (20) over a certain length, which is a key recognition sohalter (21), an electronically controllable locking mechanism (22) and the lock-side coupling element (4). 5. Lock according to claim 4, characterized in that the electronic coding of the key (23) in a serial electronic memory (25) via an n-fold connector (26), which is no longer accessible non-destructively after programming and encapsulation.

Images