EP3188136A1

EP3188136A1 - Electronic door lock and operation method thereof

Info

Publication number: EP3188136A1
Application number: EP16154026.5A
Authority: EP
Inventors: Manuel PEREIRA RODRIGUES; Carla Marisa MACHADO AFONSO; Ana Rosanete LOURENÇO REIS
Original assignee: Marques SA
Current assignee: Marques SA
Priority date: 2015-12-28
Filing date: 2016-02-03
Publication date: 2017-07-05

Abstract

Electronic door lock and operation method thereof comprising operation under low power mode; waiting for user proximity or user touch; if a user proximity or touch is detected, exiting the low power mode and proceeding; if a user wireless device is available, verifying if the device is authorized to unlock the electronic door lock; if authorized, unlocking the electronic door lock. Furthermore communicating in real-time with a central server for interrogating a database on whether the user wireless device is authorized. Furthermore finding user devices that are in a predetermined number of the most recently authorized devices; and if none is found, searching for other user devices. A capacitive sensor is placed on a front plate of the electronic door lock and the remaining electronic parts on the back, such that the capacitive sensor detects user proximity or touch on the front of the door lock but not on its back.

Description

Technical field

The present disclosure relates to an electronic door lock, in particular to an electronic door lock operable by an electronic device in the vicinity of the door lock, further in particular the device being a mobile device like a mobile phone.

Background Art

Document US2011082882 describes electronic devices for accessing or otherwise controlling functions of devices and more particularly to a system and method wherein the devices can be operated by a wireless electronic key. The electronic key utilizes GPS position data to decide if it is enabled for operation. To that end, the electronic key includes additional registers or memory space for storing limiting parameters concerning the relative position of the key for deciding whether the key should be enabled or disabled. The position limiting data may be downloaded to the key during a refresh operation when the key is placed in a cradle of the key management system. Alternatively, the position limiting data may be received by the key wirelessly via a transceiver when the key is within a field.
Document EP2220811 describes a method and device of receiving secure information from a mobile communication device to control an authorisation device in a security system, including the steps of the authorisation device: receiving an electronic key transmitted by the mobile communication device; decoding the key using a decoding technique to retrieve a hidden token; and decrypting the retrieved token to retrieve the secure information. The connection may be wireless, in particular Bluetooth, Wi-Fi, NFC or Zigbee. The method also includes that whereupon a negative compliance determination, the mobile communication device is placed on a list of invalid devices. The secure information may include access rights information to provide access to an entry point in the security system. The secure information may include function information for controlling functions on the authorisation device and/or a sequential serial number.
The method of EP2220811 also includes the authorisation device further including control means to control access to an entry point in the security system and arranged to: retrieve the access rights information from the secure information; determine if the retrieved access rights information is valid, and control the entry point to provide access upon a positive determination. The device may include a wake sensor, which can be a button, pressure pad, infra-red beam or proximity sensor to cause the authorisation device to wake up and activate a Bluetooth interface.
Document WO2012073265 describes a method and device comprising a computer provided with means for the entry and sending of data and requests for keys for opening specific electronic locks, a server provided with means for receiving requests and information from said computer, means for generating keys and means for radio frequency transmission of strings of information, a device of the type of a mobile phone provided with an NFC (Near Field Communication) radio frequency signal transceiving unit, and at least one respective electronic lock provided with an element for receiving radio frequency signals emitted by said device arranged close to said element.
Document WO2012073265 describes a method for the control and management of keys for access to spaces delimited by electronic locks and the like. It also relates to a device that can be enabled as a key according to the method. The communication between lock and device is by NFC (Near Field Communication).
Document WO2010125306 describes a lock provided with electronic circuits for transmission/reception via NFC and electric circuits for controlling mechanical locking/unlocking members, and a mobile phone provided with circuits allowing same to operate in NFC mode, using a portable telephone as a power source for remotely supply power to the lock, i.e. for transmitting energy to it in a non-galvanic manner via the NFC circuits. In case of failure of the inner battery of the lock, the latter can no longer produce any magnetic field. The absence of magnetic field, or a field of insufficient intensity, can be easily detected by the telephone when approaching the target area. In this case, the telephone is switched from the "card emulation mode" to the "reading mode", generating a magnetic field sufficient to charge a buffer capacitor provided inside the lock.
Document US2013088320 describes a wireless network hotel room management system includes a communications network. A guest room unit is situated in each guest room and is in data communication with the network. A housekeeping module is in communication with the network. The computer monitors real time status of the room. Each guest unit is configured to receive projected absence data from a guest and to communicate the same to the computer through the communications network. The system includes a room reservation module for reserving a room and receiving a room key.
Document US2007204663 describes electronically controlled door lock system, comprising: a door lock for locking and unlocking a door in response to an input signal from a key, the door lock having predetermined inherent functions; and a function expanding device having additional functions other than the predetermined inherent functions of the door lock and being replaceably attached to the door lock.
The door lock of US2007204663 comprises an authentication unit for authenticating the key of the door lock, a multi-purpose interface device for separably connecting the function expanding device to the door lock, a multi-purpose interface device control unit for controlling an operation of the function expanding device, a controller unit for controlling a whole operation of the door lock, and a driving unit for causing the door lock to perform the locking and unlocking function under the control of the controller unit.
These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure.

General Description

The present disclosure relates to an electronic door lock, in particular to an electronic door lock operable by an electronic device in the vicinity of the door lock, further in particular the device being a mobile device like a mobile phone.
in particular, it aims at providing real time communication between individual locks and central server with access control management software, Integration in a hotel management system with self-check-in possibilities, allowing customers to use their own smartphone as an authentication device, obtaining a lock with anti-tampering and long-life duration mechanism.
In authentication systems currently available, the communication between the locks and a central server is not done in real time, but act in a so called 'false network system' using standalone locks along with a management software in order to program the authentication devices on the front-desk. Contrary to this kind of systems - where each lock has an internal memory that records entry data but then needs a portable master device to log its data in computer software - the present access control system allows each lock to connect individually with a central control management software, updating data and configuration settings in real time. In order to avoid the user logging on so called "false network system", the manager has to download each lock data with a specific device in an embodiment.
The market for access control has seen a constant grow in the demand of electronic door locks for some years now. All kinds of different products are on offer covering all the necessities of specific markets. However most of the available locks are simple standalone locks which do not allow for easy and regular updates nor recovery of log data of the lock. Changing awareness of the nature of access control and authentication, besides the necessity for managing and analysing individual lock data, needs a more elaborate system, especially in larger hotels and companies.
The solution presented here allows a real time control over all locks, which are connected in a network to a common central server. This system relies in an embodiment on 4 major components: an authentication device, the lock itself, a router and a central server with control management software. The working principle of this system is based namely on wireless communication between each individual lock and a router. The router, which can group up to ten individual locks in an embodiment, is part of a wired Ethernet network in an embodiment and is connected to a central server in an embodiment with proprietary software that allows configuring and controlling all the locks in the network.
This solution is opening a new range of possibilities regarding the user friendliness of the interface between the user and the lock. Two different technologies are applied in particular in this interface, creating two possible variants of the product, one using NFC technology for authentication and the other Bluetooth Low Energy (BLE) technology. Both allow the use of smartphones, in an embodiment with specially developed applications, as a personal device for authentication. The NFC version, targeted to smartphones with Android OS, can also be used with standard NFC cards. The BLE version, adapted to function with iOS (iPhone), can also operate with a specific developed electronic FOB device.
The alliance between a network system with real time updating and authentication with a smartphone creates new possibilities of interaction with clients in the hotel market. Customers can perform check-in by themselves, on their smartphone, before or at the moment of arrival and receive the necessary entry code immediately. This way, customers can avoid the long and annoying waiting time for check-in at the hotel lobby. Furthermore, this code will only allow the entry of the room during the booked period, after which it will be automatically disabled.
It is disclosed a method for operating an electronic door lock, comprising the electronic door lock:

placing the electronic door lock under a power-saving mode;
waiting for user proximity or user touch of a front plate of the electronic door lock;
if a user proximity or touch is detected, exiting the power-saving mode and proceeding with the method;
if a user wireless device is available, verifying if the user wireless device is authorized to unlock the electronic door lock;
if authorized, unlocking the electronic door lock.

This has the advantage of avoiding powering up the device when a user is merely approaching or touching the lock by the inside (the back part of the lock), because the user either is able to open the door manually or may even not wish to open the door because, for example, the room is small and the user passes frequently close by the inside part of the door lock.
An embodiment comprises, in order to verify if the user wireless device is authorized to unlock the electronic door lock, the electronic door lock:

communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door.

This has the advantage of continuously keeping updated in real-time the knowledge if a specific device is authorized, or not.
An embodiment comprises the electronic door:

storing, in an internal memory, data regarding a predetermined number of the most recently authorized user wireless devices such that these user wireless devices will be able to unlock the door even if no communication is possible with the central server.

This has the advantage of maintaining door operation even if communication fails or the central server is not available, for example because of a power failure.
An embodiment comprises for detecting if a user wireless device is available:

finding user wireless devices that are in said predetermined number of the most recently authorized user wireless devices;
if none is found, searching for other user wireless devices.

This has the advantage of identifying much faster the presence of authorized devices because detection starts by the devices that have the highest likelihood of being authorized (those that were previously authorized).
In an embodiment, if the user wireless device is not authorized to unlock the door, the electronic door lock communicates in real-time with a central server for updating a central server database with count of times the user wireless device has not been authorized to unlock a door, such that the user wireless device will no longer be authorised to unlock a door after a predetermined number of times.
In an embodiment, the user proximity or touch is detected by a capacitive sensor.
In an embodiment, the capacitive sensor is placed on a front plate of the electronic door lock and the remaining electronic parts of the electronic door lock are placed on the back of the electronic door lock, such that the electronic door lock detects user proximity, or user touch, on the front of the door lock but not on the back of the door lock.
In an embodiment, the user wireless device is a Bluetooth or a Near Field Communication wireless device.
An embodiment comprises, when communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door, appending a data field signalling the battery status of the electronic door lock.
An embodiment comprises, when communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door, appending a data field signalling whether the electronic door lock has a pending command in execution.
It is also disclosed a non-transitory storage media including program instructions for implementing an electronic door lock, the program instructions including instructions executable to carry out any of the disclosed methods.
It is also disclosed an electronic door lock comprising a wireless data module, a proximity sensor, a data processing module, a battery module and said non-transitory storage media.

Brief Description of the Drawings

The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of invention.

Figure 1 : Schematic representation of an embodiment of the architecture of the electronic lock system.
Figure 2 : Schematic representation of an embodiment of the architecture of the configuration of the electronic lock.
Figure 3 : Schematic representation of an embodiment of the flowchart for the NFC version.
Figure 4 : Schematic representation of an embodiment of the flowchart for the BLE version.
Figure 5 : Schematic representation of an embodiment of the 3D view of the lock mechanism.
Figure 6 : Schematic representation of an embodiment of the 3D view of the disengaged mechanism.
Figure 7 : Schematic representation of an embodiment of the 3D view of the engaged mechanism.
Figure 8 : Schematic representation of an embodiment of the capacitive sensor.

Detailed Description

The electronic lock system of the authentication system adopts a modular architecture comprising four main elements (see Fig. 1 ):

Authentication device: either smartphone enabled with NFC or Bluetooth LE technology, Bluetooth LE electronic fob or a standard NFC card.
Electronic door lock with either Bluetooth LE or NFC communication interface. Routers
Central server with access control management software.

The authentication can be done with smartphones equiped with NFC (Near Field Communication) or BLE (Bluetooth Low energy) tecnology, or by the use of standard cards or tags for the NFC version.
The electronic lock controls the command to engage and disengage the mechanism. The electronic circuit is responsible for reading the authentication key sent by the authentication device. The validation key is stored in a database on the central server.
The router module is responsible for re-routing the wireless communications (e.g. MiWi) from the electronic locks to the central server, e.g. through TCP/IP communication protocol, as well as transmitting the response generated on the opposite way. The central server validates each authentication attempt. Has a local data base responsible for permissions management and event recording.
The electronic lock system relates to the electronic door lock itself, a router, a central server, authentication devices, firmware and software. The system can comply multiple routers, each one communicating in an embodiment with up to 10 locks. Each router could use a different central server. The central server can communicate with multiple routers.
The electronic door lock consists in an embodiment of a common integrated electronic circuit board that through the application of specific firmware and a specific communication module, can either use Bluetooth LE or NFC as a communication protocol between the lock and an authentication device.
The configuration of the electronic lock in an embodiment is presented in Fig. 2 . The implementation of the control board adopts embedded electronics featuring micro-controllers from Microchip.
Interfacing with the user happens in an embodiment through a pair of LEDs, one green and one red, on the front panel of the lock, an internal buzzer and a capacitive proximity detector, apart from the Bluetooth or NFC communications between the lock and the authentication device. Communication between the electronic lock and the router uses the MiWi wireless communication protocol (Microchip's proprietary solution). The lock is powered by four standard high quality AA batteries.
The router is the bridge between the MiWi network and the Ethernet cabled network. Each lock communicates with a router, and each router communicates with the central server through a TCP/IP protocol. The developed hardware is based on Microchip micro-controllers. The router is powered directly from a DC power supply.
The electronic lock system functions in an embodiment according to the following procedure:

The user approximates an authentication device or his own hand to the front panel of the lock. This action is detected by the capacitive proximity sensor which activates the procedure for detection of an authentication device.

According to the installed technology, the lock either uses an NFC or Bluetooth LE protocol to scan for a compatible authentication device. The NFC version is capable of communicating with a Mifare card or Android phones in HCE mode.
The Bluetooth LE version is configured for communicating with a proprietary Bluetooth LE electronic fob or iPhones in peripheral mode.
If a compatible device is detected an authentication key is requested.
If compatible authentication key is present, communication with the router will be established in order to request validation of this authentication key by the central server.
The server replies to the door lock, via the router, with the validation result.
The door lock then acts according to this result, either unlocking the mechanism when a valid authentication key was detected, or leaving the lock mechanism in idle and communicating a non valid request of the user.
This complete authentication process is described with more detail in the flowcharts presented in Fig. 3 and Fig. 4 .
The electronic lock features two different authentication possibilities, although not simultaneously available, NFC and BLE.
The authentication devices can use different technologies available in multiple platforms, for example as indicated on the following table.

Version Authentication Platform

NFC Card/TAG MIFARE 1K

Smartphone Android 4.4+

BLE Smartphone Android 5.0+^a

iOS 6+
Fig. 3 presents the flow chart regarding a NFC embodiment, where the following are represented:

START: The system is initiated
INITIALIZE CLOSE DOOR: the mechanism is moved to closed position
LOW ENERGY MODE: lock is on sleep mode, maximizing energy savings
USER CARD PRESENCE: an user card is detected
HAVE ACCESS: evaluates if the read key allows access
UNLOCK THE DOOR: the mechanism is activated to engage the knob
TIMER1: starts timer number 1
LOCK THE DOOR: the mechanism is activated to disengage the knob
IS THE DOOR CLOSED: checks if the door was correctly closed
WARN USER: warns the user the lock wasn't correctly closed
TIMER2: starts timer 2
WARN CENTRAL: sends a warning to the central server

Fig. 4 presents the flow chart regarding a BLE embodiment, where the following are represented:

START: The system is initiated
INITIALIZE CLOSE DOOR: the mechanism is moved to closed position
LOW ENERGY MODE: lock is on sleep mode, maximizing energy savings
USER TOUCH: capacitive sensor is activated
FOUND BLE DEVICES: lock tries to find nearby Bluetooth devices
HAVE ACCESS: evaluates if the read key allows access
UNLOCK THE DOOR: the mechanism is activated to engage the knob
TIMER1: starts timer number 1
LOCK THE DOOR: the mechanism is activated to disengage the knob
IS THE DOOR CLOSED: checks if the door was correctly closed
WARN USER: warns the user the lock wasn't correctly closed
TIMER2: starts timer 2
WARN CENTRAL: sends a warning to the central server

The lock is designed in an embodiment in such a way that all mechanical components of the locking mechanism are mounted on the same side of the lock and physically protected with a steel plate in order to block access from the exterior. This configuration prevents possible tampering with the mechanism of the lock and blocks attempts to manually override the authentication procedure. See fig. 5-7 .
The locking mechanism functions in an embodiment through the physical engagement and disengagement between the knob and the spindle. In this system there are two separate hubs, working on the same axis of rotation. Those hubs can become connected through a spring mounted pin. This engagement is achieved by a sequence of movements, starting with the rotation of a little electric motor that is connected to a worm wheel, whose rotation makes the tip of an "L" shaped spring slide along its channels. This spring has a remote center of rotation, making that as one tip slides along the worm, the other is pushing a "U" shaped slider upwards. This slider is constrained to vertical movement and pushes the pin to engage the separated hubs. With both hubs engaged the user is able to operate the spindle and open the door.
For the electronic system, the alternatives that may be applied are:

Use of micro-controllers from different manufacturers;
Use of a different communication protocol between the electronic lock and the router, and between the router and the central server (replacing MiWi and TCP/IP, for example);
Use of a different authentication logic and procedure;
Use of different authentication device besides a smartphone, an electronic fob or an NFC card;
Use of a different method to activate the scanning of compatible authentication devices.

The following are alternatives to the internal locking mechanism:

Changing the principle of operation to a system with a hub that becomes locked when the lock is idle (the user is unable to move the door handle), which unlocks only with a positive authentication (the user can move the door handle engaging the lock).
Replacement of the DC motor with a solenoid.
Using another kind of transmission movement or gearing.

The advantages of this electronic system are:

The use of a proprietary communication protocol (from Microchip™) between the lock and the router. As this communication protocol is not widespread, is it less likely to be broken (hacked) than a standard protocol;
Regular smartphones, with NFC or Bluetooth LE communication technology,
can be used as an authentication device;
The authentication procedure does not use the NFC card's NUID, but uses a number generated by the central server instead. This allows the central server to guarantee that there is no overlap in IDs.

The advantages of the present locking mechanism regarding other solutions, are:

When the system is idle the moving parts are disengaged, allowing the knob to have a free movement until its end of travel. This way the user is not tempted to force the door handle and thus applying unnecessary strain and wear on the different components of the locking mechanism.

The design of the slider, a closed "U" shape, guarantees permanent contact with the hub locking pin, even if the knob is turned.
Due to the disengagement of the system when in idle, the user could eventually maintain the knob in "opening" position during the access procedure and thus keeping the pin removed from its engagement position. The incorporation of a spring between the worm wheel and the slider allows the top part of the spring to slide across the worm wheel and to load the spring in case the sliding mechanism is unable to move. If the user releases the knob, the pin will return to its normal position and will engage the hubs thanks to the pressure kept by the spring. If by any change the user doesn't release the knob, when the motor turns in the opposite direction, the spring will unload and return to its normal idle position, avoiding possible jams.
The design of the spring and the elastic properties of the material minimize potential jams and allow for recovery to the original position after eventual malfunctioning of the sliding mechanism
The design of the base structure of the lock protects the sliding mechanism and all the other mechanical components. This design layout prevents tampering with the lock's mechanism in an attempt to manually override the authentication procedure.
The lock and all the components are interchangeable and are designed to allow for retrofitting on different kind of doors. By reversing some of the components the lock can be used on doors opening to the left side as well as to the right side.
The lock interfaces in an embodiment with the user by:

two 3mm LEDs, one red and one green, communicating the result of the authentication attempt. Blinking together is an indication that the attempt is being processed;
one buzzer, providing auditive feedback, complementing the LEDs;
a capacitive proximity detector, used to wake up the authentication system when approached by the user of the lock.

The layout of the capacitive sensor is shown in Fig. 8. The central pad serves as the capacitive sensor and the exterior pad as the signal guard.
The electronic lock is preferably not connected to the electricity grid and uses standard non-rechargeable type AA batteries for energy supply. The necessary capacity of the batteries for the lock operations for 27 operations a days for a 6 month period or 10.000 cycles, is well within the limits of the maximum capacity of standard Lithium-Ion type AA batteries.
The system monitors in an embodiment two levels of battery capacity in order to inform the user about the state of the batteries. Upon reaching the first level, a signal is transmitted to the central server and the user is warned about the necessity to change the batteries. Upon reaching the second level the door is automatically locked and the system shut down.
For a NFC module, an OEM module version PN532 NFC RFID module V3 is used in an embodiment, with the following characteristics:

communication through I²C, SPI or HSU (High Speed UART);
supports MIFARE, ISO/IEC 14443-4, Innovision Jewel and FeliCa cards;
supports P2P communication (NFCIP-1) and card emulation;
dimensions: 42.7mm x 40.4mm x 4mm;
reading distance up to 7cm;
integrated antenna;
2.7 to 5.4 V power supply.

This module is based on an integrated circuit from NXP™, code PN532, whose maximum consumption is around 77mA. In "sleep mode" the module is completely shut down and energy consumption is almost irrelevant.
A Bluetooth LE module RN4020 from Microchip Technologies is used in an embodiment with the following characteristics:

compatible with the standard Bluetooth Core v4.1, also known as Bluetooth Low Energy or Bluetooth Smart;
UART interface command;
3.0 to 3.6V power supply;
Low energy consumption: typically around 12 mA

The lock communicates with the central server through a proprietary router. This router uses in an embodiment the wireless MiWi protocol to communicate with the lock. MiWi uses considerable less energy than the more prevalent Wifi protocol. Communication between the router and the central server happens in an embodiment through a regular Ethernet network.
Visual feedback of the router with the user is provided in an embodiment through use of three LEDs:

one blue LED indicating that the device is connected to the power supply;
one yellow LED, blinking indicates pending MiWi messages
one green LED indicating the system is in set-up mode.

The router can be configured in an embodiment through the Web page made available by the device. It is possible to define net configurations as well as the IP address and the server port. To make this first configurations the router must connect to a computer. Additionally, the router has a reset button. The system resets to the original factory definitions when pressed for more than a few seconds.
The locks and the routers use in an embodiment the MiWi™ protocol for communication. This allows the use of a different antenna with a more balanced energy consumption but with a smaller reach. This configuration complies in an embodiment with the preset goal of minimum 10.000 interactions between the lock and the router in a six month period. Communication between the routers and the central server is done by Ethernet through the TCP/IP protocol.
Both protocols require in an embodiment unique MAC addresses. For stricter control, these are purchased directly to IEEE and programmed on the micro controllers. Two addresses will then have to be purchased to IEEE: numbers EUI64 for the MiWi communication between the locks and the routers; numbers EUI48 for the TCP/IP communication of the routers.
Considering the characteristics of the mechanical solution, a central circuit board was developed in an embodiment containing all the main critical components. This configuration further allows for a connection with different authentication modules, either NFC, BLE or both technologies simultaneously. According to the system requirements, the electronic central command is in an embodiment common to both authentication solutions, being only necessary to change the microcontroller firmware and connect the corresponding reading module (NFC or BLE).
Independently of the version, the lock features in an embodiment the following characteristics:

the system is put in energy saving mode (sleep mode) when its not being used;
the proximity detector wakes the system and starts the authentication procedure;
detects two levels of low battery status (15% and 1%) reporting to the central server;
detects if the door was correctly closed after an entry, reporting to the central server;
visual (red and green LEDs) and sound (buzzer) feedback to signal the opening and closing of the door, reading errors and low battery;
records the last valid authentication to allow access even when the central server operational.

Low height components, such as SLW-108-01-F-S from Samtec were applied in an embodiment. The proximity detection uses in an embodiment a copper pad connected to the PCB through a JST SM02B-SRSS-TB connector. This option uses two signals, one for proximity detection and the other to protect the signal detection, allowing it for a wider reach. The electric motor is connected in an embodiment with a SM02B-SRSS-TB connector. The connection to the batteries foresees in an embodiment the possible introduction of a reset button, using the SM04B-SRSS-TB.
A new circuit board was also developed in an embodiment to the Bluetooth module, allowing it to be connected or not depending on the desired version.
The router is composed in an embodiment of a single circuit board and is used as a communication bridge between the locks and the central server, using two communication protocols:

Ethernet for the wired connection with the central server;
MiWi for the wireless connection with the locks.

This device has, in an embodiment, the following connections:

One RJ45 connector for the Ethernet connection, as the router houses a local configuration address allowing to configure connections to the local server;
One DC connector for the power supply;
One reset button.

The system is, in an embodiment, capable of working with 3 distinct groups of users: Clients, Staff and Administrators, with the permissions management being made through the central server.
The electronic locks are, in an embodiment, capable of recording the last accepted entry key (or keys) of each category, to allow access to the rooms even when there is no connection to the central server. The Bluetooth version also saves the three last used MAC addresses to give them priority when searching after being woken up. This is necessary when too many devices are within reach of detection. After every battery replacement, in an embodiment, the system will start by analyzing the state of its components, including the communication module associated with each version.
If the router wireless connection is not available or out of reach, the lock will emit a sequence of two downward tones in an embodiment. If the respective communication module is impossible to initiate, the lock will emit a downward sequence of 3 tones. On both cases the system will blink the red LED.
If the initialization is successfully completed the lock will emit a sequence of two upward notes and will blink the green LED in an embodiment.
After the initialization process, the lock will stay on sleep mode until it is awaken by the proximity of someone or some device in an embodiment.
As soon this happens, the lock starts searching for new devices through BLE or NFC. Upon detection it will try to obtain a key and sent it to the central server, who is responsible for its validation.
The NFC version is capable of communication with MIFARE cards and with an Android App in an embodiment.
The Bluetooth version reads keys from nearby devices, which can be either be smartphones or specific devices. To increase security, the device must only provide its key after writing a lock password on a specific "characteristic". For example:

Password: 6f6e717762656e66;
Characteristic (reader authentication): 0c053983-566d-4539-b1a2-4da1ba8c3fc4;
Characteristic (access key): 0c053983-566d-4539-b1a2-4da1ba8c3fe3.

For a higher security, the keys 00-00-00-00-00-00-00-00 and FF-FF-FF-FF-FF-FF-FF-FF aren't accepted by the central server.
For communications between the routers and the central server, a hexadecimal message format was defined. This format includes 4 main parts:

MAC address of the lock/message destination;
Sent command (1byte);
Sent parameters (variable length);
CRC/checksum confirmation.

The command distribution may be as follows:

Commands

Direction	CMD range
Server -> Lock	0x00 - 0x7F
Lock -> Server	0x80 - 0xFF

Commands: Lock -> Server

Command	CMD	Parameters [Size]	Description
Low batteries	0Xbb	-	Indicates an approximate level of 15%
Open door	0xDA	-	Reports the central that the door is open for too long
Locked door	0xDC	-	Indicates that the door was closed
			after the previous warning
Verify key	0xBF	Key [8]	Sends the key to the server for verification
Clear to send	0xC0	-	Indicates the server that the next command can be sent
Boot completed	0xBC	-	Indicates the server that the boot sequence was successful
No battery	0xB0	-	Indicates the server that the lock is shutting down due to lasck of battery power

For each functionality, there are two distinct commands, one with the possible indication of a pending command and another without. Their distinction may be done through the least significant byte of the command. The answer to the key verification may include a parameter with multiple information about the lock and its user.

Commands: Server -> Lock

Commands	CMD	Parameters [Size]	Description
Key verification	Ox63	Answer [1]	Tells the lock if the key is valid or not
Key verification	Ox62	Answer [1]	Tells the lock if the key is valid or not
Key verification	Ox73	New shadow key [8]	Changes the shadow key
Key verification	Ox72	New shadow key [8]	Changes the shadow key

The authentication system allows:

to electrically command a group of locks through a centralized access control system;
to use wireless authentication methods, NFC and BLE;
communication between each lock with a router (by MiWi) communication of the router with the central server by Ethernet connection.

In terms of hardware the system may be made of two modules for which specific electronics and firmware were developed. The system has a modular and flexible architecture, i.e., both authentication solutions use the same PCB, where the corresponding authentication module and respective firmware are connected, this way maximizing the production of PCBs.
The developed solution for the lock module uses AA batteries able of lasting 6 working months, considering more than 27 openings per day (equivalent to 10.000 openings per year). The developed solution for the router module uses a DC net power supply in an embodiment and requires an Ethernet connection to connect to the central server.
The term "comprising" whenever used in this document is intended to indicate the presence of stated features, integers, steps, components, but not to preclude the presence or addition of one or more other features, integers, steps, components or groups thereof.
Flow diagrams of particular embodiments of the presently disclosed methods are depicted in figures. The flow diagrams do not depict any particular means, rather the flow diagrams illustrate the functional information one of ordinary skill in the art requires to perform said methods required in accordance with the present disclosure.
It will be appreciated by those of ordinary skill in the art that unless otherwise indicated herein, the particular sequence of steps described is illustrative only and can be varied without departing from the disclosure. Thus, unless otherwise stated the steps described are so unordered meaning that, when possible, the steps can be performed in any convenient or desirable order.
It is to be appreciated that certain embodiments of the invention as described herein may be incorporated as code (e.g., a software algorithm or program) residing in firmware and/or on computer useable medium having control logic for enabling execution on a computer system having a computer processor, such as any of the servers described herein. Such a computer system typically includes memory storage configured to provide output from execution of the code which configures a processor in accordance with the execution. The code can be arranged as firmware or software, and can be organized as a set of modules, including the various modules and algorithms described herein, such as discrete code modules, function calls, procedure calls or objects in an object-oriented programming environment. If implemented using modules, the code can comprise a single module or a plurality of modules that operate in cooperation with one another to configure the machine in which it is executed to perform the associated functions, as described herein.
The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof. The above described embodiments are combinable. The following claims further set out particular embodiments of the disclosure.

Claims

Method for operating an electronic door lock, comprising the electronic door lock:
placing the electronic door lock under a power-saving mode;

waiting for user proximity or user touch of a front plate of the electronic door lock;

if a user proximity or touch is detected, exiting the power-saving mode and

proceeding with the method;

if a user wireless device is available, verifying if the user wireless device is authorized to unlock the electronic door lock;

if authorized, unlocking the electronic door lock.
Method according to the previous claim comprising the electronic door:
storing, in an internal memory, data regarding a predetermined number of the most recently authorized user wireless devices such that these user wireless devices will be able to unlock the door even if no communication is possible with a central authorization server.
Method according to the previous claim comprising for detecting if a user wireless device is available:
firstly, finding user wireless devices that are in said predetermined number of the most recently authorized user wireless devices;

secondly, and only if none is found, searching for other user wireless devices.
Method according to any of the previous claims comprising, in order to verify if the user wireless device is authorized to unlock the electronic door lock, the electronic door lock:
communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door.
Method according to any of the previous claims wherein if the user wireless device is not authorized to unlock the door, the electronic door lock communicates in real-time with a central server for updating a central server database with count of times the user wireless device has not been authorized to unlock a door, such that the user wireless device will no longer be authorised to unlock a door after a predetermined number of times.
Method according to any of the previous claims wherein the user proximity or touch is detected by a capacitive sensor.
Method according to the previous claim wherein the capacitive sensor is placed on a front plate of the electronic door lock and the remaining electronic parts of the electronic door lock are placed on the back of the electronic door lock, such that the electronic door lock detects user proximity, or user touch, on the front of the door lock but not on the back of the door lock.
Method according to any of the previous claims wherein the user wireless device is a Bluetooth or a Near Field Communication wireless device.
Method according to any of the previous claims comprising, when communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door, appending a data field signalling the battery status of the electronic door lock.
Method according to any of the previous claims comprising, when communicating in real-time with a central server for interrogating a central server database on whether the user wireless device is authorized to unlock the door, appending a data field signalling whether the electronic door lock has a pending command in execution.
Non-transitory storage media including program instructions for implementing an electronic door lock, the program instructions including instructions executable to carry out the method of any of the claims 1-10.
Electronic door lock comprising a wireless data module, a proximity sensor, the non-transitory storage media of claim 11, a battery module and a data processing module arranged for executing said program instructions.
Electronic door lock according to the previous claim comprising a capacitive sensor for detecting the user proximity or touch.
Electronic door lock according to the previous claim wherein the capacitive sensor is placed on a front plate of the electronic door lock and the remaining electronic parts of the electronic door lock are placed on the back of the electronic door lock, such that the electronic door lock detects user proximity, or user touch, on the front of the door lock but not on the back of the door lock.
Electronic door lock according to the previous claim according to the previous claim wherein the capacitive sensor comprises a central pad electrode and an outer electrode arranged as a signal guard around the central pad electrode, in particular the central pad electrode and the outer electrode having a quadrangular shape.