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(11) | EP 2 355 067 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | System and method for locating people and/or objects inside buldings |
| (57) A system for locating people and/or objects inside buildings (40), comprising a series
of radio controlled lighting apparatuses (1-7), one or more user's radio devices (8,
9), an electronic unit (10) of control and management of the system and display of
the position of user's radio devices (8, 9) and one or more portable terminals (11,
14) for displaying the position of user's radio devices (8, 9); the lighting apparatuses
(1-7) are installed at known and prefixed positions inside the building (40) and include
a corresponding radio transceiver with FH-DSSS modulation, provided with circuits
(RSSI, ToF) suitable to measure, for each message or radio signal sent or received,
the amplitude of the received radio signal and/or the propagation delay between a
first radio signal (TXA) transmitted by a first transceiver and a second radio signal
received (RXB) by a second transceiver due to the transmission of the first radio
signal (TXA), in order to get an estimate of the distance (D) existing between a lighting
apparatus (1-7) and another.
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[0001] The present invention generally relates to a system and method for locating people and/or objects inside buildings.
[0002] More specifically, the invention concerns a system for locating people and/or objects, provided with a particular radio frequency device, inside buildings or complex industrial/commercial structures into which a series of lighting apparatuses, each which equipped with a proper radio transceiver, are installed.
[0003] Emergency lighting systems are currently known, which include a series of lighting apparatuses, wherein each apparatus is provided with devices for the self-diagnostics of the correct operation.
[0004] Emergency lighting systems with centralized diagnosis are also known, wherein a central management unit collects all the diagnostics information and also allows the operator to send commands to the various lighting apparatuses in order to synchronize the check tests of the proper operation and configure the apparatuses themselves.
[0005] Ordinary lighting systems are also known wherein each lighting apparatus incorporates a radio control feeder able to receive via radio from an electronic unit switching on, switching off, dimmer setting, etc. commands and send to the electronic unit itself, always via radio, diagnostics information and information about the actually consumed energy.
[0006] However, in these systems, the radio communication only replaces the physical connections among the various lighting apparatuses and electronic system unit, only allowing to get a system in which the communication is wireless.
[0007] Purpose of the present invention is to expand the functions offered by a radio control lighting system and, in particular, to create a system for locating people and/or objects inside buildings based on a set of lighting apparatuses equipped with radio transceivers, which at the same time allows to get the centralization of the diagnostics information and centralized control of the lighting apparatuses themselves and all their functions.
[0008] Other purpose of the present invention is to provide a system for locating people and/or objects inside buildings, which allows a better system installation and simpler maintenance, compared to the traditional locating systems.
[0009] Another purpose of the invention is to create a system for locating people and/or objects inside buildings, which is particularly efficient, reliable and sure, as well as easy to manage and with limited costs, compared to the prior art, in consideration of the achieved advantages.
[0010] Further purpose of the invention is to indicate a method for locating people and/or objects inside buildings, which can be implemented through the locating system mentioned above.
[0011] These and other purposes are achieved by a system for locating people and/or objects inside buildings, according to the attached claim 1, and a relative locating method, according to the appended claim 20.
[0013] Further purposes and advantages of the present invention will become more apparent from the following description, referring to a preferred and illustrative, but not limited, embodiment of the system for locating people and/or objects inside buildings, and from the attached drawings, where:
- figure 1 shows schematically a system for locating people and/or objects inside buildings, according to the present invention;
- figure 2 is a schematic exploded view of one of the radio control lighting apparatuses used in the system for locating people and/or objects inside buildings, according to the present invention;
- figure 3 is a schematic perspective view of a radio device used in the system for locating people and/or objects inside buildings, according to the invention;
- figure 4 is a schematic exploded view of user's radio device of figure 3, according to the present invention;
- figure 5 is a time diagram for measuring the flight time, by each radio control lighting apparatus, for each radio message received, according to the invention;
- figure 6 is a block diagram of the electronic feeder present in each radio control lighting apparatus used in the system for locating people and/or objects inside buildings, according to the present invention;
- figure 7 is a block diagram of user's radio device used in the system for locating people and/or objects inside buildings, according to the present invention;
- figure 8 shows schematically a further embodiment of the system for locating people and/or objects inside buildings, according to the present invention;
- figure 9 shows an example of industrial or commercial installation map with several buildings and areas outside the buildings included in the estate, where a system for locating people and/or objects made according to the present invention can be used.
[0014] With reference to the figures mentioned, 1, 2, 3, 4, 5, 6 and 7 indicate a plurality of radio control lighting apparatuses, 8 and 9 indicate one or more user's radio devices or target devices, while 10 indicates an electronic unit of monitoring and control of the system, with attached a screen for displaying on three-dimensional maps the position of the radio device 8, 9 and/or any PC as display device, and 11 indicate one or more portable terminals, provided with their display screens on three-dimensional maps of the position of the radio devices 8, 9.
[0015] Each radio control lighting apparatus 1, 2, 3, 4, 5, 6, 7 substantially comprises a base casing or housing 15, provided with hooks 16 for mounting, a transparent polycarbonate cover 17, inside which one or more light sources 18 (fluorescent tube or LED or high-pressure discharge lamp) are placed, connected with respective lamp socket 19, a reflector 20 and an electronic feeder 24, provided with relative terminal board 25, which incorporates a DSSS radio transceiver and an antenna as well as:
- a gauge of the power and energy absorbed by the supply system;
- a gauge or sensor 21 of the light reflected by the surfaces illuminated by the light sources 18;
- any optional power battery 22 and related electronic circuitries for feeding the light sources 18 and radio transceiver, in the absence of the supply system, with which each apparatus 1, 2, 3, 4, 5, 6 , 7 is connected;
- any optional, passive infrared (PIR) or of waves radio type, Doppler effect and high frequency (>10GHz) proximity sensor 23, able to detect the presence of people in the vicinity of the lighting apparatuses 1, 2, 3, 4, 5, 6, 7.
[0016] Each user's target device 8, 9 is an electronic portable device, for instance wearable as a bracelet or pocket or which can be inserted into a belt through a fastening 26, and comprises a plastic seal consisting of a base 27 and a lid 28, where inside there are an electronic circuit 29, with built-in DSSS radio transceiver 32 and antenna, which also houses a triaxis accelerometer and a magnetic sensor 33 of REED type, a battery or rechargeable or primary type, inserted into the compartment 30 provided with cap 31, a possible induction recharging system for charging the battery and any button 34, provided with gasket 35, which can be operated by the user to send a signal.
[0017] The operation of the system for locating people and/or objects inside buildings, which is the object of the present invention, is essentially as follows.
[0018] The lighting apparatuses 1, 2, 3, 4, 5, 6 and 7 are in fixed positions inside the building and each radio transceiver of the respective lighting apparatus 1-7 is characterized by a "spread spectrum" modulation of DSSS type (more generally of FH-DSSS type, that is, "Frequency Hopping Direct Sequence Spread Spectrum).
[0019] In addition, each radio transceiver is equipped with circuitries able to measure, for every radio message received, the amplitude of the received signal (RSSI, "Received Signal Strength Indicator", circuit) and the flight time (ToF, "Time of Flight").
[0020] In particular, the RSSI circuit measures, in dB, the amplitude of the analogical signal at the output of the antenna amplifier.
[0021] Since in the phenomenon of propagation of a radio wave, attenuation is a function of the distance D between the transmitter and the receiver (the received power reduces according to the rule 1/D2 in open field and according to the rule 1/D4 inside buildings), by measuring the amplitude of the received signal it is possible to estimate the distance D between the two elements.
[0022] The measure circuit of the ToF uses instead the measure of the delay of propagation of a message "ping-pong", for example as shown in the appended figure 5, where the messages exchanged between a transreceiving node, which transmits the signal TxA to B and receives the signal RxA from B, and a transreceiving node B, which transmits the response signal TxB to A having received the signal RxB from A, are shown in a time diagram.
[0023] It is clear that, since Tmsg and Tp are prefixed times, determined by high-precision quartz oscillators and known to both transceivers A and B, if the transceiver A is able to measure with sufficient precision Tdel time, the same can calculate ToF time according to the following equation:
[0024] The ToF measurement of time has the advantage of being linearly related to the distance D, since the propagation time Tp is determined by the speed of propagation of the radio waves, which occurs at constant speed and is equal to c = 300,000 km/s, and D = c*ToF is calculated.
[0026] The known techniques used to measure the ToF are based on repeated and/or averaged measures in order to get, statistically, a sufficient independency from the noise and other causes of imprecision typical of this technique, but both the techniques have limitations due to multiple paths of propagation of the radio waves, which, mostly in indoor environments, introduce likely even considerable errors, since it is frequent that the radio connections between two points do not occur directly, but, through reflection on distant objects, from the two nodes which are communicating at a given time.
[0027] Moreover, this imprecision is highlighted in different extent both with the RSSI technique and ToF technique.
[0028] According to the invention, the radio transceivers of each lighting apparatus 1-7 exchange two types of messages, i.e. information messages 13 and localization messages 12.
[0029] Information messages 13 allow the network to carry information from one node to another of the network and convey them to the units 10 of the system and the terminals 11.
[0030] These messages 13 carry commands given by the units 10 to the lighting apparatuses 1-7 and user's radio devices 8, 9 and, furthermore, carry control and diagnostics information from the lighting apparatuses 1-7 and radio devices 8, 9 to the units 10 of the system and to the terminals 11.
[0031] The connections with information messages 13 among the lighting apparatuses 1-7 allow the most efficient routing of the information messages 13 themselves from one end to another of the network itself (which is a network of "meshed" type).
[0032] Routing modifies dynamically depending on the needs of the network according to known algorithms of identification of the optimal routes, while the architecture of the radio interconnections modifies dynamically depending on the mutual radio availability and visibility of the nodes.
[0033] The network is able to constantly take shape as a result of the changing physical conditions of the radio connections in order to always ensure the transfer of the information messages 13 between any two nodes of the network, even if the system has very large sizes; this is guaranteed by the possibility of multiple repetitions of the information message from one node to the adjacent ones.
[0034] The localization messages 12 are optimized in order to measure the distance between pairs of transceivers and at the same time can carry information contents of small sizes.
[0035] In order to locate, the lighting apparatuses 1-7 are in fixed positions known by the system and, in particular, each lighting apparatus 1-7 is characterized by a tern of Cartesian coordinates (Xj, yj, Zj) known to the system.
[0036] When user's radio device or target 8 must determine its own position sends several locating messages to all the fixed nodes with which it is in radio visibility (that is the lighting apparatuses 1, 2, 3, 4 and 6 of the enclosed figure 1) and, then, using both the RSSI and ToF techniques the target device 8 obtains a pair of measure values of each distance from each fixed questioned network lighting apparatus.
[0037] In particular, the target device 8 gets all the following values:
[DToF(8-1), DRSSI(8-1)],
[DToF(8-2), DRSSI(8-2)],
[DToF(8-3), DRSSI(8-3)],
[DToF(8-4), DRSSI(8-4)],
[DToF(8-6), DRSSI(8-6)].
[0038] They are ten values of distance from the five questioned fixed lighting apparatuses, which can be easily transmitted to the electronic unit 10 of the system through the radio network and, in particular, in the example of the appended figure 1, through the connections 13 between the lighting apparatuses 3 and 5 and between the lighting apparatus 5 and the unit 10 or through the connections 13 between the lighting apparatuses 4 and 5 and the unit 10.
[0039] The electronic unit 10 of the system, receiving the five pairs of distances [DToF (8-j), DRSSI (8-j)], processes two different estimates of the position of the target device 8, by calculating the two terns of coordinates [(X8ToF, y8ToF, Z8ToF), (X8RSSI, Y8RSSI, Z8RSSI)], starting from the distances [D-ToF (8-j), DRSSI (8-j)] j = 1,2,3,4,6 and known positions (x1, y1, z1), (x2, y2, z2) (x3, y3, z3) (x4, y4, z4), (x6, y6, z6).
[0040] In order to calculate an estimate of the coordinates of the target 8 at least three of the five distances from known points 1, 2, 3, 4 and 6 are needed, using the triangulation method.
[0041] Similarly, the system is able to locate the target device 9 on the basis of the measures of the related distances
[DToF(9-3), DRSSI(9-3)],
[DToF(9-6), DRSSI(9-6)],
[DToF(9-5), DRSSI(9-5)],
[DToF(9-7), DRSSI(9-7)]
[0042] The electronic unit 10 is then able to calculate, at any time, at least a pair of estimates of the position of each target device 8, 9 of the system, one calculated according to the time ToF and the other one through the RSSI.
[0043] In general, for each target 2N distances (N being the fixed apparatuses with which the target is able to communicate and respect to which it is able to measure the distances and two being the methods of measure of every distance) are available.
[0044] In order to calculate a tern of coordinates of the target at least k = 3 distances are necessary, using the triangulation method.
[0045] Therefore, with N fixed apparatuses in radio visibility it is possible to measure, for each method, N distances and calculate PN positions, where:
[0046] For example, if N = 5, being K = 3, PN = 10 different estimates of the position of the target for every method of measure of the distances are obtained.
[0047] Having at disposal two methods of measure, the possible estimates of every target are actually twice, i.e. 2*PN, in the exemplified case 2*10 = 20.
[0048] In order to obtain a larger amount of information which improve the statistical number and then the goodness of the estimates, the system calculates a number of positions greater than 2*PN.
[0049] Indeed, the system also calculates all the positions related to the mixed combinations of the distances measured with the two different methods ToF and RSSI, excluding from such combinations those ones where the same section calculated by means of the two methods appears, because it would make sense to calculate a triangulation with two distances measured on the same "section" with the two different methods.
[0050] In the previous example, related to the in sight target 8 with the apparatuses 1, 2, 3, 4 and 6, all the following triple combinations are excluded:
[DToF(8-1), DRSSI(8-1), Dx],
with Dx = DToF(8-J), J = (2, 3, 4, 6)
and Dx = DRSSI(8-J), J = (2, 3, 4, 6)
[DToF(8-2), DRSSI(8-2), Dx],
with Dx = DToF(8-J), J = (1, 3, 4, 6)
and Dx = DRSSI(8-J), J = (1, 3, 4, 6)
[DToF(8-3), DRSSI(8-3), Dx],
with Dx = DToF(8-J), J = (1, 2, 4, 6)
and Dx = DRSSI(8-J), J = (1, 2, 4, 6)
[DToF(8-4), DRSSI(8-4), Dx],
with Dx = DToF(8-J), J = (1, 2, 3, 6)
and Dx = DRSSI(8-J), J = (1, 2, 3, 6)
[DToF(8-6), DRSSI(8-6), Dx].
with Dx = DToF(8-J), J = (1, 2, 3, 4)
and Dx = DRSSI(8-J), J = (1, 2, 3, 4)
[0051] In this example, it is a question of excluding forty combinations from P2N = D2N, K/K! = P10 = D10, 3/3! = 120 and in such an example eighty combinations that are calculated by the system remain valid.
[0052] There are then in such an example, eighty estimates of the position of the target 8, starting from 2N = 10 measurements performed with the two methods ToF and RSSI of the N = 5 distances from the target 8.
[0053] More generally, for any set of N apparatuses visible by a target, the system calculates Pt positions, with
Pt = 2*PN + 2*N*(DN-1,K/(K-1 )!), K=3 and
with DN-1,K =(N-1)*(N-2)*...*(N-K+1), and
PN = DN,K/K!, with DN,K = N*(N-1)*(N-2)*...*(N-K+1).
[0054] The following table summarizes the values of Pt, 2*PN and 2*n*(DN-1,K(K-1)!) for various values of N and K = 3:
| N | Pt | 2*PN | 2*N*(DN-1,K(K-1)!) |
| 4 | 32 | 8 | 24 |
| 5 | 80 | 20 | 60 |
| 6 | 160 | 40 | 120 |
| 7 | 280 | 70 | 210 |
[0055] The result is a cloud of possible points in which the target device 8 is located (eighty points in the example); some of these positions are further discarded based on the following criterion.
[0056] It is known that, in general, the ToF technique has a higher accuracy for distances greater than values in the order of 6-10 meters, due to the difficulty of measuring the very small flight time ToF, that are involved at short distances, and, therefore, the electronic unit 10 discards the data of flight time ToF lower than a certain prefixed threshold.
[0057] The remaining positions (considered valid) are used to display on the screen of the electronic unit 10 the position of the target devices 8, 9 on a three-dimensional map of the system, according to the usual techniques of 3D visualization.
[0058] On the other hand, the terminal 11 is able to query, at any time, the system in the following possible two modes.
[0059] Firstly, by querying the electronic unit 10 and exploiting the radio network made up of the lighting apparatuses 1-7 as vehicles of the information exchanged with the unit 10, through information messages 13, the terminal 11 is able to acquire the positions of the target devices 8, 9 yet calculated by the unit 10 itself, while by implementing the same calculation algorithm of the electronic unit 10, the terminal 11 can directly calculate the positions of the target devices 8, 9, directly getting the distances and coordinates of the nodes through the information messages 13 connecting all the nodes of the network itself.
[0060] The system described, by using the lighting apparatus 1-7 as fixed nodes, offers the advantage of providing a large number of fixed transceivers, which, just thanks to the large number and capillarity of their presence inside the building, allow to get a close mesh of fixed nodes.
[0061] In this way, the target devices 8, 9 can count on a large quantity of measures of distance which enable the unit 10 to get, at any time, many estimates of the position of the target device 8, 9.
[0062] Therefore, the electronic unit 10 and system terminals are able to get, at any time, a high probability of a good estimate of the position of the target devices 8, 9, thanks to the abundance of the available localization information.
[0063] A limitation of the locating systems of traditional type is given by the fact that, with the increase of the sizes of the system, it is very expensive, during installation, to locate the spatial positions of every lighting apparatus 1-7 and insert the data into the electronic unit 10.
[0064] Indeed, in buildings with several thousands of lighting apparatuses 1-7 determining the fixed positions is a process that can take a long time and significant resources, as well as involving many detection errors.
[0065] For this reason, the locating system according to the invention provides an initial "self-learning" mode, according to which, during installation, the positions of the lighting apparatuses 1-7 are detected only for a subset of the total, for example for 10% of the apparatuses installed.
[0066] Therefore, the installer mounts, in positions of known spatial coordinates, only a few lighting apparatuses 1-7, taking care to place them in building significant positions (for instance at the boundaries of the building itself, at the beginning and end of passages and/or at the four corners of rooms of large dimensions) and the installer carefully records with care the exact spatial coordinates and radio addresses of these devices.
[0067] During the installation of the lighting apparatuses 1-7, the installer acquires all the radio addresses, for example, by means of a bar codes reader, by reading the radio addresses present on the adhesive labels of the lighting apparatuses, or, by means of an RFID reader, by reading the radio address recorded in any RFID TAG contained within each lighting apparatus 1-7.
[0068] In this case, once the unit 10 has been just installed, the installer firstly records in the memory of the unit 10 all the addresses acquired from the lighting apparatuses through bar codes or RFID TAG; this operation is performed through a radio connection or serial cable from the unit 10 to the bar code or RFID TAG reader, so that, during installation, the unit 10 thus knows the addresses of all the lighting apparatuses 1-7 to set up, which have been stored in its own memory.
[0069] Furthermore, the installer can store in the electronic unit 10 the positions of the apparatuses 1-7 (10%, for example) whose position has been identified by him, linking them to the respective radio addresses.
[0070] Being a subset of the total of the lighting apparatuses 1-7, the burden of such an identification procedure then decreases significantly and, at this point, the installer can give on the unit 10 the command to start the automated procedure of configuration or auto-localization of the system.
[0071] According to such a procedure, the electronic unit 10, firstly, connects all the lighting apparatuses 1-7, arranging all the connections 13 and various paths of routing of the information travelling through these connections 13.
[0072] Subsequently, for each lighting apparatus 1-7 whose position is unknown, the unit 10 activates a localization procedure of the same type of that one used for the identification of the target devices 8, 9, by using as reference nodes the lighting apparatuses 1-7 characterized by known positions.
[0073] In this case, the advantage is due to the fact that the apparatuses installed in unknown positions are at fixed, not variable over time, positions and, therefore, the localization procedure repeated many times must provide the same result.
[0074] In other words, the iteration, for many times and at different times, of the localization procedure of a same apparatus 1-7 of unknown position allows to get various estimates of its position, which, properly mutually averaged, can improve over time the localization of the actual location.
[0075] In case that the estimates of the positions of some apparatuses 1-7 are affected by large discrepancies between the methods of measure ToF and RSSI or in case a lot of variability of the measures at different times occurs, the unit 10 automatically compiles a list of these lighting apparatuses 1-7, which it provides to the installer who can then correct the inaccuracy by physically detecting the indicated apparatuses 1-7 whose position is determined with uncertainty by the automatic mechanism.
[0076] In order lo locate in the plant of the apparatuses 1-7 to be identified, the unit 10 makes available a special function to the installer, by giving an appropriate command, through which is able to send a particular message to all the lighting apparatuses 1-7 to be identified which start flashing (for example, once every second, so that the installer, while moving inside the building, can easily detect the apparatuses 1-7 and record the coordinates and address thereof).
[0077] At the end of the procedure, the installer inserts the new data in the unit 10 and repeats the configuration procedure of the system.
[0078] The aforesaid system, therefore, with the new data, will improve the estimates of all the fixed positions of the lighting apparatuses and the installer could reiterate these procedures until to get a certain precision (considered adequate) of the fixed positions of the aforesaid lighting apparatuses 1-7; at this point, the system could be considered properly configured.
[0079] Each target device 8, 9 is able to transmit and receive information to the unit 10 of the system, through the radio network made up of the connections 13, and, in case the target devices 8, 9 are equipped with signalling buttons 34, pressing of these buttons 34 causes the transmission of a message to the unit 10, message that can be used as request for attention, and, in particular, for example, as request for assistance by the person wearing the target device 8 , 9; this function is particularly important because, combined with the information about the position of the target device 8, 9 calculated by the unit 10, makes available a function of telephone helpline with localization inside buildings.
[0080] The target device 8, 9 also incorporates an accelerometer, which, through appropriate algorithms performed by the target 8, 9 itself, allows the determination of conditions of danger for the person wearing the target device 8, 9.
[0081] For example, an absence of movement recorded by the accelerometer for a fixed period can automatically determine the transmission of an alarm message to the electronic unit 10 of the system and this, coupled with the calculation of the position, allows to automatically detect user's location wearing the target device 8, 9 and the danger condition in which he is.
[0082] The presence of the accelerometer in the target device 8, 9 also offers another important function.
[0083] In locating the position, indeed, the target device 8, 9 understands, on the basis of the analysis of the accelerometer, if it is stationary or in motion.
[0084] In the event that the target device 8, 9 is stationary, the estimate procedure of the position takes advantage of this information, since the target device 8, 9 iterates the location procedure, allowing the unit 10 to use statistical processes of average in order to improve the goodness of the position estimate.
[0085] In addition, another important function concerns the energy saving of the lighting system, since all the lighting apparatuses 1-7 can be subjected to dimmer (that is, the feeders allow to adjust the brightness of the apparatuses 1-7), it is possible to activate from the unit 10 a function of automatic activation of the lighting.
[0086] Indeed, in case the locating system is attended only by operators provided with target device 8, 9, the system normally sets itself under conditions such that to keep the light flow of the lighting apparatuses 1-7 at a minimum level lower than the necessary minimum value (since other people are present in the plant), thus getting a huge energy saving.
[0087] When, then, the operator, equipped with target device 8, 9, moves inside the plant, the lighting apparatuses 1-7, knowing the distance at which the operator is, accordingly adjust their own brightness, automatically increasing it when the operator is approaching and decreasing it when the operator is going away.
[0088] Then, in presence of a few operators, in large locating systems, energy saving can be very high, because most of the lighting apparatuses 1-7 may, at any time, remains on at very low light levels or off and automatically increase the light flow when the operator is approaching.
[0089] In this way, only a small group of lighting apparatuses 1-7 remains on at full power at any time.
[0090] The advantage of this technique, compared to the traditional techniques based on proximity sensors, represents a significant improvement of the comfort for the user, since, thanks to the timely knowledge by the system of user's position inside the system, when the user himself moves, the system allows him to feel that the lights are always on.
[0091] Indeed, the system is able to accurately estimate user's positions and movements and to foresee his movements, turning on the lights of the rooms in advance before he comes into; vice versa, the traditional systems based on proximity sensors are able to turn on the lights only when the user comes into the rooms themselves.
[0092] The electronic feeder 24 present in each lighting apparatus 1-7 essentially includes of a microcontroller A6 and a power section, consisting of the stage A1 (AC/DC converter with PFC and voltage gauge, active current and power), stage A2 (service feeder with optional battery 22) and stage A3 (switching converter for driving the light source 18), which supply the light source 18 with the proper modes.
[0093] The power converter A1-A3 is of the intensity- adjustable type, able, therefore, to drive the light source 18 to intensities which can be modulated from a minimum to a maximum allowable level for that type of source (for instance, 5%-100% for the fluorescent tubes, 0.5%-100% for the LEDs, 50% -100% for the high-pressure discharge lamps).
[0094] The stadium A1 is of the type with power factor correction (PFC, "Power Factor Correction"), the stage A3, which draws energy from the capacitor CS, consists of a switching converter, suitable for the electrical adjustment to the impedance of the light source 18 used and switching on modes, while the stadium A2 includes the service feeders needed for the operation, even with light off, of the subsystem consists of the radio transceiver A7, of "spread spectrum" type and equipped with the functions of measure of the RSSI distance and flight time ToF, and PIR proximity sensor or Doppler effect radar 23.
[0095] Moreover, the stadium A2 includes a proper converter suitable to provide the energy for the emergency operation, i.e. without 230 Volts AC power, by drawing energy from a back-up battery.
[0096] The microcontroller A6 drives all the functions of the feeder 24, also managing the light sensor 21, PIR sensor or (optional) Doppler effect radar 23 and all the various types of radio messages exchanged with the radio network, through the transceiver A7.
[0097] In particular, the light sensor 21, by measuring the light reflected by the surface illuminated by the light source 18, allows to implement an algorithm of automatic adjustment of emitted light, depending on the available room light, in order to obtain the basic function of energy saving, while, similarly, the sensor or radar 23 allows the lighting apparatus 1-7 to perform an additional power saving function, by automatically switching on and off or automatically reducing the brightness level in absence of people near the lighting apparatus itself.
[0098] The microcontroller A6 is also able to measure the power and energy absorbed by the 230 Volts AC network, through the voltage and current gauges built-in in the stage A1.
[0099] Thanks to these measures, the feeder 24 is able to count the energy consumed by the lighting apparatus 1-7, so that the system can thus determine the total energy saving achieved.
[0100] User's radio device or target device 8, 9 incorporates a microcontroller T3, which controls all the functions of the device and, in particular, detects the measures of the accelerometer T4 and state of the button 34 and REED magnetic sensor 33 and manages the radio transceiver 32.
[0101] Such a target device 8, 9 also includes a power supply T1, which provides the supply energy to the circuits drawing it from the battery T2, while a system of induction charging T6 allows to recharge the battery T2 in case the aforesaid battery T2 is a rechargeable battery.
[0102] The REED magnetic sensor 34, with which is provided the target device 8, 9, allows to automatically switching off the entire target device 8, 9 when the same is placed, when the device is not used by the operator, on a base provided with magnet.
[0103] In this way, if used the battery T2 is of non-rechargeable type, the target device 8, 9 is able to retrench the available energy without the trouble that the operator forgets the device on.
[0104] The same base provided with magnet can house the induction charge system T6 if the used battery T2 is of rechargeable type.
[0105] The portable terminal 11 of figure 1, beyond the display function, can have a different function when used in place of a target device 8 (as shown in detail in the diagram of the attached figure 8, where such a terminal is indicated with 14).
[0106] In this case, in fact, the terminal 14 is an active element for its own localization and takes shape as a real "navigator" of the system.
[0107] In particular, the terminal 14 incorporates the same DSSS radio transceiver of the portable terminal 11, suitable to measure the RSSI and ToF quantities, and is therefore able to perform the localization procedure by determining the following distances:
[DToF(14-1), DRSSI(14-1)],
[DToF(14-2), DRSSI(14-2)],
[DToF(14-3), DRSSI(14-3)],
[DToF(14-4), DRSSI(14-4)],
[DToF(14-6), DRSSI(14-6)].
[0108] In addition, in this application, the terminal 14 calculates automatically the position, on the basis of the knowledge of the positions of all the fixed points of the system, through the same calculation procedure used by electronic unit 10 and previously described.
[0109] The positions of the fixed points are then known to the terminal 14, since it is able to know them by questioning the unit 10, through the radio network.
[0110] Alternatively, the nodes themselves (i.e., the lighting apparatuses 1-7) have been previously instructed by the unit 10, which has recorded in their memory the information related to their position (in the latter case, the terminal 14 acquires the information about the fixed position directly from the lighting apparatuses 1-7).
[0111] In this way, the terminal 14 can be used by the user as a navigator inside the building where the system is installed, allowing the user to know at any moment his own position.
[0112] This feature can be used in complex installations (such as large industrial plants) in order to allow operators to know their operating position, or in public places (museums, fair areas, etc.) in order to allow visitors, provided with terminals 14, to have a navigation help in the buildings where they are.
[0113] As shown in the attached figure 8, the system described, finally, allows the simultaneous use of both user's radio device or target 9 and portable terminals 14 of "navigator" type.
[0114] Each portable terminal 14, as well as any user's radio device 8, 9, can optionally incorporate a GPS receiver, in addition to the DSSS radio.
[0115] GPS receivers can nowadays be made with very small sizes and low power consumption and can be easily integrated into the target devices 8, 9 and portable terminals 14.
[0116] In the systems of the type shown in the attached figure 8, where there is an extension of the system even outdoor (such as in the large industrial installations or in commercial areas of large extension or in fairs areas, etc.), the presence of GPS inside the terminals 9, 14 allows the activation of the function of location through GPS when the user is outdoor, thus covering any areas not fully controlled by the locating system previously described (based on the only location through DSSS radio).
[0117] In this particular system configuration, it is advantageous to also provide the electronic unit 10 of a GPS receiver, since, in such a way, the unit 10 installed at a fixed point, whose coordinates are known with precision, it is possible to apply a differential location technique of the position by means of GPS and with this technique, at the points outdoor where there is the GPS signal, it is possible to increase the precision of location of the terminals 9, 14 up to reduce the location error below one meter.
[0118] Furthermore, by providing the mobile terminals 9, 14 with GPS receiver it is achieved the further advantage that it is not necessary to provide locating system outdoor, for the large outdoor areas facing the buildings in which the locating system is active.
[0119] The only necessity will be, in this case, to have a good DSSS radio coverage of the outdoor areas, so that the mobile terminals 9, 14, once had a picture with the built-in GPS, are able to send the information to the DSSS radio network using the lighting apparatuses 1-7 as repeaters of radio messages.
[0120] Attached figure 9 shows, by way of example, the schematic map of a case of this type, including an industrial or commercial installation with several buildings 40 and courtyard areas 41 outside the buildings included in the estate, in which 36 indicates the DSSS radio lighting apparatuses, used as repeaters of messages, while 37 indicates the DSSS radio lighting apparatuses for the internal location (indoor).
[0121] Location is made with mixed DSSS (inside the buildings 40) and GPS (outside the buildings 40, in the courtyard area 41) technique.
[0122] The technical features of the system and method for locating people and/or objects inside buildings, according of the present invention, as well as the advantages, are clear from the description made.
[0123] It is, finally, clear that many other variations may be made to the localization system and method in question, without departing from the principle of novelty intrinsic in the inventive idea expressed here, as it is clear that, in the practical implementation of the invention, materials, shapes and sizes of the illustrated details can be changed, as needed, and replaced with others technically equivalent.
1. System for locating people and/or objects inside buildings (40), comprising a plurality
of radio controlled lighting apparatuses (1-7), one or more user's radio devices (8,
9), at least one electronic unit (10) of control and management of the system and
display of the position of said user's radio devices (8, 9) and one or more portable
terminals (11, 14) for displaying the position of said user's radio devices (8, 9),
characterized in that said lighting apparatuses (1-7) are installed at known and prefixed positions inside
the building (40) and include a corresponding radio transceiver with FH-DSSS modulation,
provided with circuits (RSSI, ToF) suitable to measure, for each message or radio
signal sent or received, the amplitude of said received radio signal and/or the propagation
delay between a first radio signal (TXA) transmitted by a first transceiver and a
second radio signal received (RXB) by a second transceiver due to the transmission
of said first radio signal (TXA), in order to get an estimate of the distance (D)
existing between a lighting apparatus (1-7) and another.
2. Locating system as claim 1, characterized in that each lighting apparatus (1-7) incorporates at least one meter of the power and electricity
absorbed by the power supply and at least one sensor (21) of the light reflected by
the illuminated surfaces.
3. Locating system as claim 1, characterized in that each lighting apparatus (1-7) incorporates at least one proximity sensor (23), suitable
to detect people' presence near the apparatus (1-7).
4. Locating system as claim 1, characterized in that each user's radio device (8, 9) is a portable device with a DSSS radio transceiver
(32) integrated.
5. Locating system as claim 1, characterized in that each user's radio device (8, 9) includes a supply battery, at least one accelerometer
and at least one magnetic sensor (33).
6. Locating system as claim 1, characterized in that each user's radio device (8, 9) presents at least one button (34), which can be operated
by the user in order to send a signalling.
7. Locating system as claim 1, characterized in that the radio transceivers of said lighting apparatuses (1-7) exchange each other messages
of information type (13) and localization messages (12).
8. Locating system as claim 7, characterized in that said messages of information type (13), which are transported from a lighting apparatus
(1-7) to another which are conveyed to the said electronic unit (10) and said portable
terminals (11, 14), comprise commands given by the electronic units (10) to the lighting
apparatuses (1-7) and to user's radio devices (8, 9) and control and diagnostics information,
which are sent by the lighting apparatuses (1-7) and users' radio devices (8, 9) to
the control units (10) of the system and to the portable terminals (11, 14).
9. Locating system as claim 7, characterized in that said localization messages (12) are suitable to measure the distance between pairs
of radio transceivers.
10. Locating system as claim 7, characterized in that said localization messages (12) convey information contents of small size.
11. Locating system as claim 7, characterized in that a plurality of localization messages (12) are sent, by radio, by at least one user's
radio device (8, 9), in order to determine its own position, to a set series of fixed
lighting apparatuses (1-4, 6), with which it is in radio visibility, so as to get
at least one pair of measurement values of each distance existing between said user's
radio device (8, 9) and each fixed lighting apparatus (1-4, 6) of said set series,
said pairs of values being sent to said electronic unit (10), which calculates the
estimated positions of said user's radio device (8, 9) according to a plurality of
possible mixed combinations of the distances between said user's radio device (8,
9) and said fixed lighting apparatuses (1-7).
12. Locating system as claim 1, characterized in that said portable terminal (11, 14) exchanges information messages (13) with said electronic
unit (10), in order to acquire the positions of said user's radio devices (8, 9) using
said lighting apparatuses (1-7) as nodes and/or fixed transceivers.
13. Locating system as claim 1, characterized in that, during installation, the positions of some of said plurality of lighting apparatuses
(1-7) are detected.
14. Locating system as claim 6, characterized in that said signalling button (34) is suitable to send an assistance message to the said
electronic unit (10).
15. Locating system as claim 1, characterized in that said user's radio device (8, 9) incorporates at least one accelerometer for detecting
the presence and/or absence of movement of the device (8, 9) for a predetermined period.
16. Locating system as claim 1, characterized in that said lighting apparatuses (1-7) comprise at least one electronic feeder (24) which
includes a microcontroller (A6) and a power stage (A1, A2, A3) feeding one or more
light sources (18), of adjustable intensity type.
17. Locating system as claim 1, characterized in that said user's radio devices (8, 9) incorporates a microcontroller (T3), which controls
the functions of the device (8, 9) and manages a radio transceiver (32), a feeder
(T1) and at least one magnetic sensor, which allows to automatically turn off the
device (8, 9) when said device (8, 9) is not used.
18. Locating system as claim 1, characterized in that said portable terminal (11, 14) incorporates a radio transceiver, suitable to measure
the distances between said terminal (11, 14) and at least part of said lighting apparatuses
(1-4, 6), so that said terminal (11, 14) can be used by the user as a navigator inside
the building (40) in order to know at any moment his own position.
19. Locating system as claim 1, characterized in that said user's radio devices (8, 9) and said portable terminals (11, 14) incorporate
a GPS receiver, which allows the use of a localization function in open air areas
(41), said GPS receiver being also present inside said electronic unit (10) and said
lighting apparatuses (1-7, 36) being used as messages repeaters.
20. Method for locating people and/or objects inside buildings (40), characterized in that of being implemented through a locating system as claim 1.