FR2739957A1 - Electronic module for automated guidance to vacant car parking space - Google Patents

Abstract

The electronic guidance module (1) is in a box that can be placed on the dash board of the motor vehicle. The box has an alphanumeric display (2) on its front face, and a number of control keys (30-34). The electronic circuit inside the box provides drivers for the display, response to the control keys, and external communication to gather data. Local parking data is stored in the box. The local data can be updated remotely, either by radio communication or direct connection to the box. The data is provided by a central data server coupled to the communication links. The keys allow the user to select zones in the town, and parking data associated with this zone scrolls across the display till the user stops the scrolling.

Description

Portable electronic guidance device and its application to research
car parking space
The present invention relates to a portable electronic guidance device intended to assist a user in the search for specific information.

 It relates more particularly to the application of such a device to the automated search for a car parking space, in particular in an urban parking lot.

 Although the invention is not limited to this single field, in what follows, to fix the ideas, we will place ourselves, unless otherwise indicated, within the framework of this preferred application.

In known art, when driving in an urban agglomeration and wanting to park, most often you use two empirical methods:
- The first is to randomly search for a parking lot;
- The second is to have, for a given city or area, a plan indicating the locations of parking lots.

 The second method seems more effective, but is not without drawbacks.

 Even if the locations of the parking lots are shown on the map, the latter are generally not sufficiently detailed or on a sufficient scale so that the aforementioned location can be determined with very great precision. As an example, it will be possible to determine that a parking lot exists on a given street, but it will be necessary to locate, visually, the entrance to the park by looking for the presence of an appropriate sign.

 In addition, this research being carried out, this parking lot can prove to be full, in particular in the very frequented places (center of the cities, stations, etc.), which cannot be planned in advance.

 There is a need, in particular for this application, to have more effective guidance and search means.

 On the other hand, account must be taken of specific features specific to the application. Indeed, the driver, especially if he is alone in his vehicle, must be able to remain attentive to driving and surrounding traffic, a priori dense. It is therefore essential that the aforementioned guide means do not monopolize his attention and are ergonomic. Their handling must be very simple, easy to access and the information sought must be clear, unambiguous and be able to be read very quickly, precisely so as not to divert the driver's attention.

 The invention aims to meet these needs.

To do this, it offers a portable electronic guiding device in the form of a box comprising electronic circuits for processing data with a recorded program, associated with a keyboard or a set of command keys and a screen. The data, representing information, in particular on the location of the car parks, is preferably stored in a fixed memory, of the "ROM" type (from the English "Read Only Memory" or "read only memory"). PROM "(from Anglo-Saxon" Programmable Read Only
Memory "or programmable read-only memory). This data constitutes an internal database.

 According to a first important characteristic of the invention, the screen includes only one display line. This arrangement contributes to the good readability of the information displayed, perceptible at a glance by the user.

 According to a second important characteristic, in combination with the actuation of predetermined keys in a very limited number, the data is displayed by horizontal scrolling, at least for an initial choice. This choice being validated by pressing an appropriate key, subsequent displays can be carried out either according to this mode, or according to a conventional line feed mode (vertical scrolling).

 Advantageously, the portable electronic guidance device is multi-use, in the sense that the above-mentioned fixed memory can comprise two or more categories of information. By way of nonlimiting example, in addition to the information concerning the car parks, the list of museums and other tourist sites can be saved in the memory. It is then necessary, for example, either to press one or more additional keys to make the choice between the two categories of information (or more), or a combination of keys provided individually for another use.

 Advantageously also, the screen is associated with lighting means so that the information displayed is visible whatever the ambient brightness.

 Finally, in a preferred embodiment of the portable electronic guiding device according to the invention, the electronic circuits are associated with interface circuits making it possible to put it in communication with external bodies emitting information data. This data is received by the portable electronic guidance device and updates its internal database.

 The connections with the external bodies emitting the aforementioned information data can be carried out, in particular, by connections of telephone type or similar, by radio waves, with inductive coupling, infrared radiation.

 The external bodies transmitting information data themselves may be constituted, for example, by an active or passive server or by guide terminals. In the first case, the database is updated, a priori, by prior interrogation of the server. In the second case, the update of the database can be carried out almost in real time, if guide posts are scattered in an urban area, for example near parking lots. In particular, these guide posts can broadcast, in real time, information concerning the occupancy rate of one or more parks located near them.

 The subject of the invention is therefore a portable electronic guiding device, for the automated search for at least one particular item of information, comprising a housing, a member for viewing alphanumeric data, actuation keys and electronic circuits for controlling of the alphanumeric data display member, detecting the actuation of said keys or combination of keys, and for recording at least one database allowing said search, characterized in that said alphanumeric data display member comprises a single display line, comprising a determined number of display positions and in that, under the actuation of said keys or combination of keys, said control circuits transmit data to the alphanumeric data display member to be displayed, by horizontal scrolling, following at least one direction of scrolling.

 The invention also relates to the application of such a device to the automated search for a car parking space.

The invention will be better understood and other characteristics and advantages will appear on reading the description which follows with reference to the appended figures, and among which
- Figure 1 schematically illustrates an embodiment of an electronic portable guidance device according to the invention;
- Figure 2 schematically illustrates its use of such a device inside a vehicle;
- Figure 3 is a block diagram of an exemplary embodiment of an electronic circuit allowing the operation of the portable electronic guide device according to the invention;
- Figure 4 is a flowchart illustrating steps in the information retrieval process;
- Figure 5 illustrates an embodiment of display and these control circuits ;;
- Figure 6 illustrates an additional embodiment of the portable electronic guidance device according to the invention allowing communication with information dissemination terminals.

 Figure 1 schematically illustrates an embodiment of an electronic portable guide device 1 according to the invention.

 I1 comprises a housing 10 of small dimensions, of substantially rectangular parallelepiped shape. To fix the ideas, the dimensions of the housing 10 are typically the following: length 12 cm, width 5 cm, thickness 2 cm.

 The front face is provided with a keyboard or more precisely with function keys 3, in the smallest number possible, well differentiated from one another and, preferably in relief with respect to the front wall of the housing 10, so as to be able to be operated "blind" without ambiguity. It is also provided with a display 2, advantageously with liquid crystal. The functions associated with the keys will be explained below.

 This display 2 constitutes one of the most important parts of the portable electronic guide device 1.

 According to an important characteristic, it consists of a single display line of alphanumeric data. The readability must be perfect, with good definition, so that the information displayed on this line can be read at once and quickly. To fix ideas, the display can be provided with a capacity of 16 characters, 6 mm each.

 In addition, a lighting means will advantageously be associated with this display 2 (not referenced explicitly in FIG. 1), particularly if it is a display of the liquid crystal type not visible in the dark, or even in poor lighting conditions. A backlight is then provided. This auxiliary lighting can be triggered, either manually by pressing a particular key or combination of keys, or automatically by detection, using a conventional photodetector, of a luminous flux below a preset threshold.

 The portable electronic guidance device 1 can also be provided with a conventional audible warning device 4: "buzzer", etc., the usefulness of which will appear below.

 Finally, the housing 10 of the portable electronic guide device 1 is advantageously provided with a suitable fastening means 11 thereof on the dashboard of the vehicle or in any other location within sight of the driver. They are preferably self-fixing means: magnet, clip, etc.

 FIG. 2 schematically illustrates the arrangement of an electronic portable guidance device 1 inside a vehicle V, on the dashboard T, within sight of the driver (not shown).

 The electronic circuits 5 enabling the electronic portable guide device l to operate can be produced from wired circuits associated with memory means, but also, preferably, as described in FIG. 3, based on a microcontroller or commercially available microprocessor. These are data processing circuits with a recorded program.

 The circuit architecture represented in FIG. 3 comprises a microcontroller 50 controlling the display 52 by a bus or electrical connections 520. If provision is made for auxiliary lighting 58 of the display 52, the microcontroller 50 controls the ignition of this by an electrical connection 580. This ignition can be carried out under the control of one of the keys 3 or be carried out automatically. To do this, a photoelectric detector 59 is provided which measures the light flux received by the portable electronic guide device 1, more precisely by its front face. It is sufficient to place it near the screen of display 2.

 The microcontroller 50 receives control signals from the keyboard 51 via a bus or electrical connections 510. More precisely, the microcontroller 50 continuously monitors the state of the keys of the keyboard 51 (FIG. 1: 3).

The depression of one of them results in a variation of an electrical signal detected by the microcontroller 50, which launches a series of operations depending on the key or the combination of keys pressed.

 Conventionally, in itself, the microcontroller 50 is associated with one or more memories, generally of two types: a read-only memory and a volatile random access memory.

 For reasons of convenience of description, it has been assumed, in FIG. 3, that the read-only memory is itself divided into a program memory 54, exchanging data and addresses by buses represented under the unique reference 540, and a data memory 53, exchanging data and addresses by buses represented under the unique reference 530. These two memories, 53 and 54, can in reality represent two areas of a single memory.

As indicated, a memory of type "ROM" or a memory of type "PROM" or the like ("EPROM", etc.) can be used.

 The program memory 54 stores the instructions necessary for the proper functioning of the device according to a preset program. In itself, this operating mode does not differ from the known art, and the establishment of such programs is within the reach of the skilled person.

 The database (s), specific to the applications of the invention, are stored in memory 53.

 Conventionally, the volatile memory 55 is used for the temporary storage of programs or program segments, as well as for the temporary storage of commands coming from the keys 3 and of raw or processed data coming from the memory 53. It communicates with the microcontroller 50 via an address and data bus 550.

 The microcontroller 50 can also control an optional audible warning device 4.

 FIG. 3 also shows an electric power supply unit 57. I1 usually consists of one or more rechargeable cells or batteries, and a voltage regulator. The latter supplies the voltage or voltages necessary for the operation of the circuits 5. The microcontroller 50 can control this supply 57, in particular the ignition phases (controlled ascents of the various voltages, for example) and the deactivation of the portable electronic guidance device 1. Advantageously, it can cut off the power when it detects a period of inactivity exceeding a determined time interval, so as to save the cells or batteries.

 Other conventional members (not shown) must be provided for clock circuits supplying clock signals to the various circuits (represented under the unique reference H), etc. Finally, the microcontroller 50 can be associated with memory registers or buffer memories (not shown), in addition to memory 55 and its own internal registers.

 In a preferred variant of the invention, the portable electronic guiding device must be able to communicate with external circuits, for example a server 6. To do this, interface circuits 56 are provided which communicate with the microcontroller 50 via a bus or serial links 560. These interface circuits 56 communicate with the outside world via a bus or serial links 561 and possibly an adapted output connector 562, or even an antenna disposed inside the housing (not shown) . The connector 562 can, for example, be arranged on the side or the rear face of the housing 10 (see FIG. 1).

 The exact nature of the interface circuits 56 depends on the type of links.

 The data transmissions between the external member 6 and the portable electronic guide device 1 can use any medium and in particular a telephone line or the like, a radio wave, an inductive coupling, an infrared radiation. This aspect will be explained below.

 The operating mode of the portable electronic guide device 1 will now be explained with reference to the flow diagram of FIG. 4.

 On this flowchart, only a few combinations of display sequences have been shown.

 The first step ("step I"), or preliminary step, consists in switching on the portable electronic guidance device 1. This is carried out by pressing the left button 30 "STOP / ON". The power supply 57 is activated and the display screen 2 displays default information.

 This action can be accompanied by the emission of an audible beep, if the portable electronic guidance device 1 includes an audible warning device 4, indicating the effective start of the device.

 We will first assume that the portable electronic guide device 1 is single-function and is intended for the automatic search for a parking space in a park. It is also assumed, to fix ideas, that it is a large city with sectors or districts, as is the case for Paris.

 In this case, the first information displayed by default, INFO 1, could be the rounding N, more precisely the information displayed could be "1 ER ARRONDT. ".

 From there, the motorist who wishes to find a parking lot in another district, press the key 31 (arrow to the left, in Figure 1).

 According to an important characteristic of the invention, the information will be displayed by horizontal scrolling, for all or part of the display operations, this on the action of keys or combination of keys determined, or alternatively according to the type of action on these keys. By "type of action" is meant, for example, the time of pressing a key or a combination of keys.

In particular, if the pressing time exceeds a determined threshold, the operation or the series of operations initiated may be different from that initiated by a simple pressing, that is to say of short duration.

 Preferably, the display is carried out in a loop, that is to say that once all the elementary information of a message is displayed, this begins again to be displayed in the same order, until a new action is initiated by the user.

 Monitoring of these various events and their configuration is the responsibility of the microcontroller 50.

To achieve this horizontal scrolling, the basic information,
INFO 1 to INFO N + 2, of the MSG message are transmitted in series to the display 2. Although this data has been represented in the form of a "ribbon" (in dotted lines) in FIG. 4, it must be clear that only part of the data of each elementary information item, depending on the capacity of the display 2 (for example 16 characters) is actually displayed, that is to say visible to the user.

 The display is naturally under the control of the microcontroller 50 which will seek the data at predetermined addresses of the memory 53 to present them in a pre-established order, under the control of the program recorded in the memory 54.

 To make a display by horizontal scrolling, it is possible to have recourse to hardware means, such as a shift register controlled by the microcontroller 50.

 FIG. 5 illustrates a possible embodiment of a control circuit for the display 52, more precisely display positions, for example 21 to 216, if the latter has sixteen, of the display member 2 I1 comprises a shift register 7, also comprising sixteen stages, 71 to 716. The outputs of each stage are transmitted to the inputs of control circuits 8 of the display member 2. These circuits 8, sixteen in number, 81 to 816, are quite classic. The shift register 7 receives as input (serial bus 520) the data stream to be displayed, under the control of the microcontroller 50. The outputs of the stages, 71 to 716, of the shift register 7, control, by electrical signals, the display positions of the display member 2. Also conventionally, the display positions, 21 to 216, are provided with control electrodes (not shown) activated by the electrical control signals.

 In a preferred variant, the display 52 is provided with means allowing the data to be looped back on themselves, symbolized by a link 521 closed on the input of the shift register.

 The timing of the display is ensured by clock signals, represented under the general reference H.

 It is also possible to use a purely software process. The data to be displayed are then assembled, under the supervision of the recorded program, and translated in the form of signals for controlling the display positions.

There are several display possibilities, including the following two
- continuous display by horizontal displacement of the characters of the complete message MSG (INFO 1, then INFO 2, etc.), this character by character or pixel by pixel, if each character is displayed in the form of a pixel matrix and the display circuits make it possible to differentiate each vertical row of pixels;
- in successive packets of characters, the number of characters being however less than the number of display positions.

 To fix the ideas, a long press of the key 31 (arrow to the left in Figure 1), for example for more than two seconds, initiates a continuous scrolling of the message, while a short press initiates a scrolling in packets of information, representing all or part of the various elementary information, INFO 1 to INFO N + 1, of the message MSG.

 Again, the emission of a beep or of several beeps may indicate to the user that the scrolling begins, and according to which mode it was initiated, without the latter being obliged to check the state of the 'screen.

 The scrolling speed is determined for easy reading of the information. In an alternative embodiment not explicitly illustrated, a specific combination of keys could cause the acceleration of scrolling.

In 1 "step II", the message MSG will start to scroll, according to one or the other of the above methods. In FIG. 4, the display member 2 displays during this step still a fraction of the first elementary information.
INFO 1 and a fraction of the following information: INFO 2.

 These provisions, and in particular the continuous scrolling, allow the driver to maintain his attention on driving his vehicle and to release it only for brief moments, sufficient to capture the information being displayed.

 By pressing the key 32 (arrow to the right in FIG. 1), the user can naturally reverse the direction of scrolling, under the same conditions as for scrolling in the direct direction. This step is not illustrated by the diagram in Figure 4.

 In addition, as has been pointed out, the scrolling can be carried out "in a loop", that is to say repeatedly. The user can wait until the information sought, which he would have missed, "returns" to the screen.

 In the next step ("step III"), the user selects one of the scrolling information, for example the information INFO N, which could be, in the example described "8 EME ARRONDT.". This selection is made simply by pressing the validation key 34 "V". A beep can also accompany this action.

 At the end of the previous step ("step III"), information of a first level is selected.

 Once validation has been carried out, a specific message can be displayed, for example displaying the selection, with a specific attribute, such as flashing. It is of course possible, in the event of a selection error, to cancel it.

Depending on the application, this cancellation may have the effect of resetting the process at the first stage or restarting the scrolling of information, starting from the state reached during selection or validation ("stage III").

 The process which has just been described can be repeated for different levels of information, in a similar manner, that is to say with horizontal scrolling display, continuously or in jumps. For example, after the display of the various boroughs and the selection (validation) of one of them, the portable electronic guidance device 1 could then offer all the parking lots in this borough, the last step being a step selection of one of them.

 According to a preferred embodiment of the portable electronic guiding device 1 according to the invention, the display can also be carried out in a conventional manner, that is to say by "vertical" jumps. According to this operating mode, the elementary information is displayed in "full screen" mode, that is to say on the "x" positions of the single display line (sixteen for example).

 The transition from one mode to the other takes place, a priori, under the control of the recorded program. This determines that, at a given level of the current search, the scrolling mode changes.

 The successive stages, "stage IV" and "stages V", in FIG. 4, illustrate this possibility. The ordering process is similar to that of the horizontal scroll control. It suffices, for example, to press the key 31 (arrow to the left) to cause successive jumps of the elementary information DATA 1 to DATA M + 2, M being an arbitrary number.

The set M + 2 elementary information constitutes the complete message of this display phase. In the vertical scrolling operating mode, a priori, preference will be given to a display by jumps and not continuous.

As before, also, pressing the key 32 (arrow to the right) could cause the information to “go up”: for example to redisplay the previous elementary information, for example to return from
DATA 2 to DATA 1. These data are representative of the characteristics of the parking lot selected last: number of spaces, number on the street, etc.

 Up to now, it has been assumed that the portable electronic guide device 1 according to the invention is single-function. In a preferred embodiment, this guide is multifunctional.

 One or more other databases can be registered, concurrently with the data in the "parking lots" database.

 Advantageously, it is possible to save, in the memory 53 (FIG. 3) a complementary "tourist sites" database: museums, monuments, etc. This list is not exhaustive. It can include shops (department stores, supermarkets, etc.), stations, administrations, etc.

 In this case, the user can have the choice, upon initialization of the device, either to use it only to search for a parking space, as described above, or to search for a given site or monument. This choice can be made simply by pressing a dedicated key or a combination of keys used for other functions. To fix the ideas, an initial press on the key 32 could initiate the search for tourist sites or other information, and an initial press on the key 31, the search for parking spaces.

 The search can be carried out in a similar way to the search for a parking space.

 Once this stage has been reached, the user can ask the machine to display the parking lots in the immediate vicinity of this site by pressing a dedicated key or a combination of keys. The link to the search for a parking space could also be done automatically, under the command of the recorded program, once the selection of a site has been made.

 The portable electronic guidance device 1, in the embodiment which has just been described, also has a drawback, in particular in the parking lot search application. Even if the user is guided very ergonomically, under preserved driving safety conditions, the fact remains that a parking lot can be complete without the user can find out in advance.

 In a preferred embodiment of the invention, the portable electronic guidance device 1 according to the invention is provided with an interface 56 for communication with the outside, as indicated with reference to FIG. 3.

 The exact nature of this interface essentially depends on the mode chosen for the aforementioned communications.

 According to a first variant, the portable electronic guidance device 1 can be put in communication, via the interface 56, with a data server 6, in passive or active mode. In active mode, the portable electronic guidance device 1 can selectively interrogate the server 6, for example on one or more predetermined parking lots. In passive mode, it is 1 "listening" to this server 6 and "captures" the only useful information sought when it is transmitted.

 The data collected, according to one or the other mode, are recorded, for example in the volatile memory 55. They can supplement the database recorded in the data memory 53 or even replace them. One can finally imagine that for certain types of fixed memory, for example a memory of the "PROM" type, the data thus collected are used to update ("refresh") the database.

 The physical medium of the link can be a telephone line or the like. In this case, it will be necessary to have a bi- or unidirectional modem. It should be clearly understood that this modem can be dissociated from the portable electronic guidance device 1. Indeed, a priori, the connections are established in a fixed place, for example the user's home. The latter interrogates the server 6 before leaving this home.

 An appropriate connector 562 is provided for laying down the portable electronic guiding device 1 on the modem or directly on the telephone line, as the case may be.

 Radio waves can also be used, especially in passive mode.

It suffices to provide the portable electronic guiding device 1 with an antenna (not shown), for example with an antenna constituted by a frame antenna disposed inside the housing 10. It is possible to use a subcarrier of a radio station. Advantageously, it is possible to use the method of transmitting digital information called "RDS" ("Radio Data System"). This makes it possible to transmit digital information at low speed, concurrently with an FM radio broadcast. The interface 56 then takes the form of an HF stage and a decoder.

 This second method makes it possible to "refresh" the information in the database in real or near real time. Indeed, if a local station broadcasts information of the type "number of spaces available in the car parks of the agglomeration", possibly supplemented by other services: "state of the traffic", etc., the user having preselected a given car park knows the state of occupation of it, the difficulties of access, and can direct its choice towards another if it turns out to be complete.

 According to a second variant, illustrated more particularly in FIG. 6, if there is a network of transmitting terminals, Bx, Bx + 1, etc., arranged along or near the traffic lanes Vi of an agglomeration parking lots Pi, tourist sites, shops, stations or any other place appearing in the databases recorded in the memory 53 (FIG. 3), these databases can also be updated when the vehicle V carrying the electronic device portable guide 1 passes close to these terminals. It is sufficient to have, inside these transmitting terminals, Bx, Bu + 1, low-power transmitters transmitting information, either very local if they are associated with a single site (parking lot, etc.), or concerning all of the agglomeration's sites.

 In this variant, the communication mode can be interactive, because it suffices to have a low-power on-board transmitter, placed in the housing of the portable electronic guide device 1, due to the proximity. If the transmitting terminals, Bx, Box + 1, are properly signaled (traffic signs, etc.), the on-board transmitter can be actuated, by pressing a key or a combination of keys, only for a short time, from so as to save electrical energy.

 On reading the above, it is easy to see that the invention achieves the goals it has set for itself.

 The search for predetermined information is carried out in a simple manner, in good condition of visibility and safety for the driver of a vehicle. In addition, the portable electronic guidance device offers many possibilities: real-time updating, etc.

 It should be clear, however, that the invention is not limited only to the examples of embodiments precisely described, in particular with regard to FIGS. 1 to 6.

 In particular, the number of keys, although it should preferably be limited to the smallest possible number, for reasons of ergonomics, can be arbitrary.

 The successive levels of information search to arrive at a final selection and the search strategy can be adapted without departing from the scope of the invention.

 It must also be clear that, although particularly suitable for the preferential application, the automated search for a parking space in built-up areas, the invention cannot be confined to this single type of application. It applies to many other types of research, simple or in combination, as has been shown elsewhere.

Claims (10)

REVENIDICATIONS  1. Portable electronic guidance device (1), for the automated search for at least one particular item of information, comprising a box (10), an alphanumeric data display member (2), actuation keys (30 - 34 ) and electronic circuits (5) for controlling the alphanumeric data display member (2), detecting the actuation of said keys or combination of keys (30 - 34), and for recording at least one database allowing said search, characterized in that said alphanumeric data display member (2) comprises a single display line, comprising a determined number of display positions (21 - 216) and in that, under the actuation of said keys or combination of keys (30 - 34), said control circuits (5) transmit data to the alphanumeric data display member (2) to be displayed, by horizontal scrolling, according to the m oins a scrolling direction.  2. Device according to claim 1, characterized in that the actuation of a first determined key (31), during a time interval exceeding a minimum threshold, detected by said control circuits (5), initiates the display, in continuous horizontal scrolling, of a message (MSG) of determined length, consisting of elementary alphanumeric information (INFO 1 - INFO N + 2), according to a first direction of scrolling, and in that the pressing of a first key additional (33) selects and validates one of said elementary information (INFO N).  3. Device according to claim 1, characterized in that the actuation of a first determined key (31), during a time interval below a determined threshold, detected by said control circuits (5), initiates the display in horizontal scrolling, by segments comprising a number of characters lower than said determined number of display positions (21 - 216), of a message (MSG) of determined length, consisting of elementary alphanumeric information (INFO 1 - INFO N + 2), according to a first direction of scrolling, and in that the pressing of an additional key (33) selects and validates one of said elementary information items (INFO N).  4. Device according to one of claims 2 or 3, characterized in that pressing a second determined key (32) initiates said display by horizontal scrolling, in a second direction of scrolling.  5. Device according to any one of claims 2 to 4, characterized in that pressing a second additional key (33) cancels said validation.  6. Device according to any one of the preceding claims, characterized in that it further comprises means for controlling the display of alphanumeric information (DATA 1 - DATA M + 2) of length equal to said determined number of positions d 'display (21 - 216).  7. Device according to any one of the preceding claims, characterized in that said electronic control circuits (5) comprise a microcontroller (50) communicating with at least one fixed data memory (53) for the storage of said databases.  8. Device according to claim 7, characterized in that said electronic control circuits (5) comprise interface circuits (56) allowing communications, unidirectional or bi-directional, with a data server (6) or a terminal data dissemination (Bx - Bx + l) outside, so as to be able to update said databases before use.  9. Device according to claim 8, characterized in that said communications are carried out by telephone link or by the subcarrier of a radio wave.  10. Application of an electronic portable guidance device according to any one of the preceding claims to the automated search for a parking space in an urban parking lot.