FR2828930A1 - METHOD AND DEVICE FOR ACCOMPANYING AN OBJECT GUIDED BY NAVIGATION - Google Patents

Abstract

Method of escorting an object guided by navigation, characterized by the following steps: for guidance to the destination, predetermined route data within an area is used, - at least when leaving the area determined by the road data, the position data of the object is stored, - the position data is stored at least as long as a known orientation point is not reached by the storage of the position data, - from a known orientation point, the object is accompanied by a return trip based on the stored position data.

Description

clamp despite the return force of the helical spring.

  The invention relates to a method and a device for

  escorting an object guided by navigation.

  STATE OF THE ART Navigation devices are already known which guide a vehicle on a precalculated road. Navigation devices which have access to data other than that of the routes used are able to bring the user to their destination by an alternative route which, if necessary, must be calculated. If, however, the user is outside the digital road network, he is generally asked to turn around or else he is indicated, by means of a compass,

  direction as the crow flies to a known waypoint.

  Advantages of the invention The method according to the invention is a method of accompanying an object guided by navigation characterized by the following steps: - for destination guidance, use of predefined route data completed within 'a zone, - at least when leaving the zone determined by the route data, the object position data is memorized, o - the memorization of the position data is done at least as long as the one does not reach a known orientation point by memorizing the position data, - from a known orientation point, a tracking of the object

  is done according to the stored position data.

  The device according to the invention comprises the following operating units: - a memory for a digital map, - a positioning unit, - a position memorization unit, o - a module for recognizing the state of an object , a unit for establishing a position track from the data of the position memorization unit and the state recognition data,

  - a module for destination guidance.

  3s The method and the device make it possible to accompany an object guided by navigation and in particular a motor vehicle, even

  outside the digital road network, to a known waypoint.

  The invention makes use in particular of the fact that in a navigation system in operation, a path taken previously (tracking) is automatically recorded, from a certain duration or a certain journey. In the invention, this tracking is advantageously used to accompany the object guided by navigation along the reverse path to the last waypoint, which is for example still designated on a digital map on board the vehicle. An advantage of the invention comes from the fact that the object guided by navigation or the vehicle can be guided to its very destination.

  in a non-digitized area, by accompanying it to the known route.

  Such features are particularly interesting when the driver of the vehicle has only incomplete databases to lead him to his destination, as is the case in navigation. For example, the object is escorted according to the stored position data by generating a direction arrow. to generate the direction arrow, we analyze the expected route data near the object and are related to the instantaneous speed of the object and in this case we determine whether from the route data and the radii of curvature to be expected from these as well as from the instantaneous speed of the object, an angular speed is obtained which exceeds the maximum speed tolerated for this object, and from this a turning process is indicated in the form of a corresponding direction arrow. Thus, the object is accompanied using a digital map which is generated from the stored position data and the digital map generated from the stored location data is represented in combination with a digital or predetermined map. According to other characteristics of the process: during a ride, on another road, for example as a result of a one-way street, we undertake an own command of the object, until we reach a known orientation point, from which it is possible to escort from the recorded data, the memorization of the position data is interrupted when two successive position data are similar or too little different from each other, or - the memorization of the position data does not continue or is interrupted when the imprecision of the positions exceeds a predetermined quantity. The invention proves to be particularly advantageous when the circumstances do not make it possible to turn back, for example when there is no possibility of a U-turn, in the event of a prohibition on turning, o one-way lanes or equivalent. In these cases, the driver of the vehicle starts by moving without orientation in the known road network to find there a known point of orientation from which he turns back to the road taken previously. In a non-digitized sector, that is to say when one leaves the areas provided by the route data, this process is supported according to the invention in that these unknown sectors are automatically digitized by a specific device to the object guided by navigation. If this device then detects an orientation point where the object guided by navigation has already been found, it is then

able to accompany the object.

  Accompaniment is then particularly simplified when direction indication arrows are generated from the expected route data and the speed of the object; using these arrows you can then browse the path previously traveled in the "offroad" area or a new path in a sector possibly digitized. Advantageously, the device is designed so that: - a filtering device is associated with the position memorization unit, to interrupt memorization when, according to certain predetermined criteria, the object is too immobile. or too great an imprecision of the position, - a module is provided to establish guidance indications to destination as a function of vehicle state data, - the module to obtain guidance indications to destination is in operation link with the position track, to give guidance indications to the destination during a new movement of the object on the position track, - the module for destination guidance is connected with an output unit to deliver the indications issued from a module to obtain destination guidance instructions, in particular under

  the shape of a direction arrow.

  Drawings Examples of embodiments of the invention will be described in more detail with the aid of the drawings. Thus: - Figure 1 shows a tracking when one has left the prerecorded route data,

  FIG. 2 is a connection along a position guide up to

  that at a known orientation point, to - FIG. 3 shows a device for accompanying an object guided by navigation, and

  - Figure 4 shows a ride using direction indications

tion.

  Description of the exemplary embodiments

  s The implementation of the invention requires a navigation system which is able to guide an object guided by navigation on a previously digitized road network, that is to say to give guidance indications to the driver at the 'within an area where road data has been previously digitized. In addition, the navigation system must be able to memorize the object position data, i.e. the road data, from which the data

  position of the object / vehicle can be recovered. It is partly

  particular GPS positions and / or directions and routes.

  The method according to the invention draws, when leaving the path 1 or the network (of the sector predefined by the route data)

  position data determined by the positioning unit, a

  continued (tracking), (see Figure 1). This tracking 2 is drawn until one or more new determined positions turn out to be already stored position information. If the vehicle meets at

  o minus tracking information, then the driver can be connected

  safely accompanied along this position guide until a re-

  known road bucket or to its route (see Figure 2).

  The operating mode of the escort according to the invention will be described with the aid of two exemplary embodiments: s example 1: a vehicle is guided by a navigation system and leaves the sector of the digital map located in the so it is in an unscanned area. From the moment we leave this sector, the path traveled by the vehicle is permanently drawn, so that after a half-turn we can accompany it on the same path. This process is carried out by reverse direction of the recorded path, for example in the form of a guidance to

  using arrows or a digital map.

  s example 2: the same vehicle leaves the digital map sector located in the navigation device, but due to a one-way street

  that unfavorable he cannot travel the same way in reverse.

  The driver obviously goes around the one-way street. As soon as the driver encounters an area that has been traveled in any direction whatsoever, the navigation system tries to stop it

  get to the known route according to the stored data.

  A device suitable for implementing the method according to

  the invention will be described below using FIG. 3.

  The device comprises a navigation system with a position unit 200, the position data of which it determines are compared with the data of a memory 100 for a digital map. According to the invention, this navigation system is extended by a module 300 for state recognition. This module 300 which interprets the data from the positioning device 200 and from the memory 100 decides o between the following object / vehicle states: - onroad: the vehicle is on or is traveling on a portion of the route scanned. - offroad: the vehicle is not on or is not driving on a portion

  route digitized or at a previously stored position.

  s - ontrack: the vehicle moves or rolls on a preceeded position track

duly memorized.

  A position storage unit 400 according to the invention for storing and filtering position data ensures that, on the one hand, a position track is memorized and that, on the other hand, all the positions determined by the position unit 200 are not memorized but are filtered according to predefined criteria. The criteria for filtering can be: - stability phase: stop recording, because the position values thus determined do not differ or are too little different from the 3s position determined previously, position inaccuracy too large: the recording does not is not then

continued or interrupted.

  A module 500 according to the invention for establishing indicators

  destination guidance determines the guidance indications to

  Appropriate designation from module 300, these indications can be given from position track 700 when the journey is repeated. A module 600 for ontrack destination guidance delivers, at the time

  appropriate, the destination guidance indications determined by the

  dule 500, to an appropriate output unit 800. The same bus 900 can be provided for the exchange of data between the modules / units 300, 400,

500, 600, 700 and 800.

  o The digital map generated from the recorded position data can be represented in combination with a pre-recorded digital map, so as not to overload the driver of the vehicle unnecessarily with additional information or a different form of representation. We can generate and display alternati

  or in addition to the digital map, general direction arrows

  rces from the saved ride position data.

  Advantageously, the module 500 determines indi-

  guide cations for the destination based on a route already taken

  folded inside the offroad sector. This increases both driving safety and driving comfort because the driver is

  warned in time of a change of direction.

  As a turn indication, no destination guidance instruction will be designated subsequently, which reproduces the real geographic data in the form of separating roads. We must understand the directions for the turn much more as a preparation for the

  driver who subsequently adapts his driving to the view or to the road.

  The destination guidance system analyzes the street guidance (route guidance) to wait for and does not relate them to the instantaneous speed of a vehicle. If we get from the route data and

  o the radius of curvature to be expected from these as well as from vi-

  instantaneous size of the object, an angular speed, which exceeds the maximum tolerable speed for this object (vehicle), then we await a process suitable for the turn which leads to a corresponding indication. By giving / displaying a corresponding destination guidance instruction, the driver is prepared so that he reduces speed in good time and

  can thus safely follow the street (road). This can be seen in Figure 4.

  If vehicle 5 follows route 6 previously recorded with a

  sufficiently small, only the direction arrows 7 are illuminated,

  this arrow shows the continuation of path 6 by comparison with the north. AIN-

  if, the driver is helped to choose the right direction in the case of a fork. Destination guidance according to the invention supposes that if the guidance device or the module 300 has digital information,

  i.e. road (street) data. For the offroad navigation function

  tion, these digital route data can be saved when

  we p roam the offro ad zone at the same time as the ge ogra-

  associated phiques. It is also possible to transmit such a route

  o by other systems, i.e. by wave transmission from

  shot from a central which has digital data concerning this

  offroad zone which is not known from the vehicle memory 10. The process

  destination guidance dice can also be used for common navigation devices with which the user is inside the

  s sectors predetermined by road data. For this, we must obtain

  set the process path from the digital card of memory 100

of the vehicle.

  From the observed path, the minimum radius of curvature is then calculated in the direction of travel within a defined distance o from the location of the vehicle. An advantageous development of the method tests the plausibility of the radius of curvature and noise or measurement errors are not misleadingly interpreted as curves. Another advantageous development of the method resides in the fact that the path is evaluated at a distance from the position of the vehicle depending on the speed of the vehicle. From the instantaneous speed of the vehicle v and the radius of curvature r we calculate, using the formula = v / r, the speed

  maximum angular to wait. If this speed exceeds the maximum speed

  male generally accepted and / or observed and / or entered manually, associated with this vehicle and / or driver, the output unit 800 delivers a

  : o corresponding turn instruction.

  If the vehicle is traveling at a sufficiently reduced speed, the path in the immediate vicinity is shown as straight. In

  an advantageous embodiment, the instantaneous direction corresponds to the di-

  rection on screen of the output unit 800. The nearest turn will be represented by a curvature of the arrow relative to the representation

mentioned above.

  In the embodiment shown in Figure 4, the

  vehicle comprising a destination guide according to the invention turns from the digitized sector towards a non-digitized forest path and is thus, by definition, in an offroad state. With the arrival of the offroad state, the

  vehicle path is stored in the form of a coordination chain

  nces of waypoints. After reaching an intermediate destination in the non-digitized sector, the driver chooses to be

  accompanied by the guide according to the invention.

  Destination guidance guides the driver using

  direction indications along a stored route to the destination.

  When moving away from the path, the correct direction appears to the driver

  to because a destination guide arrow shows him permanently

  the way. Before curves where the driver gets too close

  quickly, turn directions are issued.

Claims (10)

R E V E N D I C A T I O N S   1) Method for escorting an object guided by navigation, characterized by the following steps: - for destination guidance, predefined route data are used within an area, - at least when leaving the zone determined by the route data, the position data of the object are memorized, - the memorization of the position data is done at least as long as it does not reach an orientation point known by the memo o rization of position data, - from a known point of orientation, a retrieval of the object   is done according to the stored position data.   2) Method according to claim l, characterized in that the object is accompanied according to the position data   memories by generating a direction arrow.   3) Method according to claim 2, characterized in that to generate the direction arrow, we analyze the expected road data due near the object and we put them in relation to the speed ins tantance of the object.   4) Method according to claim 3, characterized in that it is determined whether from the route data and the radii of curvature to be expected therefrom as well as from the instantaneous speed of the object a speed is obtained angular which exceeds the maximum speed tolerated for this object, and from this a turning process is indicated in the form   a corresponding direction arrow.    ) Method according to claim 1, characterized in that the object is accompanied by a digital card which   is generated from the stored position data.   6) Method according to claim 5, characterized in that the digital map generated from the stored position data is shown in combination with a predetermined mine digital map. 7) Method according to claim 1, characterized in that during a ride, on another road, for example as a result of a one-way street, we undertake an own command of the object, to until that we reach a known orientation point, from which   a back-up from the recorded data is possible.   8) Method according to claim 1, characterized in that s the memorization of position data is interrupted when two successive position data are similar or too little different one from the other.   9) Method according to claim 1, characterized in that   the memorization of position data does not continue or is inter-   broken when the imprecision of the positions exceeds a predefined quantity   completed. s 10) Device for accompanying an object guided by navigation comprising the following operating units: - a memory (100) for a digital map, - a positioning unit (200), - a position memorization unit (400 ), - a module (300) for recognizing the state of an object, - a unit (700) for establishing a position track from the data   the position memory unit (400) and the recognition data birth of state (300),   - A module (600) for destination guidance.   11s) Device according to claim 10, characterized in that a filtering device is associated with the position memorization unit (400), in order to interrupt the memorization when, according to certain predetermined criteria, there is too great a phase d immobility of the object or a   too much imprecision of the position.   12) Device according to claim 10, characterized in that a module (500) is provided for establishing guidance indications to   tination based on vehicle status data.   13) Device according to claim 10, characterized in that the module (500) for obtaining guidance indications at destination is in operation link with the position track (700), to give guidance indications at destination during 'a new movement of   the object on the position track (700).   14) Device according to claim 10, characterized in that the module (600) for destination guidance is connected with an output unit (800) for delivering the indications delivered from a / from the module   (500) for obtaining destination guidance instructions, in particular   link in the form of a direction arrow.