DE10046571C2 - Procedure for finding a target position - Google Patents

Description

The invention relates to a method for retrieving egg ner target position.

For the access and operation of motor vehicles increasingly used electronic vehicle keys sets, the simple version only for remote control serve a central locking system and in expenditure execution as a data carrier, for example in a Ta be carried along and code data for authentication of an authorized user. The code data will be from a vehicle access control system in a bidi rectional, for example via radio processed data comm communication is queried and if the check is positive, it will Vehicle unlocked. Before starting the engine, the Data queried again and if the check is positive, the Engine start released.

Even modern ones, with electronic keys or data carriers leave working vehicle access control and operating systems many requests from customers for improved comfort and increased security unfulfilled. For example, it occurs in the Practice again and again that one in an unknown city parked vehicle is not found or that a electronically access-protected vehicle is stolen, whether probably the data carrier is out of direct communication range with the vehicle.

EP 0805952 B1 describes a method for guiding targets Known people, with a target position in a portable, unit equipped with a GPS system can be entered can and route guidance information can be displayed. The portable unit can have a transmitting / receiving unit communicate with a stationary transmitter / receiver unit,  which is connected to a traffic computer, which in turn ü Provided with route information via a road map memory becomes. On the portable unit this way it can ever be corresponding location of the portable unit and from Entered destination-dependent route information can be generated.

Portable GPS units are also known, geographically data from waypoints that can be entered with a Display unit are provided, the respective distance from a waypoint and the deviation of the direction of movement from show the direction to the waypoint.

In a known method for finding a parked Motor vehicle (DE 299 09 002 U1) receives a portable one Keys from the vehicle position data of the vehicle so like data on the route traveled. The data is in the key sel saved. The position data can be on the key can be displayed graphically. Likewise, the driven road represented in a manner that the driver can grasp become.

In another known method for finding a parked motor vehicle (DE 199 38 951 A1) is in the key the location of the motor vehicle is saved. To find determines the position of the key and the way back to Motor vehicle.

With the known methods is a constantly updated It is difficult to display the way back to the motor vehicle Lich.

From the published patent application DE 198 26 904 A1 is a thief steel protection system known in which both keys and Vehicle-side control device via means for position determination mung. In the question-answer dialog between keys and control unit is the position of the key and the bottom sition of the motor vehicle with transmitted. Only then is unlocked  if the two positions roughly match. However, a target position can be found again cannot be accomplished.

The invention is based, to remedy the problem Problems in the operation of vehicles described above to create conditions.

A first solution to this problem is achieved with methods according to the Features of claims 1 and 2 solved.

A target position is found again in accordance with Claim 1 using one with a satellite supported positioning device, a Compu ter, a display unit and an operating unit, portable navigation device. First, the target position by operating the control unit at be at the target position sensitive navigation device determined and saved. because after is a target finding process by pressing the operator triggered.

Then the current position of the Navigation device determined and as an updated position is stored after a predetermined period of time or travel a predetermined distance the instant position as an updated position and saved and then from the direction between the aktua positions and their direction to the target position and / or the difference between the respective distances between the updated positions and the target position regarding information displayed by the display unit a relationship between the direction of movement of the Navigati device and the direction to the target position.

The retrieval of a target position takes place according to the claim 11 using one supported by a satellite Position determining device, a geomagnetic field sensor,  a computer, a display unit and one with one Control unit provided, portable navigation device. there first becomes the target position by operating the control unit with the navigation device located at the target position and saved. Then a goal finding process triggered by operating the control unit, whereupon how repeats the current position of the navigation device is determined and saved as an updated position, as a first direction the direction of the geomagnetic field which is determined relative to the navigation device as one second direction the direction from the updated position to the target position, based on the direction of the geomagnetic field, is calculated and from the first and second Direction an information displayed by the display unit regarding the direction from the updated position of the Navigation device to the target position is calculated.

According to the vehicle key, this can be used in general to find a target position without using map material is required.

The invention is based on the schematic drawing for example and described with further details ben. They represent:

Fig. 1 is a block diagram of a vehicle key and a cooperating vehicle according to the invention fixed access control system,

Fig. 2 plan views of different embodiments of vehicle keys and

Fig. 3 angular relationships to explain the direction determination to a target point in the presence of an earth magnetic field sensor.

Referring to FIG. 1, a total of nical 2 designated electric vehicle key is a provided with an antenna 4 GPS unit 6, which in a known manner from communi cation with satellite, derives the latitude and longitude at which the antenna 4 located. (The term GPS is used in the following to represent all satellite-supported positioning devices and includes not only the global positioning system, but also, for example, the Russian GLONASS system and the future European Galileo system.) The vehicle key 2 also contains an earth magnetic field sensor 8 , which contains, for example, Hall sensors or magnetic field sensors in a manner known per se and senses the orientation of the vehicle key 2 relative to the geomagnetic field. A display unit is denoted by 10. 12 denotes an operating unit, for example buttons. 14 is a power supply; 16 is a transceiver unit with a corresponding antenna 18 . The function blocks mentioned are connected via lines which, for example, can be in the form of a bus, to a control unit 20 which contains a microprocessor 22 and a memory unit 24 .

The structure and function of the function blocks described are on are known and are therefore not explained.

A cooperating with the vehicle key 2 , vehicle-fixed system comprises a control unit 30 , which contains a microprocessor 32 and a storage device 34 . With the control unit 30 , a vehicle electronics control unit 36 , from which the lights 38 of the vehicle are controlled, an immobilizer unit 40 , which, for example, blocks the operation of an ignition device, a central locking unit 42 , a GPS Unit 44 and a transmitting / receiving unit 46 connected, which may include an antenna 48 effective in the vehicle interior and an antenna 50 effective in the vehicle exterior.

Structure and function of the vehicle-fixed system (the vehicle is indicated by dashed lines) are known per se and become therefore not explained.

The access control system included in the system can have any known structure that works with coded data and bidirectional data communication, optionally also has biometric input options, etc. The vehicle key 2 can be in a simple embodiment a mechanical key that works with a beard additionally has a remote control function, or it can be a data carrier that is queried for access and departure of the vehicle and does not have to be taken in hand.

As can be seen from the following description examples, individual function blocks and scopes can be omitted if this is not necessary for the described function of the system are such.

1. Vehicle find functions a) without interaction with the vehicle-fixed system

In a simplified embodiment of the vehicle key, the earth magnetic field sensor 8 may be missing.

When leaving the vehicle, for example, a button of the operating unit 12 which acts as a trigger button is pressed, whereupon the position of the vehicle key is determined using the GPS unit 6 and stored in the storage unit 24 .

If the vehicle is to be found again from a current position, a re-find program is started or its start-up triggered by means of a further key or by pressing the aforementioned key. After pressing the button, the current position of the vehicle key is first determined and saved. The distance to the vehicle can be immediately calculated from the stored vehicle position and the current key position and displayed in the display unit 10 . Furthermore, as soon as the key is moved, the direction in which the key is moved and compared with the direction in which the stored vehicle position lies can be calculated by respectively updating the key position and comparing it with the previous key position. The deviation between the directions can be shown in the display 10 . In addition, the respective distance to the target position can be calculated and displayed, and the change in distance can also be displayed.

It is advantageous to display the direction from the angle between the vector from the penultimate updated position to the last updated position and the vector from the last derive updated position to the destination (vehicle) and clearly indicate if the directions of this Vectors match or the angle is small.

Fig. 2 shows exemplary embodiments of vehicle keys 2. Each of the keys has two keys 52 and 54 , the key 52 being pressed, for example, for storing a destination (position of the parked vehicle) and the key 54 being pressed when a vehicle search or vehicle find process is to be triggered, within which the position of the vehicle key is updated at predetermined time or spatial intervals.

The embodiment of the key according to FIG. 2a contains two light-emitting diodes, the light-emitting diode 60 lighting up, for example, when the distance to the target decreases and light-emitting diode 62 lighting up when the distance to the target increases.

The embodiment according to FIG. 2b contains a ring 64 of light-emitting diodes, the light-emitting diode which is shown in the dark being illuminated when the direction in which the vehicle key moves deviates from the direction to the target point by approximately 45 ° in the counterclockwise direction.

The embodiment of the key according to FIG. 2c contains a display 66 in which the distance to the target point and the direction in which the direction to the target deviates from the direction of movement of the vehicle key is shown.

It goes without saying that the displays can be combined with one another and modified in a wide variety of ways. For example, only one light-emitting diode can be provided which lights up when the direction of movement of the vehicle key coincides with the direction to the destination. The luminosity can increase, for example, in accordance with the improvement in the match. The display of Fig. 2c can be used in two modes, for example, in one mode the display with arrow and distance and in a graphic mode, as is known in navigation devices, with the help of waypoints the path from the current location to the destination follows. These waypoints are, for example, entered intermediate destination points that should be reached on the way to the final destination.

The search or find function described above can also be used to find keys with the vehicle according to the invention to any destination, for example buildings, shops, etc. For this purpose, the key 52 is pressed when leaving the shop and a search is then started with the button 54 if the shop is to be found again.

The function described is extraordinary for the user Lich comfortable and simple and does not require any roads cards or other additional information or additional information data. The function is therefore available worldwide bar.

In an even more convenient expansion stage, the vehicle key 2 is additionally provided with the earth magnetic field sensor 8 .

The function of the vehicle key for this case is explained with reference to FIG. 3. Assuming that the north direction of the earth's magnetic field determined by the earth's magnetic field sensor 8 (arrow N) forms an angle α with an instantaneous orientation of the display 60 (arrow A). The computer contained in the control unit 20 can calculate the angle β, which forms the direction to the vehicle (arrow Fz) with the geographic north direction, based on the current position of the vehicle key and the stored position of the target or vehicle. By subtracting the two angles from one another, the angle γ can be determined, which is the direction to the vehicle with the current orientation A of the display 66 . As can be seen directly from FIG. 3, the spatial direction of the arrows N and Fz remains unchanged when the display 66 is rotated, since both arrows accordingly correspond to the angle α and β changing when the arrow A is rotated in their relative position on the Change display 66 . With the help of the geomagnetic field sensor 8 , the direction to the vehicle and, if desired, the north direction can thus be displayed on the display without the vehicle key having to be changed in its distance from the entered target point. This enables an extremely comfortable retrieval of the vehicle or an entered destination. In addition, a high level of reliability is achieved by combining the satellite-based system with the earth's magnetic field sensor, since both systems can control each other.

It is understood that both the inputs and the input show can be changed in many ways. at for example, the input can be made via voice input, where when it may be possible to enter a target point through text to admit. The display can be additional or only acoustic done by, for example, a tone depending on the deviation between the direction of movement of the vehicle key, or the orientation of the vehicle key etc. to the destination its frequency and / or its direction changes.

The recovery processes described above, during which their activation the respective position of the key is lukewarm fend (at predetermined intervals) is updated and a accordingly updated direction and / or distance show done, can be done with any navigation device  be ver that about the necessary hardware and software added.

b) with interaction with the vehicle-fixed system

In order to further improve the comfort and / or to avoid errors due to forgetfulness, the system can be designed in such a way that when the vehicle is switched off (for example the engine is locked and / or the doors are locked, the current location is automatically read into the storage unit 24) If the vehicle is equipped with its own GPS system, this advantageously takes place in such a way that the location determined by the vehicle-fixed GPS system is read into the memory 24 , since the vehicle still knows its location even if it is parked in a parking garage, for example, where it is not possible to determine the location using GPS, this ensures that the location of the vehicle is reliably stored on the vehicle key 2. The transmission of the GPS data can take place in such a way that this data follows the usual protocol of communication between the vehicle key and be attached to the vehicle-fixed system Agitation channels are for example via radio, 433 MHz, 868 MHz, 315 MHz or GSM. It goes without saying that, depending on the design of the vehicle key, the position data can also be transmitted via an infrared transmission path, an inductive transmission path, etc., when the key is still in the ignition lock. If it is ensured that the key is located inside the vehicle, the data transmission can follow at suitable frequencies that are not used for the data transmission outside the vehicle.

2. Vehicle access protection

The invention opens up the following possibilities for the detection of an attempted misuse in which an unauthorized person wants to gain access to the vehicle ("re lay attack"):

• a) In a minimal solution, the coordinates of the vehicle key, which can be designed as an electronic identification transmitter or identification data carrier, are automatically transferred to the control unit of the vehicle after an engine stop. For example, a transmission path used for a remote control that can be used by the vehicle key can be used. At the time the position data is transferred, the vehicle key is at least still in the immediate vicinity of the vehicle, preferably even in the vehicle or in the ignition lock, so that the position data is also that of the current vehicle position. The vehicle position defined in this way is also saved in the vehicle key and is therefore not only available for the vehicle's recovery but also for controlling vehicle access. For passive vehicle entry, the key transfers its current position to the control unit, which calculates the distance between the stored vehicle position and the current position of the vehicle key. If this distance is within a specified value and there is a valid access code, the vehicle is unlocked. If the distance is greater than the specified value, an abuse attempt has been made and the vehicle remains locked. An alarm system can be activated to indicate the attempted misuse.
  In an alternative embodiment, the vehicle has its own GPS system, so that after an engine stop the vehicle coordinates can be determined by the vehicle-fixed system and transmitted to the vehicle key.
• b) In a variant of the access control system takes over the vehicle key (ID transmitter) and not the vehicle tax device evaluates the position for access protection. To the vehicle control unit asks the application after an engine stop key. If this is in the vehicle, it can to confirm his presence. The request is for the key sel the message that the vehicle was parked, wor The key then determines its position and this as Vehicle position saves. (Alternatively, the vehicle po sition in turn by a vehicle's own GPS system and transferred to the key.) With the passive The key is given vehicle access, for example, out triggers an on by a button on the vehicle door ask, whereupon he determines his position. On the key sel can now change the distance between those saved there Calculate vehicle position and the current key position be net. If this distance is below a predetermined one Value, an answer is sent to the vehicle, whereupon the Vehicle door can be unlocked. Is the distance too large, so the key doesn't send an answer and notices that there is an attempt at abuse, for example op is displayed table or acoustically. The key can too Send a signal to the vehicle that is not lock the doors but to activate an alarm system leads. The variant described has the advantage that the current position of the key not in the request- Response process must be integrated so that no adjustment solution of the software in the vehicle control unit or the transfer protocol is required.  
• c) Another approach to increase access security lies in the fact that the vehicle key also changes its transmission stage locks automatically when its distance from the vehicle passes agreed value exceeds. The identification and storage the vehicle position is as described above. The investigators The current position of the key can be adjusted whose GPS system is carried out continuously. Alternatively and without before The previous fixed definition of the permissible distance can be made using an RF-RF system (radio-radio system) a short message sent back and forth between the key and the vehicle become. The key saves its position and locks its transmission stage as soon as the radio connection breaks off. The sen The stage remains locked as long as the distance between the keys sel and vehicle is larger than the radio realm described wide. With this variant, after receipt of a valid one Request only the state of the transmission stage can be determined to detect an abuse attempt. In the event of a miss The transmission stage can be tried as an alternative to sending alarm signal to the vehicle can be activated.
• d) A variant of the method according to c) consists of the Lock the receiver in the key and not the transmitter. This has the disadvantage, however, that an abuse attempt is no longer recognized.

3. Other functions

The vehicle key according to the invention communicating or interacting with the vehicle-fixed system can be used for a variety of other functions:
For example, since the distance between the vehicle key and the vehicle is constantly known, certain vehicle functions can be triggered as soon as the distance falls below a predetermined value, for example the operating range of a remote control. When the key is in the vicinity of the vehicle, which routinely determined by bidirectional question / answer communications who can the can via the vehicle electronic control unit 36, for example, lights 38 are turned on and / or the horn are briefly operated. This makes it easier to find the vehicle directly in a parking lot.

The logic of other vehicle functions, for example the immobilizer unit 40 can be similar to that described above with the aid of the access control, such that data communication between the vehicle key 2 and the vehicle only leads to the release of the immobilizer unit if the vehicle key 2 is in one Distance is within the near range or the communication range between the antennas 50 and 18 . If this is not the case and there is data communication between data carrier 2 and the vehicle system, this indicates misuse and can lead to the activation of an alarm system.

The remote-controlled or passive vehicle access advantageously runs according to the following rules:
R1: The position of the vehicle key (which can only be designed as a data carrier) is only evaluated for remote-controlled and "passive" access to the vehicle.

R2: The engine starts in the usual way via the Ignition switch or, with prior authenticity check inside the vehicle via a starter button or through otherwise what actuation of controls.

R3: The position of the vehicle is changed every Mon Torstop saved, preferably by handing over the Position of the key currently in use on the vehicle.

R4: The evaluation of the current distance between the The key (or data carrier) and the vehicle do this vehicle-mounted control unit. This is also possible if the vehicle is not equipped with a GPS system because the Position data of the vehicle key in the data communication tion between the vehicle key and the vehicle for Vehicle can be transferred. The vehicle-side off evaluation has the advantage that in the event of an abuse attempt controlled an alarm system in a simple manner and the Ent locking of the doors can be locked. Basically is as stated above, but also an evaluation in the key possible.

R5: After locking the vehicle with a mechanical The key is remote or passive access in the vehicle is not possible and is locked. mechanical Locking means locking without data communication tion between vehicle and key, so there is no exchange of position data and the key is not known from the lock. In this case it would be passive If access is not blocked, the vehicle would be misused access with a large distance between key and Vehicle not protected.  

The following five rules cover the following special cases:
S1: Use of several valid keys (or data carriers); This is possible because the vehicle and the keys know the vehicle position and the vehicle evaluates the distance. If the vehicle is put out of operation, for example with a key A, the position of key A is transferred to the vehicle, for example after the engine stop. If the vehicle is then to be unlocked with a key B, this key transfers its data, including its current position, to the vehicle. The control unit in the vehicle calculates the distance and decides whether it is within the permissible range or if an abuse attempt has been made. (rules applied: R1, R2, R3, R4)

S2: vehicle remains unlocked; no problem there for then no data transmission is necessary for access (applied Rules: R1, R2).

S3: automatic relocking; no problem; (Applied Rules: R1, R2, R3, R4; like S1)

S4: Workshop case (mechanical or RF locking); Is no problem; no passive entry possible; Ent locking mechanically or via RF. (applied rule: R5) Example: The vehicle is being towed to a workshop; there it is locked with the mechanical key. For a subsequent unlocking must then also be a me chanic key can be used.

An exception is a towing case in front of which the vehicle e was locked electronically (with position storage), however  is no longer at the point where its position is saved was saved. In this case, the vehicle must be mechanically be locked. One solution could be that with an in-vehicle GPS system updates the position becomes. Then the key itself no longer calculates the Target position, but after an engine stop, the driving tool coordinates determined by the vehicle-mounted GPS system and hand over the key. The distance between the Vehicle key and the vehicle is then due to the loading the current coordinates are known.

Claims (2)

1. A method for locating a target position using a portable navigation device ( 2 ) provided with a satellite-supported position determination device ( 6 ), a computer ( 22 , 24 ), a display unit ( 10 ) and an operating unit ( 12 ), comprising the following steps:

• - Determining and storing the target position by actuating the control unit with the navigation device located at the target position,
• - triggering a target finding process by operating the control unit,
• - whereupon repeated
• the current position of the navigation device is determined and stored as an updated position,
• - After a predetermined period of time has elapsed or a predetermined distance has been covered, the current position is determined and stored as an updated position and
• - From the direction between the updated positions and their direction to the target position and / or the difference between the respective distances between the updated positions and the target position, information displayed by the display unit relating to a relationship between the direction of movement of the navigation device and the direction of Target position is calculated.

2. A method for locating a target position using a portable navigation device provided with a satellite-supported position determining device 6 ), a geomagnetic field sensor ( 8 ), a computer ( 22 , 24 ), a display unit ( 10 ) and a control unit ( 12 ) ( 2 ), comprising the following steps:

• - Determining and storing the target position by actuating the control unit with the navigation device located at the target position,
• - triggering a target finding process by operating the control unit,
• - whereupon repeated
• the current position of the navigation device is determined and stored as an updated position,
• the direction of the geomagnetic field relative to the navigation device is determined as a first direction,
• - As a second direction, the direction from the updated position to the target position, based on the direction of the geomagnetic field, is calculated and
• - From the first and second directions, a display unit displaying information relating to the direction from the updated position of the navigation device to the target position is calculated.