Automobile locking system

Abstract

Locking system for access and / or driving authorization for a motor vehicle (1), with a first device (4) having at least two states and designed as a control device, and with an associated second device (5) designed as an electronic key, an ID transmitter or a chip card, wherein the first device (4) and the second device (5) have transmitters and receivers (24, 17) for electromagnetic signals (7) for their intended operation, wherein the transmitters (17, 24) are designed to be operated with a transmission channel (19) having a predetermined transmission frequency, and wherein at least one of the signals (7) transmitted between the second device (5) and the first device (4) is a coded operating signal (15) for authenticating the second device (5), so that after positive evaluation of the transmitted operating signal (15) a change in the state of the first device (4) can be effected if the second device (5) is authorized, characterized in that the receiver (24) of the first device (4) is designed to evaluate the transmitted signal (7) for validity and to activate the first device (4) only when a valid signal (7) is present, wherein the receiver (24) of the first device (4) is designed to evaluate the validity, a frequency deviation (21) of the signal (7) and a checksum (25) contained in the signal (7).

Description

[0001] The invention relates to a locking system according to the preamble of patent claim 1.

[0002] For increased security requirements, electronic locking systems that operate using electromagnetic waves are used. In motor vehicles, in particular, such locking systems are used as door locking systems for access authorization and / or as ignition lock systems, steering wheel locks, immobilizers, engine control units, or similar systems for driving authorization.

[0003] Such locking systems are known from DE 43 40 260 A1. The locking system consists of a first device, which has at least two states and is designed as a control device for unlocking and / or locking the car doors in the manner of a central locking system or the ignition lock, and an associated second device, designed in the manner of an electronic key. For their intended operation, both devices have transmitters and / or receivers for transmitting electromagnetic radio signals. During intended operation, at least one signal can be transmitted between the key and the control device as a coded operating signal for authenticating the key, so that after positive evaluation of the transmitted operating signal and thus if the key is authorized, a change in the state of the control device can be effected.The transmitter is operated with a transmission channel having a predetermined transmission frequency, so in such radio locking systems the data is sent on a radio channel.

[0004] Such locking systems have also been further developed with so-called "keyless" functionalities. With "KeylessEntry" or "PassiveEntry" functionality, manual operation of the electronic key by the user is no longer necessary. It is sufficient for the user to carry the key with them. The operating signal for access authorization is then automatically transmitted between the two devices when the user is within an effective range near the vehicle and, for example, operates the door handle. These locking systems can also feature "KeylessGo" or "PassiveGo" functionality, whereby the operating signal for drive authorization is automatically transmitted between the two devices when the user is inside the vehicle and, for example, presses a start / stop button on the dashboard.

[0005] Due to the increasing use of radio frequencies by different systems, frequencies are being used multiple times by different users and devices simultaneously. It should be noted that interference from various radio transmitters, such as baby monitors, wireless headphones, etc., can repeatedly cause malfunctions in the wireless connection.

[0006] Further locking systems or partial aspects of such locking systems are also disclosed, for example, in the documents DE 10 2005 030 082 A1, DE 10 2006 043 141 A1 and EP 1 000 824 A1.

[0007] The invention is based on the object of improving the functional reliability of such a locking system.

[0008] This object is achieved in a generic locking system by the characterizing features of claim 1.

[0009] In the locking system according to the invention, the transmitted signal is evaluated for validity in the receiver, with the first device being activated only when a valid signal is present, in particular to perform authentication. Thus, the quality of a transmission channel is evaluated using various criteria. This allows the determination of the channel on which data transmission functions without interference. This channel is then selected for transmission. Advantageously, radio transmission is thus possible even when interference occurs by selecting an appropriate channel for the multi-channel radio locking and / or Keyless Entry / Go system. Further embodiments of the invention are the subject of the dependent claims.

[0010] According to the invention, the signal's frequency deviation is evaluated to assess its validity. The signal's frequency deviation is particularly characteristic of FSK (Frequency Shift Keying) modulation of the data transmitted with the signal.

[0011] Furthermore, the signal contains a checksum, which is in turn evaluated according to the invention to assess validity.

[0012] In yet another embodiment, the signal contains an identification (ID) for the associated vehicle, which is evaluated to determine validity. These embodiments have in common that they involve easy-to-implement criteria.

[0013] A particularly preferred configuration of the locking system is as follows: It involves the detection and / or selection of a free channel for valid radio locking messages based on criteria such as SIGID (modulation index evaluation), CS (message checksum), and vehicle ID (identification).

[0014] Vehicle receivers for radio locking messages are operated cyclically to reduce average power consumption. The receiver is switched on briefly and remains off for the remainder of the cycle time. Using signal detection during the switch-on phase, the receiver evaluates whether the beginning of a valid locking message has been received. If this is detected, the evaluating (control) unit is woken up and the receiver is switched to continuous operation. It is common practice to recognize a valid radio message by its preamble with a fixed data rate and content, but this is not necessarily the case. Depending on the conditions, radio messages can be distorted or disrupted during transmission. However, random signals and / or interference signals similar to valid radio messages can also occur at the receiver.If these are interpreted as valid radio messages too frequently, the system's power consumption increases noticeably, as the evaluating (control) device is always woken up. The accuracy of the evaluation is therefore subject to compromises, leading to only moderate results regarding the actual power consumption of the receiving system.

[0015] To improve the scope for determining the evaluation accuracy, additional criteria of the received signal are used. The following criteria have proven particularly suitable for this purpose: (1) SIGID (Modulation Index Evaluation)

[0016] When transmitting with FSK modulation, the frequency deviation is a characteristic of the transmitted signal. By evaluating this frequency deviation within a specific detection window, an additional parameter is available for signal detection. This significantly improves the compromise between valid detection and resistance to false detection. (2) CS (message checksum)

[0017] To identify which of the three transmission channels, for example, correctly transmitted the "radio locking message," a checksum may be added to this radio message. This allows the radio receiver to decide for itself whether the message is valid and whether it should be transmitted to the subsequent (control) unit. (3) Vehicle ID (Identification)

[0018] To further reduce the wake-up rate of the downstream (control) unit and thus the overall power consumption of the radio system within the vehicle, the vehicle's ID (identification) is written into the radio receiver. Only messages from the vehicle keys assigned to the vehicle, i.e., with the correct ID, are forwarded to the downstream (control) unit. Messages from keys outside the vehicle are ignored.

[0019] The advantages achieved by the invention include, in particular, the fact that it enables virtually interference-free data transmission. It ensures reliable signal detection of valid radio messages and a low rate of false detection of external and / or interfering signals. This significantly increases the reliability of radio locking systems than previously possible.

[0020] An embodiment of the invention with various developments and refinements is shown in the drawings and is described in more detail below. Fig. 1 a motor vehicle equipped with a locking system, Fig. 2 a schematic block diagram of the locking system comprising two devices with a diagram for the transmission of the signals, Fig. 3 the second device of the locking system in a partially cut-away and schematic view, Fig. 4 a diagram for the transmission of a signal in a first embodiment, Fig. 5 a diagram for the transmission of a signal in a second embodiment and Fig. 6 a diagram for the transmission of a signal in a third embodiment.

[0021] In Fig. 1 shows a motor vehicle 1 with the authorized user 2. The motor vehicle 1 is provided with a locking system 3 as a door locking system for access authorization, which comprises a first device 4 designed as a control device and an associated second device 5. The second device 5 is designed as an electronic key, an identification (ID) transmitter, a chip card, a smart card, or the like. The second device 5 is in the possession of the authorized user 2, which gives them access to the motor vehicle 1 within an effective range 8.

[0022] The first device 4 has at least two states, the first state being locking and the second state being unlocking of the car doors 6. For their intended operation, the two devices 4, 5 have means for transmitting and / or receiving signals 7 by means of an electromagnetic carrier wave. At least one of these signals 7 transmitted between the second device 5 and the first device 4 is a coded, electromagnetic operating signal 15 (see Fig. 2). The coded operating signal 15 serves to authenticate the second device 5, whereby, if the second device 5 is authorized, a change in the state of the first device 4 can be effected after positive evaluation of the transmitted operating signal 15. The transmission of the coded operating signal 15 occurs when the authorized user 2 operates the door handle 16 on the car door 6 or approaches the door handle 16. This triggers the unlocking of the car doors 6 according to the operation-independent KeylessEntry functionality. The transmission of the coded operating signal 15 can also occur automatically without the cooperation of the user 2 as soon as they enter the effective area 8, although this will not be discussed in detail below. If the user 2 closes the car doors 6 from the outside, the car doors 6 are automatically locked.The automatic locking of the car doors 6 can also take place after the user has left the effective area 8.

[0023] In addition to the KeylessEntry functionality, remote-controlled locking and unlocking of the car doors 6 is also possible, which can be done by means of Fig. 3 visible actuating elements 9, designed in the form of buttons, on the second device 5 can be triggered by the user 2 in order to grant the user 2 operation-dependent access authorization to the motor vehicle 1. For example, by manually actuating the actuating elements 9, the central locking system can be locked and / or unlocked and the trunk lid can be opened by sending corresponding coded operating signals 15 from the second device 5 to the first device 4. The symbols 10 corresponding to these functions are applied to the actuating elements 9.

[0024] The locking system 3 also determines the driving authorization for the motor vehicle 1. For this purpose, the first device 4, designed as a control device, also unlocks and / or locks the electronic ignition lock or the steering wheel lock depending on the two states. Another functionally relevant component of the motor vehicle 1 can equally well be controlled accordingly by the first device 4. For example, this can enable and / or disable an immobilizer, the engine control unit, or the like. The transmission of the coded operating signal 15 for authenticating the second device 5 occurs when the authorized user 2 is in the motor vehicle 1 and actuates a start / stop switch 11. This triggers the starting process or the like of the motor vehicle 1 according to the KeylessGo functionality.

[0025] In addition, emergency operation can be provided, for example when the battery of the second device 5 is empty, in that the second device 5 can be inserted as an electronic key into the ignition lock of the motor vehicle 1 for manual operation by the user 2.

[0026] The functioning according to the keyless functionality of the locking system 3 according to the invention will now be explained with reference to the Fig. 2. First, the first device 4 sends a first electromagnetic signal 12, referred to as a wake-up signal, for the associated second device 5 by means of a transmitter / receiver 24 as a means for sending and / or receiving signals. This transfers the second device 5 from a rest state with reduced energy consumption to an activated state for its intended operation. The first device 4 then sends at least one further, third electromagnetic signal 13, which is also referred to below as an area demarcation signal. This enables the associated second device 5 to determine its location in relation to the first device 4. In particular, it can be determined whether the second device 5 is located outside the motor vehicle 1 and, if applicable, at which location in the exterior space 23 and / or in the interior 22 of the motor vehicle 1.Subsequently, the second device 5 sends a fourth signal 14 containing the information on the determined location to the first device 4 via a transmitter / receiver 17. This fourth signal 14 is also referred to below as a response signal. Finally, as already described, the fifth electromagnetic signal is transmitted as a coded electromagnetic operating signal 15 for authentication by means of the transmitter / receivers 24, 17 between the first and second devices 4, 5. The signal 15 can, in particular, consist of several sub-signals and be transmitted in a bidirectional communication between the two devices 4, 5.

[0027] For further details on bidirectional communication itself, please also refer to DE 43 40 260 A1.

[0028] The wake-up signal 12 can, for example, contain an identifier for the motor vehicle type. Upon receipt of the wake-up signal 12, all second devices 5 located within the effective range 8 that belong to the same motor vehicle type are initially activated. In a further embodiment of the locking system 3, the first device 4 sends a second electromagnetic signal 18 to the second device 5 as a selection signal between the first signal 12 and the third signal 13, as will be explained in more detail with reference to Fig. 2. The second signal 18 contains information about the more specific identity of the motor vehicle 1. This ensures that only the second devices 5 actually belonging to the first device 4 remain in the activated state. However, second devices in the activated state that do not belong to the motor vehicle 1 are returned to the idle state.

[0029] The signal 15 is transmitted as a radio signal, for example, in the HF (high frequency) range. The other signals 12, 13, 14, 18 are also radio signals that can be transmitted in the LF (low frequency) range and / or in the HF (high frequency) range as needed. For example, the carrier wave for the first signal 12 and / or the third signal 13 can have a frequency in the inductive, low-frequency LF range of approximately 20, 120, 125 kHz or the like. The carrier wave for the second signal 18 and / or the fourth signal 14 and / or the fifth signal 15 can, for example, have a frequency in the higher-frequency RF range of approximately 315, 433, 868 MHz or the like. The respective transmitter / receiver 17, 24 can be operated to transmit the signals 7 containing the corresponding data with a transmission channel 19 having a predetermined transmission frequency, as shown schematically in Fig. 3. Furthermore, the transmitter / receiver 17, 24 can be operated with at least one additional transmission channel 20. To select a transmission channel 19, 20 that is undisturbed, the transmitted signal 7 is first evaluated for validity in the receiver 24. Then, the transmission channel 19, 20 that has the valid signal 7 is selected. To reduce energy consumption, the transmitted signal 7 is also first evaluated for validity in the receiver 24. The first device 4 is then only activated when a valid signal 7 is present. This measure is primarily carried out with regard to the complex authentication using the operating signal 15.

[0030] The validity of signal 7 can be assessed using various criteria. If the data of signal 7 is encoded using FSK (Frequency Shift Keying) modulation, the frequency deviation 21 of signal 7 can be used as a criterion for validity, as shown in Fig. 4 is shown schematically. Another criterion for the validity of the signal 7 is a checksum 25 contained in the signal 7. As in Fig. As can be seen in Figure 5, a checksum 25 is added to the data 26, whereby the checksum 25 is evaluated accordingly to assess the validity for the signal 7. Another criterion is the identification (ID) 27 of the motor vehicle. As the Fig. As can be seen from Figure 6, the identification 27 is attached to the data 26, so that the signal 7 contains the identification (ID) 27 for the associated motor vehicle. The identification (ID) 27 is then evaluated to assess the validity of the signal 7.

[0031] The invention is not limited to the described and illustrated embodiment. Rather, it also encompasses all developments within the scope of the invention defined by the patent claims. Thus, such a locking system can be used not only in motor vehicles. It is also possible to use it for any other door lock, for example, located on a property or similar. List of reference symbols 1 motor vehicle 2 (authorized) users 3 locking system 4 first facility 5 second device / electronic key 6 car doors 7 Signal 8 Effective range 9 Actuating element 10 Symbol (on the actuator) 11 Start / Stop switch 12 (first) signal / wake-up signal 13 (third) signal / area demarcation signal 14 (fourth) signal / response signal 15 (fifth) signal / (coded) operating signal / code 16 Door handle 17 transmitters / receivers (in the second facility) 18 (second) signal / selection signal 19 broadcast channel 20 (additional) transmission channel 21 Frequency sweep 22 Interior (of the motor vehicle) 23 Exterior (of the motor vehicle) 24 transmitters / receivers (in the first setup) 25 Checksum 26 data 27 Identification

Claims

[1] Locking system for access and / or driving authorization for a motor vehicle (1), with a first device (4) having at least two states and designed as a control device, and with an associated second device (5) designed as an electronic key, an ID transmitter or a chip card, wherein the first device (4) and the second device (5) have transmitters and receivers (24, 17) for electromagnetic signals (7) for their intended operation, wherein the transmitters (17, 24) are designed to be operated with a transmission channel (19) having a predetermined transmission frequency, and wherein at least one of the signals (7) transmitted between the second device (5) and the first device (4) is a coded operating signal (15) for authenticating the second device (5), so that after positive evaluation of the transmitted operating signal (15) a change in the state of the first device (4) can be effected if the second device (5) is authorized, characterized by that the receiver (24) of the first device (4) is designed to evaluate the transmitted signal (7) for validity and to activate the first device (4) only when a valid signal (7) is present, wherein the receiver (24) of the first device (4) is designed to evaluate the validity, a frequency deviation (21) of the signal (7) and a checksum (25) contained in the signal (7). [2] Locking system according to claim 1, characterized bythat the receiver (24) of the first device (4) for evaluating the validity is designed to evaluate the frequency deviation (21) of the signal (7) in the case of FSK (Frequency Shift Keying) modulation. [3] Locking system according to claim 1 or 2, characterized by , that the signal (7) contains an identification (ID; 27) for the associated motor vehicle (1), wherein the receiver (24) of the first device (4) for evaluating the validity is designed to evaluate the identification (ID; 27). [4] Locking system according to one of the preceding claims, wherein the first device (4) is a control device of a central locking system for unlocking and / or locking the car doors (6), or a control device for unlocking and / or locking the ignition lock, or a control device for unlocking and / or locking the steering wheel lock, or a control device for enabling and / or disabling the immobilizer or the engine control unit. [5] Locking system according to one of the preceding claims, wherein the electromagnetic signals (7) are radio signals.

Images