SYSTEM

The invention relates to a combination of an engine control module for a vehicle and an anti-theft system, according to the preamble of claim 1.

A combination of an engine control module for a vehicle and an anti-theft system of this type aims to prevent the theft of vehicles, by disabling the engine control module as long as there is no authorised key connected to the system. The term vehicle in relation to this invention covers vehicles for the transport of persons and/or goods, such as a car, a motor cycle, an airplane, or a boat, and heavy equipment, such as a bulldozer, a tractor, a crane, a forklift, an excavator, or a drilling machine.

An anti-theft system of this type is known from US-5.600.723 (US'723). US'723 discloses a vehicle anti-theft system in the form of a mechanically interengagable electronic key and lock. The system includes stored key and vehicle identifiers in both the key and in the lock. A random number is generated in the lock each time the vehicle ignition switch is closed and that random number is used to encode one of the identifiers for transmission to the key. The key uses the corresponding stored identifier to recover the random number. The other stored identifier is then encoded using the recovered random number and the encoded other identifier is returned to the lock. The lock uses the generated random number to recover the second identifier for comparison to its stored value. If the comparison fails, vehicle operation is prevented.

A disadvantage of the known anti-theft system is that it uses a relative complicated key with multiple memory banks and active electronics. Moreover, it requires vehicle identifiers and key identifiers to be stored in both the memory banks of the key, and in the memory of the lock. This causes a risk, as thieves may steal the relevant codes from the car manufacturer, or read them electronically from the electronic key, or lock.

The invention aims to solve at least one of these problem, or at least to provide an alternative. In particular, the invention aims to provide a combination of an engine control module for a vehicle and an anti-theft system that is more robust.

This aim is achieved by a combination of an engine control module for a vehicle and an anti- theft system according to claim 1.

The invention relates to a combination of an engine control module for a vehicle and an anti-theft system. The anti-theft system comprises a control circuit and an external key. The external key comprises an input port and an output port which are operatively connectable with the control circuit. The control circuit comprises a test signal generator, an internal key, and a comparison unit. The comparison unit is configured to compare an internal signal from the control circuit with an external signal from the external key, and to provide an unlocking signal to the engine control module if the internal signal and external signal match, in particular if the internal signal and external signal are identical. The anti-theft system is configured with N channels, N being an integer and at least 4, preferably at least 5. The test signal generator is configured to provide an N-channel test signal. The external key comprises an external scrambler, the input port comprises N input terminals, the output port comprises N output terminals, and the external scrambler comprises N conductors. The N conductors each connect an input terminal with an output terminal in a scrambled manner. The internal key comprises an internal scrambler.

In the context of this invention, the terms scrambler and in a scrambled manner are to be interpreted in that at least two input ports are each connected to an output port which has a different position or channel number than the relevant input port. The term configured defines both hardware and software solutions, e.g. hardware wiring by conductive wires or traces and/or electronic components on a printed circuit board, or software implemented in a programmable computer chip.

The external key comprises simple components which makes it simple and cheap compared to the external key of US'723. Moreover, no programming is required, as the external scrambler is made of conductors. This reduces the risk of theft of programmable codes. Accordingly, the external key of the current invention is robust compared to the key of US'723.

Preferred embodiments are defined in the dependent claims.

In an embodiment, the input port of the external key is operatively connectable to the test signal generator, the external scrambler is designed to scramble the N-channel test signal into the external signal, the output port of the external key is operatively connectable to the comparison unit, the internal key is operatively connected to the test signal generator, and the internal scrambler is designed to scramble the N-channel test signal into the internal signal in a manner identical to the external scrambler. Preferably, the internal and the external scrambler are identical.

In an alternative embodiment, the input port of the external key is operatively connectable to the test signal generator, the external scrambler is designed to scramble the N-channel test signal, the output port of the external key is operatively connectable to the internal key, the internal scrambler is designed to descramble the N-channel test signal as scrambled by the external scrambler into the external signal, and the test signal generator is operatively connected to the comparison unit for providing a copy of the N-channel test signal as the internal signal.

In an alternative embodiment, the internal key is operatively connected to the test signal generator, and is operatively connectable to the input port of the external key, the internal scrambler is designed to scramble the N-channel test signal, the external scrambler is designed to descramble the N-channel test signal as scrambled by the internal scrambler into the external signal, and the test signal generator is operatively connected to the comparison unit for providing a copy of the N-channel test signal as the internal signal.

In an embodiment, the internal key comprises an input port and an output port, the input port comprising N input terminals, the output port comprising N output terminals, and the internal scrambler comprising N conductors, wherein the N conductors each connect an input terminal with an output terminal in a scrambled manner. This results in a simple hard-wired scrambler which needs no algorithms and programmable logic.

In an embodiment, the conductors are light conductors, in particular light conductive fibres. Signals through light conductors are hardly impossible to read out with an external device.

In particular, a connection between the control circuit and the input and output ports of the external key is provided via a cable with at least two times N light conductive fibres. By using a cable with conductive fibres, the control circuit can be positioned at a distance from the external key, while the conductive fibres makes it hardly impossible to read out signals with an external device.

In an alternative embodiment, the conductors are electrical conductors, in particular electrical conductive wires. This allows for a simple and affordable solution.

In an embodiment, the control circuit is embedded within the engine control module. This makes it hardly impossible to access the control circuit and make an unauthorised change to the internal key.

In an embodiment, the control circuit further comprises an all on detector, the all on detector being configured to send a blocking signal to the engine control module and/or the control circuit if there is a signal on all N channels coming from the external and/or internal key. One way an unauthorised person could try to deceive the anti-theft system is by using a false external key that provides a signal on all channels. With all channels on, there is no effect of the scrambling. By detecting such all on signal, it becomes useless to use such a false key.

In an embodiment, the control circuit further comprising a fail counter, wherein the comparison unit is further designed to provide a fail signal if said signals are not identical, the fail counter is configured to count the number of fail signals, in particular the fail counter is configured to send a blocking signal to the engine control module and/or the control circuit if a subsequent number of fail signals equals a predetermined number of fail signals, more in particular the blocking signal is a temporary blocking signal if a subsequent number of fail signals equals a predetermined first number of fail signals, and/or the blocking signal is a permanent of semi-permanent blocking signal if a subsequent number of fail signals equals a predetermined second number of fail signals. This embodiment prevents an unlimited number of tries of unlocking the anti-theft system. An optional delay after a try prevents quickly scanning multiple options. Blocking the system makes it impossible to use the vehicle after a certain number of attempts. In a particular embodiment, such blocking is lifted by entering a secret code. In another embodiment, such blocking is permanent, e.g. by automatically destroying part of the electronics, and can only be lifted by an authorised supplier.

The invention further relates to an engine comprising a combination of an engine control module for a vehicle and an anti-theft system, according to the invention.

The invention further relates to a vehicle comprising an engine according to the invention.

The invention further relates to an external key for a combination of an engine control module for a vehicle and an anti-theft system, comprising an input port and an output port which are operatively connectable with the control circuit, and an external scrambler, the input port comprising N input terminals, the output port comprising N output terminals, and the external scrambler comprising N conductors, wherein the N conductors each connect an input terminal with an output terminal in a scrambled manner.

In an embodiment, the conductors are light conductors, in particular light conductive fibres.

The invention, its effects, and advantages will be explained in more detail on the basis of the schematic drawing, in which:

Fig. 1 shows a car with an embodiment of the invention,

Fig. 2 shows an external key according to the invention,

Fig. 3 shows an internal key for a combination according to the invention,

Fig. 4 shows a first embodiment of an anti-theft system for a combination according to the invention, and

Fig. 5 shows a second embodiment of an anti-theft system for a combination according to the invention.

The figures show a combination according to the invention, which is denoted in its entirety by reference number 1 in fig. 1. The combination 1 comprises an engine control module 2 for a vehicle 4 with a motor 6 and an anti-theft system 8. The anti-theft system 8 of this embodiment is configured with eight channels, and comprises a control circuit 10 and an external key 12. The external key 12 is operatively connectable with the control circuit 10 via a cable 13 which has sixteen light conductive fibres. This enables the insertion of the external key 12 in a dedicated key hole, e.g. in the dashboard of vehicle 4, while the control circuit 10 is integrated within the engine control module 2, so that it is hardly impossible to tamper with the control circuit. Referring to figure 2, a simplified version of the external key 12 is shown for a system with only five channels. The external key 12 comprises an input port 14, an output port 16, and an external scrambler 18. The input port 14 comprises five input terminals aO, al, a4, the output port 16 comprises five output terminals bO, bl, b4, and the external scrambler 18 comprises five conductors 20, in this embodiment five light conductive fibres. The five light conductive fibres 20 each connect an input terminal aO, al, ... with an output terminal bO, bl, ... in a scrambled manner. In this example, aO is connected to b2, al is connected to b4, etc. In this way, a maximum of 119 different keys can be manufactured, because 5 channels correspond to 5!=120 different combinations, while a combination wherein all conductors 20 connect an input terminal with the same output terminal is not desirable and thus excluded from the system. In an analogous manner it can be derived that the eight-channel system of figure 4 allows for 40,319 different key combinations.

The control circuit 10 is shown schematically in more detail in figure 4. Please note that in the circuits of fig. 4 and 5, 'A' connects to 'Α', 'B' connects to 'B', and 'TS' connects to 'TS'. The 'GO' and 'FAIL' lines connect the control circuit with the engine control module 2. The control circuit 10 comprises a power supply 22, a clock control 24, a clock 26, a test signal generator 28, an external digital to light converter 30, an internal digital to light converter 32, an internal key 34, an external light to digital converter 36, an internal light to digital converter 38, an all on detector 40, a comparison unit 42, and a fail counter 44.

Referring to figure 3, the internal key 34 of this embodiment is shown for a five-channel system as well. It is similar to the external key 12. Accordingly, the reference numbers are the same plus 100. The internal key 34 comprises an input port 114, an output port 116, and an internal scrambler 118. The input port 114 comprises five input terminals aO, al, a4, the output port 16 comprises five output terminals bO, bl, b4, and the internal scrambler 118 comprises five light conductive fibres 120. The five light conductive fibres 20 each connect an input terminal aO, al, ... with an output terminal bO, bl, ... in a scrambled manner. The scramble manner of the internal key 34 is in this embodiment identical to that of the external key 12

The test signal generator 28 is configured to provide an eight-channel test signal to both the external key 12 and the internal key 34. In this embodiment, the digital test signal is converted to light pulses at converters 30 and 32, before it is transmitted to the keys 12, 34. It is noted that external key 12 is shown in figure 4 as part of the overall circuit. It is clear however, that the external key 12 is positioned in reality at a distance from the circuit, as shown schematically in figure 1. The comparison unit 42 of this embodiment is connected to the external light to digital converter 36 at 'Α', and with the internal light to digital converter 38 at 'B'. It is configured to compare an internal signal from the internal key 34 of control circuit 10 with an external signal from the external key 12.

In operation, an external key 12 is entered in the respective key hole in the dashboard of vehicle 4 (not shown) the comparison unit 42. This triggers a power on signal to the power supply 22. The clock control 24 controls the clock 26 to provide a series of pulses to the test signal generator 28 for an eight channel test signal. The test signal is split, and converted into light pulses at the external digital to light converter 30, and the internal digital to light converter 32. The light pulses from the external digital to light converter 30 are send through the cable 13 to the external key 12. Here the signal is scrambled, and returns to the control circuit 10 via cable 13. At the same time, the internal light pulses are send through the internal key 34 which scrambles the test signal in the same way as the external key 12. The light pulses are converted back to digital signals by the external light to digital converter 36, and the internal light to digital converter 38. Both the internal and the external digital scrambled signals arrive at the comparison unit 42. The comparison unit 42 provides an unlocking signal (GO) via the fail counter 44 to the engine control module 2 if the internal signal and external signal are identical.

The fail counter 44 of this embodiment is configured to count the number of fail signals, and to send a signal to the reset logic 46 of the control circuit 10 for the first and second subsequent fail signals. A timer (not shown) is included in this embodiment so that a second and third try can only be done after waiting for a predetermined amount of time, e.g. 1 minute, respectively 5 minutes. If the fail counter 44 counts a third fail signal, it blocks both the engine control module 2 and the control circuit 10 in a semi-permanent manner. That is, the blocking can only be undone by an authorised dealer with a secret unlocking code. As an alternative, the blocking is permanent by causing a high current through the electronic circuit which destroys all or part of the components. Accordingly, a new engine control module 2 with embedded anti-theft system 8 needs to be installed.

The all on detector 40 of this embodiment is configured to send a blocking signal to the engine control module 2 and the control circuit 10 if there is a signal on all eight channels coming from the external and/or internal key 34. If someone tries to tamper with the anti-theft system 8 by entering a false key that causes all channels to lit, this is detected by the all on detector 40 that sends a corresponding signal to the reset logic 46.

Figure 5 shows an alternative embodiment of an eight-channel anti-theft system 8. The same or similar components as in the previous embodiment are denoted with the same reference numerals, and are not described all in detail. The main difference with the embodiment of figure 4 is that the internal key 34 of this embodiment is a mirror of the external key 12. In other words, it provides input terminal-output terminal connections which are the same as the output terminal- input terminal connections of the external key. As an example, if the external key 12 connects input terminal aO with output terminal b2, then the internal key 34 connects input terminal a2 with output terminal bO. In other words, the internal scrambler 118 of internal key 34 is designed to descramble the eight-channel test signal as scrambled by the external scrambler 18.

The input port 14 of the external key 12 of this embodiment is operatively connectable via an external digital to light converter 30 to the test signal generator 28. The output port 16 of the external key 12 is operatively connectable to the internal key 34 via an internal light to digital converter 38. The test signal generator 28 is operatively connected via an eight-channel delay 46 to the comparison unit 42 for providing a copy of the eight-channel test signal as the internal signal.

In operation, the external scrambler 18 of the embodiment of fig. 5 scrambles the eight- channel test signal, which scrambled signal is descrambled by the internal scrambler 118, if the external key 12 matches the internal key 34. Accordingly, the original test signal arrives at the comparison unit 42 via both the scramblers 18, 118, and the eight-channel delay 46. The function of the eight-channel delay 46 is to ensure that both signals arrive at the same time at the comparison unit 42. It the signals actually match, than the engine control module 2 is released. Otherwise, one of the fail mechanisms kick into action, as described in relation to the first embodiment.

Several variants are possible within the scope of the attached claims. The features of the above described preferred embodiment(s) may be replaced by any other feature within the scope of the attached claims, such as the features described in other embodiments, and in the following paragraphs.

In a variant of the embodiment shown in fig. 5, the internal key and external key are placed in a different order, while the rest of the circuit is comparable as that of fig. 5. Thus, the internal key is operatively connected to the test signal generator and is operatively connectable to the input port of the external key. The internal scrambler is designed to scramble the N-channel test signal. The external scrambler is designed to descramble the N-channel test signal as scrambled by the internal scrambler into the external signal. The test signal generator is operatively connected to the comparison unit for providing a copy of the N-channel test signal as the internal signal.

It is clear that the schematically disclosed embodiments, and non-disclosed alternatives, can be implemented using standard electronic components, including but not limited to a clock generator, flip-flops, logic gates, and laser diodes and drivers. In the shown embodiments, the comparison unit checks whether the internal and external signal are identical. In an alternative, the signals match in another way, e.g. a of the external signal corresponds to a '0' of the internal signal while a '0' of the external signal corresponds to a T of the internal signal.

Instead of a hard-wired internal scrambler, the internal scrambler of the internal key may be a programmed logic circuit that provides the same, of a mirror of, the paths that the external scrambler defines.