ANTI-THEFT SYSTEM FOR MOTOR VEHICLES

Abstract

ANTI-THEFT SYSTEM FOR MOTOR VEHICLES Anti-theft system (100) for a motor vehicle, comprising: - a vehicle protection module (11) for authenticating an electronic key (1) for accessing the vehicle and generating in response an authorization to unlock the wheels (OK1); - at least one parking brake module (13), comprising a caliper (133) and an electric motor (131); and - parking brake control means (12) for releasing the caliper (133) only upon receipt of the authorization to unlock the wheels (OK1). Each parking brake module (13) is connected to the control means (12) by a power cable (14) with at least two power supply lines (141A, 141B) and at least one safety line (142).Each parking brake module (13) includes a safety module (132) to authenticate the control means (12) from a signal transmitted on at least one safety channel (142), and to only allow the release of the caliper (133) if the control means (12) have been authenticated. Figure 1.

Description

Title of the invention: ANTI-THEFT SYSTEM FOR MOTOR VEHICLES TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of motor vehicles, and more particularly that of anti-theft systems. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] UN (United Nations) Regulation No. 116, designated UN-R116 in English, requires an anti-theft system on private vehicles and light commercial vehicles, which makes it possible to prevent such a vehicle from being maneuvered and / or moved without having the key to the vehicle.

[0003] This regulation authorizes the use of several techniques including the blocking of a vehicle parking brake, and in particular an automatic or electric parking brake, which replaces the manual parking brake in modern vehicles.

[0004] In order to meet regulatory requirements, the anti-theft system must offer a certain level of tamper resistance to prevent it from being rendered unusable too easily. In the case of an anti-theft system using an automatic parking brake, it is therefore necessary to delay the release of the brake on the wheel in some way.

[0005] A weakness of the anti-theft protection by the automatic parking brake is the accessibility of the electrical connector of the electric brake actuator on the wheel.

[0006] An objective of the present invention is to propose an anti-theft system for a motor vehicle which has increased reliability compared to prior art systems. Summary of the invention

[0007] This objective is achieved with an anti-theft system for a motor vehicle, comprising: - a vehicle protection module, configured to authenticate an electronic vehicle access key, and to generate authorization to unlock the wheels when an authorized electronic key is authenticated; - at least one parking brake module (or EPB, for Electric Park Brake), each module comprising a caliper capable of clamping a wheel of the vehicle and an electric motor configured to, in use, tighten or loosen the caliper around the wheel; and - means for controlling the parking brake, comprising a computer and a power supply, and configured to command the release of at least one caliper only upon receipt of the unlocking authorization provided by the vehicle protection module.

[0008] In other words, the anti-theft system according to the invention comprises an automatic parking brake, including in particular at least one parking brake module equipped with a caliper and an electric motor. The caliper acts as the brake, which, when engaged, blocks the rotation of a vehicle wheel via the brake pads. When released, the caliper allows the rotation of that same wheel. The electric motor constitutes the electric actuator of the brake.

[0009] According to the invention: - Each parking brake module is connected to the parking brake control means by a power cable, the power cable having at least two electrical supply paths and at least one safety path; and - each parking brake module also includes a security module, configured to authenticate the means of controlling the parking brake from a signal passing through at least one security channel, and to only allow the release of the caliper by the electric motor if the means of controlling the parking brake have been authenticated.

[0010] According to the invention, a user authorized to maneuver and / or move the vehicle is identified by means of an electronic key, authenticated by the vehicle protection module.

[0011] When an authorized user is identified via the electronic key, the vehicle protection module generates a wheel release authorization. This wheel release authorization is sent to the parking brake control means.

[0012] In response, the parking brake control means command each parking brake module to release the caliper. This release command results in the powering of the electric motor in the parking brake module, this electric motor forming the electric actuator of the caliper.

[0013] According to the invention, it is proposed to secure the connection between the parking brake control means and the parking brake module. The objective is to prevent the electric actuator of the caliper from being fraudulently controlled using an auxiliary power supply substituted for the power supply present in the parking brake control means.

[0014] A solution to secure this link could have been mechanical, by mechanically blocking access to a connector linking together the parking brake control means and the parking brake module.

[0015] According to the invention, an ingenious solution is proposed based rather on the addition of at least one safety channel, in the power cable linking together the parking brake control means and the parking brake module.

[0016] The at least one safety channel is not used to electrically supply the electric motor that acts as the caliper actuator. Rather, the at least one safety channel is used to transmit at least one specific electrical signal, intended to allow the parking brake module to authenticate the parking brake control means.

[0017] To enable this authentication, the parking brake module is further equipped with a security module comprising a computer. The security module stores at least one authentication data point. It is configured to extract, or measure, at least one data point using the signal transmitted on at least one security channel, to compare this extracted or measured data point with the authentication data point, and to deduce information on whether or not the parking brake control means have been authenticated.

[0018] The safety module is configured to only allow the caliper to be released by the electric motor if it has duly authenticated the means of controlling the parking brake using a signal passing through at least one safety channel.

[0019] Thus, it is not sufficient for the parking brake module to be electrically powered for the electric motor to act on the caliper. The caliper actuation must also be authorized by the parking brake module's safety control system.

[0020] In practice, the safety module can, for example, control the position of a switch, or a transistor, to allow or block the passage of current between a power connector of the parking brake module, and the electric motor capable of actuating the caliper.

[0021] The invention thus provides an anti-theft system for a motor vehicle, which has increased reliability compared to prior art systems.

[0022] In a first advantageous embodiment: - the power cable includes two safety channels, connected together on the parking brake module side so as to close an electrical circuit extending further into the parking brake control means; and - the security module is configured to measure an impedance or resistance of said electrical circuit, to compare this impedance or resistance with an authentication value stored in the security module, and to deduce information relating to the authentication or not of the means of controlling the parking brake.

[0023] In a second advantageous embodiment: - the parking brake control means are configured to generate a modulated signal containing a predetermined code; - the power cable includes a safety channel, on which the modulated signal travels during operation; and - the security module is configured to receive said modulated signal, to extract said predetermined code, to compare this predetermined code to at least one authentication code stored in the security module, and to deduce information relating to the authentication or not of the means of controlling the parking brake.

[0024] The predetermined code can be encoded in the signal modulated by pulse width modulation.

[0025] Data transfer between the parking brake control means and the safety module can be implemented using a data transmission system complying with a LIN bus protocol.

[0026] Preferably, the anti-theft system according to the invention further comprises electronic control means for an actuator of a vehicle transmission chain, said electronic control means being configured to, in a vehicle start-up phase, prevent a user command from acting on the actuator, and only allow the user command to act on the actuator upon receipt of a transmission authorization provided by the vehicle protection module, the vehicle protection module being configured to generate said transmission authorization with the authorization to unlock the wheels, when the electronic key is authenticated.

[0027] The protection module can be configured to send the wheel unlock authorization and the transmission authorization only on a positive result of an electronic key authentication, a positive result of an authentication of the electronic control means of the actuator, and a positive result of an authentication of the parking brake control means.

[0028] The transmission chain actuator can be an electric traction or propulsion machine for the vehicle.

[0029] In an advantageous embodiment: - the user command is generated by a gear lever and corresponds to a command to switch from a neutral position to a forward or reverse position; - The system includes a control unit for the electric machine; and - the electronic control means of the actuator are configured so that, during the vehicle start-up phase, they do not wake up the control unit and do not transmitting a direction of rotation instruction for the electric machine corresponding to the user command, only upon receipt of transmission authorization.

[0030] The invention also covers a vehicle comprising at least two wheels and an anti-theft system according to the invention, with at least one of the wheels capable of being clamped by the caliper of one of the parking brake modules of the anti-theft system. BRIEF DESCRIPTION OF THE FIGURES

[0031] The figures are presented for illustrative purposes only and are in no way limiting of the invention. • Fig. 1 schematically illustrates an anti-theft system according to a first embodiment of the invention; • Figure [Fig. 2] schematically illustrates an anti-theft system according to a second embodiment of the invention. DETAILED DESCRIPTION

[0032] Unless otherwise specified, the same element appearing on different figures has a unique reference.

[0033] Figure 1 schematically illustrates an anti-theft system 100 for a motor vehicle, the system 100 comprising: - a vehicle protection module 11, configured to authenticate an electronic key 1 for vehicle access, and to generate an OKI wheel unlocking authorization when an authorized electronic key 1 is authenticated; - a parking brake module 13, comprising a caliper 133 suitable for clamping a wheel of the vehicle, and an electric motor 131 configured to, in use, tighten or loosen the caliper 133 around the wheel; - parking brake control means 12, comprising a computer 122 and a power supply 121, and configured to control the release of the caliper 133 only upon receipt of the OKI release authorization provided by the vehicle protection module 12; and - a power cable 14 comprising two power supply paths 141A, 141B, and at least one safety line 142 as described below.

[0034] In nominal mode, i.e. outside of a very cold mode, when the vehicle is parked with the engine off, the parking brake module 13 locks the vehicle wheel using the caliper 133 which clamps the wheel.

[0035] The electronic key 1 refers to a portable device capable of establishing bidirectional communication via a short-range radio link, and storing a unique identifier. The unique identifier allows the electronic key 1, and therefore its holder, to be authenticated for access to a motor vehicle.

[0036] The vehicle protection module 11 includes a wireless communication module (not specifically shown), enabling it to communicate with the electronic key 1. It further includes at least one control unit, which can be broken down into: - a computer 111 dedicated to user authentication, via bidirectional communication with the electronic key 1, and comparing the unique identifier sent by the electronic key 1 with at least one authorized identifier stored in a memory of said computer 111; and - a computer 112 dedicated to managing whether or not the vehicle is immobilized, configured in particular to generate an authorization to unlock the wheels, OKI, when an authorized electronic key 1 is authenticated (in other words when the computer 111a determined that the unique identifier sent by the electronic key 1 corresponds to an authorized identifier).

[0037] Communication between the electronic key 1 and the vehicle protection module 11 can form an encrypted exchange of user data.

[0038] The means 12 for controlling the parking brake and the vehicle protection module 11 are connected together, preferably by wired connection.

[0039] The parking brake control means 12 include at least one computer, and are configured to send commands to tighten or loosen respectively the caliper 133 on the vehicle wheel.

[0040] The parking brake control means 12 are configured to receive the wheel release authorization, OKI, from the vehicle protection module 11 and to command in response a release of the caliper 133.

[0041] The means 12 for controlling the parking brake include in particular a computer 122, and a power supply 121 (the power supply corresponding to the supply of the internal network of the vehicle, generally at a voltage of 12V for approximately 6A nominal).

[0042] The parking brake control means 12 are connected to the parking brake module 13 by the power cable 14. The power cable has two power supply paths 141 A, 14IB, and at least one safety path 142. Preferably, the different paths are electrically isolated from each other, but housed together in the same sheath.

[0043] Upon receiving authorization to unlock the wheels, OKI, the computer 122 controls the generation of a power supply signal, by the power supply 121. This power supply signal passes through the power cable 14, and more particularly through the two power supply paths 141A, 141B (receiving the neutral and phase respectively).

[0044] According to the invention, the parking brake control module 12 is capable of generating a safety signal, and of sending this signal to the parking brake module 13 via at least one safety channel 142 of the power cable 142.

[0045] Different examples of security signals are described below.

[0046] The parking brake module 13 includes a safety module 132, connected to the security lane 142 and configured for: - authenticate the means 12 for controlling the parking brake from the safety signal; and - only allow the release of the caliper 133 by the electric motor if the means 12 for controlling the parking brake have been authenticated by the safety module 132.

[0047] In practice, the safety module 132 controls, for example, the position of a switch, or a transistor, to allow or block the passage of the supply signal from the input terminals of the parking brake module 13 to the supply terminals of the electric motor 131.

[0048] Thus, depending on whether the means 12 for controlling the parking brake have been authenticated or not, the supply signal reaches or does not reach the electric motor 131, which blocks or allows the release of the caliper 133.

[0049] The security module 132 includes, at least, a computer equipped with a memory storing authentication data.

[0050] The security module 132 is configured to: - extract, or respectively measure, at least one piece of data using the security signal; - compare this extracted or measured data with the authentication data; and - deduce information on whether or not the parking brake control means are authenticated.

[0051] The invention thus offers additional security by ensuring that only a power signal supplied by the parking brake control means 12 can actuate the caliper 133, and thus unlock the wheel. Conversely, a power signal supplied by an external device, connected for malicious purposes to the parking brake control module 12, will not by itself be sufficient to actuate the caliper 133 and unlock the wheel, since it will lack the safety signal necessary to authorize the transfer of energy to the motor 131.

[0052] In practice, the parking brake module 13 has at least three input terminals, each capable of being connected to one of the respective supply and securing paths of the supply cable.

[0053] For clarity, the specific case in which the system 100 comprises a single parking brake module 13 has been illustrated. However, the invention also covers variants with several parking brake modules 13 as described below. above, each dedicated to locking a respective wheel of the vehicle. The vehicle may also include one or more auxiliary parking brake modules, without the additional safety feature that is the subject of the invention. There are generally two parking brake modules per vehicle, one for each of the two front wheels and one for each of the two rear wheels.

[0054] When there are several parking brake modules 13, all are connected to the same parking brake control means 12. In this case, the parking brake control module 12 can be equipped with a power distribution unit to distribute the electrical supply lines to a plurality of outputs dedicated to the respective parking brake modules 13. In contrast, the safety lines are preferably specific to each parking brake module 13 and, in practice, carry distinct signals with distinct characteristics.

[0055] According to other variants, the supply signal from the means 12 for controlling the parking brake is a three-phase signal, and the supply cable 14 then has three supply paths.

[0056] In a first embodiment of the invention, the power cable 14 comprises two safety channels 142, connected together on the side of the parking brake module 13 so as to close an electrical circuit extending further into the parking brake control means 12. The two safety channels together can be considered to close a current loop, referred to as the safety loop.

[0057] At the level of the parking brake module 13, the safety module 132 is configured to: - measure the impedance or ohmic resistance of said electrical circuit, for example using a current sensor in the security module 132, - compare this impedance or ohmic resistance with the value of an authentication data point, and - to deduce information relating to the authentication or not of the means of controlling the parking brake.

[0058] The value of impedance or ohmic resistance is measured simply by a current (or even voltage) measurement on an electrical signal circulating on the safety channels.

[0059] This impedance or ohmic resistance value depends on the physical characteristics of the safety circuits, but especially on the physical resistance and / or impedance characteristics of the components in the parking brake control means 12. Thus, measuring this impedance or ohmic resistance value is characteristic of the parking brake control means 12 and allows for their authentication.

[0060] In other words, the parking brake module 13 measures the ohmic resistance (or impedance) of the safety loop closed by the safety channels 142, and compares it to a known authentication value, characteristic of the parking brake control means 12. If the safety loop is opened or replaced by a source external to the vehicle, the caliper 133 remains in the engaged state even if a power signal reaches the input of the parking brake module 13.

[0061] The ohmic resistance (or impedance) value is specific to the parking brake control means 12 and is factory calibrated. The parking brake module 13 reads this value. This value will be compared each time the caliper 133 is to be released. Therefore, an external power supply will not allow the caliper 133 to be released without the specific ohmic resistance (or impedance).

[0062] In a second embodiment of the invention, authentication is performed using instead data encoded in a signal. In this case, the power cable 14 may include a single security channel 142, and the parking brake control means 12 are configured to generate a modulated signal in which predetermined data, or code, is encoded.

[0063] The security module 132 is then configured to receive said modulated signal, to extract said predetermined data, to compare this predetermined data with at least one authentication data, and to deduce information relating to the authentication or not of the means of controlling the parking brake.

[0064] In other words, the safety channel 142 allows communication of the predetermined code between the parking brake control means 12 and the parking brake module 13. Therefore, an external power supply connected to the parking brake module 13 will not be able to release the caliper 133.

[0065] The predetermined code may be specific to a safety module 132 and learned by the parking brake control means 12 in a preliminary calibration step at the factory. Alternatively, the parking brake control means 12 impose the predetermined code that will be learned by the safety module 132 in a preliminary calibration step.

[0066] Advantageously, the predetermined code is encoded in the modulated signal using pulse width modulation.

[0067] Furthermore, data transfer between the parking brake control means 12 and the safety module 132 is implemented using a data transmission system (more commonly known as a "fieldbus") conforming to a LIN bus protocol. The LIN bus (Local Interconnect Network) is a serial system bus used in the recent motor vehicles. The LIN bus specifications are established by the LIN consortium. Since 2016, the LIN bus has been standardized by ISO 17987.

[0068] Alternatively, the data transfer between the parking brake control means 12 and the safety module 132 can be implemented using a data transmission system complying with a CAN bus protocol (for Control Area Network).

[0069] Advantageously, the parking brake control means 12 and the security module 132 are paired during a preliminary calibration step, carried out at the factory, in order to share information relating to the authentication data.

[0070] An additional security measure can be implemented by making the transmission of the wheel release authorization, OKI, conditional upon authentication of the parking brake control means 12 by the vehicle protection module 11. For this purpose, the vehicle protection module 11 and the parking brake control means 12 are capable of establishing bidirectional communication to exchange at least one authentication data point.

[0071] An anti-theft system 100' according to a second embodiment of the invention is then illustrated with reference to [Fig. 2]. System 100' will only be described in terms of its differences from system 100 in [Fig. 1].

[0072] System 100' of [Fig.2] here comprises:

[0073] - a device 16 for generating a user control signal SI in response to a mechanical action performed by the user. Device 16 is, for example, a gear lever, capable of translating a position of the gear lever into a user command;

[0074] - electronic control means 15, implemented in at least one computer and configured to convert the user control signal SI into a setpoint S2 for the direction of rotation in one direction or the other. The means 15 include, for example, a computer for controlling an electrical machine 18;

[0075] - a control module 17 for actuator 18, configured here to convert said rotation setpoint S2 in control currents S3 of an inverter, not specifically shown; and

[0076] - an actuator 18 of a vehicle transmission chain, here constituted by a electric traction or propulsion machine including herein said inverter.

[0077] According to the invention, the electronic control means 15 are configured so that, during the vehicle start-up phase, the user control SI only allows the electric machine 18 to act upon receipt of a transmission authorization, OK2, provided by the vehicle protection module 11. In other words, the electronic control means 15 are configured so that, during the vehicle start-up phase, they only wake up the actuator control module 17 and only transmit to it a direction of rotation instruction for the electric machine 18 corresponding to the user command SI, upon receipt of the transmission authorization OK2.

[0078] The vehicle protection module 11 is then configured to generate said OK2 transmission authorization with OK2 wheel unlocking authorization, when the electronic key 1 is authenticated.

[0079] The vehicle start-up phase here refers to the operations necessary to unprotect and start the vehicle engine, these operations being carried out in particular by the vehicle driver and computers in the vehicle.

[0080] This embodiment is particularly advantageous, since it combines two safety features, namely the action on the parking brake and the action on the actuator of a transmission chain of the vehicle.

[0081] Furthermore, the action on the actuator of a vehicle transmission chain is implemented solely at the level of a computer (the electronic control means 15), thus eliminating the need for additional mechanical locking devices that could increase the vehicle's manufacturing and maintenance costs. This implementation has the advantage of preventing the vehicle from starting by an unauthorized user, without requiring significant software changes in the actuator control module 17, which consists, for example, of the electrical control means of the electric machine.

[0082] When a vehicle user has parked their vehicle in cold weather mode, the parking brake control means 12 are configured to keep the parking brake in the released position on the vehicle wheel during the start-up phase. In this cold weather mode, receiving OKI authorization to release the wheel, via the parking brake control means 12, will therefore have no effect on the vehicle wheel. However, disabling the user command intended for the drivetrain actuator 18 will always be conditional upon successful authentication of the electronic key 1. Thus, in cold weather mode, an unauthorized user may be able to move the vehicle but not turn its steering wheel or start its engine.

[0083] Locking two entities acting on the driving of the vehicle rather than a single entity, to prohibit unauthorized driving of the vehicle, improves vehicle protection while limiting specific modifications to the vehicle.

[0084] Advantageously, the gear lever 16 comprises: - a neutral position N, corresponding to a user command SI requesting the cessation of the drive wheels of the vehicle by the electric machine 18; This neutral position N is the default position of the gear lever 16 when the vehicle is stopped and asleep; - a forward driving position D, corresponding to a user command SI requesting the electric machine 18 to move the vehicle forward; and - a reverse gear position R, corresponding to a user command SI asking the electric machine 18 to reverse the vehicle.

[0085] The user command SI generated by the gear lever 16 advantageously corresponds to a command to switch from a neutral position to a forward or reverse position.

[0086] In variants, the actuator of a vehicle transmission chain is instead constituted by an active steering actuator, in an electronically controlled steering column, or by any other device capable of preventing the vehicle from rolling and / or maneuvering.

[0087] Furthermore, the invention is not limited to electric or hybrid vehicles. In the case of an internal combustion engine vehicle, the actuator of a vehicle's transmission chain is, for example, an internal combustion engine of the vehicle. In this case, the inhibition of the gear lever controls is, for example, performed by a control unit of a steering mechanism, or is replaced by an inhibition of an ignition or fuel injection device, using a control unit of the internal combustion engine vehicle.

[0088] In an advantageous embodiment, the protection module 11 is further capable of: - establishing bidirectional communication with the parking brake control means 12 in order to authenticate the latter; and - establishing bidirectional communication with the electronic control means 15 in order to authenticate the latter.

[0089] In other words, it is a matter of determining whether or not the means 15 (respectively 12) correspond to the means intended to collaborate with the protection module 11 within the system 100'. This determination is made by sending authentication data from the means 15 (respectively 12) to the protection module 11, and analyzing this authentication data by the protection module 11 to determine whether or not it corresponds to that of the means 15 (respectively 12) expected by the module 11. The communication between the protection module 11 and the means 15 (respectively 12) can constitute an encrypted exchange of authentication data.

[0090] The protection module 11 is then configured to send the wheel unlock authorization, OKI, and the transmission authorization, OK2, only if it has duly authenticated both the electronic key 1, the parking brake control means 12, and the electronic control means 15. This can be considered a successful authentication result.

[0091] This variant offers additional security, since an additional authentication condition for the parking brake control means 12 and the means 15 of electronic control. Despite the absence of any hardware addition to the vehicle to ensure this anti-theft protection, this variant requires a very significant amount of time to bypass the anti-theft protection, since it would be necessary to change the protection module 11, the electronic control means 15 and the parking brake control means 12, in order to replay the authentication chain necessary to unlock the vehicle wheel and the transmission chain actuator.

[0092] Advantageously, the protection module 11 is implemented in a separate control unit from at least one control unit implementing the electronic control means 15 and / or the parking brake control means 12. The use of several separate control units is particularly advantageous in the variant involving additional authentication conditions for the parking brake control means 12 and the electronic control means 15 by the protection module 11.

[0093] The control unit of the protection module 11 is advantageously a master control unit, and at least one control unit implementing the electronic control means 15 and / or the parking brake control means 12 is a slave control unit. Thus, for example, it is the control unit of the protection module 11 that wakes up at least one other control unit after authentication of the vehicle's electronic key 1, which adds an additional layer of protection against unauthorized driving of the vehicle, since the slave control units are inoperative until the vehicle's electronic key 1 is authenticated.

[0094] The invention is not limited to the examples described above, and covers many variants implementing, for example, a different number of parking brake modules, other types of actuators of a vehicle transmission chain, etc.

Claims

Demands

1. Anti-theft system (100; 100') for a motor vehicle, comprising: - a vehicle protection module (11), configured to authenticate an electronic key (1) for accessing the vehicle, and to generate an authorization to release the wheels (OKI) when an authorized electronic key (1) is authenticated; - at least one parking brake module (13), each module comprising a caliper (133) capable of clamping a wheel of the vehicle and an electric motor (131) configured to, in use, tighten or loosen the caliper (133) around the wheel; and - means (12) for controlling the parking brake, comprising a computer (122) and a power supply (121), and configured to command the release of at least one caliper (133) only upon receipt of the release authorization (OKI) provided by the vehicle protection module (11);characterized in that: - each parking brake module (13) is connected to the parking brake control means (12) by a power cable (14), the power cable having at least two electrical power supply channels (141A, 141B) and at least one safety channel (142); and - each parking brake module (13) further includes a safety module (132), configured to authenticate the parking brake control means (12) from a signal passing over at least one safety channel (142), and to only allow the release of the caliper (133) by the electric motor (131) if the parking brake control means (12) have been authenticated.

2. An anti-theft system (100; 100') according to claim 1, characterized in that: - the power cable (14) comprises two security channels (142), connected together on the side of the parking brake module (13) so as to close an electrical circuit extending further into the parking brake control means (12); and - the security module (132) is configured to measure an impedance or resistance of said electrical circuit, to compare this impedance or resistance with an authentication value stored in the security module (132), and to deduce information relating to the authentication or not of the means (12) of controlling the parking brake.

3. Anti-theft system (100; 100') according to claim 1, characterized in that: - the parking brake control means (12) are configured to generate a modulated signal containing a predetermined code; - the power cable (14) includes a security channel (142), on which, in use, said modulated signal travels; and - the security module (132) is configured to receive said modulated signal, to extract said predetermined code therefrom, to compare this predetermined code to at least one authentication code stored in the security module (132), and to deduce therefrom information relating to the authentication or not of the parking brake control means (12).

4. Anti-theft system (100; 100') according to claim 3, characterized in that the predetermined code is encoded in the signal modulated by pulse width modulation.

5. Anti-theft system (100; 100') according to claim 3 or 4, characterized in that the data transfer between the means (12) for controlling the parking brake and the security module (132) is implemented using a data transmission system complying with a LIN bus protocol.

6. Anti-theft system (100') according to any one of claims 1 to 5, characterized in that it further comprises electronic control means (15) for an actuator (18) of a vehicle transmission chain, said electronic control means (15) being configured to, in a vehicle start-up phase, prevent a user command (SI) from acting on the actuator (18), and only allow the user command (SI) to act on the actuator (18) upon receipt of a transmission authorization (OK2) provided by the vehicle protection module (11), the vehicle protection module (11) being configured to generate said transmission authorization (OK2) with the wheel unlocking authorization (OKI), when the electronic key (1) is authenticated.

7. Anti-theft system (100') according to claim 6, characterized in that the protection module (11) is configured to send wheel unlock authorization (OKI) and transmission authorization (OK2) only on a positive result of an authentication of the electronic key (1), a positive result of an authentication of the electronic control means (15) of the actuator, and a positive result of an authentication of the parking brake control means (12).

8. Anti-theft system (100') according to claim 6 or 7, characterized in that the actuator (18) of the transmission chain is an electric traction or propulsion machine for the vehicle.

9. Anti-theft system (100') according to claim 8, characterized in that: - the user command (SI) is generated by a gear lever (16) and corresponds to a command to move from a neutral position to a forward or reverse position; - the system (100') includes a control unit (17) for the electric machine (18); and - the electronic control means (15) for the actuator are configured so that, during the vehicle start-up phase, they only wake up the control unit (17) and transmit to it a direction of rotation instruction (S2) for the electric machine corresponding to the user command (SI), upon receipt of the transmission authorization (OK2).

10. Vehicle comprising at least two wheels and an anti-theft system (100; 100') according to any one of claims 1 to 9, with at least one of the wheels capable of being clamped by the caliper (133) of one of the parking brake modules (13) of the anti-theft system (100; 100').

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