EP1825441B1 - Electronic tachograph unit for motor vehicle - Google Patents

Description

The invention relates to a unit of a so-called tachograph control device intended to be loaded onto a motor vehicle-in particular a vehicle for transporting goods or passengers-in order to enable the control of the activities of a driver of the vehicle. . It should be noted that the term "driver" designates a person who can in turn carry out activities of driver or co-driver (also called "convoyer") of the vehicle. The tachograph comprises, in addition to this unit, at least one vehicle motion sensor, to which the unit is intended to be connected.

A tachograph has the particular function of recording, storing, producing, printing, and possibly exchanging and displaying, data, called driver data, relating to the activities of a driver of the vehicle, with a view to allow control of these activities by a controller.

The tachographs currently used are of the tachograph type with disks, such as that described by US 4,782,691 . These are analog and mechanical instruments for retranscribing conductive data on a paper disk by means of a stylus.

Following a widespread trend in the automotive field, electronic tachographs have also been developed, including microprocessor circuits for the processing and storage of driver data. The introduction of electronics into tachographs has made it possible to envisage the implementation of new equipment within the tachograph unit and the realization by it of new functions. Thus, for example, studies have focused on the replacement of known graphic discs (and still used ...) by electronic smart cards; they have resulted in the design of tachograph units, such as that described by US 4,644,368 , equipped with smart card reader / writer devices and printers in order to have a paper print of some data stored in smart cards.

The patent US 4,853,856 describes a tachograph with electronic recording of vehicle motion variables.

New standards and regulations (including the international standard ISO 16844 and, for the European Union, Regulations EC 1360/2002 and EC 2135/98 Annex 1B), defining in particular the equipment that tachographs and functions they should accomplish, have been very recently developed and should soon be applied.

At the same time, the emphasis today is on ensuring greater security in data processing, with the aim of making it impossible to falsify the data provided to the controller. This objective is shared by the new standards and regulations, which notably require the implementation of cryptographic security mechanisms within the tachograph unit.

In order to prevent fraud, it appears in particular essential that the tachograph unit be electrically powered continuously, regardless of the phase of operation of the vehicle in progress (contact established or not, engine of the stopped vehicle or engine running, vehicle to stopping or rolling vehicle ....), and this, not only in order to continuously process and store tachograph data, but also to allow a control of the activities of the driver at any time (and especially when the engine of the vehicle is stopped ...), and especially to guarantee a total integrity of the data and a perfect coincidence between the reality of the facts and the recorded data (that these concern activities of the driver or the management of the equipments of the unit) . In particular, it is not allowed to connect the tachograph unit only to a network, said network after contact, of the vehicle, which is electrically powered only after the established contact (for example by means of a key) by a user of the vehicle.

Usually, a tachograph unit has a power supply circuit, intended to be permanently supplied by a permanent electrical source of the vehicle when the unit is on board a vehicle. In practice, this power supply circuit is connected to a network, said permanent network of the vehicle, which is permanently powered by the vehicle battery. Any device connected to the permanent network is connected at all times electrically to the battery, regardless of the operating phase of the vehicle. The tachograph unit is thus constantly supplied with electricity, at least as long as the electrical source (battery) is not exhausted.

The inventors have determined that with the allocation of new equipment and functionalities to the tachograph unit, such an architecture - in which the unit is connected to the permanent network of the vehicle - no longer makes it possible to guarantee a sufficient level of security.

In fact, the new equipment envisaged is, for some, highly energy-consuming. In addition, the multiplication of the features that must now offer the tachograph unit results in an increase in the amount of energy required for the operation of the unit and forces to resize its power supply circuit.

This increase in the energy requirements of the tachograph unit gives rise to the risk of a possible and rapid depletion of the vehicle's electrical source (battery) in the event of intensive or inappropriate use of the unit in operating phases of the vehicle. vehicle where said source is not being recharged (that is, when the vehicle engine is stopped).

Under these conditions, it is impossible to guarantee an uninterrupted power supply to the tachograph unit (in periods when the vehicle engine is not running), unless the unit - or possibly the vehicle - is equipped with a rechargeable battery. emergency device capable of taking over the vehicle's battery in case of exhaustion of the vehicle. This solution is of course unsatisfactory due in particular to its cost, its complexity and the size of the additional battery to predict. It could also be envisaged to equip vehicles with batteries of higher capacity. In addition to the fact that it could only be implemented on new vehicles (existing vehicles do not have sufficient space to accommodate a resized battery, more cumbersome), such a solution would not remove any risk battery depletion and ensure maximum safety.

The invention aims first of all to overcome these disadvantages, by providing an electronic tachograph unit capable of offering a level of services (equipment, functionalities, security, etc.) equivalent to, and even greater than, that defined by the new regulations. and international standards, without the risk of exhausting the permanent electrical source (battery) of the vehicle and without however having a larger footprint than known tachograph units.

Furthermore, it should be noted that the standards and regulations impose different electrical specifications depending on whether the tachograph unit is for example intended for a conventional goods transport vehicle or a vehicle for transporting hazardous materials. In general, different electrical specifications, and sometimes divergent, are defined according to the destination of the tachograph unit.

The invention also aims to provide a range of several tachograph units which, although intended for different types of vehicle and therefore subject to different electrical rules, have a similar design and a close architecture allowing a rationalization of the production and a lower cost. The aim of the invention is to propose at least one standard version of a tachograph unit (particularly suitable for most conventional goods transport vehicles) and at least one specific version -that is an isolated version of a tachograph unit (particularly suitable for dangerous goods transport vehicles) whose differences are minor, and which can be produced by the same production line (with possible adaptations, minor and quick to implement).

Another object of the invention is to provide a tachograph unit that offers improved performance including both in terms of functionality, safety and energy efficiency. An object of the invention is to provide a tachograph unit displaying low power consumption.

The invention also aims to achieve all these objectives at lower cost, by proposing a low cost unit made from means, including electronic and electrical components, usual or possibly new but inexpensive.

In the following, the terms "off contact" mean any period during which the network after contact of the vehicle is not powered (contact not established), and the terms "after contact" designate any period during which the network after contact of the vehicle is powered.

The invention relates to a tachograph unit according to claim 1.

The invention therefore consists in assigning the tachograph data processing functions and the safety functions to a first circuit whose power supply is permanent, and in assigning certain power-consuming functions to a separate circuit which is normally powered only when the network after contact is activated.

Indeed, the inventors firstly found that the activation of the network after contact of the vehicle was generally controlled by a user of the vehicle for starting the engine of the vehicle, and that its deactivation was generally ordered immediately following the stopping said motor, so that the phases where the network after ignition is activated coincide substantially with those where the engine is running. In practice, the power operations, which can be performed only after contact, are therefore normally when the engine is running and the vehicle's power source can be recharged. The inventors have also and above all demonstrated that the neutralization of the aforementioned power operations, off contact, does not affect the proper operation of the tachograph and ensures a high level of security. In particular, they demonstrated that, against all odds, the specifications of the new regulations were fulfilled despite this temporary neutralization.

This separation of the functions of the unit into two separate circuits makes it possible to choose, for each of these circuits, a power supply (main or power) whose characteristics specifically meet the requirements of the functions allocated to said circuit. Given, according to the invention, that it is not necessary that the main power develops a high power, it is possible to use a low power supply but with a good performance, low consumption, low losses. The risks of exhaustion of the electrical source (battery of the vehicle) are thus practically non-existent. And such a power supply, although very powerful, can be obtained at low cost. Likewise, bearing in mind that power operations can only be performed after contact, that is to say - in normal and usual use of the vehicle - when the engine is running and the vehicle's electrical source can to be recharged, the performance of the power supply is relatively indifferent. It is therefore It is possible to use a low efficiency power supply - and therefore a low-cost power supply - but developing significant power, without any real risk of exhausting the vehicle's battery.

Thus, the tachograph unit according to the invention can be mounted on an existing vehicle, without it being necessary to adapt the vehicle to incorporate a higher battery life and performance, inevitably more cumbersome and expensive. In addition, the electronic and electrical architecture according to the invention has a reduced footprint compatible with its integration into a tachograph housing having the shape and dimensions of a car radio.

In addition, as will be explained below, this architecture makes it possible to develop several versions of tachograph unit, structurally very close but which meet different regulatory electrical requirements and are suitable for different types of vehicle.

Advantageously and according to the invention, the power circuit comprises at least one microprocessor, called secondary microprocessor. This secondary microprocessor is advantageously connected to a microprocessor, said main microprocessor, of the main circuit, in a master / slave relationship in which the main microprocessor is the master and the secondary microprocessor is the slave. In a preferred version of the invention, this secondary microprocessor is of the so-called single chip (monochip) type.

Advantageously and according to the invention, the main power supply is adapted to be connected (when the unit is embedded in the vehicle) to the permanent network of the vehicle.

In a version of the invention known as a standard version, the power supply is also adapted to be connected (when the unit is on board) to the permanent network of the vehicle, via the main circuit. In this standard version, the power supply is therefore permanently powered. According to the invention, the power operations are however neutralized off contact. To do this, the main circuit comprises a main microprocessor adapted to control an active state (on) or deactivated (off) of the power supply, respectively after contact or off contact. The power circuit comprises a member connected to the network after contact of the vehicle for receiving the signal after contact. The tachograph unit further comprises a signal transmission channel for the connection of this organ to said main microprocessor of the main circuit, for the purpose of transmitting the signal after contact to this main microprocessor. The unit also comprises another signal transmission channel, for the connection of this main microprocessor to the power supply, through which can be transmitted a signal able to activate or deactivate the power supply. The main microprocessor is adapted to control the activation of the power supply on receipt of the signal after contact and for (except possibly waking up by an external device, as will be explained hereinafter) to deactivate the off-contact power supply ( that is to say in the absence of reception of said signal after contact or reception of a signal representative of the deactivated state of the network after contact of the vehicle). In other words, the neutralization of the power operations is handled in software by the main microprocessor (as a function of a signal after contact received by the latter

Note that in this standard version, the main and power supplies are referenced to the same mass. Furthermore, the data and / or signal transmission channels between the two circuits preferably comprise high resistances. This standard version is particularly intended for conventional goods transport vehicles.

In another version of the invention, said isolated version, the power supply is adapted to be connected (when the unit is on board) to the network after contact of the vehicle. In this isolated version, the power supply is fed only when the network after contact is itself powered (activated). The signal after contact, as previously defined, corresponds to the electric current received by the power supply when the network after contact is activated. Out of contact, the power circuit is not powered (except possibly wakeup by a remote external device, as will be explained later), so that no power operation can be executed. In other words, the neutralization of power operations is managed purely "electrically".

Note that in this isolated version, the power supply is advantageously adapted to be referenced to the chassis of the vehicle, while the main power supply is adapted to be referenced to the permanent network of the vehicle. Thus, when the unit is on board, the main circuit and the power circuit are referenced to separate masses and no power supply line is provided between the two circuits. Furthermore, in this isolated version, the data and / or signal transmission channels between the two circuits preferably comprise optocouplers, which perform a kind of electrical isolation between the two circuits.

Thus, no electric power transmission by conduction is provided in the isolated version between the two circuits (main and power), and any unwanted transmission of electrical energy between the two circuits in case of deterioration or malfunction of a component is avoided. Such a tachograph unit according to the invention meets in particular the specifications required in the case of a vehicle for the transport of hazardous materials, but also to the voluntarily isolated architectures of certain vehicles.

It is therefore found that the basic electronic and electrical architecture of the units according to the invention makes it possible to develop a whole range of tachograph units intended for different vehicles.

The tachograph unit according to the invention comprises at least two smart card reader / writer devices, called tachograph cards, so that the unit can receive at least two tachograph cards in parallel.

• pour chaque dispositif lecteur/enregistreur, un moteur d'entraînement d'un mécanisme de déplacement d'une carte tachygraphique entre une position d'insertion/retrait et une position verrouillée de lecture/écriture,
• une imprimante,
• des moyens de retro-éclairage d'un écran d'affichage et d'un dispositif (clavier par exemple) de saisie de données par un utilisateur.

Advantageously and according to the invention, the power circuit comprises equipment, said power equipment, including:

• for each reader / writer device, a drive motor of a moving mechanism of a tachograph card between an insertion / removal position and a locked read / write position,
• a printer,
• means for backlighting a display screen and a device (keyboard for example) data input by a user.

• impression de données au moyen de l'imprimante,
• déplacement d'une carte tachygraphique entre la position d'insertion/retrait et la position verrouillée de lecture/écriture au moyen d'un mécanisme motorisé de déplacement,
• rétro-éclairage de l'écran d'affichage et du dispositif de saisie.

The power circuit is adapted to perform the following power operations:

• printing data using the printer,
• moving a tachograph card between the insertion / withdrawal position and the locked read / write position by means of a motorized movement mechanism,
• backlighting of the display screen and the input device.

To do this, the power circuit preferably comprises at least one microprocessor, adapted to drive the printer and the engines of the card reader / writer devices.

• au moins un connecteur, dit connecteur CAN, pour la connexion du circuit de puissance avec un réseau de calculateurs du véhicule, le microprocesseur secondaire étant adapté pour exécuter des opérations de communication (protocolaire et cyclique) de données avec ces calculateurs,
• un ou plusieurs connecteur(s), dit(s) connecteur(s) de gestion de flotte, pour l'échange de données utiles à la gestion de flotte ou à un afficheur déporté de données telles que des données tachygraphiques et/ou des données de distance/vitesse,
• un connecteur, dit connecteur de diagnostic, pour la communication de données relatives au diagnostic de l'unité de tachygraphe,
• un connecteur, dit connecteur vitesse/distance, pour la connexion du circuit de puissance avec un ou plusieurs calculateurs du véhicule exploitant la vitesse et/ou la distance parcourue du véhicule, le circuit de puissance étant adapté pour échanger en temps réel des signaux avec ce calculateur,
• un connecteur, dit connecteur régime moteur, pour la connexion du circuit de puissance avec un capteur de régime du moteur ou l'alternateur du véhicule, le circuit de puissance étant adapté pour recevoir en temps réel des signaux du capteur régime moteur ou de l'alternateur,
• un ou plusieurs connecteurs pour l'échange d'autres signaux tels que des signaux de contrôle par un organe externe du rétro-éclairage de l'écran d'affichage et du dispositif de saisie de données, des signaux logiques pouvant être enregistrés ou générés par l'unité de tachygraphe, d'autres signaux encore tels qu'un signal de contrôle d'un voyant d'alarme externe,
• un connecteur pour la connexion du circuit de puissance avec un appareil de communication à distance du type modem ou GSM/GPS en vue de la transmission de données depuis l'unité vers un dispositif distant de déchargement de données.

Advantageously and according to the invention, the power circuit is also adapted to provide a communication interface with vehicle computers and signal exchange channels for other vehicle components and / or remote devices (it preferably comprises for this purpose, at least one secondary microprocessor), said power circuit comprising:

• at least one connector, said CAN connector, for the connection of the power circuit with a network of computers of the vehicle, the secondary microprocessor being adapted to perform communication operations (protocol and cyclic) data with these computers,
• one or more connector (s), called the fleet management connector (s), for the exchange of data useful for fleet management or a remote display of data such as tachograph data and / or data distance / speed,
• a connector, referred to as a diagnostic connector, for the communication of data relating to the diagnosis of the tachograph unit,
• a connector, said speed / distance connector, for the connection of the power circuit with one or more computers of the vehicle exploiting the speed and / or the distance traveled by the vehicle, the power circuit being adapted to exchange signals in real time with this calculator,
• a connector, said engine speed connector, for the connection of the power circuit with a speed sensor of the engine or the alternator of the vehicle, the power circuit being adapted to receive in real time signals from the engine speed sensor or the alternator,
• one or more connectors for the exchange of other signals such as control signals by an external member of the backlight of the display screen and the data input device, logic signals that can be recorded or generated by the tachograph unit, other signals such as a control signal of an external alarm indicator,
• a connector for the connection of the power circuit with a remote communication device of the modem or GSM / GPS type for transmitting data from the unit to a remote data unloading device.

As previously mentioned, in the isolated version of the unit according to the invention, the power circuit is preferably referenced to the chassis of the vehicle, that is to say to the same mass as the CAN network of the vehicle.

• au moins une mémoire de type non volatile, et notamment une mémoire électronique de type flash,
• une horloge temps réel calendaire, reliée à une source électrique propre de secours,
• une interface de connexion, dite interface de capteur, pour la connexion de l'unité de tachygraphe au capteur de mouvement,
• pour chaque dispositif lecteur/enregistreur de cartes tachygraphiques, une interface de connexion, dite interface de carte, adaptée pour permettre une communication entre un microprocesseur principal du circuit principal et une carte tachygraphique présente en position verrouillée de lecture/écriture dans le dispositif lecteur/enregistreur,
• un écran d'affichage,
• un dispositif de saisie de données par un utilisateur tel qu'un clavier,
• un dispositif d'alarme visuelle et/ou un dispositif d'alarme sonore.

Advantageously and according to the invention, the main circuit comprises:

• at least one non-volatile type memory, and in particular a flash type electronic memory,
• a calendar real-time clock, connected to a clean emergency power source,
• a connection interface, called sensor interface, for connecting the tachograph unit to the motion sensor,
• for each tachograph card reader / writer device, a connection interface, called a card interface, adapted to allow communication between a main microprocessor of the main circuit and a tachograph card having a locked read / write position in the reader / writer device ,
• a display screen,
• a device for entering data by a user such as a keyboard,
• a visual alarm device and / or an audible alarm device.

• des opérations de calcul, traitement, enregistrement et stockage au moins des données conducteur,
• la réception de données, dites données de mouvement, émises par le capteur de mouvement, et des opérations de traitement desdites données de mouvement,
• la réception de données, dites données saisies, saisies au moyen du dispositif de saisie (clavier par exemple), et des opérations de traitement desdites données saisies,
• la détection de la présence d'une carte tachygraphique en une position de lecture/écriture dans un dispositif lecteur/enregistreur de cartes, des opérations de lecture/écriture de données dans la mémoire d'une carte tachygraphique en position verrouillée de lecture/écriture,
• des opérations, dites opérations de sécurité, mettant en oeuvre des algorithmes de chiffrement, lesquelles opérations de sécurité comprennent des opérations en vue de l'authentification mutuelle de l'unité et du capteur de mouvement, des opérations en vue de l'authentification d'au moins une partie des données reçues du capteur de mouvement par l'unité, des opérations en vue de l'authentification mutuelle de l'unité et d'une carte tachygraphique présente dans le dispositif lecteur/enregistreur en position verrouillée de lecture/écriture -ou présente dans un autre dispositif lecteur/enregistreur de cartes distant et apte à communiquer avec un microprocesseur principal du circuit principal par l'intermédiaire d'une interface de communication à distance-, des opérations en vue de l'authentification d'au moins une partie des données échangées entre l'unité et ladite carte tachygraphique,
• des opérations de détection et de traitement d'évènements, des opérations de détection et de traitement d'anomalies, l'émission de signaux d'avertissement sonores et/ou visuels correspondants,
• des opérations de contrôle et de suivi des activités de contrôle,
• l'affichage de données sur l'écran d'affichage,
• des opérations de génération de données, dites données d'impression, en vue de l'impression de données par l'intermédiaire du circuit de puissance,
• la transmission de commandes au circuit de puissance, et notamment de commandes d'impression, de commandes de déplacement de carte (en vue du déplacement d'une carte entre la position d'insertion/retrait et la position verrouillée de lecture/écriture par le moteur d'un dispositif lecteur/enregistreur).

The main circuit is adapted to perform operations, called main operations, among which:

• operations for calculating, processing, recording and storing at least the conductive data,
• receiving data, called motion data, transmitted by the motion sensor, and processing operations of said motion data,
• receiving data, said data entered, entered by means of the input device (keyboard for example), and processing operations of said data entered,
• detecting the presence of a tachograph card in a read / write position in a card reader / writer device, data read / write operations in the memory of a tachograph card in the locked read / write position,
• operations, so-called security operations, implementing encryption algorithms, which security operations include operations for the mutual authentication of the unit and the motion sensor, operations for the authentication of at least a portion of the data received from the motion sensor by the unit, operations for mutual authentication of the unit and a tachograph card present in the reader / writer device in the locked read / write position - or present in another remote card reader / writer device and able to communicate with a main microprocessor of the main circuit via a remote communication interface-, operations for the authentication of at least one part of the data exchanged between the unit and the tachograph card,
• detection and event processing operations, anomaly detection and processing operations, emission of corresponding audio and / or visual warning signals,
• control and monitoring operations of control activities,
• the display of data on the display screen,
• data generation operations, called printing data, for printing data via the power circuit,
• the transmission of commands to the power circuit, and in particular of print commands, card movement commands (for moving a card between the insertion / withdrawal position and the locked read / write position by the engine of a reader / writer device).

• des opérations d'étalonnage et des opérations de déchargement de données, le circuit principal comprenant au moins un connecteur, dit connecteur d'étalonnage/déchargement, accessible à un utilisateur, pour la connexion à l'unité d'un dispositif d'étalonnage ou de déchargement de données,
• des opérations de gestion de verrouillages d'entreprise,
• des opérations d'autotest.

Advantageously and according to the invention, the main circuit is adapted to perform also:

• calibration operations and data unloading operations, the main circuit comprising at least one connector, said calibration / unloading connector, accessible to a user, for connection to the unit of a calibration device or unloading data,
• enterprise lock management operations,
• self-test operations.

Advantageously and according to the invention, each data transmission channel between the two circuits is formed by an interface called serial interface interface or SPI ("Serial Peripheral Interface", such an interface comprising a transmission wire of a clock signal -cadence-, a data signal transmission wire in one direction and a data signal transmission wire in the other direction), possibly provided with the above high resistances or optocouplers. Such an interface has the advantage of a small footprint.

The unit preferably comprises a single data transmission channel (i.e. a single SPI), as well as two to four signal transmission channels. The number of connections between the two circuits is thus limited to its strict minimum in order, among other things, to reduce the risk of unwanted transmission of electrical energy between the two circuits, in particular in the isolated version of the tachograph unit, to enable A galvanic isolation barrier is used, but also for reasons of cost in number of optocouplers.

Advantageously and according to the invention, the power circuit comprises a secondary microprocessor and the microprocessors of the main circuit and the power circuit are formed on the same card, which allows to have on the same support two communicating computers, galvanically isolated if necessary . The card has for this purpose a barrier of galvanic isolation between the main circuit and the power circuit. Alternatively, the two circuits are carried by separate cards.

Advantageously and according to the invention, the power circuit comprises a logic interface, called the wake-up interface, which can be connected, via a connector known as a wake-up connector, to a remote communication apparatus such as a modem or a GSM / GPS, for receiving an external signal, said wake-up signal, transmitted by a device external to the unit and in particular by a remote device for unloading data. The tachograph unit further comprises a signal transmission channel for connecting this wakeup interface to a main microprocessor of the main circuit, for the purpose of transmitting the wake-up signal to the main microprocessor.

In the standard version of the tachograph unit, this main microprocessor is adapted to be able to control the activation of the power supply of the off-contact power circuit, on receipt of the wake-up signal. It is also adapted to allow the execution of operations other than power operations previously defined; in particular, it is adapted to authorize (and control) communications with the CAN network of the vehicle and communication operations with the remote data unloading device. In other words, only part of the circuit power is operational, and this limitation is handled in software by the main microprocessor.

In its isolated version, the tachograph unit comprises an additional power supply circuit, called a wake-up power supply, of the low power transducer type, arranged between the main circuit and the power circuit, and whose activation can be controlled. by the main microprocessor of the main circuit to receive the wake-up signal, out of contact. Only part of the power circuit, necessary for communication operations with the CAN network of the vehicle and with the remote device for unloading data, is operational when the power circuit is powered by the wake-up power supply. This limitation is preferably handled in software by the main microprocessor; the wake-up power supply is in this case connected to the power supply so as to power it off, and said main microprocessor is adapted to allow off-contact execution only operations other than operations power. In a variant, the wake-up power supply is directly connected to the secondary microprocessor of the power circuit and to itself, and this limitation stems from the fact that the power equipment (only connected to the power supply) is not powered when the network after contact is not activated.

It should be noted that a tachograph unit intended for a vehicle for the transport of dangerous goods is devoid of wake-up power.

The invention also relates to a tachograph unit characterized in combination by all or some of the features mentioned above and below.

The invention also extends to a motor vehicle equipped with a tachograph unit according to the invention.

• la figure 1 est une vue en perspective d'une unité de tachygraphe selon l'invention,
• la figure 2 est une vue éclatée en perspective d'une unité de tachygraphe selon l'invention,
• la figure 3 est un schéma synoptique illustrant l'architecture électronique d'une unité de tachygraphe standard selon l'invention et l'organisation de ses différents composants et équipements,
• la figure 4 est un schéma synoptique illustrant l'architecture électronique d'une unité de tachygraphe isolée selon l'invention et l'organisation de ses différents composants et équipements.

Other objects, features and advantages of the invention will appear on reading the following description which refers to the appended figures representing preferred embodiments of the invention, given solely by way of non-limiting examples, and in which: :

• the figure 1 is a perspective view of a tachograph unit according to the invention,
• the figure 2 is an exploded perspective view of a tachograph unit according to the invention,
• the figure 3 is a block diagram illustrating the electronic architecture of a standard tachograph unit according to the invention and the organization of its various components and equipment,
• the figure 4 is a block diagram illustrating the electronic architecture of an isolated tachograph unit according to the invention and the organization of its various components and equipment.

A tachograph according to the invention comprises on the one hand a tachograph unit 1, standard or isolated, and on the other hand a vehicle motion sensor, connected to the on-board unit by at least one connecting cable. The motion sensor is formed in particular by a motion detection element, a microprocessor (to which the detection element is connected) and a connector for connecting the microprocessor of the sensor to the aforementioned connecting cable.

• un microprocesseur principal 5 pour le traitement des données tachygraphiques. En variante, le circuit principal comprend un groupe de microprocesseurs en parallèle en vue d'assurer une redondance, ou une pluralité de microprocesseurs indépendants ou reliés en série qui se partagent les diverses fonctions liées au traitement des données tachygraphiques. Ce traitement devant répondre à des normes et règles strictes de sécurité et de résistance aux attaques frauduleuses, le microprocesseur principal 5 est un microprocesseur physiquement protégé, adapté pour stocker des secrets cryptographiques (clés de session, clés privées, algorithmes de chiffrement...) et exécuter des opérations de sécurité mettant en oeuvre des algorithmes de chiffrement. Dans une variante préférée, le microprocesseur principal 5 est un microprocesseur basique (non protégé) tel que ceux usuellement utilisés dans le domaine automobile, et le circuit principal comprend de plus un microprocesseur 6 physiquement protégé fournisseur de services cryptographiques, dit microprocesseur CSP, relié au microprocesseur principal 5 selon une relation maître/esclave dans laquelle le microprocesseur principal 5 est le maître et le microprocesseur CSP 6 est l'esclave. Le microprocesseur CSP 6 est dédié au stockage des secrets cryptographiques et à l'exécution de toutes les opérations de sécurité. Il possède à cette fin des caractéristiques non seulement physiques mais aussi fonctionnelles (mémoire apte à disperser les secrets qu'il renferme...) garantissant son inviolabilité. Le microprocesseur CSP 6 est par exemple similaire à ceux employés pour les cartes bancaires. Le microprocesseur CSP 6 exécute les opérations de sécurité à la demande du microprocesseur principal 5 (dont il est l'esclave) ;
• une mémoire de masse 8 non volatile de type mémoire électronique flash, dite mémoire d'application, reliée au microprocesseur principal 5, et dans laquelle est stockée une partie d'une application dite application tachygraphique, permettant (lorsqu'elle est utilisée par le microprocesseur principal 5 en association avec l'autre partie de l'application tachygraphique, résidente dans le microprocesseur principal) de réaliser toutes les fonctionnalités du tachygraphe à l'exclusion des opérations de sécurité, étant précisé toutefois que l'application tachygraphique intègre des commandes permettant de déclencher l'exécution des opérations de sécurité par le microprocesseur CSP 6 ;
• une mémoire de masse 9 non volatile de type mémoire électronique flash, dite mémoire de données, reliée au microprocesseur principal 5 et dans laquelle sont stockées les données tachygraphiques, des données dites données de fonctionnement (pour le pilotage des différents équipements du circuit principal), des données dites données annexes (aléas, données temporaires...), et éventuellement des données de sécurité non secrètes (clés publiques par exemple) ;
• une horloge temps réel calendaire 10 (date et heure) reliée au microprocesseur principal 5, laquelle horloge dispose d'une batterie de secours ;
• un dispositif 11 de saisie de données par un utilisateur, agencé en façade 2a de l'unité et piloté par le microprocesseur principal 5, ledit dispositif de saisie comprenant un clavier à touches et/ou un écran tactile ;
• un connecteur 12, dit connecteur de capteur, relié au microprocesseur principal 5, réalisant une interface de connexion de l'unité 1 avec le capteur de mouvement en vue de la réception de données de mouvement du véhicule ;
• un connecteur 13, dit connecteur de déchargement/étalonnage, agencé en façade 2a de l'unité (le connecteur est protégé par un cadre et n'est donc pas visible sur les figures 1 et 2) et relié au microprocesseur principal 5, le connecteur 13 réalisant une interface de connexion de l'unité 1 avec un dispositif d'étalonnage ou un dispositif de déchargement de données, en vue de la réception de données d'étalonnage (envoyées par le dispositif d'étalonnage) ou du déchargement (à destination du dispositif de déchargement) de données tachygraphiques ;
• deux connecteurs 141 et 151, dits connecteurs de carte, reliés au microprocesseur principal 5. Chaque connecteur de carte 141, 151 fait partie d'un dispositif 14, 15 lecteur/enregistreur de cartes tachygraphiques à puce, qui comprend : une interface mécanique (à fente, tiroir, chariot coulissant...) de réception d'une carte tachygraphique, dotée d'un mécanisme motorisé commandé pour le déplacement d'une carte 60 entre une position d'introduction/retrait et une position verrouillée de lecture/écriture ; un connecteur de carte 141, 151 permettant la liaison entre le microprocesseur principal 5 de l'unité et la puce 61 d'une carte tachygraphique présente en position de lecture/écriture dans le dispositif ; au moins un organe de détection de carte en position verrouillée de lecture/écriture, apte à transmettre un signal au microprocesseur principal 5 lorsqu'une carte est détectée en position verrouillée de lecture/écriture ;
• un écran d'affichage 16 piloté par le microprocesseur principal 5,
• un dispositif d'alarme visuelle 17 et un dispositif d'alarme sonore 18, pilotés par le microprocesseur principal 5,
• un circuit d'alimentation électrique 7, dit alimentation principale, relié de façon permanente au réseau permanent 52 du véhicule qui est lui-même alimenté de façon permanente par la batterie 51 (source électrique permanente) du véhicule. Ainsi, l'alimentation principale 7 alimente le microprocesseur principal 5 et le circuit principal en permanence quelle que soit la phase d'exploitation du véhicule en cours (hors contact ou après contact, moteur arrêté, moteur tournant, véhicule à l'arrêt, véhicule roulant...). Cette alimentation principale est une alimentation de faible puissance (compte tenu de ce que le circuit principal est dépourvu d'équipement ou composant nécessitant une puissance importante) et de bon rendement (en vue de minimiser l'énergie soustraite à la batterie du véhicule dans les périodes où cette dernière ne peut être rechargée -hors contact, moteur à l'arrêt-). Pour une plus grande clarté des figures 3 et 4, les lignes d'aliméntation partant de l'alimentation principale 7 vers les divers équipements et composants du circuit principal 3 qui doivent être alimentés, n'ont pas été représentées.

The tachograph unit 1 according to the invention comprises a reinforced secure housing 2, formed of several elements 2a (front), 2b, 2c and provided with safety seals 50. It incorporates a first circuit 4, said main circuit, which comprises at least :

• a main microprocessor 5 for processing the tachograph data. Alternatively, the main circuit comprises a group of microprocessors in parallel to provide redundancy, or a plurality of independent or serially connected microprocessors that share the various functions related to the processing of tachograph data. This treatment must meet strict standards and rules of security and resistance to fraudulent attacks, the main microprocessor 5 is a microprocessor physically protected, adapted to store cryptographic secrets (session keys, private keys, encryption algorithms ...) and perform security operations implementing encryption algorithms. In a preferred variant, the main microprocessor 5 is a basic (unprotected) microprocessor such as those usually used in the automotive field, and the main circuit further comprises a microprocessor 6 physically protected cryptographic services provider, said microprocessor CSP, connected to the main microprocessor 5 in a master / slave relationship in which the main microprocessor 5 is the master and the microprocessor CSP 6 is the slave. The microprocessor CSP 6 is dedicated to the storage of cryptographic secrets and the execution of all security operations. It possesses for this purpose not only physical but also functional characteristics (memory able to disperse the secrets it contains ...) guaranteeing its inviolability. The microprocessor CSP 6 is for example similar to those used for bank cards. The microprocessor CSP 6 executes the security operations at the request of the main microprocessor 5 (of which it is the slave);
• a nonvolatile mass memory 8 of electronic flash memory type, called application memory, connected to the main microprocessor 5, and in which is stored a part of an application called tachograph application, allowing (when used by the microprocessor main 5 in association with the other part of the tachograph application, resident in the main microprocessor) to perform all the functions of the tachograph excluding security operations, it being specified, however, that the tachograph application includes commands for trigger the execution of security operations by the microprocessor CSP 6;
• a nonvolatile mass memory 9 of flash electronic memory type, called data memory, connected to the main microprocessor 5 and in which the tachograph data are stored, data referred to as operating data (for controlling the different equipment of the main circuit), data called ancillary data (random data, temporary data ...), and possibly non-secret security data (public keys for example);
• a real-time calendar clock 10 (date and time) connected to the main microprocessor 5, which clock has a battery backup;
• a device 11 for data input by a user, arranged on the front panel 2a of the unit and controlled by the main microprocessor 5, said input device comprising a keypad and / or a touch screen;
• a connector 12, said sensor connector, connected to the main microprocessor 5, providing a connection interface of the unit 1 with the motion sensor for receiving vehicle motion data;
• a connector 13, said connector unloading / calibration, arranged on the front 2a of the unit (the connector is protected by a frame and is therefore not visible on the figures 1 and 2 ) and connected to the main microprocessor 5, the connector 13 making a connection interface of the unit 1 with a calibration device or a data unloading device, for the reception of calibration data (sent by the device calibration) or unloading (to the unloading device) of tachograph data;
• two connectors 141 and 151, called card connectors, connected to the main microprocessor 5. Each card connector 141, 151 is part of a smart card tachograph reader / writer device 14, which comprises: a mechanical interface (to slit, drawer, slide carriage ...) for receiving a tachograph card, provided with a motorized controlled mechanism for moving a card 60 between an insertion / withdrawal position and a locked read / write position; a card connector 141, 151 allowing the link between the main microprocessor 5 of the unit and the chip 61 of a tachograph card present in read / write position in the device; at least one card detecting member in the locked read / write position, adapted to transmit a signal to the main microprocessor when a card is detected in the locked read / write position;
• a display screen 16 controlled by the main microprocessor 5,
• a visual alarm device 17 and a sound alarm device 18, controlled by the main microprocessor 5,
• a power supply circuit 7, said main power supply, permanently connected to the permanent network 52 of the vehicle which is itself permanently supplied by the battery 51 (permanent electrical source) of the vehicle. Thus, the main power supply 7 supplies the main microprocessor 5 and the main circuit permanently regardless of the operating phase of the current vehicle (out of contact or after contact, engine stopped, engine running, vehicle stationary, vehicle rolling...). This main power supply is a low power supply (considering that the main circuit is devoid of equipment or component requiring significant power) and good performance (in order to minimize the energy subtracted from the vehicle battery in the periods when it can not be recharged - out of contact, engine off -). For greater clarity of figures 3 and 4 , the supply lines from the main power supply 7 to the various equipment and components of the main circuit 3 to be powered, have not been represented.

• un microprocesseur 21 dit microprocesseur secondaire, choisi parmi les microprocesseurs usuels non protégés, peu onéreux,
• des moyens de rétro-éclairage 23 de l'écran d'affichage 16 et du dispositif 11 de saisie de données, pilotés par le microprocesseur secondaire 21,
• une imprimante 24 pilotée par le microprocesseur secondaire 21,
• le moteur 142, 152 de l'interface mécanique de chaque dispositif 14, 15 lecteur/enregistreur de cartes tachygraphiques, lesquels moteurs sont pilotés par le microprocesseur secondaire 21,
• une mémoire électronique 25 reliée au microprocesseur secondaire 21, pour le stockage de données de fonctionnement (taux d'éclairage de l'écran 16, zone image des tickets à imprimer par l'imprimante 24...), de données annexes... ; une alternative avantageuse de l'invention consiste à limiter cet espace mémoire 25 à celui disponible dans le microprocesseur 21, rendant ainsi le circuit de puissance monochip,
• une interface logique de réveil 37 et un connecteur de réveil 26 auquel peut être connecté un appareil de communication à distance tel qu'un modem ou un GSM/GPS monté sur le véhicule, en vue de la réception par l'unité d'un signal de réveil envoyé par un dispositif externe à l'unité -tel qu'un dispositif distant de déchargement de données-,
• un connecteur 31 auquel est également relié l'appareil de communication à distance (modem ou GSM/GPS) pour la transmission de données depuis l'unité vers le dispositif distant de déchargement de données,
• un connecteur de vitesse/distance 27 relié au microprocesseur secondaire 21, pour la connexion de l'unité au calculateur de vitesse et de distance parcourue du véhicule, en vue de la transmission en temps réel de données entre l'unité et ce calculateur,
• un connecteur régime moteur 28 relié au microprocesseur secondaire 21, pour la connexion de l'unité à un capteur de régime moteur ou à l'alternateur du véhicule, en vue de la réception en temps réel de données entre cet organe et l'unité,
• deux connecteurs CAN 29 et 30 reliés au microprocesseur secondaire 21, pour la connexion de l'unité au réseau CAN de calculateurs du véhicule, en vue de la transmission périodique de données entre l'unité et ce réseau de calculateurs, selon un protocole d'échange prédéterminé,
• un connecteur 32 de gestion de flotte, relié au microprocesseur secondaire 21,
• un connecteur 33 de diagnostic, relié au microprocesseur secondaire 21,
• un connecteur 34 relié au microprocesseur secondaire 21 pour la transmission de signaux de contrôle du rétro-éclairage par un organe externe,
• un connecteur 35 relié au microprocesseur secondaire 21 pour la réception -avec ou sans datation- ou l'émission de signaux logiques,
• un connecteur 36 relié au microprocesseur secondaire 21 pour la transmission de signaux de contrôle d'un voyant d'alarme externe,
• un circuit d'alimentation électrique 22, dit alimentation de puissance, destiné à alimenter le circuit de puissance de façon temporaire, lorsque le réseau après contact 53 du véhicule est activé. L'alimentation de puissance est dimensionnée compte tenu des équipements et composants du circuit de puissance précédemment cités. Pour une plus grande clarté des figures 3 et 4, les lignes d'alimentation partant de l'alimentation de puissance 22 vers les divers équipements et composants du circuit de puissance 20 qui doivent être alimentés, n'ont pas été représentées.

The tachograph unit 1 according to the invention also incorporates another circuit 20, said power circuit, which comprises at least:

• a microprocessor 21 called secondary microprocessor, chosen from the usual unprotected microprocessors, inexpensive,
• backlighting means 23 of the display screen 16 and the data acquisition device 11, controlled by the secondary microprocessor 21,
• a printer 24 driven by the secondary microprocessor 21,
• the motor 142, 152 of the mechanical interface of each device 14, 15 tachograph card reader / recorder, which motors are driven by the secondary microprocessor 21,
• an electronic memory 25 connected to the secondary microprocessor 21, for the storage of operating data (lighting rate of the screen 16, image area of the tickets to be printed by the printer 24 ...), additional data ... ; an advantageous alternative of the invention is to limit this space memory 25 to that available in the microprocessor 21, thus making the power circuit monochip,
• a wake-up logic interface 37 and a wake-up connector 26 to which a remote communication apparatus such as a modem or a GSM / GPS mounted on the vehicle can be connected, for the reception by the unit of a signal alarm clock sent by an external device to the unit -as a remote device for unloading data-,
• a connector 31 which is also connected to the remote communication device (modem or GSM / GPS) for the transmission of data from the unit to the remote device for unloading data,
• a speed / distance connector 27 connected to the secondary microprocessor 21, for connecting the unit to the speed and distance calculator of the vehicle, for the purpose of real-time transmission of data between the unit and this computer,
• a motor speed connector 28 connected to the secondary microprocessor 21, for connecting the unit to an engine speed sensor or to the vehicle alternator, for the purpose of real-time data reception between this unit and the unit,
• two CAN connectors 29 and 30 connected to the secondary microprocessor 21, for the connection of the unit to the CAN network of computers of the vehicle, for the periodic transmission of data between the unit and this computer network, according to a protocol of predetermined exchange,
• a fleet management connector 32, connected to the secondary microprocessor 21,
• a diagnostic connector 33, connected to the secondary microprocessor 21,
• a connector 34 connected to the secondary microprocessor 21 for the transmission of backlighting control signals by an external device,
• a connector 35 connected to the secondary microprocessor 21 for receiving-with or without dating-or the transmission of logic signals,
• a connector 36 connected to the secondary microprocessor 21 for transmitting control signals of an external alarm indicator,
• a power supply circuit 22, said power supply, for supplying the power circuit temporarily, when the network after contact 53 of the vehicle is activated. The power supply is dimensioned taking into account the equipment and components of the power circuit mentioned above. For greater clarity of figures 3 and 4 the supply lines from the power supply 22 to the various equipment and components of the power circuit 20 which are to be powered, have not been shown.

• un canal 40 de transmission de données du type SPI (« Serial Peripheral Interface ») entre le microprocesseur principal 5 et le microprocesseur secondaire 21, par lequel le microprocesseur principal 5 peut transmettre au microprocesseur 21 des commandes de déplacement de carte, qui déclenchent le pilotage par le microprocesseur secondaire 21 du moteur 142, 152 d'un dispositif lecteur/enregistreur en vue du déplacement d'une carte tachygraphique entre la position d'insertion/retrait et la position verrouillée de lecture/écriture (dans un sens ou dans l'autre), des commandes d'impression et des données à imprimer, des commandes de rétro-éclairage de l'écran d'affichage 16, etc. ;
• un canal 41 de transmission de signaux entre le microprocesseur secondaire 21 et le microprocesseur principal 5 par lequel le microprocesseur secondaire 21 transmet au microprocesseur principal 5 des signaux d'acquittement des commandes,
• un canal 42 de transmission de signaux entre le connecteur de réveil 26 du circuit de puissance et le microprocesseur principal 5, par lequel le signal de réveil est transmis au circuit principal en vue de l'alimentation, hors contact, d'au moins une partie du circuit de puissance,
• un canal 43 de transmission au microprocesseur secondaire 21 du signal reçu du connecteur de capteur 12, pour permettre la transmission par le connecteur de vitesse/distance 27 des signaux temps réels représentatifs de la vitesse du véhicule.

The main circuit 4 and the power circuit 20 are connected by:

• a data transmission channel 40 of the SPI (Serial Peripheral Interface) type between the main microprocessor 5 and the secondary microprocessor 21, by which the main microprocessor 5 can transmit to the microprocessor 21 card movement commands, which trigger the control by the secondary microprocessor 21 of the motor 142, 152 of a reader / writer device for moving a tachograph card between the insertion / removal position and the locked read / write position (in one direction or in the other), print commands and data to be printed, backlight controls of the display screen 16, etc. ;
• a signal transmission channel 41 between the secondary microprocessor 21 and the main microprocessor 5 by which the secondary microprocessor 21 transmits control acknowledgment signals to the main microprocessor 5,
• a signal transmission channel 42 between the wake-up connector 26 of the power circuit and the main microprocessor 5, by means of which the wake-up signal is transmitted to the main circuit for the non-contact power supply of at least a part power circuit,
• a channel 43 for transmitting to the secondary microprocessor 21 of the signal received from the sensor connector 12, to allow transmission by the speed / distance connector 27 real time signals representative of the speed of the vehicle.

In the standard version of the unit, illustrated in figure 3 , the data transmission channels 40 and 41-44 can (or can not) be provided with high resistance 45.

In addition, the main power supply 7 and power supply 22 are both connected to the permanent network 52 of the vehicle and are referenced to the same mass: the positive terminal of the vehicle battery is connected (via the permanent network) to a node of the circuit principal serving in parallel a positive terminal of the main power supply 7 and a conductive line leading to a positive terminal of the power supply 22 (a diode being interposed on this line between the two circuits); the negative terminals of the battery and the main power and power supplies are referenced to the same mass.

The power supply 22 is therefore constantly powered by the vehicle battery. An additional channel 44 for transmitting signals between the main microprocessor 5 and the power supply 22, allows the main microprocessor 5 to control the activation or deactivation of the power supply, depending on the phase of use of the vehicle. course (out of contact or after contact). To do this, the wake-up interface 37, called the ApC / alarm interface, is also connected to the network after contact 53 of the vehicle, with a view to receiving a signal, said signal after contact, representative of the activation of this signal. network. When it receives such a signal after contact, via the interface ApC / alarm 37 and the channel 42, the main microprocessor 5 activates the power supply 22 via the channel 44. When it receives a wake up signal via the interface ApC / alarm 37 and the channel 42, while the network after contact 53 is deactivated, the main microprocessor 5 activates the power supply 22 but limits the use of the power circuit to only communications with the interfaces ( 26 to 36) input / output signals considered low power; in particular, no print order or card movement can be sent to the secondary microprocessor 21. The power equipment is thus neutralized off contact, when the vehicle battery can not be recharged.

In the isolated version of the unit, illustrated in figure 4 , the data transmission channels 40 and 41-43 and 48 are provided with optocouplers 46 for electrically separating the two circuits. In addition, both circuits are referenced to separate masses. The main power supply 7 of the main circuit is directly connected and referenced to the permanent network 52 of the vehicle (the negative terminal of the main power supply is connected to the ground of the permanent network). The equipment or components of the main circuit 4 are referenced to the ground of the permanent network of the vehicle or have a clean mass (this is the case of the sensor connector 12 and the calibration / discharge connector 13 where the reference masses are provided to the equipment). Furthermore, the power supply 22 is directly connected to the network after contact 53 of the vehicle and is therefore powered by the vehicle battery when the contact is established. The power supply is thus adapted to supply the power circuit when it receives, from the network after contact, a supply current acting as a signal after contact representative of the activation of the network after contact. All the equipment and components of the power circuit 20, including the power supply 22, is referenced to the chassis of the vehicle (power mass easements and vehicle bodies, including the CAN network).

In this isolated version, to allow partial use of the off-contact power circuit (alarm function), the unit comprises a transducer 47 between the two circuits, the mass of which is also connected to the chassis of the vehicle. The transducer 47 is also connected to the power supply 22, in order to power the latter. This transducer is "activated" by the main microprocessor 5 via a signal transmission channel 48. The main microprocessor 5 controls the activation of the transducer to receive, out of contact, a wake-up signal (via the channel 42). The main microprocessor 5 is further adapted to limit the use of the power circuit to only communications with the input / output interfaces (26-36) of signals deemed low power, to avoid any exhaustion of the vehicle battery. A low power transducer is enough to provide these functions.

The main circuit 4 and power 20, excluding equipment that can not be carried by a card or formed on a card (motorized card moving mechanisms, printer, connectors on the housing - unloading connector / calibration on the front before the unit, sensor connector ...-, etc.), are carried by the same card 3. In the isolated version of the unit (and preferably in all versions of the invention), said card 3 presents a physical barrier 49 for separating and galvanically isolating the circuits. Note that the optocouplers 46 (or possibly the resistors 45) are mounted on this board straddling the galvanic isolation barrier. Such a configuration offers great security against the risk of arcing between the two circuits in case of malfunction of a component.

The invention also relates to a version of the unit intended for vehicles for the transport of hazardous materials. This version is similar to the standard version or isolated but has no interface (37) and connector (26) wake up power circuit.

Claims (20)

1. Tachograph unit (1) intended to be fitted on board an automotive vehicle and to be connected to at least one motion sensor of the vehicle, which unit comprises at least two devices (14, 15) for reading/recording chip cards (60), namely tachograph cards, at least one microprocessor card for processing in a secure manner and storing data, namely tachograph data, comprising at least data, namely driver data, relating to the activities of a driver of said vehicle,
   characterised in that it comprises:

   - a first circuit (4) with microprocessor(s), namely a main circuit, configured to run operations, namely main operations, for processing in a secure manner and storing tachograph data, which main circuit comprises at least one electric power supply circuit (7), namely a main power supply, configured so that it can be permanently connected to a permanent electric power source of the vehicle so that the main power supply supplies power permanently to the main circuit when it is connected to the vehicle's permanent electric power supply

   - a second circuit (20) namely a power circuit, configured to run at least operations, namely power operations, which power circuit comprises:

   - at least one electric power supply circuit (22), namely a power supply, separate from the main power supply (7), configured so that it can supply the power circuit with power when a signal is detected, namely an after contact signal, representing the fact that a network, namely an after contact network, of the vehicle has been activated, the main circuit and the power circuit being configured so as not to allow any power operation to be run when out of contact,

   - items of equipment, namely power equipment, including:

   - for each card reader/recorder device, a motor (142, 152) for driving a tachograph card displacement mechanism between an insertion/withdrawal position and a locked read/write position,

   - a printer (24),

   - means (23) for back lighting a display screen (16) and a device (11) enabling data to be input by a user,

   the power circuit (20) being configured to run the following power operations:

   - printing data by means of the printer (24)

   - displacing a tachograph card (60) between the insertion/withdrawal position and the locked read/write position by means of a motorised displacement mechanism,

   - backlighting the display screen (16) and the input device (11),

   the main circuit (4) and the power circuit (20) being connected to one another by data and/or signal transmission channels (40-44).
2. Tachograph unit as claimed in claim 1, characterised in that the power circuit (20) comprises at least one microprocessor (21), namely a secondary microprocessor.
3. Tachograph unit as claimed in claim 2, characterised in that the secondary microprocessor (21) is connected to a microprocessor (5), namely a main microprocessor, of the main circuit based on a master/slave relationship in which the main microprocessor is the master and the secondary microprocessor is the slave.
4. Tachograph unit as claimed in one of claims 1 to 3, characterised in that the main power supply (7) is configured so that it can be connected to a network, namely a permanent network (52), of the vehicle.
5. Tachograph unit as claimed in one of claims 1 to 4, characterised in that the power supply (22) is configured so that it can be connected to the vehicle's permanent network (52) and in that the main circuit (4) comprises a main microprocessor (5) configured to issue a command to activate the power supply on receiving the after contact signal and to deactivate the power supply when out of contact.
6. Tachograph unit as claimed in one of claims 1 to 4, characterised in that the power supply (22) is configured so that it can be connected to the vehicle's after contact network (53).
7. Tachograph unit as claimed in claim 6, characterised in that the power supply (22) is configured so that it can be referenced to the vehicle's chassis.
8. Tachograph unit as claimed in one of claims 1 to 7, characterised in that the power circuit (20) is configured to establish a communication interface with computers of the vehicle and signal exchange channels for other entities of the vehicle and/or remote entities, said power circuit comprising:

   - at least one connector (29), namely a CAN connector, for connecting the power circuit to a computer network of the vehicle,

   - a connector (27), namely a speed/distance connector, for connecting the power circuit to one or more computers of the vehicle processing the speed of and/or the distance travelled by the vehicle,

   - a connector (28), namely an engine status connector, for connecting the power circuit to an engine status sensor or to the vehicle's alternator,

   - a connector (33), namely a diagnostics connector, for communicating data relating to the diagnostics of the tachograph unit.
9. Tachograph unit as claimed in claim 8, characterised in that the power circuit comprises:

   - one or more connectors (32), namely fleet management connectors, for exchanging data useful for managing the fleet or transmitting it to a display showing data such as tachograph data and/or distance/speed data,

   - one or more connectors (34-36) for exchanging other signals such as signals to enable an external entity to control the back lighting of the display screen and the data input device, the tachograph unit being capable of recording or generating logic signals, a control signal of an external alarm indicator lamp,

   - a connector (31) for connecting the power circuit to a remote communication apparatus with a view to transmitting data from the unit to a remote data downloading device.
10. Tachograph unit as claimed in one of claims 1 to 9, characterised in that the main circuit (4) comprises:

    - at least one memory (8,9) of the non-volatile type,

    - a real time clock (10) connected to a separate back-up electric power source,

    - a connection interface (12), namely a sensor interface, for connecting the tachograph unit to the motion sensor,

    - for each reader/recorder device (14, 15), a connection interface (141, 151), namely a card interface, configured to enable a communication between a main microprocessor (5) of the main circuit and a tachograph card (60) disposed in a locked read/write position in the reader/recorder device,

    - a display screen (16),

    - a device (11) enabling data to be input by a user,

    - a visual alarm device (17) and/or an acoustic alarm device (18).
11. Tachograph unit as claimed in claim 10, characterised in that the main circuit (4) is configured to run operations, namely main operations, including:

    - operations for calculating, processing, recording and storing at least driver data,

    - receiving data, namely motion data, transmitted by a motion sensor and operations for processing said motion data,

    - receiving data, namely input data, input by means of the input device (11), and operations for processing said input data,

    - detecting the presence of a tachograph card (60) in a read/write position in a reader/recorder device (14, 15), data reading/writing operations from the memory of a tachograph card in the locked read/write position,

    - operations, namely security operations, implementing encryption algorithms, which security operations comprise operations with a view to mutually authenticating the unit and motion sensor, operations with a view to authenticating at least some of the data received from the motion sensor by the unit, operations with a view to mutually authenticating the unit and a tachograph card disposed in a reader/recorder device in a locked read/write position, operations with a view to authenticating at least some of the data exchanged between the unit and said tachograph card,

    - operations for detecting and processing events, operations for detecting and processing anomalies, emitting corresponding warning signals,

    - operations for controlling and monitoring control activities,

    - displaying data on the display screen,

    - operations for generating data, namely printing data, with a view to printing data via the power circuit (20),

    - transmitting commands to the power circuit, and in particular print commands, card displacement commands.
12. Tachograph unit as claimed in one of claims 10 or 11, characterised in that the main circuit (4) is configured to run:

    - calibration operations and data downloading operations, the main circuit having at least one connector (13), namely a calibration/downloading connector, accessible to a user for connecting to the unit of a calibration or data downloading device,

    - operations for managing locks put in place,

    - self testing operations.
13. Tachograph unit as claimed in one of claims 1 to 12, characterised in that the data and/or signal transmission channels comprise optocouplers (46).
14. Tachograph unit as claimed in one of claims 1 to 13, characterised in that each data transmission channel (40) is provided in the form of an interface, namely a serial peripheral interface.
15. Tachograph unit as claimed in one of claims 1 to 14, characterised in that the power circuit comprises a secondary microprocessor (21) and in that the microprocessors (5, 21) of the main circuit and the power circuit are supported by a same card (3) which has a galvanic isolation barrier (49) between the main circuit (4) and the power circuit (20).
16. Tachograph unit as claimed in one of claims 1 to 15, characterised in that the power circuit (20) comprises a logic interface (26), namely a wake up interface, intended to be connected to a remote communication apparatus for receiving an external signal, namely a wake up signal, received from a device external to the unit, and in that the tachograph unit has a signal transmission channel (42) for connecting this wake up interface (26) to a main microprocessor (5) of the main circuit with a view to transmitting a wake up signal to the main microprocessor.
17. Tachograph unit as claimed in claims 16 and 5, characterised in that this main microprocessor (5) is configured to be able to issue commands to activate the power supply (22) when out of contact on receiving the wake up signal.
18. Tachograph unit as claimed in claims 16 and 6, characterised in that it has an electric power supply circuit (47), namely a wake up power supply, of the low-power transducer type disposed between the main circuit (4) and the power circuit (20) and in that said main microprocessor (5) is configured to enable commands to be issued to activate the wake up power supply (47) on receiving the wake up signal when out of contact.
19. Tachograph unit as claimed in one of claims 17 or 18, characterised in that said main microprocessor (5) is configured to permit, when out of contact, the running by the power circuit of solely operations other than power operations.
20. Automotive vehicle, characterised in that it is equipped with a tachograph unit as claimed in one of claims 1 to 19.

Images