FR3051269A1 - COMMUNICATION DEVICE BETWEEN AN ELECTRONIC COMPUTER AND A DEPORTE MODULE - Google Patents

Abstract

The subject of the present invention is a communication device (18) between an electronic computer (2) and at least one remote module (20), the electronic computer (2) comprising, among other things, a microcontroller (4), a first bus of communication (8) synchronous with at least a first data transfer line (10), the remote module (20) comprising control means (24), a second communication bus (80) of the synchronous type with at least a first data transfer line (100) and an asynchronous communication device (18) adapted to couple the first synchronous communication bus (8) to the second synchronous communication bus (80).

Description

The present invention relates generally to embedded electronic devices.

It relates more particularly to optimizing the integration of on-board electronic devices. The invention finds applications, in particular, in the automotive industry. It can be implemented for example in an engine control computer.

A motor vehicle nowadays includes more and more embedded electronics to manage, for example, air conditioning functions, braking management but also functions related to engine control. The management of these different functions is generally performed by computers. Thus, a motor vehicle may comprise different computers such as, for example, a computer dedicated to the management of braking, a dedicated computer to the management of the cabin and a computer dedicated to the management of engine control.

An engine control computer is in the form of a metal housing or similar, hermetic and sealed with at least one electrical connector for communication between the engine control computer and engine components via an electrical harness of the motor vehicle.

Increasingly stringent and stringent international standards concerning mainly pollution emitted by the motor vehicle lead to a complexification of the engine control computers. To meet these needs, more and more electronic functions in the engine control computer are integrated. Of course, these changes must not change the performance and driving pleasure expected by the driver.

Certain electronic functions embedded in the engine control computer such as electronic power stages generate a relatively large increase in the temperature thereof. These electronic power stages are also called output drivers and are suitable for controlling loads such as injectors, valves, electric motors. In addition, the engine control computer is generally placed inside the engine compartment of the motor vehicle in which there is a relatively high temperature that can reach values close to one hundred degrees when the motor vehicle is in operation.

Thus, design efforts during the development of the engine control computer are required to meet the requirements of international standards and also by increasing the number of functions embedded in the engine control computer.

To answer these problems, it is known from the prior art to divide the engine control computer into two engine control computers with a first engine control computer having a supervisory role and a second computer having a role of executing. To be less sensitive to electromagnetic disturbances, the communication between the two engine control computers is generally carried out using a fast communication bus type CAN of the English acronym "Controller Area Network". By the use of such a communication bus, such a solution requires the presence of embedded intelligence in the two engine control computers, that is to say at least one microcontroller in each engine control computer. This solution only makes it possible to reduce the thermal stresses at the level of the first computer; the second calculator is faced with the same problems as those mentioned above. In addition, such a solution has a significant additional cost.

The purpose of the present invention is therefore to provide a communication device between a computer and a remote module making it possible to reduce the constraints on the design of said computer without the need for embedded intelligence in the remote module. Advantageously, the communication device of the present invention will be compatible with the fast communication buses of the industry in general and the automotive industry in particular. For this purpose, the present invention proposes a communication device between an electronic computer and at least one remote module, the electronic computer comprising among others, a microcontroller, a first synchronous communication bus with at least a first data transfer line, the remote module comprising control means, a second synchronous communication bus with at least a first data transfer line and an asynchronous type communication device adapted to couple the first synchronous communication bus to the second synchronous type communication bus .

Thus, thanks to the invention, it is possible to deport at least one module of the electronic computer to reduce the thermal stress of the latter.

In an exemplary embodiment, the communication device comprises a first signal conversion stage coupled to the first synchronous communication bus and a second signal conversion stage coupled to the second synchronous communication bus for controlling the remote module without integrated intelligence in this last.

In order to improve the EMC performance, for electromagnetic compatibility, the first signal conversion stage and the second signal conversion stage are for example adapted to convert referenced signals to an electrical mass into differential signals and vice versa.

In a variant, the first signal conversion stage and the second signal conversion stage are asynchronous type communication bus transmitter / receiver stages.

To allow use in various environments of use, it is for example proposed that the first conversion stage and the second conversion stage are CAN transmitter / receiver stages.

For the sake of improving the communication performance between the electronic computer and the remote module, it is for example proposed that the asynchronous type communication device is adapted to transmit data at a rate greater than or equal to 1 Mbits / s.

To avoid structural modifications of the electronic computer, it is for example proposed that the first synchronous communication bus and the second synchronous communication bus are communication buses of the SPI type. This type of communication bus is widely used for inter-component communication in the same electronic device.

It is also proposed an electronic device comprising an electronic computer and at least one remote module with at least one communication device according to the present invention.

Details and advantages of the present invention will appear better in the description which follows, made with reference to the attached schematic drawing in which: - Figure 1 is a partial block diagram of a computer, a remote module and a device communication device according to the present invention.

For the sake of clarity of the description, only elements useful for understanding the invention will be presented in the text below. Thus, Figure 1 shows a partial block diagram of a computer that can be a computer 2 engine control or also named by the skilled person of the art ECU, the acronym "Engine Control Unit". This type of engine control computer 2 is for example installed in a motor vehicle having a heat engine. In general, this type of engine control computer 2 is placed in an engine compartment of said motor vehicle.

The engine control computer 2 shown in FIG. 1 comprises a microcontroller 4 having, among other things, a first synchronous communication module 6 coupled to a first synchronous communication bus 8. The first synchronous communication module 6 is for example an SPI type communication module; of the acronym "Serial Peripheriral Interface". This type of SPI communication module being well known to those skilled in the art, it will not be presented in detail here.

The first synchronous communication bus 8 is dedicated to communications between components and / or modules of the engine control computer 2 and can not be, as is, used for communications outside the engine control computer 2. Indeed, it is known that this type of communication bus is sensitive to electromagnetic disturbances. Thus, one skilled in the art mentions this type of bus as a bus with poor immunity to electromagnetic disturbances. The first synchronous communication bus 8 includes a first data transfer line 10, also called a transmitting line, a second data transfer line 12, also called a receiver line, a third clock signal line 14 and a fourth data line. selection 16.

The first data transfer line 10 and the second data transfer line 12 are dedicated to data transfers. These data are composed of signals referenced with respect to an electrical ground, for example that of the engine control computer 2. This data may correspond to injector opening commands of the heat engine following an accelerator pedal being urged by a driver of the vehicle. This data can also result from calculations made by the microcontroller 4 according to a strategy determined using computer programs.

The data transiting on the first data transfer line 10 and / or on the second data transfer line 12 have, for example, a 64-bit format with a bit rate of the order of 1 Mbit / s. This rate is of course clocked and in agreement with the frequency of a clock signal delivered by the third clock signal line 14. Finally, the fourth selection line 16 is adapted to deliver a signal allowing the selection of modules or circuits present in the engine control computer 2 according to a given strategy. The signals transiting on the third clock signal line 14 and on the fourth selection line 16 are also referenced with respect to the electrical ground of the engine control computer 2.

In order to relax the design constraints of the engine control computer 2 by the presence of heat flow generating modules such as power circuits, the present invention proposes, in an original way, on the one hand to separate the thermal flux generator modules. of the internal structure of the engine control computer 2 and secondly to ensure communication between said remote modules and the engine control computer 2 using a communication device 18.

In Figure 1, only one remote module is shown. In this example, it is an injection module 20 adapted to control injectors 22 of the engine of the motor vehicle. Of course, the present invention is not limited to this type of injection module 20, any other type of module such as H-type power structures, can also be remote and controlled.

The injection module 20 comprises, inter alia, a power stage 24 with, for example, electronic power components such as transistors, a second synchronous communication module 26. The injection module 20 is for example distant tens of centimeters from the engine control computer 2. It can be integrated in a metal case in order to obtain an optimal dissipation of the heat generated by the power stage 24.

The second synchronous communication module 26 preferably has identical technical characteristics to the first synchronous communication module 6 and is in fact compatible with the latter. The second synchronous communication module 26 includes a first data transfer line 100, a second data transfer line 120, a third clock signal line 140 and a fourth selection line 160 and forms a second communication bus 80. synchronous. Preferably, the second synchronous communication module 26 is of the SPI type and the signals which pass through its various lines and therefore on the second synchronous communication bus 80 are referenced with respect to the electrical ground of the engine control computer 2.

The communication device 18 includes a first signal conversion stage 28 and a second signal conversion stage 30. The first signal conversion stage 28 is integrated with the engine control computer 2 and the second signal conversion stage 30 is integrated with the injection module 20.

The first signal conversion stage 28 has a first input 32, a second input 36, a third input 38 and a first output 34. It further comprises a first output pair 40, a first input pair 42, a second pair of outputs 44 and a third pair of outputs 46.

The first input 32 is coupled to the first data transfer line 10, the first output 34 is coupled to the second data transfer line 12, the second input 36 is coupled to the third clock signal line 14 and finally the third input 38 of the first signal conversion stage 28 is coupled to the fourth selection line 16 of the first synchronous communication module 6 of the engine control computer 2.

The first signal conversion stage 28 further comprises a first transmitter / receiver circuit 48, a second transmitter / receiver circuit 50, a third transmitter / receiver circuit 52 and a fourth transmitter / receiver circuit 54. More generally, the number of communication bus transmitter / receiver circuits is identical to the number of inputs of the first signal conversion module 28. In a preferred embodiment, the transmitter / receiver circuit 48, the transmitter / receiver circuit 50, the transmitter / receiver circuit 52 and the transmitter / receiver circuit 54, are asynchronous transmitter / receiver circuits. In addition, this type of asynchronous type communication bus transmitter / receiver circuit is also named by the person skilled in the art asynchronous type of communication interface integrated circuit or also "transceiver". The word "transceiver" comes from the contraction of the English words "transmetter" and "receiver" and translated into French by transmitter / receiver.

In addition, in order to improve the communication between the engine control computer 2 and the remote module 20, it is preferentially used transmitter / receiver circuits of the CAN type, the acronym for "Controller Area Network". The internal structure of such a circuit being well known to those skilled in the art, it will not be presented here. In an exemplary embodiment, the transmitter / receiver circuits presented above are suitable for working at data rates of the order of 1 Mbit / s.

The first transceiver circuit 48 has a first input 48_1, a first output 48_2 and a second output 48_3. The first input 48_1 is coupled to the first input 32 of the first signal conversion stage 28 and is adapted to receive signals referenced to the electrical ground from the first asynchronous communication bus 8. The first output 48_2 and the second output 48_3 of the transceiver circuit 48 are coupled to the first pair of outputs 40 of the first signal conversion stage 28. The first transmitter / receiver circuit 48 thus transforms a signal referenced to the electrical earth into a differential signal. Thus, the signals from the first data transfer line 10 (referenced with respect to the electrical mase) are transformed with the first transmitter / receiver circuit 48 into differential signals passing through the first pair of outputs 40. when using such a transmitter / receiver circuit 48 the sensitivity to electromagnetic disturbances of the signals transiting on the first output pair 40 is decreased. Thus, the first output pair 40 has immunity to electromagnetic interference.

The second transmitter / receiver circuit 50 has a first output 50_1, a first input 50_2 and a second input 50_3. The first output 50_1 is coupled to the first input 34 of the first signal conversion stage 28. The first input 50_2 and the second input 50_3 of the transceiver circuit 50 are coupled to the second input pair 42 of the first signal conversion stage 28. Thus, thanks to the transmitter / receiver circuit 50, the differential signals coming from the first pair of inputs 42 are transformed into signals referenced with respect to the electrical mass on the first output 50_l.

The third transceiver circuit 52 has a first input 52_1, a first output 52_2 and a second output 53_3. The first input 52_1 is coupled to the second input 36 of the first signal conversion stage 28. The first output 52 2 and the second output 52_3 of the transceiver 52 are coupled to the second pair of outputs 44 of the first signal conversion stage 28.

The fourth transceiver circuit 54 has a first input 54_1, a first output 54_2 and a second output 54_3. The first input 54_1 is coupled to the third input 38 of the first signal conversion stage 28. The first output 54_2 and the second output 54_3 of the transceiver 54 are coupled to the third pair of outputs 4 of the first signal conversion stage 28.

The internal structure as well as the operation of the transmitter / receiver circuits 50, 52, 54 are identical to those of the transmitter / receiver circuit 48 presented above in the description.

Advantageously, thanks to the first conversion module 28, the first synchronous communication module 6 receives and transmits signals according to the SPI type format, that is to say referenced with respect to the electrical mass and allows a conversion of these same signals in differential signals outside the engine control computer 2 without the addition of additional intelligence or modifications of the software (s) of the engine control computer 2.

The second signal conversion stage disposed in the injection module 20 has a number of transmitter / receiver circuits identical to the circuit number of the first conversion stage 28. Thus, in the example of FIG. signal conversion circuit comprises a fifth transmitter / receiver circuit 56, a sixth transmitter / receiver circuit 58, a seventh transmitter / receiver circuit 60 and an eighth transmitter / receiver circuit 62. In addition, to simplify communication between the computer 2 With the engine control unit and the remote module 20, the intrinsic characteristics of the transceiver circuits of the second signal conversion stage 30 are identical to those of the transceiver circuits of the first signal conversion stage 28.

The fifth transceiver circuit 56 has a first input 56_1, a second input 56_2 and a first output 56_3. The first input 56_1 and the second input 56_2 are inputs adapted to receive differential signals and are coupled via a communication bus 70 to the first pair of outputs 40. The first output 56_3 is coupled to the first data transfer line 100 the second synchronous communication module 26. The transmitter / receiver circuit 56 thus transforms differential signals applied to these two inputs 56_1 and 56_2 into a signal referenced with respect to the electrical ground on its first output 56_3.

The sixth transceiver circuit 58 has a first input 58_1, a first output 58_2 and a second output 58_3. The first input 58_1 is adapted to receive signals from the second data transfer line 120, the first output 58_2 and the second output 58_3 are adapted to deliver differential signals to the first pair of inputs 42 via the communication bus. 70. The transmitter / receiver circuit 58 thus transforms a signal referenced to the electrical ground into differential signals.

The seventh transceiver circuit 60 has a first input 60_1, a second input 60_2 and a first output 60_3. The first input 60_1 and the second input 60_2 are inputs adapted to receive a differential signal and are coupled to the second pair of outputs 44 via the communication bus 70. The first output 60_3 is coupled to the third clock signal line. 140 of the second synchronous communication module 26. The transmitter / receiver circuit 60 thus transforms differential signals applied to these two inputs 60_1 and 60_2 into a signal referenced with respect to the electrical mass on its first output 60_3.

The eighth transmitter / receiver circuit 62 has a first input 62_1, a second input 62_2 and a first output 62_3. The first input 62_1 and the second input 62_2 are inputs adapted to receive a differential signal and are coupled via the communication bus 70 to the third pair of outputs 46. The first output 62_3 is coupled to the fourth selection line 160 of the second synchronous communication module 26. The transmitter / receiver circuit 62 thus transforms differential signals applied to these two inputs 62_1 and 62_2 into a signal referenced with respect to the electrical ground on its first output 62_3.

The intrinsic characteristics of the transmitter / receiver circuits 58, 60, 62 are identical to those of the transmitter / receiver circuit 56 and therefore will not be presented in the following description.

In an alternative embodiment, the first pair of outputs 40, the second pair of outputs 44, the third pair of outputs 46 and the first pair of inputs 42 form the communication bus 70. The communication bus 70 is for example integrated in the electrical harness of the motor vehicle.

In another alternative embodiment, only part of the lines of the first synchronous communication bus 8 and the second synchronous communication bus 80 are coupled to the communication device 18. Thus, for example, only the first data transfer line 10 and the second data transfer line 12 is coupled to the first signal conversion stage 28 and only the fifth data transfer line 100 and the sixth data transfer line 120 are coupled to the second signal conversion stage. The communication bus 70 always carries out the coupling between the first signal conversion stage 28 and the second signal conversion stage 30.

Thanks to the invention, the most generative heat flow modules, that is to say the most heat generating modules, can be dissociated from an electronic calculator, thus making it possible to relax the rules of design and also of improve the integration of such a calculator in the motor vehicle. Indeed, the most generative heat flow modules are usually also the largest. Thus, thanks to the invention, it is possible to substantially reduce the size of the electronic computer and thus improve its integration into the motor vehicle.

In addition, thanks to the invention, it is possible to add new features or new modules in the electronic computer without increasing its size due to the space released by the displacement of large modules.

Advantageously, it is possible to control remote modules without intelligence embedded in the latter; that is to say without a microcontroller in the remote module. In addition, it is possible to control a remotely remote module of the electronic computer transparently for the microcontroller of the computer, that is to say without adding new software commands to perform this communication. Indeed, the clever use of signal conversion stages in the electronic computer and in the remote module makes it possible to control the latter in a transparent manner for the microcontroller of the electronic computer. In addition, the clever use of asynchronous transmitter / receiver circuits makes it possible to control a remote module with good immunity to the electromagnetic disturbances inherent to the motor vehicle in which such a device is installed.

In addition, thanks to the use of asynchronous transmitter / receiver circuits and corresponding inputs / outputs, the engine control computer and the remote module have a better tolerance against short circuits.

Thus, the inputs / outputs coupled to the transmitter / receiver circuits accept that it is applied to a voltage of the order of the battery voltage without causing destruction thereof improving the reliability of the computer or the remote module. The exemplary embodiment provides the use of CAN tranceivers which is commonly used in the automotive industry. However, the present invention may also be implemented with other types of tranceivers, for example (non-limiting) CAN-FD, RS 485, etc. As already mentioned, the scope is not limited to the automotive industry.

Of course, the present invention is not limited to the preferred embodiment described above and illustrated in the drawing and the embodiments mentioned above but extends to all variants within the reach of the skilled person.

Claims (8)

1. Communication device (18) between an electronic computer (2) and at least one remote module (20), the electronic computer (2) comprising inter alia, a microcontroller (4), a first synchronous communication bus (8) with at least a first data transfer line (10), the remote module (20) comprising control means (24), a second communication bus (80) synchronous with at least a first transfer line (100) of data, characterized in that it comprises an asynchronous communication device (18) adapted to couple the first synchronous communication bus (8) to the second synchronous communication bus (80). 2. Communication device (18) between an electronic computer (2) and at least one remote module (20), according to claim 1 characterized in that the communication device (18) comprises a first conversion stage (28) of signals coupled to the first synchronous communication bus (8) and a second signal conversion stage (30) coupled to the second synchronous communication bus (80). 3. Communication device (18) between an electronic computer (2) and at least one remote module (20) according to claim 2, characterized in that the first signal conversion stage (28) and the second conversion stage (30) signals are adapted to convert referenced signals into differential signals and vice versa. 4. Communication device (18) between an electronic computer (2) and at least one remote module (20) according to any one of claims 2 or 3, characterized in that the first signal conversion stage (28) and the second signal conversion stage (30) are asynchronous type communication bus transmitter / receiver stages. 5. Device for communication between an electronic computer (2) and at least one remote module, according to any one of claims 2 to 4, characterized in that the first signal conversion stage (28) and the second conversion stage (30) signals are CAN transmitter / receiver stages. 6. Communication device (18) between an electronic computer (2) and at least one remote module (20) according to any one of claims 1 to 5, characterized in that the communication device (18) of the asynchronous type is suitable for transmitting data at a rate greater than 1 Mbps. 7. Communication device (18) between an electronic computer (2) and at least one remote module (20) according to any one of claims 1 to 6, characterized in that the first synchronous communication bus (8) and the second synchronous communication bus (80) are communication buses of the SPI type. 8. Electronic device comprising an electronic computer (2) and at least one remote module (20) characterized in that it comprises at least one communication device (18) as claimed in claims 1 to 7.