WO2017076342A1

WO2017076342A1 - Driving module and control unit of a motor vehicle

Info

Publication number: WO2017076342A1
Application number: PCT/CN2016/104640
Authority: WO
Inventors: Sanbao SHI
Original assignee: Valeo Equipements Electriques Moteur SAS
Current assignee: Valeo Equipements Electriques Moteur SAS
Priority date: 2015-11-04
Filing date: 2016-11-04
Publication date: 2017-05-11
Anticipated expiration: 2018-05-04
Also published as: CN106647344B; CN106647344A

Abstract

A driving module (5) associated with an equipment of a motor vehicle is provided, the driving module (5) is connected to a body controller module (3) of the motor vehicle and is configured for receiving activation signals from the body controller module (3) and for transmitting outage signals to an outage port (P2'), the outage signals indicating a status of the associated equipment in response to the received activation signals wherein the driving module (5) comprises: a microcontroller (21) configured for detecting an operativeness status of the associated equipment and for emitting command signals according to the detected operativeness status and, a control circuit (23) configured for converting the command signals emitted by the microcontroller (21) into outage signals wherein the control circuit (23) comprises a main transistor (Q1) coupled to the outage port (P2') and configured for modifying the outage signals according to its state and wherein the control circuit (23) also comprises a protection circuit (27) configured for setting the main transistor (Q1) in a blocking state in case of a voltage higher than a predetermined threshold supplied at the outage port (P2').

Description

DRIVING MODULE AND CONTROL UNIT OF A MOTOR VEHICLE

TECHNICAL FIELD

The present invention refers to a driving module associated with an equipment of a motor vehicle and configured for exchanging signals with a body controller module in order to provide information to the body controller module about the status of the associated equipment. The present invention refers in particular to the control circuit used in the driving module for adapting the signals emitted by a microcontroller of the driving module in order to be detected by the body controller module.

BACKGROUND

It is already known to use control circuits comprising a main transistor for adapting the signals emitted by the microcontroller of the driving module in order to be detected by a processing unit of the body controller module. The transistor has generally its collector connected to an outage input of the body controller module, its emitter connected to the ground and its base connected to the microcontroller, possibly via another transistor.

Thus, depending on the voltage value sent by the microcontroller, the main transistor is set in a blocking or in a passing state and a high or a low voltage signal is received by the processing unit of the body controller module.

However, with such control circuits, in case of a short circuit in the body controller module leading to a high voltage supplied to the collector of the main transistor, a large power will have to be dissipated by the said main transistor. As a consequence, an oversized main transistor has to be used to withstand such high voltage and to enable power dissipation without leading to a failure of the main transistor. However, such oversized transistor increases noticeably the cost of the control circuit and therefore of the driving module. Furthermore, in such control circuits, the main transistor works in amplifying mode which limits the value of the current outputs by the control circuit.

It is therefore an aim of the present invention to provide an inexpensive control circuit comprising a protection of the main transistor in case of a short circuit of the body controller leading to a high voltage supplied to the collector of the main transistor. It is also an aim of the present invention to enable outputting high current if necessary for the body controller.

SUMMARY

The present invention thus refers to a driving module associated with an equipment of a motor vehicle, the said driving module is connected to a body controller module of the motor vehicle and is configured for receiving activation signals from the body controller module and for transmitting outage signals to an outage port, the outage signals indicating a status of the associated equipment in response to the received activation signals wherein the driving module comprises:

- a microcontroller configured for detecting an operativeness status of the associated equipment and for emitting command signals according to the detected an operativeness status and,

- a control circuit configured for converting the command signals emitted by the microcontroller into outage signals wherein the control circuit comprises a main transistor coupled to the outage port and configured for modifying the outage signals according to its state,

and wherein the control circuit also comprises a protection circuit configured for setting the main transistor in a blocking state in case of a voltage higher than a predetermined threshold supplied at the outage port.

According to another aspect of the present invention, the main transistor of the control circuit is a NPN transistor having its collector coupled to the outage port, its base connected to the microcontroller and its emitter connected to the ground.

According to a further aspect of the present invention, the base of the main transistor is coupled to the microcontroller via a first resistor and to the ground via a second resistor and its emitter is coupled to the ground via a third resistor.

According to an additional aspect of the present invention, the protection circuit of the control circuit is configured for detecting a voltage higher than a predetermined threshold at the outage port with a second transistor and for setting the main transistor in a blocking state with a third transistor when the voltage is higher than the predetermined threshold.

According to another aspect of the present invention, the second transistor has its base connected to the microcontroller, its emitter connected to the ground and its collector coupled to the midpoint of a voltage divider comprising a fourth and a fifth resistor in series coupled between the outage port and the ground and the third transistor has its base coupled to the emitter of the second transistor, its emitter coupled to the ground and its collector coupled to the base of the main transistor.

According to a further aspect of the present invention, the second transistor has its base coupled to the microcontroller via a sixth resistor and to the ground via a capacitor and its emitter coupled to the ground via a seventh resistor.

According to an additional aspect of the present invention, the control circuit comprises an adaptation circuit coupled to the microcontroller and configured for adapting the voltage supplied by the microcontroller.

According to another aspect of the present invention, the adaptation circuit comprises a PNP transistor having its collector connected to the base of the first transistor, its emitter coupled to a second voltage supply and its base connected to the microcontroller and to the second voltage supply.

According to a further aspect of the present invention, the PNP transistor has its collector coupled to the first resistor and its base coupled to the microcontroller via an eighth resistor and to the second voltage supply by a ninth resistor.

According to an additional aspect of the present invention, the transistors are Metal Oxide Semiconductor Field Effect Transistor s “MOSFETs” .

According to another aspect of the present invention, the driving module is a lighting driving module associated with a lighting equipment of the motor vehicle.

The present invention also refers to a control unit comprising a body controller module and a driving module in accordance with one of the previous claims, the said driving module being coupled to the body controller module wherein the body controller module comprises an activation element configured for transmitting an activation signal supplied by a first voltage supply to the driving module and an outage port for receiving an outage signal from the driving module and wherein the outage port is coupled to the first voltage supply by a pull-up resistor.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features and advantages of the present invention will appear more clearly from the following description. The said description is achieved based on the attached drawings which represent, in a non-limited way, a possible embodiment.

On these drawings:

Fig. 1 refers to a diagram of a control unit comprising a body controller module and a driving module associated with an equipment of the motor vehicle；

Fig. 2 refers to a diagram of a control circuit according to a first embodiment of the present invention；

Fig. 3 refers to a diagram of a control circuit according to a second embodiment of the present invention.

DETAILED DESCRIPTION

On these drawings, the same reference numbers refer to elements having the same function.

The term “LED” refers to the acronym Light-Emitting Diode.

The terms “NPN” and “PNP” refer to a type of transistor and notably to the type of junctions used in the transistor. A NPN transistor comprises two P-N junctions having a common P layer and a PNP transistor comprises two P-N junctions having a common N layer. An N layer refers to a layer with an excess of electrons while a P layer refers to a layer with an excess of holes.

The term “IGBT” refers to the acronym Insulated Gate Bipolar Transistor.

The term “MOSFET” refers to the acronym Metal Oxide Semiconductor Field Effect Transistor.

The term “connected to” is used to define the link between two electronic elements and refers either to a direct coupling or to a connection via other elements, for example via a resistor while the term “coupled to” refers to a direct coupling (for example via an electric wire) without intermediate elements.

The following embodiments are only examples. Although the description refers to one or several embodiments, it does not necessarily mean that each reference refers to the same embodiment or that the features apply only to a single embodiment. Simple features of different embodiments may also be combined to provide other realisations.

Fig. 1 represents a diagram of a control unit 1 of a motor vehicle comprising a body controller module 3 and a driving module 5 of an equipment of the motor vehicle. The equipment refers to a lighting equipment comprising LEDs in the present case but the driving module 5 may also be adapted for other equipments of the motor vehicle. The body controller module 3 and the driving module 5 comprise communication means for communicating to each other. The body controller module 3 is configured for activating the driving module 5 when the vehicle is turned on and the driving module 5 is configured for detecting a failure of the equipment and for emitting outage signals toward the body controller module 3 according to the functioning or operativeness status of the equipment. The body controller module 3 is configured for detecting a failure of the equipment based on the outage signals received from the driving module 5.

The body controller module 3 may, for example, be linked to the driving module 5 by one or several electrical wires 7.

The body controller module 3 comprises an activation port P1 connected to a voltage supply 9, corresponding to a battery of the motor vehicle, via an activation element 11 corresponding, for example, to an activation switch. The activation switch 11 is configured to be closed at the ignition of the vehicle so that an activation signal corresponding to the voltage of the voltage supply 9 is transmitted to the driving module 5 for activating the said driving module 5.

The body controller module 3 also comprises an outage port P2 which is connected both to the voltage supply 9 via a pull-up resistor 13 and to a processing unit 15 of the body controller module 3 which is configured for processing outage signals sent by the driving module 5. The body controller module 3 also comprises a ground port P3 which is coupled to the ground 16.

The driving module 5 comprises an activation port P1'intended to be coupled to the activation port P1 of the body controller module 3.

The activation port P1'is connected to a power supply 17, for example a low-drop out regulator via a diode 19. The driving module 5 also comprises a microcontroller 21 configured for detecting a failure of the equipment associated with the driving module 5, the LEDs in the present case, and for emitting command signals when a LED failure is detected. The microcontroller 21 is supplied by the power supply 17 and is coupled to a control circuit 23 which is configured for receiving the command signals sent by the microcontroller 21 and for converting the command signals into outage signals adapted to the body controller module 3. The outage signals are transmitted to an outage port P2'of the driving module 5 destined to be coupled to the outage port P2 of the body controller module 3. The microcontroller 21 and the control circuit 23 are also coupled to a ground port P3'intended to be coupled to the ground port P3 of the body controller module 3.

Thus, when the vehicle starts, the activation switch is closed and an activation signal corresponding to a battery voltage, for example a 13V signal is transmitted from the body controller module 3 to the driving module 5. In response to this activation signal, an outage signal is sent back by the driving module 5 to the body controller module 3 for indicating that the equipment associated with the driving module 5 operates correctly.

The aim of the control circuit 23 is therefore to ensure that the outage signals received by the body controller module 3 are adapted and can be detected so that the body controller module 3 can assess the state of the equipment associated with the driving module 5 and/or the driving module 5 itself to detect the operativeness status and notably a failure or an inoperativeness. The control circuit 23 needs therefore to be reliable and resistant against a short circuit that could happen notably at the outage port P2 or P2'a nd which would lead to the supply of a high voltage at the outage port P2'.

Fig. 2 represents an electric diagram of a control circuit 23 according to the present invention. The control circuit 23 comprises an input 25 which is coupled to the microcontroller 21 for receiving the command signals. The control circuit 23 also comprises a first transistor Q1, also called main transistor, which is a NPN transistor. The base of the first transistor Q1 is connected both to the input 25 via a first resistor R1 and to the ground 16 via second resistor R2. The emitter of the first transistor Q1 is also connected to the ground via a third resistor R3. The collector of the first transistor Q1 is coupled to the outage port P2'. The outage port P2'is connected to the body controller 3 and therefore both to the processing unit 15 configured for processing the outage signals sent by the control circuit 23 and to the voltage supply 9 via a pull-up resistor 13.

The microcontroller 21 is configured to emit a high voltage signal in case of a correct functioning state of the lighting equipment and a low voltage signal in case of a failure detected in the lighting equipment, for example a failure of a LED. Furthermore, in case of a failure of the power supply or during an initialization of the microcontroller 21, the command signal transmitted to the input 25 of the control circuit 23 corresponds to a high impedance signal.

The low voltage refers to a voltage low enough to set the first transistor Q1 in a blocking state and the high voltage is a voltage high enough to set the first transistor Q1 in a passing state. Thus, if the first transistor Q1 is in a blocking state, the outage signal transmitted to the processing unit 15 corresponds to a high voltage signal provided by the voltage supply 9 and if the first transistor Q1 is in a blocking state, the outage signal transmitted to the processing unit 15 is a low voltage signal, for example lower than 1V. Thus, the first transistor Q1 works in an on/off mode so that a high current can be provided to the processing unit 15.

The control circuit 23 enables therefore to transmit outage signals corresponding to a low voltage signal (the transistor Q1 being in a passing state) if the driving module 5 is operative and functions normally and to transmit outage signals corresponding to a high voltage (the transistor Q1 being in a blocking state) for any failures of the driving module 5 and the associated equipment (LED failure, power supply outage ... ) which are either detected by the microcontroller 21 or lead to a command signal corresponding to a high impedance signal.

Furthermore, the control circuit 23 also comprises a protection circuit 27 indicated by dashed lines which is configured for setting the first transistor Q1 in a blocking state in case of a voltage higher than a predetermined threshold is supplied to the outage port P2'. Such short circuit, such as a short circuit of the pull-up resistor 13, would lead to the connection of a high voltage, the voltage of the voltage supply 9 in the present case, at the outage port P2'.

The protection circuit 27 comprises a second transistor Q2 which is a NPN transistor. The base of the second transistor Q2 is connected both to the input 25 via a sixth resistor R6 and to the ground 16 via a capacitor C. The collector of the second transistor Q2 is coupled to the midpoint of a voltage divider 29. The voltage divider 29 is made of a fourth R4 and a fifth R5 resistors coupled in series between the outage port P2'a nd the ground 16. The midpoint refers to the junction between resistors R5 and R6. The emitter of the second transistor Q2 is connected both the ground 16 via a seventh resistor R7 and to the base of a third transistor Q3 which is a NPN transistor. The collector of the third transistor Q3 is coupled to the base of the first transistor Q1 and the emitter of the third transistor Q3 is coupled to the ground 16.

Thus, in case of voltage higher than a predetermined threshold supplied to the outage port P2', for example due to a short circuit of the resistor 13, the high voltage is then supplied to the collector of the second transistor Q2. If, at the same time, the microcontroller 21 is sending a high voltage signal on the base of the second transistor Q2 (and to the base of the first transistor Q1) , the second transistor Q2 is set in a passing state so that the high voltage is transmitted to the emitter of the second transistor Q2 and therefore to the base of the third transistor Q3 which sets the third transistor Q3 in a passing state.

As a consequence, the base of the first transistor Q1 is linked to the ground 16 via the third transistor Q3 and the first transistor Q1 is set in a blocking state despite the high voltage signal sent by the microcontroller 21. As a consequence, the protection circuit 27 enables to set the first transistor Q1 in a blocking state whatever the signal sent by the microcontroller 21 in case of an abnormal high voltage supplied at the outage port P2', for example due to a short circuit.

The threshold for the voltage depends on the value of the resistors of the voltage divider 29 and the voltage threshold to set the third transistor Q3 in a passing state, the thresholds is for example set to be slightly lower than the voltage of the voltage supply 9. Such setting in a blocking state of the first transistor Q1 enables to protect the first transistor Q1 itself and the other components of the control circuit 23 in case of a short circuit at the outage port P2'. As a consequence with such protection circuit 27, the first transistor Q1 does not need to be oversized to withstand a high voltage supplied at its collector.

Besides, as the power of the command signals emitted by the microcontroller 21 may not be adapted to set the first Q1 and the second Q2 transistors of the control circuit 23 in a blocking and in a passing state or in the case wherein the microcontroller 21 may only emit a low voltage signal and a high impedance signal, the control circuit 23 may also comprise an adaptation circuit 31 as represented in Fig. 3 configured for adapting the voltage of the command signals sent by the microcontroller 21 to the thresholds for passing from a blocking to a passing state of the transistors Q1 and Q2. The adaptation circuit 31 is located between the input 25 and the first resistor R1 and comprises a fourth transistor Q4 which is a PNP transistor. The base of the fourth resistor Q4 is connected both to the input 25 via an eighth resistor R8 and to a second voltage supply 33 via a ninth resistor R9. The second voltage supply 33 is for example a voltage supply of the motor vehicle supplying a voltage of 5V or 3, 3V. The emitter of the fourth transistor Q4 is coupled to the second voltage supply 33 and the collector of the fourth transistor Q4 is coupled to the first resistor R1. Thus, the command signals of the microcontroller 21 enables to set the fourth transistor Q4 in a blocking state or in a passing state so that the voltage and current provided by the adaptation circuit 31 enables to set the first Q1 and second Q2 transistors in blocking or in a passing state.

The transistors used in the control circuit 23 may be IGBT transistors or preferably MOSFET transistors due to their lower cost.

The present invention enables therefore, by the use of a protection circuit 27 which sets the main transistor Q1 of a control circuit 23 of a driving module 5 of an equipment of a motor vehicle in blocking state, to protect the components of the control circuit 23 in case of a short circuit at the output of the driving module 5 without requiring to use an oversized transistor as main transistor Q1 in the control circuit 23. The components of the protection circuit 27 can be easily implemented in a printed circuit and their cost remains low with respect to an oversized transistor.

Claims

Driving module (5) associated with an equipment of a motor vehicle, the said driving module (5) is connected to a body controller module (3) of the motor vehicle and is configured for receiving activation signals from the body controller module (3) and for transmitting outage signals to an outage port (P2') , the outage signals indicating a status of the associated equipment in response to the received activation signals wherein the driving module (5) comprises:

- a microcontroller (21) configured for detecting an operativeness status of the associated equipment and for emitting command signals according to the detected operativeness status and,

- a control circuit (23) configured for converting the command signals emitted by the microcontroller (21) into outage signals wherein the control circuit (23) comprises a main transistor (Q1) coupled to the outage port (P2') and configured for modifying the outage signals according to its state characterized in that the control circuit (23) also comprises a protection circuit (27) configured for setting the main transistor (Q1) in a blocking state in case of a voltage higher than a predetermined threshold supplied at the outage port (P2') .
Driving module (5) in accordance with claim 1 wherein the main transistor (Q1) of the control circuit (23) is a NPN transistor having its collector coupled to the outage port (P2') , its base connected to the microcontroller (21) and its emitter connected to the ground (16) .
Driving module (5) in accordance with claim 2 wherein the base of the main transistor (Q1) is coupled to the microcontroller (21) via a first resistor (R1) and to the ground (16) via a second resistor (R2) and its emitter is coupled to the ground (16) via a third resistor (R3) .
Driving module (5) in accordance with claim 2 or 3 wherein the protection circuit (27) of the control circuit (23) is configured for detecting a voltage higher than a predetermined threshold at the outage port (P2') with a second transistor (Q2) and for setting the main transistor (Q1) in a blocking state with a third transistor (Q3) when the voltage is higher than the predetermined threshold.
Driving module (5) in accordance with claim 4 wherein the second transistor (Q2) has its base connected to the microcontroller (21) , its emitter connected to the ground (16) and its collector coupled to the midpoint of a voltage divider (29) comprising a fourth (R4) and a fifth resistor (R5) in series coupled between the outage port (P2') and the ground (16) and the third transistor (Q3) has its base coupled to the emitter of the second transistor (Q2) , its emitter coupled to the ground (16) and its collector coupled to the base of the main transistor (Q1) .
Driving module (5) in accordance with claim 5 wherein the second transistor (Q2) has its base coupled to the microcontroller (21) via a sixth resistor (R6) and to the ground (16) via a capacitor (C) and its emitter coupled to the ground (16) via a seventh resistor (R7) .
Driving module (5) in accordance with one of the claims 3 to 6 wherein the control circuit (23) comprises an adaptation circuit (31) coupled to the microcontroller (21) and configured for adapting the voltage supplied by the microcontroller (21) .
Driving module (5) in accordance with claim 7 wherein the adaptation circuit (31) comprises a PNP transistor (Q4) having its collector connected to the base of the first transistor (Q1) , its emitter coupled to a second voltage supply (33) and its base connected to the microcontroller (21) and to the second voltage supply (33) .
Driving module (5) in accordance with claim 8 wherein the PNP transistor (Q4) has its collector coupled to the first resistor (R1) and its base coupled to the microcontroller via an eighth resistor (R8) and to the second voltage supply by a ninth resistor (R9) .
Driving module (5) in accordance with one of the previous claims wherein the transistors (Q1, Q2, Q3, Q4) are Metal Oxide Semiconductor Field Effect Transistor “MOSFETs” .
Driving module (5) in accordance with one of the previous claims wherein the driving module (5) is a lighting driving module associated with a lighting equipment of the motor vehicle.
Control unit (1) comprising a body controller module (3) and a driving module (5) in accordance with one of the previous claims, the said driving module (5) being coupled to the body controller module (3) wherein the body controller module (3) comprises an activation element (11) configured for transmitting an activation signal supplied by a first voltage supply (9) to the driving module (5) and an outage port (P2) for receiving an outage signal from the driving module (5) and wherein the outage port (P2) is coupled to the first voltage supply by a pull-up resistor (13) .