MONITORING THE COHERENCE OF CURRENTS MEASURED AT THE INPUT OF INVERTERS ASSOCIATED WITH ELECTRIC DRIVE MACHINES OF A LAND VEHICLE

Abstract

A monitoring method is implemented in a land vehicle and comprising first and second electric motors, associated with first and second trains, and supplied with electric current by an electric power source, via first and second inverters subjected on their inputs to measurements of first and second currents, to deliver first and second motor torques. This method comprises a step (10-50) in which first and second values representative of absolute values of a first difference, between the first measured current and a first estimated current representative of the first delivered torque, and of a second difference, between the second measured current and a second estimated current representative of the second delivered torque, are determined, and, when this first or second value is greater than a first or second chosen threshold, the operation of the first or second motor is prohibited. Figure 3

Description

Title of the invention: MONITORING THE COHERENCES OF CURRENTS MEASURED AT THE INPUT OF INVERTERS ASSOCIATED WITH ELECTRIC DRIVE MACHINES OF A LAND VEHICLE Technical field of the invention

[0001] The invention relates to land vehicles comprising two electric motors and associated respectively with independent inverters and motor trains, and more precisely to the monitoring in such vehicles of the respective consistencies of the currents measured at the input of the inverters. State of the art

[0002] Certain land vehicles (and for example of the automobile type), comprise a powertrain (or GMP) comprising at least first and second electric motors, associated respectively with first and second independent motor trains, and capable of being supplied with electric current by an electrical power source (such as for example a power battery or a fuel cell), via respectively first and second inverters, to deliver respectively first and second motor torques.

[0003] This type of vehicle (with two independent drive trains) can operate, in particular, in four-wheel drive mode (or AWD (“All Wheels Drive”) - all-wheel drive) when its first and second drive machines simultaneously provide engine torque.

[0004] In the vehicles presented above, the battery computer, controlling the power battery (or "main" or "traction" battery) knows at all times the current which leaves the power battery and supplies, in particular, the first and second inverters via the power electrical network. However, this battery computer does not know the first and second currents which respectively supply the first and second inverters. It is therefore impossible to determine whether the first and second currents which are measured at the input of the first and second inverters (and which come from the power electrical network) are consistent respectively with the first and second torques delivered by the first and second prime movers and therefore whether there is a malfunction within a first assembly, comprising the first prime mover and the first inverter, or a second assembly, comprising the second prime mover and the second inverter.

[0005] Furthermore, it is also impossible to determine whether there is current leakage in the power grid. However, such a leak could prove (very) dangerous because the electric current that is supposed to supply the first or second prime mover could flow through other electrically conductive equipment of the vehicle, such as its structure or bodywork, and therefore could cause electrocution of a vehicle passenger or a person outside the vehicle in contact with it. In addition, this could also possibly damage at least the first or second prime mover.

[0006] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0007] It proposes in particular for this purpose a monitoring method intended to be implemented in a land vehicle and comprising first and second electric motor machines, associated respectively with first and second trains, and capable of being supplied with electric current by an electric power source, via respectively first and second inverters subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques.

[0008] This monitoring method is characterized by the fact that it comprises a step in which first and second values ​​are determined, respectively representative of absolute values ​​of a first difference, between the first measured current and a first estimated current representative of the first delivered torque, and of a second difference, between the second measured current and a second estimated current representative of the second delivered torque, and, when this first or second value is greater than a first or second chosen threshold, the operation of the first or second prime mover is prohibited.

[0009] Thanks to the invention, it is known whether each measured current is consistent with the corresponding estimated current (and consequently with the corresponding delivered motor torque), and therefore at least whether an assembly, comprising a motor machine and an inverter, is subject to a malfunction or not.

[0010] The monitoring method according to the invention may include other characteristics which may be taken separately or in combination, and in particular:

[0011] - in its step, one can prohibit the operation of the first or second prime mover when the first or second value is greater than the first or second chosen threshold for at least a chosen duration;

[0012] - in the presence of the first option, in its step, the chosen duration can be between 100 ms and 1 s;

[0013] - in its step, one can prohibit the operation of the first or second driving machine by ceasing to transmit a first torque instruction for the first prime mover or a second torque setpoint for the second prime mover;

[0014] - in its step, the first value can be equal to the absolute value of the first difference multiplied by 100 and divided by the first measured current, and the second value may be equal to the absolute value of the second difference multiplied by 100 and divided by the second measured current;

[0015] - in the presence of the last option, in its step, each of the first and second chosen thresholds can be between 10% and 20%;

[0016] - in its step, one can also carry out in the vehicle at least one chosen action among an alert of a driver of the vehicle by means of a warning light of the latter and / or a text message and / or an audible message, a recording of at least one fault code representative of a current inconsistency problem at the level of a first assembly, comprising the first prime mover and the first inverter, and / or a second assembly, comprising the second prime mover and the second inverter, and a decoupling of the electrical power source from an electrical power network coupling it at least to the first and second prime movers when the first and second prime movers are simultaneously prohibited from operating.

[0017] The invention also proposes a computer program product comprising a set of instructions which, when executed by processing means, is capable of implementing a monitoring method of the type presented above, in a land vehicle and comprising first and second electric motors, associated respectively with first and second trains, and capable of being supplied with electric current by an electric power source, via respectively first and second inverters which are subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques, to monitor the respective consistencies of these first and second measured currents.

[0018] The invention also proposes a monitoring device intended to equip a land vehicle and comprising first and second electric motors, associated respectively with first and second trains, and capable of being supplied with electric current by an electric power source, via respectively first and second inverters subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques.

[0019] This monitoring device is characterized by the fact that it comprises at least one processor and at least one memory arranged to carry out the operations consisting of determining first and second values ​​respectively representative of values absolute values ​​of a first difference, between the first measured current and a first estimated current representative of the first delivered torque, and of a second difference, between the second measured current and a second estimated current representative of the second delivered torque, and, when this first or second value is greater than a first or second chosen threshold, to trigger a prohibition of the operation of the first or second prime mover.

[0020] The invention also proposes a land vehicle, possibly of the automobile type, and comprising, on the one hand, first and second electric motors, associated respectively with first and second trains, and capable of being supplied with electric current by an electric power source, via respectively first and second inverters which are the subject respectively on their inputs of measurements of first and second currents, to deliver respectively first and second motor torques, and, on the other hand, a monitoring device of the type presented above. Brief description of the figures

[0021] Other characteristics and advantages of the invention will appear on examining the detailed description below, and the appended drawings, in which:

[0022] [Fig. 1] schematically and functionally illustrates an exemplary embodiment of a land vehicle comprising a monitoring device according to the invention and a GMP associated with a supervision computer and comprising first and second electric motor machines and associated respectively with first and second inverters,

[0023] [Fig.2] schematically and functionally illustrates an exemplary embodiment of a supervision computer comprising an exemplary embodiment of a monitoring device according to the invention, and

[0024] [Fig.3] schematically illustrates an example of an algorithm implementing a monitoring method according to the invention. Detailed description of the invention

[0025] The invention aims in particular to propose a monitoring method, and an associated monitoring device DS, intended to allow monitoring of the respective coherences of first iml and second im2 currents, measured at the input of first 01 and second 02 inverters associated respectively with first MM1 and second MM2 electric motors and forming part of a powertrain (or GMP) of a land vehicle V having two independent motor trains T1 and T2.

[0026] In the following, it is considered, by way of non-limiting example, that the land vehicle V is of the automobile type. It is for example a car, as illustrated in [Fig.l]. But the invention is not limited to this type of land vehicle. It relates in fact to any type of land vehicle comprising a powertrain (or GMP) comprising at least first and second electric motors and associated respectively with first and second inverters and with first and second independent motor trains.

[0027] Furthermore, it is considered in the following, by way of non-limiting example, that the GMP is purely electric (and therefore only comprises first MM1 and second MM2 electric motors). But the GMP could be hybrid (thermal and doubly electric).

[0028] Furthermore, it is considered in the following, by way of non-limiting example, that the first MM1 and second MM2 electric motors are supplied with electrical energy by an electrical power source BP constituting a power battery (or “main” or even “traction”), rechargeable (at least during recharging phases). But the first MM1 and second MM2 electric motors could be supplied with electrical energy by a fuel cell.

[0029] [Fig.l] schematically shows a (land) vehicle V comprising a purely electric GMP transmission chain (and therefore comprising first MM1 and second MM2 electric motors and associated respectively with first 01 and second 02 inverters), an on-board network RB, a service battery BS, an electrical power source (here a power battery (or main or traction)) BP, a converter CV, a supervision computer CS, first CM1 and second CM2 machine computers, a monitoring device DS according to the invention, and an electrical power network SP1 and SP2.

[0030] The CV converter is of the DC / DC type (“Direct Current / Direct Current”). It is therefore responsible for converting a direct current from a first voltage to a second voltage.

[0031] The on-board network RB is an electrical power supply network to which electrical (or electronic) equipment (or components) that consume electrical energy are coupled.

[0032] The service battery BS is responsible for supplying electrical energy to the on-board network RB, in addition, here, to that supplied by the converter CV powered by the electrical power source BP via the power electrical network SP1 and SP2, and sometimes instead, here, of this converter CV. For example, this service battery BS can be arranged in the form of a very low voltage type battery (typically 12 V, 24 V or 48 V). It is rechargeable at least by the (current) converter CV. It is considered in the following, by way of non-limiting example, that the service battery BS is of the 12 V Lithium-ion type.

[0033] The transmission chain has a GMP which is, here, purely electric and therefore which comprises, in particular, first MM1 and second MM2 (electric) driving machines, first AMI and second AM2 driving shafts, and first ATI and second AT2 transmission shafts. Here, the term "electric driving machine" means an electric machine arranged so as to provide a driving torque cmj (j = 1 or 2), defined by a torque setpoint cgj, to move the vehicle V when it is supplied with electrical energy (here) by the electrical power source BP (this is then referred to as providing a positive output torque), as well as possibly recovering torque, for example in a regenerative braking phase (this is then referred to as providing a negative output torque).

[0034] The operation of the GMP is supervised by a supervision computer CS. The control of the first driving machine MM1 is ensured by a first associated machine computer CM1, in particular as a function of a first setpoint cgi (j = 1) supplied by the supervision computer CS and defining the first engine torque cml (j = 1) that the latter (CS) wants the first driving machine MM1 to provide. The control of the second driving machine MM2 is ensured by a second associated machine computer CM2, in particular as a function of a second setpoint cg2 (j = 2) supplied by the supervision computer CS and defining the second engine torque cm2 (j = 2) that the latter (CS) wants the second driving machine MM2 to provide.

[0035] The first driving machine MM1 is coupled to the first motor shaft AMI, to provide it with a first motor torque cml (defined by the first setpoint cgi) by rotational drive when it is (here) supplied with electrical energy by the electrical power source BP via a first sub-part SP1 of the electrical power network. This first motor shaft AMI is here coupled to a reducer RD which is also coupled to the first transmission shaft ATI, itself coupled to a first train Tl of driving wheels, preferably via a first differential DV.

[0036] Furthermore, the first driving machine MM1 is coupled to the first sub-part SP1 of the electrical power network via the first inverter 01, which is subject to measurements of a first current iml on its input.

[0037] It will be noted that the first train (engine) T1 is here located in the front part PVV of the vehicle V. But in a variant this first train T1 could be the second train (engine) T2 which is located in the rear part PRV of the vehicle V.

[0038] The second driving machine MM2 is coupled to the second motor shaft AM2, to provide it with a second motor torque cm2 (defined by the second setpoint cg2) by rotational drive when it is (here) supplied with electrical energy by the electrical power source BP via a second sub-part SP2 of the electrical power network. This second motor shaft AM2 is here coupled to a DC coupling device which is also coupled to the second transmission shaft AT2, itself coupled to the second T2 drive wheel train, preferably via a second DR differential.

[0039] Furthermore, the second driving machine MM2 is coupled to the second sub-part SP2 of the electrical power network via the second inverter 02, which is subject to measurements of a second current im2 on its input.

[0040] The first iml and second im2 currents can be measured at the input of the first 01 and second 02 inverters by amperometric sensors, such as for example those of the so-called “shunt” type (or in parallel) (measurements in direct current or alternating current), or of the so-called “Hall effect” type (measurements in direct current or alternating current), or those of the so-called “Rogowski” type (measurements in alternating current), or those called “current transformers” (measurements in alternating current).

[0041] It will be noted that when the first train (engine) T1 is located in the rear part PRV of the vehicle V, the second train (engine) T2 is located in the front part PVV of the vehicle V.

[0042] The DC coupling device is arranged so as to couple or decouple the second driving machine MM2 from the second transmission shaft AT2, according to the needs defined by the supervision computer CS. For example, this DC coupling device can be a clutch (possibly hydraulic). But it could also be a dog clutch, for example.

[0043] The electrical power source BP is coupled to the power electrical network via an interface device DU. This interface (or isolation) device DU is arranged so as to isolate, if necessary, the electrical power source BP (here) from at least the first MM1 or second MM2 motor machine and more generally from the power electrical network SP1 and SP2. It comprises, for example, contactors (or switches), possibly based on MOSFET(s), which can each be placed in an open (or non-conducting) state or a closed (or conducting) state.

[0044] As illustrated non-limitingly in [Fig.l], the interface device DU may be part of a source box BB associated with the electrical power source BP and which also comprises voltage / current measuring means (not illustrated) and a source calculator CB. The electrical power source BP and the source box BB may constitute a source assembly (or “pack”).

[0045] The electrical power source BP is here a power battery (or main or even traction) which may, for example, comprise electrical energy storage cells, possibly electrochemical (for example of the lithium-ion (or Li-ion) or Ni-Mh or Ni-Cd type). Also for example, the electrical power source BP may be of the low voltage type (typically 450 V for illustration purposes). But it could be of the medium voltage or high voltage type.

[0046] The CV converter is also responsible, here, during the driving phases of the vehicle V for converting part of the electric current stored in the power source BP electric system to supply converted electric current to the RB on-board network and the BS service battery (to recharge it).

[0047] It will be noted, as illustrated non-limitingly in [Fig. 1], that the converter CV can be part of a charger CH also comprising a recharge calculator CR responsible, at least, for controlling the recharges of the electrical power source BP.

[0048] It will also be noted that in the example illustrated non-limitingly in [Fig.l] the vehicle V also comprises a distribution box BD to which the service battery BS, the converter CV and the on-board network RB are coupled. This distribution box BD is responsible for distributing in the on-board network RB the electrical energy stored in the service battery BS or produced by the converter CV, for the supply of the electrical components (or equipment) coupled to the on-board network RB according to power supply requests received (in particular from the supervision computer CS of the GMP).

[0049] As mentioned above, the invention proposes in particular a monitoring method intended to enable the monitoring of the respective coherences of the first iml and second hn2 currents measured at the input of the first 01 and second 02 inverters.

[0050] This (monitoring) method can be implemented at least partially by the monitoring device DS (illustrated at least partially in FIGS. 1 and 2) which comprises for this purpose at least one processor PR1, for example a digital signal processor (or DSP ("Digital Signal Processor")), and at least one memory MD. This monitoring device DS can therefore be implemented in the form of a combination of electrical or electronic circuits or components (or "hardware") and software modules (or "software"). For example, it can be a microcontroller.

[0051] The memory MD is RAM in order to store instructions for the implementation by the processor PR1 of at least part of the monitoring method. The processor PR1 may comprise integrated (or printed) circuits, or several integrated (or printed) circuits connected by wired or wireless connections. An integrated (or printed) circuit is understood to mean any type of device capable of carrying out at least one electrical or electronic operation.

[0052] In the example illustrated non-limitingly in Figures 1 and 2, the monitoring device DS is part of the supervision computer CS. But this is not obligatory. Indeed, the monitoring device DS could comprise its own dedicated computer, or could be part of another computer on board the vehicle V and providing at least one other function.

[0053] As illustrated non-limitingly in [Fig. 3], the (monitoring) method, according to the invention, comprises a step 10-50 which is implemented each time that at least one of the first MM1 and second MM2 driving machines must operate on the order of the supervision computer CS.

[0054] Step 10-50 of the method comprises a sub-step 20 in which one (for example the monitoring device DS) determines first vl and second v2 values ​​which are respectively representative of the absolute values ​​of first dcl and second dc2 differences. The first difference dcl is determined between the first measured current iml (j = 1) and a first estimated current iel (j = 1) which is representative of the first motor torque cml (j = 1) delivered by the first motor machine MM1 (i.e. dcl = iml - iel). The second difference is determined between the second measured current im2 (j = 2) and a second estimated current ie2 (j = 2) which is representative of the second motor torque cm2 (j = 2) delivered by the second motor machine MM2 (i.e. dc2 = hn2 - ie2).

[0055] It will be noted that a person skilled in the art can easily determine each estimated current iej as a function of the motor torque cmj. For example, the formula iej = cmj*W* / U / p can be used, where W is the rotation speed of the rotor of the prime mover MMj, U is the voltage across the terminals of the prime mover MMj, and p is the efficiency of the prime mover MMj.

[0056] Step 10-50 of the method also comprises a sub-step 50 in which, when the first value vl is greater than a first chosen threshold si (i.e. vl > si), one (for example the monitoring device DS) prohibits the operation of the first prime mover MM1, or, when the second value v2 is greater than a second chosen threshold s2 (i.e. v2 > s2), one (for example the monitoring device DS) prohibits the operation of the second prime mover MM2. It will be noted that when the first vl and second v2 values ​​are simultaneously and respectively greater than the first si and second s2 chosen thresholds (i.e. vl > si and v2 > s2), one (for example the monitoring device DS) prohibits the operation of the first MM1 and second MM2 prime movers.

[0057] Thanks to this comparison of each value vj (j = 1 or 2) with the corresponding threshold sj, we know whether each measured current imj is consistent with the corresponding estimated current iej (and consequently with the corresponding delivered motor torque cmj), and therefore whether an assembly, comprising a motor machine MMj and an inverter Oj, is subject to a malfunction or not.

[0058] Furthermore, it is also possible to determine whether there is a current leak in the power electrical network SP1 and SP2, since the supervision computer CS can now compare the sum of the first iml and second im2 currents measured with the current that the power battery BP supplies to the power electrical network SP1 and SP2. It is in fact considered that the current which is consumed by other equipment (or components) of the vehicle V, also coupled to the power electrical network SP1 and SP2, is negligible compared to this sum (iml + im2). In the event of detection of such a leak, the supervision computer CS can then act in consequence in order to prevent electrocution of a passenger of the vehicle V or of a person outside the vehicle V and in contact with the latter (V) or possible damage to at least the first MM1 or second MM2 prime mover.

[0059] It will be noted, as illustrated non-limitingly in [Fig. 3], that step 10-50 of the method may also comprise a sub-step 10 in which the estimated first iel and second ie2 currents are determined. These determinations are preferably carried out by the first CM1 and second CM2 machine computers. But they could also be carried out by the monitoring device DS or the supervision computer CS.

[0060] For example, and as illustrated non-limitingly in [Fig. 3], step 10-50 of the method may also comprise a sub-step 30 in which, one (for example the monitoring device DS) may compare the first value vl to the first chosen threshold si and the second value v2 to the second chosen threshold s2. If the first vl and second v2 values ​​are respectively less than or equal to the first s1 and second s2 chosen thresholds (i.e. vl < si and v2 < s2), it is considered that there are respective coherences of the first iml and second im2 measured currents, and therefore one will again carry out step 10-50 with the following first iml and second hn2 measured currents.On the other hand, if only the first value vl is greater than the first threshold chosen si (i.e. vl > si), or if only the second value v2 is greater than the second threshold chosen s2 (i.e. v2 > s2), or if the first vl and second v2 values ​​are simultaneously and respectively greater than the first si and second s2 thresholds chosen (i.e. vl > si and v2 > s2), it is considered that there is an inconsistency of at least one of the first iml and second hn2 currents measured, and therefore sub-step 30 is carried out to prohibit the operation of the first driving machine MM1 and / or the second driving machine MM2.

[0061] Preferably, in sub-step 50 of step 10-50, the operation of the first MM1 or second MM2 prime mover is prohibited (for example the monitoring device DS triggers the prohibition of) when the first vl or second v2 value is greater than the first si or second s2 threshold chosen for at least one chosen duration dt. For this purpose, one (for example the monitoring device DS) can trigger a time delay of the chosen duration dt as soon as the first vl or second v2 value becomes greater than the first si or second s2 threshold chosen for the first time. As illustrated non-limitingly in [Fig. 3], this triggering of the time delay can be done in a sub-step 40 of step 10-50 between sub-steps 30 and 50. Once sub-step 40 has been carried out, step 10-50 will be carried out again with the following first iml and second hn2 measured currents.

[0062] If before the expiry of the chosen duration dt associated the first value vl becomes lower than or equal to the first threshold si, we will again carry out step 10-50 with the first measured current iml following and the first corresponding time delay is interrupted. Similarly, if before the expiry of the associated chosen duration dt the second value v2 becomes lower than or equal to the second threshold s2, step 10-50 will be carried out again with the following second measured current im2 and the corresponding second time delay is interrupted. On the other hand, if at the expiry of the chosen duration dt of the first or second time delay the first vl or second v2 value is still higher than the first si or second s2 chosen threshold, then sub-step 50 is carried out in order to prohibit the operation of the first MM1 or second MM2 prime mover.

[0063] This option is intended to avoid prohibiting the operation of the first MM1 or second MM2 prime mover in a precipitate manner as soon as one or several successive first iml or second im2 measured currents are greater than the first si or second s2 threshold chosen, for example due to a very brief malfunction of the sensor concerned, or of the internal communication network (possibly multiplexed) on which the first iml and second im2 measured currents are transmitted, or of a computer involved in the transmission of the first iml and second im2 measured currents.

[0064] For example, the chosen duration dt may be between 100 ms and 1 s. As an illustrative example, this chosen duration dt may be equal to 500 ms. But other values ​​of chosen duration dt may be used. For example, this chosen duration dt may be chosen during the development or testing phase of a vehicle similar to vehicle V.

[0065] Also for example, in sub-step 50 of step 10-50, it is possible to prohibit the (for example the monitoring device DS can trigger the prohibition of the) operation of the first MM1 or second MM2 driving machine by ceasing to transmit the first torque setpoint cgi for the first driving machine MM1 or the second torque setpoint cg2 for the second driving machine MM2. This transfer of transmission of the first cgi or second cg2 torque setpoint is carried out by the supervision computer CS, and it is immediately interpreted by the first CM1 or second CM2 machine computer as a prohibition of consumption of the first or second current by the first MM1 or second MM2 driving machine.

[0066] Also for example, in sub-step 20 of step 10-50, the first value vl may be equal to the absolute value of the first difference dcl multiplied by 100 and divided by the first measured current iml (i.e. vl = ldcll*100 / iml = liml -iell*100 / iml), and the second value v2 may be equal to the absolute value of the second difference dc2 multiplied by 100 and divided by the second measured current im2 (i.e. v2 = ldc2l*100 / hn2 = Iim2 - ie2l*100 / hn2). In other words, the first vl and second v2 values ​​(just like the first si and second s2 thresholds chosen) are for- percentages.

[0067] In this case, in sub-step 30 of step 10-50 each of the first si and second s2 thresholds chosen may, for example, be between 10% and 20%. As an illustrative example each of the first si and second s2 thresholds chosen may be equal to 15%. But other values ​​of the first si and second s2 thresholds chosen may be used. It will be noted that the first si and second s2 thresholds chosen may possibly be different from each other. For example, the first si and second s2 thresholds may be chosen during the development or testing phase of a vehicle similar to the vehicle V.

[0068] It will be noted that in an alternative embodiment the first vl and second v2 values ​​could be respectively the absolute values ​​of the first dcl and second dc2 differences, for example.

[0069] Also for example, in sub-step 50 of step 10-50 it is also possible to carry out (for example the monitoring device DS can also trigger the carrying out) in the vehicle V at least one action which is chosen from:

[0070] - an alert to the driver of the vehicle V by means of a warning light on the latter (V) and / or a text message and / or an audio message, so that he can quickly have the vehicle V checked in an after-sales service,

[0071] - a recording of at least one fault code representative of a problem inconsistency of measured current imj at the level of the first set (MM1 and 01) and / or the second set (MM2 and 02), and

[0072] - a decoupling of the BP electrical power source from the electrical network of power SP1 and SP2 coupling it at least to the first MM1 and second MM2 prime movers, when the first MM1 and second MM2 prime movers are simultaneously prohibited from operating.

[0073] For example, in the event of a driver alert, the warning light may be part of the dashboard or be displayed on a display screen EA of the vehicle V (possibly that of the central instrument panel installed on or in the dashboard). It may be a warning light dedicated to the problem of inconsistency of measured current imj or a service warning light (not dedicated), when only one of the first MM1 and second MM2 driving machines is prohibited from operating. On the other hand, when the first MM1 and second MM2 driving machines are simultaneously prohibited from operating, it is the brake warning light of the vehicle V which is preferentially lit, because it is imperative that the driver immediately stops his vehicle V.

[0074] Also for example, in the event of a driver alert, the text alert message can be displayed on at least one screen EA of the vehicle V (for example on the dashboard or the central instrument panel) or on the screen of a smartphone of the driver.

[0075] Also for example, in the event of a driver alert, the sound (or audio) alert message can be broadcast by at least one loudspeaker of the vehicle V or of the aforementioned smartphone.

[0076] It will be noted that the storage of the (each) fault code can, for example, be done in a memory (possibly dead) of the monitoring device DS or of the supervision computer CS. This makes it possible to signal to the after-sales service which will service the vehicle V that a problem of inconsistency of measured current imj has been detected at the level of the first set (MM1 and 01) and / or of the second set (MM2 and 02), and thus to facilitate the search for the origin of this problem by this after-sales service.

[0077] It will also be noted that the decoupling of the electrical power source BP from the electrical power network SP1 and SP2 can be done at the level of the interface (or isolation) device DU, for example by action on at least some of its contactors (or switches), under the control of the source calculator CB.

[0078] It will also be noted that when the vehicle V is put back into operation after a prohibition on operation of the first MM1 or second MM2 prime mover, one (for example the monitoring device DS) can again authorize the operation of this first MM1 or second MM2 prime mover if the first vl and second v2 values ​​are again both respectively less than or equal to the first si and second s2 thresholds chosen (i.e. vl < si and v2 < s2). On the other hand, if the first vl or second v2 value is still greater than the first si or second s2 threshold chosen (i.e. vl > si or v2 > s2), the prohibition on operation of the first MM1 or second MM2 prime mover is maintained.Preferably, when the first vl or second v2 value has become higher than the first si or second s2 threshold chosen, each possible fault code stored is kept (in order to keep track of the problem of inconsistency of current measured imj at the level of the first set (MM1 and 01) and / or the second set (MM2 and 02) which has occurred).

[0079] It will also be noted that if the operation of the first MM1 and second MM2 driving machines was prohibited during the previous running of the vehicle V, this prohibition is preferably maintained (for example the monitoring device DS) for safety reasons, and therefore an intervention by an after-sales service is necessary.

[0080] It will also be noted, as illustrated non-limitingly in [Fig. 2], that the supervision computer CS (or the computer of the monitoring device DS) can also comprise a mass memory MME, in particular for storing the first iml and second im2 measured currents and any first iel and second ie2 estimated currents or first cml and second cm2 motor torques, as well as any intermediate data involved in all its calculations and processing. Furthermore, this supervision computer CS (or the computer of the monitoring device DS) can also include an input interface IE for receiving at least the first iml and second im2 measured currents and any first iel and second ie2 estimated currents or first cml and second cm2 motor torques, possibly after having shaped and / or demodulated and / or amplified them, in a manner known per se, by means of a digital signal processor PR2. In addition, this supervision computer CS (or the computer of the monitoring device DS) may also include an output interface IS, in particular for delivering each message requesting a prohibition of operation of the first prime mover MM1 and / or the second prime mover MM2, each message authorizing the resumption of operation of the first MM1 or second MM2 prime mover, and each possible message triggering an alert or storing a fault code.

[0081] It will also be noted that the invention also proposes a computer program product (or computer program) comprising a set of instructions which, when executed by processing means of the electronic circuit (or hardware) type, such as for example the processor PR1, is capable of implementing the monitoring method described above to monitor the respective consistencies of the first iml and second im2 currents measured in the vehicle V.

Claims

Claims

1. Monitoring method for a land vehicle (V) and comprising first (MM1) and second (MM2) electric motors, associated respectively with first (T1) and second (T2) trains, and suitable for being supplied with electric current by an electric power source (BP), via respectively first (01) and second (02) inverters respectively subjected on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques, characterized in that it comprises a step (10-50) in which first and second values ​​are determined, respectively representative of absolute values ​​of a first difference, between said first measured current and a first estimated current representative of said first delivered torque, and of a second difference, between said second measured current and a second estimated current representative of said second delivered torque, and,when said first or second value is greater than a first or second chosen threshold, the operation of said first (MM1) or second (MM2) prime mover is prohibited.,

2. Method according to claim 1, characterized in that in said step (10-50) the operation of said first (MM1) or second (MM2) prime mover is prohibited when said first or second value is greater than said first or second chosen threshold for at least a chosen duration.

3. Method according to claim 2, characterized in that in said step (10-50) said chosen duration is between 100 ms and 1 s.

4. Method according to one of claims 1 to 3, characterized in that in said step (10-50) the operation of said first (MM1) or second (MM2) driving machine is prohibited by ceasing to transmit a first torque setpoint for said first driving machine (MM1) or a second torque setpoint for said second driving machine (MM2).

5. Method according to one of claims 1 to 4, characterized in that in said step (10-50) said first value is equal to said absolute value of the first difference multiplied by 100 and divided by said first measured current, and said second value is equal to said absolute value of the second difference multiplied by 100 and divided by said second measured current.

6. Method according to claim 5, characterized in that in said step (10-50) each of said first and second selected thresholds is between 10% and 20%.

7. Method according to one of claims 1 to 6, characterized in that in said step (10-50) at least one action is also carried out in said vehicle (V) chosen from an alert of a driver of said vehicle (V) by means of a warning light of the latter (V) and / or a text message and / or an audible message, a recording of at least one fault code representative of a current inconsistency problem at the level of a first assembly, comprising said first prime mover (MM1) and said first inverter (01), and / or a second assembly, comprising said second prime mover (MM2) and said second inverter (02), and a decoupling of said electrical power source (BP) from an electrical power network coupling it at least to said first (MM1) and second (MM2) prime movers when said first (MM1) and second (MM2) prime movers are simultaneously prohibited from operating.

8. Computer program product comprising a set of instructions which, when executed by processing means, is suitable for implementing the monitoring method according to one of claims 1 to 7, in a land vehicle (V) and comprising first (MM1) and second (MM2) electric motors, associated respectively with first (T1) and second (T2) trains, and suitable for being supplied with electric current by an electric power source (BP), via respectively first (01) and second (02) inverters subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques, to monitor the respective consistencies of said first and second measured currents.

9. Monitoring device (DS) for a land vehicle (V) and comprising first (MM1) and second (MM2) electric motors, associated respectively with first (T1) and second (T2) trains, and suitable for being supplied with electric current by an electric power source (BP), via respectively first (01) and second (02) inverters subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques, characterized in that it comprises at least one processor (PR1) and at least one memory (MD) arranged to carry out the operations consisting of determining first and second values ​​respectively representative of absolute values ​​of a first difference, between said first measured current and a first estimated current representative of said first delivered torque, and of a second difference, between said second measured current and a second estimated current representative of said second delivered torque, and, when said first or second value is greater than a first or second chosen threshold, to trigger a prohibition of the operation of said first (MM1) or second (MM2) prime mover.

10. Land vehicle (V) comprising first (MM1) and second (MM2) electric motors, associated respectively with first (T1) and second (T2) trains, and suitable for being supplied with electric current by an electric power source (BP), via respectively first (01) and second (02) inverters subject respectively on their inputs to measurements of first and second currents, to deliver respectively first and second motor torques, characterized in that it further comprises a monitoring device (DS) according to claim 9.

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