Method for monitoring wear of a powertrain of an electric vehicle and electric vehicle implementing said method

Abstract

The invention relates to a method (100) for monitoring wear of a powertrain of an electric vehicle, the method comprising an analysis cycle (120) comprising, in the following order: preventing (121) movement of a mechanical component (12); rotating (123) the electric motor (16) in a first direction until a torque value transmitted by the electric motor reaches a predetermined threshold, thereby reaching a first angular position of the electric motor; rotating (125) the electric motor in a second direction opposite the first direction until a torque value transmitted by the electric motor reaches a predetermined threshold, thereby reaching a second angular position of the electric motor; and calculating (127) a backlash value of the powertrain based on the first angular position and the second angular position. The method (100) also includes comparing (130) the backlash value calculated (127) during the analysis cycle (120) to a reference value to monitor wear of the powertrain (14).

Description

Technical Field

[0001] The present disclosure generally relates to electric vehicles. In particular aspects, the present disclosure relates to a method for monitoring wear of a powertrain of an electric vehicle. The present disclosure may be applicable to heavy vehicles such as trucks, buses, and construction equipment, among other vehicle types. Although the present disclosure may be described with respect to a particular vehicle, the present disclosure is not limited to any particular vehicle. Background Art

[0002] Electric vehicles that use electric motors for propulsion are generally more reliable than vehicles that use internal combustion engines for propulsion due to simpler powertrain designs. However, heavy electric vehicles (such as trucks, buses, and construction equipment) are generally equipped with more complex powertrains than light vehicles (such as cars) and may, for example, be equipped with multi-speed transmissions.

[0003] Monitoring powertrain wear is important to ensure vehicle reliability and avoid costly failures. Such monitoring can be accomplished through physical inspection of the vehicle, which is costly and often inefficient for detecting mechanical wear of the powertrain's internal parts, such as the gears in the transmission. Therefore, there is a need for an easily implementable method for monitoring wear of an electric vehicle's powertrain. Summary of the invention

[0004] According to a first aspect of the present disclosure, the present disclosure relates to a method for monitoring wear of a powertrain of an electric vehicle, the powertrain comprising at least one electric motor and a transmission configured to transmit motor torque generated by the electric motor to a mechanical component of the electric vehicle to drive the mechanical component.

[0005] The method comprises an analysis cycle comprising, in the following order:

[0006] - prevent mechanical parts from moving;

[0007] - rotating the electric motor in a first rotational direction until a torque value delivered by the electric motor reaches a predetermined threshold value, thereby reaching a first angular position of the electric motor;

[0008] - rotating the electric motor in a second rotational direction opposite to the first rotational direction until the torque value transmitted by the electric motor reaches a predetermined threshold value, thereby reaching a second angular position of the electric motor;

[0009] - Calculating a backlash value of the driveline based on the first angular position and the second angular position.

[0010] The method also includes comparing the backlash value calculated during the analysis cycle to a reference value to monitor wear of the powertrain system.

[0011] A first aspect of the present disclosure may seek to monitor wear of a vehicle's powertrain system. Technical benefits may include detecting wear or defects in the powertrain system when backlash values ​​change, and improving vehicle maintenance and durability.

[0012] Optionally, in some examples, including at least one preferred example, the analysis cycle further comprises: measuring a first angular position of the electric motor after the electric motor rotates in a first rotational direction; and measuring a second angular position of the electric motor after the electric motor rotates in a second rotational direction. The backlash value is calculated as a difference between the first angular position and the second angular position. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain.

[0013] Optionally, in some examples, including at least one preferred example, before the electric motor rotates in the first rotational direction during the analysis cycle, the electric motor is in an initial angular position, and the analysis cycle further includes: calculating a first direction backlash value of the powertrain based on the first angular position and the initial angular position; and calculating a second direction backlash value of the powertrain based on the second angular position and the initial angular position. In addition, the method further includes comparing the first direction backlash value and the second direction backlash value calculated during the analysis cycle with a reference value to monitor wear of the powertrain. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain.

[0014] Optionally, in some examples, including in at least one preferred example, the analysis cycle further comprises: measuring an initial angular position of the electric motor before the electric motor rotates in a first rotational direction. The first direction backlash value is calculated as a difference between the first angular position and the initial angular position. The second direction backlash value is calculated as a difference between the initial angular position and the second angular position. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain system.

[0015] Optionally, in some examples, including at least one preferred example, the method further comprises a reference cycle performed prior to the analysis cycle, wherein the reference cycle comprises, in the following order: preventing the mechanical component from moving; rotating the electric motor in a first rotational direction until a torque value transmitted by the electric motor reaches a predetermined threshold, thereby reaching a first reference angular position of the electric motor; rotating the electric motor in a second rotational direction until a torque value transmitted by the electric motor reaches a predetermined threshold, thereby reaching a second reference angular position of the electric motor; calculating a reference backlash value of the powertrain based on the first reference angular position and the second reference angular position. The reference value compared to the backlash value calculated during the analysis cycle is the reference backlash value calculated during the reference cycle. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain.

[0016] Optionally, in some examples, including at least one preferred example, the reference cycle further comprises: measuring a first reference angular position of the electric motor after the electric motor rotates in the first rotational direction; and measuring a second reference angular position of the electric motor after the electric motor rotates in the second rotational direction. The reference backlash value is calculated as the difference between the first reference angular position and the second reference angular position. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain.

[0017] Optionally, in some examples, including at least one preferred example, before the electric motor rotates in the first rotational direction during the reference cycle, the electric motor is in an initial reference angular position, and the reference cycle further includes: calculating a first direction reference backlash value of the powertrain based on the first reference angular position and the initial reference angular position; and calculating a second direction reference backlash value of the powertrain based on the second reference angular position and the initial reference angular position. The reference values ​​compared to the first direction backlash value and the second direction backlash value calculated during the analysis cycle are the first direction reference backlash value and the second direction reference backlash value, respectively. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain.

[0018] Optionally, in some examples, including in at least one preferred example, the initial cycle further comprises: measuring an initial reference angular position of the electric motor before the electric motor rotates in the first rotational direction. The first direction reference backlash value is calculated as the difference between the first reference angular position and the initial reference angular position. The second direction reference backlash value is calculated as the difference between the initial reference angular position and the second reference angular position. Technical benefits may include obtaining more accurate monitoring of wear of the powertrain system.

[0019] Optionally, in some examples, including at least one preferred example, the analysis cycle is performed after the driver of the electric vehicle requests the electric vehicle to start and before the vehicle actually starts, and / or after the driver of the electric vehicle requests the electric vehicle to stop and before the vehicle actually stops. Technical benefits can include performing the analysis cycle without affecting the driver of the vehicle.

[0020] Optionally, in some examples, including at least one preferred example, the electric vehicle is a rechargeable battery electric vehicle, the electric motor is powered by the battery, and the analysis cycle is performed during battery recharging. Technical benefits may include performing the analysis cycle without affecting the driver of the vehicle.

[0021] Optionally, in some examples, including in at least one preferred example, the method further comprises repeating the analysis cycle over time to monitor the evolution over time of the backlash value calculated during the repeated analysis cycle. Technical benefits may include obtaining a more accurate monitoring of the evolution of wear of the driveline.

[0022] Optionally, in some examples, including at least one preferred example, the driveline includes a gearbox having a plurality of gear ratios, and the method is performed for each gear ratio of the gearbox to calculate a driveline backlash value for each gear ratio of the gearbox. Technical benefits may include locating wear locations within the driveline.

[0023] Optionally, in some examples, including at least one preferred example, the mechanical components of the vehicle include drive wheels of the vehicle, and during the analysis cycle of the method, brakes are applied to the vehicle to prevent movement of the vehicle and the drive wheels. Technical benefits may include locating wear locations within a powertrain system.

[0024] According to a second aspect of the disclosure, the disclosure relates to a vehicle, the vehicle comprising: a mechanical component; a powertrain comprising at least one electric motor and a transmission, the transmission being configured to transmit a motor torque generated by the electric motor to the mechanical component to drive the mechanical component; a sensor configured to measure an angular position of the electric motor; and a control unit. The control unit is configured to perform the method described above. The second aspect of the disclosure may seek to facilitate maintenance of the vehicle by easily detecting wear or defects in the powertrain.

[0025] The disclosed aspects, examples (including any preferred examples), and / or the appended claims may be appropriately combined with each other, which is obvious to any person skilled in the art. Additional features and advantages are disclosed in the detailed description, claims, and drawings, and in part will be obvious to those skilled in the art or recognized by practicing the disclosure as described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Examples are described in more detail below with reference to the accompanying drawings.

[0027] Figure 1 is an exemplary diagram showing a vehicle according to the present invention.

[0028] Figure 2 It is used for operation according to the example Figure 1 An exemplary flow chart of a method for a vehicle.

[0029] Figure 3 It is shown Figure 2 An exemplary illustration of an implementation of the steps of the method shown in the diagram in FIG. DETAILED DESCRIPTION

[0030] The detailed description set forth below provides information and examples of the disclosed technology in sufficient detail to enable those skilled in the art to practice the disclosure.

[0031] Figure 1 A vehicle 10 according to an example is shown in the exemplary illustration of FIG. The vehicle 10 is, for example, a heavy vehicle, preferably a truck, a bus or construction equipment.

[0032] The vehicle 10 includes two drive wheels 12 and a powertrain 14. In other examples, the vehicle 10 may include more than two drive wheels.

[0033] The drivetrain 14 is used to drive a mechanical component, which in the illustrated example is the drive wheels 12 .

[0034] The powertrain 14 includes an electric motor 16, a transmission 18, and a differential 20. The electric motor 16 includes a motor shaft 22, on which a motor gear 24 is mounted, and the motor gear is integral with the motor shaft. The electric motor 16 propels the drive wheels 12 through the transmission 18 and the differential 20, that is, the electric motor 16 transmits the motor torque to the transmission 18, and then the motor torque is transmitted to the differential 20 and the drive wheels 12.

[0035] The vehicle 10 includes a sensor 17 configured to measure the angular position θ (expressed in degrees) of the electric motor 16 and to measure the motor torque (expressed in Nm (Newton meters)) transmitted by the electric motor to the driveline 18. In the example described, the sensor 17 is integrated into the electric motor 16.

[0036] For example, sensor 17 measures the angular position θ of the electric motor by measuring the angular position of motor shaft 22 relative to the housing of the electric motor.

[0037] The transmission 18 comprises a transmission, which in the example described is a four-speed gearbox. In other words, the gearbox has four gear ratios. The gearbox comprises a main shaft 26, on which a first main gear 28, a second main gear 30 and a third main gear 32 are mounted to rotate freely about the main shaft. The gearbox also comprises a countershaft 34, on which a first countershaft 36 meshing with the motor gear 24 and a second countershaft 38 meshing with the first main gear 28 are mounted. The first countershaft and the second countershaft are integral, i.e. fixed together. The gearbox also comprises an output shaft 40, on which a first output gear 42 meshing with the second main gear 30, a second output gear 44 meshing with the third main gear 32, and a third output gear 46 meshing with the crown gear of the differential 20 are mounted. The third output gear 46 is also called a pinion. The first output gear, the second output gear and the third output gear are integral, i.e. fixed together, with the output shaft.

[0038] The gearbox also includes a first dog clutch 48 and a second dog clutch 50. The first dog clutch 48 can be engaged with the motor gear 24 or the first main gear 28 to couple the motor gear 24 or the first main gear 28 with the main shaft 26. When the first dog clutch 48 is engaged with the motor gear 24 or the first main gear 28, the motor torque transmitted to the motor shaft 22 by the electric motor 16 is transmitted to the main shaft 26. The second dog clutch 50 can be engaged with the second main gear 30 or the third main gear 32 to couple the second main gear 30 or the third main gear 32 with the main shaft 26. When the second dog clutch 50 is engaged with the second main gear 30 or the third main gear 32, and when the first dog clutch 48 is engaged with the motor gear 24 or the first main gear 28, the motor torque transmitted to the motor shaft 22 by the electric motor 16 is transmitted to the main shaft 26, then to the output shaft 40, and then to the differential 20 and the drive wheels 12. Thus, in these configurations, the driveline transmits motor torque generated by the electric motor 16 to the drive wheels 12 , and the driveline is said to be in a coupled configuration.

[0039] Thus, the illustrated example drive train provides four coupling configurations, and the transmission includes four speeds or four gear ratios, depending on the gears that the dog clutches 48 and 50 are engaged.

[0040] When the first dog clutch 48 is disengaged from the motor gear 24 and the first main gear 28, and / or when the second dog clutch 50 is disengaged from the second main gear 30 and the third main gear 32, the electric motor 16 is disconnected from the output shaft 40, the differential 20 and the drive wheels 12, and the drive train 18 is said to be in a disengaged configuration. In the example described, the drive train has three disengaged configurations. In the first disengaged configuration, the first dog clutch 48 and the second clutch 50 are disengaged from the corresponding gears, and the main shaft 26 is not driven by the motor shaft 22. In the second disengaged configuration, the first dog clutch 48 is disengaged from the motor gear 24 and the first main gear 28, and the second dog clutch 50 is engaged with the second main gear 30 or the third main gear 32, and the main shaft 26 is not driven by the motor shaft 22, as in the first disengaged configuration. In the third disengaged configuration, the first dog clutch 48 is engaged with the motor gear 24 or the first main gear 28 and the second dog clutch 50 is disengaged from the second and third main gears 30 , 32 , and thus the main shaft 26 is driven by the motor shaft 22 , but the output shaft 40 is not driven by the main shaft 26 .

[0041] In the example described, the first main gear 28, the second main gear 30 and the third main gear 32 are connected by bearings ( Figure 1 26. In addition, in the example described, the motor shaft 22, the main shaft 26, the secondary shaft 34 and the output shaft 40 are connected by bearings ( Figure 1The housing of the vehicle 10 is mounted on the chassis of the vehicle so as to rotate freely relative to the housing with minimal friction.

[0042] In the example described, the electric motor 16 is powered by a rechargeable battery that is not Figure 1 As a variant, the electric motor is powered by other means, such as by a fuel cell.

[0043] The vehicle 10 further includes a control unit 60 .

[0044] Reference now Figure 2 and Figure 3 A method 100 for monitoring wear of a powertrain system 14 of a vehicle 10 is described.

[0045] Preferably, the method 100 is executed by the control unit 60 .

[0046] All moving mechanical parts of the drivetrain 14 have clearances for normal operation. These clearances are determined during the manufacture of the drivetrain, but may increase over time due to wear.

[0047] The method 100 aims to monitor the wear of the driveline 14 by monitoring the evolution over time of backlash of mechanical parts of the driveline (including the electric motor 16 and the transmission 18 ), which backlash is caused by clearances between moving mechanical parts of the driveline.

[0048] In the described example, the mechanical parts of the drivetrain whose wear is monitored by the method 100 are the internal movable parts of the electric motor 16, namely the motor shaft 22, the motor gear 24, the main shaft 26, the first main gear 28, the second main gear 30 and the third main gear 32, the countershaft 34, the first counter gear 36 and the second counter gear 38, the output shaft 40, the first output gear 42, the second output gear 44 and the third output gear 46, and the differential 20.

[0049] For two meshing gears, the backlash value of the two gears is defined as the maximum angular distance one of the gears can move through in one direction without exerting significant force or motion on the other gear in the mechanical sequence.

[0050] Thus, in summary, the backlash value of the driveline 14 is defined as the maximum angular distance through which the electric motor 16 can move in one direction without transmitting significant torque. In other words, the backlash value of the driveline 14 corresponds to the angular distance between a first angular position of the electric motor 16, where the electric motor can transmit significant torque to the transmission 18 by rotating in a first rotational direction, and a second angular position of the electric motor, where the electric motor can transmit significant torque to the driveline by rotating in a second rotational direction opposite the first rotational direction. This angular distance corresponds to the angular distance required to compensate for all backlash in the driveline.

[0051] Therefore, the evolution of the backlash value of the driveline 14 over time represents the evolution of the wear of the driveline.

[0052] It will be appreciated that in order to measure the driveline backlash value, the mechanical components driven by the driveline 14 (in the example described, which are the drive wheels 12) must be prevented from moving so that significant motor torque can be transmitted from the electric motor 16 to the driveline 18, and the gearbox must be in a coupled configuration.

[0053] The method 100 begins with a reference loop 110 .

[0054] Preferably, the reference cycle 110 is performed after the vehicle 10 is manufactured but before it is placed in service. Alternatively, the reference cycle 110 is performed after the vehicle 10 is placed in service and after a run-in or break-in period.

[0055] According to an example, the reference cycle 110 is performed during battery recharging of the vehicle 10 .

[0056] According to another example, the reference loop 110 is executed after the driver of the electric vehicle 10 requests the electric vehicle to start and before the vehicle actually starts, or after the driver of the electric vehicle requests the electric vehicle to stop and before the vehicle actually stops.

[0057] The reference cycle 110 begins with a fixing step 111, in which the drive wheels 12 of the vehicle 10 are prevented from moving, for example, by applying brakes to the drive wheels 12 or non-drive wheels of the vehicle. In addition, the drive train 18 is arranged in a coupled configuration before or during the fixing step 111. For example, the first dog clutch 48 is engaged with the motor gear 24, and the second dog clutch 50 is engaged with the second main gear 30.

[0058] The reference cycle 110 then comprises a measurement step 112 during which an initial reference angular position θ0 of the electric motor 16 is preferably measured using the sensor 17. ref In the example described, the initial reference angular position θ0 refis arbitrarily defined as zero, i.e. equal to 0°.

[0059] The reference cycle 110 then comprises a rotation step 113 during which the electric motor 16 rotates in a first rotational direction until the torque value transmitted by the electric motor reaches a predetermined threshold value Tmax. The torque value transmitted by the electric motor is preferably measured by means of a sensor 17. The predetermined threshold value Tmax is preferably between 100 Nm and 600 Nm, for example equal to 300 Nm.

[0060] During the rotation step 113, all the play in the driveline 14 is gradually compensated until all the mechanical parts of the driveline are in contact with each other and can transmit torque in the first direction of movement. In other words, before reaching a predetermined threshold value Tmax, the torque transmitted by the electric motor 16 to the driveline 18 is low, because this torque is only used to compensate for the play. On the contrary, once all the play is compensated, the torque transmitted by the electric motor 16 to the driveline 18 increases rapidly, until it reaches the predetermined threshold value Tmax, because this torque is transmitted by the driveline to the drive wheels 12 and because the drive wheels 12 are prevented from moving by braking.

[0061] When the predetermined threshold value Tmax is reached, the electric motor 16 reaches the first reference angular position θ1 ref .

[0062] The reference cycle 110 then comprises a measurement step 114 during which the angular position of the electric motor 16 is measured, preferably by means of the sensor 17, to determine a first reference angular position θ1 ref In the example, the first reference angular position θ1 ref is relative to the initial reference angular position θ0 ref Defined as, expressed in degrees (°), positive values.

[0063] The reference cycle 110 then comprises a rotation step 115 during which the electric motor 16 is rotated in a second rotation direction opposite to the first rotation direction until the torque value delivered by the electric motor reaches a predetermined threshold value Tmax. The torque value delivered by the electric motor is preferably measured by means of a sensor 17. It should be noted that both the rotation steps 113 and 115 of the reference cycle 110 use the same predetermined threshold value Tmax.

[0064] During the rotation step 115, when a predetermined threshold value Tmax is reached, the electric motor 16 reaches a second reference angular position θ2 ref .

[0065] Similar to what was described above with reference to step 113 , during the rotating step 115 , all play in the driveline 14 is gradually compensated until all mechanical parts of the driveline are in contact with each other and can transmit torque in the second direction of movement.

[0066] The reference cycle 110 then comprises a measurement step 116 during which the angular position of the electric motor 16 is measured, preferably by means of the sensor 17, to determine a second reference angular position θ2 ref In the example, the second reference angular position is relative to the initial reference angular position θ0 ref Defined and expressed in degrees (°), as negative values.

[0067] The reference cycle 110 then comprises a calculation step 117 during which, based on the first reference angular position θ1 ref and the second reference angular position θ2 ref To calculate the reference backlash value B of the power transmission system 14 ref Here, refer to the backlash value B ref is calculated as the difference between the first reference angular position and the second reference angular position and is expressed in degrees (°).

[0068] Preferably, the reference cycle 110 then comprises a calculation step 118 during which, based on the first reference angular position θ1 ref and the initial reference angle position θ0 ref To calculate the first direction reference backlash value B1 of the power transmission system 14 ref , and based on the second reference angular position θ2 ref and the initial reference angle position θ0 ref To calculate the second direction reference backlash value B2 of the power transmission system 14 ref Here, the first direction reference backlash value is calculated as the difference between the first reference angular position and the initial reference angular position, and the second direction reference backlash value is calculated as the difference between the initial reference angular position and the second reference angular position. ref Equal to the first direction reference backlash value B1 ref With the second direction reference backlash value B2 ref The sum of the reference value B1 ref and B21 ref Is positive.

[0069] At the end of the reference cycle 110 , the initial state of the powertrain 14 is determined, which is determined by the reference backlash value B calculated during steps 117 and 118 . ref 、B1 ref and B2 refThis initial state represents the state of the powertrain system 14 after its manufacture or after its running-in period, depending on the execution time of the reference cycle 110 .

[0070] After the reference cycle 110 , the method 100 includes an analysis cycle 120 .

[0071] The analysis cycle 120 is performed during the useful life of the vehicle 10 when it is desirable to inspect the powertrain 14 for wear.

[0072] According to one example, the analysis cycle 120 is performed during battery recharging of the vehicle 10 .

[0073] According to another example, the analysis loop 120 is performed after the driver of the electric vehicle 10 requests the electric vehicle to start and before the vehicle actually starts, or after the driver of the electric vehicle requests the electric vehicle to stop and before the vehicle actually stops.

[0074] The analysis cycle 120 begins with a fixing step 121, in which the drive wheels 12 of the vehicle 10 are prevented from moving, for example by applying brakes to the drive wheels 12 or non-driven wheels of the vehicle. Furthermore, before or during the fixing step 121, the drive train 18 is set to be in the same coupling configuration as in the reference cycle 110, i.e., the same gearbox gear ratio is engaged. Thus, in the example described, the first dog clutch 48 is engaged with the motor gear 24, while the second dog clutch 50 is engaged with the second main gear 30.

[0075] The analysis cycle 120 then comprises a measurement step 122, during which the initial angular position θ0 of the electric motor 16 is measured, preferably by means of the sensor 17. In the example described, the initial angular position θ0 is arbitrarily defined as the zero value, ie equal to 0°.

[0076] The analysis cycle 120 then comprises a rotation step 123 during which the electric motor 16 is rotated in the first rotation direction until the torque value delivered by the electric motor reaches a predetermined threshold value Tmax. The torque value delivered by the electric motor is preferably measured using the sensor 17. It should be noted that the reference cycle 110 and the analysis cycle 120 use the same predetermined threshold value Tmax, the first rotation direction and the second rotation direction.

[0077] Similar to what was described above with reference to steps 113 and 115 of reference cycle 110 , during a rotation step 123 of analysis cycle 120 , all play in driveline 14 is progressively compensated until all mechanical parts of the driveline are in contact with each other and can transmit torque in the second direction of movement.

[0078] When the predetermined threshold value Tmax is reached, the electric motor 16 reaches the first angular position θ1 .

[0079] The analysis cycle 120 then comprises a measurement step 124 during which the angular position of the electric motor 16 is measured, preferably by means of the sensor 17, to determine the value of the first angular position θ1. In the example described, the first angular position θ1 is defined relative to the initial angular position θ0 and is expressed in degrees (°) as a positive value.

[0080] The analysis cycle 120 then comprises a rotation step 125 during which the electric motor 16 is rotated in the second rotational direction until the torque value delivered by the electric motor reaches a predetermined threshold value Tmax. The torque value delivered by the electric motor is preferably measured by means of a sensor 17 .

[0081] During the rotation step 125 , the electric motor 16 reaches a second angular position θ2 when a predetermined threshold value Tmax is reached.

[0082] Similar to what was described above with reference to steps 113 and 115 of reference cycle 110 , during the rotating step 125 , all play in the driveline 14 is gradually compensated until all mechanical parts of the driveline are in contact with each other and can transmit torque in the second direction of movement.

[0083] The analysis cycle 120 then comprises a measurement step 126 during which the angular position of the electric motor 16 is measured, preferably by means of the sensor 17, to determine the value of the second angular position θ2. In the example described, the second angular position is defined relative to the initial angular position and is expressed in degrees (°) as a negative value.

[0084] The analysis loop 120 then includes a calculation step 127 during which a backlash value B of the driveline 14 is calculated based on the first angular position θ1 and the second angular position θ2. Here, the backlash value B is calculated as the difference between the first angular position θ1 and the second angular position θ2 and is expressed in degrees (°).

[0085] Preferably, the analysis loop 120 then includes a calculation step 128 during which a first directional backlash value B1 of the powertrain 14 is calculated based on the first angular position θ1 and the initial angular position θ0, and a second directional backlash value B2 of the powertrain 14 is calculated based on the second angular position θ2 and the initial angular position θ0. Here, the first directional backlash value B1 is calculated as the difference between the first angular position θ1 and the initial angular position θ0, and the second directional backlash value B2 is calculated as the difference between the initial angular position θ0 and the second angular position θ2. Therefore, the backlash value B is equal to the sum of the first directional backlash value B1 and the second directional reference backlash value B2, and the reference value B1 is equal to the sum of the first directional backlash value B1 and the second directional reference backlash value B2. ref and B21 ref Is positive.

[0086] Figure 3The movement of the electric motor 16 during the analysis cycle 120 is represented. Figure 3 The diagram in shows on the horizontal axis the angular position θ of the electric motor 16 and on the vertical axis the motor torque T delivered by the electric motor. During the measuring step 122 , the electric motor 16 is in a steady state condition and delivers no motor torque, and the angular position θ corresponds to the initial angular position θ0 .

[0087] During the rotating step 123, the angular position θ increases stepwise. As the clearance of the mechanical parts of the powertrain 14 is gradually compensated by the rotation of the electric motor, the motor torque T increases simultaneously. Then, when all the clearances in the powertrain are compensated, the motor torque T increases rapidly and reaches an asymptote. Furthermore, when the motor torque T reaches a predetermined threshold value Tmax, the electric motor 16 is at a first angular position θ1.

[0088] Then, during the rotation step 125, the angular position θ is gradually reduced and the motor torque T becomes equal to zero until the angular position θ reaches the initial angular position θ0. Then, the angular position θ continues to decrease, and as the clearance of the mechanical parts of the powertrain 14 is gradually compensated by the rotation of the electric motor, the motor torque T increases simultaneously. Then, when all the clearances in the powertrain are compensated, the motor torque T increases rapidly and reaches an asymptote. In addition, when the motor torque T reaches a predetermined threshold value Tmax, the electric motor 16 is at a second angular position θ2.

[0089] Figure 3 It is shown that the backlash value B is equal to the difference between the first angular position θ1 and the second angular position θ2, expressed in degrees.

[0090] Preferably, the rotation of the electric motor 16 is between 10 rpm and 50 rpm during the rotation steps 113, 115 of the reference cycle 110 and during the rotation steps 123 and 125 of the analysis cycle 120. This relatively slow rotation speed allows all the mechanical parts within the powertrain 14 to be gradually brought together while allowing the angular position of the electric motor to be accurately measured.

[0091] After performing the analysis cycle 120 , the method 100 comprises a comparison step 130 during which the backlash value B obtained during the analysis cycle 120 is compared with a reference backlash value B obtained during the reference cycle 110 . ref and wherein, preferably, the first direction backlash value B1 and the second direction backlash value B2 obtained during the analysis cycle 120 are respectively compared with the first direction reference backlash value B1 obtained during the reference cycle 110. ref and the second direction reference backlash value B2 ref Comparisons are made to monitor the wear evolution of the drivetrain.

[0092] The backlash values ​​B, B1 and B2 obtained at the end of the analysis cycle 120 are compared to the reference backlash value B obtained at the end of the reference cycle 110. ref 、B1 ref and B2 ref The comparison of allows to detect the evolution of the wear of the driveline 14, which corresponds to the evolution of the clearance between the mechanical parts of the electric motor 16 and the transmission 18. In other words, the evolution of the clearance represents the degradation or wear of the parts of the driveline 14. Therefore, based on the evolution of the backlash values, the wear and degradation of the parts can be detected. B1, B1ref, B2 and B2ref cannot be compared, because "zero" (θ0) is never the same. Therefore, only B and Bref can be compared.

[0093] Essentially, the evolution of the backlash value can indicate either increasing driveline wear, or stagnant driveline wear, the latter being a sign of good driveline health.

[0094] For example, an increase in backlash value (corresponding to an increase in the gap between the parts) may be expressed as:

[0095] - Gear teeth wear;

[0096] - Damaged or worn bearings;

[0097] - bent, damaged or worn shafts;

[0098] - Damaged or worn adjusting shims; and / or

[0099] - Drive shaft splines are worn.

[0100] Thus, various defects and causes of wear of the powertrain system 14 may be detected during the comparison step 130 .

[0101] After the comparison step 130, if a significant evolution of the wear of the powertrain 14 is detected, i.e., if a defect is detected, the method 100 ends with an alarm step 140, during which an alarm is issued to attract the attention of the driver or controller of the vehicle 10, informing that a defect exists in the powertrain 14 and reminding that maintenance should be performed on the powertrain.

[0102] On the contrary, if no wear evolution of the powertrain is detected, that is, if the backlash values ​​B, B1 and B2 are close to or equal to the reference backlash value B ref 、B1 ref and B2 ref, then the method 100 continues. In the described example, after the waiting period, the method 100 repeats the analysis cycle 120 and then repeats the comparison step 130, as described above. For example, the waiting period is defined as a number of days or weeks before repeating the analysis cycle 120. Alternatively, the waiting period is defined as a distance that the vehicle 10 is to travel before repeating the analysis cycle 120.

[0103] Thus, the method 100 continues to monitor the evolution of the wear of the powertrain 14 over time during use of the vehicle 10 by monitoring the evolution of the backlash values ​​B, B1 and B2 until a defect or severe wear is detected.

[0104] The method 100 described above is particularly advantageous because it allows for easy detection of wear and defects within the powertrain 14 (including the electric motor 16). In fact, the method can be implemented on conventional electric vehicles without requiring structural modifications to such vehicles. Thus, the method is simple and inexpensive to implement. In particular, electric motors are typically equipped with torque and angular position sensors, such as the sensors used in the examples described above.

[0105] Furthermore, the method 100 allows for a wider variety of defects to be detected, since any defect that increases the clearance between mechanical parts of the powertrain 14 will affect the backlash value B measured by the method.

[0106] Furthermore, in addition to monitoring the backlash value B, the first direction backlash value B1 and the second direction backlash value B2 are monitored, thereby allowing for more accurate monitoring of wear within the powertrain 14. Since some defects only affect the backlash of the powertrain in one rotational direction of the electric motor, detecting an increase in only one of the backlash values ​​B1 or B2 allows for identification of the location and / or type of wear within the powertrain.

[0107] Furthermore, the method 100 places no restrictions on the driver of the vehicle 10 as it does not alter the driving of the vehicle and does not require any driver intervention.

[0108] In the above example, the method 100 is performed using only one gear ratio of the transmission. Preferably, the method 100 is performed for each gear ratio of the transmission. Thus, for the vehicle 10 of the example described, the method 100 is performed four times. Performing the method 100 for each gear ratio of the transmission is particularly advantageous because it allows the wear within the drivetrain 14 to be located.

[0109] Indeed, if the increase in the backlash value B is more significant when the method 100 is performed for a given gear ratio, it can be concluded that the wear is located at least in the mechanical parts of the driveline 14 that are driven only by the electric motor 16 when the gearbox is set in said gear ratio. For example, if the increase in the backlash value B is observed only when the first dog clutch 48 is engaged with the first main gear 28, it can be concluded that the wear is located on the first main gear 28 or on the bearings used to mount the first main gear 28 on the main shaft 26 or on the secondary shaft 34.

[0110] Furthermore, if the increase in backlash value B is constant regardless of the gear ratio in which method 100 is performed, it can be concluded that the wear is located in a mechanical part of the drivetrain 14 that is always driven by the electric motor 16 , such as the motor shaft 22 or the output shaft 40 .

[0111] Furthermore, if the increase in backlash value B is more significant for several gear ratios, but not for all gear ratios, it can be concluded that the wear is located at least in the mechanical part of the drivetrain 14 that is driven by the electric motor 16 when the gearbox is set in all said gear ratios, but is not driven by the electric motor when the gearbox is set in another gear ratio. Said mechanical part is therefore the universal gear of said gear ratio.

[0112] The vehicle 10 described above is of a standard concept. Therefore, various modifications are conceivable without affecting the execution of the method 100.

[0113] For example, the gearbox may have a number of speeds other than four, such as two or eight; and / or a number of dog clutches other than two, such as one or three.

[0114] According to other examples, the powertrain 14 does not include a differential.

[0115] According to other examples, the transmission 18 does not include a gearbox, but rather another type of transmission, such as a fixed transmission or a continuously variable transmission.

[0116] Therefore, it should be understood that the above-described method 100 may be applied to other electric vehicles having different architectures.

[0117] According to other examples, the powertrain 14 includes multiple electric motors, such as two or three electric motors. For example, the transmission 18 includes two inputs, one for each electric motor, and one output connected to the differential 20. In such examples, the method 100 is performed multiple times, preferably once for each electric motor of the vehicle.

[0118] In the above example, the motor torque transmitted by the electric motor 16 to the transmission 18 is transmitted by the transmission to the drive wheels 12 of the vehicle, which are mechanical components of the vehicle. According to other examples, the motor torque is transmitted by the transmission 18 to other mechanical components of the vehicle 10, such as, for example, a compressor, a pump and / or any other mechanical component that requires input torque to drive. In other words, the powertrain 14 is configured to drive the mechanical components to rotate. In such examples, the method 100 is performed as described above, wherein the transmission is in a coupled configuration and the mechanical components are prevented from moving during the reference cycle 110 and during the analysis cycle 120. Alternatively, the transmission 18 can simultaneously transmit the motor torque of the electric motor 16 to the drive wheels 12 and other mechanical components of the vehicle 10.

[0119] Furthermore, the above description is based on the method 100 as an example, from which various modifications can be envisioned.

[0120] According to other examples, the method 100 does not include the reference cycle 110. In such examples, the analysis cycle 120 is repeated and the backlash values ​​B, B1 and B2 determined during steps 127 and 128 of the last performed analysis cycle 120 are compared with the backlash values ​​B, B1 and B2 determined during the previously performed analysis cycle 120 to detect the evolution of the wear of the powertrain 14 over time.

[0121] According to other examples, the backlash values ​​B, B1, and B2 obtained during the analysis cycle 120 are compared with reference values ​​obtained by other means (such as by calculation or reference vehicle), instead of comparing the backlash values ​​B obtained during the reference cycle 110. ref 、B1 ref and B2 ref The backlash values ​​B, B1 and B2 obtained during the previously executed analysis cycle 120 are compared or supplemented thereto.

[0122] According to other examples, the initial reference angular position θ0 is not measured during the reference cycle 110 and the analysis cycle 120. ref and the initial angular position θ0, and therefore the first direction reference backlash value B1 is not calculated ref and the second direction reference backlash value B2 ref And the first direction tooth gap value B1 and the second direction tooth gap value B2.

[0123] Example 1: A method 100 for monitoring wear of a powertrain 14 of an electric vehicle 10, the powertrain 14 comprising at least one electric motor 16 and a transmission 18, the transmission being configured to transmit a motor torque generated by the electric motor 16 to a mechanical component 12 of the electric vehicle 10 to drive the mechanical component,

[0124] The method 100 includes an analysis cycle 120, which includes, in the following order:

[0125] - preventing 121 the mechanical part 12 from moving;

[0126] - rotating 123 the electric motor 16 in a first rotational direction until the torque value transmitted by the electric motor reaches a predetermined threshold value Tmax, thereby reaching a first angular position θ1 of the electric motor 16 ;

[0127] - rotating 125 the electric motor 16 in a second rotation direction opposite to the first rotation direction, until the torque value transmitted by the electric motor reaches the predetermined threshold value Tmax, thereby reaching a second angular position θ2 of the electric motor 16 ;

[0128] - calculating 127 a backlash value B of the powertrain 14 based on the first angular position θ1 and the second angular position θ2,

[0129] And wherein the method 100 further comprises comparing 130 the backlash value B calculated 127 during the analysis cycle 120 with a reference value B ref To monitor the wear of the powertrain system 14 .

[0130] Example 2: The method 100 of Example 1, wherein the analysis cycle 120 further comprises:

[0131] - measuring 124 the first angular position θ1 of the electric motor 16 after the electric motor 16 has rotated 123 in the first direction of rotation;

[0132] - measuring 126 the second angular position θ2 of the electric motor 16 after the electric motor 16 has rotated 125 in the second direction of rotation,

[0133] And wherein the backlash value B is calculated 127 as the difference between the first angular position θ1 and the second angular position θ2.

[0134] Example 3: The method 100 of any of Examples 1 and 2, wherein the electric motor is at an initial angular position θ0 before the electric motor 16 rotates 123 in the first rotational direction during the analysis cycle 120, wherein the analysis cycle 120 further comprises:

[0135] - calculating 128 a first directional backlash value B1 of the powertrain 14 based on the first angular position θ1 and the initial angular position θ0, and calculating a second directional backlash value B2 of the powertrain 14 based on the second angular position θ2 and the initial angular position θ0,

[0136] And wherein the method 100 further comprises comparing the first direction backlash value B1 and the second direction backlash value B2 calculated 128 during the analysis cycle 120 with a reference value B1 ref、 B2 ref A comparison 130 is performed to monitor wear of the powertrain 14 .

[0137] Example 4: The method 100 as described in combination with Examples 2 and 3, wherein the analysis cycle 120 further comprises:

[0138] - measuring 122 the initial angular position θ0 of the electric motor 16 before the electric motor 16 rotates 123 in the first rotation direction,

[0139] The first direction backlash value B1 is calculated 128 as the difference between the first angular position θ1 and the initial angular position θ0,

[0140] And wherein the second directional backlash value B2 is calculated 128 as the difference between the initial angular position θ0 and the second angular position θ2.

[0141] Example 5: The method 100 of any one of Examples 1 to 4, wherein the method 100 further comprises a reference loop 110 executed before the analysis loop 120, wherein the reference loop 110 comprises, in the following order:

[0142] - preventing the mechanical part 12 mentioned at 111 from moving;

[0143] - rotating the electric motor 16 in the first rotation direction 113 until the torque value transmitted by the electric motor reaches the predetermined threshold value Tmax, thereby reaching a first reference angular position θ1 of the electric motor 16 ref ;

[0144] - rotating the electric motor 16 in the second rotation direction 115 until the torque value transmitted by the electric motor reaches the predetermined threshold value Tmax, thereby reaching a second reference angular position θ2 of the electric motor 16 ref ;

[0145] - Based on the first reference angular position θ1 ref and the second reference angular position θ2 ref To calculate 117 the reference backlash value B of the power transmission system 14 ref ,

[0146] and wherein the reference value to which the backlash value B calculated 127 during the analysis cycle 120 is compared 130 is the reference backlash value B calculated 117 during the reference cycle 110 ref .

[0147] Example 6: The method 100 of Example 5, wherein the reference cycle 110 further comprises:

[0148] - After the electric motor 16 rotates 113 in the first rotation direction, measuring 114 the first reference angular position θ1 of the electric motor 16 ref ;

[0149] - measuring 116 the second reference angular position θ2 of the electric motor 16 after the electric motor 16 has rotated 115 in the second rotational direction ref ;

[0150] And wherein the reference backlash value B ref is calculated 117 as the difference between the first reference angular position and the second reference angular position.

[0151] Example 7: The method 100 of any of Examples 5 and 6, wherein before the electric motor 16 rotates 113 in the first rotational direction during the reference cycle 110, the electric motor is at an initial reference angular position θ0 ref , wherein the reference cycle 110 further comprises:

[0152] - Based on the first reference angular position θ1 ref and the initial reference angular position to calculate 118 a first direction reference backlash value B1 of the power transmission system 14 ref , and based on the second reference angular position θ2 ref and the initial reference angular position to calculate the second direction reference backlash value B2 of the power transmission system 14 ref ,

[0153] and wherein the reference values ​​compared 130 with the first direction backlash value B1 and the second direction backlash value B2 calculated 128 during the analysis cycle 120 are respectively the first direction reference backlash value B1 and the second direction reference backlash value B2. ref and the second direction reference backlash value B2 ref .

[0154] Example 8: The method 100 of combined examples 6 and 7, wherein the initial cycle 110 further comprises:

[0155] - before the electric motor 16 rotates 113 in the first rotation direction, measuring 112 an initial reference angular position θ0 of the electric motor ref ,

[0156] The first direction refers to the backlash value B1 ref is calculated 118 as the first reference angular position θ1 ref and the initial reference angular position,

[0157] And wherein the second direction reference backlash value B2 ref is calculated 118 as the initial reference angular position and the second reference angular position θ2 ref The difference between .

[0158] Example 9: The method 100 of any one of Examples 1 to 8, wherein the analysis cycle 120 is performed at the following times:

[0159] - after the driver of the electric vehicle 10 requests the electric vehicle to start and before the vehicle actually starts, and / or

[0160] - After the driver of the electric vehicle 10 requests the electric vehicle to stop and before the vehicle actually stops.

[0161] Example 10: The method 100 of any of Examples 1 to 8, wherein the electric vehicle 10 is a rechargeable battery electric vehicle, the electric motor 16 is powered by a battery, and wherein the analysis cycle 120 is performed during recharging of the battery.

[0162] Example 11: The method 100 of any of Examples 1 to 10, wherein the method 100 further comprises repeating the analysis cycle 120 over time to monitor the evolution over time of the backlash value B calculated 127 during the repeated analysis cycle 120.

[0163] Example 12: The method 100 of any one of Examples 1 to 11, wherein the transmission system 18 includes a gearbox having a plurality of gear ratios, and wherein the method 100 is performed for each gear ratio of the gearbox to calculate the backlash value of the driveline 14 for each gear ratio of the gearbox.

[0164] Example 13: A method 100 as described in any of Examples 1 to 12, wherein the mechanical parts 12 of the vehicle 10 include drive wheels 12 of the vehicle, and wherein during the analysis cycle 120 of the method, brakes are applied to the vehicle to prevent 121 the movement of the vehicle and the drive wheels.

[0165] Example 14: A vehicle 10 comprising:

[0166] - Mechanical parts 12;

[0167] - a powertrain 14 comprising at least one electric motor 16 and a drive train 18 configured to transmit the motor torque generated by the electric motor to the mechanical component to drive the mechanical component;

[0168] - a sensor 17 configured to obtain the angular position of the electric motor 16 ; and

[0169] - a control unit 60,

[0170] The control unit 60 is configured to perform the method 100 according to any one of Examples 1 to 13.

[0171] The terms used herein are only for the purpose of describing specific aspects and are not intended to limit the present disclosure. As used herein, unless the context clearly indicates otherwise, the singular forms "one", "a kind of" and "said" are intended to include plural forms as well. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. It should also be understood that the terms "include" and / or "comprising" when used herein indicate the presence of stated features, integers, actions, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, actions, steps, operations, elements, parts and / or their groups.

[0172] It should be understood that although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the present disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0173] Relative terms such as "below" or "above" or "upper" or "lower" or "horizontal" or "vertical" may be used herein to describe the relationship of one element to another element, as shown in the figures. It should be understood that these relative terms and those discussed above are intended to cover different device orientations in addition to the orientations depicted in the figures. It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or there may be intervening elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements.

[0174] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the present disclosure belongs. It should also be understood that, unless otherwise clearly defined herein, the terms used herein should be interpreted as meanings consistent with their meanings in the context of this specification and the relevant art, and should not be interpreted in an idealized or overly formal sense.

[0175] It should be understood that the present disclosure is not limited to the aspects described above and shown in the accompanying drawings; rather, the skilled person will recognize that many changes and modifications may be made within the scope of the present disclosure and the appended claims. In the drawings and description, various aspects have been disclosed for illustrative purposes only and not for limiting purposes, and the scope of the present disclosure is set forth in the appended claims.

Claims

1. A method (100) for monitoring wear of a powertrain (14) of an electric vehicle (10), the powertrain (14) comprising at least one electric motor (16) and a drive train (18), the drive train being configured to transmit motor torque generated by the electric motor (16) to a mechanical component (12) of the electric vehicle (10) to drive the mechanical component, The method (100) comprises an analysis cycle (120) in the following order: include: - preventing (121) the mechanical part (12) from moving; - rotating the electric motor (16) in a first rotational direction (123) until the torque value transmitted by the electric motor reaches a predetermined threshold value (Tmax), thereby reaching a first angular position (θ1) of the electric motor (16); - rotating the electric motor (16) in a second rotational direction (125) opposite to the first rotational direction until the torque value transmitted by the electric motor reaches the predetermined threshold value (Tmax), thereby reaching a second angular position (θ2) of the electric motor (16); - calculating (127) a backlash value (B) of the powertrain (14) based on the first angular position (θ1) and the second angular position (θ2), and wherein the method (100) further comprises comparing (130) the backlash value (B) calculated (127) during the analysis cycle (120) with a reference value (B ref ) to monitor wear of the power transmission system (14).

2. The method (100) of claim 1, wherein the analysis cycle (120) further comprises: include: - measuring (124) the first angular position (θ1) of the electric motor (16) after the electric motor (16) has rotated (123) in the first direction of rotation; - measuring (126) the second angular position (θ2) of the electric motor (16) after the electric motor (16) has rotated (125) in the second rotational direction, And wherein the backlash value (B) is calculated (127) as a difference between the first angular position (θ1) and the second angular position (θ2).

3. The method (100) of any one of claims 1 and 2, wherein the electric motor (16) is in an initial angular position (θ0) before the electric motor (16) is rotated (123) in the first rotational direction during the analysis cycle (120), wherein the analysis cycle (120) further comprises: include: - calculating (128) a first directional backlash value (B1) of the power transmission system (14) based on the first angular position (θ1) and the initial angular position (θ0), and calculating a second directional backlash value (B2) of the power transmission system (14) based on the second angular position (θ2) and the initial angular position (θ0), and wherein the method (100) further comprises comparing the first direction backlash value (B1) and the second direction backlash value (B2) calculated (128) during the analysis cycle (120) with a reference value (B1 ref、 B2 ref ) are compared (130) to monitor wear of the powertrain (14).

4. The method (100) of claims 2 and 3 considered in combination, wherein the analysis cycle (120) further comprises: include: - measuring (122) the initial angular position (θ0) of the electric motor (16) before the electric motor (16) rotates (123) in the first rotation direction, wherein the first directional backlash value (B1) is calculated (128) as the difference between the first angular position (θ1) and the initial angular position (θ0), And wherein the second direction backlash value (B2) is calculated (128) as the difference between the initial angular position (θ0) and the second angular position (θ2).

5. The method (100) of any one of claims 1 to 4, wherein the method (100) further comprises a reference loop (110) executed before the analysis loop (120), wherein the reference loop (110) is executed in the following order: include: - preventing (111) the mechanical part (12) from moving; - rotating the electric motor (16) in the first rotation direction (113) until the torque value transmitted by the electric motor reaches the predetermined threshold value (Tmax), thereby reaching a first reference angular position (θ1) of the electric motor (16) ref ); - rotating the electric motor (16) in the second rotational direction (115) until the torque value transmitted by the electric motor reaches the predetermined threshold value (Tmax), thereby reaching a second reference angular position (θ2 ref ); - Based on the first reference angular position (θ1 ref ) and the second reference angular position (θ2 ref ) to calculate (117) a reference backlash value (B) of the power transmission system (14) ref ), and wherein the reference value to be compared (130) with the backlash value (B) calculated (127) during the analysis cycle (120) is the reference backlash value (B) calculated (117) during the reference cycle (110). ref ).

6. The method (100) of claim 5, wherein the reference cycle (110) further comprises: include: - after the electric motor (16) rotates (113) in the first rotation direction, measuring (114) the first reference angular position (θ1) of the electric motor (16) ref ); - after the electric motor (16) rotates (115) in the second rotation direction, measuring (116) the second reference angular position (θ2 ref ); And wherein the reference backlash value (B ref ) is calculated (117) as the difference between the first reference angular position and the second reference angular position.

7. The method (100) of any one of claims 5 and 6, wherein before the electric motor (16) rotates (113) in the first rotational direction during the reference cycle (110), the electric motor is in an initial reference angular position (θ0 ref ), wherein the reference loop (110) also include: - Based on the first reference angular position (θ1 ref ) and the initial reference angular position to calculate (118) a first direction reference backlash value (B1) of the power transmission system (14) ref ), and based on the second reference angular position (θ2 ref ) and the initial reference angular position to calculate a second direction reference backlash value (B2 ref ), and wherein the reference values ​​compared (130) with the first direction backlash value (B1) and the second direction backlash value (B2) calculated (128) during the analysis cycle (120) are respectively the first direction reference backlash value (B1 ref ) and the second direction reference backlash value (B2 ref ).

8. The method (100) of claims 6 and 7 considered in combination, wherein the initial cycle (110) further comprises: include: - before the electric motor (16) rotates (113) in the first rotation direction, measuring (112) an initial reference angular position (θ0 ref ); The first direction reference backlash value (B1 ref ) is calculated (118) as the first reference angular position (θ1 ref ) and the initial reference angular position, And wherein the second direction reference backlash value (B2 ref ) is calculated (118) as the initial reference angular position and the second reference angular position (θ2 ref ) between the values ​​of .

9. The method (100) of any one of claims 1 to 8, wherein the analysis cycle (120) is performed at: - after a driver of the electric vehicle (10) requests that the electric vehicle be started and before the vehicle is actually started, and / or - after a driver of the electric vehicle (10) requests the electric vehicle to stop and before the vehicle actually stops.

10. The method (100) of any one of claims 1 to 8, wherein the electric vehicle (10) is a rechargeable battery electric vehicle, the electric motor (16) is powered by a battery, and wherein the analysis cycle (120) is performed during recharging of the battery.

11. The method (100) of any one of claims 1 to 10, wherein the method (100) further comprises repeating the analysis cycle (120) over time to monitor the evolution over time of the backlash value (B) calculated (127) during the repeated analysis cycle (120).

12. The method (100) of any one of claims 1 to 11, wherein the drive train (18) comprises a gearbox having a plurality of gear ratios, and wherein the method (100) is performed for each gear ratio of the gearbox to calculate a backlash value of the drive train (14) for each gear ratio of the gearbox.

13. A method (100) as claimed in any one of claims 1 to 12, wherein the mechanical parts (12) of the vehicle (10) include drive wheels (12) of the vehicle, and wherein during the analysis cycle (120) of the method, brakes are applied to the vehicle to prevent (121) the movement of the vehicle and the drive wheels.

14. A vehicle (10) comprising: include: - Mechanical parts (12); - a powertrain (14) comprising at least one electric motor (16) and a drive train (18) configured to transmit motor torque generated by the electric motor to the mechanical component to drive the mechanical component; - a sensor (17) configured to obtain the angular position of the electric motor (16); as well as - a control unit (60), The control unit (60) is configured to perform the method (100) according to any one of claims 1 to 13.

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