FR3099735A1 - Acquisition and control system for electric motor vehicle - Google Patents

Abstract

Acquisition and control system for an electric motor vehicle, the system comprising: - at least one first angular position sensor capable of indicating an estimate of the relative position of a rotor of the electric motor with respect to a stator of the electric motor, an electric motor control device capable of controlling an operation of the electric motor as a function of said position estimate, in which the control device is able to control, in addition to the engine, a device of the vehicle distinct from the engine as a function of said position estimation. Abstract figure: Fig. 5

Description

Acquisition and control system for electric motor vehicle

The present disclosure relates to the technical field of the control of electric motor vehicles.

More specifically, the present disclosure relates to acquisition and control systems for electric motor vehicles, to electric motor vehicles comprising such systems, to acquisition and control methods implemented by such systems, on computer programs for the implementation of such methods, and on data storage media for the implementation of such methods.

• mesurer une position angulaire et/ou une vitesse angulaire d’un élément rotatif d’un système mécanique
• et utiliser une telle mesure dans un algorithme de contrôle-commande.

Various devices are known using angular position sensors for:

• measure an angular position and/or an angular speed of a rotating element of a mechanical system
• and using such a measurement in a control-command algorithm.

In the automotive field, this is particularly the case for the implementation of driving assistance by a dedicated device.

Driving assistance devices are becoming more and more widespread, conferring an increasingly greater degree of autonomy on equipped vehicles.

Summary

This disclosure aims to expand the possibilities of using such devices in an electric motor vehicle.

• au moins un premier capteur de position angulaire apte à indiquer une estimation de position relative d’un rotor du moteur électrique par rapport à un stator du moteur électrique,
• un dispositif de contrôle du moteur électrique apte à piloter un fonctionnement du moteur électrique en fonction de ladite estimation de position,
• dans lequel le dispositif de contrôle est apte à piloter, outre le moteur, un dispositif du véhicule, distinct du moteur, en fonction de ladite estimation de position.

There is provided an acquisition and control system for an electric motor vehicle, the system comprising:

• at least one first angular position sensor capable of indicating an estimate of the relative position of a rotor of the electric motor with respect to a stator of the electric motor,
• a device for controlling the electric motor capable of controlling an operation of the electric motor as a function of said position estimate,
• in which the control device is capable of controlling, in addition to the motor, a device of the vehicle, separate from the motor, as a function of said position estimate.

The system is applicable to any type of vehicle with an electric motor, including in particular motor cars, bicycles and motorcycles having an electric motor as a means of propulsion.

In one embodiment, the system comprises at least one data bus able to transmit the position estimate to the electric motor control device and able to transmit a control signal emitted by the electric motor control device on the basis of the position estimation to the vehicle device, the vehicle device being controllable on the basis of the transmitted control signal.

• la fonction de propulsion du véhicule assurée par le moteur électrique du véhicule,
• et une fonction distincte de la propulsion du véhicule, assurée par un dispositif du véhicule distinct du moteur.

Thus, the position estimate supplied by the first angular position sensor is used in a multifunctional manner. Indeed, this position estimate is used to control both:

• the function of propulsion of the vehicle ensured by the electric motor of the vehicle,
• and a function distinct from the propulsion of the vehicle, ensured by a device of the vehicle distinct from the engine.

The control of the operation of the electric motor as a function of said position estimate is implemented in a manner specific to the type of electric motor of the vehicle.

All electric motors include a rotating element, or rotor, and a stationary element, or stator. one embodiment, the electric motor of the vehicle is a brushless motor. Such a motor, also designated by the terms “brushless” or “bldc”, is commonly used for the propulsion of all types of electric vehicles. Three main types of electric motors are currently used in the automotive industry: permanent magnet motors, induction motors, and wound rotor motors. In the case of permanent magnet motors, the rotor of a brushless motor includes at least one permanent magnet. The stator includes at least one winding (or winding) acting as an electromagnet. Conventionally, the brushless motor is three-phase and the stator comprises three groups of coils linked together.

In this example, the motor control device applies a switching sequence which consists of successively energizing the groups of stator coils. This successive supply has the effect of creating a rotating magnetic field. As the rotor's permanent magnet aligns with the magnetic field, the rotor spins, causing a motor shaft to rotate.

To implement the switching sequence, the brushless motor control device receives at each instant, via the angular position sensor, an estimate of the relative position of the rotor with respect to the stator. Based on this estimate, the motor controller drives the motor to maintain the rotation of the rotor. The motor control device can for example continuously adjust the current so that the motor operates in its maximum efficiency zone.

Generally speaking, estimating the angular position of the rotor relative to the stator allows the motor control device to maintain precise control of the motor. Indeed, any misalignment or phase change between the expected position and the actual position of the rotor relative to the stator can lead to undesirable behavior and a drop in performance of the electric motor.

• le premier capteur est monté dans le moteur,
• le système comporte un deuxième capteur apte à indiquer une évolution de position du véhicule,
• et le dispositif de contrôle est apte à comparer une première mesure issue du premier capteur à une deuxième mesure issue du deuxième capteur pour générer, en cas d’écart, un signal d’alerte.

In one realization:

• the first sensor is mounted in the engine,
• the system comprises a second sensor capable of indicating a change in the position of the vehicle,
• and the control device is capable of comparing a first measurement from the first sensor with a second measurement from the second sensor to generate, in the event of a deviation, an alert signal.

In this embodiment, the first sensor, being mounted in the electric motor, directly estimates the angular position of the motor rotor with respect to that of the motor stator.

• un capteur à effet Hall fixé au stator qui mesure une variation de champ magnétique lors du passage des pôles du rotor, la variation étant indicative d’une estimation de position angulaire du rotor,
• ou un codeur rotatif optique fixé au stator qui détecte la présence d’une strie sur le rotor, la position angulaire du rotor étant déterminée sur la base d’une table de correspondance associant la présence de ladite strie à une estimation de position angulaire du rotor,
• ou un voltmètre, en l’espèce interne au moteur électrique, qui mesure dans chaque enroulement du stator une force contre-électromotrice induite par la rotation du rotor mesurée par rapport à un point commun des enroulements appelé « neutre », les variations relatives des forces contre-électromotrices ainsi mesurées étant indicatives d’une estimation de position angulaire du rotor.

Continuing the previous example of a brushless motor, the first sensor can be:

• a Hall effect sensor fixed to the stator which measures a variation in the magnetic field during the passage of the poles of the rotor, the variation being indicative of an estimate of the angular position of the rotor,
• or an optical rotary encoder fixed to the stator which detects the presence of a groove on the rotor, the angular position of the rotor being determined on the basis of a correspondence table associating the presence of said groove with an estimate of the angular position of the rotor ,
• or a voltmeter, in this case internal to the electric motor, which measures in each winding of the stator a counter-electromotive force induced by the rotation of the rotor measured with respect to a common point of the windings called "neutral", the relative variations of the forces counter-electromotives thus measured being indicative of an estimation of the angular position of the rotor.

The estimation of this angular position by the first sensor can be repeated after a predefined time interval so as to estimate the average speed of rotation of the rotor during this time interval.

In this embodiment, the second sensor indicates a change in position of the vehicle.

Compared to a combustion engine, the torque of an electric motor is high regardless of the rotational speed of the motor rotor. For this reason, electric motor vehicles are generally devoid of gearbox and clutch. Consequently, the speed of rotation of the rotor of the electric motor is proportional to the speed of rotation of the driving wheel(s) of the vehicle.

In a particular mode of such an embodiment, the second sensor is an angular position sensor mounted on at least one wheel of the vehicle. Such a receiver is capable of measuring an angular position of said wheel of the vehicle. This angular position measurement can be repeated after a predefined time interval so as to calculate an average speed of rotation of said wheel during this time interval.

Most electric motor vehicles include a gearbox having a single transmission ratio, predefined and fixed, between the movement of a motor shaft actuated by the rotation of the rotor and the movement of a driven shaft rotating one or multiple wheel drive.

The actual value of the ratio between the average rotational speed of the rotor during a predefined time interval (as "first measurement from the first sensor") and the average rotational speed of a driving wheel of the vehicle (as as long as "second measurement from the second sensor") is then constantly equal to a unique predefined value.

In the case of a gearbox comprising a plurality of transmission ratios, the actual value is variable among a plurality of predefined values each corresponding to one of the transmission ratios.

In this particular mode, the control device compares the second measurement from the second sensor with the first measurement from the first sensor.

If the ratio between the two measurements matches the predefined value, no alert signal is generated.

• une anomalie de la transmission de puissance du moteur à la roue motrice,
• ou une usure excessive d’un pneu d’une roue,
• ou une défaillance du premier ou du deuxième capteur.

On the other hand, if the ratio between the two measurements does not correspond to the predefined value, then the control device identifies a safety defect of the vehicle which can be:

• an anomaly in the transmission of power from the engine to the drive wheel,
• or excessive wear of a tire of a wheel,
• or a failure of the first or second sensor.

For example, in the event of a transmission anomaly, the engine torque is not correctly transmitted to the driving wheel, thus the ratio between the average speed of rotation of the rotor and the average speed of rotation of the driving wheel increases. A transmission anomaly generally occurs abruptly, so it can be expected that the control device identifies such a safety fault when the ratio between the average speed of rotation of the rotor and the average speed of rotation of the driving wheel increases suddenly.

For example, if a tire on a wheel wears out, the ground exerts an increased frictional force on the tire, which slows the rotation of the wheel. Thus, the average speed of rotation of the wheel decreases, therefore the ratio between the average speed of rotation of the rotor and the average speed of rotation of the wheel increases. As wheel tire wear is progressive over time, this ratio also increases gradually over time. Provision may be made for the monitoring device to identify such a safety defect only when this ratio exceeds a predefined threshold corresponding to excessive tire wear.

• émettre une alerte visuelle, le dispositif étant un voyant d’alerte,
• et/ou émettre une alerte audio, telle qu’un bip d’alerte, le dispositif étant un haut-parleur.

The control device then generates an alert signal. The warning signal is an electrical signal intended to control a vehicle device, separate from the engine, to:

• issue a visual alert, the device being a warning light,
• and/or emitting an audio alert, such as an alert beep, the device being a speaker.

For example, in the event of a detected safety defect corresponding to an anomaly in the transmission of a motor car with an electric motor, it may be provided to light up or flash a warning light on the dashboard of the motor car to signal the anomaly of transmission to the driver.

In general, the instantaneous or repeated comparison over time of the measurements from the first and the second sensor makes it possible to identify the nature of a safety defect of the vehicle and to signal this defect via the alert signal.

In another particular mode of such an embodiment, the second sensor is an odometer.

An odometer is an angular position sensor connected to an element of the vehicle driven in rotation by the electric motor.

Typically, on a motor car, an odometer measures the angular position of an element of the transmission and associates this position with a distance traveled.

Typically, on a bicycle, an odometer is a device attached to a spoke of a wheel comprising a finger capable of incrementing a counter each time the finger passes over at least one predetermined angular position. Thus, in this example, the odometer is an angular position sensor of a wheel of the bicycle.

In general, compared to the measurement provided by an angular position sensor of a drive wheel of the vehicle as described previously, the angular position measurement provided by the odometer is treated in a similar manner as "second measurement resulting from 'a second sensor' by the engine control device and makes it possible to identify the same vehicle safety faults as previously described.

In another particular mode of such an embodiment, the second sensor is a GPS-type position receiver. Such a receiver is capable of measuring a speed of the vehicle, independently of the speed of rotation of the wheels of the vehicle or of the speed of rotation of the stator of the electric motor. The second sensor can alternatively be a vehicle camera configured to act as a position receiver.

In this particular mode, the comparison made by the control device between the first measurement from the first sensor and the second measurement from the second sensor makes it possible to identify a risk of loss of grip between a driving wheel of the vehicle and the ground. Such a loss of grip can occur, for example, in the event of strong acceleration or intense braking on poorly adherent ground.

In a situation of normal adhesion, the speed of rotation of the driving wheel(s) of the vehicle is in fact proportional to the speed of the vehicle. The actual value of the ratio between the first measurement from the first sensor and the second measurement from the second sensor is then constantly equal to a predefined value.

However, in a precarious grip situation, the speed of rotation of the drive wheel(s) is not proportional to the speed of the vehicle.

For example, in the event of significant acceleration on loose ground, a skidding phenomenon may occur, the vehicle remaining stationary although the driving wheel(s) of the vehicle are rotating.

Similarly, in the event of excessive speed in a tight bend, one or more rear wheels of the vehicle continue their rotation while sliding towards the outside of the bend and without participating in the continuation of the forward movement of the vehicle.

Conversely, in the event of intense braking on poorly adherent ground, a phenomenon of locking of one or more wheels may occur, the vehicle continuing to move forward by sliding of the driving wheel(s) of the vehicle on the ground although their rotation is stopped.

• émettre une alerte visuelle, le dispositif étant un voyant d’alerte,
• et/ou émettre une alerte audio, telle qu’un bip d’alerte, le dispositif étant un haut-parleur.

In these precarious grip situations, the actual value of the ratio between the first measurement from the first sensor and the second measurement from the second sensor differs from the predefined value. The control device detects a deviation and then generates an alert signal. The warning signal is an electrical signal intended to control a vehicle device, separate from the engine, to:

• issue a visual alert, the device being a warning light,
• and/or emitting an audio alert, such as an alert beep, the device being a speaker.

In one embodiment, the device of the vehicle separate from the engine is an active safety device arranged to correct a trajectory of the vehicle according to the warning signal.

• en contrôlant la vitesse angulaire d’une ou plusieurs roues,
• et/ou en contrôlant la direction du véhicule ;
• et/ou en contrôlant la puissance du moteur.

Trajectory correction is performed by the active safety device in order to recover grip:

• by controlling the angular speed of one or more wheels,
• and/or by controlling the direction of the vehicle;
• and/or by controlling engine power.

Thus, it is possible to take advantage of the measurements of the relative angular position of the rotor with respect to the stator carried out by a sensor internal to the engine and usually dedicated to controlling the engine, with the additional aim of detecting a loss of grip in order to signal it or to correct a trajectory of the vehicle so as to recover grip.

In the case where the vehicle is a motorcycle with an electric motor braking suddenly, causing a loss of grip of the front wheel, it may be provided that the active safety device limits the deceleration of the front wheel in order to recover the grip and prevent the motorcyclist from falling.

In the case where the vehicle is a motor car with an electric motor having excessive speed in a tight bend causing an uncontrolled skid of the rear axle (oversteer), it may be provided that the active safety device actuates a braking of the outer front wheel so as to recover control of the trajectory and put an end to the oversteer.

If, on the contrary, the front axle drifts more than the rear axle (understeer), it may be provided that the active safety device actuates braking of the inner rear wheel so as to regain control of the trajectory and avoid a road exit.

In one embodiment, the vehicle comprises a plurality of drive wheels each comprising a second wheel angular position sensor and the active safety device is arranged to correct an angular speed of each wheel as a function of the warning signal.

For example, the vehicle may be an electric-powered automobile with both front wheels driven, the tire wear of the left front wheel being excessive, and the tire wear of the right front wheel being comparatively less.

In this example, the frictional force between the ground and the tire of the left front wheel is stronger than the frictional force between the ground and the tire of the right front wheel. Thus, the rotational speed of the left front wheel is lower than the rotational speed of the right front wheel. The vehicle engine control device generates, on the basis of the comparison between the measurements from the first sensor and the second sensor of the left front wheel, a warning signal indicating that the wear of the tire of the left front wheel is excessive. Based on the generated warning signal, an electronic trajectory corrector (as an "active safety device") controls the brake of the right front wheel so as to correct the difference in angular speed between the left front wheel and the right front wheel.

Generally speaking, correcting the angular speed of each drive wheel based on the warning signal can automatically control the vehicle's trajectory and ensure safety.

In one embodiment, the first angular position sensor is positioned on a wheel of the vehicle to measure an angular position of the wheel and to determine said estimate of the relative angular position of the rotor with respect to the stator of the electric motor, and from there to control the operation of the electric motor as a function of said angular position estimate, while the electric motor has no angular position sensor.

For example, the vehicle is an electric motor bicycle. In this example, the first angular position sensor is a simple odometer normally provided to measure the angular position of a wheel of the vehicle and to determine on the basis of this angular position measurement a distance traveled by the bicycle. Knowing the transmission reduction factor of the electric bicycle, this angular position measurement is converted into an estimate of the angular position of the rotor relative to the stator of the electric motor. The multiplier factor can be fixed. Alternatively, the electric bicycle may comprise a digital speed selector capable of selecting a speed characterized by a transmission reduction factor and transmitting this reduction factor to the electric motor control device. Based on this angular position estimate, the motor control device controls the operation of the motor.

Thus, the electric motor, even without an angular position sensor, can be controlled reliably thanks to the use of the first sensor external to the motor.

In general, it is possible to equip a vehicle with an electric motor devoid of an angular position sensor, therefore having a reduced production and maintenance cost compared to a motor comprising an angular position sensor while being more compact. .

In a particular embodiment of such an embodiment, the device of the vehicle is a current speed indicator of the vehicle and the control device is able to control, in addition to the engine, the current speed indicator, according to said position estimate .

Returning to the above example of the odometer as the "first angular position sensor" of an electric motor bicycle, the measurement of the angular position of the wheel of the vehicle can also be transmitted to a current speedometer . Indeed, the average speed of the vehicle during a predetermined period of time corresponds to the distance traveled by the bicycle during this period of time. Thus, the current speed indicator can determine the current speed of the bicycle on the basis of the first measurement provided by the first sensor and a time measurement provided for example by a clock internal to the current speed indicator.

In general, a single measurement provided by a single sensor (the first position sensor) is used to drive both the vehicle engine and the current vehicle speed indicator. Thus, the vehicle production cost is minimized by the presence of a single shared sensor between the engine and the current speedometer instead of two dedicated sensors.

• le véhicule comporte un deuxième moteur électrique, et
• le dispositif du véhicule, distinct du moteur, est un dispositif de contrôle du deuxième moteur électrique apte à piloter un fonctionnement du deuxième moteur électrique en fonction de ladite estimation de position.

In one embodiment:

• the vehicle has a second electric motor, and
• the vehicle device, separate from the motor, is a control device for the second electric motor capable of controlling an operation of the second electric motor as a function of said position estimate.

For example, the electric motor vehicle may include a first electric motor and a second electric motor engaged with a same transmission shaft. An angular position sensor provides an estimate of the relative position of a rotor with respect to a stator of the first electric motor.

In this example, the relative position estimate as provided by the angular position sensor can be used to drive the operation of the first electric motor and the operation of the second electric motor through respectively synchronized switching sequences.

• un premier moteur électrique placé dans la roue avant et entraînant la rotation de la roue avant,
• et un deuxième moteur électrique placé dans la roue arrière et entraînant la rotation de la roue arrière.

For example, the electric motor vehicle may be a two-wheeler having:

• a first electric motor placed in the front wheel and driving the rotation of the front wheel,
• and a second electric motor placed in the rear wheel and driving the rotation of the rear wheel.

In this example, the first electric motor is controlled on the basis of an estimate of the relative position of a rotor with respect to a stator of the first electric motor. Such a relative position estimate is supplied by an angular position sensor, which conventionally is a Hall effect sensor present in the first electric motor. In addition, such a sensor makes it possible to determine a variation in the relative position of the rotor with respect to the stator, hence an associated variation in the angular position of the front wheel. It is generally desirable that the speed of rotation of the front wheel and the rear wheel be equal. Thus, it is possible to determine a desired rotational speed for the rear wheel based on the relative position estimation. Thus, it is possible, from the desired rotational speed of the rear wheel, to determine a desired rotational speed of the rotor relative to the stator of the second electric motor.

In this example, the relative position estimate provided by the angular position sensor is used to control not only the operation of the first electric motor, but also the operation of the second electric motor so as to obtain the desired rotational speed for the wheel back.

Another aspect of the invention is an electric motor vehicle comprising the aforementioned acquisition and control system.

• obtenir, par un premier capteur de position angulaire, une estimation de position relative d’un rotor du moteur électrique par rapport à un stator du moteur électrique,
• piloter, par un dispositif de contrôle du moteur électrique, un fonctionnement du moteur électrique en fonction de ladite estimation de position,
• et piloter, par le dispositif de contrôle du moteur électrique, un dispositif du véhicule, distinct du moteur, en fonction de ladite estimation de position.

Another aspect of the invention is an acquisition and control method for an electric motor vehicle, the method comprising:

• obtain, by a first angular position sensor, an estimate of the relative position of a rotor of the electric motor with respect to a stator of the electric motor,
• controlling, by a device for controlling the electric motor, an operation of the electric motor as a function of said position estimate,
• and driving, by the electric motor control device, a device of the vehicle, separate from the motor, as a function of said position estimate.

Another aspect of the invention is a processing circuit comprising a processor connected to a memory and to at least one communication interface with a device for controlling an electric motor and at least one device of the vehicle separate from the motor, the circuit processing being configured to carry out the steps of the aforementioned acquisition and control method.

• recevoir (REC) ladite estimation de position relative,
• délivrer un premier signal de commande (COM1) destiné à piloter le moteur électrique sur la base de ladite estimation de position relative,
• et délivrer au moins un deuxième signal de commande (COM2) destiné à piloter au moins un dispositif du véhicule distinct du moteur sur la base de ladite estimation de position relative, ce deuxième signal de commande pouvant entraîner par exemple un freinage des roues et/ou une activation d’un signal d’alerte et/ou un affichage d’une information d’assistance à la navigation, etc.

- une mémoire MEM pour stocker notamment ladite estimation de position angulaire, et les données d’un programme informatique décrit ci-après ;
- et un processeur PROC coopérant avec la mémoire MEM pour lire les données du programme et exécuter le procédé d’acquisition et de contrôle ci-avant.As illustrated on the , such a processing circuit CT may comprise, by way of example:
- a communication interface INT with a control device CTR of an electric motor and with at least one device DISP of the vehicle separate from the motor, at least one of said devices comprising at least one angular position sensor indicating an estimate of the relative position of the rotor of the electric motor with respect to the stator of the electric motor, for:

• receiving (REC) said relative position estimate,
• delivering a first control signal (COM1) intended to control the electric motor on the basis of said relative position estimate,
• and delivering at least one second control signal (COM2) intended to control at least one device of the vehicle distinct from the engine on the basis of said relative position estimate, this second control signal being able to cause, for example, braking of the wheels and/or activation of an alert signal and/or display of navigation assistance information, etc.

- A memory MEM for storing in particular said angular position estimate, and the data of a computer program described below;
- And a processor PROC cooperating with the memory MEM to read the program data and execute the above acquisition and control method.

Another aspect of the invention is a computer program comprising instructions for implementing the aforementioned acquisition and control method, when said instructions are executed by a processor.

A form of flowchart of a general algorithm of a computer program, in an exemplary embodiment, for the implementation of the proposed method is illustrated in .

• une réception MES θ(t) d’au moins une première mesure par un premier capteur de position angulaire,
• une estimation ESTIM ROT/STAT d’une position angulaire relative du rotor par rapport au stator du moteur électrique sur la base au moins de la première mesure,
• un pilotage PIL1 du moteur électrique par un dispositif de contrôle du moteur électrique sur la base d’une association de l’estimation avec une table de correspondance TAB, le pilotage PIL1 comprenant une commutation COMMUT MOT du moteur électrique
• et un pilotage PIL2 d’un dispositif du véhicule, distinct du moteur, sur la base d’une association de l’estimation avec une table de correspondance TAB, le pilotage PIL2 comprenant par exemple une détermination d’une distance DIST et/ou d’une vitesse VIT et un affichage AFF de cette distance et/ou vitesse.

The computer program implements:

• a reception MES θ(t) of at least a first measurement by a first angular position sensor,
• an ESTIM ROT/STAT estimation of a relative angular position of the rotor with respect to the stator of the electric motor on the basis of at least the first measurement,
• a piloting PIL1 of the electric motor by a device for controlling the electric motor on the basis of an association of the estimate with a correspondence table TAB, the piloting PIL1 comprising a COMMUT MOT switching of the electric motor
• and a piloting PIL2 of a device of the vehicle, distinct from the engine, on the basis of an association of the estimate with a correspondence table TAB, the piloting PIL2 comprising for example a determination of a distance DIST and/or of a speed VIT and a display AFF of this distance and/or speed.

The first angular position sensor may designate for example an angular position sensor mounted in the electric motor. The first measurement is then a measurement allowing directly to estimate the relative angular position of the rotor with respect to the stator of the electric motor.

Alternatively, the first angular position sensor may designate a sensor mounted in a device separate from the motor and measuring an angular position of a part driven in rotation by the torque of the electric motor, that is to say by the effect of the rotation of the rotor of the electric motor. The first measurement is then a measurement allowing indirectly to estimate the relative angular position of the rotor with respect to the stator of the electric motor.

Other characteristics, details and advantages will appear on reading the detailed description below, and on analyzing the appended drawings, in which:

Fig. 1

illustrates a motor car with an electric motor comprising a control and acquisition system according to an embodiment of the invention.

Fig. 2

illustrates a device for controlling an electric motor of the motor car shown in [Fig. 1].

Fig. 3

illustrates an electronic trajectory correction device of the motor car shown in [Fig. 1].

Fig. 4

illustrates an electric motor bicycle comprising a control and acquisition system according to an embodiment of the invention.

Fig. 5

illustrates a processing circuit in an exemplary embodiment, for the implementation of the proposed method.

Fig. 6

illustrates a form of flowchart of a general algorithm of a computer program, in an exemplary embodiment, for the implementation of the proposed method.

There represents a motor car mounted on wheels whose propulsion is ensured by an electric motor MOT. The mechanical power provided by the electric motor MOT is transmitted to the front wheels RAV, driving, of the motor vehicle.

The motor car also has an on-board computer or electronic control unit ECU (Electronic Control Unit) intended to manage various functions of the vehicle. The ECU on-board computer is linked to a TBL dashboard to display basic information (distance travelled, average speed, etc.) and to activate, if necessary, visual alert, warning and signaling indicators and/ or an audible warning.

• un odomètre,
• un indicateur de vitesse courante,
• un dispositif d’assistance à la navigation,
• et un dispositif de sécurité active.

The on-board computer, as an "acquisition and control system", includes in particular:
- a device for controlling the electric motor,
- four separate devices of the electric motor, which are:

• an odometer,
• a current speed indicator,
• a navigation assistance device,
• and an active safety device.

These five devices are configured to mutually transmit data by multiplexing via at least one cable of the CAN data bus type. Typically, in the case where the device separate from the electric motor is a critical device of the vehicle, such as an ABS or ESP type device, an independent data bus is provided so as to optimize safety and minimize latency in data transmission.

In the rest of this document, the operation of each of these five devices is described by first considering each device in isolation, then by considering the interaction between the different devices.

There details the operation of the electric motor and the electric motor control device.

In this instance, the electric motor MOT is a rotating electric machine of the brushless (or “brushless”) motor type with an internal rotor (or “inrunner”). The electric motor comprises a mobile part in rotation around an axis or rotor ROT, arranged inside a fixed part or stator STAT. The ROT rotor made up of two permanent magnets has the shape of a disc having two pairs of poles represented by the letters N and S on the ).

The stator STAT comprises three coils BOB1, BOB2, BOB3 fed sequentially. This creates a rotating magnetic field at the same frequency as the supply voltages. The permanent magnets of the ROT rotor tend at all times to orient themselves in the direction of the magnetic field. For the brushless MOT motor to rotate, the supply voltages must be continuously matched to keep the field ahead of the ROT rotor position in order to create motor torque.

Three Hall effect sensors CEH1, CEH2, CEH3 (or electromagnetic sensors) are arranged on the stator STAT and are used to know at any time the angular position of the rotor ROT relative to the stator STAT and adapt the supply of the coils BOB1 accordingly, BOB2, BOB3 and the magnetic field. Each CEH sensor detects the passage of a magnetic pole of a permanent magnet of the rotor.

• le capteur CEH1 seul,
• le capteur CEH2 seul,
• le capteur CEH3 seul,
• les capteurs CEH1 et CEH2,
• les capteurs CEH1 et CEH3,
• et les capteurs CEH2 et CEH3.

The three Hall effect sensors CEH1, CEH2, CEH3 are angularly distributed so as to send back six possible combinations of signals for all the possible angular positions of the rotor, corresponding respectively to the detection of the passage of an N pole of the rotor in front of:

• the CEH1 sensor alone,
• the CEH2 sensor alone,
• the CEH3 sensor alone,
• the CEH1 and CEH2 sensors,
• the CEH1 and CEH3 sensors,
• and the CEH2 and CEH3 sensors.

By way of example, in the angular position of the rotor ROT represented in , the passage of an N pole of the rotor is detected by the sensors CEH1 and CEH2. If from this position, the rotor performs a movement of 45° in the clockwise direction, the passage of an N pole of the rotor is detected only by the CEH1 sensor.

Based on this information, a device for controlling the electric motor comprising a first processing circuit CT1 ensures the switching of the electronic current in a sequential manner in the three coils. For this, the first processing circuit CT1 has six outputs Q1H_bit, Q1L_bit, Q2H_bit, Q2L_bit, Q3H_bit, Q3L_bit connected to an electronic circuit represented on the comprising six transistors TRQ1H, TRQ1L, TRQ2H, TRQ2L, TRQ3H, TRQ3L acting as electronic switches. Each output controls the opening and closing of a respective electronic switch.

The power supply to each coil BOB1 (or "phase") of the stator is controlled by a pair of electronic switches, comprising a first and a second electronic switch TRQ1H, TRQ1L.

When the first electronic switch TRQ1H is open and the second electronic switch TRQ1L is closed, a coil BOB1 is connected to ground.

When the first electronic switch TRQ1H is closed and the second electronic switch TRQ1L is open, the coil BOB1 is connected to the phase, thus a positive voltage is applied to the coil BOB1.

When the first and the second electronic switches TRQ1H, TRQ1L are both open, the coil BOB1 is neither connected to phase nor to ground.

• BOB1 reliée à la masse, BOB2 reliée à la phase et BOB3 non reliée,
• BOB2 reliée à la masse, BOB1 reliée à la phase et BOB3 non reliée,
• BOB1 reliée à la masse, BOB3 reliée à la phase et BOB2 non reliée,
• BOB2 reliée à la masse, BOB3 reliée à la phase et BOB1 non reliée,
• BOB3 reliée à la masse, BOB1 reliée à la phase et BOB2 non reliée,
• et BOB3 reliée à la masse, BOB2 reliée à la phase et BOB1 non reliée.

Thus, it is possible to control the magnetic field generated by the three coils BOB1, BOB2, BOB3 of the stator STAT by varying each coil between three states: connected to ground, connected to the phase, or connected neither to the phase nor to the mass. Six combinations of states are possible:

• BOB1 connected to ground, BOB2 connected to phase and BOB3 not connected,
• BOB2 connected to ground, BOB1 connected to phase and BOB3 not connected,
• BOB1 connected to ground, BOB3 connected to phase and BOB2 not connected,
• BOB2 connected to ground, BOB3 connected to phase and BOB1 not connected,
• BOB3 connected to ground, BOB1 connected to phase and BOB2 not connected,
• and BOB3 connected to ground, BOB2 connected to phase and BOB1 not connected.

The motor is controlled using a switching table, according to which each combination of signals from the Hall effect sensors CEH1, CEH2, CEH3 corresponds to a combination of states of the coils.

The MOT brushless motor is a synchronous motor, ie the rotor turns at the same angular speed, called “synchronism speed” as the voltage system which supplies the stator STAT. As long as the motor torque is greater than the load to be driven, the rotation of the ROT rotor is synchronized with the magnetic field. If the resistive torque becomes greater than the motor torque, and the supply voltage is not adjusted accordingly, there is a risk of stalling, i.e. the rotor ROT may no longer follow the magnetic field. From this moment, the ROT rotor oscillates, without being able to resynchronize with the magnetic field, which can cause its destruction. To avoid this, it is intended that the Hall effect sensors CEH detect a slowing down of the rotor ROT in the event of an increase in the resistive torque, and that the control device of the electric motor MOT adjusts the frequency of the commutation accordingly.

The synchronous speed of the running MOT brushless motor as determined based on measurements from the CEH Hall effect sensors is displayed on the vehicle's TBL instrument panel. The synchronous speed typically reaches several thousand revolutions per minute.

When starting the MOT brushless motor, the ROT rotor is initially stationary and cannot instantly reach such a synchronism speed. The electric motor control device MOT therefore ensures a progressive start thanks to a progressive increase in the switching frequency, at first very low, then gradually increased by controlling at all times the relative angular position of the rotor ROT with respect to the stator STAT .

Alternatively, the stator STAT can be initially unpowered, an auxiliary motor being provided and driven by the motor control device to drive the rotor up to a predefined angular speed. During this transient phase, the angular speed of the rotor is acquired by the Hall effect sensors. When this speed is equal to the predefined angular speed, the motor control device energizes the stator coils sequentially with a switching speed equal to the predefined angular speed reached by the rotor.

The angular displacement of the rotor ROT of the electric motor MOT causes, through a transmission, an angular displacement of the driving wheels RAV of the vehicle. At each instant, the average value of the instantaneous angular speeds of each of the four wheels of the motor car is proportional to the instantaneous angular speed of the rotor ROT. The proportionality factor or transmission factor is a constant whose value is of the order of ten. That is to say that the ROT rotor of the MOT electric motor completes about ten complete turns for the RAV drive wheels to complete a complete turn. The transmission factor is a known quantity, which can be fixed or selected from several possible transmission factors using a digital vehicle speed selector. Such a digital speed selector is capable of selecting a speed characterized by a transmission factor and transmitting, for example through a CAN data bus, the transmission factor to the electric motor control device.

If the motor car moves in a straight line, the instantaneous angular velocity of each of the four wheels has an identical value equal to the average value.

If the motor car is moving along a curve, the wheels of the car rotate at different speeds: the wheels on the outside of the curve rotate faster than those on the inside. This difference in speed is caused by a differential of the motor car. This differential is a known mechanical device whose function is to distribute the rotation caused by the angular displacement of the rotor of the electric motor.

The navigation assistance device includes a GPS receiver capable of locating the location of the vehicle. The navigation assistance device further comprises a second processing circuit CT2 configured to use location information provided by the GPS receiver to display a route on the dashboard or signal a point of interest to the driver. The second processing circuit CT2 of the navigation assistance device can moreover control a speedometer integrated into the dashboard of the motor car. Vehicle speed is calculated based on the vehicle's GPS position. The current speed limit can also be displayed if it is available for example in a memory of the second processing circuit CT2. An audible and/or visual alert can be triggered in the event of overrun.

The advantage of the GPS speedometer is its accuracy at constant speed. Very useful on the highway, such a speedometer loses its reliability in built-up areas due to the frequent change of speed and the much longer reaction time of the GPS than the original vehicle indicators. Furthermore, the GPS speed indicators are inoperative in the tunnels, due to the loss of the GPS signal.

The active safety device is configured to measure the angular position of each wheel of the vehicle, from optical or electromagnetic angular position sensors.

The physical principle of operation of electromagnetic angular position sensors is described previously for the case of electromagnetic sensors fixed to the stator of the electric motor and estimating the relative angular position of the rotor of the electric motor with respect to the stator.

• à une partie fixe du véhicule (par exemple le châssis), un aimant étant fixé à la roue mobile en rotation par rapport au châssis, de manière à mesurer le passage de l’aimant face au capteur, ou
• à la roue, un aimant étant fixé au châssis, de manière à mesurer le passage du capteur face à l’aimant.

To measure the angular position of each wheel of the vehicle, an electromagnetic angular position sensor can be attached either:

• to a fixed part of the vehicle (for example the chassis), a magnet being fixed to the mobile wheel in rotation relative to the chassis, so as to measure the passage of the magnet in front of the sensor, or
• to the wheel, a magnet being fixed to the frame, so as to measure the passage of the sensor facing the magnet.

Generally, for cost reasons, the sensor, being more expensive than the magnet, is fixed to the chassis. Indeed, the wheels of the motor car are likely to be replaced, which is not the case of the chassis.

• un disque cranté DCR comprenant une pluralité N de crans équirépartis angulairement et agencé dans la roue de manière solidaire à la roue,
• un capteur optique COP de position angulaire positionné face au disque cranté DCR et configuré pour détecter le passage d’un cran du disque cranté DCR,

In the example shown in , the angular position sensors of each wheel are optical. The active safety device includes for each wheel:

• a notched disc DCR comprising a plurality N of notches equally distributed angularly and arranged in the wheel in a manner integral with the wheel,
• an optical angular position sensor COP positioned facing the notched disc DCR and configured to detect the passage of a notch of the notched disc DCR,

The active safety device further comprises a second processing circuit CT2 connected by at least one data bus BUS to the optical sensor COP and able to receive each measurement from each optical angular position sensor and to control the brakes of each wheel.

Thus, when the optical angular position sensor COP of a wheel detects during a given period of time the passage of M notches of the notched disc DCR, the number of revolutions performed by the wheel during this period of time is equal to M/N.

The second processing circuit CT2 of the active safety device is configured to continuously receive the measurements from each optical angular position sensor and to compare these measurements with each other so as to:
- detect a loss of cornering grip and counteract it by braking one or more wheels, thus making it possible to improve road holding, the second processing circuit CT2 then has an electronic trajectory correction function,
- and/or detect intense braking on loose ground and in response limit the locking of the wheels, the second processing circuit CT2 then has an anti-locking function of the wheels,
and/or detect significant acceleration on loose ground and in response regulate the acceleration of the vehicle, the second processing circuit CT2 then has a traction control function.

The second processing circuit CT2 can also be configured so as to activate a visual signal, such as the activation of an alert or warning light on the dashboard, or an audible signal simultaneously with the action electronic trajectory correction, anti-lock braking or traction control.

• au moins un capteur électromagnétique ou optique de position angulaire pour mesurer une position angulaire d’au moins une roue,
• une unité de commande destiné à convertir la mesure issue du capteur en une distance parcourue par le véhicule,
• et un afficheur, typiquement sur le tableau de bord, pour afficher la distance parcourue par le véhicule.

The odometer includes:

• at least one electromagnetic or optical angular position sensor for measuring an angular position of at least one wheel,
• a control unit for converting the measurement from the sensor into a distance traveled by the vehicle,
• and a display, typically on the dashboard, to display the distance traveled by the vehicle.

• au moins un capteur électromagnétique ou optique de position angulaire pour mesurer de manière continue une position angulaire d’au moins une roue,
• une unité de commande destiné à convertir les mesures issues du capteur en une indication de vitesse courante du véhicule,
• et un afficheur, typiquement sur le tableau de bord, pour afficher l’indication de vitesse courante du véhicule.

The running speedometer includes:

• at least one electromagnetic or optical angular position sensor for continuously measuring an angular position of at least one wheel,
• a control unit intended to convert the measurements from the sensor into an indication of the current speed of the vehicle,
• and a display, typically on the dashboard, for displaying the current vehicle speed indication.

The electromagnetic or optical angular position sensors are shared with the active safety device.

As specified previously, in the example embodiment illustrated by , [Fig. 2] and [Fig. 3], a CAN data bus ensures mutual transmission of data between the electric motor control device, the odometer, the current speedometer, the navigation aid device, and the active safety device of the automobile car. Thanks to this data transmission, each of these devices has access to the measurements coming respectively from the Hall effect sensors of the electric motor, from the GPS receiver of the navigation aid device and from the optical sensors of the active safety device.

Vis-à-vis the navigation aid device, the location data received by the GPS receiver are supplemented by the measurements from at least one Hall effect sensor CEH of the electric motor MOT and supplied by the control device of the electric motor.

Indeed, the car may be in a space such as a tunnel for a long time where the reception of the GPS signal is interrupted. In such a situation, the second processing circuit CT2 of the navigation aid device has the last positions received and can estimate the position and the direction of travel of the motor car at the time of the interruption of the reception of the GPS signal. .

The measurements from the Hall effect sensors CEH of the electric motor MOT indicate the relative position of the rotor ROT with respect to the stator STAT of the electric motor MOT and thus make it possible to determine the number of revolutions performed by the rotor ROT of the electric motor MOT from interruption of GPS signal reception.

As described above, the number of revolutions performed by the rotor ROT of the electric motor MOT is proportional to the average number of revolutions performed by each of the four wheels of the motor vehicle. Thus, the measurements carried out by at least one CEH Hall effect sensor mounted in the electric motor MOT make it possible to determine, on the basis of the transmission factor, the distance traveled by the vehicle from the interruption of the reception of the GPS signal .

The location data received by the GPS receiver can also be supplemented by measurements from the COP optical or electromagnetic sensors mounted on each wheel.

Indeed, taking the previously cited example of the interruption of the reception of the GPS signal, the measurements from the COP optical sensors make it possible to determine the distance traveled by each wheel from the interruption of the reception of the GPS signal. The distance traveled by each wheel can be used to determine not only the distance traveled by the vehicle but also the angle of a possible change of direction.

• de la position et de la direction de circulation de la voiture automobile au moment de l’interruption de la réception du signal GPS, telle que déterminée à partir de mesures issues du récepteur GPS,
• de la distance parcourue par le véhicule à partir de l’interruption de la réception du signal GPS, telle que déterminée à partir de mesures issues d’au moins un capteur à effet Hall CEH monté dans le moteur MOT et/ou issues d’au moins un capteur optique COP ou électromagnétique monté dans au moins une roue,
• et, optionnellement, de l’angle d’un changement de direction éventuel à partir de l’interruption de la réception du signal GPS, tel que déterminé à partir de mesures issues des capteurs optiques COP ou électromagnétiques montés dans chaque roue.

The position of the vehicle can thus be estimated by the second processing circuit CT2 of the navigation aid device from:

• the position and the direction of travel of the motor car at the time of the interruption of reception of the GPS signal, as determined from measurements from the GPS receiver,
• the distance traveled by the vehicle from the interruption of reception of the GPS signal, as determined from measurements from at least one CEH Hall effect sensor mounted in the engine MOT and/or from at least one at least one COP or electromagnetic optical sensor mounted in at least one wheel,
• and, optionally, the angle of a possible change of direction from the interruption of the reception of the GPS signal, as determined from measurements from the COP optical or electromagnetic sensors mounted in each wheel.

Vis-à-vis the odometer, the current speedometer, and the active safety device, the measurements from the COP optical or electromagnetic sensors mounted in the wheels are supplemented by the measurements from at least one sensor Hall effect CEH of the electric motor CEH and provided by the electric motor control device.

In particular, a ratio can be determined between the angular position measurements coming respectively from the sensors mounted in the wheels and from at least one sensor mounted in the electric motor. This ratio takes on a constant value, equal to a reference value called the "transmission ratio" when the transmission of engine torque to the drive wheels is effective.

• un niveau insuffisant de fluide de transmission,
• et/ou une pièce mécanique endommagée, telle qu’un engrenage,
• et/ou un élément électronique endommagé, tel qu’un bus de données ou un capteur de position angulaire,
• et/ou une usure excessive d’un pneu.

Thus, the comparison of this ratio with a predetermined threshold value on the basis of the reference value can highlight a safety defect of the vehicle, which can be due to:

• an insufficient level of transmission fluid,
• and/or a damaged mechanical part, such as a gear,
• and/or a damaged electronic element, such as a data bus or an angular position sensor,
• and/or excessive tire wear.

Typically, the frictional force exerted by the ground on the tire creates a resistive torque which opposes the engine torque and reduces the rotational speed of the wheel. In the event of excessive tire wear, the value of the resistive torque is particularly high and the ratio between the rotational speed of the wheel and the rotational speed of the rotor of the electric motor is particularly low.

Based on the safety defect identified, the active safety device can generate a warning signal allowing the activation of a warning lamp on the dashboard of the vehicle and/or the activation of a warning signal. sound alert.

In addition, the alert signal can trigger automatic vehicle safety, for example by switching off the electric motor, so as to preserve the integrity of the vehicle and avoid additional damage.

The measurements from the optical or electromagnetic sensors mounted on each wheel can also be supplemented by the location data received by the GPS receiver.

Indeed, when the user is driving at a constant speed, for example on the highway, the determination of the location speed on the basis of the GPS signal is particularly reliable.

A single estimated value of the current speed, resulting from the fusion of the measurements obtained by the various sensors, can be displayed on the dashboard.

• d’une part, les mesures issues des capteurs montés sur les roues ou montés dans le moteur électrique qui estiment le déplacement du véhicule par roulement,
• et, d’autre part, le signal reçu par le récepteur GPS qui estime par géolocalisation le déplacement du véhicule indépendamment de l’adhérence entre les pneus du véhicule et le sol.

In addition, all driving situations resulting in a loss of grip between the wheels of the vehicle and the ground induce movement of the vehicle by sliding and not only by rolling. This shift induces a difference between:

• on the one hand, the measurements from the sensors mounted on the wheels or mounted in the electric motor which estimate the movement of the vehicle in rolling,
• and, on the other hand, the signal received by the GPS receiver which estimates by geolocation the movement of the vehicle independently of the adhesion between the tires of the vehicle and the ground.

There represents an electric motor bicycle. The bicycle notably comprises a front wheel RAV, a rear wheel RAR and an electric motor MOT, typically a brushless motor, mounted on the rear wheel RAR and able to transmit a motor torque to the rear wheel RAR, driving.

The electric motor comprises a fixed stator STAT and a rotor ROT in rotary motion with respect to the stator STAT.

The MOT electric motor also has no angular position sensor. More specifically, the MOT electric motor does not include a Hall effect sensor or an optical sensor and is also not suitable for measuring a counter-electromotive force. Thus, the electric motor MOT does not include a component capable of determining an estimate of the position of the rotor ROT with respect to the stator STAT.

Such an electric motor devoid of angular position sensor has a reduced cost and greater compactness than an electric motor comprising at least one angular position sensor. Moreover, such an electric motor is not subject to angular position sensor failure which is costly in terms of maintenance.

The bicycle further includes an ODO odometer.

The odometer includes a CPA angular position sensor mounted on the rear wheel, measuring the angular position of the rear wheel.

The odometer further comprises a third processing circuit CT3 in wired communication with the angular position sensor and with the electric motor.

The odometer further comprises a display AFF in wireless communication with the third processing circuit CT3 and placed on a handlebar of the bicycle.

• recevoir des mesures effectuées par le capteur de position angulaire,
• déterminer une position angulaire de la roue arrière RAR,
• déterminer une vitesse angulaire de la roue arrière RAR,
• estimer la position angulaire du rotor ROT du moteur électrique MOT par rapport au stator STAT,
• piloter le moteur électrique MOT sur la base de cette estimation, et
• piloter l’afficheur pour afficher une indication de vitesse courante sur la base de cette estimation.

The third processing circuit CT3 is capable of:

• receive measurements made by the angular position sensor,
• determine an angular position of the rear wheel RAR,
• determine an angular speed of the rear wheel RAR,
• estimate the angular position of the rotor ROT of the electric motor MOT with respect to the stator STAT,
• drive the electric motor MOT based on this estimate, and
• drive the display to display a current speed indication based on this estimate.

It should be noted that there is a finite time interval between the measurement of the angular position of the rear wheel RAR and the control of the electric motor MOT.

• un premier intervalle de transmission d’une mesure du capteur CPA vers le troisième circuit de traitement CT3,
• un deuxième intervalle de traitement de la mesure par le troisième circuit de traitement CT3 et de génération d’un signal de commande pour piloter le moteur électrique MOT,
• un troisième intervalle de transmission du signal de commande du troisième circuit de traitement CT3 vers le moteur électrique MOT, et
• un quatrième intervalle de mise en œuvre du signal de commande par le moteur électrique MOT.

This time interval is subdivided into:

• a first transmission interval of a measurement from the CPA sensor to the third processing circuit CT3,
• a second interval for processing the measurement by the third processing circuit CT3 and for generating a control signal to drive the electric motor MOT,
• a third transmission interval of the control signal from the third processing circuit CT3 to the electric motor MOT, and
• a fourth interval of implementation of the control signal by the electric motor MOT.

The first and third intervals are constant because the data transmission is carried out by wire.

The third processing circuit CT3 and the electric motor MOT are further configured respectively so that the second and the fourth interval are constant.

So the time interval is constant.

During this constant time interval, the angular position of the rotor ROT varies in a predictable and calculable way based on the angular velocity of the rear wheel RAR.

Thus, the third processing circuit CT3 takes this constant time interval into account by estimating the angular position of the rotor ROT not at the instant of the measurement performed by the sensor CAPT but at the end of the constant time interval and controlling the engine MOT based on this estimate.

Based on the estimation of the angular position of the rotor ROT, the third processing circuit CT3 can control the electric motor MOT. For example, the third processing circuit CT3 can drive the switching of the stator windings of an electric motor of the “brushless motor” type without a Hall effect sensor so as to maintain the movement of the rotor.

Thus, the angular position measurement performed by an angular position sensor CPA of an odometer ODO normally provided for determining and displaying a current speed indication is also used to drive an electric motor MOT without an angular position sensor.

Of course, the relative position estimate from an angular position sensor CPA external to the motor can also be used to enhance the safety of piloting any electric motor not without an angular position sensor.

In particular, such an estimate makes it possible to continue to drive the electric motor even if the angular position sensor internal to the motor, such as a CEH Hall effect sensor, suddenly fails and can no longer indicate an estimate of the relative position of the rotor ROT with respect to the stator STAT.

Claims (17)

Acquisition and control system for an electric motor vehicle, the system comprising:

• at least one first angular position sensor capable of indicating an estimate of the relative position of a rotor of the electric motor with respect to a stator of the electric motor,
• a device for controlling the electric motor capable of controlling an operation of the electric motor as a function of said position estimate,

In whichthe control device is capable of controlling, in addition to the motor, a device of the vehicle distinct from the motor as a function of said position estimate. Acquisition and control system according to claim 1, in which:

• the first sensor is mounted in the engine,
• the system comprises a second sensor capable of indicating a change in the position of the vehicle,
• and the control device is capable of comparing a first measurement from the first sensor with a second measurement from the second sensor to generate, in the event of a deviation, an alert signal.

Acquisition and control system according to claim 2, in which the second sensor is an angular position sensor mounted on at least one wheel of the vehicle. Acquisition and control system according to claim 2, in which the second sensor is an odometer. Acquisition and control system according to claim 2, in which the second sensor is a position receiver of the GPS type. Acquisition and control system according to any one of Claims 3 to 5, in which the device of the vehicle separate from the engine is an active safety device arranged to correct a trajectory of the vehicle as a function of the warning signal. Acquisition and control system according to claim 6, in which the vehicle comprises a plurality of drive wheels each comprising a second wheel angular position sensor and in which the active safety device is arranged to correct an angular speed of each wheel depending on the warning signal. Acquisition and control system according to claim 1, in which the first angular position sensor is positioned on a wheel of the vehicle to measure an angular position of the wheel and to determine said estimate of the relative angular position of the rotor with respect to the stator of the electric motor, and from there, controlling the operation of the electric motor according to said angular position estimate, while the electric motor has no angular position sensor. Acquisition and control system according to claim 8, in which:

• the vehicle device is a current vehicle speed indicator,
• and the control device is capable of driving, in addition to the motor, the current speed indicator, as a function of said position estimate.

Acquisition and control system according to any one of Claims 1 to 9, in which the first sensor is a Hall effect sensor. Acquisition and control system according to any one of claims 1 to 10, in which the electric motor is a brushless motor. Acquisition and control system according to any one of Claims 1 to 11, comprising at least one data bus capable of transmitting the position estimate to the control device of the electric motor and capable of transmitting a control signal emitted by the electric motor control device based on the position estimation to the vehicle device, the vehicle device being controllable based on the transmitted control signal. Acquisition and control system according to any one of Claims 1 to 12, the vehicle comprising a second electric motor, in which:

• the vehicle device, separate from the motor, is a control device for the second electric motor capable of controlling an operation of the second electric motor as a function of said position estimate.

Electric motor vehicle comprising an acquisition and control system according to any one of Claims 1 to 13. Acquisition and control method for an electric motor vehicle, the method comprising:

• obtain, by a first angular position sensor, an estimate of the relative position of a rotor of the electric motor with respect to a stator of the electric motor,
• controlling, by a device for controlling the electric motor, an operation of the electric motor as a function of said position estimate,

and driving, by the electric motor control device, a device of the vehicle, separate from the motor, as a function of said position estimate. Computer program comprising instructions for implementing the acquisition and control method according to claim 15, when said instructions are executed by a processor. Processing circuit comprising a processor connected to a memory and to at least one communication interface with a device for controlling an electric motor and at least one device of the vehicle separate from the engine, the processing circuit being configured to carry out the steps of method of acquisition and control according to claim 15.