WO2021023746A1

WO2021023746A1 - Acquiring and control system for a vehicle comprising an electric motor

Info

Publication number: WO2021023746A1
Application number: PCT/EP2020/071917
Authority: WO
Inventors: Thierry Lucidarme
Original assignee: Electricite De France
Priority date: 2019-08-06
Filing date: 2020-08-04
Publication date: 2021-02-11
Also published as: FR3099735A1

Abstract

Acquiring and control system for a vehicle comprising an electric motor, the system comprising: - at least one first sensor of angular position able to indicate 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 able to drive operation of the electric motor according to said position estimate, wherein the control device is able to drive, apart from the motor, a device of the vehicle distinct from the motor according to said position estimate.

Description

Title: Acquisition and control system for electric motor vehicle

Technical area

The present disclosure falls within the technical field of the control of electric motor vehicles.

[0002] More specifically, the present disclosure relates to acquisition and control systems for an electric motor vehicle, to electric motor vehicles comprising such systems, to acquisition and control methods implemented by such systems, on computer programs for implementing such methods, and on data storage media for implementing such methods.

Prior art

[0003] 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 use such a measurement in a control-command algorithm.

[0004] In the automotive field, this is particularly the case with the implementation of driving assistance by a dedicated device.

[0005] Driver assistance devices are becoming more and more widespread, giving an increasingly important degree of autonomy to equipped vehicles.

summary

[0006] The present disclosure aims to expand the possibilities of using such devices in an electric motor vehicle.

[0007] An acquisition and control system is proposed for an electric motor vehicle, the system comprising: - at least a 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 estimation,

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 estimate.

[0008] For example, “operation of the electric motor” can be understood as an operation of the electric motor relating to a propulsion of the vehicle.

[0009] The system is applicable to any type of electric motor vehicle, 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 control device of the electric motor and able to transmit a control signal emitted by the control device of the electric motor on the basis of the position estimate to the vehicle device, the vehicle device being controllable on the basis of the transmitted control signal.

[0011] Thus, the position estimate provided by the first angular position sensor is used in a multifunctional manner. Indeed, this position estimate is used to control both:

- the vehicle propulsion function provided by the vehicle's electric motor,

- And a function distinct from the propulsion of the vehicle, provided by a device of the vehicle distinct from the engine.

[0012] The control of the operation of the electric motor as a function of said position estimation is implemented in a manner specific to the type of electric motor of the vehicle. [0013] All electric motors comprise a movable element in rotation, or rotor, and a fixed element, or stator in 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 comprises 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 connected together.

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

To implement the switching sequence, the brushless motor control device receives at each moment, by 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.

[0016] In general, estimating the angular position of the rotor relative to the stator allows the motor controller 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.

[0017] In one embodiment:

- the first sensor is mounted in the engine, - the system includes a second sensor capable of indicating a change in the position of the vehicle,

- and the control device is able to compare 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 rotor of the motor relative to that of the stator of the motor.

[0019] Taking the previous example of a brushless motor, the first sensor can be:

- a Hall effect sensor attached to the stator which measures a variation in the magnetic field when the rotor poles pass, 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 estimation 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 back-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 counter-electromotive forces thus measured being indicative of an estimate 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.

[0021] In this embodiment, the second sensor indicates a change in the position of the vehicle.

Compared to a combustion engine, the torque of an electric motor is high regardless of the speed of rotation of the motor rotor. For 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.

[0023] In a particular embodiment 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 suitable for 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 drive shaft driving in rotation of one or more driving wheels.

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

[0026] In the case of a gearbox comprising a plurality of transmission ratios, the actual value is variable from 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 corresponds to the predefined value, no warning signal is generated.

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

- an anomaly in the power transmission from the engine to the drive wheel, - or excessive wear of a tire on one wheel,

- or a failure of the first or second sensor.

[0030] 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 fault usually occurs suddenly, 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 sharply.

[0031] For example, if a wheel tire wears out, the ground exerts an increased frictional force on the tire, which slows down the rotation of the wheel. Thus, the average speed of rotation of the wheel decreases, so the ratio between the average speed of rotation of the rotor and the average speed of rotation of the wheel increases. As the tire wear on the wheel is progressive over time, this ratio also increases gradually over time. Provision can be made for the monitoring device to identify such a safety defect only when this ratio exceeds a predefined threshold corresponding to excessive wear of the tire.

[0032] The control device then generates an alert signal. The warning signal is an electrical signal intended to control a device in the vehicle, separate from the engine, for:

- issue a visual alert, the device being a warning light,

- and / or emit an audio alert, such as an alert beep, the device being a speaker.

[0033] For example, in the event of a detected security fault corresponding to an anomaly in the transmission of an electric motor car, provision may be made to light or flash a warning light on the dashboard of the car vehicle to report the transmission fault 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 vehicle safety fault and to signal this fault via the alert signal. [0035] In another particular embodiment 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.

[0037] 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 during each passage of the finger in front of 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 driving wheel of the vehicle as described above, the angular position measurement provided by the odometer is treated similarly as "second measurement from a second sensor ”by the engine control device and makes it possible to identify the same vehicle safety faults as described above.

[0040] In another particular embodiment of such an embodiment, the second sensor is a GPS type position receiver. Such a receiver is capable of measuring a vehicle speed, 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 perform the role of 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 identifies a risk of loss of grip between a driving wheel of the vehicle and ground. Such a loss of grip can occur, for example, in the event of significant acceleration or intense braking on poorly adherent ground. In a situation of normal grip, the speed of rotation of the driving wheel (s) of the vehicle is in fact proportional to the speed of the vehicle. The real value of the ratio between the first measurement coming from the first sensor and the second measurement coming from the second sensor is then constantly equal to a predefined value.

[0043] However, in a situation of precarious grip, the rotational speed of the drive wheel (s) is not proportional to the speed of the vehicle.

[0044] For example, in the event of significant acceleration on poorly adherent ground, a slip phenomenon may occur, the vehicle remaining stationary although the driving wheel or wheels of the vehicle are rotating.

[0045] Likewise, in the event of excessive speed in a tight bend, one or more rear wheels of the vehicle continue to rotate while sliding out of the bend and without participating in the continued movement of the vehicle forwards.

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

In these situations of precarious adhesion, the real 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 device in the vehicle, separate from the engine, for:

- issue a visual alert, the device being a warning light,

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 as a function of the warning signal. The trajectory correction is performed by the active safety device in order to recover the grip:

- by controlling the angular speed of one or more wheels,

- and / or by controlling the direction of the vehicle;

- and / or by controlling the 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 motor and usually dedicated to controlling the motor, with the additional aim of detecting a loss of adhesion for to signal it or to correct a trajectory of the vehicle so as to recover grip.

In the case where the vehicle is an electric motor motorcycle braking suddenly, causing a loss of grip of the front wheel, it can be expected that the active safety device limits the deceleration of the front wheel in order to recover the grip and avoid a fall of the motorcyclist.

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

In the case where, on the contrary, the front axle drifts more than the rear axle (understeer), it can be provided that the active safety device actuates a braking of the inner rear wheel so as to recover control of the trajectory and avoid leaving the road.

[0054] In one embodiment, the vehicle comprises a plurality of driving wheels each comprising a second angular position sensor of the wheel and the active safety device is arranged to correct an angular speed of each wheel as a function of the alert signal.

[0055] For example, the vehicle can be a motor car with an electric motor, the two front wheels of which are driving, the wear of the tire of the front wheel. left being excessive and wear on the right front wheel tire being comparatively less.

In this example, the frictional force between the ground and the tire of the left front wheel is greater 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 monitoring device generates, based on 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 front left wheel is excessive. On the basis of 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 angular speed difference between the left front wheel and the left front wheel. front right wheel.

[0057] In general, correcting the angular speed of each drive wheel on the basis of the warning signal automatically controls the trajectory of the vehicle and ensures 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, controlling the operation of the electric motor as a function of said estimation of angular position, 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 for measuring the angular position of a wheel of the vehicle and for determining, on the basis of this measurement of angular position, 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 can include 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. On the basis of this estimation of angular position, the engine control device controls the operation of the engine.

[0060] Thus, the electric motor, even without an angular position sensor, can be driven reliably through the use of the first sensor external to the motor.

In general, it is possible to equip a vehicle with an electric motor without an angular position sensor, therefore having a reduced production and maintenance cost compared to an engine comprising an angular position sensor while being more compact.

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

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

[0064] In general, a single measurement provided by a single sensor (the first position sensor) is used to control both the vehicle engine and the current vehicle speed indicator. Thus, the production cost of the vehicle is minimized by the presence of a single sensor shared between the engine and the current speedometer instead of two dedicated sensors.

[0065] In one embodiment:

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

[0066] For example, the electric motor vehicle can comprise a first electric motor and a second electric motor engaged with the same transmission shaft. An angular position sensor provides an estimate of the relative position of a rotor relative 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 control the operation of the first electric motor and the operation of the second electric motor through respectively synchronized switching sequences.

For example, the electric motor vehicle can 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.

[0069] In this example, the first electric motor is driven based on 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 provided 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 rotational speed of the front wheel and the rear wheel are equal. Thus, it is possible to determine a desired rotational speed for the rear wheel based on the relative position estimate. Thus, it is possible, from the desired speed of rotation of the rear wheel, to determine a desired speed of rotation 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 speed of rotation for the rear wheel.

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

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 control device of the electric motor, an operation of the electric motor as a function of said position estimate,

- And control, by the control device of the electric motor, a device of the vehicle, distinct 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 control device of 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 the aforementioned acquisition and control method.

As illustrated in [Fig. 5], such a processing circuit CT may include, by way of example:

an INT communication interface with a CTR control device of an electric motor and with at least one DISP device of the vehicle separate from the engine, 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 in relation to the stator of the electric motor, for:

- receive (REC) said estimate of relative position,

- delivering a first control signal (COM1) intended to drive the electric motor on the basis of said estimate of relative position,

- And deliver 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 estimate of relative position, this second control signal being able for example to cause braking of the wheels and / or an activation of a warning signal and / or a display of navigation assistance information, etc.

- a memory MEM for storing in particular said estimate of angular position, and data from a computer program described below;

- and a PROC processor cooperating with the memory MEM to read the program data and execute the above acquisition and control process.

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.

One form of flowchart of a general algorithm of a computer program, in an exemplary embodiment, for implementing the proposed method is illustrated in [Fig. 6].

The computer program implements:

- MES 0 (t) reception of at least a first measurement by a first angular position sensor,

- an ESTIM ROT / STAT estimate 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,

- PIL1 control of the electric motor by an electric motor control device on the basis of an association of the estimate with a TAB correspondence table, the PIL1 control comprising a SWITCH 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 SPEED and an AFF display of this distance and / or speed. The first angular position sensor can designate for example an angular position sensor mounted in the electric motor. The first measurement is then a measurement making it possible 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 making it possible to indirectly estimate the relative angular position of the rotor with respect to the stator of the electric motor.

Brief description of the drawings

[0080] Other features, details and advantages will become apparent on reading the detailed description below, and on analyzing the accompanying drawings, in which:

Fig. 1

[0081] [Fig. 1] illustrates an electric motor car comprising a control and acquisition system according to an exemplary embodiment of the invention.

Fig. 2

[0082] [Fig. 2] illustrates a device for controlling an electric motor of the motor car shown in [Fig. 1]

Fig. 3

[0083] [Fig. 3] illustrates an electronic trajectory correction device for the motor vehicle shown in [Fig. 1]

Fig. 4

[0084] [Fig. 4] illustrates an electric motor bicycle comprising a control and acquisition system according to an exemplary embodiment of the invention.

Fig. 5

[0085] [Fig. 5] illustrates a processing circuit in an exemplary embodiment, for implementing the proposed method. Fig. 6

[0086] [Fig. 6] illustrates one form of a flowchart of a general algorithm of a computer program, in an exemplary embodiment, for implementing the proposed method. Description of embodiments

[0087] [Fig. 1] represents a motor car mounted on wheels, the propulsion of which is provided by an electric motor MOT. The mechanical power supplied by the MOT electric motor is transmitted to the driving, RAV front wheels of the motor car. The motor vehicle also has an on-board computer or electronic control unit ECU (Electronic Control Unit) intended to manage various functions of the vehicle. The on-board computer ECU is linked to a TBL instrument panel to display basic information (distance traveled, average speed, etc.) and to activate, if necessary, visual warning, warning and signal lights and / or an audible warning.

The on-board computer, as an "acquisition and control system", includes in particular:

- an electric motor control device,

- 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 the vehicle. data transmission. In the remainder 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.

[0092] [Fig. 2] details the operation of the electric motor and of the electric motor control device.

[0093] In this case, the MOT electric motor is a rotating electric machine of the brushless (or "brushless") motor type with an internal rotor (or "inrunner"). The electric motor comprises a movable part in rotation about an axis or ROT rotor, arranged inside a fixed part or STAT stator. The ROT rotor consisting of two permanent magnets has the shape of a disc having two pairs of poles represented by the letters N and S in [Fig. 2]).

The stator STAT comprises three coils BOB1, BOB2, BOB3 supplied sequentially. This creates a magnetic field rotating at the same frequency as the supply voltages. The permanent magnets of the ROT rotor constantly tend to orient themselves in the direction of the magnetic field. For the brushless MOT motor to run, the supply voltages must be continuously adapted so that the field stays ahead of the position of the ROT rotor in order to create a motor torque.

Three Hall effect sensors CEFI1, CEFI2, CEFI3 (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 to adapt accordingly the power supply of the coils BOB1, BOB2, BOB3 and the magnetic field. Each CEFI sensor detects the passage of a magnetic pole of a permanent magnet of the rotor.

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

- the CEH1 sensor alone,

- the CEH2 sensor alone, - the CEH3 sensor alone,

- CEH1 and CEH2 sensors,

- CEH1 and CEH3 sensors,

- and the CEH2 and CEH3 sensors. For example, in the angular position of the ROT rotor shown in

[Fig. 2], the passage of an N pole of the rotor is detected by the CEH1 and CEH2 sensors. If the rotor moves 45 ° clockwise from this position, the passage of an N pole of the rotor is detected only by the CEH1 sensor.

From this information, an electric motor control device comprising a first processing circuit CT1 ensures the switching of the electronic current sequentially in the three coils. For this, the first processing circuit CT1 has six outputs Q1 H_bit, Q1L_bit, Q2H_bit, Q2L_bit, Q3H_bit, Q3L_bit connected to an electronic circuit represented in [Fig. 2] comprising six transistors TRQ1FI, TRQ1 L, TRQ2FI, TRQ2L, TRQ3FI, TRQ3L acting as electronic switches. Each output controls the opening and closing of a respective electronic switch.

The supply of each coil BOB1 (or "phase") of the stator is controlled by a pair of electronic switches, comprising a first and a second electronic switches TRQ1 Fl, TRQ1 L. [0100] When the first electronic switch TRQ1 H is open and the second electronic switch TRQ1 L is closed, a coil BOB1 is connected to ground.

When the first electronic switch TRQ1 H is closed and the second electronic switch TRQ1 L is open, the coil BOB1 is connected to the phase, thus a positive voltage is applied to the coil BOB1.

When the first and second electronic switches TRQ1 H, TRQ1 L are both open, coil BOB1 is not connected to phase or to ground.

[0103] 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 the mass, connected to the phase, or connected neither to the phase nor to the mass. Six combinations of states are possible:

- BOB1 connected to the mass, BOB2 connected to the phase and BOB3 not connected,

- BOB2 connected to the mass, BOB1 connected to the phase and BOB3 not connected,

- BOB1 connected to the ground, BOB3 connected to the 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 the phase and BOB1 not connected.

[0104] 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 coil states.

The brushless MOT motor is a synchronous motor, that is to say that the rotor rotates 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 ROT rotor may no longer follow the magnetic field. From this moment, the rotor ROT oscillates, without being able to resynchronize with the magnetic field, which can cause its destruction. To avoid this, it is expected that the CEH Hall effect sensors detect a slowing down of the rotor ROT when the resistive torque increases, and that the electric motor controller MOT adjusts the switching frequency accordingly.

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

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

[0108] Alternatively, the stator STAT can be initially unpowered, an auxiliary motor being provided and controlled 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 supplies the stator coils sequentially with a switching speed equal to the predefined angular speed reached by the rotor.

[0109] 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 vehicle is proportional to the instantaneous angular speed of the rotor ROT. The proportionality factor or transmission factor is a constant whose value is in the order of ten. That is, the ROT rotor of the MOT electric motor makes about ten full revolutions for the RAV drive wheels to make one full revolution. The transmission factor is a known quantity, which can be fixed or selected from among several possible transmission factors using a digital vehicle speed selector. Such a digital speed selector is able to select a speed characterized by a transmission factor and to transmit, for example through a CAN data bus, the transmission factor to the control device of the electric motor.

[0110] If the motor vehicle is moving in a straight line, the instantaneous angular speed of each of the four wheels has an identical value equal to the mean value.

[0111] If the motor car moves along a curve, the wheels of the car turn at different speeds: the wheels located on the outside of the turn turn faster than those located on the inside. This speed difference is caused by a differential in the automobile car. This differential is a device known mechanics whose function is to distribute the rotation caused by the angular displacement of the rotor of the electric motor.

[0112] The navigation assistance device comprises a GPS receiver capable of locating the location of the vehicle. The navigation assistance device further includes a second processing circuit CT2 configured to use location information provided by the GPS receiver to display a route on the instrument panel or signal a point of interest to the driver. The second processing circuit CT2 of the navigation assistance device can also control a speedometer integrated into the dashboard of the motor car. Vehicle speed is calculated relative to the vehicle's GPS positioning. 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 an overrun.

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

[0114] 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 above for the case of electromagnetic sensors attached 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.

To measure the angular position of each wheel of the vehicle, an electromagnetic angular position sensor can be fixed either: - to a fixed part of the vehicle (for example the chassis), a magnet being fixed to the movable 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 attached to the frame, so as to measure the passage of the sensor facing the magnet.

[0117] Generally, for cost reasons, the sensor, being more expensive than the magnet, is fixed to the frame. This is because the wheels of the motor car are likely to be replaced, which is not the case with the chassis.

[0118] In the example shown in [Fig. 3], the angular position sensors of each wheel are optical. The active safety device includes for each wheel:

a DCR notched disc comprising a plurality N of angularly evenly distributed notches and arranged in the wheel in a manner integral with the wheel,

- an optical COP angular position sensor positioned opposite the DCR notched disc 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. each wheel.

[0120] 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 made by the wheel during this period time equals M / N. [0121] 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 one another so as to: - detecting a loss of grip when cornering 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 to detect intense braking on poorly adherent ground and in response to limit wheel locking, the second processing circuit CT2 then has an anti-locking function for the wheels,

- and / or detect significant acceleration on poorly adherent ground and in response to regulate the acceleration of the vehicle, the second processing circuit CT2 then has an anti-skid function.

[0122] 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 instrument panel, or an audible signal simultaneously with the action of electronic correction of trajectory, anti-lock of the wheels or traction control.

[0123] The odometer includes:

- at least one electromagnetic or optical angular position sensor to measure an angular position of at least one wheel,

a control unit intended to convert 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.

[0124] The current 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, to display the indication of the current speed of the vehicle.

[0125] The electromagnetic or optical angular position sensors are shared with the active safety device. As specified previously, in the embodiment illustrated by [FIG. 1], [Fig. 2] and [Fig. 3], a CAN data bus provides mutual data transmission between the electric motor control device, odometer, current speedometer, navigation aid device, and the car's active safety device. automobile. Thanks to this data transmission, each of these devices has access to the measurements originating 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.

[0127] With respect to the navigation aid device, the location data received by the GPS receiver are supplemented by the measurements coming from at least one Hall effect sensor CEFI of the electric motor MOT and supplied by the electric motor control device.

[0128] 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 received positions and can estimate the position and the direction of movement of the motor vehicle 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 made by the rotor ROT of the electric motor MOT from the interruption of the reception of the GPS signal.

As described above, the number of revolutions performed by the rotor ROT of the electric motor MOT is proportional to the average of the number of revolutions performed by each of the four wheels of the motor car. Thus, the measurements made by at least one Hall effect sensor CEH 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. . [0131] The location data received by the GPS receiver can also be supplemented by the measurements obtained from the optical COP or electromagnetic sensors mounted on each wheel.

[0132] In fact, taking the above-mentioned example of the interruption of the reception of the GPS signal, the measurements from the optical sensors COP make it possible to determine the distance traveled by each wheel from the interruption of the reception of the signal. 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.

[0133] The position of the vehicle can thus be estimated by the second processing circuit CT2 of the navigation aid device from:

- the position and direction of movement of the motor vehicle 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 the reception of the GPS signal, as determined from measurements from at least one Hall effect sensor CEH mounted in the MOT engine and / or from at least one COP optical or electromagnetic 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 optical COP or electromagnetic sensors mounted in each wheel.

[0134] With respect to the odometer, the current speed indicator, and the active safety device, the measurements taken from the optical COP or electromagnetic sensors mounted in the wheels are supplemented by the measurements taken from at least one Hall effect sensor CEH of the CEH electric motor and supplied by the control device of the electric motor.

[0135] In particular, a ratio can be determined between the angular position measurements originating respectively from the sensors mounted in the wheels and from at least one sensor mounted in the electric motor. This ratio takes a constant value, equal to a reference value called the “transmission ratio” when the transmission of engine torque to the driving wheels is effected efficiently.

[0136] Thus, the comparison of this ratio with a predetermined threshold value on the basis of the reference value can highlight a vehicle safety fault, 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 wear of a tire.

[0137] Typically, the frictional force exerted by the ground on the tire creates a resistive torque which opposes the engine torque and reduces the speed of rotation of the wheel. In the event of excessive tire wear, the resistance torque value is particularly high and the ratio between the speed of rotation of the wheel and the speed of rotation of the rotor of the electric motor is particularly low.

[0138] On the basis of the identified safety fault, the active safety device can generate an alert signal allowing the activation of a warning light on the dashboard of the vehicle and / or the activation of an audible warning signal.

[0139] In addition, the alert signal can trigger automatic locking of the vehicle, for example by switching off the electric motor, so as to preserve the integrity of the vehicle and prevent further damage.

[0140] The measurements from optical or electromagnetic sensors mounted on each wheel can also be supplemented by the location data received by the GPS receiver.

[0141] In fact, when the user is driving at a constant speed, for example on a motorway, the determination of the location speed on the basis of the GPS signal is particularly reliable.

[0142] A single value for estimating the current speed, resulting from the fusion of the measurements obtained by the various sensors, can be displayed on the instrument panel. [0143] In addition, all the driving situations resulting in a loss of grip between the wheels of the vehicle and the ground induce a movement of the vehicle by sliding and not only by rolling. This slippage induces a difference between:

- on the one hand, measurements from sensors mounted on the wheels or mounted in the electric motor which estimate the movement of the vehicle by rolling,

- and, on the other hand, the signal received by the GPS receiver which estimates by geolocation the movement of the vehicle regardless of the adhesion between the vehicle's tires and the ground.

[0144] [Fig. 4] represents a bicycle with an electric motor. The bicycle comprises in particular a front wheel RAV, a rear wheel RAR and an electric motor MOT, typically a brushless motor, mounted on the rear wheel RAR and capable of transmitting a motor torque to the rear driving wheel RAR.

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

[0146] The electric motor MOT 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 back electromotive force. Thus, the electric motor MOT does not include a component capable of determining an estimate of the position of the rotor ROT relative to the stator STAT.

[0147] Such an electric motor without an angular position sensor has reduced cost and is more compact than an electric motor comprising at least one angular position sensor. In addition, such an electric motor is not subject to angular position sensor failure which is costly in terms of maintenance.

[0148] The bicycle further comprises an ODO odometer.

[0149] The odometer includes an angular position sensor CPA mounted on the rear wheel, measuring the angular position of the rear wheel. [0150] The odometer further comprises a third processing circuit CT3 in wired communication with the angular position sensor and with the electric motor.

[0151] The odometer further comprises an AFF display in wireless communication with the third processing circuit CT3 and arranged on a handlebar of the bicycle.

[0152] 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 relative to the stator STAT,

- drive the MOT electric motor on the basis of this estimate, and

- drive the display to display a current speed indication based on this estimate.

[0153] 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.

[0154] 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 measurement processing interval by the third processing circuit CT3 and generation of 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 for the implementation of the control signal by the electric motor MOT. The first and third intervals are constant because the data transmission is carried out in a wired manner.

[0156] The third processing circuit CT3 and the electric motor MOT are furthermore configured respectively so that the second and the fourth interval are constant.

[0157] Thus the time interval is constant.

[0158] During this constant time interval, the angular position of the rotor ROT varies in a predictable and calculable manner on the basis of the angular speed of the rear wheel RAR.

[0159] Thus, the third processing circuit CT3 takes into account this constant time interval by estimating the angular position of the rotor ROT not at the instant of the measurement carried out by the sensor CAPT but at the end of the interval constant time and driving the MOT motor on the basis of this estimate.

[0160] Based on the estimation of the angular position of the rotor ROT, the third processing circuit CT3 can drive the electric motor MOT. For example, the third processing circuit CT3 can control 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.

[0161] Thus, the angular position measurement performed by an angular position sensor CPA of an ODO odometer normally provided for determining and displaying a current speed indication is also used to drive an electric motor MOT without an angular position sensor.

[0162] 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 the control of any electric motor not without an angular position sensor.

[0163] In particular, such an estimate makes it possible to continue to control the electric motor even if the angular position sensor internal to the motor, such as a Hall effect sensor CEH, suddenly fails and can no longer indicate an estimate of the relative position of the rotor ROT with respect to the stator STAT.

Claims

[Claim 1] Acquisition and control system for an electric motor vehicle, the system comprising:

- at least a 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 relating to propulsion of the vehicle as a function of said position estimation, in which the control device is able to control, in addition to the motor, a device of the separate vehicle of the motor as a function of said position estimate.

[Claim 2] An acquisition and control system according to claim 1, wherein:

- the first sensor is mounted in the engine,

- the system includes a second sensor capable of indicating a change in the position of the vehicle,

[Claim 3] An acquisition and control system according to claim 2, wherein the second sensor is an angular position sensor mounted on at least one wheel of the vehicle.

[Claim 4] An acquisition and control system according to claim 2, wherein the second sensor is an odometer.

[Claim 5] An acquisition and control system according to claim 2, wherein the second sensor is a GPS type position receiver.

[Claim 6] An acquisition and control system according to claim 3, 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.

[Claim 7] Acquisition and control system according to claim 6, in which the vehicle comprises a plurality of driving wheels each comprising a second angular position sensor of the wheel and in which the active safety device is arranged to correct a angular speed of each wheel as a function of the warning signal.

[Claim 8] An acquisition and control system according to claim 1, wherein 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 relative angular position of the rotor by relative to the stator of the electric motor, and from there, controlling the operation of the electric motor as a function of said estimation of angular position, while the electric motor has no angular position sensor.

[Claim 9] An acquisition and control system according to claim 8, wherein:

- the vehicle device is a current vehicle speed indicator,

- and the control device is able to control, in addition to the motor, the current speed indicator, as a function of said position estimate.

[Claim 10] An acquisition and control system according to any one of claims 1 to 9, wherein the first sensor is a Hall sensor.

[Claim 11] An acquisition and control system according to any one of claims 1 to 10, wherein the electric motor is a brushless motor.

[Claim 12] 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 signal. command transmitted by the control device of the electric motor on the basis of the position estimation to the device of the vehicle, the device of the vehicle being controllable on the basis of the transmitted control signal.

[Claim 13] An acquisition and control system according to any one of claims 1 to 12, the vehicle comprising a second electric motor, in which:

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

[Claim 14] An electric motor vehicle comprising an acquisition and control system according to any one of claims 1 to 13.

[Claim 15] An acquisition and control method for an electric motor vehicle, the method comprising:

- Controlling, by a control device of the electric motor, an operation of the electric motor relating to the propulsion of the vehicle as a function of said position estimate, and controlling, by the control device of the electric motor, a device of the vehicle, distinct from the motor, as a function of said position estimate.

[Claim 16] A computer program comprising instructions for carrying out the acquisition and control method according to claim 15, when said instructions are executed by a processor.

[Claim 17] Processing circuit comprising a processor connected to a memory and to at least one communication interface with a control device of an electric motor and at least one device of the vehicle distinct from the engine, the processing circuit being configured to carrying out the steps of the acquisition and control method according to claim 15.