FR2839927A1 - Control of motor and propulsion unit for motor vehicle, adapted to operation at low speed - Google Patents

Abstract

The motor propulsion unit (12) has a control (20) for the clutch (16), a control (22) for the internal combustion engine (14). Both controls are operated by a central unit (11) to satisfy an internal set value (CRVR) for the (low) speed of the vehicle. The central unit operates in response to detection of information (IVC) indicating the wish of the driver to operate in low speed mode.

Description

i. "Powertrain control device and associated method

  for operation at reduced speed "The invention relates to a device for controlling a powertrain of a motor vehicle and a method for implementing such a device. The invention relates more particularly to a device for controlling a powertrain for a motor vehicle comprising a heat engine coupled by means of a clutch controlled by a manual gearbox, or robotized, or any automated transmission capable of establishing at least two first forward gear ratios and a gear ratio reverse gear, a means of controlling the clutch,

  a means of controlling the heat engine.

  The driver of such a vehicle may need to run his vehicle at a reduced speed to maneuver in a parking lot or to fit into a queue of vehicles caught in

a traffic jam.

  These maneuvers can be very difficult to perform because they require a very precise dosage of pressing on the pedal or accelerator because of the reduced speed that the driver wishes to establish. The metering of the support on the accelerator pedal is made even more delicate when the vehicle is on a slope. The devices known from the state of the art and the methods associated therewith relate, for the most part, to vehicle architectures equipped with automatic gearboxes. For such vehicles, starting is always carried out on the first forward gear or on the reverse gear and the engine torque is gradually regulated or by means of a torque converter. As a result, these devices are unsuitable for the case of a vehicle fitted with a manual gearbox for which starting must be carried out by modulating the engine torque gradually by means of the clutch, taking into account that the starting, when it is carried out on a forward gear, is not systematically carried out on the first forward gear as is the case for an automatic gearbox, but on one

  either of the first two forward reports.

  Other devices relating to vehicle architectures equipped with manual gearboxes are also known from the state of the art, but they are only capable of controlling the closing of the clutch, without taking account of the

  torque regulation possibilities that the engine can offer.

  o The invention proposes to remedy these drawbacks by proposing a device adapted to a vehicle provided with a manual gearbox comprising speed control means at reduced speed of the clutch and of the heat engine, and a method

  for controlling said control means.

  The device is applicable to gearboxes with dual input clutch or to any automated transmission fitted

  a wet or dry input clutch.

  To this end, the invention proposes a control device of the type described above, characterized in that it comprises at least one central unit which is capable of controlling: the clutch control means for regulating the torque transmitted by the 'clutch, - the means of piloting the thermal engine to adjust the torque delivered by the engine, to satisfy an internal setpoint for running the vehicle at reduced speed, the establishment of which is triggered by the detection of at least one item of information representative of the will of

  driver to drive at reduced speed.

  o According to other characteristics of the device according to the invention: - the control device comprises at least: a first sensor which is capable of transmitting to the central unit a first information representative of the stopping or operating the heat engine, To a second sensor which is capable of transmitting to the central processing unit a second information representative of the engagement of the first or second forward gear or of the drive gear rear, to a third sensor which is capable of transmitting to the central unit a third or information representative of the actuation or re-engagement of a vehicle brake pedal, a fourth sensor which is capable of send to the central unit a fourth piece of information representative of the actuation or release of a vehicle accelerator pedal, to a fifth sensor which is capable of transmitting to the the central unit a fifth information representative of the actuation or the release of a handbrake of the vehicle, a sixth sensor which is capable of transmitting to the central processing unit a sixth information representative of the real speed of the vehicle, s To a seventh sensor which is capable of transmitting to the central processing unit seventh information representative of the position of the clutch. - the information representative of the driver's desire to drive at reduced speed corresponds to the detection by a concomitance test module: A of a value of the first information corresponds to the operation of the heat engine, A of a value of the second information correspond to the engagement of the first or second forward gear or of the reverse gear, To of a value of the third information correspond to the release of the brake pedal o of the vehicle, of a value of the fourth information corresponds to the release of the accelerator pedal from the vehicle, to a value of the fifth information corresponds to the release of the handbrake of the

veh icu.

  To a value of the sixth information correspond to a real speed of the vehicle which

  is less than a predetermined threshold speed.

  o- the central control unit comprises at least, downstream of the test module: A calculation module which is intended to compare the internal running instruction of the reduced speed vehicle with the information representative of the actual speed of the vehicle to establish a speed error, a regulation module which is intended to receive the speed error and to translate it into a clutch output torque setpoint, where an adjustment module which is intended to receive the setpoint of clutch output torque to establish a clutch positioning setpoint, To a close clutch control module which is intended to receive the clutch position setpoint and the seventh information representative of the position of I clutch to issue a clutch actuation instruction for the

clutch control means.

  the adjustment module emits an over estimate of the torque taken by the clutch for the purpose of the engine control means, the engine control means comprises means for adjusting the torque delivered by the engine which wind active at a predetermined intensity or else at an intensity proportional to the value of the value of the estimate of the torque drawn by the clutch, the central unit comprises means for converting the torque drawn by the clutch, from the engine speed, clutch output speed, or clutch temperature in information representative of the energy dissipated in where the clutch. The invention also relates to a method for implementing the device described above, characterized in that it comprises at least: To a first test step during which the central unit compares the information representative of the driver's desire to driving at a reduced speed in an active or inactive state, if the information representative of the driver's desire to drive at a reduced speed corresponds to the active state, a second stage of execution during which the central unit controls the means for controlling the clutch and the means for controlling the heat engine in order to satisfy the J 1 internal running instruction of the vehicle at reduced speed, - the second stage of execution comprises a first parallel sub-stage of test during which, the information representative of the dissipated energy or the temperature in the clutch is compared with a predetermined threshold value, - if the information representative of the dissipated energy in the clutch is greater than the predetermined threshold value, the second execution step comprises a second parallel substep during which the clutch actuation instruction is forced towards a clutch closing instruction or opening the clutch with a warning

of the driver by an audible signal.

  Other features and advantages of the invention

  will appear on reading the following detailed description for the

  understanding of which reference will be made to the accompanying drawings in which: - Figure 1 is a schematic view of a control device according to the invention; - Figure 2 is a schematic flowchart representative of a control method for a device according to the invention.

  In the following description, reference figures

  identical designate identical parts or have similar functions. There is shown in Figure 1 a control device 10

  for a motor vehicle powertrain 12.

  In known manner, the powertrain 12 comprises o an internal combustion engine 14 which is coupled by means of a clutch 16 control to a box 18 of robotic manual speeds or to an automated transmission. The box or transmission 18 is capable of establishing at least two first forward gear ratios and a reverse gear ratio. The J powertrain 12 comprises a means 20 for controlling the clutch 16 and a means 22 for controlling the heat engine 14. More particularly, the means 20 for controlling the clutch 16 can be constituted, in a nonlimiting manner of [ invention of an electromechanical actuator comprising a direct current motor or of a hydraulic actuator comprising a solenoid valve intended to control a flow of

hydraulic fluid in a cylinder.

  o The means 22 for controlling the thermal engine 14 comprises for example a motorized throttle valve which is intended to regulate the flow of gas entering a tubular inlet for the engine 14 and / or

  a device for modulating the ignition advance.

  In accordance with the invention, the device 10 comprises a central unit 11 which is capable of controlling: - the means 20 for controlling the clutch 16 to regulate the torque transmitted by the clutch 16, - the means 22 for controlling the engine 14 to adjust the torque delivered by the engine 14, or so as to satisfy an internal "CRVR" setpoint for running the vehicle at reduced speed, the establishment of which is triggered by the detection of "IVC" information representative of the will

  of the driver to drive at reduced speed.

  More particularly, as illustrated in FIG. 1, the device 10 comprises at least: - a first sensor "C1", for example a speed sensor of a crankshaft of the engine 14, which is capable of emitting of the central unit 11 a first item of information "11" representative of the shutdown or of the operation of the engine 14, a second sensor "C2", for example a switch with several positions coupled to an internal linkage of the gearbox , or a series of potentiometers linked to the axes of the box, which is likely to send to the 'central unit 11 a second information "12" representative of [' engagement in the box 18 of the first or second market report front or reverse gear, - a third sensor "C3", for example a switch s coupled to a brake pedal 24, which is capable of transmitting to the central unit 11 a third piece of information 13 "representative of actuation or release t of the brake actuation pedal 24 of the vehicle 26, or of the state of a brake pressure sensor, o - a fourth sensor "C4", for example a switch or potentiometer coupled to a pedal of accelerator 28, which is capable of transmitting to the central processing unit 11 a fourth item of information "14" representative of the actuation or release of the accelerator pedal 28 of the vehicle, - a fifth sensor "C5" , for example a switch coupled to a handbrake lever 30 of the vehicle, which is capable of transmitting to the central unit 11 a fifth item of information "15" representative of the actuation or of the release of the hand 30 of the vehicle, o - a sixth sensor "C6", for example a speed sensor driven by a bridge 25 of the vehicle, which is capable of transmitting to the 'central unit 11 a sixth information "16" representative of the actual speed of the vehicle, - a seventh "C7" sensor, for example an in contactor axially integral with a clutch stop (not shown) of the clutch 16, which is capable of transmitting to the central unit 1 1 only seventh information "17" representative of

the position of the clutch 16.

  In accordance with the invention, the information "IVC" o representative of the driver's desire to drive at reduced speed corresponds to the detection by a test module 31 of the concomitance: of a value of the first information "11" correspond to the operation of the heat engine 14, - of a value of the second information "12" correspond to ['engagement of the first or second forward gear or the reverse gear, - of a value of the third information " 13 "correspond to the release of the brake pedal 24 from the

veh icu.

  - of a value of the fourth information "14" correspond to the release of the accelerator pedal 28 of the

veh icu.

  o - of a value of the fifth information "15" correspond to the release of the parking brake 30 of the vehicle, - of a value of the sixth information "16" correspond to a real speed of the vehicle which is lower than a speed

predetermined threshold.

  The speed of the vehicle can for example be measured by a sensor dispersed on a target linked to the wheels or calculated at

from the box entry regime.

  The concomitance of this information can be established in various ways, cons. For example, each of the sensors "C1" to "C6" can control an associated switch and all the switches can be connected in series to allow the passage of a representative current of "information" IVC ". As a variant, each of the switches can be connected to a logic circuit (not represented "which determines the concomitance of the information

Associated.

  The use of this "IVC" information by unit 11 will

  described in the rest of this description in more detail in

reference to figure 2.

  As illustrated in FIG. 1, to control the means 20 o for controlling the clutch 16 and the means 22 for controlling the heat engine 14, the central control unit 11 comprises at least, downstream of the test module 31 : a calculation module 32 which is intended to compare the internal setpoint "CRVR" of running of the reduced speed vehicle to the "information" 16 "representative of the real speed of the vehicle to establish a speed error" EV ", - a module 34 of regulation which is intended to receive the error "EV" of speed and to translate it into an instruction "CCS" of s output torque of the clutch, - a module 36 of adjustment which is intended to receive the "CCS" setpoint for clutch output torque to establish a "CPE" setpoint for positioning the clutch 16, - a module 38 for close control of the clutch o which is intended to receive the "CPE" setpoint for the clutch position and the seventh information "17" representative of the position of the clutch 16 for emett re a "CAB" clutch actuation instruction for the means 20 of

clutch control 16.

  In addition, the adjustment module 36 emits an overload estimate "CIC" of the torque taken by the clutch 16 a

  [Intention of the means 22 for controlling the heat engine 14.

  To compensate for the torque taken by the clutch 16, the means 22 for controlling the heat engine o includes means for adjusting (not shown) the torque delivered by the engine 14. These means can be active to adjust the following torque a predetermined fixed intensity or, alternatively, according to an intensity proportional to the value of the value of the "CIC" estimate of the couple taken by

s the clutch 16.

  Furthermore, the central unit 11 includes means (not shown) for converting the torque taken by the clutch, of the engine speed, of the clutch output speed, or of the clutch temperature, into information information

  o "ED" representative of the energy dissipated in the clutch 16.

  The use of this information will be described in more detail.

with reference to Figure 2.

  l In this configuration, the device 10 can be piloted according to a suitable control method which has been shown in the

figure 2.

  The method comprises a first "ET1" test step during which the central unit 11 compares the "IVC" information representative of the driver's desire to drive at reduced speed to an active "1" or inactive state (not represented). Thus, the active state "1" corresponds to a vector of values "11", "12", "13", "14", "15", "16" which is equal to a reference vector for which, o as described above, the value of the first information "11" corresponds to the operation of the heat engine 14, the second information "12" corresponds to the engagement of the first or second forward gear or of the reverse gear, the third information "13" corresponds to the release of the vehicle brake pedal 24, the fourth information "14" corresponds to the release of the vehicle accelerator pedal 28, the fifth information "15" corresponds to the release of the hand brake 30 of the vehicle , and the sixth item of information "16" corresponds to a real speed of the vehicle which is less than the

o predetermined threshold speed.

  From this step "ET1", if the information "IVC" representing the driver's desire to drive at reduced speed corresponds to the active state "1", a second step "ET2" of execution is triggered by [ central unit 11. During this step "ET2", the test module 31 emits the internal setpoint "CRVR" for running at reduced speed which is processed successively in the module modules 32 for calculation, a module 34 for regulation, a module 36 for adjustment, and a module 38 for control in emetta nt successively and respectively me nt the so "EV" speed error, the setpoint "CCS" of output torque, and the setpoint "CPE" of positioning of the clutch to finally reach the "CAB" instruction for actuating the clutch. At the same time, the adjustment module 36 emits the estimate

  "CIC" of the torque taken by the clutch.

  As soon as the "CAB" instruction for actuating the clutch is emitted, the unit 11 controls the means 20 for controlling the clutch and as soon as the "CIC" estimate of the torque drawn is emitted, the unit 11 controls the means 22 for controlling the heat engine 14, thus satisfying the internal instruction "CRVR" of

  running of the vehicle at reduced speed.

  Advantageously, the second execution step "ET2" o includes an additional first substep "SET1" parallel to the test during which the information "ED" representative of the energy dissipated in the clutch or of the temperature is

  compared to a predetermined threshold value "S".

  If the "ED" information representative of the energy dissipated in the clutch or of the temperature of the clutch linings is higher than the predetermined threshold value "S", unit 11 then triggers the second execution step " ET2 "includes a second parallel" SET2 "sub-step during which the" CAB "setpoint for actuating the clutch is forced towards a" CABo "setpoint for closing the clutch, or opening with emission of a audible signal to warn the driver, and this sub-step "SET2" is looped on itself until the information "ED" representative of the dissipated energy or the temperature in the clutch becomes lower than the value "S". In the case where the information "ED" representative of the energy dissipated in the clutch is less than the value "S" of a predetermined threshold otherwise, unit 11 commands the return to the execution sequence

previously described.

  so The invention therefore advantageously makes it possible to control a powertrain 10 comprising a gearbox 18 of automated or non-automatic gears equipped with a pilot clutch for

  reduced vehicle speeds, without driver intervention.

Claims (10)

  1. Device (10) for controlling a power unit   motor vehicle thruster (12) comprising a heat engine (14) coupled by means of a clutch (16) s controlled by a manual (robotic) gearbox (18) or any automated transmission capable of establishing at least two first forward gear ratios and a reverse gear, a means (20) for controlling the clutch (16), a means (22) for controlling the heat engine (14), o characterized in that it comprises at least one central unit (11) which is capable of controlling: - the means (20) for controlling the clutch (16) for regulating the torque transmitted by the clutch (16), - the means (22) for controlling the internal combustion engine (14) to adjust the torque delivered by the engine (14), so as to satisfy an internal setpoint (CRVR) for running the vehicle at reduced speed, the establishment of which is triggered by the detection of at least one item of information ( IVC) representative   the driver's desire to drive at a reduced speed.   o 2. Control device (10) according to the preceding claim, characterized in that it comprises at least: - a first sensor (C1) which is capable of emitting a first intention to the central unit (11) information (11) representative of the shutdown or operation of the heat engine (14), - a second sensor (C2) which is capable of transmitting a second information (12 to the central unit (11) ) representative of the engagement of the first or second forward gear or the reverse gear, so - a third sensor (C3) which is capable of transmitting to the central processing unit (11) third information (13) representative of the actuation or release of a brake pedal (24) (26) of the vehicle, - a fourth sensor (C4) which is capable of transmitting to the intention of the central unit (11 ) a fourth item of information (14) representative of the actuation or of the release of a pedal (28) of the vehicle accelerator, - a fifth sensor (C5) which is capable of transmitting to the central unit (11) fifth information (15) representative of the actuation or release of a handbrake (30) of the vehicle, - a sixth sensor (C6) which is capable of transmitting to the intention of the central unit (11) a sixth information (16) representative of the real speed of the vehicle, - a seventh sensor (C7) which is capable of 'send to the central processing unit (11) seventh information (17)   representative of the clutch position (16).   3. Device (10) according to the preceding claim, characterized in that the information (IVC) representative of the driver's desire to drive at reduced speed corresponds to the detection by a test module (31) of the concomitance: - d 'a value of the first information (11) where correspond to the operation of the heat engine (14), - of a value of the second information (12) correspond to the engagement of the first or second forward gear ratio or the gear ratio reverse, - of a value of the third information (13) correspond to the release of the brake pedal (24) of the vehicle, - of a value of the fourth information (14) correspond to the release of the pedal (28) accelerator veh icu.   so - of a value of the fifth information (15) correspond to the release of the handbrake (30) of the vehicle, - of a value of the sixth information (16) correspond to a real speed of the vehicle which is less than a speed predetermined threshold.   4. Control device (10) according to one of the claims   previous cations, characterized in that the central control unit (11) comprises at least, downstream of the test module (31): - a calculation module (32) which is intended to compare the internal setpoint (CRVR) of running the vehicle at reduced speed with information (16) representative of the real speed of the vehicle to establish a speed error (EV), - a regulation module (34) which is intended to receive the error (EV) and translate it into a setpoint (CCS) of o clutch output torque, - an adjustment module (36) which is intended to receive the setpoint (CCS) of clutch output torque for establish a clutch positioning setpoint (CPE), - a module (38) for close control of the clutch s which is intended to receive the clutch position setpoint (CPE) and the seventh information (17) representative of the position of the clutch (16) to issue a clutch actuation instruction (CAB) for the means (20) of clutch control (16).   o 5. Control device (10) according to the preceding claim, characterized in that the adjustment module (36) emits an overload estimate (CIC) of the torque taken by the clutch for the intention of the means (22) of motor control thermal (14).   s 6. Control device (10) according to the preceding claim, characterized in that the means (22) for controlling the heat engine comprises means for adjusting the torque delivered by the engine (14) which wind active at a predetermined intensity or well, according to an intensity proportional to the value of the value of the estimate (CIC) of the torque taken by the clutch. 7. Control device (10) according to one of   Claims 4 to 6, characterized in that the central unit (11)   includes means for converting the torque taken by the clutch, the engine speed, the speed at the clutch output, or the clutch temperature into information (ED)   representative of the energy dissipated in the clutch (16).   8. Method for controlling a device according to   Claims 1 to 6, characterized in that it comprises at least:   - a first test step (ET1) during which the central unit compares the information (IVC) representative of the driver's desire to drive at reduced speed to an active (I) or inactive state, or - if [' information (IVC) representative of the driver's desire to drive at reduced speed corresponds to the active state (I), a second stage (ET2) of execution during which the central unit (11) controls the means (20 ) for controlling the clutch (16) and the means (22) for controlling the heat engine (14) in order to satisfy the internal setpoint (CRVR) for the vehicle to reduced speed.   9. Control method according to the preceding claim, characterized in that the second step (ET2) of execution comprises a surcrot a first substep (SET1) o parallel test during which, the information (ED) representative of the energy dissipated in the clutch (16) or the   temperature is compared to a predetermined threshold value (S).   10. Control method according to the preceding claim, characterized in that, if the information (ED) representative of the energy dissipated in the clutch is greater than the predetermined threshold value (S), the second step (ET2) of execution comprises a second parallel substep (SET2) during which the setpoint (CAB) for actuating the clutch is forced towards a setpoint so (CABo) for closing the clutch (16) or opening with a