FR2699978A1 - Control device for automatic transmission in motor vehicle - Google Patents

Abstract

The automatic transmission control device has a principal selector (1), operated by the driver, which is connected to a central processor (2) and to a gear selector mechanism. The processor has selectable programs to select 'economy' or 'sporting' mode of automatic gear changing.The central processor can be switched (18) to a programming mode where the changing of gear ratios is controlled by the driver by use of pushbutton switches (11,12) on the steering wheel. The operating parameters at each gear change are memorised and used to control automatic ratio changing once returned to normal mode.

Description

 The present invention relates to a control device for an automatic gearbox, in particular for a motor vehicle.

Already known in the prior art, a number of control devices of this type, which include means for selecting the main mode of operation of the gearbox, namely parking
P, reverse R, neutral N and forward D and means for selecting reports authorized in forward, actuable by a user and connected to a central unit for processing information and controlling the operation of the gearbox, according to au minus a baseline reporting law or program.

 In addition, this central information processing unit is also connected to means for displaying the selected position of the box, that is to say the main operating mode and / or authorized reports, arranged for example on the vehicle dashboard.

 These devices and more particularly the central information processing unit control the gearbox according to one or more gear shift laws pre-established during the construction of the vehicle, to adapt the gear changes of this gearbox, for example for economical or sporty driving of the vehicle.

 However, these laws being established once and for all, it is understandable that in some cases, they may not be suitable for the particular driving of vehicles by certain users.

 The object of the invention is therefore to solve these problems, by proposing a control device which is simple and reliable, and which can be very easily adapted to all types of driving of a vehicle equipped with an automatic gearbox. .

 To this end, the subject of the invention is a control device for an automatic gearbox, in particular for a motor vehicle, of the type comprising means for selecting the main mode of operation of the gearbox, namely parking P, reverse R, neutral N and forward gear D and authorized gearbox ratios, actuable by a user and linked to a central unit for processing information and controlling the operation of the gearbox, according to at least one gear shift law reference, characterized in that it further comprises means for engaging a programming state of the central information processing unit, in which the operation of the gearbox is controlled by the user, by means for selecting the ratios of the gearbox and the central unit stores operating parameters of the gearbox and of the vehicle in order to establish a personalized law for the passage of report and means for activating a state of automatic control of the box by the central information processing unit, according to the personalized law for passing reports.

The invention will be better understood with the aid of the description which follows, given solely by way of example and made with reference to the appended drawings, in which
- Fig.l shows a block diagram illustrating the structure of a control device for an automatic gearbox, according to the invention;
the - Fig.2 shows a block diagram illustrating the structure of a central information processing unit forming part of a control device according to the invention;
- Fig.3 shows an embodiment of means for warning of an imminent gear change forming part of a device according to the invention; and
- Fig.4 shows a flowchart illustrating the operation of a control device according to the invention.

 As can be seen in FIGS. 1 and 2, a control device for an automatic gearbox, in particular for a motor vehicle, according to the invention, conventionally comprises means for selecting the main mode of operation of the gearbox, namely parking P, reverse R, neutral N and forward D and means for selecting the authorized gear ratios of the gearbox in forward motion, operable by a user.

 These different means are for example constituted by a selection lever, designated by the general reference 1 in this figure.

 These selection means are connected to a central information processing unit designated by the general reference 2, formed by a gearbox computer comprising a microprocessor 3 (FIG. 2).

 This central information processing unit also includes a random access memory 4, an erasable read-only memory 5, analog-digital converters 6, buffers 7 and a connector 8 for connection to the rest of the circuits of the device.

 The central information processing unit 2 is also connected to various sensors and actuators designated by the general reference 9 in FIG. These various sensors include, for example, throttle opening angle, vehicle speed, engine speed, transverse acceleration, braking pressure and actuator position sensors, for example control solenoid valves. of the gearbox report.

 This central unit is also connected, for example, to the steering wheel of the vehicle designated by the general reference 10, and more particularly for example to pushbuttons 11 and 12 arranged thereon, actuable by the user and the function of which will be described more in detail later.

 The central information processing unit 2 is also connected to various information display means designated by the general reference 13 in this figure.

 These information display means are arranged for example on the dashboard of the vehicle and comprise for example a digital display indicating the gear engaged ratio, designated by the reference 14 in this figure, an alphanumeric display 15 on which are displayed information concerning the state or mode, the style and the driving program selected, which will be described in more detail below, and a visual warning of imminent gear change, designated by the reference 16 and which will also be described in more detail later.

 Finally, the central information processing unit 2 is also connected to an automatic gearbox comprising a hydraulic block equipped for example with solenoid valves and controlled electronically, this box being designated by the general reference 17 in this figure 1 .

 This device and more particularly the central information processing unit commonly operate to control the operation of the gearbox according to at least one reference gear shift law.

 This operation being conventional, it will not be described in detail later.

 According to the invention, the control device also comprises means, constituted for example by a push button with two stable positions, designated by the reference 18 in this figure, located for example near the lever 1 and allowing a user to '' activate one or other of the automatic piloting or manual piloting modes with supervised learning, of the gearbox.

 Indeed, this push button 18 makes it possible to engage, in one of its positions, a programming state of the central information processing unit, in which the operation of the gearbox is controlled manually by the user by means of gearbox selection, constituted for example by pushbuttons 11 and 12 located on the steering wheel.

 In this operating mode, the gearbox operates in the same way as a manual gearbox, the reports of which are controlled electronically under the control of the user, by means of push-buttons 11 and 12 for incrementation and decrementation of the reports according to the driving of the vehicle adopted by the user.

 In this programming state, the central unit 2 then stores various operating parameters of the gearbox and of the vehicle delivered by the various sensors mentioned above in order to establish a personalized law for the transmission of the gearbox ratios.

 Once this programming operation has been completed, the user can initiate, still using the push button 18, by passing it into its other stable position, a state of automatic control of the box by this central information processing unit, according to the personalized report shift law established in the other state of the unit.

 As indicated above, the reference laws established during the construction of the vehicle, may not be adapted to the particular mode of driving of a vehicle by a given user.

 Thanks to the specific means of the device according to the invention, the user can then enter into the central information processing unit his own gear shift law during a programming phase and recall it thereafter so that the the operation of the gearbox is checked automatically according to this personalized law.

 It is therefore understood that when the driver turns on the vehicle, and positions the lever 1 opposite the mark D, that is to say in forward gear, the display 15 indicates the latest information concerning the mode or state, the style and the program or law of conduct used previously.

When the device is initialized, that is to say for example when it leaves the vehicle, this display 15 indicates for example what corresponds to a following initial configuration
- Automatic mode, "AUTO"
- Economic driving style, "ECO"
- Reference program, "REF"
Thus, without any action on the selection members, the driver has automatic gearbox operation, according to an automatic driving style with a program for changing the reference ratio pre-established to the construction of the vehicle.

 This so-called economical driving style gives it great driving comfort and minimal fuel consumption.

 The so-called reference program allows gearbox changes to be adapted to a large number of drivers.

 The gearbox reports selected by the central information processing unit are permanently displayed on the display means 14.

 At any time, the driver has the possibility of selecting another mode, another style or another driving program by a simple action respectively on the push buttons 18, 11 or 12.

 For example, when the driver wishes to switch to the so-called sport gear change program, the vehicle being in automatic mode, economic style and reference program, an action on the push button 12 causes the gearbox to shift and more particularly from the sport-style central information processing unit, by selecting a corresponding pre-established gear shift law.

 The display 15 then presents the following information "AUTO.SPORT.REF".

 The gearbox changes are then automatically controlled so as to provide the maximum engine power according to the corresponding law.

 A new action by the driver on the push button 12 causes the central unit to return to a program corresponding to the so-called economical driving style.

 The imminent gear change visual warning 16 shown schematically in Fig. 1 is shown in more detail in Fig. 3.

 This warning is used to indicate to the user an imminent gear change.

 In fact, this alarm is a gauge type display with an indicator designated by the reference 19 in this figure, movable between two extreme marks 20 and 21 corresponding to an automatic incrementation and decrementation of the gearbox ratio.

 In automatic gearbox operating mode, the position of the gauge is always between the two extreme marks.

 This position depends mainly on the speed of the vehicle, the position of the accelerator and the gear engaged.

 An automatic gear up or down takes place when the position of this gauge respectively reaches the right mark or the left mark for example.

 It can therefore be seen that this indicator allows the driver of the vehicle to anticipate automatic changes in the gearbox ratio of the vehicle, by controlling the position and the speed of movement of the indicator.

 The device is switched to the personalized operating phase by action of the driver of the vehicle on the push button 11, the gearbox being in the automatic mode, economy or sport style position and default reference program.

 The display 15 then indicates either: "AUTO.ECO.

PERSO "or" AUTO.SPORT.PERSO. ".

 In this mode, after learning in manual mode which will be described in more detail below, the central information processing and control unit of the gearbox, automatically controls it, according to the personalized law of passage report, established manually beforehand, by the driver of the vehicle.

 It can therefore be seen that, under the same driving conditions, the gear changes memorized in manual mode are reproduced in automatic mode, under the control of the central unit.

 Starting from the predefined styles, economic and sport, it is indeed possible to establish one or more programs of personalized gear changes to satisfy the wishes of each driver, these styles of sport and economic driving can be adapted to the particular driving conditions of the vehicle by each driver.

 A new action on this push button 11 returns the control device and more particularly the central unit, to the reference program.

 The learning phase, i.e. the programming state of the central information processing unit, is engaged by the driver's action on the bistable push-button 18, the device being in mode automatic, economic or sport style, and default or personalized program.

 The display 15 then indicates either "MEM. ECO.

REF "," MEM.SPORT.REF "," MEM.ECO.PERSO "or" MEM.SPORT.PER-
SO ", depending on the style and driving program previously selected.

 The programming state of the central unit being engaged, the operation of the gearbox is controlled by the user by the gear selection means, that is to say for example by the push buttons 11 and 12 located on the steering wheel of the vehicle and allowing the user to increment or decrement the gearbox ratios according to the driving adopted. The central unit then stores various operating parameters of the gearbox and of the vehicle during gearbox gear changes by the driver, to establish a personalized gear shift law.

 In this operating mode, the central unit can be programmed to automatically change gear if the safety of the engine and gearbox requires it, which occurs mainly in engine speed situations too high.

 This programming phase of the central information processing unit and therefore learning of a personalized operation of the automatic gearbox, by the central unit, can be carried out from the economic or sport style operation of reference or from the characteristics of a personalized program previously memorized.

 In the latter case, the driver can indeed continue programming the device after switching to automatic mode, in particular to test and refine the recordings of gear changes to his liking.

 The device returns to automatic operation by action of the driver on the push button 18, this driver can then again select the different styles and programs by action on the push buttons 11 and 12.

 It will therefore be understood that these pushbuttons have two functions, one for selecting the driving styles and programs in the automatic operating mode of the device and the other for incrementing and decrementing the reports of the gearbox, by the user, in supervised learning mode of the device.

 An algorithm illustrating an example of operation of this device is represented in FIG. 4, where it can be seen that the first phase of operation of this device consists of an initialization 22 of the device during which the laws of passage of economic report and sport, are transferred into the RAM of the central information processing unit.

 A pointer to the microprocessor passage law table thereof is then positioned at the address recorded during a previous use of the vehicle.

 Thus, the vehicle finds the mode, program and style used previously.

 This initialization step is followed by a test step 23 which makes it possible to check the values of the various digital and analog signals of the device in order to diagnose a possible sensor failure or a faulty operation of the device.

 If the initialization tests are correct, the device then proceeds to a phase 24 for acquiring input parameters from the sensors described above, that is to say sensors for example of the throttle opening angle of the gas, vehicle speed, engine speed, transverse acceleration and brake pressure and actuator position.

Depending on the state of actuation of the push button 18, which is determined in step 25, this program then continues according to one or the other of the branches.
AUTO (automatic) or MEM (memorization).

 The MEM branch begins with a step 26 during which a gear change calculation takes place to locate the operating point relative to the pre-established shift laws.

 If an action on the push button 11 is detected at 27, then the table of the law of higher passage at the operating point is modified in proportion to its distance from the same operating point.

 The new vehicle and gearbox operating parameters are saved and the gearbox ratio is incremented, at 28.

 When an action on the push-button 12 is detected at 29, the same calculation as above is carried out with the table of the lower passage law and the ratio is decreased 6, at 30.

 The AUTO branch from step 25 begins with a calculation of gear change and distances from the operating point relative to the two passing laws surrounding it, at 31.

 After normalization, these values are those sent to the display 16 described above.

 Depending on the gearbox already selected, a gearshift or not is carried out as illustrated by steps 32, 33 and 34 during which the corresponding variable is incremented, decremented or remains unchanged, these different steps being designated by generally by reference 35.

 After these various operations, if an action on the push button 11 is detected at 36, a change of program is determined at 37 and if an action on the push button 12 is detected at 38, a change in style is determined at 39 conduct.

 In both cases, it is necessary to save the old gear shift laws and load the new laws into memory.

 The display 16 is then updated at 40.

 After having carried out one or the other of these calculations, the central control unit controls at 41 the solenoid valves for controlling the operation of the gearbox in order to effect the corresponding gear changes.

 At 42, the displays 14 and 15 are updated before the central unit starts again for a new general operating cycle described above.

 It will therefore be appreciated that the control device according to the invention makes it possible to achieve the association of a manual mode and an automatic mode of operation of the box for recording on the one hand and restitution on the other hand. '' a custom type of driving.

 The use of these two modes provides the driver with the advantages of both a manual gearbox and an automatic gearbox without operating difficulties.

 The imminent gear change visual warning 16 allows anticipation of automatic gearbox changes.

 This alarm adapts perfectly to the different styles or operating programs of the gearbox.

 The gearbox control strategy can be very different depending on the type of driving and it is therefore important to visually inform the driver of the intention of the central information processing unit, which can then be warned of an imminent gear change to anticipate this change by accelerating or braking to avoid it.

Claims (5)

 1. Control device for an automatic gearbox, in particular for a motor vehicle, of the type comprising means (1) for selecting the main mode of operation of the gearbox, namely parking P, reverse R, neutral N and forward D and authorized gearbox ratios, actuable by a user and linked to a central unit (2) for processing information and controlling the operation of the gearbox (17 ), according to at least one reference report shift law (economic, sport), characterized in that it further comprises means (18) for engaging a programming state of the central processing unit d information (2), in which the operation of the gearbox is controlled by the user, by means (11,12) of gearbox selection and the central unit (2) stores operating parameters of the gearbox and of the vehicle in order to establish a personalized gear shift law and of the means (18, 11, 12) of engaging an automatic control state of the gearbox by the information processing unit, according to the personalized report transfer law.  2. Device according to claim 1, characterized in that it comprises means (16) for warning of an imminent gear change of the gearbox.  3. Device according to claim 2, characterized in that the warning means comprise a gauge provided with an indicator (19) movable between two extreme marks (20,21) corresponding to an incrementation and a decrementation of the reports of the gearbox.  4. Device according to any one of the preceding claims, characterized in that the means for engaging the programming state comprise a push button (18) with two stable positions, actuable by the user.  5. Device according to any one of the preceding claims, characterized in that the gear for selecting reports includes push-buttons (11,12) for incrementing and decrementing the ratios of the gearbox.