FR2838389A1 - Method and control device for controlling engine and clutch torque on drive shaft comprises carrying clutch torque to predetermined value at same time as engine torque is controlled to eliminate clutch slipping - Google Patents

Abstract

The clutch torque (Tc1) is carried to a predetermined value and at the same time the engine torque (Te) is controlled so that slipping of the clutch is eliminated.

Description

B 14067 AP

  The present invention relates to a control device and a method for controlling an engine moment and a clutch moment on a drive shaft of a vehicle with a gearbox and an engine after a shift. of speed. On an automatic gearbox, a moment constitution, during which an engine moment is brought linearly from a starting value to the moment desired by the driver, can be achieved after a gear change. The starting value in this case depends on the speed engaged and the position of the accelerator. At the same time, the clutch moment can be increased, so as to be located above the engine moment, whereby it decreases with the reduction in slip. On this occasion it may happen that the transmissible clutch moment of the clutch still slipping exceeds the moment that the clutch transmits shortly after when the clutch is in the grip position. This means that the acceleration of the vehicle during re-engagement may become greater than immediately afterwards. This increase in acceleration may be felt by vehicle passengers to be unpleasant and

comfort reducer.

  At the beginning of the constitution of the moment, the slip of the clutch can be very important. As a result, the clutch moment does not progress constantly but is increased abruptly. This can also cause vibrations on the drive shaft, which can also be heard.

as comfort reducers.

  It can also happen that the clutch moment exceeds, again during the slippage phase, the value which will be transmitted later by the clutch in grip. In such a case, shortly before the shift from skating to grip, a greater moment than after this shift is transmitted to the wheels. This means that there is an excessive increase in vehicle acceleration, which can

  also reduce travel comfort.

  The task of the invention is to provide a control device and a method for controlling a motor moment and a clutch moment on a drive shaft of a vehicle, intended to allow an improvement in the constitution of a moment, in

  especially after a gear change.

  This goal is. in terms of process, achieved by a process for controlling an engine moment and a clutch moment on a drive shaft of a vehicle with a gearbox and an engine after a shifting, during which a clutch moment is brought to a predetermined value and o at the same time the engine moment is controlled so that the slip of

the clutch is removed.

  Consequently, with the method according to the invention, a moment constitution as constant as possible, particularly after a gear change, is achieved, so that a progression of the acceleration of the vehicle from zero to the required acceleration is

  made possible without local extremes.

  With the strategy according to the invention, the clutch moment can for example be brought from a value 0, preferably in a linear manner, to a value which corresponds to the clutch moment immediately after switching to grip. of the clutch. It is also possible to use other values. The value of the TC12 clutch moment can preferably be calculated using the following equation: Jv Ted-i-Je TT = cl2 i Je + Jv Te being the engine moment required by the driver, and / or the moment desired by the driver, Jv the moment of inertia of the vehicle, i the reduction ratio, I the moment of inertia of the engine and Tr the sum of all the moments influencing the

vehicle.

  According to an extension of the invention, the motor moment can preferably be controlled at the same time, so that the slip is reduced exactly at the instant when the clutch moment reaches the aforementioned value when switching to clutch adhesion. It is also conceivable that from this instant the moment of the motor again corresponds

  at the time desired by the driver.

  In the context of an extension of the invention, it can be provided that, if for example the motor moment cannot be controlled with sufficient precision, the speed of rotation of the motor is, for example, moreover controlled by means of modulation of the clutch moment. However, care should be taken on this occasion that the clutch moment increases uniformly during re-engagement. This type of order strategy can also be used in

as so-called pre-order.

  When the clutch is in grip, the equation of movement of the engine can be defined by means of the following equation: I ci) e = Te-Tc; and the equation of movement of the vehicle by means of the following equation: Jv gbi = Tr + i Tc 'T * C1 designating the clutch moment transmitted by the clutch in grip and gbi the speed of rotation

  the input shaft of the gearbox.

  Furthermore, the sum Tr of all the moments influencing the drive shaft can be calculated using the following equation: Tr = ti Je +, V À ae-i Te e denoting the acceleration of the speed of

motor rotation.

  The object on which the invention is based can, in terms of device, be achieved by means of a control device for a drive shaft of a vehicle with a motor and a gearbox, coupled by means of at least one clutch, intended in particular for carrying out the proposed method, in which at least one engine control unit and at least one gearbox control unit are provided, which control the engine moment and the moment of clutch so that after a gear shift a moment constitution also

constant as possible is expected.

  Other advantages and advantageous developments

  result from subclaims and drawings

  described later. It can be seen there that: FIG. 1 shows a schematic view of a drive shaft with a clutch, and FIG. 2 shows a functional diagram relating to a possible development of the method according to

the invention.

  In FIG. 1, a model of drive shaft, with the aid of which the physical behavior of the drive shaft is described, is schematically sketched The motor here has the moment of inertia I and can deliver the moment of the motor adjustable Te, which corresponds to the torque of the internal combustion engine. The

  motor rotation speed is designated by e.

  The clutch can transmit a moment, whose value is less than or equal to TC1. When the clutch is in slip, this value is exactly equal to that of TC13, when the clutch is in grip, it reaches at most TC1. The transmissible torque of the TCl clutch is adjustable. A reduction i is provided between the clutch and the vehicle. The speed of rotation of the left-hand gearbox, therefore of the gearbox input shaft, is designated by gbi. The vehicle has the moment of inertia Jv. The resistance force, which consists of rolling resistance, air resistance and downward force, influences the vehicle from the outside. The sum of all

  moments influencing the vehicle is designated by Tr.

  FIG. 2 represents a functional diagram relating to a possible development of the method according to the invention. The different process steps are

  visible on the functional diagram.

  At the start of the process, it is checked whether the clutch is on the drive shaft. When the new speed must be engaged, the clutch moment TC12 can be calculated using the following equation 1: T. _ JV ÀTe'-i Je Tr Eq. 1 c12 i À Je + Jv the motor moment Te required by the driver being designated by Te, d. In order to be able to resolve the

  right side of equation 1, you need to know Tr.

  When the clutch is in grip, the equations of motion for the engine and the vehicle are defined using the following equations: Jv e = Te - Tc Eq. 2 I g = Tr + i Tc 'Eq. 3 TC1 being the moment transmitted by the clutch during the grip. The elimination of this quantity from equations 2 and 3 as well as the resolution as a function of Tr lead to the following equation 4: r (e) e Eq. 4 From this equation, Tr can be calculated, whereby e is determined by the derivative

digital of e.

  During the method according to the invention, the clutch moment TC1 is brought linearly from 0 to TC12 during the constitution of the moment: Tct = st Eq. 5 s designating the portion of the constitution of the moment. The duration t results from equation 6: T. c12 Eq. 6 s The other stages and / or requirements of the strategy lead to the following formulas: e (r) = gbi (r) Eq. 7 Te (r) = Ted (r) Eq. 8 Ted (t) designating the moment desired by the driver at the end of the constitution of the moment. I1 is assumed here, that this is practically constant; this results in Te, d (T) = Te, d (t) = Te, d. The rotational speeds of the left and right parts of equation 7 can be determined by integrating the equations of motion 2 and 3: 6) e (O) + J. | (Te (t) -TCi (t)) dt = gbi (O) + J. | (Tr + i Tc (t)) dt Eq. 9 e 0 v 0 Tr not being significantly modified during the observed period, which means that it does not depend on t. The right side of equation 9 can be solved by introducing the equations for TCl (t). gbi (r) = J. (Tr + 2 AT TCI2) + gbi (O) Eq. 10 With equations 8 and 9, two conditions are

  linked to the time sequence of the motor moment Te.

  For Te (t), any starting point, depending exactly on two parameters still to be determined, can now be chosen. We can preferably choose a time sequence, in which t appears up to a power 2. We can also require that Te be constant when t = 0: Te (t) = Te (0) + a-t + b t2 eq. 11 The right part of equation 11 is introduced into the left part of equation 8 and resolved as a function of a: a = - (Ted-Te (0) -b) Eq. 12 The straight parts of equations 5, 10 and 11 are introduced into equation 9, integrated and resolved as a function of b: b = 3 (2 (Ted + Te (O) -Tcl2) -Je À (gbi () - e (O))) Eq. 13 Consequently, the clutch moment TC1 and the engine moment Te can be appropriately controlled using equations 5 and 11. The quantities contained in the equations can be calculated by the consecutive exploitation of the

equations 4, 1, 10, 13 and 12.

  It can be assumed that the moment desired by the driver Te, d and the resistive force remain practically constant during the re-engagement. However, this assumption should not be absolutely based. The updated values of these quantities are permanently accessible to the order code. In this way the required moment Tcl2 of the clutch, which is necessary for the calaul of the current clutch moment according to equation 5, can be adapted to each interruption according to the modified values of the moment desired by the driver Ted and the sum of all moments Tr influencing the drive joint This can also be done using parameters a and b, used to calculate the moment of

Te engine.

  During the proposed method, intended for controlling an engine moment Te and a clutch moment TC on a drive shaft of a vehicle, the process described above and represented in FIG. 2 is

  preferably applied once per cycle.

  The claims filed with the request for

  patent are formulation proposals without prejudice to obtaining patent protections beyond the initial framework. The applicant reserves the right to claim still other combinations of characteristics which are not yet disclosed.

  as in the description and / or the drawings.

  Correlations used in sub-

  claims refer to another development of

  the subject of the main claim through

  characteristics of each of the subclaims;

  they should not be regarded as a waiver of independent object-related protection for combinations of characteristics of the

correlative subclaims.

  Since the objects of the subclaims,

  having regard to the state of the art at the time of priority, may constitute own and independent inventions, the applicant reserves the right to

  be the subject of claims or declarations by

  independent dissociation. They may also also contain independent inventions comprising developments independent of the objects

  of the aforementioned subclaims.

  The exemplary embodiments should not be understood as a restriction of the invention. On the contrary, within the framework of the present disclosure, numerous adaptations and modifications are possible, in particular variants, elements and combinations and / or materials which can, for example, by combination or adaptation of different characteristics, and / or elements or process steps,

  in conjunction with those described in the description

  general, in the embodiments as well as in

  the claims and contained in the drawings, be

  taken by the specialist with a view to achieving the goal and which end up by means of characteristics which can be combined with a new object or with new process steps and / or with a new chronology of the steps, also insofar as they relate to processes construction, checking or working

RVENCICAIIONS

  1. ProcdA deLind the command of an engine moment and a clutch moment on a drive shaft of a vehicle with a gearbox and a motor after a gear shift, characterized in that the clutch moment {T.] is given a predetermined value and at the same time the engine moment (I,) is controlled so that the slip

of the clutch is removed.

  2. Method according to claim 1, characterized in that the clutch moment (Ic] is uniformly carried by a clutch moment directly after the gear change (value O) a preadmitted value, which corresponds to the clutch moment (Ic) immediately after the passage

the adhrence.

  1. [rocAd according to claim 2, caractdrisA in that the value of the clutch moment (Ic =) is calculated by means of the following equation:

7, (-!

2 0 (72 = .2 '

  f 7, + 7, 4. ProcdA according to any one of

  PREVIOUS CLAIMS, CHARACTERIZED IN THAT

  clutch slip is suppressed by controlling the engine moment (Ie) exactly the instant when the clutch moment reaches the value (Ic =) and / or the engine moment (I,) corresponds from this

  new moment at the moment desired by the driver.

  5. Method according to any one of

  preceding claims, characterized in that the

  engine rotation speed for controlling the engine moment (Te) is adjusted by changing the clutch moment (Tcl). 6. Method according to claim 4, characterized in that the clutch moment (TC1) is increased by

  evenly during re-engagement.

  7. Method according to any one of

  previous claims, characterized in that

  of the clutch adhesion, the equation of movement of the engine is predefined by means of the following equation: I (ie = Te-Tci 8. Method according to any one of

  previous claims, characterized in that

  from the clutch grip, the vehicle movement equation is defined using the following equation: Jv gbi = Tr + i Tc 9. Method according to any one of

  preceding claims, characterized in that the

  sum of all the moments influencing the drive shaft (Tr) is calibrated using the following equation: Tr = i I +) À ei À Te 10. Control device for a drive shaft of a vehicle with an engine and a gearbox, coupled by means of at least one clutch, intended in particular for carrying out the

  method according to one of claims 1 to 9,

  characterized in that at least one engine control unit and at least one gearbox control unit are provided, which control the engine moment (Te) and the clutch moment (TC1) so that '' after a gear change as constant a moment constitution is possible