WO2008029041A1 - Method of controlling a device for the controlled coupling of two dogs - Google Patents

Abstract

The invention relates to the field of the close control of the ratios of an integrated sequential gearbox, without a synchronizing mechanism, either within a conventional power train or within a hybrid power train which includes one or more electric drive motors in addition to the internal combustion engine. The coupling device comprises two dogs which rotate about the same axis and are each formed by teeth, the dogs being able to engage under the action of a mechanism which produces a force allowing the translational movement of one of the dogs, which is movable with respect to the other dog, the translation taking place along the axis of rotation of the dogs. The method comprises at least the following phases: a first approach phase without contact between the dogs, where a maximum force (Umax) is applied which allows the translation of the movable dog; a second phase where the force applied (Uanticip) is reduced in order to detect the nature of the contacts between the teeth of the dogs from among at least the following three states: no contact, contact promoting the movement of the movable dog, and contact opposing the movement of the movable dog; a phase of determining a relative angular path (161, 162, 163) between the teeth, between an initial instant and an end-of-contact instant ti; a phase of calculating and applying the force to be applied (U(t)) in order to follow the determined path (161, 162, 163).

Description

 Method for controlling a controlled coupling device of two jaw

The present invention relates to a method of controlling a controlled coupling device of two claws.

The invention relates to the field of close-ratio control of an integrated sequential gearbox, either within a conventional traction chain or within a hybrid traction system including in addition to the engine one or more electric traction motors. More generally, the invention relates to any traction chain for which it is necessary to place between the source of mechanical energy, that is to say the engine, and the wheels a sequential gearbox to meet the constraints of functioning related to the source of mechanical energy.

Usually a gearbox is made up of several shafts provided with a set of pinions making it possible to obtain several gear ratios and therefore several pairs between the input shaft of the gearbox and the output shaft. The gears are usually geared in pairs, the first being mounted integral with one of the shafts, the other being mounted crazy by default on the other shaft. An actuating device allows, according to the requested ratio, to make the idle gear integral with the shaft around which it rotates, or on the contrary to separate it from this shaft to make it free. This actuating device generally comprises, for each set of two gears, a set of two claws, a synchronization mechanism and a drive mechanism in translation of a clutch linked to the shaft to perform either a clutch or a dog clutch. Because of a part of the integration of engine control computers on the mechanical energy sources of traction, whether it is thermal engine or electric, the establishment of chains of actuation of change of automated report or the implementation of position sensors and speed to know precisely and at any time the relative speed between the two gears in rotation and in translation, steering gear change becomes easier. Under these conditions, the presence of the mechanical synchronization mechanism is no longer necessary because it is quite possible to consider reconstituting this synchronization by setting up a control algorithm ensuring the synchronization between the device of change of synchronization. ratio, the traction motor concerned by the gear change and the vehicle load.

A chain of change gear without synchronization device allows in particular to simplify the gearbox, reduce its size and thus limit its cost. In this case, a problem is to ensure a time of clutch as small as possible to minimize the discomfort of the driver. However, according to the relative positioning of the claws relative to each other at the time of contact, it appears a strong dispersion in this time of interconnection especially in the case of a too simple control of the shift actuation chain. This is the case for example when using an open loop type command or a looped command in dog position. This problem can be solved by playing on the steering mode of the shift actuation chain.

An object of the invention is in particular to control the traction motor in play to achieve better management of the relative position and angular velocity between the claws, particularly during tooth-to-tooth contact phases. For this purpose, the subject of the invention is a method for controlling a coupling device for two jaw claws rotating around the same axis and each formed with teeth, the jaw being capable of meshing under the action of a mechanism producing a force allowing the displacement in translation of one of the jaw, movable relative to the other, the translation being along the axis of rotation of the jaw. The method comprises at least the following phases:

- A first phase of approach without contact between the claws, where a maximum effort is applied allowing the translation of the mobile clutch;

a second phase where the force applied is decreased to detect the nature of the contacts between the teeth of the claws among at least the three states: no contact, contact promoting the movement of the mobile clutch and contact opposing the movement of the mobile clutch, and in case of detected contact;

a third phase of determining a relative angular trajectory between the teeth, between an initial moment and an instant ti of end of contact; and

a fourth phase of calculation and application of the effort to be applied to follow the determined trajectory.

Advantageously, the angular trajectory comprises, for example, a component defined for the relative angular position Δθ, a component defined for the relative angular velocity Δω, and a component defined for the relative acceleration Δγ.

The trajectories can be defined by conditions of values Δθi, Δcoi,

Δγi at time t-i. The angular position trajectory is for example a polynomial where the variable is the time t, the other paths in speed and acceleration being determined by successive taps with respect to time.

The detection of the nature of the contacts is for example between two positions θ-i, θr of the movable clutch corresponding to the minimum and maximum positions of the vertex O of the teeth of the mobile clutch in contact phase with the teeth of the other clutch.

If in the interval between the two positions θ-i, θr there is no contact, the maximum force is applied.

When the position of the movable clutch reaches the maximum contact position θr, the maximum force is for example applied to a position Q ₂ where begins a phase of end-of-travel regulation of the mobile clutch.

The force applied is for example produced by a motor controlled voltage U (t) function of time.

Other characteristics and advantages of the invention will become apparent with the aid of the following description made with reference to appended drawings which represent:

- Figure 1, a schematic representation of a claw coupling device comprising a synchronization mechanism; - Figure 2, a schematic representation of a clutch coupling device without synchronization mechanism according to the prior art;

FIG. 3 is a schematic representation of an example of a claw coupling device to which the invention can be applied;

- Figures 4 and 5, an illustration of possible configurations of the teeth of the jaw before jaw clutch;

- Figure 6, a representation of different possible cases of relative positioning of the teeth of the claws at the time of contact with the teeth;

FIGS. 7a and 7b, an illustration of the effect of the tooth-to-tooth contact on the relative speed variation between two jaw claws;

FIG. 8, a representation of the states of a state detection estimator that can be used by a method according to the invention; FIG. 9, an illustration of the possible phases of a method according to the invention;

FIGS. 10a and 10b, respectively illustrations of a start-up phase and a tooth contact anticipation phase implemented by the method according to the invention; - Figures 1 1a and 1 1b, respectively illustrations of a case where there is no tooth-to-tooth contact and a contact management in a first state;

- Figures 12a, 12b, 13a and 13b of the illustrations of two contact management in a second state; - Figure 14, an illustration of the position of the jaw teeth at the end of the race;

- Figure 15, an illustration of the relative positions with respect to a tooth during a dog clutch;

FIG. 16, a representation of relative position trajectories, speeds and angular accelerations used by the method according to the invention.

Figures 1 and 2 illustrate the prior art. FIG. 1 schematically represents a claw coupling device comprising a timing mechanism and Figure 2 schematically shows the same device without synchronization mechanism. FIG. 1 therefore represents an example of driving two shafts 1, 2. The shaft 1 is an input shaft of the gearbox and the shaft 2 is an output shaft of the gearbox. A pinion 3 is integral with the shaft 1 and a pinion 4 is mounted loosely on the output shaft 2. An actuating device 5 allows, according to the report requested, to make the pinion 4 integral with the shaft 2 around which it turns, or on the contrary to separate it from this tree 2 to make it free. The actuating device 5 comprises two claws 6 and 7. The clutch 6 is integral with the idler gear 4 and the dog clutch 7 is integral in rotation with the output shaft 2 around which the idler gear 4 rotates and free in translation along of the axis of rotation of the shaft 2. The clutch 6 has teeth 9 adapted to be interposed between teeth 10 of the clutch 7 so as to make the idle gear 4 of the shaft 2 around which it rotates .

The actuating device 5 also comprises a synchronization mechanism 1 1 generally comprising two cones 12 and 13 associated with each of the claws 6 and 7 and making it possible to cancel the difference in speed of rotation that can exist between the claws 6 and 7 when a clutch is desired to change gear and thus to avoid excessive shock between the gears 3 and 4. Such shocks can lead to premature wear of the jaw 6 and 7 and also to a loss of pleasure for the driver. a vehicle equipped with such a gearbox in a shift phase. The actuating device 5 further comprises a drive mechanism in translation of the clutch 7 to perform either a clutch or a clutch. To avoid overloading the figure, the steering mechanism is not shown. Arrows 14 nevertheless show the movement of the clutch 7 to obtain the interconnection. Thanks to new means, in particular calculators and relative speed sensors between the claws, mechanical synchronization mechanism using the cones 12 and 13 shown in FIG. 1 can be dispensed with. It is quite possible to reconstitute the synchronization by setting up a control algorithm ensuring synchronization between the gearshift device and the traction motor affected by the shift and the vehicle load. Such a simplification is shown in Figure 2. It allows to simplify the gearbox.

As indicated above, it has been found that according to the relative angular positioning of the claws 6 and 7 relative to each other at the time of contact between their respective teeth, there appears a strong dispersion over time to perform the interconnection.

FIG. 3 represents a jaw coupling device without a synchronization mechanism and taking up the various elements of the device of FIG. 2, namely the shafts 1 and 2, the pinions 3 and 4 and the dogs 6 and 7. The shaft 1 is for example an input shaft of a gearbox and is connected to a traction motor 18 thermal or electrical. The shaft 2 is for example an output shaft of the gearbox and is connected to the wheels of a vehicle equipped with the gearbox. The drive mechanism in translation of the clutch 7 comprises an electric motor 20 and a barrel 21 driven by the electric motor 20 via a speed reducer 22. The barrel 21 is hollowed by at least one track 23 in which a finger 24 can slide. The track 23 has for example a helical shape around a shaft 25 of rotation of the cylinder 21. The finger 24 is secured to a fork 26 driving the dog 7 in translation along the shaft 2. The translational movement of the fork 26 is represented by the arrow 27. In FIG. 3, a curve 28 is shown showing the relation, defined by the profile of the track 23, between the rotation angle θ _b of the shaft 25 and the displacement in translation of the finger 24 along an axis z parallel to the shaft 2.

The mechanism further comprises a first angular velocity sensor 30 of the rotation of the barrel shaft 25, a second angular velocity sensor 31 of the rotation of the input shaft 1 and a third angular velocity sensor 32 of the rotation of the output shaft 2. The sensors 30, 31 and 32 transmit to a computer 33 the rotational speeds of the shafts 1, 2 and 25. The computer 33 allows in particular to control the motors 18 and 20.

FIGS. 4 and 5 respectively represent two examples of shape of the teeth 9 and 10 respectively belonging to jaw 6 and 7. The teeth 9 and 10 are positioned regularly on the same mean radius around the axis of the shaft 2 so that the teeth 10 of the clutch 7 can be inserted into recesses formed between the teeth 9 of the dog clutch 6. It is assumed that the number and the shape of the teeth 9 and 10 of each clutch 6 and 7 are identical. It is quite possible to implement the invention in other geometric configurations of teeth and in particular in the case where the dog 7 is provided with large teeth 35 similar to the teeth 10 and the other clutch 6 is provided with both large teeth 36 identical to the teeth 35 and in addition to small teeth 37 of the same shape as the large teeth 36 in a reduced size and formed in the recesses formed between the large teeth 36 as shown in Figure 5.

Each tooth has two types of faces, flanks and a vertex. Each tooth 10 has two flanks 40 and 41 whose normal axis is substantially perpendicular to the axis of translation of the claws 6 and 7. The flanks 40 and 41 may be slightly inclined at an angle θf, as shown in FIG. to produce an effect opposing declutching. The angle θf is advantageously less than 10 °. The flanks 42 and 43 of the teeth 9 are parallel to the corresponding flanks, respectively 40 and 41, of the teeth 10. Each tooth 10 has a vertex 44 whose shape is substantially in a plane whose normal axis is parallel to the axis of translation of jaw 6 and 7. The shape of the vertex 44 may for example be curved but for reasons of simplicity it is considered that the vertex 44 has two plane faces 44a and 44b symmetrical with respect to a plane of symmetry of the two flanks 40 and 41 The two faces are inclined at an angle θd advantageously less than 15 °. Each tooth 9 also has a vertex 45 similar to the apex 44. As before, it can also be considered that the vertex 45 has two flat faces 45a and 45b. The curved shape, modeled by the flat faces 44a, 44b, 45a and 45b produced in the event of contact of the crown-to-apex teeth, is an increase in the difference in angular velocity between jaws (in this case the surface promotes the angular movement between teeth) , or a decrease in angular velocity between jaw (in this case the surface opposes the angular movement between teeth). Depending on the position and the initial relative angular velocity between the two claws, several geometrical contact configurations of the teeth facing each other are possible during the clutching: a) Tooth contact on the tooth tip with orientation of the tooth crown surface promoting the relative angular movement between jaw. c) Tooth-to-tooth-to-tooth contact with orientation of the tooth-crown surface opposing relative angular movement between jaws. b) Flank contact on the side of the teeth. In this case, the teeth are positioned directly in their respective hollow.

In FIG. 4, there is shown in bold line a curve-envelope 46 of the possible positions of a point O located in the middle of the vertex 44 of the tooth 10 during the contact of the teeth 9 and 10 during the interconnection. The envelope 46 makes it possible to statistically predict the probability of having one of the three configurations a) b) and c) previously described. The casing 46 is represented on an angular length c about the axis of rotation of the claws equal to 2ττ / n, where n represents the total number of teeth of one of the claws. In a first portion 46 (1) of the casing 46 of angular length a, it is in the first configuration a) of tooth-to-tooth-to-tooth contact with orientation of the tooth-crown surface promoting relative angular movement between jaw. In a second portion 46 (2) of the envelope 46 of angular length b, one is in the second configuration b) flank contact on the side of the teeth. In a third portion 46 (3) of the casing 46 of angular length a, it is found in the third configuration c) of tooth-to-tooth-to-tooth contact with orientation of the tooth-crown surface opposing the movement relative angular between jaw. It can be seen that the probability b / c of configuration b) flank on flank is much lower than the probability of the other two configurations a) and c) since b represents the clearance between the angular length of the spaces between teeth and tooth widths. that we want to limit including for reasons of comfort and pleasure of driving the vehicle. By defining the clutch time as the time taken by the claws to reach the position where the contact between teeth 9 and 10 is effective flank on the flank, it is obvious that the shortest time will be obtained if the sidewall flank configuration is first in phase of interconnection. Unfortunately, this situation is the least likely. In most cases, the claws end up in a tooth-topped configuration, which not only generates shock but also a waste of time.

As an illustration of the foregoing, an envelope curve 50 has also been shown in FIG.

FIG. 6 shows various possible cases during the interconnection, obtained with a control of the motor 20 of the drive mechanism in translation of the clutch 7 of the open-loop type, by constantly supplying it with its maximum tension. These cases are as much a source of dispersion in the times obtained by interconnection. FIG. 6 represents different relative positions of the two claws 6 and 7. For each case, the positions chronologically follow one another from the top to the bottom of FIG. 6. Arrows show the relative movement of a tooth 10 with respect to a tooth 9 In case No. 1, a crown to tooth contact is obtained to increase the angular velocity between jaws. After this contact, the teeth fall into their respective hollows and then support flank on flank.

In case No. 2, the teeth fall directly into their respective recesses and then bear flank on the flank As explained above, the time of interconnection is very short here, but the probability of occurrence of case # 2 is very low.

In case No. 3, a tooth-to-tooth-to-tooth contact is first obtained opposing the relative angular movement between jaws. In a first step, the relative angle continues to increase resulting in an inversion of the movement (therefore the speed) of translation between teeth (ascent of the tooth 10). In a second step, the relative angle stabilizes and then decreases (thus the angular relative speed is reversed) so that the translation movement is reversed again (inversion of the translation speed). Finally the teeth fall into their respective hollow and then support flank on flank. In case No. 4, as in case No. 3, a tooth-to-tooth-to-tooth contact is obtained opposing the relative angular movement between jaws. But this time, unlike in case 3, the relative angular movement between jaw is not reversed. At first, the translational movement between jaws reverses to cause a rise of the tooth 10. In a second time after passing to the top of the tooth, the translation movement is reversed again to cause a descent of the tooth 10 on the opposite side. Finally, the teeth fall into their respective hollows and then make contact flank on flank. Among all these situations, the case No. 3 is the one that leads to the longest clutching time, especially for significant relative speeds.

Faced with this diversity of situations and therefore of dispersion and lengthening of the clutching times, the invention proposes in particular a motor control of the gearshift actuation chain reducing the time of interconnection and the dispersion of this time following the situations encountered.

FIGS. 7a and 7b illustrate the effect of the tooth-to-tooth contact on the relative speed variation Δω between two jaws 9, 10. FIG. 7a illustrates the case where the relative speed, in absolute value, increases during the duration of the contact. In this case, irrespective of the sign of the relative speed Δω, the relative displacement in rotation 71a and in translation 71b of the tooth 10 relative to the tooth 9 promotes the interconnection (two jaw clutch). . FIG. 7a illustrates the two cases where Δω> 0 and Δω <0. FIG. 7b illustrates the case where, whatever the sign of the relative speed Δω, the relative displacement in rotation 72a and in translation 72b of the tooth 10 relative to to the tooth 9 promotes the decrabotage (distance of 2 jaw). . In this case, the relative speed, in absolute value, decreases during the duration of the contact.

When the relative speed before contact is constant, a tooth to tooth contact therefore results in a variation of the relative speed Δω. Thus, from the knowledge of the value and the sign of the relative speed before contact and its variation (sign of its derivative) during the duration of the contact or just after the instant of contact and the position of the barrel, defined not his angular position θb, it is possible to estimate the type of surfaces of the teeth in contact, that is to say either a surface promoting an increase in the absolute value of the relative speed or a surface promoting a decrease in the absolute value relative speed. It is then possible to estimate the relative angular position Δθ of the teeth 9, 10.

The method according to the invention estimates the nature of the surfaces in contact and the relative position of the jaw teeth in order to apply a more appropriate control. This control controls the force applied on the clutch 7 driven by the barrel 21. More particularly, with reference to FIG. 3, the control is for example a voltage setpoint U which controls the motor 20 activating the barrel 21. The higher the setpoint voltage U is, the greater the force applied on the clutch is important for example. In particular, the appropriate command allows:

or to apply the command with a reduced voltage U _min to reduce the time of interconnection situations type of case No. 3 of Figure 6 by transforming them in case No. 4, the cases No. 3 being the most consumer time for high relative speeds Δω, in the case where the tooth-to-tooth contact tends to decrease the relative speed in absolute value, until the tooth-to-tooth tip state is reached;

- either to apply a command with a maximum tension U _ma χ for example, avoiding to increase too much the time of the cases n ° 4, where the contact tooth on tooth tends to increase the speed relative in absolute value or to increase too much the clutch times of cases n ° 3 for low relative speeds Δω;

or to apply a command with a maximum voltage U _ma χ for example for situations of the type of the case n ° 1.

FIG. 8 presents the states of a state machine for detecting tooth-to-tooth contacts between the two jaw 6, 7, used by the invention. This machine, which is an estimator, has three states 81, 82, 83:

- A first state 81, noted 0 state, where there is no tooth contact on tooth; - A second state 82, noted state 1, where there is contact tooth on tooth promoting movement, that is to say that the contact has the effect of increasing the absolute value of the relative speed between the jaw;

≥ > 0 et 6> ≤ θ_b ≤ θ_v (1 ) dt - passage 84 de l'état 1 à l'état 0 : ω_b > ω_{b seuιl} et θ_b > θ_v (2)- A third state 83, noted state 2, where there is contact tooth on tooth opposing the movement, that is to say that the contact tends to decrease the absolute value of the relative speed between the jaw. The conditions for passing from one state to another are, for example, as follows: passage 83 from state 0 to state 11 ::

≥> 0 and 6> ≤ θ _b ≤ θ _v (1) dt - passage 84 from state 1 to state 0: ω _b > ω _{b threshold} and θ _b > θ _v (2)

passage 85 from state 1 to state 2: <0 (3)

transition 86 from state 2 to state 1: ≥ 0 (4)

< 0 et 6> ≤ θ_b ≤ θ_v (5) dttransition 87 from state 0 to state 2:

<0 and 6> ≤ θ _b ≤ θ _v (5) dt

passage 88 from state 2 to state 0: θ _b <θ _v (6) θi and θr are positions of the barrel which will be specified hereinafter with reference to FIGS. 10 to 14.

It should be noted that the transition from state 2 to state 0 may occur in some cases, especially in case of high relative speed, but may remain marginal compared to transitions from state 0 to states 1 and 2 and the transition from state 2 to state 1. The transition from state 1 to state 2 may not be considered.

In FIG. 8, the conditions for passing from one state to another are expressed by relations involving the angular position of the barrel θ _b , the rotational speed of the barrel cb and the temporal variation of the relative speed Δω. Given the characteristics of the kinematic chain, some relationships may be substituted by equivalent relationships expressed with other variables. For example, the position θ _b of the barrel 21 and the translational position x of the clutch 7 are equivalent, as follows:

x ≈ R _b t _a n (Ψ _max) θ _b x + _ι (7) where:

Rb expresses the effective radius of the barrel 21; Ψmax expresses the maximum angle of ramp 28;

- x, is an abscissa of origin.

However, since it is assumed that the angular position information θ _b of the barrel is available at each instant, the machine of FIG. 8 favors the writing of the conditions of passage from one state to another with this variable.

The estimation of the relative angular position Δθ _c i between jaw in state 1 is given by the following relation:

Ae ₁ = SIgHe [Au)) ^ - ^ + k- (8)

^ _c _ ^ tan (^) n

The estimation of the relative angular position ΔΘ _C 2 between jaw in state 2 is given by the following relation:

Aθ _c2 = ₊ sign {Aω) ^{X ~ X} \ _{Û Λ} + k- (9)

x, being the relative position in translation between jaw in the state 1 and in the state 2 (defined as a function of the angular position θ _b according to the relation (7), Xi being the relative position in translation between jaw corresponding to the angular position G ₁ , the magnitude R _c _dθnt expressing the average radius of the jaw 6.7, sign (Δω) expressing the sign of the relative angular velocity Δω and θd expressing the chamfer angle defined above.

FIG. 9 illustrates a control method according to the invention. A control according to the invention is based in particular on the state machine for detecting contacts between jaw described in relation to FIG. 8 and comprises, for example, the following phases:

- Phase 1: start of the interconnection phase 91;

Phase 2: anticipation 92 and detection 93 of the contact and the contact surfaces;

- Phase 3: contact management; - Phase 4: management of the end of interconnection, by regulation 94 of the end of the barrel 21.

These different phases of the control according to the position of the cylinder will also be described with reference to FIGS. 10 to 14; representing the same as those of Figure 4. Moreover, in these Figures 10 to 14, the relative positions of the teeth 9 of the clutch 6 relative to the teeth 10 of the clutch 7 are illustrated with respect to the angular positions θb of the barrel, positions equivalent to the translational positions of the barrel and therefore of the clutch 7. The positions θi and θr evoked above correspond respectively to the minimum and maximum positions of the point O of the vertices 45 of the teeth 10 in the contact phase with the teeth 9, these positions are equivalent to the positions xi, x _r of Figure 4. Phase 1 is a contactless approach phase of the clutch 7, movable relative to the clutch 6, considered fixed. It applies a maximum force for the translation of the mobile clutch. Thus, in phase 1, the control of the motor 20 is for example set to full voltage U _ma χ from the initial relative position to the position θ ₀ of the barrel, equivalent to the translation position X ₀ of the barrel. No contact between the teeth has occurred during this time, the system is in the state 0 defined relative to Figure 8, which therefore remains always the same regardless of the configurations occurring thereafter. The voltage applied to the input of the electric motor 20 is maximum in order to minimize the start-up time, therefore the clutch time. This state is illustrated by FIG. 10a and the position of the teeth 9 is such that 0 <θ _b <θ ₀ .

In phase 2, from the position θ ₀ , the control of the motor is then greatly reduced by a setpoint voltage Ua _n tiαp lower than U _m ax in order to anticipate tooth to tooth contact, this situation is illustrated by Figure 10b where θ ₀ <θ _b <θ-i. After this contact anticipation step 92, the method performs a contact detection 93:

- If in the barrel position interval between θi and θr is [θ-i, θr], the contact detection status machine remains in state 0, there has been no tooth contact on tooth and the Uantiαp command is maintained. From the position θr of the barrel, one applies again a full voltage control U = U _ma χ as illustrated in

94 in FIG. 9, until the position θb of the cylinder reaches a limit position θ ₂ as illustrated in FIG. 11a, in phase 3.

- If instead the state machine does not remain in the 0 state, from either state 1 or the state 2, it calculates the relative position Δθ _c of the teeth of jaw. The stages of phase 3 differ depending on whether the state machine is in state 1 or state 2.

If the machine is in the state 1, it is in the case illustrated by Figure 1 1b where the contact tends to increase the relative speed in absolute value. We apply again a full voltage control U = U _ma χ as illustrated in 95 of Figure 9.

If the machine is in state 2, the contact tends to decrease the relative speed in absolute value. Several commands commands 96, 97, 98 are possible according to the relative position of the jaw teeth Δθ _c and the relative value Δω. In this case, several criteria must be taken into consideration:

Criterion 1: Δ ^ <Δω _seud and (Aθ _c <Aθ _{c semn} (Aω) or Aθ _c > Aθ _{c semll} (Aω)) (1 0) Criterion 2: Δ ^> Aω _only and (Aθ _c ≥ Aθ _{c seudl} (Aω) or Aθ _c ≤ Aθ _{c only} (Aω)) (1 1)

Criterion 3.1: Δ ^ <Aω _only and {Aθ _c ≥ Aθ _{c semll} (Aω) or Aθ _c ≤ Aθ _{c seml2} (Aω)) (1 2) Criterion 3.2: Δ ^> Aω _seml and (Aθ _c <Aθ _c _ _semn (Aω) or Aθ _c > Aθ _c _ _seml2 (Aω)) (1 3)

Indices with the term "threshold" indicate that they are threshold values.

Criterion 1, defined by relation (10), is checked when the relative speed

Δω is small, less than a threshold, and the relative position of the teeth of the claws Δθ _c is close to the tip-to-tip position, ie Δθc <Δθ _c _seuιii or Δθ _c > Δθ _c _ _S euιi2, as illustrated in Figure 12a. In the case where this criterion 1 is verified, a full voltage command U = Umax is applied, as illustrated in 96 of FIG. 9, since the time necessary for the relative speed to change sign is relatively short. Once the relative speed has changed sign, then we are in state 1, that is to say in the case where the contact tends to increase the relative velocity in absolute value and we apply again a maximum voltage U = U _max as illustrated in 95 of FIG. 9. The criterion 2, defined by the relation (11), is verified when the relative speed Δω is high, greater than a threshold, and the relative position of the teeth of the jaws Δθ _c is remote from the tooth-to-tip position, ie Δθc> Δθ _c _sθuιii or ΔΘC <ΔΘ _C _SΘUII2, as illustrated in Figure 12b. In the case where this criterion 2 is verified, a voltage U = U _min is applied, as illustrated in 98 of FIG. 9, so that the tooth contact on tooth in state 2 does not take too much time. We pass the position tip of tooth on tip of the contact surfaces change and then it is in state 1. A full voltage U = U _ma χ is again applied as illustrated in 95 of FIG. 9.

The other two criteria to be considered, criterion 3.1 and criterion 3.2 defined by relations (12) and (13), are respectively illustrated by FIGS. 13a and 13b. In cases where the criteria 3.1 and 3.2 are checked, it is possible to apply either the full voltage control U = U _ma χ or U = U _mn , as illustrated in 97 of FIG. 9, because the times for passing the tip of the tooth or to change sign the relative speed under these conditions are substantially identical. Then we are in the state 1 and we apply again a full voltage U = U _ma χ as illustrated in 95 of Figure 9. From the position of the barrel θ _b = θ _r , we are in the state 0, that is to say that there is no contact tooth on tooth, and one applies a full voltage control U = U _ma χ. In phase 4, starting from the position θb = θ ₂ , the control phase 94 of the end of the barrel 21 is started on a target value corresponding to the nominal position of the arrival mode, as illustrated in FIG. 14.

The phases and the control steps as illustrated by FIG. 9 in particular can be implemented by the computer 33 controlling the motor 20.

A control according to the invention, based on a state machine contacts tooth on teeth jaw, allows to apply a command appropriate to the nature of the contacts and the relative position of the teeth of the jaw during tooth contacts on tooth. It should be noted that the calculation 93 making it possible to apply the appropriate command during phase 3 in the case of a contact opposing the movement (state 2) can be previously established and stored in the form of a cartography for example. In order to simplify the management of the contacts, for example in the case where the criterion 3.1 or 3.2 is checked or during an indeterminacy of the relative position, a default command can be applied, U = U _max for example. The angular position θb of the barrel is notably provided by the sensor 30 of FIG. 3, this sensor being initially a position sensor, the speed being obtained by drifting with respect to time the angular positions successive barrel, the data provided by the sensor 30 being taken into account by the computer 33. Preferably, the signals provided by the sensor 30 are sufficiently accurate and sampled at a sufficiently high frequency. Indeed, to be able to calculate the rotation speed of the barrel c * from the knowledge of the position of the barrel, it is necessary to derive this signal and any noise is systematically amplified by this operation. Moreover, given the low chamfer angle θd, the resolution and the sampling frequency of the cylinder position sensor must be sufficient so as to be able to correctly detect the positions θ _b corresponding to tooth-to-tooth positions, the distance between limit positions are therefore low.

The calculator also has the relative speed information between the jaws Δω and the knowledge of the geometry of the claws. In particular, a certain number of control parameters depend on the knowledge of the relative speed of rotation between the jaws Δω. This is sufficiently precise for the parameterization of the command to obtain the expected performance.

The kinematics of the actuating chain makes it possible to use either the angular position of the barrel θb, or the position in translation of the clutch x, for the estimation of the nature of the contact surfaces and the relative position of the teeth of the claws. contact. When the position of the barrel θb is in the interval [θ ₀ , θ ₂ ], the relation (7) expresses the relation between x and θ _b . Deriving this relation (7) with respect to time, we obtain a similar relation between the translation speed of the claws V _c and the speed of rotation of the barrel <"b.

Advantageously, the implementation of the invention does not require the control of the traction machine during the time of interconnection. Preferably the traction machine is controlled before the dog clutch to achieve a relative speed of rotation between the claws compatible with the requirements of the teeth and the requirements of comfort and holding. The two commands, synchronization of angular speed by the traction motor on the one hand and interconnection by the gearshift motor on the other hand, remain separate. Advantageously, the anticipation phase of tooth contact on tooth 92 makes it possible to reduce the longest times without penalizing the times. shorter, due in particular to the importance of the inertia of the electric actuator to that of the mechanical system.

The commands applied in phase 3 tooth to tooth contact management, including the U _mιn command applied for state 2, can be replaced by commands clutch effort, therefore by current commands of the electric motor 20.

In the particular case where one of the jaw is provided with large teeth and the other clutch is also provided with the same large teeth and small teeth of the same shape as the large ones as illustrated in FIG. 5, a control according to the invention can still be applied. The phases of detection and management of tooth-to-tooth contacts are then repeated. However, once the teeth of the clutch movable in translation are in the hollow of the large teeth of the opposite dog, the geometry of the claws, including the anti-release angle flanks of the teeth, ensures the interconnection when a torque is applied to one of the rotation shafts to be coupled.

The aspects of time of interconnection and dispersion of these times have been taken into account by the modes of piloting described above. In conjunction with controlling the shift actuation chain, the invention proposes controlling the traction motor in play to achieve better management of the relative angular position and speed and of translation between the jaw claws, particularly when contact tooth to tooth phases. The invention improves the performance of the method described above by controlling the traction motor 20 in the most unfavorable cases. Thus, the control method according to the invention relates in particular to the control of the motor or traction machine by relying on the state machine for detecting the contacts between jaw of FIG. 8 and on the control of the control of the gear change actuation chain described above. The invention provides control of the pulling machine from a desired relative position, relative velocity and angular relative acceleration path during the tooth to tooth contact so as to coordinate the action of the traction machine with that of the shift actuation chain and leave the tooth-to-tooth contact under given conditions. Note that the control of the traction machine during tooth-to-tooth contact is the only means of action for quickly disengaging the jaw teeth from this position. Indeed in this position, the normal axis of the tops of the tooth is substantially parallel to the radius of the dog passing through the contact point so that the contact speed between jaw is essentially a relative angular velocity. The control of the machine is therefore based on:

on generating a desired trajectory of the relative position of the teeth of the claws making it possible to control the tooth-to-tooth contact time ti as well as the relative speed and the relative acceleration at the end of contact;

- and the exploitation of an inverse model to calculate the torque that must provide the traction machine to follow the desired path, thus producing a pre-positioning.

FIG. 15 shows a tooth 9 and the envelope curve 46 of the possible positions of the point O situated in the middle of the vertex 44 of the tooth 10 during the contact of the teeth 9 and 10 during the interconnection, in a system of axes where the ordinates represent the position of the tooth, expressed by the angle θb equivalent by the position in translation x, as for Figures 10 to 14. The abscissa axis represents the relative angular positions between the teeth 9, 10 of the jaw, these positions are between two values Δθ _maX 2 and Δθmaxi, corresponding to the ends of the envelope 46. As indicated above, the tooth to tooth contact is detected by the state machine described with reference to FIG. 8. The value of the state of the contact as well as the position of the barrel 21 and the geometrical parameters of the teeth of the claws make it possible to estimate the relative angular position Δθ during tooth to tooth contact as shown in the following relation, that lque is the value of θb in the interval [θ-i, θr]:

_dent t_an(θ_d)

_tooth t _to n (θ _d )

(14)

The parameters not yet defined, R _b , and R _c _dθnt respectively represent the radius of the barrel 21, and the average radius of the jaw 6, 7. The contact state variable is equal to 1 or 2, values corresponding respectively to state 1 and state 2.

The calculation making it possible to estimate the relative angular position is executed only if there is contact, that is to say if the state machine is in the state 1 or in the state 2, the computation being executed only after detection of the contact. Upon contact, for a cylinder position θ _b _ _C ontact it corresponds two contact positions relative tooth on tooth ΔΘ01 and ΔΘ02 respectively for states 1 and 2, illustrated by Figure 15 and given by the following relations, from the relationship (14):

^R A ^tan contact ( ^ψ max) + *, - *! _{M c} ,

Δt / _Ol ≈ (15)

R _c _ tzn _tooth (θ _d)

_{A û} ^R A contact ^tan ( ^ψ max) + *, - *! , _Λcλ

Aθ _m ≈ = (16)

R _c _ * _" ** &")

The sign of the relative speed and the state of the contact make it possible to lift the indeterminacy and to know if it is ΔΘ01 or ΔΘ ₀ 2- It should be noted that during the phase of detection of the contact there has no action of the traction machine. In addition, the phases of contact detection and estimation of the relative angular position must be fast enough so that these calculations are representative of the actual situation of the claws and that the piloting actions can be conducted as soon as possible. Thus, in the case for example where the relative speed Δω> 0, there are the correspondences given by the following table:

Contact state Initial relative position Δθn Initial relative position Ae ₁

State_contact = 1 Δθ _o = ΔΘ ₀₁ AG ₁ = Δθ _max1

Contact_state = 2 Δθ _o = ΔΘ ₀₂ AQ ₁ = Δθ _max1 or AQ ₁ = Δθ _max1

The relative positions Δθ _max i and Δθ _maX 2 are the extreme positions in state 1 and state 2, given by the following relays:

_{A n} ^ i _r tan (Ψ _max) + x _i - x ₁

^{~ R} c den _t ^iΑ <θ _d )

FIG. 16 shows examples of desired trajectories 161, 162, 163 as a function of time t, respectively for the relative angular position Δθ, the relative speed Δω and the relative acceleration Δγ between the teeth 9, 10, or between the claws. . These trajectories begin at an initial moment taken equal to 0, the beginning of contact, and a time ti. A desired trajectory is expressed in the form of a polynomial whose coefficients are determined from the initial conditions at the time of the tooth to tooth contact detection, Δθ _o , ΔC0 _O , Δγ ₀ and the desired conditions at the end of the tooth contact on tooth, Δθi, ΔCC _I , Δγi at time ti. Thus, the desired trajectory of relative position is expressed for example in the form of a polynomial of degree 5 to take into account the three initial conditions and the three final conditions of contact. Is :

Δθ (t) = axt ⁵ + bxt ⁴ + cxt ³ + dxt ² + ext + f (19)

Δω and Δγ being obtained by successive derivations:

Δω (t) = 5a xt ⁴ + 4b xt ³ + 3c xt ² + 2d xt + e (20)

Δγ (t) = 20a xt ³ + 12b xt ² + 6c xt + 2d (21)

Considering the boundary conditions Δθ _o , Δω ₀ , Δγ ₀ , Δθi, ΔCc _I , Δγ-i, the parameters a, b, c, d, e, f of the trajectories can be calculated. The coefficients a, b, c are in particular a function of the time ti. This time ti represents the desired duration of tooth to tooth contact. The value of ti as well as that of the final conditions Δθ-i, Δω-i, Δγi are left to the choice of the user. However, the value of the relative angular position at the end of the contact Δθi corresponds to one of the end positions of tooth to tooth contact Δθmax or Δθ _maX 2 as illustrated in FIG. 15. The relative angular velocity value ΔC0 _I is within an acceptable range, for example | ΔCC _I | <100 rpm. The value of the angular acceleration Δγi is chosen so as to stabilize the relative movement of the claws before the flank-side contact.

The value of the relative position after detection of the contact Δθ _o is defined according to the following relation:

Xcontact ≈ Rbθb tan contact (Ψ _ma χ) + Xi (22)

This relation (22) reflects the kinematic relation between the position of the barrel θb_contact corresponding to the detection of the contact and the vertical position of the clutch x _C ontact associated. The value of the angular relative speed after detection of the contact Δω ₀ is given by the measurements of the rotational speed sensors of the shafts with which the claws are integral, the shafts of the traction machine for example. The relative angular acceleration after detection of the contact Δγ ₀ is given by the derivation of the relative speed. Depending on the values of the initial and final conditions, the parameterization of the desired trajectory makes it possible to take into account the different tooth-to-tooth contact situations previously described in cases n ° 1, n ° 3 and n ° 4.

Once a desired trajectory has been calculated, it is necessary in particular to predict the torques to be applied to follow the desired trajectory. The force transmitted by the torque C _M τ (t), a function of time, is broken down into three efforts:

a force transmitted by the actuator of the gearshift chain; a viscous friction force, linked to the friction on the shaft of the traction machine;

- an inertial effort, linked to the traction machine.

These three terms are found respectively in the following relation:

C _MT (t) = C (U ^' (O) + R (AaKt) + ω _wheel (t)) + J _MT (^ ψ- + ^^) ( ²³ )

The term of the torque C (U (t)) related to the force applied by the actuator of the shift chain is given by the following relation:

U (t) being the control voltage of the actuator, that is to say the driving motor 20 of the cylinder 21 in the case of application of a system as described in FIG. relation (24), for a given effort C (U (t)), the voltage U (t) to be applied to the motor 20 is deduced therefrom. The parameters that are not defined previously are as follows:

- Carousel is the speed of rotation of the shaft 2 secured to the wheels;

- μ is the contact dissipation coefficient; - J _MT is the inertia of the traction machine 18, brought to the shaft around which the jaws 6,7 rotate;

- R is the coefficient of viscous friction related to the shaft of the traction machine 18 and also brought back on the shaft around which the claws 6,7 rotate; - k _me ι is the electromagnetic gain of the actuator or motor 20;

- R _mΘ ι is the internal resistance of the actuator or motor 20.

The current I (t) in the motor 20 is given by the following relation:

I (t) = ^ - (25)

^R mel and the speed of rotation of the motor 20 ω _mΘ ι is equal to k _mΘ ι U (t).

The relation (24) shows that the force transmitted by the actuator of the gearshift chain C (U (t)) depends on certain parameters of components of the drive chain such as in particular:

the electromagnetic gain k _mΘ ι and / or the internal resistance R _mΘ ι of the electric motor 20;

- gear reduction ratio;

the radius and the ramp angle of the barrel 21; - the domed angle of the teeth of the claws.

The calculation of the torque requires in particular to have:

or measuring the voltage U (t) of the motor 20;

- measurement of the current I (t) of the motor; - Or the measurement of steady state speed ω _mΘ ι of the engine. Preferably, the detection time of the nature of the contact and the relative angular position between jaw must be as short as possible in order to perform as soon as possible the tracking of the angular trajectory on the tooth. If this time is too long, this can notably penalize the time of interconnection and the dispersion of this time according to the different configurations.

Claims

1. A method of driving a coupling device of two jaw (6, 7) rotating about the same axis (2) and each formed teeth (9, 10), jaw (6, 7) being susceptible s meshing under the action of a mechanism (20, 22, 21) producing a force allowing the displacement in translation of one of the jaw (7), movable relative to the other (6), the translation becoming the along the axis of rotation (2) of the jaw, characterized in that the method comprises at least the following phases: - A first contactless approach phase between the claws, where a maximum force (U _ma χ) is applied allowing the translation of the movable clutch (7); a second phase where the applied force (Uantiαp) is decreased (92) to detect the nature of the contacts between the teeth (9, 10) of the claws among at least the following three states: no contact (81), contact favoring the movement of the movable clutch (82) and contact opposing the movement of the movable clutch (83), and in the event of detected contact; a third phase of determining a relative angular trajectory (161, 162, 163) between the teeth, between an initial instant and an instant ti of end of contact; and a fourth phase of calculating and applying the force to be applied (U (t)) to follow the determined trajectory (161, 162, 163). 2. Method according to claim 1, characterized in that the determination of the angular trajectory (161, 162, 163) comprises a component defined for the relative angular position (Δθ, 161). 3. Method according to claim 2, characterized in that the angular trajectory (161, 162, 163) comprises a component defined for the relative angular velocity (Δω, 162). 4. Method according to any one of claims 2 or 3, characterized in that the angular trajectory (161, 162, 163) comprises a defined component for the relative acceleration (Δγ, 163). 5. Method according to any one of the preceding claims, characterized in that the trajectory (161, 162, 163) is defined by conditions of values (Δθ-i, Δω-i, Δγ-i) at the instant ti . 6. Method according to any one of claims 2 to 5, characterized in that the angular position trajectory (161) is a polynomial where the variable is the time t. 7. Method according to any one of the preceding claims, characterized in that the detection of the nature of the contacts is between two positions (θ-i, Qv) of the movable clutch (7) corresponding to the minimum and maximum positions of the vertex ( O) teeth (10) of the mobile clutch in contact phase with the teeth (9) of the other clutch (6). 8. Method according to claim 7, characterized in that if in the interval between the two positions (θ-i, Qv) there is no contact (81), the maximum effort (U _ma χ) is applied. 9. Method according to any one of claims 7 or 8, characterized in that when the position of the movable clutch (7) reaches the maximum contact position (Qv), the maximum force (U _ma χ) is applied until at a position (θ ₂ ) in which an end-of-travel regulation phase of the mobile clutch (7) begins. 10. Method according to any one of the preceding claims, characterized in that the force applied is produced by a motor (20) controlled voltage (U).