WO2003081091A2

WO2003081091A2 - Gearbox actuator and synchronisation method for a gearbox

Info

Publication number: WO2003081091A2
Application number: PCT/DE2003/000916
Authority: WO
Inventors: Boris Serebrennikov
Original assignee: Luk Lamellen Und Kupplungsbau Beteiligungs Kg
Priority date: 2002-03-21
Filing date: 2003-03-20
Publication date: 2003-10-02
Also published as: AU2003223883A1; FR2837555A1; FR2837555B1; WO2003081091A3; DE10312400A1; DE10391765D2

Abstract

The invention relates to a synchronisation method for a gearbox, especially an automated gearbox, whereby the electric motor of a gearbox actuator is controlled in order to supply the synchronous force, at least one synchronous voltage adapted to the synchronous force being applied to the electric motor. The invention also relates to a gearbox actuator enabling synchronisation in a gearbox, especially an automated gearbox, comprising at least one electric motor, especially for carrying out the inventive method, the electric motor being controlled by at least one synchronous voltage adapted to the synchronous force.

Description

Transmission actuator and method for performing a synchronization at a

transmission

The present invention relates to a transmission actuator and a method for performing synchronization in a transmission, in particular in an automated manual transmission, in which the electric motor of a transmission actuator is controlled in order to apply the synchronous force.

Methods for carrying out a synchronization or synchronizing strategies and transmission actuators for carrying out a synchronization in a transmission, in particular in an automated manual transmission, are known from vehicle technology.

In a possible synchronous strategy, it is provided that the kinetic energy of the electric motor of the switch actuator is converted into potential energy of the tensioned spring when the synchronous force is built up, the switching elasticity and basic rigidity of the mechanical parts between the electric motor or the electric motor and the sliding sleeve being considered. Each target synchronous force thus corresponds to a certain potential energy. The electric motor should have the same kinetic energy when moving to the synchronous position. In order to store this specific kinetic energy before moving to the synchronous position, the starting speed can be set accordingly.

The following phases are imperative for the aforementioned synchronous strategy. First, the approach speed is set in the cruise control mode. Then the synchronous position is approached. This is done in speed control mode with force limitation. The goal of this phase is friction compensation. The force limitation is defined in such a way that the approach speed can only be held against a force that is not greater than the friction. If the actuator speed drops below the stop speed during the build-up of force, another phase begins with constant tension, which corresponds to the synchronous force at the speed with the value 0. The basis of this known strategy is speed monitoring; if the speed, which is provided in the control, drops during the build-up of force, the tension can be reduced according to the friction compensation. The transition to the last phase is also carried out on the basis of the measured speeds. It has been shown that the more precisely the speed is measured, the higher the control quality of the synchronous strategy. It has also been shown that the faster the actuator is braked when the force is built up, the greater the deviation of the measured speed from the physical value. This deviation determines an additional energy which flows into the system because the tension is always higher due to the measured speed than the tension with ideal friction compensation. It can therefore be concluded that the stronger the actuator is braked when the force is built up, the greater the interruption-related spread of the synchronous force. The reason for this can be the considerable interruption-related spread of the additional energy when braking at the synchronous threshold.

Especially with very light electric motors is a z. B.5 times smaller inertia compared to other heavier motors. An equivalent mass 5 times smaller is thus provided with the same overall transmission ratio. In order to have the same kinetic energy before moving to the synchronous position, the speed can be preferred

^A ' ⁵ times bigger. If, for example, a mass is deflected against a spring, the time until the maximum spring force builds up is equal to a quarter period of the natural vibrations. That is why the duration of the force build-up is especially small

Motors ^Λ ' ⁵ times shorter. As a result, a smaller motor has 5 times more acceleration than conventional heavier motors. Accordingly, the force scatter to be expected is greater for smaller, lighter engines than for the otherwise heavier engines.

The invention is based on the object of proposing a transmission actuator and a method for carrying out a synchronization in a transmission in order to achieve the simplest possible and optimal synchronization, in particular with lighter electric motors. In addition, the synchronization should be independent of possible errors in speed monitoring. This object can be achieved procedurally by a method for performing synchronization in a transmission, in particular in an automated manual transmission, in which the electric motor of a transmission actuator is activated in order to apply the synchronous force, in which a synchronous voltage adapted to the synchronous force is applied to the electric motor becomes.

The proposed method or the synchronous strategy can preferably be used in a transmission actuator with a light electric motor or electric motor, in particular an automated manual transmission (ASG). However, it is possible that this synchronous strategy can also be used for other gearboxes with other actuator motors.

It is particularly advantageous in the method according to the invention that for synchronization only one phase is preferably provided in which the electric motor of the gear actuator is controlled or acted upon with an adapted synchronous voltage for synchronization. A value which is below the voltage required to apply the synchronizing force can preferably be used as the synchronous voltage. However, other values are also conceivable.

In a further development of the invention, it can be provided that the synchronous voltage is applied at a predetermined point in time before and / or after reaching the synchronous point. Other times may also be used. The synchronous voltage can be adapted in such a way that when the synchronous position is approached with a stationary speed of the transmission actuator corresponding to the voltage, the required synchronous force is exactly achieved. According to a training z. B. at the end of the synchronization, the synchronous voltage can be held for a predetermined time interval, so that unlocking detection is permitted, for example, by the transmission control.

In order to bring the transmission actuator into the end position after the synchronization, it can be provided according to a next development of the invention that the on the electric motor applied voltage is kept at a value of about 12V until the end position is reached.

Furthermore, the synchronous strategy according to the invention can also be suitably modified. For example, it can be provided that, in the synchronous strategy, a specially calculated intermediate voltage is first applied within a predetermined interrupt time and only then is the synchronous voltage applied. The aim of applying the intermediate voltage is to always arrive at the same phase curve before the last time period, i.e. during which the synchronous voltage is applied. Other modifications or any combination of the measures mentioned are also possible.

As part of a development of the invention, it can be provided that the intermediate voltage is calculated using the following equation:

This calculation can be implemented particularly easily in the transmission control because it is a simple linear function with constant coefficients.

Furthermore, the object on which the invention is based can be achieved in terms of the device by a transmission actuator for carrying out synchronization in a transmission, in particular in an automated manual transmission, with at least one electric motor, in particular for carrying out the proposed method, in which the electric motor has a synchronous voltage adapted to the synchronous force is controllable.

Further advantages and advantageous configurations result from the subclaims and the drawings described below. Show it:

FIG. 1 shows a diagram with different courses of a simulation for a target

Synchronous force of 800 N when shifting from 1st to 2nd gear; Figure 2 is a diagram with the course of the actuator movement until this on the

Synchronous position for the synchronous force of about 400 N is provided in the phase space;

FIG. 3 shows a diagram with different courses of the intermediate voltage with different synchronous forces;

Figure 4 shows a comparison of the simple strategy and the strategy with the

Use of intermediate voltage; and

Figure 5 is a schematic view of a model of the gear actuator.

FIG. 1 shows a simulation for a target synchronous force F _sync of 800 N for a circuit 1-2. FIG. 1 shows two diagrams one above the other, the courses of the actuator travel, the actuator speed and the synchronous force over time being shown in the upper diagram. The voltage over time is shown in the diagram below. In both diagrams, the time axis is divided into the phases "drive to synchronous position", "set synchronous force" and "wait for unlocking" as well as the phases "drive to end position" and "braking". The speed difference to be synchronized is 2.5 Fsync revolutions per minute specified.

It can be seen from FIG. 1 that the synchronous voltage U _sy nc is adapted in such a way that when the synchronous position is approached with the stationary speed of v ₀ , which corresponds to this voltage, the synchronous force is exactly achieved. In this example, the synchronous voltage is approximately 7.35 V. In the simulation shown in FIG. 1, v _{0 is} approximately equal to 135 mm / s. At steady-state speed, the force applied by the electric motor roughly corresponds to the frictional force during synchronization.

The position or the time at which the voltage jump from 12V to the synchronous voltage Usync is provided is selected in the method according to the invention in such a way that the SP error of -0.5 mm, ie when the synchronous position is 0, 5 mm closer to the neutral position, the synchronous force increase of 10% of the Synchronous force is permitted. Accordingly, the force in the simulation shown is somewhat higher than the target force. In the present simulation, the movement after unlocking is simulated in a simplified manner, so that the switching time for different switching elasticities is comparable.

The method according to the invention can be used with various switching elasticities for the actuator with a light motor. Furthermore, the switching times at the synchronous force of 200, 400, 800, 1200 N or the like can be estimated for different elasticities. The following can preferably be used as possible boundary conditions:

As a path from the end position of the old gear to the synchronous position of the target gear z. B. 13 mm and 20 mm can be selected as the path from the end position of the old gear to the end position of the target gear.

The difference in rotational speed to be synchronized, for example, 2.5 times-at approximately the target force F _z iei [rpm.] Are defined. The biasing force when removing the old gear can, for. B ^Λ A correspond to the target force F _z ι _e ι. This force is taken into account because the distance to the synchronous position becomes smaller due to the preload.

According to the invention, the synchronous _voltage U _{sync is} adapted in such a way that the synchronous position is reached at a steady speed. After the end of the synchronization, the synchronous voltage Us _yn c is held for a further 5 ms, for example, in order to leave time for the unlocking detection. Then the voltage 12V is held so long that the actuator comes to a standstill at the end position. The target gear can be recognized, for example, at the position of 18 mm. The time to reach the 18 mm travel is considered as an estimate of the switching time. Such a synchronous strategy is shown schematically in FIG. 1.

A variant of the present invention can provide a refinement of the proposed strategy, which realizes synchronization even faster. This can be achieved in particular by using a calculated intermediate voltage Uz. This variant is shown graphically in FIG. There the actuator movement up to standing at the synchronized position is shown for the synchronous force of approximately 400 N in the phase space. The position at which the voltage jump occurs is identified by S in FIG. 2 and adapted in such a way that the power transmission is about 10% of the synchronous force in the case of an SP error of -0.5 mm.

Accordingly, in the refined synchronous strategy, it is proposed that a certain voltage, namely the intermediate voltage, be specified within a further interruption time at the position identified by x_start_intermediate voltage in FIG. 2. This is because the phase curve is to be reached until the next interruption (interrupt), ie in 5 ms, and then the synchronous voltage Usync is set accordingly.

As a result, the interruption-related spread of the synchronous force can advantageously correspond to the value 0 and the time spread can be significantly reduced. If the actuator is located in the point marked A in FIG. 2, the intermediate _voltage U _{zw can be} higher than the synchronous _voltage Us _ync , and for the point B the intermediate voltage U _2W can be lower than the synchronous voltage Usync. For example, the intermediate voltage Uzw can be calculated with the tangent which is provided on the phase curve or on the line v = v ₀ .

If the voltage corresponds to the synchronous voltage Us _ync , the speed tends towards v ₀ . This results in the equation of motion of the actuator as follows:

mx = k (vθ-x) where K = (kΦi _ges ) 2 / .R _i

At point S according to FIG. 2, dv .. k dx applies

= _X = - ( _V 0 - _Vπax ) _and— = _Vma dt m dt

Consequently, the derivative at point S is the same: dv ₌ k (yo -v _πm ) dx mv _maax If the equation of the tangent is gO + g1x = v, then follows

^ ₌ V ₌ VI _and g _{0 = Vmaχ} _g _lXs dx mv _^

The specification of a constant stress is equivalent to a constant force F in the following equation:

mx = F-kx or x = f-ax where f = Flm and = k / m

Now a suitable f should be found so that the phase point (eg point A) lies at t = 5ms on the tangent (or on the line v = v ₀ ).

Solving this equation for the initial conditions ^x ^ ' ^~ ° ^. (°) = v ^ _is

χ (t) = (^ _ -i_ _{) (} ι --- _e → _{) +} L _t thereby = (v _^ - £ -e ^at + £ aaa

In 5ms the way and the speed are:

x (0.005) = ύ. + b under designations:

_{fl =} _ ^v i2a-x- (l_eχp); c = v _max exp a

_{& =} 005_l- ^ p _{; / =} l _Z «^ u», aaa

The phase point x = xA + x (0.005); ^~ ( ⁰ ' ^υ05 ) should come to the tangent, which gives the following equation:

gO + g1 (xA + a + bf) = c + df

From this linear equation you can find the f you are looking for. Then if = c + df is deeper than v ₀ , the final value should be defined from the equation v ₀ = = c + df. In the latter case, the phase point comes on the line v = v ₀ .

The intermediate voltage can then be calculated as follows:

Zw k®i "

This calculation can be easily implemented because it is a simple linear function of Vo (or Us _y n _c ) and coefficients.

The intermediate voltage is shown in FIG. 3 along the way, with several intermediate voltage profiles with different target synchronous forces (200 N, 400 N, 800 N and 1200 N) being shown. A gearbox actuator without elasticity (only basic rigidity of 1000 N / mm) is used. The path is counted from the end position in the direction of the synchronized position. The path to the synchronized position of approximately 12 mm is considered.

If, for example, the path has become greater than 9.7 mm (e.g. 10.2 mm) for the first time at the nominal force of 200 N, the intermediate voltage of 6 V is applied within the next 5 ms and then synchronous voltage Usyn _c of set about 2.2V.

FIG. 4 shows the time scatter with a comparison of the simple strategy and the strategy with intermediate voltage. In particular, the spread of the time until the end of synchronization is specified for the refined strategy with intermediate voltage. The force scatter in the strategy with the intermediate tension is approx. 2 times smaller than when using the simple strategy.

A simple model of the actuator is considered for the synchronous strategy according to the invention in order to simulate possible synchronous strategies. This model is shown schematically in FIG. 5. After reaching the synchronous position, the following equations can be given for the model:

MActor + FEasticity (x) (1 + K _Re ib) = F _E - otor - F _Re ib with elasticity MAktorΛ + cx (1 + K _Rβ ib) = F _E - otor - F _Re ib without elasticity

WO M actuator = JE- otori total

U - kΦ ^■ X ^■ i _ges

? Electric motor = ^k R ^{~ l} _S es ~ W ^Ω ; kΦ = 0,02Nm / A; a

This results in an inertia of 0.52e-5kgm2 for the lighter engine. This corresponds to 1/5 of the inertia of otherwise heavier motors. With a total gear ratio of 2500 rad / m, the equivalent actuator mass is 32.5 kg. With K _Re i _b = 0.4, the force-dependent friction of the worm gear is taken into account. 120 N is specified for the force-independent friction F _Re i _b .

The patent claims submitted with the application are proposals for formulation without prejudice for the achievement of further patent protection. The applicant reserves the right to claim further combinations of features previously only disclosed in the description and / or drawings.

Back-references used in subclaims indicate the further development of the subject matter of the main claim by the features of the respective subclaim; they are not to be understood as a waiver of the achievement of independent, objective protection for the combinations of features of the related subclaims.

Since the subjects of the subclaims can form their own and independent inventions with regard to the prior art on the priority date, the applicant reserves the right to make them the subject of independent claims or declarations of division. They can furthermore also contain independent inventions which have a design which is independent of the objects of the preceding subclaims.

The exemplary embodiments are not to be understood as a restriction of the invention. Rather, numerous changes and modifications are possible within the scope of the present disclosure, in particular such variants, elements and combinations and / or materials, which, for example, by combining or modifying individual ones in conjunction with and described in and in the general description and embodiments and the claims the drawings included Features or elements or procedural steps can be taken by the person skilled in the art with regard to the solution of the task and, by means of combinable features, lead to a new object or to new procedural steps or procedural step sequences, also insofar as they relate to manufacturing, testing and working procedures.

Claims

claims

1. A method for performing synchronization in a transmission, in particular in an automated manual transmission, in which the electric motor of a transmission _{actuator is activated in} order to apply the synchronous force, characterized in that at least one synchronous _voltage (Us _ync ) adapted to the synchronous force is applied to the electric motor becomes.

2. The method according to claim 1, characterized in that a value is used as the synchronous voltage (Us _y nc), which is below the voltage that is required to apply the synchronous force.

3. The method according to claim 1 or 2, characterized in that the synchronous voltage (Usync) is applied at a predetermined time before or after reaching the synchronization point.

4. The method according to any one of the preceding claims, characterized in that the synchronous _voltage (Us _ync ) is adapted such that when the synchronous position is approached with a stationary speed of the transmission _actuator corresponding to the synchronous _voltage (Us _ync ), the required synchronous force is exactly achieved.

5. The method according to claim 4, characterized in that after the end of the synchronization, the synchronous voltage (Usync) is held for a predetermined time interval in order to allow an unlocking detection.

6. The method according to claim 5, characterized in that thereafter the applied voltage (U) is held approximately at a value of 12 V until the gear actuator comes to a standstill at the end position without tension.

7. The method according to any one of the preceding claims, characterized in that a calculated intermediate voltage (Uzw) is applied before applying the synchronous voltage (Usync).

8. The method according to claim 7, characterized in that the intermediate _voltage (U _Zw ) is calculated within a predetermined interrupt time.

9. The method according to claim 7 or 8, characterized in that the intermediate voltage (Uz) is calculated by the following equation:

kΦi _ses

10. Transmission actuator for performing synchronization in a transmission, in particular in an automated manual transmission, with at least one electric motor, in particular for performing the method according to one of claims 1 to 9, characterized in that the electric motor with at least one of the synchronous force (F _so n) adapted synchronous _voltage (Us _ync ) can be controlled.