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EP-4609092-B1 - METHOD FOR DETERMINING THE POSITION OF A GEAR SHIFT DRUM

EP4609092B1EP 4609092 B1EP4609092 B1EP 4609092B1EP-4609092-B1

Inventors

  • Diga, Simon-Martin
  • KREIS, OLIVER

Dates

Publication Date
20260513
Application Date
20231006

Claims (5)

  1. Method for determining the position of a rotating gear shift drum (3) using means which generate current or voltage deviations on a driving electric machine (7), wherein the electric machine (7) acts on the gear shift drum (3) and is configured to rotate the gear shift drum (3) through 360 degrees, characterized in that the means are arranged so as to be distributed over the outer circumference or the end face (3a) of the gear shift drum (3), and wherein the means generate a mechanical resistance during the rotation of the gear shift drum (3), and wherein the measured current or voltage deviations are evaluated via pattern recognition (21) by a neural network (21).
  2. Method according to Claim 1, characterized in that the pattern recognition is learned by rotation of the gear shift drum (3) and measurement on the electric machine (7), wherein input variables that are collected when a vehicle is at a standstill are used.
  3. Method according to one of the preceding claims, characterized in that the pattern recognition continuously optimizes the gear shift drum position determination during operation.
  4. Method according to one of the preceding claims, characterized in that the measured input variables are evaluated out after the measurement in a time period in the past.
  5. Method according to one of the preceding claims, characterized in that the means which generate current or voltage deviations at the driving electric machine (7) is at least one pressure-exerting means which presses a ball (2) into bores (4) of the end face (3a) or of the outer circumference of the gear shift drum (3) via spring tension.

Description

The invention relates to a method for determining the position of a rotating switching drum by means that generate current or voltage deviations at a driving electric machine, wherein the electric machine acts on the switching drum and is configured to rotate the switching drum by 360 degrees and the means are arranged distributed over the outer circumference or the end face of the switching drum. State of the art The travel path of a shift drum is limited by housing-mounted mechanical end stops. The shift drum position can be uniquely referenced and thus taught by approaching both end stops and checking the calculated path length. This process can be repeated cyclically throughout the gearbox's service life, guaranteeing consistent accuracy. If these end stops are removed, the aforementioned method of learning is no longer possible. With a "360° rotary switch," the end stops are omitted so that the rotary switch can move to any position from either direction. One solution consists of a position sensor on the shift drum, which reports the absolute position to a control unit. No further learning is then necessary. However, an additional sensor always means undesirable additional component costs due to the sensor itself and the wiring. Furthermore, the requirements regarding accuracy and robustness are very high. The shift drum position, and therefore also the sensor's accuracy, is absolutely crucial for certain transmission tasks such as gear changes. and parking lock functions. This accuracy must also remain consistently high throughout the entire lifespan of the transmission. One method using an analog armature current signal and its evaluation is, for example, from the DE 195 11 307 C1 It is well known that to prevent interference pulses superimposed on the armature current signal from being included in the evaluation of a current ripple count, the analog armature current signal is typically processed before digitization, for example, by frequency filtering. These measures serve to ensure that a current ripple signal as free of interference pulses as possible is available for digitization and subsequent counting. In this context, interference pulses refer to non-commutator-induced pulses that superimpose on the armature current signal. From the EP 1 208 638 B1 A method is known that is particularly suitable for use in position detection of an adjustment device for opening and closing a window pane, a sunroof, or for adjusting a seat in a motor vehicle. Position determination, for example of the pane, can then be carried out with sufficient accuracy solely by evaluating the current ripple signal without the use of additional sensors. However, in such an application, it is necessary to determine the reference current ripple during motor start-up and thus before any movement of the window, so that the desired correction can be made simultaneously with the movement, without having to first store the entire current ripple signal and then correct it after the movement has finished with regard to determining the position of the driven element. The DE 10 2013 100 213 A1 shows a method for adapting transmission control elements to accurately locate synchronization contact points. By rotating a switching drum, a switching fork actuates the synchronizers as it passes each one. The transmitted torque is measured, and the measured current is used to determine the feedback current of the actuators. The DE 10 2010 013 962 A1 This shows a method for detecting blockage events. Position sensors are used to measure the position of the shift drum. From the DE 199 14 394 A1 A method for determining the position of a rotating switching drum is known, using means that generate current or voltage deviations at the driving electrical machine. The EP 3 770 467 A1 discloses a method for calibrating at least one rotatable switching drum in a drive train of a motor vehicle. The object of the invention is to provide a position determination of a switching drum that operates independently of stops and sensors on the basis of current peaks. Description of the invention The problem is solved by a method according to claim 1, here a method for determining the position of a rotating switching drum by means that generate current or voltage deviations at the driving electric machine, wherein the electric machine acts on the switching drum and is configured to rotate the switching drum by 360 degrees, wherein the means are arranged distributed over the outer circumference or the end face of the switching drum, and wherein the means generate a mechanical resistance during the rotation of the switching drum, and wherein the evaluation The measured current or voltage deviations are detected via pattern recognition. The invention eliminates the need for an additional position sensor for the switching drum. Referencing is achieved solely through pattern recognition in the current or voltage signal of the switching drum motor. The current signal