Actuating method and actuating apparatus for a vehicle part

Abstract

An actuating apparatus for a vehicle part contains an actuating motor for generating an actuating force under the action of which the vehicle part can be adjusted between a closed state and an open state along an actuating path. The actuating apparatus also contains a control unit which is configured to carry out an actuating method in which, according to the method, a position measure is continuously ascertained when the vehicle part is adjusted, the position measure being characteristic of the current actuating position of the vehicle part along the actuating path. Furthermore, the position measure is set to a prespecified reference value when the vehicle part is in the closed state and when a further condition is additionally met, the further condition being linked in a reproducible manner with a specific actuating position.

Claims

1. An actuating method for a vehicle part being adjusted between a closed state and an open state along an actuating path by an actuating motor, which comprises the steps of: performing an adjustment of the vehicle part by the further steps of: ascertaining continuously a position measure, the position measure being a characteristic of a current actuating position of the vehicle part along the actuating path; resetting the position measure to a prespecified reference value when the vehicle part is in the closed state and when an additional condition is further met, the additional condition being linked in a reproducible manner with a specific actuating position; and resetting the position measure to the prespecified reference value only under the additional condition that, during the adjustment, an adjustment speed of the vehicle part was within a prespecified tolerance range around a stored reference speed.

2. The actuating method according to claim 1, which further comprises identifying the closed state upon detecting a closing signal which is output by a closing signal generator.

3. The actuating method according to claim 1, which further comprises setting the position measure to the prespecified reference value only under the additional condition that the actuating motor has been activated in order to adjust the vehicle part, and that the vehicle part has been adjusted out of the open state.

4. The actuating method according to claim 1, which further comprises resetting the position measure to the prespecified reference value only under the additional condition that the actuating motor has further remained activated in a closing direction by a prespecified actuating measure after reaching the closed state or up until triggering of a block switch-off operation after reaching the closed state.

5. The actuating method according to claim 1, which further comprises setting the position measure to the prespecified reference value only under the additional condition that the actuating motor has remained activated in a closing direction up until triggering of a block switch-off operation after reaching the closed state.

6. The actuating method according to claim 5, which further comprises setting the position measure to the prespecified reference value only under the additional condition that the actuating motor was activated against the closing direction by a prespecified actuating measure after triggering of the block switch-off operation.

7. An actuating apparatus for a vehicle part, the apparatus comprising: an actuating motor for generating an actuating force under an action of which the vehicle part can be adjusted between a closed state and an open state along an actuating path; and a control unit programmed to perform an adjustment of the vehicle part by the steps of: ascertaining continuously a position measure, the position measure being a characteristic of a current actuating position of the vehicle part along the actuating path; resetting the position measure to a prespecified reference value when the vehicle part is in the closed state and when an additional condition is further met, the additional condition being linked in a reproducible manner with a specific actuating position; and resetting the position measure to the prespecified reference value only under the additional condition that, during the adjustment, an adjustment speed of the vehicle part was within a prespecified tolerance range around a stored reference speed.

8. The actuating apparatus according to claim 7, wherein said control unit is programmed to perform said adjustment of the vehicle part by resetting the position measure to the prespecified reference value only under the additional condition that the actuating motor has further remained activated in a closing direction by a prespecified actuating measure after reaching the closed state or up until triggering of a block switch-off operation after reaching the closed state.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) FIG. 1 is a diagrammatic, side view of a rear of a vehicle with a rear hatch open and with an actuating apparatus which is associated with the rear hatch; and

(2) FIGS. 2 and 3 are flowcharts of an exemplary embodiment of an actuating method which is carried out by the actuating apparatus for adjusting the rear hatch according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

(3) Parts and variables which correspond to one another are always provided with the same reference symbols in all of the figures.

(4) Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a schematic detail of a rear of a vehicle 1. The vehicle 1 has a vehicle door, which is in the form of a rear hatch 2 and can be automatically adjusted between an open state 4 and a closed state 6 along an actuating path X. The rear hatch 2 therefore forms an adjustable vehicle part of the vehicle 1 for reversibly closing a cargo space opening 8.

(5) For the purpose of adjusting the rear hatch 2, the vehicle 1 contains an actuating apparatus 10 which, in turn, contains an actuating drive 12 and also a control unit 14. The actuating drive 12 is subdivided into an actuating motor 16 and a drive mechanism 18 which is arranged between the actuating motor 16 and the rear hatch 2—in the illustrated exemplary embodiment, the drive mechanism 18 is, by way of example, a spindle drive.

(6) In the closed state 6, the rear hatch 2 (indicated in dashed lines here) bears against the vehicle body which borders the cargo space opening 8. In the open state 4, the rear hatch 2 is pivoted about a pivot axis, which runs along a roof upper edge 20, in such a way that the cargo space opening 8 is open for loading or unloading. In this case, an actuating position x of the rear hatch 2 which is designated open position x.sub.O is assigned to the open state 4 in the control unit 14. Accordingly, a closed position x.sub.S is assigned to the closed state 4.

(7) A door lock 22 is arranged on the vehicle body. A striker 24 which is arranged on the rear hatch 2 is situated in the door lock 22 in the closed state 6 and is latched to a lock catch of the door lock 22.

(8) The control unit 14 drives the actuating motor 16 during adjustment of the rear hatch 2. The rotor of the actuating motor transmits an actuating force to the drive mechanism 18 and therefore to the rear hatch 2. During the adjustment, the control unit 14 detects the revolutions of the rotor and, from the revolutions, ascertains a position measure P which is characteristic of the actuating position x of the rear hatch 2 along the actuating path X. When the rear hatch 2 is adjusted to the open position x.sub.O, the actuating motor 16 is driven until the position measure P has a value which corresponds to the value of the open position x.sub.O.

(9) In order that the position measure P reflects the actual actuating position x of the rear hatch 2 as precisely as possible, the control unit 14 is configured to regularly reset the position measure P to a prespecified reference value, that is to say to reference the position measure. During the referencing, the rear hatch 2 is advantageously arranged in a known actuating position x which can be adjusted in as reproducible a manner as possible. The closed state 6 is particularly suitable for this purpose since the rear hatch 2 bears against the vehicle body in this case. In order to indicate that the rear hatch 2 is closed, a closing signal transmitter is associated with the door lock 22. The closing signal transmitter is configured to emit a closing signal S to the control unit 14 when the lock catch is latched in around the striker 24. However, the ascertained position measure P may deviate from the actual position (that is to say the actual actuating position x) of the rear hatch 2 on account of play, slip or elastic deformations in the region of the actuating drive 12. For example, the striker 24 may already be in a latched-in position, while the actuating drive 12 is still adjusted in such a way that the ascertained position measure P indicates a slightly opened position of the rear hatch 2. In this case, referencing of the position measure P would lead to incorrect positioning of the rear hatch 2 and of the actuating drive 12 in relation to one another, and therefore to a subsequent misinterpretation of the actual actuating position x.

(10) Therefore, the control unit 14 is configured to reference the position measure P to the closed position x.sub.S as part of an actuating process which will be described in greater detail below only when two prespecified conditions are met. These conditions are selected in such a way that a reproducible arrangement of the rear hatch 2 and of the drive mechanism 18 is ensured in the closed position x.sub.S, so that the position measure P deviates as little as possible from the actual closed position x.sub.S.

(11) FIG. 2 shows a schematic flowchart of the actuating method. In a first method step 30, the control unit 14 controls the actuating motor 16 for the purpose of closing the rear hatch 2, that is to say for the purpose of adjustment from the open state 4 to the closed state 6. During the adjustment process, the control unit 14 continuously ascertains the position measure P and, from the position measure, determines an adjustment speed v.sub.I. When the striker 24 of the rear hatch 2 enters the door lock 22, the control unit 14 receives the closing signal S. The detection of the closing signal S represents a first condition for referencing of the position measure P.

(12) In response to the detection of the closing signal S, the control unit 14 checks, in a checking step 40 as a second condition, whether the adjustment speed v.sub.I has corresponded to a reference speed v.sub.R, which is stored in the control unit 14, within prespecified limits. In this case, the reference speed v.sub.R is stored in an actuating position-dependent manner. The ascertained values of the adjustment speed v.sub.I are temporarily stored in the control unit 14 for this retrospective check. If the adjustment speed v.sub.I corresponds to the reference speed v.sub.R, the control unit 14 interprets the adjustment of the rear hatch 2 to be as intended and references the position measure P in a concluding method step 50.

(13) If the adjustment speed v.sub.1 deviates from the reference speed v.sub.R beyond the prespecified limits, the control unit 14 does not reference the position measure P.

(14) In an alternative method variant which is not illustrated further, the control unit 14 continuously compares the adjustment speed v.sub.I with the reference speed v.sub.R as early as during the adjustment. Therefore, the information in respect of whether the adjustment is running as intended is already available during detection of the closing signal S.

(15) At the beginning of each adjustment, the adjustment speed v.sub.I can deviate from the reference speed v.sub.R during the start-up phase of the actuating motor 16 (on account of the acceleration). In order to not incorrectly interpret this deviation as an abnormal deviation, it is feasible within the scope of the invention for the start-up phase to be suppressed in the comparison with the reference speed v.sub.R.

(16) In a further alternative method variant, the control unit 14 checks, in the checking step 40 as a second condition, whether the adjustment of the rear hatch 2 out of the open state 4 has taken place. In this case, the referencing is likewise carried out only when this condition is met.

(17) In an alternative method variant according to FIG. 3, after detection of the closing signal S, in a method step 60, the control unit 14 drives the actuating motor 16 until the rear hatch 2 is braced against the vehicle body and the actuating motor 16 is blocked as a result. In this case, the actuating motor 16 is switched off by a so-called block switch-off operation. The control unit 16 then drives the actuating motor 16 for a prespecified number of rotor revolutions in the opposite direction (opening direction). As a result, play of the drive mechanism 18 is compensated for in a defined manner. In this state, the actuating drive 16 is mounted in an approximately force-free manner and the position measure P has a particularly low deviation from the closed position x.sub.S. The control unit 14 then references the position measure P in method step 50.

(18) In a further alternative method variant, after detection of the closing signal S, in method step 60, the control unit 14 further drives the actuating motor 16 by a prespecified number of rotor revolutions in the closing direction. As a result, run-on of the drive mechanism 18 in relation to the rear hatch 2 can be compensated for. The control unit 14 then once again carries out the referencing in method step 50.

(19) The subject matter of the invention is not limited to the exemplary embodiments described above. Rather, further embodiments of the invention can be derived from the above description by a person skilled in the art. In particular, the individual features of the invention which are described with reference to the various exemplary embodiments and the design variants of said individual features can also be combined with one another in a different way.

(20) The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: 1 Vehicle 2 Rear hatch 4 Open state 6 Closed state 8 Cargo space opening 10 Actuating apparatus 12 Actuating drive 14 Control unit 16 Actuating motor 18 Drive mechanism 20 Roof upper edge 22 Door lock 24 Striker 30 Method step 40 Checking step 50 Method step 60 Method step X Actuating path x Actuating position x.sub.S Closed position x.sub.O Open position P Position measure S Closing signal v.sub.I Adjustment speed v.sub.R Reference speed