DE10227765A1 - Seat adjustment control method for motor vehicle, involves determining adjustment position within adjustment path and deactivating protection stop when seat adjustment unit is moved and entrance aid is operated - Google Patents

Abstract

A method for controlling a seat adjustment device of a motor vehicle is provided, the seat adjustment device having at least one adjustment path between a first mechanical stop and a second mechanical stop and an adjustment position within the adjustment path being determined. In the area of at least the first of the mechanical stops, a protective stop is placed in the adjustment path, the protective stop, depending on the particular adjustment position, automatically reducing the adjustment energy, in particular stopping the adjustment movement of the seat adjustment device in the area of this protective stop. If an entry aid is actuated to facilitate entry to a seat of a motor vehicle, the seat adjustment device is adjusted in the direction of the first mechanical stop and the associated protective stop is deactivated.

Description

The invention relates to a method to control vehicle seat adjustment.

Previous control methods for seat adjustment devices of motor vehicles use one. direct measuring system for determination the adjustment position of a motor vehicle seat. A potentiometer detects this the current adjustment position along an adjustment path. A resistance value is assigned to each adjustment position. By the direct coupling between resistance value and adjustment movement there are no errors between the measured position and the real adjustment position when the measured value from the potentiometer can be read correctly.

Due to the high wear of Potentiometers for measuring the distance and the additional cabling required are increasing Position detection systems for controlling vehicle seat adjustments used to determine the position of the rotary drive movement detect the drive motor. For example, the motor current evaluated or the drive movement detected by sensors. Especially Hall sensors can for one such detection can be used. This type of indirect measurement the adjustment position by the detection of the drive movement leads however to measurement errors due to inaccuracies between the detected position and the real adjustment position, which are essentially different from each other can deviate. These measurement errors can programmatically can only be partially remedied. If an adjustment device is a Motor vehicle seat several times, for example due to frequent driver changes, actuated, this can lead to significant position errors.

The position detection systems described above for motor vehicle seat adjustment devices are used for the controlled approach to previously stored memory positions, in an adjustment path between a first mechanical stop and a second mechanical stop can be configured. to Configuration is exploited that by means of one of the aforementioned position detection systems the adjustment position within the adjustment path is determined.

In addition to this comfort function a protective stop in the area of at least one of the mechanical stops set in the adjustment path to increase the mechanical load on the adjustment system to reduce. The protective stop enables depending an automatic reduction from the specific adjustment position the adjustment energy. Ideally, the part to be adjusted reaches the adjustment device just not the stop. To do this too To ensure inclusion of other factors or tolerances, the drive motor is moved in the direction of an adjustment movement the attack, for example, in the immediate area of the protective stop braked, causing the adjustment movement of the adjustment device to stop leads in the area of this protective stop. As a result, this protective stop is assigned to the stop and at least prevents it in the direction of attack one over the protection stop further adjustment, which in the case of a Blocking in the stop would burden the adjustment mechanism. The Adjustment movement stops in the area of the protective stop and can due to inertia about go beyond the protective stop position.

The significant ones set out above Position errors also cause the positions to shift the protection stops from or to the real mechanical stops, the Position opposite the shift remain fixed. An unfavorable shift the protective stops with increasing distance from the mechanical distances would become one essential limitation of Lead adjustment path, when the protection stops are run over in the direction of the mechanical stops for load reasons should.

The invention is based on the object Basically, a method for controlling a seat adjustment device specify a motor vehicle that the mechanical load of the Adjustment system of the adjustment device by reducing the Number of adjustments in the mechanical stop reduced, without the to disposal standing adjustment path is significantly restricted by the method.

This task is accomplished through the procedure for controlling a seat adjustment device of a motor vehicle solved with the features of claim 1. Advantageous further training the invention can be found in the subclaims.

Accordingly, in the process for Control in case of actuation an entry aid the seat adjustment towards the adjusted the first mechanical stop. Especially for standardization this protective stop position assigned to the first mechanical stop the corresponding one Protection stop deactivated to the seat adjustment device until the first mechanical stop to adjust.

An entry aid makes it easier to get into a seat in a motor vehicle. Different entry aids are possible. For example, the front seat can be moved into the rearmost adjustment position in order to make it easier for the driver or the front passenger to access the front seat. In this case, the rear mechanical stop is the first mechanical stop according to the invention. Alternatively or additionally Lich the front seat can be swiveled towards the motor vehicle door as an entry aid. For two-door vehicles, an entry aid for the rear motor vehicle seats is required by folding down the backrest of a front seat and moving the front seat into the foremost adjustment position in order to form a larger space between the B-pillar of the motor vehicle. In this case the entry aid, the front mechanical stop is the first mechanical stop according to the invention.

An advantageous development of Invention provides that the Seat adjustment device until blocking on the first mechanical Stop is adjusted. Because with an adjustment in the event of actuation of the Getting started one if possible quick adjustment in the direction of the first mechanical stop required is to wait for a person who wants to get in To shorten, are security measures necessary, to a mechanical load or the risk of destroying the To minimize the adjustment system. For this purpose, advantageously in a range from a target position to the first mechanical Stop reduces the adjustment energy. This reduction enables one continuous adjustment movement with reduced adjustment energy, which is below the load limit of the first mechanical stop.

It is advantageous for reduction the adjustment energy, the drive torque or the adjustment speed reduced. This is done, for example, by means of a PWM (pulse width modulation) Motor current controlled by the motor current with a semiconductor switch controlled with a predetermined frequency of 20 kHz, for example becomes. The in the engine during Energy fed during the reduction phase leads to mechanical energy below the load limit. The target position is sufficient Arrange distance from the first mechanical stop, so that the sum from the inertia the adjustment movement shortly before the target position and the driving force of the electric motor according to the target position, especially at the first mechanical stop below the load limit. The reduction is particularly due to a falling ramp of the relationship the on time at the off time of the PWM modulation. In the blocking, the controller is controlled so that the current Motor torque increase slightly is preferably omitted.

An advantageous embodiment of this Further development of the invention provides that the target position is dependent is determined from the position of the deactivated protection stop. Opposite one independent of the protective stop position Position calculation of the target position can thus the computing effort and the memory requirement can be reduced. In addition, the target position be corrected with every normalization of the protective stop position. In a particularly simple embodiment of the invention, the target position and the protective stop position are identical.

To further reduce the mechanical Block driving is to achieve a load on the adjustment system and in particular the deactivation of the first protection stop by one correction need dependent. For example, a validity the position depending one or more parameters, for example the number of adjustments since the last standardization. Dependent on of this validity becomes a need for correction determined and in the case of this need for correction, i.e. the requirement the first protective stop is deactivated.

Advantageously, after the Blockage at the first mechanical stop at least the position the associated first protection stops corrected. This is done, for example, by that this first Protective stop position and a fixed or other parameters, for example the seat weight, depending on the distance to the blocking position is calculated and set. additionally the second protective stop advantageously also becomes the first protective stop corrected this for the first protective stop advantageously a minimum distance is set to a minimum travel distance to disposal to deliver.

In an advantageous further training the invention is the adjustment of the motor vehicle seat adjustment mapped onto a virtual position axis. The current adjustment position becomes a position value on the virtual position axis assigned. In addition, are on this virtual position axis Position of the first protection stop and the position of the first Dependent on protective stop second protective stops arranged. In the event of actuation of the Getting started, this virtual position axis becomes the adjustment path aligned when blocking at the first mechanical stop is determined. Hence must the protective stop positions on the virtual axis are not recalculated become. These protection stop positions are after the alignment of the virtual axis only from the deactivated to the active Switched state. additionally the memory positions are advantageously on the virtual axis arranged in the case of normalization and alignment of the virtual Position axis are moved accordingly.

According to an advantageous development of the invention, further seat adjustment devices of the motor vehicle seat are controlled in such a way that the seat adjustment device is moved into the first mechanical stop before reaching an obstacle, for example the position-adjustable steering wheel or the headlining. For this purpose, the further seat adjustment device is not adjusted beyond a reserve position. In particular, a backrest adjustment for an entry aid to the rear seats is only tilted forwards to such an extent that the backrest has not yet reached the steering wheel as an obstacle when the blocking occurs at the first stop. In the case of a Ver adjustable steering wheel apply to each steering wheel position, the backrest can be adjusted to the obstacle following the blocking in the first stop.

To make an expensive adjustment of this Saving the reserve position is achieved in an advantageous embodiment this development of the invention, the reserve position by a Seat control unit learned from standardization adjustments. For this, the steering wheel for example in the for blocked an entry with entry aid most unfavorable position be, then is moved into the blocking of the first stop and the position the back of a subsequent one Blockage determined on the steering wheel and saved as a lead position.

To a minimum height of the position of the headrest for accidental An advantageous further development achieves crash situations the invention the headrest position of the motor vehicle seat depending from the position of the seat adjustment controlled by taking the headrest position off a map is read out. In the case of activation of the boarding aid the seat adjustment adjusted in the direction of the first mechanical stop and the associated Protection stop deactivated and additionally the headrest adjusted in the direction of the lower stop. Instructs the headrest adjustment also a protective stop position for the lower stop, this protective stop position is additionally deactivated and the headrest adjusted up to blocking in the lower stop, so that the position the seat adjustment as well as the position of the headrest normalized to the map. This can advantageously the tolerance chain from determining the longitudinal position of the seat, Map and headrest position determination be minimized.

In addition, a learning area be provided in which the setting of a new protection stop is permitted becomes. The approval of setting a protective stop means that a setting of a related one new protection stops in this area by additional criteria dependent can be, however, local between the boundaries of this learning area, excluding negative ones Criteria.

A new protection stop will then occur set when a need for correction of the value of the previous protection stop. For example the count value across from the real position of the mechanical stop is significantly shifted, So that the previous position of the protective stop was not a sufficient reduction the adjustment energy guaranteed, before the displaced part touches the stop. Are they expected Movements within the learning range limits are described as before method. Is the position value of the protection stop, the stop or a correlating value outside of this learning range no protective stop assigned to this stop is set. however can other measures or other protective stops not assigned to this attack be set.

The invention is described below of embodiments explained in more detail with reference to drawings.

Show

1 1 shows a schematic flow diagram for the control method,

2 Schematic representation of a position detection of a motor vehicle seat adjustment.

In 1 a flowchart is shown that shows the schematic flow of the control method. In step 1, the boarding aid is activated. The actuation can take place, for example, by the direct or indirect actuation of a switch via a mechanical coupling, by means of signal transmission or via sensors.

In step 2, the current position of the adjustment device saved in step 3 is adjusted. This stored position is in the process step 12, i.e. started again after the person has entered or alternatively in a medium position that meets the security requirements. This applies in particular to the position of the headrest, which is a minimum height in order to avoid whiplash in the event of a crash should.

The adjustment in step 4 takes place preferably with the maximum possible Adjustment speed to the waiting times for the person willing to enter shorten as much as possible. This maximum speed leads too big mechanical loads on the adjustment system. Hence with the maximum speed only up to a target position, in this embodiment Proceed until protection stop SS1. Reaches the adjustment position x the protective stop position SS1. It is queried whether there is a need for correction by the current protective stop position, in particular whether a virtual Position axis to the adjustment axis of the adjustment path are corrected got to. Lies no need for correction before, the adjustment is stopped directly in method step 10, before the adjustment device reaches the first mechanical stop. As an alternative to this query you can use regardless of a need for correction reduced adjustment energy each time the entry aid is operated in the blocking of the first attack should be carried out if the maximum travel distance are available at all times. In this case is not even with a large one determined position shift ensures that for entry help the seat is adjustable up to the foremost position.

If, on the other hand, there is a need for correction in step 5, the first protective stop SS1 is deactivated in step 6. In addition, if not already ak a blocking detection is started which senses a blocking of the adjustment movement. The drive energy is reduced by moving beyond the first protection stop SS1. This reduction leads to an adjustment energy below the load limit of the mechanical system. For reduction, the drive voltage of the electric motor can be controlled via a falling function, in particular a ramp, so that the torque and / or the adjustment speed is reduced.

Becomes a during this adjustment Blockage detected in process step 8 is described below Step 9 aligned the virtual axis to this blocking. This alignment is a standardization with which the positions of the Protection stops SS1, SS2 and the memory position can be corrected. At the same time in method step 10, the energization of the drive motor switched off.

Did the person get in, for example on one of the rear seats of the motor vehicle, the adjustment device in step 12 move back to the original adjustment position become. The reset process is previously in step 11 by a reset operation or Sensor triggered. Is the corrected shift between the virtual axis and actual Adjustment position has been substantial, the stored, original Position moved too far. In this case the original Adjustment position recalculated from the old value and the adjustment device in this adjustment position or alternatively a replacement position, for example used a middle position.

The process steps 1 to 12 can for different Adjustment levels and adjustment devices of the motor vehicle seat and other adjustment devices adjusted with the entry aid of the motor vehicle, such as the steering wheel. Process steps 1 to 10 of the various are advantageously Adjustment devices are coordinated with one another in time, in particular synchronized with each other.

In 2 An adjustment path VW of a motor vehicle seat adjustment is shown schematically. The mechanically possible adjustment path VW extends from a first mechanical stop MA1 (front) to a second mechanical stop MA2 (rear). For example, in the present exemplary embodiment it is a seat longitudinal adjustment. In an analogous manner, the control method can also be applied to other adjustments, such as adjusting the inclination of the seat back.

The respective current position of the adjustable part of the adjusting device is determined by an evaluation device which, in this exemplary embodiment, evaluates the adjusting movement by means of an incremental encoder and an assigned sensor. The adjustment path VW is therefore divided into a large number of increments. In the representation of the 2 The adjustment path VW ranges from the increment with the number 5 to the increment with the number 18. This illustration is greatly simplified for illustration. In order to be able to determine the adjustment position with sufficient accuracy, a much larger number of increments, for example a few tens of thousands of increments, is necessary. The invention is not limited to the use of incremental measuring systems; rather, all other absolute and relative position determinations can also be advantageously combined with the invention.

To the mechanical load of the Any mechanical stop MA1 has to be reduced or MA2 a protective stop SS1 or SS2, also as a soft stop or soft stop. These protection stops SS1, SS2 are not in the direction of the associated mechanical stop To drive over MA1 or MA2, without the Adjustment energy is reduced so that neither the associated mechanical Stop MA1 or MA2 still the gearbox or the motor the adjustment device is damaged becomes. For this purpose, the motor is preferably braked so that the adjustment movement in front of or on the mechanical stop MA1 or MA2 for Comes to a standstill, or that the remaining forces acting on the respective stop MA1 or MA2 only are low.

In the opposite direction, however, with increasing distance from the respective mechanical stop MA1 or MA2, the protective stops can be passed over SS1 or SS2. The distance of the protective stops SS1, SS2 to the associated mechanical stop MA1 or MA2 can either be predetermined, in 1 For example, an increment, or by a control device as a function of a parameter, for example the seat weight of the motor vehicle occupant or the adjustment path VW, can be configured.

Any mechanical stop MA1 or MA2 a learning area EB1 or EB2 is assigned. This Learning area EB1 or EB2 has area limits, the dependent from the associated one mechanical stop can be calculated or specified. In this embodiment the learning area EB1 of the stop MA1 extends from the increment 4 up to increment 8 and the teach-in area EB2 from increment 15 up to the increment 20. The range limits and thus the width of the Learning areas EB1, EB2 are either predefined and take place in fixed position to the respective mechanical stop MA1 or MA2, or the range limits, for example dependent on reconfigured from learned parameters or determined parameters or measured variables.

The count values of the evaluation device for determining the position of the adjustable part of the ver Adjustment devices can lead to a shift of the determined current position to the real position of the adjusted part of the adjustment device due to measurement errors, memory errors or other program errors. The learning areas EB1, EB2 serve to restrict the approval for setting protective stops SS1 or SS2, which are each assigned to a stop MA1, MA2.

The invention is limited but not to the aforementioned embodiment. Rather are further embodiments according to the invention conceivable that the approval of putting the protection stops SS1, SS2 in dependence from the actuation an entry aid under different conditions than the previously mentioned.

MA1, MA2

mechanical attack

VW

adjustment

HN

obstacle

SS1, SS2

stop protection

SB

stopband

EB1, EB2

learning range

x

position on the virtual position axis

Claims (12)

Method for controlling a seat adjustment device of a motor vehicle, wherein - the seat adjustment device has at least one adjustment path between a first mechanical stop and a second mechanical stop, - an adjustment position within the adjustment path is determined, and - a protective stop in the area of at least the first of the mechanical stops Adjustment path is set, the protective stop, depending on the particular adjustment position, automatically reducing the adjustment energy, in particular stopping the adjustment movement of the seat adjustment device in the area of this protective stop, characterized in that when an entry aid is actuated for an easier entry to a seat, a Motor vehicle adjusts the seat adjustment device in the direction of the first mechanical stop and the associated protective stop is deactivated. A method according to claim 1, characterized in that the seat adjustment device is adjusted until blocking at the first mechanical stop, being in a range from a target position to the first mechanical Stop the adjustment energy is reduced. A method according to claim 2, characterized in that for reduction the adjustment energy, the drive torque is reduced. A method according to claim 2, characterized in that for reduction the adjustment energy the adjustment speed is reduced. Method according to one of claims 2 to 4, characterized in that that the Target position depending is determined from the position of the deactivated protection stop, preferably this corresponds. Method according to one of the preceding claims, characterized characterized that after the blocking at the first mechanical stop at least the position the associated first protection stops is corrected. A method according to claim 6, characterized in that in addition to first protective stop the second protective stop is corrected. Method according to one of claims 6 or 7, characterized in that that the first protective stop is only deactivated in the event of a need for correction. Method according to one of the preceding claims, characterized characterized in that the Adjustment path is mapped to a virtual position axis, on this virtual position axis the position of the first protection stop and the position of the second protection stop dependent on the first protection stop be firmly arranged the current adjustment position Position value is assigned on the virtual position axis, and aligned this virtual position axis to the adjustment path is determined when the blockage at the first mechanical stop becomes. Method according to one of the preceding claims, characterized characterized in that further seat adjustment devices the motor vehicle seat can be controlled so that before The seat adjuster reaches an obstacle (steering wheel, headlining) is driven into the first mechanical stop by the further Seat adjustment device, in particular a headrest adjustment or a backrest adjustment, about a reserve position that does not reach an obstacle allows is not adjusted. A method according to claim 10, characterized in that the reserve position through a seat control unit is learned using standardization adjustments. Method according to one of the preceding claims, characterized in that the headrest position of the motor vehicle seat is dependent speed is controlled by the position of the longitudinal seat adjustment and a map, when the access aid is operated, the longitudinal seat adjustment is adjusted in the direction of the first mechanical stop and the associated protective stop is deactivated and the headrest is adjusted in the direction of the lower stop, and the position of the longitudinal seat adjustment as well the position of the headrest to the map are standardized.