Method for operating an electric motor running board of a motor vehicle

Abstract

The invention relates to a method (36) for operating an electromotive running board (18) of a motor vehicle (2), comprising a board (16) driven by an electric motor (26) and mounted so as to be adjustable along an adjustment path (22) having an end stop (24). The electric motor (26) is energized to move the board (16) in the direction of the end stop (24), and a motor current (42) conducted by the electric motor (26) is detected. The energization of the electric motor (26) is terminated when a change in the motor current (42) fulfills a specific condition. The invention further relates to an electromotive running board (18).

Description

[0001] The invention relates to a method for operating an electric motor running board of a motor vehicle and to an electric motor running board for a motor vehicle. The electric motor running board has a board driven by an electric motor.

[0002] Relatively high vehicles, such as off-road vehicles or pick-up trucks, usually have running boards, also known as steps, to make getting in and out easier. These are attached below a door and extend from the lower end of the body towards the ground. This allows a person to use the running board as an intermediate step when getting in and out, and therefore also bridge relatively large differences in height. For example, the running board is rigidly attached to the body of the vehicle. The disadvantage of this is that the ground clearance of the vehicle is reduced across the board and its lateral extension is increased. If the vehicle is driven on rough terrain, it is possible that the running board comes into contact with the ground and is damaged or torn off.In addition, in the event of an accident, the risk of injury to other people is increased and the aerodynamics of the vehicle are also impaired.

[0003] To remedy this, it is known to design the running board with an electric motor. This involves a drive system with an electric motor, which drives the board, which serves as a step. A kinematics system makes it possible to pivot the board and, in particular, to raise it and stow it underneath the body when not in use. This eliminates the disadvantages of the rigid connection.

[0004] To reduce manufacturing costs, there is usually no additional sensor for determining the position of the board. To stow the board, the electric motor is usually energized until the board reaches an end stop. In this case, the board is blocked, which causes the electric motor to stop. As a result, the torque applied by the electric motor is comparatively large. Thus, based on the applied torque, which is functionally related to the electric current supplied by the electric motor, it can be determined that the board has reached the end stop. Therefore, the electric motor is stopped if the electric current supplied by the electric motor is greater than a limit value for a certain period of time. After the electric motor has come to a standstill, the mechanical stresses caused by the torque applied by the electric motor act on the kinematics.These persist until the board is moved again in the opposite direction. As a result, mechanical stress is comparatively high and wear is increased.

[0005] The invention is based on the object of specifying a particularly suitable method for operating an electromotive running board of a motor vehicle and a particularly suitable electromotive running board for a motor vehicle, wherein a mechanical load and / or manufacturing costs are expediently reduced.

[0006] With regard to the method, this object is achieved according to the invention by the features of claim 1 and with regard to the electromotive footboard by the features of claim 7. Advantageous further developments and refinements are the subject of the respective subclaims.

[0007] The method serves to operate an electric motor running board. The electric motor running board is suitable, in particular intended and configured, to be mounted on a motor vehicle or at least to form a component of the motor vehicle in the assembled state. The motor vehicle is suitably land-based and preferably has a multi-track design. In this case, it is suitably possible to position the motor vehicle essentially freely, in particular on a roadway. For this purpose, the motor vehicle expediently has corresponding wheels. In summary, it is preferably possible to position the motor vehicle essentially independently of other conditions on land. In other words, the motor vehicle is suitably not rail-guided. Preferably, the motor vehicle is a passenger car (car) or a commercial vehicle, such as a lorry (truck) or bus.

[0008] The electromotive running board has a board. The board serves for a person to climb onto and / or support themselves on and is suitable, in particular intended and configured for this purpose. In other words, the board is in particular a type of step or acts like a step. The board itself is adjustably mounted along an adjustment path, in particular by means of a mechanism / kinematics of the electromotive running board. Consequently, the adjustment path is at least partially predetermined by the mechanism / kinematics. By means of the mechanism / kinematics, the board is expediently arranged on the outside of a body of the motor vehicle in the assembled state, and by means of the mechanism or kinematics it is possible to pivot or at least adjust the board.In particular, it is possible to change the distance of the board to the ground and / or to at least partially adjust the protrusion of the board over other components of the body.

[0009] The adjustment range has an end stop. The end stop thus limits the adjustment of the board along the adjustment range on one side, and the end stop forms one of the ends of the adjustment range. For example, the end stop is specified by the mechanics / kinematics or by the body. When the board is at the assigned end of the adjustment range, the board rests against the end stop, either directly or indirectly via the mechanics / kinematics.

[0010] Preferably, the board is assigned to a door of the motor vehicle and, in particular, is arranged vertically below the door, i.e., below an opening in the body associated with the door. For example, the motor vehicle is designed in the manner of a train, tram, or bus. However, the motor vehicle is particularly preferably a passenger car (car), for example, designed in the manner of a small van, off-road vehicle, or pickup truck.

[0011] The board is driven by an electric motor of the electric-powered footboard. Thus, it is possible to move the board along the adjustment path by energizing the electric motor. The electric motor is preferably a brushed commutator motor or, alternatively, a brushless motor. For example, the electric motor is a brushless direct current (BLDC) motor. The electric motor preferably has a stator and a rotor that is mounted for rotation relative to the stator about an axis of rotation / rotation, which thus corresponds to the axis of rotation of the electric motor. The electric motor is designed such that, when energized, a rotating magnetic field is created, which causes the rotor to rotate relative to the stator. The electric motor preferably comprises a housing that at least partially surrounds and thus protects the stator.

[0012] The electric motor is expediently a component of the drive of the electric-powered footboard. The drive further comprises, for example, a gear driven by the electric motor. The board, in turn, is driven by the gear, for example, directly or indirectly via another component. At the very least, however, the gear is mechanically arranged between the board and the electric motor. The gear is preferably self-locking. Expediently, the gear comprises a worm gear.

[0013] The method provides for the electric motor to be energized to move the board towards the end stop. For example, a corresponding request is first detected for this purpose, which was generated, for example, by a user of the motor vehicle or an on-board computer of the motor vehicle. The polarity / direction / type of energization is selected in particular such that a direction of rotation of the electric motor results which leads to a movement of the board towards the end stop. In other words, the electric motor is energized in such a way that the board is moved towards the end stop, for which the direction of rotation and thus in particular the energization is selected accordingly. Suitably, a specific electrical voltage is applied to the electric motor for the energization, resulting in a motor current which is carried by the electric motor. The electrical voltage is, for example, constant or variable.In particular, the electrical voltage is pulse width modulated.

[0014] During the movement, preferably as long as the electric motor is energized, the motor current supplied by the electric motor is recorded. For example, the motor current is recorded directly, using a corresponding current sensor. However, the recording is particularly preferably carried out using a shunt. The motor current is functionally related to the torque generated by the electric motor.

[0015] The power supply to the electric motor is stopped when a change in the motor current fulfills a specific condition. In this case, the power supply is, for example, only briefly interrupted or, expediently, completely. In other words, when the condition is met, the electric motor is no longer supplied with power to move the board towards the end stop. In summary, the change in the motor current is first determined and checked to see whether it fulfills the (specified) conditions. For example, a comparison is made with a limit value or threshold. If the change fulfills the condition, the power supply to the electric motor is stopped, for which purpose in particular no further electrical voltage is applied to it. Preferably, the condition is met when the change in the motor current corresponds to an increase of at least 60 A per second.

[0016] In this method, it is not the motor current itself that is monitored, but rather the change in the motor current. Consequently, a current gradient, i.e. the gradient of the motor current, is preferably determined. When the board is moved towards the end stop and rests against it, the motor current carried by the electric motor increases comparatively sharply. In this case, the condition is particularly met. This makes it possible to switch off the electric motor early, before it generates a comparatively high torque that leads to high mechanical stress. This reduces mechanical stress and, consequently, wear. Therefore, it is not necessary to design the electromotive step to be comparatively robust, which reduces manufacturing costs and weight.Furthermore, the electric motorized running board does not require a position sensor or any other sensor to determine the board's position, thus increasing robustness and further reducing manufacturing costs. Therefore, the electric motorized running board is expediently designed without a position sensor.

[0017] For example, a check is performed immediately after the electric motor is energized to determine whether the (specific) conditions are met. However, this is preferably performed after a specific time window, e.g., greater than 1 ms and less than 1 s. Thus, the check is only performed after the electric motor is rotating at a substantially constant speed and any transient effects have subsided.

[0018] The method can also be used when the board is moved against an obstacle, so no additional components are required for anti-pinch protection or other protection when the board is moved against an obstacle. It is also not necessary to perform an additional procedure. Rather, the method can be used whenever the electric motor is energized, which reduces complexity. In summary, no additional sensor is required, and the check to see whether the condition is met ensures that no damage to the board or any obstacle against which the board is moved occurs if the obstacle is in the adjustment path. Thus, no additional effort is required, and manufacturing costs are further reduced.

[0019] For example, the adjustment path may have only a single end stop, and when the board is moved toward this end, a check is made to see whether the change in motor current meets the specific condition. Alternatively, there may be two end stops between which the adjustment path extends. In this case, for example, the check is only made to see whether the change in motor current meets the specific condition when the board is moved toward one of the end stops. Preferably, however, when the board is moved toward each of the end stops, the power supply to the electric motor is stopped when the specific condition is met. This always ensures that there is no excessive mechanical stress on the board and / or any mechanics / kinematics.

[0020] For example, to check whether the condition is met, the motor current is used directly. This reduces overhead. Alternatively, the process is first filtered to remove any noise. However, it is particularly preferred to create the time-averaged motor current and determine its change. Then it is checked whether this change fulfills the specific condition. This removes short-term fluctuations / oscillations and prevents the electric motor from being falsely stopped. In particular, a moving time-average is used. This means that relatively distant points in time when the board was far from the end stop have no influence on the change and therefore the check for the condition, which increases reliability. This also reduces memory requirements.

[0021] For example, the changes are determined based on the gradient of the motor current. In this case, a difference is expediently calculated between two consecutive values, for example measured values, of the motor current in order to obtain the current gradient between the two values. For example, the difference is compared with an assigned limit value. Suitably, several consecutive differences are used and these are filtered, for example averaged. The filtered value is then compared with the limit value to check whether the condition is met. Preferably, the number of differences is less than 100 and in particular between 2 and 10. For example, 4 or 5 differences are used. In particular, the values ​​are created with a frequency between 1 kHz and 1 Hz, between 700 Hz and 300 Hz or between 450 Hz and 550 Hz. The frequency is preferably 500 Hz.

[0022] For example, the time derivative is created as a change in the motor current, for example directly. Preferably, however, the time derivative of the time average of the motor current is created. This enables a comparatively accurate determination of the change, with short-term fluctuations having no or only minimal influence. However, it is particularly preferred to create two different time averages to determine the change. These differ, for example, in the way they are created, with different weighting factors being used, for example. For example, in combination with this or expediently alternatively, the averages differ based on the length of the respective time period.The mean values ​​are conveniently created in the same way and thus differ only in the number of time points used to determine the respective mean value.

[0023] This condition is particularly fulfilled if the mean values ​​differ by more than a threshold value. For example, the comparison is performed with a sign or, more conveniently, absolutely, so that the difference between the two mean values ​​is used. This allows the determination of the extent to which the motor current has changed to be relatively easy, while short-term changes in the motor current, such as those that occur when the board is moved toward the end stop, can still be detected relatively quickly. In summary, this reduces the effort, while the electric motor is still reliably stopped as soon as the board reaches the end stop.

[0024] Preferably, a time span between 10 ms and 40 ms is used for one of the average values, and preferably 20 ms. Thus, the motor current at the current time up to 20 ms in the past is used for this average value. Due to such a comparatively short time span, the current motor current is essentially used, with short-term fluctuations being averaged out. Thus, this average value increases essentially immediately as soon as the board reaches the end stop.

[0025] Alternatively, or particularly preferably in combination with this, a time span between 200 ms and 800 ms is used for one of the mean values, expediently the other mean value, and preferably 400 ms. This time span is comparatively long, which is why this mean value also takes into account times at which the board was still relatively far from the end stop, even if it is currently resting against the end stop. However, this mean value can be used to determine current influences and conditions that act on the electromotive footboard and influence its mechanical properties. For example, different temperatures lead to different mean values, even if the board is spaced from the end stop.It is particularly preferred to use a time period of 20 ms for one of the means and a time period of 400 ms for the other means, and to determine the change, the difference between these two means is taken.

[0026] For example, if the specific condition is met, the power supply is essentially stopped immediately and the electric motor is thus essentially stopped immediately. In this state, for example, the electric motor-driven footboard is left in this state until a new adjustment request is made and the board is moved in the opposite direction, in particular to the other end of the adjustment path. However, it is particularly preferred that after the power supply has ended, the electric motor is energized in the opposite direction for a time window, i.e. in particular turned back. The time window is, for example, fixed or adapted to the current environment / requirements. The length of the time window is preferably dimensioned such that no significant adjustment of the board occurs, at least in particular not more than 5 mm or 1 mm.In summary, the electric motor is briefly reversed, which relieves any remaining mechanical stress. This further reduces stress.

[0027] Energizing the electric motor in the opposite direction when it has been determined that it is at the end stop is independent of whether the energization is terminated when the change in the motor current fulfills the specified condition. Rather, this is considered an independent invention. In other words, the independent invention provides that after the energization of the electric motor has been terminated because the board is at the end stop, the electric motor is energized again in the opposite direction for the time window. Determining that the board is at the end stop can be done in any desired manner.

[0028] The electric running board is suitable for installation on a motor vehicle and is preferably provided and configured for installation. In other words, the electric running board, when installed, preferably forms a component of the motor vehicle. The motor vehicle is suitably land-based and, for example, a passenger car. Alternatively, the motor vehicle is a commercial vehicle, for example, a truck or a bus.

[0029] The electric motor-driven footboard comprises a board that is adjustably mounted along an adjustment path, which has an end stop, and is driven by an electric motor. The electric motor-driven footboard is operated according to a method in which the electric motor is energized to move the board toward the end stop. A motor current supplied by the electric motor is detected, and the energization of the electric motor is terminated when a change in the motor current meets a specific condition.

[0030] The electromotive running board, in particular, has a control unit that is provided and configured to carry out the method. The control unit comprises, for example, an application-specific integrated circuit (ASIC) or, particularly preferably, a computer that is suitably designed to be programmable. In particular, the control unit comprises a storage medium on which a computer program product, also referred to as a computer program, is stored. Upon execution of this computer program product, i.e., the program, the computer is prompted to carry out the method. The electromotive running board, or at least the motor vehicle, expediently has several control elements by means of which an adjustment request for adjusting the board along the adjustment path can be generated, depending on which the current supply to the electric motor is then initiated.The operating elements are conveniently connected to the control unit via signal technology, in particular via a bus system.

[0031] For example, the electric motor-driven footboard has a position sensor for directly determining the position of the footboard. However, it is particularly preferred that the electric motor-driven footboard be position-sensorless. Suitably, no other sensor is present by which the position of the footboard can be determined. In particular, no speed sensor or the like is present by which the speed of the electric motor can be determined, in particular directly measured. As a result, manufacturing costs are further reduced.

[0032] The motor vehicle comprises, in particular, a body with an opening. The opening can preferably be covered by a door that is expediently adjustably mounted on the body, for example by means of a hinge and / or a guide rail. The electric motor-driven running board is suitably assigned to the door. In particular, the board is arranged vertically below the door or at least the opening that can be covered by the door. A mechanism / kinematics of the electric motor-driven running board is suitably attached to the body at this point. The board can thus be used as a step for getting in and out through the opening to which the door is assigned. In particular, the electric motor is operated in such a way that when the door is opened, i.e. the opening is released, the board is adjusted such that it can be used by a person.For this purpose, the board is extended, so that it protrudes beyond other components of the body. When the door is closed, however, the board is expediently moved into a retracted position. Particularly preferably, the door is driven by an additional electric motor, and when the additional electric motor is operated, the drive of the electric running board is also operated. The invention further relates to such a motor vehicle.

[0033] The invention further relates to a computer program product. The computer program product comprises a number of instructions which, when the program (computer program product) is executed by a computer, cause the computer to carry out a method for operating an electric motor-driven running board of a motor vehicle, having a board driven by an electric motor, which is adjustably mounted along an adjustment path and has an end stop. In the method, the electric motor is energized to move the board toward the end stop. A motor current conducted by the electric motor is detected, and the energization of the electric motor is terminated when a change in the motor current fulfills a specific condition. The computer is expediently a component of a control unit or electronics of the electric motor door drive and is formed, for example, by means of this.The computer preferably comprises or is formed by a microprocessor. The computer program product is, for example, a file or a data carrier containing an executable program that, when installed on a computer, automatically executes the method.

[0034] The invention further relates to a storage medium on which the computer program product is stored. Such a storage medium is, for example, a CD-ROM, a DVD, or a Blu-ray disc. Alternatively, the storage medium is a USB stick or other storage device that is, for example, rewritable or only writable once. Such a storage device is, for example, a flash memory, a RAM, or a ROM.

[0035] The invention further relates to a control unit. The control unit is provided and configured to carry out a method for operating an electric motor-driven running board of a motor vehicle, having a board driven by an electric motor, which is adjustably mounted along an adjustment path having an end stop. In the method, the electric motor is energized to move the board toward the end stop. A motor current conducted by the electric motor is detected, and the energization of the electric motor is terminated when a change in the motor current fulfills a specific condition. The control unit has, for example, an application-specific integrated circuit (ASIC) and / or a microprocessor, by means of which the method is at least partially carried out.In particular, the control unit comprises a computer program product that is stored in a memory and, when the program is executed by a computer, such as the microprocessor, causes the computer to carry out the method. Preferably, the control unit, in the assembled state, is a component of the electromotive door drive and is suitable, in particular provided and configured, for this purpose. For example, the control unit is a door control unit. For example, any electromotive window lifter integrated into the door is also controlled by the control unit. The electromotive window lifter preferably comprises another electric motor, by means of which the window pane is driven. Alternatively, or in combination with this, an electromotive door drive is operated by means of the control unit. A door, which is driven by another electric motor, is assigned to this door. The board is expediently assigned to the door.

[0036] The advantages and further developments mentioned in connection with the method are to be transferred analogously to the electric motor running board / the motor vehicle / the computer program product / the storage medium / the control unit as well as to each other and vice versa.

[0037] An embodiment of the invention is explained in more detail below with reference to a drawing. In the drawings: Fig. 1 schematically shows a motor vehicle comprising a door to which an electromotive running board is assigned, Fig. 2 schematically shows in a sectional view the electromotive footboard, which includes an electric motor Fig. 3 a method for operating the electric motor footboard, and Fig. 4 the time course of a motor current carried by the electric motor.

[0038] Corresponding parts are provided with the same reference numerals in all figures.

[0039] In Fig. 1 shows a simplified schematic representation of a motor vehicle 2 in the form of a passenger car (car). The motor vehicle 2 has a plurality of wheels 4 that rest on the ground and are connected to a body 6 by means of a chassis (not shown in detail). The motor vehicle 2 is designed as a pick-up and has comparatively large wheels 4 and a correspondingly designed chassis. As a result, a lower edge 8 of the body 6 is spaced comparatively far from the ground. The body 6 has an opening 10 that can be covered by a door 12. For this purpose, the door 12 is movably mounted on the body 6 by means of a hinge 14. A board 16 of an electromotive running board 18 is arranged vertically below the door.

[0040] The electromotive running board 18 and the body 6 are in Fig. 2 is shown in detail in a sectional view perpendicular to the longitudinal axis. The essentially horizontally arranged board 16 is adjustably mounted on the body 6 along an adjustment path 22 by means of a mechanism 20. The adjustment path 22 has two end stops 24, by means of which the adjustment path 22 is limited at the end. One of the end stops 24 is formed by the lower edge 8 of the body 6. The other end stop 24 is predetermined by the mechanism 20. The board 16 is driven via a gear mechanism (not shown in detail) by means of an electric motor 26, which is designed as a brushed commutator motor. Thus, by operating the electric motor 26, it is possible to move the board 16 relative to the body 6, namely along the adjustment path 22 between the two end stops 24. When the board 16 rests against the lower edge 8, it is retracted and does not protrude laterally beyond the body 6.When the board 16 is at the other end stop, the distance to the floor is reduced and there is a lateral overhang. Thus, a person can use the board 16 as a step to enter or exit through the opening 10. In summary, the electromotive step 18 is assigned to the door 12.

[0041] The electromotive footboard 18 has a control unit 28, which includes a computer 30 in the form of a microprocessor. Furthermore, the control unit 28 has a memory 32 on which a computer program product 34 is stored. The computer program product 34 has a number of instructions which, when the program is executed by the computer 30, cause the computer 30 to execute a Fig. 3. Thus, the electromotive footboard 18 is operated according to the method 36, and the control unit 28 is provided and configured to carry out the method 36.

[0042] In the method, an adjustment request, which was generated by a user using an input device (not shown in detail), is recorded in a first step 38. The adjustment request specifies that the board 16 be moved from one of the end stops 24 to the other end stop 24, so that the board 16 can either be used as a step or is stowed away.

[0043] In a subsequent second step 40, the electric motor 26 is energized accordingly. For this purpose, a suitable electrical voltage is applied to the electric motor 26 by means of the control unit 28. This results in a motor current 42, the temporal profile of which is Fig.4. The motor current 24 is functionally related to the torque applied by the electric motor 26. The polarity of the applied electrical voltage is selected such that the resulting direction of rotation of the electric motor 26 leads to the adjustment of the board 16 along the adjustment path 22 to the desired end stop 24. In summary, in the second work step 40, the electric motor 26 is energized to move the board 16 in the direction of the desired end stop 24. Furthermore, the motor current 42 carried by the electric motor 26 is detected. The detection was carried out, for example, by means of a shunt, and the motor current 42 exhibits brief fluctuations, which are caused, for example, by contamination of the mechanism 20, due to which the board 16 is briefly braked.

[0044] In a third work step 44, a first mean value 46 and a second mean value 48 of the motor current 42 are created. The two mean values ​​46, 48 are created in the same way and each represent an unweighted moving average. The first mean value 46 is assigned a time period of 400 ms, so that it corresponds to the mean value of the motor current 42 for the last 400 ms. As a result, this is predominantly essentially smooth. However, the first mean values ​​46 differ for different points in time at which the method 36 is carried out, since this is largely determined by ambient conditions. For example, at a comparatively low temperature, the brittleness of the mechanism 20 is increased, which leads to a higher force required to adjust the board 16. As a result, the motor current 42 and therefore the first mean value 46 are generally increased.The second mean 48, on the other hand, is assigned a time span of 20 ms. As a result, the second mean 48 exhibits small fluctuations and changes and primarily moves around the first mean 46.

[0045] In a fourth work step 50, the deviation between the two mean values ​​46, 48 is determined and compared with a threshold value 52. If the mean values ​​46, 48 differ by more than the threshold value 52, a condition is met. If the motor current 42 exhibits only minor fluctuations, which are particularly statistical, the mean values ​​46, 48 differ by less than the threshold value. This is the case when the board 16 is adjusted essentially undisturbed along the adjustment path 20. However, if the board 16 hits the end stop 24, further movement of the board 16 is no longer possible. As a result, the force applied to the board 16 by the electric motor 26 increases, and thus also the motor current 42. As a result, the second mean value 48 also increases comparatively quickly. The first mean value 46, on the other hand, remains at its original level for a longer time and only begins to increase gradually.As a result, the mean values ​​46, 48 differ by more than the threshold value 52.

[0046] The threshold value 52 is selected such that if the motor current 42 increases by more than 60 A / s over the two time periods, the threshold value 52 is exceeded. If the condition is met, i.e., if the mean values ​​46, 48 differ by more than the threshold value 52, the current supply to the electric motor 26 is terminated. In summary, the current supply to the electric motor 26 is terminated when the change in the motor current 42 fulfills the specified condition, wherein the change is determined based on the two mean values ​​46, 48. The detection of the motor current 42, the formation of the mean values ​​46, 48, and the comparison with the threshold value 52 continue until the condition is met and the current supply to the electric motor 26 is terminated.

[0047] After the energization of the electric motor 26 has been terminated, a fifth work step 54 is performed. In this step, the electric motor 26 is energized in the opposite direction for a time window. For this purpose, the electrical voltage is applied to the electric motor 26 with reversed polarity. The time window is selected to be comparatively short and, in particular, shorter than 10 ms or 1 ms. As a result, any resulting tension in the mechanism 20 and / or the electric motor 26, which was caused by the movement of the board 16 against the end stop 24, is at least partially eliminated, thus reducing mechanical stress.

[0048] The invention is not limited to the exemplary embodiment described above. Rather, other variants of the invention can also be derived therefrom by those skilled in the art without departing from the scope of the invention. In particular, all individual features described in connection with the exemplary embodiment can also be combined with one another in other ways without departing from the scope of the invention. List of reference symbols 2 motor vehicles 4 wheel 6 Body 8 Bottom edge 10 Opening 12 Door 14 Hinge 16 boards 18 electric running board 20 Mechanics 22 adjustment range 24 End stop 26 electric motor 28 Control unit 30 computers 32 memory 34 Computer program product 36 procedures 38 first step 40 second step 42 Motor current 44 third step 46 first mean 48 second mean 50 fourth step 52 Threshold 54 fifth step

Claims

[1] Method (36) for operating an electromotive running board (18) of a motor vehicle (2), having a board (16) driven by an electric motor (26) which is adjustably mounted along an adjustment path (22) which has an end stop (24), in which - the electric motor (26) is energised to move the board (16) towards the end stop (24), - a motor current (42) carried by the electric motor (26) is detected, and - the current supply to the electric motor (26) is terminated when a change in the motor current (42) fulfils a certain condition. [2] Method (36) according to claim 1, characterized by that the change is determined based on a time average value (46, 48) of the motor current (42). [3] Method (36) according to claim 2, characterized bythat two mutually different temporal averages (46, 48) are created, wherein the condition is fulfilled if the averages (46, 48) differ by more than a threshold value (52). [4] Method (36) according to claim 3, characterized by that for one of the mean values ​​(48) a time period between 10 ms and 40 ms is used. [5] Method (36) according to claim 3 or 4, characterized by that for one of the mean values ​​(46) a time period between 200 ms and 800 ms is used. [6] Method (36) according to one of claims 1 to 5, characterized by that after the energization has ended, the electric motor (26) is energized in the opposite direction for a time window. [7] Electromotive running board (18) for a motor vehicle (2), which comprises a board (16) which is adjustably mounted along an adjustment path (22) which has an end stop (24) and which is driven by means of an electric motor (26), and which is operated according to a method (36) according to one of claims 1 to 6.

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