Side door drive assembly for a vehicle

Abstract

The invention relates to an electric side door drive assembly (10) for a vehicle (100), the assembly comprising: a length-adjustable electric actuator (12); a control unit (16) operatively coupled to the actuator (12) and paired with a memory unit (18) on which geometrical parameters of the vehicle (100) and operating parameters of the actuator (12) are stored; and a door movement sensor unit (20) operatively coupled to the control unit; wherein the control unit (16) is configured such that: if a stoppage of the side door (104) is detected by the door movement sensor unit (20), then on the basis of side door position data output by the door movement sensor unit (20), the geometrical parameters of the vehicle (100) stored in the memory unit (18), and operating parameters of the actuator (12), said control unit determines a required current intensity that must be supplied to the electric motor (14) of the actuator (12) in order to hold the side door (104) in its present position by means of a resulting first holding force; and said control unit supplies the required current intensity to the motor (14) of the actuator (12) for a holding operation. According to the invention, the control unit (16) is also configured such that: during the holding operation, if an externally acting force on the side door (104) and / or an externally triggered movement of the side door (104) is detected, said control unit increases the holding force by increasing the current intensity by a predetermined amount; and said control unit ends the holding operation only when a further externally acting force subsequently overcomes the increased holding force. The invention also relates to a vehicle having such an assembly, and to a method for operating such an assembly.

Description

[0001] Side door drive arrangement for a vehicle

[0002] Description

[0003] The present invention relates to an electric side door drive arrangement for a vehicle, a vehicle with at least one such side door drive arrangement, and a method for operating such a side door drive arrangement.

[0004] More recently, in the automotive sector, the approach of equipping the doors and tailgates of new vehicles with active drives has been pursued to increase user comfort. This allows for automatic or assisted opening and closing of, for example, the side doors and tailgates of automobiles, in addition to purely manual operation. For this purpose, electric drives are typically used, in particular linear actuators, which are installed between the vehicle body and a side door or tailgate attached to it.

[0005] Particularly in cases where such vehicles are parked on a slope, the side doors may tend to open further or close unexpectedly due to the vehicle's incline and the resulting swing axis of the door. This behavior is inconvenient for drivers and passengers, as it can make getting in and out of the vehicle, or loading items from the side, difficult. In some circumstances, this could even endanger people within the swing radius of the door.On the other hand, in cases where the vehicle in question is parked next to other vehicles, for example, a side door opening on its own may hit and damage a neighboring vehicle, which is why various devices and strategies have been proposed to prevent such behavior and to keep vehicle side doors at an opening angle manually specified by a user.

[0006] For example, in the prior art, permanently acting or electrically or magnetically adjustable friction brakes or magnetic brakes were used, which were integrated in particular into drive systems of such side doors and which allow side doors of vehicles to be held passively at any opening angle.

[0007] A slightly different approach was pursued in a similar application in WO 2021 / 224219 A, in which a drive with a mechanical spring element was used to compensate for a weight force in a tailgate drive, whereby in the event of a drive failure, the spring element is intended to reduce the falling speed of the tailgate. A similar approach is also known, for example, from DE 10 2008 057 014 B4.

[0008] Furthermore, for example, in DE 10 2020 112 140 A1 it has been proposed to control a drive motor of a flap assembly of a motor vehicle in such a way that, upon reaching a predetermined holding state of the flap, a holding routine is carried out in which the drive motor is controlled to provide a motor braking effect.

[0009] However, it becomes apparent that previously known side door drive arrangements with an active holding mode are disadvantageous in that, when manually operating the side doors, the problem can arise of distinguishing between desired and undesired forces acting on the respective side doors. In particular, with such side doors in an active holding mode, it is desirable that the holding mode ends as soon as an operator wants to further open or close the door. However, there is a risk that an external force or movement acting on the side door will be misinterpreted as a manual operation, and the active holding mode will be terminated accordingly, in an undesirable manner.An example of this could be the impact of a gust of wind on a corresponding side door, which could be interpreted by a control unit of the side door drive arrangement as an actuation by an operator, so that upon the impact of the gust of wind on the side door the active holding operation would be terminated and consequently the side door could open or close.

[0010] Accordingly, the object of the present invention is to eliminate the disadvantages of the prior art described above and to further develop a generic electric side door drive arrangement in such a way that it can be ensured that an active holding operation is only terminated when actuated by a human operator and that faulty terminations due to disturbances, such as gusts of wind or similar, are reliably prevented.

[0011] To solve this problem, a generic electric side door drive arrangement for a vehicle is proposed, comprising a length-adjustable electric actuator arranged between the vehicle body and the side door to open and close the side door, and for this purpose a controllable electric motor, wherein the actuator has a known return torque, a control unit operationally coupled to the actuator, to which a storage unit is assigned on which geometric parameters of the vehicle and operating parameters of the actuator are stored, and an operational door movement sensor unit coupled to the control unit, which is configured to detect a stop and its instantaneous position during the opening or closing of the side door, wherein the control unit is configured toWhen the door motion sensor unit detects that the side door has stopped, the control unit determines, based on side door position data supplied by the door motion sensor unit and the geometric parameters of the vehicle and operating parameters of the actuator stored in the memory unit, the required current and current direction to supply the electric motor of the actuator in order to hold the side door in its current position by means of a resulting first holding force, and delivers the required current to the motor of the actuator for holding operation. According to the invention, the control unit of the side door drive arrangement is further configured to increase the holding force by a predetermined amount during holding operation when an externally applied force is detected acting on the side door and / or an externally triggered movement of the side door is detected.and only if the increased holding force and / or an externally triggered movement is subsequently overcome by a further externally applied force to end the holding operation.

[0012] Accordingly, the present invention is based on the fact that, upon detection of a force acting upon the side door or the triggering of a movement during the holding mode, the holding force provided by the actuator is first increased, and the holding mode is only terminated if the resulting increased holding force is subsequently overcome. This corresponds to the typical behavior of a human operator who initially applies a first opening or closing force to the side door to open or close it from the holding mode, then notices that the holding force increases, and finally overcomes this increase by applying a stronger force.

[0013] In contrast, a gust of wind would not exhibit such behavior, as it is naturally incapable of perceiving an increase in holding force and subsequently exerting an increased force on the side door based on this. On the other hand, if the holding force increases sufficiently quickly, a human operator will ideally not perceive the two-stage holding force as such, since the additional holding force can be applied very rapidly and is designed in such a way that it cannot typically be reached by gusts of wind or similar forces.

[0014] In other words, the invention describes a specific active holding operation:

[0015] 1. Condition: The side door is in a specific position.

[0016] Position held ("holding mode"). For this purpose, an initial holding force is generated by supplying the actuator with a corresponding current.

[0017] 2. Event: During this holding operation, an externally applied force (e.g., an operator pushes / pulls on the door or a gust of wind) is detected.

[0018] 3. Response: In response, the holding force is increased by increasing the current by a predetermined amount.

[0019] 4. Condition for termination: Only when this increased holding force is overcome will the holding operation be terminated, and the door can be moved.

[0020] The technical purpose of this two-stage holding force is to differentiate between an unintentional force (e.g., wind) that should not move the door from its position and an intentional operation by an operator who wants to move the door deliberately and therefore overcomes the increased holding force.

[0021] The term "holding force" is to be understood as representing the amount of force provided by the actuator that exceeds the amount of force required to hold the side door in the desired position. While it would, in principle, be conceivable to select a holding force so high from the outset that external influences would practically preclude the side door from being operated, the graduated holding force curve chosen according to the invention results in both energy savings and reduced wear on the actuator's motor, as well as more intuitive and user-friendly operation.According to the invention, the detection of the externally triggered movement can be achieved using the aforementioned door motion sensor unit and / or an acceleration sensor, and / or the detection of the externally applied force can be achieved using a voltage induced in the actuator motor and / or using a force sensor integrated into the force path. This induced voltage can be detected by a suitable circuit or evaluation electronics, which is associated with the actuator motor in a manner known per se and is operationally coupled to the control unit. Alternatively, a contact sensor could be provided to detect contact by a user; in this context, both capacitive sensors and pushbuttons or similar devices could be used.

[0022] Furthermore, it is shown that for optimal operation of the inventive side door drive arrangement, the first holding force, based on an external door handle (if present) or an outer edge of the side door, can be between 10 and 20 N and / or the increased holding force can be between 30 and 50 N, preferably about 40 N. These holding force values ​​are selected such that even the increased holding force, in contrast to typical external influences such as gusts of wind, can be easily overcome by a human operator without being perceived as uncomfortably high, while at the same time ensuring that the necessary identification of desired and undesired side door operations can be carried out with a high degree of certainty.

[0023] Furthermore, the control unit can be configured to switch the actuator to an active support mode after overcoming the increased holding force, in which a support force acting in the direction of the externally applied force is exerted on the side door by supplying a corresponding support current to the actuator's motor, or to switch it to an active braking mode, in which a braking force acting against the direction of the externally applied force is exerted on the side door by supplying a corresponding braking current to the actuator's motor.This makes it easier for the operator to move the side door after overcoming the increased holding force, or even allows it to be carried out completely automatically, which also increases the ease of use of the side door arrangement as a whole, or more generally, a constant and defined adjusting force can be achieved by supporting or braking it depending on the moment balance.

[0024] In this context, particularly during support operation, the speed and / or acceleration of the side door can be detected, and the support current or braking current can be adjusted based on the detected speed and / or acceleration of the side door. This measure further increases the ease of operation for the corresponding side door of the vehicle for a human operator.

[0025] Furthermore, the side door drive arrangement according to the invention can also include an inclination sensor unit operationally coupled to the control unit, which is configured to detect an inclination of the vehicle relative to a horizontal plane, and / or an operational temperature sensor unit coupled to the control unit, which is configured to detect the temperature of the motor of the actuator, wherein the control unit is further configured to take the inclination of the vehicle and / or the temperature of the motor into account in a suitable manner when determining the required current.

[0026] This makes it possible, in such embodiments of the inventive side door drive arrangements, to adapt the current required for holding the door to the vehicle's inclination and / or the actuator motor's temperature. It should be noted that suitable sensors for determining vehicle inclination and electric motor temperatures are readily available on the market and can be easily integrated into the control logic of the inventive drive arrangement. Furthermore, it should be pointed out that thermal monitoring of the actuator motor can also prevent thermal overload, for example, by triggering the protective closing movement mentioned below in such a case where an undesirably high motor temperature is detected, thereby preventing thermally induced wear of the actuator motor.Furthermore, in connection with the tilt sensor unit, it should be noted that such tilt angles of the vehicle can be determined relative to a longitudinal axis of the vehicle and / or relative to a lateral axis of the vehicle, so that the corresponding tilt angles relative to a strictly horizontal orientation or position of the vehicle can be taken into account by the control unit when determining the required current. It should also be noted that the opening angle of the side door in question can be appropriately factored into the calculation of the current.

[0027] Although the type of length-adjustable electric actuator is not initially specified in the present invention, as long as it can generate an active holding force for a side door in addition to the operating modes already provided, it can be designed, in particular, as a spindle drive with a permanent magnet brushed DC motor or with a brushless DC motor. Such actuator types are known in the prior art and are characterized by reliability, durability, and simple construction. It should be noted here that the corresponding actuator motor can be designed without a brake, with a permanent brake, or with a switchable brake; however, the advantages of the present invention are particularly pronounced in embodiments that are brake-free.However, it should not be ruled out that a permanent or switchable brake may also be provided to support the holding operation in order to reduce the necessary holding currents appropriately.

[0028] Furthermore, it should be noted that in certain embodiments of the present invention, the control unit can be integrated with the actuator and, in particular, can be housed within the actuator. Alternatively, it is of course also conceivable to provide the control unit outside the actuator and merely to connect it to the actuator motor for operational purposes, whereby the corresponding control unit can then, for example, be arranged at a suitable position in the vehicle equipped with the side-door drive assembly.

[0029] Furthermore, it should be noted that the door movement sensor unit can be formed by a position encoder associated with the actuator, i.e., a device for detecting the instantaneous stroke position or the instantaneous length of the electric actuator, which allows for further improved integration of the arrangement according to the invention and a reduced overall size. Alternatively, however, the door movement sensor unit could also be formed by any other suitable sensor type, for example, a sensor unit that detects the instantaneous opening angle of the side door in the area of ​​its pivot point to the vehicle body and outputs corresponding data.

[0030] Since it can be assumed that the assembly formed from the side door drive arrangement and the side door as well as its linkage to the vehicle always has a certain intrinsic braking torque, even if no dedicated brake is provided in the drive arrangement, the control unit can furthermore be configured to first determine, before determining the required current, whether a passive holding force of the actuator is sufficient to hold the side door in its current position and to act as the first holding force.

[0031] Such a situation would arise, for example, if the actuator motor's self-locking mechanism were sufficient in certain conditions, such as small vehicle tilt angles, to hold the vehicle door in its current position with the initial holding force. In this case, no current would be needed for the actuator motor to operate in holding mode, and current would only be required for the increased holding force as described above. The passive holding force of the actuator can also be derived from the data stored in the control unit's memory or, for example, be stored independently in a separate characteristic map or parameterized based on at least one vehicle tilt angle and the door opening angle, which can then be used for evaluation in such cases.Furthermore, the resulting passive holding force can also be taken into account when calculating the required current for both the initial and the increased holding force, since it can be assumed that such inhibition of movement will always support the holding operation in some way and therefore a lower holding current would be necessary.

[0032] Alternatively or additionally, the control unit can determine whether energizing the actuator according to the respective holding force would lead to a movement of the side door, i.e., whether a case would occur in which applying the determined current would trigger a movement of the side door in the opposite direction.

[0033] While it is theoretically possible to supply the required currents directly to the actuator motor, alternative embodiments allow the control unit to convert these currents into a duty cycle for pulse-width modulation (PWM) operation of the actuator motor and supply corresponding PWM voltages to the motor. The currents in the motor then result from the PWM voltage, subject to a certain inertia of the underlying circuit. Such designs for controlling electric motors are characterized by the fact that only a single value of a predetermined voltage is pulsed to the motor at a high frequency. Here, the duty cycle corresponds to a duty cycle or a time fraction during which this constant "on" voltage is supplied.Accordingly, in such a variant of the present invention, a higher duty cycle would be applied to the increased holding force than to the initial holding force. Furthermore, to further improve the holding operation and, in particular, to establish a feedback loop, the control unit can be configured for a regulated motor operation by adjusting the required current or duty cycle, especially of the initial holding force, when movement of the side door is detected during holding operation, particularly by the door movement sensor unit.In this way, the holding operation can be easily readjusted if it turns out that, despite the initial holding current, the door begins to move in a manner that does not indicate the influence of external factors, but rather occurs, for example, with constant acceleration solely due to the effect of gravity. Possible contributing factors could be, for example, a reduced efficiency of the motor at a constant current, particularly due to overheating or aging over its service life, or external influences such as vibrations acting on the side door.

[0034] Furthermore, the control unit can be configured to limit the holding mode by terminating the power supply to the actuator motor, and thus the active holding mode, after a predefined maximum holding time. This time limitation serves, on the one hand, to protect the actuator motor from overheating, as briefly mentioned above, and on the other hand, to prevent excessive energy consumption by the actuator motor in an unlimited holding mode. The maximum holding time can be set to a constant value and stored in the control unit, or it can be adjusted variably depending on certain parameters, such as the heat generated in the actuator motor or the measured inclination of the vehicle relative to the horizontal. Alternatively, it could be overridden or shortened by an overheating protection device or similar mechanism, but not extended.

[0035] In this context, the control unit can also be configured, after the maximum holding time has elapsed, to move the side door into a state in which a passive holding force of the actuator is sufficient to hold the side door in this state, or to fully close or open the side door, as part of a protective closing or opening movement. Full closing of the side door can be considered particularly when, in the respective configuration and situation, the passive holding force of the actuator is under no circumstances sufficient to hold the side door in the corresponding state, for example, in the case of very high vehicle inclinations, or when, in the corresponding embodiment, this passive holding force is not determined or known at all.Furthermore, it may be possible to perform the protective closing movement of the side door at a lower speed than a closing movement of the side door during normal operation of the side door drive assembly, in order to ensure the safety of this protective closing operation and to prevent people or objects from being unexpectedly trapped during it. In certain situations, such as vehicle inclinations, a similar effect could also be achieved by the corresponding protective opening movement, particularly to prevent the door from slamming shut unexpectedly.

[0036] Furthermore, the corresponding side door drive assembly can also include an optical or acoustic output unit, which is operationally coupled to the control unit and configured to output a signal when a protective closing movement is imminent and / or during a protective closing movement. This can be, for example, an acoustic warning signal or a corresponding voice output, as well as, alternatively or additionally, a visual warning display. For example, the optical output unit can be integrated with an existing vehicle display, so that a warning message about an imminent or currently occurring protective closing movement can be displayed on the vehicle display in the usual way.

[0037] Furthermore, it should be noted that the vehicle parameters stored in the memory unit may include the mass and / or center of gravity of the side door, and / or the actuator's operating parameters may include one or more friction values, one or more efficiencies, one or more gear ratios, and / or one or more motor constants of the actuator. Of course, other parameters are conceivable, and it is also possible to acquire additional values ​​using extra sensor units and incorporate them into the control or regulation of the active holding operation by the control unit. Accordingly, the aforementioned parameters, as well as the values ​​already described above that are acquired by sensor units, do not constitute an exhaustive list; rather, it is conceivable to incorporate any describable or determinable value into the holding operation for which a dependency is evident.

[0038] Furthermore, it should be noted that the control unit of the arrangement according to the invention can also be configured to perform a control operation to reduce a detected deviation of an actual current from the specified required current, in particular by adjusting the duty cycle in pulse-width modulation operation. In this way, the target operation of the arrangement according to the invention is ensured even if, for example, the required current is not initially reached or is exceeded due to inefficiencies in the electrical components, whereby the actual current can be detected with a suitable measuring component and made available to the control unit.

[0039] According to a further aspect, the present invention relates to a vehicle comprising a vehicle body and at least one side door pivotally attached thereto, wherein a side door drive arrangement according to one of the preceding claims is arranged between the vehicle body and the side door. Here, the side door drive arrangement is preferably configured and provided for both automatic and assisted operation in addition to the holding operation according to the invention.

[0040] Furthermore, the present invention relates to a method for operating an electric side door drive arrangement of the type described above according to the invention, comprising determining whether the side door should stop during opening or closing and determining the instantaneous position of the side door, determining a current required for active holding operation based on side door position data, geometric data of the vehicle and operating parameters of the actuator, supplying the required current to the motor of the actuator to effect a first holding force, increasing the holding force by increasing the current by a predetermined amount upon detection of an externally applied force acting on the side door and / or an externally triggered movement of the side door, and terminating the holding operation upon subsequent overcoming of the increased holding force by a further externally applied force.Furthermore, external quantities and parameters, such as the ambient temperature, can also be incorporated into the determination of the required current. It should also be noted that, as already indicated above, the method according to the invention may also include a control mechanism for reducing deviations between the actual current and the required current.

[0041] It should be noted at this point that the further developments and optional additional features introduced above in connection with certain embodiments of the side door drive arrangement should be combinable with the method according to the invention in the same way, so that the corresponding features of the dependent claims to the side door drive arrangement according to the invention should all also be included as optional features of the method according to the invention in the present disclosure.For example, the additional step of determining whether a passive holding force of the actuator is sufficient to hold the side door in its current position, before determining the required current, as well as the provision of a maximum holding time and a subsequent termination of the holding operation, should be noted. These are to be understood and included as optional process steps in the manner just described. Further features and advantages of the present invention will become even clearer from the following description of an embodiment thereof when considered together with the accompanying figures. These show in detail:

[0042] Fig. 1 shows a schematic top view of a side door drive arrangement according to the invention; and

[0043] Fig. 2 is a flowchart illustrating a method according to the invention for operating the side door arrangement from Fig. 1.

[0044] Figure 1 schematically shows a side door drive arrangement according to the invention for a vehicle 100 (not shown in further detail) in a top view and is generally designated by reference numeral 10. The side door drive arrangement 10 comprises a length-adjustable electric actuator 12 in the form of a known spindle drive with a housing 12a and an electric actuator motor 14, wherein the actuator 12 is arranged between the vehicle body 102 and a side door 104 pivotally connected thereto and is coupled to both. It should be noted that the vehicle 100 may, for example, have two or four side doors 104 installed, all of which may be equipped with such a side door drive arrangement 10 according to the invention.

[0045] Furthermore, the side door drive assembly comprises a control unit 16, which is operationally coupled to the actuator 12 and, in particular, to the actuator motor 14 for its control and energizing. A storage unit 18 is assigned to this control unit, on which geometric parameters of the vehicle 100 and the side door 104, as well as their connection points or the hinge, and operating parameters of the actuator 12 are stored. The control unit 16 is also capable of monitoring the instantaneous motor speed of the actuator motor 14, for example, by detecting an induced voltage during manual operation. The control unit 16 is arranged within the actuator housing 12a, as is a door movement sensor unit 20 designed as a position encoder, which is configured to detect a pivot position or...to detect an opening angle and a pivoting movement of the side door 104 relative to the vehicle 102, and in particular the start or cessation of such a pivoting movement. In particular, the door speed during its movement can be determined by a time derivative of position increments.

[0046] In this context, it should also be noted that alternative variants of the arrangement according to the invention are conceivable in which the control unit 16 is not located inside the actuator housing 12a, and in which the control unit 16 can be integrated with the storage unit 18 within a microcontroller or similar embodiments thereof.

[0047] The side door drive assembly 10 also includes, as further sensor units operationally coupled to the control unit 16, a tilt sensor unit 22 assigned to the vehicle body 102, which is configured to detect an inclination of the vehicle body 102 relative to a horizontal plane, and a temperature sensor unit 24 arranged within the actuator housing 12a in the area of ​​the actuator motor 14, which is configured to detect the temperature of the actuator motor 14. In alternative versions, the tilt sensor unit 22 could, for example, also be spatially arranged within the control unit 16.

[0048] Finally, with reference to Fig. 1, the output unit 26 assigned to the vehicle 100 and operationally coupled to the control unit 16 should be mentioned, which, depending on the embodiment, may be configured to notify an occupant of the vehicle 100 about certain operating states of the side door drive arrangement 10, in particular the protective closing movement described below.

[0049] It should be noted that the side door drive arrangement 10 and in particular its control unit 16 is designed to enable operating procedures typically intended for such door drives, for example an active opening or closing operation of the side door 104 of the vehicle 100 as well as a manual opening or closing operation in which the side door 104 can be opened, closed or pivoted to any opening angle by an operator.At the same time, the side door drive arrangement 10 according to the invention also allows a so-called active holding mode, in which, by means of suitable current supply, for example by means of pulse width modulation, the side door 104 can also be held in situations with a constant opening angle in which an external force acts on it in the direction of opening or closing, which is smaller than the first holding force, i.e., in particular when the vehicle 100 is in a tilted position deviating from the horizontal or, in the case of increased hinge tilt, possibly already in the plane. With reference to the flow diagram from Fig. 2, a corresponding method for carrying out an active holding mode in the side door drive arrangement 10 from Fig. 1 will be explained below.

[0050] First, in step S1, the door movement sensor unit 20 detects that the side door 104 is in motion. In step S2, it is checked whether the door movement has fallen below a predefined threshold ("yes" in step S2), which is a criterion indicating that the side door 104 has stopped moving. Simultaneously, the current position of the side door 104, or its opening angle, is determined. As soon as it is determined that the side door 104 has stopped, the process proceeds to step S3, in which a moment balance is calculated. If this calculation shows that the passive actuator force is sufficient and therefore no force is required ("no" in step S3), the process ends at step S4, as no active holding operation is necessary.

[0051] If, on the other hand, the moment balance shows that active intervention is necessary to generate the desired holding force ("yes" in step S3), then in step S5, based on the geometry data of the vehicle 100 stored in the memory unit 18 and its recorded inclination, the required motor torque Tactuator is calculated from the torque equilibrium during holding the side door 104 using the formula (Equation 1) Tbreakaway torque + Tgravity force + Tactuator - 0. Here, the breakaway torque Tbreakaway torque depends in a known manner on the formula

[0052] (Equation 2) Tiosbrech = Flosbrech * lArm from the breakaway force Fiosbrech and the lever length of the lArm of the side door 104 off.

[0053] To calculate the moment Tgravity acting on the side door 104 and caused by gravity, known geometric and structural parameters as well as the determined inclination of the vehicle 100 are used, in particular the mass of the side door 104, the center of gravity position of the side door 104, the orientation of its pivot axis vector, the pitch and roll angles of the vehicle 100, and the opening angle of the side door 104. In this context, the opening angle represents a measure of the side door position within the meaning of the present invention, which can be determined by means of the aforementioned door movement sensor unit 20.In this context, it is conceivable that, once the pitch angle and roll angle of the vehicle 100 have been determined, a characteristic map can be created based on the unchanging properties of the side door 104 stored in the memory unit 18, in which gravity is plotted against the opening angle, so that during a movement of the side door 104 and the associated change in the opening angle, the corresponding value of gravity can be accessed quickly.

[0054] The specific calculation is based on a known transformation of the pivot axis and the center of gravity of the door by means of a reference frame transformation using respective rotation matrices or quaternions with respect to the roll angle and pitch angle of the vehicle 100. This transformation will not be discussed in detail here, as it can be readily derived from mathematical principles. The actuator torque Tactuator required to achieve the torque equilibrium from Equation 1 is, in turn, the product of the actuator force and the actuator lever arm. This lever arm depends on the attachment points of the actuator 12 to the vehicle body 102 and the side door, the orientation of the pivot axis without vehicle tilt, and the opening angle of the side door 104. Accordingly, the torque and thus the force to be applied by the actuator motor 14 for holding operation can be derived in this way.

[0055] Furthermore, since the passive holding force of the actuator 12 is known or can also be derived from its known properties according to known principles, a comparison can be made in the next step S6 to determine whether the passive holding force is already sufficient to hold the side door 104 at its current opening angle, or whether energizing the actuator motor 14 is necessary to hold the side door 104. If this is not the case ("no" in step S6), i.e., the passive holding force alone is already sufficient, the process ends at this point and proceeds to step S9, since a holding operation is achieved even without actuation of the actuator motor 14.If, however, it is determined that an energization of the actuator motor 14 is necessary to hold the side door 104 in its current state ("yes" in step S6), the process proceeds to step S7, where the current required for holding operation is calculated based on the remaining active holding force required and to be supplied by the actuator motor 14 as well as its known output characteristics.

[0056] Subsequently, in step S8, the appropriate current for the initial holding force described above is supplied to the actuator motor 14 to initiate active holding operation, for example, by means of pulse width modulation. In step S9, monitoring begins to determine whether an externally applied force is present at the side door and / or whether the side door has been externally triggered. If this is the case ("yes" in step S9), the supplied current is increased in step S10, thereby applying a higher holding force to the side door. However, as long as no such external disturbance is detected ("no" in step S9), the drive assembly 10 remains in holding operation with the initial holding force, corresponding to a continuation of step S8.

[0057] After the holding force is increased in step S10, step S11, analogous to step S9, checks whether the increased holding force is overcome, indicating human operation. Accordingly, if the increased holding force is overcome ("yes" in step S11), the active holding operation can be terminated, corresponding to a transition to S12, where, for example, an active support operation can be triggered. If, however, the increased holding force is not overcome in step S11 ("no" in step S11), the arrangement 10 can either remain in holding mode with the increased holding force or, after a certain time, revert to holding mode with the initial holding force, corresponding to a return to step S8.

[0058] In parallel, step S13 checks whether a predetermined maximum holding time has elapsed since the start of active holding mode in step S8. This maximum holding time can vary depending on the scenario and, in particular, on the required current. At lower currents, the heat generation and the energy consumption of the vehicle electrical system are lower, and the holding time can be longer. The shutdown condition can also be a signal from a higher-level control unit, for example, when the vehicle electrical system components are to go into sleep mode.If this is the case (“yes” in step S13), the active holding operation is terminated in step S14 by initiating a protective closing or opening movement of the side door through appropriate control and energizing of the actuator motor 14. This movement brings the side door 104 into a state in which the passive holding force introduced above is sufficient to hold the side door 104, or the side door 104 is fully closed or opened. During the execution of the protective closing movement, a corresponding visual and / or acoustic signal is also provided by the output unit 26 to inform the driver and / or occupants of the vehicle 100 about the protective closing movement of the side door 104.If, however, the maximum holding time has not yet expired ("no" in S9), step S15 checks whether a fault condition exists in the side door drive assembly 10, for example, whether one of the sensor units required to carry out the procedure is providing no data or obviously faulty data. Should this be the case ("yes" in step S15), the process proceeds to step S14 in the same way as described above, and the protective closing movement is carried out.

[0059] If, however, no fault condition is detected ("no" in step S15), the process proceeds again to step S8 and the holding operation is continued accordingly by supplying the required current to the actuator motor 14 until further notice.

Claims

Claims 1. Electric side door drive assembly (10) for a vehicle (100), comprising: • a length-adjustable electric actuator (12) which is arranged between a vehicle body (102) of the vehicle (100) and the side door (104) to cause the side door (104) to open and close, and for this purpose comprises a controllable electric motor (14), wherein the actuator (12) has a known return torque; • a control unit (16) operationally coupled to the actuator (12), to which a storage unit (18) is assigned, on which geometric parameters of the vehicle (100) and operating parameters of the actuator (12) are stored; and • a door movement sensor unit (20) operationally coupled to the control unit, which is configured to detect a stop and its momentary position during the opening or closing of the side door (104); wherein the control unit (16) is configured to, when the side door (104) stops as detected by the door movement sensor unit (20): • to determine, based on side door position data supplied by the door movement sensor unit (20) and the geometric parameters of the vehicle (100) and operating parameters of the actuator (12) stored in the memory unit (18), a required current intensity and current direction with which the electric motor (14) of the actuator (12) is to be supplied in order to hold the side door (104) in its instantaneous position by means of a resulting first holding force; and • to supply the required current to the motor (14) of the actuator (12) for a holding operation; characterized in that the control unit (16) is further configured to, during the holding operation, upon detection of a Upon the attack of an externally applied force on the side door (104) and / or an externally triggered movement of the side door (104), the holding force is increased by increasing the current by a predetermined amount, and the holding operation is only terminated if the increased holding force and / or an externally triggered movement is subsequently overcome by a further externally applied force.

2. Side door drive arrangement according to claim 1, wherein the detection of the externally triggered movement is carried out by means of the door movement sensor unit (20) and / or an acceleration sensor and / or the detection of the action of the externally applied force is carried out by means of a voltage induced in the motor (14) of the actuator (12) and / or by means of a force sensor integrated in the force path and / or a contact sensor is provided which is configured to detect contact by an operator.

3. Side door drive arrangement according to one of the preceding claims, wherein, with reference to an external door handle or an external door edge of the side door, the first holding force is between 10 and 20 N and / or the increased holding force is between 30 and 50 N, preferably about 40 N.

4. Side door arrangement according to one of the preceding claims, wherein the control unit is configured to switch the actuator (12) into an active support mode after overcoming the increased holding force, in which a support force acting in the direction of the externally applied force is exerted on the side door (104) by supplying a corresponding support current to the motor (14) of the actuator (12), or to switch it into an active braking mode, in which a braking force acting against the direction of the externally applied force is exerted on the side door (104) by supplying a corresponding braking current to the motor (14) of the actuator (12).

5. Side door drive arrangement (10) according to claim 4, wherein in the support mode a speed and / or acceleration of the side door (104) is further detected and the support current or braking current is adjusted on the basis of the detected speed and / or acceleration of the side door (104).

6. Side door drive arrangement (10) according to one of the preceding claims, further comprising an inclination sensor unit (22) operationally coupled to the control unit (16), which is configured to detect an inclination of the vehicle (100) relative to a horizontal plane, and / or a temperature sensor unit (24) operationally coupled to the control unit, which is configured to detect the temperature of the motor (14) of the actuator (12), wherein the control unit (16) is further configured to take into account the inclination of the vehicle (100) and / or the temperature of the motor (14) when determining the required current.

7. Side door drive arrangement (10) according to one of the preceding claims, wherein the actuator (12) is designed as a spindle drive with a permanent magnet brushed DC motor or with a brushless DC motor.

8. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is integrated with the actuator (12), in particular is contained in a housing (12a) of the actuator (12).

9. Side door drive arrangement (10) according to one of the preceding claims, wherein the door movement sensor unit (20) is formed by a position encoder associated with the actuator (12).

10. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is further configured to determine, before determining the required current, whether a passive holding force of the actuator (12) is sufficient to hold the side door (102) in its current position and to act as the first holding force, and / or whether energizing the actuator (12) according to the respective holding force would lead to a movement of the side door (104).

11. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is further configured to convert the specified required current into a duty cycle for pulse width modulation operation of the motor (14) of the actuator (12) and to supply the corresponding pulse width modulated required current to the motor (14).

12. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is configured for regular operation of the motor (14) by adjusting the required current or duty cycle when a movement of the side door (104) is detected during the holding operation, in particular by the door movement sensor unit (20).

13. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is further configured to limit the holding operation by terminating the supply of current to the motor (14) of the actuator (12) after a maximum holding time.

14. Side door drive arrangement (10) according to claim 13, wherein the control unit (16) is further configured to bring the side door (104) into a state after the maximum holding time has elapsed, as part of a protective closing movement or a protective opening movement, in which a passive holding force of the actuator (12) is sufficient to maintain the to keep the side door (104) in this state, or to fully close or open the side door (104).

15. Side door drive arrangement (10) according to claim 14, further comprising an optical or acoustic output unit (26) which is operationally coupled to the control unit (16) and is configured to output a signal when a protective closing movement is imminent and / or during a protective closing movement.

16. Side door drive arrangement (10) according to one of the preceding claims, wherein the parameters of the vehicle (100) stored in the storage unit (18) comprise a mass and / or center of gravity position of the side door (104) and / or the operating parameters of the actuator (12) comprise one or more frictions, one or more efficiencies, one or more gear ratios and / or one or more motor constants of the actuator (12).

17. Side door drive arrangement (10) according to one of the preceding claims, wherein the control unit (16) is further configured to perform a control operation to reduce a detected deviation of an actual current from the determined required current, in particular by adjusting the duty cycle in a pulse width modulation operation.

18. Vehicle (100) comprising a vehicle body (102) and at least one side door (104) pivotably attached to the vehicle body, wherein a side door drive arrangement (10) according to one of the preceding claims is arranged between the vehicle body (102) and the side door (104).

19. Method for operating an electric side door drive arrangement (10) according to any one of claims 1 to 16, comprising: • Determining a stopping of the side door (104) during an opening or closing as well as a momentary position of the side door (104) (S2); • Determining a required current based on side door position data, geometric parameters of the vehicle (100) and operating parameters of the actuator (12) (S7); • Supplying the required current to the motor (14) of the actuator (12) to produce a first holding force (S8); • upon detection of an externally applied force acting on the side door (104) and / or an externally triggered movement of the side door (104), the holding force is increased by increasing the current by a predetermined amount (S10); and • if the increased holding force is subsequently overcome by a further externally applied force, the holding operation ends (S12).

20. The method of claim 19, further comprising a regulation for reducing a deviation of an actual current from the required current.

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