Method and apparatus for determining the external force applied to a vehicle flap movable by a motor to rotate regularly about an axis - Patent 7222227

Abstract

The subject of the present invention is a vehicle flap (1) that is movable by a motor so as to rotate regularly about an axis (2) and is subjected to an external force (T z ) is a method for determining the vehicle flap (1). At least one acceleration sensor (4) is provided in or on the vehicle flap (1) as a first sensor (4). A second sensor (5) is also provided. The signals of both sensors (4, 5) are evaluated by a control unit (6). According to the invention, the second sensor (5) is designed to measure the angle and / or path of the vehicle flap (1) relative to the vehicle body (3).

Description

[Technical Field]

[0001] The present invention relates to a method for determining an external force applied to a vehicle flap that can be moved in regular rotation around an axis by a motor, in particular a method for determining a manual opening / closing force on a vehicle side door, a vehicle tailgate or a vehicle front hood, according to which at least one acceleration sensor is provided on or in the vehicle flap as a first sensor and a second sensor is implemented, the signals of both sensors being evaluated by a control unit.

[0002] A vehicle flap that can be moved by a motor in a regular rotation about an axis usually has an actuator, or more generally, an electric drive. The vehicle flap in question can be opened and closed, for example, using the drive. Partial opening and closing movements are also possible, in particular in the sense of closing the associated vehicle flap. Within the scope of the present invention, a vehicle flap is understood to be in particular a vehicle side door, but also a vehicle tailgate or a vehicle front hood. This also includes, for example, a sliding door. Such a sliding door is usually also actuated by a motor, but can be moved mainly linearly relative to the body of the associated vehicle.

[0003] To increase ease of use, the electric drive or the actuator for the vehicle flap can be controlled accordingly, for example, so that the actuation force of the actuator can be adjusted to the respective operating situation of the vehicle flap. For example, this is a common prior art procedure according to DE 10 2007 062 472 B4.

[0004] In fact, this is a method and device for adjusting the actuation force of an actuator to support the opening and closing of a door, which can be opened in a translational and / or rotational manner. For this purpose, the door position and acceleration values ​​are typically recorded with the associated sensors and transmitted to an evaluation device or control unit. The sensors include an acceleration sensor and a camera. For this purpose, the camera can be installed on the exterior mirror of the vehicle door. The camera can be used to detect whether there is contact between the operator and the vehicle door. Furthermore, the effective lever arm for primarily orthogonal forces can be determined from this. This is relatively complex, especially since the camera required in this situation must be installed additionally. Furthermore, mounting the door on or in the exterior mirror of the vehicle door can be problematic if the camera is dirty and does not send a usable signal to the evaluation device or control unit.

[0005] Further prior art from DE 10 2017 011 478 A1 relates to a method for measuring the closing force of a wing element of a vehicle. In this case, an additional external force must also be recorded. For this purpose, a combined force path measuring device is provided. The force path measuring device has an acceleration sensor by means of which a measured closing time is determined. The measured closing time corresponds to observed vibrations of the wing element of the vehicle during the transition from the open position to the closed position.

[0006] Furthermore, a microphone is installed, with the help of which a second measured closing time can be recorded. The second measured closing time characterizes the change of the vehicle's wing element from the open position to the closed position based on sound waves. The measured closing times thus determined can be compared to obtain the actual closing time, from which the recorded force can be evaluated.

[0007] The use of a microphone as a second sensor, in other words, has drawbacks comparable to those of the camera of DE 10 07 062 472 B4. In this case, there are not only problems related to dirt, but also the risk of not being able to obtain a reliable, analyzable signal from the microphone at all. This applies particularly to noticeable external noise, such as wind and / or rain.

[0008] Finally, the related prior art, DE 10 2006 018 031 B4, relates to a sensor arrangement and a method for triggering a restraint device for detecting a vehicle collision. For this purpose, a first acceleration element and a second acceleration element are implemented, which are installed inside the vehicle door or near the hinge of the vehicle door. The prior art does not address corrections to the actuation force of an actuator for moving the associated vehicle door by a motor.

[0009] Essentially, the prior art has proven itself in modifying the force of an actuator, or generally of an electric drive, for the associated vehicle flap in response to an external force applied by the operator and additionally acting on the vehicle flap. However, the prior art approaches are relatively complex and, due to the sensors used, in particular cameras and microphones, are susceptible to dirt on the vehicle, background noise, etc. In conjunction with the relatively high cost of such sensors, this has in practice resulted in the known systems finding limited widespread application and adoption in practice. The present invention seeks to improve this as a whole.

[0010] overview

[0011] The present invention is based on the technical problem of identifying such a method and associated device for determining the external forces applied to a vehicle flap that can be moved regularly around an axis by a motor, with the help of which it is possible to provide a structurally simple and functionally reliable solution, which is particularly robust against dirt, background noise, etc.

[0012] To solve this technical problem, a general method for determining the external force applied to a vehicle flap that can be moved regularly around an axis by a motor is proposed within the scope of the present invention, characterized in that a second sensor is used to measure the angle of the vehicle flap relative to the vehicle body and / or to measure the path of the vehicle flap. In other words, in the simplest case, the present invention uses only an acceleration sensor as the first sensor, and a second sensor to measure the angle or path. Both sensors can be advantageously located in or on the vehicle flap, thus providing particularly good protection from environmental influences. Additionally, the acceleration sensor, angle sensor, or path sensor in this context has a robust, durable, and functionally reliable design so that the signals of the two sensors can be easily, safely, reliably, and permanently evaluated by a control unit. This is an essential advantage.

[0013] As already explained, the second sensor is advantageously arranged on or in the vehicle flap. In addition to the two sensor signals, according to the invention, the control unit also includes mechanical characteristic values ​​of the vehicle flap in the calculation of the external forces.

[0014] These mechanical characteristic values ​​of the vehicle door are usually related to its moment of inertia. This means that when evaluating the two sensor signals, the control unit also evaluates the moment of inertia or mass moment of inertia of the vehicle door. As is known, the moment of inertia describes the inertia of a vehicle door, considered a rigid body, with respect to the change in angular velocity during rotation around a given axis. This applies at least to vehicle doors that can move around an axis in a rotating manner, such as the aforementioned vehicle side doors, but also to vehicle tailgates or vehicle front hoods. In principle, or alternatively, for example, in the case of a sliding door, its mass or mass inertia can also be very simply evaluated by the control unit instead of the moment of inertia.

[0015] As is known, the moment of inertia depends on the mass distribution of the vehicle door under consideration relative to its axis or axis of rotation. In this respect, it is not difficult to derive data on the moment of inertia using the symbol J from the design data of the relevant vehicle door. Alternatively, for vehicle side doors that move primarily in a straight line, instead of the moment of inertia J, the mass M can also be added to the two signals of the sensors and included in the evaluation of the control unit.

[0016] Preferably, the friction parameters of the vehicle flap are additionally evaluated by the control unit as mechanical characteristic values ​​of the vehicle flap. In the case of a vehicle flap that can move around an axis in a rotational manner, these friction parameters of the vehicle flap are primarily the friction values ​​of the hinges that are regularly implemented in this respect. In the case of a sliding vehicle door that moves linearly, the necessary guide friction forces are primarily observed and taken into account. The friction torque T fr can be used most frequently here and in the simplest case is proportional to or increases or decreases with the speed of the associated car flap. Therefore, a linear sliding friction is usually used. This also results in a braking torque that is linearly dependent on the speed of the car flap. Said braking torque can in particular be determined based on the signal of a second sensor, measuring the angle of the car flap relative to the body of the car. If the control unit also acts on the actuator or electric drive of the car flap, the corresponding actuation signal of the control unit can be converted into a drive torque or motor torque T. dr It can be identified by.

[0017] Based on the basic equation of motion of a car flap that can move around an axis so as to rotate,

number

[0018] The external force or corresponding torque T applied additionally and externally to the vehicle flap zIt is possible to draw conclusions about the angular acceleration of the vehicle flap under consideration, which may have a negative effect on the drive torque in the specified case. The measured variable φ is in fact the angular acceleration of the vehicle flap under consideration, which is recorded using a first sensor or acceleration sensor and transmitted to the control unit for evaluation.

[0019] A similar procedure can be used for a sliding car door that can move linearly back and forth. In this case, the angular acceleration φ mentioned above is not measured using a first sensor or an acceleration sensor. Instead, the external force F applied by the operator is measured. z and / or the force F exerted by the actuator or electric drive in this case dr causes the associated vehicle flap of inertial mass M to move with an acceleration (the second term on the left side of Equation 2 (denoted by the symbol "S" with two dots "·" signs above it in dot notation). In this case, the corresponding equation of motion evaluated by the control unit is essentially:

number

[0020] (where F fr is the friction force, s is the path of travel, and the second term on the left side of Equation 2 (denoted in dot notation by the symbol "S" with two dots "·" signs above it) is the associated acceleration. In any case, the control unit calculates the external force F from the sensor values ​​of the two sensors and the mechanical property values. z or external torque T z It becomes clear that the equations of motion are used to determine . This is done advantageously and additionally using a mathematical process known as a Kalman filter. This reduces the error in the actual measurements of the two sensors and provides an estimate of the non-measurable system variable, in this case the applied external force F. z or external torque T z Such Kalman filters are commonly known, see the corresponding description in Wikipedia, where additional references are made.

[0021] The subject of the present invention is also a device for determining the external forces exerted on a vehicle flap, which is movable by a motor so as to rotate regularly about an axis. The device has an acceleration sensor on the vehicle flap as a first sensor. The acceleration sensor is advantageously what is known as a triaxial acceleration sensor, i.e., capable of recording acceleration values ​​in the direction of all three vehicle axes: the longitudinal (X) direction of the vehicle, the transverse (Y) direction of the vehicle, and finally, the vertical (Z) axis of the vehicle. Such triaxial acceleration sensors are widely used and therefore available in inexpensive and powerful designs.

[0022] The device according to the invention also comprises an actuator or an electric drive. The vehicle flap in question can be moved using the actuator or the electric drive. Advantageously, the control unit is further designed to variably control the actuator according to a determined value of the applied external force or torque. For example, the procedure here is such that if the operator also applies an opening force to the vehicle flap, the force applied to the vehicle flap by the actuator to open it is correspondingly reduced. Similarly, the closing force of the actuator can also be reduced if the operator also applies such a closing force to the vehicle flap.

[0023] Conversely, the present invention also provides for a modification in which, for example, during the opening process, the force applied by the actuator to the vehicle flap is increased if the operator simultaneously acts on the vehicle flap in question in the closing direction. Similarly, an increase in force during the closing process is conceivable if the operator in question also acts on the vehicle flap in the opening direction. In any case, a method and an apparatus are available that allow the control unit to calculate, using simple means, the external force applied by the operator to the vehicle flap in question in addition to the actuator, taking into account a structurally simple and powerful design. All this is done in a particularly functionally reliable manner. This is an essential advantage. [Brief explanation of the drawings]

[0024] The invention will now be explained in more detail with reference to the drawings, which show only one embodiment. [Figure 1] FIG. 1 is a diagram showing a schematic diagram of the device of the present invention. Detailed Description

[0025] Figure 1 shows the external force or torque T z This shows in a very basic way a device for determining the force in question or the associated external torque T z is applied to the car flap 1 by an operator, which is according to the present embodiment and is not limited to an opening direction. According to the present embodiment, the car flap 1 is movable about an axis 2 rotatably relative to the main body or car body 3.

[0026] The basic design comprises an acceleration sensor 4 provided and arranged as a first sensor in or on the car flap 1. In this embodiment, the acceleration sensor 4 is used to measure the angular acceleration φ of the car flap 1. Also implemented is a further second sensor 5, which is a rotation angle sensor according to this embodiment. In this embodiment, the rotation angle sensor or second sensor 5 is used to determine the angle φ of the car flap 1, from which the friction torque T of the car flap 1 is calculated. fr On the other hand, the acceleration sensor 4 is configured as a three-axis acceleration sensor.

[0027] Both sensors 4, 5 are each connected to a control unit 6 which evaluates its signals and which controls an actuator 7 or electric drive which can move the vehicle flap 1 forwards or backwards as shown.

[0028] The actuator 7 is used to generate the motor torque or drive torque T dr is applied to the car flap 1 in the illustrated embodiment, as indicated in Fig. 1 by the corresponding arrow. As shown, an actuator 7 ensures the closing movement of the car flap 1 in this situation, but of course this should be understood only as an example and not as a limitation. For this closing movement shown in Fig. 1, the car flap 1 is subjected to a friction torque T fr This friction torque T fr is as previously explained.

[0029] The sensor values ​​of the two sensors 4, 5 are evaluated and processed in a control unit 6. Furthermore, mechanical characteristic values ​​of the vehicle flap 1 are also taken into account, including at least the moment of inertia J of the vehicle flap 1, which is also shown in FIG. 1. Taking into account the previously described Kalman filter, the control unit 6 calculates, as previously explained, the applied external force or, according to the present embodiment, the applied external torque T from the sensor values ​​and the mechanical characteristic values ​​using the equations of motion and the Kalman filter specified above and in the introduction. z The control unit 6 can also determine whether the actuator 7 is capable of detecting an applied external force or applied external torque T z This ensures that the actuator 7 is variably controlled in accordance with the determined value.

[0030] Furthermore, the control unit 6 controls the motor torque or drive torque T applied to the vehicle flap 1. drFor this purpose, for example, the value of the current for actuating the actuator 7 can be used to draw conclusions about the force exerted by the actuator 7 on the vehicle flap 1 in question, for example in the closing direction. dr can be derived from this, for example, taking into account known geometric specifications stored in the control unit 6. In this connection, the position of the actuator 7 relative to the axis or axis of rotation of the vehicle flap 1 is stored in the control unit 6, and the drive torque T dr can be deduced from this together with the force applied to the vehicle flap 1 by the actuator 7.

[0031] For example, the driving torque T dr is applied to the vehicle flap 1 (e.g. in the closing direction), this results in a change in position which can be recorded using the second sensor 5. If this change in position deviates from the change in position calculated, for example, using the control unit 6, then an external force or torque T z Applied to the present embodiment shown, this means that with an external force applied by the operator or an external torque applied in the opening direction, the control unit 6 will generally apply a larger force or torque T than would be required if the operator were not able to apply an opening force to the vehicle flap 1. dr The aim is to ensure that the actuator 7 is controlled by

[0032] This means that in this embodiment, the external force applied by the operator or the external torque T applied in the opening direction z As a result, the control unit 6 applies a larger force or torque T than would be required if the operator were unable to apply an opening force to the vehicle flap 1. dr The purpose of this is to ensure that the actuator 7 is controlled with

[0033] Explanation of symbols

[0034] Car flap...1, Axis…2, Car body...3, Acceleration sensor...4, Sensors...5, Control unit...6, Actuators…7, Moment of inertia...J, Torque…T z , Friction torque...T dr , Torque…T dr , Angle…φ, Angular acceleration...φ.

Claims

1. An external force (T) applied to a vehicle flap (1) that can be moved by a motor to rotate regularly around an axis (2) ｚ 1. A method for determining a At least one acceleration sensor (4) is provided on or in the vehicle flap (1) as a first sensor (4), and a second sensor (5) is mounted, the signals of both sensors (4, 5) being evaluated by a control unit (6), and the second sensor (5) is used to measure the angle of the vehicle flap (1) relative to the vehicle body (3), The control unit (6) receives the signals of both sensors as well as the external force (T ｚ ) also includes mechanical property values ​​of the vehicle flap (1).

2. 2. The method according to claim 1, characterized in that the second sensor (5) is arranged on and / or inside the vehicle flap (1).

3. 3. The method according to claim 1, wherein at least the moment of inertia (J) of the vehicle flap (1) is taken into account as a mechanical characteristic value thereof.

4. 4. The method according to claim 1, wherein the friction parameter of the vehicle flap (1), which can move around an axis in a rotational manner, is a friction value of a regularly mounted hinge, which is further evaluated by the control unit (6) as a mechanical characteristic value of the vehicle flap (1).

5. The control unit (6) calculates the applied external force (T ｚ 5. The method according to claim 1, wherein the equations of motion and a Kalman filter are used to determine the equations of motion.

6. An external force (T) is applied to a vehicle flap (1) that can be moved by a motor to rotate regularly around an axis (2). ｚ 6. An apparatus for carrying out the method according to claim 1 for determining the manual opening and closing force of a vehicle door, a vehicle tailgate or a vehicle front hood, the apparatus comprising:

1. A device comprising at least one acceleration sensor (4) as a first sensor (4) in or on the vehicle flap (1) and a second sensor (5), the signals of both sensors (4, 5) being evaluated by a control unit (6), the second sensor (5) being designed to measure the angle of the vehicle flap (1) relative to the vehicle body (3).

7. 7. The device according to claim 6, characterized in that the second sensor (5) is configured as a rotation angle sensor arranged along the axis (2).

8. 8. Device according to claim 6 or 7, characterized in that it comprises an actuator (7) applied to the vehicle flap (1).

9. The control unit (6) determines the applied external force (T ｚ 9. The device according to claim 6, wherein the actuator (7) is variably controlled depending on the determined value of .

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