Patent Application
20100037523
The present invention relates to an adjustment device for a movable body part of a motor vehicle and a method for adjusting the movable body part.
Actuators intended to make actuation of movable body parts easier or to be used as a pinch protector or closing aid are increasingly used in motor vehicles. Thus, for example, an opening and closing control system for a vehicle sliding door, which is attached on one side to a vehicle body, is known from published German patent document DE 198 13 513. The sliding door is driven by a drive source, such as an electric motor, in accordance with an inclination of the sliding door if the motor vehicle is inclined vertically in relation to a longitudinal axis of the vehicle body, i.e., if the motor vehicle stops on an inclined street.
Published German patent document DE 10 2005 019 846 discloses a control device for improving the function of the opening and closing of a hatchback equipped with a gas-filled shock absorber, having a feeler for detecting the particular opening angle of the hatchback in relation to a vehicle body. An electronic control unit receives a detected angle from the feeler and outputs a pressure regulation control signal. The gas-filled shock absorber regulates the pressure of a cylinder in accordance with the control signal of the electronic control unit.
Furthermore, a two-part hatchback having an upper body part and a lower body part is known from published European patent document EP 1 652 708. With the aid of electric motors, the upper and lower body parts are controlled in such a way that they move synchronously with respect to one another. Published Japanese patent document JP 2005 194 767 discloses a movement sensor for checking the position of a sliding door, the sensor being situated and designed in such a way that a deep discharge of a vehicle battery is avoided. In addition, a movement sensor is disclosed in published Japanese patent document JP 2005 016 252, which transfers a signal to a control configuration to activate an actuator for the soft opening or closing of a vehicle door.
It is known from published German patent document DE 197 55 259 that microprocessors for controlling various actuators may be brought into an idle mode to reduce the power consumption in a motor vehicle. Wakeup and action signals may be applied to the microprocessor via an external switch assigned to a circuit configuration, to switch the processor from the idle mode to an operating mode. The circuit configuration has an idle mode circuit for generating a wakeup signal which triggers a wakeup interrupt, when the microprocessor is to be switched from the idle mode to the operating mode, and an operating mode circuit for generating action signals, the idle mode circuit being applied to a wakeable digital input and the operating mode circuit being applied to an analog input of the microprocessor and the at least one external switch being assigned to both circuits.
An example adjustment device and method according to the present invention for adjusting a movable body part of a motor vehicle, having an actuator for adjusting the movable body part, and having a control device for activating the actuator in an operating state, the control device transitioning from the operating state to an idle state when no adjustment of the movable body part occurs within a defined period of time, may have the advantage in relation to the known related art in that, in addition to a further reduction of idle current consumption, an additional sensor element for detecting a movement of the movable body part, additional switching means, and/or a supplementary current measurement may be dispensed with in order to switch the control device back to the operating state from the idle state. This is now caused by a manual adjustment of the movable body part. It is thus advantageously sufficient that the control device may only utilize the already used detectors for position determination or, alternatively, may detect the position of the movable body part without a detector or sensor.
In an exemplary embodiment, the actuator is an electric motor which operates as a generator to generate the wakeup signal and thus exploits the back-EMF or counter-EMF (electromotive force), which acts on the windings as a result of the manual adjustment of the movable body part. A voltage and/or current pulse is thus generated by the manual adjustment of the movable body part and is used as the wakeup signal for the control device. In an alternative embodiment, the wakeup means are operationally linked to the movable body part, so that the manual adjustment of the movable body part causes a voltage and/or current change which is used as the wakeup signal for the control device. A potentiometer, in particular a slide potentiometer, and/or a Hall sensor integrated into the actuator is/are advantageously used as the wakeup means.
A further advantage results from the detection of the instantaneous position of the movable body part in the operating state of the control device by a position detector, the control device storing the instantaneous position of the movable body part detected by the position detector in a memory before its transition from the operating state to the idle state. This additionally allows an interruption of the power supply of the position detector by the control device to further reduce the idle current consumption. After the control device is switched back to the operating state, the stored position is then read out from the memory again, the control device activating the position detector again to detect the position of the movable body part. It is further advantageous for reasons of cost and to save installation space if the position detector is the Hall sensor integrated into the actuator. This may advantageously also assume the function of the wakeup means, it then however may be necessary to avoid an interruption of the power supply for the idle current reduction. Alternatively or additionally, the wakeup means operationally linked to the movable part may be used as the position detector. As with the Hall sensor, however, no measures may be taken in this case to interrupt the power supply of the wakeup means. Furthermore, it is possible to dispense completely with a position detector, in that the waviness of a commutation signal activating a commutation device of the actuator implemented as the electric motor is analyzed in the scope of a ripple count method by the control device to detect the position of the movable body part. In this case, the control device also stores the detected instantaneous position of the movable body part in the memory before its transition from the operating state to the idle state.
During the adjustment of the movable body part in the idle state or in the wakeup phase of the control device, a deviation may occur between the stored and actual positions of the movable body part. The control device therefore advantageously has correction means for correcting the position of the adjusted body part which has changed during the wakeup phase from the idle state to the operating state, the wakeup phase of the control device including the time span from the manual adjustment of the movable body part until the readout of the stored position from the memory. The correction means may, for example, be designed in the form of an algorithm or a lookup table stored in the control device, the correction value resulting as a function of the ascertained back-EMF of the actuator. In this context, a detected steepness of the back-EMF change, which represents a measure of the force action on the movable body part during the manual adjustment, may be used as a further correction value. It is also conceivable to ascertain a mean number of the clock pulses of the position detector during the wakeup phase and store it as a correction value in the control device.
To always ensure the most exact possible determination of the instantaneous position of the movable body part, it is also provided that the control device performs a calibration procedure at defined points in time in the particular final position of the movable body part, i.e., in the completely open or closed state. The frequency of the performed calibration procedures is a function of the required precision of the wakeup and adjustment procedures.
In particular, at higher ambient temperatures, a leakage current may occur via a diagnostic branch and/or a suppression circuit of the actuator, which results in an unintentional wakeup of the control device. To prevent this, electrical means are provided, which, when designed as at least one switching means, decouple the diagnostic branch and/or the suppression circuit of the actuator from an electrical ground potential. Alternatively, the electrical means may include at least one resistor network connected to the diagnostic branch and/or the suppression circuit of the actuator, which is dimensioned in such a way that a voltage drop caused by the leakage current does not exceed a defined limiting value for the wakeup of the control device.
The adjustment device according to the present invention and/or the corresponding method are particularly suitable for movable body parts in the form of a hatchback, a vehicle door, a convertible top, an engine hood, or a fuel tank cap of the motor vehicle.
The present invention will now be described with reference to the figures. Unless otherwise indicated, identical reference numerals in the figures indicate identical components having an identical mode of operation.
Electric motor 22 is activated via a control device 24, such as a microprocessor, an ASIC, or a corresponding discrete or integrated circuit. For this purpose, a corresponding control signal Ss is transmitted to control device 24, which is connected to a supply voltage U+and an electrical ground potential GND, by a signal generator (not shown), which is preferably located outside adjustment device 10. The signal generator may, for example, be designed as a radio receiver of a radio remote control for motor vehicle 14 or as switching or sampling means situated inside motor vehicle 14. However, it is also conceivable that the radio receiver is already integrated into adjustment device 10 or even control device 24.
For the sake of clarity, the illustration of a ground connection for electric motor 22 was dispensed with in
Control device 24 has a diagnostic interface 30 for diagnosing electric motor 22 via corresponding diagnostic branches 32 during the operating state. It is possible—as shown in FIG. 1—for either all terminals of electric motor 22 or activation branches 25, 26 to have a diagnostic branch 32, or for only a subset of the terminals to be monitored. Diagnostic branches 32 are connected to diagnostic interface 30 of control device 24 via circuits 34, which are explained in greater detail in connection with
A position detector 37, which is implemented here as a Hall sensor 38 and is integrated into electric motor 22, is used for the position detection of movable body part 12. The location of the rotor and thus also of movable body part 12 may be detected in a simple and known way via a magnetic disk (not shown), which is mounted in a rotationally fixed manner on a rotor shaft of electric motor 22. Other position detectors, such as AMR sensors (anisotropic magnetoresistive sensors) or the like may also be used. It is additionally possible for a potentiometer 40, which is operationally linked to the rotor shaft of electric motor 22 or movable body part 12 itself, to be used for the position detection of movable body part 12 instead of the Hall sensor 38. In the case of an operational link to movable body part 12, potentiometer 40 may be implemented in particular as a slide potentiometer. Instead of potentiometer 40, a linear sensor or the like may also be used. A further alternative results from a detection of the position of the movable body part without a detector or sensor, in that the residual waviness of a commutation signal SC which activates the commutation device of electric motor 22 is analyzed in the scope of a ripple count method by control device 24. However, the Hall sensor 38, whose position signal SP is transmitted to control device 24 for storage of the instantaneous position of movable body part 12 in a memory 42, may to be assumed as present in the exemplary embodiments hereinafter without restriction of the present invention. A corresponding procedure may also be applied to the above-mentioned alternatives to Hall sensor 38.
An example method according to the present invention for adjusting movable body part 12 will be described with reference to the flow charts in
If no further manual or automatic adjustment of movable body part 12 occurs within a defined period of time, for example 30 seconds after the last adjustment, adjustment device 10 and control device 24 is switched to an idle, sleep, or energy-saving state in step 106 and the instantaneous detected position of movable body part 12 is stored as position signal Sp in memory 42 of control device 24. Diagnostic interface 30 is deactivated and wakeup interface 36 is activated. Because the power supply for control device 24, position detector 37, and electric motor 22 is thus greatly reduced or entirely interrupted, a very low idle current results. This is important in today's motor vehicles in particular, because the increasing number of electrical consumers requires a sophisticated idle current concept to minimize or avoid a strain on the motor vehicle battery in the shutdown state of motor vehicle 14 and the associated danger of a deep discharge. If a bus activation of actuator 20 via a CAN or LIN bus of motor vehicle 14 exists, for example, it is alternatively possible according to step 108, indicated by dashed lines, to activate the idle state of adjustment device 10 using the data bus.
A manual adjustment of movable body part 12 in step 110 has the result that electric motor 22 operates as a generator, which generates a voltage and/or current pulse as a result of the resulting back-EMF or counter-EMF.
The wakeup phase and the correction of the stored position of movable body part 12 according to step 110 will now be described in detail with reference to
In step 110e, control device 24 causes an energy supply of position detector 37, which is implemented as Hall sensor 38 or potentiometer 40, for renewed detection of the instantaneous position of movable body part 12 in step 110f. In contrast, if potentiometer 40 additionally operates as wakeup means 44, a renewed application of supply voltage U+ is not necessary, because it must be applied permanently in any case to generate wakeup signal SA. In this case, step 110e may be dispensed with. This is correspondingly true if Hall sensor 38 is also used to generate wakeup signal SA in addition to its function as position detector 37.
After the instantaneous position is detected in step 110f using position detector 37, the stored position is updated in step 110g by control device 24 using the instantaneous position. It is thus ensured that adjustment device 10 operates using the correct data. Nonetheless, because of the temporary adjustment of movable body part 12 during the idle state and the wakeup phase of control device 24, the occurrence of an imprecise position signal SP is possible, because the actual position of movable part 12 and the position stored in memory 42 may deviate from one another. Control device 24 therefore has correction means 46 which allows for a correction of the position of adjusted body part 12 which has changed during the wakeup phase from the idle state to the operating state. Correction means 46 may be designed, for example, in the form of an algorithm or a lookup table stored in control device 24, a correction value determined as a function of the ascertained back-EMF of electric motor 22. In this context, the detected steepness of the back-EMF change which represents a measure of the force action on movable body part 12 during the manual adjustment may be used as a further correction value. It is also conceivable for a mean number of the clock pulses of position detector 37 to be ascertained during the wakeup phase and stored as the correction value in memory 42 of control device 24 to correct originally stored position signal SP as a function of the adjustment direction of movable body part 12. Detection of the adjustment direction—as shown in FIG. 4—is possible on the basis of the voltage and/or current pulse generated by electric motor 22.
After the possible correction of the position readout from memory 42, step 110 is ended and the method moves to step 112 as shown in
A detailed view of one of the circuits 34, shown in
Circuits 34 have a first voltage divider 48 or 49 which is wired on the one hand to activation branch 25 or 26 between the anodes of Zener diode 27 and a terminal of electric motor 22 operating as actuator 20, and is connectable on the other hand via switching means 50 to electrical ground potential GND. For this purpose, switching means 50, which are designed as a bipolar transistor, field effect transistor, relay, or the like, for example, are activatable or deactivatable using a diagnostic switching signal SDS via a second voltage divider 52. Diagnostic switching signal SDS may be a DC voltage of approximately 5 V, for example, and may be generated by a control device situated outside adjustment device 10 or by control device 24 itself.
For better clarity, only parts of the circuit 34 connected to activation branch 26 are shown in
In the operating state of control device 24, switching means 50 is activated using diagnostic switching signal SDS, SO that second resistor 48b of first voltage divider 48 has a connection to electrical ground potential GND. In this case, a unique diagnosis of electric motor 22 by control device 24 is possible as a result of the current flow via first resistor 48a of first voltage divider 48, resistor 54 of RC element 58, and diagnostic line 33.
In the idle state of control device 24, its diagnostic interface 30 is deactivated, so that a current flow may solely act on wakeup interface 36. As a result of an increased ambient temperature (e.g., 80° C.), in the event of a ground connection of first voltage divider 48, however, a leakage current may occur through Zener diode 27, which results in an unintentional wakeup of control device 24 via wakeup interface 36. A corresponding leakage current may also be caused by a suppression circuit (not shown), which is connected to electric motor 22. To avoid leakage currents of this type, switching means 50 are deactivated by setting diagnostic signal SDS to zero to decouple first voltage divider 48 from electrical ground potential GND. If capacitor 56 of RC element 58 is charged, there is also no connection to electrical ground potential GND via the capacitor 56. Because control device 24 is in the idle mode, there is no diagnosis of electric motor 22 via diagnostic interface 30.
The following example assumes a leakage current of approximately 200 μA at 80° C., which is typical for a hatchback application. This corresponds to a maximum idle current for applications in motor vehicles and to a temperature range from −40° C. to +85° C., the setting being performed via first voltage divider 49 of the circuit 34 connected to activation branch 26. If one assumes that this first voltage divider 49 has two resistors 49a and 49b having values of 6.8 kΩ and 1 kΩ, respectively, the 1 kΩ resistor being connectable to electrical ground potential GND, a voltage which drops in the amount of approximately 1.56 V via electric motor 22 results because of the leakage current of 200 μA and also drops via circuit 34 connected to activation branch 25. Although circuits 34 are predominately constructed identically in this example, the circuits 34 may have differently dimensioned components.
For example, if one assumes that first resistor 48a and second resistor 48b of first voltage divider 48 of the circuit 34 connected to activation branch 25 have values of 47 kΩ and 27 kΩ, respectively, and that second resistor 48b of first voltage divider 48 has no connection to electrical ground potential GND because of deactivated switching means 50 and resistor 54 of RC element 58, which is dimensioned at 27 kΩ, and because of charged capacitor 56, then a voltage of approximately 0.9 V is applied via resistor 64, which is dimensioned at 1 MΩ, under the consideration that a transmission voltage of 0.6 V drops via diode 60. Because resistor 62, which is connected via wakeup line 35 to wakeup interface 36 of control device 24, has a negligible value of 1.2 kΩ in relation to resistor 64, a voltage of nearly 0.9 V is accordingly also applied to wakeup interface 36.
Wakeup interface 36 is designed in such a way that a voltage of at least 1 V may be required to switch control device 24 from its idle state to the operating state. If movable body part 12 is manually adjusted, this acts on an electric motor 22, which operates as a generator as a result of the back-EMF or counter-EMF and generates a voltage pulse UA according to
Finally, it is to be noted that the exemplary embodiments shown are not restricted to
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2006 039 257.4 | Aug 2006 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2007/057945 | 8/1/2007 | WO | 00 | 9/24/2009 |
