METHOD FOR OPERATING A DRIVE DEVICE OF A MOTOR VEHICLE AND CORRESPONDING DRIVE DEVICE

Abstract

A method for operating a drive device of a motor vehicle which has at least one electric machine with a phase angle detector and an output shaft operatively connectable with the electric machine, includes: when a return value of the phase angle detector of the electric machine is constant, performing a first diagnostic operating mode of the drive device, in which the operative connection between the electric machine and the output shaft is interrupted, subsequent, the electric machine is controlled by open lop control to a defined rotational speed, and when the return value continues to be constant after controlling the electric machine to the defined rotational speed, a first operating state of the phase angle detector is recognized and otherwise a correct function of the phase angle detector is recognized.

Claims

1.-10. (canceled)

11. A method for operating a drive device of a motor vehicle which has at least one electric machine with a phase angle detector and an output shaft operatively connectable with the electric machine, said method comprising: when a return value of the phase angle detector of the electric machine is constant, performing a first diagnostic operating mode of the drive device, said performing of the first diagnostic operating mode comprising interrupting the operative connection between the electric machine and the output shaft, subsequent to the interrupting of the operative connection, controlling the electric machine by open lop control to a defined rotational speed, and when the return value continues to be constant after controlling the electric machine to the defined rotational speed, recognizing a first operating state of the phase angle detector and otherwise recognizing a correct function of the phase angle detector.

12. The method of claim 11, wherein the interrupting of the operative connection is performed by at least one of causing a shifting transmission to assume a neutral position and opening a shifting clutch.

13. The method of claim 11, wherein the drive device has a drive aggregate operatively connectable with the electric machine via a separating clutch, wherein upon initiation of the first diagnostic operating mode the operative connection is interrupted by means of the separating clutch.

14. The method of claim 11, further comprising when recognizing the first operating state performing a second diagnostic operating mode of the drive device, said second diagnostic operating mode comprising determining with a rotational speed sensor a rotational speed of a shaft that is permanently operatively connected with the electric machine, and when the rotational speed is different from zero recognizing a defect of the phase angle detector and otherwise recognizing a second operating state of the phase angle detector.

15. The method of claim 14, further comprising when recognizing the second operating state performing a third diagnostic operating mode of the drive device, said third diagnostic operating mode comprising adjusting the electric machine to the defined rotational speed by open loop or closed loop control, wherein the open loop control includes a pre-control of the electric machine to the defined rotational speed.

16. The method of claim 15, further comprising when the return value continues to be constant in the third diagnostic operating mode, recognizing a third operating state of the phase angle detector, and otherwise recognizing a correct functioning of the phase angle detector.

17. The method of claim 16, further comprising when recognizing the third operating state, performing a fourth diagnostic operating mode, said fourth diagnostic operating mode comprising determining with the rotational speed sensor the rotational speed of the shaft which is permanently operatively connected with the electric machine, and when the rotational speed the shaft is different from zero recognizing a defect of the phase angle detector.

18. The method of claim 17, further comprising switching from the fourth diagnostic operating mode into the first diagnostic operating mode, when the rotational speed of the shaft in the fourth diagnostic operating mode is zero.

19. The method of claim 18, wherein the switching from the fourth diagnostic operating mode into the first diagnostic operating mode is performed after a defined period of time.

20. The method of claim 16, further comprising when recognizing the first operating state, the second operating state or the third operating state recognizing a defect of the phase angle detector.

21. A drive device of a motor vehicle, said drive comprising: at least one electric machine with a phase angle detector and an output shaft operatively connectable with the electric machine, said drive device being configured to perform a first diagnostic operating mode of the drive device when a return value of the phase angle detector is constant, said first diagnostic operating mode comprising interrupting an operative connection between the electric machine and the output shaft, subsequent to the interrupting of the operative connection controlling the electric machine by open loop control to a defined rotational speed, and when the return value continues to remain constant recognizing a first operating state and otherwise recognizing a correct functioning of the phase angle detector.

Description

[0020] In the following the invention is explained in more detail by way of the exemplary embodiments shown in the drawing without limiting the invention. Hereby it is shown in the sole

[0021] FIGURE a schematic representation of a motor vehicle with a drive device.

[0022] The FIGURE shows a schematic representation of a motor vehicle 1, which has a drive device 2 and at least one driven axle 3 with wheels 4. The axle 3 is hereby drivable by means of the drive device 2. The drive device 2 has a drive aggregate 5, which is for example configured as an internal combustion engine. In addition the electric machine 6 is provided which can be controlled by means of a control device 7. The drive aggregate 5 can be operatively connected with the electric machine 6 via a separating clutch 8. The electric machine 6 is for example permanently and preferably rigidly operatively connected with an input shaft 9 of a shifting transmission 10. Via the shifting transmission 10 the electric machine 6 can be or is operatively connected with a here not shown output shaft of the drive device 2. The output shaft is for example an output shaft of the shifting transmission 10 and is preferably permanently and rigidly operatively connected with the axle 3 or the at least one wheel 4 of the axle 3.

[0023] The electric machine 6 has a phase angle detector 11, which is connected to the control device 7. Assigned to the shifting transmission 10 is preferably a rotational speed sensor 12, which serves for detecting the rotational speed of the input shaft 9 of the shifting transmission 10. Correspondingly the rotational speed of the electric machine 6 can also be determined By means of the rotational speed sensor 12. The shifting transmission 10 is configured so that multiple different transmission ratios between the input shaft 9 and the driven shaft or the output shaft can be established. In addition the shifting transmission 10 has a neutral position in which the operative connection between the input shaft 9 and the output shaft or the driven shaft is completely interrupted. In the neutral position of the shifting transmission 10 the electric machine 6 is thus completely decoupled from the axle 3 or the wheels 4. As an alternative or in addition a here not shown separating clutch can be provided for this decoupling.

[0024] Beside the wheels 4 of the driven axle 3 the motor vehicle 1 can of course also have non-driven wheels 13. As an alternative the wheels 13 are also assigned to a driven axle. Preferably in this case the driven axle of the wheels 13 is also operatively connected with the output shaft of the drive device 2, for example permanently and rigidly.

[0025] For the open loop control of the electric machine 6 the actual phase angle of the rotor or the motor shaft of the electric machine has to be known as accurately as possible. For determining this phase angle the phase angle detector 11 is provided, which for example operates incrementally. Preferably no signal is present at an output 14 of the phase angle detector 11 at a defined phase angle or at one of multiple defined phase angles, while a signal is present outside the phase angle or the phase angles. Of course also the opposite case can be provided i.e., that when the phase angle is present or one of the phase angles are present the signal is present, while outside the phase angle this is not the case.

[0026] When the return value of the phase angle detector 11 remains constant, in particular over a defined period of time, this may be because that the electric machine 6 does not rotate in spite of being controlled to generate a torque. However it may also be that the phase angle detector 11 and/or its connection line 15 to the control device 7 are defective. This means that when this case occurs it is desirable to perform a diagnosis to determine whether a defect is present or the drive device 2 or the motor vehicle 1 is stationary. For performing the diagnosis, reference is made to the description above.

[0027] By using the described drive device 2 and/or the method explained above a defect of the phase angle detector 11 can be determined fast and cost-effectively. Complicated retooling measures or additional sensors are not required.

LIST OF REFERENCE SIGNS

[0028] 1 motor vehicle [0029] 2 drive device [0030] 3 axle [0031] 4 wheel [0032] 5 drive aggregate [0033] 6 electric machine [0034] 7 control device [0035] 8 separating clutch [0036] 9 input shaft [0037] 10 shifting transmission [0038] 11 phase angle detector [0039] 12 rotational speed sensor [0040] 13 wheel [0041] 14 output [0042] 15 connection line