Method for operating a drive unit of a vehicle operable by muscle power and/or motor power

1 . A method for operating a drive unit of a vehicle operable by muscle power and/or motor power and comprising an electric motor and a control unit, comprising:

performing a system start of a system including the drive unit by starting the drive unit; and

actuating, in response to the system start of the drive unit, the electric motor at a start current configured such that the electric motor rotates in a reverse direction of rotation without a generation of torque which propels the vehicle.

2 . The method according to claim 1 , wherein the electric motor is actuated at the start current in response to the system start for a predefined period of time.

3 . The method according to claim 1 , further comprising:

initializing a motor sensor system and/or motor software of the vehicle during the actuating of the electric motor at the start current.

4 . The method according to claim 3 , wherein initializing the motor sensor system and/or motor software comprises rotor position calibration.

5 . The method according to claim 1 , further comprising:

further actuating the electric motor, after the actuating in response to the system start, in response to a determined rider request such that the electric motor rotates in a forward direction of rotation.

6 . The method according to claim 1 , wherein:

the vehicle comprises a freewheel between the electric motor and a drive train; and

the freewheel locks in the forward direction of rotation and opens in the reverse direction of rotation.

7 . The method according to claim 1 , wherein:

performing the system start of the drive unit is initiated in response to a manual start actuation provided through an input device.

8 . The method according to claim 1 , wherein performing the system start of the drive unit is initiated in response to a movement of the vehicle relative to an environment.

9 . The method according to claim 1 , further comprising:

further actuating the electric motor at a test current in a non-torque generating direction during the actuating at the start current.

10 . The method according to claim 9 , further comprising:

estimating at least one motor parameter of the electric motor during the further actuation of the electric motor at the test current.

11 . The method according to claim 10 , further comprising:

detecting an angular change of an electric angle, a test voltage in the non-torque generating direction, and the test current in the non-torque generating direction during the further actuation of the electric motor at the test current,

wherein the estimation of the at least one motor parameter is performed by calculating a previously known machine model of the electric motor based on the detected angular change, and/or the detected test voltage, and/or the detected test current.

12 . The method according to claim 11 , wherein the machine model features a voltage offset of the electric motor as an unknown degree of freedom.

13 . A control unit of an electric motor, which is configured to actuate the electric motor and to performing the method according to claim 1 .

14 . An electric motor comprising a control unit according to claim 13 .

15 . A method for operating a drive unit of a vehicle operable by muscle power and/or motor power and comprising an electric motor and a control unit, comprising:

actuating the electric motor at a start current configured such that the electric motor rotates in a reverse direction of rotation; and

further actuating the electric motor at a test current in a non-torque generating direction during the actuating at the start current.

16 . The method according to claim 15 , further comprising:

estimating at least one motor parameter of the electric motor during the further actuation of the electric motor at the test current.

17 . The method according to claim 16 , further comprising:

detecting an angular change of an electric angle, a test voltage in the non-torque generating direction, and the test current in the non-torque generating direction during the further actuation of the electric motor at the test current,

wherein the estimation of the at least one motor parameter is performed by calculating a previously known machine model of the electric motor based on the detected angular change, and/or the detected test voltage, and/or the detected test current.

18 . The method according to claim 17 , wherein the machine model features a voltage offset of the electric motor as an unknown degree of freedom.

19 . A method for operating a drive unit of a vehicle operable by muscle power and/or motor power and comprising an electric motor and a control unit, comprising:

performing a system start of a system including the drive unit by starting the drive unit;

actuating, in response to the system start of the drive unit, the electric motor at a start current configured such that the electric motor rotates in a reverse direction of rotation;

further actuating the electric motor at a test current in a non-torque generating direction during the actuating at the start current;

estimating at least one motor parameter of the electric motor during the further actuation of the electric motor at the test current; and

detecting an angular change of an electric angle, a test voltage in the non-torque generating direction, and the test current in the non-torque generating direction during the further actuation of the electric motor at the test current,

wherein the estimation of the at least one motor parameter is performed by calculating a previously known machine model of the electric motor based on the detected angular change, and/or the detected test voltage, and/or the detected test current.

20 . A method for operating a drive unit of a vehicle operable by muscle power and/or motor power and comprising an electric motor and a control unit, comprising:

actuating the electric motor at a start current configured such that the electric motor rotates in a reverse direction of rotation;

further actuating the electric motor at a test current in a non-torque generating direction during the actuating at the start current;

estimating at least one motor parameter of the electric motor during the further actuation of the electric motor at the test current; and

detecting an angular change of an electric angle, a test voltage in the non-torque generating direction, and the test current in the non-torque generating direction during the further actuation of the electric motor at the test current,

wherein the estimation of the at least one motor parameter is performed by calculating a previously known machine model of the electric motor based on the detected angular change, and/or the detected test voltage, and/or the detected test current.