Electric driveline and method of shifting gears

A method of shifting gears of an electric driveline from a first gear to a second gear, the electric driveline comprising:

• an electric drive motor;
• and
• a transmission, the transmission comprising:
• an output shaft, and
• a synchronizer for selectively drivingly engaging the electric drive motor with the output shaft via one of the first gear providing a first gear ratio γ1 between the electric drive motor and the output shaft and the second gear providing a second gear ratio γ2 between the electric drive motor and the output shaft;
• the method comprising the steps of:
• actuating the synchronizer to disengage the first gear and to engage the second gear, and
• synchronizing a motor speed of the electric drive motor with a target speed,
• wherein the method includes at least one of:
• (i) during the step of disengaging the first gear, controlling the electric drive motor to provide a non-zero torque while limiting an absolute value |Tmot| of the non-zero torque provided by the electric drive motor to a first maximum torque |Tdis|>0 until the first gear is disengaged, so that |Tmot|≤|Tdis| during disengagement of the first gear, wherein the first maximum torque |Tdis| is the maximum torque that allows disengagement of the first gear;
• (ii) during the step of synchronizing the motor speed with the target speed, controlling the electric drive motor to provide a non-zero torque while limiting an absolute value |Tmot| of the non-zero torque provided by the electric drive motor to a second maximum torque |Tsync|>0 until the motor speed has been synchronized with the target speed, so that |Tmot|≤|Tsync| during synchronization of the motor speed with the target speed;
• and
• (iii) during the step of engaging the second gear, controlling the electric drive motor to provide a non-zero torque while limiting an absolute value |Tmot| of the non-zero torque provided by the electric drive motor to a third maximum torque |Teng|>0 until the second gear is engaged, so that |Tmot|≤|Teng| during engagement of the second gear, wherein the third maximum torque |Teng| is the maximum torque that allows engagement of the second gear.

An electric driveline, comprising:

• an electric drive motor;
• and
• a transmission, the transmission comprising:
• an output shaft, and
• a synchronizer for selectively drivingly engaging the electric drive motor with the output shaft via one of a first gear providing a first gear ratio γ1 between the electric drive motor and the output shaft and a second gear providing a second gear ratio γ2 between the electric drive motor and the output shaft;
• and
• an electronic shift controller for controlling a gear shift from the first gear to the second gear;
• wherein the electronic shift controller is configured to:
• actuate the synchronizer to disengage the first gear and to engage the second gear, and
• synchronize a motor speed of the electric drive motor with a target speed;
• wherein the electronic shift controller is configured to control the electric drive motor to provide a non-zero torque |Tmot|>0 during synchronization of the motor speed with the target speed;
• and
• wherein the electronic shift controller is configured to limit an absolute value |Tmot| of the non-zero torque provided by the electric drive motor during synchronization of the motor speed with the target speed to a second maximum torque |Tsync|>0 until the motor speed has been synchronized with the target speed, so that |Tmot|≤|Tsync| during synchronization of the motor speed with the target speed.