METHOD FOR A VEHICLE HAVING AN ELECTRIC MACHINE

• US 20150142230A1
• Filed: 05/09/2012
• Published: 05/21/2015
• Est. Priority Date: 05/19/2011
• Status: Active Grant

• Current Assignee: Volkswagen AG
• Original Assignee: Volkswagen AG
• Inventors: Weiss, Norbert, Thiamtong, Vasoontara, Auer, Richard
• Granted Patent: US 9,694,808 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2270/145 Structure borne vibrations
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/184 with wheel brakes
• CPC Class Codes: B60W 20/40 Controlling the engagement or disengagement of prime movers, e.g. for transition between prime movers power-up or power-down of the driveline B60W30/192
• CPC Class Codes: B60W 2510/101 Transmission neutral state
• CPC Class Codes: B60W 2540/12 Brake pedal position
• CPC Class Codes: B60W 2540/16 Ratio selector position
• CPC Class Codes: B60W 2710/083 Torque
• CPC Class Codes: B60W 2710/182 Brake pressure, e.g. of fluid or between pad and disc
• CPC Class Codes: B60W 2720/30 Wheel torque
• CPC Class Codes: B60W 30/18054 at stand still, e.g. engine in idling state hill holding B60W30/18118
• CPC Class Codes: B60W 30/18127 Regenerative braking
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

The present invention relates to a method for a vehicle (10) having an electric machine (11). The electric machine (11) is coupled to at least one wheel (16) of the vehicle (10). The vehicle (10) can optionally be operated in at least a first operating mode (21) and a second operating mode (22). In the first operating mode (21), the electric machine (11) applies a torque to the wheel (16), and in the second operating mode (22) the electric machine (11) does not apply any torque to the wheel (16). In the method, a request for switching over between the first and the second operating modes (21, 22) is detected and the vehicle (10) is operated in a transition operating mode (23) if the request to switch over from the first operating mode (21) into the second operating mode (22) is detected. In the transmission operating mode (23), a torque is applied to the at least one wheel (16) counter to a rolling direction of the vehicle (10) for at least a predetermined time.

Claims

1. A method for a vehicle with an electric motor, whereby the electric motor is coupled to at least one wheel of the vehicle, and whereby the vehicle can be operated as desired at least in a first mode of operation and in a second mode of operation, whereby in the first mode of operation, the electric motor applies a torque onto the at least one wheel, while in the second mode of operation, the electric motor does not apply a torque onto the at least one wheel, whereby the method comprises the following steps:

detecting a request to shift between the first mode of operation and the second mode of operation, and

once the request to shift from the first mode of operation into the second mode of operation has been detected, operating the vehicle in a transition mode of operation, whereby in the transition mode of operation, a torque is applied onto the at least one wheel, at least for a predetermined period of time, said torque acting opposite to the direction of movement of the vehicle.

2. The method according to claim 1, whereby the step of operating the vehicle in the transition mode of operation further comprises:

ascertaining whether the predetermined period of time has expired and,

if it has been ascertained that this is the case, operating the vehicle in the second mode of operation.

3. The method according to claim 1, whereby the predetermined period of time is one second at the maximum.

4. The method according to claim 1, whereby the vehicle is only operated in the transition mode of operation if a request to shift from the first mode of operation into the second mode of operation has been detected, and the torque applied by the electric motor acts opposite to a direction of movement of the vehicle in the first mode of operation.

5. The method according to claim 1, whereby the vehicle is operated in the transition mode of operation only if a request to shift from the first mode of operation into the second mode of operation has been detected and if the brake pedal of the vehicle is actuated.

6. The method according to claim 1, whereby the first mode of operation comprises a gear setting for driving the vehicle forward (D) or in reverse (R).

7. The method according to claim 1, whereby the second mode of operation comprises a gear setting for the freewheeling (N) of at least one wheel of the vehicle that is coupled to the electric motor

8. The method according to claim 1, whereby, in the transition mode of operation, the electric motor applies the torque onto the at least one wheel.

9. The method according to claim 1, whereby, in the transition mode of operation, the electric motor applies the torque onto the at least one wheel, whereby the torque is set as a function of the torque in the first mode of operation and of a predetermined maximum recuperation torque.

10. The method according to claim 1, whereby the torque in the transition mode of operation has a predetermined torque curve, whereby the predetermined torque curve encompasses a first portion with an essentially constant torque and a second portion with a torque whose magnitude decreases.

11. The method according to claim 1, whereby, in the transition mode of operation, the electric motor applies the torque onto the at least one wheel, whereby the torque is set as a function of the position of the brake pedal of the vehicle.

12. The method according to claim 1, whereby, in the transition mode of operation, the torque is applied onto the at least one wheel by a brake device of the vehicle, whereby the torque is set as a function of the torque in the first mode of operation.

13. The method according to claim 1, whereby the electric motor is configured to generate electric energy when the torque applied by the electric motor onto the at least one wheels acts opposite to the direction of movement of the vehicle.

15. The vehicle according to claim 14, whereby the vehicle is configured to carry out the method according to claim 1.

14. A vehicle comprising:

an electric motor that is coupled to at least one wheel of the vehicle,

an operating element that serves to detect a request to shift between a first mode of operation and a second mode of operation mode of operation of the vehicle, and

a control device that is coupled to the electric motor and to the operating element,

whereby the control device is configured to operate the electric motor in such a way that, in the first mode of operation, the electric motor applies a torque onto the at least one wheel and, in the second mode of operation, the electric motor does not apply any torque onto the at least one wheel,

whereby, when a request to shift from the first mode of operation into the second mode of operation is detected, the control device operates the vehicle in a transition mode of operation, whereby, in the transition mode of operation, a torque is applied onto the at least one wheel, at least for a predetermined period of time, said torque acting opposite to the direction of movement of the vehicle.