Electric vehicle drive train with rollback detection and compensation
First Claim
1. A drive train for an electric vehicle, said drive train comprising:
- an electric motor for driving one or more wheels of the vehicle and being rotatable in opposite directions corresponding to respective opposite directions of actual vehicle movement, said electric motor having a controllable torque output magnitude;
sensing means associated with said electric motor for sensing rotational speed and direction thereof;
selector means for permitting driver selection of a direction of intended vehicle movement; and
rollback detection and compensation means connected to said electric motor, and responsive to said sensing means and said selector means, for determining vehicle rollback defined by a sensed direction of actual vehicle movement opposite to a selected direction of intended vehicle movement and for controlling the output torque magnitude of said electric motor responsive to sensed rotational speed of said electric motor and as a predetermined function thereof to counteract the vehicle rollback.
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Accused Products
Abstract
An electric vehicle drive train includes a controller for detecting and compensating for vehicle rollback, as when the vehicle is started upward on an incline. The vehicle includes an electric motor rotatable in opposite directions corresponding to opposite directions of vehicle movement. A gear selector permits the driver to select an intended or desired direction of vehicle movement. If a speed and rotational sensor associated with the motor indicates vehicle movement opposite to the intended direction of vehicle movement, the motor is driven to a torque output magnitude as a nonconstant function of the rollback speed to counteract the vehicle rollback. The torque function may be either a linear function of speed or a function of the speed squared.
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Citations
27 Claims
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1. A drive train for an electric vehicle, said drive train comprising:
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an electric motor for driving one or more wheels of the vehicle and being rotatable in opposite directions corresponding to respective opposite directions of actual vehicle movement, said electric motor having a controllable torque output magnitude; sensing means associated with said electric motor for sensing rotational speed and direction thereof; selector means for permitting driver selection of a direction of intended vehicle movement; and rollback detection and compensation means connected to said electric motor, and responsive to said sensing means and said selector means, for determining vehicle rollback defined by a sensed direction of actual vehicle movement opposite to a selected direction of intended vehicle movement and for controlling the output torque magnitude of said electric motor responsive to sensed rotational speed of said electric motor and as a predetermined function thereof to counteract the vehicle rollback. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A drive train for an electric vehicle, said drive train comprising:
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a traction battery; an electric motor connected to said traction battery for driving one or more wheels of the vehicle, said electric motor being rotatable in opposite directions corresponding to respective opposite directions of actual vehicle movement, said electric motor having a controllable torque output magnitude; sensing means associated with said electric motor for sensing rotational speed and direction thereof; selector means for permitting driver selection of a direction of intended vehicle movement; and rollback detection and compensation means connected to said electric motor, and responsive to said sensing means and said selector means, for determining vehicle rollback defined by a sensed direction of actual vehicle movement opposite to a selected direction of intended vehicle movement and for controlling the output torque magnitude of said electric motor responsive to sensed rotational speed of said electric motor and as a nonconstant function thereof to counteract the vehicle rollback. - View Dependent Claims (8, 9, 10)
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11. A drive train for an electric vehicle, said drive train comprising:
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an electric motor for driving one or more of wheels of the vehicle and being rotatable in opposite rotational directions corresponding to opposite directions of vehicle movement, said electric motor having a controllable torque magnitude; sensing means associated with said electric motor for sensing rotational speed and direction thereof; selector means for permitting driver selection of a direction of intended vehicle movement; driver input means for permitting driver selection of vehicle braking or vehicle acceleration; and control means connected to said electric motor for controlling the output torque magnitude and rotational direction thereof in response to said driver input means, said control means further comprising rollback detection and compensation means responsive to said sensing means and said selector means for determining vehicle rollback defined by a sensed direction of actual vehicle movement opposite to a selected direction of intended vehicle movement and for controlling the output torque magnitude of said electric motor responsive to sensed rotational speed of said electric motor and as a nonconstant function thereof to thereby counteract the vehicle rollback even in an absence of driver selection of one of vehicle braking and vehicle acceleration. - View Dependent Claims (12, 13, 14, 15, 16)
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17. An electric vehicle comprising:
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a frame; one or more vehicle wheels rotatably mounted on said frame; a traction battery carried by said frame; an electric motor connected to said traction battery for driving one or more wheels of the vehicle, said electric motor being rotatable in opposite directions corresponding to respective opposite directions of actual vehicle movement, said electric motor having a controllable torque output magnitude; sensing means associated with said electric motor for sensing rotational speed and direction thereof; selector means for permitting driver selection of a direction of intended vehicle movement; driver input means for permitting driver selection of vehicle braking or vehicle acceleration; and control means connected to said electric motor for controlling the output torque magnitude and rotational direction thereof in response to said driver input means, said control means further comprising rollback detection and compensation means responsive to said sensing means and said selector means for determining vehicle rollback defined by a sensed direction of actual vehicle movement opposite to a selected direction of intended vehicle movement and for controlling the output torque magnitude of said electric motor responsive to sensed rotational speed of said electric motor and as a nonconstant function thereof to thereby counteract the vehicle rollback even in an absence of driver selection of one of vehicle braking and vehicle acceleration. - View Dependent Claims (18, 19, 20, 21)
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22. A method for operating an electric vehicle including an electric motor for driving one or more wheels of the vehicle and being rotatable in opposite directions corresponding to respective opposite directions of actual vehicle movement, and a selector for permitting driver selection of a direction of intended vehicle movement, said method comprising the steps of:
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sensing a rotational direction of the electric motor corresponding to a respective direction of actual vehicle moment; determining vehicle rollback defined by the sensed direction of actual vehicle movement being opposite the intended direction of vehicle movement; sensing a rotational speed of the electric motor corresponding to a respective speed of actual vehicle movement; and controlling an output torque magnitude of the electric motor responsive to the sensed rotational speed of the electric motor and as a predetermined function thereof to counteract the vehicle rollback. - View Dependent Claims (23, 24, 25, 26, 27)
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Specification