Braking control system for an electric vehicle
First Claim
1. A controller for an electric vehicle driven by an electric motor, a speed of which is controlled according to a voltage, said controller comprising:
- an accelerator position sensor for sensing an angular position of an accelerator, said angular position being used for determining a voltage to be supplied to the electric motor;
monitor means for monitoring functions of the electric vehicle to detect a malfunction therein, said functions including battery voltage, electric motor temperature, electric motor angular position, and accelerator angular position;
braking duty factor determining means for receiving an accelerator angular position input signal from said monitor means when the malfunction is detected by said monitor means, said braking duty factor determining means calculating a braking duty factor according to said accelerator angular position input signal; and
correcting means for receiving said braking duty factor and generating a corrected voltage according to said braking duty factor by gradually decreasing the voltage supplied to the electric motor when the malfunction is detected by said monitor means;
said correcting means supplying said corrected voltage to the electric motor when the malfunction is detected.
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Accused Products
Abstract
A regenerative braking control system consumes energy generated in a period corresponding to an angle θ1 which starts in a half of a period of an AC voltage produced in a drive motor during the braking of the drive motor. The regenerative braking control system also consumes energy generated in a period corresponding to an angle θ2 that ends at the end of a half of a period of the AC voltage. The regenerative rate of braking control system utilizes a current induced in the driving coils of the drive motor at the end of the period corresponding to the angle θ1 to recharge a battery. By utilizing two periods to carry out the regenerative braking process, the recharging energy and the braking force can be controlled individually. Moreover, a controller monitors the electric control system to determine whether a malfunction is present. If a malfunction is detected, an electrical brake electrically brakes the drive motor. This electrical braking after the detection of a malfunction in the electrical system provides satisfactory controllability of the electric vehicle.
59 Citations
13 Claims
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1. A controller for an electric vehicle driven by an electric motor, a speed of which is controlled according to a voltage, said controller comprising:
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an accelerator position sensor for sensing an angular position of an accelerator, said angular position being used for determining a voltage to be supplied to the electric motor; monitor means for monitoring functions of the electric vehicle to detect a malfunction therein, said functions including battery voltage, electric motor temperature, electric motor angular position, and accelerator angular position; braking duty factor determining means for receiving an accelerator angular position input signal from said monitor means when the malfunction is detected by said monitor means, said braking duty factor determining means calculating a braking duty factor according to said accelerator angular position input signal; and correcting means for receiving said braking duty factor and generating a corrected voltage according to said braking duty factor by gradually decreasing the voltage supplied to the electric motor when the malfunction is detected by said monitor means; said correcting means supplying said corrected voltage to the electric motor when the malfunction is detected. - View Dependent Claims (2, 3, 4, 5, 6, 7, 13)
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8. A method for controlling an electric vehicle driven by an electric motor, a speed of which is controlled according to a voltage, said method comprising the steps of:
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sensing an angular position of an accelerator, said angular position being used for determining a voltage to be supplied to the electric motor; monitoring functions of the electric vehicle to detect a malfunction therein, said functions including battery voltage, electric motor temperature, electric motor angular position, and accelerator angular position; providing braking duty factor determining means for receiving an accelerator angular position input signal from said monitor means when the malfunction is detected by said monitor means; calculating a braking duty factor according to said accelerator angular position input signal; generating a corrected voltage according to said braking duty factor by gradually decreasing the voltage supplied to the electric motor when the malfunction is detected; and supplying the corrected voltage to the electric motor when the malfunction is detected. - View Dependent Claims (9, 10, 11, 12)
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Specification