Honda Giken Kogyo Kabushiki Kaisha

Honda Giken Kogyo K.k.

Tomoyuki Itoh

Hisahiro Ito

Shinji Yoshikawa

Yuji Saito

Katsuyuki Kusano

Kiyotaka Hayashi

Yasushi Kanai

Naofumi Hoshi

Kiyoshi Kimura

Morio Kayano

Yasushi Aoki

Kazuaki Takizawa

Akira Ozawa

Atsushi Shibutani

Shoji Tokushima

Koji Tamenori

Hiroaki Shinoki

Hajime Kondou

Hideyuki Jinzai

Koji Furumoto

Hisahiro Itoh

Yuuji Saito

A control device for an alternating current motor includes: a target current generating unit which generates a current order value, based on a torque order, as a d-axis target current and a q-axis target current on dq coordinates; a current detection device which detects an alternating current supplied to each phase of a polyphase alternating current motor; a coordinate transforming unit which transforms the alternating current detected by the current detection device into a d-axis current and a q-axis current on the dq coordinates; and a vector control unit which carries out a current feedback control so that the d-axis current follows up the d-axis target current and the q-axis current follows up the q-axis target current. The vector control unit further includes: an operation switching unit which, depending on whether a back electromotive voltage of the alternating current motor is greater than or equal to a predetermined value, calculates one of a d-axis deviation and a q-axis deviation from the deviation between the d-axis target current and the d-axis current and the other one of the d-axis deviation and the q-axis deviation from the deviation between the q-axis target current and the q-axis current; and an integration controlling unit which outputs a d-axis integration voltage order value proportional to an integral value of the d-axis deviation and a q-axis integration voltage order value proportional to an integral value of the q-axis deviation. An alternating current supplied to each phase of the alternating current motor is controlled based on an output of the integration controlling unit.

Control device for alternating current motor

In an electric vehicle in which regenerative braking is performed in preference to hydraulic braking, an uncomfortable vibration generated due to a sudden variation in the load of a motor, is prevented at the start of the regenerative braking. At the start of the braking, the regenerative braking force is gradually increased from a previously set regenerative initial value to a demanded braking force rather than being increased quickly to the demanded braking force, thereby preventing the generation of the vibration. A deficiency in the braking force during this time is compensated for with the hydraulic braking force. When the demanded braking force exceeds a regenerative acceptable value, the regenerative braking force does not exceed the acceptable value, and a deficiency of braking force thereafter is compensated for with the hydraulic braking force.

Brake system for an electric vehicle

A control system for an electric vehicle includes an accelerator opening detecting device for detecting a position of an accelerator, and an output command value calculating device connected to the accelerator opening detecting device for calculating an output command value of a drive motor of the electric vehicle based upon the detected accelerator opening. A motor control device is connected to the output command value calculating device, and controls the output of the motor based upon the output command value. An accelerator opening learning device learns actual accelerator opening positions, and includes at least one of a full-closure learning apparatus for generating a full-closure determined value of the accelerator based upon an output of the accelerator opening detecting device, and a full-open learning apparatus for generating a full-open determined value based upon the detected accelerator opening. The system also includes an output command value limiting device for limiting the output command value output by the output command value calculating device until the accelerator opening learning device has generated the full-closure determined value and the full-open determined value. This configuration reduces the rough and unstable output changes of a motor until the learning has been completed.

Control system for electric vehicle

When the voltage of a battery is dropped down to a first threshold value (9.5 V) or less, the driving force of a motor is decreased to a level Y(0)-Y(7) of a limit power determined in accordance with a remaining capacity of the battery. When the voltage is not restored even after a predetermined time is lapsed from the decreasing of the driving force to the level Y(0)-Y(7), the driving force is further decreased down to a lower level Y(0)-Y(7). When the voltage of the battery is restored to a second threshold value (10 V), the driving force of the motor is gradually increased up to a level Z(0)-Z(7) of a limit power determined in accordance with the capacity of the battery. Thus, it is possible to prevent a deep discharging of the battery, while minimizing the influence on the traveling of the vehicle.

A motor control device for controlling the driving and regenerative operation of a motor includes CPU, ROM, RAM and a back-up RAM. An electric power is normally supplied from a subsidiary battery through a second regulator to the back-up RAM. An electric power is also supplied to the CPU, the ROM and the RAM through a main switch and a first regulator, on the one hand, and through the first regulator and a transistor which is turned ON when the number of revolutions of the motor becomes equal to or larger than a predetermined value, on the other hand. Therefore, even if the main switch is opened during traveling of a vehicle at a high speed, the counter-electromotive force of the motor can be decreased by the motor control device which is supplied with the electric power through the transistor to maintain its function, thereby preventing damage to an inverter.

An electronic control unit for controlling an inverter mounted between a main battery and a motor in an electric vehicle includes a feed-back control device which ensures that an actual electric power calculated from an electric current and a voltage inputted to the inverter is equalized to a target electric power calculated from the motor revolution-number, an accelerator opening degree and a shift position. If a circuit between the main battery and the motor is opened during regenerative operation, so that the charging of the main battery with a regenerative electric power cannot be performed and as a result, the voltage is increased to exceed a predetermined value, a regeneration prohibiting device prohibits the regenerative operation of the motor to prevent damage to the inverter due to a counter-electromotive voltage of the motor.

A backup power supply 11 is not loaded by peripheral equipment 9 and a low-voltage battery 5. A switch controller 12 is energized by any of the backup power supply 11, the DC/DC converter 7, and the low-voltage battery 5 for controlling the energization of a relay 3L. When the power supply from the DC/DC converter 7 and the low-voltage battery 5 to the switch controller 12 is declined, it is complemented by the backup power of a low voltage from the backup power supply 11. Accordingly, the switch controller 12 is always energized with a sufficient level of the power supply regardless of the residual storage of the low-voltage battery 5.

Power supply control device for electric vehicle

In an electric vehicle including a transmission provided between a motor and driven wheels, if a shift change detecting means has detected the shift change from a 'D' range or an 'R' range to an 'N' range or a 'P' range when a stoppage detecting means has detected that the vehicle is in its substantially stopped state, a torque command value gradually-decreasing means gradually decreases the torque command value for the motor toward zero. This causes the face pressure of meshed portions of gears within the transmission to be moderately decreased, thereby preventing the generation of a striking sound due to a repulsion of the gear.

A neutral apparatus for use on an electric vehicle is disclosed. The neutral apparatus comprises a control state detector and a neutral mechanism control circuit. The control state detector detects whether or not the motor control unit is in a predetermined control state. The neutral mechanism control unit can instruct the neutral mechanism to interrupt the power train according to the output signal from the control state detector. If the motor control unit is not in the predetermined control state, this is detected by the control state detector. In response to the output signal from the control state detector, the neutral mechanism control circuit causes the neutral mechanism to interrupt the power train. Thus, power flow from the motor to the drive wheels is interrupted. The control state detector is comprised of a voltage comparator circuit for comparing the output voltage from the motor driver circuit with a reference voltage and produces an output signal. As a result, it becomes possible to monitor the control state of the vehicle during movement thereof by means of an arrangement simple in construction.

Neutral apparatus for electric vehicle

A motor torque control system has an inverter for converting a DC voltage from a battery into an AC voltage to energize an AC motor based on a command amplitude value. An input electric power calculating unit calculates an input electric power supplied from the battery based on a current and a voltage from the battery. A target electric power calculating unit calculates a target electric power to be supplied to the AC motor based on the rotational speed of the AC motor and a command torque value indicative of a torque to be produced by the AC motor. A PI control unit produces a control signal from the difference between the input electric power and the target electric power, and a PWM control unit controls the command amplitude value based on the control signal.

Torque control system for AC motor

A false-creep generator device for an electric vehicle equipped with a transmission controls an electric motor to cause the electric vehicle to creep when the accelerator pedal of the electric vehicle is not depressed, no brake is applied to the electric vehicle, the transmission is in a drive or reverse position, and the speed of travel of the electric vehicle is lower than a predetermined creep speed.

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Wako, Japan

Tomoyuki Itoh