Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Agency of Industrial Science and Technology

Other

Tsutomu Ohmae

Ryoso Masaki

Katsuji Marumoto

Nobuyoshi Mutoh

Sanshiro Obara

Hiroshi Kimura

Toshiaki Okuyama

Kazuo Tahara

Toshimi Abukawa

Hirohisa Yamamura

Taizou Miyazaki

Hisatugu Ishikura

Toshiyuki Koterazawa

Toru Tatsuzaki

Shuichi Takamatsu

Satoru Kaneko

Mitsuyuki Hombu

Fumio Tajima

Makoto Shioya

Kazuaki Tobari

Shotaro Naito

Toshihiko Matsuda

Seizi Yamashita

Yuusuke Takamoto

Shigeki Saito

Mitsuyuki Honbu

Makoto Tachikawa

Yasuo Noto

Keigo Naoi

Toshio Suzuki

Masato Sakai

Hiroshisa Yamamura

Katsuji Murumoto

Toshiyuki Koterazaka

Hideo Yano

An electric vehicle torque controller has a torque calculating unit and an actual torque detecting unit. The calculated torque is compared with the actual torque to generate a torque compensation value, which is converted to a torque current signal. The torque current signal is used to generate a slip frequency, which is added to an output of an angular speed detector and used to set a secondary magnetic flux value. A secondary magnetic flux signal is generated according to the secondary magnetic flux value and the torque current signal. A secondary magnetic flux estimating unit generates an estimated secondary magnetic flux value, which is used to determine the exciting current. Primary motor current is controlled in response to the exciting current, the torque current, motor speed and slip value.

Electric vehicle torque controller

When a voltage level determinator judges from the terminal voltage of a smoothing capacitance that a battery is in an over-charged state and cannot receive regeneration energy, a regeneration/free-wheel mode selector switches to a free-wheel mode for consuming the energy of the battery. For this purpose, a torque reducing signal generator executes a control in which only a magnetizing component of current flows through the primary winding and no driving force is generated in the motor, with the result that the energy of the battery is consumed as heat loss inside the motor. Then, when the over-charged state is eliminated and the energy receiving capability of the battery is recovered, the regeneration/free-wheel mode selector switches the mode to the regeneration mode to obtain regeneration braking.

Control method and system for regeneration braking of an electric vehicle

The object of the present invention is to provide an electric drive system which ensures effective generation of torque from the start to the maximum speed, and extended cruising distance and upgraded running performances. The drive system according to the present invention is characterized in that, in a electric vehicle to be driven by the wheels which are driven by the rotary output of two or more motors, said two or more motors comprise at least two different types of motors, and the system is provided with the control means to adjust the share of the vehicle driving force to be generated by each of said motors in conformity to the running state of said vehicle. These two or more motors comprise a combination of a low speed drive motor and high speed drive motor, and a highly efficient motor is used as said low speed motor, while a motor having a greater capacity and greater base speed than said low speed drive motor is used as the high speed drive motor. The share of the driving force of said vehicle is controlled by the control means such that up to the maximum torque is generated by said low speed drive motor, with the remaining torque generated by said high speed drive motor.

Electric vehicle drive system and drive method

An electric vehicle torque controller has a torque calculating unit and an actuate torque detecting unit. The calculated torque signal is compared with the actual torque to generate a torque compensation value, which is converted to a torque current signal. The torque current signal is used to a slip frequency, which is added to the output of an angular speed detector and used to set a secondary magnetic flux value. A secondary magnetic flux signal is generated according to the secondary magnetic flux value and the torque current signal. A secondary magnetic flux estimating unit generates an estimated secondary magnetic flux value, which is used to determine the exciting current. Primary motor current is controlled in response to the exciting current, the torque current, motor speed and slip value.

An electric vehicle control system for driving a battery powered motor with use of power inverters. First and second inverters are connected with the respective three-phase primary windings of an induction motor. If one of the inverters fails, failure detection circuits detect it, and a control unit stops the failed inverter and allows the other normal inverter to drive the induction motor to move the electric vehicle. Driving the single motor with a plurality of power inverters allows the electric vehicle to move and run even if one of the power inverters fails.

Electric vehicle control system

A control apparatus of a motor drive vehicle includes a unit for generating a target vehicle speed; a speed instruction unit for generating a target motor rotational speed of the motor based upon a preset motor control pattern in response to the target vehicle speed; a power circuit for operating the motor at the target motor rotational speed upon receipt of the target motor rotational speed; a variable transmission unit for converting a drive output from the motor into a transmission ratio for instructing a rotational speed of the drive output, and transferring the converted transmission ratio to a drive shaft of the motor drive vehicle; and a transmission ratio calculating unit for determining the transmission gear ratio based on the target vehicle speed and the target motor rotational speed thereby to instruct the determined transmission gear ratio to the variable transmission unit. A control method sets a target vehicle speed value; produces a target motor rotational speed based upon the target vehicle speed value and a preset motor control pattern; operates the motor at the target motor rotational speed; determines a transmission gear ratio based upon both of the target vehicle speed and the target motor rotational speed; and converts a rotational speed of a drive output into the transmission ratio and transfers the converted transmission ratio to a drive shaft.

Control apparatus and control method for motor drive vehicle

An electric vehicle control device is disclosed, which includes an AC motor for driving a vehicle; a main electric power conversion unit for supplying an AC voltage to the AC motor; a battery for supplying a DC voltage to the main electric power conversion unit; an auxiliary electric power conversion unit connected to the battery and adapted to be connected to a load or a power supply; a controller for controlling the main and auxiliary electric power conversion units so as to act selectively as an inverter or a converter; and a switching unit for giving selectively the AC motor the AC voltage from the main and auxiliary electric power conversion units under control of the controller. In the running mode of the electric vehicle, the controller described above makes the main electric power conversion unit act as an inverter and controls the switching unit so that the AC voltage from the main electric power conversion unit is given to the AC motor. Further, responding to detection of a failure of the main electric power conversion unit, the controller makes the auxiliary electric power conversion unit act as an inverter and controls the switching unit so that the AC voltage from the auxiliary electric power conversion unit is given to the AC motor.

Electric vehicle control device

An electric power steering apparatus for a vehicle comprises a steering shaft, an electric motor operable to generate an auxiliary steering force having a magnitude corresponding to a value of electric current supplied thereto, a steering toque sensor for detecting a steering torque applied to the steering shaft, a vehicle weight sensor for detecting a vehicle weight, and a control device. The control device is constituted to increase and decrease the value of electric current to be supplied to the electric motor in accordance with not only the increase and decrease of the value detected by the steering torque sensor but also the increase and decrease of the value detected by the vehicle weight sensor.

Electric power steering apparatus for vehicle

An electric power steering control system includes an electric motor for producing an assisting torque for the vehicle steering system through a reduction gear, a steering torque sensor fitted on the steering shaft, a controller for controlling the input to the motor in accordance with the torque sensor output, a battery for supplying power to the controller, and a voltage step-up circuit connected to the battery for driving the motor at a voltage higher than the battery voltage. The controller drives the motor at a high voltage.

Electric power steering control system

The steering power assist control comprises a main assist control and an auxiliary assist control. When an abnormality occurrence signal from the main assist control is inputted to an abnormality state detection and changing decision circuit 134, the selector circuit changes the PWM signal from the main assist control side to the auxiliary assist control side and outputs the PWM signal to a motor drive circuit. When the main assist control fails, the auxiliary assist control immediately takes over the main assist control to provide, if the operation condition permits, a continued steering power assist control. This prevents an abnormal steering state of the vehicle that would otherwise result when the steering power assist is suddenly lost.

Electric motor-driven power steering apparatus

A vehicle height control apparatus responsive to power steering operation is disclosed in which a torque signal indicative of the steering torque imparted to the steering wheel by a driver's operation thereof is used for controlling the power steering system and also for controlling the operation of actuators for adjusting damping force of shock absorber provided to each wheel thereby controlling the height of the vehicle.

Vehicle height control apparatus responsive to power steering operation

A counter is provided to count an output pulse which a pulse generator generates each time a vehicle moves by a predetermined distance. A microprocessor is provided to actuate a timer in synchronism with the leading edges of the output pulse from the pulse generator. The timer is set to a constant time interval during which the speed of the vehicle is to be detected. The microprocessor calculates the speed of the vehicle from the count of the counter which count is a value during the time interval from when the timer starts to operate to when the pulse generator generates a pulse just before or after the end point of the set time interval. Thus, the speed of the vehicle can be detected with good resolution and precision.

Speed detecting method and apparatus

A control apparatus for electric vehicles by using a chopper circuit which turns on or off a d-c drive motor responsive to the instruction of a microcomputer. The control apparatus of the present invention is characterized by the provision of a protection device. The protection device comprises means for generating a predetermined signal, means for adding the predetermined signal to a signal which varies depending upon the stepped-in amount of the accelerator pedal, means for comparing the added signal with an output signal of a current detector which detects a current that flows into the d-c drive motor, and means which sets the microcomputer when the output signal of the current detector is greater than the added signal and which permits the microcomputer to start again its operation after a predetermined period of time has passed.

Protective control apparatus for electrical vehicle

A power switching apparatus for use in the control of a D.C. load such as a D.C. motor comprises a power transistor with its emitter-collector path connected in series with the D.C. motor and a battery. A base current of the power transistor is supplied from the battery through a controllable impedance element. A control unit is provided to vary the impedance of the controllable impedance element in response to the current flowing through the emitter-collector path in such a manner that the base current changes as substantially the inverse-function of a characteristic curve indicating a D.C. amplification factor versus collector current of the power switch transistor.

Transistor switching apparatus for use in the control of a D.C. load

An automatic change-gear control device for use in an electromobile which incorporates a multi-stage change gear drive system. This automatic change gear control device selects and controls a gear ratio for an optimum ratio, depending on the running condition of a vehicle, and particularly provides a change-gear logic by detecting a load torque for every individual condition, in an attempt to improve the running performance of a vehicle at the time of acceleration or at the time of running on an upward slope.

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Hitachi, Japan

Tsutomu Ohmae