Hitachi, Ltd.

Hitachi Automotive Engineering Co., Ltd.

Shotaro Naito

Sanshiro Obara

Keiichi Tokuyama

Hirohisa Yamamura

Tsutomu Omae

Hiroshi Katada

Hiroshi Kimura

Seiji Suda

Katsuji Marumoto

Nobuyoshi Mutoh

Mitsuhiro Masuda

Shizuhisa Watanabe

Nobunori Matsudaira

Yoshihiro Yokota

Yasuo Noto

Masahiro Matsumoto

Hiroyuki Yamada

Fumio Tajima

Ryoso Masaki

Makoto Shioya

Noboru Sugiura

Osamu Suzuki

Satoshi Shimada

Masahiko Ibamoto

Motohisa Funabashi

Kunio Miyashita

Osamu Koizumi

Suetaro Shibukawa

Takanori Shibata

Kaoru Uchiyama

Masayuki Miki

Seiko Suzuki

Akira Koide

Shigeyuki Yoshihara

Akio Yasukawa

Kozo Katogi

Heikichi Kuwahara

Shigeki Tsuchitani

Mitsukuni Tsutsui

Tsutomu Ohmae

Syooichi Kawamata

Seizi Yamashita

Taiji Hasegawa

Tosio Tomite

Hisakatsu Kiwaki

Eiichi Ohtsu

Shigeru Horikoshi

Shigeki Saito

Hidemitsu Kobayashi

Shigeru Kuriyama

Masao Adachi

Junichi Takahashi

Nobuhiko Ogasawara

Tatsuhiro Tani

Yoshimitsu Onoda

Hirosi Katada

Masanori Muso

Nobuo Fujieda

Toshihiko Suzuki

A system for driving a hybrid vehicle comprising an engine; a motor/generator coupled to the engine; a battery connected to the motor/generator through an electric power converter; and a controller for controlling the engine and the motor/generator corresponding to driving condition of the vehicle, wherein the controller has a plurality of operating modes for controlling the engine and the motor/generator corresponding to an accelerator opening degree for operating the engine and a charge ratio of the battery, and the controller selects an engine running electric generating mode that the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low; an acceleration mode that the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening degree is large; and an engine running mode that only the engine is operated as the driving source of the vehicle when the charge ratio of the battery is high and the accelerator opening degree is small. It is possible to provide a system for driving a hybrid vehicle and a method of driving the hybrid vehicle which can store sufficient electric power in a battery and is excellent in the operating characteristic.

System for driving hybrid vehicle, method thereof and electric power supply system therefor

A system for driving a hybrid vehicle having an engine, a motor/generator, a battery and a controller for the engine and the motor/generator. The controller has a plurality of operating modes. In an engine running electric generating mode, the engine is operated as a driving source of the vehicle and the motor/generator and electric power generated by the motor/generator is recovered to the battery when the charge ratio is low. In an acceleration mode, the engine and the motor/generator are operated as the driving source of the vehicle when the charge ratio of the battery is high, and the accelerator opening degree or a rate of change of the accelerator opening degree is large. In an engine running mode only the engine is operate as the driving source of the vehicle when the charge ratio of the battery is high and the accelerator opening degree is small.

A method and apparatus for driving an electric vehicle having a synchronous traction motor. A peak value of induced electromotive force of the synchronous motor at a maximum allowable rotating speed is set to a value which is lower than an allowable voltage of the smoothing capacitor of the inverter and lower than a maximum allowable voltage of the power switching elements composing the inverter. The synchronous motor is thus constructed so that a peak value V,of the maximum induced electromotive force at the maximum allowable rotating speed N,of the synchronous motor satisfies a relation of V,&lE;V,where V,is an allowable voltage of the smoothing capacitor.

Driving system for electric vehicle

The invention provides driving method and apparatus for an electric vehicle having a motor for driving the vehicle, a dc electric power source, a control device including a signal generating means for generating a signal to control rotation of the motor, and a key switch for controlling OFF-ON operation of the motor. The dc electric source includes a power battery (storage battery) connected to the motor and an energy battery (a fuel cell) connected in parallel with the power battery through an energy battery control switch. A battery current/voltage control unit controls the energy battery control switch based on the current or the voltage of the power battery, the energy battery or the motor, to maintain the voltage of the dc electric power source within a given range. A charging unit charges the power battery form the energy battery when the key switch is turned off, if the charge level of the power battery is below a given value, and stops charging if the charge level is above a given value.

Method and apparatus for operating an electric vehicle having a hybrid

A semiconductor device, suitable for use in an invertor device for large currents in which IGBT chips are used and of which a high reliability is required, has an insulating plate on which are mounted semiconductor chips, a resin case enclosing the semiconductor chips, a filler resin filled into the resin case and covering the semiconductor chips and filling in the space between the semiconductor chips and the resin case, and a heatsink to which the insulating plate is attached, wherein, for purposes of attaching the insulating plate to the heatsink, the resin case is used to press the insulating plate onto the heatsink. Some benefits of this construction are that is makes it possible to eliminate the problem of fatigue failure of a solder layer previously used for attaching the insulating plate to the heatsink by dispensing with that solder layer, while at the same time improving the transfer of heat from the insulating plate to the heatsink, and thereby improving the removal of heat from the device. The construction also makes it possible to reduce cracking of the insulating plate, reduce breakage of mounting portions of the resin case and to use the device to make a small, thin, light and highly reliable invertor device.

Semiconductor device

In an electric car drive system having a car drive motor powered by a mounted direct current power supply, a control system including a signal generating means is provided to generate signals which control motor speed. The direct current power supply is composed of a power battery having secondary cells connected to the motor and an energy battery formed by fuel cells connected in parallel to said power battery via an energy battery control switch. The electric car drive system is composed of a charge control means which charges the power battery using the energy battery if the charge of the power battery is below the specified value when said key switch is turned off, and suspends charging if the charge is equal to or greater than the specified value. A battery current and voltage control controls a voltage increasing circuit connected between the energy battery and the power battery based on the current or voltage of any one of the power battery, energy battery or motor and keeps the voltage of the direct current power supply within a specified range.

Electric car drive system provided with hybrid battery and control method

An electric vehicle control system which maintains good driving performance under normal conditions, and can cut off driving current upon malfunction of a microcomputer before restarting. A setting circuit of a comparing and operating circuit has a set signal fixed to V2 if an accelerator pedal is released. If a microcomputer malfunctions to drive an inverter absent a depression of the accelerator pedal, a current flows from a battery and a battery current sensor generates an output signal n. If this value exceeds V2, a comparator is turned on, which also turns on a transistor to energize a relay and disconnects an inverter drive signal s to break the power supply from an inverter to the ac motor. Upon disconnection, an alarm lamp is lit to issue an alarm to the driver. The disconnection is held by a delay circuit until the power is reset.

Electric vehicle control system

The invention provides an electric vehicle controller in which the generated motor torque is limited when the voltage of the vehicle battery decreases during running, in order to suppress over-discharge of the battery. A high torque can be obtained for a short period, however, even in the torque limiting period, and over-discharge is prevented by stopping electric power converting means in a final stage of discharge voltage of the battery. According to the invention, during operation of the vehicle, the battery terminal voltage is monitored and compared with a first comparison value V.sub.1. If the battery voltage falls below V.sub.1, a first counter commences measurement of the time period during which this condition continues. If the time period measured by the first counter reaches a preset value t.sub.1, torque limitation is initiated. In the torque limitation state, a torque command signal, generated by the control to operate the vehicle motor, is compared with the signal generated by the vehicle accelerator, and the signal having the lower value is thereafter used to control operation of the vehicle motor. In order to provide the capability to generate higher levels of torque for brief periods during torque limitation, the torque limitation process is terminated if the accelerator pedal is released completely.

Controller for electric vehicle

A semiconductor accelerometer includes a mass portion formed at a center of a silicon plate, a frame portion formed around the circumference of the silicon plate so as to surround the mass portion and a diaphragm portion formed in the silicon plate between the mass portion and the frame portion so as to bridge the mass portion with the frame portion, one of major surfaces of the silicon plate serving as a common continuous major surface for the mass portion, frame portion and diaphragm portion. Piezoresistance elements are formed on the common continuous major surface at the diaphraqm portion and an additional Au film is formed on the common continuous major surface at the mass portion. The additional Au film constitutes in combination with the mass portion a weight which responds to an acceleration acting thereon. The mass of the additional Au film is selected in such a manner that the center of gravity of the weight is located within an area in the mass portion having a depth corresponding to the thickness of the diaphragm portion.

Semiconductor accelerometer

The invention provides a brake control apparatus for an electric motor vehicle that can control a charging current depending on a charging state of a dc power supply to avoid overcharging it. In regenerative braking, according to the invention, the charging state of a battery is detected by a charging state detector, which sends a detection signal to a control unit. When the state of charge of the battery exceeds a predetermined level, the control unit controls operating parameters of an inverter so that the charging current to the battery is decreased. If, however, insufficient torque results, the control unit turns on an electric load to increase the control torque. If further load absorption is needed, the control unit turns on electric braking means.

Brake control apparatus for electric motor vehicle

An air flow sensor unit for an internal combustion engine control system which detects an air flow rate and outputs an optical signal corresponding to the detected air flow rate to an external equipment including a bridge circuit including a temperature sensitive resistor which detects the air flow rate and outputs a first electrical signal indicative of a voltage amplitude corresponding to the detected air flow rate; a first converting circuit which converts the first electrical signal outputted from the bridge circuit into a second electrical signal indicative of a digital value corresponding to the voltage amplitude of the first electrical signal; a second converting circuit including a laser diode, for converting the second electrical signal outputted from the first converting circuit into the optical signal having the same digital value as that of the second electrical signal; a housing for accommodating the bridge circuit, first converting circuit and second converting circuit; and an apparatus of a lens and optical fiber cable secured integrally to the housing for transmitting the optical signal outputted from the second converting circuit to an external equipment.

Physical quantity sensor arrangement

A braking apparatus for an electric vehicle in which a mechanical anti-lock brake and regenerative braking cooperate with each other to improve a braking performance is realized. On condition that an accelerator is released off, the wheel rotation number is large, and a brake is trod on, a large regeneration mode is selected by a motor controller when a wheel slip is small, and a regeneration mode is selected when the wheel slip is large. When the wheel slip is small, the braking force exerted on each wheel is increased by the brake controller and the regenerative braking force is also increased so that a slip ratio comes quickly closer to 0.2. When the wheel slip is large, the brake controller reduces the braking force so that the slip ratio comes closer to 0.2. In this case, the regenerative braking force is smaller than the above case of the small wheel slip to such an extent that the operation of the brake controller is not disturbed. On condition that the accelerator is released off, the wheel rotation number is large, and the brake is released off, the regeneration mode is selected when the regeneration switch is turned on, and a coasting mode is selected when the regeneration switch is turned off.

Braking apparatus for electric vehicle

An object of the present invention is to secure safe driving of electric vehicles by enabling torque control regardless of sensor disorder. In the present invention, the mode of current sensor disorder is detected by a sensor disorder detection means. If it is found as a result that only 1 out of 3 current sensors is failing, the current of the failing current sensor is estimated by 2 normal current sensors and the torque control of the motor is continued by the ordinary torque control system. If 2 or more current sensors are found to be failing, a torque control system based on an AC current reference operation means is formed to control the motor torque based on the AC current reference. If a sensor failure detection means determines that only 1 phase is failing in the speed sensor, the motor torque is controlled by using the remaining 1 phase to detect the rotating angular speed of the motor. If all speed sensors are failing but the current sensors are normal, the motor torque is controlled by estimating the motor torque from the 3 phase AC current. If both the current sensors and the speed sensors are found to be failing, the motor torque is controlled based on the estimated torque control and rotating angular speed to continue the driving that is needed to avoid dangerous situations.

Failure detection method for electric vehicles and fail-safe control

Disclosed is an acceleration detector which has an electrically conductive mass portion formed at a free end of a cantilever, and fixed electrodes arranged opposite to the mass portion through a gap so that the value of acceleration is detected on the basis of the change of capacitance between the mass portion and the fixed electrodes, and in which at least one space is formed in the inside of the mass portion to lighten the weight of the mass portion to thereby widen the range of measurement.

Capacitive acceleration detector having reduced mass portion

A suspension control apparatus for a vehicle comprises a measuring unit for measuring relative motion between sprung mass and unsprung mass at each of wheels, a decision unit for discriminatively determining occurrence and convergence of at least one of rolling or pitching and bouncing or unsprung mass vibration on the basis of measurement data available from the measuring unit, and a control unit for controlling at least one of damping coefficient and spring constant in the suspension characteristics on the basis of the result of decision made by the decision unit.

Suspension control method and apparatus for vehicle

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Katsuta, Japan

Shotaro Naito