A vehicle electric drive system includes an internal combustion engine, an electric motor/generator driven by the engine, a first inverter/rectifier coupled to motor/generator, a bus coupled to the first inverter/rectifier, a second inverter/rectifier coupled to the bus, and a traction motor/generator coupled to an output of the second inverter/rectifier, an operator speed control member, and a controller coupled to the second inverter/rectifier for controlling a current output of the second inverter/rectifier as a function of a position of the speed control member Also included is an operator controlled foot pedal and a transducer coupled to the foot pedal and generating a signal representing foot pedal position which is supplied to the controller The controller limits current supplied by the second inverter/rectifier to the traction motor/generator to a limit current as a function of the transducer signal The controller, foot pedal and transducer cooperate to vary the limit current in response to movement of the foot pedal A spring biases the foot pedal to an upper limit position The controller causes the second inverter/rectifier to supply to the traction motor/generator a maximum amount of current, (such maximum current being a function of the foot pedal position), but not more than that required to achieve the speed commanded by the speed control

Variable current limit control for vehicle electric drive system

The invention includes an electric machine having a rotor, stator and at least one winding in the stator adapted to conduct a current, and a secondary winding, electrically isolated from the first winding and inductively coupled to the first winding, which may be used to control at least one of the output voltage and current of the first winding.

Architecture for electric machine

An electric power-steering device has a speed-reducing mechanism (17) for reducing the speed of an output shaft (16) of an electric motor (15). The speed-reducing mechanism (17) has an internal gear (39) engaged and rotated with the output shaft (16) and an external gear (40) with which the internal gear (39) internally meshes. A drive pulley (41) rotatable together with the external gear (40) and a driven pulley (42) provided so as to surround a steering shaft are connected by an endless belt (43). Speed reduction is obtained by the internal gear (39) and the external gear (40), and the speed-reducing mechanism (17) as a whole achieves a high reduction ratio without greatly reducing the diameter of the drive pulley (41).

Electric power-steering device

The present application concerns concentrated protein formulations with reduced viscosity, which are particularly suitable for subcutaneous administration. The application further concerns a method for reducing the viscosity of concentrated protein formulations.

Reduced-viscosity concentrated protein formulations

An electric power steering control system in which the steering "feel" is improved, having a steering force detector an electric motor for producing an auxiliary steering force, a motor current detector and a control unit for deciding the motor current value and rotational direction at least in accordance with the detected steering force. The motor current is limited in accordance with the detected steering force and motor current values.

Electric power steering control system

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 method using this method

A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.

Motor-driven power steering apparatus

A PWM inverter includes a plurality of arms connected in parallel with a d.c. power source. Each arm is constituted by an upper arm and a lower arm each having a switching element. A plurality of switching control signals are continuously and alternately applied to one and the other of the two switching elements constituting the same arm respectively. In the PWM inverter, shunt resistors are connected between a minus terminal of the d.c. power source and the lower arms respectively. The PWM inverter further comprises a waveform command generating circuit generating commands representative of current waveforms to be supplied to a load, a carrier wave generating circuit and sample-hold circuits. Each of the sample-hold circuits samples and holds a terminal voltage of the associated shunt resistor in synchronism with the period of the carrier wave generated from the carrier wave generating circuit and at specific timing in a conduction period of the associated switching element.

Load current detecting device for pulse width modulation inverter

Method for controlling an automatic pipe welder is disclosed. In the automatic welder which requires remote control, welding conditions for butt welding pipes are stored and an actual joint geometry or groove shape is sensed. From signals relating to the stored welding conditions and the sensed groove shape, a control command signal in actual welding is produced to effect welding under an optimum condition. On the other hand, an arc condition at an actual welding point and a melting condition of a metal are monitored and displayed to modify the welding conditions in accordance with the monitored condition to control the automatic pipe welder.

Method for controlling an automatic pipe welder

An electromobile equipped with an automatic transmission which may detect a running condition of a vehicle and selects a gear ratio suited for the running condition. In this electromobile, a build-up characteristic of an electric motor current immediately after gear-change is improved, thereby minimizing delay in power transmission so as to shorten a gear-changing duration, in an attempt to improve an operational feeding of a driver at the time of gear change.

Tsutomu Omae

Papers

Failure detection method for electric vehicles and fail-safe control method using this method

Motor-driven power steering apparatus

Load current detecting device for pulse width modulation inverter

Method for controlling an automatic pipe welder

Automatic change-gear control device for use in electromobile