Nissan Motor Company Limited

Norifumi Isaji

Shinji Ohashi

Hajime Satoh

Yasuo Matsunaga

In control apparatus and method for an electric vehicle, when the motor is determined to be locked during a run of the vehicle on an ascending slope, a limitation torque .tau.r of the motor as a function of a maximum value T.sub.JMAX of estimated junction temperatures of respective switching devices of an inverter circuit is determined, an output torque .tau.L for the motor to be escaped from the locked state is calculated as .tau.L=.tau..GAMMA.-.DELTA..tau., wherein .DELTA..tau. denotes a displacement torque, .DELTA..tau.=.DELTA..tau.+A when .tau.r&lt;.tau.c and a phase domain of the motor determined on the basis of a magnetic pole position .theta. is the same as the previous one and .DELTA..tau.=0 when .tau.r.gtoreq..tau.c and the phase domain is not the same as the previous one.

Apparatus and method for preventing overload on switching device in

A throttle control system takes a strategy of sampling sensor signal values representative of maximum open angle position (fully open position) and minimum open angle position (near fully closed position) upon starting-up of the engine in response to turning ON of an ignition switch as a primary power switch. The sampled throttle angle indicative sensor signals respectively representative of the maximum throttle valve open angle and the minimum throttle valve open angle are stored as 'secondary throttle fully open position indicative reference value' and as 'secondary throttle fully closed position indicative reference value'. Based on these stored values, correction factor for correcting a sensor signal value of a throttle angle sensor monitoring the angular position of the secondary throttle valve is derived. The correction factor is used throughout the engine operation for correcting a secondary throttle open angle indicative sensor signal value according to a predetermined characteristics. The throttle control system may also control an open angle at a fully closed position of a primary throttle valve adjusted in accordance with the engine temperature condition. Based on this, the secondary throttle valve open angle is determined so that the open angle of the secondary throttle valve at the minimum open angle position may not be smaller than the derived minimum open angle of the secondary throttle valve so as to prevent the engine from falling into engine stalling state even at cold engine condition.

Method of calibrating a throttle angle sensor

In the throttle valve control system for controlling a throttle valve by an actuator driven on the basis of PWM command signals generated according to accel pedal stroke and feed-backed throttle sensor signals, the throttle sensor signal obtained when the throttle valve is full closed is stored; the throttle sensor signal obtained when a full-close PWM command signal is applied to the actuator is detected; the full-close PWM command signal is corrected so that the stored throttle sensor signal matches the detected throttle sensor signal; and PWM command signals are generated on the basis of the corrected full-close PWM command signal. Therefore, it is possible to obtain a full-close PWM command signal whose pulse width accurately matches the actual throttle valve full-close position, irrespective of error or offset due to dispersion of the throttle sensor characteristic or A-D conversion characteristic of the control system.

Growing community of inventors

Kanagawa, Japan

Norifumi Isaji