Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kaisha

Susumu Zeniya

Takayuki Kifuku

Eiji Iwami

Yuji Takatsuka

Daisuke Tanaka

Shigeki Ohtagaki

Takashi Goto

Katsuhiko Ohmae

Norihiro Yamaguchi

Hiroyuki Kishioka

Isao Kezobo

Masahiko Kurishige

Noriyuki Inoue

Yoshihiko Kimpara

Masahiro Iezawa

Jiro Okada

Sadaaki Kamei

Akiyoshi Takashima

Yasushi Takemoto

Yusuke Fujiki

Seiichi Imaizumi

Shigeki Otagaki

A shortening of an initial diagnosis time is achieved, even after an elapse of a predetermined delay time from an ignition switch being switched to an off-state. After the ignition switch is switched to an off-state after an operation of a control device, which drives an electric motor that applies steering assistance force to a steering system, diagnosis of a power supply circuit that supplies power to the control device is carried out, and a diagnosis item to be implemented in a succeeding initial diagnosis is determined based on a result of the diagnosis.

Electric power steering device

A main controller includes: a d-axis current limiter configured to calculate a d-axis current limiting value with priority, based on a dq-converted current limiting value, and calculate a limited d-axis current command value by clipping the d-axis current command value to be the d-axis current limiting value or less; a q-axis current limiter configured to calculate a q-axis current limiting value, based on the dq-converted current limiting value and the limited d-axis current command value, and calculate a limited q-axis current command value by clipping the q-axis current command value to be the q-axis current limiting value or less; and an inverter controller configured to control motor current, based on the limited d-axis current command value and the limited q-axis current command value.

Electric power steering control apparatus and electric power steering control method

Provided are a motor control device () for controlling a motor () having a plurality of phases, for quickly and accurately detecting a phase in which an open-state fault has occurred when the open-state fault occurs in a target phase. When a power-supply voltage (Vb) is equal to or higher than a predetermined voltage (Vthr), a motor rotation speed (&#x3c9;) is equal to or lower than a predetermined speed (&#x3c9;thr), a target x-phase voltage command (Vx*) is not in the vicinity of zero, a current (Ix) of the target x-phase is equal to or lower than a predetermined current (Iu_thr), and a state in which a control error is equal to or larger than a predetermined error is detected over a predetermined time period or longer, occurrence of an open-state fault in the target phase is determined.

Motor control device and electric power steering device using same

Provided is an electric power steering control device which can realize a more appropriate countermeasure against heat in accordance with a thermal characteristic of a component used to supply a motor current. The electric power steering control device for assisting a steering force of a steering wheel of a vehicle including a control unit (). The control unit () prestores a first overheat-protection characteristic corresponding to self-heating and a second overheat-protection characteristic corresponding to an ambient temperature for each component (to) mounted in the control unit as an overheat-protection characteristic specifying a correspondence relationship between a heat-source current value of the each component and an overheat-protection coefficient, and sequentially corrects a current upper-limit value obtained for the each component by using overheat-protection coefficients of both characteristics to continue current control in accordance with a smallest current upper-limit value of results of the correction.

Electric power steering control device and electric power steering control method

An electric power steering device that can estimate an ambient temperature and apply current limiting without using ambient temperature detecting means is provided. The electric power steering device includes a motor that supplements the driver's steering force, a controller that determines and controls the quantity of current passed to the motor, and vehicle speed detecting means. The electric power steering device includes ambient temperature estimating means provided with a vehicle speed signal input from the vehicle speed detecting means and limits the quantity of current passed to the motor according to an output from the ambient temperature estimating means.

In an electric power steering apparatus in which a third motor target current is determined from a first motor target current determined on the basis of a detection torque from a steering torque detection means and a second motor target current determined using at least a detection value of the motor current detection circuit as one of inputs, and a motor drive signal is calculated on the basis of the third motor target current and a detection current from the motor current detection circuit to control a motor current, there is included a motor current detection circuit failure judgment means for judging a failure of the motor current detection circuit, and when a judgment of failure is made, at least the second motor target current is limited.

Electric power steering apparatus and control method of the same

Conventionally, there was a problem that in cases when it is difficult to place a temperature sensor in the vicinity of a heat-generating portion, overheating could not be prevented. Disclosed is an electric power steering control system including a torque sensor for detecting steering force of a steering system; a motor current determination unit for determining the motor current based on the steering force detected by the torque sensor; a temperature sensor for detecting an ambient temperature; a coefficient setting unit for setting a coefficient in accordance with the detected temperature obtained by means of the temperature sensor; a motor current detection unit for detecting a motor current being passed to a motor; a maximum current limit value calculation unit for calculating a maximum current limit value based on the detected current and the coefficient; a current limiting unit for selecting the smaller value between the motor current determined by the motor current determination unit and the maximum current limit value calculated and outputting this as a target current; and a motor current control section for passing the target current to the motor in such a way that the motor current is equal to the detected current, whereby a motor current limit being set according to temperature is applied.

Electric power steering control system

An electric power steering control system reducing steering torque without making a driver feel uncomfortable torque oscillation, including a rotation speed observer for estimating the rotation speed of a motor based on the output of a torque sensor high pass filter (HPF) and the output of a drive current HPF obtained by removing a steering frequency component from a drive current detection value.

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Tokyo, Japan

Susumu Zeniya