Patent application number | Description | Published |
20090043453 | Electric power steering system - An electric power steering system in which a current command for a brushless DC motor is determined based on a detected steering torque, a voltage to be applied is determined based on a difference between the current command value and a current value flowing to the motor, and steering assist is implemented by applying the voltage so determined to the motor. A rotational angular velocity is computed based on a detected rotor position, and it is determined that the motor is abnormal when a rotational angular velocity determination unit determines that the rotational angular velocity is equal to or less than a predetermined value, a current command value determination unit determines that the current command value is equal to or less than a predetermined value, and a voltage determination unit determines that the voltage applied to the motor falls out of a predetermined voltage range. | 02-12-2009 |
20090114471 | Electric power steering system - An electric power steering system which includes a torque detector for detecting a steering torque applied to a steering member and a steering assist brushless DC motor, whereby a plurality of phase currents are caused to flow to the brushless DC motor based on the steering torque detected by the torque detector so as to give steering assistance. A current detector for detecting each of the plurality of phase currents, an adder for adding up respective values of the currents detected by the current detectors and a determination device for determining whether or not a result of an addition by the adder falls outside a predetermined range are provided, whereby it is designed to determined as abnormal when the determination device determines that the result of the addition falls outside the predetermined range. | 05-07-2009 |
20100207558 | ELECTRIC POWER STEERING APPARATUS - A voltage detector | 08-19-2010 |
20100211266 | ELECTRIC POWER STEERING APPARATUS - In an electric power steering apparatus including a charge-discharge circuit | 08-19-2010 |
20100263960 | ELECTRIC POWER STEERING APPARATUS - When a source consisting of series-connected battery | 10-21-2010 |
20100280714 | MOTOR CONTROLLER AND ELECTRIC POWER STEERING APPARATUS - An angle calculator determines an angle of a rotor. An angular speed calculator determines an angular speed of the rotor. A command current calculator determines a command current defined on a dq-axis. An open loop controller determines a command voltage defined on the dq-axis in accordance with a circuit equation of a motor, based on the command current and the angular speed. A dq-axis/three-phase converter converts the command voltage into a three-phase command voltage. A resistance calculator and a Φ-value calculator respectively determines circuit resistance including armature winding resistance and a number of armature winding linkages which are included in the circuit equation of the motor, based on temperature of the motor detected by a temperature sensor and with reference to a table or the like which is stored in advance. | 11-04-2010 |
20100294586 | ELECTRIC POWER STEERING APPARATUS - When stopping operation of an electric power steering apparatus, a motor relay is kept in an on-state even after a power supply relay is in an off-state. A drive control portion sets a target value of a d-axis current to a value other than zero and sets a target value of a q-axis current to zero, and performs a processing same as that at the time of rotating a motor. MOS-FETs contained in a motor driving circuit are controlled such that each of driving currents of the two phases or more is not zero and the brushless motor does not rotate even supplied with these driving currents. Electric charge accumulated in a capacitor is discharged via the MOS-FETs each in an on-state, a motor relay and the windings of the brushless motor. The electric charge accumulated in the capacitor may be discharged via the excitation coil of the motor relay. | 11-25-2010 |
20100314192 | VEHICLE STEERING APPARATUS AND MANUFACTURING METHOD OF SAME - An electric power steering apparatus ( | 12-16-2010 |
20100319976 | MOTOR CONTROL DEVICE AND VEHICLE STEERING SYSTEM - A motor control device comprising a control board for controlling driving of an electric motor, the control board including a multilayer circuit board having inner layers and outer layers, a ground pattern disposed around an output shaft of the electric motor formed on one of the inner layers, and a severed portion formed on a part of the ground pattern, so as to sever through the ground pattern in a radial direction of the output shaft. The construction reduces noise from the motor control device. | 12-23-2010 |
20110000737 | VEHICLE STEERING APPARATUS - Disclosed is a vehicle steering apparatus ( | 01-06-2011 |
20110022271 | MOTOR CONTROLLER AND ELECTRONIC POWER STEERING APPARATUS - An angle calculator detects a rotation angle θa of a rotor. A three-phase/d-q axis converter outputs detected current id, iq on d-q coordinate axes by making a conversion, based on a corrected detection angle θc obtained by adding or subtracting an amount of detection deviation from a time point of current detection to or from the detection angle θa. A command current calculator calculates command current id*, iq* on the d-q coordinate axes based on a steering torque T and a speed S. A feedback controller calculates command voltages vd, vq on the d-q coordinate axes based on the command current id*, iq* and the detected current id, iq. A d-q axis/three-phase converter converts the command voltages vd, vq into three-phase command voltages, based on a corrected detection angle θb obtained by adding an amount of detection deviation from a time point when a motor is driven to the detection angle θa. The deviation can be eliminated by the command voltages, and the motor can be driven with high precision. | 01-27-2011 |
20110025238 | MOTOR CONTROLLER AND ELECTRONIC POWER STEERING APPARATUS - A command current setting portion has a target value corrector that calculates d-axis and q-axis current command values idc, iqc that are to be supplied to an open-loop controller, based on d-axis and q-axis current target values id*, iq*. When d-axis and q-axis voltage target value vd*, vq* calculated from the d-axis and q-axis current target values id*, iq* by the motor circuit equations exceed a voltage limit, this target value corrector | 02-03-2011 |
20110043144 | MOTOR CONTROLLER AND ELECTRIC POWER STEERING SYSTEM - In a motor controller, a current detection unit detects an electric current flowing through a brushless motor. An open loop control unit determines a command value indicating a level of a command voltage in accordance with a motor circuit equation, based on a command current value indicating an amount of electric current to be supplied to the brushless motor and an angular velocity of a rotor in the brushless motor. A correction unit calculates a correction value based on a difference between the command current value and a current value detected by the current detection unit when the electric current is detected by the current detection unit and corrects the command value according to the correction value, and corrects the command value according to the correction value even when an electric current is not detected by the current detection unit. | 02-24-2011 |