Abstract: 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 ?-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.

Abstract: An electric power steering apparatus includes a charge-discharge circuit including a circuit charging an auxiliary power supply by turning on and off an MOS-FET for voltage boosting and that selectively configures a first output mode in which an electric power is supplied to a motor by a first electrical conduction path to which a voltage of a battery is applied or a second output mode in which the electric power is supplied to the motor by a second electrical conduction path to which a voltage of a source of the series-connected battery and auxiliary power supply is applied. When a failure of the battery is detected, the electric power steering apparatus connects the first conduction path to an electrical conduction path to ground by continuously holding the MOS-FET in an on-state and drives the charge-discharge circuit to select the second output mode, thereby configuring a circuit to supply the motor with the electric power only from the auxiliary power supply.

Abstract: When a source consisting of series-connected battery 7 and auxiliary power supply 9 supplies an electric power to a motor 4, a MOS-FET 13 for preventing a current induced by a voltage of the auxiliary power supply 9 from being reversed upstream should be off if it operates normally. Therefore, voltages at the opposite terminals of the MOS-FET 13 should have a difference which corresponds to a voltage of the auxiliary power supply 9. Hence, the voltages at the opposite terminals of the MOS-FET 13 are detected by two voltage detectors 23 and 25 when the electric power from the auxiliary power supply 9 is supplied to the motor 4. If the potential difference between the voltages at the opposite terminals of the MOS-FET 13 is equal to or less than a predetermined value, a control circuit 24 issues a failure signal upon determination that the MOS-FET 13 suffers a short-circuit fault. A MOS-FET 15 is also monitored in the same way.

Abstract: A current sensor of a motor controller detects the current applied to a motor drive circuit and thus a phase where a failure cannot be detected would occur without taking any measures. However, an abnormal current monitor section contained in a microcomputer receives a voltage signal of an average value of the currents detected in the current sensor by allowing a signal to pass through a first LPF having a cutoff frequency sufficiently lower than the frequency of a PWM signal. Therefore, whether or not the value is within a predetermined normal range is checked, whereby whether or not some failure containing a failure of the current sensor occurs can be easily determined about every phase.

Abstract: A voltage detector 17 for detecting a voltage VB of a battery 9 as a main power supply and a voltage detector 18 for detecting a voltage VC of an auxiliary power supply 14 are provided. On the basis of an upper limit value IB previously defined as the maximum value of current through the battery 9, a control circuit 6 defines an upper limit of the electric power supplied to the motor 4 as ?·VB·IB (? representing the efficiency of the driving circuit 5) when a first output mode is selected in which the auxiliary power supply 14 is not used or defines the upper limit of the electric power supplied to the motor 4 as ?·(VB+VC)·IB when a second output mode is selected in which the auxiliary power supply 14 is used as connected in series with the battery 9.

Abstract: In an electric power steering apparatus including a charge-discharge circuit 16 that selectively configures a first output mode in which only a main power supply including a battery 9 is used to supply an electric power to a motor 4 or a second output mode in which the main power supply and an auxiliary power supply 14 are used to supply the electric power to the motor 4, and a control circuit 6 that selects the output mode of the charge-discharge circuit 16 according to the electric power required for steering assist, the control circuit 6 selects the second output mode when the electric power required for steering assist in the first output mode becomes equal to or higher than an upward threshold value P1 or selects the first output mode when the electric power required for steering assist in the second output mode becomes equal to or lower than a downward threshold value P2 that is lower than the upward threshold value P1.

Abstract: A motor controller stores values corresponding to predetermined equivalent resistance which corresponds to power loss generated by switching on and off switching elements. Voltage command values are determined by adding voltage drop values determined from values corresponding to the equivalent resistance and values of current flowing in the switching elements to target applied voltage values corresponding to current command values which correspond to target output of a motor. The switching elements arranged in a power supply line to the motor are switched on and off by control signals generated according to the voltage command values.

Abstract: A multilayer circuit substrate includes: a laminated circuit portion in which conductive layers and resin insulating layers are alternately laminated; and a metal substrate portion, wherein the laminated circuit portion is fixed to the metal substrate portion so that at least part of a lower surface of the laminated circuit portion is in contact with at least part of an upper surface of the metal substrate portion. An electronic component is mounted on the metal substrate portion.

Abstract: An angle calculation portion of a motor control apparatus determines an angle ? of a rotor, and an angular velocity calculation portion determines an angular velocity ?e of the rotor. A command current calculation portion determines command currents id* and iq* on dq axes, based on a steering torque T and a vehicle speed S. An open-loop control portion determines command voltages vd and vq on the dq axes based on the command currents id* and iq* and the angular velocity ?e, according to circuit equations of a motor. A dq-axis/three-phase conversion portion converts the command voltages vd and vq to command voltages of three phases. A three-phase voltage correction portion corrects the command voltage so that an actual time average value of a voltage applied to each phase is equal to a time average value of a voltage that is to be applied to the phase if the voltage is not decreased, in order to compensate for a decrease in the applied voltage.

Abstract: In a controller for an electric power steering apparatus, a target value calculation element, which calculates target values of the drive currents of a motor on the basis of a detected value of the steering torque, is constituted by a first integrated circuit provided in a chip. A drive signal value calculation element, which calculates drive signal values for driving the motor on the basis of the target values calculated by the target value calculation element, detected values of the drive currents of the motor, and a detected value of the rotary position of a rotor of the motor, is constituted by a second integrated circuit provided in another chip from the chip. A driving element drives the motor in accordance with the drive signal values. The first integrated circuit is connected communicably to the second integrated circuit. The calculation cycle of the drive signal values is set to be shorter than the calculation cycle of the target values.

Abstract: Conducting layers and resin-made insulating layers are alternately laminated to form a laminated circuit portion, and a metal substrate is installed so as to be in contact with an insulating layer, which is the lowermost layer. The conducting layers, the insulating layers, and the metal substrate are thermal compression bonded. In order to connect the uppermost conducting layer on which electronic component is placed with the lowermost insulating layer, a conducting layer is formed on the inner surface by copper plating to install a heat dissipating via into which a resin is filled. A conducting layer, which is the uppermost layer, is subjected to gold plating, with nickel plating undercoated. An electronic component for driving a motor is placed on the uppermost conducting layer, by which the metal substrate can be used as a motor drive circuit substrate for an electric power steering system.

Abstract: An electric power steering system is provided which is capable of providing a favorable steering feeling without using compensation logics such as of inertia compensation and friction compensation. The electric power steering system includes road-noise suppression control means (213) for controlling a steering assist motor (9) in a manner to damp torque transmission in a higher frequency region representing road noises than a frequency region representing road information. A friction value of a steering mechanism (A) is decreased enough to allow the intrinsic vibrations of the steering mechanism (A) to appear. Rotor inertia of the steering assist motor (9) is set to a value small enough to allow the frequencies of the intrinsic vibrations to be present in the frequency region where the torque transmission is damped by the road-noise suppression control means (213).

Abstract: If the magnitude of a command voltage vector is greater than a predetermined voltage value indicated by a voltage limit circle, the magnitude of a voltage vector, which corresponds to a q-axis current and which forms the command voltage vector, is adjusted so that the magnitude of the command voltage vector is equal to or less than the predetermined voltage value. Then a q-axis current estimated value is obtained based on i) the ratio of the magnitude of the voltage vector from the q-axis current after adjustment to the magnitude of the voltage vector from the q-axis current before adjustment, and ii) a q-axis current command value.

Abstract: A first restrict value calculating unit obtains a first restrict value Im1 on the basis of the integration value (Id2+Iq2) of a d-axis current detection value and a q-axis current detection value. A second restrict value calculator 50 calculates a second restrict value Im2 on the basis of the maximum value of the integration values of the squares Iu2, Iv2, and Iw2 of 3-phase current detection values. A target current value It calculated by a target current calculating unit 21 is restricted by so that a current value limiter so as to be not greater than the first restrict value Im1 and the second restrict value Im2. By using the two restrict value restricting the motor driving current, it is possible to control properly the motor driving current in accordance with a general driving condition and various steering conditions.

Abstract: 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.

Abstract: A main power supply and an auxiliary power supply for supplying power to a motor are provided. AMOS-FET for supplying power from the main power supply and a MOS-FET for supplying power from the main and auxiliary power supplies are provided. When a phenomenon in which a rotor of a motor is rotated by the going-back force of steered wheels occurs, and voltage VG of power generated by the motor satisfies the relation VG>VB+VC where VB is a voltage of the main power supply and VC is a voltage of the auxiliary power supply, a control circuit and a gate drive circuit turn off both MOS-FETs so as to charge the auxiliary power supply using the voltage VG through a parasitic diode of the MOS-FET.

Abstract: A current sensor of a motor controller detects the current applied to a motor drive circuit and thus a phase where a failure cannot be detected would occur without taking any measures. However, an abnormal current monitor section contained in a microcomputer receives a voltage signal of an average value of the currents detected in the current sensor by allowing a signal to pass through a first LPF having a cutoff frequency sufficiently lower than the frequency of a PWM signal. Therefore, whether or not the value is within a predetermined normal range is checked, whereby whether or not some failure containing a failure of the current sensor occurs can be easily determined about every phase.