Nsk Corporation

Yousuke Imamura

Masahiro Maeda

Takayoshi Sugawara

Kenji Mori

Hiroyasu Kumagai

Tomohiro Miura

Shuji Endo

Takahiro Tsubaki

Yusuke Kikuchi

Daisuke Matsumoto

Shin Kumagai

Toru Sakaguchi

Takaaki Sekine

Yuzuru Hoshi

Sachio Nakayama

Lilit Kovudhikulrungsri

Yusuke Ota

Kenichi Shimada

Yasuhiro Iwasaki

An electric power steering apparatus includes: a current command value determining section that determines a current command value based on steering torque and vehicle speed; a vibration extracting filter that extracts a first vibration component having a predetermined amplitude and first predetermined frequency range depending on motor angular velocity; a vibration extracting section that extracts a second vibration component having a second predetermined frequency range depending on motor angular acceleration; a first compensation value calculating section that calculates a first vibration suppression compensation value based on the first vibration component extracted by the vibration extracting filter; and a second compensation value calculating section that calculates a second vibration suppression compensation value based on the second vibration component; and suppresses vibrations of the motor by feeding back the first vibration suppression compensation value and the second vibration suppression compensation value calculated to the current command value.

Electric power steering apparatus

A steering apparatus for vehicles that easily obtains equivalent steering torques to vehicle driving information such as a steering angle without being affected by a road surface state and aging-changes of mechanism characteristics of a steering system. The steering apparatus includes a torsional angle control section that calculates a motor current command value based on a target torsional angle corresponding to vehicle driving information and the torsional angle, and includes a torsional angle feedback compensating section that calculates a target torsional angular velocity by a deviation between the target torsional angle and the torsional angle. A torsional angular velocity calculating section calculates a torsional angular velocity by the torsional angle, and a velocity control section calculates a pre-limitation motor current command value by performing proportional compensation based on the target torsional angular velocity and the torsional angular velocity. An output limiting section limits upper and lower limit values of the pre-limitation motor current command value, and outputs the motor current command value which is used to control the motor.

Steering apparatus for vehicles

A motor control device includes a backup electrical angle detection circuit in which an inter-sensor error correction unit calculates an advance gain equal to or more than 1 with respect to input of a steering torque equal to or more than a predetermined torque value, and multiplies an output shaft angular velocity by the advance gain to calculate a post-advance steering angular velocity for correcting the estimated angle error of the direction delayed with respect to the steering direction. Then, an estimated angle calculation unit of the backup electrical angle detection circuit integrates the post-advance steering angular velocity, and, on the basis of a value of the integration, calculates a second motor electrical angle that is an estimated value of a motor electrical angle.

Motor control device and electric power steering device including the same

[Problem] An object of the present invention is to provide a motor control unit that achieves desired performance more simply with higher accuracy by setting a frequency characteristic according to a state of the control unit and automatically adjusting a control gain by the set value, and to provide an electric power steering apparatus equipped with the same. [Means for Solving the Problem] A motor control unit that comprises a current command value calculating section that calculates a current command value of a motor applying a steering assist torque to a steering system of a vehicle, and a feedback section that controls a motor current flowing to the motor through a feedback mechanism based on the current command value comprises: a control unit state detecting section that detects at least one state of the motor control unit, and outputs the state as a control unit state; and a characteristic changing section that changes a setting of a closed loop response characteristic of the feedback section in real time depending on the control unit state.

Motor control unit and electric power steering apparatus equipped with the same

An electric power steering apparatus that reduces an uncomfortable feeling due to a noise at a steering holding and a low-speed steering time, and can smoothly steers so as to prevent a phase-lag at a high-speed steering time. The apparatus has a torque control section to calculate a current command value based on at least a steering torque, and assist-controls a steering system by driving a motor using a current control system based on the current command value. A motor angular velocity calculating section calculates a motor angular velocity from a motor rotational angle; a motor angular acceleration calculating section calculates a motor angular acceleration from the motor angular velocity; and a stability compensating section calculates a steering torque for compensation and a current command value for compensation based on the motor angular velocity and the motor angular acceleration. The steering torque compensates the steering torque, and the current command value compensates the current command value.

A motor control apparatus that calculates duty command values of respective phases for controlling currents of a motor by means of a control calculation, forms PWM-signals in correspondence to the duty command values, drives the motor by means of an inverter based on the PWM-signals, and which is provided a rotation sensor to detect a motor angle of the motor.

Motor control apparatus and electric power steering apparatus using the same

A multi-phase motor control apparatus that reduces the occurrence of the vibrations and the noises by setting the shift amount per time more finely after realizing a reduction in processing ability of a CPU by using a one-shunt type current detection circuit and an electric power steering apparatus using the same. The apparatus includes a PWM-signal generating section that generates plural second each-phase PWM-signals within two control periods based on the current estimation value and the carrier signal, and in a case that a phase shift amount of a predetermined phase in a just before control period is zero and a phase shift amount of a predetermined phase in a present control period is not zero, the phase shift control section gradually increases the phase shift amount from zero in the present control period and a next control period, and uses the second each-phase PWM-signals in the next control period.

Multi-phase motor control apparatus and electric power steering apparatus using the same

An electric power steering device includes a torque detector including an input shaft rotational angle detector and an output shaft rotational angle detector configured to respectively detect rotational angles of an input shaft and an output shaft coupled by a torsion bar arranged in a steering system of a vehicle; an electric motor configured to be controlled based on a torque detection value detected by the torque detector, and to generate a steering assistance force to be exerted on the output shaft; a motor rotational angle detector configured to detect a motor rotational angle of the electric motor; and a noise suppression unit configured to reduce a noise in a signal of the rotational angle of the output shaft detected by the output shaft rotational angle detector, by using the motor rotational angle detected by the motor rotational angle detector.

Electric power steering device

A control device for a multiple motor comprises: a drive unit constituted by a pair of upper and lower arm switching elements for driving the multiphase motor; a single current detection circuit for detecting a current value; a PWM signal generation unit for generating a plurality of first phase PWM signals within two control cycles on the basis of the current value and a carrier signal; a phase shift control unit for shifting a first PWM signal with a prescribed phase generated by the PWM signal generation unit by gradually changing the amount of phase shift within the two control cycles, and outputting the shifted first PWM signal to the drive unit; and a current detection observer for estimating a current value for the multiphase motor on the basis of the current value. The PWM signal generation unit generates a plurality of second phase PWM signals within two control cycles on the basis of the estimated current value and carrier signal. When the phase shift amount in a prescribed phase in the control cycle immediately before the present control cycle is zero and the phase shift amount in a prescribed phase in the present control cycle is not zero, the phase shift control unit gradually increases the shift amount from zero in the present control cycle and the next control cycle to thereby use the second phase PWM signals in the next control cycle.

An electric power steering apparatus that is capable of efficiently suppressing vibrations and simultaneously minimizing steering performance degradation such as an increase in a steering wheel's viscous feeling by extracting a vibration component having an arbitrary amplitude and an arbitrary frequency range depending on an electric power steering state parameter and feeding back a vibration suppression compensation value determined depending on the extracted vibration component to a current command value. The apparatus includes a current command value determining section that determines a current command value based on a steering torque and a velocity; a vibration extraction filter that extracts a vibration component having a predetermined amplitude and a predetermined frequency range depending on an electric power steering state parameter; and a compensation value determining section that determines a vibration suppression compensation value based on the vibration component extracted by the vibration extraction filter.

An electric power steering device which, when an abnormality occurs in one phase of a three-phase brushless motor, permits continuous driving of the motor using the remaining two phases without deteriorating the steering feeling. When a power distribution abnormality of a drive system of one phase of respective phase coils has been detected by an abnormality detection section, an abnormal-time phase current instruction value for using the remaining two phase coils is calculated based on a steering assist electric current instruction value, and an electric motor is driven based on that abnormal-time phase current instruction value. At that time, when an electrical angle falls within an acceleration region, the abnormal-time phase current instruction value is increased or decreased for correction in order to accelerate rotation of the three-phase brushless motor in a steering direction.

A motor control apparatus that is capable of making the whole control system robust not only with respect to motor parameter variations such as the temperature variation and the manufacturing unevenness but also with respect to disturbances while using a cheap and compact one-shunt type current detecting circuit and simultaneously diagnosing an estimation error and an electric power steering apparatus provide with the motor control apparatus.

Motor control apparatus and electric power steering apparatus provided with the same

[Problem] An object of the present invention is to provide a motor controlling apparatus that comprises a single current sensor and obtains a maximal duty range that current becomes detectable with realizing size reduction, weight saving and cost reduction and an electric power steering apparatus using the same. [Means for solving the problem] A motor controlling apparatus that calculates each phase duty command value for controlling a motor current by means of control calculation, forms PWM waveforms corresponding to each phase duty command value and drives the motor based on the PWM waveforms by an inverter, comprising: a duty shift function that uniformly either increases or decreases each phase duty command value with keeping differences in each phase duty command value; and a PWM output position changing function that decides output positions of each phase PWM signal, and wherein a single current detector is connected to power supply input side or power supply output side of the inverter, timing that a PWM signal of only one phase becomes ON state or PWM signals of two phases become ON state simultaneously is generated at fixed positions of PWM periods, and the motor current is detected.

Growing community of inventors

Maebashi, Japan

Yousuke Imamura