Nsk Corporation

Ryo Minaki

Takayoshi Sugawara

Hideki Sawada

Hiroaki Takase

Takahiro Tsubaki

Kouichi Nampei

Yukie Fujiwara

A control apparatus of a steering system for vehicles that precisely compensates an influence of the friction generated in the turning mechanism and enables a vehicle to respond properly. The control apparatus controls a turning mechanism by drive-controlling a turning actuator based on steering information communicated electrically.

Control apparatus of steering system for vehicles

An electric power steering apparatus including a torque sensor to detect a steering torque and a motor control unit to control a motor that applies an assist torque to a steering system of a vehicle, including: a function to switch a control system of the motor between a torque control system to control a motor output torque and a position/speed control system to control a steering angle of a steering in accordance with a predetermined switching trigger. The fade processing time from the torque control system to the position/speed control system and the fade processing time from the position/speed control system to the torque control system are individually set.

Electric power steering apparatus

[Problem] An object of the present invention is to provide a vector control type motor control unit that compensates a dead time of an inverter without a tuning operation, improves a distortion of a current waveform and responsibility of the current control, and suppresses sound, vibration and a torque ripple. [Means for Solving the Problem] The present invention is the vector control type motor control unit that calculates a q-axis control assist command value, calculates dq-axes current command values from the control assist command value, converts the dq-axes current command values into 3-phase duty command values, and drives and controls a 3-phase brushless motor by a PWM-controlled inverter, wherein dead time compensation of the inverter is performed by calculating 3-phase dead time reference compensation values based on a motor rotational angle, calculating 3-phase dead time compensation values by temperature-correcting the 3-phase dead time reference compensation values, and adding the 3-phase dead time compensation values to 3-phase voltage command values after performing dq-axes space vector modulation.

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

A motor control unit that vector-controls a 3-phase brushless motor based on a d-axis voltage command value and a q-axis voltage command value via an inverter with feedback-controlling, comprises: a central processing unit which comprises: a dq-axes dead time compensating section to calculate dq-axes dead time compensation values of the inverter and perform a dead time compensation; and a dq-axes disturbance estimating observer to input a d-axis current command value, a q-axis current command value, a motor rotational number, a motor angular velocity, a d-axis feedback current, a q-axis feedback current, the d-axis voltage command value and the q-axis voltage command value and calculate a d-axis disturbance compensation value and a q-axis disturbance compensation value, which cannot be compensated by the dead time compensation, by respectively adding the d-axis disturbance compensation value and the q-axis disturbance compensation value to the d-axis voltage command value and the q-axis voltage command value.

A motor control device for performing PWM control of an inverter for driving a three-phase brushless motor on the basis of a current command value, wherein the motor control device is provided with: a voltage command value computation unit for calculating a voltage command value using the current command value, and a motor rotation speed and a motor electric angle acquired for each control cycle from the three-phase brushless motor; an electric angle interpolation unit for estimating an interpolated electric angle from the motor electric angle at division intervals obtained by dividing the control cycle; a conversion unit for calculating a three-phase Duty command value from the voltage command value and the motor electric angle, and calculating a three-phase interpolated Duty command value from the voltage command value and the interpolated electric angle; and an output setting unit for switching between, and outputting, the three-phase Duty command value and the three-phase interpolated Duty command value so as to match the division intervals.

Motor control device, motor control method, and electric power steering device

An electric power steering apparatus includes a function to switch a control system of the motor between a torque control system of a torque system to control a motor output torque and a position and speed control system of a steering angle system to control a steering angle of a steering in accordance with an ON/OFF of a post-diagnosis automatic steering command being a judgment result of an automatic steering execution judging section; and a characteristic calculating section to calculate a fade gain signal Fthat applies a first fade characteristic of the torque system, a fade gain signal Fthat applies a second fade characteristic of the steering angle system, and a fade gain signal Fthat applies a third fade characteristic of the steering angle speed, sensitive to the steering torque.

A vector-control type motor control unit that calculates dq-axes control assist command values, calculates dq-axes current command values from the dq-axes control assist command values, converts the dq-axes current command values into 3-phase duty command values, and drives and controls a 3-phase brushless motor by an inverter of a PWM control, wherein a dead time compensation of the inverter is performed by calculating 3-phase dead time reference compensation values based on a motor rotational angle which is phase-corrected by using the dq-axes current command values, calculating dead time compensation values by processing the 3-phase dead time reference compensation values by a gain and a sign, and adding the dead time compensation values to dq-axes voltage command values or 3-phase voltage command values.

An electric power steering apparatus that drives and controls a motor which applies an assist torque to a steering system of a vehicle and has a function switching between an assist mode and an automatic mode, including a torsion bar torsional angle calculating section to calculate a torsion bar torsional angle based on a torque information, an output-side column shaft relative angle generating section to output an output-side relative angle from an electrical angle signal of the motor, an actual handle angle calculating section to calculate an actual handle angle based on the torsion bar torsional angle and the output-side relative angle, a resonance filter to obtain an estimated handle angle in a hands-off state from the output-side relative angle, and a hands-on/off judging section to judge a hands-on state when a time that a deviation angle between the actual handle angle and the estimated handle angle is equal to or more than a predetermined angle is continued for the predetermined time or more.

An electric power steering apparatus of a vector control system that drives and controls a motor by an inverter and applies an assist torque to a steering system of a vehicle, including the first compensation function to perform a dead time (DT) compensation based on respective phase motor terminal voltages and respective phase duty command values, the second compensation function to perform a DT compensation based on steering assist command values, the third compensation function to perform the DT compensation based on dq-axis current command values, and a temperature detecting section to detect temperature of ECU, wherein the correction of the DT compensation is performed based on the temperature, wherein switches of the compensation functions are performed by using a conditional branch due to software and a gradual-changing switch, wherein the dq-axis DT compensation values after the conditional branch and the gradual-changing switch are performed are calculated, and wherein the dq-axis voltage command values are compensated by the dq-axis DT compensation values.

An electric power steering apparatus of a vector control system that compensates a dead time of an inverter without tuning operation, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a steering sound, a vibration and a ripple. The apparatus converts dq-axes current command values calculated based on at least a steering torque into 3-phase voltage command values, converts the 3-phase voltage command values into duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle, wherein 3-phase detection voltages are estimated based on 3-phase motor terminal voltages, wherein loss voltages due to a dead time of the inverter are estimated from differences between 3-phase command voltages calculated from the duty command values and the 3-phase detection voltages, and wherein a dead time compensation of the inverter is performed by feeding-back dead time compensation values obtained by compensating the loss voltages to the 3-phase voltage command values.

An electric power steering apparatus compensates a dead time of an inverter without tuning operation, improves distortion of a current waveform and responsibility of a current control, and suppresses sound, vibration and ripple. The apparatus calculates dq-axes steering-assist command values based on at least a steering torque, calculates dq-axes current command values from the dq-axes steering-assist command values, converts the dq-axes current command values into 3-phase duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle. Dead time reference compensation values are calculated based on a motor rotational angle. Dead time compensation of the inverter adds dead time compensation values in which the dead time reference compensation values are processed by using a gain, a sign and the like, to dq-axes voltage command values or to 3-phase voltage command values.

An electric power steering apparatus of vector control system that calculates steering assist command values of dq axes based on at least a steering torque, calculates dq-axes current command values from the steering assist command values, converts the dq-axes current command values into 3-phase duty command values, driving-controls a 3-phase brushless motor by an inverter of a PWM control, and applies an assist torque to a steering system of a vehicle, wherein the electric power steering apparatus has plural dead time compensating functions of which efficiencies to respectively perform a dead time compensation of the inverter are different each other, and performs the dead time compensation by switching from one of the plural dead time compensating functions to an another dead time compensating function with a predetermined condition.

A vector control type electric power steering apparatus that compensates a dead time of an inverter, a motor back-EMF and an interference voltage by means of a mutual inductance between motor windings, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a noisy sound, vibration and a ripple. The apparatus driving-controls a three-phase brushless motor which applies an assist torque to a steering mechanism of a vehicle by using a current command value calculated based on at least a steering torque, and vector-controls the three-phase brushless motor by using dq-axis command values that are converted from the current command value via an inverter, including: a 3-phase disturbance observer to compensate respective phase disturbance voltages, which include a dead time of the inverter, for 3-phase voltage command values.

[Problem] An object of the present invention is to provide an electric power steering apparatus of a vector control system that compensates a dead time of an inverter, a motor back-EMF and an interference voltage due to a mutual inductance between motor windings, improves a distortion of a current waveform and a responsibility of a current control, and suppresses a noise, vibration and a ripple. [Means for Solving the Problem] The present invention is the electric power steering apparatus that driving-controls a 3-phase brushless motor which applies an assist torque to a steering mechanism of a vehicle by using a current command value calculated based on at least a steering torque, and vector-controls the 3-phase brushless motor, via an inverter, by converting dq-axes command values converted from the current command value into 3-phase values, comprising a dq-axes disturbance observer to compensate respective axes disturbance voltages, which include a dead time of the inverter, for the dq-axes command values, or comprising: a dq-axes disturbance observer to compensate respective axes disturbance voltages, which include a dead time of the inverter, for the dq-axes command values and a spatial vector modulating section.

An electric power steering apparatus that ideally compensates dead time of the inverter without the tuning operation, improves distortion of the current waveform and the responsibility of the current control, and suppresses sound, vibration, the ripple that the low speed steering maneuver is effective. The apparatus converts dq-axes current command values calculated based on at least a steering torque into 3-phase duty command values, controls a 3-phase brushless motor by an inverter of a PWM-control, and applies an assist torque to a steering system of a vehicle, wherein 3-phase detection voltages are estimated based on 3-phase motor terminal voltages, loss voltages due to a dead time of the inverter are estimated from differences between 3-phase correction command voltages calculated from the 3-phase duty command values and the 3-phase detection voltages, and a dead time compensation of the inverter is performed by feeding back dead time compensation values obtained by compensating the loss voltages to the dq-axes current command values.

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Tokyo, Japan

Ryo Minaki