Nsk Corporation

Nsk Steering Systems Co., Ltd.

Toru Sakaguchi

Shoya Maruyama

Shuji Endo

Kenji Mori

Hideyuki Kobayashi

Tetsuya Kitazume

Hideaki Kawada

Sakae Nejo

Atsushi Kojima

Yuzuru Hoshi

Sachio Nakayama

Lilit Kovudhikulrungsri

Toshikazu Onoe

Masahiro Maeda

Yousuke Imamura

Yuho Aoki

Yusuke Itakura

Takeshi Hara

Kazuhiro Kumaido

Satoshi Shimokawabe

Hirokazu Abe

Yoshiki Ninomiya

Yasuhide Nomura

Masahide Saito

Hideaki Okazaki

Yasushi Miyazawa

Masayuki Aoki

Mitsuhiro Fukuda

Masanori Shingou

Shinichi Tanaka

A turning control device includes: a target steering angle calculation unit configured to calculate a target steering angle of a turning mechanism, based on a second steering angle of a steering mechanism; a steering angular displacement calculation unit configured to, when a third steering angle, the third steering angle being either a first steering angle of the turning mechanism or the second steering angle, is in a range from a maximum steering angle that the third steering angle can take to a first threshold steering angle, calculate a steering angular displacement of the third steering angle with the first threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; and a corrected target steering angle calculation unit configured to correct the target steering angle with the steering angle correction value.

Turning control device

A turning control device includes: a steering angular displacement calculation unit configured to, when a third steering angle that is either a first steering angle of a turning mechanism or a second steering angle of a steering mechanism, is in an angular range from a maximum angle to a threshold steering angle, calculate a steering angular displacement of the third steering angle with the threshold steering angle used as a reference; a steering angle correction value calculation unit configured to calculate a steering angle correction value according to at least the steering angular displacement; a steering angle correction value limiting unit configured to limit the steering angle correction value according to at least a steering state, the third steering angle, and angular velocity thereof; a corrected target steering angle calculation unit configured to correct the target steering angle of the turning mechanism with a limited steering angle correction value.

An electric power steering apparatus that suppresses occurrence of an abnormal noise at end hitting without providing uncomfortable feeling of steering for a driver, attenuates impact force, and enables suppression of the abnormal noise without making a turning radius worse. The apparatus includes a viscoelastic model following control section that sets a viscoelastic model as a reference model within a predetermined range in front of a rack end, and outputs a control output to correct a current command value; and a rack end approach judging section that performs judgment of being in the predetermined range in front of the rack end based on steering position information; adjusts the control output based on at least the steering position information, a steering velocity and a steering state, and corrects the current command value by the adjusted control output.

Electric power steering apparatus

A safe electric power steering apparatus with a good steering feeling is provided that includes a function for getting out from restraint of a lateral flow or a one-sided flow, and enables acquisition of a better effect that a driver's load is reduced in the lateral flow or the one-sided flow. The safe electric power steering apparatus corrects a current command value by a motor current correction value based on a motor correction signal.

An electric power steering apparatus that calculates a first current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the first current command value, including: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end, wherein an offset is given to input or output of the viscoelastic model for preventing an overheat, resulting in suppressing a rack end hitting.

A high-performance electric power steering apparatus that includes a control system based on a physical model, includes a model following control that an output (a distance to a rack end) of a controlled object follows-up to a reference model, eliminates or reduces the occurrences of a noisy sound and a shock force at an end hitting without giving any uncomfortable steering feeling to a driver, and reduces the end hitting. The electric power steering apparatus calculates a current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the current command value, including: a configuration of a model following control including a viscoelastic model as a reference model within a predetermined angle at front of a rack end so as to suppress a rack end hitting.

An electric power steering apparatus includes a control section that includes a feed-back control section which sets a viscoelastic model as a reference model within a predetermined angle at front of a rack end. The feed-back control section includes a feed-back element to calculate a target rack displacement based on an input-side rack axial force and a control element to output an output-side rack axial force based on a position deviation between the target rack displacement and a rack displacement.

[Problem] An object of the present invention is to provide an electric power steering apparatus that constitutes a control system based on a physical model, constitutes a model following control that an output (a distance to a rack end) of a controlled object follows-up to a reference model, suppresses the occurrences of a noisy sound and a shock force at an end hitting without giving any uncomfortable steering feeling to a driver, and is capable of smoothly steering. [Means for solving the problem] In the electric power steering apparatus that calculates a first current command value based on at least a steering torque and performs an assist-control of a steering system by driving a motor based on the first current command value, the apparatus comprises a configuration of a model following control comprising a feed-back control section including a viscoelastic model as a reference model within a predetermined angle at front of a rack end, wherein the configuration of the model following control comprises a feed-back control section, and the model following control has a noise-reducing function to reduce a noise so as to suppress a rack end hitting.

An electric power steering apparatus with a good steering feeling that includes a function for getting out from restraint of a lateral flow or a one-sided flow, and enables acquisition of a better effect that a driver's load is reduced in the lateral flow or the one-sided flow.

An electric power steering apparatus that protects Zener diodes without impairing steering performances by time-integrating a loss power of the Zener diodes for protecting FETs and gradually limiting a duty ratio with an increase in an integrating loss. The apparatus includes a loss power calculating section that calculates a loss power when a difference between an ignition voltage and an inverter applying voltage is equal to or more than a predetermined voltage; an integrating loss calculating section to calculate an integrating loss of the loss power; a permissible loss calculating section to calculate a permissible loss based on a temperature; a minimum value selecting section to select a minimum value of a loss difference of the permissible loss and the integrating loss; and a limit value calculating section to calculate a limit value of the PWM-signal based on the minimum value of the loss difference and the permissible loss.

[Problem] An object of the present invention is to provide a power state diagnosis method and a power state diagnosis apparatus that pass and increase not only a d-axis current but also a q-axis current to a current value that a steering behavior does not occur to perform a diagnosis in the vector control of a motor, and determine that a power supply degraded, that the power supply is normal and that the diagnosis is not completed without giving an uncomfortable feeling to a driver, detecting a timing that there is not a driver, and needing to comprise a plurality of actuators. [Means for solving the problem] The present invention is a power state diagnosis method that diagnoses a power state of a vehicle which comprises an electrical control system supplied from a power supply and a motor controlled by a vector control method, comprising: gradually increasing a d-axis current to a current value that a steering behavior does not occur and applying the d-axis current, concurrently gradually increasing a q-axis current that is a rectangular-wave with positive and negative directions to the current value and applying the q-axis current, and determining degradation of the power supply when a voltage value of the power supply is equal to or less than a power supply threshold and a given period of time Telapses.

Power state diagnosis method and apparatus

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

An electric power steering apparatus that is capable of obtaining a more safe and comfortable handling performance by signal processing of road information and disturbances is performed to realize easy tuning, and vibration absorption level for brake is improved by a filter and a gain unit considering a frequency characteristic and a decelerating acceleration.

[Problem] An object of the present invention is to provide a power state diagnosis method and a power state diagnosis apparatus that do not need to make a control period fast and also do not need to excessively increase a responsibility, and do not give an uncomfortable feeling to a driver. [Means for Solving the Problem] The present invention is a power state diagnosis method that diagnoses a power state of a vehicle which comprises an electrical control system supplied from a power supply and a motor controlled by a vector control method, comprising: starting a diagnosis of said power state at a time that an ignition key is switched from 'OFF' to 'ON' or at a time that said ignition key is switched from &#x201c;ON&#x201d; to &#x201c;OFF&#x201d;, storing a value obtained by adding an offset to an angle of said motor that is read at a start of said diagnosis as a pseudo-motor-angle, performing said vector control based on said pseudo-motor-angle during said diagnosis, and diagnosing said power state based on a voltage that is supplied to said motor.

A highly safe electric power steering device including a control device for determining the failure of a motor current detector based on the difference between the motor current estimate value and the detected motor current value is provided. The abnormality determining unit computes the absolute value of difference between the motor current estimate value and the detected motor current value, measures the number of times when the absolute value of difference exceeded the predetermined threshold value within the predetermined period, and measures further the cumulative value of the number of times of exceeding the threshold value within the predetermined period. When the cumulative value exceeded the predetermined reference number of times for determining abnormality, the motor current detector is determined to be abnormal.

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Maebashi, Japan

Toru Sakaguchi