Method and apparatus for detecting maximum and minimum values, and torque detecting apparatus and steering apparatus comprising the maximum and minimum values detecting apparatus
AssigneeKoyo Seiko Co., Ltd.
InventorNaoki Maeda
Life of this patent
Estimating the term…
Abstract
The method and apparatus for detecting maximum and minimum values, and the torque detecting apparatus and steering apparatus comprising the maximum and minimum values detecting apparatus can detect maximum and minimum values of detection signals without setting a particular value such as a threshold. A signal processing unit provided at the maximum and minimum values detecting apparatus detects a crossing of two detection signals outputted from two MR sensors, and detects maximum and minimum values of the signals based on maximum and minimum values of the signals detected within a time interval defined by the time when a crossing is detected.
Claims20
A maximum and minimum values detecting method for detecting maximum and minimum values of a first signal and a second signal having different phases, comprising:
- a crossing detecting step for detecting a crossing of the first signal and second signal;
- a step for detecting maximum and minimum values of each of the signals within a time interval between a series of two detected crossings;
- and
- a deciding step for deciding maximum and minimum values of each of the signals based on the maximum and minimum values detected within the time interval.
A maximum and minimum values detecting apparatus for detecting maximum and minimum values of a first signal and a second signal having different phases, comprising:
- a crossing detecting unit for detecting a crossing of the first signal and second signal;
- a detecting unit for detecting maximum and minimum values of each of the signals within a time interval between a series of two detected crossings;
- and
- a maximum and minimum values deciding unit for deciding maximum and minimum values of each of the signals based on the maximum and minimum values detected within the time interval.
A torque detecting apparatus for detecting a torque applied to an input shaft based on a difference between angular displacements of the input shaft and an output shaft, comprising:
- an input shaft and an output shaft connected to each other via a connecting shaft;
- a target provided at the input shaft and output shaft, which is so shaped that an axial position thereof changes continuously as the input shaft and output shaft respectively rotates;
- a first detector for detecting a proximal portion of the target, which outputs a detection signal having a phase;
- a second detector for detecting a proximal portion of the target, which outputs a detection signal having a phase different from the phase of the detection signal outputted from the first detector at a predetermined electric angle;
- a maximum and minimum values detecting apparatus for detecting maximum and minimum values of the detection signals outputted from the first detector and second detector;
- a correcting apparatus for correcting values of the detection signals based on a median and an amplitude of the detected maximum and minimum values;
- and
- a detecting unit for detecting angular displacements in a rotational direction of the input shaft and output shaft based on the detection signals corrected by the correcting apparatus,
- the maximum and minimum values detecting apparatus comprising:
- a crossing detecting unit for detecting a crossing of a first signal and a second signal having different phases;
- a detecting unit for detecting maximum and minimum values of each of the signals within a time interval between a series of two detected crossings;
- and
- a maximum and minimum values deciding unit for deciding maximum and minimum values of each of the signals based on the maximum and minimum values detected within the time interval.
A steering apparatus comprising;
- an input shaft joined to a steering wheel;
- an output shaft joined to tire wheels;
- a torque detecting apparatus for detecting a steering torque applied to the input shaft;
- and
- an electric motor for assisting rotation of the output shaft, which is driven in a controlled manner based on the detected steering torque,
- the torque detecting apparatus comprising:
- a target provided at the input shaft and output shaft, which is so shaped that an axial position thereof changes continuously as the input shaft and output shaft respectively rotates;
- a first detector for detecting a proximal portion of the target, which outputs a detection signal having a phase;
- a second detector for detecting a proximal portion of the target, which outputs a detection signal having a phase different from the phase of the detection signal outputted from the first detector at a predetermined electric angle;
- a maximum and minimum values detecting apparatus for detecting maximum and minimum values of the detection signals outputted from the first detector and second detector;
- a correcting apparatus for correcting values of the detection signals based on a median and an amplitude of the detected maximum and minimum values;
- and
- a detecting unit for detecting angular displacements in a rotational direction of the input shaft and output shaft based on the detection signals corrected by the correcting apparatus,
- the maximum and minimum values detecting apparatus comprising:
- a crossing detecting unit for detecting a crossing of a first signal and a second signal having different phases;
- a detecting unit for detecting maximum and minimum values of each of the signals within a time interval between a series of two detected crossings;
- and
- a maximum and minimum values deciding unit for deciding maximum and minimum values of each of the signals based on the maximum and minimum values detected within the time interval.
Dependencies are inferred from the claim text.