Device for detecting rotation of rotary shaft and rotation controlling apparatus using the same
First Claim
1. A device for detecting the rotating angle of a rotary shaft comprising:
- signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween;
means for detecting levels of the center voltages and the amplitudes of said two signals from said signal generating means;
means for correcting the detected level of the center voltage and the detected amplitude of each of said two signals using the detected level of the center voltage of the other of said two signals; and
means for calculating the rotating angle of said rotary shaft using said corrected center voltages and amplitudes of said two signals.
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Accused Products
Abstract
This specification discloses inventions of a rotation detecting device for a rotary shaft and of a rotation controlling apparatus using this rotation detecting device. The rotation detecting device according to the invention comprises a signal generator for generating two signals vary their amplitude in accordance with the rotation angle of the rotary shaft and have a predetermined phase difference therebetween, part for correcting the respective center voltages output from the signal generator, part for correcting a deviation from the phase deviation between the two signals, and part for correcting the rotating amounts of the rotary shaft on the basis of the corrected two signal. The rotating amounts are represented in terms of rotating angles. A rotating torque can be obtained by calculating a difference between the rotating angles measured at two points apart from each other on the rotary shaft. The rotary shaft can be controlled in accordance with the rotating angle or the rotating torque.
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Citations
18 Claims
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1. A device for detecting the rotating angle of a rotary shaft comprising:
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signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween; means for detecting levels of the center voltages and the amplitudes of said two signals from said signal generating means; means for correcting the detected level of the center voltage and the detected amplitude of each of said two signals using the detected level of the center voltage of the other of said two signals; and means for calculating the rotating angle of said rotary shaft using said corrected center voltages and amplitudes of said two signals. - View Dependent Claims (2)
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3. A device for detecting the rotating angle of a rotary shaft comprising:
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signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a variation from a predetermined phase difference therebetween; means for detecting when said two signals output from said signal generating means have substantially equal amplitude values; means for correcting the variation from the predetermined phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values; and means for calculating the rotating angle of said rotary shaft on the basis of the corrected two signals. - View Dependent Claims (5)
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4. A device for detecting the rotating angle of a rotary shaft comprising:
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signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween; means for detecting when said two signals output from said signal generating means have substantially equal amplitude values; means for correcting the respective center voltages of each of said two signals output from said signal generating means using a characteristic of the other of said two signals; and means for correcting a variation from the phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values; means for calculating the rotating angle of said rotary shaft using the corrected two signals.
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6. A device for determining rotating torque according to the rotating angle at spaced points on a rotary shaft, comprising:
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first and second rotating angle detecting devices arranged at two different points on said rotating shaft, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween, center voltage detecting means for detecting levels of the center voltages of said two signals, means for correcting the level of center voltage of each of said two signals using the detected level of the center voltage of the other of said two signals, and means for calculating a rotating angle from said corrected two signals; and means for calculating the rotating torque of said rotary shaft according to a difference between two rotating angles calculated by said first and second rotating angle detecting means. - View Dependent Claims (8)
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7. A device for determining rotating torque according to the rotating angle at spaced points on a rotary shaft, comprising:
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first and second rotating angle detecting devices arranged at two different points on said rotary shaft, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween, center voltage detecting means for detecting the level of the center voltage of said two signals, means for correcting the level of the center voltages of each of said two signals output from said signal generating means using a detected level of the center voltage of the other of said two signals, means for detecting when said two signals have substantially equal amplitude values, means for correcting a deviation from said predetermined phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values, and means for calculating the rotating angles from said corrected two signals; and means for calculating the rotating torque of said rotary shaft according to a difference between two rotating angles calculated by said first and second rotating angle detecting means.
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9. A device for determining rotating torque according to the rotating angle at spaced points on a rotary shaft, comprising:
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first and second rotating angle detecting devices arranged at two different points on said rotary shaft, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotary shaft and have a predetermined phase difference therebetween, means for detecting when said two signals have substantially equal amplitude values, means for correcting a deviation from said predetermined phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values; means for calculating the rotating angles from said corrected two signals; and means for calculating the rotating torque of said rotary shaft according to a difference between two rotating angles calculated by said first and second rotating angle detecting means. - View Dependent Claims (10)
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11. An electric power steering apparatus wherein the rotating torque of a steering shaft is determined from the rotating angle at spaced points on the steering shaft and the output torque of an electric motor is controlled on the basis of the rotating torque, comprising:
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an electric motor, mounted in said steering shaft, for generating a supplementary torque for driving the steering shaft; first and second rotating angle detecting devices arranged at two different points between said electric motor in said steering shaft and a steering wheel, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said rotating shaft and have a predetermined phase difference therebetween, center voltage detecting means for detecting levels of the center voltages of said two signals, means for correcting the level of center voltage of each of said two signals using the detected level of the center voltage of the other of said two signals, and means for calculating a rotating angle of said steering shaft from said corrected two signals; and means for calculating the steering torque of said steering shaft according to a difference between two rotating angles calculated by said first and second rotary angle detecting means; and means for controlling the output torque of said electric motor in accordance with the value of said steering torque. - View Dependent Claims (13)
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12. An electric power steering apparatus wherein the rotating torque of a steering shaft is determined from the rotating angle at spaced points on the steering shaft and the output torque of an electric motor is controlled on the basis of the rotating torque, comprising:
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an electric motor, mounted in said steering shaft, for generating a supplementary torque for driving the steering shaft; first and second rotating angle detecting devices arranged at two different points between said electric motor in said steering shaft and a steering wheel, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude with the rotating angle of said steering shaft and have a predetermined phase difference therebetween, center voltage detecting means for detecting the level of the center voltage of said two signals, means for correcting the level of the center voltages of each of said two signals from said signal generating means using a detected level of the center voltage of the other of said two signals, means for detecting when said two signals have substantially equal amplitude values, phase correcting means for correcting a deviation of the phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values; means for calculating the rotating angles of said steering shaft from said corrected two signals; means for calculating the steering torque of said steering shaft according to a difference between two rotating angles calculated by said first and second rotating angle detection devices; and means for controlling the output torque of said electric motor in accordance with the value of said steering torque.
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14. An electric power steering apparatus wherein the rotating torque of a steering shaft is determined from the rotating angle at spaced points on the steering shaft and the output torque of an electric motor is controlled on the basis of the rotating torque, comprising:
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an electric motor, mounted in said steering shaft, for generating a supplementary torque for driving the steering shaft; first and second rotating angle detecting devices arranged at two different points located between said electric motor in said steering shaft and a steering wheel, each of said first and second rotating angle detecting devices comprising signal generating means for generating two signals which vary in amplitude in accordance with the rotating angle of said steering shaft and have a predetermined phase difference therebetween, means for detecting when said two signals have substantially equal amplitude values, phase correcting means for correcting a deviation of the predetermined phase difference between said two signals output from said signal generating means using the values of said two signals at the times said two signals have substantially equal amplitude values; means for calculating the rotating angles of said steering shaft from said corrected two signals; means for calculating the steering torque of said steering shaft according to a difference between two rotating angles calculated by said first and second rotating angle detection devices; and means for controlling the output torque of said electric motor in accordance with the value of said steering torque. - View Dependent Claims (15)
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16. A method of determining the rotating angle of a rotary shaft, comprising the steps of:
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(a) generating first and second signals which vary in amplitude with the rotating angle of said rotating shaft so as to represent a sine wave with shaft rotation and which have a predetermined phase difference therebetween; (b) storing values of the amplitude of said first signal as a maximum amplitude value and a minimum amplitude value at times in each cycle of said second signal when the amplitude of said second signal is equal to a value of the center voltage of said second signal determined from a maximum amplitude value and a minimum amplitude value of said second signal; (c) determining, from the maximum amplitude value and the minimum amplitude value of said first signal stored during each cycle, the amplitude of said first signal with respect to its center voltage and the value of the center voltage of aid first signal; and calculating the rotating angle of the rotating shaft using the determined amplitude of said first signal with respect to its center voltage and the value of the center voltage thereof. - View Dependent Claims (17, 18)
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Specification