Encoder apparatus and methods employing optical and graphical programming

An optical encoder apparatus for converting the rotational motion of an electric motor into an electrical commutation signal having a waveform and a frequency for driving said motor at an operating speed, said apparatus comprising:

• emitter means for emitting a supply radiant energy;
• photo-detection means, optically coupled to the supply of radiant energy from said emitter means, for generating an electrical signal in response to a pattern of radiant energy incident on said photo-detection means;
• and
• optical means, optically coupled to said photo-detection means, and configured to be actuated by the rotor of said motor, for modifying the pattern of radiant energy incident on said photo-detection means in accordance with a graphical function as said optical means is actuated by the rotor of said motor,
• said optical means including an optical element configured to scan relative to said photo-detection means in accordance with the motion of the rotor of said motor, said optical element containing an optically detectable pattern which is optically coupled to said photo-detection means,
• said optical means further including aperture means associated with said photo-detection means, for permitting a controlled amount of radiant energy to pass to said photo-detection means,
• said aperture means and the pattern of said optical element being defined by said graphical function, said graphical function being derived from the waveform of said commutation signal and defining a relationship between the operating speed of said motor and the frequency of said commutation signal,
• whereby said commutation signal is generated from said photo-detection means as the pattern of said optical element is scanned relative to said aperture means.

A method of controlling the speed of an electric motor having a rotor which produces rotational motion, using the optical encoder of claim 49, said method comprising the steps of:

• (a) coupling said encoder to the rotational motion of the rotor of said motor, such that said optical element is actuated by the rotor of said motor;
• (b) operating said motor to produce rotational motion of the rotor;
• (c) modifying the pattern of radiant energy incident on said photo-detection means in accordance with said graphical function as said optical element is actuated by said motor;
• (d) generating said electrical commutation signal from said photo-detection means;
• (e) amplifying said commutation signal;
• (f) driving said motor with said amplified commutation signal;
• and
• (g) varying the amplitude level of said commutation signal to control the speed of said motor.

An optical encoder apparatus for converting the motion of a rotor of a multi-phase electric motor into a plurality of electrical commutation signals each having a waveform, frequency and relative phase for driving said multi-phase motor at an operating speed, said apparatus comprising:

• a plurality of photo-detectors, each of which generates an electrical signal in response to a pattern of radiant energy incident thereon;
• and
• optical means, optically coupled to said plurality of photo-detectors, and configures to be actuated by the rotor of said motor, for modifying a pattern of radiant energy incident on each of said plurality of photo-detectors in accordance with respective graphical functions as said optical means is actuated by the rotor of said motor,
• said optical means including an optical element which contains a plurality of concentrically disposed optically detectable patterns, said optical element being configures to rotate upon actuation thereof by the rotor of said motor, such that said optically detectable patterns are made to scan past said plurality of photo-detectors in accordance with the motion of the rotor, each one of said optically detectable patterns being associated with and optically coupled to a different one of said plurality of photo-detectors,
• said optical means further including a plurality of aperture means, each one of which corresponds to a different one of said optically detectable patterns, for permitting a controlled amount of radiant energy to pass to each of said plurality of photo-detectors,
• each one of said graphical functions being associated with a different one of said optically detectable patterns and with a different one of said commutation signals, each optically detectable pattern and corresponding aperture means being defined by their associated graphical function, each graphical function being derived from the waveform of the associated commutation signal and defining a relationship between the operating speed of said motor and the frequency of said associated commutation signal,
• each one of said optically detectable patterns being associated with a different one of said commutation signals, the relative phase of each of said plurality of commutation signals being established by the position of the associated optically detectable pattern relative to the position of the corresponding aperture means and photo-detector, at a particular angular position of the rotor of said motor, the relative positions of each optically detectable pattern to the corresponding aperture means and photo-detector being different from each other,
• whereby said plurality of commutation signals are generated from said plurality of photo-detectors as said plurality of optically detectable patterns are scanned relative to said plurality of aperture means.

A method of operating a motor having a rated power frequency, speed and power voltage, using an optical encoder apparatus configured to be coupled to a shaft of said motor, wherein said apparatus includes

• photo-detection means for generating an electrical signal in response to a pattern of radiant energy incident on said photo-detection means;
• and
• optical means, optically coupled to said photo-detection means and configures to be actuated by the shaft of said motor, for modifying the pattern of radiant energy incident on said photo-detection means in accordance with a graphical function as said optical means is actuated by said motor, such that an electrical commutation signal is generated from said photo-detection means,
• said graphical function being a transform of a waveform function, said waveform function being defined by a predetermined number of waveform cycles over one revolution of the motor shaft, said predetermined number of waveform cycles being greater than the number necessary to produce the rated power frequency for said commutation signal, when said motor is operating at the rated speed;
• said method comprising the steps of:
• (a) coupling said encoder apparatus to the shaft of said motor;
• (b) operating said motor such that the shaft of said motor rotates;
• (c) generating said commutation signal from said encoder;
• (d) amplifying said commutation signal to a level that will produce a desired operating speed of said motor;
• and
• (e) powering said motor with the amplified commutation signal.

An optical encoder apparatus for converting the motion of a rotor of an A.C. induction motor into an electrical commutation signal having a waveform and frequency for driving said motor at an operating speed, wherein said A.C. motor has a designed theoretical synchronous speed, said apparatus comprising:

• photo-detection means for generating an electrical signal from a pattern of radiant energy incident on said photo-detection means;
• and
• optical means, optically coupled to said photo-detection means and configured to be actuated by the rotor of said motor, for modifying the pattern of radiant energy incident on said photo-detection means in accordance with a graphical function as said optical means is actuated by the rotor of said motor,
• said optical means including an optical element configures to scan relative to said photo-detection means in accordance with the motion of the rotor of said motor, said optical element containing an optically detectable pattern which is optically coupled to said photo-detection means,
• said optical means further including aperture means associated with said photo-detection means, for permitting a controlled amount of radiant energy to pass to said photo-detection means,
• the pattern of said optical element and said aperture means being defined by said graphical function, said graphical function being derived from a waveform function, said waveform function being determined by the waveform of said commutation signal and being defined by a predetermined number of waveform cycles over one revolution of said motor rotor, said number of waveform cycles being greater than the number necessary to produce the frequency of said commutation signal at the designed theoretical synchronous speed,
• whereby said commutation signal is generated from said photo-detection means as the pattern of said optical element is scanned relative to said aperture means.

A method of configuring an optical encoder of the type which converts cyclic motion of an electro-mechanical machine into a particular electrical signal having a frequency which is related to the speed of the cyclic motion of said machine, said method comprising the steps of:

• (a) providing a photo-detector for generating the particular electrical signal at an output of said encoder;
• (b) providing optical means for modifying a pattern of radiant energy incident on said photo-detector as a function of the cyclic motion of said machine;
• (c) specifying the particular electrical signal at the output of said encoder, the specified electrical signal having a particular waveform;
• (d) determining a waveform function based on the particular waveform of the specified electrical signal, said waveform function defining the relationship between the speed of the cyclic motion of said machine and the frequency of the specified electrical signal;
• (e) deriving a graphical function from said waveform function, said graphical function defining at least one graphically shaped pattern;
• and
• (f) configuring said encoder in accordance with said graphical function, including encoding said optical means with said at leas tone graphically shaped pattern, such that, in operation, said optical means modifies the pattern of radiant energy incident on said photo-detector in accordance with said at least one graphically shaped pattern,
• whereby, in operation of said encoder, the particular electrical signal is produced at the output of said encoder.

A method of configuring an encoder of the type which converts cyclic motion of an electro-mechanical machine into a particular electrical signal having a frequency which is related to the speed of the cyclic motion of said machine, said method comprising the steps of:

• (a) providing encoder means for generating the particular electrical signal from the cyclic motion of said machine;
• (b) specifying the particular electrical signal at an output of said encoder, the specified electrical signal having a particular waveform;
• (c) determining a waveform function based on the particular waveform of the specified electrical signal, said waveform function defining the relationship between the speed of the cyclic motion of said machine and the frequency of the specified electrical signal;
• (d) deriving a graphical function from said waveform function, said graphical function defining at least one graphically shaped pattern;
• and
• (e) configuring said encoder in accordance with said graphical function, including encoding said encoder means with said at least one graphically shaped pattern, such that, in operation, said encoder means generates an electrical signal in accordance with said at least one graphically shaped pattern,
• whereby, in operation of said encoder, said particular electrical signal is produced at the output of said encoder.

A method of controlling an electro-mechanical machine of the type which produces cyclic mechanical motion, said method comprising the steps of:

• (a) modifying a pattern of radiant energy in accordance with a mathematically defined graphical function and in accordance with the cyclic motion of said machine;
• (b) generating an electrical commutation signal in response to said modified pattern of radiant energy;
• and
• (c) driving said machine with said commutation signal.

An optical encoder apparatus for converting cyclic motion of an electro-mechanical machine into an electrical commutation signal having a waveform and a frequency for driving said machine at an operating speed, said apparatus comprising:

• photo-detection means, having a plurality of photo-responsive surfaces, for generating an electrical signal in response to a plurality of patterns of radiant energy incident on the plurality of photo-responsive surfaces respectively;
• and
• optical means, optically coupled to said photo-detection means, and configured to be actuated by the cyclic motion of said machine, for modifying said plurality of radiant energy patterns incident on said photo-detection means in accordance with a graphical function as said optical means is actuated by the cyclic motion of said machine,
• said optical means including an optical element configured to scan relative to said photo-detection means in accordance with the cyclic motion of said machine, said optical element containing an optically detectable pattern which is optically coupled to said photo-detection means,
• said optical means further including aperture means associated with said photo-detection means, for permitting a controlled amount of radiant energy to pass to each of the photo-responsive surfaces of said photo-detection means,
• said aperture means and the pattern of said optical element being defined by said graphical function, said graphical function being derived from the waveform of said commutation signal and defining a relationship between the operating speed of the cyclic motion of said machine and frequency of said commutation signal,
• whereby said commutation signal is generated from said photo-detection means as the pattern of said optical element is scanned relative to said aperture means.