Contraves Goerz Corporation

Other

Control Systems Research, Inc.

International Cybernetics Corp.

International Cybernetic Corporation

Paul F McNally

Robert G Burig

Donald H Jones

Spencer W Allen

Michael D Salcone

Matthew G Cimbala

This invention relates to a bi-polar power supply regulator. A regulator is shown and described which prevents undesirable and potentially dangerous power supply build-up in a power amplifier of the standard totem pole configuration. The regulator also enables one to construct a multi-amplifier system in a cost effective manner since the regulator controls the build-up in the bi-polar power supply which is used to drive several power amplifiers in the totem pole configuration.

Bi-polar power supply regulator bi-polar power supply regulator

A phase analog encoding system with compensation for the phase shift error inherent in a resolver position transducer. The inherent phase shift error in a resolver position transducer is compensated independent of a resolver position in a time multiplexed fashion by periodically applying a known reference signal to the resolver and measuring the electrical phase shift across only the resolver. The newly measured value of the inherent electrical phase shift is compared with the last measured value of the inherent electrical phase shift and any deviation is calculated. This deviation is used to determine the appropriate compensation value for the inherent electrical phase shift. The compensation value is subtracted from the resolver phase shift during normal operation resulting in an output signal which is independent of the inherent electrical phase shift error in the resolver position transducer. Additionally, compensation for encoding errors is developed in a calibration mode. This compensation for encoding errors can then be used during the operation of the encoding system.

Phase analog encoding system with compensation

The present invention provides a high response inexpensive microprocessor based digital control system. The digital control system uses only one detector that detects only one motion characteristic of the device controlled by the system. In the preferred embodiment, the digital control system controls the field orientation, the position and the velocity of a movable member of a brushless motor by creating commands that represent the desired position of the movable member 1024 times per second. The system also provides methods for improving the accuracy and precision of the system.

Sampled data servo control system with field orientation

A movable carriage which is connected to a smooth actuating rod for movement therewith to a desired position where it is locked to a fixed bridge permitting the actuating rod to move with respect thereto. The movable carriage or head is clamped to the actuating rod with a continual friction force which is easily overcome by the force with which the carriage is locked to the fixed bridge. The actuating rod is movable back and forth along its longitudinal axis by manual or automatic positioning apparatus. By successive moving and locking operations for the carriage, the carriage can be moved along the entire bridge while the movement of the actuating rod is more limited. The actuating rod can be a smooth metallic rod with the carriages permanently clamped thereto with a determinable friction force, alternately the carriage can be clamped to the actuating rod until the carriage is clamped to the fixed bridge. A drive motor is used for moving the actuating rod back and forth. A manual back-up is provided for manually moving the actuating rod. When more than one carriage is utilized, adjacent carriages can be moved close together. That is, movement of the carriages is not restricted to selected zones.

Linear positioning apparatus

Apparatus for generating synchronized multi-axis intermittent motion utilizing electronic encoding, memory and a position control system having feed-forward control. A plurality of slave shafts are rapidly and accurately positioned in response to the positioning of a rotatable master shaft, without mechanical interconnections therebetween. An analog transducer is attached to the master shaft providing an analog position output which is fed to a master encoder which feeds a digital output to a plurality of independent digital memory devices. Each digital memory device provides, in response, an output digital signal indicative of the desired position of an associated slave shaft. The output of each memory device, through an appropriate digital-to-analog converter, is fed to a position controller which positions the associated slave shaft as desired. The servo controller includes a feedforward input to speed positioning and reduce system lag. The feedforward velocity signal is obtained by calculating the difference between the present position of the associated slave shaft and the desired future position of the slave shaft to obtain the desired change in the slave shaft position. This difference is multiplied by the absolute value of the master axis velocity to obtain the necessary velocity feedforward signal. The velocity feedforward signal, which is a function of the change in slave shaft position and the velocity of the master shaft represents the velocity at which the slave shaft must be rotated to achieve the desired position while the master shaft moves through one digital increment.

Multi-axis motion generator utilizing feedforward control

Apparatus for generating synchronized multi-axis intermittent motion utilizing electronic encoding, memory and a servo controlled positioning system. A plurality of mechanically independent slave shafts are positioned in response to the position of a rotatable master shaft. An analog transducer is attached to the master shaft providing an analog output signal which is fed through an analog-to-digital converter. A digital representation of the master shaft position is provided by the analog-to-digital converter. The digital indication of master shaft position is fed to a plurality of independent digital memory devices each of which provides, in response, a digital position signal indicative of the desired position of an associated slave shaft. The output of each independent digital memory device is fed to a digital-to-analog converter which provides an analog output representative of the desired slave shaft position. A servo controller positions the associated slave shaft in response to the analog signal. A translator can be utilized for combining the digital output of each memory with an analog position signal from a position transducer connected to the associated slave shaft and providing an analog difference or error signal which can be utilized for proper positioning of the slave shaft. A tachometer can be utilized in the slave shaft servo for providing speed feedback information. Other means for speed feedback can be employed either by deriving a speed signal from other parameters, related to speed, or by utilizing the characteristics of the prime mover itself for speed feedback.

Multi-axis electronic motion generator

Isolating apparatus is disclosed which provides electrical isolation between an analog signal input and an equivalent analog signal output. The input analog signal is converted to a series of positive and negative pulses. Optical coupling devices are responsive to the series of positive and negative pulses for providing a series of similar positive and negative pulses which are electrically isolated but optically coupled. These isolated pulses are then converted to the equivalent analog signal output. The optical coupling comprises photo emitters one of which is activated when the analog to pulse converter output is positive and another of which is activated when it is negative. The photo emitters are operably associated with photo detectors which are operable in a switching mode. Feedback is not required around the optical coupling devices. An averaging circuit at the output provides an analog representation of the input signal.

Analog signal isolator

An absolute positioning servo for positioning a shaft in response to a digital command input which utilizes a resolver, for providing an analog position indication of the shaft, an analog to digital converter, which provides a digital indication of the shaft position, a comparator for comparing the digital command input signal with the digital indication signal and providing a differential digital error signal which is converted to an analog signal and fed back to position the shaft so that the differential digital error is 0. An analog fine control positioning means is provided which positions and maintains the shaft near the center point of the position represented by the digital command input signal when the digital differential error is 0. A signal representing the difference between the exact analog position of the shaft and the digital approximate position of the shaft is provided at the output of the translator. This is utilized to position the shaft within an angle equivalent of the least significant digital bit. The digital positioning system is utilized to move the shaft to a position within .+-. 1/2 bit of the desired position, then the analog positioning system takes over and positions and maintains the shaft within a lesser fractional portion of a bit to the absolute desired position. A short path positioning means is provided for selecting the shortest path to move the shaft to a new position indicated by the digital command input signal. That is, whenever the shaft is to be rotated to a position more than 180.degree. away, it is rotated in the opposite direction over an angle which then is necessarily less than 180.degree.. A square root function generator is provided following the digital to analog converter for the digital error signal which permits minimum positioning time for the servo system.

Servo system employing a tracking digital angle encoder

A method and apparatus for synchronizing the digitized position output of a multispeed system having overlapping position indications. The output of the multispeed position indicating system is a digital output word which is a combination of the individual outputs of the various transducers. For a two speed system a digital fine position having a high degree of accuracy is provided, and a digital coarse position indication of a lesser precision is also provided wherein the least significant coarse position digit overlaps the most significant fine position digit. An adjustment is provided for adjusting the coarse digital output as a function of the most significant digit of the fine transducer output so that nonambiguous synchronized position information is provided at all times. The appropriate adjustment can be obtained by adding a fixed number of counts, such as 5, to the coarse digital position indication and then subtracting the most significant digit of the fine position indication so that when the coarse position indication is combined with the fine position indication the desired unambiguous output results. The combined position indication can be obtained by utilizing all of the fine digital position outputs and the coarse digital outputs other than the least significant digit, which overlaps the most significant digit of the fine digital output. The coarse and fine position indicators can be resolvers which are connected to the shaft to be instrumented. The outputs of these resolvers are then converted to digital signals by analog to digital converters. The fine digital signal and the modified coarse digital signal are then combined by appropriate logic.

Synchronized multispeed transducer position indicating system

A tracking digital angle encoder utilizing a translator, for providing the difference between an analog angle input and a digital angle input, a counter, which feeds the digital angle input to the translator, a detector, which controls the counter and is connected to the output of the translator to be activated by the output of the translator exceeding a predetermined trigger value, all of which are connected to cause the counter to count to a position where the output of the translator is less than the predetermined trigger level. When the output of the translator is less than the predetermined trigger value, the output of the counter provides a digital signal which closely approximates the analog angle input to the translator. A balanced demodulator which is connected to the output of the translator and receives a signal from a reference oscillator, which is equal to the carrier frequency, provides a pure sine function output representing the difference between the analog and digital inputs to the translator. An adjustment is provided between the counter and the threshold detector which permits the level at which the threshold detector activates the counter to be varied and thus the angle, to which each bit of the counter is equivalent, can be varied. This adjustment allows easy compensation for errors due to mechanical tolerances or mechanical wear in the system being controlled. The translator also provides an output which is equivalent to the cosine of the analog angle input. This cosine output is utilized for switching the counter to its midpoint when the power is first applied if the cosine value is negative, indicating the angular position of the analog signal is in the second or third quadrant.

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Gibsonia, PA, United States of America

Paul F McNally