Rockwell Automation Technologies Incorporated

Jadav Das

Xikai Sun

Tracy M Clark

Peter M Smit

Robert H Schmidt

Mark R Cooper

Patrick E Ozimek

Dayin Xu

Neil R Bentley

Shankernarayan Ramanarayanan

John Floresta

David D Van Dorpe

Shankha S Seal

Yuhong Huang

Michaela R Kaufmann

A system and method of determining orientation of a physical location on a cart or end effector located on the cart in an independent cart system receives a feedback signal from a sensor on the cart. A multi-axis device may generate three or more signals corresponding to X, Y, and Z axes orientations. Processing may be performed on the signals to generate a value of yaw, pitch, or roll of the cart. The feedback or processed signals are transmitted from the mover to a remote device external from the track. The real-time orientation information may be used to implement closed-loop control of an actuator mounted on or external to each cart as the cart travels along the track. Power for the devices on the mover may be provided by a battery mounted on the cart or by a wireless power transfer system.

System and method for determining real-time orientation on carts in an independent cart system

A contactless monitoring system detects operating performance of movers in an independent cart system. A contactless sensor is provided on an actuator to automatically track a mover as it travels along the track. The sensor includes a transmitter configured to transmit a signal and a receiver configured to receive the signal after it is reflected off the mover. The actuator may be configured to mover the sensor in a single axis or in multiple axes of motion. As a mover travels along the track, the sensor transmits a signal towards the mover and detects the signal after it has been reflected off the mover. A controller may synchronize motion of the actuator with motion of the mover, such that the sensor may continually transmit the signal off the mover for at least a portion of the travel by the mover along the track.

System and method for contactless monitoring of performance in an independent cart system

A motor controller is provided that executes a commutation routine in one of a plurality of operating modes to regulate current provided to drive coils in a linear motion system. The motor controller generated currents for each of the drive coils in a first operating mode to minimize the copper losses in the drive coils, in a second operating mode to maximize the force applied to the mover, in a third operating mode to provide balanced currents between the drive coils, and in a fourth operating mode to provide currents according to a selected operating point that combines characteristics of the first three operating points. The motor controller may also monitor each of the drive coils for saturation and redistribute at least a portion of the current required to control operation of the mover to the other drive coils when one of the drive coils is saturated.

Method and apparatus for commutation of drive coils in a linear drive system with independent movers

A system for wirelessly transmitting power between a track and independent movers in a motion control system includes a pick-up coil provided proximate to the magnets on the movers. The fundamental component of the voltage applied to the drive coils interacts primarily with the magnetic field generated by the permanent magnets on the movers and not with the pick-up coil. Consequently, the pick-up coil does not interfere with desired operation of the movers but rather, interacts primarily with the harmonic components and has current and voltages induced within the pick-up coil as a result of the harmonic components. The energy captured by the pick-up coil reduces the amplitude of eddy currents on the mover. After harvesting the harmonic content, the pick-up coil may be connected to another circuit on the mover and serve as a supply voltage for the other circuit.

System and method for wireless power transfer in a linear cart system

An independent cart system includes an inductive link for contactless power transfer between a track and each mover as the mover travels along the track. A system for contactless data transmission between movers and a controller in the independent cart system includes a transmitter and/or receiver mounted on each mover and a complementary receiver and/or transmitter mounted on a track. The transmitter receives data to be transmitted across the inductive link and modulates a voltage present on either the primary or secondary winding to which it is coupled. The modulated voltage present on one winding induces a corresponding modulation on the voltage present on the other winding. A receiver operatively connected to the other side of the inductive link detects the modulated voltage and decodes the data from the modulated voltage received across the inductive link.

Method and apparatus for data transmission over an inductive link for an independent cart system

By configuring an encoder scale as a varying scale with successively increasing or decreasing pitch, sensors in a travel path of the scale can detect a phase difference to determine an absolute position of the scale for use in an industrial control system. Due to the successively increasing or decreasing pitch, each sensor can detect successively increasing or decreasing properties (such as magnetic fields) from the scale in a uniquely identifiable pattern. By taking the difference between readings of adjacent sensors, each sensor detecting properties of the scale, an absolute position of the scale between the sensors can be determined. The principle for feedback for the encoder system is analogous to a Nonius or Vernier principle to determine absolute position.

Encoder system for position determination with varying scale

A mover is configured to be electromagnetically propelled along a track in a linear motor track system with a force that is calculated to include compensation for gravity. A multi-axis accelerometer arranged in each segment of the track can detect an orientation or angle of the track segment for determining gravity with respect to the particular section. As a result, if the track is at an incline, such as a ramp, a desired force for moving a mover along the track can be compensated to include gravity due to the incline for achieving a desired motion result. In addition, the detected orientation of the track can be compared to an expected orientation stored by a control program to avoid a loss of performance due to physical changes in the track not matching an expected/programmed configuration of the track.

Linear motor track system with automatic gravity detection

By configuring an encoder scale as an angled or inclined magnet or pair of oppositely arranged, adjacent magnets, a magnetic field sensor in a travel path of the scale can detect an absolute position of the scale for use in an industrial control system. Due to the angle or incline, when a first side of the scale is proximal to the sensor, the sensor can detect an angle of &#x2212;180&#xb0;. As the scale moves to center with respect to the sensor, the sensor can detect an increasing angle to 0&#xb0;. Then, as a second side of the scale becomes proximal to the sensor, the sensor can detect an increasing angle to +180&#xb0;. The angle changes linearly with position. In one aspect, the pair of oppositely arranged magnets can be rotated with respect to the travel path to provide the angle. In another aspect, the pair of oppositely arranged magnets can be magnetized diagonally to provide the angle.

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Lake Grove, NY, United States of America

Jadav Das