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EP-3531140-B1 - SYSTEM AND METHOD FOR DETECTING LATENT FAULTS IN A REDUNDANT MOTOR APPLICATION

EP3531140B1EP 3531140 B1EP3531140 B1EP 3531140B1EP-3531140-B1

Inventors

  • AVRITCH, STEVEN A.
  • DICKIE, DAVID F.

Dates

Publication Date
20260506
Application Date
20190219

Claims (10)

  1. A system for monitoring a motor, comprising: a movable component having a plurality of permanent magnets (112); a plurality of stators (102) having phase windings and surrounding the movable component; a plurality of current sensors (130) each configured to detect a detected current flowing to a corresponding stator of the plurality of stators (102); a plurality of controllers, including a master controller and at least one slave controller, each configured to control the corresponding stator of the plurality of stators; characterised in that the system comprises: a monitor (128) configured to receive the detected current, perform a comparison of the detected current from each of the plurality of stators (102), and to identify a loss of redundancy of the motor the based on the comparison; wherein the monitor (128) is configured to identify whether the loss of redundancy is due to one of the plurality of controllers or the plurality of stators (102) being faulty; and wherein the system is configured to compare a first detected current flowing from a first controller to a first stator with a second detected current flowing from a second controller to a second stator and with a third detected current flowing from a third controller to a third stator; wherein the system is configured to determine whether the motor has lost redundancy if any two of the first detected current, the second detected current, and the third detected current are different by a value greater than a tolerance current level; wherein the system is further configured to determine whether one of the first stator, the second stator, and the third stator is a faulty stator if two of the first detected current, the second detected current, and the third detected current are different by a value lesser than the tolerance current level while one of the first detected current, the second detected current, and the third detected current is different by a value greater than the tolerance current level; wherein the system is configured to isolate the faulty stator by ceasing to provide current to the faulty stator.
  2. The system of claim 1, wherein each of the plurality of current sensors (130) is located in a corresponding controller of the plurality of controllers (122).
  3. The system of claim 1, wherein one of the plurality of controllers (122) is the master controller and each remaining controller of the plurality of controllers (122) is the slave controller.
  4. The system of claim 3 wherein the monitor (128) is included in the master controller.
  5. The system of any preceding claim, wherein the monitor (128) is configured to identify the loss of redundancy in response to at least one stator of the plurality of stators (102) having a different detected current than another stator of the plurality of stators (102), and wherein the plurality of stators (102) includes at least three stators, and wherein the monitor (128) is further configured to identify a faulty stator in response to identifying that the detected current of at least two of the plurality of stators are within a tolerance current level of each other, and that the detected current of the faulty stator is outside the tolerance current level, and wherein the monitor (128) is further configured to cause the faulty stator to cease receiving current.
  6. The system of any preceding claim further comprising an output device configured to output data and wherein the monitor (128) is further configured to control the output device to output a notification indicating the loss of redundancy of the motor.
  7. A method for monitoring a motor, comprising: receiving, by a monitor, a detected current corresponding to each of a plurality of stators; controlling the corresponding stator of the plurality of stators by a plurality of controllers, including a master controller and at least one slave controller; characterised by performing a comparison, by the monitor, of the detected current from each of the plurality of stators; and identifying, by the monitor, a loss of redundancy of the motor based on the comparison; wherein the monitor identifies whether the loss of redundancy is due to one of the plurality of controllers or the plurality of stators being faulty; and comparing a first detected current flowing from a first controller to a first stator with a second detected current flowing from a second controller to a second stator and with a third detected current flowing from a third controller to a third stator; determining whether a motor has lost redundancy if any two of the first detected current, the second detected current, and the third detected current are different by a value greater than a tolerance current level; determining whether one of the first stator, the second stator, and the third stator is a faulty stator if two of the first detected current, the second detected current, and the third detected current are different by a value lesser than the tolerance current level while one of the first detected current, the second detected current, and the third detected current is different by a value greater than the tolerance current level; isolating the faulty stator by ceasing to provide current to the faulty stator.
  8. The method of claim 7, wherein identifying the loss of redundancy of the motor includes identifying the loss of redundancy in response to at least one stator of the plurality of stators having a different detected current than another stator of the plurality of stators.
  9. The method of claims 7 or 8, further comprising identifying, by the monitor, a faulty stator in response to identifying that the detected current of at least two of the plurality of stators are within a tolerance current level of each other, and that the detected current of the faulty stator is outside of the tolerance current level, and further comprising preventing, by the monitor, the faulty stator from receiving current.
  10. The method of any of claims 7-9, further comprising outputting, by an output device, output data including a notification indicating the loss of redundancy of the motor.

Description

FIELD The present disclosure is directed to systems and methods for identifying a loss of redundancy due to latent faults of a motor. BACKGROUND A linear motor actuator may include a plurality of stators having windings that surround a translator rod. The translator rod may include a plurality of permanent magnets positioned thereon or coupled thereto. The linear motor actuator may further include a plurality of controllers that each provide current to a corresponding stator. As the current flows through the windings of the stators, a magnetic field is generated. The magnetic field forces the translator rod to move in either direction along a common actuation axis. A control loop may be used by the controllers to control the current provided to each stator. If a sufficiently great amount of force is requested of the linear motor actuator (i.e., an amount of force that cannot be provided without all the stators providing current) then the system may identify a fault by determining that the requested force cannot be achieved. However, conventional linear motor actuators are incapable of identifying latent faults (which may occur when the amount of force requested can be provided by current from less than all the stators) because the control loop causes the non-faulty stators to make up for the lack of current from the faulty stator. US 2009/309529 relates to a power branching system. DE 10 2016 113817 relates to a linear motor arrangement. US 2009/102647 relates to a system for controlling a plurality of stator subsections. SUMMARY The present invention is defined in the independent claims 1 and 7 with preferred embodiments disclosed in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS The subject matter of the present disclosure is particularly pointed out and distinctly claimed in the concluding portion of the specification. A more complete understanding of the present disclosures, however, may best be obtained by referring to the detailed description and claims when considered in connection with the drawing figures, wherein like numerals denote like elements. FIG. 1 is a schematic perspective view of a portion of an exemplary embodiment of a motor showing three redundant stators along a translator rod, in accordance with various embodiments of the present disclosure;FIG. 2 is a schematic view of the translator rod of FIG. 1, showing permanent magnets stacked along an actuation axis, in accordance with various embodiments of the present disclosure;FIG. 3 is a perspective view of a portion of the linear motor actuator of FIG. 1, showing an example of spacing of the stators along an actuation axis, in accordance with various embodiments of the present disclosure;FIG. 4 is an exploded perspective view of the linear motor actuator of FIG. 1 showing position sensors, in accordance with various embodiments of the present disclosure;FIG. 5 is a schematic view of the linear motor actuator of FIG. 1 showing control loops for controlling the three stators, in accordance with various embodiments of the present disclosure;FIG. 6 is a schematic view of a linear motor actuator having similar features as the linear motor actuator of FIG. 1, in accordance with various embodiments of the present disclosure;FIG. 7 is a drawing of an aircraft utilizing the linear motor actuator of FIG. 1, in accordance with various embodiments of the present disclosure; andFIG. 8 is a flowchart illustrating a method for monitoring a status of a linear motor actuator by comparing current received by multiple stators, in accordance with various embodiments of the present disclosure. DETAILED DESCRIPTION The detailed description of exemplary embodiments herein makes reference to the accompanying drawings, which show exemplary embodiments by way of illustration and their best mode. While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosure, it should be understood that other embodiments may be realized and that logical, chemical, and mechanical changes may be made. Thus, the detailed description herein is presented for purposes of illustration only and not of limitation. For example, the steps recited in any of the method or process descriptions may be executed in any order and are not necessarily limited to the order presented. Furthermore, any reference to singular includes plural embodiments, and any reference to more than one component or step may include a singular embodiment or step. Also, any reference to attached, fixed, connected or the like may include permanent, removable, temporary, partial, full and/or any other possible attachment option. Additionally, any reference to without contact (or similar phrases) may also include reduced contact or minimal contact. For purposes of explanation and illustration, and not limitation, a partial view of an exemplary embodiment of a linear motor actuator 100 in accordance with various embodiments of the disclosure is sho