Patent Publication Number: US-2023137151-A1

Title: Lock position sensing

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority to European Patent Application No. 21275154.9 filed Nov. 3, 2021, the entire contents of which is incorporated herein by reference. 
     TECHNICAL FIELD 
     The present disclosure relates to lock position sensing. In particular, the present disclosure relates to thrust reverser lock position sensing. 
     BACKGROUND 
     Lock position sensing is ordinarily carried out by providing proximity switches in order to sense the positions of mechanical locks. Typically, there are three mechanical locks per thrust reverser actuation system, with two proximity switches allocated to each lock for sensing the positions of each lock. 
     SUMMARY OF THE INVENTION 
     In one aspect, there is provided a method that includes reading data from a proximity switch and calculating an inductance value from a solenoid, the proximity switch and solenoid located in or around a lock, and processing the data from the proximity switch and the inductance value. The method further includes comparing the processed data with an expected value to confirm the lock status. 
     The lock may comprise a primary lock and a tertiary lock. The method may also further comprise determining if the lock is in an unlocked position, and, if it is determined that the lock is in an unlocked position, the method proceeds to a next stage of flight. 
     Further, if it is determined that the lock is not in an unlocked position, the method may further comprise determining whether the tertiary lock or the primary lock is unlocked. If it is determined that the tertiary lock is locked, the method may not proceed to the next stage of flight. If it is determined that the primary lock is locked, the method may further comprise reporting a primary lock fault. 
     The next stage of flight may be deploying a thrust reverser actuation system. 
     In another aspect, there is provided a method that includes calculating a first inductance value of a primary solenoid and calculating a second inductance value of a secondary solenoid, said primary and secondary solenoids located in or around a lock, and processing the first inductance value and the second inductance value. The method further includes comparing the processed values with an expected value to confirm the lock status. 
     The lock may comprise a primary lock and a tertiary lock. The method may also further comprise determining if the lock is in an unlocked position, and, if it is determined that the lock is in an unlocked position, the method proceeds to a next stage of flight. 
     Further, if it is determined that the lock is not in an unlocked position, the method may further comprise determining whether the tertiary lock or the primary lock is unlocked. If it is determined that the tertiary lock is locked, the method may not proceed to the next stage of flight. If it is determined that the primary lock is locked, the method may further comprise reporting a primary lock fault. 
     The next stage of flight may be deploying a thrust reverser actuation system. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a conventional method of sensing lock positions. 
         FIG.  2    shows a new proposed method of sensing lock positions. 
         FIG.  3    shows a further new method of sensing lock positions. 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows an example of a method for sensing the lock position. The general flow chart  10  is shown in  FIG.  1   . As an example, the method includes reading proximity switch data from a first proximity switch, as shown at step  101   a . The method also reads proximity switch data from a second proximity switch, as shown at step  101   b . The proximity switches are located around the tertiary lock and primary lock to indicate when the lock is in locked or unlocked position. For example, there may be proximity switches located around a lock that includes the tertiary lock and the primary lock, or there may be provided proximity switches around the tertiary lock and then further proximity switches around the primary lock. 
     At step  102   a , the data from step  101   a  is sent to the engine computer. At step  102   b , the data from step  101   b  is also sent to the engine computer. The data is then processed at step  103 . At step  104 , the processed data is compared with a lock command to ascertain whether the lock is in an expected position. If the proximity switches determine that the tertiary lock is in an unlocked position, step  105  confirms that the tertiary lock is in an unlocked position and the engine computer can move on the next step of flight. If the data from the proximity switches determine that the tertiary lock is not in an unlocked position, step  107   a  reports a fault in the tertiary lock and the engine computer does not move on to the next step. 
     For example, step  103  processes the data sent to the engine computer from steps  102   a  and  102   b  to compare the sensors data and determine the status of the primary and tertiary locks. If it is determined that the proximity switches data is showing that the locks are in an unlocked position then the engine computer may proceed with the next stage of flight, as shown at step  105 . If it is determined that the data comparing the lock status differ then stage  106  determines whether the difference of proximity switch data is linked to the tertiary lock as shown in step  106 . If it is the case then a tertiary lock fault is reported and the next step of the thrust reverser actuation system functionality which consists of a deploy is aborted as shown in step  107   a . If the tertiary lock proximity switch data does not differ and the difference in proximity switch data is associated with the primary lock then a primary lock fault failure is reported at step  107   b.    
     A method for lock position sensing, according to this disclosure, is shown in  FIG.  2   . A general flow chart  20  is shown in  FIG.  2   . As an example, the method includes reading a single proximity switch that is located in the system at step  21   a . Therefore, in this example method, there is only one proximity switch provided at or around a lock. The lock may include a tertiary lock and a primary lock. The method may also include calculating a solenoid inductance of a solenoid provided in or around the lock at step  21   b . At step  22   a , the data read by step  21   a  is sent to the engine computer. At step  22   b , the solenoid inductance calculated at step  21   b  is sent to the engine computer. Step  23  processes the data sent to the engine computer from steps  22   a  and  22   b  to compare the data with values to determine whether the lock is unlocked at step  24 . If it is determined that the proximity switch and/or the solenoid inductance show that the lock is unlocked, it is confirmed that the tertiary lock is unlocked and the engine computer may proceed with the next stage of flight (for example, deployment of the thrust reverser actuation system), as shown at step  25 . If it is determined that the lock is in a locked position, the method then determines whether the tertiary lock or the primary lock is unlocked. If it is determined that the tertiary lock is not unlocked then a fault is reported at step  27   a  and the engine computer does not proceed to the next stage of flight (for example, the engine computer does not proceed to deployment of the thrust reverser actuation system). If it is determined that the primary lock is locked, the method at step  27   b  reports that there must be a primary lock fault. 
     An alternative method for lock position sensing, according to this disclosure, is shown in  FIG.  3   . A general flow chart  30  is shown in  FIG.  3   . As an example, the method includes calculating an inductance value from a primary solenoid located in the system at step  31   a . Therefore, in this example method, there are no proximity switches. The method may also include calculating an inductance value of a secondary solenoid provided in or around the lock at step  31   b  or a secondary coil located in the proximity of the primary coil. The lock may include a primary lock and a tertiary lock. At step  32   a , the primary solenoid inductance value is sent to the engine computer at step  31   a . At step  32   b , the secondary solenoid inductance value calculated at step  31   b  is sent to the engine computer. Step  33  processes the inductance values sent to the engine computer from steps  32   a  and  32   b  to compare the values to determine the lock position at step  34 . If it is determined that the primary solenoid inductance value and/or the secondary solenoid inductance value show that the lock is unlocked, it is confirmed that the tertiary lock is unlocked and the engine computer may proceed with the next stage of flight (for example, deployment of the thrust reverser actuation system), as shown in step  35 . If it is determined that the lock is not in an unlocked position, the method then determines whether the tertiary lock or the primary lock is unlocked. If it is determined that the tertiary lock is locked, then a fault is reported at step  37   a  and the engine computer does not proceed to the next stage of flight (for example, the engine computer does not proceed to deployment of the thrust reverser actuation system). If it is determined that the primary lock is locked, the method at step  37   b  reports that there must be a primary lock fault. 
     Although this disclosure has been described in terms of preferred examples, it should be understood that these examples are illustrative only and that the claims are not limited to those examples. Those skilled in the art will be able to make modifications and alternatives in view of the disclosure which are contemplated as falling within the scope of the appended claims.