Displacement based dynamic load monitor

Abstract

An apparatus and method for monitoring the force severity of a mechanical press without utilizing a contact force sensor. The method continually computes values of dynamic deflection for the press being monitored and utilizes these values to compute load on the press at any point in time.

1 - 15 . (canceled)  
   
   
       16 . A method of monitoring load on a mechanical press having a slide, said method comprising the steps of: 
 determining a value of dynamic deflection, using a no-load press motion characteristic;    determining a value of static stiffness for the press being monitored;    calculating load on the press at any point of the slide stroke, using the value of dynamic deflection for the relevant point of the slide stroke and the value of static stiffness.    
   
   
       17 . The method of  claim 16 , wherein said step of determining a value of dynamic deflection comprises the steps of: 
 generating a theoretical no load value of slide displacement;    generating an actual load value of slide displacement corresponding in time to the theoretical no load value of slide displacement;    computing a difference between the theoretical no load value and the actual load value of slide displacement; and    establishing the difference between the theoretical no load value and the actual load value of slide displacement as the value of dynamic deflection.    
   
   
       18 . The method of  claim 16 , further comprising the steps of: 
 determining a plurality of values of dynamic deflection at increments of the entire slide stroke; and    calculating a plurality of load values corresponding to the plurality of dynamic deflection values.    
   
   
       19 . The method of  claim 18 , further comprising the steps of: 
 generating a plot of load vs. time for a slide stroke of the press.    
   
   
       20 - 26 . (canceled)  
   
   
       27 . A method for use with a press machine having a slide, said method comprising the steps of: 
 generating a signal indicative of slide displacement under a press no-load condition for said press machine;    generating a signal indicative of slide displacement under a press load condition for said press machine; and    comparing the no-load slide displacement signal and the load slide displacement signal.    
   
   
       28 . The method as recited in  claim 27 , wherein the comparison step further includes the step of: 
 generating at least one measure of press machine activity, using the no-load slide displacement signal and the load slide displacement signal.    
   
   
       29 . The method as recited in  claim 28 , wherein the at least one measure of press machine activity being indicative of at least one of press machine behavior, response, and performance.  
   
   
       30 . The method as recited in  claim 27 , wherein generation of the no-load slide displacement signal includes generating a theoretical no-load valuation of slide displacement.  
   
   
       31 . The method as recited in  claim 27 , wherein the step of generating the load slide displacement signal further includes the step of: 
 non-contactable monitoring of slide displacement.    
   
   
       32 . The method as recited in  claim 31 , wherein the monitoring step further includes the step of: 
 collecting slide displacement data with at least one non-contacting sensor.    
   
   
       33 . The method as recited in  claim 27 , wherein the comparison step further includes the step of: 
 generating a differential valuation between the no-load slide displacement signal and the load slide displacement signal.    
   
   
       34 . The method as recited in  claim 27 , wherein the comparison step further includes the step of: 
 generating a measure of dynamic deflection.    
   
   
       35 . The method as recited in  claim 27 , wherein the press load condition involves deployment of a tooling die configuration in the press machine, and the press no-load condition involves non-deployment of the tooling die configuration in the press machine.  
   
   
       36 . The method as recited in  claim 27 , further includes the step of: 
 determining a value of load on said press machine, using the slide displacement signal comparison.    
   
   
       37 . The method as recited in  claim 27 , further includes the steps of: 
 generating a signal indicative of dynamic deflection, using the slide displacement signal comparison; and    determining a signal indicative of load on said press machine, using the dynamic deflection signal.    
   
   
       38 . The method as recited in  claim 37 , further includes the step of: 
 repeatedly performing the dynamic deflection signal generation and load signal determination during a press operation.    
   
   
       39 . The method as recited in  claim 37 , further includes the step of: 
 providing an indication of press machine load as a function of a variable.    
   
   
       40 . The method as recited in  claim 39 , wherein the variable includes at least one of crank angle and time.  
   
   
       41 . A method for monitoring operation of a press machine having a slide, said method comprising the steps of: 
 providing a signal indicative of a no-load press machine motion characteristic; and    determining a load on said press machine, using the signal indicative of a no-load press machine motion characteristic.    
   
   
       42 . The method as recited in  claim 41 , wherein the providing step further includes the step of: 
 generating a signal indicative of slide displacement under a press no-load condition for said press machine.    
   
   
       43 . The method as recited in  claim 42 , further includes the step of: 
 generating a signal indicative of slide displacement under a press load condition for said press machine.    
   
   
       44 . The method as recited in  claim 43 , wherein the determining step further includes the step of: 
 generating a differential comparison between the no-load slide displacement signal and the load slide displacement signal.    
   
   
       45 . The method as recited in  claim 41 , wherein the no-load press machine motion characteristic including an indication of no-load slide displacement.  
   
   
       46 . The method as recited in  claim 41 , further includes the step of: 
 iteratively performing the signal providing step and load determination step over a selectable duration of slide travel.    
   
   
       47 . A method for use with a press machine having a slide, said method comprising the steps of: 
 determining an indication of dynamic deflection pertaining to said press machine, the dynamic deflection being based at least in part on a no-load press machine motion valuation; and    determining a load on said press machine, using the determination of dynamic deflection.    
   
   
       48 . The method as recited in  claim 47 , wherein the determination of dynamic deflection further includes the steps of: 
 generating a signal indicative of slide displacement under a press no-load condition for said press machine;    generating a signal indicative of slide displacement under a press load condition for said press machine; and    generating a differential comparison between the no-load slide displacement signal and the load slide displacement signal.    
   
   
       49 . A system for use with a press machine having a slide, said system comprising: 
 a first assembly to generate a signal indicative of slide displacement for said press machine under a press no-load condition;    a second assembly to generate a signal indicative of slide displacement for said press machine under a press load condition; and    a computing device coupled to said first assembly and said second assembly, said computing device being configured to operably compare the no-load slide displacement signal and the load slide displacement signal.    
   
   
       50 . The system as recited in  claim 49 , wherein said second assembly includes at least one sensor disposed in non-contacting relationship to said slide.  
   
   
       51 . The system as recited in  claim 49 , wherein said computing device being configured further to generate a differential comparison between the no-load slide displacement signal and the load slide displacement signal.  
   
   
       52 . The system as recited in  claim 49 , wherein said computing device being configured further to generate an indication of dynamic deflection based on the comparison.  
   
   
       53 . The system as recited in  claim 49 , wherein said computing device being configured further to generate an indication of load on said press machine based on the comparison.  
   
   
       54 . A system for use with a press machine having a slide, said system comprising: 
 means for providing a signal indicative of a no-load press machine motion characteristic; and    means for determining a load on said press machine, using the signal indicative of a no-load press machine motion characteristic.    
   
   
       55 . The system as recited in  claim 54 , wherein said providing means further includes: 
 means for generating a signal indicative of slide displacement under a press no-load condition for said press machine.    
   
   
       56 . The system as recited in  claim 55 , further includes: 
 means for generating a signal indicative of slide displacement under a press load condition for said press machine.    
   
   
       57 . The system as recited in  claim 56 , wherein said determining means further includes: 
 means for generating a differential comparison between the no-load slide displacement signal and the load slide displacement signal.    
   
   
       58 . An apparatus for operable use with a press machine, said apparatus comprising: 
 a first no-load press machine motion-indicating signal generator;    a second load-related press machine motion-indicating signal generator; and    a comparator, operably coupled to said first signal generator and said second signal generator.    
   
   
       59 . The apparatus as recited in  claim 58 , further includes: 
 a load calculator, operably coupled to said comparator.    
   
   
       60 . An apparatus for operable use with a press machine having a slide, said apparatus comprising: 
 a first no-load slide displacement value generator;    a second load-related slide displacement value generator; and    a comparator, operably coupled to said first value generator and said second value generator.    
   
   
       61 . The apparatus as recited in  claim 60 , further includes: 
 a load calculator, operably coupled to said comparator.