Diagnostic method for analyzing and monitoring the process parameters in the operation of reciprocating equipment

Abstract

The method of the present invention utilizes a microcomputer in combination with a CRT and a multiplicity of transducers for monitoring process parameters in the operation of a reciprocating device having a linear stroke. A profile of the process parameters including pressure and velocity are generated as a function of stroke length and time and are stored in a non-volatile memory and graphically displayed on the CRT as master traces for comparison with current data profiles. The velocity is calculated by dividing distance transversed with time or by use of a velocity position transducer.

What is claimed is: 
     
       1. A diagnostic method for analyzing and monitoring the process parameters of reciprocating equipment in which a linear reciprocating injection device is traversed over a fixed stroke length at high speed comprising the steps of: (a) dividing said stroke length into a predetermined number of incremental positions;   (b) generating analog data corresponding to at least the position of said injection device and the pressure developed by said injection device at each such incremental position;   (c) recording the time transpired in the movement of said injection device along said stroke length;   (d) deriving the velocity of said injection device at each such incremental position;   (e) graphically displaying the data corresponding to pressure and velocity on a display screen of a cathode ray tube as a function of the incremental position of said injection device along said stroke length until said velocity reaches a predetermined minimum level, with said display forming a master profile for said data;   (f) storing the data representing said master profile at a predetermined address location in a nonvolatile memory of a microcomputer;   (g) repeating the sequence of generating, .[.calculating.]. .Iadd.deriving .Iaddend.and storing analog data corresponding to pressure and velocity as a function of stroke position for a second die casting .[.operating.]. .Iadd.operation .Iaddend.to form a current profile of such data for such second operation, and   (h) displaying said current profile on said display screen along with said master profile for diagnostic comparison purposes.   
     
     
       2. A diagnostic method as defined in claim 1 wherein said minimum velocity level is a velocity of approximately zero. 
     
     
       3. A diagnostic method as defined in claim 2 wherein upon reaching said minimum velocity level said analog data is displayed as a function of time by establishing a time frame for the number of incremental positions remaining after said minimum velocity level is reached, dividing said time frame into incremental time increments and recording said analog data at each of said time increments until the increments of time equal the completion of the time frame. 
     
     
       4. A diagnostic method as defined in claim 3 .[.wherein the.]. .Iadd.further including the steps of recording .Iaddend.temperature .[.is recorded.]. .Iadd.in the reciprocating equipment .Iaddend.at each incremental position along the stroke length and .[.is.]. graphically .[.displayed in step (e).]. .Iadd.displaying said temperature .Iaddend.along with said pressure and velocity .[.and stored as master profile data in step (f).].. 
     
     
       5. A diagnostic method as defined in claim 4 further comprising programming the microcomputer .[.in which said master profile data is stored.]. to generate a cursor in the form of a vertical line upon said CRT display at any one of the incremental positions along said stroke length; adjusting the position of said line cursor to a desired position in increments corresponding to distance between said incremental positions; and displaying the data of pressure and velocity on said CRT screen corresponding to the adjusted position of said line cursor. 
     
     
       6. A diagnostic method as defined in claim 1 further comprising detecting when said predetermined minimum velocity level is reached and graphically displaying the analog data of pressure and velocity in step (e) as a function of time upon reaching said minimum velocity level and until said stroke length is completed. .Iadd.7. A diagnostic method for analyzing and monitoring the process parameters of reciprocating equipment in which a linear reciprocating device is traversed over a fixed stroke length at high speed comprising the steps of: (a) dividing a parameter indicative of movement of the device into a predetermined number of incremental data collection points;   performing, for a first ram cycle, the following steps (b)-(f):   (b) generating data corresponding to said parameter and the pressure developed by said device at each such incremental data collection point;   (c) recording the time transpired in the movement of said device along said stroke length;   (d) determining the velocity of said device at each such incremental data collection point;   (e) generating a graphical representation corresponding to pressure and velocity as a function of the device movement parameter along said stroke length;   (f) storing said data in the form of master profile data at an address location;   (g) repeating the sequence of generating data, determining velocity and storing data corresponding to pressure and velocity as a function of movement of said linear reciprocating device for a second ram cycle to form a current profile of such data for such second ram cycle; and   (h) generating a graphical representation of said current profile along   
     
     
        with said master profile for diagnostic purposes..Iaddend. .Iadd.8.  A diagnostic method as defined in claim 7 wherein the step (e) does not generate said graphical representation corresponding to said pressure and velocity as a function of the device movement parameter for a range of device movement parameters that are substantially zero..Iaddend. .Iadd.9. A diagnostic method as defined in claim 8 wherein upon reaching said near zero velocity, said data is graphically represented as a function of time by establishing a time frame for the number of data collection points remaining after said minimum velocity level is reached, dividing said time frame into incremental time increments and recording said data at each of said time increments until the increments of time equal the completion of the time frame..Iaddend. .Iadd.10. A diagnostic method as defined in claim 9 further including measuring temperature in the reciprocating equipment for data collection points along the stroke length and graphically representing said temperature along with said pressure and velocity..Iaddend. .Iadd.11. A diagnostic method as defined in claim 10 further comprising generating a cursor in the form of a vertical line for any one of the data collection points along said stroke length; adjusting the position of said line cursor to a desired point in increments corresponding to distance between said points; and generating an indication of the data of pressure and velocity corresponding to the adjusted position of said line cursor..Iaddend. .Iadd.12. A diagnostic method as defined in claim 8 further comprising detecting when said velocity level is reached, and graphically representing the data of pressure and velocity in step (e) as a function of time upon reaching said velocity level and until said reciprocating device traversal is completed..Iaddend. .Iadd.13. A method for monitoring the process parameters of a linear reciprocating device which traverses a stroke path at high speed to develop pressure, said method comprising the steps of: (a) collecting data at each of a plurality of data collection points, said data corresponding to a parameter indicative of movement of the device and the pressure developed by said device during a first ram cycle;   (b) graphically representing a first pressure and velocity profile as a function of the movement of said device along said stroke path based on said data collected by said step (a);   (c) repeating said collecting step (a) for a further ram cycle; and   (d) graphically representing a further pressure and velocity profile as a function of the movement of said device along said stroke path based on   
     
     
        said data collected by said repeated step (a)..Iaddend. .Iadd.14.  A method as in claim 13 wherein said graphically representing step (d) includes superimposing graphical representations of said first profile and said further profile..Iaddend. .Iadd.15. A method as defined in claim 13 wherein said method further comprises the steps of generating a cursor, permitting a user to move the cursor so as to point to a portion of at least one of said graphically represented first profile and said graphically represented further profile, and providing numerical information indicating pressure and velocity corresponding to said pointed-to portion of said profile..Iaddend. .Iadd.16. A method as defined in claim 13 wherein the graphically representing step (d) includes the step of graphically representing said profiles as a function of positions of said device where said device has a non-zero velocity..Iaddend. .Iadd.17. A method as defined in claim 13 wherein for a range of substantially zero velocities of said linear reciprocating device, said profiles are graphically represented as a function of time..Iaddend. .Iadd.18. A method as defined in claim 13 wherein a temperature is also measured and collected for each data collection point along the stroke length and said collected temperature is graphically represented along with said pressure and velocity..Iaddend. .Iadd.19. A method for monitoring the process parameters of a reciprocating apparatus of a type including a ram which traverses a stroke path at high speed to produce pressure, said method including the following steps: (a) providing a stored representation of a master velocity profile for said ram as a function of position of said ram along said stroke path;   (b) measuring the movement of said ram;   (c) deriving a velocity signal indicating velocity of said ram at a plurality of positions along said stroke path based on said measured movement; and   (d) generating, based on said stored representation and said velocity signal, a superimposed graphical representation of (i) said ram velocity as a function of said plurality of positions of said ram along said stroke path and (ii) said master velocity profile..Iaddend. .Iadd.20. A method as defined in claim 19 further including the steps of:   providing a stored representation of a master pressure profile for said ram as a function of position of said ram along said stroke path,   deriving a pressure signal indicating the pressure developed by said ram at said plurality of positions along said stroke path, and   generating a superimposed graphical representation of (i) said pressure signal as a function of said plurality of positions of said ram along said stroke path and (ii) said master pressure profile..Iaddend. .Iadd.21. A method as defined in claim 19 wherein the step of measuring includes dividing the stroke length into a number of increments and generating values corresponding to the position of said ram at each such increment based on said measured movement..Iaddend. .Iadd.22. A method for monitoring the process parameters of a high speed reciprocating ram, said ram traversing a stroke path at high speed to produce pressure, said method including the following steps:   (a) storing indicia of electrical signals representing a master pressure profile;   (b) measuring position of said ram along said stroke path;   (c) measuring pressure produced by said ram; and   (d) electrically generating an image including: a first graphical representation of pressure versus position of said ram along said stroke path based on said measured position and pressure, and   a second graphical representation of pressure versus position of said ram along said stroke path based on said stored master pressure profile indicia,     said first and second graphical representations being at least partially   
     
     
        superimposed in said image..Iaddend. .Iadd.23.  A method as in claim 22 wherein said steps (b) and (c) are repeated, and said storing step (a) comprises the step of storing indicia of measurements obtained by a repetition of said steps (b) and (c)..Iaddend. .Iadd.24. A method as in claim 22 wherein said method further includes the steps of: measuring the passage of time; and   also electrically generating a graphical representation of pressure versus time based on said measured time and said measured position..Iaddend. .Iadd.25. A method for monitoring a reciprocating apparatus including a ram traversing a stroke path at high speed to produce pressure, said method including the following steps:   (a) measuring movement of said ram;   (b) deriving a velocity signal from said measured movement, said velocity signal indicating velocity of said ram at a plurality of positions along said stroke path;   (c) deriving a pressure signal indicating said pressure produced by said ram at a plurality of positions of said ram along said stroke path; and (d) graphically representing said velocity and pressure signals as a function of position of said ram along said stroke path. .Iaddend. .Iadd.26. A method for monitoring a reciprocating apparatus including a ram and for electrically generating a graphical representation of results of said monitoring, said ram traversing a stroke path at high speed during a ram cycle to produce pressure, said method including the following steps:   (a) providing a time base;   (b) measuring position of said ram for a first ram cycle;   (c) measuring pressure produced by said ram for said first ram cycle;   (d) electrically generating a first graphical representation of pressure versus position of said ram for said first ram cycle based on said measured ram position and said measured pressure; and   (e) electrically generating a second graphical representation of pressure versus time for said first ram cycle based on said measured ram pressure and said time base, including the step of facilitating substantially simultaneous viewing of said first and second graphical representations.   
     
     
        .Iaddend. .Iadd.27.  A method as in claim 26 wherein: said step (d) includes the step of representing said pressure as a function of position along a first axis graduated in position increments; and   said step (e) includes the step of representing said pressure as a function of time along a second axis, said second axis being graduated in time increments, said first and second axes being simultaneously viewable. .Iaddend. .Iadd.28. A method as claim 26 wherein:   said stroke path has an end;   said method further includes determining when the ram reaches the ned of said stroke path;   said step (d) comprises representing said pressure versus position of said moving ram; and   said step (e) comprises representing said pressure versus time for pressure existing after said ram has reached the end of said stroke path. .Iaddend. .Iadd.29. Apparatus for monitoring the process parameters of reciprocating equipment, said equipment including a ram which traverses a stroke path at high speed to produce pressure, said apparatus comprising:   measuring means coupled to said ram for measuring the movement of said ram;   velocity means coupled to said measuring means for deriving a first signal indicating velocity of said ram at a plurality of positions along said stroke path based on said measured movement;   a memory storing indicia representing a master velocity profile for said ram as a function of position of said ram along said stroke path; and   imaging means coupled to said velocity means and to said memory for generating a superimposed graphical representation of (i) said velocity as a function of position of said ram along said stroke path and (ii) said   
     
     
        master velocity profile. .Iaddend. .Iadd.30.  Apparatus as defined in claim 29 wherein: said apparatus further includes pressure sensing means for providing a pressure signal indicating the pressure developed by said ram at said plurality of positions along said stroke path;   said memory also stores indicia representing a master pressure profile for said ram as a function of position of said ram along said stroke path; and   said imaging means generating a superimposed graphical representation of said pressure as a function of said plurality of positions of said ram along said stroke path and said master pressure profile. .Iaddend. .Iadd.31. Apparatus as defined in claim 29 wherein the movement measuring means includes means for dividing the stroke length into a number of incremental positions and generating values corresponding to the position of said ram at each such incremental position based on said measured movement. .Iaddend. .Iadd.32. Apparatus for monitoring the process parameters of reciprocating equipment, said equipment including a ram which traverses a stroke path at high speed to produce pressure, said apparatus including:   movement measuring means coupled to said ram for measuring the movement of said ram;   pressure measuring means for measuring the pressure produced by said ram as said ram traverses said stroke path;   means for storing indicia representing a master pressure profile for said ram; and   electrical imaging means, coupled to said storing means, said movement measuring means and said pressure measuring means, for generating an image based on said measured movement and pressure, said image including (i) a first graphical representation of pressure versus position of said ram along said stroke path, and (ii) a further graphical representation of pressure versus ram position along said stroke path based on said stored master pressure profile indicia, said first and second graphical representations being at least partially superimposed in said image.   
     
     
        .Iaddend. .Iadd.33.  Apparatus as in claim 32 wherein said first graphical representation corresponds to a first ram stroke; said storing means is coupled to said movement measuring means and said pressure measuring means; and said stored master pressure profile indicia are stored based on said measured movement and pressure for a second ram stroke different from said first ram stroke. .Iaddend. .Iadd.34. Apparatus as in claim 28 wherein: said apparatus further includes means for measuring the passage of time; and   said imaging means is also for electrically generating a graphical representation of pressure versus time based on said measured time and   
     
     
        said measured position. .Iaddend. .Iadd.35.  Apparatus for monitoring the process parameters of reciprocating equipment, said equipment including a ram coupled to a fluid which traverses a stroke path at high speed to produce pressure, said apparatus including: movement measuring means coupled to said ram for measuring the movement of said ram;   means coupled to said movement measuring means for deriving a first signal indicating velocity of said ram at a plurality of positions along said stroke path based on said measured movement;   pressure sensing means for providing a second signal indicating pressure produced by said ram at a plurality of positions of said ram along said stroke path; and   imaging means coupled to said deriving means and said pressure sensing means for generating a graphical velocity and pressure profile representation of said first and second signals as a function of said plurality of positions of said ram along said stroke path. .Iaddend. .Iadd.36. Apparatus for monitoring the process parameters of reciprocating equipment, said equipment including a ram traversing a stroke path at high speed during a ram stroke cycle to produce pressure, said apparatus comprising:   first measuring means for measuring the movement of said ram for a first ram stroke cycle;   second measuring means for measuring the pressure for said first ram stroke cycle;   third measuring means for measuring the passage of time during which said movement and pressure are measured; and   output means coupled to said first, second and third measuring means, for producing signals representing first and second substantially simultaneously viewable graphical representations based on said measured ram movement, said measured pressure, and said measured time passage, said first graphical representation showing pressure of said fluid versus position of said ram for said first ram stroke cycle, said second graphical representation showing pressure of said fluid versus time for said first ram stroke cycle. .Iaddend. .Iadd.37. Apparatus as in claim 30 wherein said output means provides signals representing an axis, signals representing said pressure as a function of position along an axis graduated in position increments, and signals representing said pressure as a function of time along a second axis being graduated in time increments, said first and second axes being simultaneously viewable. .Iaddend. .Iadd.38. Apparatus as in claim 30 further including an electronic display coupled to said output means, said electronic display displaying said first graphical representation showing pressure versus ram position for a portion of said first ram cycle corresponding to a first time period during which said ram is moving, said electronic display displaying said second graphical representation showing pressure versus time for a portion of said first ram cycle corresponding to a second time period during which said ram has substantially ceased moving. .Iaddend.