Diagnostic communications system for computer controlled machine tools

Abstract

A diagnostic communication system for machine tools interlinks a computer controlled machine tool with diagnostic and analysis equipment located at a location remote from the machine tool. The computer associated with the machine tool is connected with the diagnostic apparatus over a telephone line, and the machine tool is caused to execute a predetermined routine as a result of instructions transmitted to the computer from the diagnostic apparatus. The operating characteristics of the machine are monitored during the operation of the machine, and are communicated to the diagnostic apparatus, where they are compared with corresponding characteristics previously collected for the same machine, and with design limit parameters. Such comparisons furnish an indication of the present operating condition of the machine tool, and establish trends, which are useful in identifying the nature and location of incipient faults or failures before they occur. The system is used both as a diagnostic tool for diagnosing abnormal machine conditions and as a preventative maintenance tool for performing preventative maintenance operations on a routine basis.

What is claimed: 
     
       1. In a computer controlled machine tool system having a machine tool, a computer for said machine tool, and a power drive means connected to effect operation of said machine tool in response to signals from said computer, the combination comprising: a. control means located at a site remote from said machine .Iadd.tool .Iaddend.and connected to said computer for controlling said computer to operate said machine.[.,.]. .Iadd.tool so as to cause said computer for said machine tool to initiate execution of a set of predetermined diagnostic programs to gather diagnostic data indicative of the operating characteristics of said machine tool;.Iaddend.   b. means responsive to the operation of said machine tool for communicating .[.selected.]. .Iadd.said diagnostic .Iaddend.data from said machine tool site to said remote site.[.,.]..Iadd.;   c. means located at said remote site for comparing said .[.selected.]. .Iadd.diagnostic .Iaddend.data with .[.predetermined.]. .Iadd.previously gathered initial machine .Iaddend.data.[.,.]. .Iadd.indicative of the same operating characteristics of the machine tool when it was in its pristine state; and .Iaddend.   d. means for manifesting a difference between said .[.selected.]. .Iadd.diagnostic data .Iaddend.and said .[.predetermined.]. .Iadd.previously gathered initial machine .Iaddend.data.   
     
     
       2. Apparatus according to claim 1, including means for interconnecting said machine computer with said control means over an ordinary telephone line. 
     
     
       3. Apparatus according to claim 2, including a first modulator-demodulator unit at said machine site interconnected between said computer and said telephone line and a second modulator-demodulator unit at said remote site interconnected between said control means and said telephone line. 
     
     
       4. Apparatus according to claim 1, wherein said control means comprises means for modifying the programs performed by said computer, and means interconnecting said computer with said modifying means, whereby said machine is operated in accordance with signals originating at said remote site and not by signals originating at said machine site. 
     
     
       5. Apparatus according to claim 4, wherein said modifying means comprises storage means for storing a computer test program constituting a desired series of operations of said machine, means for transmitting said test program to said computer, and means located at said machine site for entering said program into said computer, whereby said computer is adapted to operate said machine tool in accordance with said test program. 
     
     
       6. Apparatus according to claim 1, wherein said communication means comprises a first modulator-demodulator unit interconnected between said computer and a telephone line, a second modulator-demodulator unit interconnected between said control means and said telephone line, and means for transmitting over said telephone line signals representative of the operation of said machine tool while it is controlled by said computer, and storage means located at said remote site for storing data corresponding to said signals, whereby said data is available for comparison with other data transmitted over said telephone line at a subsequent time. 
     
     
       7. Apparatus according to claim 6, wherein said storage means comprises means for storing a plurality of data items transmitted over said telephone line at spaced times, whereby said data is available for comparison with other data transmitted over said telephone line at a subsequent time. 
     
     
       8. Apparatus according to claim 1, including means located at said remote site for .Iadd.gathering .Iaddend.and storing .[.representative.]. .Iadd.diagnostic data representative .Iaddend.of .[.designed.]. operating characteristics of said machine tool .Iadd.when said machine tool is in its pristine state, .Iaddend.said comparing means being operative to compare .[.the.]. .Iadd.said diagnostic .Iaddend.data transmitted from said computer which data is representative of actual machine tool operating characteristics with .[.corresponding data representative of said designed operating characteristics..]. .Iadd.said initial machine data indicative of said operating characteristics of said machine tool when said machine tool is in its pristine state.Iaddend.. 
     
     
       9. A method for performing monitoring and diagnostic operations on a computer controlled machine tool, comprising the steps of: a. connecting the computer at the machine tool site to control apparatus at a remote site.[.,.]..Iadd.; .Iaddend.   b. controlling said computer in accordance with .Iadd.diagnostic .Iaddend.control signals originating at said remote site to cause said machine tool to be operated in accordance with said diagnostic control signals.[.,.]. .Iadd.to enable said computer to gather said diagnostic data representative of current machine tool operating characteristics; .Iaddend.   c. transmitting said .Iadd.diagnostic .Iaddend.data representative of current operating characteristics of said machine tool to said control apparatus during operation of said machine tool.[.,.]..Iadd.; .Iaddend.   d. comparing said transmitted diagnostic data with .[.predetermined.]. .Iadd.previously gathered initial machine data .Iaddend.at said remote site, .[.representative of said operating characteristics of said machine,.]. .Iadd.indicative of machine tool operating characteristics when the machine tool is in its pristine state; .Iaddend.and   e. manifesting the difference between said transmitted .Iadd.diagnostic .Iaddend.data and said .[.predetermined.]. .Iadd.previously gathered initial machine .Iaddend.data.   
     
     
       10. The method according to claim 9, wherein said connecting step comprises connecting said computer and said control apparatus over an ordinary telephone line. 
     
     
       11. The method according to claim 9, wherein said controlling step includes the step of transmitting a computer program from said control apparatus to said computer, said computer program causing said computer to operate said machine tool in a predetermined manner, causing said computer to receive said computer program for execution and executing said computer program to operate said machine tool. 
     
     
       12. The method according to claim 9, including the steps of maintaining a record of said predetermined data, and maintaining a record of said transmitted data at said remote location, whereby said predetermined data and said transmitted data are available for comparison with data transmitted from said computer at a subsequent time. 
     
     
       13. A method of monitoring and performing diagnostic operations on a plurality of separately located computer controlled machine tools, comprising the steps of: a. maintaining at a single analysis site, remote from at least some of said machine tools, a data storage file of operating characteristics collected at spaced time intervals and relating to each of said machine tools,   b. establishing a communications connection between one of said computer controlled machine tools and said remote location over a telephone line,   c. controlling the computer of said computer controlled machine tool to cause its machine tool to execute a predetermined diagnostic program,   d. transmitting data representative of the operating characteristics of said machine tool from said controlled computer to said remote site,   e. comparing said transmitted operating characteristics with corresponding characteristics maintained in said file, and   f. manifesting differences between said transmitted characteristics and said corresponding characteristics.