On-machine probing SPC data output development

Measuring data captured during programmed probing cycles on CNC machine tools equipped with Renishaw probes can now be automatically processed to provide remote up-to-the minute quality information in a statistical process control (SPC) format together with the generation of alerts against predictive trend warnings or actual problems such as results moving out of set tolerance bands. Communication for this real time information has been developed by manufacturing software specialist Seiki Systems of Brighton, in conjunction with GS Productivity Solutions (GSPS) of Bristol, resulting in a plug-in module that will benefit users of Seiki’s DNC and production monitoring Networked Manufacturing System (NMS) and GSPS’ CNC Reporter software. The CNC Reporter integration was initially demonstrated as a concept during MACH 2006 at the NEC Birmingham, between Seiki Systems, Renishaw plc and GSPS. This has now been enhanced to automatically collect the output data from a CNC machine using a Renishaw probe, via the same communications package that is in place for two-way transmission of program and collection of machine utilisation information. From the Seiki Systems’ probe data collection software, GSPS’ CNC Reporter creates real-time co-ordinate measuring machine style inspection reports direct from the machine tool to provide automated sequential reporting of measured results across all components being produced. This includes a production history with live updating to create a fully traceable record while generating the statistical environment to predict production trends. As a result, the user gains valuable information to confidently run lightly manned or unmanned production strategies. CNC Reporter works in real-time via user configurable EXCEL based spreadsheets. The software enables the user to generate individualised report templates for automatic creation of inspection reports and control charts across critical features produced on a component. These charts can be fully customised for setting control limits, out-of-tolerance features can be highlighted and with process variation being constantly tracked with areas such as tolerance drift accounted for. This enables the user to predict when and where offset correction is needed or when a change of tools should be planned or initiated. The data is drawn from the CNC control of the machine following a routine by a Renishaw touch trigger probe that is programmed to determine dimensional size or a feature position. In addition, information such as machine generated messages can also be collected via the same port which, together with information that can be output from the GSPS CNC Reporter, is used to compliment the Seiki Systems machine monitoring facility. Once available, the data can be utilised to generate remote alerts in the event of actual or predictive problems together with the generation of performance results and Overall Equipment Effectiveness (OEE) figures.