RFID intelligent tool management application system

CNC machine Tools have become the mainstream equipment in mechanical processing workshops. Generally, small CNC processing workshops are equipped with thousands of cutting tools, plus their supporting parts, the total number is tens of thousands, and there are hundreds of varieties. With the rapid increase in the number and type of cutting tools, standard and non-standard cutting tools of various types and specifications coexist in the production workshop, and a large number of cutting tools are frequently flowed and exchanged between the tool warehouse, machine tools, and machine tool equipment.

Currently, domestic processing workshops mostly rely on manual methods and paper barcodes to manage tools. Paper barcodes are easily stained in oily environments, and tool life can only be judged by experience. Due to the lack of tools, many machining processes are stopped, and machine tool operators spend a lot of time looking for tools. As the types of CNC machine tools and new product types increase, existing tool management solutions can no longer meet demand.

To this end, a tool information management system was developed based on RFID. The RFID chip is installed on the tool handle to realize the collection and management of tool information and reduce the overall production cost.

1. Current status and needs of tool management industry

Experts engaged in tool management research at home and abroad have developed many tool management software, but they cannot meet all the requirements for tool management. The existing tool management has the following problems:

① It is impossible to analyze the records and data of the entire life cycle of the tool. It only collects and monitors tool information at a point in time, and cannot obtain unprocessed data;

② Traditional tool management lacks M2M (Machine to Machine) information interaction and cannot achieve integrated management;

③Existing tool management solutions are designed to meet production needs and do not consider the cost of the entire life cycle of the tool.

In order to solve the above problems and achieve the goal of more intelligent automation in the manufacturing industry, the RFID tool information management system intelligently manages the use of tools in machine tools, transfers tool parameters to the machine tools, and adds the tools to the machine tool magazine for processing procedures. transfer. When the tool processing is completed, the tool production time is written into the RFID chip of the tool to realize functions such as real-time information collection of the tool and tool status tracking.

2. Tool information management system parameter collection and setting

The RFID tool information management system refers to the use of wireless radio frequency technology, CNC and RFID Readers and writers to adopt serial communication technology on the basis of communication between machinery and equipment (such as CNC machine tools, tool setters, etc.) and RFID readers in the manufacturing unit. , to realize information monitoring and storage management of tools during their life cycle. The entire tool life cycle generally includes planning, purchasing, marking, warehousing, lending, assembly, use, return, regrinding, scrapping, etc.

The prerequisite for machine tool tool management is that the tools have been grouped and calibrated with a tool setter. In order to realize the corresponding functions of the tool, the machine tool needs to initialize the tool magazine and write the tool processing time into the tool holder RFID. Since the reading and writing distance of high-frequency RFID is relatively short, when reading and writing the RFID of the tool holder, the antenna must be close to the RFID tag through a pneumatic device.

(1) Machine tool magazine initialization

To realize the intelligent transmission of CNC tool information, we must first rely on CNC machine tools. In order to ensure that the tool automatically enters the tool magazine when it is loaded into the machine tool, and that the tool parameters are read from the RFID tag into the machine tool magazine, the machine tool magazine needs to be initialized. The specific process is as follows:

① When there are tool changes in the machine tool, the machine tool needs to control the cutterhead to rotate once (see Figure 2) and re-initialize all tools to the machine tool magazine;

② The following operations are required for each knife: CNC drives the cylinder to lift the RFID reading head through instructions. After the cylinder is in place, CNC obtains the status of the sensor switch and starts the RFID reader. The cylinder status is maintained for 500ms, and CNC drives the RFID reading head through serial communication. The writer reads the RFID chip of the tool holder; retracts the cylinder, and after the CNC detects that the magnetic induction switch of the cylinder is in place, the tool continues to run;

③ Functions that need to be controlled: Add a button to the CNC operation interface. Each time the button is pressed, the cutterhead automatically rotates one circle, ensuring that it can rotate one circle every time the tool is changed, and initializes the machine tool magazine; it is not allowed to directly install the tool into the machine tool. Library handle.

Detailed explanation of the research on intelligent tool information management based on wireless radio frequency technology and installing RFID chips on the tool handles

(2) Tool production time record

When unloading (grouping) tools, the production volume (processing time) of the tools will be written into the tool management system. The process of writing the machine tool processing time into the RFID of the tool holder is as follows:

① Before the machine tool is unloaded or after the tools are assembled, the machine tool records the tools used, rotates the cutterhead, and writes the tool processing time one by one;

② The cylinder status is maintained for 500ms, and the CNC drives the RFID reader and writer through serial communication and writes to the tool holder RFID chip;

③Retract the cylinder, and after the CNC detects that the magnetic induction switch of the cylinder is in place, the cutterhead continues to rotate.

To ensure the smooth operation of the above solution, it is necessary to add a button to the CNC operation interface. Before unloading the tool or after setting the tool, press the button once to make the machine tool rotate once, and write the tool usage time, and finally complete the control of tool life. When operating the program process, you should pay attention to the operating specifications.

Detailed explanation of the research on intelligent tool information management based on wireless radio frequency technology and installing RFID chips on the tool handles

(3) Tool data storage in RFID chip

The tool code is important information to determine the uniqueness of the tool. Write it into RFID and manage each tool through the tool code. When writing the corresponding program, the nominal diameter, nominal length and corresponding program of the tool can be determined according to the specification and model of the tool, and then the corresponding diameter compensation and length compensation can be given according to the actual situation. Since the same tool can be installed on different machine tools, and the same machine tool can also process different products, abnormal conditions may also occur when processing products, so the above processing information needs to be displayed during processing. Through program control, the report can be dynamically displayed during the processing process to display the tool code, processed products, product quantity, abnormal information, etc., as well as the tool code, tool life, tool usage time and other information in the RFID record.

3. Hardware system composition and software development

The hardware consists of electronic tags (RFID), antennas, readers and related data interfaces. RFID tags are data carriers, consisting of chips and coupling components. Each RFID tag has a unique electronic code; the RFID tag antenna is the transponder antenna of the RFID electronic tag, which transmits radio frequency between the tag and the controller through communication induction. Signal, reader/writer is a device used to read or write RFID tag information.

Summary

By installing RFID tags on the tools for life identification and information reading and writing throughout the tool life cycle, readers and writers are installed on equipment hosts such as CNC machine tools as an information interaction interface between RFID tags and the main control system. RFID tags are used as The information carrier realizes the information interaction between the tool and the host and the host and the host to achieve the prediction of tool life. The RFID tool information management system can realize full life management of tools, reduce tool inventory by 20%, reduce tool costs by 10%, reduce preparation time by 15%, improve equipment efficiency by 10%, shorten delivery time by 10%, and reduce overall costs by more than 15%.