Research Of Wireless Communication In Portable CMMs

At present , Portable CMMs in the market are mainly articulated-arm CMMs, industrial-camera CMMs and hand-probe CMMs. Articulated-arm CMMs and light-pen CMMs (one of the hand-probe CMMs )are being researched in Tianjin University. In the two CMMs, communication is by wire. Using wire communication has some disadvantages, such as the length of the wire is restricted, the system is difficult to move and build. In order to mostly utilizing the advantages of portable CMMs, it is best to use wireless communication.Wireless MCU includes many advantages, such as easy to be designed, low cost, high communication rate, so wireless MCU has been broadly used in wireless communication. In this paper, one single IC, nRF24E1, is chosen as the control center. nRF24E1 is a SOC, which integrates enhanced 8051 and RF one small chip. By using this IC, we can use least components to make up a RF module, greatly reducing the cost and time to develop the IC.The following work has been done:1. According analysis, it is necessary to integrate wireless communication in portable CMMs. Comparing and analyzing popular wireless techniques, wireless MCU is chosen in the system.2. A lot of RF IC are compared and analyzed. In the end, nRF24E1 is selected. Design the framework of the wireless communication system in light-pen CMMs. Design the circuit and PCB.3. Software construction is presented, programme the software code. Design and carry out the system experiment, the result of the experiment testify the whole system can work successfully.4. Present the sketch map of the wireless communication system in light-pen CMMs, and the framework of the wireless communication system in articulated-arm CMMs.