An Attachable Electromagnetic Energy Harvester Driven Wireless Sensing System Demonstrating Milling-Processes and Cutter-Wear/Breakage-Condition Monitoring

Abstract

An attachable electromagnetic-energy-harvester driven wireless vibration-sensing system for monitoring milling-processes and cutter-wear/breakage-conditions is demonstrated. The system includes an electromagnetic energy harvester, three single-axis Micro Electro-Mechanical Systems (MEMS) accelerometers, a wireless chip module, and corresponding circuits. The harvester consisting of magnets with a coil uses electromagnetic induction to harness mechanical energy produced by the rotating spindle in milling processes and consequently convert the harnessed energy to electrical output. The electrical output is rectified by the rectification circuit to power the accelerometers and wireless chip module. The harvester, circuits, accelerometer, and wireless chip are integrated as an energy-harvester driven wireless vibration-sensing system. Therefore, this completes a self-powered wireless vibration sensing system. For system testing, a numerical-controlled machining tool with various milling processes is used. According to the test results, the system is fully self-powered and able to successfully sense vibration in the milling processes. Furthermore, by analyzing the vibration signals (i.e., through analyzing the electrical outputs of the accelerometers), criteria are successfully established for the system for real-time accurate simulations of the milling-processes and cutter-conditions (such as cutter-wear conditions and cutter-breaking occurrence). Due to these results, our approach can be applied to most milling and other machining machines in factories to realize more smart machining technologies.

Self-powered wireless sensor system application for cutting process con-trol

“…The system can demonstrate monitoring of the milling process in real time. To test the system [4], a CNC-machining tool with various milling processes is used. According to the test results, the system is completely autonomous and is capable of successfully perceiving vibrations in milling processes.…”

Simultaneous Wireless Power and Data Transmission Over One Pair of Coils for Sensor-Integrated Rotating Cutter

“…Due to the limitations of current wired sensor systems, and in order to reduce the invasion degree of sensor system into the milling or drilling process and increase flexibility, a series of wireless sensor-integrated systems for rotating cutter have been developed [8]- [23], in which the sensors and other electronic components, such as sensor signal processing module, wireless data transfer module, and power supply module, are all integrated into the tool holder. For the key wireless data transfer module, the common technologies, namely Bluetooth [8]- [11], ZigBee [12]- [14], WiFi [15]- [20], Radio frequency identification (RFID) [21] and sub-1 GHz radio frequency [22], [23], have been adopted to transmit the measured condition data wirelessly to a upper host computer. It can be noted that WiFi is the most widely used transmission method for tool condition monitoring, which has the potential to be competitor of other wireless transmission technologies taking into account of its relatively high transmission speed and long transmission distance.…”

“…Therefore, some researchers started to utilize the energy harvesting techniques [25], [26] for powering wireless sensing systems in rotating applications. Particularly, in the application of rotary tools, Chung et al [14] presented an attachable electromagnetic energy harvester to power the wireless vibration-sensing system, in which four magnets on the rotating spindle in milling processes make a coil induce currents to provide the required electrical energy output. However, this output energy is only enough at the spindle speed of over 1650 rpm, which undoubtedly restricts its applications.…”

Design and Implementation of a Stereo Vision System on an Innovative 6DOF Single-Edge Machining Device for Tool Tip Localization and Path Correction

“…One of the key components studied in the current works is to monitor the tool in order to establish when it should be replaced to keep good quality standards in the machined pieces. Some are based on indirect measurements, which model the wear of the tool by measuring other variables such as cutting forces [ 10 ], vibrations [ 11 ] and electrode’s profile [ 12 ]. Whereas other works measure the wear resistance of various tool structural parameters [ 13 ].…”