Tool monitoring systems are used in manufacturing facilities to determine the working conditions of different machines. Over the years, these systems have become an indispensable part of the manufacturing industry. They help interpret capabilities and working conditions of different machine parts and tools. Although all tool monitoring systems may look similar and help identify tool and machine errors, they work differently. These systems are distinguished on the basis of their underlying tool monitoring technologies. Acoustic emission, power monitoring, vibration analysis, and position monitoring are four common technologies utilized by tool monitoring systems. How do tool monitoring systems powered by these technologies work? Read this post to know the answers.
Get Introduced to 4 Key Types of Tool Monitoring Systems and their Working Methods
Most tool monitoring systems that you see today are powered by one of these technologies:
- Acoustic Emission:
Many machines used in manufacturing produce high-frequency acoustic emissions. These emissions can be used for a wide range of tool condition monitoring applications such as tool wear monitoring, identifying tools, interpreting tool life, and identifying tool breakage. The tool condition monitoring is performed using acoustic emission sensors. These sensors are generally used on the surface of the tool to identify its dynamic motion that results from acoustic emissions. This motion is converted into a voltage-time signal. This signal is further used in all steps of tool condition monitoring.
- Power Monitoring:
Power monitoring utilizes a PWM transducer that samples the current and voltage of the spindle motor. The power used to machine the material is learned and stored in the software. Subsequent cuts are compared to the original learned curve to see if too much or not enough power is being used. When a tool breaks a spike will normally be seen which crosses the break threshold and would fault the machine. If a tool is broken prior to machining or if a part has previously been machined (Double cut part) no cutting power would be seen and would stop the machine for a missing condition.
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- Vibration Analysis:
The tool monitoring systems that use vibration analysis as their basic technology utilize vibration information to analyze machine health. Vibration analysis can be used to detect a wide range of problems including bearing failures, mechanical looseness of parts, misalignment of parts, imbalance, critical speeds, and so on. It is performed using an accelerometer, which is usually built into the tool. This accelerometer will produce a voltage signal corresponding to the vibration frequency of the machine. Data produced by the accelerometer is fed to the software, which records the signal as Fourier transform or Time waveform. This data is further analyzed by algorithms, which are utilized by engineers to determine machine health.
- Position Monitoring:
In this technique, the systems use an encoder and servo motor to learn the tool position. They use a probe or wand to check this position. The tool position is stored and checked after every cycle to see if the tool is present in a certain window. If the wand doesn’t make it to the earlier recorded position or travels past it, then it may be an indication that the tool is broken.