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Setting up work coordinates in ultra-precision machining is a complex and time-intensive process that is crucial for achieving the high levels of precision and tolerance required in the final product. Although advancements in machine tool technology have enabled nano-scale movements, peripheral devices have not kept pace in terms of precision. This disparity highlights the need for a method that is both highly accurate and straightforward to implement. Existing methods in ultra-precision machining have yet to achieve the desired level of accuracy, with some losing precision during the transition from setup to actual tool use when sensors are involved. A recent study introduces a novel method utilizing electron tunneling to enhance precision and simplify the measurement process. This approach employs the tool itself as a sensor probe, ensuring accuracy is maintained even during transitions. The technique theoretically measures the minute gap between the tool and workpiece at sub-nanometer scales, similar to scanning tunneling microscopy. The system requires a precision current amplifier to measure electron tunneling currents ranging from picoamperes to nanoamperes, along with a power supply. The effectiveness of this method was evaluated on an ultra-precision machine tool with various tools and workpiece materials. Measuring the tunneling current to determine the distance between the tool and the workpiece has been shown to achieve a precision of approximately 15 nm. The precision of the method was assessed based on the combination of tools, workpieces, and the applied voltage. This method demonstrates the potential for setting up the work coordinate system in ultra-precision machine tools. [ABSTRACT FROM AUTHOR]

Accurate and rapid measuring methods for displacement of nano-scale is necessary for manipulation. Self-sensing and time-digit-conversion(TDC) are two applicable measuring methods especially suitable for room-limited workspaces and vacuum-compliance required applications, thanks to their space-saving advantage and slight thermal impact on system. The self-sensing method gives measurements in high resolution at high sampling rate but its accuracy suffers from nonlinearity, while TDC has better linearity which causes less deviation to results but has a much lower sampling rate. A Kalman filter based fusion approach with dual estimation modes and self-adaptive parameters is designed to fuse the two measurements with different sampling rates at a higher frequency. Modifications to error covariance parameters are applied to traditional Kalman filter so that sensors' generalized errors rather than their Gaussian noises are taken into consideration, and corresponding derivation is given. A series of experiments are conducted to evaluate the performance of the fused measurement.

Abstract: We propose a new concept of a nano-sensing transducer system using a nano-waveguide. The small change in physical quantity affects to the change in device parameters such as refractive index or length which is relatively absorbed and observed by the resonant signals. In principle, the stored light pulse at the specified wavelength is generated by using a soliton propagating within the ring resonators, whereas a resonant signals can be stored within the nano-waveguide, i.e. a sensing transducer, which is formed by the sensing ring device. The induced change in the resonant signals by the surrounded environment is occurred, and can be detected by using the optical/quantum processor. Such a proposed device is namely suitable to perform the measurements in the nano-scale regime such as force, stress and temperature. [Copyright &y& Elsevier]