Multi-axis platform driving method of high-precision scanning tunneling microscope

Abstract

The invention provides a multi-axis platform driving method of a high-precision scanning tunneling microscope. The multi-axis platform driving method comprises the following steps: acquiring a plurality of displacement set quantities; obtaining n single-axis model controllers; obtaining a micro-motion platform object; acquiring a displacement compensator; obtaining a decoupling controller; and acquiring a displacement output quantity. The invention further provides a method for establishing the single-axis model and a programmable chip.

Description

technical field [0001] The disclosure relates to the technical field of precision testing instruments, and in particular to a method for establishing a single-axis model, a multi-axis platform driving method for a high-precision scanning tunneling microscope, and a programmable chip. Background technique [0002] Scanning Tunneling Microscope (STM) is an instrument that can obtain nanoscale topographic features of the sample surface in real time, and is widely used in chemical, biomedical, integrated chip processing and other fields [1-3]. As an integral part of the multi-axis platform, it often plays a key role. It determines the accuracy of the system, and a small error will cause the deformity of the scanning trajectory. Because piezoelectric ceramics have the advantages of low cost, compact structure, high frequency, and powerful output, existing multi-axis platforms often use piezoelectric ceramics as drivers. However, their own nonlinear characteristics such as hystere...

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Problems solved by technology

By establishing open-loop hysteresis models such as Bouc-Wen, Preisach, and Duhem [4-6], directly changing the input signal to compensate for hysteresis characteristics can obtain a faster motion rate, but cannot track errors; Closed-loop methods such as integral differential control, adaptive control, fuzzy control, sliding mode control, and neural network control [7-9] can monitor the output in real time and adjust dynamically to achieve high precision, but the speed of motion is limited

[0004] With the development of multi-axis technology, single-axis systems can no longer meet the needs

More time-varying, nonlinear, and uncertain physical quantities will be introduced into the control system, and they often affect each other, which will cause the problem of multi-axis cross-coupling

People often use piezoelectric ceramics and transmission mechanisms to achieve multi-dimensional parallel motion. However, it is difficult to ensure the accuracy of multi-axis synchronous tracking trajectory using a single-axis control strategy.

Existing multi-axis platforms often adopt the transmission structure of flexible hinges, which have the advantages of compact structure, high resolution, no friction and no gap, etc., but their light damping characteristics will cause system vibration [10], and high-speed inter-axis motion will cause Large drive error, which restricts the motion accuracy of the system

In practical applications, this structure requires higher machining requirements and increases a lot of cost, and it is impossible to realize the multi-axis platform drive of low-cost and high-precision scanning tunneling microscope

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