Clamp Compensation in Piezo Drive Units for Smooth Positioning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing positioning systems, particularly those using piezoelectric actuators, suffer from limited stroke and disturbances in position and velocity, which hinder high-quality imaging and precise processing in applications like electron microscopy.
Innovation Solution
The implementation of a drive unit comprising a clamp element and a shear element, where a shear element drive signal is applied to compensate for misalignment between the drive unit and the mover element, using a compensation signal based on the displacement caused by contact, to improve movement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If piezoelectric actuators are used for positioning, then high precision positioning can be achieved, but the limited stroke results in choppy movement and disturbances in position and velocity
Solution Approach 1:
The positioning system is divided into multiple drive units, each comprising a clamp element and a shear element. The clamp element provides precise positioning through piezoelectric actuation, while the shear element compensates for misalignment and disturbances. This segmentation allows each element to specialize in specific functions, resolving the contradiction between precision and smoothness.
Solution Approach 2:
The shear element acts as an intermediary between the clamp element and the mover element. It compensates for misalignment and disturbances caused by the clamp element's limited stroke, thereby smoothing the overall movement while maintaining the precision provided by the piezoelectric actuator.
2Measurement precision
If clamp element contacts mover element directly, then positioning can be achieved, but misalignment causes disturbances in position and velocity
Solution Approach 1:
The shear element serves as an intermediary that compensates for misalignment between the clamp element and the mover element. By detecting and correcting positional deviations, it eliminates the harmful disturbances that would otherwise be transmitted to the mover element, while preserving the accurate positioning capability.
Solution Approach 2:
The system incorporates feedback mechanisms where the shear element monitors the position and velocity of the mover element and adjusts its action accordingly. This feedback loop detects misalignment-induced disturbances and compensates for them in real-time, maintaining positioning accuracy while eliminating harmful effects.
3Device complexity
If single drive unit is used, then system complexity is reduced, but positioning smoothness and precision are compromised
Solution Approach 1:
Each drive unit is segmented into specialized components (clamp element and shear element) with distinct functions. This segmentation within the drive unit structure enables high-quality movement while keeping the overall system design modular and manageable, balancing complexity with reliability.
Solution Approach 2:
The clamp element and shear element are combined within a single drive unit assembly, integrating precise positioning and disturbance compensation functions into one cohesive structure. This merging maintains system compactness while achieving superior movement quality through the synergistic interaction of its components.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the movement accuracy and reduces disturbances, enabling smoother and more precise positioning of workpieces, thereby improving the quality of imaging and processing in systems like electron microscopes.
Implementation Method 1
drive unit clamp element and/or drive unit shear element can be piezo elements
Implementation Method 2
drive unit clamp element and/or drive unit shear element can be piezo elements
Data Source
AI summary
A method of producing a compensation signal to compensate for misalignment of a drive unit clamp element can include applying a clamp element drive signal to a drive unit clamp element to engage a mover element, determining a first displacement of the mover element, and determining a first compensation signal based at least in part on the first displacement. The method can further comprise applying the first compensation signal to the drive unit shear elements and the clamp element drive signal to the drive unit clamp element and determining a second displacement of the mover element. If the second displacement is less than a preselected threshold, the first compensation signal can be combined with an initial shear element drive signal to produce a modified shear element drive signal. If the second displacement is greater than the preselected threshold, a second compensation signal can be determined.