Actuator-Assisted Positioning for Tilted Carrier Accuracy

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Solution Overview

Problem

Existing positioning systems for workpieces in microscopic imaging and processing face challenges with high-throughput applications, such as rapid wear of piezoelectric motors and magnetic interference from linear motors, leading to asymmetric loading and loss of positional accuracy, especially in tilted configurations.

Innovation Solution

A positioning system incorporating a guide, carrier element, motor, restraint, and actuator, where the actuator is used to displace the carrier element relative to the restraint, and a biasing member biases the carrier element against the actuator, allowing precise positioning even when the system is inclined, using piezoelectric actuators to maintain accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If piezoelectric motors are used to actuate the positioning system, then positioning precision is improved, but the motors wear out quickly in high-throughput applications

Engineering Contradiction:
Improvepositioning precisionVSAvoidmotor durability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The positioning system is divided into two independent actuation mechanisms: a linear motor for rapid positioning and piezoelectric actuators for fine positioning and maintaining precision. This segmentation allows each component to perform its specialized function without excessive wear - the linear motor handles high-speed movements while piezoelectric elements handle precision adjustments, extending overall system durability.

Inventive Principle:
Principle #1Segmentation

2Speed

If linear motors are used to move the carrier element quickly, then positioning speed is improved, but the magnetic field generated adversely affects beam quality

Engineering Contradiction:
Improvepositioning speedVSAvoidbeam deflection
Core Design Contradiction:
SpeedVSObject-affected harmful factors

Solution Approach 1:

The linear motor is operated in periodic bursts only during positioning transitions rather than continuously. The motor accelerates the carrier element to the desired position, then is deactivated. Piezoelectric actuators take over for fine positioning and holding, allowing the linear motor to remain de-energized during beam operations, eliminating magnetic interference with the beam while maintaining high positioning speed during transitions.

Inventive Principle:
Principle #19Periodic action

3Adaptability or versatility

If the carrier element is positioned in a tilted configuration to accommodate instrument angles, then adaptability is improved, but asymmetric loading causes loss of position during transitions

Engineering Contradiction:
Improveinstrument angle accommodationVSAvoidposition accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

Piezoelectric actuators serve as intermediary elements between the linear motor and the carrier element in tilted configurations. When the linear motor positions the carrier element, the piezoelectric actuators actively compensate for asymmetric loading effects by applying counteracting forces, preventing position drift during transitions and maintaining accuracy even in tilted orientations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The piezoelectric actuators dynamically adjust their output parameters (force, displacement) in real-time to counteract the asymmetric gravitational and inertial loads caused by tilted carrier element configurations. This active parameter adjustment compensates for position loss and maintains precision across varying tilt angles.

Inventive Principle:
Principle #35Parameter changes

4Stability of the object's composition

If brakes are used to prevent movement of the inclined carrier element, then position stability is improved, but transition to deenergized state causes loss of position

Engineering Contradiction:
Improveposition stabilityVSAvoidposition accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The mechanical brake system is replaced with an active piezoelectric actuation system for position maintenance. Instead of using friction-based brakes that cause position loss during engagement/disengagement, piezoelectric actuators continuously apply precise counteracting forces to hold the carrier element position, eliminating the transition losses associated with mechanical braking while maintaining stability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

The system enables accurate and precise positioning of workpieces in space-constrained environments, compensating for asymmetric loads and maintaining positional accuracy during transitions between energized and deenergized states, enhancing imaging and processing quality.

Implementation Method 1

actuator, configured to displace the carrier element relative to the restraint along the guide when the restraint is engaged with the guide

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3716311B1Actuator-assisted positioning systems and methods
Publication Date: 2026.02.25 FEI CO
  • EP3716311B1 patent drawingFigure 1
  • EP3716311B1 patent drawingFigure 2
  • EP3716311B1 patent drawingFigure 3

AI summary

A positioning system can include a guide, a carrier element configured to engage and convey a workpiece, a motor having a mover element, a restraint coupled to the carrier element, and an actuator disposed between the restraint and the carrier element. The guide can be movable relative to a horizontal reference plane such that the carrier element coupled to the guide is inclined with respect to the horizontal reference plane. At least the mover element of the motor can be coupled to the carrier element and can be configured to move the carrier element along the guide. The restraint can be configured to selectively engage the guide to restrain movement of the carrier element in at least one direction along the guide when the guide is inclined out of the horizontal reference plane. The actuator can be configured to displace the carrier element relative to the restraint along the guide when the restraint is engaged with the guide.