Piezoelectric Actuator for Bi-Directional Vibration Damping

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Solution Overview

Problem

Existing active vibration damping devices for robotic systems are complex and primarily address one-dimensional vibration damping, failing to effectively manage vibrations in cooperative control robotic systems, especially in medical procedures where high sensitivity and multi-dimensional damping are required.

Innovation Solution

A cooperatively-controlled robot system incorporating a force sensor, control system, and actuator that detects vibrational forces and applies counter-forces to actively damp vibrations, utilizing a piezoelectric bender actuator for bi-dimensional damping, with a control system determining the necessary forces and frequencies to mitigate unwanted tool vibrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing active vibration damping devices using linear actuators are used, then vibration damping capability is provided, but device complexity increases

Engineering Contradiction:

Improvevibration damping capabilityVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical linear actuators with a piezoelectric bender actuator that uses piezoelectric effect to generate bending motion. This substitution reduces mechanical complexity while maintaining vibration damping capability, as the piezoelectric actuator directly converts electrical signals to mechanical bending action without complex mechanical linkages

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters by using high-frequency electrical signals (resonant frequency range) to drive the piezoelectric actuator, enabling effective vibration damping through parameter optimization rather than complex mechanical design

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If existing vibration damping devices addressing one-dimensional damping are used, then simple device structure is maintained, but effectiveness in multi-dimensional vibration scenarios is insufficient

Engineering Contradiction:

Improvedevice structure simplicityVSAvoidvibration damping effectiveness

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent transitions from one-dimensional vibration damping to bi-dimensional damping by utilizing the bending capability of the piezoelectric actuator in multiple directions. The actuator can damp vibrations in both lateral directions perpendicular to the tool shaft, providing comprehensive multi-dimensional vibration control while maintaining structural simplicity

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Reliability

If complex active damping devices are used, then vibration control capability is improved, but response time increases

Engineering Contradiction:

Improvevibration control capabilityVSAvoidresponse time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces slow mechanical linear actuators with piezoelectric actuators that respond almost instantaneously to electrical signals. The piezoelectric effect provides extremely fast response time, enabling the system to quickly detect and damp vibrations without significant time delay

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent implements a feedback control system where vibrations are detected and counter-forces are applied in real-time. The control system continuously monitors tool vibrations and adjusts actuator output dynamically, ensuring rapid response to changing vibration conditions

Inventive Principle:

Principle #23Feedback

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 provides effective, high-frequency vibration damping with a short response time, simplicity, and cost-effectiveness, enhancing the stability of surgical tools by distinguishing between user-intended forces and unwanted vibrations, thereby improving surgical precision.

Implementation Method 1

utilizing a piezoelectric bender actuator for bi-dimensional damping

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS9873198B2Active vibration damping device

Publication Date: 2018.01.23 JOHNS HOPKINS UNIVERSITY

AI summary

According to some embodiments of the present invention, a cooperatively-controlled robot includes a robotic actuator assembly comprising a tool holder and a force sensor. The cooperatively-controlled robot further includes a control system adapted to communicate with the robotic actuator assembly and the force sensor, and an actuator in communication with the control system and mechanically coupled to a tool. The force sensor is configured to detect a vibrational force applied on the tool and send a signal to the control system based on the vibrational force. The control system is configured to receive the signal and determine a force to apply to the tool to damp the vibrational force. The control system then signals to the actuator to apply the determined force, and the actuator applies the determined force to actively damp a vibration of the tool.