Tactile Actuator Force Estimation Using Piezoelectric Vibration Sensing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices struggle to accurately calculate the magnitude of force applied to a vibrated member by a user.
Innovation Solution
An actuator unit comprising an actuator, a first sensor, and a processing circuit that processes a detection signal to estimate the force applied to a vibrated member based on the variation cycle of a physical quantity related to the vibration, using a piezoelectric film to generate charges corresponding to the differential displacement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a capacitive sensor is used to detect force applied to the vibrated member, then the device can detect user contact, but the calculation accuracy of force magnitude is insufficient
Solution Approach 1:
The patent replaces the capacitive sensing mechanism with a piezoelectric film that directly converts mechanical force into electrical signals. The piezoelectric film generates charges proportional to the applied force, enabling direct and accurate force magnitude measurement without relying on capacitive changes that are influenced by multiple factors including distance and orientation.
Solution Approach 2:
The patent changes the detection parameter from capacitive coupling (indirect measurement) to piezoelectric charge generation (direct measurement). By utilizing the piezoelectric effect, the system directly measures force magnitude through charge proportional to applied force, eliminating the indirect and less accurate capacitive measurement approach.
2Productivity
If the variation cycle of physical quantity is used to estimate force magnitude, then rapid estimation is achieved, but the system complexity increases
Solution Approach 1:
The patent utilizes the vibration characteristics of the vibrated member as a natural measurement mechanism. By detecting variations in the vibration cycle caused by applied force, the system obtains force magnitude information without requiring additional active sensing elements or complex measurement systems, thereby maintaining simplicity while achieving rapid estimation.
Solution Approach 2:
The vibrated member itself serves as the sensing element through its vibration characteristics. The force applied by the user directly modulates the vibration cycle, which is then detected and processed. This self-sensing approach eliminates the need for separate complex sensing systems while enabling rapid force magnitude estimation.
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
Enables accurate calculation of the force applied to the vibrated member with high precision, outperforming capacitive sensors and allowing for rapid estimation of force magnitude during user interaction.
Implementation Method 1
using a piezoelectric film to generate charges corresponding to the differential displacement
Data Source
AI summary
An actuator unit includes an actuator configured to cause a vibration by a vibrated member when a force is applied to the vibrated member and a first sensor configured to generate a first detection signal indicating a first relationship of a first physical quantity varying with time. The first physical quantity is related to the vibration of the vibrated member, a variation cycle of the first physical quantity changes based on a magnitude of the force applied to the vibrated member. The actuator unit also includes a processing circuit configured to process the first detection signal, extract a parameter indicative of the variation cycle of the first physical quantity, and estimate the magnitude of the force applied to the vibrated member based on the parameter.