Tactile Actuator with Adjustable Resonant Frequency
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Solution Overview
Problem
Existing haptic devices are limited in transmitting tactile signals across a wide frequency range, particularly below 160 Hz, and often produce noise when attempting to provide vibrations above this frequency, lacking durability and requiring high voltage, which restricts their application in various devices.
Innovation Solution
A tactile actuator with multiple driving modes and a control method that utilizes a combination of an elastic member and a vibrator, driven by a magnetic field, to provide distinct tactile senses across different frequency bands, including below 160 Hz, using a controller to determine current frequency and waveform based on driving modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing haptic devices use a single resonant frequency above 160 Hz, then vibration intensity is maximized, but the frequency range is limited and low frequency tactile senses below 160 Hz cannot be provided
Solution Approach 1:
The patent applies dynamics by making the resonant frequency adjustable rather than fixed. The actuator can dynamically change its resonant frequency between a first resonant frequency (above 160 Hz) and a second resonant frequency (below 160 Hz) based on operational requirements, allowing it to adapt to different frequency range needs without requiring multiple fixed-frequency actuators
Solution Approach 2:
The patent changes the resonant frequency parameter of the actuator to resolve the contradiction. By adjusting the resonant frequency parameter between two distinct values (one above 160 Hz and one below 160 Hz), the system can provide both high-frequency vibration intensity and low-frequency tactile senses, effectively expanding the covered frequency range while using a single actuator structure
2Adaptability or versatility
If haptic devices widen the driving frequency bandwidth to provide vibration above 160 Hz, then frequency coverage is improved, but noise is generated alongside the vibration
Solution Approach 1:
The patent uses dynamics to switch between different operational modes: operating at the first resonant frequency (above 160 Hz) when high-frequency vibration is needed, and operating at the second resonant frequency (below 160 Hz) when low-frequency tactile senses are required. This dynamic switching allows the system to provide wide frequency coverage while avoiding the generation of unwanted noise by not simultaneously operating in both frequency ranges
Solution Approach 2:
The patent employs periodic action by using distinct resonant frequencies for different operational purposes. The actuator periodically operates at different resonant frequencies depending on the required tactile output, allowing it to provide broad frequency coverage over time while maintaining clean vibration output at any given moment by focusing on one resonant frequency at a time
3Volume of moving object
If piezoelectric actuators are used to provide vibration, then compact size is achieved, but durability is reduced due to fragile materials
Solution Approach 1:
The patent replaces the piezoelectric mechanical system with an electromagnetic system. Instead of using fragile piezoelectric materials that deform under electric fields, the invention uses an electromagnetic actuator with a coil, magnetic circuit, and movable armature that can be driven by electrical current to produce mechanical vibration, thereby improving durability while maintaining compact dimensions
4Shape
If EAP actuators are used to provide vibration, then flexible deformation is achieved, but high voltage is required and durability against oxidation is poor
Solution Approach 1:
The patent replaces the electro-active polymer system with an electromagnetic system. Instead of relying on polymer deformation mechanisms that require high voltage and are susceptible to oxidation, the invention uses an electromagnetic actuator with a coil and magnetic circuit that produces mechanical motion through electromagnetic forces, eliminating the oxidation resistance issue and reducing voltage requirements while maintaining effective vibration capability
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 sensitive transmission of various tactile senses across a broader frequency range, including low frequencies, providing distinct sensations like vibration, tapping, and rolling efficiently without noise, thus improving upon existing haptic technology.
Implementation Method 1
a coil configured to form a magnetic field to drive the vibrator
Implementation Method 2
a coil configured to form a magnetic field to drive the vibrator
Implementation Method 3
an elastic member configured to connect the housing and the vibrator such that the vibrator vibrates with respect to the housing
Data Source
AI summary
According to one embodiment, a tactile actuator can comprise: a housing having an accommodation space therein; a cap covering at least a portion of the accommodation space; a vibration unit disposed inside the accommodation space; an elastic member for connecting the housing and the vibration unit such that the vibration unit can vibrate with respect to the housing; a coil for forming a magnetic field to drive the vibration unit; and a control unit for determining any one driving mode on the basis of collected driving information from among a plurality of preset driving modes and determining, according to the driving mode, the characteristic of a current to be applied to the coil.