Resonant Actuator Phase-Braking for Vibrotactile Control

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Solution Overview

Problem

Conventional cell phones lack the ability to generate distinctive and configurable vibrotactile haptic effects, limiting their ability to provide effective feedback to users in various settings, such as a movie theater, where auditory and visual cues are not feasible.

Innovation Solution

A method and system for controlling a resonant device by generating a first actuator signal at the resonant frequency to drive the actuator and a second actuator signal approximately 180 degrees out of phase to brake the actuator, allowing for the creation of a wide variety of vibrotactile haptic effects by actively controlling the vibration patterns.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional vibration mechanisms are used in cell phones, then the device can provide basic tactile feedback, but the ability to generate distinctive and configurable haptic effects is limited

Engineering Contradiction:

Improvehaptic effect configurabilityVSAvoidcontrol system complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system dynamically adjusts vibration parameters including frequency, amplitude, and duration to generate diverse haptic effects. The controller can switch between different vibration modes and patterns, enabling configurable feedback while using a single resonant actuator, thus achieving versatility without proportionally increasing hardware complexity

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The invention changes physical parameters of the vibration signal such as frequency, amplitude, and phase to create different haptic effects. By varying these parameters over time and combining multiple vibration patterns, the system generates distinctive and configurable feedback without requiring multiple physical actuators

Inventive Principle:

Principle #35Parameter changes

2Productivity

If resonant frequency driving is used to generate vibrations, then efficient haptic feedback is produced, but the vibration cannot be stopped quickly enough for complex patterns

Engineering Contradiction:

Improvehaptic feedback responsivenessVSAvoidvibration decay time

Core Design Contradiction:

ProductivityVSLoss of time

Solution Approach 1:

The system applies a braking force in advance or simultaneously with the driving force to counteract the resonant vibration. By using an opposing phase signal (approximately 180 degrees out of phase), the vibration is actively suppressed and stopped quickly, enabling precise control of vibration duration and allowing complex haptic patterns to be generated without excessive decay time

Inventive Principle:

Principle #9Preliminary anti-action

3Adaptability or versatility

If simple vibration patterns are used, then the device is easy to control, but distinctive and differentiated haptic effects cannot be generated

Engineering Contradiction:

Improvehaptic effect differentiationVSAvoidcontrol complexity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system uses periodic vibration patterns with varying frequencies, amplitudes, and durations to create distinctive haptic effects. By sequences of periodic vibrations and strategic use of silence intervals, complex differentiated feedback patterns are generated that are easily controllable through programmed signal sequences

Inventive Principle:

Principle #19Periodic action

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 significantly increases the perceivable haptic bandwidth, enabling crisper and more compelling vibrotactile feedback, allowing for the generation of complex patterns like those found in music, enhancing user experience by providing clear and differentiated alerts.

Implementation Method 1

a first resonant system comprising a resonant actuator... generating a first signal having a first frequency approximately resonant to the first resonant system... causing the first resonant system to vibrate

Methodology Applied

Scientific EffectResonance: Resonance

Implementation Method 2

generating a second signal having a second frequency approximately 180 degrees out of phase to the first frequency. The second signal is configured to cause a braking force on the resonant actuator

Methodology Applied

Scientific EffectPhase opposition:

Data Source

PatentUS7639232B2Systems and methods for controlling a resonant device for generating vibrotactile haptic effects

Publication Date: 2009.12.29 IMMERSION CORP

AI summary

Systems and methods for controlling a resonant device are described. One described method for braking an actuator includes generating a first actuator signal configured to drive the actuator, the first actuator signal having a first frequency approximately resonant to the actuator, and transmitting the first actuator signal to the actuator. The method also includes generating a second actuator signal, having a second frequency approximately 180 degrees out of phase to the first frequency, the second actuator signal configured to cause a braking force on the actuator, and transmitting the second actuator signal to the actuator.