Linear Actuator Array Phase Switching for Directional Haptics
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Solution Overview
Problem
Existing vibration devices, particularly those using Eccentric Rotating Mass (ERM) and Linear Resonant Actuators (LRA), struggle to provide directional haptic sensations due to their inability to define the directionality of vibratory forces, leading to complex, costly, and power-inefficient solutions with limited controllability.
Innovation Solution
The development of a Synchronized Array of Vibration Actuators in a Network Topology (SAVANT) architecture, which employs multiple linear resonant actuators (LRAs) to generate asymmetric vibration waveforms by controlling amplitude, phase, and frequency, allowing for directional haptic cues and efficient power usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If ERM or LRA actuators are used to generate vibration forces, then vibration forces can be generated from low power input, but the directionality of vibratory forces cannot be defined
Solution Approach 1:
The system divides the vibration generation function into multiple independent LRA actuators arranged in an array, where each actuator can be independently controlled to generate vibration forces in specific directions. This segmentation enables directional control while maintaining power efficiency.
Solution Approach 2:
Multiple LRA actuators are combined in a synchronized array configuration, where their individual vibration forces are superimposed to create complex directional haptic patterns. The merging of multiple actuators' capabilities provides both directionality and power efficiency.
2Ease of operation
If multiple actuators are used to provide directional haptic sensations, then directionality can be achieved, but device complexity and cost increase
Solution Approach 1:
The LRA actuators serve multiple functions: they can generate vibration forces, control directionality, and operate in synchronized arrays. This multi-functionality reduces the need for additional specialized components, thereby managing complexity despite using multiple actuators.
Solution Approach 2:
The system dynamically controls the amplitude, phase, and frequency of each LRA actuator to achieve different directional haptic effects. This dynamic control allows a single actuator array configuration to provide multiple directional capabilities without requiring physical reconfiguration.
3Force
If ERM and LRA actuators are used, then large vibration forces can be generated, but the ability to control waveform asymmetry and directionality is limited
Solution Approach 1:
The system controls multiple parameters (amplitude, phase, frequency) of each LRA actuator independently to generate asymmetric vibration waveforms and define directionality. By changing these parameters dynamically, the system achieves both large vibration forces and high waveform controllability.
Solution Approach 2:
The synchronized LRA actuator array generates asymmetric vibration waveforms by controlling the relative phases and amplitudes of individual actuators. This asymmetry enables directional haptic cues while maintaining the ability to generate large vibration forces through constructive interference.
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 enables the creation of a wide range of vibration waveforms, including directional and non-directional ones, with improved controllability and power efficiency, effectively providing human-perceptible directional haptic feedback in applications such as gaming and navigation.
Implementation Method 1
Each LRA includes a coil and a magnet that generate a vibratory force along an axis of the LRA when an oscillating electrical signal is applied to the coil
Implementation Method 2
The multiple LRAs can be used to generate asymmetric vibration waveforms that provide directional haptic cues
Data Source
AI summary
The technology provides a multi-actuator haptic vibration device that has a mounting platform and a pair of linear resonant actuators (LRAs) attached to the mounting platform. Each LRA has an axis of vibration and a moveable mass constrained to move backwards and forwards therealong, with the axes of vibration being arranged in a same direction. A controller is configured to produce haptic feedback as a combined output waveform on the mounting platform, by obtaining an input waveform corresponding to a haptic effect and computing a control component waveform for each LRA via either (i) pre-determined performance-timing tables or (ii) pre-determined performance-timing functions. The controller estimates a position of each moveable mass, controls the position of each moveable mass, and controls each LRAs with its respective computed control component waveform.