Ultrasonic Haptic Control With Variable Modulation Frequency

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Solution Overview

Problem

Existing mid-air haptic interfaces lack the capability to deliver complex tactile sensations, limiting their effectiveness in enhancing immersion in VR/AR/MR experiences and automotive applications.

Innovation Solution

A controller system for ultrasonic transducers that generates an acoustic field with variable modulation frequencies and phase shifts to create complex tactile sensations, using a multi-channel configuration with pulse-width modulation to control actuation signals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a single carrier modulation frequency is used, then the device complexity is reduced, but the capability to deliver complex tactile sensations is limited

Engineering Contradiction:
Improvecapability to deliver complex tactile sensationsVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic modulation frequency switching, allowing the system to transition between different modulation frequencies (e.g., 50 Hz and 200 Hz) to create different tactile sensations. This enables the same hardware to deliver diverse complex tactile experiences without requiring separate dedicated hardware for each sensation type, thus resolving the contradiction between adaptability and device complexity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the modulation frequency parameter of the ultrasonic carrier waves to generate different tactile effects. By varying this parameter (frequency, duty cycle) through software control, the system achieves multiple tactile sensations from a single hardware configuration, addressing the contradiction between versatility and complexity

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If fixed modulation frequencies are used, then the ease of operation is improved, but the ability to create diverse haptic effects is reduced

Engineering Contradiction:
Improvediverse haptic effectsVSAvoidease of operation
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system dynamically adjusts modulation frequencies and duty cycles based on desired tactile effects, moving from fixed to variable parameters. This allows the system to create diverse haptic effects while maintaining ease of operation through automated control algorithms that manage the complexity internally

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent uses periodic modulation of ultrasonic carriers at different frequencies to create distinct tactile sensations. By implementing periodic action with variable parameters (different frequencies, duty cycles), the system achieves diverse haptic effects while the periodic nature maintains operational simplicity through rhythmic, predictable patterns

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

Enables the generation of diverse and nuanced tactile experiences, allowing for multi-point haptic feedback and improved user interaction through precise control of ultrasonic wave patterns.

Implementation Method 1

These waves, inaudible to humans, are focused onto a predefined area of ​​space by manipulating the phase shift of the carriers, thus generating acoustic pressure

Methodology Applied
Scientific EffectAcoustic pressure: Acoustic Radiation Pressure

Implementation Method 2

Mid-air haptics recreates the sensation of touch at a distance, using an array of ultrasonic speakers that vibrate the user's skin

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 3

The carriers are modulated at low frequencies (typically between 10 Hz and 1000 Hz) so that the effect is perceptible to human mechanoreceptors

Methodology Applied
Scientific EffectAmplitude modulation: Phase Modulation

Data Source

PatentEP4645038A1Haptic interface with variable modulation frequency
Publication Date: 2025.11.05 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4645038A1 patent drawingFigure 1~3
  • EP4645038A1 patent drawingFigure 4
  • EP4645038A1 patent drawingFigure 5~6

AI summary

The invention relates to a controller for controlling an array of ultrasonic transducers capable of generating an acoustic field providing a tactile sensation at a distance, comprising: - an input interface configured to receive a delay command (Cd) and a modulation command (Cm); - a channel (11) dedicated to each ultrasonic transducer, each channel (11) comprising a control circuit (8) and a generator (7) of an actuation signal for the ultrasonic transducer capable of being controlled by a logic control signal generated by the control circuit (8) to deliver voltage pulses with a delay respecting the delay command (Cd) and a modulation exploiting a modulating signal whose modulation frequency, which is capable of taking several values, is set by the modulation command (Cm); - an output interface configured to provide the actuation signals to the ultrasonic transducers (2).