Haptic Input Actuation with Resonance-Shaped Reverberation Suppression

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Solution Overview

Problem

Existing input devices in motor vehicles suffer from reproducible suppression of post-oscillation behavior, particularly due to mechanical retuning difficulties, which affect the energy input and deflection of actuating elements, and result in unsatisfactory haptic feedback quality.

Innovation Solution

An input method and device using an electrodynamic or piezoelectric actuator with a freely oscillating excitation mass, where the electrical excitation signal has a continuous amplitude spectrum designed to ensure that the first and second natural frequencies fall within local minima of the amplitude spectrum, minimizing sustained post-oscillation by suppressing vibrations near these frequencies.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the oscillating mounting of the actuating element is dampened to suppress post-oscillation, then the suppression of post-oscillation is improved, but the energy input into the oscillating system is reduced and the resulting deflection is minimized

Engineering Contradiction:
Improvesuppression of post-oscillationVSAvoidenergy input into oscillating system
Core Design Contradiction:
Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The patent replaces mechanical damping elements with an electrical excitation signal approach. Instead of physically dampening the oscillating mounting, the system uses a control unit to generate electrical excitation signals that actively counteract and suppress post-oscillation of the actuating element, thereby maintaining mechanical energy while achieving oscillation suppression.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the parameters of the electrical excitation signal (frequency, amplitude, duration) to optimize the suppression of post-oscillation. By adjusting these electrical parameters, the system achieves effective damping without the energy losses associated with mechanical damping elements.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If mechanical tuning of the oscillating system is performed to suppress post-oscillation, then the suppression effect is improved, but the device complexity increases and mass production with reproducible results becomes difficult

Engineering Contradiction:
Improvesuppression of post-oscillationVSAvoidmechanical tuning complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical tuning procedures with a simplified electrical control system. The control unit generates electrical excitation signals that can be precisely adjusted without requiring physical modification or tuning of the mechanical oscillating system, thereby reducing device complexity and facilitating mass production.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a dynamic electrical control system that can adaptively adjust excitation parameters in real-time. This dynamic approach replaces static mechanical tuning with a flexible electronic system that can be easily reconfigured through software or control algorithms, simplifying manufacturing and ensuring reproducibility.

Inventive Principle:
Principle #15Dynamics

3Duration of action of stationary object

If subsequent haptic feedback coincides with the decaying previous haptic feedback, then the haptic feedback sequence is continuous, but the operator cannot clearly associate the feedback with the input made

Engineering Contradiction:
Improvecontinuity of haptic feedback sequenceVSAvoidassociation between feedback and input
Core Design Contradiction:
Duration of action of stationary objectVSLoss of information

Solution Approach 1:

The patent uses periodic electrical excitation signals with carefully controlled timing to generate haptic feedback. By synchronizing the excitation signal duration and frequency with the user input, the system creates distinct, well-defined haptic pulses that are temporally separated from decaying oscillations, ensuring clear association between input and feedback while maintaining continuous interaction capability.

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

The solution enables reproducible suppression of post-oscillation, allowing for high-energy input and rapid decay of haptic feedback, enhancing the quality and consistency of user interaction with the actuating element.

Implementation Method 1

an electrodynamic or piezoelectric actuator, which is intended to excite vibrations in the direction of vibration on the actuating element and generate haptic feedback

Methodology Applied
Scientific EffectElectrodynamic effect: Electromagnetic Induction

Implementation Method 2

an electrodynamic or piezoelectric actuator, which is intended to excite vibrations in the direction of vibration on the actuating element and generate haptic feedback

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 3

the electrical excitation signal has a continuous amplitude spectrum designed to ensure that the first and second natural frequencies fall within local minima of the amplitude spectrum, minimizing sustained post-oscillation by suppressing vibrations near these frequencies

Methodology Applied
Scientific EffectResonance suppression: Resonance

Implementation Method 4

an actuating element which is mounted so as to oscillate about a rest position in a direction of oscillation

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP4309027B1Input method with haptic feedback and reverberation suppression, and associated input device
Publication Date: 2025.06.25 PREH GMBH
  • EP4309027B1 patent drawingFigure 1
  • EP4309027B1 patent drawingFigure 2a
  • EP4309027B1 patent drawingFigure 2b

AI summary

The invention relates to an input device (1) for detecting a manual input with haptic feedback, said input device comprising: an actuating element (2) which is mounted so as to vibrate about a rest position in a vibration direction (b) and has an eigenmode having a first natural frequency (f1); an electrodynamic or piezoelectric actuator (4) for acting on the actuating element (2) in a vibration-inducing manner in the vibration direction (b), which actuator has an exciter mass (5) which is mounted so as to vibrate freely and can be driven by an electric excitation signal (S(t)), and an actuator eigenmode having a second natural frequency (f2); detection means (6, 8) for detecting at least a start of manual touching and/or actuation of the actuating element (2); and a control unit (12), which is electrically connected to the detection means (6, 8), for producing the electric excitation signal (S(t)) and applying the electric excitation signal (S(t)) to the electrodynamic or piezoelectric actuator (4) during or after detection of the touching and/or actuation, wherein a continuous amplitude spectrum (FFT(S(t))) is associated with the electric excitation signal (S(t)), and the first natural frequency (f1) and the second natural frequency (f2) each fall within a bandwidth range of the amplitude spectrum (FFT(S(t))) which surrounds a local minimum. The invention also relates to an associated input method.