Haptic Feedback Module Phase-Shifted Pulse Cancellation
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Solution Overview
Problem
Existing haptic feedback systems in touch interface modules, such as those used in automotive control systems, face challenges in providing impactful and timely feedback due to lingering mechanical waves that can last up to 20 ms, making it difficult to transmit rapid successive feedback and reducing user perception of haptic feedback quality.
Innovation Solution
The proposed touch interface module employs a processing and control unit to generate phase-shifted mechanical pulses that are out of phase with the existing mechanical waves, using a combination of actuator activation control signals with specific polarizations and durations to attenuate the evanescent mechanical waves, resulting in a more impactful and shorter haptic feedback experience.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electromagnetic actuators are used to generate haptic feedback, then the user perceives feedback that their command has been taken into account, but the evanescent vibrations can last up to 20 ms which interferes with transmitting rapid successive feedback
Solution Approach 1:
The patent applies preliminary anti-action by generating a counter-phase mechanical pulse before the evanescent vibration completes, specifically timed to oppose and cancel the lingering vibration. The control unit detects the mechanical wave and generates an opposing pulse that destructively interferes with the evanescent vibration, actively suppressing it rather than passively waiting for decay.
Solution Approach 2:
The system uses periodic action by sending successive haptic feedback commands at controlled intervals, with each command consisting of a primary pulse followed by a cancellation pulse. This periodic structure ensures that rapid successive feedback can be transmitted without the evanescent vibrations from previous commands interfering with subsequent ones.
2Use of energy by moving object
If the power supply to the electromagnet is stopped after maximum displacement, then energy consumption is reduced, but the induced mechanical waves continue to propagate and vibrations gradually fade away over time
Solution Approach 1:
The patent applies preliminary action by planning for the cancellation of evanescent vibrations in advance. The control unit is configured to detect the mechanical wave and generate a counter-phase pulse before the vibration naturally decays, actively terminating the vibration rather than allowing it to fade gradually. This preliminary cancellation action ensures rapid suppression while maintaining energy efficiency.
3Loss of time
If haptic feedback is spread over time to reduce evanescent vibrations, then vibration duration is reduced, but the haptic feedback becomes less frank and impactful to the user
Solution Approach 1:
The patent resolves this contradiction by applying preliminary anti-action through counter-phase pulse generation. The cancellation pulse is precisely timed to oppose the evanescent vibration without significantly extending the overall feedback duration. This active cancellation approach maintains the frank and impactful perception of haptic feedback while rapidly suppressing lingering vibrations, unlike gradual fading approaches.
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 reduces the duration of evanescent vibrations, allowing for more effective and perceivable haptic feedback, enhancing user interaction by providing a more frank and immediate sensation, especially in scenarios with high cognitive load or degraded conditions.
Implementation Method 1
a stator having an electromagnet and configured to be able to drive the mobile core according to a reciprocating translational movement
Implementation Method 2
a mobile core carrying one or more permanent magnets which can move in translation relative to the stator
Implementation Method 3
At rest, the mobile core is in a floating rest position, held by springs.
Implementation Method 4
By an inertial effect, the setting in motion of the mobile core by the stator is transmitted to the frame which in turn transmits the vibration movement to a tactile surface
Data Source
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Figure 3
Figure 4~5
AI summary
The invention relates to a haptic-feedback tactile interface module, including: a tactile surface capable of detecting at least one characteristic of a pressure exerted by a user; at least one haptic-feedback actuator configured to transmit haptic feedback to the tactile surface; and a processing and control unit connected to the tactile surface and to said at least one actuator. The processing and control unit is configured so as to activate the haptic-feedback actuator in a first time window (T1) so as to induce at least one mechanical wave propagating over the tactile surface, capable of being perceived as haptic feedback, and in a second time window (T2) so as to generate at least one mechanical pulse (202-1, 202-2, 202-3) which is phase-shifted relative to the mechanical wave in order to dampen said mechanical wave.