Stylus Surface Classification for Consistent Haptic Feedback

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Solution Overview

Problem

Conventional haptic devices for stylus devices do not adequately account for the varying textures and materials of writing surfaces, resulting in inconsistent and unnatural tactile feedback during writing or marking.

Innovation Solution

The implementation of a stylus device equipped with a tip pressure sensor and machine learning algorithms that classify the writing surface based on tip pressure data, allowing for dynamic adjustment of haptic feedback to mimic the natural feel of traditional writing instruments by controlling haptic frequency and strength according to surface roughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional haptic devices are used without surface classification, then the device structure remains simple, but the tactile feedback becomes inconsistent and unnatural across different writing surfaces

Engineering Contradiction:
Improvetactile feedback consistencyVSAvoiddevice structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary classification of the writing surface before generating haptic feedback. The machine learning model analyzes surface characteristics (roughness, texture, material) in advance and pre-determines appropriate haptic parameters, ensuring consistent and natural tactile feedback across different surfaces without requiring complex real-time adjustments during writing.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system incorporates a feedback mechanism where the classified surface information is used to adjust haptic device parameters dynamically. The machine learning model continuously monitors writing interactions and adjusts haptic feedback based on the identified surface type, creating a closed-loop system that maintains tactile feedback consistency across varying writing conditions.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If machine learning algorithms are added to classify surfaces, then haptic feedback becomes contextually appropriate, but the processing time and computational requirements increase

Engineering Contradiction:
Improvehaptic feedback adaptabilityVSAvoidprocessing time
Core Design Contradiction:
Adaptability or versatilityVSLoss of time

Solution Approach 1:

The machine learning model is pre-trained offline on extensive surface datasets before deployment. During actual writing operations, the model performs rapid inference using pre-learned surface characteristics, enabling contextual haptic adaptation without significant processing delays. The preliminary training phase transfers complex computational work to an offline setting, minimizing real-time processing requirements.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses a simplified version of the full machine learning model for real-time surface classification, employing only the essential features and parameters needed for accurate surface identification. By focusing on the most discriminative surface characteristics rather than analyzing all possible features, the system achieves adequate adaptability with reduced computational overhead and faster processing times.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of operation

If haptic feedback is dynamically adjusted based on surface classification, then the writing experience becomes more natural, but the control system complexity increases

Engineering Contradiction:
Improvewriting experienceVSAvoidcontrol system
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The system dynamically adjusts haptic device parameters (amplitude, frequency, duration, intensity) based on the classified surface type. The machine learning model maps surface characteristics to optimal haptic parameter combinations, automatically tuning the haptic feedback to match the physical properties of different writing surfaces. This parameter adaptation creates a more natural writing experience by mimicking the tactile sensations of traditional writing instruments on various surfaces.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The machine learning model serves as an intermediary layer between the surface classification sensors and the haptic actuator. It translates raw surface characteristics into appropriate haptic control commands, abstracting the complexity of direct sensor-to-actuator control. This intermediary processing simplifies the overall control architecture by centralizing the decision-making logic in a dedicated model that handles the mapping between surface properties and haptic responses.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS11726570B2Surface classifications
Publication Date: 2023.08.15 HEWLETT PACKARD DEVELOPMENT COMPANY LP
  • US11726570B2 patent drawing
  • US11726570B2 patent drawing
  • US11726570B2 patent drawing

AI summary

In some examples, an electronic device includes a tip pressure sensor to capture tip pressure data based on a writing surface. In some examples, the electronic device includes a processor to produce a classification of the writing surface based on the tip pressure data via a machine learning model. In some examples, the electronic device may include a haptic device to control haptic feedback based on the classification.