Steering Wheel Switchpack Haptic Calibration Using Internal Sensors

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Solution Overview

Problem

Current steering wheel assemblies in vehicles provide inconsistent haptic feedback due to manufacturing variations and wear over time, distracting drivers and necessitating manual recalibration which disrupts production and maintenance.

Innovation Solution

A calibration system for steering wheel assemblies that utilizes internal sensors to determine resonance frequencies of haptic motors, adjusting operational parameters to ensure consistent haptic feedback without external equipment, allowing for remote recalibration and integration into vehicle systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If haptic motors are used to provide tactile feedback in steering wheel assemblies, then user interaction quality is improved, but haptic feedback quality varies between switchpacks due to manufacturing variations and wear over time

Engineering Contradiction:
Improvehaptic feedback quality consistencyVSAvoidhaptic feedback variation
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The patent changes operational parameters of haptic motors based on measured resonance frequencies. By adjusting drive signals to match the specific resonance characteristics of each switchpack, the system compensates for manufacturing variations and wear, ensuring consistent haptic feedback quality across all units and throughout their service life.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system uses sensors to measure the resonance frequency of each haptic motor and uses this feedback information to adjust operational parameters. This closed-loop approach allows the system to adapt to individual variations and degradation over time, maintaining reliable haptic feedback performance.

Inventive Principle:
Principle #23Feedback

2Reliability

If manual calibration processes are implemented to adjust haptic feedback, then haptic quality can be normalized, but production efficiency is reduced due to additional calibration steps

Engineering Contradiction:
Improvehaptic feedback consistencyVSAvoidproduction efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The system performs self-calibration by automatically measuring its own resonance frequency using integrated sensors and adjusting its operational parameters accordingly. This eliminates the need for external calibration equipment and manual intervention, maintaining high production efficiency while ensuring consistent haptic feedback quality.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces manual mechanical calibration processes with an automated electronic system that uses sensors and controllers to measure resonance frequencies and adjust motor parameters. This substitution eliminates time-consuming manual steps while achieving the same calibration objective.

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

3Measurement precision

If resonance frequency measurement is performed using external equipment, then accurate calibration can be achieved, but system complexity and calibration time increase

Engineering Contradiction:
Improveresonance frequency measurement accuracyVSAvoidcalibration system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The system uses existing sensors in the steering wheel assembly for dual purposes: normal operational sensing and resonance frequency measurement during calibration. This multi-functionality eliminates the need for separate external measurement equipment, reducing system complexity while maintaining measurement accuracy.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses the existing sensor infrastructure as an intermediary to measure resonance frequencies. Rather than introducing external measurement devices, the system leverages the available sensors to capture vibration data and derive resonance characteristics, simplifying the overall calibration system.

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Ensures consistent haptic feedback quality across steering wheel assemblies, reducing production disruptions and maintenance burdens by automating calibration processes.

Implementation Method 1

The at least one pressure sensitive component generates electric signals in response to force applied on the switchpack. The at least one pressure sensitive component may include any one of at least one piezoelectric switch, a piezoelectric sensor

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

The pressure sensitive component may provide a haptic feedback via a haptic motor

Methodology Applied
Scientific EffectElectromagnetic actuation: Electromagnetic Induction

Implementation Method 3

the sensor senses the haptic playback emitted by the haptic motor disposed in the steering wheel assembly

Methodology Applied
Scientific EffectVibration sensing: Vibration

Implementation Method 4

identifying a resonance frequency for the switchpack based at least in part on the sensed haptic profile

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP4452683B1System and method for haptic calibration
Publication Date: 2025.10.08 TESLA INC
  • EP4452683B1 patent drawingFigure 1
  • EP4452683B1 patent drawingFigure 2
  • EP4452683B1 patent drawingFigure 3

AI summary

A switchpack for a vehicle is provided that includes a haptic motor configured to provide haptic feedback to a user in a first mode of operation and provide haptic feedback to at least one sensor in a second mode of operation. The switchpack includes at least one sensor adapted to generate electric signals in response to force applied on the at least one sensor by the user during the first mode of operation. The at least one sensor is further configured to sense the haptic feedback provided by the haptic motor during the second mode of operation.