Piezoelectric Haptic Feedback for Motor Vehicle Control Elements

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Solution Overview

Problem

Existing motor vehicle operating devices lack reliable and cost-effective methods for generating haptic feedback, often resulting in inefficient power consumption and unclear user interface interactions.

Innovation Solution

A method utilizing a piezoelectric element to move a spring-elastic element into active contact with an operating element, generating haptic feedback through translational movement and controlled activation only when necessary, combined with a proximity and touch-sensitive surface to ensure precise feedback delivery.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a piezoelectric element is used to generate haptic feedback by deforming a membrane continuously, then haptic feedback is provided to the operator, but power consumption increases and the feedback becomes less distinct

Engineering Contradiction:
Improvehaptic feedback reliabilityVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The piezoelectric element is activated only periodically when a control symbol is actually selected, rather than continuously. The system detects tool approach or touch events and triggers haptic feedback only at these specific moments, creating a periodic activation pattern that reduces power consumption while maintaining reliable feedback when needed.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The haptic feedback function is extracted from continuous operation and applied only to specific discrete events (control symbol selection). The system separates the haptic feedback generation from continuous membrane deformation, activating it only when a control symbol is selected, thereby reducing overall power consumption while maintaining feedback reliability for actual control actions.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If discrete deformation elements are moved out of the plane to create raised areas, then haptic orientation is provided, but device complexity increases

Engineering Contradiction:
Improvehaptic orientationVSAvoidstructure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Multiple functions are merged into a single integrated structure: the piezoelectric element serves both to detect control symbol selection and to generate haptic feedback through the spring-elastic element. The spring-elastic element itself provides both the deformation mechanism and the haptic feedback, eliminating the need for separate deformation elements and reducing overall device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The spring-elastic element performs multiple functions simultaneously: it acts as a mechanical element for deformation, provides haptic feedback through its elastic properties, and enables control symbol selection detection. This multi-functionality reduces the need for separate components, thereby reducing device complexity while maintaining reliable haptic orientation.

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

3Ease of operation

If the piezoelectric element is activated continuously, then haptic feedback is always available, but power consumption increases

Engineering Contradiction:
Improvehaptic feedback availabilityVSAvoidpower consumption
Core Design Contradiction:
Ease of operationVSUse of energy by moving object

Solution Approach 1:

The system uses feedback from proximity and touch sensors to determine when haptic feedback should be activated. The control unit receives signals about tool approach or touch events and activates the piezoelectric element only in response to these specific feedback signals, ensuring haptic feedback is available when needed while avoiding continuous activation and associated power consumption.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary detection of tool approach or touch events before activating the piezoelectric element. By detecting the operator's intent in advance through proximity and touch sensors, the system can prepare for and activate haptic feedback only when actually needed, rather than maintaining continuous activation, thereby reducing power consumption while ensuring ease of operation when required.

Inventive Principle:
Principle #10Preliminary action

4Ease of operation

If a spring-elastic element is moved translationally to provide haptic feedback, then familiar tactile sensation is created, but manufacturing precision requirements increase

Engineering Contradiction:
Improvetactile sensation familiarityVSAvoidpositioning precision
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The spring-elastic element provides self-centering and automatic return to its initial position through its elastic properties. When deformed by the piezoelectric element, it naturally returns to its original state without requiring precise external positioning mechanisms, thereby reducing manufacturing precision requirements while maintaining familiar tactile sensation through its self-restoring elastic deformation.

Inventive Principle:
Principle #25Self-service

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 provides reliable, energy-efficient haptic feedback that mimics familiar operating sensations, such as those from computer keyboards, while ensuring accurate activation only at intended user interface positions, reducing power consumption and enhancing user experience.

Implementation Method 1

a spring-elastic element (16) arranged directly or indirectly below the control element (11) which can be moved and/or deformed by a piezoelectric element (14)

Methodology Applied
Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentEP3496124B1Method for controlling an operating device for a motor vehicle and operating device
Publication Date: 2020.05.20 VOLKSWAGEN AG
  • EP3496124B1 patent drawingFigure 1
  • EP3496124B1 patent drawingFigure 2a~2b
  • EP3496124B1 patent drawingFigure 3~5

AI summary

The invention relates to a method for controlling a control device (1) for a motor vehicle, comprising a control element (11). In this method, a spring-elastic element (16) arranged beneath the control element (11) is moved and/or deformed directly or indirectly by a piezoelectric element (14). This is done to provide the operator with at least haptic feedback during actuation of the control element (11). The invention proposes that, when the piezoelectric element (14) is actuated, the spring-elastic element (16) is moved toward the control element (11) and brought into operative contact (W) with it. This allows the spring-elastic element (16) to be moved from a stable initial position to an unstable deformation position when the control element (11) is actuated. Upon release of the control element (11), the spring-elastic element (16) automatically returns from the deformation position to its initial position.When switching from the initial position to the deformation position and vice versa, the spring-elastic element (16) generates haptic feedback. These features allow for the simple and cost-effective generation of haptic feedback during operation using an operating device.