Active Termination Driver for Haptic Resonant Frequency Detection

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Solution Overview

Problem

Existing haptic transducer control systems face challenges in accurately determining the resonant frequency and providing robust control due to environmental factors like temperature and humidity, which affect the haptic transducer's performance.

Innovation Solution

A haptic controller with an active termination driver having a configurable output impedance, including a processor and a negative impedance converter, processes back electromagnetic force (EMF) to determine the resonant frequency and provide motion feedback, allowing for improved control and braking of the haptic transducer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If environmental factors (temperature, humidity) are not compensated for, then the haptic transducer operates with nominal resonant frequency, but the actual resonant frequency drifts leading to inaccurate control

Engineering Contradiction:

Improveresonant frequency determination accuracyVSAvoidcontrol robustness under environmental variations

Core Design Contradiction:

Measurement precisionVSReliability

Solution Approach 1:

The system continuously monitors the back EMF signal from the haptic transducer and uses this feedback to detect resonant frequency shifts caused by environmental factors. The processor adjusts the drive frequency based on this feedback to maintain accurate resonant frequency determination and robust control performance.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system dynamically changes the drive frequency parameter based on detected resonant frequency shifts. By monitoring back EMF characteristics and identifying frequency drift, the system adjusts operational parameters to compensate for environmental variations in temperature and humidity.

Inventive Principle:

Principle #35Parameter changes

2Device complexity

If the output impedance is fixed, then the driver circuit is simpler, but the ability to process back EMF and determine resonant frequency is reduced

Engineering Contradiction:

Improvedriver circuit complexityVSAvoidback EMF processing accuracy

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The output impedance is made dynamically adjustable rather than fixed. The active termination driver modifies its output impedance based on operational conditions to optimize back EMF signal processing and resonant frequency detection accuracy.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The active termination driver performs multiple functions: it drives the haptic transducer, processes back EMF signals, and enables resonant frequency determination. This multi-functional design consolidates what would otherwise require separate circuits into a single integrated component.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Ease of operation

If resonant frequency is not accurately determined, then the control system is simpler, but the motion feedback and braking capabilities are degraded

Engineering Contradiction:

Improvecontrol simplicityVSAvoidmotion feedback precision

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The system uses back EMF feedback to accurately determine resonant frequency, enabling precise motion feedback and braking control. The processor analyzes the back EMF signal characteristics to identify resonant conditions and adjusts control accordingly.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The system replaces complex mechanical sensing and control mechanisms with electrical field-based back EMF monitoring. By measuring electrical signals rather than mechanical parameters, the system achieves accurate resonant frequency determination and motion feedback with simpler hardware.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 solution enables more accurate determination of the resonant frequency and enhanced control over the haptic transducer, improving user experience by providing precise motion feedback and braking capabilities.

Implementation Method 1

The active termination driver can be configured to drive a haptic transducer and to process back electro-magnetic force (EMF) of the haptic transducer to provide motion feedback of the haptic transducer

Methodology Applied

Scientific EffectBack electromagnetic force (EMF): Electromagnetic Induction

Implementation Method 2

Haptic reproduction can refer to, among other things, techniques that can provide a corresponding touch sensation when a finger touches a display, for example. The touch sensation can be produced by control of a certain physical effect prompt associated with, or part of, the display.

Methodology Applied

Scientific EffectHaptic transducer physical effect: Electromagnetic Induction

Data Source

PatentUS9355536B2Resonance driver for determining a resonant frequency of a haptic device

Publication Date: 2016.05.31 SEMICON COMPONENTS IND LLC

AI summary

This document discusses, among other things, apparatus and methods for controlling a haptic transducer. In an example, a haptic controller can include an active termination driver having a configurable output impedance. The active termination driver can be configured to drive a haptic transducer and to process back electro-magnetic force (EMF) of the haptic transducer to provide motion feedback of the haptic transducer. In an example, the haptic controller can include a processor to provide a command signal to the active termination driver and to determine a resonant frequency of the haptic device using the motion feedback of the haptic transducer.