Inductive position sensor for electronic throttle control

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Solution Overview

Problem

Existing throttle position detection methods, such as potentiometers and magnetic sensors, face issues like wear, interference from stray magnetic fields, and operational failures, which can lead to inaccurate throttle control in vehicles.

Innovation Solution

The implementation of inductive position sensors with transmission and sensor coils mounted around a shaft, using conductive targets to determine the rotational position without physical contact and being insensitive to stray magnetic fields, providing a contactless and reliable solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If contacting solutions (potentiometers) are used for throttle position detection, then the system structure is simple, but the components are subject to wear and operational failures

Engineering Contradiction:

Improvethrottle position detection reliabilityVSAvoidsensor system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical contacting solutions (potentiometers with physical contact) with an inductive sensing system using transmission coils, sensor coils, and conductive targets. This substitution eliminates mechanical wear and contact-related failures while maintaining reliable position detection through electromagnetic coupling between the rotating target and stationary coils.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces conductive targets mounted on the rotating shaft as an intermediary element that couples the mechanical rotation to the electromagnetic sensing system. These targets modulate the magnetic field between the transmission and sensor coils, enabling position detection without direct mechanical contact between the sensor and rotating components.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If magnetic sensor solutions (hall effect, xMR) are used for throttle position detection, then contactless sensing is achieved, but the sensors are susceptible to interference from stray magnetic fields

Engineering Contradiction:

Improvemagnetic field interference resistanceVSAvoidthrottle position detection accuracy

Core Design Contradiction:

Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent converts the potential harmful effect of magnetic fields into a beneficial sensing mechanism by using the modulation of magnetic coupling between transmission and sensor coils through conductive targets. The system detects position through changes in inductive coupling caused by the rotating targets, which naturally modulate the magnetic field without being susceptible to external magnetic interference like hall effect sensors.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent replaces magnetic field-based sensing (hall effect, xMR) with inductive coupling-based sensing using transmission and sensor coils. This substitution creates a sensing system that is inherently immune to stray magnetic fields while maintaining contactless operation and precise position detection through electromagnetic coupling modulation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If inductive position sensors with multiple circuit boards are used, then wear and magnetic interference are eliminated, but the device complexity increases

Engineering Contradiction:

Improvethrottle position detection reliabilityVSAvoidmanufacturing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent divides the sensing system into multiple independent circuit boards, each handling specific functions (transmission coil driving, sensor signal reception, processing). This segmentation allows for modular manufacturing, assembly, and maintenance while achieving reliable wear-free and interference-free position detection through distributed inductive sensing elements.

Inventive Principle:

Principle #1Segmentation

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 offers a reliable and accurate throttle position detection system that is resistant to wear and magnetic interference, ensuring stable and safe throttle control in vehicles.

Implementation Method 1

each of the circuit boards including a transmission coil, sensor coils, and control circuitry that drives the transmission coil and receives signals from the sensor coils

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

the position of the target is determined by the control circuitry as the shaft is rotated

Methodology Applied

Scientific EffectInductive sensing: Electromagnetic Induction

Data Source

PatentEP3657132B1Inductive position sensor for electronic throttle control

Publication Date: 2022.09.14 INTEGRATED DEVICE TECH INC

Figure 1
Figure 2A~2B
Figure 3A

AI summary

A control that can be a throttle control of a handle-bared vehicle is presented. According to some embodiments, a control can include a plurality of circuit boards, each of the circuit boards including a transmission coil, sensor coils, and control circuity the drives the transmission coil and receives signals from the sensor coils; and one or more targets mounted on a shaft and configured to rotate over the sensor coils of the plurality of circuit boards as the shaft is rotated, wherein the plurality of circuit boards are mounted around the shaft, and wherein the position of the target is determined by the control circuitry as the shaft is rotated.