Manual Transmission Angle Sensing for Precise Shift Fork Detection

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Solution Overview

Problem

Existing sensor arrangements for manual transmissions face inaccuracies in angle detection due to wear, play, elasticities, and thermal expansion, which hinder precise automation of gear selection and shifting processes.

Innovation Solution

A sensor arrangement comprising a first and second sensor element, where the first sensor element is coupled to a rotatable actuator, and the second sensor element is secured to a mount, generating a sensor signal based on relative movement, utilizing principles such as magnetic, inductive, or optical changes to accurately detect rotational angles, with an optional evaluation circuit and temperature sensing for correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional linear displacement sensing is used for tilt fork position detection, then the system structure is simple, but measurement precision deteriorates due to wear, play, elasticities, and thermal expansion

Engineering Contradiction:

Improvetilt fork position detection accuracyVSAvoidsensor arrangement complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces conventional mechanical linear displacement sensing with a magnetic field-based sensor arrangement. The first sensor element (magnet) is coupled to the tilt fork, while the second sensor element (magnetic field sensor) is secured to the transmission housing. This substitution eliminates mechanical contact and wear, achieving precise angular position detection without the drawbacks of mechanical play and elasticity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the tilt fork and the sensing system. The magnet coupled to the tilt fork generates a magnetic field that varies with angular position, and the magnetic field sensor detects these variations. This intermediary enables non-contact measurement, eliminating direct mechanical contact and its associated wear and play.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Productivity

If automated shift operations are implemented, then productivity increases, but measurement precision requirements increase due to the need for accurate gear selection control

Engineering Contradiction:

Improveshift operation automation efficiencyVSAvoidshift element position sensing accuracy

Core Design Contradiction:

ProductivityVSMeasurement precision

Solution Approach 1:

The magnetic field-based sensor arrangement provides the high measurement precision required for automated shift operations by eliminating mechanical wear and play. The non-contact sensing method ensures consistent, accurate detection of tilt fork angular position throughout the transmission's operational life, enabling reliable automated gear selection and shifting control.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The sensor arrangement provides accurate feedback on the tilt fork's angular position to the transmission control system. This feedback enables the control system to precisely monitor and control the shifting process, ensuring accurate gear selection and enabling automated shift operations with high reliability.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If multiple sensor elements are used for angle detection, then measurement precision improves, but device complexity increases

Engineering Contradiction:

Improveangular position detection accuracyVSAvoidsensor arrangement structure

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses a magnetic field-based sensing system with two sensor elements (a magnet coupled to the tilt fork and a magnetic field sensor secured to the housing) to achieve precise angular position detection. This approach provides accurate measurement without complex mechanical linkages or multiple contact points, as the magnetic field naturally encodes the angular position information.

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 precise angle detection of shift fork positions, reducing inaccuracies and improving shifting automation efficiency by directly sensing rotations, thereby enhancing the control and controllability of manual transmissions.

Implementation Method 1

the first sensor element comprises a permanent magnet which generates a variable magnetic field with a rotation of the actuator, and the second sensor element is designed to generate the sensor signal in response to a change in the magnetic field

Methodology Applied

Scientific EffectMagnetic field generation and detection: Magnetic Field

Data Source

PatentUS11578995B2Sensor arrangement for angle detection and manual transmission

Publication Date: 2023.02.14 KNORR BREMSE SYSTEME FUER NUTZFAHIZEUGE GMBH

AI summary

A sensor arrangement detects an angle of an actuator which is rotationally arranged on a support. The arrangement includes a first sensor element and a second sensor element. The first sensor element can be coupled to the actuator in order carry out a movement with respect to the support in accordance with a rotation of the actuator. The second sensor element can be rotationally fixed on the support and can be coupled to the first sensor element in order to produce, when rotating the actuator and a thus resulting movement between the first sensor element and the second sensor element, a sensor signal which is dependent on the rotation carried out by the actuator.