Shift Fork Positioning With Hysteresis and Torque Ripple Compensation

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Solution Overview

Problem

Existing methods for actuator-driven shift fork systems fail to accurately position the gearshift sleeve due to hysteresis and torque ripple effects, leading to increased wear and mechanical play issues, which complicates the engagement and disengagement of gears in automatic transmissions.

Innovation Solution

A method utilizing a cellular automaton and learning algorithm to independently or jointly compensate for hysteresis and torque ripple effects, allowing for dynamic play correction and precise positioning of the shift fork, thereby minimizing wear and ensuring accurate gear engagement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If hysteresis compensation is implemented using traditional control loops, then positioning accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcontrol system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces traditional mechanical control loops and sensor-based feedback systems with a cellular automaton-based computational model. This software-based approach compensates for hysteresis effects through algorithmic prediction rather than physical feedback mechanisms, reducing hardware complexity while maintaining positioning accuracy.

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

Solution Approach 2:

The cellular automaton system performs self-learning and self-adjustment to compensate for hysteresis without requiring external calibration or complex control loops. The system automatically adapts to system characteristics through its inherent learning capability, eliminating the need for additional control complexity.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If torque ripple compensation is applied continuously, then positioning precision is improved, but energy consumption increases

Engineering Contradiction:
Improvepositioning precisionVSAvoidenergy consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The patent implements torque ripple compensation through periodic learning cycles rather than continuous adjustment. The cellular automaton learns torque ripple characteristics during idle periods and applies corrections only when needed, rather than continuously adjusting control signals, thereby reducing energy consumption while maintaining positioning precision.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The system performs preliminary learning of torque ripple characteristics during manufacturing or initial operation phases, storing compensation data for later use. This pre-learning approach eliminates the need for continuous real-time compensation calculations, reducing computational energy consumption during actual positioning operations.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If mechanical play is reduced through tighter tolerances, then positioning accuracy is improved, but manufacturing cost increases

Engineering Contradiction:
Improvepositioning accuracyVSAvoidmanufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent changes the control parameter space by introducing learning-based compensation algorithms that account for mechanical play variations. Instead of mechanically eliminating play through tight tolerances, the system software-compensates for play effects, allowing relaxed manufacturing tolerances while maintaining positioning accuracy.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The cellular automaton acts as an intermediary computational layer between the control input and mechanical output, mediating the effects of mechanical play. This software intermediary compensates for mechanical imperfections without requiring physical modifications to the mechanical components, reducing manufacturing costs.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If learning algorithms are implemented for play correction, then long-term positioning accuracy is improved, but initial setup time increases

Engineering Contradiction:
Improvelong-term positioning accuracyVSAvoidinitial setup time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The learning algorithm operates continuously in the background during normal system operation rather than requiring separate calibration phases. The cellular automaton learns and adapts to system characteristics during regular positioning tasks, eliminating dedicated setup time while maintaining long-term positioning accuracy through ongoing learning.

Inventive Principle:
Principle #20Continuity of useful action

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 enables precise positioning of the shift fork, reduces wear, and maintains positional accuracy, allowing for cost-effective manufacturing while ensuring reliable gear engagement and disengagement, thus extending the service life of components.

Implementation Method 1

a torque ripple of the actuator and a mechanical displacement of the gearshift sleeve are compensated independently of one another or in combination by means of a learning algorithm

Methodology Applied
Scientific EffectTorque ripple: Electromagnetic Induction

Implementation Method 2

Actuators generally have hysteresis in their motion sequence. This means that the actuator moves from a first state into a second state, for example, in the presence of a control signal. If the control signal is moved back to 'zero,' the actuator no longer completely returns to the first state, however.

Methodology Applied
Scientific EffectHysteresis: Hysteresis

Data Source

PatentUS12104692B2Method for the dynamically expanding play correction of a system affected by external sources
Publication Date: 2024.10.01 MAGNA POWERTRAIN AG & CO KG
  • US12104692B2 patent drawing
  • US12104692B2 patent drawing
  • US12104692B2 patent drawing

AI summary

A method for the dynamically expanding play correction according to a method for hysteresis compensation for an actuator and for a shift fork which is movable by this actuator via an electric motor having a rotor and a stator and which guides a gearshift sleeve, by means of a cellular automaton, wherein a torque ripple of the actuator and a mechanical displacement of the gearshift sleeve are compensated independently of one another or in combination by means of a learning algorithm.