Work Vehicle Controller Synchronizes Gear and Erpm Changes

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Solution Overview

Problem

In automatic speed control modes for work vehicles, erpm and gear changes often occur at different times and rates, leading to jerky or rough vehicle motion due to differences in system responses, which is exacerbated by continuously changing load conditions.

Innovation Solution

An electronic controller synchronizes erpm and gear changes by adjusting timing parameters, ensuring that erpm and gear changes occur substantially simultaneously, recognizing unique shifting patterns for each gear change to align the erpm change with the gear change, thereby smoothing vehicle motion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the controller simultaneously transmits control commands to implement both erpm change and gear change, then the automatic speed control mode can respond quickly to load changes, but the erpm and gear changes occur at different times and rates causing jerky vehicle motion

Engineering Contradiction:
ImproveResponse speed to load changesVSAvoidSmoothness of vehicle motion
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The controller determines the time required for the gear change to occur and initiates the erpm change in advance (or delays it) so that both changes are synchronized. This preliminary calculation and timing adjustment ensures that the erpm change starts at the appropriate moment relative to the gear change, eliminating jerky motion while maintaining quick response to load changes.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If the controller adjusts erpm and gear settings frequently to accommodate continuously changing load conditions, then the vehicle can maintain desired ground speed, but the frequent changes exacerbate the jerky motion problem

Engineering Contradiction:
ImproveAbility to accommodate changing load conditionsVSAvoidSmoothness of vehicle motion
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

Before implementing each erpm and gear change in response to load variations, the controller calculates the required timing for synchronization. By performing this preliminary timing adjustment for each change event, the system maintains adaptability to continuously changing loads while ensuring that each individual change is smooth and synchronized, preventing exacerbation of jerky motion.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2882624B1System and method for synchronizing erpm and gear changes of a work vehicle
Publication Date: 2016.12.21 CNH IND ITALIA SPA
  • EP2882624B1 patent drawingFigure 1
  • EP2882624B1 patent drawingFigure 2
  • EP2882624B1 patent drawingFigure 3~4

AI summary

A method for operating a work vehicle in an automatic speed control mode is disclosed. The method may generally include receiving an input associated with a desired ground speed of the work vehicle, determining with a controller to implement a gear change and an erpm change in order to maintain the work vehicle at the desired ground speed, wherein the gear change includes a gear prep phase and a ratio change phase and controlling a timing parameter of at least one of the gear change or the erpm change such that the ratio change phase and the erpm change occur substantially simultaneously.