Gear Shifting Control for Working Machines
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gear shifting methods in working machines with independent drive units result in significant speed drops, posing safety risks and reducing efficiency, especially when attempting to shift gears on steep slopes.
Innovation Solution
A method that redistributes tractive force across drive units by decreasing torque on one unit and increasing it on others, monitoring the total tractive force to maintain a threshold level, thereby minimizing speed drops during gear shifting.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If torque is reduced to enable gear shifting in a single drive unit, then gear shifting becomes possible, but tractive force drops significantly causing speed loss and reduced efficiency
Solution Approach 1:
The patent combines multiple drive units into a coordinated system where torque redistribution occurs across the entire drive system during gear shifting. Instead of isolating the gear shifting action to a single drive unit, the system merges the efforts of all drive units to maintain overall tractive force, thereby enabling smooth gear transitions without significant speed loss.
Solution Approach 2:
The patent implements dynamic torque redistribution during gear shifting operations. The control system continuously adjusts torque distribution among drive units in real-time, transitioning from normal operating distribution to gear-shifting-optimized distribution and back again. This dynamic adjustment ensures that tractive force is maintained throughout the gear shifting process, resolving the contradiction between enabling gear shifts and maintaining speed.
2Ease of operation
If torque is reduced on one drive unit for gear shifting, then gear change can occur, but acceleration and safety are compromised
Solution Approach 1:
Multiple drive units are merged into a coordinated system that shares the tractive force burden during gear shifting. The combined tractive force from all drive units compensates for the torque reduction in the specific drive unit undergoing gear change, thereby maintaining acceleration performance and safety without compromising gear change capability.
Solution Approach 2:
The control system performs preliminary torque redistribution before the actual gear shifting occurs. By proactively adjusting torque distribution among drive units in anticipation of the gear change, the system prepares the drive system to maintain tractive force throughout the transition, ensuring that safety and acceleration performance are not compromised during the gear change event.
3Ease of operation
If conventional gear shifting is performed on steep slopes, then gear change is achieved, but significant speed drop occurs reducing efficiency
Solution Approach 1:
The system implements dynamic torque redistribution specifically optimized for incline operations. During gear shifting on steep slopes, the control system dynamically adjusts torque distribution to account for the additional gravitational load, ensuring that tractive force is maintained throughout the gear transition. This dynamic adaptation enables efficient gear changes on inclines without significant speed loss.
Solution Approach 2:
The patent changes operational parameters during gear shifting on inclines, specifically adjusting torque distribution ratios and monitoring tractive force thresholds. By modifying these parameters in response to the incline condition and gear shifting state, the system maintains optimal performance throughout the transition, resolving the contradiction between achieving gear change and maintaining efficiency on steep slopes.
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
The invention concerns a method for controlling gear shifting of a working machine. The invention is characterized in that it comprises the steps of: determining a representation of a first total tractive force of the working machine for the entire set of drive units; initiating a procedure for redistributing the tractive force while maintaining the first total tractive force, comprising decreasing, at least partly towards a level suitable for shifting gear, the torque and tractive force of at least the first drive unit down, and increasing, in a compensational manner, the torque and tractive force of at least one of the other drive units not subject to gear shifting; monitoring, during the redistribution procedure, a representation of a second total tractive force of the working machine for the other drive units not subject to gear shifting, and, provided that the second total tractive force exceeds a threshold limit that forms a function of the first total tractive force: decreasing the torque and tractive force of at least the first drive unit down to the level suitable for shifting gear and performing gear shifting for at least the first drive unit. The invention also concerns a computer program, a computer readable medium, a control unit and a working machine related to the method.