Mobile Working Machine Gearshift Control With Virtual Position Mapping
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Solution Overview
Problem
Existing mobile working machines with multi-stage transmissions experience abrupt changes in speed and torque during gear shifts due to abrupt changes in the tractive force function, leading to undesirable acceleration or deceleration, and using a single tractive force function for all gears results in low control resolution or unattainable maximum speeds.
Innovation Solution
Implement a virtual control element position that maps the real control element position to a torque and speed, using transition functions to maintain consistent speed and torque during gear shifts, allowing for optimal control resolution and smooth transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single tractive force function is used for all gear ratios, then the control element resolution is reduced and maximum speed cannot be achieved, but using multiple tractive force functions causes abrupt changes in torque and speed during gear shifts
Solution Approach 1:
The patent divides the control element position range into multiple segments, each associated with a specific gear ratio. The virtual position mapping function segments the continuous control input into gear-specific ranges, allowing each gear to have its own optimized tractive force function while maintaining smooth transitions through virtual position continuity.
Solution Approach 2:
The patent introduces a virtual control element position as an intermediary between the real control element position and the tractive force function selection. This virtual position acts as a mediator that maps real positions to gear-appropriate virtual positions, enabling smooth gear transitions without abrupt torque changes while preserving full control resolution.
2Speed
If multiple tractive force functions are used for different gear ratios, then maximum speed can be achieved and control resolution is maintained, but abrupt changes in torque occur during gear shifts causing acceleration or deceleration
Solution Approach 1:
The patent performs preliminary mapping of the real control element position to a virtual position before selecting the tractive force function. This preliminary virtual position calculation ensures that when gear ratios change, the virtual position transitions smoothly, preventing abrupt torque changes and maintaining speed stability during gear shifts.
Solution Approach 2:
The patent changes the parameter representation from direct real control element position to a transformed virtual position parameter. This parameter transformation allows the system to maintain multiple gear-specific tractive force functions while ensuring continuous, smooth transitions during gear shifts, thereby maintaining speed stability.
3Device complexity
If the control element position is directly mapped to torque without virtual position, then the system is simple, but control resolution is lost during gear transitions
Solution Approach 1:
The patent creates a virtual copy of the control element position that is gear-specific. Instead of directly using the real control element position, the system generates a virtual position copy that is mapped according to the current gear ratio, preserving control resolution during gear transitions while adding minimal computational complexity.
Data Source
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AI summary
The invention relates to a method for operating a mobile working machine (100), wherein the mobile working machine has a drive (110) with a transmission (116) having at least two different selectable transmission stages (G1, G2), and a control element (120), comprising, when a transmission stage change occurs: providing or determining (200) a real control element position (FR) existing before the change, as well as a speed (v) of the mobile working machine existing before the change and/or a torque (M) to be set based on the previous control element position and the previous traction function before the change;Determine (210), based on the current traction force function (ZF2), an equivalent value (FA) of the control element position such that the torque to be set resulting from the equivalent value (FA) and the current traction force function (ZF2) corresponds to the torque to be set before the change, and/or such that the velocity resulting from the equivalent value and the current traction force function corresponds to the velocity present before the change.