Machine Acceleration Control via Virtual Gear Downshift
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Solution Overview
Problem
Existing machine control systems fail to prevent unintended acceleration when exiting a graded surface onto a horizontal surface, particularly when the automatic retarding control (ARC) strategy is deactivated, leading to potential speed increases that can be perceived as unintended acceleration.
Innovation Solution
A control system comprising a memory and a controller that stores a gear indicator and determines a virtual gear with a maximum speed limit equivalent to the machine's speed as it exits the graded surface, downshifting the transmission system to this virtual gear if the ARC strategy was active but is no longer active, thereby controlling speed and preventing unintended acceleration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the automatic retarding control (ARC) strategy is deactivated when the machine exits the graded surface, then the machine can operate with normal transmission control, but unintended acceleration occurs causing safety concerns
Solution Approach 1:
The control system performs preliminary actions by determining the virtual gear based on the machine's current speed before deactivating ARC. The transmission is downshifted to this predetermined virtual gear immediately upon ARC deactivation, preventing the unintended acceleration that would otherwise occur during the transition to normal operation.
2Reliability
If the transmission remains in the gear selected during ARC operation, then speed control is maintained during grading, but the machine experiences unintended acceleration when exiting the grade
Solution Approach 1:
The system dynamically adjusts the transmission gear based on the operational state. During ARC operation, the machine operates in the gear selected for grade control. When ARC deactivates upon exiting the grade, the system dynamically transitions to a different gear (the virtual gear) calculated from the current speed, allowing smooth adaptation between different operational modes without speed instability.
3Productivity
If a direct gear transition is made when ARC deactivates, then the transmission responds quickly to mode change, but sudden acceleration changes occur affecting operational stability
Solution Approach 1:
The control system uses feedback from the machine's current speed to determine the appropriate virtual gear for the post-ARC state. By calculating the virtual gear based on actual speed measurements and downshifting to this speed-appropriate gear, the system achieves quick response to mode change while maintaining operational stability and preventing sudden acceleration changes.
Data Source
AI summary
A system, method, and apparatus for controlling acceleration of a machine when the machine exits a grade. The system, method, and apparatus may determine a virtual gear having a maximum speed limit equivalent that matches the speed of the machine as the machine exits the grade. The system, method, and apparatus may also deactivate an automatic retarding control (ARC) strategy, which may be activated when the machine is on the grade to reduce and limit the speed of the machine to no more than a set speed, if the ARC strategy is active as the machine exits the grade. The system, method, and apparatus may also control automatic downshift of a transmission system to the virtual gear if the ARC mode was activing during the exit from the graded surface and is now deactive.