Engine Speed Control Before High-Gear Launch in Work Machines
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Solution Overview
Problem
When a work machine like a motor grader attempts to launch into a high-speed starting gear while the engine is at its minimum idle speed, a surge in driveline load can cause the engine to lug or stall.
Innovation Solution
A control system that includes a controller to detect a request for a transmission shift and adjust the engine speed to operate at or above a desired minimum speed before completing the shift from neutral to the high-speed gear, preventing engine stalling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the work machine launches directly into a high-speed starting gear while the engine is at minimum idle speed, then the machine can achieve faster starting speed, but the driveline load surge causes the engine to lug or stall
Solution Approach 1:
The controller increases the engine's minimum idle speed before the transmission shift to high-speed gear is completed. This preliminary action ensures the engine has sufficient power reserve to handle the driveline load surge when launching into the higher gear, preventing engine lugging or stalling while still enabling faster starting speeds
2Use of energy by moving object
If the engine operates at minimum idle speed during transmission shift, then fuel consumption is reduced, but the engine cannot handle the driveline load surge
Solution Approach 1:
The controller temporarily increases the minimum idle speed setting before the transmission shift completes, ensuring sufficient engine power is available to handle the driveline load surge. After the shift is complete, the minimum idle speed returns to its original lower setting, minimizing fuel consumption during normal operation while preventing power deficiency during the critical shift moment
Data Source
AI summary
A method of operating an engine of a work machine, via a controller, includes detecting a request for a transmission shift of a transmission of the work machine from a neutral gear to a desired starting gear; determining a current transmission output speed of the transmission; determining a desired transmission output speed of the transmission corresponding to the desired starting gear; determining a desired minimum speed of the engine based on a difference between the current transmission output speed and the desired transmission output speed; and causing, based on the request for the transmission shift, the engine to operate at or above the desired minimum speed prior to a completion of the transmission shift from the neutral gear to the desired starting gear.