Anti-lug Control Unit for Engine Stall Prevention
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Solution Overview
Problem
Heavy machinery engines experience engine stall or lug due to varying demands, particularly when the hydraulic pump load exceeds the engine's capacity, leading to undesirable engine speed decreases.
Innovation Solution
A control unit that monitors engine performance parameters like speed and torque, compares them to predetermined ranges, and selectively varies the power supplied to the hydraulic pump to prevent stall or lug by incrementally decreasing power, using look-up tables and interpolation methods to ensure the engine operates within optimal ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the hydraulic pump load is increased to meet task demands, then the productivity and attachment control capability are improved, but the engine speed decreases causing engine lug or stall
Solution Approach 1:
The control unit continuously monitors engine speed and receives operator input regarding desired hydraulic services, then adjusts pump power accordingly. This closed-loop feedback system prevents engine stall by reducing pump load when engine speed indicates impending stall conditions, while still attempting to meet operator demands when engine capacity allows.
Solution Approach 2:
The system dynamically adjusts the power supplied to the hydraulic pump based on real-time engine speed conditions and operator demands. The control unit varies pump power selectively, transitioning between different power levels to maintain engine operation within safe limits while maximizing productivity when possible.
2Reliability
If the engine speed is maintained within optimal range, then the engine reliability is improved, but the power available to the hydraulic pump is reduced
Solution Approach 1:
The control unit applies partial action by supplying only the necessary amount of power to the hydraulic pump required to perform the desired function without exceeding engine capacity. When full operator demand cannot be met due to engine limits, the system provides partial power to prevent stall while still enabling some hydraulic function.
Solution Approach 2:
The system changes the power parameter supplied to the hydraulic pump based on engine speed conditions. The control unit adjusts pump power levels dynamically, reducing power when engine speed approaches stall thresholds and increasing power when engine capacity allows, thereby optimizing both reliability and power delivery.
3Reliability
If the control unit reacts to engine speed changes, then the engine stall prevention is improved, but the response time and engine recovery time are increased
Solution Approach 1:
The control unit takes preliminary action by proactively reducing pump power when engine speed indicators suggest approaching stall conditions, rather than waiting for actual stall to occur. This anticipatory adjustment prevents stall before it happens, reducing or eliminating recovery time and maintaining continuous operation.
Data Source
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AI summary
A control unit which controls the operation of an engine which powers a hydraulic pump and a powertrain of a vehicle; the control unit configured to selectively vary the power supplied to the hydraulic pump and powertrain by the engine, the control unit further configured to: receive a first operating parameter relating to the output of the engine; and compare the first operating parameter to a first predetermined range indicative of desired engine performance, and if the first operating parameter is outside of the first predetermined range selectively varying the power supplied to the hydraulic pump until the first operating parameter of the engine is within a second predetermined range indicative of engine recovery.