Hydraulic Pump Control via Engine Torque Feedback
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Solution Overview
Problem
Existing hydraulic pump control systems in construction machines face challenges in accurately matching engine and pump loads due to limited information exchange, leading to inappropriate torque control and increased product development costs, especially under varying environmental conditions.
Innovation Solution
A system that continuously monitors and adjusts hydraulic pump torque based on real-time engine torque information and pump discharge pressure, using a hydraulic pump control device that calculates torque in proportion to the difference between current and limit outputs, ensuring appropriate load matching between the engine and hydraulic pump.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a predetermined torque increase rate is used to control the hydraulic pump, then the pump torque is limited to prevent engine speed decrease, but the torque increase delay occurs and load matching becomes inaccurate
Solution Approach 1:
The hydraulic pump control device receives actual engine torque information from the engine control unit and uses feedback control to adjust the pump torque. The control unit calculates a target pump torque based on the difference between actual and target engine torque, continuously adjusting the pump torque to match the engine's actual torque capacity, thereby eliminating torque increase delays and improving load matching accuracy.
Solution Approach 2:
The system dynamically adjusts the pump torque increase rate based on real-time engine operating conditions rather than using a fixed predetermined rate. The torque control adapts to changing engine torque capacity caused by environmental variations, allowing the pump torque to increase at an optimal rate that matches the engine's actual performance characteristics.
2Ease of manufacture
If standard load test methods are used to derive quantitative values for pump torque control, then torque limit can be determined, but product development period and cost increase due to multiple test environments
Solution Approach 1:
The patent replaces complex mechanical testing procedures with an electronic control system that directly measures and uses actual engine torque information. Instead of conducting multiple physical load tests under different environmental conditions, the system electronically receives real-time engine torque data and automatically adjusts pump torque accordingly, significantly reducing development time and cost.
Solution Approach 2:
The engine control unit itself provides the torque information needed for pump control through its own sensors and control logic. The system uses the engine's inherent capability to measure and report its actual torque output, eliminating the need for external testing equipment and multiple test environments.
3Device complexity
If limited engine information is used for pump control, then control simplicity is maintained, but accurate recognition of engine state and smooth engine-pump matching control cannot be achieved
Solution Approach 1:
The patent merges the engine control unit and hydraulic pump control device into an integrated control system. The engine control unit and pump control unit communicate and cooperate, sharing torque information and coordinating their control actions. This unified approach enables accurate engine state recognition and smooth engine-pump matching while maintaining reasonable system complexity through standardized communication protocols.
Data Source
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AI summary
The present disclosure relates to a method, a device, and a system for controlling a hydraulic pump of a construction machine, the system comprising: an engine; an engine control unit configured to control the engine by using engine limit torque information and current engine torque information of the engine; a hydraulic pump operated by power supplied from the engine; at least one actuator driven by a hydraulic pressure discharged from the hydraulic pump; and a hydraulic pump control device configured to control a limited swash plate angle of the hydraulic pump by using a torque of the hydraulic pump and the engine limit torque information received from the engine control unit.