Hydraulic Pump Torque Calibration for Work Vehicle Control
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Solution Overview
Problem
Existing work vehicles, such as hydraulic excavators, face variability in absorption torque due to differences among individual hydraulic pumps of the same model, leading to inconsistencies in fuel consumption and working performance.
Innovation Solution
A work vehicle system that includes an engine, hydraulic pump, hydraulic actuator, pump control device, storage unit, and control unit, where the control unit calculates and adjusts command data based on calibration information acquired in multiple equilibrium states to match engine and hydraulic pump torques, ensuring accurate absorption torque control regardless of hydraulic pump differences.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If command data is created uniformly without regard for differences among individual hydraulic pumps, then the control system is simple and easy to manufacture, but the absorption torque control accuracy deteriorates due to individual pump variations
Solution Approach 1:
The patent applies parameter changes by introducing individualized calibration data for each hydraulic pump. The control unit stores and uses pump-specific calibration information that adjusts the command values based on the actual characteristics of each pump, thereby compensating for individual variations while maintaining a relatively simple control architecture.
Solution Approach 2:
The patent implements feedback by using the calibration information obtained from each pump to adjust the command data. The control unit refers to the stored calibration data when calculating command values, creating a feedback loop that accounts for individual pump differences and improves torque control accuracy without requiring complex real-time sensing systems.
2Measurement precision
If calibration information is acquired in multiple equilibrium states, then the absorption torque control accuracy improves, but the calibration process time and complexity increase
Solution Approach 1:
The patent applies preliminary action by performing calibration during the pump installation or setup phase. The calibration information is acquired in advance and stored in the control unit, so that during normal operation, the system can directly use the pre-acquired calibration data without requiring additional calibration time. This shifts the time investment to a preliminary stage where it does not impact operational efficiency.
Data Source
AI summary
A control unit is configured to calculate a target absorption torque of a hydraulic pump at which the engine output torque and the absorption torque of the hydraulic pump match a target matching rotation speed of the engine. The control unit is configured to refer to command data, calculate a command current value corresponding to the target absorption torque, and output a command signal of the calculated value to a pump control device. The control unit is configured to calculate the absorption torque at calibration points at which there is an equilibrium state in which the output horsepower of the engine and the absorption horsepower of the hydraulic pump are matched. The control unit is configured to acquire calibration information including the calculated absorption torque and the command current value output to the pump control device in the equilibrium state, and calibrate the command data based on the calibration information.