Hydraulic Pump Calibration via Multi-Step Pressure Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing calibration methods for hydraulic pumps struggle with accuracy, particularly at minimum and maximum flow rates, due to difficulties in finding exact pressure change points, leading to lower calibration accuracy.
Innovation Solution
A calibration system that acquires measured pump pressure data across a range of current command values, creates tables representing relationships between pump pressure, flow rate, and current command values, and updates the pump control table based on engine rotation speed, ensuring accurate calibration of pump capacity values across all current command values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If calibration is performed using only minimum and maximum flow rates as change points, then the calibration process is simple, but the calibration accuracy deteriorates because pressure change points cannot be accurately found at these extremes
Solution Approach 1:
The patent segments the calibration process by dividing the flow rate range into multiple intervals and selecting multiple change points (minimum flow rate, maximum flow rate, and intermediate flow rates) for calibration. This segmentation allows accurate calibration at various operating points rather than relying solely on extremes, thereby improving overall calibration accuracy while maintaining process simplicity through systematic data collection.
Solution Approach 2:
The patent applies partial action by performing calibration at specific intermediate flow rates in addition to minimum and maximum flow rates. Instead of attempting to calibrate at every possible flow rate, the system selects representative intermediate points where pressure change points can be accurately identified, achieving sufficient calibration accuracy without the complexity of full-range calibration.
2Device complexity
If calibration uses only specification-based tables without actual measurement, then the system configuration is simple, but the calibration accuracy deteriorates due to manufacturing variations and aging
Solution Approach 1:
The patent implements feedback by using actual pressure measurements from the hydraulic system to correct and update the specification-based pump capacity values. The system compares measured pressure data with expected values from the control table, calculates deviations, and uses these deviations to generate corrected pump capacity values, thereby continuously improving calibration accuracy based on real system performance.
Solution Approach 2:
The calibration system performs self-service by automatically acquiring pressure data, comparing it with specification-based expectations, calculating calibration corrections, and updating the control table without requiring external intervention. The system uses its own internal resources (sensors, controller, and existing data) to perform calibration, reducing the need for complex external calibration equipment while improving accuracy.
Data Source
AI summary
Providing high accuracy calibration of a pump control table when variable capacity of a hydraulic pump is controlled based on a pump control table representing the relationship between pump capacity and current command value. The calibration: acquires data by measuring pump pressure corresponding to each current command value while changing the current command value in a multi-step manner; obtains a factor K representing a relationship between pump pressure and pump flow rate; creates a first table representing a relationship between the factor K and pump pressure; creates a second table representing a relationship between current command value and pump pressure; creates a third table representing a relationship between pump flow rate and current command value according to factor K; and creates a pump control table representing a relationship between pump capacity and current command value through engine rotation speed during pump pressure measurement.