Electro-Hydraulic Pressure Sensor Fault Diagnosis Using Parallel Controllers
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Solution Overview
Problem
The independent metering control system in electro-hydraulic systems faces challenges in fault diagnosis of pressure sensors due to incompatibility of cost and accuracy, leading to long troubleshooting times and potential safety risks.
Innovation Solution
A method for fault diagnosis of pressure sensors in electro-hydraulic systems using an explicit controller and an implicit controller in parallel, which involves receiving parameter information, estimating chamber pressures, determining opening signals for independent metering valves, calculating residuals, and comparing them with preset thresholds to identify faults.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional fault diagnosis methods are used for pressure sensors in independent metering control systems, then the system structure remains simple, but the diagnostic accuracy is insufficient and troubleshooting time is long
Solution Approach 1:
The patent segments the fault diagnosis process into multiple independent residual generation channels (r1, r2, r3, r4) corresponding to different sensor faults. Each residual is generated by comparing measurements from different sensor configurations, allowing parallel evaluation of multiple potential faults simultaneously, thereby improving diagnostic accuracy without extending troubleshooting time
Solution Approach 2:
The patent introduces residual signals as intermediary variables that mediate between raw sensor measurements and fault diagnosis conclusions. These residuals serve as intermediate indicators that capture the discrepancy between expected and actual system behavior, enabling more accurate and faster fault detection without requiring complex direct comparison of all sensor readings
2Reliability
If multiple pressure sensors are deployed to improve diagnostic coverage, then the diagnostic accuracy improves, but the system cost increases
Solution Approach 1:
The patent creates virtual copies of sensor measurement channels through mathematical modeling and signal processing. Instead of physically installing additional sensors, the system generates virtual measurement channels by processing data from existing sensors through different computational paths, achieving enhanced diagnostic coverage while avoiding the cost of additional hardware
Solution Approach 2:
The patent makes the existing pressure sensors serve multiple functions: normal control feedback and fault diagnosis. By designing the control system to utilize sensor measurements in multiple ways (both for control and for generating diagnostic residuals), the system achieves comprehensive diagnostic coverage without adding dedicated diagnostic sensors, thereby avoiding increased system cost
Data Source
AI summary
A method for fault diagnosis of a pressure sensor of an electro-hydraulic system with an explicit controller and an implicit controller in parallel is provided. The method may include receiving parameter information of the electro-hydraulic system; estimating a first chamber pressure of the hydraulic actuator online by utilizing a second chamber pressure of the hydraulic actuator; obtaining valve opening signals of the explicit controller and the implicit controller in a valve controller; converting the valve opening signals are difference-calculated to obtain two residual signals; and the residuals of an independent metering valve 1 and an independent metering valve 2 are compared with a preset threshold, respectively, to identify whether the independent metering valve 1 and the independent metering valve 2 are faulty or not. The method is simple to operate, has a fast response time and low cost for troubleshooting, and improves the diagnostic accuracy and coverage of the electro-hydraulic system.