Electro Proportional Valve Failure Detection in Construction Machinery
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Solution Overview
Problem
The risk of failure in electro proportional pressure reducing valves in construction machinery control systems can lead to unintended movement of actuators, posing safety hazards and making it difficult to detect and address failures in conventional systems.
Innovation Solution
A control system that includes pressure sensors and controllers to detect failures in electro proportional pressure reducing valves, allowing for the isolation of faulty groups by blocking the supply of pilot working fluid, thereby preventing unsafe operations and ensuring other actuators remain operational.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If electro proportional pressure reducing valves are used in the electro-hydraulic main control valve, then electronic control capability is improved, but reliability deteriorates due to increased failure risk
Solution Approach 1:
The control system is divided into multiple independent groups, each with its own electro proportional pressure reducing valves and control circuits. When a failure occurs in one group, only that specific group is affected while other groups continue to operate normally, preventing complete system shutdown and improving overall reliability.
Solution Approach 2:
Pressure sensors are installed in each group to detect the secondary pressure output from the electro proportional pressure reducing valves. The controller continuously monitors these pressure signals and compares them with expected values, enabling real-time detection of valve failures and triggering appropriate safety responses.
2Reliability
If pressure sensors and failure detection systems are added, then safety is improved, but device complexity increases
Solution Approach 1:
The monitoring system is segmented into independent channels corresponding to each actuator group. Each group has its own pressure sensor and control circuit, allowing failure detection to be implemented in a modular fashion that minimizes overall system complexity while maintaining comprehensive safety coverage.
3Reliability
If the whole vehicle stops operation when electro proportional pressure reducing valves fail, then safety is improved, but productivity deteriorates due to inability to exit danger zones
Solution Approach 1:
The actuator system is divided into multiple independent groups with separate control circuits. When a failure is detected in one group, only that group is deactivated while other groups remain operational, allowing the vehicle to maintain mobility and exit danger zones while still ensuring safety by preventing unintended movements from the faulty group.
Data Source
AI summary
A control system for construction machinery includes a main control valve installed in a hydraulic line between a hydraulic pump and actuators, and including a first group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a first spool for controlling a first group of actuators of the actuators, and a second group of electro proportional pressure reducing valves outputting a secondary pressure in proportion to an external pressure command signal to a second spool for controlling a second group of actuators of the actuators, a first pressure sensor configured to detect the secondary pressure outputted from the first group of electro proportional pressure reducing valves and a second pressure sensor configured to detect the secondary pressure outputted from the second group of electro proportional pressure reducing valves, and a controller configured to output pressure command signals to the electro proportional pressure reducing valves corresponding to a manipulation signal of the construction machinery, and configured to compare the secondary pressures detected by the first and second pressure sensors and the pressure command signals to determine to determine whether or not the electro proportional pressure reducing valves fail.