Hydrostatic Drive Fault Control for Zero-Torque Stabilization
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Solution Overview
Problem
Conventional hydrostatic drives are prone to damage and failure due to electrical faults in the electro-hydraulic adjustment units, leading to uncontrolled torque and speed, which can cause machine failure and damage.
Innovation Solution
A hydrostatic drive system with electronically controlled hydraulic machines and a control unit that detects faulty electro-hydraulic adjustment units, allowing the non-faulty units to be controlled to maintain zero torque, using electrically independent adjustment units to counteract the faulty ones, and a substitute control method to stabilize the system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electro-hydraulic adjustment units are used to control hydraulic machines, then the control precision and responsiveness are improved, but the reliability deteriorates due to electrical faults causing uncontrolled torque and damage
Solution Approach 1:
The control unit is equipped with fault detection capabilities that monitor the electro-hydraulic adjustment units in advance. When a fault is detected, the system activates backup control mechanisms (such as mechanical adjustment units or alternative control paths) to prevent uncontrolled torque and potential damage, thus cushioning against the reliability deterioration caused by electrical faults
Solution Approach 2:
The control unit acts as an intermediary between the electro-hydraulic adjustment units and the hydraulic machines. It detects faults in the electro-hydraulic units and mediates by switching to alternative control methods (such as mechanical adjustment units or direct hydraulic control) to maintain system reliability while preserving control precision
2Adaptability or versatility
If the displacement volume is made adjustable to zero to enable motor and pump operation switching, then the adaptability is improved, but the device complexity increases due to additional electro-hydraulic adjustment units
Solution Approach 1:
The control unit is designed with multi-functionality, serving both normal control operations and fault detection/management functions. This universal approach allows the system to switch between motor and pump operations while managing the complexity of multiple electro-hydraulic adjustment units through a single integrated control architecture
Solution Approach 2:
The control functions for multiple hydraulic machines and the fault detection/management capabilities are merged into a single control unit. This consolidation reduces the overall device complexity by eliminating redundant control circuits while maintaining the adaptability needed for switching between motor and pump operations
3Measurement precision
If electronic feedback control is implemented for working pressure and displacement volume, then the control accuracy is improved, but the vulnerability to electrical faults increases
Solution Approach 1:
The system implements feedback control where the control unit continuously monitors the actual values of working pressure and displacement volume from the hydraulic machines. This feedback mechanism maintains high control accuracy while the control unit is designed to detect faults in the feedback signals and switch to alternative control strategies to reduce vulnerability to electrical faults
Solution Approach 2:
The control unit includes fault detection capabilities that monitor the electronic feedback signals in advance. When faults are detected in the feedback control system, the control unit activates backup control mechanisms to cushion against the harmful effects of electrical faults while maintaining control accuracy through alternative means
Data Source
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AI summary
The invention relates to a hydrostatic drive comprising hydraulic machines (4, 8), one of which can be coupled to a drive machine (2) and another of which can be coupled to an output (14), and which are fluidically connected via a working line and also to a pressure medium sink (T) and are each designed with a displacement volume that can be adjusted to zero and to values left and right of zero, the hydraulic machines each having, for adjustment purposes, at least one electrohydraulic adjustment unit (24, 26) that can be connected to the working line and to low pressure. The invention also relates to a method for controlling the drive.