Hydraulic Steering Angle Estimation via Elasticity Compensation
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Solution Overview
Problem
Conventional hydraulic steering systems require expensive and fragile reference transducers/sensors for accurate positioning, which are difficult to install and maintain, especially in open or mobile structures, and mechanical systems are limited and hard to maintain.
Innovation Solution
A hydraulic steering system that uses a logic device to estimate the hydraulic elasticity and determine a corrected steering actuator speed, eliminating the need for a reference transducer by modeling the system's elasticity and using yaw rates to calculate a virtual rudder estimate for accurate steering.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If reference transducers/sensors are used for accurate positioning in hydraulic steering systems, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces mechanical reference transducers/sensors with a computational model that estimates steering angle by integrating motor speed measurements and compensating for hydraulic elasticity effects. This substitution eliminates fragile mechanical components while maintaining measurement precision through mathematical modeling and signal processing.
Solution Approach 2:
The patent creates a virtual model (copy) of the hydraulic system's elastic behavior to simulate and compensate for positioning errors. By modeling the hydraulic elasticity and integrating it with motor speed data, the system generates an accurate estimate of the steering angle without requiring physical sensors at the actuator location.
2Measurement precision
If reference transducers/sensors are installed in open or mobile structures, then measurement precision is improved, but ease of operation and maintenance deteriorate
Solution Approach 1:
The patent extracts the measurement function from the hydraulic actuator location (where reference transducers would be installed) and relocates it to the motor location. By measuring motor speed and using computational compensation for hydraulic elasticity, the system eliminates the need for installing fragile sensors in difficult-to-reach or exposed environments, greatly improving installation and maintenance ease.
3Device complexity
If mechanically steered autopilot installations are used without reference transducers, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The patent changes the approach from direct mechanical measurement to a computational parameter-based estimation. By integrating motor speed measurements over time and applying compensation parameters for hydraulic elasticity (modeled as air volume), the system achieves accurate steering angle estimation without complex mechanical linkages or reference transducers, resolving the contradiction between simplicity and precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accurate and reliable hydraulic steering without the need for expensive sensors, improving maintenance and expanding the system's applicability to various mobile structures by using sensor and control signals to estimate the steering angle/position.
Implementation Method 1
an estimate of the hydraulic elasticity of the steering system, which may be modeled as and/or equivalent to an estimate of the air volume trapped within the steering system
Data Source
AI summary
Techniques are disclosed for systems and methods to provide accurate positioning for a hydraulic steering system without a need for a steering reference transducer. A hydraulic steering system may include a logic device in communication with an autopilot pump controller. Control and sensor signals provided by the pump controller are used to determine a linear or uncompensated steering actuator speed and an estimate of the hydraulic elasticity of the steering system, which can be modeled as an estimate of the air volume trapped within the steering system. The hydraulic elasticity/air volume estimate is used to determine a corrected or compensated steering actuator speed, and the corrected steering actuator speed is used to accurately control the steering system.