Swing Motor Rotation Estimation from Hydraulic Pressure Signals
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Solution Overview
Problem
Construction machinery faces challenges in estimating the rotational direction and amount of rotation of swing motors without separate sensors, due to durability and cost issues with existing encoder and inertial measurement sensors, which are vulnerable to contamination and increase manufacturing costs.
Innovation Solution
The implementation of a system that uses pressure detection members and a controller to calculate the flow rate of hydraulic oil and determine the rotational direction and amount of rotation of the swing motor based on pressure differences in hydraulic oil flowing into and out of the motor, eliminating the need for separate sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate swing encoder or inertial measurement sensor is provided to detect rotational direction and speed, then measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts the rotational detection function from separate sensors (encoder or inertial measurement sensor) and integrates it into the existing hydraulic control system by using pressure detection members already present in the hydraulic lines. The controller calculates rotational direction and speed based on pressure data from these existing components, eliminating the need for additional sensors.
Solution Approach 2:
The pressure detection members originally designed for hydraulic control purposes are made to serve dual functions: both hydraulic pressure regulation and rotational direction/speed detection. This multi-functionality approach allows the system to achieve sensorless rotation detection without adding separate components.
2Measurement precision
If a separate swing encoder or inertial measurement sensor is provided, then measurement precision is improved, but reliability deteriorates due to vulnerability to contamination and durability issues
Solution Approach 1:
The patent removes vulnerable external sensors from the system and extracts the detection function into the sealed hydraulic system. By using pressure detection members that are already integrated into the hydraulic lines and protected by the hydraulic system's sealing, the solution eliminates exposure to contamination while maintaining detection accuracy.
3Measurement precision
If an inertial measurement sensor is installed to detect rotational speed, then measurement precision is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces expensive inertial measurement sensors with inexpensive pressure detection members that are already part of the hydraulic system. The pressure sensors used for hydraulic control serve dual purposes, eliminating the need for costly additional sensors and reducing manufacturing costs significantly.
Solution Approach 2:
The existing pressure detection members in the hydraulic system are made to perform multiple functions: hydraulic pressure control and rotational speed measurement. This eliminates the need for separate expensive sensors and reduces overall system cost while maintaining measurement capability.
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
This solution allows construction machinery to accurately determine the rotational direction and amount of rotation of the swing motor using pressure detection, reducing maintenance and manufacturing costs by eliminating the need for separate sensors.
Implementation Method 1
a first pressure detection member which detects pressure of the hydraulic oil passing through the first hydraulic pressure line between the first valve and the main control valve, a fourth pressure detection member which detects pressure of the hydraulic oil passing through the first hydraulic pressure line between the swing motor and the first valve
Data Source
AI summary
An embodiment of the present invention relates to construction machinery comprising: a first hydraulic pressure line which is connected to a main control valve and one side of a swing motor; a first valve arranged on the first hydraulic pressure line; a first pressure detection member which detects the pressure of the hydraulic oil passing through the first hydraulic pressure line between the first valve and the main control valve; a fourth pressure detection member which detects the pressure of the hydraulic oil passing through the first hydraulic pressure line between the swing motor and the first valve; and a control unit which calculates the flow rate of the hydraulic oil discharged from the swing motor on the basis of the pressure of the hydraulic oil detected by the first pressure detection member and the pressure of the hydraulic oil detected by the fourth pressure detection member.