Vibratory Roller Control via Phase Angle and Bouncing Detection
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Solution Overview
Problem
Existing methods for controlling vibratory rollers are time-consuming and inefficient, especially at startup, as they require complex adjustments and data analysis to achieve optimal compaction, leading to suboptimal compaction during initial phases of operation.
Innovation Solution
A method involving a dual-amplitude vibratory mechanism with predefined phase angle control and continuous monitoring of bouncing indication values, where the mechanism automatically turns off upon detection of excessive bouncing, allowing for immediate high-amplitude operation and quick frequency adjustment to prevent harmful soil compaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If complex adjustments and data analysis are performed to achieve optimal compaction, then compaction quality is improved, but operation time is increased
Solution Approach 1:
The patent applies preliminary action by pre-defining the optimal phase angle (typically 125°-135°) before operation begins. The control system automatically adjusts the vibration frequency to maintain this predefined phase angle between the eccentric force and roller drum displacement, eliminating the need for real-time complex data analysis and multiple adjustment cycles during startup and operation.
2Manufacturing precision
If vibration amplitude is gradually increased through multiple adjustment steps, then compaction optimization is achieved, but startup time is increased
Solution Approach 1:
The patent applies preliminary action by pre-establishing the optimal phase angle relationship before operation begins. The control system immediately sets the vibration frequency to maintain this predefined phase angle, allowing the vibratory roller to start operating at optimal compaction conditions without requiring gradual amplitude increases or multiple adjustment steps during startup.
Solution Approach 2:
The patent applies parameter changes by directly adjusting the vibration frequency parameter to achieve the predefined phase angle relationship. Instead of gradually increasing amplitude through multiple steps, the system changes the frequency parameter to immediately establish optimal compaction conditions, reducing startup time while maintaining compaction quality.
3Productivity
If the vibratory roller operates at high amplitude immediately, then productivity is improved, but bouncing mode operation may occur causing harmful effects
Solution Approach 1:
The patent applies feedback by continuously monitoring the actual phase angle between the eccentric force and roller drum displacement during operation. The control system compares the actual phase angle against the predefined optimal value and automatically adjusts the vibration frequency to maintain the optimal relationship, preventing bouncing mode operation even when operating at high amplitude settings.
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 approach enables fast and efficient compaction by preventing bouncing mode operation, reducing mechanical complexity, and ensuring optimal compaction shortly after startup, with less equipment cost and improved robustness.
Implementation Method 1
Vibratory rollers are widely used to compact soil and asphalt e.g. in the construction of roads and buildings. Typically, a vibratory roller comprises eccentric weights mounted on a rotating shaft to cause a roller drum to vibrate at a certain vibration frequency.
Implementation Method 2
the vibration frequency of the compacting device is continuously adjusted so as to drive the single oscillatory system towards a characteristic resonance frequency for optimization of the compaction
Implementation Method 3
a vibratory roller comprises eccentric weights mounted on a rotating shaft to cause a roller drum to vibrate
Implementation Method 4
monitoring a bouncing indication value (BIV), wherein said bouncing indication value being calculated based on an acceleration signal indicative of the vertical acceleration of the roller drum
Data Source
AI summary
The present invention relates to a method of controlling operation of a vibratory roller (1) comprising a roller drum (3) and a vibratory mechanism (2) having at least two amplitude settings. The method comprises operating the vibratory mechanism (2) in one of said at least two amplitude settings; maintaining a predefined phase angle by controlling the vibration frequency of the vibratory mechanism (2); monitoring a bouncing indication value (BIV), said bouncing indication value being calculated based on an acceleration signal indicative of the vertical acceleration of the roller drum (3); and turning off the vibratory mechanism (2) upon detection of a resonance meter value (BIV) that exceeds a predetermined bouncing value (BV), thereby preventing the vibratory roller from operating in a bouncing mode of operation.