Actuator Synchronization via Speed Estimation and Position Indicators
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing position-synchronized conveyor systems rely on encoders and gears for accurate actuator synchronization, which are costly and require maintenance, and direct position estimation from motor speed can lead to unreliable results due to error accumulation.
Innovation Solution
A method that estimates actuator positions based on rotational speed and uses periodic position indicators, such as rakes with optical or capacitive sensors, to detect position changes and control motor speed, allowing for synchronization without encoders and gears.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If encoders and gears are used for position detection, then position synchronization accuracy is improved, but system cost and maintenance requirements increase
Solution Approach 1:
The patent extracts the position detection function from complex encoder-gear systems and implements it using simple periodic position indicators (such as markers on conveyors) detected by basic sensors. This removes the unnecessary complexity of encoders and gears while maintaining position detection capability.
Solution Approach 2:
Instead of using expensive encoders to directly measure position, the patent uses simple periodic position indicators that create detectable signals. These indicators are essentially simplified copies of the position information function, achieved through markers or features on the conveyor surface that can be detected by inexpensive sensors.
2Device complexity
If direct position estimation from motor speed is used, then system complexity is reduced, but position accuracy deteriorates due to error accumulation
Solution Approach 1:
The patent implements feedback by using periodic position indicators to provide periodic position corrections to the speed-based position estimate. When a position indicator is detected, it provides feedback information that resets and corrects the accumulated position estimation error, ensuring long-term accuracy without requiring complex continuous measurement systems.
3Reliability
If periodic position indicators are used, then position error can be detected and compensated, but additional sensors and indicators are required
Solution Approach 1:
The patent uses inexpensive periodic position indicators such as markers painted on conveyor surfaces or simple mechanical features on rakes. These are essentially cheap, simple objects that provide reliable position information without the cost and complexity of expensive encoders. The indicators can be simple visual or physical features that are already part of the conveyor structure.
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 continuous tracking and control of actuator positions, achieving reliable synchronization of multiple actuators with reduced maintenance and cost, by using position indicators to detect and compensate for errors in speed estimation.
Implementation Method 1
A rake passing by a certain, predetermined position can be detected by using an optical or capacitive sensor, for example.
Implementation Method 2
A rake passing by a certain, predetermined position can be detected by using an optical or capacitive sensor, for example.
Data Source
Figure 1~2
AI summary
The present disclosure describes a method and an arrangement for synchronizing positions of at least two actuators. The actuators are actuated with electric motors which are controlled by frequency converters. For each actuator, the frequency converter is used for estimating a rotational speed of the motor, and at least one position indicator on the actuator is used for indicating when the actuator reaches a predetermined position. A position indication time instant of the actuator reaching the predetermined position is detected, and at least one position indication time difference between the detected position indication time instants is calculated. At least one of the electric motors is controlled on the basis of the at least one calculated position indication time difference.