Periodic Controller for Fluctuating Motor Variables
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Solution Overview
Problem
Existing control methods for fluctuating controlled variables, such as motor speed, suffer from slow response times, excessive computing power requirements, and inefficiencies due to periodic fluctuations and measurement inaccuracies, leading to energy waste and suboptimal system performance.
Innovation Solution
A method that determines control deviation at each measurement time and adjusts the controlled variable accordingly, using a controller clock synchronized with the sensor's sampling rate, and calculates control error based on differences between current and previous measurements, allowing for fast responses with minimal computing power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If traditional controllers compensate for fluctuations in the controlled variable within a load period, then the controlled variable is stabilized, but the system reacts too quickly causing unnecessary braking and energy waste
Solution Approach 1:
The control method uses periodic sampling at specific measurement times within each period and compares the current period's measured values with the previous period's values. This periodic approach allows the system to stabilize the controlled variable while avoiding continuous adjustments, thereby preventing unnecessary braking and energy waste during phases when the load consumes little energy or feeds energy back into the drive.
2Loss of energy
If a very soft or slow control system is used to allow larger speed fluctuations within a load period, then the system benefits from the load's moment of inertia, but the system reacts too slowly to changes in the reference input or average controlled variable
Solution Approach 1:
The control method determines control deviation at each specific measurement time within the period and adjusts the controlled variable proactively. By calculating the difference between current and previous period measurements at discrete points, the system prepares control actions in advance based on periodic trends, enabling fast response to changes in reference input or average controlled variable while still allowing the load's moment of inertia to be utilized during the period.
3Measurement precision
If complex control methods with high computing power are used, then control precision is improved, but the computing power requirement and complexity increase
Solution Approach 1:
The control method segments the control period into specific measurement times t1 to tn, where n measured values are determined at discrete points within each period. This segmentation approach allows the controller to process only n specific measurements per period rather than continuous data, significantly reducing computing power requirements while maintaining control precision through targeted sampling and comparison of corresponding measurement points between consecutive periods.
Data Source
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AI summary
The present invention relates to a method for controlling a controlled variable to a predetermined reference variable, wherein the actual value and/or the measured actual value of the controlled variable is influenced by a fluctuating effect with a certain periodicity, wherein the controlled variable is only adjusted if there is a control difference between the reference variable and a mean value of the actual value of the controlled variable averaged over the period of the periodicity, wherein within the period of each periodicity, at specific measurement times t1 to tn, measured values M1 to Mn are determined at a certain controller cycle, which correlate with or correspond to the respective actual value of the controlled variable, and/or from which the control difference between the reference variable and the mean value of the actual value of the controlled variable can be determined.According to the invention, the control deviation is determined at each specific measurement time t1 to tn, and the controlled variable is adjusted as necessary. The invention also relates to a data carrier containing a program and a motor control system, each for carrying out the method, and to a drive motor with such a motor control system.