Back-EMF Feedback for Actuator Control Precision
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuators in building systems face challenges in accurately controlling movable components due to manufacturing tolerances, leading to difficulties in precise motor control and detection of conditions like sticking, which can cause unplanned interruptions in HVAC systems.
Innovation Solution
A system utilizing back electromotive force (BEMF) feedback, where a BEMF circuit measures the BEMF produced by the motor and a processing circuit determines the active range of the motor, allowing for precise control of the movable component and detection of sticking conditions, generating alerts and driving signals to address these issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional motor control methods are used without BEMF feedback, then the device complexity is lower, but the control precision and reliability deteriorate due to manufacturing tolerances
Solution Approach 1:
The patent implements a feedback mechanism by measuring the back electromotive force (BEMF) signal from the motor and using this information to determine the motor's active range and detect sticking conditions. The processing circuit receives the BEMF signal, analyzes it to identify operational parameters, and adjusts control accordingly, creating a closed-loop control system that improves precision without requiring complex mechanical modifications
Solution Approach 2:
The patent replaces mechanical measurement methods with an electrical field-based approach. Instead of using mechanical sensors or physical indicators to detect motor position and sticking conditions, the system uses BEMF signal analysis to infer motor state, thereby reducing mechanical complexity while improving measurement precision
2Manufacturing precision
If manufacturing tolerances are reduced to improve control accuracy, then the control precision improves, but the manufacturing cost and difficulty increase
Solution Approach 1:
The patent changes the approach from controlling physical dimensions to controlling electrical parameters. By measuring BEMF signal characteristics (voltage, frequency, amplitude) and using these electrical parameters to determine motor active range and detect anomalies, the system achieves precise control without requiring tight mechanical manufacturing tolerances. This shifts the precision requirement from the mechanical domain to the electrical measurement domain
Solution Approach 2:
The patent substitutes mechanical precision requirements with electrical measurement capabilities. Instead of relying on precisely manufactured mechanical components to ensure accurate motor positioning, the system uses BEMF signal analysis to dynamically determine operational parameters, thereby reducing manufacturing complexity while maintaining or improving control accuracy
3Reliability
If BEMF-based feedback control is implemented, then the reliability improves through condition detection, but the device complexity increases due to additional circuits
Solution Approach 1:
The BEMF measurement circuit serves multiple functions simultaneously: it determines the motor's active range, detects sticking conditions, and provides feedback for control adjustment. By using a single measurement mechanism for multiple diagnostic and control purposes, the patent reduces the need for separate sensors and circuits, thereby limiting the increase in device complexity while achieving improved reliability through comprehensive condition monitoring
4Measurement precision
If the active range is determined using BEMF signal analysis, then the control accuracy improves, but the processing complexity increases
Solution Approach 1:
The processing circuit continuously monitors the BEMF signal and uses this feedback to dynamically determine the motor's active range. By analyzing the BEMF signal characteristics during motor operation and adjusting the understood active range accordingly, the system achieves high position detection accuracy without requiring complex pre-programmed position data or external reference systems
Solution Approach 2:
The motor itself provides the measurement information through its BEMF signal. The BEMF signal naturally varies with motor position and load conditions, and the processing circuit extracts active range information directly from this self-generated signal without requiring external measurement devices or complex computational models. The system uses the motor's own electrical characteristics to determine its operational parameters
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 enhances the reliability of actuator control, reduces the need for costly modifications, and mitigates unplanned interruptions by enabling precise motor control and condition detection within building systems.
Implementation Method 1
a back electromotive force (BEMF) circuit configured to measure a BEMF produced by the motor while driving the movable component
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Systems and methods for controlling a movable component using back electromotive force (BEMF)-based feedback are described. The system includes an actuator operatively coupled to the movable component. The actuator includes a motor for driving the movable component. The actuator includes a BEMF circuit for measuring a BEMF produced by the motor while driving the movable component. The system includes a processing circuit communicably coupled to the motor and the BEMF circuit. The processing circuit receives, from the BEMF circuit, a BEMF signal generated by the BEMF circuit as the motor drives the movable component. The processing circuit determines, based on the BEMF signal, an active range of the motor, which corresponds to a full stroke of the movable component. The processing circuit controls the motor to drive the movable component within the active range.