Control system and control method
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Solution Overview
Problem
Conventional motor control systems face reliability issues when the motor is stuck or stalled, as the theoretical position determined by back electromotive force does not match the actual position, leading to inaccurate control and failure to reach the target position.
Innovation Solution
A control system that samples the voltage of a phase coil with no applied voltage, converts it into a digital signal, and accumulates conversion values based on abnormality probability to determine the motor's operating state, improving reliability by eliminating occasional misjudgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the controller determines theoretical position according to back electromotive force and sends drive signal to motor, then the motor control process is simple and straightforward, but the control reliability deteriorates when motor is stuck or stalled because theoretical position does not match actual position
Solution Approach 1:
The patent introduces an intermediary detection mechanism that samples voltage during the period when no voltage is applied to any phase coil. This intermediary measurement allows the system to detect motor operating state without directly interfering with the normal drive process, thereby improving reliability while maintaining relatively simple control logic.
Solution Approach 2:
The system performs preliminary detection by sampling voltage during the natural off-period of phase coils before making control decisions. This preliminary action enables the controller to anticipate motor state changes and adjust control parameters proactively, preventing control failures before they occur.
2Measurement precision
If the controller continuously monitors motor position to detect stall conditions, then the detection accuracy improves, but the loss of time increases due to frequent sampling and processing
Solution Approach 1:
The patent utilizes the natural periodic off-periods of phase coils as sampling opportunities. Instead of continuous monitoring, the system performs voltage sampling periodically during these predetermined intervals, achieving accurate stall detection while minimizing time loss through efficient use of existing operational cycles.
3Reliability
If the system accumulates multiple conversion values to eliminate occasional misjudgments, then the reliability of operating state determination improves, but the loss of time increases due to accumulation and comparison processes
Solution Approach 1:
The system accumulates a predetermined number of conversion values obtained during normal operational cycles rather than requiring continuous additional measurements. This partial action approach achieves reliable state determination by utilizing existing sampling opportunities, minimizing extra processing time while still eliminating occasional misjudgments through statistical accumulation.
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
The system effectively determines the motor's operating state, preventing misjudgments and enhancing control reliability by counteracting occasional errors, thus ensuring accurate motor operation and avoiding resonance intervals.
Implementation Method 1
samples a voltage of a phase coil of the motor, to which no voltage is applied, during a period in which no voltage is applied to any phase coil of the motor
Data Source
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AI summary
A control system (2) and a control method, used for controlling a motor (31). The control system (2) comprises a central processing module (22) and a drive control module (23). In a period in which a voltage is not applied to any phase coil of the motor (31), the drive control module (23) collects voltages of the phase coil, converts the voltages of the coil into digital signals and stores the digital signals. The central processing module (22) reads the digital signals from the drive control module (23), accumulates the digital signals to obtain an accumulated value, and determines the operating condition of the motor (31) according to a relationship between the cumulative value and a preset threshold, thereby improving the reliability of the motor control.