Motor Driving Control Device for Stable Pattern Switching
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Solution Overview
Problem
Existing motor driving control devices face issues with unstable operation, torque and speed reduction, and abnormal noise when switching energization patterns, and require additional circuits for monitoring rotation speed, increasing costs.
Innovation Solution
A driving control device for motors that initiates rotation control using a preset first energization pattern and switches to a second pattern with a predetermined advanced angle without stopping energization, ensuring no phase short occurs, thereby stabilizing motor operation and eliminating the need for a rotation speed monitoring circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the energization pattern is switched by stopping the energization to prevent phase short, then the reliability of rotation control is improved, but the torque and rotating speed are decreased
Solution Approach 1:
The control unit determines switching timing in advance by monitoring rotation speed against a predetermined threshold, and prepares the second energization pattern with advanced angle control before switching occurs. This preliminary preparation ensures that the transition to the second pattern is smooth and maintains power output while preventing phase short.
2Reliability
If the energization pattern is switched by stopping the energization to prevent mixing of patterns, then the reliability is improved, but abnormal noise is generated upon resuming energization
Solution Approach 1:
The control unit maintains continuous energization throughout the switching process by carefully timing the transition between first and second energization patterns. The switching occurs at a moment when phase current is naturally zero or minimal, allowing pattern transition without interruption. This continuous energization eliminates the abnormal noise that would otherwise occur when restarting energization after a stop.
3Productivity
If a rotation speed monitoring circuit is added to switch energization patterns, then the productivity is improved, but the device complexity and cost increase
Solution Approach 1:
The control unit performs multiple functions using the existing rotation sensor: it detects rotation speed for switching timing determination, detects rotor position for energization pattern selection, and controls the overall motor operation. By making the control unit multi-functional, the patent eliminates the need for a separate rotation speed monitoring circuit while maintaining the ability to switch energization patterns efficiently.
4Power
If the advanced angle control is applied from the start, then the torque is maximized, but unstable operation occurs during low speed rotation just after activation
Solution Approach 1:
The control unit dynamically switches between two energization patterns based on the current rotation speed. During low-speed startup, it uses the first pattern (normal energization timing) that ensures stable operation. Once the rotation speed exceeds a predetermined threshold, it transitions to the second pattern (advanced angle energization) that maximizes torque. This dynamic adaptation allows the system to optimize performance at different operating conditions.
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 solution prevents malfunctions, maintains torque and speed, suppresses abnormal noise, and reduces costs by eliminating the need for a rotation speed monitoring circuit, while ensuring smooth pattern switching without energization interruption.
Implementation Method 1
the driving control device of the motor uses a rotational position detector such as a Hall sensor, for example, and detects a rotor position, based on an output signal from the rotational position detector
Implementation Method 2
A driving control device of a motor such as a brushless motor energizes an armature coil of each phase of the motor in accordance with a position of a rotor being rotated
Data Source
AI summary
A driving control device of a motor includes: a motor driving unit, which drives a motor in response to a driving control signal; and a control unit, which determines an energization pattern applied to an armature coil based on a detected rotational position of the rotor, wherein the control unit starts rotation control by a preset first energization pattern when activating of the motor, wherein when a predetermined time period has elapsed, the control unit adjusts energizing timing to be a timing, at which a short of each phase is not caused at switching of the energization pattern, and then outputs the driving control signal to the motor driving unit so that the rotation control is switched to rotation control of a second energization pattern, which has a predetermined advanced angle amount with respect to the first energization pattern.