Induction Motor Orientation Control for Faster Target Position Stopping
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Solution Overview
Problem
Induction motors in orientation control fail to detect correct acceleration/deceleration due to insufficient magnetic flux rise time during speed transitions, leading to prolonged orientation times.
Innovation Solution
A motor control device that includes a speed comparator, speed command calculator, acceleration command calculator, and path calculator to adjust speed commands and calculate accurate acceleration/deceleration for induction motors, ensuring sufficient detection time and precise stopping at target positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the difference between orientation speed and current speed is kept small, then the speed transition is smoother, but the detection time of acceleration/deceleration becomes insufficient leading to erroneous detection
Solution Approach 1:
The system performs preliminary speed adjustment to ensure the difference between orientation speed and current speed is not smaller than a predetermined threshold before acceleration/deceleration detection. This preliminary action guarantees sufficient detection time and prevents erroneous detection, while the control unit subsequently adjusts the orientation speed to maintain smooth transitions.
2Manufacturing precision
If the orientation speed is set close to current speed, then the orientation control is more precise, but the magnetic flux does not sufficiently rise causing insufficient torque
Solution Approach 1:
Before executing orientation control, the system performs preliminary speed adjustment to ensure the speed difference meets the threshold requirement. This ensures sufficient magnetic flux rise time and torque generation capability while maintaining precise orientation control through subsequent speed adjustments by the control unit.
3Measurement precision
If the detection time of acceleration/deceleration is extended, then the correct maximum acceleration/deceleration can be detected, but the orientation time becomes longer
Solution Approach 1:
The system performs preliminary speed adjustment to establish optimal detection conditions before actual acceleration/deceleration detection begins. This ensures sufficient detection time for accurate measurement without significantly extending the overall orientation time, as the preliminary adjustment is performed efficiently by the control unit.
Solution Approach 2:
The control unit dynamically adjusts the orientation speed parameter to maintain an optimal difference from current speed, ensuring sufficient acceleration/deceleration detection time while minimizing the impact on overall orientation time. This parameter optimization balances detection accuracy with time efficiency.
Data Source
AI summary
Provided is technology that, in orientation control of an induction motor, makes it possible to detect correct acceleration/deceleration and stop a rotation shaft at a specific target position in a shorter time. The present invention is a motor control device that controls an induction motor for driving a rotation shaft and that performs orientation control to stop the rotating rotation shaft at a target position, said motor control device comprising: a speed comparison unit that calculates the difference between the actual speed of the rotation shaft and a speed command; a speed command calculation unit that, when the absolute value of the difference is less than a predetermined threshold value, changes the speed command so that the absolute value of the difference becomes greater than or equal to the threshold value; an acceleration command calculation unit that calculates an acceleration command during the orientation control on the basis of acceleration/deceleration which is calculated from the actual speed of the rotation shaft when the speed command has been changed; and a trajectory calculation unit that, on the basis of the acceleration command, calculates the speed command and/or a position command until the target position is reached.