Stepping Motor Drive Apparatus Rotor Delay Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Stepping motors face a detection error due to follow-up delay in rotation position detection, leading to increased costs with high-accuracy rotation position detectors.
Innovation Solution
A motor drive apparatus that supplies drive signals to the stepping motor coils, uses photointerrupters to output signals changing with rotor rotation, and a control unit to determine and correct the follow-up delay by comparing signal states with and without delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a highly accurate rotation position detector is used to eliminate detection error, then measurement precision is improved, but device cost increases substantially
Solution Approach 1:
The patent creates a virtual copy of the rotor position by calculating expected position from drive signal phase and comparing it with actual position from a low-cost detector. This virtual position copy allows error correction without using expensive high-precision detectors, resolving the contradiction between measurement precision and device cost.
Solution Approach 2:
The patent introduces an intermediary calculation process that mediates between the low-cost detector and the required high precision. By computing the difference between expected position (from drive signal) and detected position, the system achieves high measurement precision through software processing rather than expensive hardware.
2Device complexity
If the rotor rotation position is detected using drive signal phase, then device complexity is reduced, but measurement precision deteriorates due to follow-up delay error
Solution Approach 1:
The patent implements feedback by continuously comparing the expected rotor position (from drive signal phase) with the actual detected position, calculating the follow-up delay error, and correcting the detected position in real-time. This feedback mechanism maintains measurement precision while keeping the detection system simple.
Solution Approach 2:
The patent changes the parameter being measured from raw detector signals to corrected position values. By transforming the detected position through mathematical correction using drive signal phase information, the system achieves high measurement precision while maintaining low device complexity.
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
Accurately detects rotor rotation position without substantial cost increase, correcting follow-up delays for precise positioning.
Implementation Method 1
uses photointerrupters to output signals changing with rotor rotation
Data Source
AI summary
A motor drive apparatus includes a drive unit to supply motor coils with sinusoidal drive signals, a signal output unit outputs signals that change with rotation of a rotor, and a control unit. The control unit acquires first information relating to the sinusoidal drive signals at a timing of change of a corresponding one of the output signals in a case where there is no follow-up delay of the rotor relative to the drive signals. When the corresponding one of the output signals is changed, the control unit acquires second information relating to the sinusoidal drive signals at a timing of change of the corresponding one of the output signals in a case where there is a follow-up delay of the rotor relative to the drive signals. The control unit corrects the follow-up delay of the rotor based on a determined difference between the first and second information.