Stepper Motor Control for Thermal Imaging Ringing Reduction
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Solution Overview
Problem
Thermal imaging applications face significant delays due to the time required to stabilize a stepper motor, leading to limitations in the number of images that can be captured within a given period without blur, as the motor takes time to stop without ringing, which affects the precision and speed of image capture.
Innovation Solution
A method and system for controlling a stepper motor to minimize ringing by carefully timing step pulses to drive the motor to a desired position and issuing counteracting pulses, allowing for quick acceleration, precise positioning, and energy-efficient operation by de-energizing the motor windings once stopped.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the stepper motor is driven to an index position and stopped using conventional methods, then the motor reaches the desired position, but the motor exhibits ringing that causes delay and blur in thermal imaging capture
Solution Approach 1:
The system applies counteracting pulses before the motor naturally stops to preemptively counteract the ringing that would occur. By determining the characteristics of subsequent pulses needed to counteract ringing and issuing these pulses at the appropriate time, the system prevents the harmful oscillation before it fully develops, thereby reducing both the stopping time and improving image capture precision.
Solution Approach 2:
The controller determines the characteristics of counteracting pulses in advance based on the motor's position and velocity, and issues these pulses at the optimal moment before the motor completes its stopping sequence. This preliminary determination and timing of counteracting pulses allows the motor to settle faster without ringing, reducing the time loss while maintaining precision.
2Productivity
If the stepper motor is stopped quickly to reduce the number of images lost per period, then the capture rate increases, but the motor rings more causing blur
Solution Approach 1:
By applying counteracting pulses that preemptively neutralize the ringing tendency, the system enables faster stopping without sacrificing image quality. The counteracting pulses are specifically timed and characterized to cancel out the oscillations that would otherwise cause blur, thus allowing higher capture rates while maintaining precision.
Solution Approach 2:
The system takes the natural ringing behavior of the motor, which is normally harmful to image quality, and converts it into a predictable phenomenon that can be counteracted. By analyzing the motor's stopping characteristics and issuing precisely timed counteracting pulses, the system transforms the harmful ringing effect into a controlled process that enables faster stopping without blur.
3Reliability
If the stepper motor is energized for longer periods to reduce ringing, then the motor stabilizes better, but the energy consumption increases
Solution Approach 1:
The controller determines and issues counteracting pulses at the optimal moment during the motor's stopping sequence, before the motor would naturally settle. This preliminary application of counteracting pulses achieves stabilization faster, allowing the motor to be de-energized sooner while maintaining reliability, thus reducing energy consumption.
Solution Approach 2:
Instead of continuous energization to maintain stability, the system uses periodic pulse sequences including counteracting pulses that are applied only when needed during the stopping process. This periodic approach achieves the necessary stabilization while minimizing the duration of energization, thereby reducing energy consumption while maintaining reliability.
Data Source
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AI summary
Controlling a stepper motor. A stepper motor is driven towards an index position. An attempt is made to stop the stepper motor on the index position in a fashion that would ordinarily cause the stepper motor to ring at the index position. Characteristics of one or more subsequent pulses that would counteract the ringing are determined. The one or more determined subsequent pulses are issued to the stepper motor.