Rotating-Body Driving Device Feedforward Control for Non-Integral Gears
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Solution Overview
Problem
Conventional image forming apparatuses using feedforward control based on a home position in each rotation of a rotary encoder are limited in correcting periodic fluctuations in surface moving speed, especially when non-integral reduction gears are used, leading to increased complexity and cost due to the need for additional components to detect home positions.
Innovation Solution
A rotating-body driving device that includes a pulse-signal generating unit, a pulse-count storage unit, and a speed-fluctuation storage unit to accumulate and store rotation speed fluctuations, allowing for feedforward control of the driving source to offset these fluctuations without requiring a home position sensor for each gear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If feedforward control is implemented using conventional home position detection methods, then periodic fluctuations in surface moving speed can be suppressed, but the device complexity and cost increase due to requiring home position sensors for each gear
Solution Approach 1:
The invention extracts the fluctuation detection function from a complex multi-sensor system and concentrates it on a single home position sensor that detects fluctuations of the carrier. By separating the detection of carrier fluctuations from gear fluctuations and using the known gear ratio relationship, the system achieves comprehensive fluctuation suppression without requiring sensors on each gear component.
Solution Approach 2:
The home position sensor serves multiple functions: it detects the home position for synchronization, measures carrier rotation fluctuations, and provides data for calculating compensation amounts for both carrier and gear fluctuations. This multi-functional use of a single sensor reduces device complexity while maintaining control reliability.
2Productivity
If non-integral reduction gears are used, then the device structure becomes more compact and efficient, but conventional feedforward control methods fail to suppress periodic fluctuations effectively
Solution Approach 1:
The invention changes the control approach by detecting carrier fluctuations and calculating compensation amounts that account for the specific non-integral gear ratio. By modifying the control parameters to match the non-integral reduction gear characteristics, the system effectively suppresses periodic fluctuations while maintaining the efficiency benefits of the non-integral gear structure.
3Reliability
If home position sensors are installed on each gear for fluctuation detection, then periodic fluctuations can be suppressed, but the manufacturing cost and device complexity increase
Solution Approach 1:
The invention merges the fluctuation detection function into a single home position sensor on the carrier, combining multiple detection requirements into one component. This consolidation reduces the number of sensors needed, lowering manufacturing costs and simplifying the overall system while maintaining the ability to suppress periodic fluctuations through calculated compensation.
Data Source
AI summary
A rotating-body driving device that includes a rotating body; a driving source; a reduction gear that includes an output shaft and a gear rotating at a non-integer ratio of rotation period to a rotation period of the output shaft, and the reduction gear reducing rotation speed of the driving source; a pulse-signal generating unit; a pulse-count storage unit; a speed-fluctuation storage unit that stores therein a rotation speed fluctuation of the output shaft; and a driving-source control unit. The driving-source control unit detects the speed fluctuation information associated with the accumulated number of pulse signals from the speed-fluctuation storage unit, and performs for the driving source a feedforward control to set off the rotation speed fluctuation.