Speed Reducer Error Phase Identification for Robot Vibration Control
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Solution Overview
Problem
Existing robot control devices face challenges in accurately and efficiently identifying the phase difference for correction signals due to trial-and-error methods, leading to prolonged identification times and potential vibration issues in robot hands.
Innovation Solution
A speed reducer angular transmission error identification system that includes a robot arm with joint drive units, variation data acquisition, periodic function calculation, and phase calculation units to accurately identify the phase of angular transmission errors, allowing for precise compensation and reduced vibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If trial and error method is used to identify phase difference, then the identification process is simple to implement, but the identification time becomes excessively long
Solution Approach 1:
The patent replaces the mechanical trial-and-error adjustment method with an automated measurement and calculation system. The phase difference identification is achieved through automated data acquisition from sensors, Fourier transform analysis, and computational phase calculation, eliminating manual iteration while reducing identification time from minutes to seconds.
Solution Approach 2:
The system performs self-identification of phase difference through automated measurement and calculation. The control device automatically acquires operation data, performs spectral analysis, calculates the phase difference, and applies correction without requiring external intervention or manual adjustment, thereby eliminating time loss while maintaining implementation simplicity.
2Measurement precision
If accurate phase difference identification is achieved, then vibration suppression becomes effective, but the system complexity increases
Solution Approach 1:
The control device integrates multiple functions into a single system: it serves as both the controller for the drive unit and the measurement device for phase difference identification. The same processor that controls motor operation also performs Fourier transform analysis and phase calculation, eliminating the need for separate dedicated measurement equipment and reducing overall system complexity.
Solution Approach 2:
The patent uses operation data from existing sensors as an intermediary to indirectly measure phase difference. Instead of requiring direct measurement of the phase difference between input and output shafts, the system measures the operational characteristics of the drive unit and derives phase information through spectral analysis, simplifying the measurement approach while maintaining accuracy.
3Device complexity
If correction signal is applied without accurate phase identification, then system simplicity is maintained, but vibration suppression effectiveness is reduced
Solution Approach 1:
The patent replaces manual or approximate phase adjustment methods with automated spectral analysis and computational phase identification. By using Fourier transform to analyze operation data and automatically calculate the accurate phase difference, the system generates precise correction signals that effectively suppress vibration while maintaining implementation simplicity through software-based solutions.
Solution Approach 2:
The system establishes a feedback loop where operation data is continuously acquired, analyzed through Fourier transform, and used to calculate and apply correction signals. The identified phase difference and amplitude information feed back into the control device to generate optimized correction signals, creating a closed-loop system that effectively suppresses vibration while maintaining simplicity through automated feedback processing.
Data Source
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AI summary
Provided is a speed reducer angular transmission error identification system including a variation data acquisition unit (42) that acquires first variation data which is data indicating a periodic variation of an operation of a second joint caused by an angular transmission error of a first motor when a first joint control unit (24) rotates an output shaft (11a) of a first motor (11) in a first direction at a constant first target speed and a second joint drive unit (27) rotates an output shaft (16a) of a second motor (16) at a constant second target speed, second variation which is data indicating a periodic variation of an operation of the second joint caused by an angular transmission error of the first motor when the first joint control unit rotates the output shaft of the first motor in a second direction at the constant first target speed and the second joint control unit rotates the output shaft of the second motor at the constant second target speed; a periodic function calculation unit (43) that calculates a first periodic function that models the first variation data and a second periodic function that models the second variation data; an average phase calculation unit (44) that calculates an average phase of periodic functions; and an angular transmission error identification unit (46) that calculates a periodic variation of an angular transmission error of the first speed reducer based on the average phase.