Speed Reducer Error Phase Identification for Robot Vibration Suppression
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Solution Overview
Problem
The existing robot control device requires time-consuming trial and error to identify the phase difference for correcting angular transmission errors in speed reducers, leading to inefficiencies in error compensation and vibration suppression.
Innovation Solution
A speed reducer angular transmission error identification system that includes a robot arm with joints, motor units, and data acquisition and calculation units to quickly identify the phase of angular transmission errors by acquiring and modeling variation data, calculating periodic functions, and determining average phases for accurate error compensation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the phase difference of the correction signal is obtained by trial and error, then the system can identify the phase difference, but it takes a long time to identify the phase difference
Solution Approach 1:
The patent replaces the mechanical trial-and-error adjustment method with a mathematical calculation system. The phase difference calculation unit computes the phase difference directly using measured values from the robot arm and speed reducer, substituting the iterative mechanical adjustment process with a deterministic mathematical formula: φ = atan2(Y2-X2, X2+X1-Y1) where X1, Y1 are robot arm measurements and X2, Y2 are speed reducer measurements.
Solution Approach 2:
The patent creates a mathematical model (copy) of the physical system's phase relationship. Instead of physically adjusting the phase through trial and error, the system creates a computational representation of the phase difference using measured position and speed data, then uses this model to directly calculate the correct phase difference value without physical iteration.
2Measurement precision
If a separate measurement unit is provided for phase identification, then the phase can be identified, but the system configuration becomes complex and manufacturing cost increases
Solution Approach 1:
The patent makes the existing measurement units (robot arm measurement unit and speed reducer measurement unit) serve dual functions. These units not only perform their primary measurement tasks but also provide data for phase difference calculation. The phase difference calculation unit utilizes the existing measurement infrastructure, eliminating the need for dedicated phase measurement hardware and reducing overall system complexity.
Solution Approach 2:
The system uses its own existing measurement capabilities to perform phase identification. The robot arm and speed reducer measurement units, already present in the system for other purposes, are leveraged to provide the data needed for phase difference calculation, making the system self-sufficient and avoiding additional measurement equipment.
Data Source
AI summary
a speed reducer angular transmission error identification system including a variation data acquisition unit that acquires first variation data indicating a periodic variation of an operation of a second joint caused by a first motor's angular transmission error when a first joint control unit rotates a first motor's output shaft in a first direction at a constant first target speed and a second joint drive unit rotates an output shaft of a second motor at a constant second target speed, second variation which is data indicating a periodic variation of an operation of second joint caused by the first motor's angular transmission error when the first joint control unit rotates the first motor's output shaft in a second direction at the constant first target speed and the second joint control unit rotates the second motor's output shaft at the constant second target speed.