Robot Arm Motion Correction Using Premeasured Error Factors
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Solution Overview
Problem
Existing robot systems face challenges in accurately positioning the extremity of a robot arm due to mechanical characteristics that cause positional errors, which are not accounted for in the programmed motion patterns.
Innovation Solution
A robot system that includes a robot arm with an extremity capable of changing position and control circuitry that stores factor information representing error factors of the robot's motion. This circuitry calculates and adjusts for positional errors based on taught positions and factor information, allowing the robot to move the extremity accurately.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the robot is controlled using a programmed motion pattern without considering mechanical error factors, then the control system is simple and easy to operate, but the positioning precision of the extremity deteriorates due to mechanical characteristics causing positional errors
Solution Approach 1:
The system performs preliminary measurement of mechanical error factors during the robot's movement, storing these factors in advance. The control circuitry then uses these pre-measured factors to calculate and correct positional errors in real-time during operation, achieving high positioning precision without complex real-time measurement systems.
Solution Approach 2:
The control circuitry acts as an intermediary between the simple programmed motion pattern and the actual robot execution. It introduces a correction step that uses pre-measured mechanical error factors to adjust the commanded positions, thereby compensating for mechanical characteristics without requiring complex hardware modifications.
2Manufacturing precision
If the robot system measures and corrects positional errors based on mechanical characteristics, then the positioning accuracy improves, but the control process and system complexity increase
Solution Approach 1:
The robot system performs self-measurement of its own mechanical error factors during normal operation. The control circuitry automatically measures the deviation between commanded and actual positions, stores these error factors, and uses them for automatic correction, eliminating the need for external calibration equipment or complex manual adjustment procedures.
Solution Approach 2:
The system implements a feedback mechanism where the control circuitry continuously monitors the robot's actual position, compares it with the commanded position, and uses the measured deviation to update error factors. These feedback-derived error factors are then used to pre-correct future motion commands, creating a closed-loop system that improves accuracy automatically.
3Measurement precision
If the system stores and applies error factor information for each robot, then positioning accuracy across multiple robots improves, but the data storage and processing requirements increase
Solution Approach 1:
The system measures and stores error factors specific to each individual robot's mechanical characteristics. Each robot has its own set of error factors that reflect its unique mechanical properties, allowing precise correction tailored to each robot without requiring excessive generalization or storage of redundant data for all robots.
Data Source
AI summary
A robot system includes: a robot having an arm; and control circuitry configured to: store factor information representing an error factor of a motion of the robot, wherein the error factor is a mechanical characteristic of the robot that causes a positional error of an extremity of the arm and wherein the factor information has been predetermined based on a comparison between a programmed motion pattern and an actual motion of the robot that is operated according to the programmed motion pattern; calculate, based on a taught position of the robot and the factor information, a positional error of the extremity that would occur during an expected motion toward the taught position; and control, based on the taught position and the positional error, the robot to move the extremity toward the taught position with a positional adjustment of the robot to reduce the positional error.