Friction Stir Welding Robot Control Against Arm Flexure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing robot welding systems face challenges in maintaining welding quality due to flexure in multijoint robots during friction stir welding, which can lead to positional deviations of the welding spindle.
Innovation Solution
A robot welding system that includes a multijoint robot, a pivot member at the leading end of its arm, and a control apparatus. The control apparatus estimates the flexure direction of the robot and sets the rotational direction of the pivot member so that the friction force generated opposes the flexure direction, thereby preventing positional deviations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If friction stir welding is performed using a multijoint robot, then productivity and automation are improved, but positional deviation of the welding spindle occurs due to robot arm flexure
Solution Approach 1:
The system estimates the flexure direction of the robot arm before welding occurs and sets the rotational direction of the pivot member in advance to generate friction force that opposes the predicted flexure. This preliminary counter-action prevents positional deviation of the welding spindle during the welding process.
Solution Approach 2:
The system dynamically adjusts the rotational direction parameter of the pivot member based on the estimated flexure direction. By changing the rotational direction parameter, the friction force direction is adjusted to counteract the flexure, thereby maintaining welding position accuracy.
2Device complexity
If the pivot member rotational direction is fixed, then device complexity is reduced, but welding quality deteriorates due to inability to compensate for flexure
Solution Approach 1:
The control apparatus estimates the flexure direction based on robot arm orientation and joint angles, then uses this feedback information to determine the appropriate rotational direction of the pivot member. This feedback mechanism enables the system to adapt to flexure conditions while maintaining relatively simple device architecture.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively suppresses positional deviations of the welding spindle due to flexure, thereby enhancing welding quality and ensuring accurate bonding of workpieces.
Implementation Method 1
a setter configuring to set, based on the flexure direction, a rotational direction of the pivot member so that a friction force generated by the pivot member being in contact with the workpiece is generated in an opposite direction of the flexure direction
Data Source
AI summary
A robot welding system that performs friction stir welding of a workpiece includes: a multijoint robot; a pivot member provided at a leading end of an arm of the multijoint robot; and a control apparatus that controls an operation of the multijoint robot and an operation of the pivot member. The control apparatus includes: an estimator configuring to use the arm of the multijoint robot to estimate a flexure direction of the multijoint robot in a case the pivot member is pushed against the workpiece; and a setter configuring to set, based on the flexure direction, a rotational direction of the pivot member so that a friction force generated by the pivot member being in contact with the workpiece is generated in an opposite direction of the flexure direction.