Machining Tool Position Control Using Force-Based Deflection Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for controlling positioning control apparatuses in machining processes face challenges in accurately calculating deflection without knowing the rigidity value, leading to positional displacement and reduced accuracy due to machining reaction forces.
Innovation Solution
A method that derives a relational expression between sideslip amount and pressing force before machining, using finite element method analysis or actual force sensor measurements, to correct position commands and prevent positional displacement during machining.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a rigidity value is used to calculate deflection amount, then correction can be performed, but the calculation becomes inaccurate when the accurate rigidity value is unknown
Solution Approach 1:
The patent performs preliminary measurement before machining to obtain the actual deflection amount. A force sensor measures the pressing force applied to the workpiece, and this data is used to calculate the real deflection amount of the positioning control apparatus, replacing the need for theoretical rigidity values.
Solution Approach 2:
The patent implements a feedback mechanism where the force sensor continuously detects the pressing force during machining, and the control device uses this real-time data to calculate and compensate for deflection. This closed-loop feedback ensures accurate correction without requiring predetermined rigidity values.
2Manufacturing precision
If pressing force is increased to prevent positional displacement, then machining accuracy improves, but deflection of the positioning control apparatus increases
Solution Approach 1:
The control device continuously monitors the pressing force through the force sensor and calculates the resulting deflection in real-time. The position command is then corrected based on this calculated deflection, creating a feedback loop that maintains machining accuracy while compensating for the deflection caused by necessary pressing forces.
Solution Approach 2:
The patent dynamically adjusts the position command parameters based on the measured pressing force and calculated deflection. By changing the position parameters in response to actual conditions rather than using fixed values, the system maintains accuracy despite variations in deflection caused by different pressing forces.
3Manufacturing precision
If real-time deflection calculation is performed during machining, then positional displacement is prevented, but calculation time increases
Solution Approach 1:
The patent performs the complex measurement and calculation operations before machining begins. The force sensor measures the pressing force, and the control device calculates the deflection amount in advance, storing this information for use during machining. This preliminary action reduces the computational burden during the actual machining process.
Solution Approach 2:
The patent replaces complex theoretical calculations with direct measurement using a force sensor. Instead of calculating deflection from first principles requiring rigidity values, the system directly measures the pressing force and uses this empirical data to determine deflection, significantly simplifying the computational process.
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
This approach allows for highly accurate machining by calculating sideslip amounts in real-time, reducing calculation complexity and improving correction accuracy, thereby preventing positional displacement and maintaining machining precision.
Implementation Method 1
detecting a pressing force acting on the machining tool during the machining
Implementation Method 2
calculating a sideslip amount corresponding to the pressing force
Data Source
Figure 1~2
Figure 3
Figure 4~5
AI summary
A method of controlling a positioning control apparatus includes the steps of: deriving a predetermined relational expression in advance, the relational expression defining a relation of a sideslip amount of a tip end of a machining tool in a second direction with pressing force generated when the tip end of the machining tool is pressed against a predetermined position on a machined surface of a workpiece in a first direction in a state where the tip end of the machining tool coincides with the predetermined position, the second direction being parallel to the machined surface of the workpiece, the first direction being perpendicular to the machined surface of the workpiece; detecting the pressing force during machining by a force sensor; calculating the sideslip amount corresponding to the pressing force detected by the force sensor, in accordance with the predetermined relational expression at any time; correcting a position command value of an arm tip of the positioning control apparatus based on the calculated sideslip amount; and machining the workpiece while moving the arm tip of the positioning control apparatus in accordance with the corrected position command value.