Machine Tool Thermal Compensation via Axis-Positioned Temperature Sensing
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Solution Overview
Problem
Existing methods for compensating temperature-dependent position changes on machine tools are imprecise and fail to adequately account for position-dependent thermal displacements, leading to increased inaccuracies in machining due to thermal bending and expansion.
Innovation Solution
A method that calculates compensation values for temperature-dependent position changes by considering both temperature differences and axis positions, allowing for precise adaptation of compensation values based on the actual position of the machine tool's axes to account for both position-independent and position-dependent thermal errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If active temperature control or cooling of machine tool parts is used, then homogeneous thermal expansion is reduced, but inhomogeneous temperature differences and thermal bending cannot be completely prevented
Solution Approach 1:
The patent replaces the mechanical/thermal control system with a computational compensation system. Instead of actively controlling temperatures to prevent thermal effects, the system measures temperatures and calculates compensation values that are applied to the control system to correct for thermal displacements, thereby substituting a complex thermal control mechanism with a computational approach
Solution Approach 2:
The patent implements a feedback mechanism by continuously measuring temperatures at multiple positions on the machine tool, calculating the resulting thermal displacements based on these measurements, and applying compensation values to the control system. This closed-loop feedback approach allows the system to adapt to actual thermal conditions rather than relying on passive thermal control
2Manufacturing precision
If temperature compensation is calculated only as a function of temperature differences, then the compensation system is simple, but position-dependent thermal displacements are not adequately compensated
Solution Approach 1:
The patent makes the compensation system dynamic by introducing position-dependent compensation values that vary with the actual positions of the machine tool axes. Instead of using static compensation values based solely on temperature differences, the system calculates compensation values that adapt to the dynamic positions of the axes, thereby accounting for position-dependent thermal displacements without requiring a fundamentally more complex measurement system
Solution Approach 2:
The patent changes the parameters used in compensation calculation from only temperature differences to include both temperature differences and axis positions. By incorporating position as an additional parameter in the compensation calculation, the system can account for position-dependent thermal effects while maintaining a relatively simple computational approach based on measured temperatures and positions
3Measurement precision
If multiple temperature measurement positions are used, then thermal displacement measurement is more accurate, but the compensation calculation becomes more complex
Solution Approach 1:
The patent segments the temperature measurement into multiple discrete positions on the machine tool, with each measurement position capturing thermal conditions at a specific location. By dividing the thermal field into multiple measurable segments rather than attempting to measure the entire thermal state at once, the system achieves more accurate thermal displacement measurement while managing calculation complexity through modular processing of individual position data
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 enables more accurate compensation for thermal displacements, reducing positional errors and improving machining accuracy by accounting for thermal deformations in all axes, especially in machines with serial kinematics and large overhangs.
Implementation Method 1
If a frame component is heated on one side by guides and drives, the material on this heated side expands in accordance with the one-sided heating
Data Source
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AI summary
The present invention relates to a method and a device for compensating for temperature-dependent position changes on a machine tool with at least one linear axis. According to the method according to the invention, at least a first temperature is determined at a first temperature measurement position of the first linear axis of the machine tool, a first temperature difference between a first reference temperature and the first temperature is determined, a first compensation value is determined as a function of the first temperature difference, and a temperature-dependent position change on the machine tool is compensated as a function of the first compensation value. The present invention is characterized in that the first compensation value is further determined as a function of an axis position of the first linear axis.