Coordinate Measuring Machine State Control for Resonance Damping
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Solution Overview
Problem
Coordinate measuring machines (CMMs) face challenges in accurately measuring objects due to dynamic errors caused by vibrations, oscillations, and deformations, especially with lighter and less stiff machine constructions, which increase measurement uncertainties and errors.
Innovation Solution
A method using a dynamic state model and state-space controller to manage natural frequencies, actively dampen vibrations, and correct positional errors by deriving controlling parameters based on actual machine states, employing Kalman filters and observers to monitor and adjust physical properties like acceleration, velocity, and position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the frame structure is made of stone (granite) to increase static stiffness, then measurement precision is improved, but the weight of the machine increases
Solution Approach 1:
The patent changes the material parameter from traditional granite to composite materials (aluminum alloy frame with carbon fiber reinforcement), fundamentally altering the weight-stiffness relationship. This allows achieving comparable stiffness with significantly reduced weight, enabling dynamic error compensation through active control systems.
Solution Approach 2:
The patent employs composite material structures, specifically aluminum alloy frames reinforced with carbon fiber, to achieve the required static stiffness without the excessive weight of traditional granite constructions. This composite approach enables both weight reduction and maintains the structural integrity needed for precise measurements.
2Productivity
If the frame structure is made lighter to reduce weight, then productivity is improved through faster acceleration, but measurement precision deteriorates due to increased vibrations and oscillations
Solution Approach 1:
The patent implements feedback control systems using sensors (accelerometers, vibration sensors) to continuously monitor dynamic behavior of the lightweight frame. This feedback enables real-time detection and compensation of vibrations and oscillations, allowing the system to maintain measurement precision despite the reduced stiffness of lighter materials.
Solution Approach 2:
The patent transitions from static error compensation to dynamic error compensation by implementing active control systems that adapt to changing operational conditions. The system dynamically adjusts control parameters based on real-time measurements of acceleration, velocity, and position, enabling precise measurement even during high-speed movements with the lightweight frame.
3Measurement precision
If dynamic error compensation is implemented through complex control systems, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical error compensation mechanisms (such as heavy granite frames requiring passive stability) with electronic and software-based control systems. This substitution uses sensors, processors, and algorithms to achieve dynamic error compensation, reducing mechanical complexity while improving adaptability and precision.
Data Source
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AI summary
Method for avoiding of excitations of oscillations of a measuring machine (1,2) and/or for reducing or damping such oscillations by actively controlling a driving unit of the measuring machine (1,2) or actively controlling an actuation of an additionally attached actuator. The method using information about an actual state of the measuring device (1,2), the actual state is derived based on a dynamic model and/or by use of a suitable sensor unit. A state controller, an actuator or a frequency-filtering element are used for counteracting or preventing oscillations.