Machine Tool Vibration Damping With Dual-Sensor Control
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Solution Overview
Problem
Existing machine tools face challenges in effectively damping unwanted vibrations during machining, often resulting in reduced productivity due to limitations in the placement and control of active vibration dampers, which can lead to instability in the control loop.
Innovation Solution
A machine tool design featuring a dual controller system with two sensors and a cascaded controller structure, where both sensors detect vibrations independently and supply actual and target values to the controller to calculate a resulting manipulated variable for the active vibration damper, allowing for efficient and stable damping of vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the active vibration damper is arranged at the location where disruptive vibration occurs, then vibration damping effectiveness is improved, but accessibility for arrangement deteriorates
Solution Approach 1:
The patent introduces a sensor as an intermediary element that measures vibration at the difficult-to-access location where vibration occurs, while the active vibration damper is placed at an accessible location. The sensor acts as a mediator between the vibration source and the controllable damper, enabling indirect control of vibration at the problematic location through the accessible sensor-damper arrangement.
2Measurement precision
If the sensor is arranged in the region where disruptive vibration occurs, then measurement precision of vibration is improved, but control loop stability deteriorates
Solution Approach 1:
The patent uses a sensor as an intermediary to detect vibration at the vibration source location with high measurement precision, while separating the sensor placement from the damper placement. This intermediary sensing approach allows accurate vibration measurement without directly coupling the control actuator at the unstable location, thereby maintaining control loop stability while achieving precise vibration detection.
3Ease of operation
If the active vibration damper is arranged at a different, more accessible location, then ease of arrangement is improved, but vibration damping effectiveness deteriorates
Solution Approach 1:
The patent employs a sensor as an intermediary device that bridges the gap between the accessible damper location and the vibration source location. The sensor detects vibration characteristics at or near the vibration source and provides feedback to the control system, which then actuates the damper at the accessible location to achieve effective vibration damping without requiring direct placement at the vibration source.
4Reliability
If the reinforcement of the control loop is increased to suppress remaining vibration, then vibration damping effectiveness is improved, but control loop stability deteriorates
Solution Approach 1:
The patent implements a feedback control system where the sensor continuously monitors vibration and provides information back to the controller, which adjusts the damper actuation accordingly. This feedback mechanism enables effective vibration suppression through precise, adaptive control without requiring excessive reinforcement of the control loop, thereby maintaining stability while achieving effective damping.
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 effective damping of vibrations while maintaining control loop stability, improving machining accuracy and productivity by allowing the active vibration damper to be placed at a more accessible location and optimizing its effectiveness.
Implementation Method 1
a first sensor is arranged on said machine element to detect the vibration to be damped
Implementation Method 2
at least one active vibration damper is arranged on said machine element to damp a vibration occurring during the machining
Data Source
AI summary
A machine tool includes a machine control unit to output control signals to drives for machine elements. A tool which machines a workpiece is thereby moved relative to the workpiece in a position-controlled manner. Arranged in a first region of one machine element is an active vibration damper to damp vibration in a second region of the machine elements as the workpiece is machined by the tool. In order to detect the vibration, a first sensor is arranged in the first region of the machine element and a second sensor is arranged on another machine element or in a different region of the one machine element. Actual values detected by the first and second sensors and corresponding target values are supplied to a dual controller which determines on the basis of these values, a resulting manipulated variable for the active vibration damper and actuates the active vibration damper accordingly.