Motor Driver PWM Frequency Tuning to Avoid Machine Tool Resonance
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Solution Overview
Problem
Electric motors in machine tools can generate resonances that lead to vibrations, potentially causing damage to the motor or other components.
Innovation Solution
A method involving connecting an energy storage unit to the machine tool, transmitting characteristic values, determining a resonance frequency, and setting a switching frequency for the motor driver to a value greater or less than the determined resonance frequency to control and regulate the electric motor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fixed PWM frequency is used for motor control, then the control system is simple to implement, but resonances occur causing vibrations and potential damage to components
Solution Approach 1:
The patent applies dynamics by making the PWM switching frequency adjustable rather than fixed. The control unit dynamically adapts the switching frequency based on detected resonance frequencies, allowing the system to operate at frequencies that avoid resonant vibrations while maintaining simple overall system architecture
Solution Approach 2:
The patent changes the parameter of switching frequency from a fixed value to a variable parameter. By detecting resonance frequencies and adjusting the PWM frequency accordingly (shifting it away from resonant frequencies), the system eliminates vibrations and prevents component damage without significantly increasing complexity
2Object-affected harmful factors
If the PWM frequency is adjusted to avoid resonance, then vibrations are reduced, but additional measurement and control steps are required
Solution Approach 1:
The patent implements feedback by detecting the resonance frequency of the motor-driven system and using this information to adjust the PWM switching frequency. The control unit continuously monitors system characteristics and adapts the operating frequency to avoid resonant conditions, thereby reducing vibrations through a closed-loop control approach
Solution Approach 2:
The patent applies preliminary action by detecting resonance frequencies in advance and pre-adjusting the PWM switching frequency to avoid resonant conditions. This proactive approach prevents vibrations from occurring in the first place, rather than attempting to mitigate them after they arise
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
Reduces vibrations by controlling the electric motor's resonance frequency, thereby preventing damage to the motor and other components.
Implementation Method 1
determining a resonance frequency value based on the at least one transmitted characteristic value of the at least one energy storage unit and on at least one characteristic value of the machine tool
Data Source
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AI summary
Method for controlling and regulating a system comprising a machine tool and at least one energy storage unit connectable to the machine tool, wherein the machine tool comprises an electric motor, a control device, a motor driver, a control device and a first transceiver, and wherein the at least one energy storage unit comprises a second transceiver.The method comprises the following steps: - Connecting the at least one energy storage unit to the machine tool; - Transmitting at least one characteristic value of the at least one energy storage unit to the machine tool; - Determining a resonance frequency value based on the at least one transmitted characteristic value of the at least one energy storage unit and on at least one characteristic value of the machine tool; and - Setting a switching frequency for the motor driver to control the electric motor to a value that is greater or less than the determined resonance frequency value.