Multi-Vibration Actuator Phase Control Without Beat Notes
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Solution Overview
Problem
Conventional vibration actuator control devices limit the range of driving speeds due to frequency differences between multiple vibration actuators, leading to reduced performance and increased likelihood of beat notes when simultaneously driven.
Innovation Solution
A vibration actuator control device with a control unit that sets phase differences and voltage values for each actuator independently while maintaining a common frequency for alternating-current voltages, allowing for a wide range of driving speeds by adjusting the elliptical motion and frequency of piezoelectric elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the driving frequency difference between multiple vibration actuators is limited to reduce beat notes, then the stability of simultaneous operation is improved, but the range of driving speeds that can be adopted is reduced
Solution Approach 1:
The patent changes the control parameters from frequency difference limitation to phase difference control. By controlling the phase difference between driving signals of multiple vibration actuators while maintaining common frequency, the system achieves both stable simultaneous operation and wide driving speed range. The phase difference can be adjusted independently to optimize performance without being constrained by frequency matching limitations.
2Object-generated harmful factors
If the driving frequency difference is set to be smaller than 1000 Hz, then the beat note is reduced, but the ranges of driving frequencies and driving speeds are limited
Solution Approach 1:
The patent transforms the control approach by changing from frequency difference control to phase difference control. This parameter change allows the system to eliminate beat notes through phase synchronization while maintaining the ability to operate across wide frequency and speed ranges. The phase difference control enables independent optimization of each actuator's driving speed without frequency matching constraints.
Solution Approach 2:
The patent introduces dynamic phase difference adjustment capability that allows the system to adapt phase differences based on operating conditions. This dynamic control enables the system to maintain stable simultaneous operation across varying driving speeds and frequencies, providing adaptability while suppressing beat notes through real-time phase optimization.
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
Enables the control of a wide range of driving speeds without producing beat notes, even when target stop positions and driving speeds of multiple vibration actuators differ, by individually adjusting phase differences and frequencies to optimize performance.
Implementation Method 1
a vibration actuator in which a contact body in contact with a vibrating body moves relative to the vibrating body by a vibration generated in the vibrating body
Data Source
AI summary
A vibration actuator control device includes a control unit and a driving unit. The control unit outputs a first control signal for controlling driving of a first vibration actuator including a first vibrating body and a first contact body, and outputs a second control signal for controlling driving of a second vibration actuator and including a second vibrating body. The driving unit (i) outputs a first alternating-current voltage in a first plurality of phases set based on the first control signal, and (ii) outputs a second alternating-current voltage in a second plurality of phases set based on the second control signal. The control unit individually sets a phase difference of the first alternating-current voltage based on the first control signal and sets a phase difference of the second alternating-current voltage based on the second control signal, and commonly sets a first alternating-current voltage frequency and a second alternating-current voltage frequency.