Power Transmission Device with Variable Stiffness and Viscosity
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Solution Overview
Problem
Existing power transmission devices face challenges in effectively suppressing oscillations in controlled objects with variable stiffness and viscosity, particularly when feedback control is unreliable due to sensor abnormalities, requiring a solution that can predict and manage vibration damping rates.
Innovation Solution
A power transmission device with variable stiffness and viscosity elements, where the stiffness and viscosity can be modified using conductive polymer actuators, allowing for controlled switching between transmission and non-transmission states to manage oscillations effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the stiffness of the elastic member is varied to improve control adaptability, then the damping constant fluctuates causing control processing difficulty, but maintaining constant stiffness limits control flexibility
Solution Approach 1:
The patent applies parameter changes by varying the viscosity coefficient C of the viscous member according to the stiffness k of the elastic member to maintain a constant damping constant h. This allows the system to adapt stiffness for different control situations while keeping damping characteristics stable for predictable control processing
Solution Approach 2:
The patent implements dynamics by making both the stiffness of the elastic member and the viscosity of the viscous member variable rather than fixed. This allows real-time adjustment of system parameters to optimize performance for different operating conditions while maintaining stable damping behavior
2Adaptability or versatility
If a nonlinear spring with variable stiffness is used to improve adaptability, then the damping rate becomes variable making control prediction difficult, but a linear spring provides stable damping at the cost of reduced adaptability
Solution Approach 1:
The patent changes the viscosity parameter of the viscous member in response to stiffness changes in the elastic member. This compensates for the variable damping effects of the nonlinear spring, maintaining reliable control prediction while enjoying stiffness adaptability
Solution Approach 2:
The viscous member acts as an intermediary element that mediates between the variable stiffness of the elastic member and the control system. By adjusting its viscosity, it compensates for stiffness variations and maintains stable damping characteristics for reliable control
3Productivity
If feedback control is used to suppress oscillation, then control response is improved, but sensor abnormalities cause inappropriate control and failed oscillation suppression
Solution Approach 1:
The patent implements beforehand cushioning by providing a viscous member that passively dampens oscillations through its viscosity. This mechanical damping provides a safety net that suppresses oscillations even when feedback control fails due to sensor abnormalities, cushioning against control failures in advance
4Reliability
If the viscosity coefficient is varied to maintain constant damping constant, then control prediction reliability is improved, but the device complexity increases
Solution Approach 1:
The patent merges the functions of stiffness adjustment and viscosity adjustment into a coordinated system. The viscosity coefficient is varied in response to stiffness changes, combining both parameter variations to achieve the dual goals of adaptability and reliable control prediction
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
The device effectively suppresses oscillations by predicting vibration behavior through adjustable damping rates, ensuring stable control processing even when sensors are in abnormal states, and simplifies the structure by integrating stiffness and viscosity modification within a single actuator system.
Implementation Method 1
the stiffness and viscosity can be modified using conductive polymer actuators
Implementation Method 2
the stiffness and viscosity can be modified using conductive polymer actuators
Implementation Method 3
a second element having variable viscosity and configured to receive the motive power from the driving element and to transmit the motive power to the driven element
Data Source
AI summary
A power transmission device 1 includes a variable stiffness unit 41, which has variable stiffness, receives a torque from a motor A2, and transmits the torque to an output unit B, a variable viscosity coefficient unit 42, which has variable viscosity, receives the torque from the motor A2, and transmits the torque to the output unit B, and a controller A4 which modifies the stiffness of the variable stiffness unit 41 and the viscosity of the variable viscosity coefficient unit 42.