Magnetic Viscous Fluid Torque Device Residual Magnetism Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing braking device with magnetic viscous fluid faces issues with residual magnetism causing non-zero rotational resistance even when no braking is applied, leading to unstable operational feel.
Innovation Solution
A torque generating device with a magnetic disk, yokes, and a coil, where a magnetic measurement portion and control unit manage the magnetic field to control residual magnetism, allowing for stable operational feel by adjusting the magnetic field generated by the coil, and optionally using a permanent magnet to maintain particle dispersion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a coil is used to generate magnetic field for braking, then braking force can be controlled, but residual magnetism causes non-zero rotational resistance when current is stopped
Solution Approach 1:
A magnetic measurement portion measures the residual magnetism in the magnetic disk, and the control unit adjusts the coil current based on this measurement to cancel out the residual magnetism. This feedback mechanism ensures that rotational resistance returns to zero when braking is released, resolving the stability issue caused by uncontrolled residual magnetism.
Solution Approach 2:
The control unit dynamically adjusts the coil current parameter to compensate for residual magnetism. By changing the current parameter based on measured residual magnetism levels, the system can actively cancel out unwanted magnetic fields and maintain stable operational feel.
2Reliability
If residual magnetism is completely eliminated, then rotational resistance can be set to zero, but magnetic particles may sediment under gravity
Solution Approach 1:
Instead of completely eliminating magnetic field, the control unit maintains a small residual magnetic field by adjusting the coil current. This parameter adjustment keeps the magnetic particles suspended in the magnetic viscous fluid, preventing sedimentation while maintaining stable operational feel.
Solution Approach 2:
The system applies a partial magnetic field (not completely eliminating it) to achieve the desired effect. By maintaining a small residual magnetic field, the system prevents particle sedimentation without creating excessive rotational resistance, achieving the optimal balance.
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 achieves stable operational feel by controlling residual magnetism and preventing particle sedimentation, ensuring zero or controlled resistance torque even without current applied to the coil.
Implementation Method 1
a magnetic viscous fluid which changes viscosity according to a magnetic field
Implementation Method 2
A Hall sensor detects the magnetic field of the magnet to detect the position of the magnet
Data Source
Figure 1(A)~1(B)
Figure 2
Figure 3
AI summary
[Object] To provide an operating device that stably improves an operational feel even with residual magnetism. [Solution] The operating device includes a magnetic disk capable of rotational motion around a rotation axis, a first yoke located on one side and a second yoke located on an other side across the magnetic disk, a coil disposed to overlap the magnetic disk when viewed in a direction along a direction in which the rotation axis extends, a magnetic viscous fluid filled between the magnetic disk and each of the first yoke and the second yoke, a magnetic measurement portion for measuring magnetism caused by a magnetic field using the magnetic viscous fluid, the magnetic disk, the first yoke, and the second yoke as a magnetic path, and a control unit configured to acquire a measured value from the magnetic measurement portion and control a magnetic field that is generated by the coil based on the measured value to change a viscosity of the magnetic viscous fluid.