MR Fluid Clutch Powertrain for Smooth Human-Hybrid Torque Assist
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional human-hybrid powertrains face challenges in seamlessly integrating human power with additional power sources, particularly due to low bandwidth issues that result in unnatural movement and discomfort, as well as inefficiencies in torque control, especially at varying speeds and inclines.
Innovation Solution
The implementation of magnetorheological (MR) fluid actuators and clutches to selectively connect and disconnect power sources, providing a variable assistance force based on sensor data, thereby enhancing the powertrain's bandwidth and adaptability to user input, allowing for smoother pedaling and reduced induced torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If conventional human-hybrid powertrains are used, then the system structure is simple, but the bandwidth is low resulting in unnatural movement and discomfort
Solution Approach 1:
The patent replaces conventional mechanical clutch systems with magnetorheological (MR) fluid actuators that use magnetic field control to调节 torque transmission. This substitution enables continuous, smooth torque modulation without mechanical engagement/disengagement, significantly increasing system bandwidth and eliminating unnatural movement sensations while the user pedals.
Solution Approach 2:
The patent implements dynamic torque control through MR fluid actuators that can rapidly adjust their coupling characteristics in response to real-time sensor feedback about user pedaling force and motor assistance levels. This dynamic adjustment capability allows the powertrain to adapt continuously to changing operating conditions, maintaining high bandwidth and natural movement feel throughout the operating range.
2Power
If additional power source is always connected, then power assistance is maximized, but torque control efficiency decreases especially at varying speeds and inclines
Solution Approach 1:
The patent employs dynamic torque control through MR fluid actuators that can rapidly adjust their coupling characteristics in response to real-time sensor feedback about user pedaling force and motor assistance levels. This dynamic adjustment capability allows the powertrain to adapt continuously to changing operating conditions, maintaining high bandwidth and natural movement feel throughout the operating range.
Solution Approach 2:
The patent changes the physical state and coupling parameters of the MR fluid through magnetic field modulation. By varying the magnetic field strength, the system dynamically adjusts the torque transmission characteristics of the MR fluid clutch, enabling efficient torque control across varying speeds and inclines while maximizing power assistance when needed.
3Device complexity
If mechanical clutch systems are used to connect power sources, then the structure is straightforward, but the torque transmission is not smooth causing discomfort
Solution Approach 1:
The patent replaces conventional mechanical clutch systems with magnetorheological (MR) fluid actuators that use magnetic field control to regulate torque transmission. This substitution enables continuous, smooth torque modulation without mechanical engagement/disengagement, significantly increasing system bandwidth and eliminating unnatural movement sensations while the user pedals.
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 solution transforms low-bandwidth powertrains into high-bandwidth systems, providing a more natural and efficient user experience by ensuring the powertrain adapts quickly to changes in user input, reducing discomfort and enhancing control, particularly on inclined surfaces and during dynamic movements.
Implementation Method 1
magnetorheological (MR) fluid actuators and clutches to selectively connect and disconnect power sources
Data Source
AI summary
A system for assisting a user in moving a device relative to a structure comprises a magnetorheological (MR) fluid actuator unit including at least one torque source and at least one MR fluid clutch apparatus having an input coupled to the at least one torque source to receive torque from the at least one torque source, the MR fluid clutch apparatus controllable to transmit a variable amount of assistance force via an output thereof. An interface is configured for coupling the output of the at least one MR fluid clutch apparatus to the device or surrounding structure. At least one sensor provides information about a movement of the device. A processor unit for controlling the at least one MR fluid clutch apparatus in exerting the variable amount of assistance force as a function of said information, wherein the system is configured for one of the MR fluid actuator unit and the interface to be coupled to the structure, and for the other of the MR fluid actuator unit and the interface to be coupled to the device for the assistance force from the MR fluid actuator unit to assist in moving the device.