CONTENTS
13.1 Introduction ................................................................................................ 240
13.2 Design of Multifunctional Actuator........................................................ 242
13.2.1 Motor Design.................................................................................. 243
13.2.2 Clutch/Brake Design..................................................................... 246
13.3 Analysis of Multifunctional Actuator..................................................... 249
13.4 Modeling of Multifunctional Actuator................................................... 251
13.5 Prototype Testing .......................................................................................254
13.6 Conclusion .................................................................................................. 258
Acknowledgments .............................................................................................. 260
References ............................................................................................................. 260
13
Multifunctional Actuators Utilizing
Magnetorheological Fluids for
Assistive Knee Braces
H. T. Guo and W. H. Liao
The Chinese University of Hong Kong
Hong Kong, China
Abstract
Knee braces are a kind of wearable lower extremity exoskeleton that can
enhance people’s strength and provide desired locomotion. It is possible
to use knee braces to assist elderly or disabled people in improving their
mobility to solve many daily life problems, like going up and down stairs
and over obstacles. A well-designed actuator is the key component for
assistive knee braces. In this design, magnetorheological (MR) fluids are
integrated into a motor to work with multiple functions as a motor, clutch,
and brake in order to meet the requirements of normal human walking. To design multifunctional actuators, several design considerations
including configurations, mechanical and electromagnetic designs, and
the influence of a permanent magnet on MR fluids are discussed. Finite
element models of the actuator are built and analyzed. Modeling of the
actuator in different functions is presented. A prototype of the actuator is
fabricated and each function is tested. Torque tracking in brake function
of the actuator is investigated. The results show that the developed multifunctional actuator is promising for assistive knee braces.
239
13.1 Introduction ................................................................................................ 240
13.2 Design of Multifunctional Actuator........................................................ 242
13.2.1 Motor Design.................................................................................. 243
13.2.2 Clutch/Brake Design..................................................................... 246
13.3 Analysis of Multifunctional Actuator..................................................... 249
13.4 Modeling of Multifunctional Actuator................................................... 251
13.5 Prototype Testing .......................................................................................254
13.6 Conclusion .................................................................................................. 258
Acknowledgments .............................................................................................. 260
References ............................................................................................................. 260
13
Multifunctional Actuators Utilizing
Magnetorheological Fluids for
Assistive Knee Braces
H. T. Guo and W. H. Liao
The Chinese University of Hong Kong
Hong Kong, China
Abstract
Knee braces are a kind of wearable lower extremity exoskeleton that can
enhance people’s strength and provide desired locomotion. It is possible
to use knee braces to assist elderly or disabled people in improving their
mobility to solve many daily life problems, like going up and down stairs
and over obstacles. A well-designed actuator is the key component for
assistive knee braces. In this design, magnetorheological (MR) fluids are
integrated into a motor to work with multiple functions as a motor, clutch,
and brake in order to meet the requirements of normal human walking. To design multifunctional actuators, several design considerations
including configurations, mechanical and electromagnetic designs, and
the influence of a permanent magnet on MR fluids are discussed. Finite
element models of the actuator are built and analyzed. Modeling of the
actuator in different functions is presented. A prototype of the actuator is
fabricated and each function is tested. Torque tracking in brake function
of the actuator is investigated. The results show that the developed multifunctional actuator is promising for assistive knee braces.
239