A UC Berkeley ME102B project in collaboration with SuitX
Meet the Team
We are a group of close friends from the University of California, Berkeley, who share a passion for mechatronics and design. Over four months, we dedicated ourselves to applying our undergraduate education to making a product that we could all be proud of.
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To learn more about each member, click on the names below.
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Diana Gomez | Yu Xuan Chua | Victor Vong
Knee Mechanism
Light, compact and modular. Exceeds performance specifications for application in pediatric exoskeletons for children with Cerebral Palsy.
 |  Top View |  Right View |  Isometric View |
|---|---|---|---|
 3D Printed Part |
Features of Design
An In Depth Explanation
By using a similar design to an excavator crane, we incorporated a 4-bar linkage design which connects the actuator to the femur component. This allows us to achieve a more favorable torque curve as compared to past designs. *Peak Force of SEA = 3200N.
To minimize the weight and size of our housing, we improvised by changing a box design into using two plates supported by standoffs. By conducting a stress analysis, we are able to replace the material at areas of low stress with 3D-printed parts. Thus our overall design will be lighter and there will be no exposed components. These 3D printed parts will be attached to our housing by using a snap-fit design which latches onto the standoffs. A box to house the electronics will also be 3D-printed.
For safety considerations, we designed a slot on the housing plate and a pin on the femur part. This pin-slot mechanism acts as a hard stop without pinch points which can pose a safety hazard.
Design
Knowledge meets curiosity
Before embarking on this incredible journey, we had doubts due to the uncertainty and ambiguity. We didn’t know if we had the necessary tools to ideate a suitable design, or to transform our ideas into reality. However, months of hard work provided us with the answers and we are more than satisfied. We believe that the result speaks for itself - check it out below!
Objectives
Knee Design
Objectives we aim to accomplish in our knee mechanism and housing design are:
Torque requirement over range of motion (110° to -5°) - This range of motion is necessary to emulate the walking gait of a regular person and to perform normal tasks such as sitting down. Thus it is crucial for us to ensure sufficient torque at every point of this range.
Weight and size reduction - We would want to minimize the weight and size of the housing for our actuator and linkages. This allows us to achieve a compact and lightweight design which will be suitable for children of a young age.
Accommodate the Series Elastic Actuator (SEA) - The SEA is a key component of our design as it includes a compliance element. This allows us to receive and measure the input from the user and respond accordingly with a suitable output. Hence, our compact housing design has to be able to accommodate the SEA which has a linear actuation.
Incorporate safety aspects - Since we are dealing with children, it is crucial for us to ensure the safety of the user by removing any safety hazards.
MechaKneeCal
Mobility assistance for a better life
Our project is targeted at assisting children with cerebral palsy, by designing a knee mechanism for a pediatric exoskeleton. Our design aims to assist them in walking by receiving input from the user and responding with an amplified output from the actuator.