Students: Louisa A. Avellar (UCB), Mircea Badescu, Stewart Sherrit, Yoseph Bar-Cohen, and Wayne Zimmerman of Caltech
Research Project Title: Pneumatic Sample Acquisition and Transfer System
Location: NASA’s Jet Propulsion Laboratory, Pasadena, California
Student:Antonia Bronars
Professor/Sponsor: Professor Alice Agogino
Mentor:Alan Zhang
Research Project Title:Actuating a Spherical Tensegrity Robot using Momentum Wheels
Abstract:
This paper presents theoretical and initial hardware exploration of spherical tensegrity robots actuated using momentum wheels. A tensegrity structure consists of rods suspended in a network of cables. It is inherently compliant and resistant to failure because of its ability to distribute external force through its tension network. This mechanical property provides shock from impact, making the tensegrity a promising candidate for space exploration. The Berkeley Emergent Space Tensegrities lab currently actuates the tensile network using motors, causing the robot to deform, shifting the center of mass, and making the robot roll. The. current actuation scheme necessitates a tradeoff in determining the stiffness of the springs enforcing the tensile network: high spring constant ensures a safe drop, while low spring constant allows for lower actuating torques and consequently smaller, lighter motors. This paper proposes using momentum wheels to actuate the tensegrity, thereby decoupling the stiffness of the tensile network and the actuation scheme of the robot.
Student: Tim K. Chan
Professor/Sponsor: Professor Alice Agogino
Mentor: Euiyoung Kim
Research Project Title: Prototyping of Wearable Notification and Tracking Device with Bluetooth Connectivity
Abstract:
We introduce the use of a wearable device for notification under distracting environment, for instance, in a rave or a conference. During the research, we came up with two models – centralized and ad-hoc. In the centralized model, the wearable device is aimed at finding people who present in the same event/venue whilst the ad-hoc model, we targeted one-to-one location tracking without the use of pre-existing network. Centralized model will be used during a populated event like a rave where it’s virtually unable for people to hear their phone ring of vibrate. Ad-hoc model will be used in situations like parents keeping track on their kids in an amusement park.
Student: Serena Chang
Professor/Sponsor: Professor Alice Agogino
Mentor: Euiyoung Kim
Research Project Title: Activity Comparisons Over Digital Artifact By Their Physical And Emotional
Distance: User’s Attention Level Upon Primary and Secondary Digital Artifacts
Abstract:
Although a majority of the Internet of Things devices have been introduced in the market places, the adoption rate of these new devices hasn’t been quite inspiring due the lack of motivation that enables users to stick with them around over a long-term time frame. Many introduced IoT devices have short life cycles and people simply go back to their traditional devices as primary interaction. Based on our research, the laptop and the smartphone are the most dominant devices regardless of the introduction of the new IoT devices. Thus, this research focuses on the usages of these two devices to explore users different attention levels upon primary and secondary digital artifacts and to compare their physical and emotional distances.
A prototyping segment of this research further explores the concept of emotional distance between users and devices in physical spaces. Indicator spectrums allow users to visually indicate their emotional state to other co-located individuals with whom they are not directly interacting, at the opposite corner of a coffee shop, for instance. Once the indicators are digitized and connected, the “mood” of a particular physical space can be assessed by IoT developers.
Student: Stephanie Chang
Professor/Sponsor: Professor Alice Agogino
Mentor: Euiyoung Kim
Research Project Title: Establishing User Spaces in Medical Exoskeleton
Abstract:
As exoskeleton technology matures and becomes increasingly commercialized, the user spectrum of such technologies need to be identified and studied. This project examines exoskeleton technology from a human centric standpoint, establishing a comprehensive range of users for such products. In order to establish context to create a spectrum of exoskeleton users, literature was collected and reviewed to discover what exoskeleton researchers identify as their target users. The functionality of different types of exoskeletons are also identified and categorized and then matched up to potential user needs from different personas. From the literature review, different categorical spectrums are established to represent the range of users who would make use of exoskeleton technologies. Examples of spectrums include age, physical age, familiarity with advance technology, etc. In addition, further research into socially sustainable assistive technologies are identified and matched up to corresponding user personas and needs.
Student: Galen Elias
Professor/Sponsor: Professor Reza Alam
Research Project Title: Load Shedding Trends of Submerged Rigid Bodies Subject to Monochromatic Water Waves
Research Areas: Design, Fluids, Ocean Engineering
Abstract:
Wave Energy Converters are devices which convert the renewable energy in ocean waves to electricity. A submerged pressure differential WEC uses a rigid absorber to split a wave’s orbital, creating a pressure gradient which drives a generator. One of the engineering challenges of WECs is to make the device robust enough to handle extreme ocean conditions, during which waves can carry upwards of 30 times more power than usual.1 As such, we looked into ways to reduce the load the device would experience under extreme conditions. Due to the high buoyancy of the device and the high-energy cost of increasing its depth, we focused mainly on the effect of changing the device’s shape. In particular, we analyzed trends in front-to-back hole placement and trends in wall thickness between holes within a constant footprint.
Student: Grant Emmendorfer
Professor/Sponsor: Professor Alice Agogino
Mentor: Alan Zhang
Research Project Title: Intuitive Controller Designs for Tensegrity Robots
Abstract
Student: Jordan Francis
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Design and Construction of a High Capacity Battery Pack for Flywheel-Hybrid Vehicles
Abstract
Student: Hunter Garnier
Professor/Sponsor: Professor Alice Agogino
Mentor: Drew Sabelhaus
Research Project Title: Force Sensors for a Quadruped Robot
Abstract:
Sensors measuring the ground reaction forces applied to a quadruped’s throughout different movements can be advantageous for any robot involved in movement. Feedback from force sensors allows for more accurate control of a robot and is integral for balance. This research report describes the process of implementing force sensors into the legs of the ULTRA Spine quadruped in order to measure the axial force of each leg during movements such as bending and torsion. Previously, the two main motions of the spine—torsion and bending—were seen qualitatively but not expressed quantitatively. Thus, data collected from performing experiments with these force sensors will be compared to the NTRT model of these movements. Although several force sensing options were explored such as load cells, strain gages and expensive optical sensors, Flex Sensors were selected because of their availability, ease of installation, and potential to eliminate confounding variables.
In addition to selecting appropriate force sensors for this application, a new hip and leg design was developed to house these force sensors. Since the previous prototype lacked storage space for electronic components, a new hip was designed and 3D printed which includes a hollow center that allows room for electronic components to be stored there. Additionally, since the previous leg attachment method was ineffective and required constant maintenance, higher-fidelity legs were waterjet cut and attached more efficiently. Different flexible materials to mount the Flex Sensors to were explored such as brass shim and spring steel. However, the spring steel was found to be more effective because, after bending, it returned to its original shape—am important aspect for repeatability of experiments.
To continually improve the ULTRA Spin toward a higher-fidelity prototype, several rapid-prototyped hardware components were replaced by machined parts. Furthermore, a new attachment method for actuating the robot was explored which would replace attaching the actuating strings directly to endcaps via springs. Instead, each string would be clamped directly onto the rubber lattice. Although this method is still being prototyped, exploration of it will be continued in the future.
Student: Hunter Garnier
Professor/Sponsor: Professor Alice Agogino
Mentor: Drew Sabelhaus
Research Project Title: ULTRA Spine
Abstract:
Due to its complexity, the ULTRA Spine Quadruped robot assembly process is extremely time consuming and tedious, making it difficult to rapid-prototype new designs. This research report describes the process of designing an elastic lattice that would replace the cables and springs that traditionally tensioned the robot. In order to create the final design, several concepts were explored, a tension test was completed on silicon rubber to find its elastic modulus, and various lattice shapes were assessed. The final design decreased the assembly time of the ULTRA Spine from three hours to approximately 7 minutes, improved the symmetry and vertebrae alignment of the robot, and will reduce the design, manufacturing and assembly process of future spine prototypes.
Additionally, a test setup to measure ground forces on the prototype’s feet is described in this report. Previously, the two main motions of the spine—torsion and bending—were seen qualitatively but not expressed quantitatively. By placing a load cell under each foot of the quadruped prototype, the forces under each could be measured while the spine underwent torsion or bending. However, this test setup was unsuccessful and did not produce convincing data.
Future plans for this project include designing a higher quality test setup to measure ground reaction forces as well as a higher fidelity spine prototype.
Student: Jimmy Huang
Professor/Sponsor: Professor Dennis Lieu
Sub Area: Biomechanical Engineering
Research Project Title: Novel Silicone-Compatible Pressure Transducer Tips and Calibration Device for Simulation Torso Design
Abstract:
This paper details the progress made during the Spring semester of 2015 in Professor Dennis Lieu’s Ballistics Impact Lab, and is a continuation of “Silicone Curing Behavior and Updated Method of Simulation Torso Construction” from Fall 2014.
Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non-penetrating injuries can still cause severe internal damage and even death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Impact Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles.
Recently, the group has been experiencing difficulties producing a homogeneous and consistent silicone simulation torso with embedded pressure transducer. One main focus of this paper is the design and manufacturing of several new, oil-tight pressure transducer tips. This includes our continued exploration of silicone-compatible materials as well as a new sensor housing design. Another area of focus is the design and manufacturing of a calibration device for new pressure transducers before they are embedded into a silicone torso. This information will hopefully be useful for new Ballistics Impact Lab researchers and for those in similar laboratories or using the same silicone material.
Student: Jimmy Huang
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: The Effect of Varying Transducer Tip Thicknesses on Peak Internal Pressures
Subarea: Biomechanical Engineering
Abstract:
This paper details the progress made during the Fall semester of 2015 in Professor Dennis Lieu’s Ballistics Impact Lab, and is a continuation of “Novel Silicone-Compatible Pressure Transducer Tips for Simulation Torso Design” from Spring 2015.
Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non- penetrating injuries can still cause severe internal damage and death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles.
Most recently, the group has been focusing its efforts towards improving the design and manufacturing method for the model torso with an embedded pressure transducer. This semester, our team set out to understand the effect of varying transducer tip thicknesses on peak internal pressures. This endeavor involved manufacturing a brand new model torso and subsequently testing different torsos with distinct tip designs. During the process we also designed and manufactured a novel calibration apparatus. This apparatus allowed us to translate peak voltages to internal pressures experienced by the model torso, and can help us to individually calibrate each sensor and tip design in the future. Finally, the lab also revisited the concept of healing the silicone in an effort to recycle spent silicone torso blocks.
Student: Jimmy Huang
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: New Silicone Tissue Stimulant and Pressure Transducer Setup for
Less Lethal Ballistics Applications
Abstract:
Less-lethal projectiles such as rubber and wooden bullets are commonly used by law enforcement for the purpose of incapacitating targets with minimum injury. However, these non- penetrating injuries can still cause severe internal damage and death. With understandable concern, investigation by Professor Dennis K. Lieu and his Ballistics Lab researchers has been underway since 2003. Originally intended to model the response of the human torso utilizing silicone, the scope of this project has extended to include the design of safer less-lethal projectiles. This paper details the progress made during the Spring semester of 2016 in Professor Dennis Lieu’s Ballistics Impact Lab, and is a continuation of ” The Effect of Varying Transducer Tip Thicknesses on Peak Internal Pressures” from Fall 2015. Most recently, the group has been focusing its efforts towards improving the design and manufacturing method for the model torso with an embedded pressure transducer. This semester, our team initially focused on exploring the concept of healing silicone in an effort to recycle old silicone torso blocks. Further along, the group set out to benchmark new silicone tissue stimulants as well as new pressure transducer alternatives for more robust less lethal ballistics setups.
Student: Shayan Javaherian
Professor/Sponsor: Professor Reza Alam
Mentor: Dr. Mohsen Saadat
Research Project Title: CalSat
Abstract:
The purpose of this research is to make underwater wireless communication possible by using ROVs and laser tractions. The calsat project is consist of two different version which they call CalSat 1 and CalSat 2. For CalSat 1 the purpose of this project is to modification of controls of two submarine model to carry out the proof of concepts of underwater optical communication using a swarm of autonomous underwater vehicles. For CalSat 2 we made our own ROV that is an Agile and robes underwater platform used for underwater communication by using laser tractions. I widely work on design, prototyping, and manufacturing of CalSat 2. CalSat 2 Has different versions which each one of them developed and improved based on the previous version. Different version of CalSat 2 are as following: CalSat 2A, CalSat 2B, CalSat 2C, CalSat 2D. Following pictures are for CalSat 2C while testing for leakage and performance in O’Brien facility at UC Berkeley.
Student:Lace Co Ting Keh
Professor/Sponsor: Professor Homayoon Kazerooni
Research Project Title: Exoskeleton Support For Stroke Rehabilitation
Abstract:
Nearly 800,000 individuals suffer a stroke each year. The growing number of individuals that require assistive recovery post stroke has been growing over the last decade. In turn, there has been a high demand for qualified physical therapists and a dire need for alternative ways to allow for safe recovery of patients. The exoskeleton industry offers unique perspective to address this demand. Exoskeletons have been used in the military to assist soldiers in carrying heavy loads. These have shown tremendous success in assisting able bodied soldiers. Exoskeletons in this industry have effectively allowed soldiers to conserve their energy when transporting gear. Furthermore, these have allowed soldiers to control the power of their legs and potentially allow for actions that would not have been possible without human augmentation.
An interesting application of the exoskeleton is its use in a medical setting. Paraplegics, quadriplegics, and post stroke patients are typically lose control of certain limbs. The exoskeleton offers a manner in which the user is able to manipulate their actions and allow a robotic system to perform specific actions for them. One of the biggest caveats faced by the exoskeleton industry is the support necessary for patients using lower limb exoskeletons. Lower limb exoskeletons are designed to be used by patients who are unable to control their lower limbs. This not only limits their ability for walking or running but also their ability to maintain balance. Because of this, patients are put at a high level or risk when using the exoskeleton because of the full reliance on the robotic systems. It is therefore necessary to design a support system for exoskeletons being used by patients who are unable to maintain balance when a malfunction occurs.
Student: Stefan Klein
Professor/Sponsor: Professor Dennis Lieu
Mentor: Daniel Talancon
Sub Area: Mechatronics Design
Research Project Title: INSTAR – Inertial Storage and Recovery
Abstract:
INSTAR (Inertial Storage and Recover) is a mechanical engineering research group headed by Professor Lieu and recent PhD graduate Daniel Talancon. Our research surrounds a flywheel energy storage device for electric vehicle applications. In the past semester working with INSTAR, I completed several tasks related to the preparation of our go-kart test platform for our Cal Day exhibit and to the rebuilding of our flywheel energy storage device. To prepare our go-kart, I flushed and bled our brake system, which returned it to working condition, but also led to me discovering a leak on the master cylinder, which will be repaired by the next Cal Day. Furthermore, I disassembled our inertial simulation test setup, which consists of two large steel disks to simulate the inertia of the kart and two magnetic brakes to simulate the mechanical brakes of the kart. I then reassembled our battery packs and reinstalled the seat and wheels. In preparation for Cal Day, where we would, for the first time, have the final flywheel on display, a polycarbonate shield in between the flywheel and driver had to be designed and machined. I oversaw and helped several of the team’s freshmen in this task. Finally, there was a significant electronics error in our kart, which caused the startup of our motor controllers to fail randomly. I traced the error to the pedal assembly of the kart, whose angular encoders tended to slip, causing a non-zero braking and throttle signal to be inputted into the motor controllers, causing the startup to fail. Regrettably, I was unable to find a permanent fix for the problem before the exhibition on Cal Day, but a pedal assembly redesign is planned to stop the problem at its source. On Cal Day, I helped present our project to prospective students and parents, which has generated some interest in new students who have already contacted our lab. Finally, I began the process of rebuilding the flywheel’s rotor. For this task I rebuilt the electric motor’s rotor, which had to have a new set of neodymium magnets epoxied to it and was then wrapped in kevlar for strength. Overall, my participation in INSTAR has helped further my education in design and mechatronics and helped keep the INSTAR project rolling even with the recent graduation of our graduate student, Daniel.
Students: Andrew Kooker and Casey Duckering
Professor/Sponsor: Professor Robert Full
Mentor: Chen Li
Sub Area: Mechatronics
Research Project Title: Micro-Robot with Ambulating and Jumping Abilities: A modification of the Biomimetic Millisystems Lab robotics for testing and analysis on animal locomotion processes
Abstract:
The goal of this project is to create micro-robots that can simulate standard insect/animal motions such as walking and running while being able to jump over encountered obstacles. The simulation of jumping mechanisms found in nature on fully mechanical robots can be used to better understand how and why they are used. Designs for robots can be created by understanding the dynamic effects of a jumping ability on motion when encountering obstacles, and simulating them effectively.
The initial step of our project dealt with simulating the simple motion of jumping on micro-robots that could already walk and run. It was important to analyze different methods of jumping from quick actuation to elastic storage; for the ability to continuously jump on command, the method of quick actuation seemed ideal. We created an actuating hinge mechanism in SolidWorks and developed the basic skeletal models for the robot in AutoCAD. By using rapid-prototyping techniques such as 3D printing and laser cutting, we were able to quickly bring these computer renditions to life for physical testing. We integrated mechanical and electrical components like gearing systems and microcontrollers for actuation, and combined these assemblies with the base-skeleton of our robot. After writing software to test the system, we analyzed the effectiveness of our design based on the robot performance and developed a second iteration of the robot accordingly.
Throughout the design process, we were required to focus on key decisions like material choice, specific component purchases, and overall integration methods. We developed many iterations of software to efficiently test the robots, and made many design changes to the jumping mechanism and robot body itself. We were also able to learn principles of re-design by taking already-developed robotic components from the Biomimetic Millisystems Lab, and further modifying them to fit our needs.
We compared the effectiveness of our designs among iterations, and mapped out performance goals for future generations of the robots. We plan to continue modifying current robot designs and creating custom completely new designs for jumping-specific robots in the future. We also hope to continue the development of unique electronic components and software to seamlessly integrate with our mechanical robots.
Student: Leslie Leung
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: The design and initial testing of flashlight-inspired battery tubes
Abstract:
The INertial STorage And Recovery (INSTAR) vehicle combines the use of battery packs and a flywheel as its energy storing and supplying components. The subject of this research centers on a new impact-resistant, fire-resistant, and well-ventilated design for battery packs consisting of rechargeable lithium ion cells. Inspired by the packaging of a flashlight, the design aims to achieve an ease of assembly and disassembly for replacement of individual cells. Housed in standard-sized aluminum tubing, six cells are preloaded by stainless steel springs fixed against polyether ether ketone (PEEK) end caps by a stainless steel bevel head screw. Current flows from one battery tube to others via copper bus bars connecting adjacent tubes together. A prototype consisting of two tubes was constructed as a proof of concept. Static testing with a voltmeter returned expected voltage readings for a single tube, two tubes in series, and two tubes in parallel. A setup scheme for dynamic testing is proposed for future study to determine the safe operating frequency range and the robustness of electrical connections during motion. The design of the casing for the complete battery packs and the battery packs’ electrical connections with the vehicle’s battery management system (BMS) are also proposed.
Student: Kevin Li
Professor/Sponsor: Professor Alice Agogino
Mentor: Lee-Huang Chen
Research Project Title: Design, Manufacturing and Testing of Tensegrity V3 Robot
Design
Abstract:
With recent advances in reusable rocketry and planetary discoveries, space exploration has come to the forefront of scientific news and research. My role in the Berkeley Emergent Space Tensegrities Lab has been to assist in developing the Tensegrity Spherical Robot V3, a robust yet compliant robotic system designed to take advantage of the unique characteristics of tensegrity structures. In doing this, I was involved in all aspects of the engineering process including hardware and software design, component manufacturing and component testing. In designing and manufacturing hardware, emphasis was placed on the ease, speed and cost of manufacturing and assembly in order to streamline the rapid iterative design process. In software design, an intuitive control scheme was developed for the twenty-four independent motors as well as a text interface for switching between manual control of individual motors and preset step sequences. Finally, in component testing, a physical drop test was developed to drop the Tensegrity V3 from heights of up to six feet, which helped confirm the compliance of the system, the strength of individual components and the accuracy of simulations.
Student: Carlin Liao
Professor/Sponsor: Professor Alice Agogino
Mentor: Julia Kramer
Research Project Title: ‘The Design Exchange’ Ontology Team
Abstract:
The work of the ontology team of the Design Exchange is primarily qualitative, focusing on categorizing and analyzing various methods in design thinking. Within the pools of “Data Gathering,” “Ideation,” “Analysis & Synthesis,” “Building/Prototyping,” and “Communications,” we have collected process descriptions for close to three hundred design methods such as Dot Voting, Visual Brainstorming, and Video Ethnography. From these processes, our team has identified more than 100 skills shared across multiple methods that may be relevant to design thinking as a professional endeavor. Following the completion of our master skill list will be the construction of a questionnaire designed to refine and verify our assessment of common design skills by surveying the professional design community, in particular those making the decision on which designers to hire.
Student: Chengming Liu
Professor/Sponsor: Professor Liwei Lin
Mentor: Casey Glick
Subarea: Fluid Mechanics
Research Project Title: Single-Layer Microfluidic Current Source via Optofluidic Lithography
Abstract
Student: Kevin Li
Professor/Sponsor: Professor Alice Agogino
Mentor: Lee-Huang Chen
Research Project Title: Design and Manufacturing of Soft Spherical Tensegrity Robot
Abstract:
With recent advances in reusable rocketry and planetary discoveries, space exploration has come to the forefront of scientific news and research. My role in the Berkeley Emergent Space Tensegrities Lab has been to assist in developing TT-4, the fourth version of the spherical tensegrity robot, a robust yet compliant robotic system designed to take advantage of the unique load-bearing characteristics of tensegrity structures. The goal for this prototype was to validate scaling of the spherical tensegrity design from the smaller TT-3, so the prototype is completely passive with the circuit boards designed specifically for drop testing. Key steps included manufacturing of hardware components and circuit boards, followed by final assembly of the TT-4 drop test prototype. Following that, a full drop test was designed and characterized to test the capabilities of the much larger TT-4. Hardware components included aluminum rods and endcaps, plastic and FDM module housings, extensions springs and fishing line. The circuit board was built for the drop testing and contained only a Teensy 3.2 microprocessor, 9-DOF absolute IMU, XBee wireless chip and voltage regulator. With a fully assembled board attached to the central payload of TT-4 as well as another attached to a module, a comparison of the G-forces between the payload and a rigid element of the robot can be made in order to validate the load-distributing characteristics of the tensegrity structure as well as the safety of a potential payload. With the hardware and software components of the TT-4 drop test prototype completed, the final step will be completing the drop test at a later date.
Student: Ryan Liu
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Protocol for Ballistics Lab Data Collection
Abstract:
In an effort to reduce long-term sustained injury from non-lethal weaponry, research was undertaken to investigate a new type of kinetic energy projectile. The projectile is similar in shape and energy transfer to currently used commercial non-lethal projectiles, but is made of a highly deformable, hyper-elastic, modified silicon rubber. Tests were conducted analytically using ABAQUS (FEA) and experimentally inside the UC Berkeley ballistics test lab. This report outlines the protocol necessary to perform ballistics lab work, which may be useful for both new ballistics lab researchers and for researchers at other laboratories alike.
Student: Hannah Ling
Professor/Sponsor: Professor Dennis Lieu
Mentor: John Madura
Research Project Title: Design/Manufacturing of Oil Circulation System for Electric Vehicle
Research Areas: Design, Manufacturing
Abstract:
The Inertial Storage And Recovery(INSTAR) kart uses an electric flywheel as part of a hybrid system to efficiently store energy from regenerative braking. The flywheel can store up to 100 kJ of energy by spinning at speeds up to 20,000 RPM. An adequate lubrication system is crucial to the safety and durability of the flywheel because it reduces wear when spinning the flywheel at high speeds. The design and components of the previous lubrication system were flawed and did not effectively lubricate the flywheel. The following report documents the features of the previous circulation system and illustrates its flaws, as well as explaining the design, part selection, and manufacturing process of a new reservoir and circulation system. Although the system is not fully assembled, the currently installed components have already improved the effectiveness of the lubrication system allowing for a greater range in the speed of flywheel testing.
Student: Jacob Madden
Professor/Sponsor: Professor Masayoshi Tomizuka
Research Project Title: Preliminary Modeling and Design of an Active-Passive Upper-Body Assistive Device
Abstract:
Assistive devices, such as exoskeletons, are widely utilized across many fields to increase power output or provide basic support for human users and have shown great potential for use in fields such as medical rehabilitation. This paper documents preliminary work completed on a hybrid active-passive upper-body exoskeleton designed for rehabilitation of stroke victims. Goals included decreased mechanical complexity and increased range of motion over previous designs, while retaining adequate support for daily use and gravity compensation during daily tasks. The work described here includes simulation modeling, mechanical design, and physical hardware testing. Results from preliminary testing indicate that the final prototype shows greater range of motion and similar support when compared to previous designs, with the potential to be integrated into existing assistive systems to assist with medical rehabilitation or miniaturized into a compact, portable system.
Student: Saunon Malekshahi
Professor/Sponsor: Professor Alice Agogino
Mentor: Edward L. Zhu
Research Project Title: Lattice-Enabled Actuation for Tensegrity Robots Featuring Cluster Scouting Functionality
Abstract:
Our paper presents a new spherical tensegrity robot capable of performing locomotion through the use of an actuator-powered lattice. Featuring a six-bar nodal actuator mount, this robot effectively delivers a rapid prototyping platform enabling the user to transition from a passive-actuated assembled state within minutes. Featuring a control scheme running on a RF wireless protocol, the TT-Unisphere provides a test platform for simulated cluster scouting between multitudes of tensegrity robots. Developed at UC Berkeley in collaboration with NASA Ames, the TT-Unisphere enables a broader scope of experimentation for tensegrity robots, namely in the domains of modeling interactive behavior for surface scouting and ergonomic assembly.
Student: Tony Ngo
Professor/Sponsor: Professor Dennis K. Lieu
Mentor: Cyndia Cao and John Madura
Research Project Title: Model Development and System Identification of INSTAR’s Test Vehicle
Abstract:
This paper serves to create a basic dynamic model of the current that runs throughout the Inertia Storage and Recovery (INSTAR) vehicle such that data can be acquired and fitted to a transfer function that represents the entire closed loop system. Using the methodology of system identification, and therefore recording the input current and output current of every subsystem, we can tune a PID controller to monitor the current that runs through the battery, and every individual motor controller. Such testing procedure is described further within the paper, where it explains how step inputs are used to receive the transient and steady state behavior of each subsystem. Though, the work within this paper does not fully address the implementation of the closed loop controller within LabView, it can be the framework to replace the open-loop model that exists within the vehicle’s code. Through the implementation of the closed loop model, efforts can be made to improve battery life, while also addressing the current draw issues that limits the performance of the vehicle. Serving as the stepping stones of more advance current controllers as well, the transfer function created can be used to optimize current flow during the different transient phases that exist while the vehicle is running. The creation of such a model can then be scaled and used to implement and optimize the concept of a triple hybrid system within a passenger vehicle.
Student: Derek Pan
Area: Design, Energy Science and Technology
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Design and Fabrication of a Novel Li-ion Battery Pack for Regenerative Braking Research
Abstract:
The InStar Lab focuses on researching the viability of a regenerative braking system that utilizes an electromechanical flywheel as interim power storage between cycles of motor braking and vehicle acceleration and/or battery recharging. As a platform for this research, a go-kart was modified to be driven by two electric motors, in turn powered by two lithium iron-phosphate (LiFePO4) battery packs. In response to certain criteria that were found lacking in the battery packs currently in use on the kart, a team of undergraduates designed and fabricated a new pack. Construction of the new pack started in Fall of 2017 and was continued through Spring 2018. Preliminary testing was done to determine the viability of its design. In addition, research was done on finding a way to implement a battery management system (BMS) with the pack’s unusual architecture, where the cells are grouped into “parallel strings.” Typically, battery packs use cells grouped into parallel banks, which are then connected in series, whereas this pack groups six cells in series inside tubes, which are then connected in parallel. Because BMS are generally designed for the former layout, most are incapable of monitoring the higher voltages that result from series groupings. This is an area that requires further research. Overall, the design was found to have shortcomings that would need to be improved for regular, long-term use, chief among these being the difficulty in implementing a BMS and the pack having too low of an electrical capacity. Nevertheless, it is a functional li-ion battery pack that is at least usable on a temporary basis, and which has led to much insight into battery technology and pack design.
Student: Nicholas Anthony Renda
Professor/Sponsor: Professor Dennis Lieu
Mentor: Daniel Talancon
Research Project Title: INSTAR RP-1: Development and Testing of an Electric Vehicle KERS Platform
Abstract:
My research this semester focused on creating a robust mounting solution for a flywheel-based energy storage system as part of the INertial STorage And Recovery (INSTAR) Lab. The flywheel is part of a Kinetic Energy Recovery System (KERS) on an electric go-kart, for the purpose of regenerative braking. The flywheel mount is designed to support the flywheel under extreme driving loads (cornering, braking, accelerating), while simultaneously damping vibrations through the use of rubber isolators. The flywheel spins up to 25,000 rpm, so special care is taken to isolate all vibrations between it and the go-kart chassis.
The mount is made of 6061-T6 aluminum billet, and was designed to be manufactured almost entirely on a waterjet machine through the use of 2d profile parts. Bolt holes were postdrilled on a drill press to ensure tight tolerances. Rubber isolators embedded in the mounting plate damp vibrations and react shear loads to the chassis. A containment system was also designed to account for special load cases, such as flywheel seizure. In this load case, the rotating steel mass stops in less than 2 rotations due to debris in the bearing or an external impact. This imparts a massive torque on the mount, which begins to rotate and shears through the rubber isolators. It then comes in contact with the containment brackets, which are designed to take the load of a seizure impact without failing.
The go-kart was tested without the flywheel to ensure proper function of all other systems, including batteries, steering, brakes, motors, pedals, and electronics. INSTAR met its goal of a fully functional kart by Cal Day, having debugged code and designed new batteries and pedals to accomplish this task. The vehicle systems were then thoroughly tested to ensure sturdiness during multiple cycles of high-intensity accelerating and braking.
Student: Nick Renda
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Load and Safety Considerations in the Design of Flywheel Kinetic Energy Recovery Systems for Electric Vehicles
Abstract:
Flywheel technology has novel applications in electric vehicles as the core component of a kinetic energy recovery system. Flywheels have quick charge and discharge rates, and can be used to recapture the energy that is generally lost using current regenerative braking technology or traditional friction brakes. One challenge to implementing these systems is mechanically connecting the flywheel to the vehicle chassis. This project focuses on the development of a robust flywheel mounting system that minimizes vibration transmission from the chassis, reacts loads under extreme driving conditions, and protects the driver in the event of a catastrophic failure.
Student: Hale Reynolds
Course Project: ME 102B
Research Project Title: “Smart” Energy Harvesting and Usage as Applied to a Bicycle Light
Abstract:
For this project, a standard battery powered Light Emitting Diode (LED) bicycle light was modified, allowing it to harvest and store all the energy required for its use.
When normally operated, the bicycle light used for this project requires four AA batteries, located in a compartment just behind the circuit board holding the LEDs, and normally operates for around nine hours before the batteries must be replaced. The batteries were removed and replaced with a coin-sized rechargeable Lithium-Ion Battery (LIB), and circuitry governing the storage and usage of the generated electricity. (The LIB and circuit take up the same space as the four AA batteries.)
To generate electricity from the normal usage of the bicycle, very strong magnets (Neodymium magnets with residual flux density of 14.7 KGs) were mechanically fixed to the spokes in a similar fashion to the typical attachment of bicycle speedometer magnets. Then a tightly wound, fine copper wire coil was attached to the bicycle fork at the location where the magnets attached to the spokes would pass. As the magnets pass the copper coil, their magnetic field induces a potential difference across the coil ends. This voltage potential then drives the flow of current through wires run along the bicycle frame to the battery compartment. Before reaching the battery, the current must pass through series of four diodes arranged as a full-wave rectifier to ensure that regardless of the direction of the magnet rotation and regardless of the magnet polarity orientation, the electricity serves to charge the battery.
To govern the usage of the charge stored in the battery, a simple control circuit was designed. For daytime operation of the bicycle, when it is light out, the generator charges the battery. Because no additional light is needed when it is bright out, the battery stores its charge and does not power the LEDs. For night riding or in other dark conditions, it is desired that the LEDs be powered to illuminate the cyclist’s way. This photosensitive functionality was achieved using two transistors, an operational amplifier, a photosensor, and a series of resistors.
The circuit governing the use of the battery’s charge is a small photosensor interfaced with an operational amplifier which was then connected to a CMOS Inverter (composed of the two transistors, one N-Channel and one P-Channel). If the output from the photosensor is high (light is incident upon it), this signal is amplified by the operational amplifier and the inverter allows no current to pass from the battery to the LEDs of the bicycle light. If the output from the photosensor is low (no light is incident upon it), this signal is still amplified by the operational amplifier, but if it is low enough, the inverter allows all the required current for full LED brightness to pass to the LEDs of the bicycle light. The resistors are used in balancing the operational amplifier, effectively calibrating the system. With the proper resistor combination, the circuit was calibrated to have the inverter transition between states at the proper, practical light intensities for day and night bicycling.
Key Points:
Through the use of this device, rather than replace four AA batteries after every nine hours of use, a smaller battery may be used to store energy generated from the normal use of the bicycle, and does not need replacing. It was found that during normal usage of the bicycle, 40% of the energy consumed from full-brightness bicycle-light use could be generated. This means that when it is bright out, and the bicycle light is off, the battery is easily charged, while at night the battery life is greatly extended. Although the energy produced by this device comes from the energy supplied by the rider, because there is no contact between moving components, and because the power generated is relatively small, there is no noticeable drag on the wheel due to energy generation. Also, in-terms of cost, the total cost of this project was much less than for a high-end bicycle light.
Student: Patrick Savidge
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Calibration of Piezoresistive Pressure Transducer Embedded in Silicone
Abstract:
The Impact Lab at UC Berkeley is in development on non-lethal bullets. Currently the lab is developing bullets made from Medical Grade Silicone Gel. These bullets are shoot at a silicone torso and the internal pressure felt by the torso is recorded. This paper outlines the process used and results obtained from calibrating the Piezoresistive Pressure sensor embedded in the silicone torso. The sensor was mounted in a small piston cylinder device and Medical Grade Silicone Gel was cured around the sensor. Various weights were applied to the device to vary the pressure applied and the output voltage from the sensor was recorded. These voltages were then applied to data obtained within the Impact Lab to determine the pressure experienced under impact testing.
Student: Arbaaz Shakir
Professor/Sponsor: Professor Alice Agogino
Mentor: Dr. Euiyoung Kim
Research Project Title: Human Centered Design: Renault
Abstract:
With the automotive industry on the cusp of a revolution as vehicles attain progressively higher levels of autonomy, car manufacturers are beginning to rethink the concept of personal mobility and re-envision meaningful interactions between people and different transportation modalities. The premise of this project takes meaning in this transformative phase of the automotive industry. With a human-centered approach and with the primary goal of creating better customer experiences, exploring what consumers will want and need in tomorrow’s transportation ecosystem, we looked to gain insight into opportunities in important new areas of potential growth and design solutions in these areas.
The first half of the project i.e. the time frame covered by this report, focused on the early stages of the design process including problem framing and user research. We uncovered areas for design exploration, unpacked consumer needs, framed and structured problems from our findings, prototyped and tested our ideas, and gathered user feedback. The synthesis driver for the project was the iterative design process. We found, from our studies, that the need for a human-machine interface between pedestrians and autonomous vehicles was not pressing, that consumers are vested in the emotion of a traditional driving experience, and that users are looking for a higher level of personalization in their transportation journeys.
Student: Kimberly Sover
Professor/Sponsor: Professor Alice Agogino
Mentor: Andrew Sabelhaus
Research Project Title: Hardware Design and Test Setup for Laika: the Quadruped Robot with a Tensegrity Spine
Abstract
Student: Kimberly A. Sover
Professor/Sponsor: Professor Alice Agogino
Mentor: Andrew P. Sabelhaus
Research Project Title: Mechanical and Electrical Design of a Fixture to Test Modeling Methods and Control of a Tensegrity Spine
Abstract:
Flexible spines for quadruped robots are a growing technology in the soft robotics field. The Berkeley Emergent Space Tensegrities Lab is currently conducting research on a tensegrity-based spine that consists of interlaced rigid cores connected by cables to create movement that mimics that of a vertebrate spine. The spine can be actuated by adjusting the lengths of the cables attached to ends of the vertebrae on the top, bottom, and sides to bend in the sagittal and coronal planes. This paper discusses the development of simplified hardware to robustly test modeling methods and control designs for the current spine prototype. As the semester began, it became clear that the current three-dimensional prototype would not be able to provide accurate data for detailed investigations into the techniques used to construct the governing state equations of the model or the development of control strategies. A stand-alone hardware setup was developed to create and capture the dynamics of a single vertebrae. Mechanically, this test setup was designed to accurately represent a core with cable attachments in two dimensions and eliminate sources of error, such as out of plane motion and fictional effects. Electrically, it was designed to have the ability to precisely dictate the forces the cables apply by using motors to change cable lengths. In addition, there is a camera vision component to the test setup that relays information about the position and rotation of the spine for closed loop control testing. Initial testing of the system, shows that we will be able to move the vertebrae by commanding the motors while tracking the state the vertebrae in real time to perform a variety of tests in both open and closed loop for verification of continued research in the lab. Future work will focus on increased performance and robustness of the test setup for application to a wider range testing possibilities.
Student: Ellande Tang
Professor/Sponsor: Professor Alice Agogino
Mentor: Lee-Huang Chen
Research Project Title: Hardware Improvements to Tensegrity robots and a Potential Alternative Actuator for Linear Motion
Abstract:
Tensegrity robots have tremendous potential for space exploration due to their deformability and compliance. Their innate impact resistance allows them to traverse rough or precipitous terrain with substantially reduced risk. However, tensegrity robots are hampered by their complex geometry, which makes them difficult to assemble and visualize on paper, as well as their primary method of actuation, which requires linear motion. This report examines the improvement of tensegrity assembly methods through improved rod end attachment hardware and re-evaluates the performance of a novel type of linear actuator inspired by twisting cable actuators as well as the double helix geometry of DNA. The new endcaps were designed to interact more favorably with the single elastic lattice of the TT-4 mini tensegrity robot. Incorporating grommets into the elastic prevents them from slipping off the rod ends as in previous designs. Additionally, the use dowel pins as wire guides improves manufacturability and allows effective end caps to be made without 3d-printing. Lastly, the introduction of threaded holes simultaneously allows for the lattice to be secured and to attach actuation cables without the need for tying knots. Combined with the other changes, this reduces tensegrity assembly time to under 5 minutes while addressing a number of the previous flaws of the design, improving durability and robustness.
The DNA actuator shows promise as an effective linear actuator. With the construction of a new, lower friction testing assembly, the characteristics of the actuator can be determined with more accuracy. The actuator in its current for displays potential as a practical linear actuator, as it displays interesting properties. Among them is the property of the required torque for actuation depending not upon load but upon the present number of rotations. These properties merit further analysis of the DNA actuator with different materials and geometric configurations.
Student: Rachel Thomasson
Professor/Sponsor: Professor Francesco Borrelli
Mentor: David Gealy
Research Project Title: Koko: A Low-Cost, 7 Degree-of-Freedom, Modular Robotic Arm
Abstract
Students: Aliakbar Toghyan and Borna Dehghani
Professor/Sponsor: Professor Alice Agogino
Mentor: Kyunam Kim
Sub Area: Controls
Research Project Title: Tensegrity Robot
Abstract:
Soft robotics and tensegrities are the new chapters to the world of robotics. The term “Tensegrity” is a combination of the words “Tensile” and “Integrity”, and it represents any structure consisting of elements that are only under tension or compression. The main objective of the Tensegrity research was to come up with a relatively low-cost but appropriate representative of NASA’s future explorer SUPERball. The purpose of making the early prototype was the initial approval of the control algorithm used for the movement of the robot, since the process of making the actual prototype in NASA is overly expensive and time consuming.
The robot consists of six rods that are connected by 24 elastic elements and it is formed into a sphere like configuration. The sphere would be able to roll by means of actuating the elastic components. As a team member I focused on designing a control algorithm for the robot. Based on simulation of the robot in Matlab, I found the optimized control algorithm for certain movements. Afterwards, I implemented the control system in the prototype and made sure that the robot had the desired motion.
Student: Varna Vasudevan
Professor/Sponsor: Professor Alice Agogino
Mentor: Danielle Poreh
Research Project Title: Redesigning Thedesignexchange Method Page To Assist Novice Designers In Embedding Design Methods Into Practice
Abstract
Student: Richard Vuu
Professor/Sponsor: Professor Professor Dennis Lieu
Mentor: John Madura
Research Project Title: Designing an adjustable pedals system for a flywheel energy storage (FES) demonstration vehicle.
Abstract
Student: Zea Wang
Professor/Sponsor: Professor Tarek Zohdi
Mentor: Maxwell Micali
Research Project Title: Variable Nozzle
Abstract:
As additive printing is gaining in popularity and increasing its uses, it is important to minimize build time while maintaining resolution throughout the part. A variable nozzle is able to accomplish this by changing the extrusion diameter while printing. A variable nozzle introduces additional flexibility in the 3D printing process. Not only will this make additive manufacturing more efficient, it will allow for artists to explore a new feature, further expanding the abilities 3D printing.
Our team’s design features the use of a mechanical iris mechanism to vary the diameter of the nozzle. This allows for the cross section of the mechanism to remain relatively circular as the diameter varies while printing. The 3D Potterbot, a ceramic printer, was chosen in order focus on the mechanical design without interference of heat and phase transitions in the material. In testing, the mechanical iris was successful in changing the size of the extruded material from 6mm to 20mm continuously. Problems came about as the iris reached the smaller diameters due to the bunching of the rubber liner between the clay and the mechanism. High pressure is also applied to the mechanism from the clay during extrusion making the rotation of the iris and therefore the changing of the diameter difficult.
This semester has been focused on testing the nozzle on a ceramics printer and documenting problems when implementing a variable nozzle. The second priority is finding ways of automating the entire system with a motor. The next steps of this research will focus mainly on the software needed when a variable nozzle is introduced. This includes changes in the slicer as well as the feed and print rates of the 3D printer in order to minimize the build time and provide the best possible resolution.
Students: Lee Weinstein and Martin Cacan
Lab: Berkeley Manufacturing Institute
Research Project Title: Battery-Replacement Scale Energy Harvesting From HVAC Flows
Abstract:
The objective of the project is to create an energy scavenging device that produces over 100 μW of power in air flows of 2-5 m/s. These operating conditions are characteristic of HVAC systems, and the power output would be sufficient to run a low-power wireless sensor node at ~1% duty cycle.
The approach we have pursued is using a cylindrical obstacle inside an HVAC flow to trip vortex shedding. A fin attached to a piezoelectric bender vibrates and harvests energy as a result of an oscillatory pressure differential caused by periodic vortex shedding off of the obstacle.
An image and a few more details are available on our lab website: http://ame.berkeley.edu/
Student: Kriya Wong
Professor/Sponsor: Professor Grace Gu
Mentor: Zhizhou Zhang, Kahraman Demir
Research Project Title: OwlFoil: Development of Bio-Inspired Multimaterial Composites
Abstract:
The power of silent flight achieved by owls extends further than simple domination of the evolutionary arms race between predator and prey. Successful modeling and printing of wings have the potential to reform turbine and aerodynamic technology in terms of both energy efficiency and noise reduction. The characteristics of owl wings that render them silent are primarily the leading edge feathers and the trailing fringe of the wing, which work jointly to break up oncoming air currents and channel them along an invariant surface, minimizing the sound during flight. The leading edge feathers, which are typically smaller and more circular in shape, are lined with tiny serrations along the feather that are called pennula, whose primary purpose is to create roughness and texture along the wing that will break up the air currents into smaller streams called micro-turbulences, which raise the noise frequency of the air rushing over the wing to a higher frequency that is not detectable by prey and also humans. The trailing fringe further differentiates the owl from other birds in that the substructure of these feathers allow them to mesh into one another when the wings unfold, such that when the feathers spread, the outer fringe of the feathers create almost a single sheet with very little overlap, maximizing area and creating smoother surface which reduces noise and tapers out into larger, less densely packed barbule areas that break the air currents further into smaller streams to reduce noise. This project aims to create a base model for the computer-aided design (CAD) of synthetic, multi-material bird feathers, specifically of the male barn owl for the rapid prototype and development of 3D-printed feathers. Using an online database of primary feathers collected from the barn owl, three models from different regions of the wing were generated taking into account external feather spline, rachis or stem characteristic, curvature and barbule density. The properties of owls’ silent flight deemed to be the most impactful have been determined to be the comb-like pennula on the leading edge feathers and the fluid-like trailing fringe of the lower wing feathers, which work together to break air currents into smaller pockets as well as smooth the underside of the wing. The successful modeling and 3D-printing of these characteristic feathers unique to the owl have the potential to transform airfoil and turbine technology. As a crucial step towards the modeling of an entire wing, this project defines the parameters necessary for the realistic multi-material generation of owl flight feathers.
Student: Michael Zhang
Area: Design, Energy Science and Technology
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Inertial Storage and Recovery (INSTAR) Research Lab Application of Electronic Differentials
Abstract:
The Inertial Storage and Recovery (INSTAR) lab is conducting research on adding alternative energy storage systems in the form of a flywheel to the traditional hybrid automobile in an effort to increase the efficiency of the vehicle. In order to test and collect data to further examine the validity and feasibility of the alternative energy storage systems, a test vehicle was built in the form of an electric go-kart. The projects in this report focus on the development of an electronic differential to increase overall efficiency of the vehicle as well as providing manufacturing support to other teams in the research lab.
Student: Sean Zhu
Professor/Sponsor: Professor Alice Agogino
Mentor: Cesar Torres
Research Project Title: Design Exchange UI
Abstract
Student: Daniel Zu
Professor/Sponsor: Professor Dennis Lieu
Research Project Title: Belt Drivetrain Design and Analysis
Abstract