Open Access. Powered by Scholars. Published by Universities.®

Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 74

Full-Text Articles in Engineering

A Simple Low-Voltage Cascode Current Mirror With Enhanced Dynamic Performance, Bradley Minch Oct 2012

A Simple Low-Voltage Cascode Current Mirror With Enhanced Dynamic Performance, Bradley Minch

Bradley Minch

In this paper, we present a simple low-voltage MOS cascode current mirror featuring a step response and an output voltage swing comparable to those of a simple mirror and and output resistance comparable to that of a stacked mirror. The proposed mirror operates with an input voltage of Vdiode+VDSsat and can operate on a minimum supply of Vdiode + 2VDSsat. We validate the proposed mirror with a combination of simulated and measured results from a circuit prototyped from transistor arrays fabricated in a 0.5-μm CMOS process through MOSIS.


An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker Oct 2012

An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker

Debbie Chachra

The engineering student experience is understood to differ for male and female students; gendered interactions affect the development of academic and professional role confidence, as well as engineering identity. The purpose of this session is twofold. First, we aim to introduce participants to concepts of gender schemas, privilege, and identity using a range of interactive activities, including brainstorming and structured discussion. Second, we intend to share information about and obtain feedback on a Gender Discussion Exploration Kit, which the participants will be encouraged to review, use, and share at their home institutions.


Student Self-Efficacy In Introductory Project-Based Learning Courses, Geoffrey Pleiss, Madeline Perry, Yevgeniya Zastavker Oct 2012

Student Self-Efficacy In Introductory Project-Based Learning Courses, Geoffrey Pleiss, Madeline Perry, Yevgeniya Zastavker

Yevgeniya V. Zastavker

The purpose of this study is to determine how introductory Project-Based Learning (PjBL) courses affect the self-efficacy of first-year engineering students. Grounded theory is used to analyze twelve interviews with first-year students about their experiences in two PjBL courses, Engineering Design and Physics Laboratory. Data indicate that students' self-efficacy within each course is correlated with the extent to which their course goal perceptions align with those intended by faculty. In Engineering Design, students' recognition of the faculty's intended course goals corresponds to higher levels of self-efficacy. Conversely, in Physics Laboratory, students' low self-efficacy is correlated with a large gap between …


An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker Oct 2012

An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker

Caitrin Lynch

The engineering student experience is understood to differ for male and female students; gendered interactions affect the development of academic and professional role confidence, as well as engineering identity. The purpose of this session is twofold. First, we aim to introduce participants to concepts of gender schemas, privilege, and identity using a range of interactive activities, including brainstorming and structured discussion. Second, we intend to share information about and obtain feedback on a Gender Discussion Exploration Kit, which the participants will be encouraged to review, use, and share at their home institutions.


En Route To Lifelong Learning? Academic Motivations, Goal Orientations And Learning Conceptions Of Entering First-Year Engineering Students, Jonathan Stolk, Katherine Chen, Robert Martello, Roberta Herter, Taylor Lobe, Boris Taratutin Oct 2012

En Route To Lifelong Learning? Academic Motivations, Goal Orientations And Learning Conceptions Of Entering First-Year Engineering Students, Jonathan Stolk, Katherine Chen, Robert Martello, Roberta Herter, Taylor Lobe, Boris Taratutin

Robert Martello

Although lifelong learning is among the most critical skills required of today's engineering graduates, the complex processes through which individuals develop the attitudes, beliefs, and skills of lifelong learners remains unclear. Instructors have only begun to understand the impacts of academic background, institutional climate, and pedagogy on students' development of the motivations and learning strategies characteristic of lifelong learners. In this ongoing mixed-methods investigation, we draw on existing motivation and self-regulated learning theories to examine how undergraduate students at a small private college and a large public university become more self-directed as they progress through the first two years of …


En Route To Lifelong Learning? Academic Motivations, Goal Orientations And Learning Conceptions Of Entering First-Year Engineering Students, Jonathan Stolk, Katherine Chen, Robert Martello, Roberta Herter, Taylor Lobe, Boris Taratutin Oct 2012

En Route To Lifelong Learning? Academic Motivations, Goal Orientations And Learning Conceptions Of Entering First-Year Engineering Students, Jonathan Stolk, Katherine Chen, Robert Martello, Roberta Herter, Taylor Lobe, Boris Taratutin

Jonathan Stolk

Although lifelong learning is among the most critical skills required of today's engineering graduates, the complex processes through which individuals develop the attitudes, beliefs, and skills of lifelong learners remains unclear. Instructors have only begun to understand the impacts of academic background, institutional climate, and pedagogy on students' development of the motivations and learning strategies characteristic of lifelong learners. In this ongoing mixed-methods investigation, we draw on existing motivation and self-regulated learning theories to examine how undergraduate students at a small private college and a large public university become more self-directed as they progress through the first two years of …


An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker Oct 2012

An Interactive Exploration Of Gender And Engineering: Unpacking The Experience, Debbie Chachra, Lynn Stein, Alisha Sarang-Sieminski, Caitrin Lynch, Yevgeniya Zastavker

Yevgeniya V. Zastavker

The engineering student experience is understood to differ for male and female students; gendered interactions affect the development of academic and professional role confidence, as well as engineering identity. The purpose of this session is twofold. First, we aim to introduce participants to concepts of gender schemas, privilege, and identity using a range of interactive activities, including brainstorming and structured discussion. Second, we intend to share information about and obtain feedback on a Gender Discussion Exploration Kit, which the participants will be encouraged to review, use, and share at their home institutions.


Harvesting Vibration Energy Using Nonlinear Oscillations Of An Electromagnetic Inductor, Christopher Lee, David Stamp, Nitin Kapania, José Oscar Mur-Miranda Jul 2012

Harvesting Vibration Energy Using Nonlinear Oscillations Of An Electromagnetic Inductor, Christopher Lee, David Stamp, Nitin Kapania, José Oscar Mur-Miranda

José Oscar Mur-Miranda

Harvesting energy from ambient vibration is a promising method for providing a continuous source of power for wireless sensor nodes. However, traditional energy harvesters are often derived from resonant linear oscillators which are capable of providing sufficient output power only if the dominant frequency of input vibrations closely matches the device resonant frequency. The limited scope of such devices has sparked an interest in the use of nonlinear oscillators as mechanisms for broadband energy harvesting. In this study, we investigate the harvesting performance of an electromagnetic harvester sustaining oscillations through the phenomena of magnetic levitation. The nonlinear behavior of the …


Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti Jul 2012

Peak Wireless Power Transfer Using Magnetically Coupled Series Resonators, José Oscar Mur-Miranda, Giulia Fanti

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies. Power transfer using magnetically coupled series resonators is maximized when the load presented to the sender is matched to the series impedance of the source. This determines an optimal separation distance between the sender and the receiver. However, the maximum power transferred only depends on the losses in the system and is independent of this distance and the resonant frequency. Closed-form expressions describe the power transferred and efficiency for all distances and system values. These expressions are validated with systems operating at 23 kHz, 40 kHz …


Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe Jul 2012

Wireless Power Transfer Using Weakly Coupled Magnetostatic Resonators, José Oscar Mur-Miranda, Giulia Fanti, Yifei Feng, Keerthik Omanakuttan, Roydan Ongie, Albert Setjoadi, Natalie Sharpe

José Oscar Mur-Miranda

Wireless power transfer can create the illusion of portable devices with infinite power supplies and enable applications that are currently unimaginable because of power constraints. Magnetic induction has been extensively used for wireless power transfer, but its efficiency depends on magnetic coupling that decays as the inverse cube of distance. At long enough distances, the magnetic coupling is weak enough that the effect of the receiver coil on the sender coil can be neglected. In this weakly coupled limit, series resonance in both the sender and the receiver increases the power transfer. Compared to magnetic induction, the power transfer increases …


Power Mems And Microengines, Alan Epstein, Stephen Senturia, G. Ananthasuresh, Arturo Ayon, Kenneth Breuer, Kuo-Shen Chen, Fredric Ehrich, Gautam Gauba, Reza Ghodssi, C. Groshenry, Stuart Jacobson, Jeffrey Lang, Chuang-Chia Lin, Amit Mehra, José Oscar Mur-Miranda, Steve Nagle, D. Orr, Ed Piekos, Martin Schmidt, Gregory Shirley, Mark Spearing, Choon Tan, Sheng-Yang Tzeng, Ian Waitz Jul 2012

Power Mems And Microengines, Alan Epstein, Stephen Senturia, G. Ananthasuresh, Arturo Ayon, Kenneth Breuer, Kuo-Shen Chen, Fredric Ehrich, Gautam Gauba, Reza Ghodssi, C. Groshenry, Stuart Jacobson, Jeffrey Lang, Chuang-Chia Lin, Amit Mehra, José Oscar Mur-Miranda, Steve Nagle, D. Orr, Ed Piekos, Martin Schmidt, Gregory Shirley, Mark Spearing, Choon Tan, Sheng-Yang Tzeng, Ian Waitz

José Oscar Mur-Miranda

MIT is developing a MEMS-based gas turbine generator. Based on high speed rotating machinery, this 1 cm diameter by 3 mm thick SiC heat engine is designed to produce 10-20 W of electric power while consuming 10 grams/hr of H2. Later versions may produce up to 100 W using hydrocarbon fuels. The combustor is now operating and an 80 W micro-turbine has been fabricated and is being tested. This engine can be considered the first of a new class of MEMS device, power MEMS, which are heat engines operating at power densities similar to those of the best large scale …


Work In Progress- Understanding Discomfort: Student Responses To Self-Direction, Jonathan Stolk, Mark Somerville, John B. Geddes, Rob Martello Jul 2012

Work In Progress- Understanding Discomfort: Student Responses To Self-Direction, Jonathan Stolk, Mark Somerville, John B. Geddes, Rob Martello

Mark Somerville

The literature consistently reports that students express some degree of discomfort when they are thrown into self-directed learning environments. In this paper, we present the preliminary results of an investigation of the causes of student discomfort in several different self-directed project-based courses. Our results suggest that student motivation and opportunities for the development of deep understanding and transferable skills are important in creating a positive self-directed learning experience. Negative experiences and student discomfort in self-directed environments may stem from problems with self-regulation, low self-perceptions of content learning, lack of personal engagement with the topic, and difficulties related to the social …


Non-Traditional Assessments For New Learning Approaches: Competency Evaluation In Project-Based Introductory Materials Science, Jonathan Stolk, Mark Somerville, Steven Krumholz Jul 2012

Non-Traditional Assessments For New Learning Approaches: Competency Evaluation In Project-Based Introductory Materials Science, Jonathan Stolk, Mark Somerville, Steven Krumholz

Mark Somerville

Over the last twenty years, NSF and the engineering community have called for systemic changes in engineering education, including an emphasis on contextual understanding; increased teaming skills, including collaborative, active learning; and an improved capacity for life-long, self-directed learning. In addition, ABET has called for engineering graduates that demonstrate an ability to apply science and engineering, and ABET requires assessment processes designed to measure student achievement of learning outcomes. Olin College has responded to these calls for change by embracing new learning approaches and assessment techniques, and by developing project-based courses that encourage experiential understanding of content and aid the …


Work In Progress - A Provisional Competency Assessment System, Mark Somerville, Debbie Chachra, Jonathan Chambers, Ellen Cooney, Kristen Dorsey, John Geddes, Gill Pratt, Kathryn Rivard, Ann Schaffner, Lynn Stein, Jonathan Stolk, Stephen Westwood, Yevgeniya Zastavker Jul 2012

Work In Progress - A Provisional Competency Assessment System, Mark Somerville, Debbie Chachra, Jonathan Chambers, Ellen Cooney, Kristen Dorsey, John Geddes, Gill Pratt, Kathryn Rivard, Ann Schaffner, Lynn Stein, Jonathan Stolk, Stephen Westwood, Yevgeniya Zastavker

Mark Somerville

Over the last two years Olin College has been defining and implementing a provisional system to develop and assess student competency levels. The system particularly emphasizes the importance of creating a community of practice that includes not only faculty but also staff and students. In this paper we provide an overview of the design process, and comment on the results of our first year of implementing the system.


Drowning In Method, Thirsty For Values: A Call For Cultural Inquiry, Jonathan Stolk, Mark Somerville, Debbie Chachra Jul 2012

Drowning In Method, Thirsty For Values: A Call For Cultural Inquiry, Jonathan Stolk, Mark Somerville, Debbie Chachra

Mark Somerville

A decade or more has passed since publication of most calls for reform in engineering education. In the ensuing time, there has been significant work on the design, implementation, and transferability of appropriate methodsand techniques - accompanied by, in most cases, little discussion of the values and beliefs of the people involved. But many theories of change rely on a fundamental shift in human beliefs and values, and purport that institutionalization of methods is impossible without this shift. Given this, now may be a reasonable time to re-visit the questions: What are the values of people involved in engineering education, …


Engineering Students' Conceptions Of Self-Directed Learning, Jonathan Stolk, John Geddes, Mark Somerville, Robert Martello Jul 2012

Engineering Students' Conceptions Of Self-Directed Learning, Jonathan Stolk, John Geddes, Mark Somerville, Robert Martello

Mark Somerville

Researchers have developed numerous theories and developmental models to describe self directed learning, lifelong learning, and self-regulated learning. The literature includes a large body of research that illustrates the cognitive, metacognitive, motivational, affective, and behavioral attributes of self-directed learners; the influences of social and physical environment on self-directed learning development; and the roles of self-perceptions, causal orientations,learning conceptions, and demographics in determining certain self-directed learning responses. But how do undergraduate engineering students characterize and critique self-directed learning? This paper evaluates the responses of engineering students to questions regarding the definition of self-direction and the primary positive or negative factors contributing …


The Search For Design In Electrical Engineering Education, David Kerns, Sherra Kerns, Mark Somerville, Gill Pratt, Jill Crisman Jul 2012

The Search For Design In Electrical Engineering Education, David Kerns, Sherra Kerns, Mark Somerville, Gill Pratt, Jill Crisman

Mark Somerville

The importance of "design" in engineering education is well established and a cornerstone of most new engineering curricula as well as accreditation criteria Electrical and computer engineering (ECE) programs view many elements of design in ways similar to other engineering disciplines. However, in some respects other disciplines within engineering, such as Mechanical Engineering (ME), view design in broader terms, and perhaps gain value that electrical and computer engineering educators may miss. This paper describes how design is typically viewed in ECE programs, bow it's viewed in other engineering areas, particularly ME, and suggests some new possibilities for enhancing design education …


Floating-Gate Devices: They Are Not Just For Digital Memories Anymore, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

Floating-Gate Devices: They Are Not Just For Digital Memories Anymore, Paul Hasler, Bradley Minch, Chris Diorio

Bradley Minch

Since the first reported floating-gate structure in 1967, floating-gate transistors have been used widely to store digital information for long periods in structures such as EPROMs and EEPROMs. Recently floating-gate devices have found applications as analog memories, analog and digital circuit elements, and adaptive processing elements. Floating-gate devices have found commerical applications, e.g. ISD, for long-term non-volatile information storage devices for analog applications. The focus of floating-gate devices has been towards fabrication in standard CMOS processes, as opposed to the specialized processes for fabricating digital non-volatile memories. Floating-gate circuits can be designed at any or all of three levels: analog …


Synthesis Of Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio Jul 2012

Synthesis Of Multiple-Input Translinear Element Networks, Bradley Minch, Paul Hasler, Chris Diorio

Bradley Minch

We describe two systematic procedures for synthesizing multiple-input translinear element (MITE) networks that produce an output current that is equal to product of a number of input currents, each of which is raised to an arbitrary rational power. By using the first procedure, we obtain a MITE network, called a two-layer network, that is relatively insensitive to mismatch in the MITE weight values. By using the second procedure, we arrive at a MITE network, called a cascade network, that reduces the fan-in required of each MITE. We illustrate each ofthese procedures with an example.


A Floating-Gate Technology For Digital Cmos Processes, Bradley Minch, Paul Hasler Jul 2012

A Floating-Gate Technology For Digital Cmos Processes, Bradley Minch, Paul Hasler

Bradley Minch

We discuss the possibility of developing high-quality floating-gate memories and circuits in digital CMOS technologies that have only one layer of polysilicon. Here, the primary concern is whether or not we can get adequate control-gate linearity from MOS capacitors. We employ two experimental procedures to address this issue and find acceptable floating-gate circuit behaviour with MOS capacitors. First, we simultaneously characterize an MOS capacitor and a linear capacitor; the experimental data show that MOS capacitors behave similarly to linear capacitors over a finite, but usable range. Second, we characterize two typical floating-gateMOS circuit primitives, a floating-gate amplifier and a multiple-input …


Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio Jul 2012

Adaptive Circuits Using Pfet Floating-Gate Devices, Paul Hasler, Bradley Minch, Chris Diorio

Bradley Minch

In this paper, we describe our floating-gate pFET device, with its many circuit applications and supporting experimental measurements. We developed these devices in standard double-poly CMOS technologies by utilizing many effects inherent in these processes. We add floating-gate charge by electron tunneling, and we remove floating-gate charge by hot-electron injection. With this floating-gate technology, we cannot only build analog EEPROMs, we can also implement adaptation and learning when we consider floating-gate devices to be circuit elements with important time-domain dynamics. We start by discussing non-adaptive properties of floating-gate devices and we present two representative non-adaptive applications. First, we discuss using …


Roach: An Autonomous 2.4g Crawling Hexapod Robot, Aaron Hoover, Erik Steltz, Ronald Fearing Jul 2012

Roach: An Autonomous 2.4g Crawling Hexapod Robot, Aaron Hoover, Erik Steltz, Ronald Fearing

Aaron M. Hoover

This work presents the design, fabrication, and testing of a novel hexapedal walking millirobot using only two actuators. Fabricated from S2-glass reinforced composites and flexible polymer hinges using the smart composite microstructures (SCM) process, the robot is capable of speeds up to 1 body length/sec or approximately 3 cm/s. All power and control electronics are onboard and remote commands are enabled by an IrDA link. Actuation is provided by shape memory alloy wire. At 2.4 g including control electronics and battery, RoACH is the smallest and lightest autonomous legged robot produced to date.


Medic: A Legged Millirobot Utilizing Novel Obstacle Traversal, Nicholas Kohut, Aaron Hoover, Kevin Ma, Stanley Baek, Ronald Fearing Jul 2012

Medic: A Legged Millirobot Utilizing Novel Obstacle Traversal, Nicholas Kohut, Aaron Hoover, Kevin Ma, Stanley Baek, Ronald Fearing

Aaron M. Hoover

This work presents the design, fabrication, capabilities, and obstacle traversal mechanics of MEDIC (MillirobotEnabled Diagnostic of Integrated Circuits), a small legged robot able to overcome a varied array of obstacles. MEDIC features a hull that keeps its body in contact with the ground at all times, and uses only four actuators to move forward, turn, mount obstacles, and move in reverse. The chassis is fabricated using a Smart Composite Microstructures (SCM) approach and the robot is actuated by coiled Shape Memory Alloy (SMA). MEDIC also features a camera which will be useful for navigation in the future.


Systematic Study Of The Performance Of Small Robots On Controlled Laboratory Substrates, Chen Li, Aaron Hoover, Paul Birkmeyer, Paul Umbanhowar, Ronald Fearing, Daniel Goldman Jul 2012

Systematic Study Of The Performance Of Small Robots On Controlled Laboratory Substrates, Chen Li, Aaron Hoover, Paul Birkmeyer, Paul Umbanhowar, Ronald Fearing, Daniel Goldman

Aaron M. Hoover

The design of robots able to locomote effectively over a diversity of terrain requires detailed ground interaction models; unfortunately such models are lacking due to the complicated response of real world substrates which can yield and flow in response to loading. To advance our understanding of the relevant modeling and design issues, we conduct a comparative study of the performance of DASH and RoACH, two small, biologically inspired, six legged, lightweight (~10 cm, ~20 g) robots fabricated using the smart composite microstructure (SCM) process. We systematically examine performance of both robots on rigid and flowing substrates. Varying both ground properties …


Fast Scale Prototyping For Folded Millirobots, Aaron Hoover, Ronald Fearing Jul 2012

Fast Scale Prototyping For Folded Millirobots, Aaron Hoover, Ronald Fearing

Aaron M. Hoover

We present a set of tools and a process, making use of inexpensive and environmentally friendly materials, that enable the rapid realization of fully functional large scale prototypes of folded mobile millirobots. By mimicking the smart composite microstructure (SCM) process at a 2–10X scale using posterboard, and commonly available polymer films, we can realize a prototype design in a matter of minutes compared with days for a complicated SCM design at the small scale. The time savings enable a significantly shorter design cycle by allowing forimmediate discovery of design flaws and introduction of design improvements prior to beginning construction at …


A Rapidly Prototyped 2-Axis Positioning Stage For Microassembly Using Large Displacement Compliant Mechanisms, Aaron Hoover, Srinath Avadhanula, Richard Groff, Ronald Fearing Jul 2012

A Rapidly Prototyped 2-Axis Positioning Stage For Microassembly Using Large Displacement Compliant Mechanisms, Aaron Hoover, Srinath Avadhanula, Richard Groff, Ronald Fearing

Aaron M. Hoover

Compliant mechanisms provide an attractive alternative to conventional rigid mechanisms in the design of ultra low-cost precision positioning systems. The desirable performance characteristics of these mechanisms including freedom from backlash, long life, light weight, and ease of fabrication/assembly make them an ideal solution to the problem of inexpensive precision positioning for microassembly. This paper presents a design for a 2 axis precision positioning system which makes use of large displacement compliant mechanisms, a room temperature and pressure molding fabrication process, commodity hardware, and a piecewise linear interpolation compensation scheme to achieve positioning performance suitable for automated assembly of sub-centimeter robotic …


Analysis Of Off-Axis Performance Of Compliant Mechanisms With Applications To Mobile Millirobot Design, Aaron Hoover, Ronald Fearing Jul 2012

Analysis Of Off-Axis Performance Of Compliant Mechanisms With Applications To Mobile Millirobot Design, Aaron Hoover, Ronald Fearing

Aaron M. Hoover

We present an approach to quantifying the off-axis stiffness properties of parallel compliant mechanisms used in the design of mobile millirobots. By transforming the stiffness of individual flexure elements and rigid links comprising a compliant mechanism into a global coordinate system, we enable the formulation of an equivalent mechanism stiffness. Using that stiffness in concert with an energy-based performance metric, we predict theperformance of a compliant mechanism subjected to a prescribed set of forces in the global coordinate system. We analyze a flexure-based Sarrus linkage and use the performance metric to improve the design by adding topological redundancy. Finally, our …


Rapidly Prototyped Orthotweezers For Automated Microassembly, Aaron Hoover, Ronald Fearing Jul 2012

Rapidly Prototyped Orthotweezers For Automated Microassembly, Aaron Hoover, Ronald Fearing

Aaron M. Hoover

We describe the design, fabrication, and testing of an ultra-low cost orthotweezers system for microassembly. By utilizing rapid prototyping technology, compliant mechanisms, and commodity-grade actuators and sensors, we significantly reduce the complexity and cost of the previous Orthotweezers system without sacrificing functionality. With a force resolution of 0.7mN and a worst case mean positioning repeatability of 23 mum, the system is capable of dexterously manipulating rectangular parts with dimensions 200 mum times 200 mum times 100 mum. Such blocks can then be temporarily attached to thin, delicate, or oddly shaped parts to enable handling and ultimately assembly of micromechanical structures. …


Bio-Inspired Design And Dynamic Maneuverability Of A Minimally Actuated Six-Legged Robot, Aaron Hoover, Samuel Burden, Xiao-Yu Fu, S. Sastry, Ronald Fearing Jul 2012

Bio-Inspired Design And Dynamic Maneuverability Of A Minimally Actuated Six-Legged Robot, Aaron Hoover, Samuel Burden, Xiao-Yu Fu, S. Sastry, Ronald Fearing

Aaron M. Hoover

Rapidly running arthropods like cockroaches make use of passive dynamics to achieve remarkable locomotion performance with regard to stability, speed, and maneuverability. In this work, we take inspiration from these organisms to design, fabricate, and control a 10cm, 24 gram underactuated hexapedal robot capable of running at 14 body lengths per second and performing dynamic turning maneuvers. Our design relies on parallel kinematic mechanisms fabricated using the scaled smart composite microstructures (SCM) process and viscoelastic polymer legs with tunable stiffness. In addition to the novel robot design, we present experimental validation of the lateral leg spring (LLS) locomotion model's prediction …


Perimeter Patrol On Autonomous Surface Vehicles Using Marine Radar, Elena Oleynikova, Nicole Lee, Andrew Barry, Joseph Holler, David Barrett Jul 2012

Perimeter Patrol On Autonomous Surface Vehicles Using Marine Radar, Elena Oleynikova, Nicole Lee, Andrew Barry, Joseph Holler, David Barrett

David Barrett

Perimeter patrol enhances the utility of autonomous surface vehicles (ASVs) by enabling many security and scientific missions, including harbor protection, water sampling, and geological survey. We present a novel approach to perimeter patrol that uses only two sensors: commercial off-the-shelf available marine radar and the heading information from a GPS. Our algorithm performs computer vision morphological operations on the radarimage to find a suitable path around shore and choose an appropriate next waypoint. Our method has proved robust to a variety of field conditions, allowing us to demonstrate the autonomous navigation of a 3.5 km perimeter lake.