Approximated Control Affine Dynamics Mode For An Agricultural Field Robot Considering Wheel Terrain Interaction,
2016
University of Central Florida
Approximated Control Affine Dynamics Mode For An Agricultural Field Robot Considering Wheel Terrain Interaction, Pablo Menendez-Aponte
Electronic Theses and Dissertations
As populations and the demand for higher crop yields grow, so to does the need for efficient agricultural wheeled mobile robots. To achieve precise navigation through a field it is desirable that the control system is designed based on an accurate dynamic model. In this paper a control affine model for a custom designed skid-steer differential drive wheeled mobile robot is found. The Terramechanic wheel terrain interaction is adopted and modified to consider wheels with a torus geometry. Varying slip ratios and slip angles are considered in the terrain reaction forces, which is curve-fitted using a nonlinear least squares approach …
Kinematical Modelling And Its Analytical Inverse Kinematic Solution For The Handling Mechanism Of An Agricultural Robot,
2016
University of Central Florida
Kinematical Modelling And Its Analytical Inverse Kinematic Solution For The Handling Mechanism Of An Agricultural Robot, Sinem Gozde Defterli
Electronic Theses and Dissertations
Early detection of the crop diseases helps to prevent failure in the amount and the quality of the production. In agricultural robotics, the idea of a disease detection robot is a fresh and an innovative hot-button topic. The exclusion of the diseased parts from the strawberry plants for further analyses is one of the main tasks of a recently developed strawberry robot. To this purpose, the handling mechanism in the robot needs to achieve an accurate manipulation task to reach the target. Reaching, cutting and storing the diseased leaf are challenging and delicate processes during the procedure of the handling …
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators,
2016
University of Kentucky
Small Satellite Noncommutative Rotation Sequence Attitude Control Using Piezoelectric Actuators, Joshua L. Evans
Theses and Dissertations--Electrical and Computer Engineering
Attitude control remains one of the top engineering challenges faced by small satellite mission planning and design. Conventional methods for attitude control include propulsion, reaction wheels, magnetic torque coils, and passive stabilization mechanisms, such as permanent magnets that align with planetary magnetic fields. Drawbacks of these conventional attitude control methods for small satellites include size, power consumption, dependence on external magnetic fields, and lack of full control authority. This research investigates an alternative, novel approach to attitude-control method for small satellites, utilizing the noncommutative property of rigid body rotation sequences. Piezoelectric bimorph actuators are used to induce sinusoidal small-amplitude satellite …
Optimal Attitude Control Of Agile Spacecraft Using Combined Reaction Wheel And Control Moment Gyroscope Arrays,
2015
Air Force Institute of Technology
Optimal Attitude Control Of Agile Spacecraft Using Combined Reaction Wheel And Control Moment Gyroscope Arrays, Cole C. Doupe
Theses and Dissertations
This dissertation explores the benefits of combined control moment gyroscope (CMG) and reaction wheel array (RWA) actuation for agile spacecraft. Agile spacecraft are capable of slewing to multiple targets in minimum time. CMGs provide the largest torque capability of current momentum exchange actuation devices but also introduce singularity events in operation. RWAs produce less torque capability than CMGs but can achieve greater pointing accuracy. In this research, a combined RWA and CMG (RWCMG) system is evaluated using analytical simulations and hardware experiments. A closed-loop control scheme is developed which takes advantage of the strengths of each actuator set.The CMGs perform …
Lightweight Deployment Mechanism Of Solar Arrays For Use In Cubesats,
2015
Utah State University
Lightweight Deployment Mechanism Of Solar Arrays For Use In Cubesats, John Wood Ellis
Undergraduate Honors Capstone Projects
Cube satellites, also referred to as CubeSats, were developed in the late twentieth century, and have since served as a cost-effective method of gathering out-of-this-world data. The development of these small-scale satellites have helped universities and small companies worldwide to perform important experiments, as well as gather critical data in order to provide for further space exploration. Cube satellites are designed to be self-sustaining, by using solar cells to capture impinging thermal energy and convert it to power to be consumed by the electronics housed within the satellite itself. In order to function properly, these cells are extended in an …
Sub-Orbital Spaceflight – An Addition To Our Multi-Modal Transportation System,
2015
Embry-Riddle Aeronautical University
Sub-Orbital Spaceflight – An Addition To Our Multi-Modal Transportation System, Scott Haeffelin
Space Traffic Management Conference
The number of commercial spaceflights will be increasing by orders of magnitude over the next several decades. The current volume of space traffic can be managed on a case-by-case basis and there is little impact to the National Airspace System (NAS). This will change as more spaceports become operational, commercial sub-orbital flight companies begin serving their customers and as the cost of these flights begin to decrease. Current regulatory paths seek to allow the flexibility in the regulations for this industry to flourish while also maintaining a high standard of safety. There are, however, many nearsighted and old fashioned assumptions …
Lunar Icecube: Nextstep Lunar Cubesat Mission And Instrument Concept,
2015
Morehead State University
Lunar Icecube: Nextstep Lunar Cubesat Mission And Instrument Concept, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint presentation created by Professor Bob Twiggs associates titled "Lunar IceCube: NEXTSTEP Lunar Cubesat Mission and Instrument Concept" from November 12, 2015.
Estimating Terrace Agriculture: Implications Towards Archaeology And Ancient Civilizations,
2015
University of Alabama in Huntsville
Estimating Terrace Agriculture: Implications Towards Archaeology And Ancient Civilizations, Zachary Burkhardt, Kel Markert
Von Braun Symposium Student Posters
No abstract provided.
Design And Development Of A Sensor Payload For Low-Altitude Rocket Deployment,
2015
University of Alabama in Huntsville
Design And Development Of A Sensor Payload For Low-Altitude Rocket Deployment, Alex Christley
Von Braun Symposium Student Posters
No abstract provided.
Design And Fabrication Of A Boosted Dart Rocket System,
2015
University of Alabama in Huntsville
Design And Fabrication Of A Boosted Dart Rocket System, Davis Hunter, Bradley Henderson
Von Braun Symposium Student Posters
No abstract provided.
Small Packages Can Get Big Results,
2015
Morehead State University
Small Packages Can Get Big Results, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint presentation created by Professor Bob Twiggs titled "Small Packages can get Big Results" from October 16, 2015.
Modular Heat Dissipation Technique For A Cubesat,
2015
Air Force Institute of Technology
Modular Heat Dissipation Technique For A Cubesat, Melih Eken
Theses and Dissertations
In recent years, due to their many advantages, interest in larger scale CubeSats, such as 3U and 6U, has been increased. Correspondingly, dissipating the heat from the heat generating components in the CubeSat has become a challenge for thermal control. In this research, a modular approach was developed to dissipate heat from the overheating components in a CubeSat. To accomplish this, both experimental and computational methodologies were used. A 6U CubeSat was computationally modeled and the model correlated by experimental test results. Subsequently, validated CubeSat thermal model was used to design a modular heat dissipater. Validation and performance experiments of …
A Nonequilibrium Finite-Rate Carbon Ablation Model For Radiating Earth Re-Entry Flows,
2015
Air Force Institute of Technology
A Nonequilibrium Finite-Rate Carbon Ablation Model For Radiating Earth Re-Entry Flows, Christopher R. Alba
Theses and Dissertations
Vehicles entering planetary atmospheres at high speed require an ablative heat shield in order to withstand the high thermal energy flux to the body. The interaction between the ablative products and the flow field is not well characterized. Numerical simulations were conducted to investigate the influence of carbon ablation on shock layer radiation. Data collected from experiments performed in the X-2 expansion tunnel at the University of Queensland was used to compare to the simulations. The model was a short half-cylinder made of isomolded graphite and was tested in 8.6 km/s Earth entry flow. The model surface was heated within …
Brief Look At The Environment Of Space,
2015
Morehead State University
Brief Look At The Environment Of Space, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs titled "Brief Look at the Environment of Space" from September 10, 2015.
A Brief History Of Space - Sse 120 Session 1,
2015
Morehead State University
A Brief History Of Space - Sse 120 Session 1, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space - Session 01" from August 30, 2015.
A Brief History Of Space - Sse 120 Questions 01,
2015
Morehead State University
A Brief History Of Space - Sse 120 Questions 01, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space - Questions 01" from August 26, 2015.
A Brief History Of Space - Sse 120 Questions 02,
2015
Morehead State University
A Brief History Of Space - Sse 120 Questions 02, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space - Questions 02" from August 25, 2015.
A Brief History Of Space - Sse 120 Questions 04,
2015
Morehead State University
A Brief History Of Space - Sse 120 Questions 04, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space - Questions 04" from August 25, 2015.
A Brief History Of Space - Sse 120 Questions 03,
2015
Morehead State University
A Brief History Of Space - Sse 120 Questions 03, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "A Brief History of Space - Questions 03" from August 25, 2015.
What Is Orbital Debris?,
2015
Morehead State University
What Is Orbital Debris?, Robert J. Twiggs
Robert "Bob" Twiggs STEM Education Collection
A PowerPoint Presentation created by Professor Bob Twiggs on "What is Orbital Debris?" from August 24, 2015.
