Engineering Commons^™

Formation Control With Collision Avoidance For Fixed-Wing Unmanned Air Vehicles With Speed Constraints, Christopher Heintz

Theses and Dissertations--Mechanical Engineering

Advances in the miniaturization of powerful electronic components and motors, the democratization of global navigation satellite systems (GNSS), and improvements in the performance, safety, and cost in lithium batteries has led to the proliferation of small and relatively inexpensive unmanned aerial vehicles (UAVs). Many of these UAVs are of the multi-rotor design, however, fixed-wing designs are often more efficient than rotary-wing aircraft, leading to a reduction in the power required for a UAV of a given mass to stay airborne. Autonomous cooperation between multiple UAVs would enable them to complete objectives that would be difficult or impossible for a single …

On The Impact Of Gravity Compensation On Reinforcement Learning In Goal-Reaching Tasks For Robotic Manipulators, Jonathan Fugal, Hasan A. Poonawala, Jihye Bae

Electrical and Computer Engineering Faculty Publications

Advances in machine learning technologies in recent years have facilitated developments in autonomous robotic systems. Designing these autonomous systems typically requires manually specified models of the robotic system and world when using classical control-based strategies, or time consuming and computationally expensive data-driven training when using learning-based strategies. Combination of classical control and learning-based strategies may mitigate both requirements. However, the performance of the combined control system is not obvious given that there are two separate controllers. This paper focuses on one such combination, which uses gravity-compensation together with reinforcement learning (RL). We present a study of the effects of gravity …

A Comparative Analysis Of Reinforcement Learning Applied To Task-Space Reaching With A Robotic Manipulator With And Without Gravity Compensation, Jonathan Fugal

Theses and Dissertations--Electrical and Computer Engineering

Advances in computing power in recent years have facilitated developments in autonomous robotic systems. These robotic systems can be used in prosthetic limbs, wearhouse packaging and sorting, assembly line production, as well as many other applications. Designing these autonomous systems typically requires robotic system and world models (for classical control based strategies) or time consuming and computationally expensive training (for learning based strategies). Often these requirements are difficult to fulfill. There are ways to combine classical control and learning based strategies that can mitigate both requirements. One of these ways is to use a gravity compensated torque control with reinforcement …

Scalable Control Architecture For Variable-Rate Turn Compensation, Michael P. Sama, Joe D. Luck, Timothy S. Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

The objective of this study was to determine if a CAN bus could be used to implement variable-rate turn compensation in a manner that is scalable by encoding application rates for an entire implement into a single data message. A variable-rate turn compensation test fixture was developed that used a CAN bus to communicate application rates to 16 individual nodes using a 2-byte data message (80-bit extended identifier CAN messages). The system assumed that the physical structure of an implement was linear and that the control nodes were equally spaced. Application rates for the outer-most nodes were broadcasted and the …

A Tutorial On Learning Human Welder's Behavior: Sensing, Modeling, And Control, Y. K. Liu, W. J. Zhang, Yu Ming Zhang

Electrical and Computer Engineering Faculty Publications

Human welder's experiences and skills are critical for producing quality welds in manual GTAW process. Learning human welder's behavior can help develop next generation intelligent welding machines and train welders faster. In this tutorial paper, various aspects of mechanizing the welder's intelligence are surveyed, including sensing of the weld pool, modeling of the welder's adjustments and this model-based control approach. Specifically, different sensing methods of the weld pool are reviewed and a novel 3D vision-based sensing system developed at University of Kentucky is introduced. Characterization of the weld pool is performed and human intelligent model is constructed, including an extensive …

The Modeling, Analysis And Control Of Resilient Manufacturing Enterprises, Yao Hu

Theses and Dissertations--Electrical and Computer Engineering

The resilience of manufacturing enterprises is an important research topic, since disruptions have severe effects on the normal operation of manufacturing enterprises, especially as manufacturing supply chains become global. Although many case studies have been carried out to address resilience in organizations, a systematic method to model and analyze the resilience dynamics in manufacturing enterprises is not well developed. This study is intended to conduct research on quantitative analysis and control for resilience.

After reviewing the literature addressing resilience, a modeling framework is presented to characterize the resilience of a manufacturing enterprise responding to disruptive events, which includes inventory ow …

A Simple Method To Improve Autonomous Gps Positioning For Tractors, Jaime Gomez-Gil, Sergio Alonso-Garcia, Francisco Javier Gómez-Gil, Tim Stombaugh

Biosystems and Agricultural Engineering Faculty Publications

Error is always present in the GPS guidance of a tractor along a desired trajectory. One way to reduce GPS guidance error is by improving the tractor positioning. The most commonly used ways to do this are either by employing more precise GPS receivers and differential corrections or by employing GPS together with some other local positioning systems such as electronic compasses or Inertial Navigation Systems (INS). However, both are complex and expensive solutions. In contrast, this article presents a simple and low cost method to improve tractor positioning when only a GPS receiver is used as the positioning sensor. …

Simulation And Control Of A Quadrotor Unmanned Aerial Vehicle, Michael David Schmidt

University of Kentucky Master's Theses

The ANGEL project (Aerial Network Guided Electronic Lookout) takes a systems engineering approach to the design, development, testing and implementation of a quadrotor unmanned aerial vehicle. Many current research endeavors into the field of quadrotors for use as unmanned vehicles do not utilize the broad systems approach to design and implementation. These other projects use pre-fabricated quadrotor platforms and a series of external sensors in a mock environment that is unfeasible for real world use. The ANGEL system was designed specifically for use in a combat theater where robustness and ease of control are paramount. A complete simulation model of …

Uniaxially-Driven Controlled Biaxial Testing Fixture, Fadi K. Abu-Farha, Marwan K. Khraisheh

Mechanical Engineering Faculty Patents

A uniaxially-driven controlled biaxial testing fixture includes a base, a first coupler mounted to the base, and a load input drive rack mounted for linear movement with respect to the base. A second coupler and a first specimen grip are both mounted to the load input drive rack. Second, third and fourth specimen grips are also mounted for linear movement with respect to the base. First, second and third drive mechanisms connect the load input drive rack to the second, third and fourth specimen grips. Together the four specimen grips are oriented to provide biaxial application of force to a …

Seasonal Aeration Rates For The Eastern United States Based On Long-Term Weather Patterns, Michael D. Montross, Samuel G. Mcneill, Thomas C. Bridges

Biosystems and Agricultural Engineering Faculty Publications

Most aeration fans are sized to produce a minimum airflow rate of 0.1 m³/min/t (0.1 cfm/bu) in on-farm grain storage structures. At this airflow rate a significant amount of time is required to move a cooling front completely through a bin. The desired grain temperature and prevailing weather conditions will have a significant effect on required fan size. Thirty years of weather data were analyzed for the eastern United States to determine the amount of time available in temperature windows between 0 to 15.C and 0 to 17.C. Contour maps were generated with ArcMap 8.3 for the percentage …

A Survey Of Electronic Environmental Controllers, Richard S. Gates, Douglas G. Overhults, Larry W. Turner

Biosystems and Agricultural Engineering Faculty Publications

Sixteen commercially available electronic environmental controllers were evaluated. The units were classified according to enclosure type, analog versus microprocessor based control, power supply, sensors, alarms, control relays and triac output, interval timers, outside temperature feedback, and retail price. An assessment of these controllers indicated several critical limitations in the application of this technology.

The use of integrated controllers for animal production has the potential for substantial improvements in production efficiencies. If the limitations observed in the present controller technology, as represented by this sample, are addressed, industry acceptance of the technology can be accelerated. A uniform standard to address this …

Harvester Guidance Control System, George B. Day V, Timothy D. Smith

Biosystems and Agricultural Engineering Faculty Patents

A guidance control system for a harvester or like machinery includes a steering linkage operatively connected to at least one ground engaging wheel. Harvester steering is controlled through the linkage by either an operator controlled steering wheel or a sensor responsive self-steering mechanism. The sensor responsive self-steering mechanism includes a guide assembly pivotally mounted to the harvester. The guide assembly includes a pair of laterally spaced, cooperating tines that define a path therebetween for plants being harvested. A sensor positioned on each tine senses the position of plants as they are harvested. A control circuit is responsive to the sensors …