Mechanical Engineering Commons^™

Development Of Guidance, Navigation, And Control Systems For Multi-Spacecraft Assembly In Proximity Operations, Mohammed Ayman Atallah

Theses

This thesis presents the development of Guidance, Navigation, and Control (GNC) algorithms for multi-spacecraft assembly in proximity operations. A 3-DOF mathematical model of spacecraft relative translational motion is derived using the Euler-Lagrange method. Additionally, a 6-DOF mathematical model of spacecraft relative translational and rotational motion is derived using the twistor method, with consideration for the kinematic coupling effect. A new Linear Time-Invariant (LTI) model is developed based on the twistor model, which is utilized in the design of the GNC systems. Both LTI Model Predictive Control (MPC) and Linear Time-Varying (LTV) MPC algorithms are employed to develop Guidance and Control …

Real-Time Suitable Predictive Control Using Spat Information From Automated Traffic Lights, Pradeep Bhat, Bo Chen

Michigan Tech Publications, Part 2

Traffic intersections throughout the United States combine fixed, semi-actuated, and fully actuated intersections. In the case of the semi-actuated and actuated intersections, uncertainties are considered in phase duration. These uncertainties are due to car waiting queues and pedestrian crossing. Intelligent transportation systems deployed in traffic infrastructure can communicate Signal and Phase Timing messages (SPaT) to vehicles approaching intersections. In the connected and automated vehicle ecosystem, the fuel savings potential has been explored. Prior studies have predominantly focused on fixed time control for the driver. However, in the case of actuated signals, there is a different and significant challenge due to …

Microgrid Energy Management During High-Stress Operation, Thomas Price, Gordon Parker, Gail Vaucher, Robert Jane, Morris Berman

Michigan Tech Publications

We consider the energy management of an isolated microgrid powered by photovoltaics (PV) and fuel-based generation with limited energy storage. The grid may need to shed load or energy when operating in stressed conditions, such as when nighttime electrical loads occur or if there is little energy storage capacity. An energy management system (EMS) can prevent load and energy shedding during stress conditions while minimizing fuel consumption. This is important when the loads are high priority and fuel is in short supply, such as in disaster relief and military applications. One example is a low-power, provisional microgrid deployed temporarily to …

Nonlinear Model Predictive Control Of Wave Energy Converter, Isha Malekar

Dissertations, Master's Theses and Master's Reports

In this report model predictive control (MPC) is applied to a simulated, spherical, point absorber wave energy converter to maximize energy extraction. Constraints are applied to the buoy's displacement and the power take-off (PTO) generator force. The WEC's "truth” model uses nonlinear Froude-Krylov (FK) hydrostatic and hydrodynamic forces. This is in contrast with previous studies where linear approximations are used in the form of a hydrostatic stiffness force and a wave excitation force. The nonlinear forces become significant when the vertical displacement of the buoy exceeds about 40% of the buoy's radius. Two versions of MPC are compared where optimal …

Comparison Of Optimal Energy Management Strategies Using Dynamic Programming, Model Predictive Control, And Constant Velocity Prediction, Amol Arvind Patil

Masters Theses

Due to the recent advancements in autonomous vehicle technology, future vehicle velocity predictions are becoming more robust which allows fuel economy (FE) improvements in hybrid electric vehicles through optimal energy management strategies (EMS). A real-world highway drive cycle (DC) and a controls-oriented 2017 Toyota Prius Prime model are used to study potential FE improvements. We proposed three important metrics for comparison: (1) perfect full drive cycle prediction using dynamic programming, (2) 10-second prediction horizon model predictive control (MPC), and (3) 10-second constant velocity prediction. These different velocity predictions are put into an optimal EMS derivation algorithm to derive optimal engine …

Characterizing Meteorological Forecast Impact On Microgrid Optimization Performance And Design, Robert Jane, Gordon G. Parker, Gail Vaucher, Morris Berman

Michigan Tech Publications

A microgrid consists of electrical generation sources, energy storage assets, loads, and the ability to function independently, or connect and share power with other electrical grids. Thefocus of this work is on the behavior of a microgrid, with both diesel generator and photovoltaic resources, whose heating or cooling loads are influenced by local meteorological conditions. Themicrogrid's fuel consumption and energy storage requirement were then examined as a function of the atmospheric conditions used by its energy management strategy (EMS). A fuel-optimal EMS, able to exploit meteorological forecasts, was developed and evaluated using a hybrid microgrid simulation. Weather forecast update periods …

Adaptive Control For Inflatable Soft Robotic Manipulators With Unknown Payloads, Jonathan Spencer Terry

Theses and Dissertations

Soft robotic platforms are becoming increasingly popular as they are generally safer, lighter, and easier to manufacture than their more rigid, heavy, traditional counterparts. These soft platforms, while inherently safer, come with significant drawbacks. Their compliant components are more difficult to model, and their underdamped nature makes them difficult to control. Additionally, they are so lightweight that a payload of just a few pounds has a significant impact on the manipulator dynamics. This thesis presents novel methods for addressing these issues. In previous research, Model Predictive Control has been demonstrably useful for joint angle control for these soft robots, using …

Wind Turbine Wake Interactions - Characterization Of Unsteady Blade Forces And The Role Of Wake Interactions In Power Variability Control, Daniel Curtis Saunders

Graduate College Dissertations and Theses

Growing concerns about the environmental impact of fossil fuel energy and

improvements in both the cost and performance of wind turbine technologies has spurred

a sharp expansion in wind energy generation. However, both the increasing size of wind

farms and the increased contribution of wind energy to the overall electricity generation

market has created new challenges. As wind farms grow in size and power density, the

aerodynamic wake interactions that occur between neighboring turbines become

increasingly important in characterizing the unsteady turbine loads and power output of

the farm. Turbine wake interactions also impact variability of farm power generation,

acting …

Position And Stiffness Control Of Inflatable Robotic Links Using Rotary Pneumatic Actuation, Charles Mansel Best

Theses and Dissertations

Inflatable robots with pneumatic actuation are naturally lightweight and compliant. Both of these characteristics make a robot of this type better suited for human environments where unintentional impacts will occur. The dynamics of an inflatable robot are complex and dynamic models that explicitly allow variable stiffness control have not been well developed. In this thesis, a dynamic model was developed for an antagonistic, pneumatically actuated joint with inflatable links.The antagonistic nature of the joint allows for the control of two states, primarily joint position and stiffness. First a model was developed to describe the position states. The model was used …

Comparing Efficacy Of Different Dynamic Models For Control Of Underdamped, Antagonistic, Pneumatically Actuated Soft Robots, Morgan Thomas Gillespie

Theses and Dissertations

Research in soft robot hardware has led to the development of platforms that allow for safer performance when working in uncertain or dynamic environments. The potential of these platforms is limited by the lack of proper dynamic models to describe or controllers to operate them. A common difficulty associated with these soft robots is a representation for torque, the common electromechanical relation seen in motors does not apply. In this thesis, several different torque models are presented and used to construct linear state-space models. The control limitations on soft robots are induced by natural compliance inherent to the hardware. This …

Incorporating Driver’S Behavior Into Predictive Powertrain Energy Management For A Power-Split Hybrid Electric Vehicle, Lei Feng

Dissertations, Master's Theses and Master's Reports

The goal of this series of research is to advance hybrid electric vehicle (HEV) energy management by incorporating driver’s driving behavior and driving cycle information. To reduce HEV fuel consumption, the objectives of this research are divided into the following three parts.

The first part of the research investigates the impact of driver’s behavior on the overall fuel efficiency of a hybrid electric vehicle and the energy efficiency of individual powertrain components under various driving cycles. Between the sticker number fuel economy and actual fuel economy, it is well known that a noticeable difference occur when a driver drives aggressively. …

Temperature Control In Friction Stir Welding Using Model Predictive Control, Brandon Scott Taysom

Theses and Dissertations

Temperature is a very important process parameter in Friction Stir Welding (FSW), but until lately active control of temperature has not been practiced. Recently, temperature control via a PID controller has proven to be effective. Model Predictive Control (MPC) is a control method that holds promise, but has not been attempted in FSW before. Two different model forms are developed for MPC and are evaluated. The first is a simple first-order plus dead time (FOPDT) model. The second is the Hybrid Heat Source model and is more complex; it combines the heat source method and a 1D discretized thermal model …

Performance Comparison Of Control Methods For Tankless Water Heaters, David P. Yuill, Andrew H. Coward, Gregor P. Henze

David Yuill

Tankless water heaters (TWH) have several advantages and disadvantages when compared with storage water heaters. One disadvantage is that the outlet temperature of the water is difficult to control. To address this problem, the authors apply seven different control approaches and con- duct experiments to test the effectiveness of each approach. The experiments are carried out on a commercially available electric TWH, using a test method and apparatus developed by the authors. The seven approaches include various configurations of feedback or feed-forward con- trol, or both. One fairly simple approach devised in this project combines feedback and feed-forward control. This …

Development Of A Model Predictive Controller For Tankless Water Heaters, Gregor P. Henze, David P. Yuill, Andrew H. Coward

David Yuill

This paper describes the development of a novel approach to temperature control of tankless water heaters (TWHs). Conventional methods of controlling TWHs typically allow a high degree of error in the outlet water temperature when subjected to disturbances in flow rate or inlet water temperature. Poor control affects comfort, safety, and energy consumption associ- ated with TWHs. The novel control approach presented here uses model predictive control (MPC) to minimize the outlet temperature error. A dynamic heat transfer model of an electric TWH is developed and validated and used within a MPC-based controller. The controller is interfaced to a physical …