Prototyping and Testing a Miniaturized Floating Spacecraft Simulator

Floating spacecraft simulators are robotic vehicles which imitate satellite movement in space. The use of floating spacecraft simulators permits experimental validation of Guidance, Navigation and Control (GNC) algorithms on Earth, before applying them in space, where errors could be catastrophic. Furthermore, FSS constitute an important research and educational tool for university students in space systems engineering curricula. However, all FSS currently in use are custom developed and expensive items. This master thesis covers the development, assembling and testing process of a new Floating Spacecraft Simulator for teaching and research purposes, named MyDAS, standing for Mini Dynamic Autonomous Spacecraft Simulator. By introducing MyDAS, a small, simple and affordable FSS enables broader utilization of FSS for research and education at university and high-school levels. Different propulsion configurations for MyDAS and their corresponding equations of motion are discussed. For one specific configuration, off-the-shelf pneumatic and electronic components are selected and tested. A modular and standardized 3D printed frame holds all parts together, creating a final rigid vehicle. In the end, MyDAS is tested in a variety of experiments with full hardware functionality accomplished.Universität der Bundeswehr Hamburg Fakultät für Maschinenbau Professur für Mechatronik Holstenhofweg 85 22043 Hamburg, GermanyGerman Armed ForcesApproved for public release; distribution is unlimited

Motion Control of Hexapod Robot Using Model-Based Design

Six-legged robots, also referred to as hexapods, can have very complex locomotion patterns and provide the means of moving on terrain where wheeled robots might fail. This thesis demonstrates the approach of using Model-Based Design to create control of such a hexapod. The project comprises the whole range from choosing of hardware, creating CAD models, development in MATLAB/Simulink and code generation. By having a computer model of the robot, development of locomotion patterns can be done in a virtual environment before tested on the hardware. Leg movement is implemented as algorithms to determine leg movement order, swing trajectories, body height alteration and balancing. Feedback from the environment is implemented as a internal measurement unit that measures body angles using sensor fusion. The thesis has resulted in successful creation of a hexapod platform for locomotion development through Model-Based Design. Both a virtual hexapod in Sim-Mechanics and a hardware hexapod is created and code generation to the hardware from the development environment is fully supported. Results include successful implementation of hexapod movement and the walking algorithm has the ability to walk on a flat surface, rotate and alter the body height. Implementation also contains a successful balancing mode for the hexapod whereas it is able to keep the main body level while the floor angle is altered

Current sensing feedback for humanoid stability

For humanoid robots to function in changing environments, they must be able to maintain balance similar to human beings. At present, humanoids recover from pushes by the use of either the ankles or hips and a rigid body. This method has been proven to work, but causes excessive strain on the joints of the robot and does not maximize on the capabilities of a humanlike body. The focus of this paper is to enable advanced dynamic balancing through torque classification and balance improving positional changes. For the robot to be able to balance dynamically, external torques must be determined accurately. The proposed method of this paper uses current sensing feedback at the humanoids power source to classify external torques. Through understanding the current draw of each joint, an external torque can be modeled. After being modeled, the external torque can be nullified with balancing techniques. Current sensing has the advantage that it adds detailed feedback while requiring small adjustments to the robot. Also, current sensing minimizes additional sensors, cost, and weight to the robot. Current sensing technology lies between the power supply and drive motors, thus can be implement without altering the robot. After an external torque has been modeled, the robot will undertake balancing positions to reduce the instability. The specialized positions increase the robot\u27s balance while reducing the workload of each joint. The balancing positions incorporate the humanlike body of the robot and torque from each of the leg servos. The best balancing positions were generated with a genetic algorithm and simulated in Webots. The simulation environment provided an accurate physical model and physics engine. The genetic algorithm reduced the workload of searching the workspace of a robot with ten degrees of freedom below the waist. The current sensing theory was experimentally tested on the TigerBot, a humanoid produced by the Rochester Institute of Technology (RIT). The TigerBot has twenty three degrees of freedom that fully simulate human motion. The robot stands at thirty-one inches tall and weighs close to nine pounds. The legs of the robot have six degrees of freedom per leg, which fully mimics the human leg. The robot was awarded first place in the 2012 IEEE design competition for innovation in New York

Researcher's guide to the NASA Ames Flight Simulator for Advanced Aircraft (FSAA)

Performance, limitations, supporting software, and current checkout and operating procedures are presented for the flight simulator, in terms useful to the researcher who intends to use it. Suggestions to help the researcher prepare the experimental plan are also given. The FSAA's central computer, cockpit, and visual and motion systems are addressed individually but their interaction is considered as well. Data required, available options, user responsibilities, and occupancy procedures are given in a form that facilitates the initial communication required with the NASA operations' group

SmallKat MQP

The SmallKat MQP is providing a quadrupedal robotic platform to help research and design new gaits, test sensors, and teach engineering students. Current options limit small companies, universities, and hobbyists due to their complexity, large size, and immense cost. SmallKat is a low-cost robotic platform with customizability and adaptability in mind. To allow for a multitude of gait designs, it is designed with 4-DoF legs controlled by powerful custom servo motors, 9-DoF IMUs, and custom microcontrollers. The body is constructed using additive manufacturing with PLA plastics, and even has a continuum tail for added body control. The higher level controller runs on a single-board computer for added performance when computing kinematics and dynamics, and controlling different gaits

On Development of Autonomous HAHO Parafoil System for Targeted Payload Return

22nd AIAA Aerodynamic Decelerator Systems Technology Conference, Daytona Beach, FL, March 25-28, 2013.An autonomous HAHO (high altitude, high-opening) parafoil system design is presented as a solution to the final descent phase of an on-demand International Space Station (ISS) sample return concept. The system design is tailored to meet specific constraints defined by a larger study at NASA Ames Research Center, called SPQR (Small Payload Quick-Return). Building on previous work in small, autonomous parafoil systems development, a SPQR compatible evolution of an existing advanced parafoil delivery system is designed, built, and test-flown deployed from unmanned air vehicles and high-altitude balloons. Results of the preliminary tests of the original and SPQR-compatible systems are presented, and applicability of the test article to actual spaceflight conditions is discussed