High Accuracy Fuel Flowmeter, Phase 1

Technology related to aircraft fuel mass - flowmeters was reviewed to determine what flowmeter types could provide 0.25%-of-point accuracy over a 50 to one range in flowrates. Three types were selected and were further analyzed to determine what problem areas prevented them from meeting the high accuracy requirement, and what the further development needs were for each. A dual-turbine volumetric flowmeter with densi-viscometer and microprocessor compensation was selected for its relative simplicity and fast response time. An angular momentum type with a motor-driven, spring-restrained turbine and viscosity shroud was selected for its direct mass-flow output. This concept also employed a turbine for fast response and a microcomputer for accurate viscosity compensation. The third concept employed a vortex precession volumetric flowmeter and was selected for its unobtrusive design. Like the turbine flowmeter, it uses a densi-viscometer and microprocessor for density correction and accurate viscosity compensation

A Proposed Approach to Mechatronics Design and Implementation Education-Oriented Methodology

Mechatronics engineer is expected to design engineering systems with synergy and integration toward constrains like higher performance, speed, precision, efficiency, lower costs and functionality. The key element in success of a mechatronics engineering education-program, and correspondingly, Mechatronics engineering graduates, is directly related to a well-structured mechatronic system design course and the applied structural design methodology. Guidelines for structural design methodology and tools for the development process of mechatronic products, that can be applied in educational process is highly required. This paper proposes mechatronics systems design education-oriented methodology, which aims to integrate multidisciplinary knowledge, in various stages through the design process and development of mechatronics product. The proposed mechatronics design methodology is described, discussed and applied with the help of example student final year graduation project; design and implementation of mechatronics mobile robotic guidance system in the from of smart wheelchair- Mechatronics Motawif, to help and support people with disabilities and special needs to perform specific predetermined tasks, particularly, performing Al Omrah and motion around holy Kaba, Makka. Keywords: Mechatronics, Design methodology, Parallel design, Synergistic integration, Modeling/ Simulation, Prototyping, Mobile robot, Motawif

Designing and Implementing a Model Vehicle Platoon with Longitudinal Control

Decreasing fuel consumption and increasing road capacity are both desired in regards to heavy duty vehicles. One proposed way of doing this is by having vehicles travelling at close distances to reduce the air drag, and thereby reducing their fuel consumption. This thesis address the platooning problem on model-scale vehicles as they are a desirable demonstration platform since they can be driven indoors. This thesis considers the implementation and evaluation of the longitudinal control of a model-scale vehicle platoon where Model Predictive Control is utilised. The concept of platooning on real full-size vehicles is briefly discussed and some of its benefits are described. The thesis then discusses and evaluates what sensors are necessary to equip the model vehicles with and how to implement them, in addition to a discussion and evaluation of inter-vehicular communication in an indoor environment is provided. Then, based on the available sensors, a heuristic feedback controller and a model-based controller is designed as distance controllers, as well as a feedback controller used for speed control, and then connected in a cascading structure. The two controllers are then evaluated in simulations based on different scenarios and finally results from a working implementation on the model-scale vehicles are presented. The end results from this thesis are a demonstration platform of two model-scale electrical vehicles as well as two different distance control algorithms both based on using the cruise control developed in the vehicles

Master of Science

thesisThe objective of this research is to improve the ability of a human operator to drive an omnidirectional robot by using omnidirectional force-feedback. Omnidirectional vehicles offer improved mobility over conventional vehicles and can potentially benefit people requiring motorized transportation and industries where vehicles must operate in confined spaces. However, omnidirectional vehicles require more skill to control due to the additional degrees of freedom inherent in the vehicle’s design. We hypothesize that providing force-feedback to the driver through an omnidirectional joystick will allow the robot to assist the driver in navigating and avoiding collisions with obstacles in a manner that is natural to the operator. This research is the first attempt to use true omnidirectional 3-DOF (degree of freedom) force-feedback to provide navigational assistance for a human to drive an omnidirectional vehicle. While 2-DOF force-feedback has been used in a limited capacity for obstacle avoidance on omnidirectional vehicles, this is the first study to include a third rotational axis of force-feedback and use it to guide a driver along planar collision-avoiding trajectories with a natural coordination of orientation. Unique intellectual merits put forth by this research include use of a novel omnidirectional haptic device and force-feedback strategies to guide operators and experiments to quantify the ability of force-feedback to improve omnidirectional driving performance and driver experience in a real time scenario

Fuel Estimation Using Dynamic Response

New regulations governing satellites in geostationary orbit require satellites to transfer into a parking orbit as part of the decommissioning process. These regulations increase the demand for accurate fuel estimation techniques for satellites. This study estimates the change in fuel mass from the dynamic response of the Air Force Institute of Technology\u27s simulated satellite (SimSAT) to known control inputs. With an iterative process, the moment of inertia of SimSAT about the yaw axis was estimated by matching a model of SimSAT to the measured angular rates. A change in fuel mass was then estimated from the known relation between the change in moment of inertia to the change in fuel mass. Fuel masses of 1, 2, and 3 kilograms were estimated. The fuel estimation process developed in this study was able to estimate the fuel as 1.5664 ? 3.7157 kg, 2.8880 ? 3.8875 kg, and 3.9114 ? 3.4648 kg respectively. While the theory behind the estimation process is sound, the implementation still requires work

SPHERES Tethered Formation Flight Testbed: Application to NASA’s SPECS Mission

This paper elaborates on theory and experiment of the formation flight control for the future space-borne tethered interferometers. The nonlinear equations of multi-vehicle tethered spacecraft system are derived by Lagrange equations and decoupling method. The preliminary analysis predicts unstable dynamics depending on the direction of the tether motor. The controllability analysis indicates that both array resizing and spin-up are fully controllable only by the reaction wheels and the tether motor, thereby eliminating the need for thrusters. Linear and nonlinear decentralized control techniques have been implemented into the tethered SPHERES testbed, and tested at the NASA MSFC's flat floor facility using two and three SPHERES configurations. The nonlinear control using feedback linearization technique performed successfully in both two SPHERES in-line configuration and three triangular configuration while varying the tether length. The relative metrology system, using the ultra sound metrology system and the inertial sensors as well as the decentralized nonlinear estimator, is developed to provide necessary state information

Multi-MAV Deployment

The goal of this project was to develop a system of coordinated micro aerial vehicles along with an unmanned ground vehicle in order to advance the development of collaborative systems. The design objectives were to maximize flight time and mobility of a quad-rotor, and to minimize the size of the system. Analysis, design, construction, and testing of an autonomous quad-rotor and ground vehicle for collaborative operations were completed. The resulting system was capable of deployment and hover

AN EVALUATION OF THE TRAVELING WAVE ULTRASONIC MOTOR FOR FORCE FEEDBACK APPLICATIONS

The traveling wave ultrasonic motor is considered for use in haptic devices where a certain input-output relation is desired between the applied force and the resulting motion. Historically, DC motors have been the standard choice for this purpose. Owing to its unique characteristics, the ultrasonic motors have been considered an attractive alternative. However, there are some limitations when using the ultrasonic motor for force-feedback applications. In particular, direct torque control is difficult, and the motor can only supply torque in the direction of motion. To accommodate these limitations we developed an indirect control approach. The experimental results demonstrate that the model reference control method was able to approximate a second order spring-damper system