Learning Unit Systems Engineering Design Methodology with examples utilizing Advanced Vehicles for Space Transportation
Activity – Conceptual Design – Identification of A Robot Obstacle Avoidance Subsystem
Download 0.76 Mb.
|
- Navigate this page:
- The Robot Construction and Competition Project”
- Enemy Target Light Locating Subsystem
- Acceptance Criteria Weight Score
- Highest weighted score is the winning Conceptual Design Learning Unit Module 4
|
Activity – Conceptual Design – Identification of A Robot Obstacle Avoidance Subsystem (60 minutes) Refer to the robot in the learning unit entitled “Learning Unit-A Robot Construction and Competition Project” for complete details. That learning unit identifies the creation of two modules, a “Bumper Sensor Module” and a “Navigation Sensor Module” as shown below: Bumper Sensor Module The robot should be equipped with two bumpers, mounted across the front of the robot. No matter what angle from which an obstacle was hit by the robot, one of the two switches behind the bumpers would be triggered and the robot advised to take evasive action. The two bumper arms should directly come in contact with each of the two contact switches. Navigation Sensors A light sensor for the navigation light and a light sensor for the target lights were placed on the robot. The light sensor for the navigation light was placed on the front of the robot facing upwards at about a 45-degree angle to try to detect a more direct light. Shielding was used to isolate the different light angles in respect to the navigation light and its associated light sensor. The target light sensor should be placed directly in front of the robot, to be in the line of sight with the target lights. Shielding can also be used to improve its directionality.
For the “Systems Engineering Design Methodology” learning unit, develop a conceptual design matrix utilizing both a 2 bumper robot and a 3 bumper robot design. For example, there can be two side bumpers and one front bumper, or there can be two front bumpers and a rear bumper.) In conjunction with the bumper design, identify the number of target light sensors and the number of beacon light sensors. There can be a left and right beacon light sensor or a front and back beacon light sensor. Additionally, there can be various scenarios for target light sensors. The trade offs being that the more sensors and bumpers you utilize, the more accurate control of the robot that is maintained, but the more difficult the software development process becomes. That was the reason that “The Robot Construction and Competition Project” uses a minimum number of bumper and light detecting sensors. A typical conceptual design matrix might look like the following:
Learning Unit Module 4: Example of Development of Earth-to-Orbit Space Craft by System Level Analysis T  he development of efficient Earth-to-Orbit (ETO) vehicles has been in the forefront of NASA research since the dawn of the space age. Among the major stumbling blocks is the development of an efficient propulsion system that is reusable, safe and cost-effective. Although NASA uses rockets or thrusters powered by hydro-carbon based fuel, it is well known that conventional chemical rockets, whether liquid or solid, monopropellant or bipropellant, are fundamentally limited by their available combustion reaction energies and heat transfer tolerances to exhaust speeds of a few thousand meters per second. Effective space missions entail exhaust velocities of at least an order of magnitude higher.
This exercise involves a conceptual design of a cost-effective ETO Space Craft for NASA (the customer) that is both reusable and capable of handling a larger payload. NASA’s current plans call for the development of space colonies on the moon by 2024. Exploration of Mars for colonization is to follow. Since a comprehensive development of such a spacecraft is beyond the scope of the current learning unit, this exercise will only consider ETO and space propulsion systems for spacecrafts. T  he current propulsion systems in use by NASA for ETO applications involving the Space Station are hydrocarbon based and they are to be phased out by 2010 to ensure that future missions are cost effective. The available alternatives include: electric propulsion systems, the space elevator, as well as hybrids of these systems. The generic chemical thrusters utilize hydrocarbon fuels and involve a nozzle to accelerate the combustion products to provide the thrust.
T  he science and technology of electric propulsion (EP) encompass a broad variety of strategies for achieving very high exhaust velocities in order to r educe the total propellant burden and corresponding launch mass of present and future space transportation systems. These techniques group broadly into three categories: electro-thermal propulsion, wherein the propellant is electrically heated, then expanded thermodynamically through a nozzle; electrostatic propulsion, wherein ionized propellant particles are accelerated through an electric field; and electromagnetic propulsion, wherein current driven through a propellant plasma interacts with an internal or external magnetic field to provide a stream-wise body force. Such systems can produce a range of exhaust velocities and payload mass fractions an order of magnitude higher than that of the most advanced chemical rockets, which can thereby enable or substantially enhance many attractive space missions. The attainable thrust densities (thrust per unit exhaust area) of these systems are much lower, however, which predicates longer flight times and more complex mission trajectories. In addition, these systems require space-borne electric power supplies of low specific mass and high reliability, interfaced with suitable power processing equipment.
Directory: edu -> nycri -> units -> milesthangam edu -> 100 Village Primary School Music Classrooms edu -> Instructions for the Preparation of Camera-Ready Contributions to the Conference Proceedings edu -> Between global market and international and regional cooperation edu -> Biographies of Patriots of Color at The Battle of Bunker Hill John Ashbow Colony: Connecticut Age: 22 Race: Native American Status: Free Rank: Private Position: Rail Fence Unit: Putnam/Durkee edu -> a geospatial Activity a buffer from the Storms edu -> Guide to Preparedness edu -> Social Sciences Teaching Unit Levels 2 6 Environmental Justice milesthangam -> Learning Unit-a robot Analysis and Construction ( robocon ) Project Download 0.76 Mb. Share with your friends:
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||