CAD Group Assignment PDF

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Problem identification and mission statement of group assignment...

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JEE113 Design and Communication Assessment – Part 1 Sea-State Nine Pty Ltd. has commissioned us to designed an autonomous surface vessel(ASV). The company desires that the vessel is subjected to meet the following constraints 1. The dimensions are restricted to 0.25 x 0.25 x 0.25 2. Vessel is required to achieve fully autonomous status 3. Must be positively buoyant during the mission 4. Capable carrying the payload as per required 5. External design of the vessel are required to be water proof while the electronic systems are required to be adequately water resistant. 6. A maximum cost of 20$ excluding the material supplied by the client.

The problems above are faced by the customers and we would have to solve these problems to match his specifications. In order to solve the problem, the following deliverables and criteria has to be resolved first. 1. What material quality are we supplied with? 2. How do you want the geometry of the ASV to look? 3. The positions and angles of which the load is being placed. 4. Inertia problem shooting 5. How much weight do you want the ASV to carry 6. When would you want the project to finish 7. When would we acquire the supplies 8. What type of software system does it requires

1. Geometry constraint The shape of the ASV is very important because the body has to be streamline for it to cruise at its’ designated speed and to maintain its dynamic stability. Furthermore, the vessel has to be strong enough to withstand the impact generated from the waves. Moreover, for the shape of the ASV to be determined, factors such as the cost, volume, portability, stability, speed of which it is required to cruise and the weight has to be known. Firstly, the weight and volume of the payload should be identified as it is required in order for the ASV is able to be positively buoyant throughout the mission.

2. Material constraint The material of the ASV should be identified to reduce the cost of the production of the ASV. Furthermore, the material of the ASV should also be known to reduce the pollution while the ASV is conducting its’ mission throughout the course while maintaining waterproof and remain its buoyancy. As for now, the materials supplied by the client will be 2 motors, 2 prop/shaft and a control system

3. The positions and angles of which the load is being placed.

The goal of this is to pinpoint the exact coordinates of the load on the ASV. By doing so, we will be able to determine if the load will have a negative effect on the ASV such as capsizing, slowing the speed of the ASV and tilting of the ASV. Furthermore, we would also be able to modify the ASV’s center of gravity and center of buoyancy to prevent a negative effect on the ASV from occurring.

4. Load Distribution

The fourth issue for this groups ASV is load distribution on the vessel with one of our goals to ensure it is designed and assembled dimensionally correct and in alignment to prevent wobbling and consequential inertial force overshooting. In theory, when a vessel floats in the water the forces of buoyancy and gravity balance each other because they are equal (Kimball, 2016). Moreover, different load affects the centre of gravity and stability of a ship whilst a fully loaded vessel brings the centre of gravity and the centre of buoyancy force closer together making the vessel most stable (Unknown, 2016). Moreover, the distribution of the load along the x and y axes on a vessel affect the moment of inertia and thus need to be proportionate to prevent rolling and for optimal efficiency. Furthermore, Newton's third law is: For every action, there is an equal and opposite reaction. Thus, when a boat tips due to an uneven load distribution, a restorative buoyant force counteracts the initial tipping and keeps the vessel upright (Unknown, 2016). Additionally, the moment of inertia for pitching requires an extra force to correct and stop it (Kimball, 2006). Consequently, the vessel will overshoot and tip too far and can overshoot again before returning back to equilibrium. This back and forth motion can repeat and last for a few prior to the moving water quickly absorbing the vessel’s energy (Kimball, 2006). Therefore, the components which need to be considered to this issue are sticking to the dimensions previously outlined in the constraints while also making some mechanical design modifications. Therefore, the group will aim to have the load distributed symmetrically around the mid line and placed low on the vessel’s y axis. Moreover, other considerations will be the the inertial forces, balance of thrust and resistance due to turn a self-propulsion point, correction for non-self-propulsion point and the rudder force (ABS, 2006).

5. The amount of weight the ASV should carry

The weight of the payload is essential as it may affect the resistance of the ASV while cruising. Apart from the weight of the payload, the initial weight of the ASV should also be known as it is required to find out the battery volume, instrument payload and the volume of the pontoons. Furthermore, we have to calculate of the initial efficiency and specification of the autonomous surface vessel before measuring the efficiency and specifications of the ASV and the weight.

6. The completion date of the project.

The goal of this information is to distribute the workload among group members. Furthermore, this allows us to form a work schedule which we would then follow in order to work towards the completion of our project.

7. The arrival date of the supplies

The purpose of this information is to allow our group to structure a detailed work timeline. We would then be able to structure a proper work schedule for our group members to work towards the due date. In addition, this is important as it prevents our workload from being halted. This would be effective as we would be able to know the resources we have to work with once we have obtained the supplies.

8. Software System Requirements

Software From a top view, this project has two different levels of programming; the first level is the higher level decision making software, which for this group will be Arduino. Arduino is an open-source prototyping platform based on easy-to-use hardware and software, able to read inputs and turn it into an output such as: activating a motor. The lower level software is the CMUcamPixycam5, a hardware-based programming which will control basic motor control and sensor integration. Pixy can easily connect to lots of different controllers because it supports several interface options, and in this groups case will connect to Arduino via a cable receiving instructions in the form of script.

References:

American Bureau of Shipping (ABS), 2006. ‘Guidance Notes on the Application of Ergonomics to Marine Systems’, Houston, TX. Accessed 20th April 2016. Unknown Author, 2016. ‘Equilibrium and Stability’, NCS Pearson, vol.1, p.1, Available from URL:http://www.tutorvista.com/content/physics/physics-i/forces/equilibrium-andstability.php, Accessed 20th April 2016. Kimball, John. 2006. ‘Physics of Sailing’, CRC. United States of America. vol. 1, p. 99-102, Accessed 20th April 2016....