Attitude Control of a Spacecraft Report Writing, NASA & Sensors Actuators & Controllers - Engineering Assignment Help

Assignment Task

Attitude Control of a Spacecraft

This is an individual assignment that involves systems analysis, systems modeling, controller design, and performance evaluation via simulation. Where appropriate, employ tools and show understanding of the concepts and methods covered during the module. The assignment is broken down into four parts.

1. Design Concepts 

In this part, you should consider two actuation methods for controlling the attitude (pointing direction)  of rockets and satellites: reaction wheels and thrust vectoring.  Broadly consider the different requirements for attitude control in rockets and satellites. Use the categories: performance, environment, dynamics, and integrated system. Use your requirements analysis to explain why reaction wheels are commonly used for satellites but not for rockets. Note that sensor requirements are covered in part 3 and do not need to be included here. A number of references are given below, but you should not restrict yourself to these. An introduction to the technologies can be found in [1, 2]. Reference [3] provides details that will help you dig deeper in thinking about the requirements for thrust vectoring in rockets. Settle on a design for a particular size/type of space vehicle (rocket I satellite), using either vectored thrust or reaction wheel. It is important to define the vehicle mission and link this back to the system requirements and forward to the control objectives. 

2. System Modelling 

In this part you should develop equations of motion for attitude control, using either reaction wheels or vectored thrust for the chosen space vehicle. For simplicity, the model is expected to focus on only one or two degrees of freedom. For the rocket with vectored thrust, the dynamics are similar to that of an inverted pendulum, and the general modeling approach can be found in [4]. Once you have found the equations of motion, identify the input and output variables, determine possible sources of external disturbance, and where possible estimate the likely magnitude of such disturbances. For example, if the rocket is launched from Earth there may be aerodynamic effects  (NASA often suspends launches in high winds). Or perhaps there is some parameter uncertainty due to  (say) fuel use reducing the mass of a satellite, or it may be the satellite attitude can be changed with solar panels in different positions, which would affect the moment of inertia. Create a state-space model of the system and use Simulink to represent the inputs, outputs, and disturbances. Run simulations to check the reasonableness of the model, and if possible, compare results with published data, to further validate the correctness of the model.

Note: for vectored thrust, there will be some dynamics in the thrust actuator, which should also be represented. For a reaction wheel, there will be an upper limit to the speed of the wheel. There may be other constraints or limitations that you can include in the system model. 

3. Control System and Performance Evaluation 

In this part, you need to design a controller, select suitable control parameters, and verify that the system meets the design requirements set in Part 1.  

The controller can be based on PID control, state-space control or it can be nonlinear control (e.g. based on/off switching or sliding mode). The choice of method should be justified to some extent. Also,  depending on your chosen ‘mission’ (from part 1) your control objectives can be in the form of a  regulator problem or a tracking problem. It is important to be clear at the outset what the control objectives are and why they are chosen, again with reference to part 1. Be sure to consider possible external disturbances and/or parameter changes in the plant and test the robustness of the controller when such changes are included. If you cannot meet the requirements, you may need to re-evaluate them, but not to the extent that the mission (of part 1) is compromised. If you can greatly exceed the requirements, then perhaps you should reduce the performance (and cost?) of the actuation system. Finally, for part 3, review the sensor requirements of the system. How accurately do you need to control the attitude (angle)? In practice how will you measure this? For robustness, is there some sensor redundancy you can make use of? If a sensor fails, how would you deal with this? Expand the model to include sensor error/noise and assess the effect on performance. 

4. Conclusions/ Recommendations 

State your conclusions, to include a set of recommendations for your ‘customer’ who is expecting to finance the spacecraft. Connect the conclusions to specific findings from the earlier sections. 

Overall Report 

The report should be in a professional style with a title page, contents, summary, references, and a clear structure. Plots from the simulation should have axis labels and you should avoid screenshots of  Simulink Scope windows. All figures should be numbered and include informative captions. All external information sources should be referenced. Students can discuss methods and approach with others, but the technical content – such as model parameters and simulation output – should be your own, as should the written content. Reports are expected to be around 15-20 pages; aim for quality and conciseness, not excessive text. Feel free to use appendices for additional ‘boring details.

This Engineering Assignment has been solved by our Engineering Experts at My Uni Paper. Our Assignment Writing Experts are efficient to provide a fresh solution to this question. We are serving more than 10000+Students in Australia, UK & US by helping them to score HD in their academics. Our Experts are well trained to follow all marking rubrics & referencing style.

Be it a used or new solution, the quality of the work submitted by our assignment Experts remains unhampered. You may continue to expect the same or even better quality with the used and new assignment solution files respectively. There’s one thing to be noticed that you could choose one between the two and acquire an HD either way. You could choose a new assignment solution file to get yourself an exclusive, plagiarism (with free Turnitin file), expert quality assignment or order an old solution file that was considered worthy of the highest distinction.