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Hi, and welcome to this course sequence on spacecraft dynamics and control.

Â My name is Hanspeter Schaub, and

Â I'm a professor at the University of Colorado at Boulder.

Â A little bit myself quickly.

Â I do research on spacecraft dynamics, including formation flying,

Â relative motion descriptions, and also some exciting work on chars astronomics.

Â Where we're using electron guns and ion guns to create tractor beams essentially,

Â to attract, repel spacecraft.

Â I've also been involved on several spacecraft missions including as

Â the ADCS lead on one of them.

Â And I'm currently involved in a deep space mission doing attitude dynamics control

Â applications.

Â So this topic that you're about to hear about is very near and dear to my heart.

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What is this class going to cover?

Â There are three main sections.

Â After a brief introductory stuff about vectors and notations and so

Â forth really to the three primary topics are going to be rigid body, kinematics,

Â rigid body kinetics, and control.

Â So what do these words actually mean?

Â Kinematics is the description of motion.

Â So that means if you go to rigid body which I've got my little foam cube here.

Â Foam is always good when professors throws things around and when we drop him.

Â So for what this means is, rigid body kinematics,

Â we're describing the orientation, how do we now point space craft to point at

Â a particular star and to look down and point at a Earth location and

Â doing science I need to scan certain part of the atmosphere.

Â How do we describe such motions and we've translation there is infinity of ways that

Â you can describe your position relative to somebody else, there is distant and

Â a heading that you can use like asthma elevation and direction but you can also

Â use just regular cartesian coordinates go this far east, north, south, up down

Â those kinds of coordinates, it attitude we have an infinity of ways to describe or

Â in there's the classic yawning, pitching and rolling that people are familiar with,

Â but there are a million other coordinates that have a lot of benefits.

Â They all have challenges and they have benefits and we're going to go over both

Â pros and cons of these and really show you fundamentally how to describe it.

Â This is going to be now very, very useful because we can take and add it to

Â the descriptions of object and you have attitude description of another object and

Â then, you need to know the attitude of one relative to another.

Â How do we add subtract orientation?

Â What is fundamental operators?

Â That's rigid body kinematics.

Â The second section is rigid body kinetics.

Â That means we are now taking into account mass inertia forces and

Â torques acting on a spacecraft.

Â So the thrusters out here firing and this whole thing starts to pitch and

Â it starts to translate, how do you describe all these stuff mathematically?

Â How do we derive these equations of motion to predict and

Â how do we solve them numerically?

Â And then we also look at system that are dual spinners.

Â Sometimes, you have spacecraft that have a rigid part and

Â another big rigid part that's spinning, that's a very popular communication

Â satellite design some deep space missions, we'll look at gravity gradient torques,

Â we're looking at a system of space craft equipped with multiple rotating wheels.

Â Like control remote gyroscopes and reaction wheels and those devices.

Â We also look at free spinning motion.

Â In space, most of the time,

Â we're not controlling because we don't have much fuel or energy.

Â So, we have to exploit the natural dynamics and

Â that will be a big chunk of kinetics as well.

Â What's the naturally tumbling motions?

Â How does this object like to move?

Â Depending on it's shape, geometry mass distribution.

Â 3:28

Then the last chunk is Control.

Â This is where we take the natural dynamics and go well this isn't quite stable.

Â I want it to be pointing here in this direction and then we add feedback on top

Â of it where you sense the environment you sense whatâ€™s going on and you say well I'm

Â pointing about three degrees too low how do I change my wheel speed how do I twist.

Â How do I apply torts, how do I apply thrusters to reorient this and

Â guarantee that I will be stable, I won't overshoot it

Â won't undershoot I can specify what the performance going to be and

Â (UNKNOWN) attitude it's a non linear problem so

Â we'll be dealing with non linear control definitions and

Â we'll be looking at ways to actually define stability for

Â very large departures not just small oscillators

Â federation, so that kind of test this part apart.

Â Everything else would be covered in this lectures.

Â So that's the three main topic areas that we cover here and

Â the course sequences you're about to see are actually coming from

Â my lectures that I teach here every year at the University of Colorado.

Â So we've taken out some of things that are very course specific like talking over

Â homeworks and assignments and that different arrangements and

Â we're getting to the guts of the technical stuff.

Â That's what you'll be seeing, it's kind of edited together over the days.

Â And we'll be adding supplementary material as well.

Â But you're following along pretty much with the exact same

Â material that we do in class.

Â And I have posted a variety of problems that you can solve.

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Another thing is textbook.

Â These course sequences are set up and

Â designed where I'm providing you everything here that you need to know

Â from the lectures, from the slides and so forth.

Â But if you want auxiliary reading, the class that I teach is really based on this

Â textbook here called Analytical Mechanics of Space Systems.

Â And it's a book that's used in many, many schools,

Â I think over 20 schools now use it.

Â Variety of aspects is based from dynamics and we do as well.

Â So the material you're seeing is going to touch chapter one.

Â Focus a lot on chapter three, that's the kinematics for kinetics.

Â And then we jump to chapter eight,

Â which deals with different nonlinear control solutions.

Â So three, four and eight are the focus here and interest.

Â But that's the quick intro.

Â I really look forward to working you here,

Â I hope you enjoy this material as much as I do.

Â This is a class that I get a lot of feedback on from students who graduated,

Â been in the industry for a while, worked at NASA, JPL, and then a few years later,

Â see them again.

Â They go, you know, Dr. That was a really useful stuff I handed that class,

Â at the time maybe it was full of details but now that i'm using it this is material

Â that I find that i'm using all the time, 3D representation dynamics is not just for

Â space craft this is also sued for aircraft, surface vehicles, under water

Â vehicles, robotics, even computer vision and gaming industry use some of this work

Â how to describe orientation to computational efficiency and so forth.

Â So, it's a great fundamental topic.

Â We going to be applying it to space which is fine exciting application.

Â But what you learn is the fundamentals of how to do rigid body dynamics.

Â Thanks.

Â