# Classes - Beard

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# Comments & Suggestions - ECE 674/ME 634

As an introduction to use doku-wiki you must have double backslashes (\\) to indicate a newline. To have a space between entries leave an empty line in the code. To edit a section please select the “edit” button after the section not before. A quick tutorial on additional syntax is available here. You can enter equations by using latex syntax like

• <latex>
\dot{x}=f(x,u) \\
\frac{3}{4 \pi}   \sqrt{4 \cdot x^2   12}\\
\lim_{n \to \infty}
\sum_{k=1}^n \frac{1}{k^2} = \frac{\pi^2}{6}\\
\it{f}(x) = \frac{1}{\sqrt{x} x^2}\\
e^{j \pi} + 1 = 0}\;
</latex>

## Preface

Table of contents 10.10 spacing off Page vii. UAS is defined as wing span between 4-10 feet and MAV with wingspan less than 5 feet. Is the overlap on purpose? You could avoid confusion by defining the UAS between 5-10 feet. (Joe Nichols)

## 1. Introduction

On page 1 last paragraph DOF is used I assume it means degree-of-freedom but that is never specifically stated. (RLC) \\

## 2. Coordinate Frames

This comment is for Chapter 2 (The button on the comments page took me here). Comment: Throughtout Chapter 2 the unit vector k has a ^ over the top while the unit vectors i and j do not. Recommend standardizing for consistency. (Joe Nichols) In addition i^, j^, k^ correction stated above, the figures all still use i^, j^, and k^ even though the i^ and j^ in the text has been corrected to be i, and j. -Colin

In the text if figure 2.11, a lot of variables are specified, which was very useful. I spent a few minutes flipping back through the book before I read that to find variables that were used in equations. It would be very convenient if there was a section earlier in the chapter that basically said “we will be using the following variables: airspeed (Va), windspeed (Vw), …” that could be used as a quick reference since a lot of variables are used and spread throughout the document. -Blake

The derivation of Eqn. 2.1 was kinda sketchy to me. Would be better if an example of the dot product operations was shown explicitly. - Joe Winkler\\ Don't understand “combining” Eqns. 2.2 & 2.3 to generate a rotation matrix. - Joe Winkler\\ Law of Cosines explanations on page 19 make no sense. Where does 'V' show up? - Joe Winkler\\ Figure 2.12 is confusing. - Joe Winkler\\

Section 2.2.8 - Figure 2.10 - Crab angle should be shown as defined in the equation Xc = X - psi - Robert - 4th paragraph - 2nd line - “Let Vw be the windspeed…” not “Let Vw is the windspeed…” - Robert

## 3. Kinematics and Dynamics

For equations 3.1 and 3.2, <latex>c\theta, c\phi, c\psi, s\theta, s\phi,</latex> and <latex>s\psi</latex> are used. I assume these mean cosine and sine of the specified variable as in the 483 labs, but it should probably be specified for readers who haven't seen that notation. -Blake

In the paragraph between equations 3.1 and 3.2, it mentions “the velocity relative to the surround air mass.” I believe it should be “the velocity relative to the surrounding air mass.” -Blake

Section 3.2 - 1st paragraph, 2nd line - “along each of the axis” instead of “along each of axis” - Robert - 2nd parag., 2nd line ' “Equation (3.1) assumes zero ambient wind” not “assumes that zero ambient wind” - Robert

Section 3.3.1 - in Note 1 for Mass - the 2nd “m” should be “m” not “m” - Robert

mav_dynamics.c from Chapter 3 of the CDROM is missing the equation for Gamma6 - Colin

Section 3.3.2 * Gamma3 and Gamma5 do not match the equations on the CDROM -jn(Joe Nichols) * In mad_dynamics.c we are supposed to enter equations 3.15-2.18. There are two issues. One, variables l,m,n from equation 3.18 are labeled tau in the c file. Two, the variables wn,we,wd in equation 3.15 are not included as inputs into the c file. -Michael Williams * Some explanation of how J is found in equ. 3.10 would be useful. -Michael Williams

Eqns. 3.15 thru 3.19 * All the dynamic equations in chapter three have dots above them, implying derivatives, but in the s-function C file, the places where we're supposed to input equations, there's no “dot” in the variable names. Are these intended to refer to eqns. 3.15 thru 3.18? (Joe Winkler)

## 4. Forces and Moments

typos: fig 4.2 “drag” vice “draft”; section 4.2.3 last sentence, first paragraph, should be “fy” vice “fx”; section 4.2.4 fifth paragraph, second sentence “UAS is said to “be” dynamcially stable. jn

typos: “define” vs. “defined” right before definition of dynamic pressure. Also, “a” vs. “as” right before equations to convert between elevons and aileron-elevator signals (right before section 4.2.2). -brandon

In the equation: <latex> C_{L}(\alpha) = C_{L_{O}} + C_{L_{\alpha}} \cdot \alpha\\</latex>, which is slightly after eqn 4.4, <latex> C_{L_{O}}\\</latex> is not defined. This term is also used in eqn. 4.6. How is this coefficient defined? -brandon

The first full sentence after eqn. 4.7 also contains a typo. “functions” should be changed to “function” (ie. The sigmoid function…) -brandon

Possible typo: word right before eqn 4.8. Should it be “lift” instead of “list”? -brandon typo: fig 4.7 “low angle-of-attack” vs. “low angle-of-attach” -brandon

Section 4.2.4: If a disturbance is applied to the MAV, the MAV is said to by dynamically stable if… Should be “If a disturbance is applied to the MAV, the MAV is said to *be* dynamically stable if…” - Joe Winkler

I found a small grammatical correction. The first sentence in Section 4.2 should read “As an MAV,” instead of “As a MAV.” -Colin

Possible typo: Equations 4.5, 4.6, and 4.10 use “sign” and “sin.” -Colin

I believe it actually is sign and not sin, since if we look at equation 4.10, we have <latex>2sign(\alpha)sin^3(\alpha)</latex> and not <latex>2sin^4(\alpha)</latex>. I used alpha/abs(alpha) in place of sign - Blake

Page 48, just below the center of the page is a sentence that reads “According to [21], spactial wavelengths…” seems like it should read, “According to [21], spatial wavelengths…” - Joe Winkler

Section 4.5, Chapter Summary: The top of the page reads “The total forces on the MAV are be summarized as follows”. Should remove the word “be”
The bottom of the page reads, “The total the torques on the MAV are be summarized as follows:“
It seems like “The total torques on the MAV are summarized as follows:” would be better. - Joe Winkler

Section 4.2, the first line of the body of text following Eqn. 4.1, is the word “planform” a typo for “platform”? - Joe Winkler

In Eqn. 4.4, there are a lot of “C sub M”'s flying around, but in appendix C there are only “C sub m”, lower case m instead of capital M. Is this a typo? Because it's generating confusion in my coding. - Joe Winkler

The air frame parameters has a CL0 and a Cl0 which has caused me alot of grief. I think that distinguishing parameters by nothing more than capitalization is asking for confusion, especially when we have so many to keep straight. -Michael Williams

Project 4 would be much easier if all the necessary equations were in the summary. The equations for Rbv, Va, alpha, beta, sigma, Cd, and Cl needed for the project but are scattered randomly throughout the preceding pages. -Michael WilliamsStrike-through Text

## 5. Linear Design Models

The paragraph in section 5.1 just before the “1. Wings-level flight. In wings-level…” should be “The objective of this section is to describe…” (the “to” was omitted in the text). -Blake

In the paragraph in section 5.1 starting with “2. Constant altitude turn. In…” constant velocity during a turn is discussed. As velocity is a vector and includes direction, this is incorrect. Rather, it should discuss constant speed or constant acceleration (assuming a circular orbit). -Blake

The last paragraph in section 5.1 (just before section 5.1.1), there is a duplicate “the” (”…subsumes the the first two conditions,…”). -Blake In chapter 4 and chapter 5 so many different variables are introduced that it's near impossible to keep them all straight. It makes the book very difficult to follow. I really think there needs to be an appendix that lists all the different symbols used for the variables and gives a brief description of what they're used for. I'm constantly coming across symbols and having to go back and search previous chapters for the description of what the symbol means. It would be helpful if the meaning of the symbol would be used several times after it is introduced. It would also be helpful to remind the reader what certain symbols are if they haven't been used in a while, like what was done with Va on page 69. -Michael Williams

I know you don't intend to list every step of each derivation, but there are a few equations that I absolutely cannot follow. I just have to trust and memorize the results because I have no idea how you got to that point. One example is going from Va = … to Vadot = … on page 68. - Michael Williams

Typically captions in textbooks are set apart from the rest of the text. They are usually indented on each side, and are written with smaller type or occasionally bolded. In this book it's very easy to be reading along and then read the caption as part of the paragraph. It interrupts your train of though, and makes to book more difficult to read than it otherwise would be. -Michael Williams

Bottom of page 66 in section 5.2, below figure 5.1 there is an equation reference that has a broken link. - Peter Niedfeldt

The last sentence on page 82 reads “et the initial states in your original Simulink simulation.” The “et” should be “Set.” -Colin

In the equations for av1,av2, and av3 it's unclear that the stared terms are the equilibrium values that come from the trim function. - Michael Williams

What made the chapter 5 assignment difficult was going through the text and finding all the variables and equations that weren't in the summary. The assignment took me three weeks when realistically it only should've taken one. Some of the equations that it would be nice to have in the summary are av1, av2, av3, a_phi1, a_phi2, and several of the variable that are in those equations. it would also be nice to have known that the Va in the equations for a_phi is arbitrarily set in the param file. -Michael Williams

## 6. Autopilot Design using Successive Loop Closure

In the paragraph above figure 6.3 (and in general), readability would be increased by changing ”…a factor of 5 to 10 slower…“ to ”…a factor of 5 to 10 times slower…“ -Blake

The first paragraph in section 6.1, line 5 has an improperly placed comma after “loop closure”. - Blake

In the example above figure 6.7 (currently page 93), “Assuming that we would a rise time under…” needs to be changed (ie, “Assuming that we would need…” or “Assuming that we want…”). -Blake

In the first complete paragraph below figure 6.17 (currently page 102), the sentence “If the airspeed increases above its nominal value, then the aircraft if caused to pitch up which results in…” needs to be rewritten (perhaps “if” should be “is”). -Blake

The sentence above equation 6.6 (currently page 103) has repeated words at the end (”…is given by is given by“). -Blake

On page 109, altitude is misspelled as “altitud”. - Blake

The first line of section 6.2.6 (currently page 114) needs to have an “s” added after “deal”. -Blake

Some of the variables in the included simulink files use a different naming scheme than the book does. It would be nice to have that consistent. - Michael Williams

On page 115, the altitude hold zone block is empty. -Blake

figure 6.20 (current page 107). q' should be q. Also, pitch_ki is not used in our simulation. It would be helpful to have a parallel figure for the lateral controls. Joe Nichols

In section 6.4.2 we take the equation for h(s) assume that it's the same as a second order transfer function. But the equation for h(s) has a zero that's not accounted for in the generic second order equation. What effect does this zero have? -Michael Williams

On page 97 you show a graph and then use the phrase: “We can see that the rise time and overshoot response have not been significantly degraded by the addition of the integral gain, however, the settling time response has been altered significantly.” It sounds like you are comparing the graph to another one that's listed earlier, except you never show the graph that you're comparing against. -Michael Williams

A simulink file is provided for tuning the gains for everything except for side slip. It would be nice if that file were also included. -Michael Williams

## 8. Sensors for Small and Miniature UAVs

Section 8.5 - update the GPS Vg and Chi equations (8.12 & 8.13) with the equations for Vg & Chi from Ch 9 section 7 (not numbered) (As far as I know, no one has been able to get the EKF working well unless they make this change) - Robert Leishman

## 9. State Estimation

Most of the graphs are hard to follow because the key is in the heading. To simplify the key could be added inside the graph, with - - - lines and —– lines to represent each part. - Robert Comstock

In Algorithm 5 line 4 there is a missing parentheses at the end. – Robert Comstock

This chapter NEEDS a section on tuning the kalman filter. –Michael Williams

## 10. Waypoint and Orbit Following

Equation 10.5 needs a sign change to match the correct equation in the algorithm. -Blake

In Algorithm 8 Id is initialized and used, but never updated. -Mike

## 11. Path Manager

Algorithm 12 on page 197 is cut off at the bottom. -Colin

page 184 Fig. 11.5 and Page 186 Algorithm 10 line 18– the second term of the center equation should be added instead of subtracted. -PCN

Page 186 equation for defining the half plane. Recommend that you use p instead of q in this equation. q is used as a unit vector in subsequent pages in this chapter. The use of q here is confusing. Joe Nichols

The notation in 11.1 should better match the notation in Algorithm 9 - this should include the labels in the figures. I am having a hard time figuring out what a, q, r, etc are in each of the sections because they do not seem to match. Robert L.

Algorithm 9 doesn't actually explain how to know which direction to turn, and the sample code for design project 11.1 requires that information. -Michael Williams

Line 9 of algorithm 9 doesn't do anything because a,b, and c are set and never used. (at least the way the sample code in project 11.1 has things laid out, a,b, and c aren't persistent) - Michael Williams

## 13. Cameras on Small and Miniature UAVs

I think that the last line of example code before section 2 has an extra character. Instead of plot\_handle2, drop out the '\' and let it be plot_handle2 as in the previous line of example code. PCN

In the first paragraph of appendix B, the statement “Simulink is essentially, a sophisticated tool for solving …” doesn't need a comma. -Blake

The first paragraph of B.1.1 includes ”…discrete state, the input u, a flag, followed by user defined…“. It needs an “and” (ie, ”…the input u, and a flag, followed by…“). -Blake

## C. Airframe Parameters

It appears that the caption, “The following aerodynamic coefficients for an A-4D fighter aircraft [1].” is misplaced. Should be after table C.1 pehaps. (Joe Nichols) There is no value listed for Cprop in Table C.1. (Joe Nichols)

In Table C.1, The values for the various J's have “kg - m^2”. Is that a subtraction, or should it read “kg*m^2” as a physical unit? - Joe Winkler