Difference between revisions of "Errata: Example 8.10 missing factor of v, a1 and a2 flipped"

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Line 14: Line 14:
 
       \begin{bmatrix} 0 & 0 & -{\color{blue} v} \sin\theta \\ 0 & 0 & {\color{blue} v} \cos\theta \\ 0 & 0 & 0 \end{bmatrix}
 
       \begin{bmatrix} 0 & 0 & -{\color{blue} v} \sin\theta \\ 0 & 0 & {\color{blue} v} \cos\theta \\ 0 & 0 & 0 \end{bmatrix}
 
       \right|_{(x_\text{d}, u_\text{d})}
 
       \right|_{(x_\text{d}, u_\text{d})}
     = \begin{bmatrix} 0 & 0 & 0 \\ 0 & 0 & v_\text{r} \\ 0 & 0 & 0 \end{bmatrix},
+
     = \begin{bmatrix} 0 & 0 & 0 \\ 0 & 0 & {\color{blue} v_\text{r}} \\ 0 & 0 & 0 \end{bmatrix},
 
</math></center>
 
</math></center>
 
This leads to an error in the definition of <math>w_2</math> later in the example.  In addition, the coefficients <math>a_1</math> and <math>a_2</math> are swapped, so the definition of <math>w_2</math> should be:
 
This leads to an error in the definition of <math>w_2</math> later in the example.  In addition, the coefficients <math>a_1</math> and <math>a_2</math> are swapped, so the definition of <math>w_2</math> should be:
 
<center><math>
 
<center><math>
     w_2 = -\frac{l}{v_\text{r}}(\frac{a_2}{v_\text{r}} e_y + a_1 e_\theta).
+
     w_2 = -\frac{l}{v_\text{r}}(\frac{{\color{blue} a_2}{{\color{blue} v_\text{r}} e_y + {{\color{blue} a_1} e_\theta).
 
</math></center>
 
</math></center>
 
The final controller then becomes
 
The final controller then becomes
Line 25: Line 25:
 
   - \begin{bmatrix}  
 
   - \begin{bmatrix}  
 
     \lambda_1 & 0 & 0 \\
 
     \lambda_1 & 0 & 0 \\
     0 & \dfrac{a_2 l}{v_\text{r}^2} & \dfrac{a_1 l}{v_\text{r}} \end{bmatrix}
+
     0 & \dfrac{{\color{blue} a_2 l}{v_\text{r}^{\color{blue} 2} & \dfrac{{\color{blue} a_1 l}{v_\text{r}} \end{bmatrix}
 
  \begin{bmatrix} x - v_\text{r} t \\ y - y_\text{r} \\ \theta \end{bmatrix}
 
  \begin{bmatrix} x - v_\text{r} t \\ y - y_\text{r} \\ \theta \end{bmatrix}
 
  + \begin{bmatrix} v_\text{r} \\ 0 \end{bmatrix}.
 
  + \begin{bmatrix} v_\text{r} \\ 0 \end{bmatrix}.
 
 
</math></center>
 
</math></center>

Revision as of 04:59, 7 October 2021

Chapter Output Feedback
Page 8-28
Line -4
Version 3.1.5
Date 6 Oct 2021

Example 8.10 (Steering control with velocity scheduling) is missing a factor of in the definition of that propagates through the example. In addition, the coefficients and are swapped in the definition of .

The equation for should read:

This leads to an error in the definition of later in the example. In addition, the coefficients and are swapped, so the definition of should be:

Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://en.wikipedia.org/api/rest_v1/":): {\displaystyle w_2 = -\frac{l}{v_\text{r}}(\frac{{\color{blue} a_2}{{\color{blue} v_\text{r}} e_y + {{\color{blue} a_1} e_\theta). }

The final controller then becomes

Failed to parse (unknown function "\begin{bmatrix}"): {\displaystyle \begin{bmatrix} v \\ \phi \end{bmatrix} = - \begin{bmatrix} \lambda_1 & 0 & 0 \\ 0 & \dfrac{{\color{blue} a_2 l}{v_\text{r}^{\color{blue} 2} & \dfrac{{\color{blue} a_1 l}{v_\text{r}} \end{bmatrix} \begin{bmatrix} x - v_\text{r} t \\ y - y_\text{r} \\ \theta \end{bmatrix} + \begin{bmatrix} v_\text{r} \\ 0 \end{bmatrix}. }