## 3 Orientation Controller Design
### Determination of the Steering Play  
The steering of the robot has a noticeable play. It occurs due to mechanical connections on the one hand and due to serving on the other hand. It always causes slight instability in the system. It can also be seen when driving the robot in a controlled manner. When driving, especially when reversing, it performs a slight lurching movement to the side. \begin{table}
\begin{tabular}{c c c c c c c c c c c} \hline \hline
**Steering** & **Pt. 1** & **Pt. 2** & **Pt. 3** & **Pt. 4** & **Pt. 5** & **Pt. 6** & **Circle** & **Radius** & **Steering Angle (Rad)** & **Steering Angle (Degree)** \\ \hline \(-100\) & 2.700 & 2.000 & 1.500 & 1.050 & & & 2.566 & 1.599 & \(-0.2088\) & \(-11.96^{\circ}\) \\  & 0.011 & 0.109 & 0.353 & 1.097 & & & 1.604 & 1.621 & \(-0.2084\) & \(-11.94^{\circ}\) \\ \hline \(-90\) & 2.700 & 2.000 & 1.500 & 1.075 & & & 2.677 & 1.602 & \(-0.2084\) & \(-11.94^{\circ}\) \\  & 0.023 & 0.126 & 0.439 & 1.064 & & & 1.621 & 1.602 & \(-0.2084\) & \(-11.94^{\circ}\) \\ \hline \(-80\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.900 & & 2.456 & 1.832 & \(-0.1830\) & \(-10.49^{\circ}\) \\  & 0.061 & 0.096 & 0.314 & 0.771 & 0.910 & & 1.877 & & \\ \hline \(-70\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.775 & & 2.466 & 1.873 & \(1.873\) & \(-0.1791\) & \(-10.26^{\circ}\) \\  & -0.021 & 0.017 & 0.233 & 0.675 & 1.033 & & 1.873 & & \\ \hline \(-60\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.325 & 2.737 & 3.255 & \(-0.1040\) & \(-5.96^{\circ}\) \\  & 0.013 & 0.097 & 0.257 & 0.512 & 0.901 & 1.082 & 3.268 & 3.255 & \(-0.1040\) & \(-5.96^{\circ}\) \\ \hline \(-50\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.400 & 2.447 & 2.632 & \(-0.1283\) & \(-7.35^{\circ}\) \\  & 0.138 & 0.169 & 0.302 & 0.561 & 0.987 & 1.103 & 2.758 & 2.632 & \(-0.1283\) & \(-7.35^{\circ}\) \\ \hline \(-40\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.005 & 2.752 & & \\  & 0.226 & 0.266 & 0.339 & 0.499 & 0.603 & 0.789 & 7.207 & 6.981 & \(-0.0487\) & \(-2.79^{\circ}\) \\ \hline \(-30\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.000 & 2.923 & 8.205 & \(-0.0414\) & \(-2.37^{\circ}\) \\  & 0.184 & 0.230 & 0.302 & 0.389 & 0.499 & 0.716 & 8.383 & & \\ \hline \(-20\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.000 & 2.783 & 11.420 & \(-0.0298\) & \(-1.71^{\circ}\) \\  & 0.358 & 0.390 & 0.430 & 0.403 & 0.591 & 0.702 & 11.777 & & \\ \hline \(-10\) & 2.700 & 2.000 & 1.500 & 1.000 & 0.500 & 0.000 & 3.070 & 25.894 & \(-0.0131\) & \(-0.75^{\circ}\) \\  & 0.326 & 0.348 & 0.371 & 0.407 & 0.453 & 0.506 & 26.217 & & \\ \hline \(10\) & 0.525 & 1.000 & 1.250 & 1.425 & 2.000 & 2.500 & \(-1.009\) & 93.999 & 0.0036 & 0.21\({}^{\circ}\) \\  & 0.092 & 0.082 & 0.077 & 0.073 & 0.059 & 0.039 & \(-93.895\) & & \\ \hline \(20\) & 0.300 & 1.000 & 1.250 & 1.425 & 2.000 & 2.500 & \(-0.951\) & 14.830 & 0.0230 & 1.32\({}^{\circ}\) \\  & 0.083 & 0.153 & 0.192 & 0.222 & 0.328 & 0.438 & 14.830 & 14.830 & 0.0230 & 1.32\({}^{\circ}\) \\ \hline \(30\) & 0.500 & 1.000 & 1.250 & 1.425 & 2.000 & 2.500 & \(-0.046\) & 6.197 & 0.0548 & 3.14\({}^{\circ}\) \\  & 0.097 & 0.159 & 0.207 & 0.250 & 0.428 & 0.620 & 6.270 & 6.1 The robot is moved with a steering value of zero to determine the steering play. Two path recordings are carried out. In the first, the front wheels of the robot are pushed so far to the left before driving off that the steering servo tries to correct the steering angle but cannot do so. The second measurement pushes the front wheels to the right accordingly. The circle radii of the two paths can be determined from the paths obtained, which the robot draws on the floor with a felt-tip pen. It was ensured that only points representing the stationary case were used to determine the radii so that the overstretching of the steering was not measured. The orbit data from Table 3 were measured with this method. The individual measuring points are not listed for the sake of clarity. The steering angle deviation from the target value is the same in both cases.