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Changes for page Ball Physics

Last modified by Soeren Domroes on 2025/01/30 12:18
From version 8.1
edited by stu104225
on 2020/03/07 11:40
Change comment: There is no comment for this version
To version 3.1
edited by stu104225
on 2020/03/03 18:55
Change comment: There is no comment for this version

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... ... @@ -1,132 +3,55 @@
1 -The **ball physics model**'s main objective is to provide a point in time to the controller, when the ball is predicted to be hittable, in order to not let the ball fall into the drain.
2 -
3 3  \\
4 4  
5 -\\
3 +== Task ==
6 6  
5 +The ball physics model is meant to do things ...
7 7  
8 -
9 -{{toc/}}
10 -
11 -== Ball trajectory ==
12 -
13 -----
14 -
15 -The trajectory of a ball can be modeled to be parabolic. From two point //p// and //p_old// with corresponding timestamps, the velocity //v// is computed.
16 -For a
17 17  \\
18 18  
19 -\\
20 -
21 -[[image:attach:Bildschirmfoto von 2020-03-07 12-21-22.png]]
22 -\\\\like so: .... [TODO]
23 -
24 24  == Configuration ==
25 25  
26 -----
11 +=== Points of interest ===
27 27  
28 -=== Prediction parameters ===
13 +\\
29 29  
30 -(% class="wrapped" %)
31 -|=(((
32 -Parameter
33 -)))|=(((
34 -Description
35 -)))|=(((
36 -Default value
37 -)))
38 -|(((
39 -PREDICTION_FRAME
40 -)))|(((
41 -window size for prediction - How far
15 +[[image:attach:physics_points.png]]
42 42  
43 -into the future are predctions calculated at most.
44 -)))|(((
45 -70ms
46 -)))
47 -|(((
48 -PREDICTION_STEP_SIZE
49 -)))|(((
50 -size of the steps for the forward search
51 -)))|(((
52 -10ms
53 -)))
54 -|(((
55 -REFINEMENT_FACTOR
56 -)))|(((
57 -The prediction step size for the reverse search is
58 -PREDICTION_STEP_SIZE divided by REFINEMENT_FACTOR.
59 -)))|(((
60 -10
61 -)))
17 +=== Flipper range ===
62 62  
63 -When setting the PREDICTION_FRAME keep in mind, that predictions, that reach multiple frames into the future, are likely to be overwritten, when new frames arrive and new predictions are calculated.
64 -Nevertheless it is reasonable to calculate predictions beyond the next frame in case a ball is not recognized on the next frame.
19 +\\
65 65  
66 -With the default values up to 7 predictions are calculated if the ball is not predicted to be in flipper range roughly within the next two frames.
21 +\\
67 67  
68 -The REFINEMENT_FACTOR is also the worst case number of predictions calculated during the reverse search part of the prediction process.
23 +\\
69 69  
70 70  \\
71 71  
72 -=== Flipper range ===
27 +[[image:attach:physics2.png]]
73 73  
74 -The model of the area, where the the flippers can hit a ball is computed from a set of five points. These points are set to real world coordinates in meter
29 +\\
75 75  
76 -and should not need further adjustment after the camera is correctly calibrated (see [[doc:World Coordinate System]]).
31 +=== Inlane Area ===
77 77  
78 -The values for the left flipper are set to be symmetrical.
33 +[[image:attach:physics_inlane.png]]
79 79  
80 -[[image:attach:physics_points.png]]
35 +\\
81 81  
82 -(% class="wrapped" %)
83 -|=(((
84 -Point#
85 -)))|=(((
86 -Description
87 -)))
88 -|(((
89 -1
90 -)))|(((
91 -center point of the circle that the flippers tip moves o
92 -)))
93 -|(((
94 -2
95 -)))|(((
96 -highest point a ball can be at when it hits the resting flipper
97 -)))
98 -|(((
99 -3
100 -)))|(((
101 -lowest point a ball can be at when it hits the resting flipper
102 -)))
103 -|(((
104 -4
105 -)))|(((
106 -lowest point a ball can be at when it hits the fully triggered flipper
107 -)))
108 -|(((
109 -5
110 -)))|(((
111 -highest point a ball can be at when it hits the fully triggered flipper
112 -)))
37 +=== Prediction parameters ===
113 113  
114 114  \\
115 115  
116 -From these points an area, where the ball is deemed to be hittable, is computed.
41 +\\
117 117  
118 -[[image:attach:physics2.png]]
43 +\\
119 119  
120 120  \\
121 121  
122 -=== Inlane Area ===
47 +\\
123 123  
124 -Since the trajectory prediction does not consider collisions in general, we need a different kind of predictions for the inlanes,
125 -i.e. the path feeding a falling ball from the playfield to the flippers, behind the slingshot.
126 -A ball is considered to be in an inlane, when it is in a rectangualar area, with one edge given by the begin of the flipper
127 -and the other by a point at highest, outermost position of the angled part of the inlane.
49 +\\
128 128  
129 -In this area the vertical accelleration is deactivated in the prediction, since it would cause the prediction to assume the would slide into the wall.
130 -Though in reality the still is some accelleration, a simple linear prediction has shown to be practical in this less critical area.
51 +\\
131 131  
132 -[[image:attach:physics_inlane.png]]
53 +\\
54 +
55 +\\
Confluence.Code.ConfluencePageClass[0]
Id
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1 -71401659
1 +71401639
URL
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1 -https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/PP18/pages/71401659/Ball Physics
1 +https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/PP18/pages/71401639/Ball Physics