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Changes for page Ball Physics

Last modified by Soeren Domroes on 2025/01/30 12:18
From version 3.1
edited by stu104225
on 2020/03/03 18:55
Change comment: There is no comment for this version
To version 6.1
edited by stu104225
on 2020/03/04 17:32
Change comment: There is no comment for this version

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... ... @@ -1,55 +1,124 @@
1 +The **ball physics model** is meant to do things ... [TODO]
2 +
1 1  \\
2 2  
3 -== Task ==
4 4  
5 -The ball physics model is meant to do things ...
6 6  
7 -\\
7 +{{toc/}}
8 8  
9 -== Configuration ==
9 +== Ball trajectory ==
10 10  
11 -=== Points of interest ===
11 +----
12 12  
13 -\\
13 +The trajectory of a ball can be modeled to be parabolic.
14 +\\\\\\like so: .... [TODO]
14 14  
15 -[[image:attach:physics_points.png]]
16 +== Configuration ==
16 16  
17 -=== Flipper range ===
18 +----
18 18  
19 -\\
20 +=== Prediction parameters ===
20 20  
21 -\\
22 +(% class="wrapped" %)
23 +|=(((
24 +Parameter
25 +)))|=(((
26 +Description
27 +)))|=(((
28 +Default value
29 +)))
30 +|(((
31 +PREDICTION_FRAME
32 +)))|(((
33 +window size for prediction - How far
22 22  
23 -\\
35 +into the future are predctions calculated at most.
36 +)))|(((
37 +70ms
38 +)))
39 +|(((
40 +PREDICTION_STEP_SIZE
41 +)))|(((
42 +size of the steps for the forward search
43 +)))|(((
44 +10ms
45 +)))
46 +|(((
47 +REFINEMENT_FACTOR
48 +)))|(((
49 +The prediction step size for the reverse search is
50 +PREDICTION_STEP_SIZE divided by REFINEMENT_FACTOR.
51 +)))|(((
52 +10
53 +)))
24 24  
25 -\\
55 +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.
56 +Nevertheless it is reasonable to calculate predictions beyond the next frame in case a ball is not recognized on the next frame.
26 26  
27 -[[image:attach:physics2.png]]
58 +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.
28 28  
60 +The REFINEMENT_FACTOR is also the worst case number of predictions calculated during the reverse search part of the prediction process.
61 +
29 29  \\
30 30  
31 -=== Inlane Area ===
64 +=== Flipper range ===
32 32  
33 -[[image:attach:physics_inlane.png]]
66 +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
34 34  
35 -\\
68 +and should not need further adjustment after the camera is correctly calibrated (see [[doc:World Coordinate System]]).
36 36  
37 -=== Prediction parameters ===
70 +The values for the left flipper are set to be symmetrical.
38 38  
39 -\\
72 +[[image:attach:physics_points.png]]
40 40  
41 -\\
74 +(% class="wrapped" %)
75 +|=(((
76 +Point#
77 +)))|=(((
78 +Description
79 +)))
80 +|(((
81 +1
82 +)))|(((
83 +center point of the circle that the flippers tip moves o
84 +)))
85 +|(((
86 +2
87 +)))|(((
88 +highest point a ball can be at when it hits the resting flipper
89 +)))
90 +|(((
91 +3
92 +)))|(((
93 +lowest point a ball can be at when it hits the resting flipper
94 +)))
95 +|(((
96 +4
97 +)))|(((
98 +lowest point a ball can be at when it hits the fully triggered flipper
99 +)))
100 +|(((
101 +5
102 +)))|(((
103 +highest point a ball can be at when it hits the fully triggered flipper
104 +)))
42 42  
43 43  \\
44 44  
45 -\\
108 +From these points an area, where the ball is deemed to be hittable, is computed.
46 46  
47 -\\
110 +[[image:attach:physics2.png]]
48 48  
49 49  \\
50 50  
51 -\\
114 +=== Inlane Area ===
52 52  
53 -\\
116 +Since the trajectory prediction does not consider collisions in general, we need a different kind of predictions for the inlanes,
117 +i.e. the path feeding a falling ball from the playfield to the flippers, behind the slingshot.
118 +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
119 +and the other by a point at highest, outermost position of the angled part of the inlane.
54 54  
55 -\\
121 +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.
122 +Though in reality the still is some accelleration, a simple linear prediction has shown to be practical in this less critical area.
123 +
124 +[[image:attach:physics_inlane.png]]
Confluence.Code.ConfluencePageClass[0]
Id
... ... @@ -1,1 +1,1 @@
1 -71401639
1 +71401645
URL
... ... @@ -1,1 +1,1 @@
1 -https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/PP18/pages/71401639/Ball Physics
1 +https://rtsys.informatik.uni-kiel.de/confluence//wiki/spaces/PP18/pages/71401645/Ball Physics