1
00:00:00,210 --> 00:00:02,800
‫Now, you might think that this is all.

2
00:00:03,180 --> 00:00:12,410
‫However, it's not what we have discussed so far is rotation about an axis using fixed angles.

3
00:00:12,840 --> 00:00:20,280
‫We call them fixed angles because we have been rotating our body frame about the fixed inertial frame

4
00:00:20,280 --> 00:00:20,970
‫axis.

5
00:00:21,810 --> 00:00:32,280
‫However, you can also rotate your body frame about, for example, first Z axis by 90 degrees, then

6
00:00:32,280 --> 00:00:34,550
‫you will end up in this configuration.

7
00:00:35,130 --> 00:00:44,910
‫But now, instead of rotating about the inertia frame y axis, you can rotate about the body frame y

8
00:00:44,910 --> 00:00:50,840
‫axis and then you will end up in this configuration if you rotate by 90 degrees.

9
00:00:51,510 --> 00:00:57,190
‫When you do that, then we say that you're using oilor angles, not fixed angles.

10
00:00:57,540 --> 00:01:05,430
‫In other words, you're rotating about the moving frame, not about the fixed frame, about the moving

11
00:01:05,430 --> 00:01:05,850
‫frame.

12
00:01:06,390 --> 00:01:13,650
‫So you also have to specify that when describing an attitude of an object in space and you also have

13
00:01:13,650 --> 00:01:15,240
‫12 conventions there.

14
00:01:15,690 --> 00:01:18,150
‫We will discuss it more in the next video.

15
00:01:18,780 --> 00:01:19,710
‫Thank you very much.