1
00:00:00,000 --> 00:00:04,590


2
00:00:04,590 --> 00:00:08,670
To gain greater adaptivity in
natural terrain conditions,

3
00:00:08,670 --> 00:00:11,250
animals are observed
to regularly jump over

4
00:00:11,250 --> 00:00:12,630
large obstacles.

5
00:00:12,630 --> 00:00:15,630
At the Ohio State
University, dynamic control

6
00:00:15,630 --> 00:00:19,210
of two types of jumps have
been developed for a quadruped.

7
00:00:19,210 --> 00:00:22,860
They are the standing
jump and the running jump.

8
00:00:22,860 --> 00:00:24,600
The model used in
the development

9
00:00:24,600 --> 00:00:28,320
has a size and weight similar
to that of a large dog.

10
00:00:28,320 --> 00:00:31,650
It uses simple telescoping
and springy legs.

11
00:00:31,650 --> 00:00:34,920
The terrain shown is
divided into a half meter

12
00:00:34,920 --> 00:00:36,900
by half meter grid.

13
00:00:36,900 --> 00:00:40,380
Here, a quadruped is
shown jumping over a wall

14
00:00:40,380 --> 00:00:42,630
with a height of about 1 meter.

15
00:00:42,630 --> 00:00:44,820
The motion traces of
the body and the feet

16
00:00:44,820 --> 00:00:47,250
are also displayed.

17
00:00:47,250 --> 00:00:49,980
During takeoff, the
front and the back legs

18
00:00:49,980 --> 00:00:53,070
are coordinated to impart
appropriate amounts

19
00:00:53,070 --> 00:00:56,220
of linear and angular
momentum to the body.

20
00:00:56,220 --> 00:00:59,220
While in flight, leg
motions are planned

21
00:00:59,220 --> 00:01:03,120
to maximize clearance
and prepare for landing.

22
00:01:03,120 --> 00:01:05,084
Note the ballistic
motion for the system.

23
00:01:05,084 --> 00:01:08,010


24
00:01:08,010 --> 00:01:12,120
During landing, the front
legs and the back legs in turn

25
00:01:12,120 --> 00:01:16,080
remove all the linear and
angular momentum of the body.

26
00:01:16,080 --> 00:01:18,870
Adaptation to
terrain-level variation

27
00:01:18,870 --> 00:01:22,680
is shown here where the
landing and the takeoff levels

28
00:01:22,680 --> 00:01:23,850
are different.

29
00:01:23,850 --> 00:01:28,350
In order to achieve a greater
span, the running jump is used.

30
00:01:28,350 --> 00:01:31,050
As it is shown
approaching a ditch,

31
00:01:31,050 --> 00:01:33,390
the quadruped is
running at 4 meters

32
00:01:33,390 --> 00:01:36,090
per second in a bounding gait.

33
00:01:36,090 --> 00:01:38,790
Unlike the standing
jump, at no time

34
00:01:38,790 --> 00:01:42,960
are the front and the back legs
on the ground simultaneously.

35
00:01:42,960 --> 00:01:46,230
During the transition from
a bounding gait to a jump,

36
00:01:46,230 --> 00:01:48,720
the quadruped applies
the appropriate amounts

37
00:01:48,720 --> 00:01:51,840
of linear and angular
momentum to the body

38
00:01:51,840 --> 00:01:55,110
to give a desired
jumping height and span.

39
00:01:55,110 --> 00:01:59,130
The jump is then characterized
by an extended flight phase.

40
00:01:59,130 --> 00:02:03,120
Unlike a standing jump, part
of the energy during landing

41
00:02:03,120 --> 00:02:07,590
is reused for transition
back into a bounding gait.

42
00:02:07,590 --> 00:02:10,259
A number of bounding
cycles are needed

43
00:02:10,259 --> 00:02:13,050
to regain the original
running speed.

44
00:02:13,050 --> 00:02:16,170
A variety of terrain conditions
with different takeoff

45
00:02:16,170 --> 00:02:19,300
and landing levels
have also been tested,

46
00:02:19,300 --> 00:02:22,740
including that of a
terrain step, shown here.

47
00:02:22,740 --> 00:02:25,800
With further refinements
to the jumping algorithms,

48
00:02:25,800 --> 00:02:29,550
application may be found
in high-speed locomotion

49
00:02:29,550 --> 00:02:32,120
over irregular terrain.

50
00:02:32,120 --> 00:02:44,000