15.6 Landing Stability Tests
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3. Test Gantry and One-Dimensional Follow-Up Subsystem
Test gantry could support the one-dimensional follow-up subsystem and provide
sufficient test space. The one-dimensional follow-up system was generally designed
in passive mode. In order to minimize the interference force caused by follow-up lag
to the test model, the mass and follow-up friction factor of the follow-up subsystem
should be as small as possible. The follow-up capability of the one-dimensional
follow-up subsystem should cover the maximum horizontal landing velocity of the
lunar lander with certain margin.
4. Lift and Release Device
The lift and release device was composed of lift device, rope, sling rope, release
device of sling rope, length adjusting device of sling rope, horizontal rope, release
device of horizontal rope and length adjusting device of horizontal rope. The specific
functions of each part are as follows.
(1) Lift device: to connect the rope and implement the one-dimensional follow-up
of the rope to the test model by the follow-up device.
(2) Rope: to connect the test model with lift device. During the test, the gravitational component of the lunar lander could be balanced. In order to minimize
the rope angle change caused by displacement changes of test model mass
center caused by attitude change and cushion stroke, the length of the rope
should be designed specially.
(3) Sling rope: to achieve the initial attitude of the lunar lander and the vertical
landing velocity.
(4) Release device of sling rope: to release sling rope at the set position by
triggering of pyrotechnic.
(5) Length adjusting device of sling rope: to adjust the length of sling rope. The
initial attitude angle of the test model could be achieved by adjusting the relative
length of sling rope.
(6) Horizontal rope: to achieve the horizontal landing velocity of the test model
parallel to the guide track.
(7) Release device of horizontal rope: to release horizontal rope at the set position
by triggering of pyrotechnic.
(8) Length adjustment device of horizontal rope: to adjust the length of the
horizontal rope to achieve different horizontal landing velocity.
5. Simulated Landing Surface
The simulated landing surface could simulate typical lunar terrain and mechanical
property of lunar soil, including friction factor, load bearing strength and slope of
landing surface.
When the size of simulated landing surface was designed, it was necessary to
consider the space motion of the test model and the slip during contact with landing
surface. Generally, it was determined by theoretical calculation and simulation analysis. The stiffness and strength constraints should be comprehensively considered
when simulated landing surface was designed. The fundamental frequency should
505
3. Test Gantry and One-Dimensional Follow-Up Subsystem
Test gantry could support the one-dimensional follow-up subsystem and provide
sufficient test space. The one-dimensional follow-up system was generally designed
in passive mode. In order to minimize the interference force caused by follow-up lag
to the test model, the mass and follow-up friction factor of the follow-up subsystem
should be as small as possible. The follow-up capability of the one-dimensional
follow-up subsystem should cover the maximum horizontal landing velocity of the
lunar lander with certain margin.
4. Lift and Release Device
The lift and release device was composed of lift device, rope, sling rope, release
device of sling rope, length adjusting device of sling rope, horizontal rope, release
device of horizontal rope and length adjusting device of horizontal rope. The specific
functions of each part are as follows.
(1) Lift device: to connect the rope and implement the one-dimensional follow-up
of the rope to the test model by the follow-up device.
(2) Rope: to connect the test model with lift device. During the test, the gravitational component of the lunar lander could be balanced. In order to minimize
the rope angle change caused by displacement changes of test model mass
center caused by attitude change and cushion stroke, the length of the rope
should be designed specially.
(3) Sling rope: to achieve the initial attitude of the lunar lander and the vertical
landing velocity.
(4) Release device of sling rope: to release sling rope at the set position by
triggering of pyrotechnic.
(5) Length adjusting device of sling rope: to adjust the length of sling rope. The
initial attitude angle of the test model could be achieved by adjusting the relative
length of sling rope.
(6) Horizontal rope: to achieve the horizontal landing velocity of the test model
parallel to the guide track.
(7) Release device of horizontal rope: to release horizontal rope at the set position
by triggering of pyrotechnic.
(8) Length adjustment device of horizontal rope: to adjust the length of the
horizontal rope to achieve different horizontal landing velocity.
5. Simulated Landing Surface
The simulated landing surface could simulate typical lunar terrain and mechanical
property of lunar soil, including friction factor, load bearing strength and slope of
landing surface.
When the size of simulated landing surface was designed, it was necessary to
consider the space motion of the test model and the slip during contact with landing
surface. Generally, it was determined by theoretical calculation and simulation analysis. The stiffness and strength constraints should be comprehensively considered
when simulated landing surface was designed. The fundamental frequency should