502
15 System Testing and Validation Technology of Lunar Lander
lander test model would be separated from lift, release and separation device. Then
the lunar lander test model would free fall and touch the landing surface.
3. Simulated Landing Surface
In order to simulate the contact characteristics between the landing gear foot pad
of the lunar lander and the landing surface during soft landing, simulated landing
surface should be designed. Simulation of landing surface could simulate typical
lunar terrain and mechanical property of lunar surface. The parameters should be
simulated were including friction factor, load bearing strength, slope, and etc.
4. Ground Measurement Subsystem
The ground measurement subsystem consisted of a high-speed camera system and
an acceleration/strain measurement system. During the test, the high-speed camera
system would measure the parameters of interested points with time, such as displacement, cushion stroke, landing velocity, attitude angle, angular rate, and angular acceleration, and the acceleration/strain measurement system would measure the time
history of acceleration and strain response.
15.5.4 Test Example
During development of the Chang’E-3 lunar lander, the landing impact test and the
test system were designed and developed. The landing impact test was conducted,
as shown in Fig. 15.12.
15.6 Landing Stability Tests
15.6.1 Test Objective
The objective of the landing stability test was to examine influence on landing stability
of the lunar lander caused by landing attitude, landing velocity, landing surface terrain
and mechanical property of lunar soil, to verify landing stability under extreme
conditions and correct landing stability simulation model.
15.6.2 Test Constraints and Methodology
When the test system for landing stability test was designed, the following constraints
should be considered:
15 System Testing and Validation Technology of Lunar Lander
lander test model would be separated from lift, release and separation device. Then
the lunar lander test model would free fall and touch the landing surface.
3. Simulated Landing Surface
In order to simulate the contact characteristics between the landing gear foot pad
of the lunar lander and the landing surface during soft landing, simulated landing
surface should be designed. Simulation of landing surface could simulate typical
lunar terrain and mechanical property of lunar surface. The parameters should be
simulated were including friction factor, load bearing strength, slope, and etc.
4. Ground Measurement Subsystem
The ground measurement subsystem consisted of a high-speed camera system and
an acceleration/strain measurement system. During the test, the high-speed camera
system would measure the parameters of interested points with time, such as displacement, cushion stroke, landing velocity, attitude angle, angular rate, and angular acceleration, and the acceleration/strain measurement system would measure the time
history of acceleration and strain response.
15.5.4 Test Example
During development of the Chang’E-3 lunar lander, the landing impact test and the
test system were designed and developed. The landing impact test was conducted,
as shown in Fig. 15.12.
15.6 Landing Stability Tests
15.6.1 Test Objective
The objective of the landing stability test was to examine influence on landing stability
of the lunar lander caused by landing attitude, landing velocity, landing surface terrain
and mechanical property of lunar soil, to verify landing stability under extreme
conditions and correct landing stability simulation model.
15.6.2 Test Constraints and Methodology
When the test system for landing stability test was designed, the following constraints
should be considered: