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15 System Testing and Validation Technology of Lunar Lander
the mechanical environment caused by thrust pulsation of the engine would have a
certain effect on measurement accuracy of the high-precision navigation sensors of
GNC subsystem, as well as the pulsation response of structure on camera imaging.
In order to determine the pulsation environment of the lunar lander and its effects on
GNC sensors, it was necessary to conduct test validation on the ground.
5. Joint Firing Test of Throttling Engine and GNC CCU
According to the result of ranging and speedometer, by autonomous formulation of
control strategy, the GNC CCU would control the engine in real time. Because of the
high control frequency, the engine should respond quickly, which should be realized
by joint work of GNC subsystem and propulsion subsystem. In order to examine
joint work performance, it was necessary to conduct special test and validation on
the ground.
6. Test of Plume Effect on Thermal Control
Large throttling engine (7500 N throttling engine for the Chang’E-3) was generally
applied to achieve soft landing deceleration. When the lunar lander was approaching
lunar surface, the plume of the engine would interact with the lunar surface and be
reflected to the bottom of the lunar lander, which would affect the thermal control
material at the bottom of the lunar lander, instruments on the bottom plate and the
landing gears. In addition, the force of plume on the lunar lander would also affect
its landing attitude. In order to determine the thermal effect of engine plume on the
lunar lander, it was necessary to test the plume effect on the lunar lander.
15.4 Hovering, Obstacle Avoidance and Slow Descent Tests
15.4.1 Test Objective
The objective of ground validation test for hovering, obstacle avoidance and slow
descending was to simulate the actual flight process of hovering, obstacle avoidance
and slow descending, so as to fully examine the correctness of flight procedure design.
At the same time, the landing kinematics of the lunar lander could be simulated to
verify the autonomous navigation control algorithm based on navigation sensors,
as well as to simulate the reflection characteristics of lunar surface and motion of
the lunar lander so that the dynamic performance of navigation sensors could be
examined.
15 System Testing and Validation Technology of Lunar Lander
the mechanical environment caused by thrust pulsation of the engine would have a
certain effect on measurement accuracy of the high-precision navigation sensors of
GNC subsystem, as well as the pulsation response of structure on camera imaging.
In order to determine the pulsation environment of the lunar lander and its effects on
GNC sensors, it was necessary to conduct test validation on the ground.
5. Joint Firing Test of Throttling Engine and GNC CCU
According to the result of ranging and speedometer, by autonomous formulation of
control strategy, the GNC CCU would control the engine in real time. Because of the
high control frequency, the engine should respond quickly, which should be realized
by joint work of GNC subsystem and propulsion subsystem. In order to examine
joint work performance, it was necessary to conduct special test and validation on
the ground.
6. Test of Plume Effect on Thermal Control
Large throttling engine (7500 N throttling engine for the Chang’E-3) was generally
applied to achieve soft landing deceleration. When the lunar lander was approaching
lunar surface, the plume of the engine would interact with the lunar surface and be
reflected to the bottom of the lunar lander, which would affect the thermal control
material at the bottom of the lunar lander, instruments on the bottom plate and the
landing gears. In addition, the force of plume on the lunar lander would also affect
its landing attitude. In order to determine the thermal effect of engine plume on the
lunar lander, it was necessary to test the plume effect on the lunar lander.
15.4 Hovering, Obstacle Avoidance and Slow Descent Tests
15.4.1 Test Objective
The objective of ground validation test for hovering, obstacle avoidance and slow
descending was to simulate the actual flight process of hovering, obstacle avoidance
and slow descending, so as to fully examine the correctness of flight procedure design.
At the same time, the landing kinematics of the lunar lander could be simulated to
verify the autonomous navigation control algorithm based on navigation sensors,
as well as to simulate the reflection characteristics of lunar surface and motion of
the lunar lander so that the dynamic performance of navigation sensors could be
examined.