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7 Guidance, Navigation and Control Technology …
7.4 Design Methodology
7.4.1 System Configuration
Generally, there are three parts in GNC system including controller, sensors and actuators [6]. According to the task requirements, the configuration of GNC subsystem
of the Chang’E-3 lunar lander was determined as follows (as Fig. 7.1) after the
redundant design of the subsystem and the product status was considered.
1. Controller
Central Control Unit, including control computer, image processing board, secondary
power supply, subsystem power supply and distribution.
2. Sensors
Including Star Tracker Sensor, Digital Sun Sensor, Analog Sun Sensor, IMU
(including gyro assembly, accelerometer assembly, IMU processing circuits), Laser
Rangefinder, MRVS, 3-D Laser Image Sensor, Optical Image Sensor, Touch-down
Switches (affiliated to landing cushion subsystem) and Gamma Shutdown Sensor.
3. Actuators
Propulsion subsystem composed of a 1500 N ~ 7500 N throttling engine, 16 × 150 N
and 12 × 10 N thrusters.
7.4.2 Operational Modes
Only one part of the GNC subsystem should run during a certain flight phase.
Different function systems were formed as required. One operation mode of the
GNC subsystem was a generalization of operation modes of the GNC subsystem
that performed the same or similar tasks and functions at certain phases of the lunar
lander mission.
There was no definite standard for the operation modes. The operation modes of
the GNC subsystem of the Chang’E-3 lunar lander were given in Table 7.2.
7.4.3 Component Design
The GNC subsystem usually consisted of three major parts: sensors, controllers and
actuators as described in Sect. 7.4.1.
The sensors could be classified into attitude sensors and navigation sensors. There
were typical attitude sensors including infrared Earth sensors, sun sensors and star
sensors, inertial sensors including gyros and accelerometers, radio sensors including
7 Guidance, Navigation and Control Technology …
7.4 Design Methodology
7.4.1 System Configuration
Generally, there are three parts in GNC system including controller, sensors and actuators [6]. According to the task requirements, the configuration of GNC subsystem
of the Chang’E-3 lunar lander was determined as follows (as Fig. 7.1) after the
redundant design of the subsystem and the product status was considered.
1. Controller
Central Control Unit, including control computer, image processing board, secondary
power supply, subsystem power supply and distribution.
2. Sensors
Including Star Tracker Sensor, Digital Sun Sensor, Analog Sun Sensor, IMU
(including gyro assembly, accelerometer assembly, IMU processing circuits), Laser
Rangefinder, MRVS, 3-D Laser Image Sensor, Optical Image Sensor, Touch-down
Switches (affiliated to landing cushion subsystem) and Gamma Shutdown Sensor.
3. Actuators
Propulsion subsystem composed of a 1500 N ~ 7500 N throttling engine, 16 × 150 N
and 12 × 10 N thrusters.
7.4.2 Operational Modes
Only one part of the GNC subsystem should run during a certain flight phase.
Different function systems were formed as required. One operation mode of the
GNC subsystem was a generalization of operation modes of the GNC subsystem
that performed the same or similar tasks and functions at certain phases of the lunar
lander mission.
There was no definite standard for the operation modes. The operation modes of
the GNC subsystem of the Chang’E-3 lunar lander were given in Table 7.2.
7.4.3 Component Design
The GNC subsystem usually consisted of three major parts: sensors, controllers and
actuators as described in Sect. 7.4.1.
The sensors could be classified into attitude sensors and navigation sensors. There
were typical attitude sensors including infrared Earth sensors, sun sensors and star
sensors, inertial sensors including gyros and accelerometers, radio sensors including