7.4 Design Methodology
229
Sensors
Electronic Circuits
Controller
Actuators
Electronic Circuits
Star Sensor Head
Star Sensor Head
Star Sensor Head
Digital Sun
Sensor
Analog Sun
Sensor ×2
Gyro ×6
Laser
Rangefinder
Microwave Range
and Velocity
Sensor
3-D Laser Image
Sensor Head
Optical Image
Sensor
of Landing
Cushion Subsystem
Touchdown
Switches
Gama Shutdown
Sensor
Accelerometer ×6
Star Sensor
Circuit
Star Sensor
Circuit
Star Sensor
Circuit
IMU Circuit
3-D Laser Image
Sensor Circuit
Stepper Motor
Windings
1500N~7500N
Throttling
Engine
150N Thrusters
×16
Propulsion Power
Distribution
Propulsion
Circuit
Central Control
Unit
10N Thrusters
×12
Latching Valves
×15
Propulsion
Subsystem
Fig. 7.1 Schematic diagram of GNC subsystem of the Chang’E-3 lunar lander
RF sensors and magnetometers. There were typical navigation sensors including
relative range and velocity sensors, imaging navigation sensors, etc.
The controller could be implemented by analog circuits, digital circuits or electric
computers.
Generally, there are three types of actuators including jet actuator, electromechanical actuator and environmental actuator. The jet actuator discharges the gas (work