240
7 Guidance, Navigation and Control Technology …
2. Software Configuration
Based on the design of subsystem components and above software characteristics,
there were 10 types of software in GNC subsystem as shown in Table 7.3. The 10
types of software were embedded in the corresponding GNC subsystem components
(host computers) to implement various functions of the GNC subsystem.
3. Software Function
Functions of the 10 types of GNC subsystem software are shown in Table 7.4.
4. Design of CCU Software
The control computer software was the “nerve center” of the entire subsystem
and played the role of comprehensive dispatching and commanding. T design
methodology and ideas of the CCU software are described in this section.
The CCU software was a multi-task real-time operating system, and consisted of
system software and application software, both of which were burned in the PROM.
The software tasks could be classified into control, triple computer comparison,
telecommand and telemetry, system monitoring and spare as shown in Table 7.5.
Each task was uniformly scheduled and managed by the system software, according
to its priorities and criticalities. Except the spare task, each task should be completed
within a specified period of time.
The GNC subsystem application software of the Chang’E-3 lunar lander was
designed to inherit the mature design concept of the Chang’E-1. The main operation modes included launch, Sun orientation, star orientation 2, inertial attitude adjustment, star orientation 4, orbit control orientation, non-control, and rate
damping.
The control modes of powered descent phase included main deceleration, quick
attitude adjustment, approaching, hovering, hazard avoidance, and slow descending.
Under each mode, data of star tracker sensors, Laser Rangefinder, MRVS, and IMU
are obtained for attitude and orbit determination, as well as to complete the GNC
Table 7.3 Software configuration of GNC subsystem
No.
Name
Configuration
1
Computer system software
1
2
Computer application software
1
3
Image Process Board DSP software
1
4
APS Star Tracker system software
1
5
APS Star Tracker application software
1
6
APS Star Tracker star catalog software
3
7
MRVS range DSP software
1
8
MRVS velocity DSP software
1
9
MRVS Power Distribution Controller software
1
10
IMU software
1
7 Guidance, Navigation and Control Technology …
2. Software Configuration
Based on the design of subsystem components and above software characteristics,
there were 10 types of software in GNC subsystem as shown in Table 7.3. The 10
types of software were embedded in the corresponding GNC subsystem components
(host computers) to implement various functions of the GNC subsystem.
3. Software Function
Functions of the 10 types of GNC subsystem software are shown in Table 7.4.
4. Design of CCU Software
The control computer software was the “nerve center” of the entire subsystem
and played the role of comprehensive dispatching and commanding. T design
methodology and ideas of the CCU software are described in this section.
The CCU software was a multi-task real-time operating system, and consisted of
system software and application software, both of which were burned in the PROM.
The software tasks could be classified into control, triple computer comparison,
telecommand and telemetry, system monitoring and spare as shown in Table 7.5.
Each task was uniformly scheduled and managed by the system software, according
to its priorities and criticalities. Except the spare task, each task should be completed
within a specified period of time.
The GNC subsystem application software of the Chang’E-3 lunar lander was
designed to inherit the mature design concept of the Chang’E-1. The main operation modes included launch, Sun orientation, star orientation 2, inertial attitude adjustment, star orientation 4, orbit control orientation, non-control, and rate
damping.
The control modes of powered descent phase included main deceleration, quick
attitude adjustment, approaching, hovering, hazard avoidance, and slow descending.
Under each mode, data of star tracker sensors, Laser Rangefinder, MRVS, and IMU
are obtained for attitude and orbit determination, as well as to complete the GNC
Table 7.3 Software configuration of GNC subsystem
No.
Name
Configuration
1
Computer system software
1
2
Computer application software
1
3
Image Process Board DSP software
1
4
APS Star Tracker system software
1
5
APS Star Tracker application software
1
6
APS Star Tracker star catalog software
3
7
MRVS range DSP software
1
8
MRVS velocity DSP software
1
9
MRVS Power Distribution Controller software
1
10
IMU software
1