4.4 Mechanism Design and Verification of Lunar Lander
145
(a)
(b)
(c)
(d)
Fig. 4.26 Lunar rover transfer process. (a) Before deployment; (b) Deployment of ladders;
(c) Deployment of four-bar linkage assembly; (d) Transfer of the lunar rover to lunar surface
was complex and there were many factors during operation on lunar surface, the
kinematics and dynamics of mechanism was conducted for the transfer mechanism
including the dynamic simulation analysis of ladders deployment and transfer on
lunar surface.
1) Dynamic simulation analysis of ladders deployment
The ladders assembly of the transfer mechanism was foldable and composed of a short
ladder and a long ladder connected by hold down and release mechanism. During
launch, the ladders were folded and held down on the lateral side of the lander. After
the lander was landed the hold down and release mechanism was released, then
the ladders were deployed and held down. During deployment of the ladders, the
movement of the long ladder was constrained by the linkage between the long ladder
and the short ladder in order to ensure that the movement path of the long ladder
was certain before the linkage didn’t work, so the movement interference between
the transfer mechanism and landing legs could be avoided during the deployment
of the ladders. The dynamic simulation of the ladders deployment of the transfer
mechanism was conducted. The simulation analysis showed that the linkage could
effectively restrain the trajectory of the long ladder and interference with landing
legs could be avoided as shown in Fig. 4.27.
2. Dynamic simulation analysis of transfer process on lunar surface
The dynamic simulation analysis of transfer process on lunar surface included the
analysis of the startup torque and adaptability to lunar terrain.
The four-bar linkage type of the lunar rover transfer mechanism was designed
for the Chang’E-3 lunar lander. The active force was lunar gravity for motion of the
transfer mechanism. When the maximum pitch was +15° after the lander was landed,
145
(a)
(b)
(c)
(d)
Fig. 4.26 Lunar rover transfer process. (a) Before deployment; (b) Deployment of ladders;
(c) Deployment of four-bar linkage assembly; (d) Transfer of the lunar rover to lunar surface
was complex and there were many factors during operation on lunar surface, the
kinematics and dynamics of mechanism was conducted for the transfer mechanism
including the dynamic simulation analysis of ladders deployment and transfer on
lunar surface.
1) Dynamic simulation analysis of ladders deployment
The ladders assembly of the transfer mechanism was foldable and composed of a short
ladder and a long ladder connected by hold down and release mechanism. During
launch, the ladders were folded and held down on the lateral side of the lander. After
the lander was landed the hold down and release mechanism was released, then
the ladders were deployed and held down. During deployment of the ladders, the
movement of the long ladder was constrained by the linkage between the long ladder
and the short ladder in order to ensure that the movement path of the long ladder
was certain before the linkage didn’t work, so the movement interference between
the transfer mechanism and landing legs could be avoided during the deployment
of the ladders. The dynamic simulation of the ladders deployment of the transfer
mechanism was conducted. The simulation analysis showed that the linkage could
effectively restrain the trajectory of the long ladder and interference with landing
legs could be avoided as shown in Fig. 4.27.
2. Dynamic simulation analysis of transfer process on lunar surface
The dynamic simulation analysis of transfer process on lunar surface included the
analysis of the startup torque and adaptability to lunar terrain.
The four-bar linkage type of the lunar rover transfer mechanism was designed
for the Chang’E-3 lunar lander. The active force was lunar gravity for motion of the
transfer mechanism. When the maximum pitch was +15° after the lander was landed,