Analyze And Research Of Off-Road Technologies Of Spherical Mobile Robot For Lunar Explore

The moon is the nearest planet to the earth, lunar explore action is very important for humans. Mobile exploration robot is an important irreplaceable tool for lunar explore. Spherical mobile robot is a completely sealed system. The control system, electric motor and power source are all contained in the spherical shell which is used as movement mechanism. The spherical mobile robot's structure is simple. It can move with large agility on the ground. It can roll with zero turning radius and does not have the risk of falling over. It has high moving efficiency. It has its own superiority to be used in the planet explore task.But the off road capability of traditional spherical robot is not enough for lunar explore tasks. In this paper we do the analyze and research of off road capability for lunar explore tasks,we research the planar motion the slope motion and the hopping motion of spherical robot,lunar soil is widely distributed over the moon, when the Lunar explore spherical robot move in the moon it will interact with the lunar soil. The model of interaction of mobile spherical robot and lunar soil is created. Parameters of this model are researched and realizability of the spherical robot rolling on the lunar soil area is proved.We get the sinkage when the spherical robot is static or moving. We also get the force situation of the robot.Fuzzy sliding mode controller is established for control the spherical robot on the soil area with level and unknown gradient.Slope is widely distributed over the moon. Traditional spherical robot's gradeability is not enough for using in these terrains. For enhance the gradeability of spherical robot, a new kind of spherical robot with climb link mechanism is designed. This kind of spherical robot can move in traditional way by the pendulum or move across large gradient slope by the new climb link mechanism.The mechanics model of the new spherical robot across slope by the climb link mechanism is created. Then the model is simulated by simulation software. The simulation result verifies the mechanism model's accuracy. Then parameters which can influence the climbing ability of spherical robot are analyzed and optimized. Then the mechanical model of this new spherical robot named BYQ-X was made out based on this analysis result. The mechanical structure and motion control system are detailed introduced. Finally, the accuracy of the mechanical model and the validity of the climb link mechanism are verified by tests of mechanical model.BYQ-X's gradeability is enhanced by the climb link mechanism, but it can't turn when the climbing link mechanism is unfolding. For this problem the structure of robot is improved. The new robot called B YQ-XI can do the zero-radius turning movement in two motion modes. Because that the rear-wheel also afford driving force so the climbing ability of variable structure spherical mobile robot is enhanced. The mechanics model of the new variable structure spherical mobile robot climbing slope and turning is created. Then these models are simulated by simulation software. The simulation result verifies the mechanism model's accuracy. Then parameters which can influence the gradeability of spherical robot are analyzed. From the analyze of these parameters we found that the BYQ-XI have better gradeability and can be smaller. This work will be the theoretical basis of the further improvement of the new variable structure spherical mobile robot. Finally, the accuracy of the mechanical model, the validity of the climb link mechanism and the flexibility of turning are verified by tests of mechanical model.Rocky area is widely distributed over the moon.The moon's gravity is one sixth of Earth's. Hopping is a good way of obstacle crossing. A new kind of jumping mechanism which can automatically storage, lock and release, and movement repetitively is designed. With application of this jumping mechanism, a hopping spherical robot with hopping ability is developed. The robot moves like traditional spherical robot in the flat environment. While in the environment with obstacles and ditches, the robot hop across them. So the ability of spherical robot adapting to the complex terrain is enhanced. Mechanical analysis during the hopping motion period of the robot is done and the factors affecting hopping ability are analyzed. To verify the validity of the mechanical design, the robot's dynamics model are simulated by simulation software. Finally, we make a mechanical model of spherical mobile robot with hopping ability. The motion and hopping experiments are made. The result shows the mechanism design is valid and the dynamical analysis of the robot is right.The hopping spherical robot can move in traditional way by the pendulum or jumping by Hopping mechanism.The track of jumping depend on the robot's horizontal velocity and the pendulum's angle. Fuzzy sliding mode controller is established for control the track.The stability analysis of the proposed controllers, along with simulation and experimental studies is carried out. In the practical using the hopping spherical robot will be used on the slope that the gradient is unknown. An adaptive neural network sliding mode controller is created for this situation. The stability analysis of the proposed controllers, along with simulation and experimental studies is carried out.