Configuration Design and Motion Performance Analysis of a New Wheeled Rolling Robot

A new wheeled rolling robot is designed based on planar 3-RRR parallel mechanism and spoke wheel with variable diameter, by adjusting the 3-DOF outputs of the planar 3-RRR parallel mechanism, the deformation and rolling motion of the rolling robot are realized, the rotation output of the parallel mechanism realizes the differential change of the diameter of the two supporting wheels of the rolling robot, and the moving output of the parallel mechanism changes the mass distribution of the system, so that the rolling robot can complete the forward, backward, turning and other motions. Based on the introduction of the performance parameters, driving system, variable diameter wheel configuration and motion mechanism of the rolling robot, the eccentric driving torque is analysis and the existing space of the eccentric torque is given, so as to further complete the selection of the driving motor of the robot. This article analysis three typical motions of robots and its performance parameters, such as straight movement, turn movement, climbing exercise, and builds a simple prototype under laboratory conditions to verify the feasibility of the three movements.

Multi-Loop Rover: A Kind of Modular Rolling Robot Constructed by Multi-Loop Linkages

This paper proposes a new kind of modular rolling robot called multi-loop rover (MLR), which is essentially a multi-loop linkage that is able to roll and switch its rolling directions. For ease of rolling, the MLR retains a multi-loop topological structure composed of a number of strut and node modules. First, the modular design and assembling method are introduced to construct an MLR. Then, the mobility is analyzed based on screw theory, and a brief formula is presented to calculate the degree-of-freedoms of the robot. The results show that all node modules only have translational motions, which can significantly reduce the complexity of kinematics. The forward and inverse kinematics are conducted to show the deformation properties. Based on the kinematic rolling principle, the morphing strategies for rolling and turning functions are developed. Finally, a physical prototype is manufactured and a serial of experiments are carried out to verify the proposed method.

Research on Model, Experiment and Application of Gravity Valve

In this paper, two kinds of gravity valves are designed: copper bead gravity valve and hose gravity valve. Firstly, the stress distribution on the substrate of the gravity valve is simulated when the copper bead and the substrate of the gravity valve is in the non-touched, half-touched or full-touched states respectively, and the fluid leakage laws are also analyzed in the different states, by ABAQUS 6.16. The flow rate control effects of the copper bead gravity valve with different cone angle are measured and analyzed experimentally, and the optimal cone angle are obtained. Secondly, the cross-section shapes of the hose are compared and analyzed by FEA (Finite Element Analysis) for several kinds of hose gravity valve. It is concluded that the shuttle hose has the best performance. Then the shuttle hose gravity valve is made and its flow characteristics are measured and analyzed with different length of the hose. Finally, the two kinds of gravity valve are compared and applied. The copper bead gravity valve is used in chemical reaction self-driven rolling robot. The hose gravity valve is used to control the end of bending brake stably for the angle sensor, and the hose gravity valve can also be used to establish mechanical feedback loop to facilitate the flow rate control by the angle.