Rough Terrain Vehicle Using Rocker Bogie Mechanism
Rough Terrain Vehicle Using Rocker Bogie Mechanism report
Abstract: It is obvious that rovers are essential vehicles of today’s solar system exploration. A lot of the rover designs have been developed for planetary surface in order to understand the geological history of the soil, ground and atmosphere. Exploration operations need high speed and long distance travel in a short period due to foreign environment, climate and communication restrictions. Several mechanisms have been invented in recent years for working of rovers on rough terrain. Although their different applications have found a widespread usage in mobile robotics, their low speed operation is still a challenging problem. In this research, a new suspension mechanism has been delineate and its kinematic scrutiny results were discussed. Standard rocker-bogie suspension mechanism, which has been designed in the late 90’s, has excellent weight distribution for different surfaces on rough terrain. New design, mostly related to rocker-bogie suspension system, has a inbuilt advantage with linear bogie motion which protects the whole system from getting rolled over during high speed implementation. This improvement increases the strength of structure on field operations and also allows the higher speed exploration with similar object obstruction height capacity as rocker-bogie. In this study, new bogie mechanism consisted of double-lambda mechanism, which has been in first presented by Pafnuty Lvovich Chebyshev in 1869, is solved by analytics to define the positions and singular configurations. An improved structural synthesis formula also has been introduced for such mechanisms with lower and higher kinematic couples. By using structural synthesis methods, a developed mechanism has been designed with double-lambda mechanism. Force equations and moment functions were also produced with equation of motion method.By design it is a wheel robot which comprises of 6 motorized wheels. The word “rocker” describes the back part of the larger links present both sides of the suspension system and these rockers are connected to each other and the vehicle chassis through a selectively modified differential in order to balance the bogie. By construction it has main frame containing two linkages on each side that are called the “rocker” (see Figure 1).One end of the rocker is connected to the back wheel, and the other end is connected to maintain center of gravity of entire vehicle as accordance with the motion, when one rocker moves down-word, the other goes upward (Figure 1).It plays vital role to maintain the average pitch angle of both rocker and bogie by allowing both rockers to move as per the situation. As per the actual design, one end of a rocker is jointed with a drive wheel and the other end is pivoted to a bogie which gives required moment and degree of freedom.