Introduction
Everyone might know what a rover is. It is a space exploration device designed to move across the surface of celestial bodies. Have you ever wondered how these rovers are capable of traversing the rough and rocky terrains of a planet? Different kinds of suspension systems are employed to help them achieve this task. Rocker-Bogie is one such suspensionsystem which is very popular and widely used. It is currently NASA’s favoured design for wheeled mobile rovers. NASA’s Curiosity rover uses this mechanism.
Design & Features
The largest link on each side is called rocker. It has two joints: one connected to the drive wheel and the other connected to the second link called Bogie. Bogie has drive wheel on each end.
The primary feature of rocker bogie is its simple and reliable design. It uses no springs or stub axles. It is thus capable of climbing over obstacles that are upto twice the size of wheel’s diameter. It offers good stability along its travel by keeping all the six wheels on the ground.
Each side of suspension moves independently allowing the rover to traverse terrains where the left and right rockers have to go over different sizes of obstacles. By proper design, the rover can be made to sustain tilt upto 50 degrees. Power is given to both front and back wheels enabling the rover to traverse obstacles without slip.
One major disadvantage is regarding the travel speed of the rover. At present, the speed is limited to about 10 cm/s to minimize dynamic shocks and damage upon impact.
There is still a lot to study and explore in this field. The design can be optimized to make it more cost effective and improve its strength and rigidity. One major concern would be to increase the travel speed so that it can be utilised to a greater extent.
