Rover End Effector Design for Material Extraction from Earthlike Planets

Abstract

In exploration of any earth-like planet, it is very essential to a robot to collect material sample from that planet. Therefore the robot must have some end effector which can extract material from that surface. In this work, by considering various parameters, a scoop type end effector having three degree of freedom has been designed to reduce the resistance force of extraction materials. First the kinematic analysis of the end effector and static torque calculations is analyzed and a prototype has been fabricated with a servo-controlled system. The performance of the end effector has been evaluated by performing several experiments such as extracting soil and burned coal materials. The lowest amount of time during one operation is 21 seconds and maximum weight of the materials extracted has been found as 89 grams. The prototype with proper modifications can also work for extracting ammunitions and underground explosives that are too dangerous for the human being or difficult to handle.

Conclusion

After examining the requirements, the most appropriate shovel type end effector has been selected and proposed to reduce resistance force. An end effector for material extraction from earth like surface has been successfully designed and fabricated using cheap and locally available materials. The fabricated model of the robot has been also provided with correct joint angles to move end effector to required position and orientation within its workspace. The prototype has been experimented with two types of materials, one is splits of soil and another is splits of burned coal. The average time needed from extracting to unloading the materials from both material surface for 45° is 23.5 seconds, for 90° is 26.83 seconds and for 120° is 29.83 seconds. The weight of material extracted from soil surface is 72.55 gm and from burned coal surface is 57.44 gm. The performance of the robotic end effector for material extracting from a surface closely to Mars is quite satisfactory. However, the performance of the system could be exalted further to produce more accurate and reliable results. Some of the recommendations for such improvement include increasing the ability of digging the surface to extract material from hard rocky surface by using hydraulic system or linear actuator, design and implementation of different types embedded sensors to achieve vibration control and smooth motion of end effectors, wireless control of the robotic end effector. The scopes of this type of end effectors are: in the applications of extracting the ammunition that is undergrounded due to dangerous to human being, extracting or removing something from surface where human being can’t reach, picking and placing the materials from inconvenient environment, raising the explosives that is hidden in any place, applying for industrial purpose where human being can’t perform the job.

References