Our robotic arm will be able to pick up objects on the assembly line, travel horizontally along the same axis, and deposit the object at a new location along that axis. Since it is moving all on the same axis, it will take up as little space as possible. This introduces the possibility of having multiple arms along the line sorting and building products. We aim to have the motor in the base, an arm composed mainly of four-bar linkages, and a claw gripper. The claw will have an escapement mechanism to cycle between open and closed positions, and gears that rotate two four-bar linkages. The claw is able to pick up various size objects with different weights. Additionally, we plan on automating the process of picking and placing to mimic the function of the arm working on an actual assembly line.
Analysis that will need to be performed prior to the fabrication includes the following. We need to understand the motion profiles of the linkages as well as the rotary motion from the base to the claw. Furthermore, we will analyze the force profile of the grabber, the arm’s geometry/dimensions, and overall design via SolidWorks simulation. We would like to use the minimum amount of materials so the arm can take up as little space as possible, and we need to analyze the rotation of the base with respect to the other components such as wires.
The most exciting part of this project is learning how to design a functioning robotic arm. Specifically, going from an idea, to drawings, to CAD models, to fabrication. We are really excited about using the knowledge gained in lecture about four-bar linkages and applying it to the real world application of building a robotic arm that streamlines the manufacturing process. The main challenge will be to design a linkage system to account for the complex motion of the arm, an escapement mechanism to alternate between open and closed positions of the gripper, and powering these seemingly independent mechanisms in concert with a single rotary input. Furthermore, it will be a challenge to automate this process in addition to using our mechanical engineering knowledge for the build itself. The greatest constraint of all in this project is the limited timeframe in which we have to complete it in addition to balancing the other assignments in this course.
Juliana is interested in extending this arm in the future for streamlining the manufacturing process that builds plant grow chambers for her mechanical engineering internship. Specifically, the base of the design is complex and needs to be lifted up to address any issues within the assembly process. So an extension of this robotic arm would be making it strong enough to lift heavy objects and keeping it steady prior to moving to another position along the assembly. Tyler is interested in designing robots to lower costs associated with manufacturing. Many industry robots utilize expensive actuators to complete simple movements that could otherwise be accomplished with linkage systems. He hopes to iterate on this project and use it as inspiration in industry. Leo is interested in how easily this mechanism can be duplicated so that warehouses can have these lined up back to back. Since the mechanism will be designed to use up as little square footage as possible, there can be multiple next to each other.
Preliminary design has been focused on the smaller movements, rather than the entire movement of the entire arm. For the claw, a design has been decided upon and will be tested. Our design is taken from the image below (sourced from https://www.pinterest.com/pin/605804587362494274/). The two gears rotate together, providing the input for the two four bar linkages. Since the mechanism is a four bar linkage, it can be easily analyzed once dimensions are decided. Design for the arm is still in an early stage. The actual mechanism to change the end position of the claw is not determined at the time of this writing.
