ROBOTIC ARM

Abstract

The goal of this study is to create a model that can be used to design and manufacture cost-effective robotic arms by
relating desired performances to the components that are necessary, their composition, and their cost. To establish
this connection, one must be well-versed in the ideas of performance speed, power, accuracy, and precision.
Rotational speed is a common measure of speed when discussing electric motors. The amount of force that a motor
can transmit via an arm is called its torque, and it is a measure of its strength. The grouping of rounds determines
their precision, whereas accuracy measures how near an average of many bullets is to the target's center. A robotic
arm is comprised of many supporting components, the most important of which are the motors, bearings, and frame.
All of these components are chosen according to the user's performance requirements.
While servos and stepper motors require distinct mechanics and electronics to operate, they are both commonly used
electro motors in arms used in residential and professional settings. In general, servos are more costly, have more
features (such as internal position feedback, a feedback loop that can be connected to the outside world, and greater
running speeds), and produce more torque. Stepper motors are often less expensive than servos, operate at low
speeds, lack internal position feedback, and may be equipped with a gearbox to enhance torque. The formula for
determining the necessary motor torque and, by extension, the motor's resolution, will be presented in this article.
Deep groove ball bearings and angular contact bearings are the most common types of bearings used in robotic
arms, however there are many others. Angular contact bearings work well with modest axial and radial stresses,
such as those experienced at the arm's rotating base or inside the arm itself when dealing with high inertia. Deep
groove ball bearings excel in applications where radial loads predominate, such as in an arm that handles low inertia
loads. You may get the internal radial clearance by multiplying the bearing's bore and outer diameter by the arm's
length; however, this leads to system imprecision, which is necessary for smooth and consistent bearing functioning.
Using tubular material for the robotic arm's frame is recommended when the arm will be exposed to strong forces
perpendicular to the arm. The optimal strength-to-weight ratio is achieved by using sheet metal when the arm is
mostly used for light lifting loads. In order to improve this ratio, it is advised to use theoretical optimization tools.
The displacement under load on the arm may be calculated using other modeling or finite element tools. In order to
verify the accuracy of the models discussed in this article, a working prototype was created using the data given
here. It was determined that the motor size model was correct. While the model provides a good approximation of
the endeffector's accuracy, it fails to account for manufacturing errors.