# Low-Cost Automation for Gravity Compensation of Robotic Arm
## 2 Related Works  
In this section, the most relevant works and researches related to the development of robot control systems based on open-source software and hardware are analyzed. The research approach proposed in this work is also described from a technical point of view, which will allow it to be related to different control platforms. Due to their great capacity for performing repetitive tasks that can mean a problem for people's health, the implementation of robotic arms is a powerful alternative as part of automation, in addition, robotic arms have great precision and control over different processes such as welding, painting, agriculture, foundry, palletizing, assembly and loading, and unloading applications [4; 5; 6; 7]. Several research works [8; 9; 10] describe the design and prototyping of the gravity compensation used in modular robots and provide examples of robot shapes configured using the gravity compensation modules and motion experiments of the robots. In the experiments, some motionsthat the robots could perform and could not perform are considered due to the lack of the gravity compensation level and module rigidity as the main factor of the failures. A novel example about robotic applications is presented in [11], where the assistance of robotics and automation allows an advanced drilling system to be developed through technological innovation that minimizes risks and provides greater efficiency and safety resulting in more controlled production. Also in [12], it is mentioned that robot applications together with the Internet of Things (IoT) can make possible the development of advanced services that consolidate design methodologies based on distributed architectures, making possible the interaction between controllers of different origin, allowing a cross-platform work approach for generalized environments. With the great use of robots at the industrial level, the ROS framework has been developed as a potential alternative for the control and development of robotic applications. In the research work presented in [13], software for robots is defined as a complex code to perform, because it requires large-scale software integration, this due to the compatibility that must exist between controllers and the perception between sensors and actuators. One way to manage this complexity is based on the application of ROS, mainly due to its compatibility with Open Source based systems, which allows integration and implementation on different hardware requirements. As presented in [14], the adoption of ROS as a design platform for robotic applications has allowed the community of researchers to develop advanced mobile handling services through the control performed on the robot hardware, leading to the use of multiplatform systems which currently show greater compatibility thanks to the integration of ROS. The evolution in robot programming has led to the development of different control algorithms, through which you can send several types of messages to the actuators in a way that allows interaction with the objects to be manipulated within the real environment to improve this interaction. As specified in [15], both for rotary or prismatic joints, its accuracy can be improved by modifying the control in its joint space because the control over the Cartesian space entails greater difficulty. It is necessary to make a good control over the joints because an incorrect follow-up of the proposed trajectories could cause inaccurate movements causing damage to the robot or incomplete tasks. As an example, in the work presented in [10], a collection of packages consisting of different controllers and tools for the KUKA youBot is highlighted, where three different control, position, speed, and torque methods have been implemented, demonstrating through control tests, results with submillimeter precision. Various design concepts for gravity compensation are available in the literature. The actuator power needed to support joint torque in a robotic arm caused by the weight of robot links can be a huge problem.