Editorial Feature

Building an End-Effector for Robotic Control

An end-effector is the device at the robotic arm end that is designed for interactions with the environment. The nature of the end-effector is based on the use of the robot. In strict terms, the end-effector is the last link or the end of the robot. Tools are fitted at this endpoint. The wheels that make up the feet to a humanoid robot are not end-effectors, they simply aid the robot’s mobility.

Types of end-effectors include:

  • Mechanical grippers
  • Negative pressure (vacuum)
  • Magnetic
  • Hooks
  • Ladles (scoops liquid or powder)
  • Others (electrostatic).

The gripper may have two, three, four or even five fingers. Four general categories of robotic grippers include:

  • Impactive – claws or jaws that grasp physically by direct impact upon the object.
  • Ingressive – needles, pins or hackles that penetrate physically the object surface used in carbon, textile and glass fiber handling.
  • Astrictive – suction forces applied to the surface of the object by magneto, electro or vacuum adhesion.
  • Contigutive – needs direct contact to enable adhesion such as glue, surface tension or freezing.

Research

Verma A et al (2011) published a study on the end-effector position analysis of SCORBOT-ER Vplus Robot. This paper details the kinematic analysis of SCORBOT-ER Vplus robot arm that is used for performing successful robotic manipulation tasks in its workspace. The SCORBOT-ER Vplus is a vertical articulated robot with five degrees of freedom and all the joints are revolute as is demonstrated in the following video:

Programming Scorbot ER V @ UNB Robotics

This study used the Denavit-Harbenterg (D-H) model of representation to model robot links and joints along with a 4x4 homogeneous matrix. This is a safe and reliable robotic system designed for training and laboratory applications. This system enables students to gain practical and theoretical experience in automation, robotics and control systems. For a set of joint parameters, the MATLAB 8.0 is used for solving this mathematical model.

Toklu E et al (2011) identified the need for a novel range of end-effectors, which is suitable for non-rigid products and introduced a new non-contact gripping device. The operation of the end-effector is based on the principle of generating a high speed fluid flow between the product surface and the end-effector hence creating a vacuum that levitates the product. Finite element analysis and optimization methodology are used to discuss the lifting forces and conditions. The end-effectors were optimized to lift non-rigid food materials such as jelly blocks.

The results showed that the non-contact end-effectors developed based on numerical analysis results are highly successful and these are applied to handle non-rigid and rigid materials with smooth surfaces. A vacuum is caused by the radial flow through the nozzle. The vacuum created is capable of lifting materials with porous surfaces and structures covered by viscous substances.

Current Applications

End-effectors are designed to suit a range of applications as detailed below:

  • Welding robots normally perform spot welding. A spot welder is mounted to the robot and the robot is used to position the welder at each weld point.
  • Assembly robots are commonly used for assembling especially in manufacturing setups. Here a robot will normally have a vacuum cup or a pneumatic gripper to move parts through the process.
  • Painting or spraying robots use a small spray gun as the end-effector. They have special equipment to ensure that no sparks are generated. They are mostly equipped with a coat that prevents paint from collecting on the arm surface. The coat is a consumable and changing the same is quite easy. In this application, the robot’s reach is quite critical as the robot should be capable of spanning large distances.
  • NASA has two robots that are popular, each of which have distinct end-effectors. Dextre has a retractable socket drive and built-in grasping jaws. The end-effectors of NASA’s most recent humanoid Robonaut are very similar to human hands.
  • The end-effector of a dispensing robot is a hot glue gun. It is important to maintain the surface velocity and also the angle of application.
  • Inspection robots use vision systems, lasers, or other types of measurement tools as an end-effector. The path or velocity of the robot is not critical here but the end-effector needs to be positioned correctly for maximum performance.
  • Material handling robots range from palletizers to machine loading and unloading robots.
  • Material removal robots may include those that pick a part and present it to a cutter and robots that wield a material removal device or a cutter.
  • In the medical sector, the tele-operated da Vinci medical robot has tool tips that include robotic scissors, robotic forceps and a robotic scalpel.

Future Developments

Companies such as Comau Aerospace are developing advanced end-effectors, which combines fastener insertion and drilling operations into a single unit. It is possible to mount the same onto a robot or other machines.

The end-effector is lightweight as well as reliable, robust and accurate. All required components are housed onboard to create a single, turnkey solution end-effector with a number of functional packages.

Sources and Further Reading

  • Allyson Pulsipher and Kasey Greenland. End Effectors. 2007.
  • Toklu E and Erzincanli F. Investigation of flow and vacuum lifting force on a non-contact end effector for robotic handling of non-rigid material. Scientific Research and Essays. 2011;6(29):6152-6161.
  • Owens Design – End Effector Selection and Design.
  • Verma A and Deshpande V.A. End-Effector Position Analysis of SCORBOT-ER Vplus Robot. International Journal of Advanced Science and Technology. 2001;29:61-66.

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of AZoM.com Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Citations

Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Kaur, Kalwinder. (2019, April 17). Building an End-Effector for Robotic Control. AZoRobotics. Retrieved on December 13, 2024 from https://www.azorobotics.com/Article.aspx?ArticleID=88.

  • MLA

    Kaur, Kalwinder. "Building an End-Effector for Robotic Control". AZoRobotics. 13 December 2024. <https://www.azorobotics.com/Article.aspx?ArticleID=88>.

  • Chicago

    Kaur, Kalwinder. "Building an End-Effector for Robotic Control". AZoRobotics. https://www.azorobotics.com/Article.aspx?ArticleID=88. (accessed December 13, 2024).

  • Harvard

    Kaur, Kalwinder. 2019. Building an End-Effector for Robotic Control. AZoRobotics, viewed 13 December 2024, https://www.azorobotics.com/Article.aspx?ArticleID=88.

Tell Us What You Think

Do you have a review, update or anything you would like to add to this article?

Leave your feedback
Your comment type
Submit

While we only use edited and approved content for Azthena answers, it may on occasions provide incorrect responses. Please confirm any data provided with the related suppliers or authors. We do not provide medical advice, if you search for medical information you must always consult a medical professional before acting on any information provided.

Your questions, but not your email details will be shared with OpenAI and retained for 30 days in accordance with their privacy principles.

Please do not ask questions that use sensitive or confidential information.

Read the full Terms & Conditions.