Assembly and palletizing of Space Frame using Fanuc M10ID/12 Robot

The project seeks to address the need for automation in manufacturing through the process automation of assembly and palletization of a versatile and modular “space frame” using a popular robot whose simulation is easily comprehensible and doable, with the same being readily transferred to the real robot assembly environment able to accommodate changes in frequency and variability of the process.

Space Frame

A space frame is a modular and robust structure which can be used as a unit of assemblage for fences, panels, cages, tiles, etc. It can also be used as support structures during construction work. They have potentially higher resistance towards varying temperature & wear and can have the capacity to withstand high loads, given the right design, fabrication and securing mechanism. It can also have a high degree of reusability, as well as easy maintenance and repair

Fanuc M-10iD/12 Robot

The FANUC M-10iD/12 robot is used for the purposes of this project. It is a versatile 6-axis robot with high axis speeds and precision. It has a payload capacity of 12kg while the robot, itself, weighs just 145kg. It also boasts a reach of 1441mm. It has a repeatability of 0.02mm and an articulated structure. It has floor, upside-down and angle mount capabilities.

The M-10iD/12 robot in the lab comes fitted with the following grippers as standard.Electromagnetic Gripper,Vacuum Gripper,2-Jaw Gripper,3-Jaw Gripper.But inorder to Automate the above process we have used only the Magnetic and Vacuum gripper

Objective

Methodology

Design of Space Frame

The design of the space frame had to be done considering the constraints we were dealt with. The available work volumes in the laboratory, the grippers available for use, the payload of the robot, material costs, ease of fabrication, and suitability for industrial application were the chief criteria that determined the design of the space frame.

Design of Fixtures

The default fixtures and layout of the laboratory work environment necessitated the inclusion of separate fixtures on which to carry out the assembly and palletization processes. The weights of the individual parts and assembled frames, dimensions of the parts and the frames, magnetic properties, dimensions of work environment, distance from robot and material costs were the design considerations.

Fabrication

The designs were submitted to an independent third-party contractor. The fabrication was done as a joint effort by the aforementioned professionals and the members of the project team under their supervision.

Simulation

The simulation had to be done using user-friendly and accessible software. The software chosen for this was FANUC’s own ROBOGUIDE 9.10. Not only was it realistic and customizable to a high degree, the program written on the computer was directly transferable to the real robot, which needed only fine-tuning afterward.

Detailed Dive into simulating the movenment of the Robot Virtually

Any articulated arm robot has a work volume and any operations involving the robot has to be carried out inside this volume. The work volume of a robot lies between the maximum and minimum reach of the robot. In a perfect world the complete work volume of the robot is available to assemble the space frame but we had additional constraints; some of the noteworthy ones are as follows:

The maximum reach of the M10iD/12 robot was specified to be 1.441180 meters but the protective cages were bolted well before this limit ,due to which the work volume was reduced

The robot M10iD/12 could carry out certain standard pick and place operations for demonstrative purposes using its various grippers, for which certain standard tables were fabricated and bolted in front of the robot. This further limited the available space in the work volume of the robot.

The space behind the robot was ominously occupied by the wires connecting the control system and the pneumatic compressors which are used to operate the two jaw and three jaw grippers. Therefore the operations of the space frame were possible only in front of the robot.

Due to all these constraints a Work Environment Layout was Designed

Work Environment Layout Design

The measurements which were taken to build the work environment is as follows:

The Draft of the Work Environment is shown in the figure

Simulation Softwear

FANUC ROBOGUIDE is a robot simulation software that simulates both the robot’s motion and application commands. FANUC ROBOGUIDE version 9.1 is used to simulate the robot for this project. It allows for easy design and creation of the workspace layout and the placement of required elements within it to achieve the desired application. The robot can be programmed offline and the program can be transposed to physical applications. The simulations carried out in ROBOGUIDE maintain accuracy in relation to the real-world application. On a larger, industrial scale, this reduces downtime and reduces losses in production. Path planning of robot motion is intuitive and accompanied by simple animations. The CAD data of designed components, parts and fixtures can be directly imported to ensure accuracy and realism. Alternatively, ROBOGUIDE itself contains an extensive library of highly efficient, application specific tools to simplify programming efforts

Since this project involves a material handling application, HandlingPRO work cell is used. HandlingPRO is used for applications including loading, packaging, assembly, and material removal. Features of this work cell include CAD to path programming, conveyor line tracking and machine modelling.

Work environment Layout Design on Fanuc ROBOGUIDE

For any robot simulation to be meaningful and transposable to real world applications, the arrangement of various components in the three-dimensional environment of the robot must be at ideal locations within the robot’s reach. This type of arrangement enhances accuracy and optimizes the performance of the robot. FANUC ROBOGUIDE is used to design the layout and environment of the robot. This design is done in accordance to the physical measurements and dimensions taken directly from the college lab in which the FANUC M-10iD/12 is housed.

Many of the components that constitute the layout such as, Parts table, Assembly table, stacking table are designed using CATIA version 19 and the respective CAD files are generated. These CAD files are then directly imported into ROBOGUIDE and integrated into the layout. The remaining components required for the simulation are sourced from ROBOGUIDE’s extensive library of application specific parts and fixtures. These components are then arranged in three-dimensional space at ideal locations within the reach of the robot to optimize its performance.

The above figure shows the completed layout designed in ROBOGUIDE. It is done in accordance to the initial CAD design . However, the dimensions of the guard cage are increased in order to sufficiently accommodate the work volume of the robot. This is only a recommended correction, and the simulation is not dependent on it; in other words, it will work in exactly the same way in the artificially constrained environment of the college laboratory. Once the design of the layout is complete, the robot is programmed to execute the required assembly

Programming the Robots Motion

The programming of the M-10iD/12 robot is done on the Teach Pendant using the multitude of functions offered by the controller. Certain simulation programs are also defined directly in the simulator to supplement the functioning of the robot. These are mainly the pick and place programs that inform the robot about the locations and grippers with which each part is to be picked and placed.

Payload Configuration

The robot payload can be defined as the total weight a robot arm can lift. This includes the weight of the end of arm tooling. The setting of the payload is done using the Teach Pendant. Since the mass of the frame coupled to the gripper and its fixture is much less than 12 kg (which is the payload of the robot) the robot is well within its operational limits.

Position Registers

Position registers are memory allocations that store positional values and coordinates. They are used to record and store coordinates of points within the work cell to which the robot must move in order to perform the desired operation. The locus of these points forms the motion path of the robot

Simulation Programs

Simulation programs are programs that are defined directly in the simulator. These programs allow the addition of instructions such as ‘Pickup’ and ‘Drop’. They are mainly utilized in the stage of the simulation where the gripper is required to actuate to pick up or place a part

The payload configuration ,Position Registers and Simulation Programs are used to in the program which simulates the robots motion on ROBOGUIDE

program

Key Functions in the Program

• UFRAME_NUM: This function is used to set user frame number. Since no tool frames are being used, it is set to zero.
• UTOOL_NUM: This function is used to set user tool number. Since only one tool is used, it is set to one.
• PAYLOAD: It allows for the selection of payload. Here, a single payload of 12kg is defined.
• OVERRIDE: This allows the user to increase or decrease the speed of robot motion without altering the program.
• CALL: It allows for programs stored in the memory to be called.
• J PR[] 200mm/sec CNT 25: This function denotes joint movement of the robot to the position specified in the position register 'PR[]'. '200mm/s' denotes the speed with which the robot arm is to move. 'CNT' represents continuous motion.
• L PR[] 200mm/sec CNT 25: This is similar to the previous function. However, 'L' denotes linear movement. Thus, a linear path is created to the position specified in the position register 'PR[]'.
• WAIT: This is a function that specifies the time (in sec) the robot must remain in the current position before the next command is executed.

There are only two control programs defined and that is Homing and main.The below image shows the complete program

One controller program can also be called inside another. In this case, 'Homing' is called multiple times inside 'Main'. Various simulation programs are also called inside 'Main'. Once the above programs have been entered into the Teach Pendant, the program 'Main' is run to complete the required simulation.

Simulation of the Pick and Place application

The below video shows the simulation of the pick and place application using the Fanuc M10iD/12 Robot

Result

It can be inferred from the success of the process that the objectives the project started out with were satisfied. Each of the criteria considered was met. The primary mission of automating the process was clearly fruitful. The additional adaptability and variability objectives were just as successfully met. The process can be adapted for more than two frames by, among other means, having a conveyor belt feeding the parts to the robot instead of static tables in an industrial environment. Other operations like adding permanent joints (welds, rivets, adhesives, etc) or mechanical locks can be achieved by using suitable grippers, which are both available in the market for purchase as well as on the software for simulation. On the basis of this, it was concluded that the project could be proclaimed a success

Conclusion and Future Scope of Work

The project serves as an initial attempt to understand robot manipulation and its application in industry. While the objectives of the project were achieved, it raises questions about the future, specifically the development of autonomous systems powered by artificial intelligence. However, considerations such as the smooth transition, worker displacement, retraining, safety, and sustainable development must be addressed. Overall, the project is seen as a foundational step towards further exploration and future endeavors in automation.

References

1. J Frohm, Lindstrom, M Winroth, J Stahre, "The Industry’s View on Automation in Manufacturing", IFAC Proceedings Volume 39, Issue 4, 2006.
2. Robert Krug, Todor Stoyanov, Vinicio Tincani, Henrik Andreasson, Rafael Mosberger, Gualtiero Fantoni, Achim J Lilienthal, "The Next Step in Robot Commissioning: Autonomous Picking and Palletizing", IEEE Robotics and Automation Letters Volume 1, 2006.
3. Boubekri, N. and Chakraborty, P. (2002), "Robotic grasping: gripper designs, control methods and grasp configurations – a review of research", Integrated Manufacturing Systems, Vol. 13 No. 7, pp. 520-531.
4. Lihui Wang, Shadi Keshavarzmanesh, Hsi-Yung Feng, Ralph O Buchal, "Assembly Process Planning and its Future in Collaborative Manufacturing: A Review", The International Journal of Advanced Manufacturing Technology 41, 132 (2009).
5. Bram Westerweel, Rob J.I. Basten, Geert-Jan van Houtum, "Traditional or Additive Manufacturing? Assessing Component Design Options through Lifecycle Cost Analysis", European Journal of Operational Research, Volume 270, Issue 2, 2018, Pages 570-585.