Robotic Manufacturing Cell

From Mindworks
Jump to navigation Jump to search
Work Cell
Team Name CyberCrew
Sponsors
Team Members
  • Iulian David
  • Mark Leitner
  • Faihan Aldouseri
  • Abdulmuhsen Alhajeri
Duration Summer 2018 - Fall 2018
Faculty Adviser Dr. Steven Beyerlein
Mentor
  • Ankit Gupta
Client
  • University of Idaho ME department

The Integration of two robotic entities into a miniature assembly line, in order to make a product involving operations of barcode scanning, part manipulation, fixture design, and supervisory control.


Problem Definition[edit]

In past projects, teams have not been able to integrate the two robots into one process. Our goal this year is to ensure this happens. New end effectors will be necessarily designed in order to assemble the products. The final process, put simply, will be to mechanically sort through various male and female pieces using a ramp. Once the two are separated into their respective destinations, the arm will grab the male pieces, scan them, and place each into their respective destination in the construction zone, then grab the female pieces and place them on top of the male ones. The other robot will then push the pieces together using the constructed end effector. Afterwards, a conveyor will distribute the pieces. This way, the two robots will be working together in one manufacturing process.


Background[edit]

2013-2014 In Spring 2013 The Boeing Company donated DENSO robotic arms to The University of Idaho College of Engineering. That fall Mechanical and Electrical Engineering students, as a part of Team Roboshow, were tasked to learn basic programming of the robotic arms and create a work-cell for the arms. Their work-cell incorporated multiple safety features as well as a clear poly-carbonate enclosure for public demonstration. The team was able to successfully program the robot to use a dry-erase marker to create logos and patterns on a white board.

2014-2015 The following year another design team, known as Team Vandalbot, was formed to design a manufacturing process which could assemble various rivet and nut-plate assemblies in order to automate a repetitive task currently done by factory workers. The team was able to demonstrate this process and provide documentation for future teams.

Summer-Fall 2016 During the Summer and Fall of 2016 Do All Robotics completely redesigned the robotic manufacturing cell. They made the cell larger which allowed for operators to have easier access to the robots for things like maintenance or changing end effectors. They also made the work cell fully modular allowing future teams to rearrange the cell for their specific needs. New pedestals for the robots were also designed because the originals were very unsteady. The team also performed stress analysis on the new pedestals to ensure they wouldn't break or fall over during operation. The team also programmed the robots to do tasks such as stack cups and write with a marker on a board. Finally the team also created a simple beginners manual that included all the basics needed to run the robot.

Summer-Fall 2017 The next year, the design team for the Robotic Arm Manufacturing Cell, Team CSRM, integrated a simple vision system involving a scanner, so that the arms could sort through two varied parts. These parts, a rectangle and a hexagon, were created by the team members, as well as the fixtures these parts were based in. Their process involved one of the robotic arms picking up pieces from a randomized mixture, then scanning the object to sort between the two. To pick the objects up, the robot used a pneumatic gripping mechanism.

Client Needs[edit]

Our client is Ankit Gupta, the professor for the industrial automation class. Working on this project could inspire future assignments for the class, as well as requests for perhaps even more progression for students to learn about these robotic arms. This will enable enhancements to improve the class. As the request for this specific project, we are tasked to integrate the two arms into one manufacturing process. Other requirements involve using the scanner to “see” which part is which: male or female. In order to perform this process, unique end effectors and fixtures will need to be designed, which will be available for future class use as well.


Deliverables[edit]

  • Incorporate two robots in one manufacturing process
  • Design and construct male and female parts
  • Design and construct end effectors to assemble the parts
  • Design and construct an incoming queue ramp
  • Design and construct a fixture for the assembled part
  • Use the scanner to sort through various pieces
  • Design and construct a conveyor
  • Integrate all 4 equipment to work together

Design Specifications/Constraints[edit]

Device Specification Variable Limit
Robotic Arm Fixture Mass 5 Kg
Robotic Arm 1 Gripper Pressure .39 MPa
Robotic Arm 2 (Nr. 196-549) Arm Maximum Coordinate length 762 mm on x-axis
Ramp Female Slide Angle 40°
Ramp Male Slide Angle 62°
Conveyor Maximum Belt Tension Force 5 lbf for 0.139 HP Motor
Conveyor Kinetic Friction Nylon-Dry Aluminum μ=0.21

Project Learning[edit]

  • Step 1: Load queue, establish connection with Arduino (Operator loads assembly parts into the ramp, checks Arduino Serial Monitor for connection)
  • Step 2: Exit Cell (Operator departs manufacturing cell)
  • Step 3: Start Program (Operator executes code)
  • Step 4: Scan Males (The males are grabbed out of the ramp and scanned for color type with bar code scanner)
  • Step 5: Move males to intermediate storage (Robot 1 (R1) will move males to intermediate storage as the base of assembly)
  • Step 6: Scan Females (The females are grabbed out of the ramp and scanned for color type with bar code scanner)
  • Step 7: Move females to intermediate storage (Robot 1 (R1) will move females to intermediate storage as the top of assembly)
  • Step 8: Assembly (Robot 2 (R2) will push female part with designed "Finger" end effector, clamping the pieces to create assembly)
  • Step 9: Moving Assemblies to Conveyor (Robot 1 will move each assembly to a specified location on the conveyor)
  • Step 10: Turning on Conveyor (Robot 2 will move over the scanner to send a signal to the Arduino)
  • Step 11: Distribution (Conveyor will turn on and move all of the assemblies to storage)
  • Step 12: Product Storage (Final assemblies will be placed in a box once it is put together)
Flow Chart Description
Manufacturing Flow Chart
Initially, before the program is started, an operator needs to both load the ramp queue with the male and female parts. Each will fall into its own lane. The operator also needs to ensure a connection is established with the Arduino. The operator then must leave the cell. The male parts are scanned and distributed to the assembly zone. Each color has a set location in the zone. Once the three males are in their destinations, Robot 1 will then do the same with the female parts, scanning to determine color, and placing each onto the respective male. Robot 1 stops in a specified location to clear the way for Robot 2 to push the assemblies together. A TCP/IP signal is sent from Robot 1 to Robot 2 to tell it to move. Once the parts are assembled, Robot 2 will send a signal to Robot 1 to pick up each assembly and place them onto the conveyor belt. When this process is completed, Robot 1 will return to the same position as before and send another signal to Robot 2 in order for it to move to the scanner, which will send a signal to the Arduino. When this signal is received, the motor will turn on, moving the conveyor belt and distributing the aseemblies.

Design Solution[edit]

Proof of concept[edit]

Primary Achieved Goal Description Methodology
2018 CyberCrew preliminary process.gif
Initially we had three choices to implement the connection between the two robot arms.
  • MINI I/O Method - as shown in the first segment of the picture, Mini I/O represents a vast number of ports, but only 8 of them have the capacity to connect different devices. The problem consists of a time consuming process of reconnecting devices. Any devices have to be soldered to be connected. Mini I/O, as mentioned before, has a limit of only 8 devices able to connect, meaning that every time one will need to put any other devices, it will require the disconnection and soldering of the color coded wire back. We decided to figure out another way of sending the signal between robots.
  • Scanner Signal - In the second segment of the picture, the bar code is shown under the robot arm. This is one way to send a signal to Robot 2, but in this case both robots serve as clients, and the bar code scanner is the manipulator of them. When Robot 1 is done with its task it goes and scans the bar code which serves as a command for Robot 2 to start its task. The problem with this method is several extra movements which results in increasing the cycle time and increasing the energy consumed. It also requires more feedback to connect other devices.
  • TCP/IP - This method is shown in the third segment of the picture. This is the best method to connect two robots to communicate with each other. The connection between IP's of two robots happens via an Ethernet hub. The best thing about this is it allows one to connect a vast number of devices which support IP protocol. When IP protocols are established it is much easier to connect devices because it eliminates physical wire connections.
2018 CyberCrew Methods.JPG

System Architecture[edit]

Solid Model Description Physical Model
Cell Layout
The room layout has a diagonal equipment arrangement which allows Robot 1 to make a 180° rotation from the beginning of the process to the end. This arrangement seemed to be the most efficient way to assemble and deliver the part.
Cell Layout physical

Part Design[edit]

Male and Female Parts
2018 CyberCrew MalePart.PNG
2018 CyberCrew FemalePart.PNG
Final Design

The manufacturing cell will operate with two unique types of parts: male and female. During the process, male parts will serve as a bottom base of the whole assembly and the female part will be placed onto the top of the male part, creating the final assembled product. There will be 3 assemblies with free different colors: Gold, Silver, and Black.

The Male part has:

  • Design Software: 3D SolidWorks
    • 2" height
    • 2" outer diameter
    • 1-0.001" inner diameter of rod (slip fit)
    • 1" rod height

The Female part has:

  • Design Software: 3D SolidWorks
    • 1" height
    • 2" outer diameter
    • 1" inner diameter (slip fit)
    • hollowed through
  • Manufactured: Sindoh 3D Printer
  • Material: 100% PLA (plastic)


Male part has a channel for the o-ring which serves the function of clamping the two parts together.

Ramp Design[edit]

Solid Model Description Physical Model
3D Ramp Assembly
The ramp is designed to sort the male and female parts. In the Robotic Manufacturing Cell the ramp is the first station to deliver the parts. The top base of the ramp is designed to have a 20° slope in the x-direction and a 45° slope in the z-direction, that way all female parts slide to the left side and all male pats slide to the right side because of the angled plate attached right above female side. This obstruction limits the access of the males to only the left side of the ramp for male parts and guides them straight to this side. In the physical picture , it can be observed that each end of the slide has a special end fixture designed exactly for the parts, and they are removable. The slope of each slide is different because of the different centroid of each part, which is calibrated to slide not very fast and not very slow, and to dump over the end fixtures of the ramp.
Physical Ramp Assembly

Push Finger Design[edit]

Solid Model Description Physical Model
3D Push Finger full assembly
3D Push Finger Exploded View
Push finger designed for Robot 2, functioning by pushing the assembly together until it clamps.

The total length of the end effector is 7.5 inches and it is composed of:

  • Plastic End (it is made 100% PLA (plastic) manufactured by a 3D printer to not impact the parts as the robot pushes the pieces together)
  • Front Washer (it is made of steel and serves as a stop for the spring at both ends)
  • Hollow Cylinder (it is made of aluminum 6061 alloy, and it serves as a base trajectory for spring)
  • Cylinder Base/Cylinder Holder (it is made 100% PLA (plastic) manufactured on a 3D printer. Serves as a holder for the aluminum cylinder which drives straight through the holder and supports forces from the spring through washer.)
  • Back Washer (made of brass and manufactured using a CNC lathe and manual mill machine. The main function is to stop the spring from expanding. It also serves as a way to adjust end effector stiffness.)
  • Adapter (made of 100% PLA (plastic) and manufactured on a 3D printer. The main function is to connect the end effector to Robot 2.)
Physical Push Finger Assembly

Gripper Design[edit]

Solid Model Description Physical Model
3D Gripper full assembly
3D Gripper Exploded View
The Gripper is used by Robot 1 to grab the parts of the assembly and put them in the desired places.

The material used for building this end effector is 100% PLA (plastic) for the claws, manufactured in a 3D printer. The Gripper arms are made from aluminum manufactured on the CNC Mill Machine. The claws were made from PLA material because it was necessary to maintain the flexibility to change the claws if it was decided a different shape of parts were required. The 3D printer makes this manufacturing process quick and easy. The parts have a 2 inch diameter, which was why we maintained the 2 inch diameter between the claws.

Physical Gripper Assembly

Fixtures Design[edit]

Solid Model Description
Storage

The figure represents the assembly storage. Robot 1 will grab the parts and place each in the spot designated, based on the bar code. Each part has a different color, and therefore a different barcode, so each part has its own location. In this station the assembly process takes place, requiring the function of both robot arms. The storage fixture has a capacity of 3 assemblies, as shown in the figure. The material is wood, and the manufacturing process utilized was the laser cutter. Hole dimensions are also shown as can be seen.

Barcode Scanner[edit]

Physical Model Description Technical Manual
COGNEX Dataman 260
The Barcode Scanner has one of the main functions in the manufacturing cell. It functions to scan, recognize the parts, and give relay a string to Robot 1. The scanner has resolution of 752 x 480 pixels. The other specifications you can find in the Reference Manual attached to the following link → Scanner Reference Manual, Scanner Quick Reference Manual
Scanner Range

Conveyor Design[edit]

Solid Model Description Physical Model
3D Conveyor Assembly
For delivering the finished parts to the final destination, we built an automated conveyor belt. The conveyor frame is built from 8020 aluminum profiles of 6061 series alloy. The belt is made from rubber material on the top and the bottom (drive side of the belt) is made from a material close to that of Nylon. The friction coefficient obtained experimentally between two surfaces (Dry Aluminum and the Unknown Material) is 0.21, which is close to the friction factor of Dry Aluminum and Nylon.

The frame of the Conveyor consists of two parts. Part one is the Base Frame, which presents the longest base side of the frame. The second part of the frame is the adjustable part, designed specifically for tightening the belt. The belt also has a tightening mechanism which is shown in the pictures, made with a 6" long bolt screwed into a tightening mechanism base attached to the base frame. The 6" tightening rods have a cap at the end which serves as a concentric part for the contact point between the base frame and the adjustable part of the frame. On top of each side of the frame, a ruler can be located, which helps define the tightening force in pounds per each unit of the ruler scale defined experimentally and described in technical documentations.

Physical Belt Conveyor Assembly
Conveyor Control Equipment
Equipment Description
Stepper Motor
The Conveyor Belt is driven by a Nema 23 Stepper Motor, which has a maximum torque of 1.8 N-m at 60 RPM or less and a power supply of 24VDC. The transmission to the shaft is provided by the combination of two 3D-printed timing pulleys and a T159 series timing belt. The gear ratio is 2 to 1.
Stepper Driver
The Stepper Motor is driven by a stepper, and as is shown in the picture, it can control the Torque and RPM by changing the Pulse rate. The highest Torque will be at 4.20A from the Table.
Arduino Ethernet
To integrate the Conveyor in the automated system, we used an Arduino with Ethernet IP function, to be able to connect the conveyor via Ethernet to an already installed hub.
Circuit Diagram Assembly
Physical Circuit
Wiring Diagram
Circuit Box Physical

Design Validation[edit]

Air Hoses[edit]

2018 CyberCrew Design Validation 1.JPG

Arduino Connection[edit]

2018 CyberCrew Design Validation 2.JPG

Conveyor Belt Connection[edit]

2018 CyberCrew Design Validation 3.JPG

Conveyor Alignment[edit]

2018 CyberCrew Design Validation 4.JPG

Team Members[edit]

Team "CyberCrew"
Member Biography Discipline
Iulian David
2018 CyberCrew Iulian.jpg
I am originally from Moldova, which is a small country in Eastern Europe. I always liked to disassemble different mechanisms and take a look at what was inside and how it worked, that is why I decided to pursue mechanical engineering. In Moldova I finished 3 years of the Mechanical Engineering program in Technical University of Moldova, then I decided to move to the USA. After a couple years living in the USA, I transferred all my credits to University of Idaho to continue my studying in the same program. Now I am a Senior in Mechanical Engineering program at University of Idaho and I am going to graduate in December 2018. My goal is to obtain the maximum experience and knowledge to be able to invent something new, which will make life easier. Mechanical Engineering
Mark Leitner
2018 CyberCrew Mark.jpg
Coming from Richland, Washington, I grew up in the Hanford area. It seemed everyone who lived around me was an engineer. However, it took me a while to realize that I actually wanted to pursue this. After switching majors a couple times, I realized that I missed math, so I switched into the major my sophomore year. Some eventual goals of mine are to live somewhere warm, travel, and have a job that can support my terrible spending habits. Mechanical Engineering
Faihan Aldouseri
2018 CyberCrew Faihan.jpg
I am from Kuwait, which is located in the Middle East. I was born and grew up in Al Ahmadi which has two sides: civilian and industrial. In addition, I graduated from high school and started studying in the famous college of Kuwait starting in 2006. After several years through working as a diesel mechanic and industrial inspector, I realized that I have to complete my studies to improve my knowledge and lifestyle. l like mechanical engineering because I always helped my father to do mechanic stuff on our farm. Mechanical Engineering
Abdulmuhsen Alhajeri
2018 CyberCrew Abdul.jpg
I am from Kuwait. It is a small country but there are lots of companies due to the oil we have back home. So, engineering is an important major to learn and bring back home due to the many companies. I chose Mechanical engineering for two reasons. First, because I like working with machines. Second, because this major has a good future. I hope to gain experience as quickly as I can. Mechanical Engineering

Additional Documentation[edit]