Robotic Workstation

The Roboshow Senior Design team is tasked with designing the safety enclosure and workstation for one of the Denso robots to showcase the robots capabilities to students, faculty and visitors and provide a safe and reliable research platform for advancing robotic technologies.Our goal is for the robot enclosure have a lasting influence on the engineering department by advancing graduate research and providing applied teaching to undergraduates. We also want the robot to be a showcase to attract future students.

Background
In the spring of 2013, The Boeing Company generously donated multiple Denso robot arms to the College of Engineering of the University of Idaho. These lightweight, compact robots are designed for a wide-range of industrial and manufacturing applications. A description of Denso’s VS-G series can be found here: http://www.densorobotics.com/products/vs-g-series/features. The Mechanical Engineering department is currently exploring ways in which to incorporate these robots in the curriculum and to make them available for academic and sponsored research. During the first stage of this process, the Mechanical Engineering department is looking to grow its institutional knowledge through the development of a mobile robotic research station.

Design Task
The task is to design and build a portable industrial robot research station featuring a Denso Robotic Arm. The completed design should include a mobile platform for the robot arm, including a transparent safety enclosure, an installed and tested teaching pendent and controller software, and a manufactured end-effector for use in a demonstration of the robot’s capabilities We are tasked to design a safety enclosure that conforms to industrial best practices and applicable standards and demonstrates relevant academic and research activities during high visibility university events.

Enclosure Design
Relatively mobile Multiple Safety redundancies Modular Integrated controller storage Expandable to multiple robots Fit within freight elevator Arm must fully extend in x,y, and z directions without collision
 * Have wheels or ability to be transported
 * Easy to move, and disassemble
 * Door Switches, Light Curtain, Protective glass/wire mesh, and emergency stop button
 * Easy to replicate for future projects and combine with other enclosures
 * Industrial electronic storage box, RC7 controller mount
 * Storage under enclosure
 * Max dimensions to fit are 46”x84”x78”
 * Full extension should include length of the end effector
 * Arm X and Y radius is 34”
 * Arm max height is 43”

Timeline
2/21/14 Design Review 3/11/14 3rd Snapshot 3/31/14 5/2/14 Engineering Expo
 * Finalized enclosure design
 * End effector design options
 * End effector prototype
 * Enclosures assembled

5/9/14 Client Handoff
 * Operation Manual finished

Parts
Robot Controls Enclosure Materials

Current Safety Features

Previous Safety Features

Our previous ideas for safety are either replaced in functionality by the eGard or dropped from the project due to cost. One of the first things we wanted was a safety light curtain. It would shut off the robot if anything passed through the light gates; however it would use to much of the budget and could just be replaced with polycarbonate. Before we found the eGard, we were looking at individual safety modules which would be connected by relays, but the eGard has everything we need and is in one system.

Testing
Since we haven't finalized the enclosure design yet the only testing has been on the robotic arm. We wired the the safety controls have been running it in a controlled environment.We have been testing programs in WINCAPs then using the pendant to run them. So far, we successfully ran a number of programs including: drawing a sine wave, drawing an I,drawing a circle, and drawing a square while not rotating the last joint.To visually see the programs, a whiteboard frame and marker holder were developed so that the robot can actually draw on the whiteboard. IBmnc8pH23A

Current Design
3 Piece Design

 The design was chosen for functionality as well as aesthetics. The polycarbonate keeps everyone safe but allows a full viewing and teaching experience with the robot. The robot will be moved only occasionally so simple parts are favored over complex deconstruction methods. The three piece design has one main piece and two side pieces. The main piece is larger and holds the robot as well as the electronic equipment below the robot platform. The two side pieces hang on opposite sides of the central piece. The sides are attached as shown with the brace.The design is simple and uses fewer parts. Fewer parts make disassembling and regular maintenance easy.The frame also features 80/20 on the base to allow the robot's origin to be moveable. To save on cost the prototype is using plywood for the base.

Safety Measures
Safety is a major concern with the enclosure. We researched and incorporated OSHA and NFPA standards into our design to give a more professional level of safety. The main safety system is regulated through the eGard. The eGard will also support switching from the computer to the teaching pendant with a toggle switch.

End Effector
We want an easy to implement and relatively simple end effector for research. We narrowed our options down to two designs. We discovered that it can be less expensive to buy an end effector than put in the money and time to make one ourselves. The end effectors we looked at follow the same mechanics generally but are already guaranteed to work.

Linear Actuator
The linear actuator is the simpler of the two. It maintains constant contact and a servo motor turns to open and close the grip. Currently the design doesn't close all the way but with modifications it could.

Rainbow Claw
The rainbow claw is efficient but complicated. The claw can grip better and is more compact than our other design. It features more moving parts and the claw extends as it closes.

Previous Designs and options
Two Piece Design

Our first conceptual design was the two piece design.The two piece design uses two identical sides to make up the enclosure. Separation of the enclosure is needed to fit on the service elevator for transport. The partitions are depicted above. The robot is affixed to both sides in the center.The front and back use polycarbonate sheets and a wire mesh is used for the doors. The lower portion of the design will store the controller and safety equipment on one side. The other side can store objects for demonstration such as an armature. Caster wheels are used on the bottom.

Collapsible Design

The collapsible design is made of one central piece with two attached sides. The design is similar to the 3 piece, but instead of having sides that can be removed, the sides collapse to minimize space like an accordion. The sides also have supports that reach the ground instead of hanging, but still remove the shelving on the lower portion. 

Design Options
Safety light curtain

We have decided that the light curtain was not cost effective for the project but it may be beneficial for other projects.The safety light curtain can be used to have a completely open viewing area on one side of the enclosure. A problem is if the robot is manipulating an object the curtain can't stop the object if it is thrown past. To fix this, we can use a detachable polycarbonate sheet when objects are being used otherwise leave it off.

Top of enclosure

The top of the enclosure will likely be a simple mesh covering. The top shouldn't interfere with visibility, but a top may be wanted to keep objects out. However we the enclosure is tall enough that it would be difficult to put an object over the top. As a result we haven't finalized what to do with the top.

Base

We have decided to use legs instead of wheels however there are some tradeoffs. The base design can use wheels or just legs on the ground. With wheels, the enclosure can be pushed around anywhere. Another option is just have it lifted by a jack and transported. Getting rid of the wheels would improve stability but might hurt mobility since some parts would need to be carried until we got them to a jack.

Multiple safety redundancies

We do want multiple fail-safes but we want to design around an informed operator currently. We use safety procedures to supplement a lack of automatic safety checking. For example, instead of having magnetic switches on the sides we can just have the operator perform safety checks on the sides.

Team Experience
 Our Team 





