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For my senior project, I wanted to create an electro-mechanical project that would best encompass a variety of aspects learned throughout my curriculum at Cal Poly Pomona, as well as my internship which I have participated in for the past year.  It was suggested that I make a motion control system.  This system could take a 2-D CAD file, convert it to G-code, and create the outline desired.  I felt it was a good project and encompassed a lot of electrical/mechanical/software design.

The software tools that I used in the design of this project are AutoCAD Electrical and SolidWorks.  AutoCAD Electrical helped generate the schematics for the inital design of the electrical panel.  These schematics aided in the wiring of our electrical components and provided an overall layout for our panel ( 28.5″ X 28.5″).

Figure 1- Panel Layout

This panel layout shown in figure 1 is a perfect 1:1 ratio for all of the components we used.  It was printed using a large plotter.  Using this we could then drill all of the necessary holes for the wireway, din rail and motor drivers.  The completed panel is shown below in figure 2.

Figure 2- Completed Panel Layout

After powering up the panel using 208 Volts, it was checked for driver errors and shorts along the terminal blocks.  Everything worked great on the initial power up with minimal errors.  Now that the electrical phase is done, I need to house the panel in an enclosure.  Since the project is going to be housed indoors, an enclosure with a Nema 1 rating will work just fine.  The enclosure is a (N1C303612LP) 36 x 30 x 12.63 inch Nema 1 enclosure sold by Automation Direct.  My panel has a depth of about 9 inches, and the 12.63 inch this enclosure provides is perfect.

The next step is to move on to the mechanical aspect.  Currently, we are designing a three axis system( X, Y and Z).  Shown below in figure 3 is our X-axis design.  We are using an aluminum plate for the base, Bosch Rexroth runner blocks and rails to provide support for the Y- and Z-axis.  The ball screw will be used to help drive the plate in the X direction.

Figure 3- X Axis Mechanical Design

As we progress in the mechanical design I will update it with more pictures, along with the overall status of our project.

Update 5/15/2011

Recieved my Nema 1 rated enclosure from automation direct and have put my panel into it.  It fits very nicely, and I have drilled holes to allow my feedback and power cables to run from inside the panel to the motors.  Figure 4 shows the completed panel,

General Design: The design will incorporate a steel constructed ramp designed to withstand 800 lbs of load. The ramp will be actuated by an electric gear motor. The gear motor being utilized is a modified off the shelf auto winch. The winch provides the power necessary to actuate the ramp from a vertical (retracted) position to a horizontal position that would be able to engage any boat dock or platform that is +/- 8 inches of the pontoon boat platform level. While there is plenty of torque from the modified winch, the speed of rotation requires a 20:1 gear reduction. Automation Direct offers a large selection of wormgear reducers. A wormgear has been selected for this application that will be supplied by Automation Direct. There will be more to come as this project progresses.

Pleasantville High School Solar Array (and it’s creators!)

The Industrial Technology students at Pleasantville High School in Pleasantvile, Iowa (southeast of Des Moines) are building a multi-mirror solar hot water heater.  The main assembly is now complete, and the next challenge for the students is to motorize and automate the array so that it can track the sun throughout the day.

The above picture, taken last semester, shows most of the students that designed and started building the solar panel over a year ago.  The project is now in it’s third semester, and many new students have designed parts and incorporated them into the panel.  When the project is complete the hot water will be used to heat the Industrial Technology shop at the school.

The students of Metals class are designing the brackets for holding the gearing and the Automation Direct Sure Step stepping motors for tracking the sun.

The electronics class is researching the circuitry for inputting the sun position info into AutomationDirect’s DL06 PLC which will also be controlling the stepping systems. As the teacher I will take on the task of learning the ladder logic software. Everyone has input from the different subjects so no one gets left out. Our goal is completion of all mechanical parts by mid November with a controlled test of the components. We then plan to uploading the programming software by mid-December.

Check back soon for more updates…

…capacitance capacitors. The use of 10 gauge wire allows us to have low resistance and therefor lower voltage losses. We are making a 3 stage accelerator for our project and we will use about 100 feet to complete the number of wrappings needed to make the three coils.  We will post more details as the project progresses…

Update 9/26/2010

We are one step closer to completing the coil accelerator project, and more details are emerging on the construction.  Our original plan was to use six 10,000 μF capacitors (two per coil), but we could not find a sponsor willing to donate them.  So we decided to try to earn the money to purchase them which was taking some time to accumulate.  As we were earning the money, we were able to get an offer of a donation from Automation Direct of multiple capacitors of a somewhat smaller capacitance, but which would also work.

We also learned that we might be able to accurately time the firing of the pulses of the three coils  with a CLICK PLC (Programmable Logic Controller) from Automation Direct.  The PLC outputs would have to actuate separate solid state relays rated for high voltages and currents involved.

We plan on using a Chrony F-1 chronograph to precisely measure the velocity of the projectiles.

Initially, we will fire only the first coil and record the FPS to determine the exact time the projectile gets to the second coil and so on to set the exact timing of the coils.  Our Science teacher has insisted that we focus on the safety aspects of this project.  One precaution that we are planning to take involves using electrical lineman’s gloves and he told us we might be able to receive them as a donation from an electrical lineman’s college or even the local IBEW union.  We will be contacting them next.  If anybody has a pair (or two) of lineman’s gloves that they are willing to donate, please post a reply…  Thanks!

Update 11/16/10

Our project is coming along quite nicely. We have decided to abandon the idea of the PLC/Relay system and go for what are called SCR’s. SCR’s (or Silicon Controlled Rectifiers) are a semiconductor that act like a very high voltage/current switch. We plan on using 3 per trigger because of their limited power capacity. Another update to our project is that we will be upping the power eventually and use 10 capacitors per bank instead of 5. We were able to acquire a large 40 Watt solar panel donated by Aurora power and Design, along with two Trojan T-105 6v deep cycle batteries, and the 12v solar charge controller to charge them. We are looking to get a 1000 watt inverter and a 400vac step-up transformer to give us the voltage we need, but we may also consider a 800v system by wiring half of the capacitors in series.  If anyone has either lying around that they would be willing to donate, I would greatly appreciate your help.  Some more changes in the project include:

• 1/2 inch diameter pipe instead of a 1.1″ diameter pipe
• the pipe will be PVC instead of Aluminum
• Previously mentioned, we won’t be using a 12v-400v transformer
• A larger solar panel will charge a larger battery bank that powers the inverter, transformer, and any other electronics.
• A larger bank of capacitors will be used.
• Our accelerator will be cart mounted and not handheld.
• Previously mentioned, we won’t be using a PLC or relays but use SCR’s instead.

If you have any questions, feel free to comment and we’ll keep you posted on the progress.

12/17/2010

Our project is slowly moving forward and a few crucial parts are still missing. The most important part at this point would be the SCR’s. We recently contacted Industrial Semiconductor Inc. to see about getting 9 donated. He asked for more details on the project soon after we sent the first email, and he has not responded back since. The coil accelerator cannot function as a 3 stage system without them, otherwise, too much power will be lost.

Aurora Power & Design recently donated a 55 watt solar  panel and 10 A charge controller for our project to charge the batteries, which we have yet to find a donation for, and I went and picked it up. It will be very useful in the coil accelerator project for charging it in the field.

As a bonus of the project, we are looking at cooling the coils with LN2, or liquid nitrogen. Our science teachers told us if we provide the dewar, they’re provide the liquid nitrogen. So we need to find a donation of a 10 liter dewar and then that will cool the coils by a factor of 10, letting us squeeze all the power we can out of it. If anyone knows where we can obtain a 10 liter dewar, please write to us in the comments!

Here are the missing parts:

• 9 SCR’s
• 1000 watt inverter
• 400 vac step-up transformer
• 2 Trojan T-105 Batteries
• Triggering Mechanism for the SCR’s (PLC?)
• Wheeled cart
• containment chambers to house the liquid nitrogen
• 10 Liter dewar

If you have any tips, or donations please write in the comments!

VIDEO: Humanoid Robot \”Hubert 2010\”

I am creating a stationary multi-axis Humanoid Robot that I call the “Hubert 2010.”  Here are the details:

Humanoid robots have been in development for many years and with advances in closed-loop industrial automation technology (Sensors, motion control, pneumatics, PLC’s, & PAC’s) the possibility of using household humanoid robots to help us with daily tasks is becoming an ever closer possibility.

Thanks to companies like Automation Direct, some fortunate finds on Ebay, and company contributions it has been possible to create a potentially advanced and expensive project like mine on a reasonable budget.  I originally was going to drive my humanoid robot with a Parallax basic stamp and interface it with an old Allen Bradley solid state DC output card.  Given the limited capability of the basic stamp to execute multiple functions simultaneously and it’s limited drive current, it would have been unpractical to complete my project using the basic stamp… After months of research I stumbled across AutomationDirect’s CLICK PLC.  Yes, it is practically free and it offers advance functions and unsurpassed simplicity for beginning users of PLC’s.  This little guy is great and pack an unexpected punch of PLC power.

I first purchased a basic CPU model of the CLICK PLC and then upgraded to the more recent analog version of the CLICK PLC.  Within 30 days of working with the CLICK PLC I became fluent with the controller and was already automating my project.  Currently I am driving my robot using the “DRUM” instruction in a “Time Based Mode.”  In order to prevent this robot from crashing I will need a closed loop control system incorporating several different sensors, multi-valving pneumatic techniques and advanced PLC math to serve as a solution to the operation of my Humanoid Robot.

One of the initial challenges of my humanoid robot was the mechanics.   How could I get one multi-axis joint to move without it affecting the movement of another adjoining multi-axis joints?  How can I make everything move with a full range of motion and eliminate binding of each actuator?  How can I electrically control it not to move in a certain direction when lets say its leaning at a 45 degree angle?  There are many challenges presented in such an advanced project and Automation Direct has many of the tools I need to help me with these challenges.  For example, take a look at AutomationDirect’s new line of  ”Nitra” Pneumatics.

If you look at my YouTube video you will see a lot of motion and dancing around of pneumatic components.  At this point it’s hard to make sense of all the motion.  Try to envision a neck, head, arms, and hands when observing this robot in motion.  The video only shows the shoulder “Shrug,” “Pectoral in-out,” and  ”Waist twist” left and right movements.”  But if you look closely you can see that I have already built-in the ability to lean left and right as well as forward and backwards.  At this point I have not yet automated these functions as I am working to incorporate additional sensors for the necessary closed loop control circuitry.

I am using various switches and sensors including: fiber, inductive proximity, capacitive, pezio, laser, and limit switches.  It is also important to utilize flow control  (or “speed controllers” as they are known in the pneumatically world) to ensure the appropriate pressures.  I plan to use a planetary gear assembly and stepper motor to control the arm & lift action of the shoulders when the arms are finished.  Servo motors will be used to finely control the head and neck movements when the project is complete. To complete my control project I plan to add a C-more Micro HMI to initiate the various movements and to monitor and navigate the program.

Automation Direct has all the tools and components one needs to build their own automated project(s).  I wish I had known about them sooner.   Their pricing make possible the  growth of innovation by DIY engineers on a limited budget such as myself and many others!

To move the items, we use a main conveyor with two infeed and two outfeed conveyors attached to it. The two infeed conveyors transfer cargo to the main conveyor as long as cargo in not coming along on the main. If an item is sensed within 100ms of the infeed point then the infeed conveyors are delayed for 200ms or until the photo switch clears.

The two outfeed conveyors remain off until activated by a color sensing photo eye that is programmed to detect 3 colors. When the appropriate color is detected the corresponding conveyor is turned on, and a pneumatic cylinder pushes the item from the main conveyor onto the desired outfeed conveyor. The outfeed conveyor runs until it is deactivated by a discharge photo eye. The discharge photo eye’s purpose is to determine if an item was successfully discharged and  starts a time-out and shutdown sequence. If, during this shutdown period,  another item needs to be transferred to that conveyor, the shutdown sequence is reset.

Graphical Representation of Conveyor on C-more HMI

This system is controlled by a CLICK PLC and C-MORE HMI touch panel from Automation Direct, and PUSH BUTTONS. The photo-eyes are used to give the locations of the items are from Banner and the three color photo sensor is from IDEC. All photo eyes used in this project are PNP. The outputs on the PLC are relay type.  here-is-a-small-clip-of-the-project-in-action.

Capstone Project in Electrical Engineeering at Kettering University

As an electrical engineering  senior design capstone project at Kettering University located in Flint Michigan, we were required to build a pinball machine. The machine was to utilize a PLC to control scoring inputs, light outputs, reset button, and control the electromagnets and doorbell. The PLC my group selected was the DirectLogic DL-06, and we planned to use the freely downloadable DirectSoft100 programming software to program it. We were able to program basic features, but when we tried to program more advanced features we found that we were exceeding the 100 word limit.  We contacted Automation Direct and they were kind enough to donate a full version of DirectSoft5 to Kettering. With the unrestricted programming package we were able implement all the features we desired – such as the doorbell and flashing lights when the game is won.

Check out our YouTube video to see more about our pinball machine.

Here’s the link to YouTube: Kettering University Titanic Pinball Machine

They have promised to post a write up here soon.  Until then here’s a link to their site,  be sure to check out the “Tech” page, with YouTube vids and much more about the Necronomicar, and the cannon: “Boom, Boom”.

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