User:Medelen8/ENES100/Shaker Table Auto Design

Problem Statement
To design an earthquake simulator that will oscillate back and forth about an inch, and with the capability to hold up to about 5-10 lbs to test different kind of small scale building models to test the strength of their structure.

Requirements for each element or component derived from system level goals and requirements

 * 1) shaker table holds 5-10 lbs building models
 * 2) oscillate an inch back and forth
 * 3) have control of frequency moving the table
 * 4) weight (less than 20lbs)
 * 5) Mobility to move around

Below are the different kinds of materials needed to complete the build to our project. Also within these tables list the quantity of the materials and the lengths of the each piece that is needed for the project.



Work cited from, "Walch, Katie, Robert J. Barron, and Jimmy F. Diehl. "Earthquake Shake Table." Geo.mtu.edu. N.p., 2001. Web. Feb.-Mar. 2014."

Alternatives in design
After 2 weeks of brainstorming by our team we managed to come up with two different designs to potentially used for our final design. our group looked at the two different designs to see what we can do differently. Plus we found a certain design to where it is similar to one of our original designs. So we took the first design and modified it so that the platform is separate from the motor and the electrical equipment and is connect by a long 7 inch armature. With these two separate from on another it gives the electrical wiring more space to work with and is able to have the platform next to the wring versus underneath where you cannot access it as easily. An other alteration was to replace a electronic drill being used to spin the axel for shaking the table with a stepper motor controlled by an arduino.

The initial design
Above design was our final design that passed our expectation of being automatic safe shaker table. Due to complication of the mechanism it was hard to maintain the constant speed but we were on our schedule due to our simple design that we got it from WEBSITE GOES HERE (Walch, Katie, Robert J. Barron, and Jimmy F. Diehl. "Earthquake Shake Table." Geo.mtu.edu. N.p., 2001. Web. Feb.-Mar. 2014.) One example of problem solving would be trying to choose a design that we all agree on. We had a design ( first picture) that had a platform, and in the middle there is a jagged middle piece glued to the top of the plywood board. Then a motor with a gear that will be attached to it and would be by the jagged piece to cause it to go back and forth. Underneath the first picture os another design we came up with before the final design was chosen and in this design it had two L shaped wooden rods in a suspension that would be connected to the platform raised about 1-2 inches, and where the motor will be placed it right underneath the platform and the armature will be connected to the motor where a steel rod will go around it and hit the board in order to move the platform

Experimental prototypes and testing conducted during design
For our project we didn't have any prototypes built to test for our design but we did have to test the code to make the motor rotate one direction then spin the opposite way while having the ability to control how fast it will spin through a frequency knob. We tested and configured many different way to test how to control and spin the motor.

When testing this design for checking if the code worked we had problems with actually turning the motor on. This is before we decided to add more power from a battery or an outlet. In the video we have is an example of the first good sign as the lights start to blink as we spin the motor ourselves.



Appropriate optimization in the presence of constraints
not appliciable

Iteration until convergence
not applicable

The final design
The final design that we decided on is broken down into three different components that if put all together should be able to hold up to 10 pounds of weight on a platform that will be moving back and forth about an inch. Broken down to each main component of the shaker table, the three components are the base, moving platform, electrical pieces/wiring placements and all the materials they will need to know to build this device.

The Base

With the first component, the base, it should be able to support both the other components and hold a certain amount of weight for testing the different structures placed on the platform. The base is made up of four 2 by 4 inch boards, two measuring 40 inches and two measuring 36 inches. Then will be covered by a 2 by 3 feet plywood board that will be secured by 8 four inch screws. On top of the plywood there will be two dowel rods secured by 3 inch screws that will be holding two freely moving dowel rods supporting the moving platform. The base will also house the electrical parts of the shaker table in a one foot space to the right of the base. The entire base should be able to be mobile to take and show many different tests for building models.

The Platform (moving board)

In the picture to the right u will see a drawn picture of the moving platform that will rest on two dowel rods that will be freely roaming in between four axles secured on the base. The scale of each square in the picture is the same as 2 inches, solid dark lines are the edges and dotted lines meant there is wood underneath this separated part; Dots mean there are 4" ceiling hooks dug into specific places the wood and other mechanical pieces are labeled and listed. What the platforms main purpose is to support a range of certain types of small scale building models weighing between 4-10 pounds while oscillating back and forth, about an inch, to test if the strength of this model can withstand a certain magnitude of an earthquake. The magnitude of the earthquake will be controlled by a certain knob, using a code on an arduino, to test different levels of magnitude of small building models. The platform itself will be attached by a long flat metal piece screwed to the platform and screwed to a rotating metal disk connected to a motor through a gear system. If someone were to turn the machine on, the gear system would cause the motor to turn. Rotating the metal piece attached to the platform around in a circle causing the board to go back and forth.

The electrical wiring/ housing

The electrical wiring components are made up of an arduino, monster motor shield, motor, wires, frequency knob, battery and an on off switch. When all put together it should be able to move the platform back and forth about an inch. The battery gives the machine its power and will be attached to some wires leading to the on off switch and than the arduino that has the monster motor shield attached to the top of the arduino. The power will be enhanced by the monster motor shield thus giving the machine its power to move the platform as well as the weight added to the machine for testing. From the monster shield the frequency knob will be attached next so that one can control the voltage given off by the battery by turning it one way or the other. Then the motor, which will be raised about three inches on a block of wood to account for the platforms height, comes after the frequency knob. Once all this circuitry is put together should allow the machine to do what it is meant to do. Where all this electrical work is put is in a box that will cover the entire right side of the machine. This box is six inches tall, 2 feet in diameter and a foot in length which should give the wiring to this project enough space to place everything.

Technical and scientific knowledge
For our project working on the automatic shaker table you need to have knowledge on how to use an arduino and some simple electrical wiring. The reason one needs to know knowledge about an arduino is so that you can program a code that can move the platform back and forth about an inch. While, simultaneously being able to have the ability to control the frequency through a knob to test different types of magnitudes that earthquakes can produce. Using this code the arduino should be able to tell the stepper motor controlling the platform to rotate in one direction and then shortly after rotate the other direction, producing the table to shake back and forth. One will also need to know the knowledge of how to sodder the motor to the frequency knob which is attached to the monster motor shield that is controlled by the arduino can should be able to flip a swith to turn on and off.

This is the code that we are using in our project to control the motor and it's speed. const int stepsPerRevolution = 48; // change this to fit the number of steps per revolution // for your motor // initialize the stepper library on the motor shield Stepper myStepper(stepsPerRevolution, 12,13); // give the motor control pins names: const int pwmA = 3; const int pwmB = 11; const int brakeA = 9; const int brakeB = 8; const int dirA = 12; const int dirB = 13; int x = 0; void setup { Serial.begin(9600); // set the PWM and brake pins so that the direction pins // can be used to control the motor: pinMode(pwmA, OUTPUT); pinMode(pwmB, OUTPUT); pinMode(brakeA, OUTPUT); pinMode(brakeB, OUTPUT); digitalWrite(pwmA, HIGH); digitalWrite(pwmB, HIGH); digitalWrite(brakeA, LOW); digitalWrite(brakeB, LOW); // initialize the serial port: Serial.begin(9600); // set the motor speed (for multiple steps only): myStepper.setSpeed(2); }
 * 1) include 

void loop { myStepper.step(48); myStepper.step(-48);

delay(2000);

}

Creativity, problem solving, and group decision-making
When it came to decision making our group had to collaborate a lot to agree on a certain design and components to put in our final design. We asked ourselves many questions about the circuitry of our design like for instance: Problem solving was a big part of making our automatic shaker table work. Our biggest problem in our project was figuring out a code that can control the frequency of the motor as well as tell the motor to rotate one way than the other way to produce the oscillating effect of the table platform. Probably our second biggest problem was designing the whole entire shaker table and deciding which design to pick. The way we got around this problem was by setting up the different designs and comparing them to the manual shaker table to see whether the different criteria is better or worse in each design. The third project was the winner and thus our final design to move on with making the table in real life. Some minor problems were figuring out what type of materials and the measurements for the entire project.
 * whether to use a regular or monster motor shield?
 * whether to use an arduino or not to use one to power and control the motor?
 * picking between our three designs we came up with?
 * deciding how much torque will be used for the motor?





Prior work in the field, standardization and reuse of designs (including reverse engineering and redesign)
There wasn't much prior work in the field when in came to designing this kind of project and same goes for standardization in this project. We had used the basic design of this base from multiple pictures we found of the internet and the platform was made up of a smaller version of the base while using the same kind of ceiling hooks.

Modeling and/or Simulation


The video below is a demonstration of how our project was similar in the begin after we changed the electric drill to a motor.The idea was also change to house the electrical equipment inside a wooden box.

[Shaker Table using Drill]

Performance, life cycle cost and value
The performance of our machine is to move a platform that is on two rolling dowel rods back and forth about an inch to test small scale building models and their different structures to see if they can with stand a certain magnitude of earthquake. By controlling the amount of resistance given we can control how fast the motor will spin and thus controlling the platform to go faster or slower. The life cycle of our project should last for a a couple of decades since the materials are make out of wood and the value should be no more than 30 dollars for all the wood, screws and pieces that are put into our machine.

Aesthetics and human factors
There aren't that many aesthetics apart of our project but some that can be listed could be that our project is made up of purely wood. Some human factors that are apart of our project is if some one wants to change the frequency, somebody can with the knob that is implemented within our circuitry.

Implementation, verification, test and environmental sustainability
For our group to implement this project we will have to test it by the base and platform being built and figuring out the codes. The codes are what we tested in order to see if the platform will shake. The final design will be tested to verify how reliable it is and showing how it works. Many different things of this design can be changed and necessary for things to be added for this design to be more perfected.

Maintainability, reliability, and safety
Design is based on no maintenance so that it keeps running till you want but just in case Keep few rubber bands and few wires so if something breaks or if wires get lose you can change it anytime. After every use take a short break to cool down the motor as it will have less opening for the air circulation. Reliability depends on how the structure is used, heavier the weight, hotter the motor will get to move the platform and will take longer to cool down. There are no safety concerns as most of our mechanical work is under cover and its on wood so there is no risk of electric shock.

Robustness, evolution, product improvement and retirement
The evolution of our project started from scratched and worked its way all the way to the final design phase. We knew we had to have a motor, wires, arduino and a table that can be controlled by a certain knob that can move back and forth about an inch. We came up with three different designs and than our group voted on which one fit the best with the criteria for the job. Now our project is ready to evolve to the next stage which is actually building the table itself. Once the design is fully built and ready for testing different models the design can be used for years to come or be retired if it is not used.