Shengosng Cho
8/30/2016
In ME154, we formed a group of four people, and we designed a machine that would automatically walk to the middle of the road and raise up a stop sign when it senses people crossing the road. The project mainly was divided into 6 parts: linkage system design, force analysis, sensor design, the machine’s body design, the prototype manufacturing, and product testing. I was involved in most of them except sensor design because one of the team members who was taking Mechatronics took care of it. During the machine design process and the prototype making process, I experienced success and failure.
8/30/2016
In ME154, we formed a group of four people, and we designed a machine that would automatically walk to the middle of the road and raise up a stop sign when it senses people crossing the road. The project mainly was divided into 6 parts: linkage system design, force analysis, sensor design, the machine’s body design, the prototype manufacturing, and product testing. I was involved in most of them except sensor design because one of the team members who was taking Mechatronics took care of it. During the machine design process and the prototype making process, I experienced success and failure.
In the linkage
design, we successfully designed a 4-bar linkage for our machine using skills
we learned in ME154. Then it comes to the force analysis of the links. I failed
because I made a bad assumption on the weight of the stop sign resulting a large
needed torque on the crank (driver link). I went back and corrected the weight
of the stop sign after some researches, and the resulting torque was then approved
by the professor. After force analysis, we were to design the body of the
machine, it had to be stable enough to be one the road and not too heavy so the
motor was able to move the machine. We came up with a design using wood sheets
and wood rods, and the design was successful.
The manufacturing
process was a fun part. First, we drew out all the parts on the wood sheets and
started cutting using machine saw. One part of the process which I experienced failure
was that I could not cut the wooden rods perpendicularly, therefore it would
not stand on its own. I brought the rods into the ME41 (machine shop Lab) and
asked the instructor for help. He introduced me another cutting saw which did
the job. Then I used machine drill to put the parts together with screws and
bolts. Overall, the manufacturing was successful.
The final part
comes to product testing. Our motor which ran the 4-bar linkage had no problem.
However, the motor which ran the wheels was not strong enough to move the
machine. We went and bought another motor and made it a 4-wheel drive. After we
put in the motor, the machine worked like a charm.
Link of the final
prototype:
In this machine
design experience, I learned how to work as a team, how to use machine drills
and saws, and how to make assumptions after doing researches. Hopefully the
experiences will help me in the Spartan Superway project.
