April 5, 2012

Five LSU engineering seniors are building a 1-by-1-foot wheeled robot capable of harnessing energy from a blow dryer, light bulb and battery, and then delivering that energy to a motor that will raise a flag.

The robot, which sports a solar panel and tiny windmill, is part of the students’ requirements for an LSU senior design course, and is the group’s entry into the Institute of Electrical and Electronic Engineers Robotics Competition April 21 in Tulsa, Okla.  The project’s goal is to design a small, battery-powered robot that can navigate an 8-foot-square playing field to collect “green energy” and then deliver that energy to a motor that will raise a flag.

“The robot is to harvest energy from two of three alternative energy sources and use the energy collected to raise a flag,” said Amelia Simpson, who worked on the electronic and power portions of the project.  “Whichever team raises the flag the highest after two rounds wins the competition.”

Simpson’s team and the others in the LSU senior design course are required to take the problem from the initial formulation to the final product, including construction and testing.  They must consider budgetary, safety and other usual constraints encountered in the profession.

Josh Kozan helped design the electronics for the robot.  He said as soon as the robot is powered on, a combination of a camera, microphone and other power source will help determine if the light bulb, hair dryer or battery is supplying the power.

“There is a camera on it to determine if the light bulb is on, a microphone to hear if the hair dryer is on, and if those two are not on then the battery must be on,” Kozan said.  “The robot will then go to that source to collect as much power from that source as possible.  After one minute, the power source that was just on will turn off.  The robot will then find another source to collect energy from.  After the robot has obtained enough energy, it will bring that energy to the flag and raise it.”

Willis Thimmesch worked on the robot controller and the techniques to make the robot navigate the course.  He said their robot design is unique in many ways—particularly in how the group decided to control the robot’s motors.

“To power a motor, you can simply send it (the robot) a constant voltage for it to ‘free run,’ making it run as fast as it can,” he said.  “However, to get to the middle speeds that we would need for navigation, you would have to use a square wave.”

A square wave is a type of waveform defined by a square where the electrical signal has only two levels.  The signal switches between these levels at regular intervals, and the switch is instant.  These qualities show as a square pattern of a wave on a graph.  This allows the robot to move at different speeds.

The controller the engineering students used has a set of four bits to control an electronic oscillator—an electric circuit that produces an electronic signal—that makes the square wave, he explained.

“This means there are 16 unique speeds for our robot,” Thimmesch said.

Simpson said the group is pleased with the way their robot collects energy.

“Our robot is unique because it contains a windmill and solar panels that will be used to collect the energy from the three sources,” she said.

Kozan said the group is using electrical engineering skills they learned at LSU to make the project successful.

“The classes that I have taken helped me to design the electronics for the robot,” he said.  “Some of the circuits that I designed I pulled from class notes or from my book.”

Simpson mirrored Kozan’s statement.

“Our process incorporates all facets of electrical engineering we’ve learned,” she said.  “First, the purpose is to harvest energy from alternative energy sources of wind, light and hydroelectric.  This requires us to determine how to collect and store the power.

“Second, we have to design all electronics for the robot including the charging circuit, power supply for the motors, and the motor controller circuit.  Lastly, we are using a microcontroller to program the robot’s movement.  This requires knowledge of computer programming and using inputs and outputs to communicate with the robot.”

Thimmesch said the project is near completion.  However, he said there has been a minor setback because of a change in the competition rules, forcing the group to be able to detect which source will be on at a certain time instead of programming in a predetermined route.

“This change means we need to create two more devices to detect if a light bulb or a hair dryer are on nearby,” he said.  “Considering the worst-case scenarios of a well-lit, very busting and noisy room, this is definitely an issue.”

Kozan said he feels confident they can handle any unforeseen issues.

“Most of the circuits are complete and working,” he said.  “We are to use our microcontroller, which is basically a computer, to control the wheels.  We still have some work to do, but we hope to be complete in a few weeks.”

Simpson said the project has enhanced her electrical engineering skills.

“I have concentrated on power, so working on this robot has helped me learn more about the electronics and computer side of electrical engineering,” she said.

Kozan said he is happy seeing the electronics he designed and built working in action.

“It is unbelievably rewarding to see something that you spent months designing on paper actually work in front of you,” he said.

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Article written by LSU Manship student Stephen Owens. If you would like to read the original blog post, click here.



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