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Kristopher Li

Engineering & Design

  • Projects
  • About

Utsushi

Utsushi (うつし) is the act of emulating a masterpiece in order to learn and improve upon the original. This interpretation of "utsushi" is a robotic sketch artist machined from brass and aluminum.

With a belt drive system and cam-actuated pen, it is capable of creating captivating line drawings with a uniquely mechanical aesthetic.  

Mechanek

Mechanek is an active head and neck restraint system made to dynamically adjust based on vehicle sensor data in order to reduce the injuries of race car drivers.

To learn more about the project, visit www.mechanek.com

 

Awards
2015 Make: Pitch Your Prototype Grand Prize
2015 Intel-Cornell Cup First Place
2015 Intel-Cornell Cup Media Award
2015 Francis G. Tatnall Prize, MEAM
2015 Shapeways Education Grant
 

Check

Minimalist chess set - CNC turned brushed aluminum and brass pieces and laser cut walnut chessboard with concrete inserts.

Carbon

Carbon fiber skateboard deck with birch core and aluminum reinforcement plates.

Hammerhead

A palm-sized hammerhead shark CNC machined from a solid block of aluminum. 

Prototyped using machining wax. 

Further exploration of the unique hammerhead shape led to the use of quadratic edge decimation for creating low-polygon versions. 

NERO

NERO is a remote control "spy boat" with carbon fiber hull. 

The hull of NERO is fabricated using carbon fiber through a wet layup process. A mold was machined from MDF using a ProtoTRAK CNC mill and then prepared by hand. A similar mold making process was used in order to create the vacuum formed camera cover. The brains of the boat consist of a M2 microcontroller, integrating the brushless DC motors, ESCs, 2 DOF camera gimbal, video streaming, and water cooling system. The water cooling system is receives cooling air from the air intake protected by Injen's Hydro-Shield.

Robockey

Robockey is an annual tournament at the University of Pennsylvania. It serves as a capstone project to MEAM 510: Design of Mechatronic Systems. In 2014, 24 teams made of 89 mechatronics students competed. Each team designs, fabricates, and programs three autonomous robots that compete against each other in a game of robotic hockey.

Above the rink, a "constellation" of infrared LEDs serve as a navigation tool for the robots. Using unique infrared cameras salvaged from Wii Remotes, each robot then utilizes coordinate transformations to determine their relative location to the rink's origin. The electronic puck also emits infrared light radially, and is tracked by the robots using infrared phototransistors. These phototransistors and other various sensors feed information to the MAEVARM M2 microcontroller which determines the robot's actions. Additional phototransistors are used to sense if a bot as possession of the puck. If one of the attacking robots gains possession, it is capable of rapidly plotting and traversing a path to the opponents goal. At the "two-point line",  the strikers are also capable of shooting the puck for double points if the 18V push solenoid is charged and ready to fire. The high voltage of the solenoid booster circuit and brushed DC motors are carefully separated from the logic circuits on-board. Our team utilized a unique stacked perfboard design so that each independent perfboard could be connected via a series of headers along each board. This allows for signals and power to be passed along each board, and allows all pins of the microcontroller to be accessed from any layer of circuitry. Limit switches placed along the back of the goalie and sides of the strikers allow for verification of the wall location when executing certain commands. 

Each robot has large brushed DC motors that attach to the wheels via aluminum spur gears. These gears were implemented in order to adhere to the strict size restrictions of the competition by mounting the motors off-center. To gain more traction as well as a head-to-head advantage, each of the robots was loaded with lead shot. This allowed for an average team weight of approximately 7 lbs and ultimately proved to be a huge asset in the tournament.

The basic programming of the strikers allowed for the ability to locate, control, and score with the puck. However, our team also implemented inter-robot communications in order to add an additional level of strategy. Whenever a robot gains possession of the puck, the behavior of the other robots is slightly altered. For example, when one striker gains possession and moves to score, the other striker acts as a "midfielder" by shadowing the first robot in the case of a rebound or loose puck. Most importantly, this prevents the robots from contesting the puck simultaneously, which results poor puck control and potential damage.

 

Sentry

Miniature infrared tracking robot featuring five LTR-4206 phototransistors, brushed DC motor, and 3D printed outer-casing.

Bike Light

Adjustable frequency and duty cycle bike light machined from 6061 alloy aluminum.

Stirling Engine

Gamma-type Stirling engine machined from aluminum, brass, and steel.

pianissimo

Laser-cut acrylic and MDF miniature model of a grand piano

Vise Stop

Custom designed vise stop machined from carbon steel

Maze Bot

A two-wheeled robot operated via microcontroller gamepad built to rapidly navigate through a maze while carrying a 500 gram cylindrical mass.

Opener

Bottle opener keychain machined from carbon steel

Utsushi

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Mechanek

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Check

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Carbon

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Hammerhead

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NERO

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Robockey

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Sentry

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Bike Light

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Stirling Engine

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pianissimo

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Vise Stop

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Maze Bot

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Opener

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