Rochester Institute of Technology TigerBot P13201

Group Members Chris Atwood Mechanical Engineer CAD, Structural design Sasha Yevstifeev Electrical Engineer Controls, PCB, Rachel Lucas Mechanical Engineer CAD, Structural design Graeme Buckley Electrical Engineer Power, Wiring, lead Nick Towle Computer Engineer Embedded Development

Project Description Design and build a humanoid robot that has the ability to mimic a human walking gait. Improve upon the mechanical designs of previous Tigerbot iterations Provide a solid code framework capable of supporting all of Tigerbot’s functions Develop electrical components unique to Tigerbot, providing a modular wiring system.

System Overview

Design Summary Mechanical Structure Designed using CAD tools and stress analysis Water jet cut aluminum Electrical design Two custom made PCBs Power board and foot sensor board Daisy chain wiring design Computer design Roboard w/ Lubuntu OS

Mechanical Design 23 degrees of freedom (4 per arm, 6 per leg, 2 in the head, 1 in the torso) Designed to be 32” at shoulder height and roughly 25 lbs. Custom aluminum parts for a lightweight, sturdy frame High-torque XQ servos used due to large torque requirements Batteries placed on the back of the robot Circuit boards recessed into the chest for a protected and central location

Software Design TigerBot Runs two servers HTTP Server Socket-based TCP Server iPhone component Client which connects to the Tigerbot’s servers Web browser Can browse pages hosted by the Tigerbot which contain key information

Software Design (cont.) server.cpp Runs in the background always, listens for new connections and requests from clients, spawns child threads to complete the requests. ik.cpp Can be used to either move the servos to a specific position, or to cause the Tigerbot to walk with specified velocity, step length, and time interval. foot.cpp Can be called to read in current data from the foot sensors and report that data back to its caller. sensor.cpp Can be called to read in current data from the magnetometer, accelerometer, and gyroscope and report that data back to the caller.

Electrical Design Custom Foot sensor PCB SPC 5000mAh Li-Po BatteryLynxmotion SSC 32 6-axis IMU Custom PCB made for power distribution. Provides proper voltage to all components. Added fuse and switches for protection. Current Sense capability for overcurrent protection. Custom PCB foot sensor interface Provides signal conditioning for four Flexiforce piezoresistive force sensors. Uses 8 channel 12-bit ADC with I 2 C I 2 C communication with Roboard reduces wiring. Custom Power Board PCB Flexiforce Sensor

Results The TigerBot robot has been structurally completed. The robot has been successfully fully wired including power, Servo, and sensors. The robot as a walking algorithm that allows for assisted walking Contributed to the further improvements of the tiger bot project Robot cost close to $4000 due to high torque servos. Cost 60% more then the budget.

Future Improvements Add wireless capability Design manipulators at the end of the arms Increase the number of peripheral sensors (IR, PING, Voice recognition)

Thank You Questions?