Cost Learning and Path Planning
Apr, 2014 - Apr, 2014
Team Members: Chao Liu
- Built a route planner for the Penn Campus;
- Selected a bag of features based on a high resolution aerial photograph and generate the training set by labelling the paths which are reasonable;
- Implemented reinforcement learning method to learn the cost associated with each feature;
- Used Dijkstra's algorithm to find the optimal path;
Localization and Mapping
Mar, 2014 - Apr, 2014
Team Members: Chao Liu
- Mapped the structure of an indoor environment using information from an IMU and LIDAR sensor on a mobile robot;
- Pre-processed the data and used odometry measurements and yaw gyro readings to make 2D map;
- Constructed the surrounding 2D map using a particle filter and occupancy grid algorithm with LIDAR sensor data;
November 10, 2013 - December 20, 2013
Team Members: Chao Liu, Chenyang Zhu, Hanfei Sun
- Designed a vehicle robot with Omni-wheels and holonomic control;
- Hacked a toy connon and placed it on the vechile robot;
- Designed a circuit with an IMU, a xBee and so on and a PID controller for a quadrotor;
- Designed a device with muscle(EMG) sensors and an IMU to measure the muscle activation and motion and output some control commands to the vehicle robot and the quadrotor;
- Controlled the vehicle robot to shoot the quadrotor.
Yelp Rating Prediction
November 20, 2013 - December 10, 2013
Team Members: Chao Liu, Jianqiao Li, Shuotian Chen
- Process the data with NLP methods to know more properties of the words;
- Used Naïve Bayes, SVM and our own kernel to train the data and got a model.
July 2013 - August 2013
Team Members: Jay Davey, Chao Liu, Yanwei, Gabby, Uriah, Seethu, Chatty
- Designed a force sensor with IR and phototransistors and designed the PCB with Eagle;
- Used mbed(NXP LPC1786) to control servos for the tablet motion with servo controller;
- Used mbed(NXP LPC1786) and designed a P controller to control the gripper force;
- Controlled the DC motors of the base and the mast with Pololu Serial Motor Controller and used encoders to do the feedback control using C++;
- Designed PID controller for the base motion control and mast rotation control.
February 2013 - March 2013
Team Members: Chao Liu
- Chose FT5306 to be the touchscreen controller and designed the interface circuit for the microcontroller(Cortex-M4) and the capacitive touchscreen;
- Wrote the code with C language to control the communication between FT5306 and M4 with I2C;
- Designed the PCB layout with Eagle.
January 2013 - February 2013
Team Members: Chao Liu, Matthew Gus
- Designed a automatic robot to deliver something from one room to another room;
- Used 4 67:1 Metal Gearmotors and 4 Omni wheels to control the robot with holonomic control;
- Designed a remote controller with mRF wireless module which enable someone to input the room number;
- Designed an arm and used servo to control the arm to knock the door;
Laser Range Finder
December 2012 - June 2013
Team Members: Chao Liu, Chatty
- As the team leader, formed the team; designed a device to measure the distance between the object and itself;
- Used a laser diode to shine a laser line onto the target object;
- Controlled a camera(OVM7690) to take a picture of the line from the laser diode using RGB RAW mode;
- Designed an algorithm to detect the position of the line on the picture to calculate the distance between the target object and the device;
- Made the Makefile to compile the inline assembly language and used inline assembly language to speed up the data processing;
- Used Eagle to design the PCB.
November 2012 - December 2012
Team Members: Chao Liu, Burke Kevin, Rui Zhang, Sehrawat Sukreeti
- Designed 3 moving robots to compete in Hockey games;
- Used C language to control ATmega32U4 to output PWM to control the motors;
- Designed an algorithm to localize the robot itself in the rink with a COMS camera which can take -a photo of the 4 Fixed stars above the rink;
- Used multi-channel ADC technology to get signals from 8 phototransistors and then used PD controller to control the robot to move towards the puck and also move to the goal continuously;
- Used one Timer of the microcontroller to design a delay function and then control the solenoid to kick the puck at a suitable time.
November 2012 - December 2012
Team Members: Chao Liu, Bhargava Chatty, Dawei Wang
- Designed a system that can make people feel an object with PHANToM(a device with joints, end-effector and encoders);
- Simulated a ball and push the users out of the ball whenever they come inside, using a virtual spring mapping(the force should push them straight out of the ball, and the magnitude of the force should be proportional to their penetration depth);
- Designed a system to output a viscous damping force that always acts to slow the user down(this force should act in the opposite direction to the user's velocity vector, and its magnitude should scale with the magnitude of their velocity vector);
- Designed a filter to process the data from the encoders to make the system stable.
Puma Robot Control
October 2012 - November 2012
Team Members: Chao Liu, Chaoyi Huang, Jiali Shen
- Calculated the forward kinematics and inverse kinematics of Puma 260 and make a kinematics program with Matlab which can calculate the position of the end-effector with 6 inputs(joint angles of 6 joints) and get the most suitable angles of 6 joints with the input(the position of the end-effector and the former angles of 6 joints);
- Simulated the movement of Puma 260 in the Matlab and designed an algorithm to control the robot to draw a picture;
- Controlled the real robot to draw the picture.
Team Members: Chao Liu, Burke Kevin, Rui Zhang
- Designed a robot which can be fully self-contained with only two coaxially-mounted wheels touching the ground;
- Chose suitable motors(Pololu 47:1 25mm motor), acquired the position information of the robot with a gyro and an accelerometer(MPU6050) and Hall Effect Trans(SS494B), and then processed the data with an ADC;
- Sent the data to ATmega32U4 to control 2 I/O pins to produce a suitable PWM output to make the robot balanced;
- Used Kalman Filter to get rid of the undependable data from the sensors and use PD controller to determine the relationship between the PWM and the signals.
Study of Rotor Shaft System Helth Monitor with Ultrasonic Guided Wave and Its Transducer
October 2011 - June 2012
Team Members: Chao Liu, Prof. Xiaoyu Wang, Prof. Daoshun Wang, Yanyan Yang
- Applied ultrasonic guided-waves to detecting rotor systems to obtain the accurate testing data;
- Chose microcontroller(ATmega32) and designed the circuit by Altium, including the counters(74177 & 74LS393), high speed storage device(W29C040), D/A transducer(DAC0832), DDS chip(AD9851), input keyboard(4×4) and display(12864);
- Wrote programs to produce Ultrasonic Guided-Waves and control the input and output device.
Study on Non-Repair Dynamic Balance Device of Wheelsets in Vehicles
August 2012 - November 2011
Team Members: Chao Liu, Chao Zou, Dongju Wang, Zailin Ge
- Ensure the dynamic balance via regulating the circumferential positions of the objects with a certain mass in the tapered groove which can avoid causing physical damage to the wheel, and extend life expectancy of wheel sets;
- Designed and simulated testing apparatus by AutoCAD;
- Chose piezoelectric accelerometers and established the algorithm and simulated the operation of trains;
- Collected, filtered and amplified the signals and processed them by Visual Basic;
- Tested the reliability of the device.