AUTOMATED AVOIDING AND MAPPING ROBOT

Tài liệu nghiên cứu khoa học

VIETNAM TI MCU CONTEST 2012 1 MCU DESIGN CONTEST 2012 Project Title AUTOMATED AVOIDING AND MAPPING ROBOT Group member: 1. Tran Hoang An 08ECE , Center of Excellence, Danang University of Technology – The University of Danang 2. Doan Thanh Thien 08ECE , Center of Excellence, Danang University of Technology – The University of Danang 3. Giao Duy Vinh 08ECE , Center of Excellence, Danang University of Technology – The University of Danang Advisor: Eng. Nguyen The Nghia, Department of Electronic and Telecommunication Engineering Danang University of Technology – The University of Danang Da Nang, 2012 VIETNAM TI MCU CONTEST 2012 2 ACKNOWLEDGEMENT This project would not have been possible without the support of our advisor, Mr. Nguyen The Nghia, Department of Electronics and Telecommunication, Da Nang University of Technology and Mr. Le Thai Hung, Texas Instruments, Vietnam. They were abundantly helpful and offered invaluable assistance, support and guidance. We would also like to convey special thanks to the Advanced Program in Electronics and Communication for providing the financial means and laboratory facilities. VIETNAM TI MCU CONTEST 2012 3 ABSTRACT The goal of this project is to create a mobile object-avoiding and mapping robot. The robot must be able to detect objects and have enough intelligence to avoid collision, while a computer is responsible to draw a map of the surrounding environments. The robot detects obstacles using an ultrasonic sensor. This sensor is attached to a servo to enable the spinning of the sensor itself, and update the distance data from three different directions. This data is returned to computer via a wireless transceiver. A piece of software available on computer will do the job of analyzing this data and draw a map of the areas in which the robot is moving. MEMBERS’ TASKS ASSIGNMENTS Tran Hoang An: - Write programs for the MSP430FG4618 microcontroller to control the operations of ultrasonic sensor, servo and motors via the driver circuit. - Come up with the avoiding algorithm and write programs for the MSP430FG4618 microcontroller to fulfill the avoiding function. Giao Duy Vinh: - Design and assembly driver circuit using L298 IC - Build robot (Connect all hardware with each other such as servo, motors, driver circuit, MCU, ultrasonic and design appearance of the robot Doan Thanh Thien: - Make printed circuits - Design mapping software with Visual Studio 2010 - Design RF module VIETNAM TI MCU CONTEST 2012 4 INTRODUCTION Robots have been very popular in our daily lives. Robots have replaced humans in the assistance of performing those repetitive and dangerous tasks which humans prefer not to do or are unable to do. Robots applications are easily found in surgery, transportation, automatic manufacturing systems, etc. Even though it’s going to take engineers and scientists a long time to design robots that can actually do many of the things that humans can do, robots have been considered as one of the greatest inventions of all time. One of the most important features of any robots is the capability to move around and navigate. For our project, we decided to build a robot system that can smoothly run in a particular environment, detecting objects from various directions, and avoiding them when it comes close to them. The locomotion is enabled by two motors which drive the two wheels. An ultrasonic sensor is deployed to give the robot awareness of the surroundings. The intelligence to process information is provided by TI’s MSP430FG4618 microcontroller. VIETNAM TI MCU CONTEST 2012 5 1. System specifications Figure 1: The Robo t Detailed Specifications: Length: 15 cm Width: 14 cm Height: 11 cm Weight: 0.950 kg The robot is powered by a main source of 12 V DC from a 12 V rechargeable battery. The two wheels are attached to a pair of motors, which are driven by two 9 V motors. The H-bridge circuit is used to control the directional rotation of the motors. The ultrasonic sensor is tied to a 6 V servo, whose spinning causes the sensor to rotate to desired directions for object detection. The Robot’s intelligence is provided by TI’s MSP430FG4618 microcontroller. VIETNAM TI MCU CONTEST 2012 6 2. Block diagram Figure2: Block Diagram Explanations: Automated Avoiding function: Trigger signal from the MCU is sent to ultrasonic sensor. The sensor then sends echo signal back to the microcontroller. After processing echo signal, the microcontroller will control the robot’s movement by sending PWM signals to the H bridge motor control circuit. Additionally, the microcontroller also controls the servo which makes the ultrasonic sensor turn left and turn right. Mapping function: The data from MSP430FG4618 will be sent to computer through a RF module. This module consists of an nRF24L01 transceiver and MSP430G2553 Launchpad. After that, the data is sent to computer through COM port and we use Visual Studio 2010 and C# language to draw a map of robot’s surrounding environment. VIETNAM TI MCU CONTEST 2012 7 3. Full Schematic Figure 3: Full Schematic VIETNAM TI MCU CONTEST 2012 8 Figure 4: H-Bridge Motor Control Circuit Schematic Explanations: The MSP430FG4618 microcontroller is driven by a battery source of 3 V, which is attached on the back of the experimenter’s board. Our main voltage source is a 6 V rechargeable battery, which can make 5 V sources with 5 V voltage regulators, respectively. The H-bridge, which is our case is the L298 IC, requires a voltage source of 5 V, which is provided from one of the L7805CV regulators while a 6 V source needed to feed the motors. Since the ultrasonic sensor needs 5 V source and the servo works properly under a voltage source from 4.8 to 6 V, we decided to use output from a L7805CV regulator as the sources for these parts. VIETNAM TI MCU CONTEST 2012 9 4. System Hardware description 4.1 Batteries All parts of the robot except the microcontroller, which uses a 3 V battery, are powered by a 6 V rechargeable battery. Figure 5: 6 V Rechargeable Battery 4.2 Motor 4.2.1 Normal Motor To control its two wheels, the robot uses two motors, which are linked with the microcontroller via a driver circuit. Detailed Specifications: Voltage: 6 V Current: 64.4 mA Resistance: 140 Ω Figure 6: Motor [1] VIETNAM TI MCU CONTEST 2012 10 4.2.2 Servo Motor A Servo consists of 5 main parts: a three wire DC motor, a gear train, a potentiometer, a control circuit and an output shaft bearing. Three wires from DC motor have three different colors with different functions. The positive and negative power wires are colored red and black. The control signal is sent to the servo via a yellow-colored wire to regulate the shaft’s angular positions. Figure 7: Main components of a servo. [2] The following figure shows three cases associated with three different positions of the shaft. Figure 8: Three operation phases of servo . VIETNAM TI MCU CONTEST 2012 7 3. Full Schematic Figure 3: Full Schematic VIETNAM TI MCU CONTEST 2012 8 Figure 4: H-Bridge Motor Control Circuit Schematic. information is provided by TI s MSP430FG4618 microcontroller. VIETNAM TI MCU CONTEST 2012 5 1. System specifications Figure 1: The Robo t Detailed Specifications: