The BioloidRobot

ProjectPresenters:

Michael Gouzenfeld

Alexey Serafimov

Supervisor:

Ido Cohen

Winter 2012-2013

Department of Electrical Engineering

The project’s goal

Making the robot independently approach to a ball and kick it

The project’s main tasks• Creating an API for embedded robot’s controller in C,

which will allow controlling the robot on higher level

• Creating an image processing mechanism for the robot’s

camera in C++

• Creating a protocol for communication between the image

processing unit on PC and the robot

• Creating the decision making controller – the “brain”

The Bioloid Robot(Premium Upgrade Kit ++)

Dynamixel AX-12 motor x 20

Robotis Wireless CMOS Camera

230x240, 30 FPS

CM-510 controller based on Atmel

ATmega1281 8-bit AVR microcontroller

DMS – Distance Measurement

Sensor (IR)

ZigBee Zig-110 Wireless Module

2-Axis Accelerometer

The general ideaThe Robot The Controller PC

Dynamixels ZigBee

Sensors CameraCamera Receiver

USB Image Processing Unit

Main Controller

Wireless Data Processing Unit

ZigBeeUART

Motion Controller

PeripheralDevices

Wireless connection

Communication

SW Utilities

Indicators

Sensors

Motion control

Motion Controller structure

MainAll modules initialization

The main procedure

MotionDynamixels management

AccelerometerAccelerometer data processing

ADCAnalog port data

processing

BodyRobot’s body

movement management

ButtonsRobot’s CM-510

buttons handling

BuzzerRobot’s sound management

DMSRobot’s distance

measurement data processing Errors

Failures handling

HeadRobot’s body

movement management

LEDsRobot’s CM-510 LEDs handling

MemoryATmega1281 memory

management

UtilitiesGeneral helper

functions

ZigBeeWireless

communication controller

• Dynamixel’s Offset – a dynamixel’s absolute angle• Dynamixel’s Speed – a dynamixel’s speed of rotating

Motion control Terminology

• Pose – a set of dynamixels’ offsets (except for the head)• Page – a set of poses to be played sequentiallyExcept for the poses, page also holds an information about: play time, delays, next page to play etc.

Motion control Terminology

• Memory program space – the memory space, where the code resides

• Memory data space – the memory space, where the data resides

The user can’t access the program space directly due to AVR processor’s Harvard architecture, but using special functions

Motion control Terminology

• Robot’s Head – the robot’s head is an add-on of 2 dynamixels and a camera to the original Premium Upgrade Kit

The head has 2 degrees of freedom: tilt and pan

Motion control Terminology

Motion control Memory management

• To avoid spending time on teaching the robot new poses, the poses

provided by manufacturer are used

• The manufacturer (ROBOTIS) places all the motion data in the program

space

• Original pages of poses are copied from program space to data space

• The data space is to small to hold all the pages, so a sort of caching

mechanism was implemented, based on the random replacing policy

Motion control Pose playing

• The challenge is setting the robot’s pose, such as all the dynamixels will

start and end their motion simultaneously.

• This is performed by the next means:

• Calculating the correct speed for each dynamixel to move with, according to

the offset to be performed.

• Sending a broadcast message on the Dynamixel’s bus, such as all off it get

the moving command at the same time

Motion control Page playing

• When playing a page of poses, there are defined speeds and delays for

each pose, so the dynamixel’s speeds are adjusted accordingly

• After reaching the end of page, there is a jump to the Next Page (one of

the page’s properties).

• Also there is a Stop Page pointer to jump there if something’s wrong

Motion control Motion cycle

ZigBee command arrived?

What kind of command?

Preload relevant pages into the cache

Play the pose(s)

Any sensors changed?

Body

No Play the initial pose

Yes

Correct the pose(s)

Yes

Move headHead

Perform management operations such as:

update default dynamixels offsets

Management

No

Motion control Motion cycle

• Some explanations to the previous slide:

• During the motion play, the sensors are sampled and some corrections to

the motion can be made. For example:

• If accelerometer detects falling, the appropriate dynamixels are moved to avoid it

• If DMS detects close object while walking, the robot will try to avoid the obstacle

by walking around it

• If a button is pressed, robot returns to its initial pose

• As a result of ZigBee command the relevant page sequence is being played,

but after each pose there is a check if the ZigBee command has changed, so

another sequence will be played

Image processingGeneral principles

• The general principles of the tracking:

• Choosing the object’s color, which should be different from the background color

• The image processor calculates the average geometrical location of the chosen color

on the screen.

• The command to move robot’s head is sent to the robot, such as the average

geometrical location will be at the center of the screen (in infinite loop).

Wireless communicationGeneral principles

• Wireless communication between Main Controller and robot is performed

using ZigBee protocol (not talking about video data, only the commands)

• The commands are generated (and can be received) by the Wireless Data

Processing unit and are sent to the robot.

• With correct ZigBee devices configuration the command generation from RC-

100 (remote controller) is also supported

Main Controller (not implemented yet )

General principles• The Main Controller is responsible for making a decision about a command to

be sent to the robot according to results received from the Image Processing

unit.

• The Image Processing unit provides the Main Controller with data about the

object’s (ball) location, such as:

• The relative angle in horizontal plane

• Estimated distance

• The Main Controller sends the movement commands to the robot

• The above actions are done in the loop until the robot finally is in the ball-kick

position

• The kick command is sent

Future development possible directions

• Placing the main controller on the robot (some lite weight, but strong computing device),

to make the robot completely independent

• Upgrading the accelerometers (called “gyro” by the manufacturer) with the real gyros, to

improve robot’s stability (falling prevention)

• Improving the motion algorithms and flows by the principle:

• Efficiency in cost of modularity

• Upgrading the camera for better performance

• Improving image processing for new features to be possible, such as:

• Easy obstacle overcoming instead of avoiding

• Adding some device to the robot, which will allow:

• Navigation

• Shortest path finding

• ...

The End