1. Dynamixel Modules Serially controller servo motors
Company Robotis
Serially controller servo motors
Defacto Industry standard
used be ~80% RoboCup Teams that build robots

2. 3.2 Dynamixels
Two types of dynamixels are available for Bioloid GP – AX-12, and AX-18.
Dynamixels are complex actuators for robot servo.
Use daisy-chainable bus connections of 1-3 mbps.
The dynamixels receives digital commands of a serial nature,
process
and send a status signal back to the device.
Dynamixels work with CM-5, CM-530, or higher level controller well through TTL network protocol of RS485 using USB2Dynamixel adapter.
It is found that dynamixels will be automatically shut down if overloaded for 30% to 40% of its torque.
There are multiple supporting programming languages including C/C++, Java, Python, C#, Matlab, Labview Visual Studio, etc..

3. How Standard Servo Motors work?
Conventional Servo motors are used for positioning
every 20ms you need to send a pulse to the servo motor,
the width of this pulse then determines the position the shaft rotates to.
This has to be done for every servo motor in the system => large overhead on main mcu.

4. How Dynamixels Servo Motors work?
Use serial communication:
TTL serial (3 wire) or RS485 (4 wire), and
1Mbps to 3Mbps communication speeds.
Dynamixels are ‘networked’:
each Dynamixel has a unique ID,
they are connected via a Daisy Chain, and
255 Dynamixels can be connected to each network.

5. Why is this an advantage …
Daisy-chained wiring reduces wiring in the robot/project,
- You can now exchange more data with the Dynamixel.
Settings
Goal Position
Moving Speed
Voltage & Torque Limit
Temperature Limit
Angle Limits (min & max)
Control Parameters
Variables
Current Position
Current Speed
Current Load
Current Voltage
Current Temperature

6. Control Parameters …. CW – clockwise CCW – counter clockwise
1. Compliance
2. PID Control

7. Again - why are these advantages ….
Positioning Conventional servo involves:
working out arc to be travelled, i.e. from Xo to Yo
working out time you need servo to move from Xo to Yo
calculate intermediate positions – t*(Yo – Xo)/T
sending a pulse every 20ms with new target position

8. Again - why are these advantages ….
Positioning Dynamixel involves:
sending a command – move to Yo at speed Z
Result:
Dynamixels distribute the intelligence around your robot project.

9. There are other advantages …
360o Rotating mode
Dynamixels can be used as a rotating motor at a number of speeds.
Torque OFF mode
motors shaft can be moved whilst recording shaft position …. ability to teach & repeat sequences easily.

10. Why are Dynamixels ideal for Robotics …
Daisy-chained wiring reduces wiring in the robot project,
Intelligence is distributed,
Commands are simplified,
Parameters can be monitored in real time,
Setting can be made within Dynamixel to physically protect itself,
Each Dynamixel module can be tuned by either Complaince or PID Control techniques,
Use Torque OFF mode to ‘teach’ robot movement sequences.

11. Intro to Robotis Products Educational Robotic Kits
Tribotix | Newcastle, Australia | P: | F: | W:
Intro to Robotis Products Educational Robotic Kits

12. 2.3 Bioloid
Robotis supports multiple versions of Bioloid kit from beginner, comprehensive, expert to premium.
In the humanoid style, it supports premium, GP and Darwin.
2.3.1 Bioloid Preminum
Bioloid premium is a medium level robot kit for
hobbies, educators and researchers.
The central unit of the
premium is CM-530 controller [12, 13], which allows the user
to easily connect the AX-12A servo motors, the sensors and
any communication devices that are needed by the project.
Each accessory has a unique ID so that configuration of the
system will be unambiguous.

13. Dynamixel AX-12A is an
integrated motor with several features, such as:
position and speed can be controlled in 1024 steps,
feedback for angular position, angular velocity, and load torque can be set up in the motion,
wiring is with daisy chain connection and supports many dynamixel units with very few resources.
Three types of assembly construction were provided.
In addition, 23 other types of assembly are supported.
The limitation is the actuators in this level does not support enough torque therefore some of the pose cannot be completed in a type of assembly.

14. Tribotix | Newcastle, Australia | P: +61 2 49578255 | F: +61 2 49578244 | W: www.tribotix.com
Examples …. BIOLOID Kit

15. Solenoids Plunger attracted or repelled by current through a coil.
May be driven by a relay or transistor.