1. Seis Piernas – The Step Climberby
Amit David Jayakaran
Date: 12-Dec-02
Instructor: Dr. A. A Arroyo
Dr. E. M. Schwartz
TAs: Jason Plew
Uriel Rodriguez
Department of Electrical and Computer Engineering
EEL 5666
Intelligent Machines Design Laboratory

2. The Final Verdict in 10 mins
Initial Expectations
Changes made
Capabilities and Behaviors
Sensors
Learning
Conclusions

3. Initial Expectations Capable of climbing 6” steps
Length to width ratio
Height of robot
Servo power (rated far above capability)
Servos not capable of putting out a uniform torque at all angles
Flexibility in the mechanical setup

4. Initial Expectations Self calibrating Double Tripod Gait
Too much flexibility
Double Tripod Gait
Not enough power in the servos

5. Changes made Removed bump switched below the legs for calibration
Redesigned legs slightly
Settled for a less efficient gait

6. The Robot

7. The Robot

8. The Robot

9. The Robot

10. The Legs

11. Capabilities and Behaviors
Performs obstacle avoidance
Walks with the six leg gait/swim
Capable of climbing 3” steps
Able to know if it missed the step and will retry before giving up

12. Sensors The IRs for obstacle detection The IR for step detection
The accelerometer to check the inclination of the robot with the horizontal.
Very sensitive so not totally reliable
Built my own board and surface mounted the chip!
Built a confidence system to improve reliability
Dropped bump sensors due to difficulty of implementation

13. Learning Practically everything was new to me Servos and PWM control
25 Amps is never enough
IR and its application
Smoke is not a good sign
Microcontrollers (Interrupts/Input Capture/ADC)
10 hours of battery charge gives you only 20 minutes of quality time

14. Learning Servos are expensive
Don’t bolt everything down until close to demo day
Soldering irons cause burns
Don’t trust data sheets
Stepping on your robot will kill it
No system is truly rigid
Robots are very moody

15. Conclusions The best learning experience ever
Writing code to check every module really helps (USART is God’s gift)
Although I spent more time working more on other peoples robots than my own I really enjoyed it
Have written a lot of routines that will really help anyone who does a walker in the future with the Atmel

16. Conclusions
I love debugging and since Murphy is our friend I really got a lot of hands-on, not just with my project but with others too.
Over all satisfied with the output and performance of my project

17. Suggestions for future
Make students visit the lab more frequently so that everyone gets a feel of what others are doing and learns from it
Encourage more team activity. I did it this whole semester and have learned not just all that I needed for my robot but stuff like
Break beams
Shaft encoders
Flex Sensors
Pyro detector
CMU Cam communication
Beacons
Practical Gearing
Line Following

18. Seis Piernas
Questions ?

19. Thank You
The End