1. Skid (Tank) Steering

2. Skid (Tank) Steering
ROBOT B A

3. How to be sure it will go straight?
Building a Robot
Skid (Tank) Steering
ROBOT
How to be sure it will go straight? B A

4. How to be sure it will go straight?
Building a Robot
Skid (Tank) Steering
ROBOT
How to be sure it will go straight? B A

5. How to be sure it will rotate correctly?
Building a Robot
Skid (Tank) Steering
ROBOT A B
How to be sure it will rotate correctly?

6. How to be sure it will rotate correctly?
Building a Robot
Skid (Tank) Steering
ROBOT A B
How to be sure it will rotate correctly?

7. How to be sure it will rotate correctly?
Building a Robot
Skid (Tank) Steering
ROBOT A B
How to be sure it will rotate correctly?

8. What is better, four wheels or two wheels?
4 Wheels vs. 2 Wheels
ROBOT
What is better, four wheels or two wheels?

9. Building a Robot 4 Wheels vs. 2 Wheels ROBOT ROBOT
Think always about the center of gravity for your wheeled vehicle

10. Building a Robot
4 Wheels vs. 2 Wheels
ROBOT
ROBOT

11. Center of Gravity
Bad designs?
good designs?

12. Building a Robot Center of Gravity
Often the answer depends on your requirements, the specification of the robot

13. Building a Robot
Center of Gravity

14. Building a Robot
Center of Gravity

15. Wheelbase

16. Building a Robot
Wheelbase

17. Building a Robot Wheelbase
You must consider early in design how you want your robot to rotate and move in narrow spaces.

18. Building a Robot
Wheelbase

19. Chain Alignment
Important aspect of design is the alignment of chains, gears or pulleys.
This relates also to cams and fourbars.
motor

20. Supporting Shafts
motor

21. Building a Robot Supporting Shafts motor
Shafts must be well-supported!

22. Building a Robot Supporting Shafts motor This is a really bad design.
Many early designs from this class were like this, although I told students not to do this.

23. Building a Robot
Supporting Shafts
motor

24. Building a Robot
Supporting Shafts
motor

25. Building a Robot
Supporting Shafts
motor

26. Building a Robot
Supporting Shafts
motor

27. Building a Robot
Supporting Shafts
motor
Best designs,
If you can.

28. Pivots There are many pivots in robot arms, head, legs, etc.
Do not forget to design them well
Teflon Washer
Nylock
Nylock
Steel Washer

29. Robot Base Example
It is good to have some experience with advanced robot kits like Tetrix of Vex before you design your own robot parts.

30. Building a Robot

31. Robot design goals Simple: easy to replicate and less to go wrong!
Ask: Is there an easier solution?
Robust: don’t want robots falling apart on the table!
Compact
Small enough to turn in tight spaces
Keep the center of gravity between the wheels
Wire routing – tuck wires in so they don’t get pulled loose
Predictable and reliable
Behavior should be consistent and repeatable
Aesthetics: it’s nice to have a good looking robot!

32. Some Robust Techniques
Shielding light sensors
Solid construction
Using good batteries
Going straight (enough)
Reliable Navigation

33. Dynamic Environment
Even with good design, construction and programming, there can still be problems
At first, robots and programs are designed assuming a well known (static) environment without any interference
Unfortunately, things do change: sunlight, spotlights, camera flashes, dust on the tables and wheels, the battery power level, etc
There are ways to mitigate some of these

35. Materials used
Zan Hecht
Nathan Gray
Gaurav S. Sukhatme