hexapod robot
DESCRIPTION
This is a Hexapod robot developed at the Robotics Lab, DTUTRANSCRIPT
Hi-Tech Robotics Team 1
HEXAPOD
Hi-Tech Robotics Team 2
Hexapod:
A hexapod is a robot that walks on six legs. Locomotion: hexapods are controlled by gaits, some of
which are,• Alternating tripod: 3 legs on the ground at a time• Quadruped• Crawl: move just one leg at a time
A-Pod Ziggy
Introduction
Hi-Tech Robotics Team 3
Hexapod: Hardware Components
Servo: Futaba S3003
Hi-Tech Robotics Team 4
Hexapod: Hardware Components
Microcontroller: ATMega32
Hi-Tech Robotics Team 5
Development Board: from Robokits.com
Hexapod: Hardware Components
Hi-Tech Robotics Team 6
Hexapod:
Compiler/Debugger: AVR Studio 5.0 Programming Language: Embedded C Simulation Software: Proteus (ISIS 7 Professional) Terminal Program: XCTU
Programming
Hi-Tech Robotics Team 7
Servo PWM code:
Using predefined PWMs of ATMega32• Timer 1, fast PWM mode• Clock freq. of 1MHz• PWM period set to 20ms by setting timer TOP(ICR1)
value at 20000
Shortcomings: Predefined PWM outputs available: 4 PWM channels required: 12
Version 1
Hi-Tech Robotics Team 8
Servo PWM code:
Using Bit-Bang technique: manually implement PWM on any pin by repeatedly turning the pin on and off for the desired times.• Advantage: any digital output pin can be used. • Timer 1, CTC mode
All PWMs start at 0 count, duty cycles end in decreasing order of their pulse width.
Shortcomings: Results not satisfactory: lack of precision, unsuitable for hexapod gait programming
Version 2
Time(ms)Duty cycle 1 ends
All PWMs start 0
Duty cycle 2 ends
Duty cycle 3 ends
End of PWM cycle
Hi-Tech Robotics Team 9
Servo PWM code:
Using Bit-Banging• Timer 1, CTC mode
The next PWMs duty cycle starts at the end of first one’s Satisfactory results: good precision, suitable for hexapod gait programming
Version 3
Time(ms)Duty cycle 1 endsDuty cycle 2 starts
Duty cycle 1 starts start
0Duty cycle 2 endsDuty cycle 3 starts
Duty cycle 3 ends
End of PWM cycle
Hi-Tech Robotics Team 10
Hexapod: The complete code
Gait mechanism: Alternating tripod
12 PWM channels available on pins B0-7, D4-7 Motion commands transmitted from Laptop to Hexapod through serial cable
• Using USART feature of AtMega 32• Using XCTU terminal program installed in the laptop
Motion controls:• Standby• Push-up• Move Forward• Move Left• Move Right• Move Backward
Hi-Tech Robotics Team 11
Hexapod: A Glimpse
Hi-Tech Robotics Team 12
Presentation by: Himanshu Rao
THANK YOU