autonomous robotic hexapod

AUTONOMOUS ROBOTIC HEXAPOD

with Wireless Transmitter

Justin Limb

Computer Engineering Program, Engineering Department, Utah Valley University

Keywords – Autonomous, Range Sensor, PIR sensors, Color Sensor, Robot, RGB LED,

Bluetooth

Abstract

A hexapod robot is a mechanical vehicle that walks on six legs that allow for a great deal

of flexibility in how it can move while simultaneously manipulating a payload. Mobile robots

are becoming increasingly popular in recent decades and can often be found in many industries

and universities for research. Mobile robots have the capability to navigate their environment

such as an automated guided vehicle used to transport goods around large facilities, warehouses,

container ports, and hospitals. Mobile robots utilize vision sensors and lasers that follow

external markers to create internal maps for navigation. Three-dimensional sensors such as time-

of-flight or stereovision cameras may be used in complex environments where the conditions and

variables may differ on a case by case basis [1]. Although the mobile robot for this project is not

useful in regard to productivity, its features of navigating itself and responding to its

environment, as that of a real insect, is both entertaining and educational.

The objective of this project is to create a mechatronics system that incorporates

computer programming, applied electrical theory, and dynamic mechanical design. The same

design principles applied to complex robots used in industry have been implemented in this

simplistic robot with the use of feedback control to sense its surroundings, process data, and

make decisions for determining its output. The legs of this hexapod include three rotating joints

that have been sourced with sensors embedded in the feet to detect contact with the ground. In

addition, this hexapod is equipped with a moving tail, 3-axis moving head, functioning

mandibles with pressure and range sensors, eyes with PIR sensors to detect motion of threats,

and a color sensor to allow its external shell to camouflage with its environment via RGB LED’s.

Internally, there are sensors to monitor servo thermal overload, battery voltage and amperage

draw. The hexapod functions by one of two modes: manual-mode by means of a Bluetooth

transmitter with navigating buttons, and auto-mode with the aid of sensors to navigate its

surroundings and defend itself from potential threats.

Figure-1: Completed Hexapod Robot

Figure-2: Top-View Reference

Figure-3: Bottom-View Reference

Figure-4: Transmitter Reference

Figure-5: Walk & Turn Cycle Illustration (Created with SolidWorks)

Figure-6: Colored JST-Connectors

Figure-7: Base System Power Schematic (Created with Circuit Maker)

Figure-8: Simulated Robot Base PCB – FRONT VIEW (MCU Port shown without microcontroller) [7]

Figure-9: Complete Base Schematic w/out Power Circuit (Created with CircuitMaker)

Figure-10: Base Sensors Schematic (Created with CircuitMaker)

Figure-11: Base RGB LED’s Schematic (Created with CircuitMaker)

Figure-12: Base Servo Motor Schematic (Created with CircuitMaker)

Figure-13: Base Robot Software Flow Chart (Created with Excel)

Figure-14: Transmitter Software Flow Chart (Created with Excel)

Figure-15: Oscilloscope screenshot of I2C protocol