Implementation of Solenoids for Cylindrical or Spherical Robotic

Locomotion

Presenters

Joel Lawrence Justin Moses

Spherotm ball robot controlled by iPhone/iPad

Commercially available

Spherical Robots

Movement is controlled by internal mechanisms◦ Counter-pendulum◦ Gyroscope◦ Internal rotor

Omnidirectional Can traverse many types of terrain Have no top – bottom orientations Sealed off from the environment

Typical Spherical Robots

Cannot stop quickly Cannot overcome obstacles greater than

the radius of the sphere Hard to have a zero-turn radius (hard to turn

about the z axis)

Limitations of Spherical Robots

Use solenoids!Solution

Allow for greater control of movement Robot can stop sooner Robot has the potential to jump to

overcome obstacles

Why Solenoids?

Weight Cost Open to the environment High power consumption

Disadvantages

Solenoids use inductance to control a plunger

Can be push, pull, or push-pull

Usually have springs to automatically retract or extend after turned off

Solenoids and Implementation

Uses solenoids with plungers extending from the shell

Only two rows to show proof of concept

Built inside a hamster ball

Spherical Design

Use a cylinder instead of a sphere

Use the body of a pen to stop the plungers

Everything else stays the same

Simplified Design

TI MSP430 as the microcontroller Either a TIP31 or a MJE3055 BJT 7805 5v rectifier IC Standard 120 Vac to 12 Vdc wall plug Coded using Code Composer Studio

Controlling the Robot

Used LEDs to indicate which solenoid should be activated

Original 2N3904 transistors failed

Testing