Monkeybot

Team Members

Nelson Rosa, Nathan Henry

Nathan Henry - Senior, Mechanical Engineering
Nelson Rosa - Ph.D Student, Mechanical Engineering

Overview

The goal of this project was to create a brachiating robot capable of swinging itself side to side or climbing. This two link robot has electro-magnets on each end and a DC motor at the pivot. With one magnet on, the robot swings under gravity and is aided by a input torque from the motor. This torque allows the swinging robot to overcome friction and pump energy into the system. Once the swinging arm has enough energy, the second magnet reaches a point at the same height or above the first magnet. At this point, the second magnet is turned on the motor is turned off. Now the process is repeated, swinging on the second magnet.

We attempted to control the motor using both a closed loop control, with rotary encoders, and an open loop control, using a time based algorithm.

Video of the monkeybot climbing

Control Method

Closed Loop Control

Laser Rotary Encoder

We first attempted to control the DC motor using feedback from a rotary encoder placed directly over each magnet. From this encoder, using both the A and B channels, we are able to determine the sign of the top link's velocity.