Design Description

The design uses a flexion- and electromyography-based interface to measure the actions of a human pilot to command a robotic arm whose five degrees of freedom to mimic anthropomorphic movement.

The device is capable of reproducing wrist flexion, shoulder lifting, elbow bending, forearm rotation, and hand clenching. The robot uses five servos to execute these functions, the lesser three of which are located in its hand, while the stronger are located in its elbow and shoulder. The device can manipulate various objects of respectable mass to achieve a goal; however, the design’s constraints limit its motion to one plane and its size to one half. This conserves the arm’s mechanical strength to accomplish tasks.

The interface used to control the device uses three flexion and two bioelectrical sensors mounted on a glove and sleeve on the right arm. The flexion sensors on the glove and sleeve are located on the back of the ring finger, base of the palm, and outside of the elbow. Each bioelectrical sensor requires positive, negative, and ground electrodes; the former two are each used on the inside of the forearm’s base and the front of the shoulder, while the ground is placed on another inactive part of the body.

The sensors transmit the data they collect to a MATLAB software that translates them into commands. However, unlike the flexion sensors, the software cannot use the bioelectrical signals without amplification and denoising. An electrical circuit was built to accomplish this with power from two nine-volt batteries and two noise filters before connecting to the data acquisition and software feeds.