EXO-ARM relies on a central structure consisting of 3 support rings, one below the nxt, another slightly past the elbow joint, and one located right behind the touch sensor. Each of these support rings are connected by several beams that run down the entire structure. these beams enclose the arm of a person wearing it. These beams also provide a steady base of additional attachments or sensors. There are 2 main joints, the elbow and hand. The elbow uses a 1.6:1 ratio connected to a worm gear that rotates a 40 tooth gear attached to the front part of the arm.
At the tip of the EXO-ARM is a light weight 3 fingered claw. It can be equiped with a small foldable bipod for extra stability and to act as a base. The 2 lower fingers are used to grab the objects while the top finger is used to stabilize it and keep it in place. All the claws move at a gear ratio of 1.6:1
In addition to the standard bionic arm functions, I equipped the EXO-ARM with a magaziene fed mini gun that can shoot targets by sound, sight or control buttons. With the extra range finder program you can even pick up or shoot tagets in the dark of around the corner. The mini gun works by pushing a fireing mechanism back and forth. Then, the mechanisim pushed a connector piece out of a beam.
The program features 4 different purposes, motor control over the elbow and hand, sound activated gun, range finder and flashlight. the motors in the elbowand hand wait until until a certain command is entered in the control pad. The motors stop moving or move in the opposite direction if another command is entered in the nxt control pad. Included in the program is a special suquence for a range finder. First, the ultrasonic sensor detects the distance of the closest object and converts the distance into text. Then the text is diplayed on the screen as inches and the process reapeats over and over again. The flashlight is able to turn on and of automatically depending on the amount of light in a given area. First, the light sensor detects ambeint light intensity and if it falls under a specific amount the light, the sensor switches to reflective. Once the light intencity increases, the light sensor switces back to ambient light. Of course, all of this happens all at once on the same program. I havent been able to update the software for my standard nxt so far but the program is still effective.
A couple of additional pictures. Picture 1:front view. Picture 2:rear view. Picture 3:side view with bipod deployed. Picture 4:front view with flashlight deployed. Picture 5: side view with handgrip deployed.
Well, this is it. This is the end of this project. Right now I will be working on an updated version of the EXO-ARM and hopfuly, I will post it before the competion ends. I am planing to improvethe speed, responsiveness and weight. Utill then, feel free to post any questions or complements below. See ya!