The MAC Rover 2.0 is mounted on a sturdy treaded base to move from location to location. The Driving base contains 2 XL motors for power, 2 IR receivers, 1 light sensor, and 1 set of lights as well as some extension cords. The tracks are connected to the motors with a small sequence of gears that is geared down for power. The base is surprisingly fast for its size. The Motors are controlled by an IR receiver connected to a battery box on the shoulder. The tracks are designed to climb over some objects, but not to let the rover topple to the ground. The Light sensor is positioned near one of the lights (also controlled with an IR receiver) in order to allow the power functions to communicate with the NXT. Depending on the bright ness of the light, the NXT does different operations.
Picture 1 The Driving Base
Picture 2 The Motors and gears
Picture 3 The tracks
Picture 4 The IR receivers
Picture 5 The Light Sensor
The MAC Rover 2.0’s arm is a large 4 DoF arm that can bend at the elbow and shoulder, spin the wrist, and close the hand. The arm uses 1 XL motor, 3 Linear actuators, 1 pneumatic pump, 2 pneumatic cylinders, 1 pneumatic switch, 3 NXT motors, 1 NXT, 2 battery boxes, and 1 touch sensor. I will discuss the inner mechanisms of the arm in the next sections.
Picture 1 The Arm
Picture 2 The Hand open
Picture 3 The hand closed
Picture 4 The Elbow
Picture 5 The Shoulder
The Forearm is actually very similar to the original MAC Rover’s arm. It uses a similar multiplexer (which works by using a clutch system to toggle through three different functions with two motors) to power the hand, wrist, and joint. (if you want to see how the multiplexer works in better detail, see the MAC rover) The hand and wrist are also very similar to the original’s hand and wrist. The first function of the multiplexer is connected to the wrist, the second is connected to the hand, and the third is connected to the elbow. The hand uses a linear actuator to close, and it is designed to grab both large objects like cups and small objects like pencils. The wrist uses a gear to turn a turntable. The third function turns a pneumatic switch that controls the cylinders in the elbow.
Picture 1 The Multiplexer
Picture 2 The Switching mechanism
Picture 3 The Hand mechanism
Picture 4 The wrist removed
Picture 5 The switch
The Lower arm contains the NXT and battery boxes, 1 NXT Motors, 2 Pneumatic cylinders, 1 XL motor, 1 pump, and 2 linear actuators. The Pneumatic cylinders are connected to the elbow to bend the arm. The XL motor is connected to a powerful pump to maximize speed and air output. The NXT motor is connected to a strong sequence of gears that power the linear actuators. The actuators control the shoulder movement. The NXT and battery boxes are connected to the back of the shoulder to act as a counterweight to the massive arm. (Please note that due to the size of the arm, it is very slow yet very strong.) The touch sensor is used to switch functions.
Picture 1 The Cylinders
Picture 2 The pump
Picture 3 The Motor
Picture 4 The shoulder
Picture 5 The NXT and battery boxes and the touch sensor
The MAC Rover 2.0's multiple joints give it an enormous range of motion. With that range of motion, it can perform tasks like pick up and putting down objects, pouring drinks, carrying objects to different locations, drawing, and opening drawers. I successfully made the MAC Rover 2.0 pick up a cup, carry it to a sink, and pour it into the sink. Unfortunately, I accidentally deleted the program, so I do not have a screenshot of it. Basically, when you push the touch sensor, it switches functions and displays the current function on the screen. The lights are controlled with a speed remote that controls the brightness. If the bright ness is low, the current function moves one direction. If the brightness is high, the function moves the other direction. This controls the Hand, wrist, elbow, and shoulder. The air compressor is controlled with a remote.
While I was making the MAC Rover 2.0, I had a few problems with weak mechanisms. The biggest problem was that the original shoulder design was way to weak. Repositioning the actuators fixed this problem but limited the range of motion. I have posted a video. Search "MAC Rover 2.0" in a search engine to find it. Thanks for reading. Please comment and rate! Thanks. MSEP``````````````````````````````````````````````````(The picture is the "cast" from one of my latest videos)