Robotic Arm: Team Provolone
Can they build it? YES, they can.
Team Provolone is arguably the best team for the Robot Arm Lab. They are dedicated to success and will not stop until the job is done. The team's design hinges on uniqueness and versatility, which will make the design a cutting-edge prototype produced to complete the assigned test with efficiency and grace.
The Provolone team decided to use a turn-table type base that stabilizes the arm. The first servo is hidden within the base. The second servo is mounted at the end of the upper arm by large black brackets. Coming from this joint is the short lower arm that is attached to the pencil holder. The team decided to go for a short arm approach that keep the arm steady and removes a lot of weight from the first servo.
the basis of the code is the construction of a nx2 Matrix MAT that contains all the points needed to be connected in order to draw a circle and a square. The first section of the matrix is the division of the circle into many equal sized points. The number of points in the circle can be changed in order to adjust accuracy. The second part of the matrix is the division of the square into 16 points. This is done using the radius of the circle as a basis for the construction of the points. After the matrix is constructed, it translated to have the center of the circle at a specific point (x0,y0). Then the points of the matrix go through inverse and forward kinematics to find the position of the lower arm and the displacement angle of the two joints. Then, the angle is converted into pulse widths that create a command string that is sent to the servos. Simultaneously, graphs of the points in MAT and the path of the arm are displayed on screen.
At first, the circle drawn by the arm was oval shaped. This is because the center of the circle and the radius of the circle were out of reach of the robot arm, making the arm distort the image. After fixing these values, the robot still had trouble drawing a circle and a square. This might be cause by the jerky movement of the servos and the friction of the pencil on the paper.