Robotarm_notes.pdf

1 Terms I. II.

Manipulator – A device or system that effects a change. End effector – The device connected to the manipulator, used to effect the change e.g (Gripper

2 Servo How does a servo work? Servos are made up of a dc motor, potentiometer and a control circuit. Gears are used to reduce the servo speed for the potentiometer. The potentiometer changes it’s resistance based on the position of the motor. A control circuit receives a desired angle from the user and feedback from the potentiometer. The circuit then turns on the motor when the feedback angle and desired angle don’t match. The motor is turned off when they match. To control the servo, a pulse width modulation (PWM) signal is used.

3 Robot Build The robot is made up of 6 MG996R servos. An Arduino and a servo shield, are used to control the servos.

4 Forward Kinematics Forward kinematics is a method of getting the position of a manipulator, based on its angles. The goal with forward kinematics, is to get the position and rotation of the end effector in reference to a certain position. The reference rotation is commonly labelled as 𝑅 0 and the end effector rotation, as 𝑅 𝑁

5 Reverse kinematics Inverse kinematics are methods of getting the angles of all the joints when given the end effector position and rotation. There are multiple ways of getting these angles https://www.alanzucconi.com/2017/04/10/robotic-arms/

Look for spiral cable wrapping