Overview

For our mechatronics class, groupmates and I designed and built a snake like robotic arm that can be used to maneuver in hard to reach places with a variety of end effectors. With two actuated sections of the arm, each driven by four strings with two motors, we can move our arm in orientations traditional robotic arms could not. Another advantage of our robot is the weigh distribution, since the motors are located at the base our arm is much lighter and requires less torque from the motors since each segment of our arm does not need to support the weight of the motor and gearbox of the following link. Custom, and stackable, planetary gear boxes atop stepper motors allow us to actuate the robot. Our design features cables to drive this system, with a nylon center spine and multiple disks along the spine to increase flexibility. Along our center spine we have many unactuated disks which function as feed throughs to align the cables. Every three unactuated disks we have an actuated disk where the four driven cables terminate, our robot has two actuated disks hence the two independently actuated sections. Our robot features a teleoperated mode where a controller can be used to move the arm and a path following mode. The path following mode allows the arm to follow a prescribed path where an optimizer computes the most efficient actuation of the motors to arrive to the specified points. To increase positional accuracy there are two IMU's placed on each of the actuated sections, the data from these sensors are passed through a Kalman Filter to provide accurate state estimation for each sections joint angles.