Laser Operated Utility Cart

Abstract

The objective of this undergraduate student project was to design a laser remotecontrolled utility cart. The intent was to design and build the cart from discrete electronic components and mechanical parts utilizing a multitude of engineering disciplines the Engineering Technology program offered at the University of Maryland Eastern Shore. The cart was required to perform the following motions; going forward, going in reverse, turning right, turning left and stopping. These motions were remote-controlled by laser light aimed at five different photoresistors embedded in the rear section of the cart. Completion of a project required: 1. Designing and constructing a laser controlled electronic circuit to operate the cart. 2. Designing and constructing a mechanical frame, assembling a drive mechanism to utilize an electrical DC motor to move the cart and a stepper motor to steer it. The electronic controlling circuit was designed and constructed on a prototype board so that students could modify or trouble shoot any malfunction section easily. The control circuit consisted of a laser switching circuit, clock generator, pulse sequencing circuit and relays to deliver high current to the DC and stepper motors. The cart was assembled out of pine and blast wood to keep the weight down to a minimum. The cart's rear axle was coupled to the shaft of a DC motor with high torque that could move the cart forward and backward. Steering was done by a stepper motor in order to have better control during turning.