This robot was designed and constructed for my final project in RBE 2001 at WPI. The robot was tasked with removing old “solar collectors” from a house with two different roof heights and angles, and moving them to a staging area. The robot then needed to pickup a new collectors and place them on the roof. All tasks were completed autonomously, with user input required from the IR remote to begin each task in the sequence.

The robot design utilizes a Romi chassis from Pololu as its base, and features a four bar lift mechanism and four bar gripper mechanism to manipulate the solar collectors. The four bar lift features a 1:25 transmission to increase torque as needed to lift the aluminum plate. The system uses several sensors to navigate and complete tasks autonomously. These include quadrature encoders, an ultrasonic rangefinder, an IR receiver, and a reflectance sensor array. 

The linkage synthesis for the four bar lifting mechanism was performed in Solidworks and designed such that the arm can reach all three required positions and angles with just one actuator. The design of all 3D printed parts including the deck, walls, arm, gears, and gripper assembly was also done in Solidworks. Extensive analysis and calculations were performed to guide the design process and evaluate the final design. The robot was programmed in C++, making use of a state machine and non-blocking functions to allow the robot to respond to an emergency stop signal at any time. The video linked below shows a demonstration of the robot completed the required tasks.