Integrated STEM in Mechatronics Engineering 35: Drawing Robots

By Laura Roa & Jaime Kochan STEMIA High School

In an innovative approach to STEM education, the Mechatronics Engineering 35 course has been designed to integrate Science, Technology, Engineering, and Mathematics through an exciting project: building a hanging drawing robot. This course harnesses high-level Arduino engineering kits and MATLAB software, providing students with a rich, hands-on learning experience.?

The Arduino engineering kits empower students to build and control complex robotics systems, combining hardware and software in a seamless learning environment. Through this process, students gain practical insights into circuit design, sensor integration, motor control, and image processing. The project began with students learning about Proportional-Integral-Derivative (PID) control as they used Simulink to collect data from the encoder of a DC motor. Students then assembled the robot which used two dc motors to navigate a vertical whiteboard, and a servo motor to control the marker position. Students then used trigonometry to decompose robot movement along with linear mechanics to transform board coordinates into angular displacement of the DC motors using MATLAB scripts.??

Next, students learned about the practical limitations of drawing on a vertical whiteboard using the robot. Students drew free-body diagrams to account for tension and gravitational forces, and used the DC motor datasheets and their knowledge regarding systems of equations to code an equation that could calculate the motor torque at each location on the board. After using MATLAB to create torque plots, students set limits to robot movements, so that the motors would not exceed 30% of the motor stall torque.?

Lastly, students learned about image processing to extract relevant data from drawings and output board coordinates that the robot could draw. To accomplish this, students used image filters in MATALB, by turning a color image into grayscale, binarizing it, and performing morphological operations of dilation and erosion. Then using recursion to extract pixels and merging these into segments that the robot can draw, and lastly applying a scaling factor to turn pixels into whiteboard distances.?

Assembling and programming the hanging drawing robot provides a comprehensive educational experience. It encourages innovation and critical thinking while teaching students to collaborate effectively. Through this course, students are not only prepared to tackle future engineering challenges but also inspired to explore the creative intersections of technology, design, mathematics, and science to solve real world challenges.?