4DOF Robot Arm Safety Implementation Using Ultrasonic Proximity and Current
Sensors
This project focused on modernizing a legacy 4-DOF Krishna robotic manipulator from the 1990s to
enhance safety, control precision, and adaptability for research and education. The upgrade
involved rewiring outdated components, integrating an Arduino-based control system, and
implementing real-time safety features such as ultrasonic sensors for human detection and
current sensing for approximate impedance control. A step-based position mapping approach
replaced encoders, ensuring effective motion tracking.
Key technologies included SolidWorks for mechanical redesign, MATLAB and Simulink for control
simulations, Python for sensor data analysis, and Arduino with INA260 current sensors for force
estimation. The upgraded system provides a scalable human-robot interaction platform, ensuring
safe, compliant motion while setting the foundation for advanced robotic research in force
control, adaptive compliance, and collaborative automation.