Development of a Legged Robot for Diverse and Challenging Terrains

Legged robots provide superior mobility over wheeled systems when operating on uneven and discontinuous terrain. However, many existing quadruped robots rely on expensive actuators and complex control architectures, limiting their accessibility for education and early-stage research. This paper presents the design, calibration, and experimental evaluation of a low-cost quadruped robotic platform constructed using readily available materials and hobby-grade actuators. A modular mechanical architecture with two-degree-of-freedom planar legs is developed using an acrylic chassis and servo-based actuation. To address the inherent inaccuracies and nonlinearities of low-cost servos, a software-based calibration and compensation framework is proposed to improve joint angle accuracy and gait repeatability. Furthermore, a systematic experimental study is conducted to quantify the trade-offs between payload, power consumption, gait stability, and actuator thermal behaviour. Experimental results demonstrate that the proposed calibration method reduces joint angle error by up to 35% and improves gait consistency under load. The performance evaluation identifies practical operational limits of hobby-grade servos for quadruped locomotion and provides design guidelines for developing affordable legged robots for education and prototyping.