Akademik Veri Yönetim Sistemi
SYMMETRY, cilt.1, sa.1, ss.1-27, 2025 (SCI-Expanded)
Natural and unconstrained locomotion remains a fundamental challenge in creating truly
immersive virtual reality (VR) experiences. This paper presents the design and control of
a novel robotic omnidirectional treadmill (ODT) based on the bilateral symmetry of two
cooperative five-bar planar mechanisms designed to replicate realistic walking mechanics.
The central contribution is a human in the loop control strategy designed to achieve stable
walking in place. This framework employs a specific control strategy that actively repositions
the footplates along a dynamically defined ‘Line of Movement’ (LoM), compensating
for the user’s motion to ensure the midpoint between the feet remains stabilized and
symmetrical at the platform’s geometric center. A comprehensive dynamic model of both
the ODT and a coupled humanoid robot was developed to validate the system. Numerical
simulations demonstrate robust performance across various gaits, including turning and
catwalks, maintaining the user’s locomotion center with a maximum resultant drift error of
11.65 cm, a peak value that occurred momentarily during a turning motion and remained
well within the ODT’s safe operational boundaries, with peak errors along any single axis
remaining below 9 cm. The system operated with notable efficiency, requiring RMS torques
below 22 Nm for the primary actuators. This work establishes a viable dynamic and control
architecture for foot-tracking ODTs, paving the way for future enhancements such as haptic
terrain feedback and elevation simulation.