Sudipta Saha

Chandra Shekhar, Jagnyashini Debadarshini, Sudipta Saha

Detection and classification of vehicles are very significant components in an Intelligent-Transportation System. Existing solutions not only use heavy-weight and costly equipment, but also largely depend on constant cloud (Internet) connectivity, as well as adequate uninterrupted power-supply. Such dependencies make these solutions fundamentally impractical considering the possible adversities of outdoor environment as well as requirement of correlated wide-area operation. For practical use, apart from being technically sound and accurate, a solution has to be lightweight, cost-effective, easy-to-install, flexible as well as supporting efficient time-correlated coverage over large area. In this work we propose an IoT-assisted strategy to fulfil all these goals together. We adopt a top-down approach where we first introduce a lightweight framework for time-correlated low-cost wide-area measurement and then reuse the concept for developing the individual measurement units. Our extensive outdoor measurement studies and trace-based simulation on the empirical data show about 98% accuracy in vehicle detection and upto 93% of accuracy in classification of the vehicles over moderately busy urban roads.

Sourabha Bharadwaj, Karunakar Gonabattula, Sudipta Saha et al.

An efficient communication mechanism forms the backbone for any multi-robot system to achieve fruitful collaboration and coordination. Limitation in the existing asynchronous transmission based strategies in fast dissemination and aggregation compels the designers to prune down such requirements as much as possible. This also restricts the possible application areas of mobile multi-robot systems. In this work, we introduce concurrent transmission based strategy as an alternative. Despite the commonly found difficulties in concurrent transmission such as microsecond level time synchronization, hardware heterogeneity, etc., we demonstrate how it can be exploited for multi-robot systems. We propose a split architecture where the two major activities - communication and computation are carried out independently and coordinate through periodic interactions. The proposed split architecture is applied on a custom build full networked control system consisting of five two-wheel differential drive mobile robots having heterogeneous architecture. We use the proposed design in a leader-follower setting for coordinated dynamic speed variation as well as the independent formation of various shapes. Experiments show a centimeter-level spatial and millisecond-level temporal accuracy while spending very low radio duty-cycling over multi-hop communication under a wide testing area.