Sunil Kumar Agrawal

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This paper provides a practical framework for planning and control of formations of multiple unmanned ground vehicles to traverse between goal points in a dynamic environment. This framework allows on-line planning of the formation paths using search algorithm based on the current sensor data. The formation is allowed to dynamically change in order to avoid(More)
—In this paper, we address the design of an autopilot for autonomous landing of a helicopter on a rocking ship, due to rough sea. A tether is used for landing and securing a helicopter to the deck of the ship in rough weather. A detailed nonlinear dynamic model for the helicopter is used. This model is underac-tuated, where the rotational motion couples(More)
— In this paper, we investigate design and performance of a flapping mechanism which generates flapping motion through resonant excitation similar to flight apparatus of insects. The desired flapping motion is based on optimum aerodynamic efficiency. The mechanism is driven by a conventional motor and gearbox. The rotary motion is converted into oscilltory(More)
In this paper, we address the design of an autopilot for autonomous landing of a helicopter on a rocking ship, due to rough sea. A tether is used for landing and securing a helicopter to the deck of the ship in rough weather. A detailed nonlinear dynamic model for the helicopter is used. This model is underactuated, where the rotational motion couples into(More)
Gait training of stroke survivors is crucial to facilitate neuromuscular plasticity needed for improvements in functional walking ability. Robot assisted gait training (RAGT) was developed for stroke survivors using active leg exoskeleton (ALEX) and a force-field controller, which uses assist-as-needed paradigm for rehabilitation. In this paradigm(More)
—In this paper, the dynamic model of a wheeled inverted pendulum (e.g., Segway, Quasimoro, and Joe) is analyzed from a controllability and feedback linearizability point of view. First, a dynamic model of this un-deractuated system is derived with respect to the wheel motor torques as inputs while taking the nonholonomic no-slip constraints into(More)
—Cable-suspended robots are structurally similar to parallel ac-tuated robots but with the fundamental difference that cables can only pull the end-effector but not push it. From a scientific point of view, this feature makes feedback control of cable-suspended robots more challenging than their counterpart parallel-actuated robots. In the case with(More)