Smooth control of an articulated mobile robot with switching constraints

The paper describes a smooth controller of an articulated mobile robot with switching constraints. The use of switching constraints associated with grounded/lifted wheels is an effective method of controlling various motions; e.g. the avoidance of a moving obstacle. A model of an articulated mobile robot that has active and passive wheels and active joints with switching constraints is derived. A controller that accomplishes the trajectory tracking of the robot’s head and subtasks using smooth joint input is proposed on the basis of the model. Simulations and experiments are presented to show the effectiveness of the proposed controller

Robotic Endoscope

The endoscope has become ubiquitous and indispensable, changing many surgical procedures from life-threatening to outpatient. Use of the endoscope is limited by the ability to safely navigate circuitous paths, provide a stable tip in situ, and generate force where and as needed. Our lab developed a prototype robotic endoscope which mitigates these limits and is able both to contort to follow a convolved path and to generate tip-force in any direction. This design can be mounted at the extracorporeal end of any control system, extending existing surgical robots' utility. The effectors' actuators (stepper motors in this prototype) are external to the effector and transmit force via cables (aka tendons), and, assuming nonferromagnetic robot-segment composition, the design is safe for use with MRI and X-ray. A hollow core allows for in situ tool exchange, and hollow wall channels allows for routing permanent tools to the effector tip (e.g., vacuum, saline, fiber optics).Doctor of Philosoph