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Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled...
This paper presents an omnidirectional active vision system that has been developed for the autonomous acquisition of detailed images of multiple targets. Omnidirectional and perspective camera technologies are integrated to create a robust vision system that combines the strengths of both camera types. A compact, inexpensive and highly modular design is presented in which system modules are stacked...
Five scheduling policies that have been developed and implemented to manage the active resources of a centralized active vision system are presented in this paper. These scheduling policies are tasked with making target-to-camera assignments in an attempt to maximize the number of targets that can be imaged with the system's active cameras. A comparative simulation-based evaluation has been performed...
The 10 mm incisions used in minimally invasive cancer surgery prevent direct manual palpation of internal organs, making intraoperative tumor localization difficult. A tactile sensing instrument (TSI), that uses a commercially available sensor to measure distributed pressure profiles along the contacting surface, has been developed to facilitate remote tissue palpation. The objective of this research...
The restricted access conditions during minimally invasive surgery (MIS) result in perceptual-motor relationships that are unfamiliar to the novice surgeon and require training to overcome. To aid in MIS skills assessment and training, a novel sensorized instrument has been designed. Strain gauges attached to the instrument measure forces and torques acting at its tip, corresponding to all 5 degrees...
Measuring the position of a tendon-driven rotating link, based on the state of the tendons at the proximal end is challenging. Specifically, tendon elasticity and Coulomb friction can cause significant nonlinearities in the relationship between the motion at the proximal end of the tendon and the motion of the link. An extended Kalman filter (EKF) is proposed as a potential method to refine estimates...
Restricted access during minimally invasive surgery precludes manual palpation, making the localization of lung tumours challenging. This paper investigates the force sensing performance that would allow an instrumented kinesthetic probe to localize tumours based on stiffness variations of the lung parenchyma. Agar injected into ex vivo porcine lungs produced a model approximating commonly encountered...
Minimally invasive surgery is a technique that provides numerous benefits to the patient, but presents challenges to the surgeon in that dexterity, hand-eye coordination and haptic perception are compromised. Robot-assisted minimally invasive approaches have addressed the problems of dexterity and coordination; however, the lack of kinesthetic and tactile feedback remains a significant drawback. Despite...
This paper describes the design and implementation of a set of building blocks for the construction of adaptive modular sensing systems. A hardware architecture is proposed which allows the development of a general set of modular components with embedded knowledge about their capabilities. These modular components are referred to as transducer interface modules (TIMs). A knowledge representation scheme...
In this paper, a software architecture and knowledge representation scheme that enables the combination and reconfiguration of modular sensor and actuator components is described. The proposed software architecture utilizes a realtime operating system with a pre-emptive kernel, which simplifies the implementation of the architecture itself through the modularization and concurrent execution of its...
The growing popularity of omnidirectional vision technology has spawned numerous multi-camera designs that integrate various different camera types. This paper presents an omnidirectional vision system that combines a catadioptric camera, a fisheye camera and an active perspective camera. Aligning these cameras vertically provides a number of beneficial features, such as allowing simple peripherally-guided...
In this paper, a novel reconfigurable surveillance system that incorporates multiple active-vision sensors is presented. The proposed system has been developed for visual-servoing and other similar applications, such as tracking and state estimation, which require accurate and reliable target surveillance data. In the specific implementation case discussed herein, the position and orientation of a...
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