Bradley Hamner

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Comprehensive Automation for Specialty Crops is a project focused on the needs of the specialty crops sector, with a focus on apples and nursery trees. The project's main thrusts are the integration of robotics technology and plant science; understanding and overcoming socioeconomic barriers to technology adoption; and making the results available to(More)
This paper concerns an outdoor mobile robot that learns to avoid collisions by observing a human driver operate a vehicle equipped with sensors that continuously produce a map of the local environment. We have implemented steering control that models human behavior in trying to avoid obstacles while trying to follow a desired path. Here we present the(More)
This paper presents a motion planning method for mobile manipulators for which the base locomotion is less precise than the manipulator control. In such a case, it is advisable to move the base to discrete poses from which the manipulator can be deployed to cover a prescribed trajectory. The proposed method finds base poses that not only cover the(More)
The fundamental difference between autonomous robotic assembly and traditional hard automation, currently utilized in large-scale manufacturing production, lies in the specific approaches used in locating, acquiring, manipulating , aligning, and assembling parts. An autonomous robotic assembly manipulator offers high flexibility and high capability to deal(More)
This paper presents an outdoor mobile robot capable of high-speed navigation in outdoor environments. Here we consider the problem of a robot that has to follow a designated path at high speeds over undulating terrain. It must also be perceptive and agile enough to avoid small obstacles. Collision avoidance is a key problem and it is necessary to use(More)
Here we consider the problem of a robot that must follow a previously designated path outdoors. While the nominal path, a series of closely spaced via points, is provided with an assurance that it will lead to the destination , we can't be guaranteed that it will be obstacle free. We present an efficient system capable of both following the path as well as(More)
Here we present five large data sets with range-only measurements between a mobile robot and stationary nodes. Each data set consists of range measurements, surveyed locations of the stationary radio nodes, dead-reckoned trajectory of the robot, and ground truth from a sophisticated inertial navigation system/global positioning system mounted on a robot(More)
— Safe robot navigation in tree fruit orchards requires that the vehicle be capable of robustly navigating between rows of trees and turning from one aisle to another; that the vehicle be dynamically stable, especially when carrying workers; and that the vehicle be able to detect obstacles on its way and adjust its speed accordingly. In this paper we(More)