Organizational Unit:
Institute for Robotics and Intelligent Machines (IRIM)
Institute for Robotics and Intelligent Machines (IRIM)
Permanent Link
Research Organization Registry ID
Description
Previous Names
Parent Organization
Parent Organization
Includes Organization(s)
Organizational Unit
Organizational Unit
ArchiveSpace Name Record
Publication Search Results
Now showing
1 - 8 of 8
-
ItemModeling of biodynamic feedthrough in backhoe operation(Georgia Institute of Technology, 2009-10) Humphreys, Heather C. ; Book, Wayne J. ; Huggins, James D.An advanced backhoe user interface has been developed which uses coordinated control with haptic feedback. Results indicate that the coordinated control provides more intuitive operation that is easy to learn, and the haptic feedback also relays meaningful information back to the user in the form of force signals from digging forces and system limitations. However, results show that the current system has significant problems with biodynamic feedthrough, where the motion of the controlled device excites motion of the operator, resulting in undesirable forces applied to the input device and control performance degradation. This unwanted input is difficult to decouple from the intentional operator input in experiments. This research presents an investigation on the effects of biodynamic feedthrough on this particular backhoe control system, using system identification to empirically define models to represent each component. These models are used for a preliminary simulation study on potential methods for biodynamic feedthrough compensation.
-
ItemA virtual reality operator Interface station with hydraulic hardware-in-the-loop simulation for prototyping excavator control systems(Georgia Institute of Technology, 2009-07) Elton, Mark D. ; Enes, Aaron R. ; Book, Wayne J.A multimodal operator interface station is developed to display a realistic virtual reality depiction of a compact excavator performing general digging tasks. The interface station includes engine audio feedback and a near life-size operator display attached to a full-size cab. The excavator dynamics are determined by models of the hydraulic system, the linkage system, and the soil digging forces. To maximize the fidelity of the hydraulic model, certain ldquovirtualrdquo components of the model are replaced with real-time hardware-in-the-loop (HIL) simulations of the actual hardware. HIL simulation is done in a geographically isolated facility, with Internet based communication between HIL and the remote operator interface. This is the first reported high-fidelity operator interface to be combined with remote hydraulic HIL simulations.
-
ItemA novel approach to fabric control for automated sewing(Georgia Institute of Technology, 2009-07) Winck, Ryder C. ; Dickerson, Stephen L. ; Huggins, James D. ; Book, Wayne J.This paper describes a novel fabric manipulation method for fabric control during the sewing process. It addresses issues with past attempts concerning fabric position and tension control. The method described involves replacing the current sewing feed mechanism with a servo controlled manipulator to both feed and control the fabric. The manipulator is coupled with a machine vision system that tracks the threads of the fabric to provide real-time position control that is robust with respect to fabric deformations. A prototype of the manipulator is used to demonstrate the feasibility of the concept, reaching accelerations up to 27 g’s and following a closed loop trajectory with open loop control while operating in coordination with an industrial sewing machine. The system described also offers a general solution to high accuracy and high acceleration position control systems.
-
ItemAutomatic coordination and deployment of multi-robot systems(Georgia Institute of Technology, 2009-03-31) Smith, Brian StephenWe present automatic tools for configuring and deploying multi-robot networks of decentralized, mobile robots. These methods are tailored to the decentralized nature of the multi-robot network and the limited information available to each robot. We present methods for determining if user-defined network tasks are feasible or infeasible for the network, considering the limited range of its sensors. To this end, we define rigid and persistent feasibility and present necessary and sufficient conditions (along with corresponding algorithms) for determining the feasibility of arbitrary, user-defined deployments. Control laws for moving multi-robot networks in acyclic, persistent formations are defined. We also present novel Embedded Graph Grammar Systems (EGGs) for coordinating and deploying the network. These methods exploit graph representations of the network, as well as graph-based rules that dictate how robots coordinate their control. Automatic systems are defined that allow the robots to assemble arbitrary, user-defined formations without any reliance on localization. Further, this system is augmented to deploy these formations at the user-defined, global location in the environment, despite limited localization of the network. The culmination of this research is an intuitive software program with a Graphical User Interface (GUI) and a satellite image map which allows users to enter the desired locations of sensors. The automatic tools presented here automatically configure an actual multi-robot network to deploy and execute user-defined network tasks.
-
ItemSteerability in Planar Dissipative Passive Robots(Georgia Institute of Technology, 2009) Gao, Dalong ; Book, Wayne J.Steerability is intuitively the ability to change directions. In this paper, a formal definition is given for the steerability of a robot achieved either passively or actively. A dissipative passive robot uses only passive actuators such as brakes and clutches (a clutch is essentially a brake plus a gearbox) to redirect or steer operator-imposed motion by dissipating energy. While it has safety and ergonomic advantages, which are essential for human interactions, it also has difficulties in redirecting certain motions since passive actuators cannot add energy. The force generated from a passive actuator is used to measure the steerability. A steerability theorem was then developed for a manipulator with generalized passive actuators. The steerability analysis for an example diamond-shaped manipulator shows the difference in steerability when using only brakes or a combination of brakes and clutches. Further analyses show the difference comes from the ability of a clutch to change the direction of the generated force in the subject robot by altering the effective gear ratios
-
ItemSimultaneous Cooperative Exploration and Networking Based on Voronoi Diagrams(Georgia Institute of Technology, 2009) Kim, Jonghoek ; Zhang, Fumin ; Egerstedt, Magnus B.We develop a strategy that enables multiple intelligent vehicles to cooperatively explore complex territories. Every vehicle deploys communication devices and expands an information network while constructing a topological map based on Voronoi diagrams. As the information network weaved by each vehicle grows, intersections eventually happen so that the topological maps are shared. This allows for distributed vehicles to share information with other vehicles that have also deployed communication devices. Our exploration algorithms are provably complete under mild technical assumptions. A performance analysis of the algorithms shows that in a bounded workspace, the time spent to complete the exploration decreases as the number of vehicles increases. We further provide an analytical formula for this relationship. Time efficiency of the algorithms is demonstrated in MATLAB simulation.
-
ItemControl of reconfigurability and navigation of a wheel-legged robot based on active vision(Georgia Institute of Technology, 2008-07-31) Brooks, Douglas AntwonneThe ability of robotic units to navigate various terrains is critical to the advancement of robotic operation in real world environments. Next generation robots will need to adapt to their environment in order to accomplish tasks that are either too hazardous, too time consuming, or physically impossible for human-beings. Such tasks may include accurate and rapid explorations of various planets or potentially dangerous areas on planet Earth. This research investigates a navigation control methodology for a wheel-legged robot based on active vision. The method presented is designed to control the reconfigurability of the robot (i.e. control the usage of the wheels and legs), depending upon the obstacle/terrain, based on perception. Surface estimation for robot reconfigurability is implemented using a region growing method and a characterization and traversability assessment generated from camera data. As a result, a mathematical approach that directs necessary navigation behavior is implemented to control robot mobility. The hybrid wheeled-legged rover possesses a four-legged or six-legged walking system as well as a four-wheeled mobility system.
-
ItemA hardware-in-the-loop simulation testbed for emulating hydraulic loads representing the complete dig cycle of a construction machine(Georgia Institute of Technology, 2008) Enes, Aaron R. ; Book, Wayne J.A hardware-in-the-loop (HIL) simulation testbed is designed to be capable of emulating the entire domain of hydraulic workport loads incident on a test valve during normal work cycle operations of a certain hydraulic construction machine, such as a backhoe or excavator. The HIL testbed is a useful tool during rapid prototyping of control algorithms for the test valve, and for performing controlled experiments with the valve in the context of developing valve control algorithms to improve the overall energy efficiency of hydraulic systems. This paper discusses four key topics: the architecture of the real-time simulation and testbed control process, the modeling and validation of the emulated machine dynamics, the controller development for the HIL testbed, and some initial performance testing of the HIL testbed.