1,721,000 research outputs found
The Control System of the U.B. Hand II: an Overview of the Hardware Design and Implementation
No full textThe paper describes the control system of the University of Bologna Robotic Hand
Optimization and control problems in the design of a variable reluctance motor drive
No full textA prototype robust controller for variable reluctance motor is proposed. A three-level cascade control structure is adopted for this highly nonlinear system. The three control levels are all described but a particular emphasis is put on the torque-sharing compensator, designed with nonlinear optimization techniques to resolve redundancy in the torque generation of VR motor. The proposed controller is first verified by means of extensive simulation experiments. The architecture of the laboratory prototype controller is presented and experimental results on NSK-Megatorque motor are reported too. Presented results prove feasibility and good performance of the proposed controller, suitable for a very simple and rather inexpensive fully hardware implementation
A Multiprocessor-Controlled AC Motor Drive System with High Quality Input/Output Waveforms
No full textNonlinear trajectory generator for motion control systems
No full textThe paper presents a trajectory generator for point-to-point movements in the field of motion control systems such as are used in robotics. A nonlinear dynamic trajectory generator is proposed. It is a closed loop system which provides the best trajectory compatible with the user selectable constraints on motion state variables (velocity, acceleration, etc.). Constraints on state variables can be fixed or task dependent. They can be changed during system operation without impairing filter stability or introducing overshoot in the trajectory
A Smart Sensory and Actuation System for the University of Bologna Robotic Hand: Latest Developments and Implementations.
No full textThe control system of the U.B. robotic Han
A prototype controller for variable reluctance motors
Full text linkA three-level cascade structure is proposed for the control of a variable reluctance (VR) motor. In order to deal with the highly nonlinear behavior of VR motors, the controlling system includes two variable-structure controllers for current and velocity loops as well as an intermediate torque-sharing compensator. The intermediate compensator has been designed by means of nonlinear optimization techniques in order to reduce the torque ripple and to get the maximum motor velocity. The proposed controller has been validated through extensive simulation experiments. The architecture of a prototype controller is presented and the actual performance measured on a VR motor is discussed in comparison with simulations. The results show practical feasibility and good performance of the proposed controller, which is also suitable for a very simple and quite inexpensive fully hardware implementatio
Modeling and control strategies for a variable reluctance direct-drive motor
No full textA high-performance ripple-free dynamic torque controller for a variable-reluctance (VR) motor intended for trajectory tracking in robotic applications is designed. A modeling approach that simplifies the design of the controller is investigated. Model structure and parameter estimation techniques are presented. Different approaches to the overall torque controller design problem are discussed, and the solution adopted is illustrated. A cascade controller structure consisting of a feedforward nonlinear torque compensator, cascaded to a nonlinear flux or current closed-loop controller is considered, and optimization techniques are used for its design. Although developed for a specific commercial motor, the proposed modeling and optimization strategies can be used for other VR motors with magnetically decoupled phases, both rotating and linear. Laboratory experiments for model validation and preliminary simulation results of the overall torque control system are presente
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
- …
