This paper presents (i) to propose a PID-type composite controller for controlling flexible arms modeled by the singular perturbation approach and (ii) to investigate a tuning method based on the proposed controller s...
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This paper presents (i) to propose a PID-type composite controller for controlling flexible arms modeled by the singular perturbation approach and (ii) to investigate a tuning method based on the proposed controller structure. For the slow sub-controller, PD plus disturbance observer is used, which eventually takes on PID form, and for the fast sub-controller, modal feedback PID control is utilized. Effects of design parameters of the controller on the closed loop response are investigated. Through simulation and experiments, the adequacy and performance of the proposed method are verified.
Enveloping grasp system not in static equilibrium results in dynamical motion. In this article, we develop a method based on dynamical-balance to solve motion analysis problem for an active-external grasp, that is to ...
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Enveloping grasp system not in static equilibrium results in dynamical motion. In this article, we develop a method based on dynamical-balance to solve motion analysis problem for an active-external grasp, that is to determine contact forces and accelerations consistent with the dynamics and friction law for a given torque-wrench pair. Since the method is analytic in nature, it may give chance of better efficiency and more direct insight than a relevant linear complementarity formulation, though the solutions are same. The method is verified using two examples: one is a simple grasp system with one frictional contact, and the other is a relatively general one with all frictionless contacts.
This work investigates the efficacy of software simulations of electronic circuits laboratories to support beginning electrical engineering students. Experiment 1 was a formative evaluation of an Electronic Laboratory...
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This work investigates the efficacy of software simulations of electronic circuits laboratories to support beginning electrical engineering students. Experiment 1 was a formative evaluation of an Electronic Laboratory Simulator (ELS), as an optional add-on to physical labs for 120 subjects at four universities. All subjects received the same treatment: their normal classes and physical labs, with optional use of simulated labs. Subjects took written tests specific to the lab's content, before and after using each simulated lab. Only subjects who took both pre- and post-tests were included. Pre- and post-test comparisons indicated significant improvement in both theory and lab knowledge when scores for all labs were combined, but inconsistent performance on individual labs. As the treatment included other learning opportunities in addition to simulated labs, the results were not attributed to the simulations, but provided initial indications and qualitative data on subjects' experiences. These helped to improve the labs and the implementation strategies. Experiment 2 used 40 college sophomores in a beginning electronic circuits lab. Physical lab subjects received seven physical labs. Combined lab subjects received a combination of seven simulated labs and two physical labs. The latter repeated two of the simulated labs to provide physical lab practice. Both treatments used the same assignments. Learner outcome measures were: (a) time required to complete a new criterion physical lab;(b) score on written lab and theory tests over all the labs;and (c) comments on the lab experience. The group that used combined simulated and physical labs performed significantly better on the written tests than the group using entirely physical labs. Both groups were equivalent in time to complete the criterion physical lab. Comments about the simulated labs were generally positive, and also provided specific suggestions for changes.
In this paper, a simple direct parameter update rule is presented to suppress the vibration more quickly, considering the dynamics of flexible subsystem. Different from most of adaptive control schemes in multilink fl...
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In this paper, a simple direct parameter update rule is presented to suppress the vibration more quickly, considering the dynamics of flexible subsystem. Different from most of adaptive control schemes in multilink flexible robots, which is a model-independent approach, the proposed adaptive control utilizes model parameters and updates them. Usually, the precise modeling of multi-link flexible robot is hard to obtain and even if we can get it, it is difficult to use in the online control tasks. Due to these reasons, a simplified model is used to describe the robot dynamics. The modelling errors and other structured uncertainty are considered as parameter perturbation. We verify the effectiveness of the proposed algorithm through experiments.
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