This paper discusses energy-harvesting from atmospheric turbulence for small unmanned aerial vehicles, theoretically through simulations and practically through experimental flights. A comparison between different sce...
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ISBN:
(数字)9781624105784
ISBN:
(纸本)9781624105784
This paper discusses energy-harvesting from atmospheric turbulence for small unmanned aerial vehicles, theoretically through simulations and practically through experimental flights. A comparison between different scenarios for flight within sinusoidal wind profile is presented. A significant improvement in performance with active control of elevator has been found for an energy-harvesting mode when compared to auto-stabilization of fixed-stick flight. Moreover, a detailed decomposition of stochastic wind profile generated from Kaimal spectrum has shown which frequencies and magnitudes contribute mostly to the energy-transfer process. It was found that wind with higher turbulence intensity potentially provides more energy for transfer to the aircraft. Furthermore, the paper reveals biologically inspired sensory system for wind field estimation. It describes the necessary equipment and control algorithms for exploitation of atmospheric energy. Some initial flight tests are performed in order to determine the average power consumption of the motor and evaluate the performance of sensors. Moreover, additional flights for autonomous exploitation of several atmospheric phenomena have been presented and analysed.
The present work deals with diminishing the effects of wireless communication latency in time-sensitive networks. It takes advantage of modern approaches that offer bounded latency and it focuses on methods to cope wi...
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ISBN:
(数字)9781728152974
ISBN:
(纸本)9781728152981
The present work deals with diminishing the effects of wireless communication latency in time-sensitive networks. It takes advantage of modern approaches that offer bounded latency and it focuses on methods to cope with the nondeterministic delays introduced by communication *** observer-predictor scheme module is designed and added in the control loop to prevent the performance degradation when a wireless network is introduced. The goal is to allow the use of same controllers used in wired networks. This module may exploit information provided by the wireless communication devices, such as expected latency, timestamp, and time synchronization along the *** proposed module allows the controller to have a performance similar as when in a wired network. This enables wireless networked control in systems with low time constants (i.e. timesensitive).Lab experiments are presented in real-time to illustrate the observer-predictor scheme module proposed. Finally, the conclusions and future work are presented.
This paper aims to develop distributed feedback control algorithms that allow cooperative locomotion of quadrupedal robots which are coupled to each other by holonomic constraints. These constraints can arise from col...
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ISBN:
(数字)9781538682661
ISBN:
(纸本)9781538682678
This paper aims to develop distributed feedback control algorithms that allow cooperative locomotion of quadrupedal robots which are coupled to each other by holonomic constraints. These constraints can arise from collaborative manipulation of objects during locomotion. In addressing this problem, the complex hybrid dynamical models that describe collaborative legged locomotion are studied. The complex periodic orbits (i.e., gaits) of these sophisticated and high-dimensional hybrid systems are investigated. We consider a set of virtual constraints that stabilizes locomotion of a single agent. The paper then generates modified and local virtual constraints for each agent that allow stable collaborative locomotion. Optimal distributed feedback controllers, based on nonlinear control and quadratic programming, are developed to impose the local virtual constraints. To demonstrate the power of the analytical foundation, an extensive numerical simulation for cooperative locomotion of two quadrupedal robots with robotic manipulators is presented. The numerical complex hybrid model has 64 continuous-time domains, 192 discrete-time transitions, 96 state variables, and 36 control inputs.
Path tracking control is the key to ensure that the laser guided automated guided vehicles (LGAGVs) can deliver the goods to the designated place quickly and safely. However, it is very difficult to build accurate AVG...
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ISBN:
(数字)9781728160672
ISBN:
(纸本)9781728160689
Path tracking control is the key to ensure that the laser guided automated guided vehicles (LGAGVs) can deliver the goods to the designated place quickly and safely. However, it is very difficult to build accurate AVG dynamic model because of the variety of LGAGV dynamic types. In addition, a lot of manual test work is needed in traditional path tracking control, which makes the design of LGAGV path tracking challengeable. In this paper, the deep reinforcement learning (RL) is used to realize the design of LGAGV path tracking controller. Firstly, according to its characteristics, LGAGV path tracking problem is described as a Markov decision process (MDP) with continuous state and continuous action under the unknown transition probability. Then, a reliable control policy was learnt by LGAGV through the Proximal Policy Optimization (PPO) without any additionally exploring the possibilities. The simulation results show that the distance error and the stability of the control motor are better than the traditional model free algorithmic control when the angle error is fitting.
The Collider is a door that only opens to those who don't believe in its existence. Anyone who wants to pass through it must make a 10-meter run toward the door, without deceleration, before it springs open rapidl...
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The Collider is a door that only opens to those who don't believe in its existence. Anyone who wants to pass through it must make a 10-meter run toward the door, without deceleration, before it springs open rapidly at the last instant. A series of sensors along the runway detect the runner's speed, which is instantly analyzed by a computer algorithm that finally decides whether to open the door or not. The Collider provocatively asks the question: Do we trust the technologies we build? How should we trust them? Audiences find their own answers in participation, with their own bodies.
This paper focuses on a class of control system of permanent magnet synchronous motor (PMSM) with the time delay link. Because of the delay of the inverter, the delay of the conditioning circuit, and the dead zone, th...
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ISBN:
(数字)9781728162836
ISBN:
(纸本)9781728162843
This paper focuses on a class of control system of permanent magnet synchronous motor (PMSM) with the time delay link. Because of the delay of the inverter, the delay of the conditioning circuit, and the dead zone, there is a time delay between the input voltages of the motor and the output voltages of the controller. However, this time delay link is ignored in conventional vector control algorithms with respect to the d-q model, which inevitably leads to poor system stability and even divergence. In order to solve this problem, a novel control algorithm based on the mathematical model considering the time delay link is proposed in this paper. On one hand, the nonlinear time delay link is linearized and converted into a first-order inertial link through the Taylor series expansion method. Thus, nonlinear d-loop and q-loop are linearized. But the systems are changed into second-order systems. On the other hand, proportional-integral (PI) controllers with respect to the third-order optimum design method are designed to solve the design problem of controllers for higher-order systems than the conventionally d-q model. Experimental results show that the control algorithm proposed in this paper has good system stability with small current fluctuations, torque fluctuations, and speed fluctuations.
The field of soft robotics has evinced considerable interest recently due to its importance in several practical applications. Teleoperation of a soft manipulator to do a multitude of tasks in a remote environment is ...
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ISBN:
(数字)9781538682661
ISBN:
(纸本)9781538682678
The field of soft robotics has evinced considerable interest recently due to its importance in several practical applications. Teleoperation of a soft manipulator to do a multitude of tasks in a remote environment is one such promising application. The dexterity and conformity of a soft robot can be constructively utilized for enhanced motion planning and manipulability in cluttered environments. To that end, this paper investigates an adaptive task space bilateral teleoperation framework for soft robots with dynamic uncertainties assuming a non-redundant rigid master manipulator and a redundant soft slave manipulator under the piecewise constant curvature hypothesis. First, the dynamics of the soft robot are approximated as a rigid link manipulator with elastic joints using an existing augmented formulation in the literature. The task space adaptive bilateral teleoperation framework is then introduced based on this rigid-robot-like formulation. The null space velocity of the soft robot is also exploited to achieve sub-task objectives. Finally, the proposed control algorithms are experimentally investigated on a planar soft robot and the results are discussed pointing out the important observations.
This article proposes a two-degree-of-freedom control to command the torque of an electric traction machine in a hybrid electric vehicle equipped with a dual-clutch transmission in various driving situations. Here, th...
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ISBN:
(数字)9781538682661
ISBN:
(纸本)9781538682678
This article proposes a two-degree-of-freedom control to command the torque of an electric traction machine in a hybrid electric vehicle equipped with a dual-clutch transmission in various driving situations. Here, the torques of the clutches are taken into account, which need to be compensated in some driving scenarios (e.g. engine start via one clutch where a specific torque profile is transmitted). To do so, we first analyze the specific structure of the given powertrain in order to evaluate the controllability and observability of the nonlinear system. Then the feedforward-part of the controller is designed with an exact linearization of a reduced drivetrain model. For the feedback-part we propose gear-dependent linear-quadratic regulators obtained by linearizations around appropriate operating points of the vehicle. Additionally, an extended Kalman-Filter is designed in order to filter the noisy measurement on the one hand and to estimate the unknown clutch torques on the other. The performance of the control algorithm is illustrated by simulations of an accelerating vehicle perturbed by a torque transmitted over the clutches.
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