To enhance the safety of a humanoid robot when it is operating a complex environment, a number of methods that combine visual and force information have been presented. These methods are generally divided into two app...
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To enhance the safety of a humanoid robot when it is operating a complex environment, a number of methods that combine visual and force information have been presented. These methods are generally divided into two approaches. The first approach is to coordinate the visual controller and force controller in a parallel way, and the second approach is to coordinate them in series. However, these two approaches do not consider the interaction between the visual controller and force controller. Specifically, the first approach does not consider the interaction between the controllers. The second approach only considers the effect of the output of the visual controller on the force controller, while the effect of the force controller on the visual controller is not considered. This study presents a design for a new flexible controller for a humanoid robot that considers the interaction of visual and force information. The advantages of the proposed method are that it simultaneously incorporates the functions of a visual servo controller and a flexible controller as well as its ability to consider the interaction of visual and force information when a humanoid robot is operating.
Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a c...
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Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a common axis. Due to the existence of the rotating mode, the desired relative position between every two agents is time-varying, and a Lyapunov-based approach is employed to solve the rotating formation control problem. Finally, simulation results are provided to illustrate the effectiveness of the theoretical results.
An adaptive distributed differential evolution algorithm is proposed based on the change of the individual's fitness value. Firstly, the initial population is divided into several subpopulations. When the migratio...
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An adaptive distributed differential evolution algorithm is proposed based on the change of the individual's fitness value. Firstly, the initial population is divided into several subpopulations. When the migration condition is satisfied, the best individual in each subpopulation will replace the worst individual of its neighbor subpopulations according to the Von Neumann topology. The migration mechanism among subpopulations enables the information to be communicated in the whole population. Meanwhile, the adaptive mechanism of F and CR is presented for assigning different F and CR to each individual according to the individual's fitness. Numerical results show that, the proposed algorithm is beneficial to explore the solution space, which can avoid the premature convergence and search the excellent solutions.
This paper proposes a coordination control strategy of voltage source converter based multi-terminal DC (VSC-MTDC) transmission system for integrating large-scale offshore wind power. Using a typical five-terminal DC ...
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A robust recursive least-squares(RLS) adaptive filter against impulsive noise is proposed for the situation of an unknown desired *** minimizing a saturable nonlinear constrained unsupervised cost function instead of ...
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A robust recursive least-squares(RLS) adaptive filter against impulsive noise is proposed for the situation of an unknown desired *** minimizing a saturable nonlinear constrained unsupervised cost function instead of the conventional least-squares function,a possible impulse-corrupted signal is prevented from entering the filter’s weight updating ***,a multi-step adaptive filter is devised to reconstruct the observed "impulse-free" noisy sequence,and whenever impulsive noise is detected,the impulse contaminated samples are replaced by predictive *** on simulation and experimental results,the proposed unsupervised robust recursive least-square adaptive filter performs as well as conventional RLS filters in "impulse-free" circumstances,and is effective in restricting large disturbances such as impulsive noise when the RLS and the more recent unsupervised adaptive filter fails.
In this paper, we study the coordinated obstacle avoidance algorithm of multi-agent systems when only a subset of agents has obstacle dynamic information, or every agent has local interaction. Each agent can get parti...
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In this paper, we study the coordinated obstacle avoidance algorithm of multi-agent systems when only a subset of agents has obstacle dynamic information, or every agent has local interaction. Each agent can get partial measuring states information from its neighboring agent and obstacle. Coordinated obstacle avoidance here represents not only the agents moving without collision with an obstacle, but also the agents bypassing and assembling at the opposite side of the obstacle collectively, where the opposite side is defined according to the initial relative position of the agents to the obstacle. We focus on the collective obstacle avoidance algorithms for both agents with first-order kinematics and agents with second-order dynamics. In the situation where only a fixed fraction of agents can sense obstacle information for agents with first-order kinematics, we propose a collective obstacle avoidance algorithm without velocity measurements. And then we extend the algorithm to the case in switched topology. We show that all agents can bypass an obstacle and converge together, and then assemble at the opposite side of the obstacle in finite time, if the agents׳ topology graph is connected and at least one agent can sense the obstacle. In the case where obstacle information is available to only a fixed fraction of agents with second-order kinematics, we propose two collective obstacle avoidance algorithms without measuring acceleration when the obstacle has varying velocity and constant velocity. The switched topology is considered and extended next. We show that agents can bypass the obstacle with their positions and velocities approaching consensus in finite time if the connectivity of switched topology is continuously maintained. Several simulation examples demonstrate the proposed algorithms.
Most current researches working on improving stiffness focus on the application of control *** controller in closed-loop hydraulic controlsystem takes effect only after the controlled position is deviated,so the cont...
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Most current researches working on improving stiffness focus on the application of control *** controller in closed-loop hydraulic controlsystem takes effect only after the controlled position is deviated,so the control action is *** dynamic performance against force disturbance and dynamic load stiffness can’t be improved evidently by advanced control *** this paper,the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil is *** this basis,the conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put *** a scheme using double servo valves to realize flow feedforward compensation is presented,in which another fast response servo valve is added to the regular electro hydraulic servo system and specially utilized to compensate the compressed oil volume caused by load impact in *** two valves are arranged in parallel to control the cylinder ***,the model of flow compensation is derived,by which the product of the amplitude and width of the valve’s pulse command signal can be *** determination rules of the amplitude and width of pulse signal are concluded by analysis and *** the proposed scheme,simulations and experiments at different positions with different force changes are *** simulation and experimental results show that the system dynamic performance against load force impact is largely improved with decreased maximal dynamic position deviation and shortened settling *** is,system dynamic load stiffness is evidently *** paper proposes a new method which can effectively improve the dynamic stiffness of electro-hydraulic servo systems.
To achieve the accurate measurement of the hydraulic valve opening position, two different measurement circuits were designed respectively for two-coil and three-coil differential solenoid inductance displacement sens...
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To achieve the accurate measurement of the hydraulic valve opening position, two different measurement circuits were designed respectively for two-coil and three-coil differential solenoid inductance displacement sensors. Compared the pros and cons of their static and dynamic performances. The peripheral measurement circuit based on the AD698 was improved, so as to enhance the sensitivity of displacement detection. The different sensor measurement circuits were tested to compare the static output characteristics of these two types of sensors. The experimental results show that AD698 sensor measurement circuit is featured with small nonlinear error, high repeatability, and low hysteresis error. Sensitivity varies with the range of the measurement. When the sensor measuring ranges of conditions are defined, it is appropriate to increase sensitivity. In Valvistor hydraulic cartridge valve system, AD698 measurement circuit would be used to test the real-time dynamic detection. When the system pressure is maintained constant, the valve opening size influences the response speed of the sensor measuring circuit. The greater the pressure valve, the faster the dynamic response of the valve. The relationship between main valve displacement and flow rate is also detected in these experiments.
Stable walking of bipedal humanoid is an crucial and challenge issue of research in bipedal robots. And the structure of shoe sole plays a significant role in preventing someone from slipping in human life. The humano...
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ISBN:
(纸本)9781479973989
Stable walking of bipedal humanoid is an crucial and challenge issue of research in bipedal robots. And the structure of shoe sole plays a significant role in preventing someone from slipping in human life. The humanoid robot foot often skid while the robot is walking fast, and it may cause serious harmfulness. This study presents some foot pads for humanoid robot to improve its stability and reliability. First, anti-skid foot for a humanoid robot is proposed in this paper. Second, the material and pattern of foot pads are selected. Finally, the better foot pads are chosen by several experiments and the effectiveness of the new foot pads is confirmed by comparison experiments.
The research of networked fire controlsystem simulation plays an important role in modern warfare. Federates of simulation systems based on High Level Architecture (HLA) have a poor reusability. In order to improve t...
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The research of networked fire controlsystem simulation plays an important role in modern warfare. Federates of simulation systems based on High Level Architecture (HLA) have a poor reusability. In order to improve their reusability, the idea of componentization was used to divide federates into several smaller reusable modules by analyzing the internal information flow of the federates. By component technology, three types of small components which have better reusability were designed, including common components, special components and communication components. These components can be used to build a multiple complex models which can be combined with new simulation frameworks to form defense simulation systems for different attacking targets. A simulation task was designed to verify the flexibility and reusability of the designed components and to improve the function of the federates, which effectively improved development efficiency of simulation systems.
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