The no-wait hybrid flowshop scheduling problem is studied to minimize the makespan. This class of problem is characterized by the processing of n jobs through m stages with one or more machines at each stage, and ther...
详细信息
The no-wait hybrid flowshop scheduling problem is studied to minimize the makespan. This class of problem is characterized by the processing of n jobs through m stages with one or more machines at each stage, and there is no-wait restriction between stages. An integer programming model is first formulated. Then the complete scheduling scheme for a given job sequence is built, and a new heuristic based on the scheduling scheme is proposed. Computational experience demonstrates the effectiveness of the heuristic algorithm in finding near optimal schedules.
This investigation is to apply the so-called component synthesis vibration suppression (CSVS) based feedforward control and the conventional PD feedback control to the vibration control of a flexible spacecraft. The p...
详细信息
This investigation is to apply the so-called component synthesis vibration suppression (CSVS) based feedforward control and the conventional PD feedback control to the vibration control of a flexible spacecraft. The proposed control design process is two fold: design of the attitude controller followed by the design of a flexible vibration attenuator. The attitude control law design is based on the Lyapunov stability theory to achieve a stabilizing closed-loop system. The shaped command input controller based on the CSVS method is designed for the reduction of the flexible vibration by modifying the command input, which only requires information about the natural frequency and damping of the closed-loop system. To extend the CSVS method to the system with the on-off actuators, the pulse-width pulse-frequency (PWPF) modulation is introduced to control the thruster firing and integrated with the CSVS method. The simulation results have been proven the potential of this technique to control flexible spacecraft
This paper presents a real-time simulation system based on ve-DYNA. A vehicle dynamics model is built with ve-DYNA, and then a hardware-in-the-loop simulation (HILS) system for a kind of vehicle control unit is develo...
详细信息
This paper presents a real-time simulation system based on ve-DYNA. A vehicle dynamics model is built with ve-DYNA, and then a hardware-in-the-loop simulation (HILS) system for a kind of vehicle control unit is developed with dSPACE. Comparing the simulation results with the experiment results, it shows that the HILS system can provide a precise realtime simulation system for the development of vehicle control unit.
Inspired by the biological immune system, the artificial endocrine system (AES) has drawn great research interest from different communities during the past decade. The AES is a novel branch of computational intellige...
详细信息
Inspired by the biological immune system, the artificial endocrine system (AES) has drawn great research interest from different communities during the past decade. The AES is a novel branch of computational intelligence methods. This paper gives a comprehensive overview of the AES under a preliminary theoretical framework, which is based on the interpretative models of biological endocrine system. Some typical AES-based algorithms with their applications are discussed here. We address a few key issues in the current state-of-the-art AES research work. The possible future directions of the AES are also pointed out.
This paper presents a class of adaptive ant colony optimization algorithm and proves its convergence properties. The global searching and convergence ability are improved by adaptively changing the pheromone trails ev...
详细信息
This paper presents a class of adaptive ant colony optimization algorithm and proves its convergence properties. The global searching and convergence ability are improved by adaptively changing the pheromone trails evaporation factors and decreasing lower pheromone bound. Markov process analysis is used to prove convergence properties of the algorithms. It is shown that its current solutions of the system converge, with probability one, to an optimal solution of the system
A general framework for solving combinatorial optimization problems heuristically by the ant system approach is developed. Based on the two different conditions, some convergence properties for ant colony system (ACS)...
详细信息
A general framework for solving combinatorial optimization problems heuristically by the ant system approach is developed. Based on the two different conditions, some convergence properties for ant colony system (ACS) are presented. The global searching and convergence ability are improved by adaptively changing the lower pheromone bound. It is shown that ACS is guaranteed to find an optimal solution with probability 1
Slip-ratio control of EV is one of the fundamental traction control problems especially for the unknown road condition. In order to regulate the slip-ratio around a constant value, a robust nonlinear control law at th...
详细信息
Slip-ratio control of EV is one of the fundamental traction control problems especially for the unknown road condition. In order to regulate the slip-ratio around a constant value, a robust nonlinear control law at the torque level is proposed in this paper. In this control scheme, a nonlinear observation algorithm is designed to estimate the car velocity by using the wheel speed information. And an adaptive method is introduced to approximate the nonlinear friction parameters. Then, by means of the backstepping technology, a new torque control strategy for PMSM with vector transformation is presented to achieve the desired torque for the robust traction. The simulation results shows that the goal of traction control is achieved
This paper addresses the traction control problem for the electrical vehicles (EVs) driven by permanent magnet synchronous motor (PMSM). A robust nonlinear control law at the torque level is proposed firstly to cope w...
详细信息
This paper addresses the traction control problem for the electrical vehicles (EVs) driven by permanent magnet synchronous motor (PMSM). A robust nonlinear control law at the torque level is proposed firstly to cope with the unknown tyre reaction force. A parameter estimation function will be introduced for the adaptive control of the system with unknown friction forces. Then, a new torque control strategy for PMSM with vector transformation is introduced to achieve the desired torque for the robust traction. It's shown that by using a kind of backstepping design approach, the goal of traction control can be achieved at electrical control level of the PMSM
In this paper, a novel testing method for on-ground test of space manipulator is introduced. The configurations of the testbed and the manipulator are described in detail. To accomplish the test of three-dimensional m...
详细信息
In this paper, a novel testing method for on-ground test of space manipulator is introduced. The configurations of the testbed and the manipulator are described in detail. To accomplish the test of three-dimensional movement, a modified testbed using air-bearings is designed. By adopting the two-step testing method, which is presented in this paper, the three-dimensional positioning accuracy and the three-dimensional attitude accuracy of the space manipulator can be measured. The main idea of this method is to divide a three-dimensional movement into two planar movements, which can be performed on the testbed. The equations of data processing are deduced. The analysis shows that the mentioned testing method is practical for the research of space manipulators
The Chinese experimental space system for on-orbit robotistic services (CESSORS) is to be developed by Shenzhen Space technology Center. CESSORS consists of two satellites and a mounted robotic manipulator. In this pa...
详细信息
The Chinese experimental space system for on-orbit robotistic services (CESSORS) is to be developed by Shenzhen Space technology Center. CESSORS consists of two satellites and a mounted robotic manipulator. In this paper, the design of the two satellites and the manipulator is described in detail, as well as the target detecting system and the ground teleoperation system. The planned missions include calibration of robot manipulator, teleoperation of the manipulator, coordinated control, on-orbit robotistic services, on-orbit target chasing and approaching, and flying around inspection. This paper introduces the components of CESSORS, and shows the on-orbit missions
暂无评论