Cooperative lifting by two cranes is widely used in the current construction site. Since the influence of changeable load in the cooperative lifting process, it is essential to take the load distribution into consider...
详细信息
Cooperative lifting by two cranes is widely used in the current construction site. Since the influence of changeable load in the cooperative lifting process, it is essential to take the load distribution into consideration while planning the lifting path to ensure the safety of the whole lifting process. However, most researches did not consider the reasonable actual load distribution or just used a certain load in the lift process. This paper analyzes the relationship between crane operations and the pose of the lifted object. Then based on this relationship, this paper gives the method calculating the distribution of actual load over each crane that the planning approach is based. This paper also gives calculation methods and constraints for the skew angle of each lifting rope. The results of simulation show the effectiveness of this calculation method.
This paper investigates the issue for stability of linear system with time-varying delay. First, by combining the Free-matrix technique and the B-L inequality, a new inequality named Free-matrix Legendre inequality is...
详细信息
This paper investigates the issue for stability of linear system with time-varying delay. First, by combining the Free-matrix technique and the B-L inequality, a new inequality named Free-matrix Legendre inequality is proposed. Then, based on this inequality, two sets of stability criteria are developed which are less conservative than the existing ones due to the fact that more freedom are introduced. Finally, a numerical example is given to illustrate the advantage of our method.
Due to the unknown complexity of geological conditions, drilling operations are difficult to carry out. It is of great value to implement drilling measurement while drilling. However, due to the poor working condition...
详细信息
Due to the unknown complexity of geological conditions, drilling operations are difficult to carry out. It is of great value to implement drilling measurement while drilling. However, due to the poor working conditions underground, information transmission for the drilling process may be affected, which leads to the loss and conflicts of the data. It is necessary to use effective method to deal with the data and to make evaluation for the drilling process. In this paper, we present a D-S data fusion method and use fused data to form a framework to evaluate efficiency for the drilling process. We can efficiently analyze the entire drilling process and optimize the drilling parameters based on this framework.
This paper concerns the stability problem of systems with time-varying delay. A single integral of the second-order derivative is introduced to Lyapunov-Krasovskii functional for considering more delay-cross relations...
详细信息
The performance of phase-locked loop(PLL) severely affects the system's stability in a three-phase *** methods tend to adopt the idea of single synchronous coordinate transformation,which implements the phase sync...
详细信息
ISBN:
(纸本)9781538629185
The performance of phase-locked loop(PLL) severely affects the system's stability in a three-phase *** methods tend to adopt the idea of single synchronous coordinate transformation,which implements the phase synchronization through controlling the q-axis voltage to zero.A novel three-phase PLL is proposed in this paper based on this *** order to obtain better convergence rate near zero,the input of closed-loop PLL is replaced by the ratio of q-axis voltage and d-axis *** fastness and convergence of the system are further analyzed in *** and experiment results show that proposed method can lead to better rapidity,and the phase-locked process is superior to traditional digital PLL methods.
Speed control mode of a DC motor without knowing the specific parameters of the motor is *** approximate mathematical model of the control system is obtained by the system identification when the output of the system ...
详细信息
ISBN:
(纸本)9781538629185
Speed control mode of a DC motor without knowing the specific parameters of the motor is *** approximate mathematical model of the control system is obtained by the system identification when the output of the system is measured by loading the specific input *** PID control algorithm is adopted and the P,I,and D parameters are obtained by auto *** in the loop(HIL) experiments are carried out on MATLAB and Arduino platform,in which the experimental results demonstrate the feasibility of the proposal.
A novel adaptive robust control (ARC) is presented for the four-motor driving servo systems with the uncertain nonlinearities and actuation failures, such that the load tracking control is achieved with the proximat...
详细信息
A novel adaptive robust control (ARC) is presented for the four-motor driving servo systems with the uncertain nonlinearities and actuation failures, such that the load tracking control is achieved with the proximate optimal-time. By applying the proposed scheme, several control objectives are achieved. First, the nonlinear synchronization algorithm is presented to maintain the velocity synchronization of each motor, which provides fast convergence without chatting. Moreover, the time-varying bias torque is applied to eliminate the effect of backlash and reduce the waste of energy. Then, the ARC is designed to achieve the proximate optimal-time output tracking with the transient performance in L2 norm, where the friction and actuation failures are addressed by the adaptive scheme based on the norm estimation of unknown parameter vector. Finally, the extensive simulated and experimental results validate the effectiveness of the proposed method.
Microgrid provides an effective technical approach for distributed generation system connected to the power *** are renewable sources such as wind power, photovoltaic in the microgrid, which the power volatility of di...
详细信息
Microgrid provides an effective technical approach for distributed generation system connected to the power *** are renewable sources such as wind power, photovoltaic in the microgrid, which the power volatility of distributed generation limits the effective scheduling and real-time performance of microgrid. Energy storage device is used to stabilize the volatility of distributed generation, make sure the feasibility of distributed generation optimal scheduling. Microgrid optimizes scheduling the energy allocation od various types of distributed generation in technology, economy, environment and other aspects. In order to solutio the multi objective optimization of microgrid energy allocation, a Strength Pareto Evolutionary Algorithm based optimal method was proposed. Finally, the correctness and feasibility of the proposed method were verified through the simulation.
In the continuous annealing line heating process, it is hard to get an accurate predict result only by a steady state model as it is a complex, strongly time-delayed and confounding process. This study provides a meth...
详细信息
In the continuous annealing line heating process, it is hard to get an accurate predict result only by a steady state model as it is a complex, strongly time-delayed and confounding process. This study provides a method for building a dynamic model. First analyzes the mechanism of the annealing line to get the main parameters, and then use the data-driven modeling method to get a steady state model, finally combines with dynamic algorithm to establish a dynamic model. This modeling method improves the accuracy of predict result to guarantee the efficiency of enterprises.
Traditional artificial live work asks for a high standard with operator's mental state and technical level in high-voltage and strong-magnetic environment, which not only reduces the efficiency of modern productio...
详细信息
Traditional artificial live work asks for a high standard with operator's mental state and technical level in high-voltage and strong-magnetic environment, which not only reduces the efficiency of modern production and living but also causes potential threats to the safety of operators. Therefore, developing robot live work has great significance for both academic research and industrial applications. A key problem of the live work for an industrial robot is recognition and positioning of the hexagon-shaped screw in substation with high accuracy. To solve this problem, this article designs a hexagon-shaped screw recognition and positioning system based on binocular vision in transformer substation. A method for stereo matching including 3 steps is proposed: edge noise of the target is reduced by median filter at the beginning; then the target can be obtained through the image segmentation method of adjusting threshold; further moments are used to express the centers of hexagons in 2 images which work as stereo matching points. Finally depth information can be obtained due to visual geometric relationships based on stereo model and camera calibration parameters based on camera model. The experiment results show that the binocular system designed in this article can accurately identify the target with good stability, and the measurement error is controlled in 4%.
暂无评论