As an efficient business process execution language which supports web services, BPEL4WS is widely supported by the academic and the industrial circles. According to the shortcomings such as number of computer terms, ...
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The paper presents a target tracking algorithm which is based on the mean shift algorithm and the normalized moment of inertia (NMI) feature, because the result of the moving target tracking in the air is not satisfac...
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In the field of radar data processing, track interruption seriously affects target tracking, track fusion, and other tasks. The existing track segment association algorithms have low correlation accuracy in dense dist...
In the field of radar data processing, track interruption seriously affects target tracking, track fusion, and other tasks. The existing track segment association algorithms have low correlation accuracy in dense distributed or long-time interruption situations. To this purpose, a dense multi-target track segment association (DMTTSA) algorithm is proposed. Firstly, two identical networks based on the multi-head probability sparse (ProbSparse) self-attention are used to capture the long-term dependencies of the tracks. Then, the bidirectional quadruplet hard sample loss (BiQuaHard loss) is constructed to make the tracks belonging to the same targets closer and the tracks belonging to the different targets farther. Finally, DMTTSA takes the closest track pairs in the feature space as the associated tracks and divides the unassociated tracks into the birth and dead tracks in chronological order. Some comparative experiments are carried out to show the anti-noise performance of the DMTTSA, as well as the effectiveness of solving the problem of dense multi-target track interruption.
The information fusion of vision sensor and Millimeter Wave(MMW) radar can enhance the adaptability of the Unmanned Ground Vehicle(UGV) to the complex environment. Space alignment is the basic step of information fusi...
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The information fusion of vision sensor and Millimeter Wave(MMW) radar can enhance the adaptability of the Unmanned Ground Vehicle(UGV) to the complex environment. Space alignment is the basic step of information fusion. Based on the alignment problems camera and MMW radar has existed, firstly, according to the max velocity of UGV and the different attention on the close and far object, the calibration distance is determined and divided; then, a space alignment method is presented through the corresponding space point sets in image pixel coordinate of camera and polar coordinate of MMW radar. the results are verified through the experiment and the error is also analyzed.
This paper aims to present a robust attitude control strategy with guaranteed transient performance. Firstly, a Lyapunov-based control law is designed to achieve high-performance attitude control in the absence of dis...
This paper aims to present a robust attitude control strategy with guaranteed transient performance. Firstly, a Lyapunov-based control law is designed to achieve high-performance attitude control in the absence of disturbance and parameter variation. The proposed control law uses small feedback gains to suppress the control torque at large attitude error, and increases those gains with the convergence of attitude error to accelerate the system response. The overshooting phenomenon is also avoided by imposing a restriction on the parameter selection. Then, the integral sliding mode control technique is employed to improve the robustness, where the Lyapunov-based control law is used as the equivalent control part. Theoretical analysis and simulation results verify the effectiveness of the proposed strategy.
With the industry becoming larger and more complicated, the technology of fault diagnosis becomes more and more important. Due to the strong coupling and non-stationarity of the compound fault, the existing fault diag...
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ISBN:
(纸本)9781665401166
With the industry becoming larger and more complicated, the technology of fault diagnosis becomes more and more important. Due to the strong coupling and non-stationarity of the compound fault, the existing fault diagnosis methods cannot accurately identify all single faults’ detailed information contained in the compound fault. This paper proposes a compound fault separation and diagnosis method based on FSACNN and DAN. Firstly, in order to highlight certain frequency segments, frequency segment attention module is added to CNN. Secondly, a compound fault feature separation framework based on DAN is proposed, which can separate compound fault to two fault components accurately. Thiredly, a signature matrix is introduced into ELM to improve the performance of the classifier. Finally, ablation experiments are designed to prove the advantage of the proposed method.
The electric parallel six wheel-legged robot (EPSWLR) is characterized by heavy load and fast moving speed. But the body will shake and vibrate while passing through rough roads, which affects its stability. In order ...
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ISBN:
(数字)9789881563903
ISBN:
(纸本)9781728165233
The electric parallel six wheel-legged robot (EPSWLR) is characterized by heavy load and fast moving speed. But the body will shake and vibrate while passing through rough roads, which affects its stability. In order to solve this problem, the single-leg structure based on Stewart structure was equivalent to the impedance system composed of mass block, spring and damping in this paper. Due to changes in environmental forces and environmental impedance parameters caused by environmental changes, the traditional impedance control (IC) still causes force error at the foot end of robot and thus results in poor vibration isolation effect. Therefore, a new adaptive algorithm was proposed in this paper and added to IC algorithm to reduce the force error caused by environmental changes and thus improve the vibration isolation effect. In this paper, the characteristic equation of adaptive impedance control (AIC) algorithm was first obtained and the condition for system stability was calculated based on Routh-Hurwitz stability criterion. Finally, the stability of this system was verified. The simulation experiment combining MATLAB and Adams was designed and performed with EPSWLR. The effectiveness of AIC was proved by monitoring the changes in the force of single leg and the attitude of robot body.
In the modern war, many combat units combat collectively has become the main form. In the task management of the combat units, the calculation is large and the real-time requirement is high. To solve the problem bette...
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ISBN:
(纸本)9781538629185
In the modern war, many combat units combat collectively has become the main form. In the task management of the combat units, the calculation is large and the real-time requirement is high. To solve the problem better, a joint task management method of sensor and weapon based on distributed management system is proposed. Firstly, the distributed management system is constructed according to the target trajectory and the distribution of combat units. In the system, all the combat units are divided into several combinations, which only consist of a few combat units. As a result, the problem scale is reduced, and the real-time requirement of battlefield is met. Secondly, joint task management model of sensor and weapon is established. We consider time constraints and resource constraints to ensure the feasibility of the attack scheme, and consider the impact between sensor and weapon to achieve better combat effect. A discrete particle swarm optimization algorithm based on crossover strategy (CDPSO) is proposed to solve the model. The results show that the performance of the proposed algorithm is satisfactory in joint task management of sensor and weapon.
Considering the uncertainties parameters and unknown dynamics of permanent-magnet synchronous motors in real applications, a composite controller strategy for electromechanical actuator is proposed in this paper. The ...
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Considering the uncertainties parameters and unknown dynamics of permanent-magnet synchronous motors in real applications, a composite controller strategy for electromechanical actuator is proposed in this paper. The composite strategy consists of a disturbances observer based on linear extended state observer that suppresses disturbances by feedforward compensation and a Lyapunov stability-based position controller. A non-singular terminal sliding mode position controller is used here due to its good performance, under which state errors would converge to zero in finite time. Besides, special forms of load torque, hinge moment, and sinusoidal torque disturbances have been taken into consideration in this paper. The proposed control strategy is verified via simulation. High performance with respect to position tracking and robustness to load disturbances and parametric uncertainties of the motor have been demonstrated.
In the contemporary manufacturing environment, flexible production is growing in popularity due to its quick adaptation and response to the market changes and customized requirements. Multi-type products under small-b...
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ISBN:
(数字)9781728169040
ISBN:
(纸本)9781728169057
In the contemporary manufacturing environment, flexible production is growing in popularity due to its quick adaptation and response to the market changes and customized requirements. Multi-type products under small-batch-based operations are commonly seen in flexible production. Therefore, dedicated buffers are sometimes used to separate different types of parts that are being processed on one production system. Besides, the steady-state analysis may be ineffective because of the small-batch-based operation, as a result, transient analysis becomes indispensable in investigating the transient behavior of flexible production lines. In this work, we investigate the performance evaluation issue in flexible production systems with multi-type products, two machines obeying the Bernoulli reliability model, and dedicated buffers in real-time. Based on Markovian analysis, a set of auxiliary production lines are presented to decouple the dynamics of the original system. Then, the transient performance measures of interest are approximately evaluated from the auxiliary production lines to avoid the issue of system state explosion. The state explosion is common when applying the Markovian approach. Finally, the proposed analytical algorithm is validated to be with high precision through numerical experiments in contrast with the Monte Carlo simulation.
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