The shipborne helicopter is an essential maritime combat force of the modern navy. However, as the most advanced shipborne helicopter landing assistance system, the ASIST still suffers from the significant disadvantage of the uncontrollable driving speed of the claw. This paper aims to propose an implementation scheme of the EASIST transmission system by selecting an asynchronous motor as the direct power source to solve the problem. On this basis, the speed controller is built by combining the vector control algorithm with an ANFIS control algorithm. In addition, the capture and traction characteristics of EASIST are analyzed, and the capture track of the claw and the maximum load in the traction process are obtained. Finally, the dynamics model of the transmission system is established by power bond graph theory, and the system simulation test is carried out. Simulation results show that the proposed EASIST reduces the capture time by about 60% and dramatically reduces the capture speed. And when towing the shipborne helicopter, EASIST can keep a good speed-tracking effect under the action of wildly varying load force. The research results of this paper are of great significance to broaden the application scope of ASIST and improve the traction efficiency, which plays a vital role in enhancing the combat effectiveness of shipborne helicopters.

Here, a model‐free linear active disturbance rejection controller (LADRC) integrating dead‐zone inverse compensation for an electro‐hydraulic proportional (EHP) system with an unknown dead‐zone is proposed. Unlike the existing LADRC design idea, the presented method uses a new hydraulic system block diagram to select the order of LADRC instead of the highest degree of the system. Furthermore, the rationality of order selection is illustrated by the frequency domain analysis theory. To solve the dead‐zone of the proportional valve, a novel structural transformation is proposed by constructing a new dead‐zone, which has a definite physical meaning and can be obtained by the experimental measurement. Then, the dead‐zone disturbance is reduced, and the burden of the observer is relieved. At the same time, the controller parameters are decreased from three to two equivalent PI controller. Besides, the stability of the closed‐loop system is analysed by the describing function method. The performance of the proposed control solution has been investigated through extensive comparative experiments under different working conditions. The experimental results successfully demonstrate the effectiveness and practicality of the presented method.

Since modern times, the increase in shipborne equipment has brought tremendous pressure to the energy supply system. Establishing an accurate and reliable energy consumption model that reflects the dynamic characteristics of the system will provide an essential theoretical reference for energy efficiency optimization. This paper proposes a modeling method that considers both the dynamic characteristics and energy consumption characteristics of the system, based on the power bond-graph theory. Firstly, the transmission principle and energy transfer process of hydraulic and electric helicopter traction devices are analyzed. Then, the energy consumption is analyzed, and the state equation and energy equation of the system are established. Finally, the simulation tests are carried out. The results show that the proposed dynamic modeling method is reasonable and effective and can well reflect the dynamic characteristics and energy consumption characteristics of the system.

The construction machinery and vehicles, especially the explosion-proof and explosion-isolation ability of the vehicles are playing an increasingly important role in the complex and unpredictable emergency rescue field. In this paper, the explosion-proof housing of hydraulic system power unit applied in engineering machinery is investigated, wherein the power unit includes motor, power supply and control element. Motor-driven hydraulic pump provides the necessary power for the hydraulic system. The gas explosion process, basic parameters, flame acceleration mechanism and the theory model of gas explosion in finite space are analyzed. Relevant mathematical models of the experimental gas explosion for explosion-proof cavity are established. Furthermore, the models are analyzed by numerical method. We simulate the dynamic process of explosion by software. The analysis, examination and simulation of structural strength are conducted on the explosion-proof cavity according to the maximum explosion pressure obtained from the simulation results. The reasonable design parameters satisfying the explosion-proof requirements are obtained. The explosion-proof cavity which is processed according to the design parameters is tested. The explosion-proof performance is verified by analyzing the experimental results. According to the test standard, the impact test, thermal test, pressure test, overpressure test and propagation test under internal ignition for the cavity are conducted. The results show that the pressure test coincides with the simulation results. The remaining test results also satisfy the experimental purpose. The reasonableness of the design of the explosion-proof cavity is verified, which can meet the actual requirements of the equipment.

Aiming the chain transmission system in the rapid secure device (RSD) of shipborne helicopter, an individual fault was that the chain was broken, and then the system gave an alarm. According to the above question, the RSD reliability growth test bench was built to conduct a reliability growth test study on the chain transmission system in a single RSD test prototype. After the cause of the fault was found, a part of the chain in the test prototype was tested by the chain pulling test machine. According to the test results, the reliability optimization design of the chain transmission system was carried out, and the optimization design scheme was determined. A suitable reliability growth test plan for the chain transmission system was formulated using the Duane model analysis method. Through the reliability growth test, the Class B failure statistics of the chain transmission system were obtained, and then the reliability growth Duane model of the total test time of the chain transmission system was established. Using the army materiel systems analysis activity (AMSAA) model analysis method, the approximate unbiased estimation of the instantaneous mean time between failures (MTBF) of the chain transmission system was carried out, the trend test of the reliability growth of the chain transmission system was carried out, and the confidence interval of the instantaneous MTBF at the end of the test time was obtained to verify that the reliability optimization design meets the planning requirements and provide a reference for the reliability growth research of the whole RSD equipment.INDEX TERMS Rapid secure device, chain transmission, reliability growth, Duane model, AMSAA model.