Simulation analysis of cooperative motion fuzzy control of distributed lifting units

In the technology of hydraulic lifting system, it is not only necessary to ensure that the displacement and velocity accuracy of each hoist reach a certain value, but also to ensure that under the control of load balance to make each hoist smooth lift. In the conventional method, the PID control method can realize the synchronization of the function. However, the system cannot be controlled and adjusted in real time during the control parameter period, resulting in instability and uncertainty of the system. Aiming at this problem, this paper adds the fuzzy adaptive controller to carry out the master-slave control of the system. AMESim and MATLAB co-simulation were used to model the overall model of the hydraulic system. At the same time, the pressure compensator and variable throttle port model in the hydraulic reservoir were selected to build. The pressure compensator is used to keep the pressure difference of the throttle orifice constant, so as to complete the control and design of the hydraulic lifting system. Finally, the simulation results obtained not only can effectively improve the instability of the hydraulic lifting process, but also greatly improve the operation speed of the system.

Hydraulic synchronizing lifting steel template based on AMEsim modeling simulation technology research

Steel formwork is used for concrete casting and forming, and plays a key role in the construction of high-rise buildings with asymmetrical large loads. In order to make the inner and outer formwork can be lifted synchronously, the difficult problem of unbalanced inner and outer formwork must also be overcome. According to the synchronization principle of the hydraulic lifting system and the performance parameters of its main components, AMESim model was created and the simulation was done for two hydraulic cylinders bearing the same heavy load and different weight load respectively. Therefore, the synchronization scheme of shunt valve is proposed.

Design and Efficiency Analysis of Closed Loop Pump Controlled Circuit Hydraulic Lifting System of Wheel Loaders Based on Gravity Self-Balancing Hydraulic Cylinder

In the hydraulic lifting systems of wheel loaders, the valve controlled systems are used to drive the hydraulic cylinder to complete frequent lifting and falling operations. The gravitational potential energy of the lifting system, accumulated in the lifting process, is converted into heat energy through the throttling port of the valve during the falling processes, which results in significant throttling loss and severe system overheating. To solve the problems, a potential energy regeneration and utilization system is proposed, where the closed loop pump controlled circuit based on the gravity self-balancing hydraulic cylinder is adopted to eliminate throttling loss, and the gravity self-balancing chamber of the cylinder is directly connected with accumulator to recycle gravity potential energy. In the research, the structure and working principle of the proposed hydraulic system is analyzed first, then the co-simulation model and the test prototype are established to investigate the working and energy characteristics of the proposed system. Test results indicate that, compared with the traditional valve controlled hydraulic system, 58.9% energy consumption reduction can be expected for the hydraulic pump by adopting the proposed system under the same working condition.

Simulated and Experimental Analysis of a Log Crane With Conventional and Direct Driven Hydraulics

The present paper compares the efficiency and dynamic behavior of a log crane while using two alternative transmissions. Firstly, the conventional mobile hydraulic valves with a load-sensing pump is used, and secondly, a novel electric-hydraulic energy converter and a direct driven hydraulic actuator is used. By applying lumped parameter models and the theory of centralized pressure, the hydraulic system models are constructed in MATLAB & Simulink environment. MathWorks Simscape Multibody is used in modeling of the multi-body system of the crane. The results of the simulation models are compared with those measured in the laboratory. Based on the verification results, such modes of operation in which the agreement between simulated results is the closest are selected for further investigation. The effectiveness of the system equipped with an electro-hydraulic converter is compared with that of the conventional system with a load sensing pump. Detailed models for components are given in the paper, and the results are discussed based on what obtained through simulation and experiments. The electric-hydraulic converter used in direct driven circuit is a novel prototype developed at LUT University. It has good power stiffness, and it provides good torque properties in a wide RPM area. The prototype is used in operating the lift or tilt cylinder, which is altered by using fast switching valves. The actual test circuit does not have electric storage. The ability of the converter to recover potential energy from the lifting system inertia is approximated in the efficiency comparisons.

Enhancement of mobile scissor lifting system for windy environments

This paper focuses on the enhancement of mobile scissor lifting system for windy environments. This study was necessitated in order to address the lack of support arm problem on the mobile scissor lifting system for the strong wind environment such as Minna in Niger State Nigeria. The outstation broadcasting operations in Minna metropolis are usually challenging during windy days as wind often affects the stability and efficiency of the outstation broad-casting platforms. This research employs electronic control circuit to control mechanical hydraulic actuated scissor lifting system in response to variations in wind speed. The mechanical components were designed using solidworks software. The control unit was remodeled using Proteus 8.0 software with the code written in Arduino integrated development environment (IDE). The model simulation results for both electronic and mechanical system reveal the possibility of achieving system stability with the resultant signal fidelity in outstation telecommunication broad-cast within windy areas. The experiment result shows that the system was capable of lifting the telecommunication platform 2 meters high within 20 seconds considering the load range of 500 to 1000 kg. An overload alert mechanism was incorporated to signal the operators of excessive loading. Then, the system automatically deploys its support arms to counter the attendant consequences of the strong wind thereby restoring the stability of the mobile scissor lift. Therefore, the authors conclude that the enhanced mobile scissor lifting system would be deployed in the windy environment for the maximum attainment of stability objectives while physical model from this design should be subsequently fabricated in the near future.

A Physics-Based Multidisciplinary Approach for the Preliminary Design and Performance Analysis of a Medium Range Aircraft with Box-Wing Architecture

The introduction of disruptive innovations in the transport aviation sector is becoming increasingly necessary. This is because there are many very demanding challenges that the transport aviation system will have to face in the years ahead. In particular, the reduction in pollutant emissions from air transport, and its impact on climate change, clearly must be addressed; moreover, sustainable solutions must be found to meet the constantly increasing demand for air traffic, and to reduce the problem of airport saturation at the same time. These three objectives seem to be in strong contrast with each other; in this paper, the introduction of a disruptive airframe configuration, called PrandtlPlane and based on a box-wing lifting system, is proposed as a solution to face these three challenges. This configuration is a more aerodynamically efficient alternative candidate to conventional aircraft, introducing benefits in terms of fuel consumption and providing the possibility to increase the payload without enlarging the overall aircraft wingspan. The development and analysis of this configuration, applied to a short-to-medium range transport aircraft, is carried out through a multi-fidelity physics-based approach. In particular, following an extensive design activity, the aerodynamic performance in different operating conditions is investigated in detail, the structural behaviour of the lifting system is assessed, and the operating missions of the aircraft are simulated. The same analysis methodologies are used to evaluate the performance of a benchmark aircraft with conventional architecture, with the aim of making direct comparisons with the box-wing aircraft and quantifying the performance differences between the two configurations. Namely, the CeRAS CSR-01, an open-access virtual representation of an A320-like aircraft, is selected as the conventional benchmark. Following such a comparative approach, the paper provides an assessment of the potential benefits of box-wing aircraft in terms of fuel consumption reduction and increase in payload capability. In particular, an increase in payload capability of 66% and a reduction in block fuel per pax km up to 22% is achieved for the PrandtlPlane with respect to the conventional benchmark, while maintaining the same maximum wingspan.

Analysis of longitudinal coupling dynamic characteristics of deep sea mining vessel and stepped lifting pipe

In deep-sea mining, the coupling dynamic response between the mining vessel and the lifting pipe is a significant problem, which directly affects the structural design of the lifting system and the safety of field operation. The characteristics of coupled motion model have not been fully considered in the existing research. Therefore, this paper uses time-domain coupled numerical model as the research object, considering ocean current, surface wave, pipe dynamics and vessel-pipe contact mechanics, to study the dynamic behavior of the lifting pipe and mining vessel during the process of deep-sea mining using AQWA and OrcaFlex softwares. The response amplitude operator (RAO) is used to compare the measured and simulations dynamic response of the mining vessel. There is a very good agreement in RAO between the experiments and simulations. The coupling simulation results show that the coupling effect has a significant effect on the time domain dynamic response of the lifting pipe, but has little effect on the average effective tension and longitudinal amplitude along the pipe length. The research results of this paper are of great significance to the safety design of deep-sea mining lifting system and the planning of deep-sea operation activities.