Research on Hydraulic System of Hydraulic Driven Garden Pulverizer Based on AMESim Simulation

To analyze a certain type of trees crusher working condition, to consider the limitation of electric, the motor driven pulverizer can only work in a fixed place. Therefore, a set of hydraulic system is used to replace the motor. So it can get rid of electricity, and move conveniently, applying to the suburbs, parks, roadsides, which means expanding the range of application. Secondly, in view of the pulverizer speed higher than the motor speed, it is necessary to add the auxiliary speed regulating device. Besides , to adjust speed is more troublesome, and the hydraulic motor can directly drive the pulverizer. Therefore to adjust the flow of the hydraulic motor can change the speed of the pulverizer. In addition, base on the characteristics of work start, and stop, with a long time, big moment of inertia for Pulverizer, and it is the growth process of the motor driving pulverizer. The rotary inertia equivalent to the motor end will increase the square of the reduce ratio, and the load of the machine obviously. Driving by hydraulic motor straightly, and this problem will be avoided. Finally, in the light of the large start-up torque, and the high speed at working time of the pulverizer, the constant power pumps is choosed to meet the work demand. Constant power pumps can adjust the flow and pressure according to the different load automatically, thus more energy are saved. Hydraulic system simulation model is established based on the AMESim simulation, which verify the scheme is feasible

Simulation and Experiment Research on the Proportional Pressure Control of Water-assisted Injection Molding

Water-assisted injection molding（WAIM）,a newly developed fluid-assisted injection molding technology has drawn more and more attentions for the energy saving,short cooling circle time and high quality of products.Existing research for the process of WAIM has shown that the pressure control of the injecting water is mostly important for the WAIM.However,the proportional pressure control for the WAIM system is quite complex due to the existence of nonlinearities in the water hydraulic system.In order to achieve better pressure control performance of the injecting water to meet the requirements of the WAIM,the proportional pressure control of the WAIM system is investigated both numerically and experimentally.A newly designed water hydraulic system for WAIM is first modeled in AMEsim environment,the load characteristics and the nonlinearities of water hydraulic system are both considered,then the main factors affecting the injecting pressure and load flow rate are extensively studied.Meanwhile,an open-loop model-based compensation control strategy is employed to regulate the water injection pressure and a feedback proportional integrator controller is further adopted to achieve better control performance.In order to verify the AMEsim simulation results WAIM experiment for particular Acrylonitrile Butadiene Styrene（ABS） parts is implemented and the measured experimental data including injecting pressure and flow rate results are compared with the simulation.The good coincidence between experiment and simulation shows that the AMEsim model is accurate,and the tracking performance of the load pressure indicates that the proposed control strategy is effective for the proportional pressure control of the nonlinear WAIM system.The proposed proportional pressure control strategy and the conclusions drawn from simulation and experiment contribute to the application of water hydraulic proportional control and WAIM technology.

Pressure performance improvement by dual-mode control in digital pump/motor

Due to the advantages of low cost,fast response and pollution resistance,digital hydraulic pump/motor can replace conventional variable hydraulic pump/motor in many application fields.However,digital hydraulic components produce large hydraulic impact at variable moments,which will shorten the service life of mechanical components.Through the simulation analysis of the variable process of digital pump/motor,it is found that the discontinuous flow caused by displacement step changes is the fundamental cause of hydraulic impact.The data analysis results of experimental tests are in good agreement with the simulation analysis results.In view of hydraulic secondary components,a variable control method based on dual-mode operating characteristics is proposed.The TOPSIS algorithm is used to give comprehensive evaluation of the displacement control results after this method.The results show that the control quality of digital pump/motor after adopting the control method has been effectively improved,with an average improvement of about 40%.

An experimental study of the dual-loop control of electro-hydraulic load simulator (EHLS)

This paper investigates motion coupling disturbance（the so called surplus torque）in the hardware-in-the-loop（HIL）experiments.The＇＇velocity synchronization scheme＇＇was proposed by Jiao for an electro-hydraulic load simulator（EHLS）in 2004.In some situations,however,the scheme is limited in the implementation for certain reasons,as is the case when the actuator＇s valve signal is not available or it is seriously polluted by noise.To solve these problems,a＇＇dual-loop scheme＇＇is developed for EHLS.The dual-loop scheme is a combination of a torque loop and a position synchronization loop.The role of the position synchronization loop is to decouple the motion disturbance caused by the actuator system.To verify the feasibility and effectiveness of the proposed scheme,extensive simulations are performed using AMESim.Then,the performance of the developed method is validated by experiments.