Research On Parameter Matching And Control Of Potential Energy Recovery System Of Asymmetric Pump With Constant Pressure Storage

At present,construction machinery has low energy efficiency and higher waste gas emission problem.With "14th Five-Year Plan" and carbon peaking and carbon neutrality goals proposed,energy saving and emission reduction is the current development trend in the field of construction machinery.High frequency operation of construction machinery,hydraulic system often has a large waste of energy.Efficient recovery and utilization of system feedback energy is an effective measure to save energy and reduce emissions of construction machinery.The dissertation carried out the research on energy-saving technology of construction machinery under the support of National Natural Science Foundation of China,which focuses on the goal of green,low-carbon and smooth operation.In order to achieve low energy loss and smooth operation,combined with intelligent optimization algorithm,a potential energy recovery scheme,method of parameter matching and optimal design of new key energy-saving components which has the advantage of high energy storage density and stable operation for construction machinery were explored from the aspects of energy-saving scheme design,key energy-saving components and control method.The topic selection has important theoretical significance and engineering application value.Aiming at the problems of low energy storage density and unstable filling and discharging pressure of bladder accumulator in energy recovery system,a potential energy recovery system of asymmetric pump with constant pressure storage was proposed.A constant pressure accumulator is introduced in the closed volume drive circuit of asymmetric pump to keep the oil pressure constant during the filling and discharging process.The energy storage density of constant pressure accumulator has more advantages than the energy storage efficiency of bladder accumulator,but its key component diaphragm has higher requirements for air tightness,intensity and flexibility,and it has not been successfully produced.Therefore,a kind of constant-pressure accumulator combined with carbon fiber and nitrile rubber was proposed,and the intensity of its key components was checked.And trial production was carried out.Finally,the feasibility of potential energy recovery system of asymmetric pump with constant pressure storage was tested by experiment.Aiming at the problems of long time spent in parameter matching and low efficiency of manual parameter adjustment for potential energy recovery system of asymmetric pump with constant pressure storage,a rapid parallel optimization method based on multi-Core CPU for complex hydraulic product was proposed.Two acceleration strategies were proposed,CVODE solver acceleration and multi-core CPU acceleration.The parameter optimization and performance constraints of complex hydraulic product was realized using swarm intelligent algorithm by treating CVODE simulated program as a particle.The main parameter of triangle groove was optimized to reduce flow pulsation using PSO.The flow pulsation before and after the optimization was analyzed.Analysis result showed that the outcomes of optimization has lowered flow pulsation by 36 percent without pressure increase of plunger cavity.The proposed method solves the optimization problem that the simulation of hydraulic system is dependent on professional simulation software,CVODE simulated program can run independently in windows.Compared with multi-threading,the multi-process parallel method has the advantages of easy programing.On the 8 core CPU processor,the efficiency of the multi-core parallel method is 10 times greater than Simulation X and is about 5 times greater than dual-core processor.In order to improve the optimization performance of the parallel optimization method based on multi-Core CPU and avoid that a single rule of a population cannot effectively balance global search performance and local search performance,a new multi-state simulation optimization algorithm was proposed.The optimization algorithm draws on the idea of FEA state simulation which include solid,liquid and gas of three basic physical states.On the basis of three basic physical states,the proposed algorithm formulates a variety of different complex model,and the population individuals follow a variety of motion rules in different iteration stages.The reasonable complex model can be confirmed through experiments of 6 static test functions.The dissertation conducted complete experiments against Enhancing artificial bee colony algorithm with multi-elite guidance(MGABC),Artificial bee colony algorithm with an adaptive greedy position update strategy(AABC),Multi-strategy ensemble artificial bee colony(MEABC),Self-adaptive heterogeneous PSO(fk-PSO),and APO with CEC2013 test problem.Experimental results show that the synthesis method achieves a good performance in comparison to its counterparts as a consequence of its better exploration– exploitation balance.The conditions for convergence are deduced through analyzing the algorithm based on discrete-time linear system theory.The above new multi-state simulation optimization algorithm combined with parallel optimization method based on multi-Core CPU was used to match the parameters of the energy recovery system of the excavator arm with different tonnage.The forces on the boom cylinder of the no-load excavator working device under different positions and poses are analyzed,and the minimum load on the boom cylinder is taken as the matching condition for parameter matching,so as to ensure that the potential energy can be recovered in any state.Parameter matching based on multi-state simulation optimization algorithm is used to reasonably select relevant parameters,so that the boom energy recovery and utilization system can improve the performance and energy saving efficiency of the operating mechanism under the premise of meeting the normal working conditions of the operating mechanism,and realize the purpose of product serialization of asymmetric axial piston pump.The recommended values of the main parameters of the potential energy recovery system with asymmetric pump of different tonnage excavators were obtained,including the asymmetric pump displacement,the type of constant pressure accumulator and bladder accumulator,the angle of the swash plate of the asymmetric pump in the falling stage and its energy saving efficiency,and the structural parameters of the corresponding displacement of the asymmetric pump were obtained.Aiming at the problem of flow pulsation caused by angle oscillation of swash plate of variable displacement mechanism,an anti-interference control method was proposed to improve the variable displacement control performance.By contrast with common anti-interference control methods,the sliding mode control method is determined to be used in the variable displacement control test of asymmetric pump.Then the parallel optimization method based on particle swarm optimization algorithm was used to set the main control parameters.The simulation results and variable displacement test results show that the sliding mode control method can effectively reduce the oscillation and flow pulsation of swashplate angle.