In order to meet the requirements of wind tunnel test for some large-scale models,a five-degree-of-freedom manipulator should be designed in a specific wind tunnel environment to support the test model to carry out wind tunnel test.By analyzing the gravity and aerodynamic load of the model,the installation and use space of the manipulator and the index requirements,the series-parallel structure is adopted to realize the design of the five-degree-of-freedom manipulator in the specific wind tunnel environment.The results of finite element analysis show that the manipulator meets the requirements of stiffness,strength,accuracy and stroke,and can meet the requirements of wind tunnel test for a kind of model,which is of great value.
In order to solve the problems of difficult development and poor maintainability of display and control logic simulation software of avionics system in current flight training simulator,a modular and loosely coupled display and control system function simulation idea is proposed,in which the display and control logic judgment and display picture simulation are designed independently.The display and control logic simulation module is constructed based on the finite state machine(FSM)theory according to the interactive,multiple input and multiple output temporal logic decision-making characteristics of the display and control system,and is implemented by Simulink/Stateflow.The results show that the design idea and structure are reasonable,the development process is intuitive,and the program is easy to maintain and transplant,which is conducive to improving the display and control logic simulation and development efficiency.
In order to realize convenient and efficient workflow aided design and parameter optimization,the object-oriented type and graphical editing interface for parameter configuration of graphic elements such as arrow lines and nodes are designed for the activity-on-arrow network diagram,which can automatically generate the relationship model of graphic elements while the user edits the network graph.Topology traversal is used to automatically determine the standardization of the network diagram,calculate the critical path and time parameters,and provide a convenient tool for users to optimize the workflow.The results show that the design can provide assistance for multi-domain workflow optimization.
In order to study the secondary engraving problem caused by the unequal rifling height between the revolver bushing and the barrel bushing of revolver automata,a finite element model reflecting the rifling height difference was established to analyze the secondary engraving process of the belt.Through numerical simulation,the stress,deformation and temperature were obtained when the belt was completely squeezed into the revolver bushing and the barrel bushing.The simulation results were in good agreement with the notch of the belt recovered in live firing,which indicated that the established finite element model had a certain credibility.The simulation results show that the unequal height of the bore liner and the barrel liner has a significant effect on the belt squeezing process.The half-height bore liner can make the belt squeeze into the bore liner more smoothly,but the belt will produce stronger impact when it squeezes into the barrel liner for the second time;Full-height rifling is more difficult when the belt is squeezed into the revolver liner,but it is smoother when the belt is squeezed into the barrel liner twice.
Aiming at the problems of machining errors and installation errors in the production process of a certain type of solid material propellant,a compensation strategy for positioning position errors was proposed.By Using the DH method which is commonly used in the field of robotics,the kinematics modeling is carried out,the modeling parameter error is regarded as a variable that changes with the drive command,and the coordinate measuring machine is used as a measuring tool to identify the actual axis equation of the linear axis and the rotary axis,and then the state matrix of the actual coordinate system of each link is re-established.The relationship curve between the errors of the elements of the actual homogeneous coordinate transformation matrix and the given driving instructions is fitted,and the ideal homogeneous coordinate transformation matrix is compensated.Simulation results show that the position error is reduced by about 40%after compensation,which verifies the effectiveness of the method.
