Modeling Analysis And Experimental Research On Human-machine System Of A Grenade Weapon

As one of the important weapons in the battlefield,the individual weapon with high precision,large range,great power and good manipulative can effectively improve the operational effectiveness of weapons and the soldiers’ ability to survive in wartime.It has great theoretical value and military significance to carry out ergonomics analysis and firing efficiency research on individual soldier weapons combined with human influence factors.In order to optimize the firing efficiency of an individual grenade weapon,the man-machine system model and experiment were studied to solve the problem of poor shooting precision and the difficulty of controlling the gun.The main research work and research results were as follows:(1)The motion of the individual weapon during firing process was abstracted as a motion response problem of an elastic connected multi-rigid-body system under transient impulse excitation.According to the motion characteristics of the weapon system and the characteristics of human biomechanics,a new kind of man-machine system motion model was established.The weapon system and human arms were simplified into a rigid body(Al),the head and the upper trunk were simplified into anther rigid body(A2).The recoil motion,pitch rotation,horizontal rotation of weapon and the horizontal rotation and pitch rotation of the upper body were defined as five degrees of freedom of the system.The equivalent elastic coefficient and damping coefficient were applied to constrain the degrees of freedom of rigid bodies and a new model research method is provided for the ergonomics research of the individual grenade weapon.(2)The system dynamics equation was derived by second kinds of Lagrange method,and the system dynamics model was established.Through the simulation analysis of the model,the relationship between the quality of the weapon,the Y axis value of the weapon centroid(the high and low position of the centroid),the equivalent damping coefficient Cx(the damping coefficient of the rigid body A2 recoil movement)and the shoulder force were studied.The fitting equation of the peak value of the shoulder force to weapon mass,The fitting equation of the peak value of the shoulder force to the Y coordinate value of the weapon centroid,the peak fitting equation of the shoulder force to the equivalent damping coefficient Cx were obtained respectively.The conclusion shown that to increase the weapon mass and reduce the Y coordinate value of the weapon centroid can effectively reduce the shoulder force.(3)The relationship between the weapon mass,the X axis value of the weapon centroid,the Y axis value of the weapon centroid,the Y axis value of the shoulder point and the stability of the weapon motion was studied.The fitting equations of each parameter to the weapon’s pitch angle,and the fitting equations of each variable to the weapon’s horizontal rotation angle were obtained.The conclusion shown that to increase the weapon mass,to reduce the X axis coordinate value of the weapon centroid and the Y coordinate value of the weapon centroid,to reduce the Y axis coordinate value of the shoulder point can reduce the rotation angle displacement of the weapon’s pitching and the horizontal rotation angle of the weapon.(4)The relationship between the equivalent damping coefficient Ca(damping coefficient of the rigid body A2 pitching rotation)and the angular displacement of a weapon pitching rotatio,and which between the value of Cθ(the damping coefficient for controlling the pitch rotation of the rigid body Al)and the angular displacement of a weapon pitching rotation were studied.The fitting equation of the weapon’s pitch angle to Ca and The fitting equation of the weapon’s pitch angle to Cθ were obtained.The relationship between the equivalent damping coefficient Cp and the horizontal angular displacement of weapon,and which between the value of Cγ and the horizontal angular displacement of weapon were studied.The fitting equation of the weapon’s horizontal angle to Cβ and The fitting equation of the weapon’s horizontal angle to Cγ were obtained.Through the study of Cα、Cθ、Cβ、Cγ,the conclusion shown that the shooter should maintain the tension of the waist muscles,and the muscle that controls the stability of the weapon should be in the normal tensioning degree.(5)An ergonomics system motion test system based on orthogonal high-speed photogrammetry and a shoulder force measurement system based on piezoelectric three-dimensional force sensor were build up.By measuring the motion and shoulder force of an experimental prototype of a remote single soldier grenade,the displacement curve of the weapon,the angular displacement curve of the weapon pitching,the angular displacement curve of the horizontal rotation of the weapon and the shoulder force curve were obtained.The experimental curve was compared with the simulation curve,and the results shown that the simulation curve was consistent with the experimental curve,and the feasibility of the study of the man-machine system model was verified.The motion measurement and shoulder force measurement of the improved prototype are carried out,and the pitch angle,displacement curve and shoulder force curve of the prototype were improved.Comparing the test results of the improved prototype with the test results of the experimental prototype,the peak value of the shoulder force was obviously reduced,the angle displacement of the pitching rotation and the horizontal rotation angle of the projectile firing time weapon were reduced,the stability of the weapon shooting movement and the ergonomics efficiency were improved,and the effectiveness of the improved prototype was verified.The research results provide the design guidance and reference for the parameter value selection of weapon mass and centroid.It provides theoretical support for the effective improvement of shooting stability and the reliability of weapon control under the condition of large range.The rational control of the force of the waist and shoulder of the shooter was provided with the theoretical basis and the implementation method.The firing efficiency and training level were improved effectively,which lays the foundation for further research on ergonomics of individual soldier weapons.