The impact force on the hand wheel gunner workload and system ergonomics

        As we all know, the human person and constitutes a machine gun system. Handwheel is man a gun system is an important interface unit, the size of the force and gunner hand wheel load and system efficiency has a close relationship.
        The purpose of this study is to reveal the influence of the handwheel to force the gunner load and system efficiency, and provide a reliable scientific basis for the determination of artillery handwheel force and about the job system.
        Equipment and methods
        1. controlled object: howitzer and anti-aircraft guns. Both hand wheel gun has a different operating mechanism and kinetics.
        2. subjects: Each handwheel artillery gunners 15, male, with an average age of 9.1 to 1 (15 a 21) years.
        3. The aim of monitoring the handwheel ergonomics: with a special television camera and monitor system monitoring aiming error, interpretation accuracy can reach 0.1 mil, aimed at measuring time with a stopwatch. Entire targeting system shown in Figure 1.
        4. workload monitoring: ECG telemetry heart rate monitoring subjects. The average heart rate before the start of the experiment was resting heart rate, reached equilibrium after the job starts to work after heart rate, stop working after the first 3m in the heart of the recovery heart rate.
        5. Lift Box work: Box weight 78 kg, lift transport distance 10 m, every 305 to lift only one time, continue to work Z Om in. 6.
         Experimental procedure: Before the formal operation of the subjects were aimed at targeting training. Then limited time, so make the greatest efforts aiming subjects, until the error is minimized so far, this error is called "static error."
        Gun sighting error monitoring system experiment directed by the main trial. High gunner wheel, gun skill wheel angle deviation in the level of state direction to aim 80 degrees; howitzer low angular deviation of 250 mils, direction angle deviation from 10 mil.
        Subjects make barrel after migration in place, immediately transferred back to the gun barrel, to aim. Aiming to complete the trial by the emperor Table timing, interpretation and recording at the same time aiming error, called "operator error."
        If you aim for no more than a predetermined value (for anti-aircraft artillery to 105 of howitzer to 405), subjects the rest on standby, to a predetermined time and then the next aim handwheel operation. If you aim for more than the predetermined value, then immediately begin the next round of job. Repeat endless, until the completion of 15 subjects each aiming to end a handwheel force experiments. Then start another group handwheel force experiments. Lift me jobs on antiaircraft experiment only, subjects completed immediately put into force a set of hand wheel lift me job after sighting operation.
        The experimental results.
        1. handwheel workloads: lists the average heart rate of the subjects under different conditions. From values ​​in the table, regardless of why the group handwheel force, howitzer average working heart rate and recovery heart rate subjects are significantly higher than the corresponding value antiaircraft subjects (p <..05); in the same kind of gun , the work force of the heart rate and hand wheel size has not exhibited to determine the relationship. At the gun, the subjects lifted me after work aimed at the average heart rate and recovery time jobs only under the same group was significantly higher than the value of the handwheel force when conditions do not lift the box, but higher than the maximum handwheel force group does not lift the box values ​​(p <.0 05).
        2. Hand wheel system ergonomics: howitzer subjects each time the average aiming error, its values ​​were less than 0.5 mils (single maximum no more than 0.8 mils).
        In addition to the maximum (1 2 0, 6 o N), the minimum (45,20 N) groups handwheel total average power conditions are significantly different operations (p <0.0 5) between the error, the total average power of the other groups each Operation error no significant difference between (p> ..05). In addition to the most vigorous group, the total average operation is also no significant difference between the static error and the average error. Average targeting error antiaircraft subjects are shown in Table 2 below. When the handwheel force 1 70, 1 20 N, the total was significantly higher than the corresponding average operator error value when the other two power groups (P <0.0 5).
        In the other two groups handwheel force conditions, operator error is basically the same, and does not exceed a predetermined value, after the lift operator error box operations was significantly higher than the corresponding value is not the time to lift the box (P <0.0 5). On the gun, in each group handwheel force conditions, operator error were significantly higher than the static error. The first four times the average antiaircraft subjects aimed at substantially the same time different hand wheel loading conditions; however, with the increase in the number of targeting, aiming gradually lengthen the time; at 1 70, 1 2 o N handwheel force grew faster than conditions fast, from fifth after aiming aiming values ​​significantly longer than the other two groups corresponding force conditions.
        The discussion is a simple and easy to measure heart rate and physiological parameters and can better reflect the workload, it is the strength and activity, oxygen consumption is linearly related, but in addition to the work load, but also by many other factors affect the Court, to cause some practical difficulties. This study is under exactly the same conditions on the load of similar jobs are compared, and therefore the size of the workload is relatively reliable. Experimental results show that the howitzer gunner hand is high workload high, indicating that there are other factors that affect the workload gunner hand wheel force except outside, one of the more important is the moment of inertia of artillery, deflection range and speed of rotation of the handwheel structure Parameters will also have a role.
        In this experiment subjects workload artillery handwheel force, the result of inertia, offset range and speed and other factors working together. Our subjects were asked to make the greatest efforts to quickly and accurately complete the handwheel operation, so the workload is not affected by the subjects of the handwheel force size. Because in the hand wheel force reduction, aiming to speed up the pace of subjects; in addition to excessive force in the hand wheel condition, aiming error readily change the wheel forces are not very clear.
        Handwheel force influence on the system efficiency is mainly reflected in the targeting time. On howitzer, operator error and static error almost no difference. This static error is clearly targeting the system itself by the artillery targeting structural and human capacity decisions. On the anti-aircraft artillery operator error was significantly higher than the static error, indicating that the operation error contained dynamic component because the rotation speed.
        This difference is mainly due to the characteristics of the decision itself artillery.
        Conclusion The current operating mode by artillery and requirements, according to the study results, the artillery operating force made the following recommendations:
        (1) howitzer, height, direction handwheel force should not exceed 70,40 N; the number of continuous operation should not exceed 15 times.
        (2) The anti-aircraft guns, large and small hand wheel force should not exceed 90,50 N; continuous operation times not more than 7 times.
        (3) Before antiaircraft targeting job, gunner should avoid heavy load operations.