Abstract: Based on human-machine simulation and human-machine comprehensive evaluation methods, the diameter of handwheel, the height difference of mounting axis and the sectional dimension of grip were studied to improve the ergonomics of aiming operation of towed gun-howitzer. In the simulation evaluation, the dynamic operation behavior of gunner was simulated, and his operating posture was evaluated by using multiple indexes. During comprehensive evaluation, the real samples of 4 shapes of grips, i.e., spindle-shaped, clinder-shaped, pear-shaped and cone-shaped, were grasped and evaluated with the reference of the comment set. According to the logic of simulation and comprehensive evaluation,the theoretical model of evaluating and optimizing the handwheel of sighting device was derived and constructed from up-to-down in terms of application layer, evaluation layer, data layer and knowledge layer. The result shows that the optimization design of handwheel size should first adopt a wheel diameter of 250 mm and the height difference between the mounting axes of two wheels should be 200 mm. If the grip is in the shape of a spindle, cylinder or pear, the sectional diameter should is considered 30 mm in priority. If the grip is cone-shaped, its sectional diameter can refer to 34 mm. The sectional diameter can be flexibly adjusted within a reasonable range to well fit for the size of the gunner’s hands. The proposed theoretical model aims to accurately capture the optimal reference range of handwheel elements through rapid evaluation and is used to support the optimized design for the purpose of relieving the fatigue on hands, upper limbs, shoulders and back, reducing the risk of injury and thus improving the comfort.

Key words: towedgun-howitzer, sightingdevice, handwheelsize, ergonomic, human-machinesimulationevaluation, human-machinecomprehensiveevaluation