Analysis of Effective Vision for Counterbalanced Trucks with Mast Based on the Quick Image Recognition Methods

Counterbalanced trucks with mast are used widespread in the modern warehousing and logistics industry. However, a limited and insufficient operator vision often leads to the decrease of operational efficiency and even collisions, which reduces the safety of goods and operators. Therefore, based on the quick image recognition methods, the comprehensive influences of forklift operating conditions, the features of cargo size and the height of drivers on the effective vision of operators were systematically investigated through the Jack Ergonomic Engineering Software. The results revealed that the ratio of vision obstruction (RVO) of operators is closely related to forklift operating conditions, dimensions of cargo, height of drivers, and sitting posture. As the width and height are increased, the RVO increases significantly. In addition, compared to the width and height of cargo, the growth rate of RVO is increased much slower due to the perspective principle of human eyes. The methods and results of this study not only achieve precise quantitative characterization of forklift vision, but also provide a basis for structural design improvements for manufacturers and scientific guidance for warehouse managers to plan operations, which could enhance the safety and efficiency of logistics operations.