This paper proposes an algorithm to improve path planning and tracking performance for autonomous robots using a Four- Wheel Steering (4WS) system in constrained environments. Traditional Ackermann steering systems face limitations in narrow spaces, which the 4WS system aims to address. By extending the Hybrid A* algorithm to adapt to the unique characteristics of the 4WS system, and integrating it with Model Predictive Control, the study achieves efficient path planning and precise tracking in complex environments. A distinctive aspect of the proposed approach is its adaptive control strategy, dynamically switching between three modes—Normal driving, Pivot, and Parallel movement—based on the vehicle's motion state, thus enhancing both flexibility and efficiency. The algorithm's performance was validated through MATLAB simulations in a logistics warehouse setting, showing high path tracking accuracy in confined spaces. The study effectively demonstrates the feasibility of the proposed method in a simulated environment.

The heat-sealing strength of pouch film greatly affects the reliability of the lithium ion secondary battery. In this paper, the researchers investigated and evaluated the properties of the heat-sealing strength of pouch film, such as heat, pressure, time, thickness of the heat-seal, and the polypropylene material. The heat-sealing strength showed a high value at 180℃ for 3 seconds. However, under the conditions of higher temperatures and longer times, deformation and bulging of polypropylene were observed. The heat-sealing strength tended to increase when decreasing heat-seal thickness. The heat-sealing strength varied according to the type of polypropylene. In addition, to avoid defects that may have occurred in the process of manufacturing the lithium ion secondary battery, the heat-sealing strength in the state where the impurities remained was evaluated.

This paper studied the adhesive strength and electrolyte resistance of the pouch film according to the kind of the extruded resin, which is the basis of the numerous variables in extrusion lamination. After preparing a pouch film by using various extruded resins, we measured the adhesive strength and electrolyte resistance between the aluminum foil and the CPP film. The minimal difference was observed between the adhesive strength with the extruded resin. Also, the extruded resin used in the experiment did not satisfy the electrolyte resistance. An electrolyte resistance was obtained by addition of the functional resin to the extruded resin. The addition of functional resins resulted in improved adhesive strength and electrolyte resistance, that were measured to be approximately 1300 gf/15 mm and 800 gf/15 mm, respectively, at 85℃ for 7days.

In this study, the intention is the determination of the optimum laminate conditions for the improvement of the chemical resistance of the aluminum-pouch films that are widely used as a packaging material for the secondary battery. Here, the properties including the initial adhesive strength and the electrolyte resistance between the metal-film layer with aluminum and the sealant layer with cast polyprophylene (CPP) film were investigated. Regarding the lamination condition, the lamination temperature, speed, and pressure conditions were changed. A roll-to-roll dry lamination-coating system was used in the surface-treatment agent coating, adhesive coating, and film lamination. For the lamination conditions of the aluminum and CPP films, the initial adhesive strength of the laminated-pouch film manufactured with a 110oC temperature and a 6.0 M/min line speed is 1200 gf/15 mm. The measured adhesive strength of the 85oC electrolyte resistance after its immersion for 7 days is 600 gf/15 mm.

Pouch film is manufactured by laminating aluminum foil, polyamide film and polypropylene film with an adhesive or extrusion resin. However, a surface treatment is required for the aluminum because bonding does not occur easily between the aluminum foil and the polymer film. Thus, for this study, surface treatment experiments were performed in order to confirm the effect on adhesion strength. First, a variety of surface treatment solutions were coated on aluminum foil, and contact angle and surface morphology analysis was carried out for the surface-treated aluminum. For lamination of the surface-treated aluminum foil with polyamide film, a polyurethane base adhesive was prepared for the adhesive strength test specimens. The adhesive strength between the aluminum foil and the polyamide film of the resulting specimens was measured (UTM). With such an experiment, it was possible to evaluate the effect on adhesive strength of the various surface treatments.

In this study, we investigated the adhesive strength by molecular weight, mixture ratio, coating thickness, lamination temperature and aging condition of adhesive in manufacture process of Nylon-Aluminum for secondary aluminum pouch. It found that as the molecular weight of adhesive gets lower, the adhesive strength increases. In the mixture ratio, as the content of hardener get higher and as the content of solvent get lower, the adhesive strength increases. Also, as the coating thickness of adhesive get thicker, the adhesive strength increase. In addition, the adhesive strength is higher at 90 degrees of lamination temperature. So, it found that 90 degrees of lamination temperature is appropriate. In the aging condition when aged for 5 days, it found that the reaction and curing of adhesive is sufficient by measuring the adhesive strength.