In considering the problem of saving spaces during the transportation of items from one station to another, for example, in warehouses, factories, hospitals, etc., an automatic transportation system (ATS) that could take advantage of the above ceiling spaces for the transportation of products is considered. Such a system guarantees that the activities occurring in the floor area will be maintained as usual. To achieve this requirement, the ceiling spaces of a building are used to construct an automatic multi-station multi-container (MSMC) transportation system. This system can transport items from one place to another in the whole system. This system is designed to utilize the spaces above the ceiling, and it has the advantage of saving floor space for transportation operations. This will increase the operational capability of the industries and also improve the productivity of the industry in which this system is implemented. The entire transportation system includes (1) the essential conveying system (which is a functional conveyor module with a specified number of containers); (2) the control block that can monitor and operate the system; and (3) the sensor block for detecting and identifying the containers. The content of this article focuses on the introduction of the mechanical system (1); the control system (2); and the operating principle of the whole system (3).

Underwater vehicles are a powerful tool that can assist oceanologists with measuring the state of oceans on a large scale. The heading control is essential for the underwater vehicle to follow a specific path. This study describes the general decoupled dynamics of underwater vehicles, which is a nonlinear second-order differential equation considering linear and quadratic damping hydrodynamics. A novel aspect of this study is the development of a new analytical solution for the second-order nonlinear differential equation, which involves the heading motion of the underwater vehicle. In this study, the time-optimal trajectory is formulated as the closed-form solution for the heading dynamics of the underwater vehicle. The concept of this trajectory is based on the shortest arrival time when the maximum force from the thrusters is applied to the underwater vehicle. Finally, a simulation of the time-optimal trajectory and evaluation of the robustness of the controller were demonstrated in order to verify the effectiveness of the proposed trajectory for controlling underwater vehicles.