PLC-based Multimodal Control Logic Design and Implementation in Ship Main Engine Remote Control System

This study proposes a PLC (Programmable Logic Controller) based multimodal control logic design and implementation scheme for ship main engine remote control system. The precise control of ship's speed is realized by establishing the nonlinear full volume equation of ship's main engine operation, which covers the key physical quantities such as main engine speed regulation, propeller thrust, ship's motion resistance and dynamic response. Four control modes, namely, normal navigation, acceleration navigation, deceleration navigation and emergency stop, are designed to optimize the stability of navigation speed and acceleration performance through proportional-integral control logic, respectively. In the actual test, the system shows good control effect, with the speed stabilized at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$12 \mathrm{m} / \mathrm{s}$</tex> under normal conditions, the speed of the ship gradually increased to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$16.5 \mathrm{m} / \mathrm{s}$</tex> during acceleration, smoothly reduced to <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$12 \mathrm{m} / \mathrm{s}$</tex> during deceleration, and the speed of the main engine rapidly reduced to 0 in 15 seconds during emergency stopping. The study also analyzes the influence of aerodynamic forces on the control system and proposes the corresponding correction methods. Meanwhile, the hardware and software reliability analysis of the system shows that the stability and reliability of the system can be effectively improved by redundant design and software testing. This study provides a theoretical basis and practical guidance for the optimization and application of ship main engine remote control system.