Study on down-cutting ladder trencher of an underwater construction robot for seabed application

Abstract

This paper presents the basic physics required to predict the performance of a down-cutting operation of a complete mechanical system including underwater tracked vehicle (UTV) and ladder trencher (LT) in a subsea application. The bar forces on a complete LT are assessed, by considering the forces generated by individual cutting tools when they are mounted on an LT. The thrust or traction requirements for the overall system (UTV and LT) are then estimated, and the required tractive thrust and normal reaction forces of the overall system can be calculated. In order to analyze the weight and balance requirements of the UTV, the moment of the LT caused by the cutting system is studied. The energy and power needed to drive the LT are then estimated and considered in relation to the tool characteristics. To demonstrate the application of various equations to practical problems of machine design or performance analysis, a number of numerical simulations are performed using the derived approach. This simulation provides important insight into the behavior of the trenching machine that can be used to design a trenching machine for the required working conditions. For this, the parameter study and sensitivity analysis are conducted to determine the variations of the operational and geometric parameters, and to observe how the cutter tools and material condition affect the forces, moment, weight, and power components.