Research On Task Planning Method For Operational Underwater Robot

Human beings need various high-tech equipment including underwater robots to understand and develop the ocean,and operational underwater robots are a kind of efficient marine operation equipment that can replace humans in underwater field operations.However,the redundancy of degrees of freedom,nonlinearity,strong coupling,and interference by hydrodynamic forces of these systems has led to the improvement of their operational performance as a challenging topic in the field of underwater robotics.When operational underwater robots perform tasks in complex underwater environments,task planning needs to be done under given constraints due to resource constraints and also optimization as a high-level planning task to ensure its safety.This paper addresses the task planning problem of underwater constraints,optimization objectives,physical limitations,and resource invocation to comprehensively improve the performance of operational underwater robots for autonomous tasks,and the main work of the paper is as follows:(1)System modeling.The operational underwater robot system mainly includes two subsystems: underwater robot and underwater manipulator.Firstly,the framework of the underwater robot subsystem is built according to the requirements,and the performance parameters of the underwater manipulator are described.Secondly,the coordinate systems required for the operational underwater robot are constructed,and the kinematic models of the two systems are derived based on the relevant principles in the corresponding coordinate systems.On this basis,the interactions between the two are focused on,and finally,the overall mathematical model of the operational underwater robot is obtained by simplifying the structure.(2)Task planning study.By defining and classifying the constraints such as action definition,optimization goals,and physical limitations of the operational underwater robot operation,a multi-task prioritized task planning method is developed,and the specific processing strategy of the method is given.By specifying the application requirements of the system underwater operation tasks,six categories of general operation task details are given.Among them,the lowest priority trajectory optimization task,which combines the trajectory optimization method of an underwater manipulator,is defined by the trajectory optimization objective function.The parallel coordination scheme proposed in this paper ensures that the different priority tasks in the action phase of the operational underwater robot maintain and activate their states,and then plan feasible task solutions in terms of task prioritization and scheduling.Simulation experiments are conducted to verify the feasibility and effectiveness of the proposed approach.(3)Simulation testing.To address the deployment application of the task planning method in the operational underwater robot control system,the underwater scenario was constructed by importing the system simulation scenario model through the ROS-based simulation experiment platform UWSim.Finally,the underwater scenario simulation test of the operational task of the operational underwater robot was completed by defining the command distribution through the XML file,and the underwater manipulator motion experiment was conducted.The proposed method was further validated.