# A Method for Supervisory Control of Manipulator of Underwater Vehicle
###### Abstract  
A novel method for supervisory control of multilink manipulators mounted on underwater vehicles is considered. This method is designed to significantly increase the level of automation of manipulative operations, by the building of motion trajectories for a manipulator working tool along the surfaces of work objects on the basis of target indications given by the operator. This is achieved as follows: The operator targets the camera (with changeable spatial orientation of optical axis) mounted on the vehicle at the work object, and uses it to set one or more working point on the selected object. The geometric shape of the object in the work area is determined using clouds of points obtained from the technical vision system. Depending on the manipulative task set, the spatial motion trajectories and the orientation of the manipulator working tool are automatically set using the spatial coordinates of these points lying on the work object surfaces. The designed method was implemented in the C++ programming language. A graphical interface has also been created that provides rapid testing of the accuracy of overlaying the planned trajectories on the mathematically described surface of a work object. Supervisory control of an underwater manipulator was successfully simulated in the V-REP environment. supervisory control; underwater unmanned vehicle; multilink manipulator; cloud point; mathematical model; deep-sea research; spatial trajectory; underwater operations; control system +
Footnote †: journal: Marine Science and Engineering  
0000-0001-770-0000-0000-0000-0000-0000-0000-0000-0000-0000-0000-00000-00000-00000-00000-00000-00000-00000-000000-00000-000000-000000-00  
The routine collection of sediment (Figure 1), geological rock, and bacterial mat samples very often led to operator fatigue within a short period of time, to a significant increase in operation time, to errors in operations, and even to damage to working tools and samplers. During manipulative operations, an UUV is exposed to undesirable dynamic impacts from the surrounding aquatic environment and the moving MM. These impacts shift the UUV position from the work object and complicate the control of the MM. To solve these problems, there are systems [21; 22; 23] that allow holding an UUV performing a manipulative operation in the desired spatial position with great accuracy. Moreover, if an MM has a greater number of degrees of mobility than is required for operations, the system [24] generates control signals for its actuators in such a way that this MM has the least impact on the UUV. These systems are indispensable for providing accurate operations in the UUV hovering mode. However, to facilitate manual control of MM, additional supervisory control systems are required. To increase the efficiency of manipulative operations and reduce the load on operators, computer systems have been created [25] that allow operations to be performed on-line in a supervisory mode. In this control mode, the operator sets only simple target indications for the MM. Based on these indications, control signals for all the MM actuators are generated in a real-time mode. Some components of such systems have been tested on the ROV Jason [26]. To simplify the manual control of MMs, a strategy with the use of the P300 Brain-Computer Interface is proposed [27]. However, all the systems considered do not allow identification of the shape of the work objects or automatically building complex spatial motion trajectories of MM working tools over the surface of these objects. With the development of technical vision systems (TVS) and environmental object recognition technologies, a new trend has arisen to increase the level of automation of many manipulative operations. The approach proposed in [28] is the use of a stereo camera mounted on the MM gripper, which allows determining the position and orientation of a known object with a pre-installed \"Fiducial marker\".