Motion control method for autonomous berthing of unmanned surface vessel

Abstract

The invention discloses a motion control method for the autonomous berthing of an unmanned surface vessel and belongs to the unmanned surface vessel autonomous berthing motion control field. The method includes the following steps that: a current control system mode is determined according to the current berthing state of the unmanned surface vessel; the current actual speed or heading of the unmanned surface vessel is obtained, and the control deviation and deviation change rate of the heading or speed are obtained; with the control deviation and deviation change rate of the heading or the speed adopted as the input of a fuzzy controller, an appropriate control parameter variation quantity is selected on the basis of the current control system mode, and a control parameter is updated; andwith e(t) adopted as the input of the controller, and the controller outputs a desired control command to an actuator. According to the motion control method of the invention, improvement is made onthe basis of the traditional PID controller, and the controller has two modes, namely, a remote end mode and a nearshore mode; an adaptive fuzzy control rule is added, so that the controller can dynamically and adaptively adjust the control parameter according to berthing behavior change; and therefore, a motion control problem under the influence of weak maneuverability, large disturbance and a strong bank effect during the autonomous berthing of an under-driven unmanned surface vessel can be solved.

Description

technical field [0001] The invention belongs to the field of motion control of autonomous berthing of unmanned boats, and in particular relates to a motion control method for autonomous berthing of unmanned boats. Background technique [0002] The unmanned boat is a nonlinear underactuated control system. It not only faces a large environmental disturbance when berthing autonomously, but also suffers adverse effects such as poor rudder efficiency caused by low speed and large disturbance caused by the wall effect. , so the autonomous berthing control of unmanned boats is a major problem in the field of automatic control of unmanned boats. [0003] Publication date July 21, 2017, publication number CN106970636A, the patent application titled "a control system for controlling the speed of aircraft and its control method" is used to control the speed of aircraft, and its control system includes conventional PID controllers, Fuzzy PID controller and weight assignment module, th...

AI Technical Summary

Problems solved by technology

As for the speed, the speed at the end of the wharf is very low. If there is an overshoot, it will easily cause a large trajectory tracking error (that is, the actual trajectory oscillation), which will lead to the phenomenon of "180-degree reversal" in the desired heading; In other words, due to the poor rudder effect due to low speed, once the course is overshooted, it is difficult to correct the heading in a very limited space; and the berth is generally very close to the shore, and the overshooting of the heading is likely to cause the unmanned boat to hit the wharf, resulting in ACCIDENT

The traditional PID controller is a data-driven control algorithm based on offline data, which cannot be adjusted online according to the actual situation, and its motion control performance is difficult to guarantee

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