The paper presents a concept of application of optical displacement sensor type Sharp GP2Y0A02 in the linear positioning system containing rodless pneumatic actuator and programmable controller. The coupling circuit between sensor and controller, containing voltage controlled current source was proposed. The properties of measuring system were investigated, and some mathematical models of its static characteristic were found using the less squares method. The analysis of residual errors, and sum of squared residual errors were performed. Finally, the model minimizing the mentioned quantities, as well as measuring range of investigated system were selecte

The paper shows properties of the follow-up system for rudder deflection using a hydraulic pump of constant delivery. Several solutions of a system using a three-point controller with dynamic feedback to enhance the steady-state accuracy are discussed. The results of simulative research are presented.

This article presents properties of a follow-up system executing ship’s rudder deflection using a constant delivery hydraulic pump. Furthermore, a solution is discussed which increases static and dynamic accuracy of such a system using the rudder angular velocity signal. This signal has been used for changing the level of a three-position controller insensitivity. The paper also shows the method of determination of the function describing variations of dead-zone width of the three-point controller. Two kinds of such function are shown, namely linear and quadratic. A computer model was prepared in MATLAB-Simulink environment, showing the operation of the system with correction of error signal, which carries out given by function variations of points of switching. Also included are the simulation results of the described solution, indicating a significant enhancement of accuracy of rudder angle control process for the steady state as well as during transients.

Autonomous underwater vehicles are vehicles that are entirely or partly independent of human decisions. In order to obtain operational independence, the vehicles have to be equipped with specialized software. The task of the software is to move the vehicle along a trajectory while avoiding collisions. In its role of avoiding obstacles, the vehicle may sometimes encounter situations in which it is very difficult to determine what the next movement should be from an ad hoc perspective. When such a situation occurs, a planning component of the vehicle software should be run with the task of charting a safe trajectory between nearby obstacles. This paper presents a new path planning algorithm for a Biomimetic Autonomous Underwater Vehicle. The main distinguishing feature of the algorithm is its high speed compared with such classic planning algorithms as A*. In addition to presenting the algorithm, this paper also summarizes preliminary experiments intended to assess the effectiveness of the proposed algorithm.

This article presents the problem of overloading of the steering gear controlled by an autopilot in high sea states and ways of reducing it. The author proposes a new method of estimating the steering gear load by counting the number of machine reversals in a selected time period. A block diagram of such solution is presented along with the results of simulations of system operation in different sea states. The results obtained, in terms of number of reversals, depend significantly on the state of sea, providing a means to estimate the current state of the sea as well as the expected difficulty in exploiting the steering gear.