The Sea Route Planning for Survey Vessel Intelligently Navigating to the Survey Lines

Marine surveying is an important part of marine environment monitoring systems. In order to improve the accuracy of marine surveying and reduce investment in artificial stations, it is necessary to use high-precision GNSS for shipborne navigation measurements. The basic measurement is based on the survey lines that are already planned by surveyors. In response to the needs of survey vessels sailing to the survey line, a method framework for the shortest route planning is proposed. Then an intelligent navigation system for survey vessels is established, which can be applied to online navigation of survey vessels. The essence of the framework is that the vessel can travel along the shortest route to the designated survey line under the limitation of its own minimum turning radius. Comparison and analysis of experiments show that the framework achieves better optimization. The experimental results show that our proposed method can enable the vessel to sail along a shorter path and reach the starting point of the survey line at the specified angle.

Design and Development of Roll Cage and Steering System of Go-Kart

Go-kart is a one of the motor sport which is played globally. This racing does not require any professional drivers or greater speed. It is a light weight and cheaper vehicle which does not require suspension and differential. In this paper we are concentrating on Roll cage and steering system of Go-kart. While keeping it light weight, chassis material is selected as AISI 1018 which give more tensile strength, machinability, and can sustain maximum load. For designing and analysis CATIA and ANSYS soft wares were used. Whereas in steering system the Ackermann steering mechanism is used for attaining maximum cornering speed, without the slippage of tires. This also gives us minimum turning radius, helping us to take sharp turns when the driver has to take sharp corners.

Surface Electromyography-Controlled Automobile Steering Assistance

Disabilities of the upper limb, such as hemiplegia or upper limb amputation, can limit automobile drivers to steering with one healthy arm. For the benefit of these drivers, recent studies have developed prototype interfaces that realized surface electromyography (sEMG)-controlled steering assistance with path-following accuracy that has been validated with driving simulations. In contrast, the current study expands the application of sEMG-controlled steering assistance by validating the Myo armband, a mass-produced sEMG-based interface, with respect to the path-following accuracy of a commercially available automobile. It was hypothesized that one-handed remote steering with the Myo armband would be comparable or superior to the conventional operation of the automobile steering wheel. Although results of low-speed field testing indicate that the Myo armband had lower path-following accuracy than the steering wheel during a 90° turn and wide U-turn at twice the minimum turning radius, the Myo armband had superior path-following accuracy for a narrow U-turn at the minimum turning radius and a 45° turn. Given its overall comparability to the steering wheel, the Myo armband could be feasibly applied in future automobile studies.

A Methodology for Modelling Tugger Train Systems Using Modelica

In this paper, the authors present a methodology to develop a modular model of a tugger train system using Modelica language. The presented system is composed by a tugger and three passive trolleys. The model allows to estimate the path of the trolleys relative to the path of the tugger vehicle and it can be used to estimate the maximum velocities when in a curve. A review of common vehicle models from the literature is presented. Some concepts of the Modelica language are introduced in order to support the model of the shown system. The presented model is a simplified representation of the system for planar motion developed in Modelica language using the Open Modelica OMEdit software2. The vehicle models are modelled by custom classes and linked with the aid of blocks from the Open Modelica standard library. This model was mainly used to understand the behavior of the vehicles during U-turns, estimate the minimum turning radius and maximum velocities during the turn. The methodology allows a modular approach combining vehicle and multibody modelling.

Computation of Vehicle Motion Path upon Entering Turn

Curvilinear motion of a vehicle as a part of assembly which takes place mainly on headlands is the most complicated element of its kinematics. Turns are carried out with gradual transition from infinitely large to minimum radius (upon transition from straight motion to motion along simple curve) and from minimum to infinitely large radius (upon transition from motion along simple curve to straight motion). Herewith, curvilinear motion along path of variable radius (upon entering turn and coming out of turn) is a significant portion (quite often more than one half) of all motion of the assembly on the curve. This article presents the procedure of derivation of parametric equations for analytical prediction of theoretical coordinates of motion points of tractor kinematic center upon entering turns. This procedure is based on universal equation for determination of theoretical minimum turning radius of wheeled vehicle. The proposed equations make it possible to determine theoretical path of entering turn of vehicle depending on the following variables: engineering parameters such as base, distance between kingpins, maximum turn angles of internal steered wheels, and operating parameters such as vehicle forward speed, angular turning speed of steered wheels in transverse plane; and to select reasonable properties on this basis.

Maneuverability Analysis of a Novel Portable Modular AUV

ZFAUV is a novel portable modular AUV. There are four fixed thrusters at tail, and two tunnel thrusters are set at front. The maneuverability of ZFAUV is relatively high. It can turn around in situ, move lateral or move up/down vertical. The yaw and pitch can be controlled by tunnel thrusters or differential control of tail thrusters, but differential control will reduce the forward force. Different from propeller-rudder AUVs, the turning radius is related to speed forward: the smaller the speed forward, the smaller the turning radius. The minimum turning radius tends to be zero. The mathematical model is built first; then CFD is used to predict the thrust and torque of tail thrusters and tunnel thrusters. Through numerical simulation, zigzag maneuver analysis in horizontal plane, and trapezoidal steering maneuver analysis in vertical plane, the maneuverability of ZFAUV is obtained. The maneuverability of ZFAUV becomes worse with the increase of speed. The maneuverability of differential control is better than that of tunnel control. In the case of specific thrust distribution of tail thrusters and tunnel thrusters, ZFAUV can turn around in situ (the maximum angular velocity is about 24.1°/s), move lateral or move up/down vertical (the maximum velocity is about 0.4m/s). Finally, an example, PID parameters tuning, is given to illustrate the application of maneuverability analysis. The dynamic performance of ZFAUV can be quickly and accurately analyzed by mathematical method, which has important guiding significance for the choice of control strategy and experiments and also has reference value for the later development of AUVs.

Analysis of ground handling characteristic of aircraft with electric taxi system

Electric landing gear drive equipped with traction motors can provide taxi capability without the use of main engines or tractor. The ground handling characteristic of aircraft with electric taxi system is analyzed. The new mathematic model of aircraft ground maneuver is established, considering the 6-degree-freedom aircraft body and the flexible main strut and the powered wheel. Quasi-steady method is applied to calculate tire side forces and moments, to determine side slip. The simulation for the ground steering response of aircraft with electric taxi system is done by employing ADAMS and Simulink co-simulation platform. The dynamic responses of aircraft ground steering and landing gear spin-up and spring back are simulated. Different taxi conditions including powered nose wheel mode and powered main wheel mode are compared. Four conclusions are obtained: electric taxi system helps the aircraft turn on the spot and the turning radius is smaller than the aircraft using engines; differential powered main wheel mode has the minimum turning radius while turning-circle with uniform velocity, and it has smaller difference between two vertical loads of main landing gear than powered nose wheel mode; in the case of the same steering angle, the extreme velocity of differential powered main wheel mode before side slip is larger than powered nose wheel mode; and pre-rotation of powered main wheel decreases the spin-up drag load and spring back drag load.