Abstract:
Control systems available in the market of the electric drive for transfer of freights on vessels in the conditions of heaving of the sea are based on contact measurement of distance between the deck of the accepting vessel and a cargo platform or freight by means of the tense cables or metal beams. Fixing of tracking devices takes a lot of time and in most cases is unsafe for the personnel. The developed experimental installation is deprived of these shortcomings. The functional schemes of the systems of control of the cargo crane electric drive and also experimental installation are developed. Experimental installation of realization of freights transfer to the shaking platform generally consists of the Arduino microcontroller, the ultrasonic sensor of measurement of distance of HS-SR04, the infrared sensor of Sharp distance, the three-axial accelerometer MMA7361 and the module of a wireless communication ZigBEE. The installation consists of two experimental complexes. The complex N 1 using signals from ultrasonic sensors provides a delay of speed of freight lowering while reaching the platform/deck and/or indication to the crane operator. This complex operation is possible in the wide range of weather conditions when unloading freight to the platform (the platform plane is stationary) and only it is partially possible when loading freight from a platform to the vessel deck, especially at strong heaving of the water surface (the plane of the vessel has longitudinal, cross and vertical shift). Complex N 2 uses the integrated three-axial accelerometer of capacitor type as a data registrar on the vessel and its freight movement. Accelerometers represent sensors of linear acceleration. Having respectively subjected an output signal to single or double integration it is possible to receive the speed and shift. Carrying out data archiving on the on-board computer in real time (and also from the moment of exit from the starting point to the end point) it is possible to receive a three-dimensional model (vector) of the movement of the sensor and the vessel as well. Using the obtained data, it is possible to estimate the dynamic impacts on the vessel (on the various elements of the vessel while increasing in number of sensors) and to predict the necessity of replacement of the vessel fasteners.