Articulostesis

Development of agricultural machinery aided guidance system based on GPS and GIS

The agriculture machinery guidance technology is one of precision agricultural important technologies. Based on GPS and GIS, it can raise working efficiency and improve the quality, reduce production costs, reduce driver working difficulty. This research's general goals realize the aided guidance function foragriculture machinery driving on road and straight line operation in the field by lightbar. The system uses Visual Basic 6.0 and MapObjects 2.2, uses the RS232 serial port communication, uses the AgGPS 332 receiver, uses the DGPS signal offered by Satellite Based Augmentation Systems, uses touch-screen vehicle carries computer for the superior computer, applies the existing area electronic map,develops region's farmland and path's geographic information system, enables the farm machinery to obtain the guidance information for transportation between the fields. When farm machinery works in field without guidance line, system can make guidance straight line at first traveling schedule according to the A and B points, uses light-bar guidance. Lightbar's hardware circuit uses the 89S52 Singlechip micro-processor and outside expands two piece of 74HC245 to actuate the LED. The system has realized to agriculture machinery's guidance function and could record operating course and calculate area and review operation that is convenient for agricultural production and information management.

Adaptive and predictive non linear control for sliding vehicle guidance: application to trajectorytracking of farm vehicles relying on a single RTK GPS

When designing an accurate automated guidance vehicle system, a major problem is sliding and pseudo-sliding effects. It is especially the case in agricultural applications, where a five centimeters accuracy with respect to the desired trajectory is required, even if vehicles move on a slippery ground. Previous works have established that RTKGPS was a very suitable sensor to achieve automated guidance with such a high precision: several control laws have been designed for vehicles equipped with that sensor, and provide the expected guidance accuracy as long as vehicles do not slide. Further control developments have been previously proposed to take sliding into account: guidance accuracy in slippery environment has been shown to bepreserved, except transiently at beginning/end of curves. In this paper, design of such a control law is first recalled and discussed. Model predictive control method is then applied in order to preserve guidance accuracy even during these transitions. Finally, the global control scheme is implemented, and improvements with respect to previous guidance laws are demonstrated through full-scaleexperiments.

Rejection of sliding effects in car like robot control: application to farm vehicle guidance using a single RTK GPS sensor

A very accurate vehicle guidance is required in numerous agricultural applications, as seeding, spraying, row cropping,... Accuracy in vehicle localization can be obtained in realtime from a RTK GPS sensor. Several control laws, relying on this sensor, have beenpreviously designed and provide satisfactory results as long as vehicles do not slide. However, sliding has to occur in agricultural tasks (sloping fields, curves on a wet land, ...). The challenge addressed in this paper is to preserve vehicle guidance accuracy in such situations. A nonlinear adaptive control law is here designed. Simulation results and field experiments, demonstrating thecapabilities of that control scheme, are reported and discussed.

GIS and GPS Based Vehicle Guidance System

In order to enhance level of vehicle guidance system (VGS) in China, the framework, subsystem and critical technologies of VGS were studied, and geographic information system (GIS), Global Positioning Systems (GPS), etc. were applied into corresponding subsystems. Paying attention to the...