Research in Agricultural Engineering, 2003 (vol. 49), issue 3

Field capacity determination from GPS spatial data

P. Kovaříček, J. Hůla

Res. Agr. Eng., 2003, 49(3):75-79 | DOI: 10.17221/4955-RAE  

For agricultural machinery management the actually reached machines capacity has a considerable importance. The data recorded by GPS monitoring enable to correct machines work productivity under concrete operational conditions. Assessment of machine aggregates operation records has proved effect of the operational factors onto operational efficiency reached on particular plots. The theoretical efficiency given by exploitation characteristics of machines has decreased effect of higher share of non-productive travels within small and irregular plots almost by 25%. In this paper we are dealing with searching for correlation between field speed and travelled...

Research of sugar-beet tubers mechanical properties

J. Skalický

Res. Agr. Eng., 2003, 49(3):80-84 | DOI: 10.17221/4956-RAE  

Approach to the problems of sugar-beet tubers surface damage dependence on harvesting technology. Investigation of sugar-beet tubers damage when falling on wood and iron surfaces and in the next case tuber damage caused by their fall on the tuber heap. Research of damage rate dependence on the fall height. Evaluation of damage rate was carried by the I.I.R.B. method (method used by all sugar-beet growing countries of Western Europe). The results refer that no considerable differences in damage rate after the fall on the wood or iron bottoms have been ascertained. The height of 1.5 m can be considered in all cases as the limit value of the tubers fall,...

Exploitational indicators, Diesel fuel consumption and work quality during disc tiller skimming

J. Hůla, P. Kovaříček, V. Mayer

Res. Agr. Eng., 2003, 49(3):85-90 | DOI: 10.17221/4957-RAE  

During the shallow soil tillage after winter wheat harvest the tractor JOHN DEERE 8200 with disc tiller DOWLANDS 4500 operation was monitored. For dependence of the set field speed within plots acreage the function of type y = 0.43 Ln x + 10.76 was chosen. Average Diesel fuel consumption at first skimming on plots of total acreage 611.4 ha was 7.98 l/ha, for evaluation of Diesel fuel consumption dependence on particular plots acreage was chosen a logarithmic model of function y = -0.81 Ln x + 10.35. For the engine Diesel fuel consumption dependence on average length of working drives through the plots the logarithmic...

The outer quality loss during grain post-harvest treatment and handling

P. Kroupa

Res. Agr. Eng., 2003, 49(3):91-102 | DOI: 10.17221/4958-RAE  

In the paper are presented results of grain outer quality loss investigation during its post-harvest treatment. Objective was to determine the grain damage during its transport by bucket elevators of type "SANFON" at bucket peripheral velocity 2.0 m/s and 2.8 m/sof capacity 40 t/hand 80 t/h, respectively. The damage was investigated at counter-flow and parallel-flow bucket filling. From the measured results resulted the conclusion, that the bucket elevators tend rather to grain crushing, i.e. fraction creation than to smaller damage. On basis of partial knowledge chain elevators have no significant tendency to fraction generation, but incline considerably...

Safety aspects for automatic guidance of agricultural machines and low-cost solutions

U. Klee, L. Hofmann, P. Pickel

Res. Agr. Eng., 2003, 49(3):103-109 | DOI: 10.17221/4959-RAE  

Automatic steering devices for farm machinery and tractors have the task to relieve the driver from the physical and mental stress of monotonous steering work. Simultaneously, they are intended to help exploit machines and tractors closer to their full performance and improve the quality of work. However, it is not possible to rule out malfunctions or breakdowns of sensors, gaps in guidance lines, obstacles in the field such as ditches or pylons, temporary hazards like the sudden appearance of animals in front of a moving machine or a temporary lack of concentration of the operator. Most of these problems may be prevented by a safety system for automatically...

Comparison of the operation of milking machine control valves and a newly designed regulating device

J. Fryč

Res. Agr. Eng., 2003, 49(3):110-114 | DOI: 10.17221/4960-RAE  

One of the basic demands for milking machines is to maintain a constant vacuum level if air consumption by milking machine is changed. The author designed a device with reducing valve for vacuum level regulation and a simultaneous vacuum pump control enabling electric power to be reduced. The paper deals with a comparison of the operation of standard control valves with the newly designed device used for vacuum regulation from the viewpoint of dynamic properties. When measuring vacuum stability by applying various regulation methods and a subsequent statistical evaluation of the results obtained it was proven that the function of the newly designed...

Engine combustion chamber tightness diagnostics

J. Pošta, B. Kadleček, T. Hladík

Res. Agr. Eng., 2003, 49(3):115-118 | DOI: 10.17221/4961-RAE  

The modern combustion engines and their systems are getting more complicated and sophisticated nowadays. It is no more possible to verify their function or actual technical state directly. Thus various methods of indirect diagnostics are being developed more and more rapidly. The on-board diagnostics is being increasingly applied to monitor and measure suitable diagnostic signals during operation, deviations from required or expected values are then recorded. This trend requires the application of completely disassembly-free techniques of measurements and the real-time analyzing of measured figures. This paper presents the results of the research on...

Ecological aspect of mobile systems operated in terrain conditions

A. Janeček, M. Mikleš

Res. Agr. Eng., 2003, 49(3):119-123 | DOI: 10.17221/4962-RAE  

In this paper is evaluated an optimal constructional and operating performance of the mobil terrain system, that works in forest ecosystems from point of view of volume of processed biomass and total amount of logging transport erosion. A monitored terrain system, working in forestry, is considered as a production system, with its material and energy flow. The determination value, that optimizes the production system, is the operating and constructional performance. In this paper is evaluated the amount erosion in dependence of cutting mass, by means of mathematics and from system point of view. The conditions for the mobile terrain system work, that...