Template-Type: ReDIF-Article 1.0 Author-Name: P. Kovaříček Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Author-Name: J. Hůla Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Title: Field capacity determination from GPS spatial data Abstract: 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 unit path and defined classes of size, length and plot shape. The resulting knowledge of field efficiency on plots properties will enable to make more accurate the machines planned operation. Keywords: machinery management, coefficient of field time utilization, spatial data, GPS Journal: Research in Agricultural Engineering Pages: 75-79 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4955-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4955-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0001.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4955-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Skalický Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Title: Research of sugar-beet tubers mechanical properties Abstract: 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, when share of heavily damaged tubers reached acceptable values of 10-15%, but that the share increases significantly at higher falling height. The lifting bodies construction requires also a knowledge of dependence between root depth and force for tuber release from soil in relation to the tuber weight. Medium force needed for tubers lifting ranges from 17 to 27 kp, maximum value 50 kp was found out for tubers of weight above 3 kg. Keywords: sugar-beet, tuber damage, fall height, root depth, force for tuber release Journal: Research in Agricultural Engineering Pages: 80-84 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4956-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4956-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0002.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4956-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Hůla Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Author-Name: P. Kovaříček Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Author-Name: V. Mayer Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Title: Exploitational indicators, Diesel fuel consumption and work quality during disc tiller skimming Abstract: 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 model of function y = -1.83 Ln x + 18.95 was chosen. After first skimming by disc tiller on the soil surface has remained 31.1 wt % of winter wheat post-harvest remainders, in depth of 0-50 mm was found-out of 31.0% of post-harvest remainders, 37.9 wt % of crop remainders was found-out in depth of 50-100 mm. After the second skimming by the blade tiller most of the post-harvest remainders was worked-in to the depth of 50-100 mm (54.3 wt %). After the following pre-seeding soil preparation by combinatory was recorded dislocation of most of crop remainders to depth of 0-50 mm (58.4 wt %). Keywords: skimming, disc tiller, machines operations monitoring Journal: Research in Agricultural Engineering Pages: 85-90 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4957-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4957-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0003.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4957-RAE Template-Type: ReDIF-Article 1.0 Author-Name: P. Kroupa Author-Workplace-Name: Research Institute of Agricultural Engineering, Prague, Czech Republic Title: The outer quality loss during grain post-harvest treatment and handling Abstract: 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 to the transported grain total mechanical damage at performance significantly lower than is the nominal one. In that case total mechanical damage ranged from 1.78 to 1.98%. Auger conveyers tend rather to total mechanical damage of transported grain than to the fraction creation. This is caused mainly by the friction between the transported grain and transporting "trough". Total mechanical damage is in range from 1.36 to 1.73%. Belt elevators are friendly to transported grain and therefore are evitable for grain horizontal transport in lines for reception, treatment and storage of food grain crops. Keywords: outer quality, bucket elevator, chain elevator, auger elevator, belt elevator, fraction, total mechanical damage, grain Journal: Research in Agricultural Engineering Pages: 91-102 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4958-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4958-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0004.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4958-RAE Template-Type: ReDIF-Article 1.0 Author-Name: U. Klee Author-Workplace-Name: Martin-Luther-University Halle-Wittenberg, Halle, Saxony-Anhalt, Germany Author-Name: L. Hofmann Author-Workplace-Name: Martin-Luther-University Halle-Wittenberg, Halle, Saxony-Anhalt, Germany Author-Name: P. Pickel Author-Workplace-Name: Martin-Luther-University Halle-Wittenberg, Halle, Saxony-Anhalt, Germany Title: Safety aspects for automatic guidance of agricultural machines and low-cost solutions Abstract: 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 steered agricultural machinery developed at the Department of Agricultural Engineering of the Martin-Luther-University in Halle. The function of the components of the safety system and preliminary results obtained in field experiments are introduced and discussed. Keywords: automatic steering, DGPS, GIS, safety system Journal: Research in Agricultural Engineering Pages: 103-109 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4959-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4959-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0005.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4959-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Fryč Author-Workplace-Name: Mendel University of Agriculture and Forestry, Brno, Czech Republic Title: Comparison of the operation of milking machine control valves and a newly designed regulating device Abstract: 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 regulating device was comparable with the best reducing valves used so far. Keywords: milking machine, vacuum control, control valve, vacuum stability Journal: Research in Agricultural Engineering Pages: 110-114 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4960-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4960-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0006.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4960-RAE Template-Type: ReDIF-Article 1.0 Author-Name: J. Pošta Author-Workplace-Name: Czech University of Agriculture, Prague, Czech Republic Author-Name: B. Kadleček Author-Workplace-Name: Czech University of Agriculture, Prague, Czech Republic Author-Name: T. Hladík Author-Workplace-Name: Czech University of Agriculture, Prague, Czech Republic Title: Engine combustion chamber tightness diagnostics Abstract: 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 relation between the starter's starting current and the engine combustion chamber tightness. The experiments were carried out for common four-cylinder engine. Keywords: combustion chamber tightness, instantaneous starting current, compression pressure, on-board diagnostics Journal: Research in Agricultural Engineering Pages: 115-118 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4961-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4961-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0007.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4961-RAE Template-Type: ReDIF-Article 1.0 Author-Name: A. Janeček Author-Workplace-Name: Czech University of Agriculture, Prague, Czech Republic Author-Name: M. Mikleš Author-Workplace-Name: Czech University of Agriculture, Prague, Czech Republic Title: Ecological aspect of mobile systems operated in terrain conditions Abstract: 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 insure optimal, i.e. minimal value of erosion will be determined. The theoretical results are verified. The optimal values of soil erosion are determined by experimental measurements. The principles of the paper are based on theses of ecological synthesis that determine coupling between dissipative energy of a production system and its ecological cleanliness of work. Keywords: mobile terrain system, forest ecosystem, mathematical simulation Journal: Research in Agricultural Engineering Pages: 119-123 Volume: 49 Issue: 3 Year: 2003 DOI: 10.17221/4962-RAE File-URL: http://rae.agriculturejournals.cz/doi/10.17221/4962-RAE.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/rae-200303-0008.txt Handle: RePEc:caa:jnlrae:v:49:y:2003:i:3:id:4962-RAE