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Article type: Cover
1998 Volume 99 Pages
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Published: September 25, 1998
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Article type: Appendix
1998 Volume 99 Pages
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Article type: Appendix
1998 Volume 99 Pages
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Article type: Index
1998 Volume 99 Pages
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Article type: Index
1998 Volume 99 Pages
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Takashi MORIMOTO, Tatsuya YASHIRO, Kohei OHTSU
Article type: Article
1998 Volume 99 Pages
1-12
Published: September 25, 1998
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Recently, most inertial navigation system (INS) are strapdown type. The strapdown inertial navigation system is consisted of 3-optical gyros and 3-accelerometers, and onboard navigation computer. The inertial navigation system has position errors that grow slowly with time, and these errors are unbounded. These errors are suppressed by using the data from GPS. The difference between GPS and INS is the input data to Kalman filter. The estimated data by Kalman filter is feedback to decrease these errors. The performance of this bounded INS depends upon the accuracy of the error model installed into Kalman filter in the onboard computer. The accuracy of the error model is currently checked after installation into the onboard computer. Therefore, the cost of check is expensive. Authors designed a pre-check simulator of the accuracy of the error model before install. This paper describes the validity and the structure of the simulator.
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Sakae NAGAOKA
Article type: Article
1998 Volume 99 Pages
13-20
Published: September 25, 1998
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This paper describes the effects of GPS equipped aircraft on the global system performance specification defined in the manual on the implementation of reduced vertical separation minima (ICAO Doc 9574). The relationship between the standard deviation of the lateral path-keeping errors and the lateral overlap probability is investigated for the GPS equipped aircraft under several assumptions. The calculated lateral overlap probability is about four times larger than the value described in the manual. The results suggest the need for revising the description of the global system performance specification given in the ICAO manual.
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Eiji KONDOH, Naoto TANAKA, Akio YASUDA, Kohichi OKAMOTO
Article type: Article
1998 Volume 99 Pages
21-28
Published: September 25, 1998
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We tried to evaluate the adaptability of RTK-GPS to future construction of an ultra large scale floating steel structure, named 'Mega-Float', by the analysis of the acquired data on a very-large-scale model. The standard deviation of short term variation in each direction is less than 1cm. It is smaller than the nominal accuracy of the receiver and seems to be a measure of the amplitude of the oscillation. The deviation in vertical direction increases with the increase of significant wave height. Those in the other directions also reflect wave height variation. Noise level inferred from many patterns of temporal variation of the calculated positions is less than 1 or 2mm. Although when determining the absolute position, the noise level may reach the order of the nominal value mentioned above, due to drift and jump of the calculated positions, it is ensured that only RTK-GPS has an enough accuracy for the offshore construction of such a huge floating structure.
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Takeyasu SAKAI, Kazunobu KOREMURA
Article type: Article
1998 Volume 99 Pages
29-35
Published: September 25, 1998
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For a precision approach and landing system of aircraft using GPS, it is nessessary to improve the system performance such as positioning accuracy, integrity, continuity and availability. A possible way for improving the performance may be to use pseudolites (pseudo-satellites) located on the ground near airport in addition to ordinally GPS satellites. In this paper, we investigated how the positioning accuracy can be improved through the DOP analysis. Since efficiency of pseudolites may depend on relative locations of themselves with regard to runway and aircraft, we computed DOP values expected at a paticular airport with pseudolites located various positions arround. Pseudolites moving on the grid centered at the runway threshold of the airport, corresponding DOP values are presented. The result shows that a pseudolite located near the runway threshold improves the accuracy considerably. In case of using two pseudolites, they should be located on both sides of the approach course. Consideration to the relations with line-of-sights from the threshold to GPS satellites is also contained.
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Hitoi FUKUDA, Hideki HAGIWARA, Kazuo SUGAI, Yuzo KUSAKA
Article type: Article
1998 Volume 99 Pages
37-46
Published: September 25, 1998
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In this study, speed performance and operation limit of a high speed ship (HSS) "TSL-A" in waves were estimated. Using the wave data produced by a fine-mesh wave forecast model and the statistical ocean current data, comprehensive weather routing simulations of the TSL-A were performed. The isochrone method was adopted to determine the minimum time route (MTR). From the results of the simulations, the followings were obtained. (1) The MTR of HSS is largely affected by the operation limit in calculating ship's speed in waves. (2) Ship weather routing is very effective also for the HSS if there is wide sea area on both sides of the great circle route to avoid adverse wave conditions. (3) In some wave conditions, the MTR of HSS becomes very sensitive to the departure time. (4) The route optimization not only can shorten the passage time but also can improve the punctualness of operation. (5) The optimum route simulations can be used to determine the speed and seakeeping performance of the HSS to be put into service between the given ports.
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Hiroshi MATSUKURA, Nobuo KIRIYA, Yasuji KANAI
Article type: Article
1998 Volume 99 Pages
47-56
Published: September 25, 1998
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This paper describes the detection method for floating targets with visible ray sensor in airborne remote sensing. As a typical example of floating targets a lifeboat is discussed, but this method can be adopted for other floating targets whose colors are not like those of the surface of the sea. Pictures of the lifeboat on the sea are taken by two experiments. The distribution model of these pictures' each pixel in the 3-dimentional RGB distribution graph is proposed. By using the model, a detection method for floating targets by evaluation of the difference between the colors of the sea and that of these pictures' each pixel is proposed and verified experimentally.
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Yuzo KUROBE, Noboru MATSUDA, Yoshitaka UKON
Article type: Article
1998 Volume 99 Pages
57-63
Published: September 25, 1998
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When a ship propeller operates at zero ship speed, known as the bollard condition, high pressure fluctuations are induced around it. In water of restricted depth pressure fluctuations could cause churning up of mud at the sea bottom and in some cases enviromental problems in harbors, canals and rivers. Since these phenomena are not fully understood and the qualitative prediction is difficult, it is necessary to study the fundamental nature of these fluctuations. In this work, the pressure fields around the model propellers operating in the bollard condition were measured. Measured results are classified into three types of fluctuating pressures as follows: (1) Periodic and low pressure fluctuations induced by the propeller blade thickness effect and the propeller loading. (2) Random and high pressure fluctuations induced by the propeller-hull vortex. (3) Unsteady and low pressure fluctuations induced by the propeller wake. Pressures due to the propeller-hull vortex were found to be the highest, while pressures due to the propeller itself and pressures due to the propeller wake were found to have almost equal magnitude. Extensive experimental data given in this paper are useful for predicting unfavorable phenomena caused by propellers operating under the bollard condition.
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Katsuji YAMAGUCHI, Hiroshi YAMANOUCHI, Takahiro MAJIMA
Article type: Article
1998 Volume 99 Pages
65-71
Published: September 25, 1998
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The velocity and the amount of oil outflow from the side damaged model tank with double hull to still water are measured under the various conditions for the drafts, double side widths, shape and size of rupture. The oil outflow is occurred due to (1)the difference between the static pressure of oil and surrounding water at the side damage-stage 1- and (2)the distribution of static pressure difference along the longitudinal size of the puncture between oil and surrounding water-stage 2- after the oil outflow due to stage 1 is ended. The experimental results show that the velocity of oil outflow from side damaged double hull tank is decreased with increasing the distance between the inner hull plating and the outer hull plating. The oil outflow rate during stage 2 is smaller than that of stage 1.
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Masayoshi KUBO, Kenji ASAKI, Kazusei YAMAMOTO, Katsumasa TOKUBUCHI
Article type: Article
1998 Volume 99 Pages
73-82
Published: September 25, 1998
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In the previous reports, the authors investigated a setting method of "Oil Curtain" which is a new device proposed by the authors to prevent spilt oil diffusion. Through the past experiments, some problems on the setting workability were clarified. In this paper, some conditions required in the setting work are discussed and a practical method of setting and stowing the curtain is proposed. In addition, the practicability is examined through some experiments. The obtained results are summarized as follows. (1) Most of oil spills occur at the early stage after an accident when a single-hull tanker runs aground. Therefore, an effective countermeasure to prevent or reduce spilt oil diffusion should be taken in a few minutes just after the accident. (2) A proposed method, which the rolled curtain is mounted on a handrail around the hull and set by only releasing the fastening, is practical in the setting work, because the curtain can be set for about 1 minute. Furthermore, as the work can be carried out with only one hand, it is possible that safety in the work is ensured by holding worker's posture with another hand.
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Eiichi NISHIKAWA, Yuichirou NOGUCHI, Makoto UCHIDA, Shingo KAJITANI
Article type: Article
1998 Volume 99 Pages
83-90
Published: September 25, 1998
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In September 1997, the IMO MEPC (Marine Enviroment Protection Committee) adopted the new International Convention on the regulation of air pullutants discharge from ships. According to the convention, nitorogen oxides NOx, sulfur oxides SOx, and other air pollutants such as ozone depleting substances will be being controlled for the ships newly built after the year of 2000. In responding to the international situation, several investigations have been reported recently on the contribution of air pollutants discharged from ships in the domestic coastal region. The authors also reported previously on the NOx and SOx discharge from ships in the Osaka-bay. Since then, however, the sea traffic situation has been changed due to some events such as the opening of Kansai Airport, so the discharge of NOx, SOx from ships in the Osaka-bay has been investigated here again. The investigation is carried out by three steps. The first is to investigate the OD-table of all ships sailing in the Osaka-bay. The second is to study the emission factor of each ships of various kind at various operating conditions, and the third is to estimate the discharge amount from all ships. The results reveal that the amount discharged from ships is not small, and both amounts of NOx and SOx reach to the comparable level with the discharge amount from land area. The results suggest therefore that some measurs are needed for controlling the air pollutants discharged from ships in order to improve the air pollution in the Osaka-bay area.
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Takahiro MAJIMA, Katuji YAMAGUCHI, Shinobu FUJII, Hiroshi YAMANOUCHI
Article type: Article
1998 Volume 99 Pages
91-99
Published: September 25, 1998
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International Maritime Organization (IMO) recognized that chronic exposure to benzene vapors in air may cause leukemia even if the concentration is very low such as a few parts per million. It is necessary to investigate the actual conditions of vapor emission from tankers and concentration on tankers. The purpose of this research is to provide data on benzene concentration from chemical tanker during benzene transfer operations. Measurements of benzene vapor concentration for benzene tankers during loading, unloading, transit and housekeeping operations were made. The tests were conducted during routine operations for typical size of cargoes. The vapor samples were collected in the vapor sample bottle, bag or canister and were subsequently analyzed by gas chromatography. The followings are found. 1)The measured benzene vapor concentrations depend on each phase of the transportation cycle and sampling place. 2)Maximum concentration occurs during housekeeping operation. 3)The benzene concentrations in accommodation are lower than pump room and on deck.
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Masao FURUSHO, Kouichi MACHIDA, Yoshikazu FUJIOKA
Article type: Article
1998 Volume 99 Pages
101-107
Published: September 25, 1998
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The visual perception of a target at sea is the most important factor in good seamanship and therefore the need in keeping a proper lookout is paramount in preventing maritime traffic accidents. This study shows the environmental factors and visual conditions concerning a good lookout which are extracted from 1, 000 reports of the Marine Accidents Inquiry Agency. Authors deduce from these reports the background factors of visual perception in the case of ship collisions. They are as follows; 1. In daytime, it is difficult to see other ships when in the sun's direction and when the sun's altitude is from -9 to 40 degrees. 2. In cloudy weather, and when the sun's altitude is more than 40 degrees, the influence of the luminance in the sky is small from the visual perception. 3. In nautical twilight, which is when the sun's altitude is from -9 to 0 degrees, the number of ship collisions is few when compared with when the sun's altitude is under 40 degrees. 4. Many ship collisions occur between the times of from 6 : 00 to 8 : 00 A.M and from 2 : 00 to 3 : 00 P.M. 5. When the sun's altitude is about 20 degrees above the horizon the luminance of the sky in the sun's direction affords maximum brightness and thus minimum visibility.
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Masayoshi KUBO, Michiyasu ODANI, Hiroyuki MINAKAMI, Kazusei YAMAMOTO
Article type: Article
1998 Volume 99 Pages
109-115
Published: September 25, 1998
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Japanese industries are changing their manufacturing plants from Japan to overseas. Corresponding to the base shifting, optimum arrangement of their distribution centers in Japan must be changed. However, the shifting examples of distribution centers seem to be few. They are still remaining at the inland positions. We had a opportunity to hear a view on the distribution systems. Gathering some informations of transportation system, we investigate the distribution system and find out a great deal of merits, that is, cheap distribution fee and small transportation ton・km when the distribution centers are shifted from the existing inland places to a wharf zone.
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Katsuhiko SAITO, Masayoshi KUBO, Gang LIU
Article type: Article
1998 Volume 99 Pages
117-124
Published: September 25, 1998
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We measure the various impacts of packages when they are transported by the overnight small parcel delivery services. Especially we pay attention to the differnce of the levels of dynamic impacts between "Fragile Cargo" and "Normal Cargo". The impacts are measured by the enviromental recorders in the "Fragile" and "Normal" dummy cargoes. It is cleared that strong impacts are happened when the cargoes are sorted in a terminal and the impacts of the "Fragile Cargo" are not always very smaller than that of the "Normal Cargo". The all equivalent drop height of the impacts are less than 30cm. So a cargo handling of the services can be judged "careful" by the JIS regulation. But we must pay attention that the packaging of the cargo is made by an amateur and many cargoes are broken during transportation.
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Shigeo MITA, Kuniaki SHOJI, Chisato NONOMURA
Article type: Article
1998 Volume 99 Pages
125-131
Published: September 25, 1998
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In the previous papers, we discussed an experimental study on effect of shock absorption of pelprene protective device which is made from polyester elastomer named pelprene. This time we made a study on the shock absorption of soft polyurethane form as the basic research for the study of resin protective device. Though this study is still continuing we reached condition. This report deals with model experiments used bow model and its numerical analysis by finite element method. The following results are obtained. (1) The shock absorption properties of soft polyurethane form become clear and it's the same as pelprene protective device. (2) Numerical analysis result gives fairly good agreement with the static penetration test result.
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Kinzo INOUE, Hiroyuki SADAKANE, Yasuyuki TODA, Hideyuki TACHIBANA
Article type: Article
1998 Volume 99 Pages
133-143
Published: September 25, 1998
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It has been recommended that the pilot ladder should be secured to the ship's side by a suitable means at a point above the lower platform of the accommodation ladder. This is expected to be the best solution as the safety countermeasure to prevent the twisting of a pilot ladder and the moving far from the ship's side. In order to show the effectiveness of this countermeasure, the full scale experiments were carried out. When the pilot ladder is secured at a point 5 metres above the sea level, the twisting angle was only 45 degrees at most. The lower the securing point becomes, the smaller the twisting angle reduces. And the present paper suggested that 1.8 metres length of the spreader bar may be too short to prevent the turning around of the pilot ladder.
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Katsuhiro HARANO, Motonobu IMASATO
Article type: Article
1998 Volume 99 Pages
145-154
Published: September 25, 1998
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The shock absorbing effects and the evaluating methods by using cushion sheets on a seat in a free fall life-boat were investigated experimentally. The following results are obtained. (1) The shock absorbing effects on an actual free fall life-boat is estimated by the performances of the absorbing material and the profiles of shock waves acting on the boat. (2) The effects of shock absorbing material is depend on the spectra of the shock wave profiles. In the case of 20 to 30mm thick soft cushion sheets, the shock absorbing effects is observed when the frequency is higher that 10Hz, and it is estimated that the peak values of a shock wave measured in an actual boat will be reduced by 20%. (3) The shock absorbing characteristics of a dummy and the cushion sheets are remarkably depend on the magnitude of the shock, so that the tests should be performed on around the actual shock level acting on boats.
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Kinzo INOUE, Hideo USUI
Article type: Article
1998 Volume 99 Pages
155-162
Published: September 25, 1998
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When the anchorages are arranged at a harbour, it is neccessary to consider the maneuvering difficulty of the navigating ship between the anchored ships. However, nobody has researched how design the arrangement of the anchorages from the view point of the maneuvering difficulty up to now. In the present paper, the relationship between the condition of the arrangement of anchorages and the maneuvering difficulty has systematically analyzed by applying the Environmental Stress Model for the problems of the navigating ship between the anchored ships. Based on this analysis, the way to fix quantifalively the design elements of the arrangement of anchorages under condition that the maneuvering difficulty comes to an allowable level for mariners was considered. And, the distance needed between the anchored ships has been proposed on the basis of the diagram in accordance with the length of navigating ship and the mean length of anchored ships.
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Kinzo INOUE, Wataru SERA, Kenji MASUDA
Article type: Article
1998 Volume 99 Pages
163-171
Published: September 25, 1998
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In order to assess the marine traffic safety, three kinds of stresses such as : (1)the burden due to environmental conditions, (2)the risk during the ship handling and (3)the task load due to ship's manoeuvrability should be taken into account. In the previous paper, the Environmental Stress (ES) model has been proposed to evaluate the ship handling difficulty. In the present paper, the relationship between the "difficulty" and the "risk" is described, and the methodology of evaluating the risk hidden in the ship handling process is proposed. Under the condition that the rudder angle and the engine revolution will not be changed, a ship's pass can be predicted by the MMG model. The envelope area drawn by these predicted paths is needed to avoid the hidden collision risk against a ship or shore. We call this Potential Area of Water (PAW). The level of the risk potential is calculated as the time to collision. This evaluating method and the ES model were applied to the experiment using ship handling simulator. It was made clear that the results of the calculation based on these models were in accordance with the rating by the subjects of the experiment.
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Hiroki IWASAKI, Keisuke TSUJI, Yasumi KOTHO, Yoshitaka FUKUO
Article type: Article
1998 Volume 99 Pages
173-179
Published: September 25, 1998
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In the train an operation using the ship maneuvering simulator, we pick up the slalom ship maneuvering. We got train the slalom ship maneuvering for 3 ship maneuvering beginners. On the other hand, we quite concretely presented a proposition of this slalom ship maneuvering and found out an ideal operation law that there is with fast-simulation. For this, we decide to say a model maneuvering of slalom ship maneuvering. We compared the two, phase aspect traces of a model maneuvering with the beginner's maneuvering. We drew the next three phase aspect traces and calculated matching. There are phase aspect traces of p( : ship course)-r( : circling angular speed), r-r( : circling corner acceleration) and y( : horizontal transition)-v( : horizontal speed). Every training, we averaged their matching and tried to observe the change. We were able to confirm that the matching gets good, every time we experience a number of times of a training for the beginners.
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Shinya NAKAMURA
Article type: Article
1998 Volume 99 Pages
181-188
Published: September 25, 1998
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It is desirable to set the boundary of the maximum permissible level of marine traffic safety, when designing the feasible plans of marine traffic routes and so on. The Blocking Coefficient (BC value), which express the potential collision risk, is one of the practical and objective index to grasp the level of marine traffic safety. So, it is the goal of this paper to set the boundary of the permissible level of marine traffic, using the BC value. At first, the author proposes a model to express mental load of navigator (including the internal process). Subsequently, using the results obtained through ship-handling simulator experiments, author shows the relationship between the subjective degree of mental load and the BC value, and also points out the knowledge based on the concept of the mental load model proposed in this paper. The main point of the knowledge, related the boundary of the maximum permissible level of marine traffic safety, is as follows, ・ The traffic condition, the BC value exceed 0.6 (0.4) has being kept the same situation more than 1min. (3min.), is the boundary of the maximum permissible level of marine traffic safety from a viewpoint of the mental load.
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Hisaaki TAKAYAMA, Shigeaki YADA, Yasuhiro YAMAGUCHI
Article type: Article
1998 Volume 99 Pages
189-196
Published: September 25, 1998
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In the present study we experimented man's pulling force on oarsmanship by a human power and evaluated its quantity for the new face of Cutter-crew of 6 universities in west Japan in October 1996. The experiment of "the basis pulling" means a pair of crewmen sitting on the No.7th and No.8th sheets with powerful rowing named "Tan-riki" was carried out by 2 preparing connection oars with distortion gauges. Meantime, other 5 pairs should be with no rowing. These experiments were carried out six times by every pair in turn. And also "the whole pulling", which means 12 crewmen rowing with "Tan-riki" and "the dash pulling", means 12 crewmen rowing with a hypothesis of the most powerful rowing for a race same as before a pair of the No.7th and No.8th crewmen were recorded for each university. All the experiments were held at Togitsu port in Omura-Bay during still water. We measured the area of output wave-like by analogue data records and calculated man's pulling force(kgf/s) for each univertity. The result was as follows : 1) The output wave-like analogue data record shows the characteristic of the oarsmanship of each university. 2) "The basis pulling" at the 12 crewmen from No.1 to No.12 of each university was calculated. The mean values were from 8.5 to 11.6kgf and their standard deviations were from 1.06 to 1.61kgf. 3) Basing on "the basis pulling", output ratios of the No. 7th and No. 8th crewmen of each university of "the whole pulling", and "the dash pulling" were calculated out. The order of the output ratios had a high correlation to the race result. 4) Race speed of the boat during still water was from 5.0 to 5.7 knots. They were corresponded to the total resistance from 33.0 to 43.6kgf (displacement of boat in 2, 700kgf) by the towing test. Consequently, effective horsepower of each university became from 1.1 to 1.7ps. We also quantitatively estimated the indicated horsepower of a crew, which was about from 0.29 to 0.43ps according to the position of grip, rowlock as well as blade of an oar.
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Shigeaki SHIOTANI, Nobuyuki FUJITOMI, Shigemasa YAMAZATO
Article type: Article
1998 Volume 99 Pages
197-207
Published: September 25, 1998
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The information of ship waves generated by a small high speed boat and ship motions of a small boat in ship waves are very important to prevent the damages of the small boat and the dangers of passengers on board. The authors has researched about the characteristics of ship waves by three kinds of small boats in field experiment ; the displacement type vessel, the high speed boat and the planing boat. As results, we have obtained many characteristics of ship waves generated by these boats. This paper deals with the measurements of ship motions of a small boat in ship waves generated by a small high speed boat. The experiments of ship motions were carried out in real sea field. The ship waves of a high speed boat and the rolling and the pitching of a small boat oscillating in these ship waves were measured. The experimental data were compared with the results of ship motion estimated by a very simple method. As result, we obtained the characteristics of ship motions of a small boat in ship waves.
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Hiroyuki SADAKANE, Norio YUDA, Daisuke TAKAI
Article type: Article
1998 Volume 99 Pages
209-214
Published: September 25, 1998
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We have shown oscillation characteristics of a boat on ship-generated waves. In order to explain the oscillation characteristics dynamically, it is necessary to know the characteristics of the wave exciting forces caused by ship-generated waves, which have the transient properties and the feature of three dimensional wave pattern. And if the above wave forces can be obtained by calculation, we can easily examine the oscillation characteristics of ships of different forms and various sizes of ships. In this paper, we carry out following studies : (1) The ship-generated wave forces are measured by model experiments using water tank. (2) A means of estimating simply the ship-generated wave forces is developed under some assumptions. (3) A part of the calculated results are compared with the measured. (4) By using the calculation means developed, the effects of ship-size on the wave forces are examined.
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Shunsuke TAKAOKA, Yujiro MURAYAMA, Masayoshi KUBO
Article type: Article
1998 Volume 99 Pages
215-226
Published: September 25, 1998
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The largest problem of sail equipped motor vessel is large swing motion by sail at anchoring. The above vessel has higher probability of dragging anchor than normal vessel. However, this important problem has been left unsolved. In this report, we develop a 2 dimension bird' s-eye view anchoring simulator of the above type vessel by using personal computer and the evaluation of safety anchoring is also presented. The sail assisted effect at anchoring presents good results as follows. (1) Swing motion and tension of chain become smaller than those of normal vessel. (2) Automatic control system shows high responsibility at change of wind direction.
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Masayoshi KUBO, Shinji MIZUI, Toshiharu YOSHIDA, Kazuhiro INOUE
Article type: Article
1998 Volume 99 Pages
227-234
Published: September 25, 1998
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Many habors have been constructed facing to the open sea front in Japan. In a rigorous season the shipping activities are often interrupted due to strong wind and heavy seas. However, these severe situation is not recognized for the poor information. So, we developed measurement system of ship motions and we carry out a filed observation of fishery boat entering into harbor under quartering sea condition. Furthermore, we observe wave heights and wave directions using wave sensors installed on the sea bottom of harbor entrance. The obtained results are summarized as follows : (1) The encounter waves can be calculated by wave heights observed at a fixed point, the two-dimensional ship positions and the main wave direction obtained from the wave direction sensor data. (2) As an example, the period of the observed waves is about 8.4 seconds, whereas that of the encounter waves is about 20 seconds. As the breakwater is constructed in order to shelter the main waves, the entering boat receives the waves almost from behind, and the period of encounter waves becomes longer than that of the actual waves. (3) It is found that the water velocity along running boat direction correspond with the changing of boat speeds beneath the encounter waves.
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Duc-Hung NGUYEN, Jin-Seok PARK, Kohei OHTSU
Article type: Article
1998 Volume 99 Pages
235-245
Published: September 25, 1998
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This paper treats of the applications of the pole assignment self-tuning control theory to the identification and design of ship's auto-pilot systems. An on-line estimation algorithm known as the Recursive Least Squares Algorithm is used to identify parameters of the control system. Two typical types of the pole assignment self-tuning control algorithms that can be linked to the on-line estimation algorithm to form self-tuning control systems for ships are introduced. The authors discuss how to choose the control parameters by the rules of thumb in the actual sea trials. The pole assignment self-tuning controllers designed to steer ships are verified by experiments aboard the training ship Shioji Maru of Tokyo University of Mercantile Marine. The aboard experiments result in the confirmation that it is possible to keep and to change the ship's course as desired by the designed controllers.
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Kuniji KOSE, Satoru TAKASE, Yasuhiro IIJIMA
Article type: Article
1998 Volume 99 Pages
247-254
Published: September 25, 1998
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When the ships pass through the Kurushima strait, they are forced to alter the channel in accordance with the direction of the tidal stream. This unique traffic rule often causes the ship's violations of safty at the gateways of strait. The principal objective of this paper is to generally review this unique traffic rule. As a result of simulation studies of current effects in Kurishima strait, having obtained several valid indication of current effects, when relatively comparing the unique traffic rule in Kurushima Strait with the general maritime traffic rule. We obtained it more difficult to maneuver in the general maritime traffic rule than in that local rule.
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Kuniji KOSE, Satoru TAKASE
Article type: Article
1998 Volume 99 Pages
255-262
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
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The procedure to obtain the current effects is shown here. Ship motion can be measured by using of kinematic GPS(KGPS), which has a high accuracy. Force and moment of current can be derived from motion measurement of ship as a difference between total force acting on ship and forces based on a motion and operation of rudder. We carried out the experiment of maneuverability and passing through the KURUSHIMA strait using KOJIMA that is training ship. Firstly we investigated a maneuverability of KOJIMA by free running test. Next we analyzed the effects of current inKURUSHIMA strait, which is compared with the effects evaluated from current velocity measured by Doppler sonar.
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Article type: Appendix
1998 Volume 99 Pages
App3-
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
JOURNAL
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Article type: Appendix
1998 Volume 99 Pages
App4-
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
JOURNAL
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Article type: Appendix
1998 Volume 99 Pages
App5-
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
JOURNAL
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Article type: Appendix
1998 Volume 99 Pages
App6-
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
JOURNAL
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Article type: Cover
1998 Volume 99 Pages
Cover2-
Published: September 25, 1998
Released on J-STAGE: January 15, 2017
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