Development of the Virtual Sailing Dinghy Simulator
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DEVELOPMENT OF THE VIRTUAL SAILING DINGHY SIMULATOR Norman R Saunders, Department of Pharmacology, University of Melbourne, Parkville, Victoria 3010, Australia. [email protected] Frank D Bethwaite, Bethwaite Design Pty Ltd, 2 Waine Street Harbord NSW 2096. [email protected]. Mark D Habgood, Department of Pharmacology, University of Melbourne, Parkville, Victoria 3010, Australia. [email protected] Jonathon Binns, Australian Maritime College, Locked Bag 1-357, Launceston, Tasmania, 7250, Australia. [email protected] ABSTRACT Virtual Sailing dinghy simulators (VS1 and VS2) have been developed from a prototype devised at the University of Tasmania, which in turn stemmed from mechanical simulators built at the University of Southampton in the 1980s. The VS2 consists of a Laser or Byte hull mounted on rollers and a steel frame. Computer controlled pneumatic rams provide for roll and tiller “feel” (eg weather helm). Controls for steering and sheeting are as in the normally rigged dinghy. The sailor is in a loop between the output side of the computer which controls the simulator and the input to the computer which measures the response of the sailor (hiking, steering and sheeting) on the simulator. The sailor views a computer screen which provides an image of where the dinghy is sailing and data on wind direction, gusts, position on race course. Software options provide for a wide range of variables: eg dinghy type, wind strength and direction, gusts, race conditions. The VS2 has a wide range of applications including teaching beginners and fast-tracking their early skill development, simulator racing and physiological measurements on elite sailors. INTRODUCTION Most international sports have put considerable effort over the last 20-30 years into developing a scientific basis for the development and assessment of fitness and skills in participants, particularly the elite. This has been based to an important degree on equipment that reproduces essential features of performance in the laboratory eg treadmill, cycle ergometer and rowing ergometer. This approach has largely been ignored by competitive sailors, who generally use generic exercise programs for physical fitness and rely on on-the-water sailing to develop their skills, which are of a high order compared with many sports. Hiking benches have been used extensively for many years, in order to introduce an element of sports specific exercise into training regimes and there have been a few attempts to produce simulators of sailing dinghies, but these were mechanically based and lacked the possibility of interaction between the sailor and a physical simulation of a boat’s performance (eg Harrison et al 1988; Walls and Saunders 1995; Voigatis et al 1996; Blackburn 2000). The VS1 and VS2 had their origins in the mechanical simulators developed by John Harrison at the University of Southampton (Harrison et al 1988) and an advanced mechanical simulator developed at the University of Tasmania (Walls and Saunders 1994). Although originally aimed at measuring physiological fitness and improving the performance of competitive sailors, experience with these simulators has shown that they also have the potential to attract new entrants into sailing and fast track them onto the water with sufficient skills to sail safely and independently. METHODS Design and construction The design and construction of the simulator hardware and interface with the computer was carried out by Tamar Designs (now Tyco Flow Pacific Pty Ltd) Exeter, Tasmania. The VS2 consists of a Laser, Byte, Megabyte or Optimist hull mounted on rollers and a steel frame. Computer controlled pneumatic rams provide for roll and tiller “feel” (eg weather helm). Controls for steering and sheeting are as in the normally rigged dinghy. The sailor is in a loop between the output side of the computer which controls the simulator and the input to the computer which measures the response of the sailor (hiking, steering and sheeting) on the simulator. The sailor views a computer screen which provides an image of where the dinghy is sailing and data on wind direction, gusts, position on race course. Software development Software options provide for a wide range of variables: eg dinghy type, wind strength and direction, gusts, race conditions. Because of problems with the VS1 software developed at the University of Tasmania (see Binns et al, 2002), the simulator software has been completely re-written. This took two programmers six months to complete and new features are now being worked on. To produce the VS2 software a total of over 40,000 new lines of code were needed. The visual representations, physical modelling and data acquisitions systems were completely rewritten using modularisation of the code; this makes upgrades relatively easy and rapid to perform, something that was next to impossible with the original University of Tasmania software. Six classes of racing dinghy have now been programmed; Laser (Standard, Radial and 4.7), Byte Megabyte and Optimist. Data for these dinghies was obtained from class data available on the internet; for the Laser see www.laserinternational.org, for the Byte see www.blackdogmarine.com and for the Optimist see www.optiworld.org. Three different sail plan options were coded for the Laser dinghy (standard, radial and 4.7) including data for total sail area, centre of pressure, chord and aspect ratio. The characteristics of these three dinghy classes have been coded into the new program, details of which can be found in Binns et al (2002). The visual representations of these dinghies are shown in Figure 1. In order to make the simulator mobile, for use at different venues, King Trailers (Hobart) were contracted to design and build a flatbed trailer on which the simulator can be operated. Experience of use of sailing simulators obtained so far. (i) Promotion of sailing in commercial boat shows. (ii) Teaching novices (iii) Assessment of skills and posture of established sailors RESULTS The computer image from which the sailor operates is illustrated in Figure 1 for the Standard Laser and the Optimist dinghies. An illustration of a VS1 simulator in use is shown in Figure 2. The simulator has been used in boat shows in Australia, the UK, Holland and the USA as a means of promoting sailing to the general public. In the UK, Performance Sailcraft organised a winter National Simulator competition, using two VS1 simulators. The competition attracted 800 entries with the finals held at the 2001 London Boat Show at Earl’s Court (see www.lasersailing.com). In the recent Melbourne Boat Show (3-7 July) a VS2 simulator was used by at least 148 visitors to the Show. Of these, 83 were complete beginners, mostly children. In 5 to 10 min instruction almost all could sail round a triangular course ie they leaned to steer, trim the sail, beat, tack , gybe and round marks on different points of sailing. Another VS-2 simulator was used in the Sydney International Boat Show (312 July – 5 August). Because of a different format in show organization there was appreciably less time for the simulator to be used. However, some 120 people used the simulator. Of these x were complete beginners. The others covered a wide spectrum of ability from successful international sailors (including one Laser Radial world champion) to club sailors. Many of the beginners in both Melbourne and Sydney asked for advice about how to start sailing. In future boat shows it is hoped to be able to organize liason with local sailinfg schools and clubs A VS-2 simulator was used in a 2 day “Learn to sail” course for children at the Sandy Bay Sailing Club in Tasmania in December 2002. Twenty one of about 30 children (age range 8 – 14) had instruction on the simulator before going on the water in Optimist dinghies. The coaches reported that of the children who had been on the simulator, all of the girls and the boys over 10 years old were more confident and learned on-water skill more rapidly than those who had not been on the simulator and boys 10 and under. The problems experienced with these younger boys both on-water and on the simulator appeared to relate to a short attention span. A trial is underway in the University of Melbourne in which 30 novice sailors were assigned randomly to two programs: (1) A standard instructional program involving initial theoretical session followed by a simple introduction to on water experience in Lasers or a Tasar under the supervision of coaches. (2) A simulator course in which groups of 5-6 students attended 4 evening classes involving instruction on a simulator. After this the simulator students were introduced to sailing on water (in Lasers and a Tasar). A formal comparison of on-water performance by both groups has still to be undertaken, but some clear differences between the groups are already apparent. In the simulator group 4 students were lost from one subgroup after the fist evening class. The other 9 completed the course and went sailing. They persisted with on-water sailing in spite of some difficult weather conditions which lead to several of the students capsizing. The coaches reported that all 11 students could beat, tack and sit out (hike) without difficulty. In contrast 8 of the on water group gave up and the rest had considerably more difficulty than the simulator group in learning elementary boat handling skills. In preliminary experience with the Victorian state youth squad, it has become apparent that a sailing simulator will be a valuable tool for studying and correcting hiking posture. Back pain appears to be quite common in competitive dinghy sailors especially in Lasers. It should be considered unacceptable for young people to injure themselves through sailing with inadequate hiking posture. The top female Australian junior Laser Radial sailor was out of sailing for several months at the beginning of 2003, because stress fractures in her vertebrae.