شبیه‌سازی و ارزیابی حرکت قایق ربات خودران

با توجه به نیاز بیشتر جمعیت رو به افزایش جهان به مواد غذایی، محققان به دنبال افزایش تولید کمی و کیفی محصولات با گرایش به سمت پایش برخط، کنترل هوشمند تجهیزات و بررسی کیفیت محصولات کشاورزی به‌خصوص در زمینه پرورش آبزیان هستند. در این پژوهش شبیه‌سازی یک قایق خودران مدل انجام شده است تا کنترل این نوع از شناورها را در محیط‌های مختلفی مانند اسکله‌ها، سد‌ها، بنادر، رودخانه‌ها، زیست‌بوم‌های آبی و مزارع پرورش آبزی انجام داده و امکان بررسی و پایش وضعیت زیست‌محیطی، عمق آب و شاخصه‌های مورد نیاز دیگر را فراهم آورد. موقعیت و زاویه حرکت قایق با استفاده از داده‌های gps و imu تعیین شده است. مدل سیالاتی و نیرویی قایق به کمک ضرایب هیدرودینامیکی و آئرودینامیکی ارائه و در محیط متلب به کمک رانگ کوتای کلاسیک (rk4) شبیه‌سازی شده است. برای ارزیابی عملکرد قایق ربات خودران، یک مسیر مستطیل شکل با طول 20 متر در عرض 15 متر در یک استخر انتخاب شد و 4 گوشه این مستطیل به‌عنوان نقطه مسیر به سامانه ناوبری معرفی گردید. بیشینه خطای موقعیت مکانی عرضی و طولی قایق ربات خودران به‌ترتیب cm 135 و cm 149 محاسبه شد. همچنین در آزمون کنترلر pid سرعت پیشروی با سرعت تنظیمی cm s^-1 40 میانگین و انحراف معیار به‌ترتیب cm s^-1 40 و cm s^-12 به‌دست آمد. مسیر حرکت قایق تقریباً بر روی مسیر شبیه‌سازی شده قرار داشت و نتایج به‌دست آمده از دقت خوب این مدل حکایت دارد.

Simulation, Development and Evaluation of an Autonomous Robotic Boat Used in Aquacultures

IntroductionAs the world population grows up, the quantity and quality of human food must be improved. The production yield of marine aquaculture and farming of aquatic organisms, as a valuable source of food, will be increased. Regular and online monitoring of the physical, chemical, and biological qualities of water and environmental parameters in such these controlled environments can be achieved by using advanced world technologies, such as autonomous boats. In this study, simulation of an autonomous boat has been done to help better understanding and control of this type of vessel in various environments such as dams, ports, rivers, aquatic ecosystems, and aquaculture. Hence, the main goal of this paper is to simulate and evaluate the guidance and navigation system of an autonomous boat based on the Fourth order of RungeKutta for determining the changes of water quality indices in a fish farming ponds.Materials and Methods In order to achieve the main goal of this study, an autonomous boat was designed and built. This boat as a generalpurpose robotic trimaran boat has dimensions of 110 cm x 37 cm x40 cm and is made of Plexiglas 2 mm thick. Maximum forward speed of the boat is 125 cm s1 (at 6850 rpm of brushless motors) and the turning radius is less than 61 cm. The environmental data can be transferred using Internet of Things (IOT), smartphones, SMS, and mini PC. The position and heading of the boat are determined using GPS and IMU data. The hydrodynamic and aerodynamic forces, moments, and coefficients of the boat model are determined and then applied in the mathematical simulation as the input of classic RungeKutta (RK4). The performance of the robotic boat navigational and control systems evaluated in a rectangular track with a length of 20 m and a width of 15 m in a fish farming pond in Karaj and 4 waypoints. The local coordinates of four corner of the mentioned rectangular in the pond was (0, 0), (0, 20), (15, 20), and (15, 0). The purpose of control system was to conduct the actuators in such way that boat be able to go to the next point. When the boat reaches the target distance of one m of the desired point, the next point will be introduced as a new target. The set point of boat speed was 0.4 m s1 and zero state vector was [0, 0, 0, 0, 0, 0]. Results and DiscussionThe maximum error of position and heading of the autonomous boat is 135 cm and 11 degrees, respectively. Also, in the speed PID controller test (40 cm s1), the average and standard deviation of the speed calculated as 40 cm s1 and 2 cm s1, respectively. Maximum difference between the heading obtained from the Kalman filter and received from the GPS is 11 degrees. In some situations that high precision of heading angle is not required, the GPS data can provide such accuracy of the heading. Among the variables of longitudinal, latitude, time to reach the target area, yaw rate, heading, and forward speed the minimum and maximum of percentage error are related to forward speed and yaw rate, respectively. These values show good performance of the simulated model and PID controllers.Conclusions In this study, motion simulation and evaluation of a robotic boat was carried out using a model boat and MATLAB software. The mathematical model simulated the real boat behavior correctly and the boat can be used safely in fish farming ponds to monitor environmental conditions and water quality.