Research Of Ship Anti-collision System Based On Laser Rangefinder Theory

Ship has longest history in the transportation tools, and it has been a very important one till now. Now ships turns larger and quicker, while the number, intensity and load age of dangerous goods increase continuously. Ship accidents happen frequently, which threatens the safety of ships and environment of the sea.Not only merchantmen collided with each other, the accidents often happen between merchantmen and fisher. Because of the great difference tonnage between them, once there is collision, lots of loss of people and property will be countless. Collision between ships is a main factor which influences the safety of transportation on the sea. So avoiding colliding is very important. Nowadays avoiding colliding on the sea when ships are pulling in harbor mainly depends on transportation administration system. Otherwise it depends on radar. Radar is too expensive for middle and small especially light ships, because of the high price of radar. But these ships'safety is very important parts of the transportation safety on the sea. So this paper proposes a simple, efficacious and economical auto-avoiding collision system of the ships on the sea.After comparing non touching measurement technology existing, laser measurement technology was chosen as academic basis. Range sensor system suit for environment of the sea chosen to meter aging the distance. Avoiding collision system was designed, researched and developed after researching the key avoiding collision technology.This thesis is based on well-developed laser measurement technology, and researched and developed auto voiding collision system of the ship on the sea.the system auto inspects the situation around, and can do real-time scanning special spots. The system can do omnidirectional scanning, get the comparatively instance and direction of the ships and barrier. The data will be analyzed and a suitable threshold will be set. If the measurement result is beyond the threshold the system will give an alarm. The operator can adjust the direction of the ship to avoid collision or do an emergency measures.The core of the system is laser measurement technology. The system uses microchip, AT89C51to control measurement. Three-dimensional electronic PAN-TILT-ZOOM(PTZ) is important part of the system. The position of the sensor is changed neatly by electronic PTZ, and the angle of the sensors is got. The keyboard and displaying circuit are designed. The sould-light alarm circuit can remind the operators in time. The software of the system can pick up and analyze data, and control the upright and horizontal position. The main job of this thesis is divided into following parts:(1) The hardware design of the systemThe key technology of the system is how to measure the distance accurately, including static and dynamic distance, single spot scanning and multi-spots scanning. The laser measuring sensors of high capability can measure the distance of the single static spot. But it is very difficult sensor(2) System software designThe sensor system has general serial interface. The interface to MCU is easy to realize. The communication with each other has wary of parameter choice. Besides, the sensor system has its own instruction, each bit of which is presented by two ASCII code of hex. In accepting of measurement of distance, the system contains the distance information with certain format. The software design needs to analyze the distance information, and then display it with certain way.The horizontal control of PTZ determines the angle orientation of sensor.The system adopts time-division to implement. The horizontal and vertical electromotor of Electric PTZ are constant rotate speed. Through the time-division, namely the constant rotate speed, the system will compute the time of per angle. And then it will apply interrupt when the time is up to the necessary time of per angle. This interrupt service will judge the direction of scanning, at the same time the angle adds or reduce one at once. Considering the horizontal angel, the direction of right front is the zero angle. we take the left as the negative direction with the counter reducing one and the right as positive with the counter adding one.(3) Experience in SystemAfter completing the whole system, some related adjusting and experience has done and several important problems have been solved:1) Set precise communication parameter and realize right controlling of the measuring sensor. 2) Analyze the operating instruction and return value and realize accurate communication with the measuring sensor.3) Process the return value and realize precise decoding.ConclusionThe Voiding Collision System developed in this paper can measure distance for boats in hundreds meter radius and alarm circuit will realize its function when the distance is above value established before. The measuring sensor used in the system and PTN can work in the worse condition in sea. This system is so economical and accurate that it satisfy the demand of middle or small marines. It has much applied value.Development of Crashworthiness for medium(small)-sized Marine Based on the Theory of Laser Measuring Distance.