CN102285431A - Navigable ship draft real-time measuring device and measuring method - Google Patents

Abstract

The real-time measuring device and measuring method for the draft of a navigable ship according to the present invention are composed of a detection door, an automatic lifting control device for the detection door, and a data acquisition and processing device; the detection door is a mounting frame, and is composed of a detection door The automatic lifting control device controls it to reach a predetermined depth position below the water surface, and is placed below the water surface that the navigable ship will pass through. An array of ultrasonic ranging sensors is installed on it, and the front of the ultrasonic ranging sensor is upward; The distance sensor array measures the vertical distance from the bottom of the entire ship to the detection door mounting frame, and all the measurement data constitute a data set C; then according to the installation depth H of the ultrasonic ranging sensor array on the detection door mounting frame, the water depth at the bottom of the ship will be obtained The data set D, where D=HC; then find the maximum value in the data set D, which is the draft D _max of the navigable ship, that is, D _max =MAX(D).

Description

Device and method for real-time measurement of draft of navigable ships

technical field

The real-time measuring device and measuring method for the draft of a navigable ship according to the present invention relate to the measurement technology, in particular to the detection technology of overdraft of a ship lock or a navigable ship in a channel.

Background technique

At present, with the continuous increase of inland waterway shipping volume, the number and density of shipping ships have increased significantly, and various ship accidents have become increasingly serious threats to shipping safety, and their impact is also growing. Among them, the most serious and urgent problem is the overdraft of navigable ships. In order to ensure the safety of water traffic in inland rivers, the state needs to invest hundreds of millions of dollars every year and deploy thousands of waterway workers to dredge mud, clear obstacles and blast to ensure the smooth flow of waterways. However, driven by interests, some ship owners disregarded the country’s prohibition on overloading of shipping, and adopted methods such as concealing the draft tonnage of ships, manufacturing fake waterlines, and passing through shallow water areas at night to evade the inspection of law enforcement agencies.

The draft data of a ship is directly related to the safety of the ship, especially the driver of a large ship must master the draft data of the six parts of the ship's left, right, bow, middle and stern (referred to as the six-sided water gauge data), in order to correctly grasp the ship's loading situation and match it with Other data calculate the very important stability parameters such as the ship's stability height, ship's rocking period, forward and backward trim, left and right trim, heel angle, and pitch angle. Since the water gauge data on the six sides of the ship is still obtained by manual observation of the water gauge scale on the side of the ship, it can only be carried out when docking or anchoring, and when anchoring and observing the draft of the outer deck, it is necessary to put a rope ladder, which is both troublesome and difficult. Danger.

The draft of a ship refers to the vertical distance between the water plane and the plane of the bottom of the ship. The draft of a ship varies with the load of the ship and the density of the overboard water. After measuring the draft of the ship, the displacement and load of the ship at that time can be obtained by consulting the relevant ship curves and calculations. The draft should be measured when the ship enters and leaves the lock and port, crosses the shoal, berths at the pier and loads and unloads cargo. At present, the ship draft measurement methods at home and abroad can be divided into the following categories:

(1) Waterline manual observation method

This method relies on long-term trained observers to obtain the actual draft of the ship by observing the water gauge mark of the ship, then conducts manual observation, manual recording and manual comparison, and finally compares, synthesizes and averages the observation results to obtain the final value. However, visually measuring the size of the ship's waterline has many disadvantages: the range of observation points is small and few, and statistical principles cannot be used to process the data; the observed data cannot be checked and corrected afterwards due to lack of detailed records, which may There are hidden major errors; it is greatly affected by the ability and status of personnel, the measurement time is long, and the cost is high; it is greatly affected by the weather environment; the observation needs to be carried out on board, and it cannot be applied to the rapid departure detection of the channel management department requirements.

(2) Water gauge method

Ultrasonic water gauge and load measurement are based on the principle of ultrasonic distance measurement, and measure the draft of the ship based on the side deck of the hull. The device hangs the ultrasonic sensor on the side of the hull through a measuring bracket. The sensor can move up and down along the side of the ship relative to the bracket and is fixed at a certain height. The purpose is to keep a proper distance between it and the water surface, thereby reducing the area of the beam reaching the water surface. , to improve ranging accuracy. The instrument measures the return time of the ultrasonic echo, and according to the local sound velocity at that time, measures the distance from the main deck of the hull to the water surface and other parameters, calculates the draft value, and searches the ship's load data file to obtain the ship's load. The accuracy of ultrasonic measurement is affected by many factors, but the error of the sound velocity directly affects the accuracy of the measurement, and the sound velocity is related to the density of the medium, and the air density in the air is greatly affected by the temperature. At present, this method can only be installed on a ship for detection, and it cannot be applied to the requirements of the waterway management department for its rapid departure detection.

(3) Pressure sensing method

The change of water depth can be reflected by the change of water pressure. Using this characteristic, a pressure sensor is installed at the position of the ship’s unloaded waterline. When the ship is loaded with cargo, the draft becomes deeper. According to the value obtained by the pressure sensor, after conversion, The draft of the ship can be obtained. Measuring the draft of a ship through a pressure sensor requires the pressure sensor to be installed directly on the outside of the hull. The working environment is harsh. After a long period of use, due to the compression deformation of the semiconductor silicon chip, time drift will occur. The sensor that this method adopts also can only be installed on the ship and detects, also can't be applicable to the requirement of its rapid departure detection of waterway management department.

(4) Laser ranging method

The laser distance measuring sensor that this method adopts also can only be installed on the ship and detects, also can't be applicable to the requirement of its rapid departure detection of the waterway management department.

(5) Water gauge mark recognition method based on image processing

The image processing technology is applied to the measurement of the ship's water gauge marking, that is, multiple cameras and light sources are used to image the water gauge markings on the bow, midship, and stern of the ship on both sides, and then the water gauge markings are imaged using image processing methods. Quickly identify the waterline and the waterline, so as to obtain the overall draft of the ship. This method can overcome a series of problems caused by the manual observation method of the waterline, and at the same time, it can completely record the change of the waterline position during the entire observation period, and there is a large space for subsequent data processing and utilization. The equipment developed by this method has the advantages of simple operation, low cost, high efficiency and accuracy. The imaging system used in this method is generally installed on a ship, and cannot perform off-board detection, so it cannot be applied to the rapid detection requirements of the waterway management department.

In view of the problems existing in the above-mentioned prior art, it is very necessary to study and design a new type of real-time measuring device and method for draft of navigable ships, so as to overcome the existing problems in the prior art.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to research and design a novel real-time measuring device and method for the draft of a navigable ship, so as to solve the existing problems in the prior art of relying on the draft of the ship and being unable to realize Ship inspection and other issues.

The present invention uses underwater ultrasonic ranging sensor arrays to perform parallel ranging, performs three-dimensional scanning and ranging on the bottom of the navigable ship passing by the channel, obtains a three-dimensional point cloud map of the bottom of the navigable ship, and processes the three-dimensional point cloud data to obtain the navigable ship. water volume. Among them, the water level of the waterway varies greatly in different flood seasons. In order to make the ultrasonic ranging sensor work in the best state and facilitate maintenance in future use, the installation depth of the ultrasonic ranging sensor should be adjusted according to the actual situation.

The real-time measuring device and measuring method for the draft of a navigable ship according to the present invention are composed of a detection door, an automatic lifting control device for the detection door, and a data acquisition and processing device. The detection door is a mounting frame, which is controlled by the automatic lifting control device of the detection door to reach a predetermined depth position below the water surface, and is placed below the water surface where the navigable ship will pass. The face of the ultrasonic distance measuring sensor is connected to the measurement and control computer of the data acquisition and processing device through the data line.

The detection door automatic lifting control device described in the present invention is made up of PLC controller, frequency converter and hoist, installs a frequency converter and a hoist respectively on the left gate wall of navigable ship lock and the right gate wall, and the hoist of left hoist The end of the left wire rope on the drum is connected to the left end of the detection door installation frame; the right wire rope end on the reel of the right winch is connected to the right end of the detection door installation frame.

A relative value encoder is installed on the variable frequency motor shaft of the winch according to the present invention, and the relative value encoder feeds back the rotation signal of the motor shaft to the frequency converter. An absolute encoder is installed on the reel shaft of the winch, and the absolute encoder feeds back the rotation signal of the reel to the PLC controller, and the PLC controller calculates the wire rope output rope according to the number of turns, the angle and the diameter of the reel rotation. The length is used to control the position of the end of the wire rope, and the PLC controller is connected to the measurement and control computer of the data acquisition and processing device through the data line.

The data collection and processing device of the present invention is composed of a measurement and control computer, a man-machine interface, and an array of ultrasonic ranging sensors. The ultrasonic range-finding sensor array is composed of several ultrasonic range-finding sensors evenly distributed on the detection door. The front side of the ultrasonic distance measuring sensor is upward, that is, the measurement direction is measured from bottom to top. The data measured by the ultrasonic ranging sensor is sent to the measurement and control computer for processing through RS485 serial communication. The measurement and control computer is connected with the detection door automatic lifting control device through RS485 serial communication. The measurement and control computer is connected to the Internet through a network data line.

Measurement method step of the present invention is as follows:

The first step is to start the total power supply of the system.

The second step, start the detection door automatic lifting control device, move the detection door installation frame (6) to the measurement position specified underwater, that is, the detection door installation frame (6) drops to the depth value H underwater, and the detection door After the mounting frame (6) is in a stable position, wait for the arrival of the ship to be tested.

In the third step, when the ship to be measured arrives, the ultrasonic ranging sensor array is activated, and the ultrasonic ranging sensor array emits ultrasonic waves from underwater to the water surface, and receives signals returned when the ultrasonic waves touch the bottom surface of the ship.

In the fourth step, the ultrasonic ranging sensor array measures the vertical distance from the bottom surface of the entire ship to the detection door installation frame, and all the measured data constitute the data set C. Then, according to the installation depth H of the ultrasonic ranging sensor array of the detection door installation frame, the water depth data set D at the bottom of the ship will be obtained, where D=HC. Then find the maximum value in the data set D, which is the draft D _max of the navigable ship, that is, D _max =MAX(D).

Processing of measurement data according to the invention. According to the principle of ship draft detection, the maximum water depth at the bottom of the ship is the actual draft of the ship. The data collected by the sensor is the distance from the bottom of the ship to the sensor array, and the collected data can be converted into the distance from the bottom of the ship to the water surface according to the installation depth of the sensor array at this time. Then traverse the data set of the distance between the bottom of the ship and the water surface to find the maximum value of the measured data, and then the draft of the ship can be obtained.

Description of drawings

The present invention has 4 accompanying drawings, wherein:

Figure 1 is a schematic structural diagram of the draft detection system of a navigation ship;

Fig. 2 is a schematic view of the structure of the winch;

Fig. 3 is a block diagram of the detection door automatic lifting control device;

Figure 4 is a block diagram of the data acquisition and processing device.

In the figure: 1. Left hoist 2. Left wire rope 3. Right wire rope 4. Hoist 5. Right gate wall 6. Installation frame 7. Ultrasonic ranging sensor 8. Left gate wall 9. Absolute encoder 10. Reel 11. Reducer 12, variable frequency motor 13, relative value encoder.

Detailed ways

The specific embodiment of the present invention is as shown in the accompanying drawings.

The real-time measuring device and measuring method for the draft of a navigable ship are composed of a detection door, an automatic lifting control device for the detection door, and a data acquisition and processing device.

The detection door is a mounting frame 6, and is controlled by the automatic lifting control device of the detection door to reach a predetermined depth position below the water surface, and is placed below the water surface that the navigable ship will pass through. An array of ultrasonic ranging sensors 7 is installed above the detection door, as shown in Figure 1, the front of the ultrasonic ranging sensors 7 is upward; the ultrasonic ranging sensors 7 are connected to the measurement and control computer of the data acquisition and processing device through data lines.

The detection door automatic lifting control device of the present invention is made up of PLC controller, frequency converter and winch, on the left gate wall 8 and the right gate wall 5 of navigable ship lock respectively install a frequency converter and a winch, left winch The left wire rope 2 ends on the reel of 1 are connected to the left end of detection door installation frame 6;

A relative value encoder 13 is installed on the variable frequency motor 12 shaft of the winch of the present invention, as shown in Figure 2, the relative value encoder 13 feeds back the rotation signal of the motor shaft to the frequency converter; the reel 10 of the winch A reducer 11 is installed between the frequency conversion motor 12, and an absolute encoder 9 is installed on the shaft of the reel 10 of the winch, as shown in Figure 2, the absolute encoder 9 feeds back the rotation signal of the reel 10 to the PLC controller , the PLC controller calculates the length of the steel wire rope according to the number of turns of the reel, the angle and the diameter, and controls the position of the end of the steel wire rope. The PLC controller is connected to the measurement and control computer of the data acquisition and processing device through the data line, as shown in Figure 3 .

The data acquisition and processing device of the present invention is composed of a measurement and control computer, a man-machine interface, and an array of ultrasonic ranging sensors, as shown in Figure 4; the array of ultrasonic ranging sensors is composed of several The above ultrasonic distance measuring sensor is composed of; the front of the ultrasonic distance measuring sensor is upward, that is, the measurement direction is measured from bottom to top; the data measured by the ultrasonic distance measuring sensor is sent to the measurement and control computer for processing through RS485 serial communication; the measurement and control computer passes RS485 The serial communication is connected with the automatic lifting control device of the detection door; the measurement and control computer is connected with the Internet through the network data line.

The measurement steps of the real-time measurement method for the draft of a navigable ship according to the present invention are as follows:

The first step is to start the total power supply of the system;

The second step is to start the automatic lifting control device of the detection door, and move the detection door installation frame 6 to the designated measurement position underwater, that is, the depth value of the detection door installation frame 6 descending to the water is H, and the position of the detection door installation frame 6 is After stabilization, wait for the arrival of the ship to be tested;

Step 3: When the ship to be measured arrives, start the ultrasonic ranging sensor array, which emits ultrasonic waves from underwater to the water surface, and receives the signal returned when the ultrasonic waves hit the bottom of the ship;

The fourth step, the ultrasonic ranging sensor array measures the vertical distance from the bottom surface of the entire ship to the detection door mounting frame 6, and all the measurement data constitute a data set C; then according to the installation depth of the detection door mounting frame 6 ultrasonic ranging sensor array H, will get the data set D of water depth at the bottom of the ship, where D=HC; then find the maximum value in the data set D, which is the draft D _max of the navigable ship, that is, D _max =MAX(D).

Example

The real-time detection system for the draft of navigable ships is installed at the entrance of the downstream ship lock of a water conservancy project.

The detection door is a truss of general steel structure, as shown in Figure 1. The main chord is φ104×6 ordinary carbon steel pipe for welding, and the vertical and oblique bars are φ60×3 ordinary carbon steel pipe for welding. The total length of the truss is 36 meters, the height is 1.8 meters, the section is rectangular, and the width is 1.2 meters.

The automatic lifting control device of the detection door adopts the existing PLC controller and frequency converter in the market. The hoist is modified by an ordinary hoist, that is, an absolute encoder is installed on the drum shaft, and a relative encoder is installed in the motor.

Two hoists are installed on the top of the lock walls on both sides of the lock, as shown in Figure 1. The wire rope is wound on the drum of the winch, and the end is connected to one end of the detection door. The frequency converter is placed in the electrical cabinet of the winch, and a PLC controller is placed in the electrical cabinet of one of the winches. The PLC controller controls the frequency conversion control of the two winches, and keeps the detection door at the depth position according to the depth value H set by the measurement and control computer.

The measurement and control computer adopts the existing industrial-grade control computer products on the market, and uses industrial-grade touch screen products as the man-machine interface. The ultrasonic distance measuring sensor also adopts the existing general-purpose products on the market, and 32 ultrasonic distance measuring sensors are evenly distributed on the On the mounting frame, an array of ultrasonic ranging sensors is formed.

Set the underwater depth H of the detection door to 8 meters through the man-machine interface. After the detection door reaches the preset underwater depth H, it will no longer move, and will only be raised out of the water when maintenance is required. The measurement and control computer can start the detection through the man-machine interface, and can also start the detection through the end user of the Internet. Measurement data can be displayed on the man-machine interface or on the Internet user terminal.

Claims (5)

1. A real-time measuring device for draft of a navigable ship is characterized in that it is made up of a detection door, a detection door automatic lifting control device and a data acquisition and processing device; the detection door is a mounting frame (6), and is composed of The automatic lifting control device of the detection door controls it to reach a predetermined depth position below the water surface, and is placed below the water surface that the navigable ship will pass through, and an array of ultrasonic distance measuring sensors (7) is installed on it, and the front of the ultrasonic distance measuring sensors (7) is upward; The distance sensor (7) is connected to the measurement and control computer of the data acquisition and processing device through a data line. 2. The real-time measuring device for draft of a navigable ship according to claim 1, characterized in that the automatic lifting control device for the detection door is made up of a PLC controller, a frequency converter and a hoist, and is placed on the left gate wall of the navigable ship lock ( 8) and the right gate wall (5) respectively install a frequency converter and a winch, the left wire rope (2) end on the reel of the left winch (1) is connected to the left end of the detection door installation frame (6); the right winch The right wire rope (3) end on the reel of (4) is connected to the right end of detection door installation frame (6). 3. according to claim 1 and 2 described navigable ship draft real-time measuring devices, it is characterized in that a relative value encoder (13) is installed on the shaft of the variable frequency motor (12) of the winch, and the relative value encoder (13 ) feeds back the rotation signal of the motor shaft to the frequency converter; an absolute encoder (9) is installed on the reel (10) shaft of the hoist, and the absolute encoder (9) converts the rotation signal of the reel (10) Feedback to the PLC controller, the PLC controller calculates the length of the steel wire rope according to the number of turns, angle and diameter of the drum, and controls the position of the end of the steel wire rope. The PLC controller is connected to the measurement and control computer of the data acquisition and processing device through the data line. 4. The real-time measuring device for draft of a navigable ship according to claim 1, wherein said data acquisition and processing device is composed of a measurement and control computer, a man-machine interface, and an array of ultrasonic ranging sensors; said ultrasonic ranging The sensor array is composed of a number of ultrasonic distance measuring sensors evenly installed on the detection door; the front of the ultrasonic distance measuring sensor is upward, that is, the measurement direction is from bottom to top; the data measured by the ultrasonic distance measuring sensor is passed through RS485 serial The communication is sent to the measurement and control computer for processing; the measurement and control computer is connected to the automatic lifting control device of the detection door through RS485 serial communication; the measurement and control computer is connected to the Internet through the network data line. 5. A method for real-time measurement of draft of a navigable ship, characterized in that the steps of the measurement method are as follows: The first step is to start the total power supply of the system; The second step, start the detection door automatic lifting control device, move the detection door installation frame (6) to the measurement position specified underwater, that is, the detection door installation frame (6) drops to the depth value H underwater, and the detection door After the mounting frame (6) is in a stable position, wait for the arrival of the ship to be tested; Step 3: When the ship to be measured arrives, start the ultrasonic ranging sensor array, which emits ultrasonic waves from underwater to the water surface, and receives the signal returned when the ultrasonic waves hit the bottom of the ship; The fourth step, the ultrasonic ranging sensor array measures the vertical distance from the bottom surface of the entire ship to the detection door mounting frame (6), and all the measurement data form a data set C; then according to the detection door mounting frame (6) ultrasonic ranging sensor The installation depth H of the array will obtain the water depth data set D at the bottom of the ship, where D=HC; then find the maximum value in the data set D, which is the draft D _max of the navigable ship, that is, D _max =MAX(D).

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