Lifting control method and system of lifting type ship charging pile

Abstract

The invention provides a lifting control method and system for a lifting type ship charging pile. The lifting control method comprises the steps that historical water level data of a reservoir area is obtained, a ship stop point of a ship to be charged is determined, and then the highest lifting position is determined according to the historical water level data of the reservoir area; a laser radar is used for conducting scanning distance measurement from the vertical downward direction to the ship stop point, distance values measured in the scanning process are recorded, all the distance values are fitted into a distance change curve, and then the water surface height and the ship edge height are determined according to the distance change curve; a safety distance is set, then the maximum safety stroke of lifting of the charging pile is calculated according to the highest lifting position, the water surface height and the ship edge height, and the charging pile is controlled to descend at a constant speed according to the maximum safety stroke. The problems that in the prior art, a lifting type charging pile cannot automatically control the lifting height of a lifting table according to the position of a charging port when a ship is berthed, consequently, the charging pile is inconvenient to use for charging the ship, and the labor cost is increased are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of intelligent charging of ships, and in particular to a lifting control method and system for a lifting type ship charging pile. BACKGROUND

[0002] An electric ship is a water transportation tool that uses electric energy as a power source, drives a propulsion system through an electric motor, and has the characteristics of environmental protection, high efficiency, and low noise, and is applied to various fields such as transportation, tourism, and operation.

[0003] The electric ship has a limited cruising range and needs to be frequently charged. There are ship charging devices in various ports. When the electric ship arrives at the charging area and is charged, the crane in the charging device needs to move the charging head to the charging port of the ship according to the position positioned on the ship.

[0004] Current charging piles are mostly fixedly arranged on the shore. After the ship is docked, a relatively long charging line is used to connect the charging pile and the charging interface. However, the excessively long charging line not only causes waste of electric energy, but also causes abrasion and breakage of the charging line after long-time use, thereby causing a safety hazard. Therefore, in some ship docking places, a lifting type charging pile is designed. After the ship is docked, the charging pile is lowered to the charging port of the ship by using a lifting platform, and then a relatively short charging line is used to connect the charging pile and the charging port.

[0005] Although the lifting type charging pile solves the problem of excessively long charging lines, it still has some deficiencies to be overcome. First, due to the influence of wind and waves, water level, and the design of the ship itself, the position of the charging interface of the ship is different at each time of docking. If the lowering height of the lifting platform carrying the charging pile is to be accurately controlled, manual operation is needed. A large number of ships are docked at the wharf, which requires a large amount of manpower. If the lowering height of the lifting platform is controlled in an automatic control mode, only a fixed docking height of the lifting platform can be set, and then the height of the lifting platform is manually adjusted by the staff on the ship, which also increases the labor cost and is inconvenient for using the charging pile to charge the ship. SUMMARY

[0006] In view of the deficiencies in the prior art, the present application provides a lifting control method and system for a lifting type ship charging pile, which solves the problem in the prior art that the lifting type charging pile cannot automatically control the lifting height of the lifting platform according to the position of the charging port when the ship is docked, thereby causing inconvenience in using the charging pile to charge the ship and increasing the labor cost.

[0007] According to an embodiment of the present application, a lifting control method for a lifting type ship charging pile comprises the following steps. Obtaining historical water level data of the storage area and determining the ship docking point of the ship to be charged, and then determining the highest lifting position according to the historical water level data of the storage area; Using laser radar to scan and measure the distance from the vertical downward direction to the ship docking point, recording the distance values measured in the scanning process, and fitting all the distance values into a distance change curve, and then determining the water surface height and the ship along height according to the distance change curve; Setting a safety distance, then calculating the maximum safe stroke of the charging pile lifting according to the highest lifting position, the water surface height and the ship along height, and controlling the charging pile to descend uniformly according to the maximum safe stroke.

[0008] Preferably, the shore corresponding to the ship docking point is provided with a ship positioner, which comprises a positioning laser, an excitation laser and an alarm; When determining the ship docking point of the ship to be charged, if the excitation laser does not detect the ship and the positioning laser measures the distance between the ship and the laser range finder within the preset range, it is determined that the charging ship is located at the ship docking point, and if the excitation laser detects the ship or the positioning laser measures the distance between the ship and the laser range finder not within the preset range, the alarm alarms to inform that the ship to be charged is not at the ship docking point.

[0009] Preferably, before using the laser radar to scan and measure the distance, the weather data at the ship docking point is obtained, and the weather influence value is calculated according to the weather data, if the weather influence value is within the preset range, the distance measurement is continued, and if the weather influence value is not within the preset range, the gain alternating measurement method is used to measure the distance value.

[0010] Preferably, the weather data includes environmental visibility and environmental illumination value.

[0011] The calculation of the weather influence value is as follows: wherein, is the weather influence value, is the environmental visibility, is the minimum laser emission power of the laser radar, and C is the optical system parameter of the laser radar, is the environmental illumination value.

[0012] Preferably, the method for measuring the distance value using the gain alternating measurement method comprises: The laser radar measures with the minimum gain, and records the first distance of the first received echo; The laser radar measures with the maximum gain, and records the second distance and the third distance of the first received echo and the second received echo respectively; According to the time when the laser radar receives the echo, the validity of the first distance, the second distance and the third distance is judged. in response to the third distance being invalid, the first distance or the second distance being valid, selecting the first distance or the second distance as the distance value; in response to the third distance being invalid, the first distance and the second distance both being valid, selecting the maximum value between the first distance and the second distance as the distance value; in response to the third distance being valid, selecting the third distance as the distance value.

[0013] Preferably, if the sum of the water surface height and the safety distance is less than the ship rail height, the difference between the lifting highest position and the ship rail height is taken as the maximum safe travel, and if the sum of the water surface height and the safety distance is greater than or equal to the ship rail height, the difference between the lifting highest position and the sum of the ship rail height and the safety distance is taken as the maximum safe travel.

[0014] Preferably, the method for controlling the lifting of the charging pile at a constant speed according to the maximum safe travel comprises: determining the cable length according to the maximum safe travel, and deriving an outer diameter change function of the cable reel according to the cable length; constructing a rotating speed function of the rotating motor according to the outer diameter change function, and then controlling the rotating motor to rotate according to the rotating speed function, so that the charging pile is lifted at a constant speed.

[0015] In another aspect, according to an embodiment of the present application, there is also provided a lifting control system for a lifting type ship charging pile, which uses the lifting control method for a lifting type ship charging pile described above, comprising: a data collection module, configured to acquire historical water level data of a storage area and weather data at a ship berthing point, and store a set safety distance; a control module, configured to control the laser radar to perform scanning and distance measurement and record the distance values measured in the scanning process, and control the charging pile to descend at a constant speed; an analysis module, configured to fit all the distance values into a distance change curve, then determine the water surface height and the ship rail height according to the distance change curve, and calculate the maximum safe travel of the charging pile according to the lifting highest position, the water surface height and the ship rail height.

[0016] Compared with the prior art, the present application has the following beneficial effects: The present application uses a laser radar to perform scanning and distance measurement, determines the water surface height and the ship rail height according to the measured distance values, so that the maximum safe travel of the charging pile descending can be determined according to the real-time water surface height and ship rail height under the premise of maintaining a safety distance, regardless of the wind and waves, the water level and the design of the ship itself, and then the charging pile is automatically controlled to lift and descend, so that manual control and fixed lifting positions are no longer needed, and it is convenient to use the charging pile to charge the ship. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 This is a diagram of the lifting control method for a charging pile according to an embodiment of the present invention. Detailed Implementation

[0018] The technical solutions of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0019] like Figure 1 As shown in the figure, an embodiment of the present invention proposes a lifting control method for a lifting-type ship charging pile, including: Obtain historical water level data of the reservoir area and determine the berthing point of the vessel to be charged, and then determine the highest lifting position based on the historical water level data of the reservoir area; Based on the historical water level data provided by the reservoir area, the highest and lowest water levels in the reservoir area can be obtained. Therefore, the highest design position of the lifting platform equipped with the charging pile should be greater than the highest water level, and the highest design position of the lifting platform should be used as the highest lifting position of the charging pile. For example, if the highest water level detected is 175m and the lowest water level is 145m, then the highest design position of the lifting platform equipped with the charging pile should be at least greater than 175m.

[0020] Since the angle for scanning and ranging using lidar is fixed, the vessel to be charged needs to be moored at a preset mooring point. During the mooring process, a vessel locator set up on the shore corresponding to the mooring point is used to locate the vessel to be charged, ensuring that the vessel to be charged is fixed at the mooring point.

[0021] The ship locator includes a positioning laser, an activation laser, and an alarm. The positioning laser is located in the middle of the berthing point to determine whether the ship to be charged is berthed at the berthing point. The activation laser is located at the entrance of the berthing point to determine whether the ship to be charged has entered the berthing point and to activate the positioning laser.

[0022] When the excitation laser does not detect a ship and the positioning laser measures the distance between the ship and the laser rangefinder within a preset range, it is determined that the ship to be charged is located at the ship docking point. If the excitation laser detects a ship or the positioning laser measures the distance between the ship and the laser rangefinder outside the preset range, the alarm will sound, informing the ship to be charged that it is not at the ship docking point.

[0023] The laser radar is used to scan and measure the distance from the vertical downward direction to the ship's docking point, and the distance values ​​measured during the scanning process are recorded. All distance values ​​are then fitted into a distance variation curve (the horizontal axis is the laser emission angle, and the vertical axis is the distance value). The water surface height and the ship's edge height are then determined based on the distance variation curve.

[0024] In addition, due to the limitation of laser radar application, an important factor limiting the application of laser radar is the rain, fog, haze and dust environment. Because the outgoing light of the laser radar is generally interfered by the reflection and refraction of rain, fog and haze particles in the rain, fog and haze environment, errors are generated. Water often appears in foggy weather, and if foggy weather occurs, in addition, in a strong light irradiation environment, the laser radar will also be affected. Therefore, weather data needs to be obtained to correct the measurement of the laser radar.

[0025] First, the weather data including the environmental visibility and the environmental light value is obtained, and the weather influence value is calculated according to the following calculation formula according to the weather data: Among them, is the weather influence value, is the environmental visibility, is the minimum laser emission power of the laser radar, and C is the optical system parameter of the laser radar, is the environmental light value, which can be understood as the light noise.

[0026] If the weather influence value is within the preset range, the distance is continued to be measured, and if the weather influence value is not within the preset range, the gain alternating measurement method is used to measure the distance value: The laser radar measures with the minimum gain (at least 1 times gain), and records the first distance corresponding to the first echo; The laser radar measures with the highest gain (generally 10 times gain), and records the second distance and the third distance corresponding to the first echo and the second echo.

[0027] The present application adopts the minimum and maximum gain alternating measurement, that is, two measurements are a group, the first measurement is low gain measurement, and the second measurement is high gain measurement. Then, one value is selected from the two measurement results as a reliable value. When the low gain measurement is performed, because the signal gain is not large, the echo signal reflected by the rain, fog and haze environment is weak and is not enough to trigger the radar ranging. Only the first echo generated by the measured object can be received. Based on this, the low gain can better penetrate the rain, fog and dust environment. At the same time, because the reflection signal of the low gain is weak, the object far away cannot be effectively identified, so it is suitable for near distance measurement.

[0028] In the high gain measurement, the signal gain is large, and the echo signal reflected by the rain, fog and haze environment can be received by the radar. At this time, the first echo is generated by the rain, fog and haze environment, and the second echo is generated by the measured object. The two echoes are recorded and analyzed. When the second echo value is valid, it means that the laser radar effectively detects the measured object in the high gain measurement. The distance can be calculated through the second echo. When the measured distance is too close or the rain, fog and haze environment is not enough to generate an effective second echo signal, the second echo obtained by the high gain measurement or the first echo obtained by the low gain measurement is the effective value. Therefore: If the third distance is invalid, the first distance or the second distance is valid, the first distance or the second distance is selected as the distance value; If the third distance is invalid, the first distance and the second distance are both valid, the maximum value of the first distance and the second distance is selected as the distance value; If the third distance is valid, the third distance is selected as the distance value.

[0029] After determining how to accurately record the distance value, the laser radar is used for scanning detection, and the laser radar is arranged directly below the charging pile. Since the water surface is definitely below the lifting platform, the wave emitted by the laser is quickly attenuated and easily reflected to other directions. Therefore, when scanning and measuring the distance (starting from the vertical direction to the ship body and water surface demarcation point), the laser radar is difficult to receive a return wave with sufficient signal strength. Therefore, in this stage, the recorded distance value is inaccurate. When reflected on the distance change curve, the curve in this section is discontinuous, irregular and has large fluctuations. From the scanning to the ship body and water surface demarcation point, the laser radar can normally receive the return wave. Therefore, according to the distance value measured at the ship body and water surface demarcation point and the corresponding laser emission angle, the distance between the charging pile and the water surface can be derived by using the cosine theorem.

[0030] Then, the ship body is scanned. The distance change curve at this time is a continuous curve without large fluctuations, and the overall trend is gradually decreasing. This section of the curve is a decreasing curve. When scanning to the ship side, the distance change curve will immediately start to increase. This section of the curve is an increasing curve. Therefore, according to the distance value and the corresponding laser emission angle of the intersection point of the above-mentioned decreasing curve and the increasing curve in the distance change curve, the distance between the ship side and the charging pile can be derived by using the cosine theorem.

[0031] The laser radar is used for scanning and measuring the distance. The water surface height and the ship side height are determined according to the measured distance value. In this way, under the premise of maintaining a safe distance, regardless of the wind and wave, the water level and the design of the ship itself, the maximum safe stroke of the charging pile descending can be determined according to the real-time water surface height and the ship side height. Then, the charging pile is automatically controlled to rise and fall, and manual control and fixed lifting position setting are no longer needed, which facilitates the use of the charging pile to charge the ship.

[0032] The safe distance is set, and then the maximum safe stroke of the charging pile descending is calculated according to the highest lifting position, the water surface height and the ship side height, and the charging pile is controlled to descend at a constant speed according to the maximum safe stroke.

[0033] The water level can be calculated from the highest lifting position and the distance between the charging pile and the water surface. The hull height can be calculated from the highest lifting position and the distance between the hull and the charging pile. If the sum of the water level and the safe distance is less than the hull height, the difference between the highest lifting position and the hull height is taken as the maximum safe travel. If the sum of the water level and the safe distance is greater than or equal to the hull height, the difference between the highest lifting position and the hull height and the safe distance is taken as the maximum safe travel.

[0034] The maximum safe travel distance is the cable length of the lifting device. Therefore, the outer diameter variation function of the cable reel of the lifting device can be derived using the following formula: Where S is the maximum safe travel, i is the number of rotations of the cable reel, D0 is the outer diameter of the cable reel in the initial state, and d is the diameter of the cable.

[0035] The rotational speed function of the motor speed and the charging pile descent speed is as follows: According to the above formula, as time progresses, i increases, the outer diameter decreases, and the motor speed n automatically increases to keep the charging pile's descent speed v constant.

[0036] Taking a cable reel rotating 5 revolutions as an example, assuming the initial outer diameter of the cable reel is D0 = 1850 mm, the descent speed of the charging pile is v = 75 mm / s, and the cable diameter is d = 51 mm, then: Current outer diameter Di = 1850 - 102 × 5 = 1850 − 510 = 1340 mm The current length released per revolution, Li = π × 1340 ≈ 3.1416 × 1340 ≈ 4209.74 mm Set the motor speed n = 4209.7475 ≈ 0.01781 revolutions per second. Distance S traveled (based on lap count): =3.1416×5×(1850-51×(5-1))=3.1416×5×(1850-204)=3.1416×5×1646≈3.1416×8230≈25850.48mm.

[0037] The lengths released in the first 5 rounds are added together: the first round is π×1850, the second round is π×1748 (1850-102), and so on, the total S≈25850mm.

[0038] After rotating 5 times, the outer diameter decreases and the length extended per rotation shortens. Therefore, the motor speed needs to be increased to about 0.01781 revolutions per second to maintain the speed, and the moving distance is about 25.85m.

[0039] In another aspect, the embodiment of the present application also provides a lifting control system of the lifting type ship charging pile, which uses the lifting control method of the lifting type ship charging pile and comprises: a data collection module, which is configured to acquire historical water level data of a warehouse area and weather data at a ship berthing point and store a set safe distance; a control module, which is configured to control the laser radar to perform scanning ranging and record distance values measured in the scanning process and control the charging pile to descend at a constant speed; an analysis module, which is configured to fit all the distance values into a distance change curve, then determine a water surface height and a ship rail height according to the distance change curve, and calculate a maximum safe stroke of the charging pile in lifting according to the highest lifting position, the water surface height and the ship rail height.

[0040] Finally, it should be explained that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A lifting control method for a lifting-type ship charging pile, characterized in that: include: Obtain historical water level data of the reservoir area and determine the berthing point of the vessel to be charged, and then determine the highest lifting position based on the historical water level data of the reservoir area; The laser radar is used to scan and measure the distance from the vertical downward direction to the ship's mooring point, and the distance values ​​measured during the scanning process are recorded. All distance values ​​are fitted into a distance variation curve, and then the water surface height and ship's edge height are determined based on the distance variation curve. Set a safe distance, then calculate the maximum safe travel distance for raising and lowering the charging pile based on the highest lifting position, water level, and ship edge height, and control the charging pile to descend at a uniform speed based on the maximum safe travel distance.

2. The lifting control method for a lifting-type ship charging pile as described in claim 1, characterized in that: A ship locator is installed on the shore corresponding to the ship berthing point. The ship locator includes a positioning laser, an excitation laser, and an alarm. When determining the berthing point of the vessel to be charged, if the excitation laser does not detect the vessel and the positioning laser measures the distance between the vessel and the laser rangefinder within a preset range, the vessel to be charged is determined to be at the berthing point. If the excitation laser detects the vessel or the positioning laser measures the distance between the vessel and the laser rangefinder outside the preset range, the alarm will sound, informing the vessel to be charged that it is not at the berthing point.

3. The lifting control method for a lifting-type ship charging pile as described in claim 1, characterized in that: Before using lidar for scanning and ranging, weather data at the ship's docking point must be obtained, and the weather impact value must be calculated based on the weather data. If the weather impact value is within the preset range, ranging continues; if the weather impact value is not within the preset range, the distance value is measured using the gain alternation measurement method.

4. The lifting control method for a lifting ship charging pile as described in claim 3, characterized in that: The weather data includes ambient visibility and ambient light levels.

5. The calculation of the weather impact value is as follows: in, This is the weather impact value. For environmental visibility, Let C be the minimum laser emission power of the lidar, and C be the optical system parameters of the lidar. This represents the ambient light level.

6. The lifting control method for a lifting ship charging pile as described in claim 3, characterized in that: Methods for measuring distance values ​​using the alternating gain measurement method include: The lidar measures at minimum gain and records the first distance of the first received echo; The lidar was used to measure at maximum gain, and the second and third distances of the first and second received echoes were recorded respectively. The validity of the first, second, and third distances is determined based on the time it takes for the lidar to receive the echo; If the third distance is invalid, but the first or second distance is valid, then the first or second distance is selected as the distance value. If the third distance is invalid, but the first and second distances are both valid, then the maximum value between the first and second distances is selected as the distance value. If the third distance is valid, then the third distance is selected as the distance value.

7. The lifting control method for a lifting-type ship charging pile as described in claim 1, characterized in that: If the sum of the water level and the safe distance is less than the height of the ship's edge, the difference between the highest lifting position and the height of the ship's edge is taken as the maximum safe travel. If the sum of the water level and the safe distance is greater than or equal to the height of the ship's edge, the difference between the highest lifting position and the height of the ship's edge and the safe distance is taken as the maximum safe travel.

8. The lifting control method for a lifting-type ship charging pile as described in claim 1, characterized in that: Methods for controlling the charging pile to rise and fall at a uniform speed based on the maximum safe travel include: The cable length is determined based on the maximum safe travel, and the outer diameter variation function of the cable reel is derived based on the cable length; The rotation speed function of the turntable motor is constructed based on the outer diameter change function, and then the rotation speed function is used to control the rotation of the turntable motor so that the charging pile can be raised and lowered at a uniform speed.

9. A lifting control system for a lifting-type ship charging pile, characterized in that: The system uses a lifting control method for a lifting ship charging pile as described in any one of claims 1-7, comprising: The data collection module is used to acquire historical water level data of the reservoir area and weather data at ship berthing points, as well as store the preset safety distances; The control module is used to control the lidar to perform scanning and ranging, record the distance values ​​measured during the scanning process, and control the charging pile to descend at a constant speed. The analysis module is used to fit all distance values ​​into a distance variation curve, then determine the water surface height and the ship's edge height based on the distance variation curve, and calculate the maximum safe travel distance of the charging pile's lifting and lowering based on the highest lifting position, the water surface height, and the ship's edge height.

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