Port quay crane lower active alignment system and alignment method

Abstract

The application discloses a port shore-to-ship crane active alignment system and alignment method, which comprises a plurality of groups of reflectors, an unmanned truck control end and a background control end. Each reflector is installed at the bottom of the shore-to-ship crane and directly above each lane, and has a triangular reflector body. The unmanned truck control end is provided with a positioning module and a scanning module. The positioning module real-time positions the position information of the unmanned truck, and the scanning direction of the scanning module is upward. The background control end stores port map information, operation task information and an effective position area calibrated according to the operation task information. The background control end communicates with the unmanned truck control end in real time, dispatches operation tasks to the unmanned truck, and acquires the position information of the unmanned truck. After the unmanned truck enters the effective position area, the scanning module is started to scan and identify the position information of the reflector, the position that the unmanned truck needs to move is calculated in real time, and active alignment is realized.

Description

Technical Field

[0001] This invention relates to the field of port truck alignment technology, specifically to an active alignment system and method under a port quay crane. Background Technology

[0002] With the accelerated development of smart ports, more and more automated equipment has replaced manual operations at the dock. Quay crane truck alignment systems generally use laser scanning ranging technology, pattern recognition, and automatic control technology. Based on the type of operation, the position that the truck needs to be adjusted to is displayed on the guide sign, so that the truck can be accurately stopped in advance at the quay crane lifting position, reducing the time for quay crane spreader to align the truck and improving the efficiency of dockside operations.

[0003] The current quay crane truck alignment system has the following main defects:

[0004] 1. For unmanned container trucks, active alignment can be achieved by reading guidance information from the quay crane's backend system. However, a quay crane often has multiple lanes. When multiple unmanned container trucks are simultaneously in different lanes under the same quay crane, they cannot simultaneously receive guidance information from the backend system. The quay crane operator needs to manually switch the alignment system to identify which lane, and then the unmanned container truck in the corresponding lane can receive the guidance information and align itself. In busy port environments, this can significantly impact operational efficiency.

[0005] 2. By installing scanning modules on the quay crane and setting markers on the container truck, the maintenance and calibration of the scanning modules become difficult.

[0006] 3. Using the outline of the container as a marker to identify the container's location involves complex calculations, low detection accuracy, and slow speed. For example, the invention patent application with application number 200910052974.3, entitled "Dock Truck Guiding System and Method", describes this type of technical solution. At the same time, its scanning module is set under the quay crane, making maintenance difficult.

[0007] Therefore, it is necessary to propose a new automatic positioning system for port quay cranes. Summary of the Invention

[0008] The purpose of this invention is to provide an automatic positioning system for port quay cranes that features easily identifiable markers, low computational complexity, and high accuracy.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] The active alignment system under the port quay crane includes:

[0011] Several sets of reflectors are installed at the bottom of the quay bridge, each corresponding to the top of each lane. The reflectors have triangular reflector bodies.

[0012] The unmanned truck control terminal is equipped with a positioning module and a scanning module. The positioning module locates the position information of the unmanned truck in real time, and the scanning module scans upward.

[0013] The back-end control terminal stores port map information, operation task information, and effective location areas marked according to the operation task information. The back-end control terminal communicates with the unmanned truck control terminal in real time, dispatches operation tasks to the unmanned truck, and obtains the location information of the unmanned truck. After the unmanned truck enters the effective location area, it starts the scanning module to scan and identify the reflector location information, calculates the position that the unmanned truck needs to move in real time, and realizes active alignment.

[0014] Preferably, each set of reflectors includes three reflector bodies arranged in a straight line parallel to the lane direction; the unmanned truck control terminal also includes a laser rangefinder used to measure the distance between the container body and the cab.

[0015] Preferably, the reflector includes a bracket that is magnetically attached to the bottom of the quay crane.

[0016] Another object of the present invention is to provide an active alignment method under a port quay crane, comprising:

[0017] S1. System Construction: Several sets of reflectors are fixed to the bottom of the quay crane, with each set of reflectors located directly above each lane. The reflectors have triangular reflector bodies. The scanning module and positioning module are mounted on the unmanned truck and connected to the unmanned truck control terminal. The scanning module is set on the top of the unmanned truck, with the scanning direction upward. The back-end control terminal is configured with port map information. The back-end control terminal marks and stores the effective location area according to the back-end guidance information for different task types.

[0018] S2. The unmanned truck control terminal receives the task information sent by the background control terminal and transmits the current location information and vehicle speed information in real time. When it is determined that the current location of the unmanned truck is in the effective location area, the scanning module is started to scan the reflector body.

[0019] S3. The back-end control terminal identifies and confirms the position of the reflector body based on the scanning results of the scanning module, filters and combines the task information to calculate the distance that the vehicle needs to move in real time.

[0020] S4. The unmanned truck control terminal executes the calculation results of S3, enabling the unmanned truck to achieve active alignment.

[0021] Furthermore, in S2, the center of the rear wheel of the unmanned truck is used as the positioning point, and the positioning information of the rear wheel center is calculated based on the relative position of the positioning module and the center of the rear wheel of the vehicle.

[0022] Furthermore, in S1, the effective position region includes the effective position endpoint B and the effective position starting point D. Along the driving direction, the effective position endpoint B = C + L BC C represents the position of the center of the rear wheels after the unmanned truck arrives at the parking spot and stops, and L represents the position of the center of the rear wheels. BC The distance to the end before point C; the effective starting point D = CL CD D represents the distance after point C.

[0023] Further, in S1, each reflector group includes three reflector bodies arranged in a straight line parallel to the lane direction; then S3 performs the quay crane / yard crane angle inverse distance calculation, which calculates the distance from the rear axle center to the parking point based on the identified reflectors, thus...

[0024]

[0025] In the formula, S is the distance from the center of the rear axle of the unmanned truck to the parking point. - offst - S1 represents the distance between the scanning module and the rear axle center of the unmanned truck along the vehicle's travel direction. y1, y2, and y3 represent the distances from the three reflector bodies to the scanning module along the vehicle's travel direction in the scanning module's coordinate system. S1 is the calibration value from the reflector body to the parking point.

[0026] Furthermore, the method for identifying the reflector body in S3 is as follows:

[0027] (1). flag is initially set to false;

[0028] (2) Pre-screen points that meet the verification conditions from the targets detected by the scanning module;

[0029] (3) If the number of pre-screened points is between the minimum and maximum point values, proceed to the next step; otherwise, exit.

[0030] (4). Calculate the distances L1, L2, and L3 between each pair of pre-screening points;

[0031] (5) Select three points from the pre-screening points to form a combination that satisfies the following conditions:

[0032] a. The distance d12 between point 1 and point 2 is within the range (L1-delta_range_, L1+delta_range_);

[0033] b. The distance d23 between point 2 and point 3 is within the range (L2-delta_range_, L2+delta_range_);

[0034] c. The distance d13 between point 1 and point 3 is within the range (L-delta_range_, L+delta_range_);

[0035] d. If on the shore bridge: the y-coordinate of point 1 < the y-coordinate of point 2 < the y-coordinate of point 3;

[0036] (6) Iterate through all three-point combinations and find the optimal combination with the smallest error.

[0037] err1 = fabs(d13-L);

[0038] err2 = fabs(d12 - L1);

[0039] err3 = fabs(d23-L2);

[0040] err4 = fabs(d12 + d23 - d13);

[0041] err=max(max(err1, err2), err3)*err_weight_+err4*(1-err_weight_);

[0042] The optimal combination of three points is the reflector body target.

[0043] Furthermore, S3 also includes a box distance correction step, then we have,

[0044] (4) If boxpos_lidar > 0 and the current task type is box delivery, then execute the subsequent steps; otherwise, terminate. boxpos_lidar is the distance between the container body and the cab, which is measured by a laser rangefinder.

[0045] (5) dist_comp = boxpos_lidar - box_rel, where box_rel is the calibrated distance between the container body and the cab. Calculate fabs(dist_comp). If its value is less than 0.5, proceed to the next step; otherwise, return to step (1).

[0046] (6) s'=s+dist_comp, S' is the corrected distance from the rear axle center of the unmanned truck to the parking point.

[0047] Furthermore, after the box correction, interference cancellation is also included. The interference cancellation method is as follows:

[0048] To initialize flag to false, the following conditions must be met simultaneously for flag to become true;

[0049] ① The angle inverse distance calculation for quay cranes / yard cranes has two consecutive distance outputs;

[0050] ② The distance is always within a certain range (output_range_limit_min_, output_range_limit_max_);

[0051] ③ The distance change relative to the previous time step is within a certain range (delta_dist_limit_min, delta_dist_limit_max);

[0052] When flag is true, it will be set to false only if the distance output calculated by the angle inverse distance of the quay crane / field crane is less than output_range_limit_min_. After that, flag will become true again only if the angle inverse distance calculation of the quay crane / field crane has two cumulative or two consecutive distance outputs, and conditions ② and ③ are met.

[0053] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0054] 1. This invention proposes a port quay crane active alignment system that is significantly different from existing technologies. It places a marker (i.e., a triangular reflector body) under the quay crane and mounts a scanning module on the truck. The reflector body is made of metal, is passive, and requires no maintenance. The scanning module is located on the unmanned truck, facilitating its maintenance and calibration. The triangular reflector body, mounted on the quay crane for scanning and identification by the scanning module, is easy to identify, requires minimal computation, has a fast recognition speed, and high accuracy. In this active alignment system, a set of reflectors is installed above each lane, enabling automatic alignment even without remote lane switching by the quay crane operator. This solves the problem in existing quay crane alignment systems where operators need to manually switch which lane to identify, thus meeting the requirements of automated operations.

[0055] 2. In this invention, the reflector has three reflector bodies, which are arranged in a straight line parallel to the lane direction. This helps to improve the recognition accuracy, and the positioning accuracy can reach the centimeter level, meeting the operational requirements. The unmanned truck control terminal of this invention also includes a laser rangefinder, which detects the deviation value of the container when it is carrying a box, so as to improve the correction value and further improve the accuracy.

[0056] 3. In this invention, the reflector includes a bracket, which is magnetically attached to the bottom of the quay bridge, thus avoiding damage to the quay bridge. Attached Figure Description

[0057] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0058] Figure 1 This is a schematic diagram of the topology of the present invention;

[0059] Figure 2 This is a schematic diagram of the reflector arrangement of the present invention;

[0060] Figure 3 This is a schematic diagram of the reflector body of the present invention;

[0061] Figure 4 This is another schematic diagram of the reflector body of the present invention;

[0062] Figure 5 This is an anatomical diagram of the reflector body of the present invention;

[0063] Figure 6 This is a schematic diagram of the reflector assembly of the present invention;

[0064] Figure 7 This is a disassembled schematic diagram of the reflector assembly of the present invention;

[0065] Figure 8 This is another schematic diagram of the reflector assembly of the present invention;

[0066] Figure 9 This is a schematic diagram of the installation of the reflector of the present invention under the quay bridge;

[0067] Figure 10 This is a flowchart illustrating the implementation of the present invention;

[0068] Figure 11 This is a schematic diagram of the effective area of ​​the present invention;

[0069] Figure 12 This is a schematic diagram illustrating the principle of calculating the distance to the quay crane / field crane reflector according to the present invention;

[0070] Figure 13 This is a schematic diagram of the process for correcting the distance between boxes according to the present invention.

[0071] Explanation of reference numerals in the attached figures:

[0072] The reflector body 100, the reflective surface 110, the right-angled triangle plate 120, the slot 121, the threaded hole 122, the bolt through hole 123, and the second threaded hole 124;

[0073] 200, 210, 211, 220, 230, 240, 241, 241, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 242, 243, 243, 250, 251, 252;

[0074] Scanning module 300;

[0075] 400 unmanned container trucks;

[0076] 500 quay bridge. Detailed Implementation

[0077] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0078] Example 1

[0079] Please refer to Figure 1 As shown, the present invention discloses an active alignment system under a port quay crane, including a set of reflectors, an unmanned truck control terminal, and a background control terminal.

[0080] The reflectors are installed at the bottom of the quay bridge for each lane, and the reflectors have a triangular reflector body.

[0081] The unmanned truck control unit is equipped with a positioning module, a scanning module, a laser rangefinder, and a communication module. The positioning module is a BD / RTK positioning module, which can read positioning signals in real time and calculate the positioning information of the rear wheel center based on its position relative to the center of the vehicle's rear wheels. The scanning module is installed on the roof of the unmanned truck, with its scanning direction upward. To adapt to adverse weather conditions such as heavy fog, the scanning module in this invention is a millimeter-wave radar. The laser rangefinder is installed in the vehicle's cab and is used to measure the distance between the cargo box and the driver's cab. The communication module is used for communication with the back-end control unit.

[0082] The backend control unit includes a port map information module, a work task information module, a quay crane / yard crane angle inverse distance calculation module, a distance correction module, and an interference cancellation module. The port map information module stores port map information and works with the positioning module to monitor the approximate location of vehicles. The work task information module, based on backend guidance information for different task types (40-foot, 45-foot, double 20-foot, single 20-foot, etc.), offline calibrates the effective area and parking point, and stores the calibration results. Thus, when the positioning module locates a vehicle entering the effective area, it activates the scanning module to scan the reflector body. The quay crane / yard crane angle inverse distance calculation module uses the scan results as input to calculate the vehicle's distance from the parking point. The distance correction module corrects the distance output by the quay crane / yard crane angle inverse distance calculation module based on container offset. The interference cancellation module eliminates interference, outputs the final result, and achieves active alignment.

[0083] Please refer to Figure 2 As shown, in this embodiment, the reflector includes three reflector bodies arranged in a straight line, and the straight line is parallel to the lane direction; the unmanned truck control terminal also includes a laser rangefinder, which is used to measure the distance between the container body and the cab.

[0084] Compared to traditional automatic positioning systems for port quay cranes, this invention utilizes millimeter-wave radar in its scanning module, offering strong anti-interference capabilities and overcoming the shortcomings of traditional lidar systems, which are susceptible to interference in conditions such as heavy fog and rain. Furthermore, the reflector body 100 is specifically designed for millimeter-wave radar detection, making it easier to identify and avoiding false detections. In addition, the millimeter-wave radar is mounted on a vehicle, facilitating power supply and maintenance, and making calibration more convenient.

[0085] Please refer to Figure 3 , Figure 4 and Figure 5 As shown, the reflector body 100 has three reflective surfaces 110, which are perpendicular to each other in pairs, thus forming a triangular region with an opening. This triangular region is the scanning area, and its opening faces the scanning module 300. The triangular region has three vertices E. It should be understood that the statement "opening faces the scanning module 300" does not mean that the opening must be directly opposite the scanning module 300. As long as the opening is within the scanning range of the scanning module 300, it is considered to be facing the scanning module 300.

[0086] Please refer to Figure 5As shown, the reflector body 100 includes three right-angled triangles 120. Each right-angled triangle 120 has a slot 121 in a region parallel to its right-angled side. The width of the slot 121 is adapted to the thickness of the right-angled triangle 120. In this way, each triangle can be overlapped by the slot 121 and its right-angled side, and finally overlapped to form a triangle with all edges perpendicular to each other.

[0087] Each right-angled triangle 120 has several threaded holes 122 on its other right-angled side, and each slot 121 has a bolt through hole 123 corresponding to the threaded hole 122 on its back side. In this way, after several connecting bolts (not shown in the figure) pass through each bolt through hole 123, they are locked onto the threaded hole 122, thus completing the splicing of the right-angled triangle 120.

[0088] This type of splicing structure, because all the right-angled triangles have the same 120° dimensions, is easy to mass-produce. Compared to forming methods such as welding, it has the advantage of better dimensional uniformity.

[0089] Furthermore, due to the special nature of quay cranes, drilling is generally not permitted. Therefore, this invention designs a bracket suitable for quay cranes to connect the reflector body.

[0090] Please refer to Figures 6-8 As shown, the bracket 200 includes a base 210, a magnet 220, a frame 230, and a connector 240. The top of the base 210 is open to form a receiving area 211; the magnet 220 is locked in the receiving area 211; the upper end of the frame 230 is connected to the bottom surface of the base 210, and the lower end is connected to the connector 240, which is connected to the reflector body 100. See also... Figure 9 As shown, as long as the quay crane has a steel structure bottom surface, the support 200 can be attracted to the steel structure bottom surface by the magnet block 220.

[0091] In this embodiment, the connector 240 is an adjustable connector 240, which includes a hinge seat 241, an adjustment seat 242, and a rubber pad 243. The hinge seat 241 is fixed to the lower end of the frame 230, the adjustment seat 242 is rotatably hinged in the hinge seat 241, and the reflector body 100 is rotatably connected to the adjustment seat 242.

[0092] Specifically, the hinge seat 241 has a first arc-shaped slot 2411 concentric with its hinge center, and the adjusting seat 242 has a first threaded hole 2421 corresponding to the first arc-shaped slot 2411. A locking bolt passes through the first arc-shaped slot 2411 and locks in the first threaded hole 2421. In this way, the final swing adjustment position of the hinge seat 241 can be fixed.

[0093] The reflector body 100 is provided with a second threaded hole 124. The connecting surface of the adjusting seat 242 is provided with a second bolt through hole 2422 corresponding to the second threaded hole 124 and a plurality of second arc-shaped strip holes 2423 coaxial with the second bolt through hole 2422. In this way, a locking bolt passes through the second bolt through hole 2422 and the rubber pad 243 in sequence and is locked in the second threaded hole 124. Through the deformation of the rubber pad 243, the final position of the reflector body 100 can be fixed.

[0094] To prevent tilting caused by strong winds, the support frame 200 also includes two windproof frames 250. Since the wind mainly exists on the front and rear sides (i.e., the scanning direction of the scanning module 300), the two windproof frames 250 are distributed on the front and rear sides of the frame 230. The two windproof frames 250 are diagonally supported, and their bottom supports 251 are adjustablely connected to the frame 230, while their top supports 252 abut against the bottom surface of the steel structure of the quay crane.

[0095] In the description of the above embodiments, it should be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0096] In the description of the above embodiments, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0097] Example 2

[0098] This invention discloses an active alignment method under a port quay crane, which includes...

[0099] S1. System Construction: Several sets of reflectors are fixed to the bottom of the quay crane, with each set of reflectors located above one lane. Each reflector has a triangular reflector body. The scanning module and positioning module are mounted on the unmanned truck and connected to the unmanned truck control terminal. The scanning module is set on the top of the unmanned truck, with the scanning direction upward. The back-end control terminal is configured with port map information. The back-end control terminal marks and stores the effective location area according to the back-end guidance information for different task types.

[0100] S2. The unmanned truck control terminal receives the task information sent by the background control terminal and transmits the current location information and vehicle speed information in real time. When it is determined that the current location of the unmanned truck is in the effective location area, the scanning module is started to scan the reflector body.

[0101] S3. The back-end control terminal identifies and confirms the position of the reflector body based on the scanning results of the scanning module, filters and combines the task information to calculate the distance that the vehicle needs to move in real time.

[0102] S4. The unmanned truck control terminal executes the calculation results of S3, enabling the unmanned truck to achieve active alignment.

[0103] In S1, the valid position area includes the valid position end point and the valid position start point. Please refer to [reference needed]. Figure 11 As shown in the figure, the arrow represents the driving direction of the unmanned truck, point A represents the parking point (x, y) in the task when the task is issued, point B represents the effective position endpoint, point C represents the position of the rear axle center after the unmanned truck stops at the parking point, and point D represents the effective position starting point.

[0104] In the picture:

[0105] AC segment: The distance from the parking point to the center of the rear wheel, with positive values ​​along the driving path;

[0106] Section BC: Effective area, along the driving path, is a distance in front of the parking point. In this embodiment, it is taken as 4 meters based on experience, so that the vehicle can be detected in advance and the vehicle can be aligned.

[0107] CD segment: The effective area, along the driving path, is a distance after the parking point. In this embodiment, the empirical value is taken as 2 meters.

[0108] path_angle: driving path direction angle, field crane: -1.24; quay crane: starboard 1.9, port -1.9; since the parking point and vehicle positioning when the mission is launched are both latitude and longitude information, the distance can be converted to the vehicle coordinate system based on path_angle.

[0109] Therefore, along the driving direction, the effective position endpoint B = C + L BC L BC The distance to the end before point C; the effective starting point D = CL CD D is the distance after point C (i.e., dist_offset_r).

[0110] To improve the accuracy of the measurement, in S1, each group of reflectors includes three reflector bodies, which are arranged in a straight line and the line is parallel to the direction of the lane. In this embodiment, the interval between each reflector body is 1 meter.

[0111] Thus, in S2, using the center of the rear wheel of the unmanned truck as the positioning point, the positioning information of the rear wheel center is calculated based on the relative position of the positioning module and the center of the rear wheel. When the unmanned truck is operating, the system is first initialized; the vehicle speed is acquired; the histogram filter motion is updated; based on the acquired task information, parameters are reconfigured, and the histogram filter is initialized; the effective position area is calculated; finally, the current position of the unmanned truck is located through the positioning module. If the current position is within the effective position area, the subsequent S3 operation is executed; otherwise, the process returns to the histogram filter motion update step.

[0112] Please refer to Figure 12 As shown, S3 performs the inverse distance calculation for the quay crane / yard crane angle. It calculates the distance from the rear axle center to the parking point based on the identified reflector, and thus...

[0113]

[0114] In the formula, S is the distance from the rear axle center of the unmanned truck to the parking point, distance-offst - S1 represents the distance between the scanning module and the rear axle center of the unmanned truck along the vehicle's travel direction. y1, y2, and y3 represent the distances from the three reflector bodies to the scanning module along the vehicle's travel direction in the scanning module's coordinate system. S1 is the calibration value from the reflector body to the parking point.

[0115] The method for identifying the reflector body in S3 is as follows:

[0116] (1). flag is initially set to false;

[0117] (2). Pre-screen points that meet the verification conditions from the targets detected by the scanning module. The verification conditions include signal-to-noise ratio (SNR), radial distance (R), X coordinate, and Y coordinate. In this embodiment, the SNR is set to be greater than 30. The radial distance (R), X coordinate, and Y coordinate are set according to the specific box type (e.g., 40 feet, 45 feet, double 20 feet, and single 20 feet). For different box types, the position of the unmanned truck relative to the quay crane is within a certain range. This constraint can filter out some noise points.

[0118] (3) If the number of pre-screened points is between (num_min_, num_max_), continue to the next step; otherwise, exit. In this embodiment, the maximum number of points is 30 and the minimum number of points is 3.

[0119] (4) Calculate the distance between each pair of pre-screening points;

[0120] (5) Select three points from the pre-screening points to form a combination that satisfies the following conditions:

[0121] a. The distance d12 between point 1 and point 2 is within the range (L1-delta_range_, L1+delta_range_);

[0122] b. The distance d23 between point 2 and point 3 is within the range (L2-delta_range_, L2+delta_range_);

[0123] c. The distance d13 between point 1 and point 3 is within the range (L-delta_range_, L+delta_range_);

[0124] d. If on the shore bridge: the y-coordinate of point 1 < the y-coordinate of point 2 < the y-coordinate of point 3;

[0125] Where delta_range_ is the deviation threshold, which is 20cm in this embodiment. L, L1, and L2 are the prophetic conditions, which are the distances between any two of the three endpoints of the reflector.

[0126] (6) Iterate through all three-point combinations and find the optimal combination with the smallest error.

[0127] err1 = fabs(d13-L);

[0128] err2 = fabs(d12 - L1);

[0129] err3 = fabs(d23-L2);

[0130] err4 = fabs(d12 + d23 - d13);

[0131] err=max(max(err1, err2), err3)*err_weight_+err4*(1-err_weight_);

[0132] In this embodiment, the weight is set to 0.4, and the optimal combination of the three points obtained is the reflector body target.

[0133] In the case of container delivery, the parking point will vary depending on the position of the container on the trailer. Therefore, it is necessary to obtain the calibrated distance of the container on the trailer, box_rel, to prepare for subsequent container delivery distance correction.

[0134] Because the crane may sway during container loading, causing the container's position on the container to change, please refer to the following when retrieving the container: Figure 13 As shown, S3 also includes a box distance correction step to compensate for the vehicle's travel distance based on the box's position, resulting in:

[0135] (1) If boxpos_lidar > 0 and the current task type is box delivery, then execute the subsequent steps; otherwise, terminate. boxpos_lidar is the distance between the container body and the cab, which is measured by a laser rangefinder.

[0136] (2) dist_comp = boxpos_lidar - box_rel, where box_rel is the calibrated distance between the container body and the cab. Calculate fabs(dist_comp). If its value is less than 0.5, proceed to the next step; otherwise, return to step (1).

[0137] (3) s' = s + dist_comp, where s' is the corrected distance from the rear axle center of the unmanned truck to the parking point.

[0138] Because vehicle vibrations can cause fluctuations in detection values, interference cancellation is also included after the belt box correction. The interference cancellation method is as follows:

[0139] To initialize flag to false, the following conditions must be met simultaneously for flag to become true;

[0140] ① The angle inverse distance calculation for quay cranes / yard cranes has two consecutive distance outputs;

[0141] ② Each distance is within a certain range (output_range_limit_min_, output_range_limit_max_); output_range_limit_min_ refers to the theoretical minimum allowable distance of the reflector from the center of the rear axis, and output_range_limit_max_ refers to the theoretical maximum allowable distance of the reflector from the center of the rear axis.

[0142] ③ The distance change relative to the previous time step is within a certain range (delta_dist_limit_min, delta_dist_limit_max); in this embodiment, delta_dist_limit_min is -1m and output_range_limit_max is 2m.

[0143] The combination of three sets of verification conditions eliminates the possibility of large deviations in the output value of a single output, which could lead to inaccurate detection results.

[0144] When flag is true, it will be set to false only if the distance output calculated by the angle inverse distance of the quay crane / field crane is less than output_range_limit_min_. After that, flag will become true again only if the angle inverse distance calculation of the quay crane / field crane has two cumulative or two consecutive distance outputs, and conditions ② and ③ are met.

[0145] In this way, the vehicle speed information can be used to calculate the vehicle's travel distance, which is then used for filtering. The distance output from the previous test and the vehicle's travel distance are combined with the distance calculated from the current test to achieve automatic alignment.

[0146] In the several embodiments provided by this invention, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus and method embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the invention. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0147] In addition, the functional modules in the various embodiments of the present invention can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0148] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for active alignment under a port quay crane, characterized in that, include: S1. System Construction: Several sets of reflectors are fixed to the bottom of the quay crane, with each set of reflectors corresponding directly above each lane. The reflectors have triangular reflector bodies. The scanning module and positioning module are mounted on the unmanned truck and connected to the unmanned truck control terminal. The scanning module is set on the top of the unmanned truck, with the scanning direction upward. The back-end control terminal is configured with port map information. The back-end control terminal marks and stores the effective location area according to the back-end guidance information for different task types. S2. The unmanned truck control terminal receives the task information sent by the background control terminal and transmits the current location information and vehicle speed information in real time. When it is determined that the current location of the unmanned truck is in the effective location area, the scanning module is started to scan the reflector body. S3. The back-end control terminal identifies and confirms the position of the reflector body based on the scanning results of the scanning module, filters and combines the task information to calculate the distance that the vehicle needs to move in real time. S4. The unmanned truck control terminal executes the calculation results of S3 to enable the unmanned truck to achieve active alignment; In S2, the center of the rear wheel of the unmanned truck is used as the positioning point, and the positioning information of the rear wheel center is calculated based on the relative position of the positioning module and the center of the rear wheel of the vehicle. In S1, the effective position area includes the effective position endpoint B and the effective position start point D. Along the driving direction, the effective position endpoint B = C + L BC C represents the position of the center of the rear wheels after the unmanned truck arrives at the parking spot and stops, and L represents the position of the center of the rear wheels. BC The distance before point C; the effective starting point D = CL CD L CD This represents the distance after point C. In S1, each group of reflectors includes three reflector bodies arranged in a straight line parallel to the lane direction; then S3 performs the quay crane / yard crane angle inverse distance calculation, which calculates the distance from the rear axle center to the parking point based on the identified reflectors, thus... ； In the formula, S is the distance from the center of the rear axle of the unmanned truck to the parking point. This refers to the distance between the scanning module and the center of the rear axle of the unmanned truck along the vehicle's direction of travel. , , S1 represents the distance from the three reflector bodies to the scanning module along the vehicle's driving direction in the coordinate system of the scanning module, and S2 represents the calibration value from the geometric center of the three reflector bodies to the parking point. The method for identifying the reflector body in S3 is as follows: (1) flag is initially false; (2) Pre-screen points that meet the verification conditions from the targets detected by the scanning module; (3) If the number of pre-screened points is between the minimum and maximum point values, continue to the next step; otherwise, exit. (4) Calculate the distances L1, L2, and L3 between each pair of pre-screening points; (5) Select three points from the pre-screening points to form a combination that satisfies the following conditions: a. The distance d12 between point 1 and point 2 is within the range (L1-delta_range_, L1+delta_range_); b. The distance d23 between point 2 and point 3 is within the range (L2-delta_range_, L2+delta_range_); c. The distance d13 between point 1 and point 3 is within the range (L-delta_range_, L+delta_range_); d. If on the shore bridge: the y-coordinate of point 1 < the y-coordinate of point 2 < the y-coordinate of point 3; (6) Iterate through all three-point combinations and find the optimal combination with the smallest error. err1 = fabs(d13-L); err2 = fabs(d12 - L1); err3 = fabs(d23-L2); err4 = fabs(d12 + d23 - d13); err=max(max(err1, err2), err3)*err_weight_+err4*(1-err_weight_); The optimal combination of three points obtained is the reflector body target; S3 also includes a box distance correction step, so we have: (1) If boxpos_lidar > 0 and the current task type is box delivery, then execute the subsequent steps; otherwise, terminate. boxpos_lidar is the distance between the container body and the cab, which is measured by a laser rangefinder. (2) dist_comp = boxpos_lidar - box_rel, where box_rel is the calibrated distance between the container body and the cab. Calculate fabs(dist_comp). If its value is less than 0.5, proceed to the next step; otherwise, return to step (1). (3) s' = s + dist_comp, where s' is the corrected distance from the rear axle center of the unmanned truck to the parking point; Following bin correction is interference cancellation, which is performed as follows: To initialize flag to false, the following conditions must be met simultaneously for flag to become true; ① The angle inverse distance calculation for quay cranes / yard cranes has two consecutive distance outputs; ② The distance is always within a certain range (output_range_limit_min_, output_range_limit_max_); ③ The distance change relative to the previous time step is within a certain range (delta_dist_limit_min, delta_dist_limit_max); When flag is true, it will only be set to false if the distance output of the quay crane / field crane angle inverse distance calculation module is less than output_range_limit_min_. After that, flag will only become true again if the quay crane / field crane angle inverse distance calculation module has two cumulative or two consecutive distance outputs, and conditions ② and ③ are met.

2. A port quay crane active alignment system, employing the port quay crane active alignment method as described in claim 1, characterized in that, include: Several sets of reflectors are installed at the bottom of the quay bridge and are located directly above each lane. The reflectors have triangular reflector bodies. The unmanned truck control terminal is equipped with a positioning module and a scanning module. The positioning module locates the position information of the unmanned truck in real time, and the scanning module scans upward. The back-end control terminal stores port map information, operation task information, and effective location areas marked according to the operation task information. The back-end control terminal communicates with the unmanned truck control terminal in real time, dispatches operation tasks to the unmanned truck, and obtains the location information of the unmanned truck. After the unmanned truck enters the effective location area, it starts the scanning module to scan and identify the reflector location information, calculates the position that the unmanned truck needs to move in real time, and realizes active alignment.

3. The active alignment system under the quay crane as described in claim 2, characterized in that: Each set of reflectors includes three reflector bodies arranged in a straight line parallel to the lane direction; the unmanned truck control terminal also includes a laser rangefinder used to measure the distance between the container body and the cab.

4. The active alignment system under the quay crane as described in claim 2, characterized in that: The reflector includes a bracket that is magnetically attached to the bottom of the quay crane.

Images