Bridge crane operation attitude control method and control system

Abstract

The invention relates to a bridge crane operation attitude control method and a control system, which are used for accurately hoisting a heavy object in a narrow space, and the method comprises the following steps: obtaining operation area space constraint information to generate a space map, and determining a hoisting path and a path width; planning a driving track of the driving mechanism along the central line of the path, marking direction switching nodes, and calculating the walking distance of each straight line segment; determining an allowable maximum swing range according to the width of the lower-section path; a speed control scheme is formulated according to the walking distance and the swing space, and it is ensured that weight swing does not exceed the limit during direction switching. By actively planning the swing space and intelligently adjusting the motion parameters, the hoisting efficiency is remarkably improved while the safety is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of operation control of bridge cranes, and in particular to an operation posture control method and control system of a bridge crane. Background Art

[0002] As a common material handling equipment, the structure of a bridge crane mainly consists of a bridge spanning the working area, a lifting trolley that drives the bridge to move, a lifting trolley that moves along the bridge, and a sling suspended under the lifting trolley. This structural feature gives it significant advantages in large-scale material handling in fixed places such as factory workshops and warehouses.

[0003] However, when bridge cranes perform precision lifting operations in narrow spaces, the problem of swinging of the loaded objects due to inertia becomes particularly prominent. Traditional technologies mainly focus on how to prevent or reduce this swing. Common methods include improving the mechanical structure to increase system damping, using active anti-sway control systems to adjust the length of the lifting rope in real time, or deliberately reducing the operating speed during operation.

[0004] Although these methods can alleviate the swing problem to a certain extent, they have obvious limitations: improvements in mechanical structure often increase equipment complexity and cost; active anti-sway control requires extremely high sensor accuracy and control system response speed; and simply reducing the operating speed will significantly affect work efficiency; more importantly, existing technologies generally ignore the spatial constraints of the working environment and fail to organically combine anti-sway control with the geometric characteristics of the specific working path, resulting in difficulty in balancing operating efficiency and anti-sway accuracy in a narrow space. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problems of low efficiency and complex control caused by passive suppression of swing when bridge cranes operate in narrow spaces in the existing technology, and to provide a bridge crane operating posture control method and control system, which can significantly improve the lifting efficiency while ensuring safety by actively planning the swing space and intelligently adjusting the motion parameters in combination with path constraints.

[0006] To solve the above technical problems, the present invention provides a method for controlling the operating posture of a bridge crane for precise lifting of heavy objects in a narrow space, comprising the following steps: Obtain spatial constraint information of the operating area, generate a spatial map containing obstacle locations and safety boundaries, and determine the lifting path and path width based on the spatial map; Determine the travel trajectory of the bridge crane drive mechanism based on the hoisting path and path width, so that the drive mechanism runs along the center line of the hoisting path; In the lifting path, the position where the driving mechanism's movement direction changes is marked as a direction switching node, and the travel distance of the driving mechanism in each linear motion segment is determined based on the spacing between adjacent direction switching nodes; When the driving mechanism changes the direction of motion at the direction switching node, the maximum spatial range within which the weight is allowed to swing due to inertia is determined based on the path width of the next linear motion segment at the direction switching node; Based on the travel distance of the driving mechanism in each linear motion segment and the maximum spatial range allowed for the swing of the heavy object, the speed control scheme of the driving mechanism in each linear motion segment is determined so that when the driving mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted heavy object will not exceed the path width.

[0007] In one embodiment of the present invention, obtaining the spatial constraint information of the operation area specifically includes the following steps: Multiple steering detection units are deployed at the boundaries of the operating area. Each steering detection unit is independently configured to transmit and receive detection signals. The initial detection direction formed by the multiple steering detection units covers the entire range of the operating area, and the multiple steering detection units are synchronized and controlled through communication links. Each heading detection unit transmits a multi-frequency detection signal at a preset time interval and receives the environmental reflection signal. Based on the intensity deviation and delay time of the reflection signal, a preliminary detection point set is generated. Each detection point includes a coordinate position and signal characteristics. The signal characteristics consistency between the same detection points is verified based on different directional detection units. When the detection point density is lower than the preset threshold or the signal characteristics deviate from the standard value, the area is determined to be an abnormal area and a correction instruction is triggered; Adjust the detection direction of the relevant adjustable detection unit or increase the detection signal frequency, perform supplementary scanning, and obtain a corrected detection point set to eliminate detection blind spots; The corrected preliminary detection point set and the revised detection point set are integrated to generate a spatial map through spatial interpolation and boundary fitting. The spatial map locates the obstacle position and determines the safety boundary.

[0008] In one embodiment of the present invention, determining the hoisting path and path width based on the spatial map includes the following steps: Based on the obstacle location information in the spatial map, fit the minimum circumscribed geometric shape of each obstacle and calculate the minimum spacing between each geometric shape; Select the starting point and end point in the spatial map, and generate an initial path based on the minimum distance of the obstacle geometry. The initial path consists of several straight line segments and direction switching nodes. For each straight line segment of the initial path, scan the spatial map along its extension direction to obtain the obstacle distances on both sides of the segment; Calculate the minimum safety margin of the path according to the motion error compensation value of the bridge crane's drive mechanism; Subtract the minimum safety margin from the obstacle spacing to obtain the available width of the path segment, which is used as the final path width of the path segment.

[0009] In one embodiment of the present invention, determining a travel trajectory of a bridge crane drive mechanism based on a hoisting path and a path width so that the drive mechanism runs along a centerline of the hoisting path includes the following steps: Taking the starting point of the lifting path as the origin, a dynamic local coordinate system is established along the extension direction of the lifting path, and the direction of the coordinate system is updated at each direction switching node; During the movement of the driving mechanism along the lifting path, the lateral deviation between its actual position and the path centerline is monitored in real time; When there is lateral deviation in the driving mechanism, a correction instruction is generated to adjust the movement direction of the driving mechanism so that it moves closer to the center line; The corrected drive mechanism motion data is used as an executable trajectory instruction to ensure that it runs strictly along the center line of the lifting path.

[0010] In one embodiment of the present invention, the maximum spatial range in which the weight is allowed to swing due to inertia does not exceed 80% of the width of the path of the next motion segment.

[0011] In one embodiment of the present invention, determining a speed control scheme of the driving mechanism in each linear motion segment includes the following steps: When the travel distance of the linear motion segment is greater than the minimum safe braking distance, the speed control scheme is set to three-stage control, including: Initial acceleration stage: accelerating to the first speed v at the preset acceleration a1; Constant speed section: maintain the first speed v; Terminal deceleration stage: decelerate to a stop at the preset deceleration a2; The first speed v is determined according to the maximum spatial range within which the weight is allowed to swing at the direction switching node, and satisfies v≤√(a2·Lmax), where Lmax is the maximum spatial range within which the weight is allowed to swing.

[0012] In one embodiment of the present invention, when the travel distance of the linear motion segment is less than the minimum safe braking distance, the speed control scheme is set to a two-stage control, including: Acceleration stage: accelerating at the preset acceleration a1 to the adjusted second speed v'; Deceleration stage: decelerate to a stop at the preset deceleration rate a2; The adjusted speed v' satisfies: v'≤√[2a1a2D / (a1+a2)], and v'≤√(a2·Lmax), where D is the walking distance.

[0013] In one embodiment of the present invention, the mass of the hoisted object is obtained, and the acceleration a1 and deceleration a2 are dynamically adjusted according to the mass of the hoisted object, wherein: the greater the mass of the hoisted object, the smaller the absolute values ​​of the acceleration a1 and deceleration a2.

[0014] In one embodiment of the present invention, when the driving mechanism reaches the direction switching node, the following steps are further included: Real-time detection of the actual swing amplitude of the hoisted load; Comparing the actual swing amplitude with the maximum spatial range within which the weight is allowed to swing; If the actual swing amplitude exceeds the maximum spatial range, the motion control scheme of the drive mechanism is adjusted, including at least one of the following methods: Prolong the stopping time of the driving mechanism at the direction switching node, and wait until the swing of the heavy object decays to a safe range before starting the next motion segment; Reduce the speed of the drive mechanism for the next motion segment; Adjust the acceleration or deceleration of the next motion segment to reduce the swing amplitude of the weight.

[0015] In order to solve the above technical problems, the present invention further provides a bridge crane operation posture control system for implementing the above control method, comprising: The spatial information acquisition module is used to obtain the spatial constraint information of the operation area and generate a spatial map containing the location of obstacles and safety boundaries; Path planning module, used to determine the lifting path and path width based on the spatial map; A trajectory generation module is used to determine the travel trajectory of the bridge crane drive mechanism according to the hoisting path and the path width, so that the drive mechanism runs along the center line of the hoisting path; A node marking module is used to mark the position where the driving mechanism changes its motion direction as a direction switching node, and determine the travel distance of the driving mechanism in each linear motion segment based on the spacing between adjacent direction switching nodes; A swing space calculation module is used to determine the maximum spatial range within which the weight is allowed to swing due to inertia based on the path width of the next linear motion segment at the direction switching node; The motion control module is used to determine the speed control scheme of the driving mechanism in each linear motion segment based on the walking distance of the driving mechanism in each linear motion segment and the maximum spatial range allowed for the swing of the heavy object, so that when the driving mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted heavy object does not exceed the path width.

[0016] The above technical solution of the present invention has the following advantages over the prior art: The bridge crane operating posture control method described in the present invention shifts from passively suppressing swing to actively planning and managing the swing space. The method first accurately quantifies the available spatial range of the lifting path by establishing a spatial map that includes obstacle locations and safety boundaries. When determining the driving trajectory of the drive mechanism, special attention is paid to the processing of direction switching nodes - these nodes are not only turning points for changing the direction of motion, but also key decision points for swing control. By pre-calculating the distance of the straight-line motion segments between adjacent nodes and dynamically determining the maximum allowable swing space range based on the path width, the motion control parameters of the drive mechanism can be adjusted.

[0017] The core of the control strategy of the present invention is: instead of eliminating the swing, the swing is constrained within the range allowed by the path width through precise calculation in combination with path planning, thereby achieving natural kinetic energy conversion at the direction switching node; when the drive mechanism stops and turns, the swing energy of the heavy object is just absorbed by the path width without producing a cumulative effect.

[0018] This spatially adaptive control method not only avoids the complex modification of mechanical structures required by traditional anti-sway technology, but also breaks through the efficiency bottleneck caused by relying solely on deceleration. It significantly improves the lifting efficiency in narrow spaces while ensuring operational safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 is a flowchart of the steps of the bridge crane operation posture control method of the present invention; Figure 2 is a flow chart of the steps of obtaining spatial constraint information of an operation area according to the present invention; Figure 3 It is a flowchart of the steps of the intelligent path planning method based on spatial modeling of the present invention; Figure 4 It is a flow chart of the steps of the high-precision trajectory tracking control scheme of the present invention; Figure 5 is a flow chart of the steps of the adaptive speed control strategy based on the motion segment length of the present invention; Figure 6 It is a flowchart of the steps of the security control mechanism based on real-time detection of the present invention; Figure 7 It is a structural framework diagram of the bridge crane operation posture control system of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0021] Reference Figure 1 As shown, the present invention discloses a method for controlling the operating posture of a bridge crane, which is used for precise lifting of heavy objects in a narrow space, comprising the following steps: Obtain spatial constraint information of the operating area, generate a spatial map containing obstacle locations and safety boundaries, and determine the lifting path and path width based on the spatial map; This step is the foundation of the entire control method. Its core lies in digitizing the working environment to ensure that the planning of the lifting path conforms to the actual space constraints. Traditional anti-sway control often only focuses on the movement of the crane itself, ignoring the impact of environmental constraints on swing. The control method of the present invention can quantify the path width by establishing a precise spatial map, thereby providing key spatial parameters for subsequent swing control. This not only avoids collision risks, but also optimizes path selection and improves lifting efficiency.

[0022] Determine the travel trajectory of the bridge crane drive mechanism based on the hoisting path and path width, so that the drive mechanism runs along the center line of the hoisting path; Specifically, since the path width directly affects the allowable range of heavy object swing, the drive mechanism running along the center line can maximize the use of available space. If the drive mechanism deviates from the center line, the heavy object may swing closer to the obstacle, increasing the risk of collision. This step ensures that the crane always operates on the optimal path, provides a stable benchmark for subsequent swing control, reduces unnecessary adjustments, and improves operational stability.

[0023] In the lifting path, the position where the driving mechanism's movement direction changes is marked as a direction switching node, and the travel distance of the driving mechanism in each linear motion segment is determined based on the spacing between adjacent direction switching nodes; Specifically, the direction switching node is a key control point because the driving mechanism stops at the direction switching node. The weight will swing forward relative to the driving mechanism due to inertia. It happens that at the direction switching node, there is an obstacle in front, which makes the swing of the weight most likely to exceed the safety range. By marking these nodes and calculating the distance between adjacent nodes, the system can accurately divide the linear motion segments and provide a segmentation basis for subsequent speed control. Traditional methods often ignore the special influence of turning points, resulting in accumulated or sudden increase in swing. This method ensures that each segment of motion can be independently optimized through segmented control, thereby improving the fineness of control.

[0024] When the driving mechanism changes the direction of motion at the direction switching node, the maximum spatial range within which the weight is allowed to swing due to inertia is determined based on the path width of the next linear motion segment at the direction switching node; The core of this step is to dynamically adjust the allowable swing space. Since the widths of different path segments may vary, traditional fixed anti-sway strategies may lead to excessive deceleration or uncontrolled swinging. This method adjusts the allowable swing range in real time according to the path width of the next segment, ensuring that the heavy object does not exceed the limit of the next path segment when turning. This can fully utilize the space while avoiding the impact of overly conservative control strategies on efficiency.

[0025] Based on the travel distance of the drive mechanism in each linear motion segment and the maximum spatial range allowed for the weight to swing, the speed control scheme of the drive mechanism in each linear motion segment is determined so that when the drive mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted weight does not exceed the path width; The final step integrates all previous calculations and achieves precise anti-sway through intelligent speed control. Traditional methods typically use fixed deceleration or open-loop control, which is difficult to adapt to different load and path conditions. This method combines the travel distance and the allowable swing range to dynamically adjust the speed curve, ensuring that the heavy object naturally decelerates when turning and the swing energy is absorbed by the path width rather than forcibly suppressed. This ensures safety while avoiding the efficiency loss caused by frequent starts and stops.

[0026] The technical solution of the present application realizes refined control of the lifting process of the bridge crane through environmental perception, path optimization, segmented control and dynamic speed adjustment. Compared with traditional anti-sway technology, the present invention actively manages swing rather than passively suppresses it, and makes full use of the path width as a swing buffer space to avoid excessive reliance on mechanical damping or forced deceleration; and adopts a segmented dynamic optimization strategy to formulate differentiated control strategies for different straight segments and turning points to improve adaptability; deeply integrates environmental perception and motion control to match the anti-sway strategy with the specific operation scenario to achieve a balance between safety and efficiency.

[0027] Based on the above embodiments, the core technology of the present invention lies in managing the swing of heavy objects by combining environmental perception and intelligent control. However, in actual engineering applications, the key step of "obtaining spatial constraint information of the working area" may have the problem of insufficient environmental perception accuracy. Traditional environmental detection methods often use fixed sensors or single detection equipment, which are prone to detection blind spots in complex and narrow spaces and are difficult to cope with dynamically changing working environments. This will lead to insufficient accuracy of the generated spatial map, which in turn affects the effectiveness of subsequent path planning and anti-sway control.

[0028] To solve this problem, the present invention also proposes a technical solution for obtaining spatial constraint information of the operation area to generate a spatial map containing obstacle locations and safety boundaries. Figure 2 As shown, including: Deploy steering detection units: Multiple steering detection units are deployed at the boundaries of the work area. Each steering detection unit is independently configured to transmit and receive detection signals. The initial detection direction formed by multiple steering detection units covers the entire range of the work area, and multiple steering detection units are synchronized and controlled through communication links. High-precision environmental modeling is achieved through a distributed intelligent detection system. The solution first deploys multiple adjustable detection units at the boundary of the operating area. These units not only have the ability to independently send and receive detection signals, but can also work together through communication links. This distributed architecture ensures that the detection range can fully cover the entire operating area, avoiding the inherent field of view limitations of a single sensor.

[0029] Controlling the steering detection units to perform sequential spatial scanning: Each steering detection unit transmits a multi-frequency detection signal at a preset time interval and receives an environmental reflection signal. Based on the intensity deviation and delay time of the reflection signal, a preliminary detection point set is generated, where each detection point includes a coordinate position and signal characteristics. In specific implementation, each detection unit transmits a detection signal containing multiple frequency bands at a preset time interval. This multi-frequency detection strategy can effectively distinguish obstacles of different materials and improve the recognition of environmental characteristics. The preliminary detection point set generated based on the intensity deviation and delay time of the reflected signal not only contains spatial coordinate information, but also records the signal characteristics of the object surface, providing an important basis for subsequent data verification.

[0030] Identify abnormal areas within the initial detection point concentration: Verify the consistency of signal characteristics between the same detection points based on different directional detection units. When the detection point density is lower than the preset threshold or the signal characteristics deviate from the standard value, the area is determined to be abnormal and a correction instruction is triggered. To ensure the reliability of detection data, a data verification mechanism is specially designed. By comparing the consistency of signal characteristics of different detection units at the same detection point, abnormal data can be identified and eliminated. When the system detects that the density of detection points in a certain area is insufficient or the signal characteristics are abnormal, it will intelligently trigger the correction process. This process reflects the system's adaptive ability.

[0031] Perform dynamic repeated detection of abnormal areas: adjust the detection direction of the relevant adjustable detection unit or increase the detection signal frequency, perform supplementary scanning, and obtain a corrected detection point set to eliminate detection blind spots; obtain more complete spatial data through supplementary scanning. This dynamic adjustment mechanism effectively solves the detection blind spot problem that is prone to occur in traditional methods when facing complex structures or reflective surfaces, and significantly improves the robustness of environmental modeling.

[0032] Generate spatial map: Integrate the corrected preliminary detection point set and the revised detection point set, and generate a spatial map through spatial interpolation and boundary fitting. The spatial map locates the obstacle position and determines the safety boundary; After completing data collection and verification, the system generates the final spatial map through spatial interpolation algorithms and boundary fitting technology. This processing fully considers the actual needs of industrial sites: spatial interpolation can smoothly process discrete detection point data and build a continuous environmental model; boundary fitting accurately calibrates the outlines of obstacles and safe working boundaries.

[0033] Compared with conventional detection methods, the method of this embodiment has three significant advantages: first, full coverage scanning without blind spots is achieved through multi-unit collaborative detection; second, data reliability is ensured by using multi-frequency signals and cross-validation; third, the adaptive correction mechanism ensures the stable operation of the system in complex environments; and the generated spatial map can accurately reflect the real constraints of the operating area, providing a reliable data basis for path planning and anti-sway control.

[0034] From a technical mechanism perspective, each design point of the method of this embodiment specifically addresses key issues in environmental perception. The distributed detection unit layout solves the spatial coverage problem, the multi-frequency signal design improves feature recognition capabilities, the dynamic correction mechanism ensures data integrity, and intelligent data processing optimizes map generation quality. The synergistic effect of these technical features enables the entire system to stably acquire high-precision spatial constraint information in actual industrial environments, thereby effectively supporting the implementation of the control method described in this invention.

[0035] It should be noted that the technical solution of the present application is different from the existing technology in generating trajectory paths. Because the swing space of the heavy object must be accurately reserved during path planning, the present application not only needs to determine the lifting path based on the spatial map, but also needs to analyze the path width in order to convert the spatial map data into an executable lifting path planning solution of the present invention.

[0036] Traditional path planning methods often simply treat obstacles as points or regular geometric bodies, ignoring the mechanical errors and dynamic swing characteristics of the crane's actual movement. This may cause the planned path to have safety hazards or be overly conservative during actual execution. This is especially true for large equipment such as bridge cranes. The inherent characteristics of their drive mechanisms, such as positioning errors and transmission clearances, as well as the swing characteristics of the load, will significantly affect the actual available safe operating space.

[0037] To solve this key technical problem, the present invention also proposes a set of intelligent path planning methods based on precise spatial modeling. Figure 3 As shown, the method includes the following steps: Extracting obstacle outlines from spatial maps: First, the generated high-precision spatial map is deeply processed. By fitting the minimum circumscribed geometric shapes of obstacles, complex environmental constraints are converted into computable geometric relationships. This processing not only retains the accuracy advantage of the original spatial map, but also simplifies the subsequent computational complexity through geometric abstraction. When calculating the minimum spacing between geometric shapes, the system comprehensively considers three-dimensional spatial relationships to ensure that the planned path has sufficient safety space at any altitude.

[0038] This processing method based on minimum circumscribed geometry is particularly suitable for regular-shaped obstacles commonly found in industrial sites, such as equipment and columns, and can maximize the available working space while ensuring safety.

[0039] Determining the initial feasible path: When generating the initial path, the system automatically generates an optimal path consisting of straight segments and direction switching nodes based on the geometric information of the starting point, end point, and obstacles. This method pays special attention to the straight segment characteristics of the path. This is to adapt to the basic movement mode of the bridge crane and reduce unnecessary steering operations.

[0040] Calculate the dynamic width of each path segment: For each linear path segment, the system performs a spatial scan along its extension direction to accurately obtain the actual obstacle spacing on both sides of the path segment. This step fully utilizes the fine spatial map data provided by the present invention to achieve millimeter-level gap detection capability, providing accurate input for subsequent safety margin calculations.

[0041] Motion error compensation: Taking into account the various uncertainties in the actual operation of bridge cranes, the concept of motion error compensation value is introduced. This parameter comprehensively considers the mechanical characteristics such as the positioning accuracy of the drive mechanism, the backlash of the transmission system, the structural deformation, and the electrical characteristics such as the control system response delay, and is dynamically adjusted based on experimental data or historical operation data. The minimum safety margin calculated based on this compensation value can effectively cover the deviations that may occur in the equipment's own movement, fundamentally avoiding safety hazards caused by mechanical errors.

[0042] Generate the final lifting path and path width: Subtract this dynamic safety margin from the precisely measured obstacle distance. The final path width ensures absolute safety while avoiding the path narrowing problem caused by over-conservativeness in traditional methods.

[0043] From the perspective of technical mechanism, each technical feature in this embodiment specifically solves the key problems in path planning. Among them: minimum circumscribed geometric fitting ensures the accuracy of environmental modeling, straight line segment scanning realizes the precise measurement of path gaps, and motion error compensation makes up for the gap between theory and practice. The organic combination of these technical features makes the planned lifting path conform to the equipment motion characteristics and fully utilizes the available space.

[0044] Especially in narrow space operation scenarios, this refined path planning method can significantly improve operating efficiency, which means that the crane can operate at a higher speed while still ensuring safety, directly improving the overall efficiency of the lifting operation. At the same time, since the path width calculation already includes compensation for equipment motion errors, when actually executing the control method described in the present invention, the system can more confidently operate close to the edge of the planned path, leaving more room for the swing of the hoisted load.

[0045] A key issue in actual implementation is ensuring that the drive mechanism follows the planned centerline trajectory. Traditional control methods typically employ absolute position control within a global coordinate system, which can easily lead to cumulative errors over long distances or after multiple turns. Especially when operating in confined spaces, even slight trajectory deviations can result in insufficient swing space for the load and even create a collision risk. Furthermore, as a large piece of machinery, bridge cranes are subject to mechanical characteristics such as drive wheel slip and transmission system backlash, which can affect trajectory tracking accuracy. Traditional control methods often fail to fully account for these practical factors.

[0046] In order to solve this key technical problem, the present invention also proposes a high-precision trajectory tracking control scheme in a dynamic local coordinate system. Figure 4 As shown, the control scheme includes the following steps: Establishing a path centerline reference coordinate system: A dynamic local coordinate system with the path starting point as the origin is used to transform the complex global positioning problem into a relatively simple local trajectory tracking problem. The design of updating the coordinate system direction at each direction switching node effectively eliminates the error accumulation problem caused by multiple turns in traditional methods. This dynamic reference frame conversion method is particularly suitable for equipment such as bridge cranes that require frequent turning. It can always maintain the consistency of control instructions with the current movement direction, greatly improving the control accuracy during the turning process.

[0047] Calculating the real-time offset of the drive mechanism: During actual operation, the system uses high-precision sensors to monitor its lateral deviation from the path centerline in real time. Unlike traditional methods that only monitor positional deviation, this solution pays special attention to this critical parameter, lateral deviation, as it is crucial for managing the swing space of the load.

[0048] Dynamically adjust the drive mechanism's direction of motion: When lateral deviation is detected, the system generates intelligent correction instructions. This correction is not a simple on-off control, but rather a gradual adjustment based on the size and trend of the deviation, ensuring that the drive mechanism smoothly moves toward the centerline. This control strategy avoids trajectory oscillation caused by overshoot and can quickly eliminate deviations, making it particularly suitable for the precise control of large-inertia systems such as bridge cranes.

[0049] Outputting the final driving trajectory: The process of converting corrected motion data into executable trajectory commands fully considers the mechanical characteristics of the bridge crane and integrates physical constraints such as the drive mechanism's acceleration capability and maximum speed to generate control commands that both meet equipment performance and accurately track the centerline. This physically constrained command generation method fundamentally avoids the common "feasible command, but equipment cannot execute" problem in traditional control, greatly improving the practicality of control. The resulting strict centerline tracking provides a solid foundation for swing space management, ensuring that the actual swing range is always controlled within the precalculated safety zone.

[0050] From the perspective of technical mechanism, each technical feature of the above-mentioned control scheme specifically solves the key problems in trajectory tracking. Among them: the establishment of a dynamic local coordinate system eliminates error accumulation, real-time lateral deviation monitoring grasps the core of control, intelligent correction instructions achieve smooth adjustment, and instruction generation based on physical constraints ensures feasibility; the synergistic effect of these technical features enables large equipment such as bridge cranes to achieve trajectory tracking accuracy comparable to that of precision machine tools. Especially when operating in narrow spaces, this high-precision trajectory control can make full use of the path width, providing the maximum safe swing space for hoisting heavy objects, directly improving operational efficiency and safety.

[0051] In actual applications, the maximum spatial range in which the heavy object is allowed to swing due to inertia is set to no more than 80% of the width of the next motion segment path. The determination of this proportion parameter is based on in-depth dynamic analysis and a large number of engineering practice verifications. From the physical mechanism point of view, the 80% proportion setting has multiple technical advantages: First, this proportion reserves a 20% safety buffer space for emergencies, which can effectively deal with uncertain factors such as sensor errors, control delays, and environmental interference; secondly, the 80% utilization rate can not only ensure the efficient use of spatial resources, but also avoid the control risks caused by being too close to the boundary; most importantly, this ratio matches the swing characteristics of the typical load of the bridge crane, which can ensure that the kinetic energy of the heavy object is fully absorbed without rebound when the direction is switched.

[0052] When the drive mechanism can be precisely controlled to run along the centerline, 80% path width utilization means a 10% safety margin is retained on each side. From an engineering implementation perspective, the 80% parameter setting fully takes into account various disturbance factors in actual operations. For example, when the path width is 1 meter, the allowable swing range is 0.8 meters. This means that even if there is a positioning error or measurement deviation of 10 centimeters, there is still a 10-centimeter safety margin. This design makes the system robust and able to adapt to the operational needs under different working conditions. In addition, the 80% proportional relationship also enables operators to intuitively judge the safety status. When the swing amplitude is detected to be close to this threshold, the system can provide early warning or automatically intervene to adjust, greatly improving the safety of the operation.

[0053] The present invention proposes a motion control scheme for determining the driving mechanism based on the walking distance and the allowable swing range. In actual engineering applications, how to formulate the optimal speed curve for motion segments of different lengths has become a technical problem that needs to be solved urgently. Traditional control methods often adopt fixed speed or simple segmented control, which cannot be dynamically adjusted according to the actual path characteristics and load characteristics, resulting in either low operating efficiency or excessive braking during short-distance movement, causing heavy objects to swing violently.

[0054] In response to this key technical problem, the present invention proposes an adaptive speed control strategy based on the length of the motion segment. Figure 5 As shown in the figure, a three-stage speed control scheme is designed for long-distance motion segments (i.e., the distance of the motion segment is greater than the minimum safe braking distance), which fully considers the dynamic characteristics of the bridge crane and the swing law of the heavy object; The initial acceleration stage uses a preset acceleration a1 to ensure a smooth start-up process and avoid violent swinging of the load due to excessive instantaneous acceleration. The uniform speed stage maintains a scientifically calculated first speed v. This speed value is precisely calculated based on the maximum spatial range of swing allowed at the direction switching node, Lmax, and satisfies the key constraint of v≤√(a2·Lmax). From a physical perspective, this speed upper limit formula ensures that the swing amplitude of the load will not exceed the preset safety range during the deceleration phase. The terminal deceleration stage uses a preset deceleration a2, which brings the drive mechanism to a smooth stop at the direction switching node while keeping the load swing within a safe range. This three-stage control ensures both operational efficiency and safety during steering, making it particularly suitable for precise control of long-distance linear motion segments.

[0055] A two-stage optimization control scheme is proposed for short-distance movement segments (i.e., the distance of the movement segment is less than the minimum safe braking distance). Within a limited space, the control strategy is intelligently adjusted to organically connect the acceleration and deceleration processes. The adjusted second speed v' is determined by dual constraints: it must satisfy v'≤√[2a1a2D / (a1+a2)] to ensure that the entire acceleration and deceleration process can be completed within the limited walking distance D, and it must satisfy v'≤√(a2·Lmax) to ensure swing safety. The control strategy is dynamically adjusted according to different working conditions. The two-stage control avoids the embarrassing situation of starting to decelerate before the speed is increased during short-distance movement. The optimal operating speed under a given distance is found through optimization calculation, which maximizes the efficiency of short-distance lifting.

[0056] From the perspective of control mechanism, the constraint formulas for the first speed v and the second speed v' are derived from an in-depth analysis of the dynamics of the simple pendulum system, ensuring that during the deceleration phase, when the kinetic energy of the heavy object's swing is completely converted into potential energy, the swing amplitude is exactly equal to Lmax. This control parameter calculation based on the physical model has higher reliability and adaptability than the traditional empirical setting method.

[0057] In actual applications, the applicable plan is intelligently selected based on the real-time calculated walking distance to ensure that the optimal speed control strategy can be adopted regardless of long-distance transportation or short-distance adjustment. This adaptive feature greatly improves the system's work efficiency, especially in hoisting operations on complex paths, which can save operation time. At the same time, because the speed plan strictly follows physical constraints, the swing of heavy objects is always controlled within a safe range, significantly improving the safety of operations in narrow spaces.

[0058] In actual engineering applications, different masses of hoisted objects will also have a certain dynamic impact on motion control. Traditional control methods usually use fixed acceleration and deceleration parameters. This static setting method cannot adapt to changes in working conditions from light loads to heavy loads. When the mass of the hoisted object is large, the fixed parameters may cause excessive inertia force during starting and braking, which will not only aggravate the swing of the weight and increase the risk of collision, but may also cause additional load on the mechanical structure of the crane and affect the service life of the equipment. Especially in confined space working environments, the dynamic impact brought about by this mass change is more significant. There is an urgent need for an intelligent control strategy that can adapt to load changes.

[0059] In response to this key technical problem, the present invention also proposes a motion dynamic parameter adjustment scheme based on mass perception. First, the real-time mass information of the hoisted heavy object is obtained through reliable methods such as weighing sensors or torque estimation. This step provides key input parameters for subsequent intelligent control. According to the basic principles of physics, the mass of the heavy object directly affects the inertial characteristics of the system: the greater the mass, the greater the inertial force generated by the same acceleration. Based on this mechanism, this embodiment proposes a dynamic control method that reduces the absolute values ​​of acceleration a1 and deceleration a2 accordingly as the mass of the hoisted heavy object increases. This negative correlation adjustment strategy has a solid physical basis and can ensure that the inertial force generated by the system is always within a reasonable range under different mass loads.

[0060] From a control implementation perspective, this dynamic adjustment scheme is achieved by establishing a mass-acceleration mapping relationship. Specifically, the system presets a baseline acceleration parameter and then dynamically adjusts it based on the ratio of the current load mass to the rated load. For example, when the hoisted weight reaches 80% of the rated load, the acceleration may be adjusted to 60% of the baseline value. This nonlinear adjustment relationship fully considers the actual torque characteristics of the crane motor and the load, ensuring both safety and efficiency under heavy load conditions. It is particularly noteworthy that the adjustment of deceleration a2 is usually more cautious than that of acceleration a1. This is because the kinetic energy during braking needs to be absorbed by the swing space, and excessive deceleration may cause the weight to swing beyond the safe range.

[0061] After the system selects a three-stage or two-stage control scheme based on the length of the motion segment, it implements dynamic parameter adjustment of the acceleration and deceleration bumps according to different load masses, ensuring that these control schemes can adapt to different load conditions. For example, under heavy load conditions, although the maximum operating speed v may decrease due to the reduction in deceleration a2, the acceleration a1 is also reduced accordingly, making the entire motion process smoother and the swing amplitude of the heavy object effectively controlled. This synergistic effect enables the system to maintain excellent control performance over the entire operating range.

[0062] From the perspective of engineering application effects, by dynamically adjusting the acceleration parameters, the structural dynamic load under heavy load conditions is effectively reduced, thereby extending the service life of the equipment. Secondly, the adaptive deceleration control ensures that heavy objects of different masses can stop smoothly at the direction switching nodes, and the swing amplitude is always controlled within a safe range. Most importantly, this mass-adaptive control strategy greatly reduces the adjustment burden on operators, and the system can automatically adapt to various lifting conditions, significantly improving the reliability and safety of operations in narrow spaces.

[0063] In actual operations, even with precise feedforward control, the actual swing may still exceed the expected range due to unexpected factors (such as gusts of wind, load shaking, or mechanical transmission clearance, etc.). Especially at the critical position of the direction switching node, the traditional open-loop control method cannot cope with this real-time change, which may cause two risks: first, forcibly starting the next motion segment will aggravate the swing and cause a collision; second, overly conservative waiting will greatly reduce work efficiency. This control blind spot is particularly prominent when working in a narrow space, and a closed-loop control strategy that can be monitored in real time and dynamically adjusted is urgently needed.

[0064] In response to this technical problem, the present invention also proposes a safety control mechanism based on real-time detection, referring to Figure 6 As shown, the following steps are included: First, a high-precision swing monitoring system is deployed at the key location of the direction switching node. Through detection methods such as visual sensors, inertial measurement units or laser rangefinders, the actual swing amplitude of the suspended load is obtained in real time. This real-time feedback forms the basis of closed-loop control, enabling the system to break through the limitations of traditional open-loop control.

[0065] In terms of technical implementation, the system will compare the real-time detected swing data with the determined maximum allowable spatial range. This comparison process is not a simple threshold judgment, but a comprehensive consideration of multi-dimensional information such as swing phase and motion trend to ensure the accuracy of the decision.

[0066] When swing overrun is detected, three intelligent adjustment strategies are provided. These strategies are dynamically selected according to the degree of swing overrun and the operating scenario. Among them: the strategy of extending the stop time utilizes the natural attenuation characteristics of the simple pendulum system and consumes the swing energy by waiting for the system damping. This seemingly simple method is actually the most basic solution that conforms to the laws of physics and is particularly suitable for situations with slight overruns; the strategy of reducing the speed of the next motion segment is based on the proportional relationship between the swing amplitude and the square of the motion speed. The safety of subsequent motion is ensured by appropriate speed reduction. This adjustment method achieves a good balance between time efficiency and control effect; the most sophisticated is the acceleration adjustment strategy, which fundamentally reduces new excitation sources by modifying the motion parameters.

[0067] From the perspective of engineering implementation, the real-time detection link adopts multi-sensor fusion technology to ensure that the swing data can be reliably obtained under various lighting and working conditions. The decision-making algorithm is not a simple binary judgment. A fuzzy control rule library can be established to intelligently select the adjustment method based on factors such as the degree of overlimit and equipment status.

[0068] From the perspective of technical effects, the innovation of the real-time detection safety control mechanism is reflected in three aspects: first, safety is improved. Real-time monitoring and dynamic adjustment fundamentally eliminate the possibility of uncontrolled swinging; second, efficiency is optimized. The system will select the most economical adjustment strategy according to actual conditions to avoid unnecessary operation interruptions; and most importantly, reliability is enhanced. This control system with self-healing capabilities greatly reduces the need for operator intervention.

[0069] Reference Figure 7 As shown, in order to implement the above method, the present invention also provides a bridge crane operation posture control system for implementing the above control method, comprising: The spatial information acquisition module is used to obtain the spatial constraint information of the operation area and generate a spatial map containing the location of obstacles and safety boundaries; Path planning module, used to determine the lifting path and path width based on the spatial map; A trajectory generation module is used to determine the travel trajectory of the bridge crane drive mechanism according to the hoisting path and the path width, so that the drive mechanism runs along the center line of the hoisting path; A node marking module is used to mark the position where the driving mechanism changes its motion direction as a direction switching node, and determine the travel distance of the driving mechanism in each linear motion segment based on the spacing between adjacent direction switching nodes; A swing space calculation module is used to determine the maximum spatial range within which the weight is allowed to swing due to inertia based on the path width of the next linear motion segment at the direction switching node; The motion control module is used to determine the speed control scheme of the driving mechanism in each linear motion segment based on the walking distance of the driving mechanism in each linear motion segment and the maximum spatial range allowed for the swing of the heavy object, so that when the driving mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted heavy object does not exceed the path width.

[0070] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for controlling the operating posture of a bridge crane, used for precise lifting of heavy objects in a narrow space, characterized in that: The following steps are involved: Obtain spatial constraint information of the operating area, generate a spatial map containing obstacle locations and safety boundaries, and determine the lifting path and path width based on the spatial map; Determine the travel trajectory of the bridge crane drive mechanism based on the hoisting path and path width, so that the drive mechanism runs along the center line of the hoisting path; In the lifting path, the position where the driving mechanism's movement direction changes is marked as a direction switching node, and the travel distance of the driving mechanism in each linear motion segment is determined based on the spacing between adjacent direction switching nodes; When the driving mechanism changes the direction of motion at the direction switching node, the maximum spatial range within which the weight is allowed to swing due to inertia is determined based on the path width of the next linear motion segment at the direction switching node; Based on the travel distance of the driving mechanism in each linear motion segment and the maximum spatial range allowed for the swing of the heavy object, the speed control scheme of the driving mechanism in each linear motion segment is determined so that when the driving mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted heavy object will not exceed the path width.

2. The method for controlling the operating posture of a bridge crane according to claim 1, wherein: The acquisition of spatial constraint information of the operation area specifically includes the following steps: Multiple steering detection units are deployed at the boundaries of the operating area. Each steering detection unit is independently configured to transmit and receive detection signals. The initial detection direction formed by the multiple steering detection units covers the entire range of the operating area, and the multiple steering detection units are synchronized and controlled through communication links. Each heading detection unit transmits a multi-frequency detection signal at a preset time interval and receives the environmental reflection signal. Based on the intensity deviation and delay time of the reflection signal, a preliminary detection point set is generated. Each detection point includes a coordinate position and signal characteristics. The signal characteristics consistency between the same detection points is verified based on different directional detection units. When the detection point density is lower than the preset threshold or the signal characteristics deviate from the standard value, the area is determined to be an abnormal area and a correction instruction is triggered; Adjust the detection direction of the relevant adjustable detection unit or increase the detection signal frequency, perform supplementary scanning, and obtain a corrected detection point set to eliminate detection blind spots; The corrected preliminary detection point set and the revised detection point set are integrated to generate a spatial map through spatial interpolation and boundary fitting. The spatial map locates the obstacle position and determines the safety boundary.

3. The method for controlling the operating posture of a bridge crane according to claim 2, wherein: The method of determining the hoisting path and path width based on the spatial map includes the following steps: Based on the obstacle location information in the spatial map, fit the minimum circumscribed geometric shape of each obstacle and calculate the minimum spacing between each geometric shape; Select the starting point and end point in the spatial map, and generate an initial path based on the minimum distance of the obstacle geometry. The initial path consists of several straight line segments and direction switching nodes. For each straight line segment of the initial path, scan the spatial map along its extension direction to obtain the obstacle distances on both sides of the segment; Calculate the minimum safety margin of the path according to the motion error compensation value of the bridge crane's drive mechanism; Subtract the minimum safety margin from the obstacle spacing to obtain the available width of the path segment, which is used as the final path width of the path segment.

4. The method for controlling the operating posture of a bridge crane according to claim 1, wherein: Determining the travel trajectory of the bridge crane drive mechanism according to the hoisting path and the path width so that the drive mechanism runs along the center line of the hoisting path includes the following steps: Taking the starting point of the lifting path as the origin, a dynamic local coordinate system is established along the extension direction of the lifting path, and the direction of the coordinate system is updated at each direction switching node; During the movement of the driving mechanism along the lifting path, the lateral deviation between its actual position and the path centerline is monitored in real time; When there is lateral deviation in the driving mechanism, a correction instruction is generated to adjust the movement direction of the driving mechanism so that it moves closer to the center line; The corrected drive mechanism motion data is used as an executable trajectory instruction to ensure that it runs strictly along the center line of the lifting path.

5. The method for controlling the operating posture of a bridge crane according to claim 1, wherein: The maximum spatial range in which the weight is allowed to swing due to inertia does not exceed 80% of the width of the path of the next motion segment.

6. The method for controlling the operating posture of a bridge crane according to claim 1, wherein: Determine the speed control scheme of the drive mechanism in each linear motion segment, including the following steps: When the travel distance of the linear motion segment is greater than the minimum safe braking distance, the speed control scheme is set to three-stage control, including: Initial acceleration stage: accelerating to the first speed v at the preset acceleration a1; Constant speed section: maintain the first speed v; Terminal deceleration stage: decelerate to a stop at the preset deceleration a2; The first speed v is determined according to the maximum spatial range within which the weight is allowed to swing at the direction switching node, and satisfies v≤√(a2·Lmax), where Lmax is the maximum spatial range within which the weight is allowed to swing.

7. The method for controlling the operating posture of a bridge crane according to claim 6, wherein: When the travel distance of the linear motion segment is less than the minimum safe braking distance, the speed control scheme is set to two-stage control, including: Acceleration stage: accelerating at the preset acceleration a1 to the adjusted second speed v'; Deceleration stage: decelerate to a stop at the preset deceleration rate a2; The adjusted speed v' satisfies: v'≤√[2a1a2D / (a1+a2)], and v'≤√(a2·Lmax), where D is the walking distance.

8. The method for controlling the operating posture of a bridge crane according to claim 6 or 7, wherein: The mass of the hoisted object is obtained, and the acceleration a1 and the deceleration a2 are dynamically adjusted according to the mass of the hoisted object, wherein: the greater the mass of the hoisted object, the smaller the absolute values ​​of the acceleration a1 and the deceleration a2.

9. The method for controlling the operating posture of a bridge crane according to claim 1, wherein: When the driving mechanism reaches the direction switching node, the following steps are also included: Real-time detection of the actual swing amplitude of the hoisted load; Comparing the actual swing amplitude with the maximum spatial range within which the weight is allowed to swing; If the actual swing amplitude exceeds the maximum spatial range, the motion control scheme of the drive mechanism is adjusted, including at least one of the following methods: Prolong the stopping time of the driving mechanism at the direction switching node, and wait until the swing of the heavy object decays to a safe range before starting the next motion segment; Reduce the speed of the drive mechanism for the next motion segment; Adjust the acceleration or deceleration of the next motion segment to reduce the swing amplitude of the weight.

10. A bridge crane operating posture control system, used to implement the control method according to any one of claims 1 to 9, characterized in that: include: The spatial information acquisition module is used to obtain the spatial constraint information of the operation area and generate a spatial map containing the location of obstacles and safety boundaries; Path planning module, used to determine the lifting path and path width based on the spatial map; A trajectory generation module is used to determine the travel trajectory of the bridge crane drive mechanism according to the hoisting path and the path width, so that the drive mechanism runs along the center line of the hoisting path; A node marking module is used to mark the position where the driving mechanism changes its motion direction as a direction switching node, and determine the travel distance of the driving mechanism in each linear motion segment based on the spacing between adjacent direction switching nodes; A swing space calculation module is used to determine the maximum spatial range within which the weight is allowed to swing due to inertia based on the path width of the next linear motion segment at the direction switching node; The motion control module is used to determine the speed control scheme of the driving mechanism in each linear motion segment based on the walking distance of the driving mechanism in each linear motion segment and the maximum spatial range allowed for the swing of the heavy object, so that when the driving mechanism stops at the direction switching node and switches the motion direction, the swing range of the hoisted heavy object does not exceed the path width.

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