Hook detection system

Abstract

The invention relates to a crane system (2) comprising: a trolley (7) for supporting a load and movable in a horizontal direction to provide movement of the load in the horizontal direction, respectively; and a carrying member (10) supported by the trolley (7) and configured to carry a load in use. The sensors (22, 24) are used to measure an angle of the load bearing member (10) relative to the trolley (7), and the controller (20) is configured to provide a dynamic model of the trolley (7) to determine an estimated angle of the load bearing member (10) during movement of the trolley (7). The controller (20) is configured to compare the estimated angle to the measured angle and to control the horizontal movement of the trolley (7) in accordance with the comparison.

Description

[0001] This disclosure relates to a hook detection system and method for crane systems. Background Technology

[0002] In overhead cranes or bridge cranes, the lifting mechanism is capable of moving along the bridging member. Ropes or cables are suspended from the lifting mechanism to support the load. During use, the load may snag on another object. This can cause damage to the load, ropes or cables, the object, and / or the user (e.g., if the load becomes unhooked and moves uncontrollably).

[0003] The existing technical solution can be found in WO 2013 / 041770. In this document, the system measures the oscillation or "swing" of the rope during use. This swing value is then compared with a predetermined threshold derived experimentally.

[0004] The inventors have identified numerous problems with existing solutions. Because the predetermined thresholds are derived experimentally, the systems are prone to error and can only be used within systems where parameters have already been calculated. For example, each crane system exhibits different dynamic characteristics, and therefore experimental thresholds must be determined accordingly for each system. Determining such experimental values ​​is time-consuming. Consequently, existing systems are not universal and are difficult to adapt to different crane systems.

[0005] The present invention aims to overcome or improve one or more of the problems mentioned above. Summary of the Invention

[0006] According to a first aspect of the invention, a crane system is provided, comprising: a trolley or hoist for supporting a load and capable of moving horizontally to correspondingly provide horizontal movement of the load; a load-bearing member supported by the trolley / hoist and configured to bear the load in use; a sensor for measuring the angle of the load-bearing member relative to the trolley / hoist; and a controller configured to provide a dynamic model of the trolley / hoist to determine an estimated angle of the load-bearing member during movement of the trolley / hoist; wherein the controller is configured to compare the estimated angle with the measured angle and control the horizontal movement of the trolley / hoist based on the comparison.

[0007] The controller can be configured to determine the difference between the estimated angle and the measured angle. The controller can also be configured to determine whether the difference exceeds a threshold. An error value can be defined for the difference between the estimated angle and the measured angle.

[0008] The controller can be configured to slow down the crane (i.e., reduce its speed) when the threshold is exceeded.

[0009] When a threshold is exceeded, the controller can be configured to drive the crane at a lower speed. The speed can be non-zero. The speed can be maintained (i.e., the crane is still actively driven). The speed can decelerate towards zero. The threshold may include a first threshold.

[0010] When a threshold is exceeded, the controller can be configured to stop the crane. The threshold may include a second threshold. The second threshold may be greater than the first threshold. The controller can be configured to activate the brake. The controller can reduce the power supplied to the motor until the crane reaches zero speed.

[0011] When a threshold is exceeded, the controller can be configured to drive the crane in the direction that reduces the angle difference. When the threshold is exceeded, the controller can also be configured to prevent travel in the first direction and permit travel in a second direction. The second direction can be the direction opposite to the first direction. The first direction can be the direction of travel before the threshold is exceeded. The crane can be configured to move in the second direction at a speed lower than the crane's normal or maximum speed.

[0012] When the threshold (e.g., a third threshold) is exceeded, the controller can be configured to automatically move the crane in a second direction. The controller can be configured to move the crane until the difference between the estimated angle and the measured angle reaches the threshold. The threshold can be a case where the difference between the estimated angle and the measured angle is less than or equal to zero and / or a case where the measured angle indicates that the load-bearing member is extending in the vertical direction. The controller can be configured to move the crane until the measured angle reaches the threshold. The threshold can be a case where the measured angle is less than or equal to zero and / or a case where the measured angle indicates that the load-bearing member is extending in the vertical direction.

[0013] When the difference between the estimated angle and the measured angle is outside a predetermined range or below / above a predetermined threshold, the controller can be configured to maintain normal operation of the crane (i.e., without applying deceleration or stopping). During normal operation, any determination of the angle difference can be ignored. Another threshold may be greater than the first threshold and / or the second threshold. This other threshold may indicate an erroneous or unrealistic angle difference.

[0014] When the crane moves in a given direction and the measured angle indicates that the load is at an angle relative to the estimated angle toward the given direction, the controller is configured to maintain normal operation of the crane.

[0015] The crane can be configured to vary the effective length of the load-bearing member to provide vertical movement of the load during use (e.g., via a lifting mechanism). If the threshold or range of the vertical position is exceeded, the controller can be configured to ignore any determination of the angle difference. The controller can prevent the length of the load-bearing member from changing in one or more directions.

[0016] The dynamic model can be a function of one or more of the following: the length of the load-bearing member; or the acceleration or velocity of the hoist / lifting vehicle. Acceleration or velocity can be the vertical and / or horizontal velocity of the hoist / lifting vehicle. The dynamic model may include a pendulum model. The dynamic model may include a state observer. The system may include an acceleration sensor. The controller may determine the acceleration of the hoisting vehicle via operating parameters (e.g., speed commands) configured to drive the motors of the hoisting vehicle.

[0017] The crane system may include a sensor configured to measure the effective length of the load-bearing member. The length sensor may include a rotary encoder (e.g., on the motor or drum of the lifting system). The effective length may be calculated periodically (e.g., between 0.1 seconds and 1 second). The effective length can be determined when the length of the load-bearing member has changed by a predetermined threshold (e.g., every 10 cm).

[0018] Angle and / or length sensors include laser, optical, time-of-flight, or radio-based systems used to determine the effective position of the load-bearing member. The sensors can determine virtual length and / or angle. Angle sensors may include one or more inclinometers. Angle sensors may include rotary encoders.

[0019] The crane can be mounted to a bridging member or gantry. The bridging member or gantry is capable of movement along one or more axes. The crane is capable of movement in two horizontal directions. Dimensions can be provided in the horizontal plane. The controller can measure the angle of the load-bearing member in the corresponding dimension. Accordingly, the estimated angle and / or measured angle are determined in both dimensions. The controller can be configured to drive the crane in the corresponding dimension.

[0020] The controller can be configured to continuously monitor the angle and / or length of the load-bearing member. The controller can operate in real time. The controller may include a proportional controller for controlling the speed.

[0021] According to another aspect of the invention, a method of operating a crane system is provided, the method comprising: providing a trolley or hoist for supporting a load and capable of moving in a horizontal direction to correspondingly provide horizontal movement of the load; providing a load-bearing member supported by the trolley / hoist and configured to bear the load in use; measuring the angle of the load-bearing member relative to the trolley / hoist; providing a dynamic model of the trolley / hoist to determine an estimated angle of the load-bearing member during movement of the trolley / hoist; and comparing the estimated angle with the measured angle, and controlling the movement of the trolley / hoist based on the comparison.

[0022] The load-bearing component may include a motor for changing its length. The hoist / lifting vehicle may include a motor for moving its horizontal position. The bridging component or gantry may include a motor for moving its horizontal position.

[0023] Cranes may include overhead cranes and / or cantilever cranes.

[0024] According to another aspect, a computer program or computer-readable medium is provided, the computer program or computer-readable medium comprising program instructions that, when executed by a computer, cause the computer to perform a computer process for implementing the method of claim 15.

[0025] Where feasible, any aspect of the invention may be combined with any other aspect of the invention.

[0026] describe

[0027] The embodiments of the present invention are described below by way of example only, with reference to the accompanying drawings:

[0028] Figure 1A A schematic diagram of the first crane system is shown;

[0029] Figure 1B A schematic diagram of the second crane system is shown;

[0030] Figure 2 A schematic diagram of a dynamic pendulum model is shown;

[0031] Figure 3 A schematic diagram of the control mechanism is shown;

[0032] Figure 4 A schematic diagram of the control system is shown.

[0033] Figure 1 schematically illustrates a crane system 2. The crane includes a bridge crane or an overhead crane. Crane 2 includes a bridging section 4. A lifting mechanism 6 is mounted to the bridging section 4 and is movable along its length. The bridging section 4 may include trusses, beams, rails, or cantilever beams, etc. The lifting mechanism 6 includes a bracket or trolley 7 movably mounted to the bridging section 4. The bracket may include wheels, bearings, or rollers for providing movement of the bracket. Movement may be achieved by a motor 8 disposed on the trolley 7. The motor may include a gearbox, etc. The gearbox is then operatively connected to the wheels / bearings / rollers. In other embodiments, the trolley 7 may be driven via an external drive component (e.g., via a screw drive or a circulation loop).

[0034] A motor may be provided to enable movement of the gantry / bridging section, wherein the gantry / bridging member 4 is movable. The motor may include a gearbox. The gearbox may be connected to wheels, etc., to drive the gantry / bridging member. The gantry / bridging member 4 may be mounted to a gantry, rail, guide, or support structure to allow its horizontal movement. The gantry / bridging member 4 is capable of moving along rail 9 or a pair of rails. The bridging member may include one or more wheels 11 configured to engage the ground, rail, or support structure (if provided). The bridging member may include multiple outriggers 13. The wheels 11 are mounted on the outriggers 13. This provides an arrangement similar to a gantry crane.

[0035] exist Figure 1A In the illustrated embodiment, the track 9 can be mounted on a fixed structure. Therefore, the wheels 11 are directly mounted to the bridging member 4. This provides an arrangement similar to an overhead crane.

[0036] A load-bearing member 10 is disposed on the hoist 6 to allow connection to a load during use. The load-bearing member 10 is typically flexible. For example, it may include a rope, cable, or chain. The rope may be made of metal (e.g., steel) or polymer / synthetic rope. In some embodiments, the load-bearing member may be rigid or include rigid portions. A connector 12 is disposed at an end of the load-bearing member 10 for connection to a load. The connector 12 may include a hook, metal ring, or loop, etc. The load-bearing member 10 is shown schematically in FIG. 1, and it can be understood that the load-bearing member 10 may be wrapped around a pulley (e.g., to form a pulley system) and / or include multiple parallel members. The “end” of the load-bearing member 10 may include the lowest point of the load-bearing member 10 during use.

[0037] Crane 2 can be configured to raise / lower loads. For example, crane 6 may include a winch, pulley system, and / or other lifting mechanisms for vertical movement of the load during use. The winch / pulley can extend or retract the load-bearing member 10. A drum (e.g., a rope reel) or spindle may be provided to store the load-bearing member 10. A motor may be provided to enable vertical movement (i.e., to rotate the drum). The motor may include a gearbox.

[0038] A remote controller 14 may be provided to provide operation of the crane 2. The remote controller 14 may allow adjustment of the position of the crane 7 along the bridging member 4 and / or the vertical position of the load. The remote controller 14 may be wired or wireless. The remote controller 14 may include a suspension controller or a radio controller.

[0039] It is understood that the exact form of the crane is irrelevant to this invention, and generally, the system includes a crane that can move in the horizontal direction. The crane may include any suitable type of crane, such as one or more of the following: overhead cranes / bridge cranes; tower cranes; gantry cranes (e.g., with movable bridging sections); deck cranes; cantilever cranes; or hammer cranes. Typically, any of the aforementioned drive motors is an electric motor.

[0040] During normal operation, due to the inertia of connector 12 and / or the load and / or friction on it, connector 12 lags behind the movement of the crane 7. Therefore, the load-bearing member 10 is angled relative to the vertical direction 16 during use, at least for a portion of the travel of the crane 7. The load-bearing member 10 may be angled. Angle. The system is configured to estimate the angle and then compare the estimated angle with a measured angle of the load-bearing member. If the load or connector 12 is hooked by an object, the angle will typically increase as the gantry 7 moves forward while the load remains stationary. Therefore, this increase in the measured angle relative to the estimated angle can be used to determine whether the load or connector 12 is hooked or not moving in the desired manner for other reasons.

[0041] refer to Figure 2 A method for determining the estimated angle is described. The load on the crane can be approximated by a dynamic model of a pendulum, where connector 12 acts as the pendulum. H is defined as the length of the pendulum (i.e., the distance to the center of mass of the hook / load). Let be the angle of the rope, and 'a' be the acceleration of the hoist (or bridging element). Therefore, the model can be defined as:

[0042]

[0043] Where g≈9.8 is the gravitational acceleration constant, and ω is the angular velocity.

[0044] Acceleration 'a' can be determined by any suitable method. For example, acceleration can be determined by differentiating the inverter speed command. Additionally or alternatively, the hoist may include a rotary encoder for determining the hoist's speed and acceleration accordingly. In some embodiments, the hoist 7 may include inertial sensors and / or position sensors. Acceleration data may be low-pass filtered, for example, to filter out erroneous or unrealistic data.

[0045] Assuming a constant pendulum length H (the lift changes slowly compared to pendulum dynamics) to linearize, and transforming into a state... The state space format.

[0046]

[0047]

[0048]

[0049] The period of a pendulum is defined by the following formula:

[0050]

[0051] This system provides a "state observer." The state observer provides an estimate of the state of the physical system to provide its model or control mechanism. The state observer for a pendulum system is defined by the following equation:

[0052]

[0053]

[0054]

[0055] in It is the observer gain.

[0056] The gain can be calculated by setting the characteristic polynomial of the system to the desired polynomial. The desired polynomial is chosen as... , where p is the location of the pole. In this example, since the system is oscillating and oscillation is not desired, p is set on the real axis. Other choices are also possible (e.g., some values ​​may be negative in the complex plane). L can then be solved by the following equation:

[0057]

[0058]

[0059] Since the system is modeled as a pendulum, the observer poles in this example are set relative to the pendulum period. The system's poles and settling time... The relationship is Given. If the settling time is set to half the pendulum period. Then p is defined by the following formula:

[0060]

[0061] Where c o =1 is a tuning parameter that can be used to tune the settling time of the observer relative to the pendulum period.

[0062] The correction amount performed by the observer based on the angle error can be determined by another tuning parameter c. e Settings. Tuning parameters are defined as follows: This causes the parameter scaling to adjust the observer gain. For hook detection, typically only a small correction should be made to the observer state to detect pendulum behavior that differs from normal oscillation. Typically, the error gain is... Therefore, the observer gain is a function of the pendulum length, as defined by the following equation:

[0063]

[0064] The observer gain is a function of the rope length. This length can change when the lifting mechanism 6 is used to move the load in the vertical direction. A sensor is used to determine the effective length of the load-bearing member 10. The length sensor may include an external encoder (e.g., pulse or absolute) on the axis of the lifting motor, gear, or rope drum (e.g., to monitor the number of shaft / drum rotations). Alternatively, the length may be determined via an inverter that monitors the lifting position (e.g., motor encoder or motor speed feedback).

[0065] The effective length is updated at regular intervals (e.g., every 0.1 seconds or 1 second) and / or when the rope length changes by a certain threshold (e.g., 10 cm). Therefore, the observer is updated based on the current operating point. The observer typically operates in real-time or near real-time.

[0066] It is understandable that the above mechanism is an example of a state observer used to determine the dynamic movement of a pendulum. Other methods can be used to derive the observer dynamics, and different observer feedback gains L can be chosen accordingly.

[0067] Simultaneously or in parallel, the system is configured to determine the actual angle of the load-bearing member 10 / connector 12. An angle sensor is used to measure the actual angle. The system runs a pendulum observer model and compares the measured rope angle with the observer's estimated angle. A comparison is made. If the angles differ by a predetermined amount, a hook is detected accordingly. In this embodiment, the hoist is capable of moving in two dimensions in the horizontal plane. For example, the hoist moves in both the "lifting vehicle" and "bridging" directions. Therefore, two pendulum observers are used, one in each direction. Similarly, a dual-axis rope angle sensor is required.

[0068] Various methods can be used to determine the angle or inclination of a load-bearing member, such as one or more of the following:

[0069] • Inclinometer, which is attached to a portion of the support member 10 and / or connector 12. The inclinometer may be attached near the terminal end of the support member 10 (the end adjacent to the hoist 7 and / or connector 12). Multiple inclinometers may be provided. The inclinometers may be spaced apart along the axis of the support member 10. The angle can be determined as the average value of the inclinometers. The sensor may be located at or near the fixed end of the support member 10 (i.e., the end not configured to be wound up). This ensures that the sensor is not fed into the drum, etc.

[0070] • Connect the load-bearing component 10 to the fixed end joint or the potentiometer or encoder on the pivot of the hoist 7.

[0071] • Optical sensors are used. For example, one or more cameras can be provided to determine the position of the carrier member 10 and / or connector 12. Two or more cameras can be used to capture stereo images of the carrier member / connector, thereby allowing its position to be determined. The system can use machine learning or AI to allow for accurate detection.

[0072] • Use a Time-of-Flight (ToF) system. For example, RADAR, LIDAR, or laser ranging systems can be used. This allows for passive detection of the position of load-bearing components / connectors.

[0073] • Use an active tracking system. The carrier component / connector is configured to emit a signal that allows its location to be determined. For example, the system may use one or more of the following: ultrasonic; radio beacon; or ultra-wideband (UWB) radio components.

[0074] It is understood that when using laser, optical, ToF, or active tracking systems to determine the position of the load-bearing member / connector, virtual angles can be determined (i.e., instead of calculating physical angles, virtual angles are calculated given the known length and position of the load-bearing member 10 / connector 12). In some implementations, it is not necessary to determine angles at all, because the position or displacement can be determined absolutely. Similarly, such systems can be used to determine the effective rope length H or other variables in a state observer.

[0075] Angular error Defined as the estimated angle Angle of measurement Function for the difference between:

[0076]

[0077] in It is the angle measured in the first dimension. It is the angle measured in the second dimension, and , It is the corresponding angle estimate. and This can refer to angles measured in the direction of movement of the crane (i.e., along the axis of the bridging member) and in the direction of movement of the bridging member, respectively.

[0078] In other embodiments, the crane 7 moves along a single axis. Angular error. Defined as:

[0079]

[0080] in It is the angle measured in the first dimension, and It is the corresponding angle estimate.

[0081] When the angle error The value exceeds the threshold Hooking is detected when the threshold is exceeded. (Right now, When the angle exceeds a threshold in the direction of travel, the hook detection system is activated. Since angles exceeding the threshold in the direction of travel generally do not indicate hooking or other undesirable movement, angle errors exceeding the threshold in the direction of travel can be ignored from hook detection.

[0082] Typically, the angle difference used in the above text The angle difference can be limited to predetermined parameters. For example, if the difference exceeds a threshold, the measurement can be ignored. This helps eliminate large noise spikes or large angle tracking errors that could cause instability in the system. It can be understood that such a system can simply ignore angle measurements outside of predetermined parameters. For example, if the measured angle is more than 90 degrees from the vertical, it is unlikely to represent a real-world value.

[0083] In the event of a snag, this system is used to prevent further entanglement or damage to the system or load. This is achieved by slowing down and / or stopping the hoist. In this embodiment, in the event of an error... When a first threshold is exceeded, the crane 7 is configured to decelerate. The crane 7 can decelerate to a predetermined speed. The predetermined speed can be less than or equal to 50%; preferably less than or equal to 30% of the maximum speed of the crane 7. This allows the load or load-bearing member 10 to untangle itself or release its hook. The system continues to monitor the angle of the load-bearing member 10 and determine the error. .

[0084] If error If the second threshold is exceeded, the crane 7 is configured to come to a complete stop. A brake or other deceleration force (e.g., reverse motion) may be activated. Alternatively, power to the motor 6 may be denied, and friction may stop the crane 7. This allows for manual intervention by the user. Typically, the user moves the crane 7 in the reverse direction, for example, using a remote control 14. The crane 7 can be moved until the load-bearing member 10 is in the vertical direction 16 or until the load has been untangled. The system can be configured to prevent movement in the forward direction to prevent further tangling. For example, the system is configured to deactivate or ignore commands to drive in the forward direction and only allow drive in the reverse direction.

[0085] In some implementations, the system can automatically reverse the direction of the crane 7. The system can be configured to reverse the crane 7 until an error occurs. or absolute angle Less than a predetermined threshold. For example, the system can drive the crane 7 until the load-bearing member 10 forms an angle of less than 0 to 5 degrees with the vertical direction.

[0086] Once a hook is detected, if the following absolute angle is below a predetermined threshold... At this time, the detection system may become inactive:

[0087]

[0088] Typically, this type of threshold It is close to zero and significantly less than the activation threshold. (Right now, The system then allows the user to move the crane 7 in the forward direction. The system then continues to monitor angular errors. As previously described during its operation. In other embodiments, the user can manually reset the system.

[0089] Control mechanism in Figure 3 The details are shown in the diagram. Each action corresponds to the measured angle. As shown, where Indicates the angle of movement away from the direction (e.g., towards the left side of Figure 1), and This indicates the angle of movement away from the direction (e.g., towards the right side of Figure 1). The system determines the estimated angle. And measure the actual angle When the angle is negative or less than the estimated angle. In the case where the bearing member 10 is traveling forward toward the estimated angle, the error is... Ignored. From the perspective of measurement. Greater than the estimated angle But less than the threshold angle In the case of error If the value is less than the threshold and therefore no action is taken, and the error... It can be ignored.

[0090] Once the angle is measured Angle exceeding the threshold ,error The value is greater than the threshold and therefore the hook detection system is activated (i.e., If the angle being measured... Angle less than the second threshold If the angle is slowed, the crane 7 is simply decelerated. The crane 7 can continue moving at a predetermined speed. It is understood that the predetermined speed can vary proportionally to the detected angle. For example, multiple thresholds of the measured angle can be provided, and the speed can decrease with each threshold. Alternatively, the speed can decrease in a continuous, gradual manner.

[0091] If the angle being measured Subsequently, the angle exceeded the second threshold. (For example, because the load is still hooked), the crane 7 comes to a complete stop. The user then manually moves the crane 7 back until the load-bearing member 10 is nearly vertical and the system is deactivated (i.e., The mobile crane 7 allows for the measurement of angles. The speed at which the crane 7 moves can be limited to a predetermined value. This value will typically be lower than the crane's normal or maximum operating speed.

[0092] In some implementations, the crane 7 can be configured to automatically move backward until the error is reached. Reaching a certain threshold. This value indicates that the crane 7 is vertically positioned above the load (i.e., The situation and / or the angle is close to and / or less than the estimated value. The situation.

[0093] If at any time, the angle measured Angle greater than the first threshold Then the error This can be ignored. This avoids significant errors or the introduction of instabilities in the state observer.

[0094] When the hook detection system is activated ( This prevents lifting (i.e., vertical movement). This prevents the user from using lifting movement to further increase the entanglement. In this embodiment, lifting (i.e., reducing the length of the load-bearing member 10) is prevented. Lowering (i.e., increasing the length of the load-bearing member 10) may be permitted to help the load untangle or release the hook. In some embodiments, all lifting may be prevented, for example, to prevent the load from impacting the ground in the event that the hoist 6 is reversed.

[0095] Although the system is described with reference to movement in a single direction / dimension, it is understood that this arrangement can be used accordingly in any direction or dimension of travel. It is understood that the system can be used to move the bridging member / gantry to achieve movement of the crane. When the direction of travel combines movement of the crane and the bridging member, the system will operate accordingly on both the crane and the bridging member. Therefore, in general, the system moves the crane 7 around the horizontal plane by directly driving the crane 7 or by driving the bridging member / gantry 4 on which the crane is placed.

[0096] exist Figure 4 The diagram schematically illustrates a hook detection system 18. This system includes a controller 20. The controller 20 may include any suitable processing system. The controller 20 may include one or more of the following: a processor; a microprocessor; a microcontroller; volatile and / or non-volatile memory; a SoC, etc. The controller 20 may include analog and / or digital computing devices. The controller 20 may include an embedded or industrial PLC. Any of the aforementioned parameters (e.g., thresholds) and / or pendulum model parameters may be stored in non-volatile memory. These parameters may be input and / or configured to match the hook detection thresholds desired by the crane and the crane operator.

[0097] Angle sensor 22, length sensor 24, and optical / ToF / active tracking system 26 (if provided) are configured to operatively communicate with controller 20. Acceleration data 28 is provided to the controller (e.g., via a separate sensor or as part of a drive system).

[0098] Controller 20 is operatively connected to inverter 30. Controller 28 can provide an appropriate frequency to the inverter to drive motor 8 accordingly. When the crane 7 is not driven by the onboard motor 8, controller 28 is operatively connected to the offboard crane drive unit accordingly.

[0099] In some implementations, the controller 28 may be embedded in or integrated with the inverter 30.

[0100] The remote control unit 14 is operatively connected to the controller 28. The remote control unit 14 includes one or more inputs that allow control of the crane 7. These inputs can provide horizontal (i.e., along the bridging member 4) and / or vertical movement. This allows the system 2 to operate in a conventional manner.

[0101] The controller 20 includes a travel controller 32, a state observer 34, and a hook detection subsystem 36. The travel controller 32 is configured to drive the motor (to drive the crane and / or bridging component) according to instructions provided by the remote controller 14 and / or the hook detection system 36 (e.g., to decelerate, reverse, or stop the motor 8). The travel controller 32 can provide acceleration data 28. The state observer 34 is configured to determine an estimated angle as previously described. The hook detection system 36 is configured to compare the estimated value from the state observer 34 with the angle measured from the angle sensor 22.

[0102] This system provides detection of hooking of loads on cranes, thereby helping to prevent accidents and / or damage to the loads. The system uses a dynamic model to determine estimates of normal operating angles. Therefore, the threshold at which operation is considered abnormal (i.e., due to hooking) is determined by the dynamic model. This provides a more accurate and flexible system than experimentally determined systems, such as those provided in WO 2013 / 041770. Therefore, this system can be used with minimal configuration in a variety of different crane types or arrangements.

[0103] Once a snag is detected, the system automatically reduces the risk of further danger. The system can automatically reverse the hoist to help release the snag.

Claims

1. A crane system (2), the crane system comprising: A crane (7) is used to support a load and is capable of moving horizontally to provide a corresponding horizontal movement of the load; A load-bearing member (10), which is supported by the crane (7) and configured to bear the load in use; Sensors (22, 24) are used to measure the angle of the load-bearing member (10) relative to the crane (7); Controller (20), configured to provide a dynamic model of the hoist (7) to determine an estimated angle of the load-bearing member (10) during movement of the hoist (7); and The controller (20) is configured to compare the estimated angle with the measured angle and control the horizontal movement of the crane (7) based on the comparison.

2. The crane system of claim 1, wherein the controller (20) is configured to determine the difference between the estimated angle and the measured angle, and to determine whether the difference exceeds a threshold.

3. The crane system according to claim 2, wherein the controller (20) is configured to decelerate the crane (7) when the threshold is exceeded.

4. The crane system according to claim 2 or 3, wherein when the threshold is exceeded, the controller (20) is configured to drive the crane (7) at a lower non-zero speed.

5. The crane system according to any one of claims 2 to 4, wherein when the threshold is exceeded, the controller (20) is configured to stop the crane (7).

6. The crane system according to any one of claims 2 to 5, wherein when a threshold is exceeded, the controller (20) is configured to prevent travel in the first direction and permit travel in the opposite direction.

7. The crane system according to any one of claims 2 to 5, wherein the controller (20) is configured to maintain normal operation of the crane (7) when the difference between the estimated angle and the measured angle is higher than another threshold.

8. The crane system of claim 7, wherein the other threshold is greater than the first threshold.

9. The crane system according to any of the preceding claims, wherein when the crane (7) moves in a given direction and the measured angle indicates that the load-bearing member (10) is angled toward the given direction relative to the estimated angle, the controller (20) is configured to maintain normal operation of the crane (7).

10. The crane system according to any of the preceding claims, wherein the trolley (7) is configured to vary the effective length of the load-bearing member (10) to provide vertical movement of the load in use, and wherein, if the threshold is exceeded, the controller (20) is configured to prevent the length of the load-bearing member (10) from changing in one or more directions.

11. The crane system according to any of the preceding claims, wherein the dynamic model is a function of one or more of the following: the length of the load-bearing member (10); or the acceleration or velocity of the hoisting vehicle (7).

12. The crane system according to any of the preceding claims, the crane system comprising a sensor (24) configured to measure the effective length of the load-bearing member (10).

13. The crane system of claim 12, wherein the angle sensor (26) and / or the length sensor (24) comprises a laser, optical, time-of-flight, or radio-based system for determining the effective position of the load-bearing member (10) and determining the virtual length and / or angle.

14. The crane system according to any of the preceding claims, wherein the crane (7) is capable of moving in two dimensions in a horizontal plane, and the estimated angle and / or measured angle are determined accordingly in two dimensions.

15. A method of operating a crane system (2), the method comprising: A crane (7) is provided, which is used to support the load and is capable of moving in a horizontal direction to provide a horizontal movement of the load accordingly; A load-bearing member (10) is provided, which is supported by the crane (7) and configured to bear the load in use; Measure the angle of the load-bearing component relative to the hoisting vehicle (7); A dynamic model of the hoisting vehicle (7) is provided to determine the estimated angle of the load-bearing member (10) during the movement of the hoisting vehicle (7); as well as The estimated angle is compared with the measured angle, and the movement of the crane (7) is controlled based on the comparison.

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