Method and device for operating slewing cantilever crane and slewing cantilever crane

Abstract

The invention relates to a method for operating a slewing crane (2) by means of a state control, the state control enabling control of a movement of a suspension load (L) at least in one direction of movement and being based on a state vector, the method comprising the following steps:-capturing a state variable of the state vector, the state variables include information about a position (x, theta) and a speed (x ', theta') of a movable suspension point (AUP) to which the load system is suspended, and information about a load position # imgabs0 # and a load speed # imgabs1 # of a center of mass of the load system with respect to the suspension point (AUP) to which the load system is suspended, the state variables including information about a position (x, theta) and a speed (x ', theta') of the movable suspension point (AUP) to which the load system is suspended. The invention relates to a load system comprising: a lifting cable (HSL), a load holding device (UF) located at the lower end of the lifting cable (HSL), and a load (L) suspended below the load holding device (UF),-determining at least one manipulated variable (u * LK, u * DW, u * HW) for moving a suspension point (AUP) in at least one direction of movement on the basis of a state control; and operating the slewing crane (2) as a function of the at least one manipulated variable (u * LK, u * DW, u * HW).

Description

Technical Field

[0001] The present invention relates to a slewing jib crane and in particular to a method for controlling the movement of a suspended load and in particular to measures for preventing shimmy. Background Art

[0002] Cranes, and in particular slewing jib cranes or loading cranes, such as tower cranes, mobile cranes, etc., move a load by suspending the load from hoisting ropes on a jib, lifting the load, moving the load in a substantially horizontal plane, and lowering the load. The movement of the jib is thus effected by a suitable drive device, and the lifting and lowering of the load is performed by means of a hoisting mechanism connected to the hoisting ropes.

[0003] In the case of loading and unloading cranes, the time required for the transport cycle can be critical for trouble-free operation. During the transport cycle, the crane's unproductive downtime will be minimized and the crane's productive operating time will be maximized.

[0004] For example, in the case of a tower crane, the load is moved by rotating the boom and moving the trolley along the boom. In the case of a mobile crane, the load is moved by rotating the boom and, if applicable, by luffing the boom up and down along a horizontal luffing axis. The drive and hoisting mechanism are typically controlled manually by the crane operator by operating appropriate operating elements on the crane control unit. During acceleration and braking, the suspended load deflects relative to the suspension point on the boom, triggering a pendulum movement. A pendulum movement can pose a potential hazard to both construction workers and construction equipment. To prevent such undesirable pendulum movement of the suspended load, measures are known in the prior art for damping the pendulum movement during crane operation.

[0005] For example, document DE 10 2009 032 270 A1 discloses a method for controlling the drive of a mobile crane. A target motion of the boom end is used as an input variable, based on which control variables for controlling the drive are calculated. The vibration dynamics of the system consisting of the drive and the crane structure are taken into account when calculating the control variables in order to reduce natural vibrations.

[0006] EP 1 628 902 B1 discloses a crane for handling a load suspended from a load rope. The crane comprises a slewing mechanism for rotating the crane, a luffing mechanism for tilting the boom, and a hoisting mechanism for lifting the load suspended from the rope. Using path control, a model-based optimal control trajectory is calculated based on a nonlinear model approach and updated by feeding back state variables. The output variables of the path control are directly or indirectly incorporated as input variables into the crane's position or velocity control system. Reference variables for the path control are generated in such a way as to achieve load motion with minimal pendulum deflection.

[0007] Document EP 1 652 810 B1 discloses a method of controlling a crane operating unit for suppressing oscillation of a load suspended on a rope of the crane by operating a control device having a filter unit to perform control.

[0008] To prevent shimmy, it is known to implement predictive control of crane motion to suppress shimmy in crane applications. For example, see J. Smoczek et al., “Robust Predictive Control of an Overhead Crane,” https: / / doi.org / 10.5604 / 01.3001.0010.2940.

[0009] The “Cycoptronic” function is known from the “Liebherr Electronics” brochure dated September 2012 from Liebherr Werk Nenzing GmbH, which shows the swing-free operation of a mobile harbor crane when loading and unloading ISO containers between a cargo ship and the port edge area.

[0010] In particular, with complex crane structures, conventional pendulum damping devices are not sufficient to adequately damp or suppress pendulum oscillations. In particular, due to the various deformations of the crane structure, the various dynamic effects when lifting, lowering, and moving the load cannot be satisfactorily modeled using physical models, and therefore pendulum oscillations cannot be adequately damped.

[0011] Conventional methods are typically based on an assumed approximate load position, which is approximately determined, for example, based on the hoist rope angle relative to the vertical (typically at the hoist rope's suspension point on the boom). However, wind pressure and other dynamic influences can cause lateral oscillations in the hoist rope, resulting in the measured hoist rope angle not corresponding to the angle between the suspension point on the boom and the load's center of gravity. Furthermore, during crane operation, the load to be suspended is suspended from a load-bearing device, such as a hook block, so that the significant weight of the load-bearing device causes a double pendulum system that often performs chaotic oscillatory motions when excited. This is difficult to predict using conventional physical models, significantly compromising the quality of pendulum damping based solely on the hoist rope angle. Furthermore, inadequate prediction of the load's oscillation can also lead to intervention in the pendulum damping algorithm, exacerbating the oscillation in the worst case.

[0012] The object of the present invention is to provide a method and a device for operating a slewing jib crane, as well as a slewing jib crane and a computer program product for carrying out the method, which dampen or suppress shimmying in an improved manner and also enable additional operating modes, so that the transport process of loads is safer, faster and easier to perform. Summary of the Invention

[0013] This object is achieved by a method for operating a slewing jib crane by means of state control according to claim 1 and by a corresponding device and a slewing jib crane according to the independent claims.

[0014] Further embodiments are disclosed in the dependent claims.

[0015] According to a first aspect, a method for operating a slewing jib crane by means of state control is provided, wherein the state control enables control of the movement of a suspended load in at least one direction of movement and is based on a state vector, the method comprising the following steps:

[0016] detecting state variables of a state vector, the state variables comprising information about the position and velocity of the movable suspension point, and comprising information about the position and velocity of the load of a mass center of a load system relative to the suspension point, the load system being suspended from the movable suspension point, the load system comprising a hoisting rope, a load carrying device arranged at the lower end of the hoisting rope, and a load suspended below the load carrying device,

[0017] - determining, based on the state control, at least one actuation variable for moving the suspension point in the at least one direction of movement;

[0018] - operating the slewing jib crane as a function of the at least one actuation variable.

[0019] As mentioned at the outset, one of the fundamental issues when transporting loads using a slewing jib crane is damping or suppressing the oscillation of the suspended load to an extent that enables construction site workers to quickly and safely lift and lower the load, as well as attach and detach it. The goal is to dampen oscillation at each stage of load transport so that it does not occur and the load can be lifted and lowered in a shorter time period.

[0020] The load system consists of a suspended load, a load-carrying device, a hoisting rope of adjustable length connecting the load-carrying device to a suspension point, and a sling system suspending the suspended load from the load-carrying device. Due to the mass of the hoisting rope and the mass of the load-carrying device at the lower end of the hoisting rope, the oscillating load system forms a multi-pendulum system with the suspended load. This multi-pendulum system cannot be easily modeled and often results in unstable oscillations when lateral forces are applied. Therefore, accurately determining the actual load position is not easy.

[0021] The actual load position may indicate the relative position of the center of mass of the entire load system relative to the suspension point on the boom and may be provided as, for example, an indication of the lateral load deflection relative to a vertical line through the suspension point and / or an indication of the yaw angle of the suspension point of the load system relative to a vertical line through the suspension point in one or more lateral directions of motion. The load velocity may correspond to the relative velocity of the center of mass of the entire load system relative to the suspension point.

[0022] Common shimmy damping methods for suppressing shimmy vibrations estimate the load position, i.e., the load deflection or shimmy angle, based specifically solely on the hoisting rope angle and hoisting rope length at the suspension point of the boom and the load velocity, obtained by determining the derivative of the hoisting rope angle. However, in practice, this does not result in a useful determination of the load position and load velocity for performing state control. Using this simplified load position determination, particularly when using a state controller, can lead to inaccurate control behavior and, consequently, inadequate shimmy vibration suppression during crane operation.

[0023] In this respect, it is advantageous to interpret the control as moving the load to the actual load position or a load position determined in an improved manner, thereby eliminating the destructive effects of estimation errors of the load position.

[0024] To this end, the load position of the center of mass can be determined based on the following: the hoisting rope angle, which indicates the angular deviation of the hoisting rope attached to the suspension point relative to a vertical line passing through the suspension point; the load rope angle, which indicates the angular deviation of the center of mass with respect to the suspension point on the load carrying device relative to the vertical line; the hoisting rope length between the suspension point and the center of mass of the load carrying device; and the load rope length, i.e. the length of the sling between the suspension point and the center of mass of the load.

[0025] More precise determination of the load position enables the use of state control to operate the slewing jib crane. In this case, the state control is suitable for implementing various modes for operating the slewing jib crane. The state control is based on a state vector and, when target specifications are provided, provides corresponding actuation variables for at least one direction of motion, in particular, corresponding adjustment speeds of the drive devices, such as the adjustment speed of the trolley travel unit of a tower crane or the adjustment speed of the luffing angle of the jib of a mobile crane and / or the adjustment speed of the slewing mechanism. The state control is performed cyclically according to a time-defined control cycle, in particular with a control cycle duration between 10 ms and 500 ms, preferably between 50 ms and 150 ms.

[0026] It has been found to be advantageous for the state control operated on the slewing jib crane control unit to use a state vector which indicates, on the one hand, the position and velocity of the suspension point of the load system with respect to the direction of movement, and, on the other hand, the load position, i.e., the position of the center of mass of the load system relative to the suspension point (e.g., load deflection, swivel angle).

[0027] The load velocity, i.e., the angular velocity, is determined in particular by differentiating the change in load position over time (load deflection / swing angle). The swing angle indicates the actual load deflection, i.e., the deflection of the center of mass, about the suspension point on the cantilever relative to a vertical line through the suspension point in at least one direction of motion, i.e., the radial x-direction and / or the tangential y-direction.

[0028] Directly applying state control to such a state vector makes it possible to prevent any inaccuracies caused by elastic deformations and / or by lateral effects on the load and the load suspension. Since the dynamics of the individual motion systems are very different, the state control can be configured to act separately on the slewing mechanism for boom rotation and on the drive for luffing the boom, for example, on a mobile crane, or on the slewing mechanism for boom rotation and on the trolley travel unit for moving the trolley and on the hoisting mechanism, for example, on a tower crane. Thus, the movement of the load in the radial direction can be controlled by controlling the corresponding drive for luffing or by controlling the trolley travel unit for moving the trolley according to the actuation variable, while the movement in the tangential direction, i.e., the movement around the axis of rotation of the boom, can be achieved by controlling the slewing mechanism for boom rotation.

[0029] The controls can thus be configured and implemented separately from one another. Thus, various functions, including the pendulum damping function, can be implemented in different directions of movement, and the corresponding state controllers can be adapted in an appropriate manner to the different actuation dynamics of the drive (slewing mechanism, trolley travel unit, etc.).

[0030] By using a state controller, the trajectory of the actuation variables for controlling a drive device for moving a suspended load can be precisely specified so that, for example, shimmying of the moving load is prevented during its movement.

[0031] Suppressing the occurrence of oscillations of the load in all stages during crane operation makes it possible to suppress shimmy at any time during the load transportation process, i.e., the processes of attaching the load, lifting the load, moving the load, setting down the load, and detaching the load, thereby ensuring a faster transportation process because waiting time due to the damping oscillation process can be prevented.

[0032] The load system forms a multi-pendulum system between the suspension point on the trolley LK and the center of mass of the suspended load. Along the load suspension, there are additional, non-negligible masses, such as the load-carrying device, which forms an additional vertex of the pendulum motion. It has been found that if the load position relative to the suspension point on the boom is determined more precisely using sensor fusion methods or alternative methods, the double-pendulum or multi-pendulum system of the load system, consisting of the hoisting rope, the load-carrying device, the load rope, and the suspended load, can be treated as a single pendulum for the purpose of state control.

[0033] In principle, the actual load position can be determined in various ways. For example, a positioning system that determines position vectors of a stationary point and a point on the suspended load can be used to determine the load position. For this purpose, positioning systems based on camera systems or transponder systems, as known, for example, from DE 10 2020 120 699 A1, can be used.

[0034] Furthermore, determining the relative load position using sensor data fusion using a first angle sensor device and a second angle sensor device that detect and transmit angle data to a control unit has proven effective. The first angle sensor device is positioned at the suspension point of the hoisting rope on the boom to determine the hoisting rope angle in the x- and / or y-direction, i.e., radially and / or tangentially relative to the boom's axis of rotation. The hoisting rope angle is determined relative to a vertical line passing through the suspension point.

[0035] Because the hoisting rope angle of the hoisting rope needs to be determined relative to the vertical, it is preferable to provide compensation for the measured boom angle at the hoisting rope's suspension point. In this case, the rotation angle difference relative to the rotation angle about the boom's pivot point caused by the elastic bending of the boom can be taken into account, for example, by using known physical models or by measurement. Furthermore, the vertical luffing angle (in the vertical direction) and the luffing angle difference (inclination angle) caused by the elastic bending of the boom can also be taken into account by using known physical models or by measurement.

[0036] By means of a second angle sensor device, for example, suspended from the load-carrying device by a hoisting rope, the load rope angle of the suspended load relative to a perpendicular through the suspension point of the load on the load-carrying device can be determined in the x- and / or y-direction. By fusing the hoisting rope angle and the load rope angle (each in the same direction), if the hoisting rope length, i.e., the distance between the suspension point on the boom and the center of mass of the load-carrying device, is known, and if the length of the sling device or the load rope used to suspend the load from the load-carrying device is known or specified, the relative load position, i.e., the lateral load deflection of the center of mass of the load system relative to the perpendicular through the suspension point, or the sway angle of the center of mass of the load system relative to the perpendicular through the suspension point on the boom, can be determined. The load position can be determined by applying trigonometric functions known per se, or by approximating using linear functions based on relatively small hoisting rope and load rope angles, both less than 5°.

[0037] Then, the slewing jib crane can be operated using a state controller based on the assumed virtual simple pendulum system without considering the elastic deformation of the crane structure due to the torsional moment and bending moment, making it easier to implement the corresponding state control.

[0038] It can be provided that the state control is achieved by updating the parameterization of the state space description in the state space when the state of the crane changes, in particular when the hoisting rope length changes, and in particular depending on the mass of the suspended load and / or the radial position of the suspension point; and determining a linear combination of control deviations of the state variables by means of a pole configuration method or a method based on the LQ method, which linear combination is used to calculate at least one actuating variable for the movement of the suspension point.

[0039] Therefore, the state space representation of the direction of motion in the radial direction (x direction) corresponds to:

[0040]

[0041] System matrix A LK and input vector b LK An example parameterization of is as follows:

[0042]

[0043] And for example:

[0044]

[0045] where x corresponds to the radial x position of the suspension point, Corresponding to the swing angle in the radial direction (as the load position), c corresponds to a predetermined constant, and T corresponds to the value of the load when the actuation variable u is LKThe time constant of the transfer function for tracking the suspension point during (preferably velocity) control, g corresponds to the gravity constant, and l corresponds to the pendulum length l of the load system. "'" represents the first-order time derivative, and """ represents the second-order time derivative. Z corresponds to the state vector, A LK corresponds to the system matrix, and b LK Corresponding to the input vector. System matrix A LK and input vector b LK Other parameterizations of are also possible. The system matrix A LK corresponds to a 4×4 system matrix, and b LK 4-dimensional input vector of state-space parameters corresponding to the state-space representation of radial motion with suspension points.

[0046] Here, the system matrix A LK and input vector b LK The parameterization of changes with each change in the pendulum length l.

[0047] By applying the pole placement method or the LQ method, the updated system matrix A can be obtained. LK Generate the x-direction related control vector Kx = [K1, K2, K3, K4] for the control equations applied to the motion of the suspension point T :

[0048]

[0049] Where t is the current time step of the control, u * LK are the controlled actuating variables, and x(t), x′(t), are the currently measured and determined state variables.

[0050] Pole placement methods and LQ methods are known in the prior art, for example from Holger Lutz, Wolfgang Wendt "Taschenbuch der Regelungstechnik", Europa-Lehrmittel, 2021, ISBN 9783808558706 and Otto It is known in “Regelungstechnik”, Vde Verlag GmbH, 2022, ISBN 9783800755189.

[0051] Furthermore, the state space representation of the motion direction in the tangential direction (y direction or θ direction) can correspond to:

[0052]

[0053] System matrix A DWand input vector b DW An example parameterization of is as follows:

[0054]

[0055] And for example:

[0056]

[0057] where θ corresponds to the location of the suspension point, Corresponding to the swing angle in the tangential direction, I A Corresponding to a predetermined value, in particular as a function of the mass of the load system, I A corresponds to the inertia moment acting on the slewing mechanism, m corresponds to the mass of the load system, and u DW corresponds to the input variable (preferably the speed) for the slewing mechanism, ie the input variable of the drive device for the movement of the suspension point in the tangential direction. DW corresponds to a 4×4 system matrix, and b DW Input vector corresponding to the state-space parameters of the state-space representation of the tangential motion with the suspension point. Other parameterizations of the system matrix and input vector are also possible.

[0058] By applying the pole placement method or the LQ method, the y-direction-dependent control vector Ky = [K5, K6, K7, K8] for the control equations applied to the motion of the suspension point can be obtained. T .

[0059] Where t is the current time step of the control, u * DW is the actuating variable of the control to be set, and θ(t), θ′(t), are the currently measured and determined state variables.

[0060] This also makes it easy to adapt the state control to different crane configurations by selecting a manageable number of control parameters. The state control can be based on a state vector Z, which includes the load position and load velocity (relative to the suspension point), i.e., the load deflection and load deflection velocity in one or two transverse directions of motion and / or the swing angle and swing angular velocity. The state vector Z can also include an indication of the current actuation position and adjustment speed of the relevant actuating element, i.e., boom, trolley, etc., in the relevant x-direction or y-direction. The current adjustment speed in the x-direction corresponds to or is a function of, for example, the luffing speed of the boom in a mobile crane or the trolley speed in a tower crane, and the angular rotation speed of the boom in the y-direction. Thus, the control position corresponds, for example, to the luffing angle or position of the trolley on the boom with respect to the x-direction and the rotation angle with respect to the y-direction.

[0061] It can be provided that the state control is operated to implement a shimmy damping function, in particular in the case of manual or automatic crane operation specifying a speed of the suspension point for at least one of the directions of movement, wherein, for the shimmy damping, target specifications for information on the load position of the center of mass of the load system and the load speed are specified in each case as zero, a target specification for the speed of the suspension point is specified as zero, and a target specification for the position of the suspension point is specified as a position as a function of the specified speed of the suspension point.

[0062] Active state control by specifying load position and load speed That is, pendulum damping is achieved by specifying the load deflection to be 0 and the load deflection velocity to be 0, and / or by specifying the pendulum angle to be 0 and the pendulum angular velocity to be 0. This means that the control objective is to ensure that the center of mass of the load system has no relative motion with respect to the suspension point and that the center of mass is exactly perpendicular to the suspension point.

[0063] Manual or automatic specification of the target variable x′ for the target velocity of the suspension point soll ,θ′ soll The target specification for the suspension point's position corresponds to zero, while the target specification for the suspension point's position is determined based on the speed of the suspension point specified by the crane operator. Thus, the target suspension point position can be generated by the temporal accumulation of distance increments, each of which corresponds to the product of the target speed specification specified by the crane operator and the control cycle duration, to prevent overshoot when reaching the end position. Thus, for example, when operated by a crane operator, the speed of movement for luffing the boom or trolley in the x-direction and / or for rotation of the boom in the y-direction can be specified to move the load in accordance with the operator's request.

[0064] The target specification can be input using a joystick or the like and corresponds to a desired control speed of the corresponding drive, in particular in the form of a motor speed of a drive in the form of a slewing mechanism and / or a trolley travel unit, etc. The target speed specification can indirectly specify an actuating variable for the movement of the suspension point via a control, or correspond to a mechanical coupling by means of an overdrive or gear reduction in the transmission according to a specified coupling function (known for the crane configuration).

[0065] By specifying the target state, various operable functions can be realized. When the pendulum damping function is used during ongoing crane operation, the adjustment speed (x-direction and / or y-direction) specified by the crane operator is cyclically accumulated according to the control cycle duration to the target specification x of the position of the suspension point in the x-direction or y-direction. soll ,θ soll , whereas in this case no target specification is assumed for the velocity of the suspension point.

[0066] The pendulum damping function is active during crane operation. Crane operation is characterized by one of the target specifications being different from zero, or by an operating element for moving the crane being operated. The pendulum damping function may remain active until a predetermined subsequent time has elapsed after operation of the operating element has ceased.

[0067] The implementation of a state control enables further comfort functions for the operation of the slewing jib crane.

[0068] As described above, control is performed only during active crane operation and terminates within a predetermined subsequent time after operation ceases or after automatic control of crane motion ends. However, residual oscillation may persist after crane operation ends and after state control is deactivated, for example due to interference. In this regard, even when the slewing jib crane is stationary, the oscillation damping function can be activated for a predetermined period of time by the crane operator or another construction site worker communicating with the crane control unit by actively actuating a first operating element, wherein target state variables for load position and load velocity, i.e., the oscillation angle and oscillation angular velocity, or load deflection and load deflection velocity, are set to zero. Following actuation of the first operating element, state control remains active for a predetermined subsequent time of between 5 and 20 seconds, or until the load position and load velocity indicate no load motion for a specified period of time, e.g., between 1 and 5 seconds, or indicate load motion less than a predetermined threshold.

[0069] Furthermore, after actuating the corresponding first operating element, the peak position of the oscillation can be determined in a manner known per se and set as the target position. Furthermore, the follow-up time of the activated state control can be set according to the oscillation period duration, wherein the follow-up time can be set according to half the period duration.

[0070] It can be provided that the state control is operated or is operable to implement a disturbance variable compensation function, wherein target specifications for information about the position of the suspension point determined based on the stored absolute position of the load and a target specification for the speed of the suspension point to be zero are continuously provided to the disturbance variable compensation function, and in particular by setting the corresponding control deviations of the load position and the load speed of the center of mass of the load system to zero during activation of the disturbance variable compensation function regardless of the load position and the load speed of the center of mass of the load system, wherein, in particular, the target specifications for the information about the position of the suspension point are determined based on the current load position of the center of mass, the pendulum length of the load system and the current position of the suspension point.

[0071] Thus, the disturbance variable compensation function can be provided as a further alternative or additional operating function. Thus, after activating the disturbance variable compensation function, for example by actuating a second operating element, the current absolute position of the load can be specified or stored as a target position. The current absolute position of the load can thus be determined as the current position of the suspension point on the boom at the time the disturbance variable compensation function was activated and the existing load position in the form of a superimposed deflection relative to the vertical in one or two transverse directions, wherein the absolute position of the load is calculated using the load deflection or swivel angle, for example by applying trigonometric functions. Control is then performed according to a target specification for the absolute position of the suspension point, which is cyclically adjusted according to the corresponding load position and the corresponding load velocity of the center of mass of the load system. Thus, during the activation of the disturbance variable compensation function, the corresponding control deviation or the associated elements (factors) of the control vector K are set to zero, and the load position and load velocity are not taken into account in the control.

[0072] The disturbance variable compensation function can be activated and deactivated manually. If active crane operation is requested, the disturbance variable compensation function can be switched off automatically, since the active pendulum damping method is then activated and the stored absolute position of the center of mass of the load system does not need to be maintained.

[0073] It can be provided that the state control is operated or operable to perform a positioning function, wherein, for the state control, information about the relative position and relative velocity of the center of mass of the load system being zero is specified as a target specification, and, in particular, by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero during the activation of the positioning function without taking into account the position and velocity of the suspension point.

[0074] According to the positioning function, when a suitable third operating element is operated, particularly by a construction site worker communicating with the slewing jib crane's control unit via a mobile operating device, control of the load position and load velocity relative to the load system's center of mass can be activated, while control of the suspension point's position is not performed. Consequently, only the load position (load deflection or swivel angle) or load velocity (load deflection velocity or swivel angular velocity) is controlled to zero in each case. While the third operating element, preferably configured as a touch element, remains activated, the load or load-carrying device can be manually moved. By applying a lateral force to the load-carrying device or load, the activated positioning function causes the load-carrying device to shift laterally, as the activated state control attempts to return the load position (load deflection or swivel angle) deviated from zero due to the lateral force to a target specification of zero. Consequently, the corresponding drive device is moved such that a compensating movement occurs in the direction of the force applied to the load-carrying device. After deactivating or releasing the third operating element, the aforementioned pendulum damping control can be activated for a predetermined period of time, for example, between 5 and 20 seconds, to reduce any remaining oscillations.

[0075] It can be provided that, when a load is to be lifted, the state control is operated or is operable to implement a load lifting function, wherein information about the load position is determined when the lifting force on the lifting rope exceeds a predetermined lifting force threshold and the load has not yet been lifted, wherein the state control is performed with a target specification of zero load position and load velocity as well as the velocity of the suspension point, wherein in particular by setting the corresponding control deviations or associated elements (factors) of the control vector K to zero during the activated load lifting function without taking into account the control deviations relative to the position of the suspension point.

[0076] In particular, the load lifting function can be activated during ongoing crane operation when a suspended load is being lifted. In practice, when attaching a load, the center of mass and the suspension point of the hoisting ropes are often not exactly perpendicular. When the load is lifted, potentially significant oscillations can occur due to the non-zero relative position of the load system's center of mass. Therefore, before lifting the load, the hoisting ropes are tensioned. This tensioning of the hoisting ropes can be detected by monitoring the increase in force on the hoisting ropes during the tensioning process. Activating the state control, while the load is not yet lifted, compensates for deviations from zero in the load position (the deflected swing angle or the detected load deflection), and the control deviation relative to the swing angle / load deflection is brought to zero. As a result, the suspension point on the boom is positioned exactly above the load system's center of mass, and when this is achieved, the load can be lifted without oscillation. In particular, in this case, it can be provided that lifting the load is delayed until the swing angle is controlled to zero.

[0077] Furthermore, the state control is operated or operable to implement a position approach function, wherein a stored absolute position of the load is approached and the load is brought to rest at this position, wherein the absolute position of the load is stored according to a user request, wherein the state control is performed with target specifications for the position of the suspension point corresponding to the stored position, with target specifications for the velocity of the suspension point being zero, and wherein the target specifications for the position of the center of mass and the velocity being zero are performed as soon as the position of the suspension point during ongoing crane operation approaches the stored position of the suspension point, in particular below a predetermined threshold distance.

[0078] By activating the position approach function by operating the fourth operating element, a specific position can be approached in one or more directions of movement, namely, in the x-direction and / or the y-direction. Thus, crane operation is activated, and the load is moved according to the crane operation. When the current position approaches a stored position, the load stops at the stored position, and the function is then deactivated. Therefore, after stopping the load at the stored load position, the load can continue to move in any direction. Once the threshold distance is exceeded again, the position approach function can be reactivated.

[0079] The position approach function is controlled based on the state of the suspension point by monitoring the distance of the suspension point's position relative to its stored positions in the x- and / or y-direction. If the distance drops below a specified threshold, the manually or automatically specified target specification for the suspension point's velocity is set to zero, and the stored load position is set to the target specification. The load position (swing angle or load deflection) and load velocity (swing angular velocity or relative load velocity) are then also set to zero. The stored suspension point positions thus set limits that cannot be exceeded during ongoing crane operation without first stopping the load at the relevant position or limit. The stored positions can be deleted by deactivating the position approach function.

[0080] Based on the channel function, a motion trajectory can be specified as a sequence of target load positions along which the movement of the suspended load is controlled or controllable. For example, the motion trajectory can be specified using a trajectory influenced by load position tolerances, such as a range of absolute load positions within which load movement is permitted. If the load reaches an absolute position at the limit of the specified range of motion, the load's movement is stopped and the load is guided along the limit of the range of motion so that it moves within the extreme range. In this way, prohibited areas can be avoided if they exist on the direct travel path between the starting position and the target position.

[0081] According to a further aspect, a device, in particular a control unit, for operating a slewing jib crane by means of state control can be provided, wherein the state control enables control of the movement of the suspended load in at least one direction of movement and is based on a state vector, wherein the device is configured to:

[0082] detecting state variables of a state vector, the state variables comprising information about the position and velocity of a movable suspension point and information about the position and velocity of the load of a load system with respect to the suspension point, the load system being suspended from the movable suspension point, the load system comprising a hoisting rope, a load-carrying device arranged at the lower end of the hoisting rope, and a load suspended below the load-carrying device,

[0083] - determining, based on the state control, at least one actuation variable for moving the suspension point in the at least one direction of movement;

[0084] - controlling the slewing jib crane as a function of the at least one actuating variable.

[0085] According to a further aspect, the method according to the invention can be implemented on a slewing jib crane by means of a control unit, wherein a computer program product for executing the method is used in the control unit, with the aid of which the control unit receives instructions for executing the individual method steps, with the aid of which the aforementioned advantageous technical effects are achieved, so as to realize the aforementioned functions on the slewing jib crane.

[0086] According to a further aspect, a slewing jib crane is provided, comprising one or more drive devices for moving a suspension point for a load system and the above-mentioned device, wherein the slewing jib crane is controlled by controlling the one or more drive devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] The preferred embodiments are described in more detail below with reference to the accompanying drawings, in which:

[0088] Figure 1 It is a schematic diagram of a tower crane;

[0089] Figure 2 and Figure 3 is a view of the load system as a multiple pendulum or a simple pendulum;

[0090] Figure 4 Is used for operation Figure 1 Schematic diagram of a control unit of a tower crane;

[0091] Figure 5 is a flow chart showing the pendulum damping function;

[0092] Figure 6 is a flow chart illustrating the disturbance variable compensation function;

[0093] Figure 7 is a flow chart illustrating a positioning function;

[0094] Figure 8 is a flow chart illustrating a load lifting function;

[0095] Figure 9 is a flow chart illustrating the location proximity function. DETAILED DESCRIPTION

[0096] Figure 1 A schematic side view of a tower crane 2 for lifting, moving and lowering a load L is shown. The tower crane 2 represents an example of a slewing jib crane within the meaning of the present description. The tower crane 2 comprises a tower T arranged to be at least partially fixed to a base G having an imaginary vertical axis H, and a trolley boom KA extending from the tower T. Figure 1As shown, the trolley arm KA is not configured for luffing. In an example not shown, the trolley arm KA can also be configured for luffing, wherein the luffing trolley arm KA is moved by means of a luffing drive.

[0097] The tower crane 2 includes a slewing mechanism DW arranged on a rotation axis for rotating at least the trolley boom KA about a vertical axis H. The tower crane 2 includes a rotation angle sensor device 510, which is configured as a rotation angle sensor for determining a rotation angle θ_u of the trolley boom KA about the vertical axis H in an xy plane. The xy plane is generally defined as a tangential y direction and a radial x direction.

[0098] The trolley LK, which is movable along the trolley boom KA, comprises a first deflecting roller 202 and a second deflecting roller 204 for deflecting the hoisting rope HSL in the direction of the load carrier UF, which can be configured as a bottom block or a hook block. The load carrier UF comprises at least one deflecting roller 302 for the hoisting rope HSL and may also comprise a plurality of deflecting rollers for the hoisting rope HSL.

[0099] The hoisting rope HSL is guided from the hoisting mechanism HW via a first deflecting roller 202 of the trolley LK, one deflecting roller 302 of the load carrier UF and a second deflecting roller 204 of the trolley LK for winding and unwinding the hoisting rope HSL. The hoisting rope HSL is attached to the distal end portion 4 of the trolley boom KA.

[0100] The hoisting mechanism HW can include a brake, an electric motor, a transmission, and a rope winch in a manner known per se. A hoisting rope HSL is wound up onto the rope winch of the hoisting mechanism HW to lift the load L and wound out to lower the load L. For example, the hoisting rope HSL is guided from the hoisting mechanism via two deflection rollers 20 and 22 arranged at or near the vertical axis H to the deflection roller 202 of the trolley LK.

[0101] The hoisting rope length l1 is determined by means of a hoisting rope length sensor 610, for example in the form of a rotation angle sensor that counts the rotations of the hoisting mechanism HW. For example, the distance between the load carrier UF, assumed to be the hoisting rope length l1, the trolley LK, and the suspension point AUP can be determined by detecting the rotational position of the hoisting mechanism HW.

[0102] according to Figure 1 A mass sensor device 620 is coupled to the deflecting roller 22 and detects the mass m of the suspended load L or the load system at the suspension point AUP on the trolley LK. The mass sensor device 620 measures, for example, the tension applied to the deflecting roller 22. The sensor signal determined by the sensor device 620 represents the mass m.

[0103] The first angle sensor device 210 arranged on the trolley LK is configured to determine the respective hoisting rope angles of one or more sections HSL#1, HSL#2 of the hoisting rope HSL between the trolley LK and the load carrying device UF relative to the vertical line passing through the suspension point AUP. (in the y-direction and in the x-direction). The first angle sensor device 210 can, for example, comprise a distance measuring system (optical or ultrasonic based) which measures the distance between the first angle sensor device 210 and the section of the hoisting rope HSL as a function of the hoisting rope angle and derives therefrom the hoisting rope angle (in the y-direction and in the x-direction). The methods known per se for determining the hoisting rope angle can be used. Other known methods of measuring the angle of the hoisting rope. The angles (in the y-direction and in the x-direction) corresponding to the distance between the suspension point AUP and the mass center of the load carrying means UF relative to the vertical line passing through the suspension point AUP. The first angle sensor device 210 communicates with the control unit 100 to provide it with information about the angle of the corresponding hoisting rope. information.

[0104] A second angle sensor device 310 arranged on the load carrying means UF, for example in the form of a gyroscope, is configured to determine the load rope angle in the x-direction or in the y-direction relative to a perpendicular through the suspension point ANP of the load L to the load carrying means UF. Load rope angle Indicates the angle in the x-direction or y-direction between the distance between the suspension point ANP and the center of mass of the suspended load and the direction of the vertical line passing through the suspension point ANP. The second angle sensor device 310 is in communication with the control unit.

[0105] The load rope length l2 of the load rope LSL, or in case of another sling arrangement, the distance between the load carrying device UF and the center of mass of the load L is for example specified or user-determinable. Alternatively, the distance can also be determined by using appropriate measuring devices.

[0106] The trolley travel unit KW, which is arranged to be fixed to the trolley boom KA, is connected to the trolley LK by means of a trolley rope KSL for movement along the trolley boom KA. The trolley travel unit KW comprises a brake, an electric motor, a transmission, and a double-rope winch. The double-rope winch comprises two sections connected by a common shaft. When the double-rope winch rotates in the direction of rotation, the common shaft winds up one section of the trolley rope KSL and unwinds the other section, thereby moving the trolley LK.

[0107] A position sensor device 420 (e.g., a rotation angle sensor that counts the number of revolutions of the trolley travel unit KW) is arranged fixed to the frame 402 and generates a sensor signal indicating the position x of the trolley LK. The position x of the trolley LK corresponds to the position of the suspension point AUP.

[0108] The angular difference sensor device 410 is configured to determine the rotational angle difference Δθ between the rotation angle θ_u of the trolley arm KA about the vertical axis H and the current rotational angle θ of the position of the trolley LK about the vertical axis H. The angular difference sensor device 410 for determining the rotational angle difference Δθ is arranged to be fixed to the trolley arm KA, in particular, to the trolley arm KA or to the frame 402 of the trolley travel unit KW. The angular difference sensor device 410 can be configured, for example, to determine the lateral distance between the angular difference sensor device 410 and a section KSL#1 of the trolley cable KSL, located between the deflection roller 6 fixed at the proximal end of the trolley arm KA and the trolley LK, using ultrasonic measurement technology. The deflection roller 8, arranged at the distal end of the trolley arm KA, deflects the trolley cable KSL from the trolley travel unit KW toward the trolley LK. The rotational angle difference Δθ can then be determined in the angular difference sensor device 410 or in the control unit 100 based on the sensor signal representing the distance. Furthermore, other methods known per se for determining the rotation angle difference Δθ are also suitable. The angle difference sensor device 410 is used to determine the deviation between the rotation angle θ_u of the trolley arm KA caused by the elastic deformation of the trolley arm KA and the actual rotation angle θ of the suspension point AUP of the trolley LK or the load system.

[0109] The trolley travel unit KW includes a frame 402 and a drive unit fixed to the frame 402 for winding and unwinding the trolley rope KSL. An angle difference sensor device 410 fixed to the frame 402 is configured to determine a rotation angle difference Δθ between a rotation angle θ_u of the trolley boom KA about the vertical axis H of the tower T of the tower crane 2 and a current rotation angle θ of the trolley LK or the suspension point AUP about the vertical axis H.

[0110] Another tilt sensor device 220, for example in the form of a gyroscope, is fixed to the trolley LK, in particular to the chassis of the trolley LK, and is used to determine the tilt angle of the trolley LK relative to the horizontal plane. (luffing angle difference). The tilt sensor device 220 determines a sensor signal that characterizes the tilt of the trolley LK relative to the horizontal plane, in particular the tilt angle relative to the horizontal plane in the xh plane spanned by the vertical axis h and the longitudinal axis x of the trolley boom KA. In order to calculate the current hoisting rope angle in the x direction The control unit 100 may consider the tilt angle As a tool for determining the angle of the hoisting rope relative to the vertical line passing through the suspension point AUP This is necessary because the first angle sensor device 210 usually tilts together with the trolley LK and is used to measure the angle of the lifting rope. This angle error cannot be identified.

[0111] The control unit 100 is configured as a conventional data processing device and performs processing to operate the slewing mechanism DW, the hoisting mechanism HW, and the trolley travel unit KW according to all or part of the following variables: rotation angle θ_u, rotation angle difference Δθ, hoist rope angle Load rope angle for hoisting rope length l1 The length of the load rope l2, the mass of the suspended load, the position x of the trolley travel unit, and the inclination angle

[0112] In order to control the slewing mechanism DW, the hoisting mechanism HW and the trolley travel unit KW, the actuation rate u * DW 、u * HW 、u * KW is specified as an actuation variable for the motor arranged therein. In other embodiments, control can also be performed by torque specification.

[0113] The hoisting rope HSL suspended on the trolley LK, the load carrying device UF, the load rope LSL and the load L form a load system. The load system represents a multi-pendulum, whose suspension point AUP is assumed to be between the two sections HSL#1 and HSL#2 of the hoisting rope HSL. Figure 2 and Figure 3 , and comprises two sections HSL#1 and HSL#2 of a hoisting rope HSL, a load-carrying device UF suspended from the hoisting rope HSL, a load rope LSL arranged below the load-carrying device UF, and a load L arranged on the load rope LSL. In this context, a multi-pendulum or double pendulum is understood to be a load system located below the trolley LK or below the deflection rollers 202, 204 of the trolley LK, respectively.

[0114] The operating unit 900 is provided for operating the crane. The operating unit 900 is configured as, for example, a control panel in the cab of the crane operator and / or as a remote control device configured to communicate with the control unit 100. For example, the joystick 910 of the operating unit 900 can be used to implicitly transmit a target variable S specifying a movement speed in the x-direction and / or in the y-direction to the control unit 100. sollFurthermore, the lifting or lowering of the load by means of the lifting mechanism HW can be specified by the user in the form of a target variable. The target variable includes u * LKsoll 、u * DWsoll and / or u * HW soll and the actuation rates of the motors for the trolley travel unit KW, the slewing mechanism DW and / or the hoisting mechanism HW can be specified and converted into corresponding movements of the suspension point AUP and changes in the hoisting rope length l1 in a manner known per se according to the mechanical specifications to obtain the target specification x' soll ,θ' soll and / or l' soll The target specification can also be specified directly as x' soll ,θ' soll and / or l' soll .

[0115] Figure 2 Shown Figure 1 Schematic diagram of a double pendulum in a tower crane. In this double pendulum formed by the sections HSL#1 and HSL#2 of the hoisting rope HSL, the load carrying device UF, the load rope LSL and the load, there are two relevant angles relative to one direction: the hoisting rope angle at the suspension point AUP relative to the vertical line passing through the suspension point AUP and the angle of the hoisting rope relative to the vertical line passing through the suspension point AUP. and the load rope angle at the suspension point ANP relative to the vertical through the suspension point ANP

[0116] Figure 3 A simplified diagram of the multiple pendulums proposed in this specification for preventing or reducing pendulum motion is shown. For the state control described below, Figure 2 The multiple pendulums shown are treated as a single pendulum. The relevant parameters in this case are the pendulum angle of the load L relative to the deflection of the trolley LK Direct measurement using robust sensor technology is difficult. Therefore, for one direction, the hoist rope angle obtained as described above is used. Hoisting rope length l1, load rope length l2 and load rope angle To calculate the swing angle To compensate for the hoist rope angle in the x-direction The inclination angle of the trolley cantilever KA relative to the horizontal direction can be considered The angle of the lifting rope in the x direction is obtained For the hoisting rope angle in the y direction No such correction is required.

[0117] Since the mass of the load L is assumed to be significantly higher compared to the mass of the load carrying means UF, the inclination of the load carrying means UF corresponds to the inclination of the suspended load and thus results in That is, for the x direction and for the y direction

[0118] Reference Figure 1 , Figure 4 The diagram shows a method for determining the setting u by the control unit 100 for the trolley LK, the slewing mechanism DW and the lifting mechanism HW. * LK 、u * DW 、u * HW The respective actuation rate can be specified, for example, as a percentage of the maximum speed (rated speed) of the respective drive motor (trolley travel unit KF, slewing gear DW and hoisting gear HW).

[0119] Reference Figure 4 In the swing angle calculation block 110 of the control unit 100, the swing angles in the x-direction and the y-direction can be calculated in different ways.

[0120] The exact calculation gives the length l of the double pendulum as follows:

[0121]

[0122] And the swing angle in the x and y directions Respectively resulting in:

[0123]

[0124] This calculation can be simplified by an approximation of the form of sensor fusion, where:

[0125] l=l1+l2

[0126]

[0127] Among them, the factor k x and k y can be specified as a constant, in particular in the range between 0.25 and 0.75; or can be set according to a characteristic diagram or function based on the hoisting rope length l1 and / or the mass of the suspended load L, for example

[0128] The control unit 100 is supplied with at least the above-mentioned sensor variables and target variable S soll , to determine the speed u according to the state control device 120* LK 、u * DW 、u * HW The target variables may include a target speed or a target torque of the trolley travel unit KW, a target speed or a target torque of the slewing mechanism DW, and a target speed or a target torque of the hoisting mechanism HW.

[0129] Furthermore, a function block 130 is provided, which controls the operation of the state control device 120 , and in particular controls the operation of the state control device 120 according to the operation of the operation unit 900 , so that various operation functions can be implemented.

[0130] In the rotation angle calculation block 140 , the rotation angle θ determined by the rotation angle sensor device 510 is added to the rotation angle difference Δθ measured by the angle difference sensor device 410 and a corrected rotation angle θ is provided for the actual rotation angle of the trolley arm KA about the vertical axis H.

[0131] With the help of appropriate derivative blocks 150, 160, 170, 190, the swing angle can be generated The time derivative of the corrected rotation angle θ and the velocity x' of the suspension point AUP is θ' and x'.

[0132] Furthermore, the position x of the trolley LK (as the position of the suspension point AUP) is provided by the state-controlled position sensor device 420. The trolley speed x' (as the speed of the suspension point AUP) can be provided to the state control device 120 as a time derivative by means of the derivative block 190. Alternatively, the trolley speed x' can be read directly from the control unit 900, since the trolley speed is indicated very accurately there with a known (measured) motor speed and a known transmission ratio.

[0133] A control parameter block 180 is provided for determining a control vector Kx=[K1, K2, K3, K4] for the corresponding motion direction (x-direction and / or y-direction) from the system matrix A and the input vector b, based on the mass m of the load system measured by the mass sensor device 620, based on the position x of the trolley LK (or the suspension point) measured by the position sensor device 420, and based on the length l1 of the hoisting rope or the total pendulum length l of the multi-pendulum. T Ky=[K5,K6,K7,K8] T The control parameter K is provided to the state controller 120 and is a function of the mass m, the pendulum length l, and, where applicable, the position x of the trolley LK (or suspension point).

[0134] When at least one of the parameters mass m, pendulum length l, and position x of the trolley LK (or suspension point) changes, in particular by exceeding a predetermined absolute or relative deviation value (e.g., 2%) according to a state-space parameter determination method known per se, the system matrix A and the input vector b are updated. Using the system matrix A and the input vector b, the control parameter block 180 performs a pole placement method known per se or an LQ method known per se to determine the corresponding control vectors Kx, Ky based on the state-space description.

[0135] The state control device 120 can be described using a state-space expression. In this state-space expression, a linear nth-order system is decomposed into n first-order subsystems to achieve a simple control parameterization. The state control of the trolley travel unit KW and the slewing mechanism DW can be considered separately.

[0136] In the state control of the trolley travel unit KW, the swing angle in the x direction Its angular velocity The position x of the car and the velocity x' of the car LK are considered as state variables.

[0137] The purpose of state control is to calculate the state variables of the state variable vector Z and the specified target variable S soll =u * KWsoll ,u * DWsoll ,u * HW , or if necessary in the corresponding transformation x' soll ,θ' soll 、l' soll Afterwards, the actuation variable u is calculated * LK 、u * DW 、u * HW Therefore, the control deviation of the state variable is multiplied by the corresponding updated control parameters from the control vector Kx, Ky. The sum of these products is then the corresponding desired actuation variable.

[0138] The state space expression of the car LK is as follows:

[0139]

[0140] where x' corresponds to the acceleration of the car LK (i.e. the suspension point AUP), and Angular acceleration corresponding to the swing angle. A LK corresponds to a 4×4 system matrix, and b LK Corresponds to the input vector with state space parameters for the state space description of the trolley travel unit KW. System matrix ALK An example of parameterization of and input vector b may be as follows:

[0141]

[0142] Where a1, a2, a3, b1, b2 are system parameters for control, which can be determined in a known manner, for example by physical modeling or empirically. The control vector K can be determined by appropriate application of the pole placement method or the LQ method, so that for the actuating variable u * LK The calculation rules for period calculation are as follows:

[0143]

[0144] In normal operation with active pendulum damping, the desired velocity u of the trolley (i.e., the suspension point AUP) is * LKsoll The nominal speed is specified by the operating unit 900 (in particular a joystick etc.) in the range from -100% to 100%. This nominal speed is converted into a speed x' of the trolley or more precisely the suspension point AUP according to the mechanical coupling to the trolley or more precisely the suspension point AUP.

[0145] In the state control of the rotary mechanism DW, the swing angle in the y direction Its angular velocity The rotation angle θ of the trolley cantilever and the rotation angular velocity θ′ of the trolley cantilever are considered as state variables.

[0146] The state space expression of the rotary mechanism DW is as follows:

[0147]

[0148] where θ” corresponds to the rotational angular acceleration, and Corresponds to the angular acceleration in the y direction of the pendulum angle. DW corresponds to a 4×4 system matrix, and b DW Corresponds to the input vector of state space parameters with the state space description for the slewing mechanism DW. System matrix A DW and input vector b DW An example parameterization of is as follows:

[0149]

[0150] Wherein, a4, a5, a6, b3, b4 are control parameters for control, which can be determined in a known manner, for example, by physical modeling or empirical determination. Control vector Ky = [K5, K6, K7, K8] Tcan be determined by appropriately applying the pole placement method or the LQ method so that the actuating variable u is obtained * DW The calculation rules for period calculation are:

[0151]

[0152] In normal operation with active pendulum damping, the desired rotational speed u of the slewing mechanism is * DWsoll The nominal speed is specified by the operating unit 900 (in particular, a joystick, etc.) in the range from -100% to 100%. This nominal speed is converted into the rotational angular speed θ' of the trolley boom or the angular speed θ' of the suspension point AUP according to the mechanical coupling with the trolley or the suspension point AUP.

[0153] The state controller may also include the hoist mechanism HW and may include the total pendulum length l and the pendulum speed l' as state variables. Therefore, the control model may have the following structure:

[0154]

[0155] State control uses the target variable u * DWsoll 、u * LKsoll and u * HWsoll As the target specification. Then, the corresponding target specification for control corresponds to the converted θ' soll 、x' soll and l' soll , which is composed of the target variable u * DWsoll 、u * LKsoll and u * HWsoll (Target specification) The corresponding drive device DW, LW, HW speed is converted into the corresponding movement speed of the rotary mechanism and trolley travel unit KW in the lateral direction (x, y) and the corresponding movement speed of the load in the vertical direction (h).

[0156] The control may follow a control cycle duration between 10 ms and 500 ms. The control system may have an observer that precalculates the state variables for the next time step. The observer structure is known from the prior art and will not be described in more detail herein.

[0157] Compared with conventional control systems, the actuation variable u of the load is calculated based on the available state variables * LK 、u * DW、u * HW The optimal trajectory (when counteracting the occurrence of oscillations that lead to pendulum motion) is determined so that violent pendulum motions caused by the crane operator or crane operation do not occur. Consequently, subsequent damping of the oscillating pendulum system is unnecessary. After the load has been lifted, and after activating the state control to perform the pendulum damping function using the corresponding target specification S, the target variables are converted into target specifications θ, x'set, and l'set, based on the corresponding mechanical coupling between the trolley travel unit KW, slewing gear DW, and hoisting gear HW and the trolley LK, trolley boom KA, and load-carrying device UF, and are taken into account in the control:

[0158] For the x-direction:

[0159]

[0160] For the y direction:

[0161]

[0162] where t is the current time step of the control, and x(t), x′(r), θ(t),θ′(t), is the currently measured and determined state variable.

[0163] The following applies to the pendulum damping function during crane operation:

[0164] x soll =f(u LKsoll )

[0165] x′ soll =0

[0166]

[0167] θ soll =f(uDw soll )

[0168] θ′ soll =0

[0169]

[0170] The function for determining the target position of the suspension point corresponds to:

[0171] x soll (t)=f(u * LKsoll )=x soll (t-1)+x' soll (t-1)*△t

[0172] θ soll (t) = g(u * DWsoll )==θ soll (t-1)+θ' soll (t-1)*△t

[0173] Here, Δt is the duration of a control cycle, for example between 10 ms and 100 ms. Furthermore, the functions f() and g() may also take into account a ramp function of the speed in order to limit the rate of change of the specified variable.

[0174] The entire control system can be described by the above state controller.The state controller is always active during the operation of the tower crane and remains active for a specified subsequent time after the end of the operating specification to prevent any subsequent oscillations.

[0175] Alternatively, the control can also be applied to only one or two of the moving parts, namely the movement of the trolley (i.e., the x movement of the suspension point AUP) (x direction), the rotational movement of the trolley boom (i.e., the y movement of the suspension point AUP) (y direction), or the movement of the lifting mechanism (h direction). Therefore, the considered states of the state control device 120 are reduced by the corresponding parameters.

[0176] In order to use the pendulum damping function implemented by the state control device, further additional functions for operating the tower crane can be implemented.

[0177] For this purpose, for example, a first operating element 920 can be provided on the operating unit 900, which the user can use to damp existing load or residual pendulum vibrations that occur after a load transport operation using a pendulum damping function. This pendulum damping function corresponds to the conventional pendulum damping function described above. When the first operating element 920, which can be configured as a push button switch, is operated, the pendulum damping function is activated and remains active for a subsequent time period, for example, between 5 seconds and 30 seconds, preferably between 5 seconds and 15 seconds, and in particular, 10 seconds, after the operation of the first operating element 920 is completed. The subsequent time period can be predefined or depend on the current pendulum length l. Therefore, the corresponding subsequent time can be variably predefined using a function or a lookup table based on the pendulum length l.

[0178] By providing the functionality of the first operating element 920 , a crane operator of a tower crane has the option of reducing shimmying that occurs due to brief, sudden application of forces to the load system, for example when crane operation is inactive, ie when there is no active transport movement.

[0179] Furthermore, when the first operating element 920 is actuated, the target position of the load can first be determined, which is used as an additional target specification for control. Typically, the position of the load L corresponds to the position x of the trolley (i.e., the suspension point AUP) and the current rotation angle θ of the boom. These data are then stored as the target specification x store ,θ store , and is used to divide the target specification θ' soll＝0 、x' soll＝0 and l' soll＝0 The pendulum damping is outside the control (no control for crane operation) and thus state control is performed. The following then applies to the target specifications in the above regulatory rules:

[0180] x soll =x store

[0181] x′ so11 =0

[0182]

[0183] θ soll =θ store

[0184] θ′ soll =0

[0185]

[0186] Figure 5 A corresponding flow chart illustrating the pendulum damping function is shown.

[0187] In step S1 , it is checked whether the pendulum damping function is activated when the crane is inactive. If this is the case (optional: yes), the process continues with step S2; otherwise (optional: no), the process continues with S1 .

[0188] In step S2, the position x, θ of the vehicle LK (i.e., the suspension point AUP) is temporarily stored as x store ,θ store , and is assumed to be the target variable for subsequent control.

[0189] In step S3, state control is performed, wherein, in addition to the target specification θ' for the pendulum damping soll＝0 、x' soll＝0 and l' soll＝0 In addition, it is assumed that the target specification x soll =x store ,θ soll =θ store , and execute state control accordingly.

[0190] In step S4, check whether the pendulum damping function has ended and whether the subsequent time has passed. If this is the case (optional: yes), then the process ends, otherwise (optional: no), the program returns to step S3 and continues state control.

[0191] A disturbance variable compensation function can be provided by means of a functional extension that can be activated or deactivated via the second operating element 930. This disturbance variable compensation function can, for example, take into account external influences on the load system, such as wind pressure or ground vibrations, and maintain the current position of the load L despite (persistent) disturbances. If the function is activated by operating the second operating element 930, it remains active until it is terminated by a corresponding operation of the second operating element 930. The disturbance variable compensation function remains active only if the crane is not actively operated, i.e., if the load is not moved within external target specifications.

[0192] Figure 6 A flow chart illustrating the disturbance variable compensation function is shown.

[0193] In step S11, it is checked whether the interference variable compensation function is activated when the crane is inactive. If this is the case (optional: yes), the process continues with step S12. Otherwise (optional: no), the process continues with S11.

[0194] In step S12, the current absolute load position px soll 、py soll The current absolute load position px to be stored as the target specification. soll 、py soll Can be identified as:

[0195]

[0196] In step S13, the state control is activated, wherein the state control is provided with the position x of the vehicle according to the control cycle. soll and the rotation angle θ soll Different target specifications. Pendulum length l soll Remain unchanged.

[0197] Then the following applies to keep the absolute position of the payload px soll 、py soll :

[0198]

[0199] These values ​​are determined continuously, i.e. recalculated for each control cycle, since the swivel angle and the angular velocity of the pendulum It can change continuously as the interference effect changes.

[0200] The target specification of the state variables during active disturbance variable compensation is then:

[0201]

[0202] x′ soll =0

[0203]

[0204] θ' soll =0

[0205]

[0206] Among them, x soll ,θ soll The control cycle is continuously updated as described above. Therefore, it is possible to react appropriately to changing disturbances and the absolute position of the load remains unchanged.

[0207] The state variables are marked as undefined by setting the corresponding control deviation or the associated elements (factors) of the control vector K to zero during the active disturbance variable compensation function. Not considered in the control.

[0208] In step S14, it is checked whether the interference variable compensation function has ended. If so (optional: yes), the process ends, otherwise (optional: no), the system returns to step S13 and continues state control.

[0209] The disturbance variable compensation function can be deactivated by correspondingly actuating the second operating element 930 or by a joystick actuation to initiate load transport.

[0210] The positioning function can be activated by actuating a third operating element 940 (e.g., in the form of a push button switch). The positioning function remains active as long as the third operating element 940 is actuated and remains active for a predetermined subsequent time (e.g., between 5 seconds and 30 seconds, preferably between 5 seconds and 15 seconds, e.g., 10 seconds). The positioning function is configured to move the load by manually pushing and pulling the load in the drop zone, thereby guiding the load to the correct desired load position with high precision.

[0211] Figure 7 A flow chart illustrating the positioning function is shown.

[0212] In step S21, it is checked whether the positioning function is activated when the crane operation is inactive. If this is the case (optional: yes), the process continues with step S22. Otherwise (optional: no), the process continues with S21.

[0213] In step S22, the state controller is activated without considering the target specifications of the position x, θ and the speed x', θ', the carriage LK and the slewing mechanism DW, wherein the target specifications are assumed to be as follows:

[0214] x soll =Undetermined

[0215] x′ soll =Undetermined

[0216]

[0217] θ soll =Undetermined

[0218] θ′ soll =Undetermined

[0219]

[0220] The state variable x marked as undefined is not considered in the control process soll , x′ soll ,θ soll ,θ′ soll , since during an active disturbance variable compensation function the corresponding control deviation or the associated elements (factors) of the control vector K are set to zero.

[0221] In step S23, it is checked whether the positioning function has ended. If this is the case (optional: yes), the process ends, otherwise (optional: no), the program returns to step S22 and continues state control.

[0222] The third operating element 940 must be permanently activated during positioning to prevent uncontrolled movement of the load L. When the load L or the load carrying device UF is pulled, the swivel angle deviates from zero. The state control device is forced to perform a compensating movement in the pulling direction, so that the load moves in the corresponding direction according to the pulling. Once the tension is removed, the trolley LK positions itself accurately above the load L and thus fixes the new load position.

[0223] Furthermore, a load-lifting function can be implemented that is permanently activated or can be activated using the fourth operating element 950, which provides additional safety when lifting a load. If the trolley LK (i.e., the suspension point AUP of the hoisting rope) is not positioned exactly vertically above the center of mass, lifting the load will cause an immediate oscillation that depends on the lateral offset of the suspension point AUP relative to the center of mass. In practice, this is almost always the case, as crane operators are generally unable to position the load-carrying device UF exactly above the center of gravity of the load.

[0224] By using the above-described state control means, when the load carrying means UF is fastened before the load L is lifted, the suspension point AUP can be accurately positioned above the centre of mass.

[0225] Reference Figure 8 The flow chart shown in FIG. 1 illustrates the load lifting function in more detail.

[0226] In step S31 , the crane operator activates the hoisting mechanism HW, for example using the fourth operating element 950 , in order to lift the load according to specifications.

[0227] In step S32, it is checked whether the load lifting function is activated. If this is the case (optional: yes), the process continues with step S33. Otherwise (optional: no), the process ends by returning to step S36.

[0228] In step S33, the lifting force is monitored using the mass sensor device 620. If the lifting force exceeds a predetermined threshold lifting force value that can be determined from the weight of the load carrying device UF, the hoisting rope HSL and the load rope LSL, it can be assumed that the hoisting rope HSL is taut and the measured swing angle Indicates the offset of the center of mass relative to the suspension point AUP on the trolley LK. In this case (optional: yes), the process continues with step S34, otherwise (optional: no), the process returns to step S33 and continues to wait for the threshold lifting force value to be reached.

[0229] Then, in step S54, state control is started by specifying the target specification:

[0230] x soll =Undefined

[0231] x' soll =Undefined

[0232]

[0233] θ soll =Undefined

[0234] θ′ soll =Undefined

[0235]

[0236] By setting the corresponding control deviation or the associated element (factor) of the control vector K to zero during an active disturbance variable compensation function, the state variables marked as undefined are not taken into account during the control process.

[0237] In step S35, it is checked whether the swing angle has been reached and the angular velocity of the pendulum The target specification is that all corresponding control deviations are below a specified threshold, for example, less than a specified threshold of 0.3° for the corresponding swing angle. Typically, this threshold can be a function of the hoist rope length. For example, for a hoist rope length greater than 20 m, the threshold is 0.1°, and for a hoist rope length l1 less than 20 m, the threshold is 0.2° to 0.3°. If this is the case (optional: yes), the process continues with step S36. Otherwise, the state control of step S34 continues.

[0238] State control is therefore further executed before the lifting force is further increased to a point beyond which the actual load is lifted. This enables the trolley LK to be precisely positioned above the center of gravity of the load so that the load can be lifted without initial oscillation (i.e. vertical).

[0239] Then, the load is increased in step S36.

[0240] Furthermore, a position approach function can be activated using the fifth operating element 960. This position approach function ensures that when approaching a stored position, the stored position is approached and the load L is stopped at the stored position without oscillation. Only after stopping at the stored position is the position approach function deactivated again, and the load can be moved in any direction according to the crane operator's operation.

[0241] In step S41, it is checked whether the position proximity function has been activated. If this is the case (optional: yes), for example when the fifth operating element 960 is operated, the current absolute position x, θ of the load L or the trolley LK (i.e. the suspension point AUP) is can be stored in step S42 (eg, as x store ,θ store ).

[0242] If the absolute load position is stored according to the position proximity function, then in step S43 the crane may be operated in a conventional manner.

[0243] In step S44, it is checked whether the current absolute position of the load L or the position of the suspension point AUP is approaching the stored position, which is determined by continuously performing queries. If it is determined (optional: yes), in step S45, the stored position x soll =p x ,θ soll =p y is assumed to be the target position of the load, and the state control is performed accordingly. In this case, further actions by the crane operator (or the automated crane control system) are independent of further target specifications. After determining the approximate stored position, only the positions x, θ are specified as target specifications, so that the state controller performs pure position control. The target specification then corresponds to:

[0244] x soll =p x ;

[0245] x′ so11 =0

[0246]

[0247] θ soll =p y ;

[0248] θ′ soll =0

[0249]

[0250] State variables marked as undefined are not taken into account in the control process by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero during the active position approach function.

[0251] If it is determined in step S46 that the stored position has been reached (optional: yes), the state control is temporarily ended in step S47. Otherwise (optional: no), the process proceeds to step S45.

[0252] If the position that has been approached is deviated again due to activation of the crane operation, the position approach function is reactivated and the process proceeds to step S43.

[0253] It may be provided that when the fifth operating element 960 is operated again, the stored load position is forgotten.

Claims

1. A method, in particular a computer-implemented method, for operating a slewing jib crane (2) by means of state control, wherein: The state control enables control of the movement of the suspended load (L) in at least one direction of movement and is based on a state vector, the method comprising the following steps: - detecting state variables of said state vector, said state variables containing information about the position (x, θ) and the velocity (x', θ') of the movable suspension point (AUP) and about the position of the load of the center of mass of the load system relative to said suspension point (AUP) with respect to said at least one direction of movement and load speed the load system being suspended to the movable suspension point according to information of the load carrier, the load system comprising a hoisting rope (HSL), a load carrying device (UF) arranged at the lower end of the hoisting rope (HSL), and, where appropriate, a load (L) suspended below the load carrying device (UF), - determining, based on the state control, at least one actuation variable (u) for moving the suspension point (AUP) in the at least one direction of movement * LK ,u * DW ,u * HW ); - according to the at least one actuation variable (u * LK ,u * DW ,u * HW ) operates the slewing cantilever crane (2).

2. The method according to claim 1, wherein The state control is implemented in such a way that when the state of the crane changes, in particular when the length (l1) of the hoisting rope and / or the radial position of the suspension point (AUP) changes, and in particular as a function of the mass of the load system, a parameterization of the state space description in the state space is updated and a linear combination of control deviations of the state variables indicated by control vectors (Kx, Ky) is determined by a pole placement method or an LQ method, said linear combination being used to calculate the at least one actuating variable (u) for moving the suspension point (AUP). * LK ,u * DW ,u * HW ).

3. The method according to claim 1 or 2, wherein: The at least one actuation variable (u * LK ,u * DW ,u * HW ) includes: the adjustment speed of the trolley travel unit (KW) of the tower crane or the adjustment speed of the boom angle of the mobile crane (KA) and / or the adjustment speed of the slewing mechanism (DW).

4. The method according to claim 1 , wherein: The load position as the relative position of the center of mass of the load system with respect to the suspension point is indicated as a function of a hoisting rope angle indicating an angular deviation of the hoisting rope attached to the suspension point (AUP) relative to a vertical line passing through the suspension point (AUP) and a load rope angle indicating an angular deviation of the center of mass of the load (L) at the suspension point on the load carrying device (UF) relative to the vertical line, wherein the load position is also determined in particular from the hoisting rope length (l1) between the suspension point (AUP) and the mass center of the load carrying device (UF) and / or the load rope length (l2) between the suspension point (ANP) and the mass center of the load, wherein in particular the load position Indicated as the swing angle of the center of mass relative to the vertical through the suspension point (AUP) Alternatively indicated as the perpendicular distance of the center of mass to the perpendicular line through the suspension point (AUP).

5. The method according to claim 1, wherein The state control is operated to implement a pendulum damping function, in particular in case a manual or automatic crane operation specifies a speed of the suspension point (AUP) for at least one of the movement directions, or in case a first operating element (920) is operated for activating the pendulum damping function, wherein for pendulum damping the load position with respect to the center of mass of the load system is and the load speed The target specifications of the information are in each case specified as zero, the target specifications of the speed (x') of the suspension point (AUP) are specified as zero, and the target specifications of the position of the suspension point (AUP) are specified as the position as a function of the specified speed of the suspension point (AUP).

6. The method according to claim 5, wherein: When all target variables are set to zero, shimmy damping remains active for a predetermined subsequent time.

7. The method according to claim 1, wherein The state control is operated or operable to implement a disturbance variable compensation function, wherein the state control is continuously supplied with target specifications for the position of the suspension point (AUP) determined from the stored absolute position of the load and a target specification for the speed of the suspension point (AUP) to be zero, and in particular by adjusting the load position of the center of mass of the load system during the activated disturbance variable compensation function and the load speed The corresponding control deviation is set to zero without considering the load position of the center of mass of the load system and the load speed , wherein, in particular, the target specification of the specification of the position of the suspension point (AUP) is based on the current load position of the center of mass , the pendulum length (l) of the load system and the current position of the suspension point (AUP).

8. The method according to claim 7, wherein: The disturbance variable compensation function can be activated and deactivated by means of a second operating element (930) and is in particular deactivated during active crane operation of load transport, wherein the absolute position of the load (L) is in particular stored when the disturbance variable compensation function is activated.

9. The method according to claim 1, wherein The state control is operated or operable to perform a positioning function, wherein the load position of the center of mass of the load system is provided to the state control and the load speed The specification of zero is used as the target specification and is achieved in particular by setting the corresponding control deviation or the associated elements (factors) of the control vector K to zero during the activated positioning function regardless of the position (x, θ) and speed (x', θ') of the suspension point (AUP).

10. The method according to claim 1, wherein: When a load (L) is to be lifted, the state control is operated or operable to implement a load lifting function, wherein the load position is determined when the lifting force on the hoist rope (HSL) exceeds a predetermined lifting force threshold and the load (L) has not yet been lifted. Specifications, where the state control is based on the load position and the load speed and a target specification of zero speed (x', θ') of the suspension point (AUP), in particular by setting the corresponding control deviations or the associated elements (factors) of the control vector K to zero during the activated load lifting function without taking into account the control deviations relative to the position (x, θ) of the suspension point (AUP).

11. The method according to claim 1, wherein: The state control is operated or operable to implement a position approach function, wherein a stored position is approached and the load (L) is brought to rest at the position, wherein the current position is stored according to a user request, wherein the state control is performed with target specifications of a position (x, θ) of the suspension point (AUP) corresponding to the stored position, a target specification of a speed (x', θ') of the suspension point (AUP) being zero, and the load position is performed as soon as the position of the suspension point (AUP) during ongoing crane operation approaches the stored position of the suspension point (AUP), in particular below a predetermined threshold distance. and the load speed A target specification of zero.

12. A device, in particular a control unit (100), for operating a slewing jib crane (2) by means of state control, wherein: The state control enables control of the movement of the suspended load (L) in at least one direction of movement and is based on a state vector, wherein the device is configured to: - detecting state variables of said state vector, said state variables containing information about the position and velocity (x', θ') of the movable suspension point (AUP) and about the position of the load of the center of mass of the load system relative to said suspension point (AUP) and load speed The load system is suspended to the movable suspension point according to information of the load carrying device, the load system comprising: a hoisting rope (HSL), a load carrying device (UF) arranged at the lower end of the hoisting rope (HSL), and a load (L) suspended below the load carrying device (UF), - determining, based on the state control, at least one actuation variable (u) for moving the suspension point (AUP) in the at least one direction of movement * LK ,u * DW ,u * HW ); - according to the at least one actuation variable (u * LK ,u * DW ,u * HW ) controls the slewing cantilever crane (2).

13. A slewing cantilever crane (2), comprising: - one or more drive means for moving the suspension point for the load system; - Device according to claim 12, wherein the slewing jib crane (2) is controlled by controlling the one or more drive devices (LW, DW).

14. A computer program product comprising instructions which, when the program is executed by at least one data processing device, cause the at least one data processing device to perform the steps of the method according to any one of claims 1 to 11.

15. A machine-readable storage medium comprising instructions, which, when executed by at least one data processing device, cause the at least one data processing device to perform the steps of the method according to any one of claims 1 to 11.

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