Device for operating a jib slewing crane and jib slewing crane

Abstract

Device, in particular control unit (100), for operating a jib slewing crane (2) using a state control system, wherein the state control system controls the movement of an attached load (L) at least in one direction of movement and is based on a state vector, wherein the device is configured to: - Acquisition of state variables of the state vector, which includes information on a position and a velocity (x', θ') of a movable suspension point (AUP) to which a load system comprising a lifting rope (HSL), a load-bearing device (UF) arranged at a lower end of the lifting rope (HSL) and a load (L) suspended below the load-bearing device (UF) is attached, and information on a load position (φ x , φ y ) and a load velocity (φ' x , φ' y ) of a center of mass of the load system with respect to the suspension point (AUP), - Determine at least one control variable (u* LK, u* DW , u* HW ) for the movement of the suspension point (AUP) in at least one direction of movement based on state control; - Controlling the jib slewing crane (2) depending on at least one control variable (u* LK , u* DW . u* HW ).

Description

Technical area

[0001] The invention relates to jib cranes for controlling a movement of a suspended load and in particular to measures for preventing pendulum swing. Technical background

[0002] Cranes, and in particular jib cranes or handling cranes, such as tower cranes, mobile cranes, and the like, enable the movement of a load by suspending the load from a lifting rope on a boom, lifting the load, moving the load in a substantially horizontal plane, and setting it down. The movement of the boom is effected by suitable drive devices, and the lifting and setting down of the load is carried out using a hoist connected to a hoist rope.

[0003] For handling cranes, the time required for a transport cycle can be crucial for trouble-free operation. During a transport cycle, the goal is to minimize unproductive downtime and optimize the crane's productive operating time.

[0004] For example, in a tower crane, the load is moved by rotating the boom and by moving a trolley along the boom. In mobile slewing cranes, the load is moved by rotating the boom and, if necessary, by luffing the boom up and down about a horizontal luffing axis. The drive devices and the hoist are usually controlled manually by a crane operator using suitable controls on a crane control unit. During acceleration and deceleration, the suspended load is deflected relative to the suspension point on the boom, thus triggering a pendulum movement. A pendulum load can pose a potential hazard to both construction workers and construction equipment. To prevent such undesirable pendulum movement of the suspended load, state-of-the-art measures for dampening the pendulum movement during crane operation are known.

[0005] For example, DE 10 2009 032 270 A1 discloses a method for controlling a drive of a mobile crane, wherein a target movement of the boom tip serves as the input variable, based on which a control variable is calculated to control the drive. When calculating the control variable, the vibration dynamics of the system consisting of the drive and the crane structure are taken into account in order to reduce natural vibrations.

[0006] EP 1 628 902 B1 discloses a crane for handling loads suspended from a load rope, comprising a slewing gear for rotating the crane, a luffing gear for tilting a boom, and a hoist for lifting the load suspended from the rope. A path control system calculates an optimal control trajectory based on a nonlinear model approach and updates it through feedback of state variables. The output variables of the path control system are directly or indirectly input into a closed-loop control system for the position or speed of the crane. The reference variables for the path control system are generated in such a way that a load movement with minimized pendulum deflections is achieved.

[0007] From EP 1 652 810 B1 a method for controlling a crane operating unit for suppressing vibrations of a load suspended from a rope of a crane is known, in which control is carried out by actuating a control device having a filter unit.

[0008] To prevent swaying, predictive control of crane motion is known for applications in cranes to suppress swaying. See, for example, 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 from Liebherr Werk Nenzing GmbH dated September 2012. This function enables the sway-free operation of a mobile harbor crane when handling ISO containers between freighters and a harbor edge area.

[0010] Especially in complex crane structures, conventional sway control devices are insufficient to adequately dampen or suppress sway. In particular, the diverse dynamic effects during lifting, lowering, and moving of the load due to the diverse deformations of the crane structure cannot be adequately modeled using a physical model, so the sway cannot be adequately dampened.

[0011] Conventional methods are generally based on an assumed load position, which is determined approximately, for example, using a hoist rope angle with respect to the vertical, usually at the hoist rope suspension point on the boom. However, wind pressure and other dynamic influences can cause transverse oscillations of the hoist rope, so that the measured hoist rope angle does not correspond to the angle of the distance between the suspension point on the boom and the load's center of gravity. Furthermore, in crane operation, the load to be suspended is attached to a load-handling device, such as a bottom block, so that the non-negligible weight of the load-handling device creates a double pendulum system that often executes a chaotic oscillating motion when excited.This is difficult to predict using conventional physical models, significantly impairing the quality of sway control based solely on the hoist rope angle. Furthermore, the insufficient predictability of the load's sway can also lead to an intervention by the sway control algorithm, which can, in the worst case, amplify the sway.

[0012] It is an object of the present invention to provide a method and a device for operating a jib crane as well as a jib crane and a computer program product for carrying out the method, which dampens or suppresses a pendulum oscillation in an improved manner and further enables additional operating modes in order to make the transport process of the load safer, faster and easier to carry out. Disclosure of the invention

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

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

[0015] According to a first aspect, a method for operating a jib crane using a state control is provided, wherein the state control effects a control of a movement of a suspended load at least in one direction of movement and is based on a state vector, comprising the following steps: - Recording state variables of the state vector, which includes information on a position and a speed of a movable suspension point to which a load system comprising a hoist rope, a load-handling device arranged at a lower end of the hoist rope and a load suspended below the load-handling device is attached, and information on a load position and a load speed of a center of mass of the load system relative to the suspension point, - Determining at least one manipulated variable for moving the suspension point in the at least one direction of movement based on the state control; - Operation of the jib crane depending on at least one control variable.

[0016] As mentioned at the beginning, a fundamental problem when transporting a load using a jib crane is dampening or suppressing the sway of the suspended load to such an extent that construction workers can lift and lower the load, as well as suspend and unsuspend the load, quickly and safely. The goal is to dampen the sway during every phase of load transport, preventing sway and thus allowing the load to be lifted and lowered in a shorter time.

[0017] The load system comprises the suspended load, a load-handling device, a hoisting rope of adjustable length that connects the load-handling device to the suspension point, and a lifting device with which the suspended load is suspended from the load-handling device. Due to the mass of the hoisting rope and the mass of the load-handling device at the lower end of the hoisting rope, the oscillating load system with the suspended load forms a multiple pendulum system, which is not trivial to model and typically leads to erratic pendulum oscillations when subjected to lateral forces. Therefore, an exact determination of the actual load position is not easily possible.

[0018] The actual load position may indicate a relative position of a center of mass of the entire load system with respect to the suspension point on the boom and may be provided, for example, as an indication of a lateral load deflection relative to a perpendicular through the suspension point and / or as an indication of a sway angle relative to a suspension point of the load system with respect to a perpendicular through the suspension point in one or more lateral directions of movement. The load velocity may correspond to the relative velocity of the center of mass of the entire load system with respect to the suspension point.

[0019] Common pendulum oscillation damping methods for suppressing pendulum oscillation estimate the load position, i.e., the load deflection or the pendulum angle, in particular exclusively based on the hoist rope angle of the hoist rope at the boom suspension point and the hoist rope length, and the load speed by determining a derivative of the hoist rope angle. In reality, however, this does not allow for a useful determination of the load position and load speed for implementing state control. Using such a simplified determination of the load position leads, especially when using a state controller, to inaccurate control behavior and consequently to inadequate suppression of pendulum oscillation during crane operation.

[0020] In this regard, it is advantageous to design a control system for a movement of the load to an actual or an improved determined load position and thus to eliminate the disturbing effect of the estimation error for the load position.

[0021] For this purpose, the load position of the center of gravity can be determined depending on a hoist rope angle, which indicates an angular deviation of the hoist rope attached to the suspension point from the vertical through the suspension point, on a load rope angle, which indicates an angular deviation of a center of gravity with respect to a suspension point on the load suspension device from the vertical, on a hoist rope length between the suspension point and a center of gravity of the load suspension device, and on a load rope length, i.e. a length of the lifting device, between the suspension point and the center of gravity of the load.

[0022] A more precise determination of the load position is made possible by using state control for the operation of the jib crane. State control is suitable for implementing various operating modes of the jib crane. State control is based on a state vector and, given the specified target values, delivers a manipulated variable for at least one direction of movement, in particular an adjustment speed of a drive device, such as an adjustment speed of a trolley of a tower crane or an adjustment speed of a luffing angle of a boom of a mobile slewing crane and / or an adjustment speed of a slewing gear. State control is executed cyclically according to time-defined control cycles, in particular with control cycle durations of between 10 ms and 500 ms, preferably between 50 ms and 150 ms.

[0023] It has been shown that a state control system operated on a control unit of the jib crane is advantageous with a state vector which specifies, for a direction of movement, on the one hand the position and the speed of the suspension point of the load system and, on the other hand, the load position, ie the position of the center of mass of the load system relative to the suspension point (e.g. load deflection, pendulum angle).

[0024] The load velocity, i.e., the oscillation angle velocity, is determined in particular by temporally differentiating the change in load position (load deflection / oscillation angle). The oscillation angle indicates the angle of the actual load deflection, i.e., the deflection of the center of mass, relative to the suspension point on the boom to the perpendicular through the suspension point in at least one direction of movement, i.e., in a radial x-direction and / or a tangential y-direction.

[0025] The direct application of a state control to such a state vector makes it possible to avoid any inaccuracies resulting from elastic deformations and / or caused by transverse influences on the load and the load attachment. The state control can be designed, for example, to act on the slewing gear for the boom rotation and the drive device for a boom luffing in a mobile crane or, for example, on a slewing gear for the boom rotation and a trolley for moving a trolley in a tower crane as well as on a hoist separately, since the dynamics of the individual movement systems are very different. Thus, a movement of the load in the radial direction can be controlled by controlling the corresponding drive device for luffing or by controlling the trolley to move the trolley according to a manipulated variable, while a movement in the tangential direction, i.e.around the axis of rotation of the boom, can be achieved by controlling the slewing gear for a boom rotation.

[0026] The controls can be designed and implemented separately from one another. This allows various functions, including a sway damping function, to be implemented in different directions of motion, and the corresponding state controllers can be adapted appropriately to the different actuation dynamics of the drive devices (slewing gear, trolley, etc.).

[0027] By using a state controller, it is possible to precisely specify the trajectories of the manipulated variables for controlling the drive devices for moving the suspended load, so that, for example, pendulum swinging of the moving load is avoided during the load movement.

[0028] Suppressing the swinging of the load in all phases during crane operation makes it possible to suppress swaying at any time during the load transport process, i.e. a process of suspending the load, lifting the load, moving the load, lowering the load and unsuspending the load, and thus ensure a faster transport process, since waiting times due to swinging processes can be avoided.

[0029] The load system forms a multiple pendulum system between the suspension point on the trolley LK and the center of mass of the suspended load. This system includes other non-negligible masses along the load suspension, such as the load suspension device, which forms another vertex of a pendulum motion. It has been determined that the double or multiple pendulum system of the load system, consisting of hoist rope, load suspension device, load rope, and suspended load, can be considered a single pendulum for the implementation of state control if the load position relative to the suspension point on the boom is determined more accurately using sensor fusion or alternative methods.

[0030] In principle, the actual load position can be determined in a variety of ways. For example, a localization system that determines a position vector from a fixed point and a point on the attached load can be used to determine the load position. For this purpose, camera- or transponder-based localization systems can be used, for example, as known from DE 10 2020 120 699 A1.

[0031] Furthermore, determining the relative load position by fusion of sensor data from a first angle sensor device and a second angle sensor device has proven effective. These two angle sensor devices record angle data and transmit them to a control unit. The first angle sensor device is arranged at the suspension point of the hoist rope on the boom in order to determine a hoist rope angle in the x- and / or y-direction, i.e., in the radial and / or tangential direction relative to the boom rotation axis. The hoist rope angle is determined relative to the perpendicular through the suspension point.

[0032] Since the hoist rope angle of the hoist rope must be determined relative to the vertical, compensation of the measured boom angle at the hoist rope suspension point can preferably be provided. In this case, a rotation angle difference from the rotation angle around the boom pivot point due to elastic bending of the boom can be taken into account, e.g., using a known physical model or by measurement. The luffing angle (in the vertical direction) and a luffing angle difference (tilt angle) of the boom in the vertical direction due to elastic bending of the boom can also be taken into account, e.g., using a known physical model or by measurement.

[0033] With the help of the second angle sensor device, e.g. on the load handling device attached to the hoist rope, a load rope angle of the attached load with respect to the vertical through a suspension point of the load on the load handling device can be determined in the x and / or y direction. By merging the hoist rope angle and the load rope angle (each in the same directions), if the hoist rope length is known, i.e. the distance between the suspension point on the boom and the center of gravity of the load handling device, and if the length of the lifting gear or load rope with which the load is attached to the load handling device is known or specified, the relative load position, i.e. the lateral load deflection of the center of gravity of the load system with respect to the vertical through the suspension point or the pendulum angle of the center of gravity of the load system with respect to the vertical 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 an approximation based on the relatively small hoist rope angles and load rope angles of < 5° each using a linear function.

[0034] The jib crane can then be operated based on the thus assumed virtual single pendulum system using the state controller without considering the elastic deformation of crane structures due to torsional and bending moments, so that the implementation of the corresponding state control is possible in a simpler way.

[0035] It can be provided that the state control is implemented in that, in the event of a change in a crane state, in particular in the event of a change in a hoist rope length, and in particular depending on a mass of the suspended load and / or a radial position of the suspension point, a parameterization of a state space description is updated in the state space and a linear combination of the control deviations of the state variables is determined by a method of pole specification or a method based on the LQ method, which is used to calculate the at least one manipulated variable for moving the suspension point.

[0036] Thus, a state space representation for a direction of movement in the radial direction (x-direction) corresponds to [x′x″φ′xφ″x]=ALK[xx′φxφ′x]+bLKuLK

[0037] An example parameterization of the system matrix A LK and the input vector b LK is as follows: ALK=[01000a10000010a2a30] BLK=[0b10b2]

[0038] And for example: [x′x″φ′φ″x]=[01000−1T00000101lT−gl0][xx′φxφ′x]+[0CT0ClT]uLK where x is the radial x-position of the suspension point, φ x the pendulum angle (as load position) in radial direction, c a given constant, T a time constant of a transition function of following the suspension point when controlled with the manipulated variable u LK (preferably a velocity), g the gravitational constant and I a pendulum length I of the load system. "' " means the first time derivative and " " the second time derivative. Z corresponds to the state vector, A LK a system matrix and b LK an input vector. Other parameterizations of the system matrix A LK and the input vector b LK are possible. The system matrix A LK corresponds to a 4x4 system matrix and b LKa 4-dimensional input vector with state-space parameters of the state-space representation for the radial motion of the suspension point.

[0039] Here the parameterization of the system matrix A changes LK and the input vector b LK with each change in the pendulum length I.

[0040] By applying a pole specification procedure or an LQ method, an updated system matrix A LK an x-direction related control vector Kx= [K1, K2, K3, K4] T for a control equation applied to the movement of the suspension point: u∗LK=(xset−x(t))⋅K1+(x′set−x′(t))⋅K2+(φxset−φx(t))⋅K3+(φ′xset−φ′x(t)) ⋅K4 with t the current time step of the control, u* LK the control variable and x(t), x'(t), φ x (t), φ' x (t) the current measured and determined state variables.

[0041] The pole specification method and the LQ method are widely known from the state of the art, for example from Holger Lutz, Wolfgang Wendt “Handbook of Control Engineering”, Europa-Lehrmittel, 2021, ISBN 9783808558706 and Otto Föllinger, “Control Engineering”, Vde Verlag GmbH, 2022, ISBN 9783800755189.

[0042] Furthermore, a state space representation for a direction of motion in the tangential direction (y-direction or θ-direction) can correspond to [θ′θ″φ′yφ″y]=ADW[θθ′φyφ′y]+bDWuDW

[0043] An example parameterization of the system matrix A DW and the input vector b DW is as follows: ADW=[01000a40000010a5a60] bDW=[0b30b4]

[0044] And for example: [θ′θ″φ′yφ″y]=[01000mxgllA0000010(mx2gllA+gl)−gl0][θθ′φyφ′y]+[01lA0xllA]uDW where θ is the position of the suspension point, φ y the pendulum angle in the tangential direction, I Aa given I, which depends in particular on the mass of the load system A a moment of inertia acting on the slewing gear, m the mass of the load system, and u DW an input variable (preferably a speed) for the rotating mechanism, i.e. a drive device for a movement of the suspension point in the tangential direction. A DW corresponds to a 4x4 system matrix and b DW an input vector with state-space parameters of the state-space representation for the tangential motion of the suspension point. Other parameterizations of the system matrix and the input vector are also possible.

[0045] By applying the pole setting method or the LQ method, a y-direction related control vector Ky= [K5, K6, K7, K8] T for a control equation applied to the movement of the suspension point: u∗DW=(θset−θ(t))⋅K5+(θ′set−θ′(t))⋅K6+(φyset−φy(t))⋅K7+(φ′yset−φ′y(t)) ⋅K8 with t the current time step of the control, u* DW the control variable to be set and θ(t), θ'(t), φ y (t), φ' y (t) the current measured and determined state variables.

[0046] This also makes it possible to easily 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 the load speed (relative to the suspension point), i.e., a load deflection and a load deflection speed and / or the oscillation angle and the oscillation angular speed in one or two lateral directions of movement. The state vector Z can further include an indication of the current actuating position and adjustment speed of the respective actuating element, i.e., the boom, the trolley, and the like, in the respective x- or y-direction.The current adjustment speed in the x-direction corresponds to or depends on, for example, the luffing speed of the boom on a mobile crane or the trolley speed on a tower crane, and in the y-direction, the angular rotation speed of the boom. Accordingly, the adjustment position, for example, corresponds to the luffing angle or the position of the trolley on the boom for the x-direction and the rotation angle for the y-direction.

[0047] It can be provided that the state control is operated in order to implement a sway damping function, in particular when a manual or automated crane operation specifies a speed of the suspension point for at least one of the directions of movement, wherein for the purpose of sway damping a target specification of the information on the load position and the load speed of the center of mass of the load system is specified as zero, the target specification for the speed of the suspension point is specified as zero and the target specification for a position of the suspension point is specified as a position determined depending on the specified speed of the suspension point.

[0048] Oscillation damping is achieved with active state control by specifying a load position and a load speed of φ xsoll , φ ysoll = 0, φ' xsoll , φ' ysoll, ie by specifying a load deflection of 0 and a load deflection speed of 0 and / or by specifying a pendulum angle of 0 and a pendulum angular speed of 0. This means that the control objective is that there is no relative movement of the center of mass of the load system to the suspension point and that the center of mass is exactly perpendicular below the suspension point.

[0049] The target value x' soll , θ' sollFor the speed of the suspension point, a manually or automatically specified target value corresponds to zero, while the target specification of the position of the suspension point is determined depending on the speed of the suspension point specified by the crane operation. The target position of the suspension point can thus be determined by the temporal accumulation of distance increments, each of which corresponds to the product of the target speed specified by the crane operation and the control cycle duration, in order to avoid overshoot when the end position is reached. For example, when operated by the crane operator, a movement speed of the luffing of the boom or trolley in the x-direction and / or by rotating the boom in the y-direction can be specified in order to move the load according to the operator's request.

[0050] The target value can be entered via a joystick or the like and corresponds to a desired adjustment speed of a corresponding drive device, in particular in the form of a motor speed of the drive device in the form of a slewing gear and / or a trolley, etc. The target value of the speed can indirectly specify the control variables for the movement of the suspension point via the control system or, in accordance with a mechanical coupling, through a step-up or step-down gear according to a predefined coupling function (known for the crane configuration).

[0051] By specifying target states, various operating functions can be implemented. In the sway damping function during ongoing crane operation, the adjustment speed (x and / or y direction) specified by the crane operator becomes a target value for the position of the suspension point in the x and / or y directions. soll , θ soll cyclically accumulated depending on the control cycle duration, while in this case no target value for the speed of the suspension point x' soll , θ' soll is accepted.

[0052] The sway control function is active during crane operation. Crane operation is characterized by one of the target values ​​being other than zero, or by a control element being operated to move the crane. The sway control function can remain active as long as a predetermined follow-up time has not yet elapsed after a control element is no longer operated.

[0053] The implementation of the state control enables the implementation of additional comfort functions for the operation of the jib crane.

[0054] As described above, the control is only executed during active crane operation and ends after a predetermined run-on time after the operator is no longer in control or after the automatic control of a crane movement has ended. However, it may happen that a residual sway remains after the crane operation has ended and after the state control has been deactivated, for example due to interference or the like. In this regard, by actively actuating the first control element by a crane operator or by another construction site employee who has an appropriate communication link with the crane control unit, the sway damping function can be activated for a predetermined period of time even when the jib crane is stationary, whereby the target state variables of the load position and the load speed, i.e. the sway angle and the sway angular speed or the load deflection and the load deflection speed, are set to zero.After actuation of the first control element, the state control remains active for a predetermined follow-up time of between 5 and 20 s or until the load position and the load speed indicate no load movement for a certain period of time, e.g. between 1 s and 5 s, or indicate a load movement of less than a predetermined threshold value.

[0055] Furthermore, after actuating the corresponding first control element, a peak position of the pendulum oscillation can be determined in a conventional manner and set as the target position. Furthermore, the follow-up time of the active state control can be set according to the oscillation period, whereby the follow-up time can be set according to half the period.

[0056] It can be provided that the state control is operated or operable to implement a disturbance compensation function, wherein the disturbance compensation function is continuously provided with a target specification of the information on the position of the suspension point, which is determined depending on a stored absolute position of the load, and a target specification of the speed of the suspension point of zero, and the load position and the load speed of the center of gravity of the load system are disregarded, in particular by setting the corresponding control deviations of the load position and the load speed of the center of gravity of the load system to zero during the activated disturbance compensation function, wherein in particular the target specification of the information on the position of the suspension point is based on the current load position of the center of gravity,a pendulum length of the load system and the current position of the suspension point.

[0057] A disturbance compensation function can thus be provided as a further alternative or additional operating function. When the disturbance compensation function is activated, e.g. by operating a second control element, the current absolute position of the load can be specified or saved as the target position. The current absolute position of the load is determined as the position of the suspension point on the boom at the time the disturbance compensation function is activated and the current load position in the form of a deflection from the vertical by addition in one or both lateral directions, whereby the absolute position of the load is calculated using the load deflection or the pendulum angle, e.g. by applying trigonometric functions.The control then occurs according to the target values ​​for an absolute position of the suspension point, which are cyclically adjusted to the respective load position of the load system's center of mass and the corresponding load speed. The load position and load speed are not taken into account during the control process, in particular by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero while the disturbance compensation function is activated.

[0058] The disturbance compensation function can be manually activated and deactivated. The disturbance compensation function can be automatically deactivated when active crane operation is requested, as the active sway control procedure is then activated and a stored absolute position of the load system's center of mass is no longer to be maintained.

[0059] It can be provided that the state control is operated or operable to carry out a positioning function, wherein the state control is given the information on the relative position and the relative speed of the center of mass of the load system as target specifications of zero and the position and the speed of the suspension point are disregarded, in particular by setting the corresponding control deviations during the activated positioning function or the associated element (factor) of the control vector K to zero.

[0060] According to the positioning function, upon actuation of a suitable third control element, in particular by a construction site employee connected to the control unit of the jib crane via a mobile control device, a control of the load position and load speed of the center of gravity of the load system can be activated, whereby no control is performed on the position of the suspension point. Thus, only the load position (load deflection or the pendulum angle) or the load speed (load deflection speed or the pendulum angle speed), each of which is zero, is controlled. While the third control element, which is preferably designed as a touch element, is kept active, the load or the load handling device can be moved manually.By exerting a lateral force on the load handling device or the load, the active positioning function causes the load handling device to be displaced laterally, as the active state control attempts to return the load position (load deflection or oscillation angle), which deviates from zero due to the lateral force, back to the target value of zero. This moves the corresponding drive devices so that the compensating movement occurs in the direction of the force exerted on the load handling device. After deactivating or releasing the third control element, the oscillation damping control described above can be activated for a specified period of time, for example, between 5 and 20 seconds, to reduce any remaining residual vibrations.

[0061] It can be provided that the state control is operated or operable to implement a load lifting function when a load is to be lifted, wherein the information on the load position is determined when a lifting force on the hoisting rope exceeds a predetermined lifting force threshold value and the load has not yet been lifted, wherein the state control is carried out with target specifications for the load position and the load speed and a speed of the suspension point of zero, wherein the control deviation for the position of the suspension point is not taken into account, in particular by setting the corresponding control deviations or the associated element (factor) of the control vector K to zero during the activated load lifting function.

[0062] In particular, the load lifting function can be activated when the suspended load is lifted during ongoing crane operation. In practice, it is common for the load to be suspended with the center of mass and the suspension point of the hoist rope not being exactly vertical. When the load is lifted, a significant pendulum movement could occur due to the relative position of the center of mass of the load system being other than zero. For this reason, the hoist rope is first tightened before the load is lifted until it is taut. The tension in the hoist rope can be detected by monitoring an increase in force on the hoist rope during a tightening process. Active state control when the load has not yet been lifted means that the load position deviating from zero (the deflected pendulum angle orThe detected load deflection is compensated for and the control deviation regarding the oscillation angle / load deflection becomes zero. This positions the suspension point on the boom exactly over the center of gravity of the load system, and when this is achieved, the load can be lifted without any oscillation occurring. In particular, the lifting of the load is delayed until the oscillation angle is controlled to zero.

[0063] Furthermore, the state control can be operated or operable to implement a position approach function in which a stored absolute position of the load is approached and the load is brought to a standstill there, wherein an absolute position of the load is stored according to a user request, wherein the state control is carried out with a target specification for the position of the suspension point which corresponds to the stored position, a target specification for the speed of the suspension point of zero, a target specification for the position and the speed of the center of mass of zero, as soon as the position of the suspension point has approached the stored position of the suspension point during ongoing crane operation, in particular below a predetermined threshold distance.

[0064] According to the position approach function, which is activated by operating a fourth control element, a specific position can be approached in one or more directions of movement, i.e., in the x and / or y directions. This activates the crane control, and the load is moved according to the crane control. If the current position approaches the stored position, the load is stopped at the stored position and the function is then deactivated. Thus, after the load has stopped at the stored load position, the load can continue to be moved in any direction. As soon as the threshold distance is exceeded again, the position approach function can be reactivated.

[0065] The position approach function is based on state control for the x-direction and / or the y-direction by monitoring the distance between the suspension point position and the stored suspension point position. If the distance falls below a specified threshold, the manually or automatically specified target speed of the suspension point is set to zero, and the stored load position is used as the target. The load position (oscillation angle or load deflection) and the load speed (oscillation angular speed or relative load speed) are then also set to zero. Thus, by saving the suspension point position, a limit is set that cannot be exceeded during ongoing crane operation without first stopping the load at the relevant position or limit. The stored position can be deleted by deactivating the position approach function.

[0066] According to a corridor function, a movement trajectory can be specified as a sequence of target load positions along which the movement of the attached load is controlled or controllable. For example, the movement trajectory can be specified based on a tolerance-based trajectory of load positions, e.g., as a range of absolute load positions within which movement of the load is permitted. If the load reaches an absolute position at the limit of the specified movement range, the movement of the load is stopped and the load is guided along the limit of the movement range, so that the load moves along a boundary area. In this way, prohibited areas can be avoided if a prohibited area lies on the direct travel path between the start position and the target position.

[0067] According to a further aspect, a device, in particular a control device, for operating a jib crane with the aid of a state control can be provided, wherein the state control effects a control of a movement of a suspended load at least in one direction of movement and is based on a state vector, wherein the device is designed to: - Recording state variables of the state vector, which includes information on a position and a speed of a movable suspension point to which a load system comprising a hoist rope, a load-handling device arranged at a lower end of the hoist rope and a load suspended below the load-handling device is attached, and information on a load position and a load speed of a center of mass of the load system with respect to the suspension point, - Determining at least one manipulated variable for moving the suspension point in the at least one direction of movement based on the state control; - Control of the jib crane depending on at least one control variable.

[0068] According to a further aspect, the method according to the invention can be implemented by means of a control unit on the jib crane, wherein a computer program product is used in the control unit to execute the method, on the basis of which computer program product the control unit receives commands to execute the individual method steps, by means of which the aforementioned advantageous technical effects are achieved in order to enable the previously described functions on the jib crane.

[0069] According to a further aspect, a jib crane is provided, comprising one or more drive devices for moving a suspension point for a load system and the above device, wherein the jib crane is controlled by controlling the one or more drive devices. Brief description of the drawings

[0070] Preferred embodiments are described in more detail below in conjunction with the following figures. They show: Fig. 1 a schematic representation of a tower crane; Fig. 2 and Fig. 3 representations of the load system as a multiple or single pendulum; Fig. 4 a schematic representation of the control unit for operating the tower crane of the Fig. 1; Fig. 5 a flow chart illustrating a pendulum damping function; Fig. 6 a flowchart illustrating a disturbance compensation function; Fig. 7 a flowchart illustrating a positioning function; Fig. 8 a flowchart illustrating a load lifting function; Fig. 9 a flowchart illustrating a position approach function. Description of embodiments

[0071] Fig. 1 shows a schematic side view of a tower crane 2 for lifting, moving and setting down a load L. The tower crane 2 represents an example of a jib crane in the sense of this description. The tower crane 2 comprises a tower T which is at least partially fixed to a base G and has an imaginary vertical axis H and a trolley jib KA projecting from the tower T. The trolley jib KA is in the Fig. 1 not designed to be luffing. In an example not shown, the trolley boom KA can also be designed to be luffing, whereby the luffing trolley boom KA is moved by means of a luffing drive.

[0072] The tower crane 2 comprises a slewing gear DW arranged on the rotation axis for rotating at least the trolley boom KA about the vertical axis H. The tower crane 2 comprises a rotation angle sensor device 510, designed, for example, 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.

[0073] A trolley LK, which can be moved along the trolley boom KA, comprises a first and a second deflection pulley 202, 204 for deflecting a hoist rope HSL toward a load-handling device UF, which can be designed as a bottom block or a hook block. The load-handling device UF comprises at least one deflection pulley 302 for the hoist rope HSL, but can also comprise a plurality of deflection pulleys for the hoist rope HSL.

[0074] The hoist rope HSL is guided from a hoisting gear HW for winding and unwinding the hoist rope HSL over the first deflection pulley 202 of the trolley LK, a deflection pulley 302 of the load handling device UF, and the second deflection pulley 204 of the trolley LK. The hoist rope HSL is attached to a distal section 4 of the trolley boom KA.

[0075] The hoisting gear HW can, as is known per se, comprise a brake, an electric motor, a gearbox, and a cable winch. The hoisting rope HSL is wound onto the cable winch of the hoisting gear HW to raise the load L, and it is unwound to lower the load L. The hoisting rope HSL is guided, for example, from the hoisting gear via two deflection pulleys 20 and 22 arranged at or near the vertical axis H to the deflection pulley 202 of the trolley LK.

[0076] A hoist rope length I1 is determined using a hoist rope length sensor 610, for example, in the form of a rotation angle sensor that counts the revolutions of the hoist HW. For example, by detecting the rotational position of the hoist HW, the distance between the load handling device UF and the trolley LK and the suspension point AUP can be determined, which is assumed to be the hoist rope length I1.

[0077] A mass sensor device 620 is according to Fig. 1 is coupled to the deflection pulley 22 and detects the mass m of the suspended load L or the load system at a suspension point AUP on the trolley LK. The mass sensor device 620 measures, for example, a tensile force exerted on the deflection pulley 22. A sensor signal determined by the sensor device 620 represents the mass m.

[0078] A first angle sensor device 210 arranged on the trolley LK is used to determine a respective hoist rope angle φ 1y , φ 1x(in the y-direction and in the x-direction) of one or more sections HSL#1, HSL#2 of the hoist rope HSL located between the trolley LK and the load-handling device UF to the perpendicular passing through the suspension point AUP. The first angle sensor device 210 can, for example, have a distance measuring system (optical or ultrasonic-based) that measures distances, dependent on the hoist rope angle, between the first angle sensor device 210 and a section of the hoist rope HSL and determines the hoist rope angle φ therefrom. 1y , φ 1x (in the y-direction and in the x-direction). Other known measuring methods for determining the hoist rope angle φ 1y , φ 1x are applicable. The hoist rope angle φ 1y , φ 1x(in the y-direction and in the x-direction) corresponds to an angle of the distance between the suspension point AUP and a center of mass of the load-carrying device UF to the vertical through the suspension point AUP. The first angle sensor device 210 is connected to a control unit 100 in order to provide there an indication of the respective hoist rope angle φ 1y , φ 1x to provide.

[0079] A second angle sensor device 310, arranged on the load-handling device UF and designed, for example, as a gyroscope, is configured to determine a load cable angle φ2x, φ2y in the x-direction or y-direction to the perpendicular passing through the attachment point ANP of the load L to the load-handling device UF. The load cable angle φ2x, φ2y indicates the angle between the distance between the attachment point ANP and the center of mass of the attached load and the perpendicular through the attachment point ANP in the x-direction or y-direction. The second angle sensor device 310 communicates with the control unit.

[0080] For example, a load rope length I2 of the load rope LSL or, in the case of another lifting device, a distance between the load suspension device UF and the center of mass of the load L is preset or can be determined by a user. Alternatively, this can also be measured using a suitable measuring device.

[0081] A trolley KW, fixed to the trolley jib KA, is connected to the trolley LK by a trolley cable KSL for its movement along the trolley jib KA. The trolley KW comprises a brake, an electric motor, a gearbox, and a double cable winch. The double cable winch comprises two sections connected by a common axle. When the double cable winch rotates in one direction, the winch winds up one part of the trolley cable KSL and unwinds the other part, thus moving the trolley LK.

[0082] A position sensor device 420, for example, a rotation angle sensor that counts the revolutions of the trolley KW, is arranged fixedly to the frame 402. This sensor device generates a sensor signal that indicates the position x of the trolley LK. The position x of the trolley LK corresponds to the position of the suspension point AUP.

[0083] An angle difference sensor device 410 is configured to determine a rotation angle difference Δθ between the rotation angle θ_u of the trolley boom KA about the vertical axis H and a current rotation angle θ of the position of the trolley LK about the vertical axis H. The angle difference sensor device 410 for determining the rotation angle difference Δθ is arranged fixedly to the trolley boom KA, in particular on the trolley boom KA or on a frame 402 of the trolley chassis KW. The angle difference sensor device 410 can be configured, for example, to determine, using ultrasonic measurement technology, a lateral distance between the angle difference sensor device 410 and a section KSL#1 of the trolley rope KSL, which is located between a deflection pulley 6 proximal to the trolley boom KA and the trolley LK. A deflection pulley 8 arranged distally to the trolley boom KA deflects the trolley rope KSL from the trolley chassis KW to the trolley LK.The rotation angle difference Δθ can then be determined either in the angle difference sensor device 410 or in the control unit 100 as a function of the sensor signal representing the distance. Other known options for determining the rotation angle difference Δθ are also applicable. The angle difference sensor device 410 serves to determine the rotation angle θ_u of the trolley boom KA, which deviates from the actual rotation angle θ of the trolley LK or a suspension point AUP of the load system due to elastic deformation of the trolley boom KA.

[0084] The trolley KW comprises the frame 402 and a drive unit arranged fixedly relative to the frame 402 for winding and unwinding a trolley rope KSL. The angle difference sensor device 410 arranged fixedly relative to the frame 402 is configured to determine the angle difference Δθ between a rotation angle θ_u of the trolley jib KA about a vertical axis H of a tower T of the tower crane 2 and a current angle of rotation θ of the trolley LK or the suspension point AUP about the vertical axis H.

[0085] A further inclination sensor device 220, which is arranged fixedly on the trolley LK, in particular in relation to its chassis and is designed, for example, as a gyroscope, serves to determine an inclination angle Δφ (tilt angle difference) of the trolley LK to a horizontal plane. The inclination sensor device 220 determines a sensor signal which characterizes an inclination of the trolley LK to a horizontal plane, in particular an inclination angle to a horizontal plane lying in an xh plane spanned by the vertical axis h and the longitudinal axis x of the trolley boom KA. The control unit 100 can be used to calculate the current hoist rope angle φ 1x in the x-direction, take into account the inclination angle Δφ as a correction to the hoist rope angle φ 1x to the vertical through the suspension point AUP. This is necessary because, as a rule, the first angle sensor device 210 tilts with the trolley LK and this angle error is taken into account when measuring the hoist rope angle φ1x does not recognize.

[0086] The control unit 100 is designed as a conventional data processing device and carries out a method to operate the slewing gear DW, the hoisting gear HW and the trolley KW depending on all or part of the following variables: the angle of rotation θ_u, the angle of rotation difference Δθ, the hoist rope angle φ 1x , φ 1y , the load rope angle φ 2y , φ 2x the hoist rope length I1, the load rope length I2, the mass of the suspended load, the position x of the trolley and the inclination angle Δφ.

[0087] To control the slewing gear DW, the hoisting gear HW and the trolley KW, the motors provided therein are assigned setting speeds u* DW , u* HW , u* KW specified as control variables. In other embodiments, the control can also be achieved by specifying a torque.

[0088] The hoist rope HSL suspended from the trolley LK, the load suspension device UF, the load rope LSL, and the load L form a load system. The load system represents a multiple pendulum, whose suspension point AUP is assumed to be between two sections HSL#1, HSL#2 of the hoist rope HSL. The multiple pendulum is described in the following Fig. 2 and Fig. 3 and comprises the two sections HSL#1, HSL#2 of the hoist rope HSL, the load suspension device UF suspended from the hoist rope HSL, a load rope LSL arranged below the load suspension device UF and the load L arranged on the load rope LSL. In this context, a multiple or double pendulum is understood to mean the load system located below the trolley LK or below the deflection pulleys 202, 204 of the trolley LK.

[0089] An operating unit 900 is provided for crane operation. The operating unit 900 is designed, for example, as a control panel in the crane operator's cab and / or as a radio remote control that communicates with the control unit 100. For example, by means of a joystick 910 of the operating unit 900, target values ​​S soll are transmitted to the control unit 100, which indicate a movement speed in the x-direction and / or y-direction. Furthermore, the lifting or lowering of the load using the HW hoist can be specified by the user in the form of a target value. The target values ​​include u* LKsoll , u* DWsoll , and / or u* HWsoll, and can specify setting speeds for the motors of the trolley KW, the slewing gear DW and / or the hoist HW and can be converted into corresponding movements of the suspension point AUP and a change in the hoist rope length I1 according to the mechanical design in a known manner in order to achieve target values ​​x' soll , θ' soll , and / or I' soll The target values ​​can also be entered directly as x' soll , θ' soll , and / or I' soll be specified.

[0090] Fig. 2 shows a schematic diagram of the tower crane from the Fig. 1 existing double pendulum. In this double pendulum, which is formed by the sections HSL#1, HSL#2 of the hoist rope HSL, the load suspension device UF, the load rope LSL and the load, two relevant angles arise in one direction: the hoist rope angle φ1 at the suspension point AUP in relation to the vertical through the suspension point AUP and the load rope angle φ2 at the suspension point ANP in relation to the vertical through the suspension point ANP.

[0091] Fig. Figure 3 shows the simplification of the multiple pendulum proposed in this description to prevent or reduce pendulum motion. The multiple pendulum from Fig. 2 is considered a single pendulum for the state control described below. A relevant parameter is the pendulum angle φ of the deflection of the load L relative to the trolley LK. This is difficult to measure directly with robust sensors. For one direction, the pendulum angle φ is therefore calculated using the hoist rope angle φ1, the hoist rope length I1, the load rope length I2, and the load rope angle φ2, which are obtained as described above. To compensate for the hoist rope angle φ 1x In the x-direction, the angle of inclination Δφ of the trolley boom KA to the horizontal can be taken into account, so that for the hoist rope angle φ 1x in x-direction φ 1x .= φ1 + Δφ This correction is for the hoist rope angle φ 1y in y-direction not necessary.

[0092] Due to the assumed significantly higher mass of the load L compared to the mass of the load handling device UF, the inclination of the load handling device UF corresponds to the deflection of the suspended load and thus φ2, ie φ 2x for the x-direction and φ 2y for the y-direction.

[0093] Fig. 4 shows in reference to Fig. 1 the signal flow for the determination of control variables in the form of control speeds u* to be set LK , u* DW , u* HW for the trolley LK, the slewing gear DW or the hoist HW by the control unit 100. The respective setting speed can be specified, for example, in % of the maximum speed (nominal speed) for the respective drive motor (trolley KF, the slewing gear DW and the hoist HW).

[0094] The pendulum angle φ x , φ y in x and y direction can be calculated with reference to Fig. 4 can be calculated in different ways in a pendulum angle calculation block 110 in the control unit 100.

[0095] In an exact calculation, the length I of the double pendulum is l=(l1cos(φ1x)+l2cos(φ2x))2+(l1sin(φ1x)+l2sin(φ2x))2

[0096] And the pendulum angles φ x , φ y in x-direction or y-direction to φx=arcsin((l1sin(φ1x)+l2sin(φ2x))l) φy=arcsin((l1sin(φ1x)+l2sin(φ2x))l)

[0097] This calculation can be simplified by approximation in the form of a sensor fusion with l=l1+l2 φx=kxφ1x+(1−kx)φ2x φy=kyφ1y+(1−ky)φ2y where the factors k x and k y as constants, in particular in a range between 0.25 - 0.75, or according to a characteristic map or a function depending on the hoist rope length I1 and / or a mass of the suspended load L, e.g. as kx=ky=l1l1+l2.

[0098] At least the above sensor variables and target variables S soll supplied to the setting speeds u* LK , u* DW , u* HW according to a state control 120. The setpoints can be a setpoint speed u* KWsoll or a target torque for the trolley KW, a target speed u* DWsoll or a target torque for the slewing gear DW and a target speed u* HWsoll or a target torque for the HW hoist.

[0099] Furthermore, a function block 130 is provided which controls the operation of the state control 120, in particular depending on an operation of the control unit 900, so that various operating functions can be realized.

[0100] In a rotation angle calculation block 140, the rotation angle θ determined by the rotation angle sensor device 510 and the rotation angle difference Δθ measured by the angle difference sensor device 410 are added and a corrected rotation angle θ for an actual rotation angle of the trolley boom KA about the vertical axis H is provided.

[0101] Using suitable derivative blocks 150, 160, 170, 190, the time derivatives for the pendulum angles φ x , φ y , the corrected angle of rotation θ and the speed x' of the suspension point AUP as φ' x , φ' y , θ' and x' are formed.

[0102] Furthermore, the position x of the trolley LK (as the position of the suspension point AUP) is provided to the state controller by the position sensor device 420. Using the derivation block 190, a trolley speed x' (as the speed of the suspension point AUP) can be provided to the state controller 120 as a time derivative. Alternatively, the trolley speed x' can be read directly from the control unit 900, because it is available there very accurately given a known (measured) motor speed and a known transmission ratio.

[0103] A control parameter block 180 is provided to determine control parameters in the form of a control vector Kx=[K1, K2, K3, K4] depending on a mass m of the load system, which is measured by the mass sensor device 620, depending on a position x of the trolley LK (or the suspension point), which is measured by the position sensor device 420, and on a hoist rope length I1 or total pendulum length I of the multiple pendulum. T , Ky=[K5, K6, K7, K8] T for the respective direction of movement (x and / or y direction) from the constantly updated system matrix A, which depends on the mass m, the pendulum length I, and, if applicable, the position x of the trolley LK (or the suspension point), and the input vector b. The control parameters K are provided to the state controller 120.

[0104] The system matrix A and the input vector b are updated upon a change in at least one of the variables mass m, pendulum length I, and position x of the trolley LK (or the suspension point), in particular by more than a predetermined absolute or relative deviation value (e.g., 2%) according to a known determination method for state-space parameters. Using the system matrix A and the input vector b, the control parameter block 180 executes a known pole specification method or a method based on a known LQ method to determine the respective control vector Kx, Ky based on the state-space description.

[0105] The state control 120 can be described using a state-space representation. In the state-space representation, n-order linear systems are decomposed into n first-order subsystems to enable simple control parameterization. The state controls for the trolley KW and the slewing gear DW can be considered separately.

[0106] In the state control for the trolley KW, the oscillation angle φ x in the x-direction, whose pendulum angular velocity φ' x , the position x of the trolley and the speed x' of the trolley LK are taken into account.

[0107] The task of the state control is to determine from the state variables of the state variable vector Z and the specified target variables Ssoll = u* KWsoll , u* DWsoll , u* HW or if necessary after appropriate conversion x' soll , θ' soll , I' soll the manipulated variables u* LK , u*DW , u* HW The control deviations of the state variables are multiplied by the updated control parameters from the control vectors Kx, Ky. The sum of these products is then the desired manipulated variable.

[0108] The state space representation for the running gear LK is: [x′x″φ′xφ″x]=ALK[xx′φxφ′x]+bLKuLK; where x'' is the acceleration of the trolley LK (ie the suspension point AUP) and cp'' X correspond to the angular acceleration of the pendulum angle. A LK corresponds to a 4x4 system matrix and b LK an input vector with state-space parameters of the state-space description for the trolley KW. An example parameterization of the system matrix A LK and the input vector b can be as follows: ALK=[01000a10000010a2a30] bLK=[0b10b2]

[0109] Where a1, a2, a3, b1, b2 are system parameters for the control, which can be determined in a known manner, e.g., by physical modeling or empirically. By appropriately applying the pole specification method or the LQ method, the control vector K can be determined, so that the calculation rule for the cyclic calculation of the manipulated variable u* LK results in: u∗LK=(xset−x(t))⋅K1+(x′set−x′(t))⋅K2+(φxset−φx(t))⋅K3+(φ′xset−φ′x(t)) ⋅K4

[0110] In normal operation with active pendulum damping, the desired speed u* is set by the control unit 900, in particular a joystick or the like. LKsollof the trolley (i.e., the suspension point AUP) in the range from -100 to 100% of a given nominal speed. This is converted into the speed x' of the trolley or the suspension point AUP according to the mechanical coupling to the trolley or the suspension point AUP.

[0111] In the state control for the slewing gear DW, the pendulum angle φ y in the y-direction, whose pendulum angular velocity φ' y , the rotation angle θ of the trolley boom and the rotation angular velocity θ' of the trolley boom are taken into account.

[0112] The state space representation for the slewing gear DW is: [θ′θ″φ′yφ″y]=ADW[θθ′φyφ′y]+bDWuDW where θ'' is the angular acceleration and φ'' y correspond to the angular acceleration of the pendulum angle in the y-direction. A DW corresponds to a 4x4 system matrix and b DWan input vector with state-space parameters of the state-space description for the slewing gear DW. An example parameterization of the system matrix A DW and the input vector b DW is as follows: ADW=[01000a40000010a5a60] bDW=[0b30b4]

[0113] Where a4, a5, a6, b3, b4 are control parameters for the control, which can be determined in a known manner, e.g., by physical modeling or empirically. By appropriately applying the pole specification method or the LQ method, the control vector Ky = [K5, K6, K7, K8] T be determined, so that the calculation rule for the cyclic calculation of the manipulated variable u* DW results in: u∗DW=(θset−θ(t))⋅K5+(θ′set−θ′(t))⋅K6+(φyset−φy(t))⋅K7+(φ′yset−φ′y(t)) ⋅K8

[0114] In normal operation with active pendulum damping, the desired rotation speed u* is set by the control unit 900, in particular a joystick or the like. DWsoll of the slewing gear in the range of -100 to 100% of a specified nominal speed. This is converted into the angular speed θ' of the trolley boom or an angular speed of the AUP suspension point, depending on the mechanical coupling to the trolley or the AUP suspension point.

[0115] The state controller can also include the hoist HW and include the total pendulum length I and the pendulum length velocity I' as state variables. The control model can accordingly have the following structure: [x′x″φ′xφ″xθ′θ″φ′yφ″yl′l″]=[ALKADW→ALK00000000000 0000000000000ADW000000000000000000000000AHW][xx′φ xφ′ xθθ′φ yφ′ yll′]+[bLK000000000000bDW00000000bHW][uLKuDWuHW]

[0116] The state control uses the setpoints u*DWsoll , u* LKsoll and u* HWsoll as target values. The corresponding target values ​​for the control then correspond to the converted θ' soll , x' soll and I' soll , which results from the conversion of the target values ​​u* DWsoll , u* LKsoll and u* HWsoll (Target specifications) corresponding speeds of the drive devices DW, LW, HW into the corresponding movement speeds of the slewing gear and the trolley KW in lateral directions (x, y) and the load in the vertical direction (h).

[0117] The control system can follow a control cycle duration of between 10 ms and 500 ms. The control system can include an observer that calculates the state variables in advance for the next time step. Observer structures are known from the state of the art and will not be discussed in detail here.

[0118] In contrast to a conventional control system, an optimal trajectory of the manipulated variables u* is determined based on the available state variables. LK , u* DW , u* HW (neutralizing any oscillation that may lead to swaying) of the load, so that no strong swaying movement caused by the crane operator or the crane operation can occur. Subsequent damping of the oscillating pendulum system is therefore not necessary. After activating the state control to perform a sway damping function by a corresponding target value Sset after lifting the load, the target values ​​are converted into the corresponding target values ​​θ' soll , x' soll and I' soll according to the respective mechanical coupling between the trolley KW, the slewing gear DW and the hoist HW to the trolley LK, the trolley boom KA and the load handling device UF are converted and taken into account in the control: For the x-direction: u∗LK=(xset−x(t))⋅K1+(x′set−x′(t))⋅K2+(φxset−φx(t))⋅K3+(φ′xset−φ′x(t)) ⋅K4 For the y-direction: u∗DW=(θset−θ(t))⋅K5+(θ′set−θ′(t))⋅K6+(φyset−φy(t))⋅K7+(φ′yset−φ′y(t)) ⋅K8 with t the current time step of the control and x(t), x'(t), φ x (t), φ' x (t), θ(t), θ'(t), φ y (t), φ' y (t) the current measured and determined state variables.

[0119] The following applies to the sway damping function during crane operation: xsoll=f(uLKsoll) x'soll=0 φxsoll=0 φ'xsoll=0 θsoll=f(uDWsoll) θ'soll=0 φysoll=0 φ'ysoll=0

[0120] The functions for determining the target position of the suspension point correspond to xset(t)=f(u*LKset)=xset(t−1)+x'set(t−1)*Δt θset(t)=g(u*DWset)==θset(t−1)+θ'set(t−1)*Δt

[0121] Where Δt is the control cycle duration, for example, between 10 ms and 100 ms. Furthermore, the functions f() and g() can also incorporate ramp functions for the speeds to limit the rates of change of the specified variables.

[0122] The entire control system can be described by the above-mentioned state controller. The state controller is active at all times during tower crane operation and remains active for a specified overrun time after the end of an operating command to prevent any post-oscillation.

[0123] Alternatively, the control can also be applied to only one or two of the motion components, i.e., the movement of the trolley (i.e., x-movement of the suspension point AUP) (x-direction), the rotary movement of the trolley boom (i.e., y-movement of the suspension point AUP) (y-direction), or the movement of the hoist (h-direction). Accordingly, the considered states of the state control 120 are reduced by the respective quantities.

[0124] To utilize the sway control function achieved by state control, additional functions can be implemented to operate the tower crane.

[0125] For this purpose, for example, a first operating element 920 can be provided on the operating unit 900, with which the user can dampen existing load or residual pendulum oscillations that occur after a load transport process according to a pendulum damping function. This pendulum damping function corresponds to the conventional pendulum damping function described above, which is activated upon actuation of the first operating element 920, which can be designed as a pushbutton switch, for example, and remains active during a follow-up time of, for example, between 5 and 30 s, preferably between 5 and 15 s, in particular 10 s, after the end of actuation of the first operating element 920. The follow-up time can be fixed or depend on a current pendulum length I. Thus, the respective follow-up time can be variably specified by a function or a look-up table depending on the pendulum length I.

[0126] By providing the function of the first control element 920, the crane operator of the tower crane has the possibility of reducing a pendulum oscillation that occurs during inactive crane operation, ie no active transport movement takes place, e.g. due to a brief, sudden force acting on the load system.

[0127] Furthermore, when the first control element 920 is actuated, a target position of the load can be determined, which is used as an additional target specification for the 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 angle of rotation θ of the boom. This information is then stored as target specifications x store , θ store stored and in addition to the target values ​​θ' soll =0, x' soll =0 and I' soll=0 (no control for crane operation) is assumed for sway damping, and the state control is carried out accordingly. The following then applies to the target specifications in the above control specification: xsoll=xstore x'soll=0 φxsoll=0 φ'xsoll=0 θsoll=θstore θ'soll=0 φysoll=0 φ′ysoll=0

[0128] Fig. Figure 5 shows a corresponding flow chart to illustrate this oscillation damping function.

[0129] In step S1, a check is made to determine whether the sway control function is activated during inactive crane operation. If this is the case (alternative: Yes), the process continues with step S2. Otherwise (alternative: No), the process continues with step S1.

[0130] In step S2, the position x, θ of the trolley LK (ie the suspension point AUP) is defined as x store , θ storetemporarily stored and adopted as the target value for subsequent control.

[0131] In step S3, the state control is carried out, where the target values ​​x soll = x store , θ soll = θ store , I soll in addition to the target values ​​θ' soll =0, x' soll =0 and I' soll =0 for sway damping and the state control is carried out accordingly.

[0132] In step S4, a check is made to determine whether the sway control function has ended and a follow-up time has elapsed. If this is the case (alternative: Yes), the process is terminated; otherwise (alternative: No), the system returns to step S3 and continues state control.

[0133] A disturbance compensation function can be provided using a functional extension that can be activated or deactivated by a second control element 930. The disturbance compensation function can, for example, take into account external influences on the load system, such as wind pressure or vibrations of the subsurface, and maintain the current position of the load L despite the presence of (ongoing) disturbing influences. If the function is activated by actuating the second control element 930, it remains active until it is terminated by corresponding actuation of the second control element 930. The disturbance compensation function remains active only as long as the crane is not actively operated, i.e., the load is not moved by external commands.

[0134] In Fig. Figure 6 shows a flow chart illustrating the disturbance compensation function.

[0135] In step S11, a check is made to determine whether the disturbance compensation function is activated during inactive crane operation. If this is the case (alternative: Yes), the process continues with step S12. Otherwise (alternative: No), the process continues with step S11.

[0136] In step S12, the current absolute load position p xsoll , p ysoll The current absolute load position p to be saved xsoll , p ysoll can result as Pxsoll=x+sin(φx)⋅l Pysoll=θ+arctansin(φy)⋅lx

[0137] In step S13, the state control is activated, whereby the state control is assigned varying target values ​​for the position x according to the control cycles. soll the trolley and the angle of rotation θ soll The pendulum length I soll remains unchanged.

[0138] To maintain the absolute position p xsoll , pysoll the load then applies: xsoll=pxsoll−sin(φx)⋅l θsoll=pysoll−arctansin(φy)⋅lx

[0139] These values ​​are determined continuously, ie recalculated for each control cycle, since with varying disturbance influences the oscillation angle φ x , φ y and pendulum angular velocities φ' x , φ' y can change constantly.

[0140] The target values ​​of the state variables are then during the active disturbance compensation function xsoll=pxsoll−sin(φx)⋅l x′soll=0 φxsoll=uncertain φ′xsoll=uncertain θsoll=pysoll−arctansin(φy)⋅lx θ′soll=0 φysoll=uncertain φ′ysoll=uncertain where x soll , θ sollare continuously updated according to the control cycles described above. This allows for appropriate response to changing disturbances, while the absolute position of the load remains unchanged.

[0141] The state variables φ marked as indeterminate x , φ' x , φ y , φ' y are ignored in the control by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero while the disturbance compensation function is activated.

[0142] In step S14, a check is made to determine whether the disturbance compensation function has been completed. If this is the case (alternative: yes), the process is terminated; otherwise (alternative: no), the system returns to step S13 and continues with the state control.

[0143] The disturbance compensation function can be deactivated by actuating the second control element 930 or by joystick operation to initiate load transport.

[0144] By actuating a third control element 940 (e.g., in the form of a pushbutton switch), a positioning function can be activated. The positioning function remains active as long as the third control element 940 is actuated and is active during a predetermined follow-up time, for example, between 5 and 30 seconds, preferably between 5 and 15 seconds, for example, 10 seconds. The positioning function allows the load to be moved by manually pushing and pulling in the settling area, thus directing it with high precision to the correct desired load position.

[0145] In Fig. Figure 7 shows a flow chart to illustrate the positioning function.

[0146] In step S21, a check is made to determine whether the positioning function is enabled when the crane is inactive. If this is the case (alternative: Yes), the process continues with step S22. Otherwise (alternative: No), the process continues with step S21.

[0147] In step S22, the state controller is activated, but the target values ​​of the positions x, θ and speed x', θ' of the trolley LK and the slewing gear DW are not taken into account, whereby the target values ​​are assumed as follows: xsoll=unspecified x'soll=unspecified φxsoll=0 φ'xsoll=0 θsoll=uncertain θ'soll=uncertain φysoll=0 φ'ysoll=0

[0148] The state variables x marked as indeterminate soll , x' soll , θ soll , θ' sollare ignored in the control by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero while the disturbance compensation function is activated.

[0149] In step S23, a check is made to determine whether the positioning function has been completed. If this is the case (alternative: Yes), the process is terminated; otherwise (alternative: No), the system returns to step S22 and continues the state control.

[0150] The third control element 940 must be permanently actuated during positioning to avoid uncontrolled movements of the load L. The pendulum angle φ deviating from zero when pulling the load L or the load handling device UF x , φ yThe state control forces the load to compensate for the tension, so that the load is moved in the corresponding direction. As soon as the tension force is removed, the trolley LK positions itself exactly over the load L, thus fixing the new load position.

[0151] Furthermore, a load lifting function can be implemented that is permanently active or can be activated using a fourth control element 950, ensuring additional safety when lifting the load. If the trolley LK, i.e., the suspension point AUP of the hoist rope, is not positioned exactly perpendicular to the center of gravity, an immediate pendulum oscillation can occur when lifting the load, which depends on the lateral offset of the suspension point AUP from the center of gravity. This is almost always the case in practice, since the crane operator usually cannot position the load handling device UF precisely over the load center of gravity.

[0152] By using the state control described above, the suspension point AUP can be positioned exactly above the center of gravity when tightening the load handling device UF before the load L is lifted.

[0153] The load lifting function is described in the flow chart of the Fig. 8 is explained in more detail.

[0154] In step S31, the hoist HW is activated to lift the load according to the instructions of the crane operator, e.g. using a fourth control element 950.

[0155] In step S32, a check is made to determine whether the load lifting function is activated. If this is the case (alternative: Yes), the process continues with step S33. Otherwise (alternative: No), the process ends with a jump to step S36.

[0156] 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, which can be determined by the weight forces of the load-carrying device UF, the hoist rope HSL and the load rope LSL, it can be assumed that the hoist rope HSL is taut and the measured pendulum angle φ x, φ y indicates the offset of the center of mass to the suspension point AUP on the trolley LK. In this case (alternative: Yes), the method continues with step S34; otherwise (alternative: No), the method returns to step S33 and continues waiting for the threshold lifting force value to be reached.

[0157] Now, in step S54, the state control is started by specifying the following as target specifications: xsoll=unspecified x'soll=unspecified φxsoll=uncertain φ'xsoll=0 θsoll=uncertain θ'soll=uncertain φysoll=0 φ'ysoll=0

[0158] The state variables marked as indeterminate are ignored in the control by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero while the disturbance compensation function is activated.

[0159] In step S35 it is checked whether the target setting of the pendulum angle φ xsoll = 0, φ ysoll = 0 and the pendulum angular velocity φ' xsoll = 0, φ' ysoll= 0 has been reached, i.e., all corresponding control deviations are below a predefined threshold value of, for example, less than 0.3° of the corresponding pendulum angle. This threshold value can generally be dependent on the hoist rope length, e.g., 0.1° for hoist rope lengths of more than 20 m and 0.2 - 0.3° for hoist rope lengths I1 of less than 20 m. If this is the case (alternative: yes), the method continues with step S36. Otherwise, the state control of step S34 continues.

[0160] Before the lifting force is further increased beyond the point at which the load is actually lifted, the state control is further executed. This enables the precise positioning of the trolley LK over the load center of gravity, so that the load can be lifted vertically, without initial oscillation.

[0161] The load is then lifted in step S36.

[0162] Furthermore, a position approach function can be implemented using a fifth control element 960. The position approach function ensures that, when approaching a stored position, the load L is moved to the stored position and stopped there 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 instructions.

[0163] In step S41, a check is made as to whether a position approach function has been activated. If this is the case (alternative: Yes), e.g., when the fifth control element 960 is actuated, a current absolute position p x = x + sin(φ x ) · l, py=θ+arctansin(φy)⋅lx the load L or the trolley LK (ie the suspension point AUP) x, θ are stored (e.g. as x store , θ store ).

[0164] If an absolute load position is stored according to the position approach function, the crane can be operated in the conventional manner in step S43.

[0165] In step S44, a check is made to determine 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 a continuous query. If this is the case (alternative: Yes), the stored position x is stored in step S45. soll = p x , θ soll = p yas the target position for the load, and the state control is assumed to be executed accordingly. Further operation by the crane operator (or an automated crane control system) is irrelevant for the further target specification. After determining the approach to the stored position, only the positions x, θ are specified as the target specification, so that the state controller operates purely as a position control. The target specifications then correspond to: xsoll=px; x′soll=0 φxsoll=0 φ′xsoll=0 θsoll=py; θ′soll=0 φysoll=0 φ′ysoll=0

[0166] The state variables marked as indeterminate are ignored in the control by setting the corresponding control deviation or the associated element (factor) of the control vector K to zero during the activated position approach function.

[0167] If the stored position is determined to have been reached in step S46 (alternative: Yes), the state control is initially terminated in step S47. Otherwise (alternative: No), the process continues with step S45.

[0168] If the approached position is left again by activating the crane operation, the position approach function is activated again and the process continues with step S43.

[0169] It can be provided that the stored load position is forgotten by pressing the fifth control element 960 again. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2009 032 270 A1

[0005] EP 1 628 902 B1

[0006] EP 1 652 810 B1

[0007] DE 10 2020 120 699 A1

[0030] Cited non-patent literature

[0000] J. Smoczek et al., “Robust Predictive Control of an Overhead Crane,” https: / / doi.org / 10.5604 / 01.3001.0010.2940

[0008] Liebherr Electronics” of Liebherr Werk Nenzing GmbH from 09 / 2012

[0009] Holger Lutz, Wolfgang Wendt “Pocketbook of Control Engineering”, Europa-Lehrmittel, 2021, ISBN 9783808558706

[0041] Otto Föllinger, “Control Engineering”, Vde Verlag GmbH, 2022, ISBN 9783800755189

[0041]

Claims

[1] Device, in particular control device (100), for operating a jib crane (2) with the aid of a state control, wherein the state control effects a control of a movement of a suspended load (L) at least in one direction of movement and is based on a state vector, wherein the device is designed to: - Recording of state variables of the state vector, the information on a position and a speed (x', θ') of a movable suspension point (AUP), to which a load system comprising a hoist rope (HSL), a load suspension device (UF) arranged at a lower end of the hoist rope (HSL) and a load (L) suspended below the load suspension device (UF) and information on a load position (φ x , φ y ) and a load speed (φ' x , φ' y ) of a center of mass of the load system with respect to the suspension point (AUP), - Determine at least one manipulated variable (u*LK , u* DW , u* HW ) for moving the suspension point (AUP) in the at least one direction of movement based on the state control; - Control of the jib crane (2) depending on at least one control variable (u* LK , u* DW . u* HW ). [2] Device according to claim 1, wherein the device is designed with the state control in that, in the event of a change in a crane state, in particular in the event of a change in a hoist rope length (I1) and / or a radial position of the suspension point (AUP), and in particular depending on a mass of the load system, a parameterization of a state space description is updated in the state space and, by means of a method of pole specification or the LQ method, a linear combination of the control deviations of the state variables is determined, which is specified by a control vector (Kx, Ky), and is used to calculate the at least one manipulated variable (u* LK , u* DW, u* HW ) is used to move the suspension point (AUP). [3] Device according to claim 1 or 2, wherein the at least one manipulated variable (u* LK , u* DW , u* HW ) an adjustment speed of a trolley (KW) of a tower crane or an adjustment speed of a luffing angle of a boom (KA) of a mobile slewing crane and / or an adjustment speed of a slewing gear (DW). [4] Device according to one of claims 1 to 3, wherein the device is designed to determine the load position (φ x , φ y) as the relative position of the centre of gravity of the load system with respect to the suspension point depending on a hoist rope angle, which indicates an angular deviation of the hoist rope attached to the suspension point (AUP) from the vertical through the suspension point (AUP), from a load rope angle, which indicates an angular deviation of a centre of gravity of the load (L) at a suspension point on the load handling device (UF) from the vertical, and to determine the load position (φ x , φ y ) in particular further dependent on a lifting rope length (I1) between the suspension point (AUP) and a center of gravity of the load-carrying device (UF), and / or a load rope length (I2) between the attachment point (ANP) and the load center of gravity, and in particular to determine the load position (φ x , φ y ) as pendulum angle φ x , φ y) of the centre of mass with respect to the vertical through the suspension point (AUP) or as the vertical distance of the centre of mass from the vertical through the suspension point (AUP). [5] Device according to one of claims 1 to 4, wherein the device is designed to operate the state control in such a way that a sway damping function is realized when, in particular, the manual or automated crane operation specifies a speed of the suspension point (AUP) for at least one of the directions of movement or a first operating element (920) is actuated for activating the sway damping function, wherein for sway damping a target specification of the information on the load position φ x , φ y ) and the load speed (φ' x , φ' y) of the center of mass of the load system is specified as zero, the target value for the speed (x') of the suspension point (AUP) is specified as zero and the target value for a position of the suspension point (AUP) is specified as a position determined depending on the specified speed of the suspension point (AUP). [6] Device according to claim 5, wherein the device is designed to keep the pendulum oscillation damping active for a predetermined follow-up time when all target variables are set to zero. [7] Device according to one of claims 1 to 6, wherein the device is designed to operate the state control in such a way that a disturbance compensation function is realized, wherein the state control is continuously provided with a target specification for the position of the suspension point (AUP), which is determined as a function of a stored absolute position of the load, and a target specification of the speed of the suspension point (AUP) of zero, and the load position (φ x , φ y ) and the load speed (φ' x , φ' y ) of the center of mass of the load system are disregarded, in particular by taking the corresponding control deviations of the load position φ x , φ y ) and the load speed (φ' x, φ' y) of the center of mass of the load system during the activated disturbance compensation function are set to zero, whereby in particular the target specification of the position of the suspension point (AUP) is based on the current load position (φ x , φ y ) of the center of mass, a pendulum length (I) of the load system and the current position of the suspension point (AUP). [8] Device according to claim 7, wherein a second operating element (930) is provided to activate or deactivate the disturbance compensation function, and in particular to deactivate the disturbance compensation function during active crane operation for load transport, wherein in particular when the disturbance compensation function is activated the absolute position of the load (L) is stored. [9] Device according to one of claims 1 to 8, wherein the device is designed to operate the state control in such a way that a positioning function is carried out, wherein the state control is provided with the information on the load position (φ x , φ y ) and the load speed (φ' x , φ' y ) of the centre of mass of the load system are set to zero and the position (x, θ) and the speed (x', θ') of the suspension point (AUP) are disregarded, in particular by setting the corresponding control deviations during the activated positioning function or the associated element (factor) of the control vector K to zero. [10] Device according to one of claims 1 to 9, wherein the device is designed to operate the state control in such a way that a load lifting function is realized when a load (L) is to be lifted, wherein the information on the load position (φ x , φy ) is determined when a lifting force on the hoist rope (HSL) exceeds a specified lifting force threshold value and the load (L) has not yet been lifted, whereby the state control is carried out with target specifications for the load position φ x , φ y ) and load speed (φ' x, φ' y ) and the speed (x', θ') of the suspension point (AUP) is zero, whereby the control deviation to the position (x, θ) of the suspension point (AUP) is disregarded, in particular by setting the corresponding control deviation or the associated element (factor) of a / the control vector K to zero during the activated load lifting function. [11] Device according to one of claims 1 to 10, wherein the device is designed to operate the state control in such a way that a position approach function is realized, in which a stored position is approached and the load (L) is brought to a standstill there, wherein a current position is stored according to a user request, wherein the state control is provided with a target specification for the position (x, θ) of the suspension point (AUP), which corresponds to the stored position, a target specification for the speed (x', θ') of the suspension point (AUP) of zero, a target specification for the load position φ x , φ y ) and the load speed (φ' x, φ' y ) from zero as soon as the position of the suspension point (AUP) has approached the stored position of the suspension point (AUP) during ongoing crane operation, in particular below a predetermined threshold distance. [12] Jib crane (2) comprising: - one or more drive devices for moving a suspension point for a load system; - the device according to one of claims 1 to 11, wherein the device is designed to control the jib crane (2) by controlling the one or more drive devices (LW, DW).

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