Crane And Method For Controlling Same

Abstract

A crane including electric actuators for lifting and/or traveling loads and/or crane elements, a generator for supplying the actuators with energy, an internal combustion engine for driving the generator, inputs for entering control commands for the actuators, and a control device for controlling the actuators in dependence on the control commands entered. The control device has a determination device for determining and/or estimating a future power demand of the electric actuators with reference to the actuation of the inputs with which control commands for the actuators are entered, and the current operating condition of the actuators, and an engine control unit for controlling the internal combustion engine in dependence on the estimated/determined future power demand.

Claims

1. A crane comprising: electric actuators; a generator for supplying the electric actuators with energy; an internal combustion engine for driving the generator; input means for entering control commands for the actuators; and a control device configured to control the actuators in dependence on the control commands entered; wherein the control device comprises: a determination device configured to estimate and/or determine a future power demand of the actuators on the basis of the actuation of the input means and the current operating condition of the actuators; and an engine control unit configured to control the internal combustion engine in dependence on the estimated/determined future power demand.

2. The crane according to claim 1, wherein the control device further comprises an acceleration control module configured to control the acceleration of the internal combustion engine and/or the actuators such that with increasing future power demand, the internal combustion engine is brought into its operating condition determined for the future power demand, before the actuators reach the future power demand.

3. The crane according to claim 2, wherein the acceleration control module is further configured such that the internal combustion engine is adjusted with a minimally necessary and/or a smallest possible acceleration with which the operating condition of the internal combustion engine required for the determined future power demand is just reached in time.

4. The crane according to claim 1, wherein the acceleration control module comprises: determination means configured to determine a point in time and/or a time period in which the actuators reach the future power demand; and acceleration determination means configured to determine the acceleration of the internal combustion engine in dependence on the determined point in time or the determined time period.

5. The crane according to claim 1, wherein the engine control unit comprises a speed control device configured to variably control the speed of the internal combustion engine in dependence on the future power demand and the current operating condition of the actuators.

6. The crane according to claim 5, wherein the speed control device is further configured to adjust a minimally necessary and/or a smallest possible change in speed with which the future power demand is reached.

7. The crane according to claim 1, wherein the engine control unit includes a torque control device configured to variably control the torque of the internal combustion engine in dependence on the future power demand and the current operating condition of the actuators.

8. The crane according to claim 1, wherein the electric actuators are directly and completely supplied with energy from the generator.

9. The crane according to claim 1, wherein the control device is further configured to actuate the actuators via a frequency converter.

10. The crane according to claim 1, wherein the control device is further configured to limit the velocity and/or acceleration of the actuators by considering the performance limit of the internal combustion engine.

11. The crane according to claim 1, wherein the determination device is further configured to determine the future power demand of the electric actuators with reference to one or more of: a strength of the actuation of the input means; a velocity of the actuation of the input means; a direction of the actuation of the input means; the number of actuators concerned with an entered control command; the identity of the actuator concerned with a control command; the velocity requested by the entered control commands; and the requested direction of the actuating movement of the actuator concerned with the control commands.

12. The crane according to claim 1, wherein the engine control unit is further configured to determine the speed of the internal combustion engine in dependence on the speed-voltage curve of the generator.

13. A method for controlling a crane (1) with electric actuators for lifting and/or traveling loads and/or crane elements, a generator for supplying the electric actuators with energy, an internal combustion engine for driving the generator, input means for entering control commands for the actuators, and a control device for controlling the actuators in dependence on the control commands entered, the method comprising: detecting an actuation of the input means and/or the control commands generated by the actuation of the input means; calculating and/or estimating and/or determining a future power demand of the actuators by the control device with reference to the detected actuation of the input means and/or with reference to the detected control commands generated by the actuation of the input means; and adjusting the internal combustion engine with regard to the speed and/or torque to an operating point in which the internal combustion engine provides the calculated/estimated power demand substantially without an excess of power, before the actuators reach the operating point requested by the control commands of the input means and the corresponding power demand.

14. The crane according to claim 1, wherein no intermediate storage of the electric energy generated by the generator is provided.

15. A crane comprising: a determination device for one or both determining and estimating a future power demand of actuators on the basis of the actuation of input means for entering control commands for the actuators and a current operating condition of the actuators; and an engine control unit for controlling an internal combustion engine that drives a generator that supplies the actuators with energy in dependence on the determined/estimated future power demand.

16. The crane according to claim 15 further comprising: the actuators comprising electric actuators; the generator; the internal combustion engine; the input means; and an acceleration control module configured to control the acceleration of one or both of the internal combustion engine and the electric actuators such that with increasing future power demand, the internal combustion engine is brought into an operating condition determined for the future power demand, before the electric actuators reach the future power demand; wherein the determination device, the engine control unit and the acceleration control module form a control device configured to control the actuators in dependence on the control commands entered; wherein the acceleration control module is further configured such that the internal combustion engine is adjusted with a minimally necessary and/or a smallest possible acceleration with which the operating condition of the internal combustion engine required for the determined future power demand is just reached in time; and wherein the engine control unit comprises a speed control device configured to: variably control the speed of the internal combustion engine in dependence on the future power demand and the current operating condition of the electric actuators; and adjust the minimally necessary and/or the smallest possible change in speed with which the future power demand is reached.

17. The crane according to claim 16, wherein the engine control unit includes a torque control device configured to variably control the torque of the internal combustion engine in dependence on the future power demand and the current operating condition of the actuators; wherein the electric actuators are directly and completely supplied with energy from the generator; wherein the control device is further configured to actuate the actuators via a frequency converter; and wherein the control device is further configured to limit the velocity and/or acceleration of the actuators by considering the performance limit of the internal combustion engine.

18. The crane according to claim 17, wherein the determination device is further configured to determine the future power demand of the electric actuators with reference to one or more of: a strength of the actuation of the input means; a velocity of the actuation of the input means; a direction of the actuation of the input means; the number of actuators concerned with an entered control command; the identity of the actuator concerned with a control command; the velocity requested by the entered control commands; and the requested direction of the actuating movement of the actuator concerned with the control commands.

19. The crane according to claim 18, wherein the engine control unit is further configured to determine the speed of the internal combustion engine in dependence on the speed-voltage curve of the generator.

20. The crane according to claim 19, wherein the acceleration control module comprises: determination means configured to determine a point in time and/or a time period in which the actuators reach the future power demand; and acceleration determination means configured to determine the acceleration of the internal combustion engine in dependence on the determined point in time or the determined time period.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG. 1 is a schematic representation of a crane in the form of a container stacking crane with rubber tires, wherein the partial views a and b show the crane in front and side views, and

[0029] FIG. 2 is a schematic representation of the control device of the crane, which estimates or determines the future power demand of the electric actuators of the crane of FIG. 1 in advance and controls the internal combustion engine of the crane of FIG. 1, which drives its generator to supply the electric drives with energy, in dependence on the future power demand.

DETAIL DESCRIPTION OF THE INVENTION

[0030] To facilitate an understanding of the principles and features of the various embodiments of the invention, various illustrative embodiments are explained below. Although exemplary embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways.

[0031] As used in the specification and the appended Claims, the singular forms a, an and the include plural references unless the context clearly dictates otherwise. For example, reference to a component is intended also to include a composition of a plurality of components. References to a composition containing a constituent is intended to include other constituents in addition to the one named.

[0032] In describing exemplary embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0033] Ranges may be expressed as from about or approximately or substantially one value and/or to about or approximately or substantially another value. When such a range is expressed, other exemplary embodiments include from the one value and/or to the other value.

[0034] Similarly, as used herein, substantially free of something, or substantially pure, and like characterizations, can include both being at least substantially free of something, or at least substantially pure, and being completely free of something, or completely pure.

[0035] Comprising or containing or including is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.

[0036] The characteristics described as defining the various elements of the invention are intended to be illustrative and not restrictive. For example, if the characteristic is a material, the material includes many suitable materials that would perform the same or a similar function as the material(s) described herein are intended to be embraced within the scope of the invention. Such other materials not described herein can include, but are not limited to, for example, materials that are developed after the time of the development of the invention.

[0037] As shown in FIG. 1, the crane 1 can be configured as container stacking crane, which includes a gantry 2 that can be traveled on a container loading station by means of a traveling gear 4 provided with rubber tires, for example. On the gantry 2 a transversely movable bridge 3 can be arranged, on which a hoisting harness 5, by means of which a container 21 can be grasped, is mounted to be lifted and lowered.

[0038] For adjusting the crane elements electric actuators are provided, in particular a hoisting drive 6 for lifting and lowering the hoisting harness 5, which for example can be effected by means of a hoisting cable and corresponding cable winches, then a bridge drive 7 by means of which the bridge 3 can be traveled along the gantry 2, and a traveling drive 8 by means of which the traveling gear 4 can be driven.

[0039] The electric actuators 6, 7 and 8 can be fed with electric energy by a generator 9 which can be driven by an internal combustion engine 10 for example in the form of a diesel engine.

[0040] For controlling the crane positioning movements input means 14 are provided for a crane operator, which can be arranged in a crane operator stand 22 and for example can comprise a joystick 15, input keys, control levers or slide switches and the like. By means of the input means 4 control commands can be generated or entered, which serve the actuation of the actuators in the form of the hoisting drive 6, the bridge drive 7 and the traveling drive 8.

[0041] In dependence on the control commands an electric control device 11 can then actuate the actuators, which advantageously can be effected via a frequency converter which in a known way can convert the frequency generated by the generator 9.

[0042] The control device 11 furthermore adapts the speed and/or the torque of the internal combustion engine 10 to the respective crane operating condition to on the one hand provide for handling the crane without any disadvantages in terms of performance and on the other hand achieve the lowest possible fuel consumption.

[0043] As shown in FIG. 2, the control device 11 therefor can comprise a determination device 12 by means of which the future power demand of the actuators and hence the power required by the internal combustion engine 10 and the generator 9 is calculated and determined or estimated with reference to the current operating condition of the actuators 6, 7 and 8 and the actuation of the input means 14. For this purpose, various sensor signals and/or items of information are supplied to the determination device 12, which can indicate the actuation of the input means, the crane operating condition and the structural characteristics of the crane. In particular, as is shown in FIG. 2, information on the actuation of the joystick 15, information on the actuation speed, information on the actual performance of the actuators and/or of the internal combustion engine and/or of the generator, information on further operating parameters such as internal combustion engine speed, internal combustion engine torque, traveling or adjustment speed of the actuators or of other crane elements, and/or information on the actual load on the crane elements and/or other information can be supplied to the determination device 12.

[0044] As described above, the determination device 12 of the control device 11 therefrom calculates the future power demand which occurs when the electric actuators 6, 7 and 8 reach the operating point requested by the control commands entered.

[0045] From the determined future power demand, the engine control unit 13 of the control device 11 then calculates the operating point or operating range required therefor, in particular the speed and/or torque of the internal combustion engine 10.

[0046] The engine control unit 13, as shown in FIG. 2, also considers the conditions and necessities of the generator 9, in particular what speed the generator actually needs to be able to provide the voltage and amount of electricity necessary for the future power demand. Generator characteristics such as voltage output via speed and the like can be considered here. In addition, framework conditions such as a fixed reference voltage needed can be considered.

[0047] As the result of this calculation process the engine control unit 13 then determines the actual operating point for the internal combustion engine 10, wherein the engine control unit 13 here can also calculate the acceleration with which the internal combustion engine 10 is brought to the new operating point. The engine control unit 13 and/or the control device 11 therefor can include an acceleration control module 16 which by time determination means 17 calculates the point in time or the time period at which or in which the electric actuators 6, 7 and 8 reach the anticipated operating point at which the future power demand actually occurs. Then, acceleration determination means 18 therefrom calculate the necessary acceleration for the internal combustion engine 10.

[0048] As shown in FIG. 2, the engine control unit 13 and/or the control device 11 can do only with an actuating speed command for the engine. It is not necessary to additionally also generate an actuating signal for the torque, although this would be possible in principle.

[0049] A speed controller 19 and/or a torque controller 20 of the engine control unit 13 then bring the internal combustion engine 10 into the desired operating point.