Patent Application
20180179029
Construction jobsites typically contain a variety of elements such as equipment, power lines, structures, building materials, and personnel. Depending on the phase of a project, there are changing arrangements of these elements while the building project itself progresses toward completion. During any given phase, however, a crane operator is required to take safety precautions so as not to run the boom into obstacles during operation of the crane. To do so, the crane operator often requires another worker on the ground that spots and watches for any impending problems, such as coming too close to an obstacle. This worker may then signal to the crane operator to move away from the obstacle or to shut the crane down. This includes inefficiencies and the need to pay the worker for just monitoring crane function visually.
The ability to alter crane functions with respect to defined areas or forbidden zones within the operational radius of cranes has been made generally available to the construction industry. This capability has evolved as the use of electronics and software for control systems has progressed. This capability is utilized in an operator aid device that can be referred to as a Working Range Limiter or WRL. When a WRL typically defines a forbidden zone it is seen as a map as viewed from above the jobsite.
A traditional WRL is useful for avoiding obstacles when the obstacles occur in the plane of movement, but fails when the geometry becomes more complicated. For example, if a building is marked as a forbidden zone to prevent a boom from impacting the building, a mobile crane will never be able to lift a load to the top of the building because to do so necessarily entails a portion of the crane entering the forbidden zone. If instead, the building is not designated as being in the forbidden zone, the crane could accidentally move into the proximity of the building when swinging the boom.
Likewise, in the case of a tower crane, if a building is marked as a forbidden zone to prevent a boom, trolley or hook from impacting the building, the tower crane may not be able to lift a load to the top of the building. If instead, the building is not designated as being in the forbidden zone, the tower crane could inadvertently be moved into close proximity of the building when swinging the boom or moving the trolley along the boom.
It would be beneficial to develop a system that provides a desired proximity between crane components and obstacles like a traditional WRL system, while allowing the crane to extend into what would traditionally be considered a forbidden zone.
A method for controlling a boom of a crane in proximity of obstacles at a worksite is disclosed. In one aspect, the method includes saving, in a memory, coordinate data representing a coordinate system at the worksite; saving, in the memory, obstacle data representing a forbidden volume in the coordinate system; saving, in the memory, boom data representing the location of the boom; and limiting movement of the boom, by a computing device, to avoid the boom entering the forbidden volume, the limiting based on a computed minimum distance between the boom and the forbidden volume using the coordinate data, the obstacle data, and the boom data.
In some embodiments, saving obstacle data includes inputting data representing the forbidden volume. In some embodiments, the boom rotates relative to the crane about a central axis, and saving coordinate data includes saving data representing the central axis.
In some embodiments, saving obstacle data includes using the boom to identify at least two coordinates of the forbidden volume. In some embodiments, the forbidden volume is a rectangular prism and the at least two coordinates include the front, top left corner of the forbidden volume and the front, top right corner of the forbidden volume.
In some embodiments, the crane includes lower works, upper works rotatable relative to the lower works about an axis of rotation, and the boom is disposed on the upper works, and using the boom to identify at least two coordinates of the forbidden volume includes aiming the boom in a first direction at a front face of the forbidden volume and determining a horizontal distance between the face and the axis of rotation to determine a first vector corresponding to the front face of the forbidden volume; aiming the boom in a second direction at a front, top left corner of the forbidden volume and determining a second vector corresponding to the second direction of the boom; intersecting the second vector and a plane to define a first coordinate of the obstacle data; aiming the boom in a third direction at a front, top right corner of the forbidden volume and determining a third vector corresponding to the third direction of the boom; and intersecting the third vector and the plane to define a second coordinate of the obstacle data. In some embodiments, aiming the boom includes at least one of aligning the boom using a video camera attached to the boom and aligning the boom using a laser pointer attached to the boom.
In some embodiments, limiting movement of the boom includes establishing a slowdown threshold distance between the boom and the forbidden volume; and changing a crane function responsive to the computed minimum distance between the boom and the forbidden volume being less than the threshold distance. In some embodiments, changing the crane function includes slowing down the movement of the boom in at least one direction that moves the boom closer to the forbidden volume. In some embodiments, limiting movement of the boom further includes establishing a shutdown threshold distance between the boom and the forbidden volume; and stopping the movement of the boom in response to the computed minimum distance between the boom and the forbidden volume being less than the shutdown threshold distance. In some embodiments, the crane function is selected from a group including telescoping in, telescoping out, booming up, booming down, swinging left, and swinging right.
In some embodiments, the method further includes computing, with the computing device, a maximum swing angle of the boom, a maximum extension of the boom, a maximum boom-up, and a maximum boom-down of the boom.
In some embodiments, determining a horizontal distance between the face and the axis of rotation comprises measuring a distance from the axis of rotation to the face.
In some embodiments, determining a horizontal distance between the face and the axis of rotation comprises placing a hook of the crane proximate the forbidden volume; and using a rated capacity indicator (RCL) hook radius to determine the horizontal distance.
In some embodiments, the data representing the forbidden volume is a building information model, and saving obstacle data comprises aligning the building information model in the coordinate system.
In another aspect a system for controlling a boom of a crane in proximity of obstacles at a worksite is disclosed. The system includes a crane control system configured to control operation of a crane boom; a processor in operable communication with the crane control system; and memory in operable communication with the processor, the memory storing data includes data representing a coordinate system; data representing the crane boom; data representing a forbidden volume; and computer executable instructions for execution by the processor, the computer executable instruction configured to calculate a minimum distance between the crane boom and the forbidden volume based on the data representing the crane boom and the data representing the forbidden volume, and to cause the crane control system to limit movement of the boom based on the calculated minimum distance.
In some embodiments, the computer executable instructions are further configured to determine at least two coordinates of the forbidden volume using the boom. In some embodiments, the system further includes a boom aiming system for aiming the boom at the at least two coordinates of the forbidden volume. In some embodiments, the boom aiming system is a system selected from a group including a laser pointer and a video camera system. In some embodiments, the crane control system limits the motion of the boom in response the calculated minimum distance being less than a threshold distance, and the data further includes a threshold distance value. In some embodiments the crane control system stops the motion of the boom in response to the calculated minimum distance being less than a critical distance, and the data further includes a critical distance value. In some embodiments, the data representing the forbidden volume is a building information model, and the computer executable instructions are further configured to establish the location of the forbidden volume within the coordinate system using the boom.
According to an embodiment, a tower crane includes a mast, a rotating bed coupled to the mast, a boom mounted on the rotating bed, and a hook block connected to the boom. A method for controlling a crane component of a tower crane in proximity of obstacles at a worksite is executable by a computing device having a processor and memory, and includes saving, in the memory, coordinate data representing a coordinate system at the worksite having an origin at a base of an axis of rotation of the rotating bed and fixed relative to the mast, wherein the boom is rotatable on the axis of rotation, saving, in the memory, obstacle data representing a forbidden volume in the coordinate system, saving, in the memory, crane component data representing the location of the crane component, and limiting movement of the crane component, by the computing device, to avoid the crane component entering the forbidden volume, the limiting based on a computed minimum distance between the crane component and the forbidden volume using the coordinate data, the obstacle data, and the crane component data. The crane component is one or more of the boom and the hook block.
According to another embodiment, a system for controlling a crane component of a tower crane in proximity of obstacles at a worksite includes a crane control system configured to control operation of the crane component, a processor in operable communication with the crane control system and memory in operable communication with the processor. The memory stores data including data representing a coordinate system having an origin at a base of an axis of rotation of the rotating bed and fixed relative to the mast, data representing the crane component, data representing a forbidden volume and computer executable instructions for execution by the processor. The computer executable instructions are configured to calculate a minimum distance between the crane component and the forbidden volume based on the data representing the crane component and the data representing the forbidden volume, and to cause the crane control system to control movement of the crane component based on the calculated minimum distance. The crane component is one or more of the boom and the hook block.
The present embodiments will now be further described. In the following passages, different aspects of the embodiments are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.
The computing device and controls may also control the movement of the rotating bed 116, which causes the boom 110 to swing left and swing right. The computing device and controls may also control the boom 110 to move up (boom-up) and move down (boom-down). These six directions (tele-out; tele-in; boom-up; boom-down; swing left; and swing right) may each be represented by a vector, each of which may be processed and tracked using appropriate algorithms as will be explained. Impact with obstacles on a worksite may be avoided by conducting vector analysis and continual monitoring of the orientation of the boom 110.
In a networked deployment, the computer system 300 may operate in the capacity of a server or as a client-user computer in a server-client user network environment, or as a peer computer system in a peer-to-peer (or distributed) network environment. The computer system 300 may also be implemented as or incorporated into various devices, such as a personal computer or a mobile computing device capable of executing a set of instructions 302 that specify actions to be taken by that machine, including and not limited to, execution of certain applications, programs, and with the option of accessing the Internet or Web through any form of browser. Further, each of the systems described may include any collection of sub-systems that individually or jointly execute a set, or multiple sets, of instructions to perform one or more computer functions.
The computer system 300 may include a memory 304 on a bus 320 for communicating information. Code operable to cause the computer system to perform any of the acts or operations described herein may be stored in the memory 304. The memory 304 may be a random-access memory, read-only memory, programmable memory, hard disk drive or any other type of volatile or non-volatile memory or storage device.
The computer system 300 may include a processor 308, such as a central processing unit (CPU) and/or a graphics-processing unit (GPU). The processor 308 may include one or more general processors, digital signal processors, application specific integrated circuits, field programmable gate arrays, digital circuits, optical circuits, analog circuits, combinations thereof, or other now known or later-developed devices for analyzing and processing data. The processor 308 may implement the set of instructions 302 or other software program, such as manually programmed or computer-generated code for implementing logical functions. The logical function or any system element described may, among other functions, process and/or convert an analog data source such as an analog electrical, audio, or video signal, or a combination thereof, to a digital data source for audio-visual purposes or other digital processing purposes such as for compatibility of computer processing.
The computer system 300 may also include a disk or optical drive unit 315. The disk drive unit 315 may include a computer-readable medium 340 in which one or more sets of instructions 302, e.g., software, can be embedded. Further, the instructions 302 may perform one or more of the operations as described herein. The instructions 302 may reside completely, or at least partially, within the memory 304 and/or within the processor 308 during execution by the computer system 300. One or more databases in memory may store a Cartesian coordinate system, and may relate positions of obstacles and the boom a crane to each other in 3D space within the database.
The memory 304 and the processor 308 also may include computer-readable media as discussed above. A “computer-readable medium,” “computer-readable storage medium,” “machine readable medium,” “propagated-signal medium,” and/or “signal-bearing medium” may include any device that includes, stores, communicates, propagates, or transports software for use by or in connection with an instruction executable system, apparatus, or device. The machine-readable medium may selectively be, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium.
The computer system 300 may further include a crane controller 350, a working range limiter 360, and a rated capacity limiter 365. The crane controller 350 may be coupled with the processor 308 and the bus 320 and be configured to control components of the crane, including the boom 110 and the rotating bed 116, in response to receiving control signals from the processor 308.
The rated capacity limiter 365 (also referred to as a moment limiter in the art) provides information for crane operators to ensure that the crane devices work safely in the range of design parameters. The working range limiter 360 provides information for crane operators to ensure that the crane devices work safely outside of a restricted volume. The working range limiter 360 and the rated capacity limiter 365 may each monitor the operations of the crane through a plurality of sensors, and provide information regarding the limits of the cranes to an operator. In some embodiments the functionality of the working range limiter 360 and the rated capacity limiter 365 may be combined into a single unit. When the crane 90 lifts objects, the reading changes continuously with the operation of the crane 90. The sensors provide information on the length and angle of the crane boom 110, the lifting height and range, the rated load, the lifted load and so on. If the crane 90 works nearly beyond the permitted scope, the rated capacity limiter 365 and/or the working range limiter 360 may sound an alarm, may light an indicator, or modify the operation of the crane. In some embodiments, the working range limiter 360 may also be adapted to act as a controller of the boom 110, the telescoping portion 112, and the rotating body 116 to allow the crane 90 to continue operation while avoiding the restricted volume.
Additionally, the computer system 300 may include an input device 325, such as a keyboard and/or mouse, configured for a user to interact with any of the components of the computer system 300. It may further include a display 370, such as a liquid crystal display (LCD), a cathode ray tube (CRT), or any other display suitable for conveying information. The display 370 may act as an interface for the user to see the functioning of the processor 308, or specifically as an interface with the software stored in the memory 304 or the drive unit 315.
The computer system 300 may include a communication interface 336 that enables communications via the communications network 200. The network 200 may include wired networks, wireless networks, or combinations thereof. The communication interface 336 network may enable communications via any number of communication standards, such as 802.11, 802.17, 802.20, WiMax, cellular telephone standards, or other communication standards.
Accordingly, the method and system may be realized in hardware, software, or a combination of hardware and software. The method and system may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. A typical combination of hardware and software may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein. Such a programmed computer may be considered a special-purpose computer, and be specially adapted for placement within the cab 120 and control of the crane 90.
The method and system may also be embedded in a computer program product, which includes all the features enabling the implementation of the operations described herein and which, when loaded in a computer system, is able to carry out these operations. Computer program in the present context means any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function, either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form.
The order of the steps or actions of the methods described in connection with the disclosed embodiments may be changed as would be apparent to those skilled in the art. Thus, any order appearing in the Figures or described with reference to the Figures or in the Detailed Description is for illustrative purposes only and is not meant to imply a required order, except where explicitly required.
The definition of the quasi-volume can begin with the plane 402 that contains the front rectangular face 405. To define this plane 402, in block 502, a vector normal to the face 405 is found, as well as a point contained within the plane 402. Both of these can be provided by the definition of a vector 460 that points from the origin 92 of the coordinate system 98 to the forbidden volume 400 that is normal to the front rectangular face 405. This vector 460 is referred to as {right arrow over (R)}Bldg.
The direction of vector 460 is found by swinging the rotating bed 116 of the crane to point the boom 110 towards the forbidden volume 400, and recording the swing angle 463 which is referred to as αBldg. The magnitude of vector 460 (the vector endpoint providing a point contained within the plane 402) is created by extending the telescopic boom 110 to have the tip of the telescopic boom 110, where the hook block is located, at the distance desired for the creating quasi-volume front face 405, and recording the current hook radius (which is a common element measured by a crane control system). For this step the hook block can be at any desired height.
Note that the preferred embodiment is not expected to have the quasi-volume be coincident with the actual building object. The quasi-volume would be expected to have some buffer or distance away from the building object. The positioning of the hook block is actually indicating the buffer desired. In another embodiment, if the actual building object location was desired for the quasi-volume, a manual measurement could be taken from the hook block to the actual building, and this value manually entered to the programming to be added to the {right arrow over (R)}Bldg magnitude. Manual measurement may be necessary to prevent accidental impact between the boom 110 and the object. Also note that the vector, {right arrow over (R)}Bldg 460 is in the XY plane of the coordinate system 98; therefore, the boom up/down angle is not relevant. The crane operator may use his normal view of the building object to point the boom 110 at the object. While it is preferable that the vector {right arrow over (R)}Bldg 460 be perpendicular to the face 405, the swing angle 463, αBldg, may be off from the true perpendicular direction without introducing large errors. If the swing angle 463 is off by 5 degrees in either direction, it will only introduce a 0.4% error in radial distance for the vector 460, {right arrow over (R)}Bldg.
With the front face plane 402 defined by vector, {right arrow over (R)}Bldg 460, the boundary of the face 405 may be determined in block 503. The boundary of the face 405 may be defined by two locations, the left top point 410 and the right top point 411 for the quasi-volume. The locations are determined by pointing the boom 110 at each location 410, 411 on the actual building object and recording the swing angle and the boom angle. For other building shapes, other points may be used.
In block 505, a similar procedure is used for the other top location 411 by intersecting a similar direction vector, {right arrow over (r)}Right from pointing the boom 110 to the top right location 411 and intersecting the direction vector {circumflex over (r)}Right with the plane for the front face 402 to obtain the location of the right top point {right arrow over (R)}Right.
The front top edge 466 is now defined by these two points, and can be modeled as {right arrow over (R)}FrontTop={right arrow over (R)}Right−{right arrow over (R)}Left. A direction unit vector for the front top edge is
A direction unit vector for the normal to the front face 405 is
A direction unit vector for the left edge 467 and right edge 468 of the front face, pointing from the top points 410 and 411 to the ground is {circumflex over (r)}Down=−{circumflex over (k)}, where {circumflex over (k)} is the unit vector for the vertical direction and is aligned with the Z axis of the coordinate system 98.
The extent of the left edge 467 and the right edge 468, can be any value that is sufficient to cover the height of the building or forbidden zone; the bottom edge of the quasi-volume is not relevant to the crane operation, so the distance can extend into the ground; for instance, it might be set to 500 meters. This extent can be applied to the direction vector {circumflex over (r)}Down to arrive at points for the remaining vertices of the front face 402.
In block 506, the remainder of the forbidden zone is determined. For the top face 401, the left top location point 410 and the right top location point 411 already define two of the points on the top face 401. The {circumflex over (r)}Bldg direction vector 460 is used to set the other two points for the top face. As with the front face 402, any value for the extent of the face can be used that is sufficient to cover the reach of the crane; again, it might be set to 500 meters. Telescopic booms are often used to position a load on top of the building object, and not beyond it, so this extent is not considered critical.
For the left face 403, as well as the right face 404, the left top location point and the left lower location point already define two of the points on the face. The {circumflex over (r)}Bldg direction vector is used to set the other two points for the face. As with the top face, any value for the extent of the face can be used that is sufficient to cover the reach of the crane; again, it might be set to 500 meters. In block 507 the WRL setup is completed.
As shown in
In another embodiment, the positioning of the boom may be enhanced using a pointing device 700 on a base section of the boom 110. For example, the pointing device 700 may identify a location (and thus boom and swing angles) such as the top left or top right corner of the forbidden volume. This information may be recorded by the computer system 300, and may be combined with a distance determined between the end of the boom 110 (where a crane hook 150 naturally hangs down). The pointing device 700 may be a camera, a laser, or other pointing device for lining up with a determined threshold of accuracy the boom with the outer boundaries of the obstacle 400. In some embodiments, the pointing device 700 may further contain a distance measurement device such as a laser rangefinder to determine a distance between the location and the end of the boom. The distance between the end of the boom and the location may then be converted into a distance in the XY plane.
The distance between the end of the crane 90 (or from the crane hook 150) and the forbidden volume 400 may be determined manually or with a computing device. The distance may be based on a minimum distance from a centerline-of-rotation of the boom with respect to the obstacle 400, e.g., from the hook 150 a distance taken perpendicularly to a middle section of the obstacle.
With the forbidden quasi-volume now defined within the coordinate system, and considering that the boom is also represented as a known vector (169) within the coordinate system, the invention can provide appropriate alterations of the control system to avoid undesirable interactions between the boom and the job site object using the method 900 of
In block 901 coordinate data is saved to memory. The coordinate data provides a reference for orientating the crane and its special relationship to objects around it. One example of saving coordinate data includes identifying the location of the pivot point of the boom as shown in block 906. In block 902, boom data is saved to memory. The boom data may be the known vector 169 and may be determined automatically by the crane control system. In block 903, obstacle data is saved to memory. The obstacle data may be saved to memory using the method 500 shown in
This distance is the basis for a critical proximity vector 473, which is the minimum distance between a point on the boom and the forbidden volume. With the boom modeled as a known vector 169, vectors may be computed for crane function motions. The first motion is the telescoping motion 471, the second motion is swinging left and right 470, and the third motion is boom up/down 472. For each motion there is a direction, and they are represented by six unit vectors within the coordinate system as follows: Telescope out: {circumflex over (t)}TO, Telescope in: {circumflex over (t)}TISwing left: {circumflex over (t)}SL, Swing right: {circumflex over (t)}SR, Boom up: îBU, and Boom down: {circumflex over (t)}BD. The telescope out unit vector is coincident with the boom vector 169 and is computed as {circumflex over (t)}TO={circumflex over (r)}Boom. The telescope in unit vector is {circumflex over (t)}TI=−1·{circumflex over (t)}TO. The swing left direction vector is computed as {right arrow over (T)}SL={circumflex over (k)}×{circumflex over (t)}TO, the swing left unit vector is computed as
and the swing right unit vector is {circumflex over (t)}SR=−1·{circumflex over (t)}SL. The boom up unit vector is computed as {circumflex over (t)}BU{circumflex over (t)}TO×îSL and the boom down unit vector is {circumflex over (t)}BD=−1·{circumflex over (t)}BU. The critical proximity vector 473 starts at the nearest point on the boom, and this point may be along the length of the boom (and not at the end of the boom).
In block 905, a scale factor for each crane function is determined for alterations of the control system. A value of 1.0 for a particular scale factor would indicate the crane function would be unaltered. A value of 0.0 for a particular scale factor would indicate the crane function would be shutdown. A value of 0.5 for a particular scale factor would indicate the crane function would be slowed by 50 percent.
The scale factors correspond to the six crane functions as follows: Telescope out: fTO; Telescope in: fTI; Swing left: fSL; Swing right: fSR; Boom up: fBU; and Boom down: fBD.
The value for the scale factor may be based on two thresholds for the critical proximity distance 473. The critical proximity distance is dProx=|{right arrow over (T)}Prox|. As the crane boom approaches the quasi-volume, this critical proximity distance decreases. When the critical proximity distance reaches a slowdown threshold (δ1), the crane function will begin to slow down. When the critical proximity distance reaches a shutdown threshold (δ0), the crane function will stop. These thresholds may be universal for the crane (applied to all crane functions), or the thresholds may be specific to each function. Considering the drift that is typical when stopping crane swing motions, particular threshold values for the swing function would be expected. However, the preferred embodiment described here will use a universal value for simplicity.
The critical proximity distance and the thresholds are used to create a scaling of the crane function based on the degree to which the proximity distance is between the thresholds as follows:
This relationship may be applied if the critical proximity distance has “entered” the threshold “zone”. Otherwise, the crane functions would not be altered and the scale factors would be set to 1.0.
The degree to which each crane function may require alteration within the threshold zone may be based on the position of the boom. The degree of alteration may be based on taking the dot product of the critical proximity unit vector and the earlier computed crane motion direction unit vectors. If the crane boom is swinging left toward a wall on the left, the critical proximity vector will be pointing to the left (from the boom to the wall), and the swing left motion vector will likewise be pointing to the left. The dot product in this case will be relatively close to 1, and would indicate that the swing left function should be directly altered. However, the swing right direction will be a unit vector pointing to the right; and the dot product in this case (still with respect to the critical proximity vector pointing to the left) will be relatively close to −1. The following computations determine the crane function alteration factors (one for each function direction):
ϵTO={circumflex over (t)}TO·{circumflex over (t)}Prox
ϵTI={circumflex over (t)}TI·{circumflex over (t)}Prox
ϵSL={circumflex over (t)}SL·{circumflex over (t)}Prox
ϵSR={circumflex over (t)}SR·{circumflex over (t)}Prox
ϵBU={circumflex over (t)}BU·{circumflex over (t)}Prox
ϵBD={circumflex over (t)}BD·{circumflex over (t)}Prox
The process of determining the crane function scale factors is now described. Initially the crane function scale factors may be set to 1.0. Each crane function direction may then be evaluated. If the critical proximity distance is between the crane function thresholds, and the direction dot product indicates that the crane function direction should be altered, then the scale factor may be computed as one of the following (depending on the crane function direction being evaluated):
f
TO=−1−ϵProx·ϵTO
f
TI=−1−ϵProx·ϵTI
f
SL=−1−ϵProx·ϵSL
f
SR=−1−ϵProx·ϵSR
f
BU=−1−ϵProx·ϵBU
f
BD=−1−ϵProx·ϵBD
If the direction dot product indicates that a crane function direction should be altered, and the critical proximity distance is at or beyond the shutdown threshold, the crane function scale factor would be set to 0.0.
In another example, there may be a building information model (BIM) of the obstacle (such as a building, or other non-rectangular-shaped object), then the BIM may be incorporated into the crane 3D workspace when there are at least two points available with which to align the BIM within the coordinate system.
The present disclosure is not limited for use in conjunction with a mobile crane, however. For example, the embodiments described above, including, for example, the techniques, systems, analyses and methods described above, may be implemented with a tower crane 1090 as well. Further description of the various techniques, systems, analyses, methods and the like described above may be omitted below, where the techniques, systems, analyses, methods and the like in the embodiments below are the same or substantially the same as those described above.
As will be described below, a tower crane includes a mast, a rotating bed coupled to the mast, a boom mounted on the rotating bed and a hook block connected to the boom. In one embodiment, a method for controlling a crane component of a tower crane in proximity of obstacles at a worksite includes, saving, in the memory, coordinate date representing a coordinate system at the worksite having an origin at a base of an axis of rotations of the rotating bed and fixed relative to the mast, wherein the boom is rotatable on the axis of rotation. The method also includes saving, in the memory, obstacle data representing a forbidden volume in the coordinate system. In addition, the method includes saving, in the memory crane component data representing the location of the crane component. The crane component data may be, for example, a modeled crane component stored in the memory. Movement of the crane component may be limited, by the computing device, to avoid the crane component entering the forbidden volume. Such limiting is based on a computed minimum distance between the crane component and the forbidden volume using the coordinate data, the obstacle data and the crane component data. The crane component may be, for example, one or more of the boom and the hook block. As described below, the boom may be a luffing jib or a hammerhead jib, for example.
In another embodiment, a system for controlling the crane component in proximity of obstacles at the worksite includes a crane control system (also referred to herein as a “crane controller”) configured to control operation of the crane component, a processor in operable communication with the crane control system, and a memory in operable communication with the processor, the memory storing data. The data includes data representing the crane component, data representing the forbidden volume and computer executable instructions for execution by the processor. The instructions are configured to calculate a minimum distance between the crane component and the forbidden volume based on the data representing the crane component and the data representing the forbidden volume. The instructions may then cause the crane control system to control movement of the crane component based on the calculated minimum distance. The crane component is one or more of the boom and the hook block.
Referring generally to
The tower crane 1090 also includes a boom 1110, 2110 mounted on the rotating bed 1116. As understood by those skilled in the tower crane art, the boom 1110, 2110 may also be referred to as a jib, such as a hammerhead jib, or a luffing jib, as will be described below. Hammerhead jibs include, for example, saddle jibs and flattop jibs. Hammerhead jibs include a trolley moving underneath and alongside the jib and a hook block suspended by one or more flexible members from the trolley. In the tower crane art, it is also understood that a hammerhead jib may incorporate two trolleys and a hook block suspended therefrom, utilizing specific reeving of the flexible member(s) onto the double trolley arrangement (not shown). Referring to
A hook block 1150 may be suspended from a free end of the luffing jib 1110, and connected thereto with a flexible member, such as a rope. The hook block 1150 is configured for vertical movements in response to hoist-in and hoist-out functions, which cause the rope to be wound or unwound, respectively, from a hoist (not shown). Vertical movement of the hook block 1150 may also be affected by the boom-up and boom-down movements. The boom-up and boom-down movements also move the hook block 1150 in a horizontal direction. That is, the boom-up and boom-down movements change a hook radius. The hook block 1150 is also configured for swinging movement with swinging movement of the luffing jib 1110.
Crane component movements may be controlled by the computer system 300, for example, by the crane controller 350. For example, the crane controller 350 may be operably connected to one or more actuators configured to control movements of the crane components. Such movement control may include, for example, starting or stopping movement, or changing a speed of the movement by increasing or decreasing movement speed. Such control may also include lock-out functionality to prevent movement or operation of crane components. In one embodiment, the crane components may include the luffing jib 1110, the rotating bed 1116, the hook block 1150 and/or the hoist. Accordingly, crane functions, including movements of the crane components, may be controlled.
In one embodiment, the computer system 300 is configured to control movement of the rotating bed 1116, which causes the luffing jib 1110 to swing left and swing right. The computer system 300 may also control the luffing jib 1110 to move up (boom-up) and move down (boom-down). These four directions (boom-up, boom-down, swing-left and swing-right) may each be represented by vectors, each of which may be processed and tracked using appropriate algorithms as will be explained. Interference with obstacles 80, such as a building, on a worksite may be avoided by conducting vector analysis and continual monitoring of the orientation of the luffing jib 1110.
A coordinate system has an origin at a base of the axis of rotation 1094 of the rotating bed 1116. In one embodiment, the coordinate system is the same as the coordinate system 98 described in the embodiments above, and shown, for example, in
Referring to
Referring again to
Referring still to
Referring to
Alternatively, or in addition, the front face normal vector 1460 may be determined by measuring a distance between the mast 1093 and a nearest corner of the building 80 or forbidden volume 400. Such a distance may represent a hypotenuse of a right triangle, shown at 1461 in
Using the techniques above for determining the front face normal vector 1460, a vector 1462 representing a distance between the tower mast 1093 and a face of building 80 or forbidden volume 400 adjacent to the front face, may be determined as well. However, it is understood that determining such a vector 1462 is optional and is not required in the methods and systems described herein.
In another embodiment, the tower crane 1090, and in turn, the tower crane mast 1093 may be positioned relative to the forbidden volume 400 or building 80 such that a vector extending normal to a face of the forbidden volume 400 or building 80 will intersect the tower mast 1093. With the tower crane 1090 positioned as such, this normal vector is the front face normal vector 1460, and generally corresponds to the front face normal vector 460 described in the embodiments above. Referring to
In block 1503, a boundary of the face 405 may be determined, for example, as described in the embodiments above. In one embodiment, the top left and the top right locations 410, 411 (see
In one embodiment, determining coordinates for the top left point 1504 and top right point 1505 may be performed, as noted above, by recording position information of the hook block 1150 at the top left and top right points, respectively. In another embodiment, determining coordinates of the top left point may include creating a first position vector extending from the origin of the coordinate system (e.g., a point along the axis of rotation 1094) to the top left point 410 identified with the hook block 1150 or end of the luffing jib 1110. A location of the top left point 410 may be determined by intersecting the first position vector and a plane for the front face 402 (see
Modeling of a front top edge 466 (see
With further reference to
In one embodiment, in block 1901, coordinate data is saved to memory. The coordinate data provides a reference for orientating the tower crane 1090 and its relationship to objects around it, such as the obstacle 80 (e.g. the building) and/or the forbidden volume 400. One example of saving coordinate data includes identifying the location of the crane component, such as a pivot point (e.g., the axis of rotation 1094) of a boom, such as luffing jib 1110, or a location of the hook block 1150, as shown in block 1906. In block 1902, crane component data is saved to memory. In one embodiment, the crane component data may be boom data, represented by luffing jib vector 1169, and/or hook block data represented by hook block model 2169. The component data may represent, for example, a location of a crane component, such as the boom, including the luffing jib 1110, and the hook block 1150.
In one embodiment, the hook block model 2169 may be a 3D model. For example, in an embodiment, the hook block model 2169 may be a circle in a 3D space, disposed substantially in a horizontal plane. The hook block model 2169 may be sized and shaped to be larger than the actual hook block 1150. Accordingly, the hook block model 2169 provides a buffer around the actual hook block 1150 to account for swinging and swaying of the hook block 1150 that may occur in the course of normal use. It is understood, however, that the hook block model 2169 is not limited to the horizontally positioned circle in the 3D space described above. For example, other suitable shapes are envisioned, including, but not limited to, elliptical, square, trapezoidal, cubical and other prisms, cylindrical, conical, spherical, pyramidal, and the like. In one embodiment, the hook block model 2169 may be a shape that substantially corresponds to the actual shape of the hook block 1150. The size, for example, a width or diameter, of the hook block model 2169 may correspond to one or more a predicted or detected range of motion of a swinging or swaying hook block 1150, such that swinging or swaying motion of the hook block 1150 is within or substantially within the hook block model 2169. In one embodiment, the modeled hook block 2169 may be sized to include a load coupled to the hook block 1150.
The luffing jib vector 1169 and/or the hook block model 2169 may be determined automatically by the computer system 300 and may be line segments or other shapes disposed in a 3D environment. The luffing jib vector 1169 may be used to model the luffing jib 1110. In block 1903, obstacle data is saved to memory. The obstacle data may be saved to memory using the method 1500 shown in
The luffing jib vector 1169 and hook block model 2169 data may be saved to memory during operation of the tower crane 1090. The distance from the luffing jib 1110 and/or the hook block 1150 to the quasi-volume features (such as faces and edges of forbidden volume 400) may be computed in block 1904 based on the boom data and/or hook block data and the obstacle data (e.g., the forbidden volume 400). In one embodiment, a direction unit vector may be computed using the luffing jib vector 1169 or hook block model 2169 in the manner described in the embodiments above and discussed with reference to
Referring again to
For each motion there is a direction which may be represented by unit vectors within the coordinate system as follows: swing-left, swing-right, boom-up, boom-down and hook-down. Calculation of these unit vectors may be carried out substantially the same as described above with reference to the boom 110 and FIG. 10. It is understood, however, that the unit vectors associated with the luffing jib 1110 may be different from the unit vectors associated with the telescoping boom 110 in that the luffing jib 1110 may optionally omit unit vectors associated with telescoping movement.
In one embodiment, the boom proximity vector 1473 starts at the nearest point on the luffing jib 1110 to the forbidden volume 400, and this point may be along the length of the luffing jib 1110 (and not necessarily at the end of the luffing jib). The boom proximity vector 1473 may be converted to a direction unit vector as described in the embodiments above with respect to the critical proximity vector 473. Alternatively, or in addition, the computer system 300 may convert the hook block proximity vector 2473 to a direction unit vector using techniques similar to those in the embodiments above, but taking into account the motions of the hook block 1150.
Referring again to
In one embodiment, positioning of the luffing jib 1110 or hook block 1150 may be enhanced by manual or electronic assistance as described in the embodiments above, and shown, for example, in
According to one embodiment, when the proximity distance (i.e., the distance associated with boom proximity vector 1473 or hook block proximity vector 2473) reaches a slowdown threshold distance, the crane function will begin to slow down. For example, the rotating bed 116 may be controlled such that movement of the luffing jib 1110 and hook block 1150 may be slowed in a swinging direction, a lift actuator (not shown) may be controlled such that movement of the luffing jib 1110 and/or hook block 1150 may be slowed in a lifting direction, or the hoist may be controlled such that movement of the hook block 1150 in a vertical direction may be slowed. When the proximity distance reaches a shutdown threshold, the crane function will stop. For example, movement of the luffing jib 1110 or the hook block 1150 may be stopped, by controlling the rotating bed 1116, lifting actuator and/or the hoist. In addition, further operation of the luffing jib 1110 and/or hook block 1150 may be locked out. These thresholds may be universal for the crane (applied to all crane functions), or the thresholds may be specific to each function.
The degree to which each tower crane function may require alteration within the threshold zone may be based on the position of the luffing jib 1110. In one embodiment, the degree of alteration may be based on taking the dot product of the boom proximity unit vector and the earlier computed tower crane motion direction unit vectors. For example, if the luffing jib 1110 is swinging left toward a wall on the left, the boom proximity vector 1473 will be pointing to the left (from the job to the wall), and the swing-left motion vector will likewise be pointing to the left. The dot product in this case will be relatively close to 1, and would indicate that the swing-left function should be directly altered. However, the swing-right direction will be a unit vector pointing to the right; and the dot product in this case (still with respect to the critical proximity vector pointing to the left) will be relatively close to −1. Crane function alteration factors may be computed in substantially the same manner as described above and the process of determining crane function scale factors may be substantially the same as described above. The degree of alteration of the hook block 1150 motion may be similarly determined.
While the embodiments above, described with reference to the luffing jib 1110 and
According to one embodiment, a coordinate system may have an origin at a base of the axis of rotation 1094 of the rotating bed 1116. In one embodiment, the coordinate system is the same as the coordinate system 98 described in the embodiments above, but has an origin that is positioned relative to the tower crane 1090. For example, in one embodiment, the coordinate system may be fixed relative to the lower works 1093, i.e., the tower crane mast, of the tower crane 1090. However, in other embodiments the coordinate system could be fixed relative to the rotating bed 1116 such that the X axis would remain constant along the hammerhead jib 2110. Other coordinate systems are possible and could be based on any origin within the construction zone. In one embodiment, coordinate data stored in the memory includes the axis of rotation 1094 of a boom, such as the hammerhead jib 2110.
Movements of the hammerhead jib 2110 include swinging, or slewing, movements in response to the rotating bed 1116 being controlled to move. Movements of the hook block 1150 and trolley 2112 may be controlled as well. Such movements include substantially horizontal, or radial, movement caused by the moving the trolley 2112 along the hammerhead jib 2110 toward and away from the tower mast 1093, and swinging movement together with the hammerhead jib 2110, in response to the rotating bed 1116 being controlled to move. In one embodiment, a trolley motor (not shown) is configured to drive the trolley 2112 along the hammerhead jib 2110. As described above, such control of movements may include, for example, starting and stopping movement, controlling speed of the movement by increasing or decreasing speed of the crane component (e.g., the hammerhead jib 2110, the trolley 2112, the hook block 1150), and/or preventing operation or movement of the crane component.
In one embodiment, the crane component movements may be controlled by the computer system 300, for example, the crane controller 350. For example, the computer system 300 may be operably connected to an actuator to control movement of the rotating bed 1116, and consequently, control swinging movement of the hammerhead jib 2110, trolley 2112 and hook block 1150. The computer system 300 may also be operably connected to the trolley motor to cause movement of the trolley 2112 and the hook block 1150 along the hammerhead jib 2110. The computer system 300 may also be connected to the hoist to control raising and lowering of the hook block 1150. Thus, the hammerhead jib 2110, trolley 2112 and the hook block 1150 are configured for swing-left and swing-right movements. The trolley 2112 and the hook block 1150 are configured for trolley-in and trolley-out movements along the hammerhead jib 2110, and the hook block 1150 is configured for hook-up and hook-down movements, in response to hoist-in and hoist-out movements.
A hook radius may be changed, for example, by moving the trolley 2112 along the hammerhead jib 2110, i.e., by way of the trolley-in and trolley-out movements. The horizontal position of the hook block 1150 may be measured, for example, relative to the tower mast 1093, vertical axis of rotation 1094, or from a reference point along the hammerhead jib 2110.
During normal operation of the tower crane 1090, the hammerhead jib 2110 would not enter the forbidden volume 400 because the hammerhead jib 2110 is positioned above the forbidden volume 400. However, it remains possible for the hook block 1150, disposed below the hammerhead jib 2110, to enter the forbidden volume 400 in response to movement of the trolley 2112 along the hammerhead jib 2110 toward the forbidden volume 400, or in response to unwinding of the rope from a hoist (not shown) to lower the hook block 1150, i.e., the hook-down movement.
With further reference to
The hook block and boom proximity vectors 4473, 3473 may be determined in a manner similar to the proximity vector 473, hook block proximity vector 2473 and boom proximity vector 1473 described in the embodiments above.
Still referring to
For each motion there is a direction, and the directions are represented by five unit vectors within the coordinate system as follows: trolley-out, trolley-in, swing-left, swing-right, and hook-down. Unit vectors for each motion may be calculated similar to the unit vectors described above with respect to motions 470, 471, 472, 1470 and 1472, as appropriate. However, it is understood that the calculations may be adjusted to account for the different movements carried out by the tower crane 1090, described above. In addition, the hook block and boom proximity vectors 4473, 3473 may be converted to respective direction unit vectors in a manner similar to that of the critical proximity vector 473, boom proximity vector 1473 and hook block proximity vector 2473 in the embodiments above. The dot products of the hook block proximity vector 4473 and the motion vectors 2470, 2471, 2472, as applicable, and/or the dot products of the boom proximity vector 3473 and the motion vectors 2470, 2471, 2472, as applicable, may provide a basis for controlling or preventing crane functions.
Control or prevention of crane functions and movements may be carried out as described in the embodiments above. For example, a threshold distance may be established between the crane component and the forbidden volume 400 and a crane function may be changed or stopped based on a computed minimum distance between the crane component and the forbidden volume being equal to or less than the established threshold distance. In one embodiment, the established threshold distance may be a slowdown threshold distance, whereby a movement of the crane component or crane function is slowed in response to the computed minimum distance being equal to or less than the slowdown threshold distance. Alternatively, or in addition, the threshold distance may include a shutdown threshold distance, whereby movement of the crane component or crane function is stopped in response to the computed minimum distance being equal to or less than the shutdown threshold distance.
In one embodiment, identifying the two points 410, 411, is sufficient to create the forbidden volume, for example, by the computer system 300. For example, when the forbidden volume 400 is prismatic, the height information associated with each point 410, 411, and distance information between the points 410, 411, are sufficient to generate the forbidden volume 400.
In one embodiment, one or more cameras may be connected to the trolley 2112 to view the hook block 1150. The one or more cameras may be used to guide the hook block 1150 to the points 410, 411, which may be used to define the forbidden volume 400. The hook block 1150 may be guided to the points 410, 411, for example, by controlling, with the computer system 300, or manually, swinging motion of the hammerhead jib 2110, motion of the trolley 2112 along the hammerhead jib 2110 and operation of the hoist to raise or lower the hook block 1150.
Alternatively, or in addition, a range finding system, such a laser-type system, may be connected to the tower crane 1090, for example, at the trolley 2112. In one embodiment, the crane operator may move the hook block 1150 directly over the obstacle 80 and use the range finding system to set a proper vertical distance for a buffer above the obstacle 80. The buffer may then be used when generating the forbidden volume 400. In addition, if a dimension or shape of the obstacle is changing with time, for example, as it is being constructed, the tagging and range-finding methods above may be used update the obstacle 80 or forbidden volume 400 stored in the memory.
Accordingly, in the embodiments described above and shown in
The computer system 300 may control crane functions, including movement of crane components, based on a comparison of one or more of the boom proximity vector 3473 and the hook block proximity vector 4473 to an established threshold distance, such as a slowdown threshold distance or a shutdown threshold distance. Such crane functions may include, for example, swing-left and swing-right movements of the hammerhead jib 2110 and hook block 1150, trolley-in and trolley-out movements of the trolley 2112 and hook block 1150 along the hammerhead jib 2110, and/or hook-down movements of the hook block 1150 via hoist operation, to avoid the hammerhead jib 2110 or hook block 1150 from entering the forbidden volume 400 and/or coming into contact with the obstacle 80.
Accordingly, in the embodiments above, a customer may define a 3D forbidden volume around an obstacle, such as a building, and a crane operator may be guided to control or restrict crane functions based on the first and/or second proximity vectors. Alternatively, or in addition, the computer system 300 may control or restrict crane functions based on the first and/or second proximity vectors.
Referring to
For example, in step 2503, the hook block 1150 may be positioned by controlling movement of crane components, such as the rotating bed 1116, the hoist (not shown) and/or the hammerhead jib 2110, with the computer device 300, or manually, to position the hook block 1150 at the locations 410, 411, as shown in
Thus, in steps 2504 and 2505, locations, or coordinate information, of the top left 410 and the top right 411 points, as shown in
In some embodiments, the computer system 300 may calculate a maximum swing angle of the boom in each direction, a maximum boom-up angle and a maximum boom-down angle. The computer system 300 may also calculate a maximum hook down and hook up extent. Further, the computer system 300 may calculate a maximum trolley-out extent and a maximum trolley-on extent. In some embodiments, distances between various crane components and, for example, the obstacle 80 or forbidden volume 400, may be measured using conventional distance measuring techniques.
In the embodiments described above, the tower crane 1090 may be, for example, a hammerhead jib tower crane or a luffing jib tower crane. In one embodiment, the tower crane 1090 may be a self-erecting crane. In other embodiments, the systems described herein may be used in conjunction with a crawler crane having a lattice boom. For example, a hook block vector, hook block proximity vector, and minimum distance between a hook block and a forbidden volume may be provided for hook blocks used with mobile cranes, crawler cranes, industrial cranes and the like.
In the embodiments above, the computer system 300 is illustrated generally as being positioned in the operator cab 120, 1120. For example, as shown in
It is understood that various features from the embodiments above may be used together with, or replace certain features, from the other embodiments described above. That is, various features described with respect to one embodiment above, may be used together with or implemented in the other embodiments above.
It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. For example, the obstacles can be of any kind, not just rectangular or related to a structure under construction. For example, the forbidden volume could contain a power line as a natural obstacle for which the computer system 300 may monitor and with which to avoid interference, all the while avoiding collision with the forbidden volume. Such changes and modifications can be made without departing from the spirit and scope of the present embodiments and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.
This application is a continuation-in-part of U.S. patent application Ser. No. 15/850,185 filed on Dec. 21, 2017, which is a continuation of U.S. patent application Ser. No. 14/974,812, filed Dec. 18, 2015, now U.S. Pat. No. 9,850,109, which claims the benefit of provisional U.S. Patent Application Ser. No. 62/096,041, filed Dec. 23, 2014, the disclosures of which are incorporated herein by reference in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| 62096041 | Dec 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14974812 | Dec 2015 | US |
| Child | 15850185 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15850185 | Dec 2017 | US |
| Child | 15902111 | US |
