Patent Description:
The rated capacity of a crane refers to a maximum total load the crane is designed to lift in a particular configuration. The particular configuration includes parameters which remain substantially constant during a lift operation, such as the weight of a counterweight and outrigger extension length, and parameters which may vary during the lift operation, such as an operating radius (i.e., the moment arm of the load suspended from the boom) and a swing angle (i.e., a rotational position of a boom relative to a reference point of a carrier unit of the crane in a horizontal plane). The operating radius varies with changes in boom length (for example, in response to extension or retraction of a telescoping boom) and lift angle (i.e., the angle between the boom and the horizontal plane). In general, as the operating radius increases, a load moment increases and the rated capacity decreases. Conversely, as the operating radius decreases, the load moment decreases and the rated capacity increases. To this end, load charts are provided which indicate the rated capacity at different operating radii and/or lift angles.

A conventional crane Rated Capacity Limiter (RCL) system is configured to monitor a current load lifted by the crane and the current operating radius, for example, based on information received from one or more crane sensors and/or operator input. For example, the conventional crane RCL system may determine the current load based at least in part on information received from a pressure sensor detecting hydraulic pressure in a lift cylinder supporting the boom. The current operating radius may be determined based at least in part on information received from a sensor detecting a length of the boom and a sensor detecting the lift angle of the boom.

The conventional crane RCL system is further configured to determine an operating condition of the crane and may control crane operations based on the operating condition. For example, the conventional crane RCL system may control the boom to prevent movement of the current load to an operating radius where the current load exceeds the rated capacity.

A mobile crane typically includes a plurality tires for rolling contact with a support surface such that the crane may be self-propelled for transport on a road or at a worksite. The mobile crane also includes outriggers which can be deployed to engage the ground, lift the tires from the ground and support the mobile crane during a lift operation.

As an example, <CIT> discloses a crane according to the preamble of claim <NUM>. Additionally, it discloses a system and a method for monitoring a load lifted by a crane according to the preamble of claim <NUM>, the system comprising: a processor and a non-transitory computer-readable storage medium configured to store program instructions and the processor is configured is interpret and execute the program instructions to: determine a load lifted by the telescoping boom; receive pitch and/or roll information of the carrier unit from a slope sensor disposed on the carrier unit;adjust coordinates of the crane in a coordinate system based on the pitch and/or roll information;determine a transformed operating radius using the adjusted coordinates; and compare the load lifted to a rated capacity at the transformed operating radius.

It may be desirable to perform a lift operation for a relatively lightweight load without deploying the outriggers, such that the crane is supported on its tires during the lift operation. However, the crane may be susceptible to deflection in the direction of the load due to compression of the tires. Such deflection has the result of increasing the operating radius without changing a lift angle or boom length. Thus, the conventional RCL system does not detect the change in operating radius. Consequently, the conventional RCL system may compare the current load to a rated capacity in a load chart at a smaller operating radius than the current operating radius, which may affect accuracy of the comparison.

Accordingly, it is desirable to provide a crane and a system and method for the controlling crane in which deflection of a carrier unit is accounted for when monitoring the current load and the current operating radius.

According to the invention, a crane includes a carrier unit having a chassis, tires connected to the chassis, a carrier deck and outriggers, the outriggers movable to a deployed condition in which the outriggers engage an underlying support surface and lift the tires from the support surface such that the outriggers support the carrier unit, and a retracted condition in which the outriggers are disengaged from the support surface and the tires are engaged with the support surface, such that the tires support the carrier unit. The crane further includes a superstructure mounted on the carrier unit, the superstructure having a telescoping boom, and a slope sensor operably connected to the carrier unit and configured to detect a pitch and/or a roll of the carrier unit during a lift operation. The crane also includes a system for monitoring a load lifted by the telescoping boom. The system is configured to determine the current load lifted by the telescoping boom, receive pitch and/or roll information of the carrier unit from the slope sensor, adjust coordinates of the crane in a coordinate system based on the pitch and/or roll information, determine a transformed operating radius using the adjusted coordinates, and compare the load lifted to a rated capacity at the transformed operating radius. Additionally, the system is configured to monitor the load lifted with the outriggers in the retracted condition, and it is further configured to control vertical extension of the outriggers based on the pitch and/or roll information during movement of the outriggers to the deployed condition for leveling the carrier unit.

According to the invention, a system is provided for monitoring a load lifted by a crane, the crane having a carrier unit and a superstructure mounted on the carrier unit, the superstructure having a telescoping boom. The system includes a processor and a non-transitory computer-readable storage medium configured to store program instructions and the processor is configured is interpret and execute the program instructions to determine a load lifted by the telescoping boom, receive slope information of the carrier unit from the slope sensor, the slope information including the detected pitch and roll of the carrier unit;control vertical extension of outriggers to level the carrier unit based on the slope information; and monitor the load lifted by the crane during an on-rubber lift operation based on the slope information, wherein to monitor the load lifted by the crane, the system is configured to:determine a current load lifted by the telescoping boom;adjust coordinates of the crane in a coordinate system based on the slope information;determine a transformed operating radius using the adjusted coordinates; and compare the current load lifted to a rated capacity at the transformed operating radius.

According to the invention, a method is provided for monitoring a load lifted by a crane. The crane includes a carrier unit having a chassis, tires connected to the chassis, a carrier deck and outriggers, a superstructure mounted on the carrier unit, the superstructure having a telescoping boom. The crane also includes a slope sensor operably connected to the carrier unit and configured to detect a pitch and/or a roll of the carrier unit during a lift operation. The method includes determining a load lifted by the telescoping boom, receiving pitch and/or roll information of the carrier unit during a lift operation with the outriggers in the retracted condition such that the carrier unit is supported on the tires, wherein the pitch and/or roll information includes the detected pitch and/or roll of the carrier unit;adjusting coordinates of the crane in a coordinate system based on the pitch and/or roll information;determining a transformed operating radius using the adjusted coordinates; and comparing the load lifted to a rated capacity at the transformed operating radius.

Referring to <FIG>, a crane <NUM> according to embodiments herein generally includes a carrier unit <NUM> and a superstructure <NUM> rotatably mounted on the carrier unit <NUM> and configured for rotation relative to the carrier unit <NUM>. The carrier unit <NUM> includes various crane components, such as a chassis <NUM>, one or more tires <NUM> connected to the chassis <NUM>, a carrier deck <NUM> and outriggers <NUM>. The chassis <NUM> supports the one or more tires <NUM>, the carrier deck <NUM> and the outriggers <NUM>, as well as other components such as a powertrain (not shown). The one or more tires <NUM> are configured for rolling engagement with the ground, a road, or similar support surface to facilitate rolling movement of the crane <NUM>. For example, the powertrain may provide torque to the one or more tires <NUM> to propel the crane <NUM> for movement along the support surface. The carrier deck <NUM> generally defines an upwardly facing top surface of the carrier unit <NUM>.

The outriggers <NUM> may be arranged in a deployed condition, in which the outriggers <NUM> are extended horizontally outward relative to the chassis <NUM> to one or more extension positions, and vertically to engage an underlying support surface. Continued vertical extension of the outriggers <NUM> may cause the outriggers <NUM> to lift the tires <NUM> from the support surface, such that the crane <NUM> is supported on the outriggers <NUM>. The outriggers <NUM> may also be arranged in a retracted condition, in which the outriggers <NUM> are retracted horizontally inward toward the chassis <NUM> and vertically to disengage the support surface. Accordingly, in the retracted condition, the tires <NUM> may engage the support surface and the crane <NUM> may be supported on the tires <NUM>. In an embodiment, horizontal extension and retraction of the outriggers may be accommodated by a telescoping box and arm assembly (not shown), and vertical extension and retraction may be accommodated by a jack (not shown) operably connected to the telescoping box and arm assembly, for example, at or near a distal end of the arm.

The superstructure <NUM> also includes various crane components, such as a rotating bed <NUM> rotatably mounted on the carrier unit <NUM>, an operator's cab <NUM>, a counterweight assembly <NUM> and a telescoping boom <NUM>. The rotating bed <NUM> is rotatably mounted to the carrier unit <NUM> via a bearing structure and is configured to be driven in a first rotational direction, or alternatively, a second rotational direction opposite to the first rotational direction, about a generally vertical axis. The rotating bed <NUM> directly or indirectly supports the operator's cab <NUM>, the counterweight assembly <NUM> and the telescoping boom <NUM>, as well as other crane components such as one or more hoists (not shown), such that these components are rotatable in the first and second rotational directions with the rotating bed <NUM>. The operator's cab <NUM> may include a user interface for allowing a crane operator to interact with a control system of the crane <NUM> as discussed further below, for example, to control operations of one or more crane components. The counterweight assembly <NUM> includes one or more weight units supported on a frame. The weight units may be installed and removed from the frame in a desired manner to provide a selected counterweight.

The telescoping boom <NUM> includes a base section <NUM> pivotably mounted on the rotating bed <NUM> for movement through a vertically oriented range of lift angles and one or more telescoping sections <NUM> configured for movement out of and into the base section <NUM> generally along a boom axis to change the boom length LG. One or more hoists (not shown) are configured to wind up and pay out a flexible member <NUM>, such as a rope or cable. A lifting appliance <NUM>, such as a hook block, is connected to a free end of the flexible member <NUM> and is suspended from a free end of the telescoping boom <NUM>. A lift cylinder <NUM> is pivotably connected directly or indirectly between the base section <NUM> and the rotating bed <NUM>. The lift cylinder <NUM> is operable to raise or lower the telescoping boom <NUM> through the range of lift angles. The rotating bed <NUM> is rotatable in the first and second rotational directions to cause rotation of the telescoping boom <NUM> through a range of horizontally oriented swing angles.

Referring now to <FIG> and <FIG>, the crane <NUM> further includes a control system <NUM>, sometimes referred to as a Crane Control System (CCS). The control system <NUM> may be implemented as one or more computing devices located at the crane <NUM>, remote from and communicably connected to the crane <NUM>, or a combination thereof. The control system <NUM> is operably connected to various crane components (including actuators of the crane components) of the carrier unit <NUM> and the superstructure <NUM> and may control operations of one or more of the crane components. For example, the control system <NUM> may control movements of one or more crane components, including starting, stopping, preventing and allowing movements of the crane component and/or controlling a speed, acceleration and/or deceleration of the crane component.

According to an embodiment, the control system <NUM> includes a crane controller <NUM>, a rated capacity limiter (RCL) <NUM> and a working range limiter (WRL) <NUM>. The crane controller <NUM> may be configured to send and/or receive control signals to various crane components to control movements of the crane components.

The RCL <NUM> is a system that generally operates to monitor a current load lifted (i.e., a hook load) by the telescoping boom <NUM> of the crane <NUM> relative to the rated capacity of the crane <NUM> at an operating radius (i.e., a hook radius). For example, the RCL <NUM> may determine the current load lifted and the operating radius based on information received from one or more crane sensors, user input, stored data and/or combinations thereof. The RCL <NUM> may identify a rated capacity at an operating radius, for example, from a stored load chart which includes rated capacities at different operating radii or lift angle and boom length combinations. The RCL <NUM> may compare the current load lifted by the crane to the rated capacity at the operating radius and control operations of one or more crane components based on the comparison. For example, the RCL <NUM> may control movements of the telescoping boom <NUM> (i.e., boom-up, boom-down, swing-left, swing-right, telescope-in and/or telescope-out movements) based on the comparison of the current load lifted to the rated capacity at the operating radius. In some embodiments, the RCL <NUM> may provide a control signal for controlling crane component movements directly to the crane component. In other embodiments, the RCL <NUM> may provide the control signal via the controller <NUM> to control movements of the crane component.

The WRL <NUM> is a system that generally operates to monitor a position of a crane component relative to a position of a restricted volume. For example, the WRL <NUM> may determine the position of the crane component based on information received from one or more crane sensors, user input, stored data and/or combinations thereof. The WRL <NUM> may identify the restricted volume, for example, based on stored position information, such as position information included in a worksite model, information received from one or more sensors (including crane sensors and/or external sensors communicably connected to the WRL <NUM>), information received via user input and/or combinations thereof. The restricted volume may represent an obstacle, such as a building, at a worksite and define a volume in which operation of one or more crane components should be avoided. Accordingly, the WRL <NUM> may compare the crane component position information to the restricted volume position information and control operations of the crane component based on the comparison. For example, the WRL <NUM> may control movements of the telescoping boom <NUM> (i.e.. , boom-up, boom-down, swing-left, swing-right, telescope-in and/or telescope-out movements) based on the comparison of telescoping boom position information to the restricted volume position information. In some embodiments, the WRL <NUM> may provide a control signal for controlling crane component movements directly to the crane component. In other embodiments, the WRL <NUM> may provide the control signal via the controller <NUM> to control movements of the crane component.

The control system <NUM> further includes computer components <NUM>, such as a processor <NUM>, a memory device <NUM>, a storage device <NUM>, a communication device <NUM>, an input device <NUM> and/or an output device <NUM> which may be connected to one another, for example, on a bus (not shown). In an embodiment, the computer components <NUM> may be operably connected to the controller <NUM>, the RCL <NUM> and the WRL <NUM>. However, it will be appreciated that the computer components <NUM> may be implemented in each of the controller <NUM>, the RCL <NUM> and the WRL <NUM> or distributed among the controller <NUM>, the RCL <NUM> and the WRL <NUM>. It will be further appreciated that although shown independently, any of the controller <NUM>, the RCL <NUM> and the WRL <NUM> may be integrated with another one or more of the controller <NUM>, the RCL <NUM> and the WRL <NUM> and provided as a single unit configured to perform the operations of the individual components described above.

In an embodiment, the processor <NUM> may be a computer processor, such as a microprocessor, configured to interpret and execute program instructions. The processor <NUM> is further configured to effect various operations (including movements) of one or more crane components in response to executing the program instructions. For example, the processor <NUM> may cause the controller <NUM> to provide a control signal for controlling movements of the telescoping boom <NUM>. It will be appreciated that the operations of the controller <NUM>, the RCL <NUM> and the WRL <NUM> described herein may be carried out or otherwise effected by the processor <NUM> in response to executing program instructions.

The memory device <NUM> may be a non-transitory computer-readable storage medium configured to store information, such as the program instructions to be executed by the processor <NUM>. The memory device <NUM> may be, for example, Random-Access Memory (RAM), Read-Only Memory (ROM) or other type of suitable memory device for storing information and/or executable program instructions. The storage device <NUM> is configured to store, for example, information, software, executable program instructions and the like which may, for example, be accessed or referenced by the processor <NUM>. The storage device <NUM> may also store information collected during operation of the crane <NUM>, such as information received by the control system <NUM> from one or more sensors or user input. In one embodiment, one or more load charts may be stored in the storage device <NUM> and/or memory device <NUM> and can be accessed or referenced, for example, by the RCL <NUM>. The storage device <NUM> may be a non-transitory computer-readable storage medium and may include, for example, a hard disk and an associated drive and/or other similar, suitable storage devices and associated drives.

The communication device <NUM> is configured to transmit and/or receive information from/to the control system <NUM> and/or between components of the control system <NUM>. For example, the communication device <NUM> may be provided as a communication interface having a transceiver or transceiver-like component to transmitting information to, and/or receiving information from, one or more other devices, such as other communication-enabled devices, components, sensors and the like.

The input device <NUM> may include, or form part of, a user interface configured to receive information from a user, such as the crane operator. The input device <NUM> may include, or be operably connected to, one or more operator controls by operation of which the user may provide information to the input device <NUM>. The one or more operator controls may include, for example, a lever, joystick, knob, button, dial, switch, keyboard, keypad, pointer device, touch screen display, one or more sensors such as a biometric sensor, audio sensor, light sensor and the like, including various combinations thereof. The controller <NUM> may send a control signal to control movements of a crane component in response to information received by the input device <NUM>.

The output device <NUM> may also include, or form part of, a user interface configured to provide information to a user, such as the crane operator. The output information may be provided visually, for example, on a display screen or with one or more lights (e.g., LEDs), audibly, for example by one or more audio speakers, and/or by way of haptic or vibratory feedback or alerts, for example, at an operator control. In some embodiments, the input device <NUM> and the output device <NUM> may be provided as a single device or include components provided as a single device, for example, a display screen or touch screen display. The output information may serve as an alert or an alarm.

The crane components may be operated to conduct various movements by controlling operations of corresponding component actuators. To this end, the control system <NUM> may be operably connected to one or more component actuators to control operations of the component actuators. For example, the control system <NUM> may be operably connected to outrigger actuators <NUM> for controlling movements (e.g., horizontal extension and retraction and vertical extension and retraction) of the outriggers <NUM>; a rotating bed actuator <NUM> for controlling movements (e.g., rotation in the first and second rotational directions) of the rotating bed <NUM> to cause swing-left and swing-right movements of the telescoping boom <NUM> through the range of swing angles; a boom actuator <NUM> for controlling movements (e.g., telescope-out and telescope-in) of the telescoping sections <NUM> of the telescoping boom <NUM> to increase or decrease the boom length; and a lift cylinder actuator <NUM> for controlling movements (e.g., extension and retraction) of the lift cylinder <NUM> to cause boom-up and boom-down movements of the telescoping boom <NUM> through a range of lift angles.

Further, the control system <NUM> may be operably connected to one or more crane sensors configured to provide information to the control system <NUM> about the crane, a crane component, crane surroundings, the environment, atmospheric conditions (e.g., temperature, wind speed, and the like), and/or other information which may affect crane operations. The information may be provided as a parameter value or information from which a parameter value may be derived. In an embodiment, the crane sensors may include one or more tire sensors <NUM> configured to provide tire pressure information of one or more tires <NUM>; one or more slope sensors <NUM> configured to provide slope information (e.g., pitch information and/or roll information) of the crane <NUM>; one or more outrigger sensors <NUM> configured to provide outrigger extension and/or pressure/load information of the outriggers <NUM>; one or more swing angle sensors <NUM> configured to provide swing angle information of the rotating bed <NUM> and/or the telescoping boom <NUM>; one or more boom length sensors <NUM> configured to provide boom length information of the telescoping boom <NUM>; one more lift angle sensors <NUM> configured to provide lift angle information of the telescoping boom <NUM>; and one or more lift cylinder pressure sensors <NUM> configured to provide lift cylinder pressure information of the lift cylinder <NUM>. Other sensors may be implemented as well, for example, a lift cylinder angle sensor for providing lift cylinder angle information to the control system <NUM>, and/or additional flow, pressure, load, proximity sensors and the like. It will be appreciated that although <FIG> shows various crane sensors associated with particular crane components, the crane sensors may be mounted or positioned with different crane components suitable for providing the intended information described herein.

Referring now to <FIG> and <FIG>, the RCL <NUM> may determine a current load lifted by the crane <NUM>. In an embodiment, the RCL <NUM> may determine the load lifted by the crane <NUM> based, at least in part, on information received from one or more crane sensors. For example, the RCL may receive lift cylinder pressure information from the one or more lift cylinder pressure sensors <NUM> and determine the load lifted by the crane <NUM> based on the lift cylinder pressure information. In one embodiment, the RCL <NUM> may calculate the current load lifted based on a formulaic relationship between the lift cylinder pressure and the current load lifted. Alternatively, or in addition, the RCL <NUM> may retrieve the current load lifted from the memory device <NUM> or storage device <NUM> based on known load values corresponding to different lift cylinder pressures or based on user input information, for example, when the load is known.

The RCL <NUM> may also determine an operating radius of the current load lifted by the crane <NUM> based, at least in part, on information received from one or more crane sensors. For example, the RCL <NUM> may receive lift angle information from one or more lift angle sensors <NUM> and boom length information from one or more boom length sensors <NUM> and determine the operating radius based on the lift angle information and the boom length information. In one embodiment, the RCL <NUM> may calculate the operating radius based on formulaic relationship between the lift angle, boom length and operating radius. Alternatively, or in addition, the RCL <NUM> may retrieve the operating radius from the memory device <NUM> or storage device <NUM> based on known operating radii values corresponding to different lift angles and boom lengths.

The operating radius of the load lifted by the crane <NUM> may further be determined based on a pitch and/or roll of the crane <NUM>. The pitch of the crane <NUM> generally refers to rotation of the carrier unit <NUM> (e.g., chassis <NUM>, carrier deck <NUM>) and/or rotating bed <NUM> about an axis extending laterally across the crane <NUM>. Thus, the pitch of the crane <NUM> results in an upward or downward deflection of a front end or a rear end of the carrier deck <NUM>. The roll of the crane <NUM> generally refers to rotation of the carrier unit <NUM> (e.g., chassis <NUM>, the carrier deck <NUM>) and/or the rotating bed <NUM> about an axis extending longitudinally along the crane <NUM>. Thus, the roll of the crane <NUM> results in an upward or downward deflection of the left or right lateral sides of the carrier deck <NUM>. The RCL <NUM> may receive pitch information and roll information (referred to collectively as "slope information") from one or more crane sensors. For example, the RCL <NUM> may receive information regarding deflection of the carrier unit <NUM> at different locations from one or more crane sensors and may then calculate slope information based on information regarding deflection of the carrier unit <NUM>.

The control system <NUM> (including the RCL <NUM>) may receive slope information from one or more slope sensors <NUM>, mounted on the carrier unit <NUM>, for example, the chassis <NUM> or carrier deck <NUM>, or on the superstructure <NUM>, for example, on the rotating bed <NUM>. During movement of the outriggers <NUM> to the deployed condition, such that the tires <NUM> are lifted from the support surface and the crane <NUM> is supported on the outriggers <NUM>, the slope sensor <NUM> may provide pitch and roll information to the control system <NUM> to allow for leveling of carrier unit <NUM>, for example, the carrier deck <NUM>. For example, the control system <NUM> may control vertical extension of one or more outriggers <NUM> to effect a change in pitch and/or roll of the carrier deck <NUM> until the carrier deck <NUM> is substantially level. The crane <NUM> may perform a lift operation with the outriggers <NUM> deployed. During such a lift operation, pitch and/or roll of the carrier deck <NUM> is expected to be relatively small and may not substantially affect the operating radius.

However, in some scenarios, it may be beneficial or permissible to perform a lift operation with the outriggers <NUM> in the retracted condition, such that the crane <NUM> is supported on the tires <NUM>. Such a lift operation is commonly referred to as an "on-rubber" lift operation. Generally, during an on-rubber lift operation, the carrier deck <NUM> is expected to pitch and/or roll to a greater extent than during a lift operation performed with deployed outriggers <NUM>, due to deformation of the tires <NUM>. Pitch and/or roll of the crane <NUM> during the on-rubber lift operation may cause an increase in operating radius, and consequently, may cause a decrease in the rated capacity (i.e., maximum permissible load at an operating radius).

According to embodiments herein, the RCL <NUM> is configured to determine an operating radius further based, at least in part, on the slope information (i.e., pitch information and/or roll information). In one embodiment, the slope information may be received by the RCL <NUM> from the slope sensor <NUM>. The RCL <NUM> may monitor the current load lifted at the operating radius determined based at least in part on the slope information. For example, the RCL <NUM> may compare the current load lifted to a rated capacity of the of the crane <NUM> at the operating radius determined based at least in part on the slope information. Further still, the RCL <NUM> may control operations of one or more crane components, such as the telescoping boom <NUM>, based on the comparison of the current load lifted to the rated capacity at the operating radius determined based at least in part on the slope information. For example, the RCL <NUM> may reduce or limit a speed, and/or prevent or limit movement of the telescoping boom <NUM> in a direction which may cause the rated capacity to approach the current load lifted, within a predetermined threshold.

With reference to <FIG> and <FIG>, the RCL <NUM> is configured to provide a coordinate system XYZ for the carrier unit <NUM>. The RCL <NUM> may determine coordinates for a plurality of points in the coordinate system XYZ. For example, the RCL <NUM> may determine X and Z coordinates for three points u, v, w in the coordinate system XYZ which may correspond to predetermined points on the crane <NUM> as shown in <FIG>. For example, point 'u' may correspond to a base pivot axis of the telescoping boom <NUM> and may serve as an origin for the coordinate system XYZ. Points 'v' and 'w' may also correspond to points in a geometric layout of the telescoping boom <NUM>. For example, point 'v' may correspond to a pivot axis formed by a connection of the lift cylinder <NUM> to the base section <NUM> of the boom <NUM>, and point 'w' may correspond to a base pivot axis of the lift cylinder <NUM>.

Referring to <FIG> and <FIG>, the RCL <NUM> may transform the coordinates based on the slope information. For example, the RCL <NUM> may determine a lean angle of the crane <NUM>, such as a lean angle of the carrier unit <NUM>, based on the slope information. In an embodiment, the lean angle may be determined based on a pitch angle and a roll angle, which may be determined based on the slope information. The coordinates may be adjusted using the lean angle. A lean angle for the actual position of the telescoping boom <NUM> may be determined as well. With a known lean angle, the coordinate transformations may account for the pitch and the roll of the crane <NUM> about a point on the carrier unit <NUM>.

General coordinates of points located on the telescoping boom <NUM>, or related components (e.g., the lift cylinder <NUM>) may be translated to have the carrier unit <NUM> rotation point (i.e., the point on the carrier unit <NUM> about which the carrier unit <NUM> pitches and/or rolls) as the origin of the coordinate system. The coordinates may be rotated about the Y-axis using the lean angle. The coordinates may then be translated back to have the origin at the original location, i.e., at the base pivot axis (point 'u') of the telescoping boom <NUM>. Such operations may be performed by the RCL <NUM>.

Alternatively, with reference to <FIG>, the RCL <NUM> may transform the coordinates of the of the points using a rotational coordinate system transformation for the base pivot axis (at point 'u') of the telescoping boom <NUM>. Thus, the base pivot axis of the telescoping boom <NUM> may remain at the origin of the coordinate system. However, the reference point 'w' does shift and the lift cylinder angle is altered.

Accordingly, in the embodiments above, the RCL <NUM> may determine an adjusted, or transformed operating radius based on the slope information, such that the transformed operating radius takes into account a pitch and/or roll of the crane <NUM>, for example, during an on-rubber lift operation.

The RCL <NUM> may additionally be configured to store, for example, crane geometry information, crane weight information, or both, and may use such information to determine the transformed operating radius. For example, the crane geometry information may be used by the RCL <NUM> to create a geometric model of the crane <NUM> or a crane component, such as the telescoping boom <NUM>. The crane geometry information may include, for example, various dimensions, distances between components, coordinate system information, coordinate information of reference points and/or crane components, and the like. The crane geometry information may be provided, for example, based on sensor information and/or user input. Weight information may include, for example, a weight profile of the crane <NUM>, a weight of the load lifted by the crane, weights of various crane components and the like.

Referring again to <FIG>, a geometric layout of the telescoping boom <NUM> in XZ plane of an XYZ coordinate system includes the reference points 'u', 'v' and 'w. ' In addition, the telescoping sections <NUM> are shown each having a first end A<NUM>, A<NUM>. Ai at a proximal end and a second end B<NUM>, B<NUM>. Bi+<NUM> at a distal end. A length L<NUM>, L<NUM>. Li of each telescoping section <NUM> is the distance between the second end B<NUM>, B<NUM>. Bi+<NUM> and the first end A<NUM>, A<NUM>. Ai of the respective telescoping sections <NUM>. The base section <NUM> is shown having a second end B<NUM> at a distal end and having a length L<NUM>. In addition, a length of the base section <NUM> to the pivot connection axis at reference point 'v' is shown as Lz. A length of the telescoping boom <NUM> is shown as LG. A lift angle of the telescoping boom <NUM> is shown as β<NUM>. A lift cylinder angle is shown as αZ.

Accordingly, with further reference to <FIG>, the following coordinates may be determined: <MAT> where:
Xu: Horizontal (x-axis) position of the reference point 'u'; <MAT> where:.

Still referring to <FIG>, the following 'Z' coordinates are determined: <MAT> where:
Zu: Vertical (Z-axis) position of the reference point 'u'; <MAT> where:.

According to an embodiment, the lift cylinder angle αZ may be determined as:.

<FIG> is another perspective view of the carrier unit <NUM> according to an embodiment. In <FIG>, the carrier unit <NUM> may be oriented in the first coordinate system XYZ. In an embodiment, the roll angle convention may be based on a right-handed positive direction of the carrier X-axis direction. A positive roll angle may lower the right-handed side of the crane and raise the left-handed side of the crane. A positive pitch angle may be based on the right-handed positive direction for the carrier Y-axis direction. A positive pitch angle may lower the front of the carrier unit <NUM> and may raise the rear of the carrier unit <NUM>. The X and Z coordinates may correspond to a midplane of the telescoping boom <NUM>.

A lean angle may be determined to adjust the coordinates in the first coordinate system XYZ, such as the X, Z coordinates in the midplane of the telescoping boom <NUM>. A unit vector near the X axis direction ("X unit vector") based on the effect of the pitch angle may be determined. A unit vector near the Y axis direction ("Y unit vector") based on the effect of the roll angle may be determined as well. A maximum lean angle may be determined from a Z unit vector based on the X unit vector and the Y unit vector. The maximum lean angle may then be determined based on the Z unit vector.

The X unit vector may be identified as: <MAT> where:
ωP: Pitch angle.

The Y unit vector may be identified as: <MAT> where:
ωR: Roll angle.

The maximum lean angle may be determined from the following vector: <MAT>.

The maximum lean angle may then become the following: <MAT>.

The Z unit vector may be projected to the XY plane as a projected Z unit vector <NUM> (see <FIG>). A projection <NUM> of the telescoping boom <NUM> to the XY plane may be determined based a swing (or slew) angle of the telescoping boom <NUM>. The lean angle for the actual position of the telescoping boom <NUM> may then be determined based on the maximum lean angle, the projected Z unit vector <NUM> and the projected boom <NUM> in the XY plane.

The projection <NUM> of the Z unit vector to the XY plane may be determined as follows: <MAT>.

The projection <NUM> of the telescoping boom <NUM> to the XY plane may be determined as follows: <MAT> where:
α: Swing angle.

The lean angle for the actual position of the telescoping boom <NUM> may then become the following: <MAT>.

Referring now to <FIG>, with the lean angle known, coordinate transformations may be used to account for the pitch and roll of the carrier unit <NUM> (and the crane <NUM>). The crane <NUM> may rotate about a point on the carrier unit <NUM>, for example, at a horizontal distance hc from the Z-axis. The point may be shown at a vertical distance (hp2d in <FIG>). In one embodiment, the vertical distance may correspond to the distance from the base pivot axis 'u' of the telescoping boom <NUM> to the carrier deck <NUM>. The telescoping boom base section <NUM> elevation angle may be preserved when accounting for the lean effects because a separate sensor may be used to detect the elevation angle. Point 'v' may be a position of the boom, and not the turntable. The base pivot axis at point 'u' would shift. Thus, adjusted coordinates may then be determined.

The coordinates may be adjusted as follows: <MAT> <MAT> <MAT> <MAT> <MAT> <MAT>.

In an embodiment, a general coordinate of a point on the boom system may have X and Z coordinates. The coordinates may be translated to have the carrier rotation point (see <FIG>) as the origin based on the general coordinate of a point on the telescoping boom system and the coordinate for the carrier rotation point. The coordinates may be rotated about the Y-axis based on the lean angle and the translated coordinates. The coordinates may then be translated back to have the origin at the original locations, i.e., where the boom base pivot axis 'u' originally was.

The following may indicate the general coordinate of a point on the boom system: <MAT>.

The coordinates may be translated to have the carrier rotation point as the origin, in the following manner: <MAT> where: <MAT>.

The coordinates may be rotated about the Y-axis using the following (the lean angle calculated earlier may utilized): <MAT>.

The coordinates may be translated back to have the origin at the original locations (where the boom pivot originally was) as follows: <MAT>.

With further reference to <FIG>, coordinates of the telescoping boom <NUM> may be transformed in manner described above, and the transformed telescoping boom <NUM>' is shown in broken lines, taking into account the slope information. In addition, the transformed operating radius is shown at R', while the original operating radius is shown at R. The transformed reference points u', v' and w' are shown in <FIG> taking into account the slope information. In an on-rubber lifting operation, the RCL <NUM> may measure an operating radius from a center line of rotation of the superstructure, which may have shifted in response to a pitch and/or roll of the carrier unit <NUM>. The RCL <NUM> may determine the operating radius during an on-rubber lifting operation in the manner described above. For example, the coordinates of different points on the crane may be adjusted to account for a pitch and/or roll of the carrier unit <NUM>.

<FIG> is a diagram showing a geometric layout of a portion of the telescoping boom <NUM> and the carrier unit <NUM> according to an embodiment. With reference to <FIG>, another approach to account for the lean during an on-rubber lifting operation may be to use a rotational coordinate system transformation for the boom pivot. In such an approach, the boom pivot 'u' remains at the origin. However, point 'w' does shift and the angle αz is altered. The change in angle may affect the FBD of the boom system that it may be seen to improve predicted values.

Referring to <FIG>, according to an embodiment, a method <NUM> for monitoring a load lifted by a crane may include, at <NUM>, determining a load lifted by a telescoping boom <NUM> of the crane <NUM>, at <NUM>, receiving pitch and/or roll information of a carrier unit <NUM> of the crane <NUM>, for example, from a slope sensor <NUM>, and at <NUM>, adjusting coordinates of the crane <NUM> in a coordinate system based on the pitch and/or roll information. At <NUM>, the method may further include determining a transformed operating radius R' using the adjusted coordinates, and at <NUM>, comparing the load lifted to a rated capacity at the transformed operating radius R'.

Accordingly, in the embodiments above, the RCL <NUM> may determine an operating radius (also referred to as a transformed operating radius R') of a crane <NUM>, for example, during an on-rubber lift operation using pitch and/or roll information, i.e., slope information, received from the slope sensor <NUM>. In one embodiment, the transformed operating radius R' may refer to an operating radius R that has been adjusted to account for pitch and/or roll of the crane <NUM>. The pitch and/or roll information may be indicative of a pitch and/or roll of the carrier unit <NUM>. The pitch and/or roll information may also be indicative of a pitch and/or roll of the superstructure <NUM>.

The RCL <NUM> may transform coordinates of the crane <NUM> based on the pitch and/or roll information from the slope sensor <NUM>, to account for the pitch and/or roll of the crane <NUM>. By accounting for the pitch and/or roll of the crane <NUM>, the RCL <NUM> may determine the transformed operating radius of the crane <NUM> during, for example, an on-rubber lift operation.

In the manner above, the RCL <NUM> may monitor the load lifted by the crane <NUM> and determine the operating condition (for example a load utilization) of the crane <NUM> during the on-rubber lifting operation based on a comparison of the load lifted by the crane <NUM> to the rated capacity at the transformed operating radius R'. That is, the RCL <NUM> may use an operating radius determined based on the pitch and/or roll information received from the slope sensor <NUM> to monitor the load lifted by the crane <NUM> and determine the operating condition of the crane.

It is understood that the relative directions described above, e. g, "upward," "downward," "upper," "lower," "above," "below," are used for illustrative purposes only and may change depending on an orientation of a particular component. Accordingly, this terminology is non-limiting in nature. In addition, it is understood that one or more various features of an embodiment above may be used in, combined with, or replace other features of a different embodiment described herein.

Claim 1:
A crane (<NUM>) comprising:
a carrier unit (<NUM>) having a chassis (<NUM>), tires (<NUM>) connected to the chassis (<NUM>), a carrier deck (<NUM>) and outriggers (<NUM>), the outriggers (<NUM>) movable to a deployed condition in which the outriggers (<NUM>) engage an underlying support surface and lift the tires (<NUM>) from the support surface such that the outriggers (<NUM>) support the carrier unit (<NUM>), and a retracted condition in which the outriggers (<NUM>) are disengaged from the support surface and the tires (<NUM>) are engaged with the support surface, such that the tires (<NUM>) support the carrier unit (<NUM>);
a superstructure (<NUM>) mounted on the carrier unit (<NUM>), the superstructure (<NUM>) comprising a telescoping boom (<NUM>);
a slope sensor (<NUM>) operably connected to the carrier unit (<NUM>) and configured to detect a pitch and/or a roll of the carrier unit (<NUM>) during a lift operation; and
a system (<NUM>) for monitoring a load lifted by the telescoping boom (<NUM>), the system (<NUM>) configured to:
determine the current load lifted by the telescoping boom (<NUM>);
receive pitch and/or roll information of the carrier unit (<NUM>) from the slope sensor (<NUM>);
adjust coordinates of the crane (<NUM>) in a coordinate system based on the pitch and/or roll information;
determine a transformed operating radius (R') using the adjusted coordinates; and
compare the current load lifted to a rated capacity at the transformed operating radius (R'),
characterized in that the system (<NUM>) is configured to monitor the load lifted with the outriggers (<NUM>) in the retracted condition, and
wherein the system (<NUM>) is further configured to control vertical extension of the outriggers (<NUM>) based on the pitch and/or roll information during movement of the outriggers (<NUM>) to the deployed condition for leveling the carrier unit (<NUM>).