Patent Description:
Power machines, for the purposes of this disclosure, include any type of machine that generates power for the purpose of accomplishing a particular task or a variety of tasks. One type of power machine is a work vehicle. Work vehicles are generally self-propelled vehicles that have a work device, such as a lift arm (although some work vehicles can have other work devices) that can be manipulated to perform a work function. Work vehicles include loaders, excavators, utility vehicles, tractors, and trenchers, to name a few examples.

Loaders can be used to perform a variety of tasks using travel, lift, tilt and auxiliary functions. Commonly, loaders are used to transport material and/or to perform a variety of tasks with attached implements. When operating a loader to perform a task, one or more persons, animals, vehicles or other objects may approach the work area in close proximity to the power machine.

<CIT> relates to a shovel which is provided with a traveling body, a rotating body which is mounted rotatably on the traveling body, an object detection means which detects prescribed objects in the periphery of the shovel, a control means which, when an object has been detected, restricts action of the shovel or notifies of detection of the object, and a cancellation means which cancels the movement restriction or notification. Upon cancellation by the cancellation means, the carrying out of said cancellation is notified to the periphery.

<CIT> relate to an obstacle determination unit which determines that a detected object is an obstacle when the object detected by a distance sensor is located in a monitoring region that is set in a blind spot of an operator. In addition, the obstacle determination unit sets the monitoring region so that a region showing a lower traveling body is excluded in accordance with the turning angle detected by an angle sensor. A stop control unit determines, on the basis of the turning angle detected by the angle sensor, whether a component, that is, the lower traveling body and/or an upper turning body, of construction machinery may collide with an obstacle when the component is operated, and stops operation of the component that is determined to be likely to collide.

The invention for which protection is sought is defined by the independent claim(s).

Disclosed embodiments include power machines such as loaders, and systems used on power machines, that are configured to detect the presence of an object in a zone adjacent the rear or sides of the power machine and to responsively control the power machine to stop or slow work functions. Some disclosed embodiments also illuminate a zone or a portion of a zone in which an object can be been detected.

Disclosed embodiments include power machines and methods of providing controlling power machines in work areas having obstacles. A system of one or more controllers or computers can be configured to perform particular operations or actions by virtue of having software, firmware, hardware, or a combination of them installed on the system that in operation causes or cause the system to perform the actions. One or more computer programs can be configured to perform particular operations or actions by virtue of including instructions that, when executed by data processing apparatus, cause the apparatus to perform the actions.

One general aspect includes a power machine (<NUM>, <NUM>, <NUM>) including: a power system (<NUM>, <NUM>, <NUM>) having: a power source (<NUM>, <NUM>), a power conversion system (<NUM>, <NUM>) driven by the power source, a traction system including left and right drive motors (326a, 326b) coupled to and receiving power through the power conversion system to implement travel functions and move the power machine, and work actuators (<NUM>, <NUM>) coupled to and receiving power through the power conversion system to implement work functions. The power machine also includes user inputs (<NUM>) actuable by an operator of the power machine and configured to responsively provide user input signals to control the work and travel functions of the power machine. The power machine also includes at least one object detection sensor (<NUM>) configured to detect a presence of an object (<NUM>; <NUM>) within one or more monitored zones (<NUM>; <NUM>; <NUM>) surrounding the power machine and to responsively provide object detection signals indicative of detection of the presence of the object. The power machine also includes a zone illumination system (<NUM>) configured to illuminate all or part of any of the monitored zones in which the presence of the object was detected. The power machine further includes a controller (<NUM>) coupled to the user inputs, the at least one object detection sensor, the zone illumination system, and the power conversion system, the controller configured to receive the user input signals and the object detection signals and to responsively control the power conversion system to control the traction system and work actuators and thereby control work and travel functions of the power machine, where upon detection of the object within the one or more monitored zones the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

Implementations may include one or more of the following features. The power machine where the controller is further configured such that, upon detection of the object within the one or more monitored zones, the controller controls the power conversion system (<NUM>) to slow or stop performance of at least one of the travel functions and the work functions using the traction system and the work actuators, altering normal control responsive to the user input signals. The power machine where the controller is configured such that, upon detection of the object within the one or more monitored zones, the controller controls the power conversion system (<NUM>) to slow or stop the travel functions of the power machine using the traction system, despite user input signals commanding travel, to prevent a collision with the object. The power machine where the controller is configured such that, upon detection of the object within the one or more monitored zones, the controller controls the power conversion system (<NUM>) to allow at least some work functions using the work actuators.

The power machine where the power conversion system includes left and right drive pumps (324a; 324b) driven by the power source and coupled, respectively, to the left and right drive motors (326a; 326b). The power machine where the power conversion system includes: an implement pump (324c) driven by the power source; and a control valve (<NUM>) receiving pressurized hydraulic fluid from the implement pump and selectively providing the pressurized fluid to the work actuators. The power machine and further including: a frame (<NUM>; <NUM>); a lift arm assembly (<NUM>) pivotally coupled to the frame; an implement carrier (<NUM>) pivotally coupled to the lift arm assembly; where the work actuators include a lift actuator (<NUM>), coupled between the frame and the lift arm assembly and configured to raise and lower the lift arm assembly, and a tilt actuator (<NUM>) pivotally coupled between the lift arm assembly and the implement carrier and configured to rotate the implement carrier relative to the lift arm assembly.

The power machine where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating a portion of ground within the monitored zones in which the presence of the object was detected, which is not part of the claimed invention. The power machine where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating a boundary of the monitored zones in which the presence of the object was detected, which is part of the claimed invention. The power machine where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating the detected object, which is not part of the claimed invention.

One general aspect includes a power machine (<NUM>, <NUM>, <NUM>) including: a power system (<NUM>, <NUM>, <NUM>) including: a power source (<NUM>, <NUM>), a power conversion system (<NUM>, <NUM>) driven by the power source, a traction system including left and right drive motors (326a, 326b) coupled to and receiving power through the power conversion system to implement travel functions and move the power machine, and work actuators (<NUM>, <NUM>) coupled to and receiving power through the power conversion system to implement work functions. The power machine also includes user inputs (<NUM>) actuable by an operator of the power machine and configured to responsively provide user input signals to control the work and travel functions of the power machine. The power machine also includes at least one object detection sensor (<NUM>) configured to detect a presence of an object (<NUM>; <NUM>) within one or more monitored zones (<NUM>; <NUM>; <NUM>) surrounding the power machine and to responsively provide object detection signals indicative of detection of the presence of the object. The power machine also includes a controller (<NUM>) coupled to the user inputs, the at least one object detection sensor, and the power conversion system, the controller configured to receive the user input signals and the object detection signals and to responsively control the power conversion system to control the traction system and work actuators and thereby control work and travel functions of the power machine, where upon detection of the object within the one or more monitored zones the controller controls the power conversion system to slow or stop performance of at least one of the travel functions and the work functions using the traction system and the work actuators, altering normal control responsive to the user input signals. Other embodiments of this aspect include corresponding computer systems, apparatus, and computer programs recorded on one or more computer storage devices, each configured to perform the actions of the methods.

Implementations may include one or more of the following features. The power machine where the controller is configured such that, upon detection of the object within the one or more monitored zones, the controller controls the power conversion system (<NUM>) to slow or stop the travel functions of the power machine using the traction system, despite user input signals commanding travel, to prevent a collision with the object. The power machine where the controller is configured such that, upon detection of the object within the one or more monitored zones, the controller controls the power conversion system (<NUM>) to allow at least some work functions using the work actuators.

The power machine and further including a zone illumination system (<NUM>) coupled to the controller and configured to illuminate all or part of any of the monitored zones in which the presence of the object was detected, where upon detection of the object within the one or more monitored zones the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected. The power conversion system where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating a portion of ground within the monitored zones in which the presence of the object was detected, which is not part of the claimed invention.

The power machine where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating a boundary of the monitored zones in which the presence of the object was detected, which is part of the claimed invention.

The power machine where the controller controls the zone illumination system to illuminate all or part of the monitored zones in which the presence of the object was detected by illuminating the detected object, which is not part of the claimed invention.

This Summary and the Abstract are provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.

The concepts disclosed in this discussion are described and illustrated with reference to exemplary embodiments. These concepts, however, are not limited in their application to the details of construction and the arrangement of components in the illustrative embodiments and are capable of being practiced or being carried out in various other ways. The terminology in this document is used for the purpose of description and should not be regarded as limiting. Words such as "including," "comprising," and "having" and variations thereof as used herein are meant to encompass the items listed thereafter, equivalents thereof, as well as additional items.

Disclosed embodiments include power machines such as loaders, and systems used on such power machines that are configured to detect objects within one or more zones on the sides and/or rear of the machine and to responsively limit or stop operations of the power machine. For example, upon the detection of an object within or approaching a zone to the sides or rear of the power machine, the travel, lift and/or other functions of the power machine can be slowed or stopped. In some disclosed embodiments, an illumination of the zone or other visual indication is implemented by the power machine. For example, in some embodiments a laser traces a boundary of the zone, or other light sources are used to illuminate the zone.

These concepts can be practiced on various power machines, as will be described below. A representative power machine on which the embodiments can be practiced is illustrated in diagram form in <FIG> and one example of such a power machine is illustrated in <FIG> and described below before any embodiments are disclosed. For the sake of brevity, only one power machine is illustrated and discussed as being a representative power machine. However, as mentioned above, the embodiments below can be practiced on any of a number of power machines, including power machines of different types from the representative power machine shown in <FIG>. Power machines, for the purposes of this discussion, include a frame, at least one work element, and a power source that is capable of providing power to the work element to accomplish a work task. One type of power machine is a self-propelled work vehicle. Self-propelled work vehicles are a class of power machines that include a frame, work element, and a power source that is capable of providing power to the work element. At least one of the work elements is a motive system for moving the power machine under power.

<FIG> is a block diagram that illustrates the basic systems of a power machine <NUM>, which can be any of a number of different types of power machines, upon which the embodiments discussed below can be advantageously incorporated. The block diagram of <FIG> identifies various systems on power machine <NUM> and the relationship between various components and systems. As mentioned above, at the most basic level, power machines for the purposes of this discussion include a frame, a power source, and a work element. The power machine <NUM> has a frame <NUM>, a power source <NUM>, and a work element <NUM>. Because power machine <NUM> shown in <FIG> is a self-propelled work vehicle, it also has tractive elements <NUM>, which are themselves work elements provided to move the power machine over a support surface and an operator station <NUM> that provides an operating position for controlling the work elements of the power machine. A control system <NUM> is provided to interact with the other systems to perform various work tasks at least in part in response to control signals provided by an operator.

Certain work vehicles have work elements that are capable of performing a dedicated task. For example, some work vehicles have a lift arm to which an implement such as a bucket is attached such as by a pinning arrangement. The work element, i.e., the lift arm can be manipulated to position the implement for the purpose of performing the task. The implement, in some instances can be positioned relative to the work element, such as by rotating a bucket relative to a lift arm, to further position the implement. Under normal operation of such a work vehicle, the bucket is intended to be attached and under use. Such work vehicles may be able to accept other implements by disassembling the implement/work element combination and reassembling another implement in place of the original bucket. Other work vehicles, however, are intended to be used with a wide variety of implements and have an implement interface such as implement interface <NUM> shown in <FIG>. At its most basic, implement interface <NUM> is a connection mechanism between the frame <NUM> or a work element <NUM> and an implement, which can be as simple as a connection point for attaching an implement directly to the frame <NUM> or a work element <NUM> or more complex, as discussed below.

On some power machines, implement interface <NUM> can include an implement carrier, which is a physical structure movably attached to a work element. The implement carrier has engagement features and locking features to accept and secure any of a number of implements to the work element. One characteristic of such an implement carrier is that once an implement is attached to it, it is fixed to the implement (i.e. not movable with respect to the implement) and when the implement carrier is moved with respect to the work element, the implement moves with the implement carrier. The term implement carrier as used herein is not merely a pivotal connection point, but rather a dedicated device specifically intended to accept and be secured to various different implements. The implement carrier itself is mountable to a work element <NUM> such as a lift arm or the frame <NUM>. Implement interface <NUM> can also include one or more power sources for providing power to one or more work elements on an implement. Some power machines can have a plurality of work element with implement interfaces, each of which may, but need not, have an implement carrier for receiving implements. Some other power machines can have a work element with a plurality of implement interfaces so that a single work element can accept a plurality of implements simultaneously. Each of these implement interfaces can, but need not, have an implement carrier.

Frame <NUM> includes a physical structure that can support various other components that are attached thereto or positioned thereon. The frame <NUM> can include any number of individual components. Some power machines have frames that are rigid. That is, no part of the frame is movable with respect to another part of the frame. Other power machines have at least one portion that is capable of moving with respect to another portion of the frame. For example, excavators can have an upper frame portion that rotates with respect to a lower frame portion. Other work vehicles have articulated frames such that one portion of the frame pivots with respect to another portion for accomplishing steering functions.

Frame <NUM> supports the power source <NUM>, which is configured to provide power to one or more work elements <NUM> including the one or more tractive elements <NUM>, as well as, in some instances, providing power for use by an attached implement via implement interface <NUM>. Power from the power source <NUM> can be provided directly to any of the work elements <NUM>, tractive elements <NUM>, and implement interfaces <NUM>. Alternatively, power from the power source <NUM> can be provided to a control system <NUM>, which in turn selectively provides power to the elements that capable of using it to perform a work function. Power sources for power machines typically include an engine such as an internal combustion engine and a power conversion system such as a mechanical transmission or a hydraulic system that is configured to convert the output from an engine into a form of power that is usable by a work element. Other types of power sources can be incorporated into power machines, including electrical sources or a combination of power sources, known generally as hybrid power sources.

<FIG> shows a single work element designated as work element <NUM>, but various power machines can have any number of work elements. Work elements are typically attached to the frame of the power machine and movable with respect to the frame when performing a work task. In addition, tractive elements <NUM> are a special case of work element in that their work function is generally to move the power machine <NUM> over a support surface. Tractive elements <NUM> are shown separate from the work element <NUM> because many power machines have additional work elements besides tractive elements, although that is not always the case. Power machines can have any number of tractive elements, some or all of which can receive power from the power source <NUM> to propel the power machine <NUM>. Tractive elements can be, for example, track assemblies, wheels attached to an axle, and the like. Tractive elements can be mounted to the frame such that movement of the tractive element is limited to rotation about an axle (so that steering is accomplished by a skidding action) or, alternatively, pivotally mounted to the frame to accomplish steering by pivoting the tractive element with respect to the frame.

Power machine <NUM> includes an operator station <NUM> that includes an operating position from which an operator can control operation of the power machine. In some power machines, the operator station <NUM> is defined by an enclosed or partially enclosed cab. Some power machines on which the disclosed embodiments may be practiced may not have a cab or an operator compartment of the type described above. For example, a walk behind loader may not have a cab or an operator compartment, but rather an operating position that serves as an operator station from which the power machine is properly operated. More broadly, power machines other than work vehicles may have operator stations that are not necessarily similar to the operating positions and operator compartments referenced above. Further, some power machines such as power machine <NUM> and others, whether or not they have operator compartments or operator positions, may be capable of being operated remotely (i.e. from a remotely located operator station) instead of or in addition to an operator station adjacent or on the power machine. This can include applications where at least some of the operator controlled functions of the power machine can be operated from an operating position associated with an implement that is coupled to the power machine. Alternatively, with some power machines, a remote-control device can be provided (i.e. remote from both of the power machine and any implement to which is it coupled) that is capable of controlling at least some of the operator controlled functions on the power machine.

<FIG> illustrate a loader <NUM>, which is one particular example of a power machine of the type illustrated in <FIG> where the embodiments discussed below can be advantageously employed. Loader <NUM> is a skid-steer loader, which is a loader that has tractive elements (in this case, four wheels) that are mounted to the frame of the loader via rigid axles. Here the phrase "rigid axles" refers to the fact that the skid-steer loader <NUM> does not have any tractive elements that can be rotated or steered to help the loader accomplish a turn. Instead, a skid-steer loader has a drive system that independently powers one or more tractive elements on each side of the loader so that by providing differing tractive signals to each side, the machine will tend to skid over a support surface. These varying signals can even include powering tractive element(s) on one side of the loader to move the loader in a forward direction and powering tractive element(s) on another side of the loader to mode the loader in a reverse direction so that the loader will turn about a radius centered within the footprint of the loader itself. The term "skid-steer" has traditionally referred to loaders that have skid steering as described above with wheels as tractive elements. However, it should be noted that many track loaders also accomplish turns via skidding and are technically skid-steer loaders, even though they do not have wheels. For the purposes of this discussion, unless noted otherwise, the term skid-steer should not be seen as limiting the scope of the discussion to those loaders with wheels as tractive elements.

Loader <NUM> is one particular example of the power machine <NUM> illustrated broadly in <FIG> and discussed above. To that end, features of loader <NUM> described below include reference numbers that are generally similar to those used in <FIG>. For example, loader <NUM> is described as having a frame <NUM>, just as power machine <NUM> has a frame <NUM>. The loader <NUM> should not be considered limiting especially as to the description of features that loader <NUM> may have described herein that are not essential to the disclosed embodiments and thus may or may not be included in power machines other than loader <NUM> upon which the embodiments disclosed below may be advantageously practiced. Unless specifically noted otherwise, embodiments disclosed below can be practiced on a variety of power machines, with the loader <NUM> being only one of those power machines. For example, some or all of the concepts discussed below can be practiced on many other types of work vehicles such as various other loaders, excavators, trenchers, and dozers, to name but a few examples.

Loader <NUM> includes frame <NUM> that supports a power system <NUM>, the power system being capable of generating or otherwise providing power for operating various functions on the power machine. Power system <NUM> is shown in block diagram form, but is located within the frame <NUM>. Frame <NUM> also supports a work element in the form of a lift arm assembly <NUM> that is powered by the power system <NUM> and is capable of performing various work tasks. As loader <NUM> is a work vehicle, frame <NUM> also supports a traction system <NUM>, which is also powered by power system <NUM> and is capable of propelling the power machine over a support surface. The lift arm assembly <NUM> in turn supports an implement interface <NUM>, which includes an implement carrier <NUM> that is capable of receiving and securing various implements to the loader <NUM> for performing various work tasks and power couplers <NUM>, to which an implement can be coupled for selectively providing power to an implement that might be connected to the loader. Power couplers <NUM> can provide sources of hydraulic or electric power or both. The loader <NUM> includes a cab <NUM> that defines an operator station <NUM> from which an operator can manipulate various control devices <NUM> to cause the power machine to perform various work functions. Cab <NUM> can be pivoted back about an axis that extends through mounts <NUM> to provide access to power system components as needed for maintenance and repair.

The operator station <NUM> includes an operator seat <NUM> and a plurality of operation input devices, including control levers <NUM> that an operator can manipulate to control various machine functions. Operator input devices can include buttons, switches, levers, sliders, pedals and the like that can be stand-alone devices such as hand operated levers or foot pedals or incorporated into hand grips or display panels, including programmable input devices. Actuation of operator input devices can generate signals in the form of electrical signals, hydraulic signals, and/or mechanical signals. Signals generated in response to operator input devices are provided to various components on the power machine for controlling various functions on the power machine. Among the functions that are controlled via operator input devices on power machine <NUM> include control of the tractive elements <NUM>, the lift arm assembly <NUM>, the implement carrier <NUM>, and providing signals to any implement that may be operably coupled to the implement.

Loaders can include human-machine interfaces including display devices that are provided in the cab <NUM> to give indications of information relatable to the operation of the power machines in a form that can be sensed by an operator, such as, for example audible and/or visual indications. Audible indications can be made in the form of buzzers, bells, and the like or via verbal communication. Visual indications can be made in the form of graphs, lights, icons, gauges, alphanumeric characters, and the like. Displays can be dedicated to provide dedicated indications, such as warning lights or gauges, or dynamic to provide programmable information, including programmable display devices such as monitors of various sizes and capabilities. Display devices can provide diagnostic information, troubleshooting information, instructional information, and various other types of information that assists an operator with operation of the power machine or an implement coupled to the power machine. Other information that may be useful for an operator can also be provided. Other power machines, such walk behind loaders may not have a cab nor an operator compartment, nor a seat. The operator position on such loaders is generally defined relative to a position where an operator is best suited to manipulate operator input devices.

Various power machines that are capable of including and/or interacting with the embodiments discussed below can have various different frame components that support various work elements. The elements of frame <NUM> discussed herein are provided for illustrative purposes and frame <NUM> is not the only type of frame that a power machine on which the embodiments can be practiced can employ. Frame <NUM> of loader <NUM> includes an undercarriage or lower portion <NUM> of the frame and a mainframe or upper portion <NUM> of the frame that is supported by the undercarriage. The mainframe <NUM> of loader <NUM>, in some embodiments is attached to the undercarriage <NUM> such as with fasteners or by welding the undercarriage to the mainframe. Alternatively, the mainframe and undercarriage can be integrally formed. Mainframe <NUM> includes a pair of upright portions 214A and 214B located on either side and toward the rear of the mainframe that support lift arm assembly <NUM> and to which the lift arm assembly <NUM> is pivotally attached. The lift arm assembly <NUM> is illustratively pinned to each of the upright portions 214A and 214B. The combination of mounting features on the upright portions 214A and 214B and the lift arm assembly <NUM> and mounting hardware (including pins used to pin the lift arm assembly to the mainframe <NUM>) are collectively referred to as joints 216A and 216B (one is located on each of the upright portions <NUM>) for the purposes of this discussion. Joints 216A and 216B are aligned along an axis <NUM> so that the lift arm assembly is capable of pivoting, as discussed below, with respect to the frame <NUM> about axis <NUM>. Other power machines may not include upright portions on either side of the frame, or may not have a lift arm assembly that is mountable to upright portions on either side and toward the rear of the frame. For example, some power machines may have a single arm, mounted to a single side of the power machine or to a front or rear end of the power machine. Other machines can have a plurality of work elements, including a plurality of lift arms, each of which is mounted to the machine in its own configuration. Frame <NUM> also supports a pair of tractive elements in the form of wheels 219A-D on either side of the loader <NUM>.

The lift arm assembly <NUM> shown in <FIG> is one example of many different types of lift arm assemblies that can be attached to a power machine such as loader <NUM> or other power machines on which embodiments of the present discussion can be practiced. The lift arm assembly <NUM> is what is known as a vertical lift arm, meaning that the lift arm assembly <NUM> is moveable (i.e. the lift arm assembly can be raised and lowered) under control of the loader <NUM> with respect to the frame <NUM> along a lift path <NUM> that forms a generally vertical path. Other lift arm assemblies can have different geometries and can be coupled to the frame of a loader in various ways to provide lift paths that differ from the radial path of lift arm assembly <NUM>. For example, some lift paths on other loaders provide a radial lift path. Other lift arm assemblies can have an extendable or telescoping portion. Other power machines can have a plurality of lift arm assemblies attached to their frames, with each lift arm assembly being independent of the other(s). Unless specifically stated otherwise, none of the inventive concepts set forth in this discussion are limited by the type or number of lift arm assemblies that are coupled to a particular power machine.

The lift arm assembly <NUM> has a pair of lift arms <NUM> that are disposed on opposing sides of the frame <NUM>. A first end of each of the lift arms <NUM> is pivotally coupled to the power machine at joints <NUM> and a second end 232B of each of the lift arms is positioned forward of the frame <NUM> when in a lowered position as shown in <FIG>. Joints <NUM> are located toward a rear of the loader <NUM> so that the lift arms extend along the sides of the frame <NUM>. The lift path <NUM> is defined by the path of travel of the second end 232B of the lift arms <NUM> as the lift arm assembly <NUM> is moved between a minimum and maximum height.

Each of the lift arms <NUM> has a first portion 234A of each lift arm <NUM> is pivotally coupled to the frame <NUM> at one of the joints <NUM> and the second portion 234B extends from its connection to the first portion 234A to the second end 232B of the lift arm assembly <NUM>. The lift arms <NUM> are each coupled to a cross member <NUM> that is attached to the first portions 234A. Cross member <NUM> provides increased structural stability to the lift arm assembly <NUM>. A pair of actuators <NUM>, which on loader <NUM> are hydraulic cylinders configured to receive pressurized fluid from power system <NUM>, are pivotally coupled to both the frame <NUM> and the lift arms <NUM> at pivotable joints 238A and 238B, respectively, on either side of the loader <NUM>. The actuators <NUM> are sometimes referred to individually and collectively as lift cylinders. Actuation (i.e., extension and retraction) of the actuators <NUM> cause the lift arm assembly <NUM> to pivot about joints <NUM> and thereby be raised and lowered along a fixed path illustrated by arrow <NUM>. Each of a pair of control links <NUM> are pivotally mounted to the frame <NUM> and one of the lift arms <NUM> on either side of the frame <NUM>. The control links <NUM> help to define the fixed lift path of the lift arm assembly <NUM>.

Some lift arms, most notably lift arms on excavators but also possible on loaders, may have portions that are controllable to pivot with respect to another segment instead of moving in concert (i.e. along a pre-determined path) as is the case in the lift arm assembly <NUM> shown in <FIG>. Some power machines have lift arm assemblies with a single lift arm, such as is known in excavators or even some loaders and other power machines. Other power machines can have a plurality of lift arm assemblies, each being independent of the other(s).

An implement interface <NUM> is provided proximal to a second end 232B of the lift arm assembly <NUM>. The implement interface <NUM> includes an implement carrier <NUM> that is capable of accepting and securing a variety of different implements to the lift arm <NUM>. Such implements have a complementary machine interface that is configured to be engaged with the implement carrier <NUM>. The implement carrier <NUM> is pivotally mounted at the second end 232B of the arm <NUM>. Implement carrier actuators <NUM> are operably coupled the lift arm assembly <NUM> and the implement carrier <NUM> and are operable to rotate the implement carrier with respect to the lift arm assembly. Implement carrier actuators <NUM> are illustratively hydraulic cylinders and often known as tilt cylinders.

By having an implement carrier capable of being attached to a plurality of different implements, changing from one implement to another can be accomplished with relative ease. For example, machines with implement carriers can provide an actuator between the implement carrier and the lift arm assembly, so that removing or attaching an implement does not involve removing or attaching an actuator from the implement or removing or attaching the implement from the lift arm assembly. The implement carrier <NUM> provides a mounting structure for easily attaching an implement to the lift arm (or other portion of a power machine) that a lift arm assembly without an implement carrier does not have.

Some power machines can have implements or implement like devices attached to it such as by being pinned to a lift arm with a tilt actuator also coupled directly to the implement or implement type structure. A common example of such an implement that is rotatably pinned to a lift arm is a bucket, with one or more tilt cylinders being attached to a bracket that is fixed directly onto the bucket such as by welding or with fasteners. Such a power machine does not have an implement carrier, but rather has a direct connection between a lift arm and an implement.

The implement interface <NUM> also includes an implement power source <NUM> available for connection to an implement on the lift arm assembly <NUM>. The implement power source <NUM> includes pressurized hydraulic fluid port to which an implement can be removably coupled. The pressurized hydraulic fluid port selectively provides pressurized hydraulic fluid for powering one or more functions or actuators on an implement. The implement power source can also include an electrical power source for powering electrical actuators and/or an electronic controller on an implement. The implement power source <NUM> also exemplarily includes electrical conduits that are in communication with a data bus on the excavator <NUM> to allow communication between a controller on an implement and electronic devices on the loader <NUM>.

Frame <NUM> supports and generally encloses the power system <NUM> so that the various components of the power system <NUM> are not visible in <FIG>. <FIG> includes, among other things, a diagram of various components of the power system <NUM> that are controlled responsive to detection of an object in embodiments as described below. Power system <NUM> includes one or more power sources <NUM> that are capable of generating and/or storing power for use on various machine functions. On power machine <NUM>, the power system <NUM> includes an internal combustion engine. Other power machines can include electric generators, rechargeable batteries, various other power sources or any combination of power sources that are capable of providing power for given power machine components. The power system <NUM> also includes a power conversion system <NUM>, which is operably coupled to the power source <NUM>. Power conversion system <NUM> is, in turn, coupled to one or more actuators <NUM>, which are capable of performing a function on the power machine. Power conversion systems in various power machines can include various components, including mechanical transmissions, hydraulic systems, and the like. The power conversion system <NUM> of power machine <NUM> includes a pair of hydrostatic drive pumps 224A and 224B, which are selectively controllable to provide a power signal to drive motors 226A and 226B. The drive motors 226A and 226B in turn are each operably coupled to axles, with drive motor 226A being coupled to axles 228A and 228B and drive motor 226B being coupled to axles 228C and 228D. The axles 228A-D are in turn coupled to tractive elements such as wheels 219A-D, respectively. The drive pumps 224A and 224B can be mechanically, hydraulic, and/or electrically coupled to operator input devices to receive actuation signals for controlling the drive pumps.

The arrangement of drive pumps, motors, and axles in power machine <NUM> is but one example of an arrangement of these components. As discussed above, power machine <NUM> is a skid-steer loader and thus tractive elements on each side of the power machine are controlled together via the output of a single hydraulic pump, either through a single drive motor as in power machine <NUM> or with individual drive motors. Various other configurations and combinations of hydraulic drive pumps and motors can be employed as may be advantageous.

The power conversion system <NUM> of power machine <NUM> also includes a hydraulic implement pump 224C, which is also operably coupled to the power source <NUM>. The hydraulic implement pump 224C is operably coupled to work actuator circuit 238C. Work actuator circuit 238C includes lift cylinders <NUM> and tilt cylinders <NUM> as well as control logic (such as one or more valves) to control actuation thereof. The control logic selectively allows, in response to operator inputs, for actuation of the lift cylinders and/or tilt cylinders. In some machines, the work actuator circuit also includes control logic to selectively provide a pressurized hydraulic fluid to an attached implement.

The description of power machine <NUM> and loader <NUM> above is provided for illustrative purposes, to provide illustrative environments on which the embodiments discussed below can be practiced. While the embodiments discussed can be practiced on a power machine such as is generally described by the power machine <NUM> shown in the block diagram of <FIG> and more particularly on a loader such as loader <NUM>, unless otherwise noted or recited, the concepts discussed below are not intended to be limited in their application to the environments specifically described above.

Referring now to <FIG>, shown is a diagram of a power system <NUM>, which is one more particular embodiment of power system <NUM> discussed with reference to <FIG>, and which is controlled responsive to detection of an object within a zone around the power machine. Power system <NUM> can by employed on machines such as loader <NUM>. As shown in <FIG>, power source <NUM>, corresponding to power source <NUM> in <FIG>, is an engine, typically a diesel engine, though disclosed embodiments are not limited to this particular type of power source. Like power system <NUM>, power system <NUM> includes power conversion system <NUM> having a pair of drive pumps, left drive pump 324A and right drive pump 324B in a pump package, and an implement pump 324C. The engine <NUM> can directly drive the pumps, can indirectly drive the pumps through a belt driven coupling mechanism, or can drive the pumps using any other type of coupling. Power conversion system <NUM> can also include a charge pump <NUM> which pumps hydraulic fluid from tank <NUM> to charge the inputs to drive pumps 324A and 324B.

Implement pump 324C can be, in some embodiments, a constant displacement gear pump which provides a constant displacement of pressurized hydraulic fluid to a control valve <NUM> of a work actuator circuit 338C, corresponding to work actuator circuit 238C shown in <FIG>. The control valve <NUM> is an open center parallel valve that has three spools, a lift spool 340A providing hydraulic fluid to the lift actuator(s) <NUM>, a tilt spool 340B providing hydraulic fluid to the tilt actuator(s) <NUM>, and an auxiliary hydraulic spool 340C providing hydraulic fluid through an auxiliary port <NUM> to auxiliary functions such as those of work actuators located on an attached implement. The hydraulic spools have priority in the receipt of the constant supply of hydraulic fluid in the order shown (e.g., the lift spool has priority over the tilt and auxiliary spools, and the tilt spool has priority over the auxiliary spool). A controller <NUM> controls the positions of the spools of control valve <NUM>, for example using solenoids. Hydraulic fluid passing through the various spools, and corresponding actuators (e.g., lift actuator(s) <NUM>, tilt actuator(s) <NUM>, etc.) when the spools are energized by controller <NUM>, exits the control valve <NUM> and is returned to tank <NUM>. Alternatively, implement pump 324C can be a variable displacement pump without departing from the scope of any embodiment in this discussion.

In exemplary embodiments, the drive system of power system <NUM> is a hydrostatic system. Each drive pump 324A and 324B is coupled to one or more motors. In a skid steer loader, each drive pump is a variable displacement pump coupled to one motor with left drive pump 324A providing hydraulic fluid to left drive motor 326A and right drive pump 324B providing hydraulic fluid to right drive motor 326B. The displacement of each of pumps 324A and 324B is controlled by controls signals from controller <NUM>, and the displacement can be controlled in either direction to control forward and rearward movement of the power machine. Motors 326A and 326B can be constant displacement motors. Further, motors 326A and 326B can be multiple speed motors, having two or more speeds which can be shifted into, with different constant displacements in each speed. The hydraulic circuits between drive pump 324A and drive motor 326A, and between drive pump 324B and drive motor 326B can be closed loops circuits. Typically, there will be some leakage of hydraulic fluid in the pumps, and a case drain line <NUM> provides hydraulic fluid leaking from the pumps back to tank <NUM>. This hydraulic fluid leakage can also be provided through a cooler (not shown) before returning to tank <NUM> for purposes of cooling the hydraulic fluid in the system. When controlling drive functions of the power machine, controller <NUM> provides electronic signals to stroke the two drive pumps 324A and 324B independently of each other to cause hydraulic fluid to be provided to the hydraulic drive motors 326A and 326B. In some embodiments, controller <NUM> also provides electronic signals to control the displacement speeds of the motors 326A and 326B, which are typically two-speed motors.

Disclosed embodiments include loaders or other power machines, and systems used on power machines that are configured to detect the presence of an object in one or more zones to the sides or rear of the machine, and to responsively control operation of the machine to slow or stop travel and/or work functions. Controller <NUM> is configured, in some embodiments, to provide or aid in such control as is described below. For example, controller <NUM> can control the drive or implement pumps of the power conversion system <NUM>, the control valve <NUM>, or optionally the engine <NUM>, responsive to various inputs, including detection of an object in the one or more zones.

<FIG> illustrates system <NUM> that can be employed on power machines such as loader <NUM> according to some embodiments. The system <NUM> includes power system <NUM> and components configured to define and illuminate a zone in which objects can be detected and, if an object is detected, provide control over the power system in response to the objection. Controller <NUM> is configured to control the power conversion system <NUM>, the control valve <NUM>, or optionally the engine <NUM> in response to signals from user inputs <NUM>. Examples of user inputs <NUM> include joystick controllers, levers, foot pedals, touch screen inputs, switches, etc., though other user inputs can be utilized as well. Under normal operation, responsive to input signals from user inputs <NUM>, controller <NUM> controls the power conversion system <NUM>, the control valve <NUM>, etc., to perform work functions, such as causing the machine to travel, raising and lowering of a lift arm, controlling a tilt actuator to control positioning of an implement, and/or controlling auxiliary functions on the implement.

System <NUM> also includes one or more object detection sensors <NUM> configured to detect the presence of an object within one or more zones surrounding the power machine. <FIG> is a diagrammatic top view illustration of a power machine <NUM> including system <NUM> in which sensor(s) <NUM> detect the presence of an object <NUM> within a zone <NUM> to the rear and rearward sides of the machine. <FIG> is a diagrammatic top view illustration of power machine <NUM> in which sensor(s) <NUM> detect the presence of an object <NUM> within one of zones <NUM> and <NUM> to the sides of the machine. <FIG> is a diagrammatic top view illustration of power machine <NUM> in which sensor(s) <NUM> monitor all of zones <NUM>, <NUM> and <NUM> for the presence of an object. The size, shape, number, and locations of the monitored zones can vary and is not intended to be limited to the shape or locations of the zones shown in <FIG>. Further, the size of the zones can vary as desired. For example, in some embodiments, the zones include all areas to the sides and rear of the power machine within <NUM> feet of the machine. Other sized zones can be used in other embodiments. Object detection sensor(s) <NUM> can include any type of sensors, or combinations of types of sensors, which can be used to detect an object such as a human or animal, a vehicle, etc. For instance, sensor(s) <NUM> can include radar or low power radar sensors, laser sensors, optical sensors or cameras with image processing circuitry for object recognition, infrared sensors, motion sensors, etc..

Upon detection of an object (e.g., objects <NUM> or <NUM> shown in <FIG>) in a monitored zone adjacent to power machine <NUM>, controller <NUM> controls the power conversion system <NUM>, the control valve <NUM>, etc., to slow or stop the performance of work functions, overriding or altering normal control (e.g., responsive to user input signals when an object has not been detected). In some embodiments, the travel or work group functions are halted altogether, despite the commands from the user inputs <NUM>. In other embodiments, the functions are merely slowed. In still other embodiments, certain functions are stopped, while others are slowed. For instance, travel functions may be stopped entirely to prevent a collision with the object, despite user input commands to travel, while lift arm or auxiliary functions are allowed to continue, responsive to the user inputs, but with slower or reduced power movements.

System <NUM> also includes a zone illumination system <NUM>, controllable by the controller <NUM>, configured to illuminate all or part of a monitored zone upon detection of an object. For instance, referring to the diagrammatic side view power machine illustration of <FIG>, upon detection of an object <NUM> within zone <NUM> to the rear of the power machine, a light source <NUM> of zone illumination system <NUM> illuminates a portion <NUM> of the ground within zone <NUM>. The zone illumination system <NUM> and light source <NUM> can be configured to illuminate an entire zone, to illuminate a portion of a zone, or to illuminate a boundary of the zone or a portion of the zone. For instance, the light source can be an LED array (or other type of light source) which is directed to illuminate an entire zone where an object was detected. In the alternative, the light source can be a tracing laser configured to illuminate a boundary around the zone or the object within the zone. By providing the illumination with system <NUM>, the operator of the power machine can more easily visually identify the object. Also, illumination of the zone or portion of the zone can provide a visual indication to a person outside of the power machine of the zone surrounding the machine.

Claim 1:
A power machine (<NUM>; <NUM>; <NUM>) comprising:
a power system (<NUM>; <NUM>; <NUM>) including a power source (<NUM>; <NUM>), a power conversion system (<NUM>; <NUM>) driven by the power source, a traction system coupled to and receiving power from the power conversion system to implement travel functions and move the power machine, and work actuators (<NUM>; <NUM>) coupled to and receiving power through the power conversion system to implement work functions;
user inputs (<NUM>) actuable by an operator of the power machine and configured to responsively provide user input signals to control the travel functions of the power machine;
at least one object detection sensor (<NUM>) configured to detect a presence of an object (<NUM>; <NUM>) within one or more monitored zones (<NUM>; <NUM>; <NUM>) surrounding the power machine and to responsively provide object detection signals indicative of detection of the presence of the object;
wherein the power machine is characterized by further comprising:
a zone illumination system (<NUM>) configured to illuminate a boundary of any of the monitored zones in which the presence of the object was detected, wherein the zone illumination system (<NUM>) is configured to allow the operator of the power machine to identify the object in the monitored zone; and
a controller (<NUM>) coupled to the user inputs, the at least one object detection sensor, the zone illumination system, and the power conversion system, the controller configured to receive the user input signals and the object detection signals and to responsively control the power conversion system to control the traction system, wherein upon detection of the object within the one or more monitored zones the controller controls the zone illumination system to illuminate the boundary of any of the monitored zones in which the presence of the object was detected.