Patent Description:
A work machine such as a wheel loader includes a bucket pivotable in a direction of dumping at a tip end of a boom pivotable in an upward/downward direction. An operator performs an excavation work by operating an operation apparatus to pivot the bucket in the direction of dumping to set the bucket at a substantially horizontal position and to thereafter run the work machine to push the bucket into a pile of soil. An object is thus loaded into the bucket. The operator revolves the boom or a vehicular body to have the work machine face a transportation machine such as a dump truck, and raises the boom above a box. As the operator pivots the bucket in the direction of dumping, the object loaded in the bucket falls on the box and the object is transferred to the transportation machine. By repeating such a cycle a plurality of times, a loading work is performed.

In a motion of a work machine such as a wheel loader, an accelerator for running the work machine should be operated and levers for operating the boom and the bucket should be operated to control motions of the bucket. Therefore, it is not easy to realize efficient motions and skills are required. Therefore, a function to check a motion state of the work machine to allow training for driving is demanded.

In this connection, for example, <CIT> discloses a technique to transmit information to a remote facility to give the information to an operator who remotely steers the work machine at the remote facility. In the publication, however, information during works is merely directly given to the operator.

PTL <NUM>: <CIT>
Document <CIT> relates to a shovel comprising: an imaging device; a temporary storage device that temporarily stores image data acquired by the imaging device; a plurality of sensors that each detect a plurality of physical quantities relating to an operation state of the shovel; an abnormality information storage device; and a control device that determines whether or not an operation is abnormal based on detection values detected by the sensors, and transmits the image data, which corresponds to a period from a first time prior to a time at which the operation is determined to be abnormal to at least the time at which the operation is determined to be abnormal, from the temporary storage device to the abnormality information storage device when the operation is determined to be abnormal. Document <CIT> relates to a diagnostic information providing apparatus for a construction machine. The apparatus comprises a sensor for detecting status variables related to an operating state of a hydraulic excavator or ambient environment, and a controller. The controller stores combinations between a plurality of snapshot items and one or more status variables related to each of the snapshot items in advance, acquires or extracts status variable data, which is regarded as being related based on the stored combinations, from corresponding detected signals of the sensor with respect to the snapshot item selected by a selection command from an operator, thereby displaying the status variable data on a display unit, and compares each of the status variables or a value computed based on a plurality of status variables with a predetermined reference value range. When the status variable or the computed value is outside the predetermined reference value range, the controller determines a failure of a corresponding part, and displays the failed part or the related status variable on the display unit. Document <CIT>- <CIT> relates to a display device of a shovel having a boom, an arm, and an attachment including an end attachment includes an operation analysis start input section for starting operation analysis of the shovel and accumulating the history of the operation analysis, and a stability confirmation input section for displaying stability information of the shovel based on the result of the operation analysis.

In this connection, the present invention was made to solve the problem above, and an object thereof is to provide a display system of a work machine capable of showing a motion state of the work machine and a method of controlling the same.

This object is solved by the display system according to claim <NUM> and a method of controlling a display system according to claim <NUM>.

The display system of the work machine and the method of controlling the same according to the present invention can show a motion state of the work machine.

Though an embodiment according to the present invention will be described below with reference to the drawings, the present invention is not limited thereto. Constituent elements in each embodiment described below can be combined as appropriate. Some of the constituent elements may not be used.

A wheel loader <NUM> as an exemplary work machine will be described in an embodiment. <FIG> is a side view of wheel loader <NUM> as an exemplary work machine according to the embodiment. As shown in <FIG>, wheel loader <NUM> includes a vehicular body frame <NUM>, a work implement <NUM>, a traveling unit <NUM>, and a cab <NUM>. A vehicular body of wheel loader <NUM> is constituted of vehicular body frame <NUM>, cab <NUM>, and the like. Work implement <NUM> and traveling unit <NUM> are attached to the vehicular body of wheel loader <NUM>.

Traveling unit <NUM> runs the vehicular body of wheel loader <NUM> and includes running wheels 4a and 4b. Wheel loader <NUM> can be self-propelled as running wheels 4a and 4b are rotationally driven, and can perform a desired work with work implement <NUM>.

Vehicular body frame <NUM> includes a front frame <NUM> and a rear frame <NUM>. Front frame <NUM> and rear frame <NUM> are attached to each other in a manner swingable in a lateral direction. A steering cylinder <NUM> is attached to front frame <NUM> and rear frame <NUM>. Steering cylinder <NUM> is a hydraulic cylinder. As steering cylinder <NUM> extends and contracts as being driven by hydraulic oil from a steering pump (not shown), a direction of travel of wheel loader <NUM> is laterally changed.

A direction in which wheel loader <NUM> travels in straight lines is herein referred to as a fore/aft direction of wheel loader <NUM>. In the fore/aft direction of wheel loader <NUM>, a side where work implement <NUM> is arranged with respect to vehicular body frame <NUM> is defined as the fore direction and a direction opposite to the fore direction is defined as the aft direction. A lateral direction of wheel loader <NUM> is a direction orthogonal to the fore/aft direction in a plan view. A right side and a left side in the lateral direction in facing front are defined as a right direction and a left direction, respectively. An upward/downward direction of wheel loader <NUM> is a direction orthogonal to the plane defined by the fore/aft direction and the lateral direction. A side in the upward/downward direction where the ground is located is defined as a lower side and a side where the sky is located is defined as an upper side.

The fore/aft direction refers to a fore/aft direction of an operator who sits at an operator's seat in cab <NUM>. The lateral direction refers to a lateral direction of the operator who sits at the operator's seat. The lateral direction refers to a direction of a vehicle width of wheel loader <NUM>. The upward/downward direction refers to an upward/downward direction of the operator who sits at the operator's seat. A direction in which the operator sitting at the operator's seat faces is defined as the fore direction and a direction behind the operator sitting at the operator's seat is defined as the aft direction. A right side and a left side at the time when the operator sitting at the operator's seat faces front are defined as the right direction and the left direction, respectively. A foot side of the operator who sits at the operator's seat is defined as a lower side, and a head side is defined as an upper side.

Work implement <NUM> and running wheel (front wheel) 4a are attached to front frame <NUM>. Work implement <NUM> includes a boom <NUM> and a bucket <NUM>. A base end of boom <NUM> is rotatably attached to front frame <NUM> by a boom pin <NUM>. Bucket <NUM> is rotatably attached to boom <NUM> by a bucket pin <NUM> located at a tip end of boom <NUM>. Front frame <NUM> and boom <NUM> are coupled to each other by a boom cylinder <NUM>. Boom cylinder <NUM> is a hydraulic cylinder. As boom cylinder <NUM> extends and contracts as being driven by hydraulic oil from a work implement pump <NUM> (see <FIG>), boom <NUM> moves upward and downward. Boom cylinder <NUM> drives boom <NUM>.

Work implement <NUM> further includes a bell crank <NUM>, a tilt cylinder <NUM>, and a tilt rod <NUM>. Bell crank <NUM> is rotatably supported on boom <NUM> by a support pin 18a located substantially in the center of boom <NUM>. Tilt cylinder <NUM> couples a base end of bell crank <NUM> and front frame <NUM> to each other. Tilt rod <NUM> couples a tip end of bell crank <NUM> and bucket <NUM> to each other. Tilt cylinder <NUM> is a hydraulic cylinder. As tilt cylinder <NUM> extends and contracts as being driven by hydraulic oil from work implement pump <NUM> (see <FIG>), bucket <NUM> pivots upward and downward. Tilt cylinder <NUM> drives bucket <NUM>.

Cab <NUM> and running wheel (rear wheel) 4b are attached to rear frame <NUM>. Cab <NUM> is arranged in the rear of boom <NUM>. Cab <NUM> is carried on vehicular body frame <NUM>. A seat where an operator sits and an operation apparatus are arranged in cab <NUM>.

A position detection sensor <NUM> is arranged on an upper celling side of cab <NUM>. Position detection sensor <NUM> includes a GNSS antenna and a global coordinate operator. The GNSS antenna is an antenna for a real time kinematic-global navigation satellite system (RTK-GNSS). An inertial measurement unit (IMU) <NUM> is arranged in cab <NUM>. IMU <NUM> detects an inclination of vehicular body frame <NUM>. IMU <NUM> detects an angle of inclination of vehicular body frame <NUM> with respect to the fore/aft direction and the lateral direction.

<FIG> is a schematic block diagram showing a configuration of the entire system including wheel loader <NUM> according to the embodiment. Referring to <FIG>, the entire system according to the embodiment includes wheel loader <NUM> and a second processor provided to be able to establish wireless or wired communication with wheel loader <NUM>.

Wheel loader <NUM> includes an engine <NUM>, a motive power extraction unit <NUM>, a motive power transmission mechanism <NUM>, a cylinder driving unit <NUM>, a first angle detector <NUM>, a second angle detector <NUM>, a pivot mechanism <NUM>, and a first processor <NUM> (a controller).

Engine <NUM> is, for example, a diesel engine. Output from engine <NUM> is controlled by adjusting an amount of fuel to be injected into a cylinder of engine <NUM>. Engine <NUM> is provided with a temperature sensor <NUM>. Temperature sensor <NUM> outputs a detection signal representing a temperature to first processor <NUM>.

Motive power extraction unit <NUM> is an apparatus that distributes output from engine <NUM> to motive power transmission mechanism <NUM> and cylinder driving unit <NUM>. Motive power transmission mechanism <NUM> is a mechanism that transmits driving force from engine <NUM> to front wheel 4a and rear wheel 4b, and it is implemented, for example, by a transmission. Motive power transmission mechanism <NUM> changes a speed of rotation of an input shaft <NUM> and outputs resultant rotation to an output shaft 23a. A vehicle speed detection unit <NUM> that detects a speed of wheel loader <NUM> is attached to output shaft 23a of motive power transmission mechanism <NUM>. Wheel loader <NUM> includes vehicle speed detection unit <NUM>.

Vehicle speed detection unit <NUM> is implemented, for example, by a vehicle speed sensor. Vehicle speed detection unit <NUM> detects a speed of movement of wheel loader <NUM> by traveling unit <NUM> (<FIG>) by detecting a rotation speed of output shaft 23a. Vehicle speed detection unit <NUM> functions as a rotation sensor that detects a rotation speed of output shaft 23a. Vehicle speed detection unit <NUM> functions as a movement detector that detects movement by traveling unit <NUM>. Vehicle speed detection unit <NUM> outputs a detection signal representing a vehicle speed of wheel loader <NUM> to first processor <NUM>.

Cylinder driving unit <NUM> includes work implement pump <NUM> and a control valve <NUM>. Output from engine <NUM> is transmitted to work implement pump <NUM> through motive power extraction unit <NUM>. Hydraulic oil delivered from work implement pump <NUM> is supplied to boom cylinder <NUM> and tilt cylinder <NUM> through control valve <NUM>.

First hydraulic pressure detectors 28a and 28b that detect a hydraulic pressure in an oil chamber in boom cylinder <NUM> are attached to boom cylinder <NUM>. Wheel loader <NUM> includes first hydraulic pressure detectors 28a and 28b. First hydraulic pressure detectors 28a and 28b include, for example, a pressure sensor 28a for head pressure detection and a pressure sensor 28b for bottom pressure detection.

Pressure sensor 28a is attached to a head side of boom cylinder <NUM>. Pressure sensor 28a can detect a pressure (a head pressure) of hydraulic oil in the oil chamber on a side of a cylinder head of boom cylinder <NUM>. Pressure sensor 28a outputs a detection signal representing a head pressure of boom cylinder <NUM> to first processor <NUM>. Pressure sensor 28b is attached to a bottom side of boom cylinder <NUM>. Pressure sensor 28b can detect a pressure (a bottom pressure) of hydraulic oil in the oil chamber on a side of a cylinder bottom of boom cylinder <NUM>. Pressure sensor 28b outputs a detection signal representing a bottom pressure of boom cylinder <NUM> to first processor <NUM>.

For example, a potentiometer attached to boom pin <NUM> is employed as first angle detector <NUM>. First angle detector <NUM> detects a boom angle representing a lift angle (a tilt angle) of boom <NUM>. First angle detector <NUM> outputs a detection signal representing a boom angle to first processor <NUM>. Specifically, as shown in <FIG>, a boom angle θ represents an angle of a straight line LB extending in a direction from the center of boom pin <NUM> toward the center of bucket pin <NUM> with respect to a horizontal line extending forward from the center of boom pin <NUM>. A case that straight line LB is horizontal is defined as boom angle θ = <NUM>°. A case that straight line LB is located above the horizontal line is defined as a positive boom angle θ. A case that straight line LB is located below the horizontal line is defined as a negative boom angle θ. A stroke sensor arranged in boom cylinder <NUM> may be employed as first angle detector <NUM>.

For example, a potentiometer attached to support pin 18a is employed as second angle detector <NUM>. Second angle detector <NUM> detects a bucket angle representing a tilt angle of bucket <NUM> with respect to boom <NUM> by detecting an angle of bell crank <NUM> (bell crank angle) with respect to boom <NUM>. Second angle detector <NUM> outputs a detection signal representing a bucket angle to first processor <NUM>. The bucket angle is, for example, an angle formed between straight line LB and a straight line that connects the center of bucket pin <NUM> and a cutting edge 6a of bucket <NUM> to each other. A stroke sensor arranged in tilt cylinder <NUM> may be employed as second angle detector <NUM>.

Pivot mechanism <NUM> pivotably couples front frame <NUM> and rear frame <NUM> to each other. Front frame <NUM> is pivoted with respect to rear frame <NUM> by extending and contracting an articulation cylinder coupled between front frame <NUM> and rear frame <NUM>. By angling (articulating) front frame <NUM> with respect to rear frame <NUM>, a radius of revolution in revolution of the wheel loader can be made smaller and a ditch digging work or a grading work by offset running can be done. Pivot mechanism <NUM> is provided with an articulation angle sensor <NUM>. Articulation angle sensor <NUM> detects an articulation angle. Articulation angle sensor <NUM> outputs a detection signal representing the articulation angle to first processor <NUM>.

Position detection sensor <NUM> outputs a detection signal representing a position of wheel loader <NUM> to first processor <NUM>. IMU <NUM> outputs a detection signal representing an angle of inclination of wheel loader <NUM> to first processor <NUM>.

As shown in <FIG>, wheel loader <NUM> includes in cab <NUM>, an operation apparatus operated by an operator. The operation apparatus includes a forward and rearward travel switching apparatus <NUM>, an accelerator operation apparatus <NUM>, a boom operation apparatus <NUM>, a shift change operation apparatus <NUM>, a bucket operation apparatus <NUM>, and a brake operation apparatus <NUM>.

Forward and rearward travel switching apparatus <NUM> includes a forward and rearward travel switching operation member 49a and a forward and rearward travel switching detection sensor 49b. Forward and rearward travel switching operation member 49a is operated by an operator for indicating switching between forward travel and rearward travel of the vehicle. Forward and rearward travel switching operation member 49a can be switched to a position of each of forward travel (F), neutral (N), and rearward travel (R). Forward and rearward travel switching detection sensor 49b detects a position of forward and rearward travel switching operation member 49a. Forward and rearward travel switching detection sensor 49b outputs to first processor <NUM>, a detection signal (forward travel, neutral, or rearward travel) representing a command to travel forward or rearward indicated by a position of forward and rearward travel switching operation member 49a. Forward and rearward travel switching apparatus <NUM> includes an FNR switch lever capable of switching among forward travel (F), neutral (N), and rearward travel (R).

Accelerator operation apparatus <NUM> includes an accelerator operation member 51a and an accelerator operation detection unit 51b. Accelerator operation member 51a is operated by an operator for setting a target rotation speed of engine <NUM>. Accelerator operation detection unit 51b detects an amount of operation onto accelerator operation member 51a (an amount of accelerator operation). Accelerator operation detection unit 51b outputs a detection signal representing an amount of accelerator operation to first processor <NUM>.

Brake operation apparatus <NUM> includes a brake operation member 58a and a brake operation detection unit 58b. Brake operation member 58a is operated by an operator for controlling deceleration force of wheel loader <NUM>. Brake operation detection unit 58b detects an amount of operation onto brake operation member 58a (an amount of brake operation). Brake operation detection unit 58b outputs a detection signal representing an amount of brake operation to first processor <NUM>. A pressure of brake oil may be used as an amount of brake operation.

Boom operation apparatus <NUM> includes a boom operation member 52a and a boom operation detection unit 52b. Boom operation member 52a is operated by an operator for raising or lowering boom <NUM>. Boom operation detection unit 52b detects a position of boom operation member 52a. Boom operation detection unit 52b outputs to first processor <NUM>, a detection signal representing a command to raise or lower boom <NUM> indicated by the position of boom operation member 52a.

Shift change operation apparatus <NUM> includes a shift change operation member 53a and a shift change operation detection unit 53b. Shift change operation member 53a is operated by an operator for controlling shift change from input shaft <NUM> to output shaft 23a in motive power transmission mechanism <NUM>. Shift change operation detection unit 53b detects a position of shift change operation member 53a. Shift change operation detection unit 53b outputs a shift change detection command indicated by the position of shift change operation member 53a to first processor <NUM>.

Bucket operation apparatus <NUM> includes a bucket operation member 54a and a bucket operation detection unit 54b. Bucket operation member 54a is operated by an operator for causing bucket <NUM> to carry out an excavation motion or a dumping motion. Bucket operation detection unit 54b detects a position of bucket operation member 54a. Bucket operation detection unit 54b outputs to first processor <NUM>, a detection signal representing a motion command in a tilt-back direction or a dump direction of bucket <NUM> indicated by a position of bucket operation member 54a.

Articulation operation apparatus <NUM> includes an articulation operation member 55a and an articulation operation detection unit 55b. Articulation operation member 55a is operated by an operator for angling (articulating) front frame <NUM> with respect to rear frame <NUM> with pivot mechanism <NUM> being interposed. Articulation operation detection unit 55b detects a position of articulation operation member 55a. Articulation operation detection unit 55b outputs to first processor <NUM>, a detection signal representing a left angling command or a right angling command indicated by a position of articulation operation member 55a.

First processor <NUM> is implemented by a microcomputer including a storage such as a random access memory (RAM) or a read only memory (ROM) and a computing device such as a central processing unit (CPU). First processor <NUM> may be implemented as some of functions of a controller of wheel loader <NUM> that controls motions of engine <NUM>, work implement <NUM> (boom cylinder <NUM>, tilt cylinder <NUM>, and the like), and motive power transmission mechanism <NUM>. A signal representing a forward and rearward travel command detected by forward and rearward travel switching apparatus <NUM>, a signal representing a vehicle speed of wheel loader <NUM> detected by vehicle speed detection unit <NUM>, a signal representing a boom angle detected by first angle detector <NUM>, a signal representing a head pressure of boom cylinder <NUM> detected by pressure sensor 28a, and a signal representing a bottom pressure of boom cylinder <NUM> detected by pressure sensor 28b are mainly input to first processor <NUM>.

Wheel loader <NUM> further includes a display <NUM> and an output unit <NUM>. Display <NUM> is implemented by a monitor arranged in cab <NUM> and viewed by an operator.

Output unit <NUM> outputs work machine motion information including motion information of wheel loader <NUM> to a server (a second processor <NUM>) provided outside wheel loader <NUM>. Output unit <NUM> may output work machine motion information including motion information of wheel loader <NUM> every prescribed period or may collectively output work machine motion information over a plurality of periods. Output unit <NUM> may have a communication function such as wireless communication and may communicate with second processor <NUM>. Alternatively, output unit <NUM> may be implemented, for example, by an interface of a portable storage (such as a memory card) that can be accessed from second processor <NUM>. Second processor <NUM> includes a display that performs a monitor function and can show a motion image based on work machine motion information output from output unit <NUM>.

Wheel loader <NUM> in the present embodiment performs an excavation motion for scooping an excavated object such as soil in bucket <NUM> and a loading motion for loading objects (an excavated object <NUM>) in bucket <NUM> onto a transportation machine such as a dump truck <NUM>.

<FIG> is a schematic diagram illustrating a work step of wheel loader <NUM> based on the embodiment. Wheel loader <NUM> excavates excavated object <NUM> and loads excavated object <NUM> on a transportation machine such as dump truck <NUM> by successively repeating a plurality of steps as follows.

As shown in <FIG>, wheel loader <NUM> travels forward toward excavated object <NUM>. In this unloaded forward travel step, an operator operates boom cylinder <NUM> and tilt cylinder <NUM> to set work implement <NUM> to an excavation attitude in which the tip end of boom <NUM> is located at a low position and bucket <NUM> is horizontally oriented, and moves wheel loader <NUM> forward toward excavated object <NUM>.

As shown in <FIG>, the operator moves wheel loader <NUM> forward until cutting edge 6a of bucket <NUM> is pushed into excavated object <NUM>. In this excavation (pushing) step, cutting edge 6a of bucket <NUM> is pushed into excavated object <NUM>.

As shown in <FIG>, the operator thereafter operates boom cylinder <NUM> to raise bucket <NUM> and operates tilt cylinder <NUM> to tilt back bucket <NUM>. In this excavation (scooping) step, bucket <NUM> is raised along a bucket track L as shown with a curved arrow in the figure and excavated object <NUM> is scooped into bucket <NUM>. An excavation work for scooping excavated object <NUM> is thus performed.

Depending on a type of excavated object <NUM>, the scooping step may be completed simply by tilting back bucket <NUM> once. Alternatively, in the scooping step, a motion to tilt back bucket <NUM>, set the bucket to a neutral position, and tilt back the bucket again may be repeated.

As shown in <FIG>, after excavated object <NUM> is scooped into bucket <NUM>, the operator moves wheel loader <NUM> rearward in a loaded rearward travel step. The operator may raise the boom while moving the vehicle rearward, or may raise the boom while moving the vehicle forward in <FIG>.

As shown in <FIG>, the operator moves wheel loader <NUM> forward to be closer to dump truck <NUM> while keeping bucket <NUM> raised or raising bucket <NUM>. As a result of this loaded forward travel step, bucket <NUM> is located substantially directly above a box of dump truck <NUM>.

As shown in <FIG>, the operator dumps the excavated object from bucket <NUM> at a prescribed position and loads objects (excavated object) in bucket <NUM> on the box of dump truck <NUM>. This step is what is called a soil ejection step. Thereafter, the operator lowers boom <NUM> and returns bucket <NUM> to the excavation attitude while the operator moves wheel loader <NUM> rearward. The above is typical steps defining one cycle of the excavation and loading work.

<FIG> shows a table showing a method of distinguishing a work step of wheel loader <NUM> based on the embodiment. In the table shown in <FIG>, a row of "work step" at the top lists names of work steps shown in <FIG>. In rows of "forward and rearward travel switching lever," "operation of work implement," and "pressure of cylinder of work implement" below, various criteria used by first processor <NUM> (<FIG> and <FIG>) for determining under which step a current work step falls are shown. More specifically, in the row of "forward and rearward travel switching lever," criteria for a forward and rearward travel switching lever are shown with a circle.

In the row of "operation of work implement," criteria for an operation by an operator onto work implement <NUM> are shown with a circle. More specifically, in a row of "boom", criteria for an operation onto boom <NUM> are shown, and in a row of "bucket", criteria for an operation onto bucket <NUM> are shown.

In the row of "pressure of cylinder of work implement," criteria for a current hydraulic pressure of the cylinder of work implement <NUM> such as a hydraulic pressure of a cylinder bottom chamber of boom cylinder <NUM> are shown. Four reference values A, B, C, and P are set in advance for a hydraulic pressure, a plurality of pressure ranges (a range lower than reference value P, a range of reference values A to C, a range of reference values B to P, and a range lower than reference value C) are defined by reference values A, B, C, and P, and these pressure ranges are set as the criteria. Magnitude of four reference values A, B, C, and P is defined as A > B > C > P.

By using a combination of criteria for "forward and rearward travel switching lever," "boom", "bucket", and "pressure of cylinder of work implement" for each work step as above, first processor <NUM> can distinguish a currently performed step.

A specific operation of first processor <NUM> when control shown in <FIG> is carried out will be described below. A combination of criteria for "forward and rearward travel switching lever," "boom", "bucket", and "pressure of cylinder of work implement" corresponding to each work step shown in <FIG> is stored in advance in a storage 30j (<FIG>). First processor <NUM> recognizes a currently selected forward and rearward travel switching lever (F, N, or R) based on a signal from forward and rearward travel switching apparatus <NUM>. First processor <NUM> recognizes a type of a current operation onto boom <NUM> (lowering, neutral, or raising) based on a signal from boom operation detection unit 52b. First processor <NUM> recognizes a type of a current operation onto bucket <NUM> (dump, neutral, or tilt back) based on a signal from bucket operation detection unit 54b. First processor <NUM> recognizes a current hydraulic pressure of the cylinder bottom chamber of boom cylinder <NUM> based on a signal from pressure sensor 28b shown in <FIG>.

First processor <NUM> compares combination of the recognized forward and rearward travel switching lever, the type of the operation onto the boom, the type of the operation onto the bucket, and the hydraulic pressure of the lift cylinder at the current time point (that is, a current state of work) with combination of criteria for "forward and rearward travel switching lever," "boom", "bucket", and "pressure of cylinder of work implement" corresponding to each work step stored in advance. As a result of this comparison processing, first processor <NUM> determines to which work step the combination of criteria which matches best with the current state of work corresponds. The combination of criteria corresponding to the excavation and loading motion shown in <FIG> is as follows by way of example.

In the unloaded forward travel step, the forward and rearward travel switching lever is set to F, the operation of the boom and the operation of the bucket are both set to neutral, and the pressure of the cylinder of the work implement is lower than reference value P. In the excavation (pushing) step, the forward and rearward travel switching lever is set to F, the operation of the boom and the operation of the bucket are both neutral, and the pressure of the cylinder of the work implement is within the range of reference values A to C. In the excavation (scooping) step, the forward and rearward travel switching lever is set to F or R, the operation of the boom is raising or neutral, the operation of the bucket is tilt back, and the pressure of the cylinder of the work implement is within the range of reference values A to C. For an operation of the bucket, such a criterion that tilt back and neutral are alternately repeated may further be added because, depending on a state of an excavated object, a motion to tilt back bucket <NUM>, set the bucket to a neutral position, and tilt back the bucket again may be repeated. In the loaded rearward travel step, the forward and rearward travel switching lever is set to R, the operation of the boom is neutral or raising, the operation of the bucket is neutral, and the pressure of the cylinder of the work implement is within the range of reference values B to P. In the loaded forward travel step, the forward and rearward travel switching lever is set to F, the operation of the boom is raising or neutral, the operation of the bucket is neutral, and the pressure of the cylinder of the work implement is within the range of reference values B to P. In the soil ejection step, the forward and rearward travel switching lever is set to F, the operation of the boom is raising or neutral, the operation of the bucket is dump, and the pressure of the cylinder of the work implement is within the range of reference values B to P. In the rearward travel · boom lowering step, the forward and rearward travel switching lever is set to R, the operation of the boom is lowering, the operation of the bucket is tilt back, and the pressure of the cylinder of the work implement is lower than reference value P.

Information on the work step determined by first processor <NUM> is output as a part of work machine motion information to second processor <NUM> through output unit <NUM>. Though a scheme for determination of a work step by first processor <NUM> is described in the present example, the work step may be determined by second processor <NUM> without particularly being limited as such.

<FIG> is a diagram illustrating a functional block of second processor <NUM> according to the embodiment. Referring to <FIG>, second processor <NUM> includes an input unit <NUM>, a display <NUM>, a memory <NUM>, a communication unit <NUM>, and a CPU <NUM>.

Input unit <NUM> includes a mouse, a keyboard, a controller, a touch panel, and the like. An input command is generated by operating input unit <NUM>. For example, an input command is generated by operating a mouse, operating a keyboard, operating a button on the controller, or performing a touching operation onto the touch panel.

Display <NUM> includes a display of liquid crystals or the like. Memory <NUM> includes a storage such as a RAM or a ROM. Memory <NUM> stores a program for implementing functional blocks that performs various types of processing as the program is read by CPU <NUM>. Memory <NUM> stores as work machine motion data, work machine motion information transmitted from wheel loader <NUM>.

Second processor <NUM> according to the embodiment performs processing for replaying a motion state of wheel loader <NUM> based on work machine motion data stored in memory <NUM>. Work machine motion data will be described later. Replay processing includes both of processing of a still image at one certain time point and processing of moving images that continuously change over time.

CPU <NUM> implements various functional blocks based on a program stored in memory <NUM>. Specifically, CPU <NUM> includes a selector <NUM>, a motion image generator <NUM>, a display controller <NUM>, an event determination unit <NUM>, and an event registration unit <NUM>.

Selector <NUM> selects as time of replay, time in work machine motion data stored in memory <NUM>. Motion image generator <NUM> generates motion image data of wheel loader <NUM> based on work machine motion data in accordance with the time of replay selected by selector <NUM>. Display controller <NUM> outputs to display <NUM>, a replay screen including a motion image based on the motion image data of wheel loader <NUM> generated by motion image generator <NUM> and controls display <NUM> to show the replay screen. Event determination unit <NUM> determines whether or not an event has occurred based on the work machine motion information stored in memory <NUM>. Event registration unit <NUM> has memory <NUM> register therein in association with the work machine motion information, event information on the event determined as having occurred by event determination unit <NUM>. Second processor <NUM> corresponds to an exemplary "display system of a work machine" according to the present invention. Selector <NUM>, motion image generator <NUM>, event determination unit <NUM>, event registration unit <NUM>, display <NUM>, and memory <NUM> correspond to an exemplary "selector", an exemplary "motion image generator," an exemplary "event determination unit," an exemplary "event registration unit," an exemplary "display", and an exemplary "storage" according to the present invention, respectively.

<FIG> is a diagram illustrating a work machine table stored in memory <NUM> according to the embodiment. Referring to <FIG>, the work machine table includes work machine motion data arranged in a time-series manner.

By way of example, a plurality of pieces of work machine motion data are stored in the work machine table. Specifically, pieces of work machine motion data corresponding to time points "<NUM>:<NUM>:<NUM>", "<NUM>:<NUM>:<NUM>", "<NUM>:<NUM>:<NUM>", "<NUM>:<NUM>:<NUM>", and "<NUM>:<NUM>:<NUM>" on a time line are shown. By way of example, the time corresponds to time of reception by communication unit <NUM> of second processor <NUM>, of data (work machine motion information) transmitted from output unit <NUM> of first processor <NUM>. The time is not limited to time of reception of the information by communication unit <NUM> of second processor <NUM> but may be time of transmission by output unit <NUM> of first processor <NUM> or another reference time.

Work machine motion data includes work machine motion information and event information associated with the work machine motion information.

Event information is information on an event that is occurring. The event information is set by event registration unit <NUM>, although description will be provided later. Therefore, before setting by event registration unit <NUM>, event information in work machine motion data is blank.

The work machine motion information includes vehicle information CN, operation information T, position information P, an operator ID, and a vehicular body ID that are brought in correspondence with time. Vehicle information CN is information on wheel loader <NUM>. Specifically, vehicle information CN includes information on work implement <NUM> and information on a vehicle including traveling unit <NUM> except for work implement <NUM>. Though an example in which vehicle information CN includes information on both of work implement <NUM> and the vehicle is described in the present example, the vehicle information may include any one of them. Information on work implement <NUM> includes work implement data relating to detection signals from first angle detector <NUM>, second angle detector <NUM>, and first hydraulic pressure detectors 28a and 28b and a work step. A state of an attitude of work implement <NUM> can be sensed based on the work implement data.

Information on the vehicle includes vehicle data relating to detection signals from temperature sensor <NUM>, vehicle speed detection unit <NUM>, and articulation angle sensor <NUM>. A state of traveling unit <NUM> can be sensed based on the vehicle data. Operation information T includes work implement operation information on work implement <NUM> and vehicle operation information. The work implement operation information includes work implement operation data relating to detection signals from boom operation detection unit 52b and bucket operation detection unit 54b. A state of an operation onto work implement <NUM> can be sensed based on the work implement operation data. The vehicle operation information includes vehicle operation data relating to detection signals from forward and rearward travel switching operation member 49a, accelerator operation detection unit 51b, shift change operation detection unit 53b, articulation operation detection unit 55b, and brake operation detection unit 58b. A state of an operation onto the vehicle can be sensed based on the vehicle operation data. Though an example in which operation information T includes both of work implement operation information and vehicle operation information is described in the present example, the operation information may include any one of them.

Position information P is information relating to a position of wheel loader <NUM>. Specifically, position information P includes position data relating to a detection signal from position detection sensor <NUM> and inclination data relating to a detection signal from IMU <NUM>.

The operator ID is information for identification of an operator of wheel loader <NUM>. By way of example, the operator ID is stored in advance in a key used for start-up of the engine of the work machine by the operator. First processor <NUM> obtains the operator ID from the key at the time when the engine of the work machine is started up.

The vehicular body ID is information for identification of the vehicular body of wheel loader <NUM>. By way of example, the vehicular body ID is stored in advance in storage 30j of first processor <NUM>. Though an example in which the vehicular body ID is stored in storage 30j of first processor <NUM> is described in the present example, the vehicular body ID may be stored in advance in memory <NUM> of second processor <NUM> without being limited as such.

<FIG> is a flowchart illustrating event registration processing by second processor <NUM> according to the embodiment. Referring to <FIG>, event determination unit <NUM> obtains work machine motion data stored in the work machine table in memory <NUM> (step ST0).

Then, event determination unit <NUM> determines whether or not an event has occurred based on the obtained work machine motion data (step ST4). Event determination unit <NUM> determines whether or not the obtained work machine motion data satisfies a prescribed event condition.

By way of example, regarding an event condition, when a temperature is equal to or higher than a prescribed temperature, an overheat event is determined as having occurred in the present example. For example, information on the vehicle included in vehicle information CN includes vehicle data relating to a detection signal from temperature sensor <NUM>. Event determination unit <NUM> determines whether or not the temperature is equal to or higher than a prescribed temperature based on data obtained from the detection signal from temperature sensor <NUM>.

Regarding another event condition, in the present example, an event is determined as having occurred based on information on a work step. For example, vehicle information CN includes work implement data including a work step. Event determination unit <NUM> determines whether or not an event has occurred based on the work implement data. When the work implement data includes information on an excavation work step, an excavation event is determined as having occurred.

Without being limited as such, various event conditions can be provided. A prescribed event may be determined as having occurred based on one piece of data in the obtained work machine motion information or based on combination of a plurality of pieces of data.

When event determination unit <NUM> determines in step ST4 that an event has occurred (YES in step ST4), it gives a registration instruction to event registration unit <NUM>.

Then, event registration unit <NUM> has event information registered in accordance with the registration instruction from event determination unit <NUM> (step ST6).

Then, event registration unit <NUM> determines whether or not checking of all pieces of work machine motion data included in the work machine table has ended (step ST8).

When event registration unit <NUM> determines in step ST8 that checking of all pieces of work machine motion data has ended (YES in step ST8), event registration processing ends (end). When event registration unit <NUM> determines in step ST8 that checking of all pieces of work machine motion data has not ended (NO in step ST8), the process returns to step ST0. The work machine motion data in the work machine table for which checking has not ended is obtained and the processing above is repeated.

When an overheat event has occurred by way of example, event registration unit <NUM> has the event registered in the work machine motion data, as event information associated with the work machine motion information. When an excavation event has occurred by way of example, event registration unit <NUM> has the event registered in the work machine motion data, as event information associated with the work machine motion information. This is also applicable to other pieces of work machine motion data. Event information shown in <FIG> is thus set.

<FIG> is a diagram illustrating a detailed functional block of motion image generator <NUM> according to the embodiment. Referring to <FIG>, motion image generator <NUM> includes a motion state image generator <NUM>, a position state image generator <NUM>, a vehicle state image generator <NUM>, a management information image generator <NUM>, and an event information image generator <NUM>. Each functional block of motion image generator <NUM> is implemented by a program stored in advance in memory <NUM>.

Motion state image generator <NUM> generates motion state image data based on the work machine motion data. Position state image generator <NUM> generates position state image data based on the work machine motion data. Vehicle state image generator <NUM> generates vehicle state image data based on the work machine motion data. Management information image generator <NUM> generates management information image data based on the work machine motion data. Event information image generator <NUM> generates event information image data based on the work machine motion data.

<FIG> is a diagram illustrating a replay screen <NUM> on display <NUM> according to the embodiment. Referring to <FIG>, replay screen <NUM> is provided with a plurality of screens where various types of information on wheel loader <NUM> corresponding to a certain time of replay (time of a work "<NUM>/<NUM>/<NUM>/<NUM>:<NUM>:<NUM>") of wheel loader <NUM> are shown. The plurality of screens are in synchronization with the time of the work. In the present example, motion image generator <NUM> generates motion image data of wheel loader <NUM> based on the work machine motion data corresponding to a certain time of replay (the time of the work) stored in the work machine table. The time of replay may be information only on time or may include information on a date.

Display controller <NUM> controls display <NUM> to show replay screen <NUM> based on the motion image data generated by motion image generator <NUM>. In the present example, motion image data includes motion state image data, position state image data, vehicle state image data, management information image data, and event information image data.

Specifically, display controller <NUM> controls display <NUM> to show a motion screen <NUM> where movement of wheel loader <NUM> is shown, based on the motion state image data. Display controller <NUM> controls display <NUM> to show a position screen <NUM> where wheel loader <NUM> is shown, based on the position state image data. Display controller <NUM> controls display <NUM> to show a state screen <NUM> where information on a state of wheel loader <NUM> is shown, based on the vehicle state image data. Display controller <NUM> controls display <NUM> to show an event display screen <NUM> where a list of events that have occurred in wheel loader <NUM> is shown, based on the event information image data. Display controller <NUM> controls display <NUM> to show a management screen <NUM> where management information of wheel loader <NUM> is shown, based on the management information image data. Display controller <NUM> provides a command bar <NUM> for giving various commands relating to replay processing to replay screen <NUM>.

Command bar <NUM> includes a play button, a stop button, a pause button, a fast forward button, and a fast reverse button. As a manager operates the button, various types of processing relating to replay processing can be performed. As the manager operates the play button, processing for continuously replaying motion images of wheel loader <NUM> (moving image replay processing) that change over time from a certain time of replay is performed. As the manager operates the pause button, processing for replaying a motion image of wheel loader in accordance with a certain time of replay (still image replay processing) is performed.

Motion screen <NUM> is shown based on the motion state image data. Motion screen <NUM> includes an inclined state image <NUM>, an articulated state image <NUM>, and a work state image <NUM>.

Motion state image generator <NUM> generates first motion state image data based on 3D model geometrical data for generating a reference image of a 3D model geometry of wheel loader <NUM> and work implement data included in vehicle information CN. The 3D model geometrical data is stored in advance in memory <NUM>. The 3D model geometrical data includes data on a model geometry of each of the work implement, the vehicular body, and the wheel that composes a reference image of the 3D model geometry. The first motion state image data may be image data representing an inclination or an articulation angle of the vehicle.

Display controller <NUM> has work state image <NUM> shown based on the first motion state image data, the work state image showing a state of works by wheel loader <NUM>. Work state image <NUM> includes a work implement model image <NUM> showing a 3D model of wheel loader <NUM> and a road surface image <NUM> that shows a road surface model on which wheel loader <NUM> runs.

Display controller <NUM> can allow expression of a state of running in work implement model image <NUM> and road surface image <NUM> as being combined. Specifically, by way of example, forward movement of work implement model image <NUM> can be expressed by sliding road surface image <NUM> from the left to the right without change in position of work implement model image <NUM>. Display controller <NUM> may express a degree of a state of running in work implement model image <NUM> by adjusting a moving speed of road surface image <NUM>. For example, display controller <NUM> may provide such an expression that work implement model image <NUM> moves forward at a high speed by increasing a speed of sliding road surface image <NUM>. In contrast, display controller <NUM> may provide such an expression that work implement model image <NUM> moves forward at a low speed by lowering a speed of sliding road surface image <NUM>. Display controller <NUM> may adjust the speed of sliding road surface image <NUM> based on vehicle speed data included in vehicle information CN. Display controller <NUM> has work implement model image <NUM> shown based on time-series first motion state image data. Time-series states of works by wheel loader <NUM> can thus be reproduced. A field of view can also be changed by accepting setting of a direction of the field of view of a virtual camera in reproduction of the states of works.

Motion state image generator <NUM> generates second motion state image data based on side surface geometrical model data for generating a reference image of a geometry of a side surface model of wheel loader <NUM> and inclination data included in position information P. Display controller <NUM> has inclined state image <NUM> shown based on the second motion state image data. Inclined state image <NUM> shows a state of inclination of the vehicular body of wheel loader <NUM>. In the present example, exemplary inclination by <NUM>° is shown. Display controller <NUM> has inclined state image <NUM> shown based on the time-series second motion state image data. Time-series states of inclination of the vehicular body of wheel loader <NUM> can thus be reproduced.

Motion state image generator <NUM> generates third motion state image data based on top-view geometrical model data for generating a reference image of a geometry of a top view model of wheel loader <NUM> and articulation angle data included in vehicle information CN. Display controller <NUM> has an articulated state image <NUM> shown based on the third motion state image data. Articulated state image <NUM> shows a state of articulation of wheel loader <NUM>. In the present example, a state of right angling by <NUM>° is shown. Display controller <NUM> has articulated state image <NUM> shown based on the time-series third motion state image data. Time-series articulated states of wheel loader <NUM> can thus be reproduced.

State screen <NUM> is shown based on vehicle state image data. State screen <NUM> includes a time bar <NUM> that indicates designated time, an operation state image <NUM>, a vehicle state image <NUM>, and a work step state image <NUM>. Time bar <NUM> indicates certain time of work. Time bar <NUM> in the present example is provided as being movable to a position corresponding to any time of work.

Vehicle state image generator <NUM> generates first vehicle state image data based on operation information T in work machine motion data over a prescribed period. Display controller <NUM> has operation state image <NUM> shown based on the first vehicle state image data, the operation state image showing a state over a prescribed period of the operation member operated by an operator. Operation state image <NUM> includes a designated operation state image 221A corresponding to certain time of work and an operation transition state image 221B showing a state of transition of operations over the prescribed period. Designated operation state image 221A shows a state of accelerator operation apparatus <NUM> (an accelerator pedal), boom operation apparatus <NUM> (a boom lever), bucket operation apparatus <NUM> (a bucket lever), and brake operation apparatus <NUM> (a brake). In the present example, <NUM>% for the accelerator pedal, <NUM>% for the boom lever, <NUM>% for the bucket lever, and a brake OFF state are shown. Operation transition state image 221B shows a state of transition of operations onto accelerator operation apparatus <NUM> (accelerator pedal), boom operation apparatus <NUM> (boom lever), bucket operation apparatus <NUM> (bucket lever), and brake operation apparatus <NUM> (brake) over the prescribed period (<NUM> in the present example).

An operation state is shown in a grayscale for accelerator operation apparatus <NUM> (accelerator pedal), boom operation apparatus <NUM> (boom lever), and bucket operation apparatus <NUM> (bucket lever). Specifically, a value of a ratio of operations onto the operation member is larger, the color is denser (blacker), and as a numeric value is smaller, the color is lighter (whiter). Though an example where an operation state is expressed with the grayscale is described in the present example, the operation state may be shown with a heat map. For example, by changing a color at the time when boom operation apparatus <NUM> (boom lever) is operated to perform a raising motion or a lowering motion, which operation is being performed can visually intuitively be known. This is also applicable to bucket operation apparatus <NUM> (bucket lever). A value of an amount of operations onto an operation member may be shown in a graph. For brake operation apparatus <NUM> (brake), a brake ON state or a brake OFF state is shown. What kind of operation has been performed on an operation member for a prescribed period can thus readily be known.

Vehicle state image generator <NUM> generates second vehicle state image data based on vehicle information CN in work machine motion data over a prescribed period. Display controller <NUM> has vehicle state image <NUM> and work step state image <NUM> shown based on the second vehicle state image data, the vehicle state image and the work step state image showing a state of wheel loader <NUM> over the prescribed period. Vehicle state image <NUM> includes a designated vehicle state image 222A corresponding to certain time of work and a vehicle transition state image 222B showing a state of transition of the vehicle over the prescribed period. In the present example, designated vehicle state image 222A shows an example where a vehicle speed of wheel loader <NUM> is at <NUM>/h.

Vehicle transition state image 222B shows a state of transition of the vehicle speed of wheel loader <NUM> over the prescribed period (<NUM> in the present example). How the vehicle speed of wheel loader <NUM> has varied over the prescribed period can readily be known.

Work step state image <NUM> includes a designated work step state image 223A that shows a work step corresponding to certain time of work and a work step transition state image 223B that shows a state of transition of work steps over the prescribed period. Designated work step state image 223A shows excavation as the work step in the present example. Work step transition state image 223B shows an example in which the work step is varied to unloaded forward travel, excavation, and loaded forward travel during the prescribed period. How the work steps of wheel loader <NUM> have varied during the prescribed period can thus readily be known.

Display controller <NUM> controls operation transition state image 221B, vehicle transition state image 222B, and work step transition state image 223B to move from the right to the left in accordance with time of work corresponding to time bar <NUM> by way of example. Time bar <NUM> can be moved to a position of any time of work during the prescribed period based on input through input unit <NUM>.

Position screen <NUM> is shown based on the position state image data. Position screen <NUM> includes a work position image <NUM> and a movement track image <NUM>.

Position state image generator <NUM> generates position state image data based on map data that shows a work map and position data included in position information P. Display controller <NUM> has work position image <NUM> and movement track image <NUM> shown based on the position state image data, the work position image showing a position of works by wheel loader <NUM> on the work map, the movement track image showing a track of movement of wheel loader <NUM>. Work position image <NUM> is provided as being movable in accordance with movement track image <NUM> that shows a track of movement of wheel loader <NUM>. Display controller <NUM> has work position image <NUM> and movement track image <NUM> shown on the work map based on time-series position state image data. Time-series states of movement of works by wheel loader <NUM> can thus be reproduced. Movement track image <NUM> includes a speed change region <NUM>. Speed change region <NUM> refers to a region where a speed of movement of wheel loader <NUM> has changed. By providing speed change region <NUM> in movement track image <NUM>, change in speed of wheel loader <NUM> can visually be determined. Though one speed change region <NUM> is shown in the present example, a plurality of regions may be provided without particularly being limited as such. Change in speed is shown by change in hatching pattern by way of example. Without being limited to such representation, change in speed of wheel loader <NUM> may visually be determined based on a color or another highlighted representation. Work position image <NUM> can be changed to any position of works along movement track image <NUM> based on input through input unit <NUM>.

Event display screen <NUM> is shown based on event information image data. Event display screen <NUM> includes an event list. Event information image generator <NUM> generates event information image data based on event information in work machine motion data. Display controller <NUM> has the event list shown based on the event information image data. In the present example, overheat and a work step are shown as events. Work steps are further subcat-egorized and steps such as excavation and unloaded forward travel are listed. Time of each event is shown in a tree format.

In the present example, selection from among events shown in the tree format can be made based on an item indicating time of occurrence of that event. For example, by designating an item "<NUM>/<NUM>/<NUM>/<NUM>:<NUM>:<NUM>" that indicates time of overheat, work machine motion data in the work machine table brought in correspondence with that time is selected. Then, motion image data of wheel loader <NUM> is generated based on the selected work machine motion data. A state of occurrence of an event of wheel loader <NUM> can thus readily be reproduced.

Management screen <NUM> is shown based on management information image data. Management screen <NUM> includes a time image <NUM> that shows time of replay processing, a vehicular body ID image <NUM>, and an operator ID image <NUM>. Management information image generator <NUM> generates first management information image data based on time information in work machine motion data. Display controller <NUM> has time image <NUM> corresponding to time of replay (time of a work) shown based on the first management information image data. In the present example, "<NUM>/<NUM>/<NUM>:<NUM>:<NUM>:<NUM>" is shown as time image <NUM>.

Management information image generator <NUM> generates second management information image data based on a vehicular body ID in the work machine motion data. Display controller <NUM> has vehicular body ID image <NUM> shown based on the second management information image data. In the present example, "X" is shown as vehicular body ID image <NUM>.

Management information image generator <NUM> generates third management information image data based on the operator ID in the work machine motion data. Display controller <NUM> has operator ID image <NUM> shown based on the third management information image data. In the present example, "A" is shown as the operator ID image. Display controller <NUM> has time, the vehicular body ID, and the operator ID shown based on the first to third management information image data. Time-series management information on wheel loader <NUM> can thus readily be reproduced.

In the embodiment, a manager can select a position to replay a motion image of wheel loader <NUM>. <FIG> is a flowchart illustrating replay position selection processing by second processor <NUM> according to the embodiment. Referring to <FIG>, selector <NUM> determines whether or not it has accepted input from input unit <NUM> (step S2). When selector <NUM> has not accepted input from input unit <NUM>, it maintains a state in step S2.

When selector <NUM> determines that it has accepted input from input unit <NUM> (YES in step S2), it determines whether or not the input is operation input onto time bar <NUM> (step S4). When selector <NUM> determines that the input is not the operation input onto time bar <NUM> (NO in step S4), the process proceeds to step S20.

When selector <NUM> determines that the input is operation input onto time bar <NUM> (YES in step S4), it accepts a command to select a position of time bar <NUM> (step S6). For example, a position of end of an operation through input unit <NUM> is accepted as the command to select a position of time bar <NUM>.

Then, selector <NUM> selects time of work corresponding to the position of time bar <NUM> as time of replay (step S9). Then, motion image generator <NUM> generates motion image data of wheel loader <NUM> based on work machine motion data, in accordance with the time of replay selected by selector <NUM> (step S10).

Then, display controller <NUM> performs replay processing based on the motion image data of wheel loader <NUM> generated by motion image generator <NUM> (step S12). Specifically, as described with reference to <FIG>, display controller <NUM> outputs a replay screen including a motion image to display <NUM> and controls the display to show the replay screen. By selecting a position of time bar <NUM>, the manager can perform processing for replaying the motion image at the replay position corresponding to an arbitrary position of time bar <NUM>.

Then, display controller <NUM> determines whether or not replay processing has ended (step S14). When display controller <NUM> determines that replay has not ended (NO in step S14), the process returns to step S2 and the processing above is repeated.

When display controller <NUM> determines that replay processing has ended (YES in step S14), the process ends. When selector <NUM> determines in step S20 that an operation onto time bar <NUM> has not been performed, it determines whether or not an operation onto work position image <NUM> has been performed. When selector <NUM> determines that an operation onto work position image <NUM> has not been performed (NO in step S20), the process proceeds to step S24.

When selector <NUM> determines that an operation onto work position image <NUM> has been performed (YES in step S20), it accepts a command to select a work position (step S22). For example, a position of end of an operation using input unit <NUM> is accepted as a command to select a position of work position image <NUM>. Work position image <NUM> is provided as being movable as following a track in movement track image <NUM>.

Then, selector <NUM> selects time of work corresponding to the position of work position image <NUM> as time of replay (step S9). Since subsequent processing is similar to the above, detailed description thereof will not be repeated.

The manager can perform processing for replaying a motion image at a replay position corresponding to an arbitrary position of work position image <NUM> by selecting the position of work position image <NUM>. When selector <NUM> determines that an operation onto work position image <NUM> has not been performed, it determines whether or not an operation onto an event list has been performed.

When selector <NUM> determines that an operation onto the event list has not been performed (NO in step S24), the process returns to step S2. When selector <NUM> determines that an operation onto the event list has been performed (YES in step S24), it accepts a command to select event information (step S26). For example, a command to select event information designated by an operation onto input unit <NUM> is accepted. For example, input to select time corresponding to excavation or overheat is accepted.

Then, selector <NUM> selects time of acceptance of selection input as time of replay (step S9). Since subsequent processing is similar to the above, detailed description thereof will not be repeated. The manager can perform processing for replaying a motion image at a replay position corresponding to an arbitrary position of an event by performing an operation onto the event list.

Replay screen <NUM> is shown as a result of replay processing by second processor <NUM> according to the embodiment. Replay screen <NUM> shows motion screen <NUM>, state screen <NUM>, and position screen <NUM> generated based on work machine motion data corresponding to certain time of work by way of example.

In motion screen <NUM>, by way of example, work state image <NUM> showing a state of works by wheel loader <NUM> is shown. In state screen <NUM>, by way of example, operation state image <NUM> is shown. In position screen <NUM>, work position image <NUM> showing a position of works by wheel loader <NUM> on a work map is shown. The manager can readily know on the screens, when, where, and what kind of work an operator of wheel loader <NUM> has done.

Since the manager can arbitrarily select a position to replay a motion image of wheel loader <NUM>, for example, the manager can make effective use of the same in training driving by an operator. The manager can provide appropriate training relating to a state of an operation by an operator by checking, for example, operation state image <NUM> on state screen <NUM>. By checking the event list, it can also be made use of for trouble shooting or investigation of complaints.

Though an example in which the work machine table is stored in memory <NUM> of second processor <NUM> is described in the embodiment, it may be stored, for example, in storage 30j of first processor <NUM> without particularly being limited as such. Replay processing may be performed based on the work machine table stored in storage 30j of first processor <NUM>.

Though a configuration in which various functional blocks are implemented by CPU <NUM> of second processor <NUM> is described in the embodiment, some or all of the functional blocks may be implemented by first processor <NUM> without being limited as such.

Though an example in which replay screen <NUM> is shown on display <NUM> of second processor <NUM> is described in the embodiment, replay screen <NUM> may be shown on display <NUM> of wheel loader <NUM>. Display <NUM> and first processor <NUM> of wheel loader <NUM> may be integrated into one device. Without being limited to wheel loader <NUM>, for example, replay screen <NUM> may be shown on a display of a portable terminal provided to communicate with second processor <NUM>.

An example in which a plurality of screens in synchronization with time of a work are shown on replay screen <NUM> is described in the embodiment. Specifically, though an example in which replay screen <NUM> includes motion screen <NUM>, state screen <NUM>, position screen <NUM>, event display screen <NUM>, and management screen <NUM> as the plurality of screens is described, all of these screens do not particularly have to be shown, and for example, two or more screens may be shown. For example, motion screen <NUM> and state screen <NUM> may be shown on replay screen <NUM>. Combination with another screen can also naturally be made.

Functions and effects of the embodiment will now be described. As shown in <FIG>, the display system of the work machine in the embodiment is provided with memory <NUM> that stores the work machine table where time-series work machine motion information is stored, motion image generator <NUM> that generates a motion image of wheel loader <NUM> based on the work machine motion data stored in the work machine table, and display <NUM> that shows the motion image. As shown in <FIG>, in the work machine table, the time-series work machine motion information including the motion information of wheel loader <NUM> is stored as the work machine motion data. The motion image of wheel loader <NUM> is generated based on the work machine motion data stored in memory <NUM> and the motion image is shown on display <NUM>. Therefore, the motion state of wheel loader <NUM> can be shown.

As shown in <FIG>, the display system of the work machine in the embodiment is further provided with selector <NUM> that selects as time of replay, time in the work machine motion data stored in memory <NUM>. Motion image generator <NUM> generates the motion image of wheel loader <NUM> based on the work machine motion data, in accordance with the time of replay selected by selector <NUM>. Since time of replay can be selected by means of selector <NUM>, a motion state of wheel loader <NUM> can be shown at an arbitrary position.

The work machine table where the work machine motion information is stored is provided in storage 30j of first processor <NUM> within wheel loader <NUM> or memory <NUM> of second processor <NUM>. Since the work machine table can be arranged also in another external device without being limited to wheel loader <NUM>, a degree of freedom of the display system of the work machine can be improved.

As shown in <FIG>, the display system of the work machine in the embodiment is further provided with event determination unit <NUM> and event registration unit <NUM>. Event determination unit <NUM> determines whether or not an event has occurred based on the work machine motion information. Event registration unit <NUM> has the occurred event stored in the work machine table as the work machine motion data, in association with the work machine motion information. Whether or not a prescribed event has occurred in wheel loader <NUM> can be known.

As shown in <FIG>, the display system of the work machine in the embodiment is further provided with selector <NUM> that selects time to replay the work machine motion information in accordance with an event that has occurred. The motion state of wheel loader <NUM> can be replayed and checked in accordance with the event information stored in the work machine table.

As shown in <FIG>, event display screen <NUM> shows a list of events that have occurred. Selector <NUM> selects time to replay the work machine motion information in accordance with an operation onto the event list. A motion state of wheel loader <NUM> can be replayed and checked in a simplified manner based on the events that have occurred, in accordance with the event list shown on event display screen <NUM>.

Selector <NUM> selects time to replay the work machine motion information in accordance with an input command provided through input unit <NUM> onto replay screen <NUM> shown in <FIG>. A motion state of wheel loader <NUM> can be replayed and checked in a simplified manner by using an input interface of replay screen <NUM>.

Motion image generator <NUM> is provided in first processor <NUM> within wheel loader <NUM> or in second processor <NUM>. Since the motion image generator can be arranged also in another external device without being limited to wheel loader <NUM>, a degree of freedom of the display system of the work machine can be improved.

Display <NUM> is provided in first processor <NUM> within wheel loader <NUM> or in second processor <NUM>. Since the display can be arranged also in another external device without being limited to wheel loader <NUM>, a degree of freedom of the display system of the work machine can be improved.

Wheel loader <NUM> includes work implement <NUM> and traveling unit <NUM>. The work machine motion information shown in <FIG> includes vehicle information CN, and vehicle information CN includes motion information of at least one of work implement <NUM> and traveling unit <NUM>. A motion state of at least one of work implement <NUM> and traveling unit <NUM> of wheel loader <NUM> can be replayed and checked.

The work machine motion information shown in <FIG> includes operation information T, and operation information T includes operation command information of at least one of work implement <NUM> and traveling unit <NUM>. A motion state resulting from an operation command, of at least one of work implement <NUM> and traveling unit <NUM> of wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, the work machine motion information includes position information on a position of wheel loader <NUM>. A position state of wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, the work machine motion information further includes identification information for identification of an operator or a vehicular body. When a plurality of operators or a plurality of vehicular bodies are provided, they can readily be distinguished from one another based on the identification information.

As shown in <FIG>, the work machine is a wheel loader. A motion state of wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, motion image generator <NUM> is provided with motion state image generator <NUM> that generates a motion image of a motion state of the work machine based on the work machine motion information and vehicle state image generator <NUM> that generates a motion image of an operation state corresponding to the motion state of the work machine. Therefore, as shown in <FIG>, an operation state corresponding to the motion state can be replayed and checked together with the motion state of wheel loader <NUM>.

As shown in <FIG>, motion image generator <NUM> is provided with motion state image generator <NUM> that generates a motion image of a motion state of the work machine based on vehicle information CN in the work machine motion information. As shown in <FIG>, a motion state of wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, motion image generator <NUM> is provided with vehicle state image generator <NUM> that generates a motion image that shows change over time in operations by the work machine based on operation information T in the work machine motion information. As shown in <FIG>, an operation state of wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, motion image generator <NUM> is further provided with position state image generator <NUM> that generates a motion image of the work machine that shows a position of works by the work machine on a work map based on position information P in the work machine motion information. As shown in <FIG>, a position of works by wheel loader <NUM> can be replayed and checked.

As shown in <FIG>, the display system of the work machine in the embodiment is further provided with selector <NUM> that accepts a command to select a work position through input unit <NUM> and selects time to replay the work machine motion information. Processing for replaying a motion image of wheel loader <NUM> corresponding to an arbitrary position of works can be performed.

A method of controlling a display system of a work machine in the embodiment includes storing time-series work machine motion information including motion information of the work machine, generating a motion image of the work machine based on the work machine motion information, and showing the motion image. As shown in <FIG>, in the work machine table, the time-series work machine motion information including the motion information of wheel loader <NUM> is stored as the work machine motion data. The motion image of wheel loader <NUM> is generated based on the work machine motion data stored in memory <NUM> and the motion image is shown on display <NUM>. Therefore, the motion state of wheel loader <NUM> can be shown.

Though a wheel loader is described as the work machine by way of example, a work machine such as a hydraulic excavator, a dump truck, or a crawler dozer is also applicable.

Claim 1:
A display system (<NUM>, <NUM>) of a work machine (<NUM>), which includes a work implement (<NUM>) and a machine main body, the display system comprising:
a storage (30j, <NUM>) that stores time-series work machine motion information including motion information of the work machine (<NUM>), wherein the motion information of the work machine (<NUM>) includes work implement data relating to detection signals from a detector or sensor, and position information (P) of the work machine (<NUM>),
characterized by further comprising:
a motion image generator (<NUM>) that generates time-series first, second, and third motion state image data of the work machine (<NUM>), wherein:
- the first motion state image data is based on 3D geometrical model data stored in advance in the storage (30j, <NUM>) for generating a reference image of a 3D model geometry of the work machine (<NUM>) and on the work implement data included in the work machine motion information,
- the second motion state image data is based on side surface geometrical model data for generating a reference image of a geometry of a side surface model of the work machine (<NUM>) and inclination data included in the position information (P) of the work machine (<NUM>), and
- the third motion state image data is based on top-view geometrical model data for generating a reference image of a geometry of a top view model of the work machine (<NUM>) and articulation angle data included in the work machine motion information; and
a display (<NUM>) that shows a motion screen (<NUM>) based on the time-series first, second, and third motion state image data, including:
- a work state image (<NUM>) based on the first motion state image data,
- an inclined state image (<NUM>) based on the second motion state image data, and
- an articulated state image (<NUM>) based on the third motion state image data.