State estimation system, dump truck, and state estimation method

Abstract

To acquire temperature in an inner surface of a dump body.SOLUTION: Provided is a state estimation system of a dump truck including an engine and a dump body. The dump body includes a flow path through which exhaust gas discharged from the engine circulates. A cargo is loaded in the dump body. The state estimation system includes: an exhaust gas flow rate acquisition unit that acquires an exhaust gas flow rate indicating detection data of the flow rate of the exhaust gas flowing in the flow path; an exhaust gas temperature acquisition unit that acquires exhaust gas temperature indicating detection data of temperature of the exhaust gas flowing in the flow path; and a body temperature estimation unit that estimates body temperature indicating temperature at a predetermined portion in the inner surface of the dump body that is in contact with the cargo on the basis of the exhaust gas flow rate and the exhaust gas temperature.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a state estimation system, a dump truck, and a state estimation method. [Background technology]

[0002] A dump truck has a dump body on which cargo is loaded. When discharging cargo from the dump body, the dump truck performs a dumping operation of the dump body. When the dumping operation is performed, the cargo is discharged from the dump body due to the action of gravity. If the cargo is wet, even when the dumping operation is performed, at least a portion of the cargo may remain attached to the inner surface of the dump body and not be discharged from the dump body. To prevent the cargo from adhering to the inner surface of the dump body, a known technique is to circulate exhaust gas emitted from the dump truck engine through a flow path provided in the dump body. By circulating high-temperature exhaust gas through the flow path of the dump body, the dump body is heated by the exhaust gas and the cargo dries. This prevents the cargo from adhering to the inner surface of the dump body. Patent Document 1 discloses a technique for heating the dump body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] US Patent Application Publication No. 2018 / 0194260 Summary of the Invention [Problem to be solved by the invention]

[0004] Even if the dump body is heated by exhaust gas, if the temperature of the inner surface of the dump body is unknown, it may be difficult to perform the dump operation at an appropriate time. If a temperature sensor that detects the temperature of the inner surface of the dump body is installed in the dump body, the temperature of the inner surface of the dump body becomes clear, but this may increase the cost of the dump body.

[0005] The present disclosure aims to obtain the temperature of the inner surface of a dump body. [Means for solving the problem]

[0006] According to the present disclosure, there is provided a state estimation system for a dump truck having an engine, a dump body having a flow path through which exhaust gas emitted from the engine flows, and on which cargo is loaded, the state estimation system comprising: an exhaust gas flow rate acquisition unit that acquires an exhaust gas flow rate indicating detection data of the flow rate of exhaust gas flowing into the flow path; an exhaust gas temperature acquisition unit that acquires an exhaust gas temperature indicating detection data of the temperature of exhaust gas flowing into the flow path; and a body temperature estimation unit that estimates a body temperature indicating the temperature of a specified portion of the inner surface of the dump body that comes into contact with the cargo based on the exhaust gas flow rate and the exhaust gas temperature. [Effects of the Invention]

[0007] According to the present disclosure, the temperature of the inner surface of the dump body is obtained. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view showing a dump truck according to an embodiment. [Figure 2] FIG. 2 is a perspective view showing the dump body according to the embodiment. [Figure 3] FIG. 3 is a diagram schematically illustrating a dump truck according to the embodiment. [Figure 4] FIG. 4 is a view showing the inside of the cab according to the embodiment. [Figure 5] FIG. 5 is a diagram schematically illustrating a work site where a dump truck according to the embodiment operates. [Figure 6] FIG. 6 is a functional block diagram showing a state estimation system according to the embodiment. [Figure 7] FIG. 7 is a diagram for explaining a predetermined portion of the inner surface of the dump body according to the embodiment. [Figure 8] FIG. 8 is a flowchart showing a state estimation method according to the embodiment. [Figure 9] FIG. 9 is a block diagram illustrating a computer system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings, but the present disclosure is not limited to the embodiments. The components of the embodiments described below can be combined as appropriate. In addition, some components may not be used.

[0010] [Dump truck] 1 is a side view showing a dump truck 1 according to an embodiment. In the embodiment, the dump truck 1 is a manned dump truck that is operated by a driver. The dump truck 1 is a rigid frame dump truck.

[0011] As shown in FIG. 1, the dump truck 1 includes a vehicle body 2, a traveling device 3, an engine 6, a dump body 10, and a hoist cylinder 7.

[0012] The vehicle body 2 supports a dump body 10. A cab 9 is provided on the upper front part of the vehicle body 2. The driver of the dump truck 1 sits inside the cab 9.

[0013] The traveling device 3 supports the vehicle body 2 and travels. The traveling device 3 has a plurality of wheels 4. The front wheels 4 are steering wheels. The rear wheels 4 are driving wheels. A tire 5 is attached to each of the plurality of wheels 4. The dump truck 1 travels as the wheels 4 rotate.

[0014] The engine 6 is a power source for the dump truck 1. The traveling device 3 and the hoist cylinder 7 each operate based on the power generated by the engine 6. The engine 6 is supported on at least a portion of the vehicle body 2. The engine 6 is an internal combustion engine. An example of the engine 6 is a diesel engine. The engine 6 generates power by burning fuel. When the fuel is burned, exhaust gas is emitted from the engine 6.

[0015] The dump body 10 is loaded with a load. An example of the load that can be loaded onto the dump body 10 is earth and sand. The lower rear portion of the dump body 10 is connected to the bracket 8 of the vehicle body 2 via a rotation pin 8P. The dump body 10 is rotatable around the rotation pin 8P.

[0016] The hoist cylinder 7 generates power to rotate the dump body 10. The hoist cylinder is a hydraulic cylinder. The hoist cylinder 7 is disposed between the vehicle body 2 and the dump body 10.

[0017] The dump body 10 changes between a loaded position and an upright position by the extension and contraction of the hoist cylinder 7. The loaded position refers to a position in which the dump body 10 is lowered so as to be closest to the vehicle body 2 within its movable range. The upright position refers to a position in which the dump body 10 is raised so as to be farthest from the vehicle body 2 within its movable range. When the dump body 10 is in the loaded position, a load is loaded on the dump body 10. The dump truck 1 travels when the dump body 10 is in the loaded position. When the dump body 10 is loaded with a load, the dump body 10 changes from the loaded position to the upright position, and the load is discharged from the dump body 10 by the action of gravity.

[0018] In the embodiment, the operation of changing the dump body 10 from the loaded posture to the upright posture when the dump body 10 is loaded with a load is appropriately referred to as a dumping operation. When the dumping operation of the dump body 10 is performed, the load is discharged from the dump body 10.

[0019] In this embodiment, the dumping operation of the dump body 10 includes an operation of rotating the dump body 10 rearward. That is, in this embodiment, the dump body 10 discharges the load rearward in a rear dump manner.

[0020] [Dump body] Fig. 2 is a perspective view showing the dump body 10 according to the embodiment. As shown in Fig. 2, the dump body 10 has a front plate 11, a bottom plate 12 connected to the lower end of the front plate 11, side plates 13 connected to the left and right ends of the front plate 11 and the left and right ends of the bottom plate 12, and a protector plate 14 connected to the upper end of the front plate 11.

[0021] The front plate 11, the bottom plate 12, the side plates 13, and the protector plate 14 are integral with each other. Each of the front plate 11, the bottom plate 12, the side plates 13, and the protector plate 14 is made of a steel material.

[0022] When the dump body 10 is in the loaded position, the protector plate 14 is disposed above the cab 9. The rear end of the protector plate 14 is connected to the upper end of the front plate 11. The lower end of the front plate 11 is connected to the front end of the bottom plate 12.

[0023] The side plates 13 are arranged on the right and left sides of the center of the dump body 10 in the left-right direction. The side plates 13 include a right side plate 13R arranged on the right side of the center of the dump body 10 and connected to the right end of the front plate 11 and the right end of the bottom plate 12, and a left side plate 13L arranged on the left side of the center of the dump body 10 and connected to the left end of the front plate 11 and the left end of the bottom plate 12, respectively.

[0024] The front plate 11 has a front surface facing forward and a rear surface facing in the opposite direction to the front surface. The bottom plate 12 has a bottom surface facing upward and a lower surface facing in the opposite direction to the bottom surface.

[0025] The side plate 13 has an inner surface facing the center of the dump body 10 in the left-right direction and an outer surface facing in the opposite direction to the inner surface.

[0026] In the dump body 10, a loading space in which cargo is loaded is defined between the rear surface of the front plate 11, the bottom surface of the bottom plate 12, and the inner surfaces of the side plates 13. The cargo comes into contact with at least a portion of the rear surface of the front plate 11, the bottom surface of the bottom plate 12, and the inner surfaces of the side plates 13. In the embodiment, the rear surface of the front plate 11, the bottom surface of the bottom plate 12, and the inner surfaces of the side plates 13 of the dump body 10 that come into contact with the cargo are collectively referred to as the inner surfaces of the dump body 10, as appropriate.

[0027] The dump body 10 has an inlet 21 through which exhaust gas discharged from the engine 6 is introduced, a flow path 23 through which the exhaust gas discharged from the engine 6 flows, and an exhaust port 22 through which the exhaust gas that has flowed through the flow path 23 is discharged. In the flow path 23, the inlet 21 side is synonymous with the upstream side of the exhaust gas, and the exhaust port 22 side is synonymous with the downstream side of the exhaust gas.

[0028] The inlet 21 is provided on the front surface of the front panel 11. The inlet 21 is provided on the upper right part of the front surface of the front panel 11. The inlet 21 may also be provided in the center of the front surface in the left-right direction.

[0029] The vehicle body 2 has a conduit that guides exhaust gas emitted from the engine 6 to an inlet 21. When the dump body 10 is in the loaded position, the outlet of the conduit is connected to the inlet 21. When the dump body 10 is in the loaded position, the exhaust gas emitted from the engine 6 is supplied to the inlet 21. When the dump body 10 is in the upright position, the outlet of the conduit is separated from the inlet 21. When the dump body 10 is in the upright position, the exhaust gas emitted from the engine 6 is discharged from the outlet of the conduit.

[0030] The exhaust port 22 is provided on the lower surface of the bottom plate 12. The exhaust port 22 is provided in the rear part of the lower surface of the bottom plate 12. The exhaust port 22 may also be provided in the rear part of the side plate 13.

[0031] The flow path 23 is provided inside the dump body 10. At least a portion of the flow path 23 is provided in the side plate 13. Exhaust gas discharged from the engine 6 flows into the flow path 23 from the inlet 21. The exhaust gas that has flowed through the flow path 23 is discharged from the exhaust port 22.

[0032] The flow path 23 includes a first flow path 23A provided at the upper end of the right side plate 13R, a second flow path 23B provided at the boundary between the front plate 11 and the right side plate 13R, a third flow path 23C provided at the lower end of the right side plate 13R, a fourth flow path 23D provided at the boundary between the front plate 11 and the bottom plate 12, a fifth flow path 23E provided at the boundary between the front plate 11 and the left side plate 13L, a sixth flow path 23F provided at the upper end of the left side plate 13L, and a seventh flow path 23G provided at the lower end of the left side plate 13L.

[0033] The upper and lower ends of the right side plate 13R each include a reinforcing member such as a rib. The upper and lower ends of the left side plate 13L each include a reinforcing member such as a rib. The first flow path 23A, the third flow path 23C, the sixth flow path 23F, and the seventh flow path 23G are provided in the reinforcing member of the dump body 10.

[0034] The first flow path 23A extends in the front-rear direction at the upper end of the right side plate 13R. The first flow path 23A may be inclined with respect to the front-rear direction. The front end of the first flow path 23A is connected to the inlet 21. The exhaust gas that flows into the first flow path 23A from the inlet 21 flows through the first flow path 23A toward the rear end of the first flow path 23A.

[0035] The second flow path 23B is provided at the boundary between the front plate 11 and the right side plate 13R. The second flow path 23B slopes downward and rearward. The upper end of the second flow path 23B is connected to the inlet 21. The exhaust gas that flows into the second flow path 23B from the inlet 21 flows through the second flow path 23B toward the lower end of the second flow path 23B.

[0036] The third flow path 23C is provided at the lower end of the right side plate 13R. The third flow path 23C is inclined upward toward the rear. The front end of the third flow path 23C is connected to the lower end of the second flow path 23B. The exhaust gas that flows from the second flow path 23B into the third flow path 23C flows through the third flow path 23C toward the rear end of the third flow path 23C.

[0037] The fourth flow path 23D extends in the left-right direction at the boundary between the front plate 11 and the bottom plate 12. The right end of the fourth flow path 23D is connected to the lower end of the second flow path 23B. The exhaust gas that flows from the second flow path 23B into the fourth flow path 23D flows through the fourth flow path 23D toward the left end of the fourth flow path 23D.

[0038] The fifth flow path 23E is provided at the boundary between the front plate 11 and the left side plate 13L. The fifth flow path 23E is inclined forward as it faces upward. The lower end of the fifth flow path 23E is connected to the left end of the fourth flow path 23D. The exhaust gas that flows from the fourth flow path 23D into the fifth flow path 23E flows through the fifth flow path 23E toward the upper end of the fifth flow path 23E.

[0039] The sixth flow passage 23F extends in the front-rear direction at the upper end of the left side plate 13L. The sixth flow passage 23F may be inclined with respect to the front-rear direction. The front end of the sixth flow passage 23F is connected to the upper end of the fifth flow passage 23E. The exhaust gas that flows from the fifth flow passage 23E into the sixth flow passage 23F flows through the sixth flow passage 23F toward the rear end of the sixth flow passage 23F.

[0040] The seventh flow passage 23G is provided at the lower end of the left side plate 13L. The seventh flow passage 23G is inclined upward toward the rear. The front end of the seventh flow passage 23G is connected to the left end of the fourth flow passage 23D. The exhaust gas that flows from the fourth flow passage 23D into the seventh flow passage 23G flows through the seventh flow passage 23G toward the rear end of the seventh flow passage 23G.

[0041] The rear end of the first flow path 23A, the rear end of the third flow path 23C, the rear end of the sixth flow path 23F, and the rear end of the seventh flow path 23G are each connected to the exhaust port 22 via a flow path provided on the lower surface of the bottom plate 12. The exhaust gas that has flowed through the flow paths 23 is discharged from the exhaust port 22 below the bottom plate 12.

[0042] Exhaust gas supplied from engine 6 to inlet 21 is branched into first flow path 23A and second flow path 23B. This reduces exhaust resistance of engine 6 and suppresses deterioration of the fuel consumption rate of engine 6.

[0043] [Exhaust gas flow] Fig. 3 is a diagram schematically illustrating a dump truck 1 according to an embodiment. As shown in Fig. 3, the dump truck 1 includes an engine 6, a conduit 24, an aftertreatment device 15, a conduit 25, a dump body 10, an exhaust gas flow sensor 16, an exhaust gas temperature sensor 17, an outside air temperature sensor 18, a load weight sensor 19, a controller 60, and an output device 35.

[0044] The conduit 24 connects the exhaust gas outlet 6B of the engine 6 and the exhaust gas inlet 15A of the aftertreatment device 15. The exhaust gas discharged from the exhaust gas outlet 6B of the engine 6 is supplied to the aftertreatment device 15 by flowing through the conduit 24.

[0045] The aftertreatment device 15 purifies the exhaust gas emitted from the engine 6. An example of the aftertreatment device 15 is a urea SCR (Selective Catalytic Reduction) system that purifies the exhaust gas by reducing nitrogen oxides (NOx) contained in the exhaust gas using a selective catalyst and a reducing agent.

[0046] The conduit 25 connects the exhaust gas outlet 15B of the aftertreatment device 15 to the inlet 21 of the dump body 10. The exhaust gas discharged from the exhaust gas outlet 15B of the aftertreatment device 15 flows through the conduit 25 and is supplied to the flow path 23 of the dump body 10.

[0047] The exhaust gas discharged from the aftertreatment device 15 and flowing into the flow path 23 via the inlet 21 flows through the flow path 23 and is then discharged from the exhaust port 22 .

[0048] The exhaust gas flow sensor 16 detects the flow rate of exhaust gas flowing into the flow path 23 of the dump body 10. In the embodiment, the exhaust gas flow sensor 16 is arranged near the exhaust gas outlet 6B of the engine 6 and detects the flow rate of exhaust gas flowing out from the exhaust gas outlet 6B of the engine 6. The exhaust gas flow sensor 16 may be arranged in an intermediate portion of the conduit 24, near the exhaust gas inlet 15A of the aftertreatment device 15, near the exhaust gas outlet 15B of the aftertreatment device 15, or in an intermediate portion of the conduit 25. The exhaust gas flow sensor 16 may be arranged near the inlet 21 of the dump body 10 and detect the flow rate of exhaust gas flowing into the inlet 21.

[0049] The exhaust gas temperature sensor 17 detects the temperature of the exhaust gas flowing into the flow path 23 of the dump body 10. In the embodiment, the exhaust gas temperature sensor 17 is arranged near the inlet 21 of the dump body 10 and detects the temperature of the exhaust gas flowing into the inlet 21. Note that the exhaust gas temperature sensor 17 may also be arranged near the exhaust gas outlet 6B of the engine 6 and detect the temperature of the exhaust gas flowing out from the engine 6. The exhaust gas temperature sensor 17 may be arranged in an intermediate portion of the conduit 24, in the vicinity of the exhaust gas inlet 15A of the aftertreatment device 15, in the vicinity of the exhaust gas outlet 15B of the aftertreatment device 15, or in an intermediate portion of the conduit 25.

[0050] The outside air temperature sensor 18 detects the temperature of the outside air around the dump body 10. The outside air temperature sensor 18 is disposed, for example, on the upper part of the vehicle body 2. Before exhaust gas is supplied to the flow path 23 of the dump body 10, the temperature of the outside air and the temperature of the dump body 10 are substantially equal. By detecting the temperature of the outside air, the outside air temperature sensor 18 can detect the temperature of the dump body 10 before exhaust gas is supplied to the flow path 23.

[0051] The load weight sensor 19 detects the weight of the load loaded on the dump body 10. The traveling device 3 has a suspension cylinder that supports the rear wheels 4. In this embodiment, the load weight sensor 19 is disposed on the suspension cylinder. The weight of the dump body 10 is known data. The load weight sensor 19 can detect the weight of the load loaded on the dump body 10 by detecting the weight of the dump body 10.

[0052] The controller 60 includes a computer system. The controller 60 is mounted on the vehicle body 2.

[0053] The output device 35 outputs predetermined output data. The output device 35 is disposed inside the cab 9. The output device 35 provides the output data to a driver in the cab 9. In the embodiment, the output device 35 includes a display device. The display device displays display data as the output data.

[0054] [Cab] Fig. 4 is a diagram showing the inside of the cab 9 according to the embodiment. As shown in Fig. 4, inside the cab 9, an operator's seat 31, a steering wheel 32, an accelerator pedal 33, a brake pedal 34, an output device 35, and an operation device 40 are arranged.

[0055] Inside the cab 9, a cigarette lighter 36, a power window switch 37, a side lamp switch 38, and an option switch 39 are arranged on the right side of the operating device 40. Examples of the option switch 39 include a fog lamp switch or a rotating light switch.

[0056] The driver of the dump truck 1 sits in the driver's seat 31. The driver operates the steering wheel 32 to change the traveling direction of the dump truck 1. By operating the steering wheel 32, the front wheels 4 are steered. The driver operates the accelerator pedal 33 to accelerate the traveling device 3. By operating the accelerator pedal 33, the rotation speed of the rear wheels 4 increases, and the traveling device 3 accelerates. The driver operates the brake pedal 34 to decelerate or stop the traveling device 3.

[0057] The output device 35 provides predetermined output data to the driver. The output device 35 includes a display device that displays display data as output data. The output device 35 includes a display 71 that displays the display data, and a display controller 72. The display 71 includes a flat panel display such as a liquid crystal display (LCD) or an organic electroluminescence display (OLED).

[0058] The operating device 40 is operated by the driver and includes a shift lever 42, a hoist switch 43, a parking brake switch 44, and a hoist switch lock knob 45.

[0059] The shift lever 42 is operated to change the speed stage of the traveling device 3. The shift lever 42 is also operated to switch the dump truck 1 between forward and reverse. The hoist switch 43 is operated to drive the hoist cylinder 7. Operation of the hoist switch 43 causes the dump body 10 to perform a dumping operation. The parking brake switch 44 is operated to activate the parking brake of the dump truck 1. The hoist switch lock knob 45 is operated to disable the hoist switch 43.

[0060] [Worksite] 5 is a diagram schematically illustrating a work site 50 where a dump truck 1 according to an embodiment operates. The dump truck 1 is a self-propelled off-road dump truck that operates at the work site 50. In the embodiment, the work site 50 is a mine. A mine refers to a business site where minerals are extracted.

[0061] The work site 50 has a loading area 51, an unloading area 52, and a conveying path 53. The loading area 51 is an area where a loading machine 54 such as a hydraulic excavator performs a loading operation of loading cargo onto the dump body 10 of the dump truck 1. The unloading area 52 is an area where a dump truck 1 performs an unloading operation of unloading cargo from the dump body 10. The conveying path 53 is a passageway for the dump truck 1 that connects the loading area 51 and the unloading area 52. The dump truck 1 travels on the conveying path 53 to travel back and forth between the loading area 51 and the unloading area 52.

[0062] [State estimation system] 6 is a functional block diagram showing a state estimation system 100 according to an embodiment. The state estimation system 100 is mounted on a dump truck 1. The state estimation system 100 estimates a body temperature Te indicating the temperature of a predetermined portion MP on the inner surface of the dump body 10 that comes into contact with a load, based on detection data from an exhaust gas flow rate sensor 16 and detection data from an exhaust gas temperature sensor 17. The state estimation system 100 also determines whether or not the dump operation of the dump body 10 is appropriate, based on the estimated body temperature Te.

[0063] 7 is a diagram illustrating a predetermined portion MP on the inner surface of the dump body 10 according to the embodiment. As described above, in the dump body 10, the loading space in which cargo is loaded is defined between the rear surface of the front plate 11, the bottom surface of the bottom plate 12, and the inner surfaces of the side plates 13. The inner surfaces of the dump body 10 that come into contact with the cargo include the rear surface of the front plate 11, the bottom surface of the bottom plate 12, and the inner surfaces of the side plates 13.

[0064] The predetermined portions MP are temperature estimation points on the inner surface of the dump body 10 at which the temperature is estimated by the state estimation system 100. A plurality of predetermined portions MP are defined on the inner surface of the dump body 10. As shown in FIG. 7 , in the embodiment, the predetermined portions MP are defined at ten locations on the inner surface of the dump body 10. Of the plurality of predetermined portions MP, at least some of the predetermined portions MP are defined near the flow path 23.

[0065] Of the multiple predetermined portions MP, the first predetermined portion MP1, the second predetermined portion MP2, and the third predetermined portion MP3 are defined at the upper end of the front panel 11. In the left-right direction, the first predetermined portion MP1 is defined at the right end of the front panel 11, the second predetermined portion MP2 is defined at the center of the front panel 11, and the third predetermined portion MP3 is defined at the left end of the front panel 11.

[0066] Of the multiple predetermined portions MP, the fourth predetermined portion MP4, the fifth predetermined portion MP5, and the sixth predetermined portion MP6 are each defined at the lower end of the front panel 11. In the left-right direction, the fourth predetermined portion MP4 is defined at the right end of the front panel 11, the fifth predetermined portion MP5 is defined at the center of the front panel 11, and the sixth predetermined portion MP6 is defined at the left end of the front panel 11.

[0067] Of the multiple predetermined portions MP, the seventh predetermined portion MP7 and the eighth predetermined portion MP8 are each defined at the lower end of the right side plate 13R. In the front-rear direction, the seventh predetermined portion MP7 is defined at the center of the right side plate 13R, and the eighth predetermined portion MP8 is defined at the rear of the right side plate 13R.

[0068] Of the multiple predetermined portions MP, a ninth predetermined portion MP9 and a tenth predetermined portion MP10 are defined at the lower end of the left side plate 13L. In the front-to-rear direction, the ninth predetermined portion MP9 is defined at the center of the left side plate 13L, and the tenth predetermined portion MP10 is defined at the rear of the left side plate 13L.

[0069] The predetermined portions MP do not have to be defined at ten locations on the inner surface of the dump body 10, and may be defined at any number of locations.

[0070] As shown in FIG. 6, the state estimation system 100 includes an exhaust gas flow rate sensor 16, an exhaust gas temperature sensor 17, an outside air temperature sensor 18, a cargo weight sensor 19, a controller 60, and an output device 35.

[0071] The controller 60 includes a body characteristic memory unit 61, a cargo characteristic memory unit 62, an exhaust gas flow rate acquisition unit 63, an exhaust gas temperature acquisition unit 64, an outside air temperature acquisition unit 65, a cargo weight acquisition unit 66, a body temperature estimation unit 67, a cargo state estimation unit 68, and a dump suitability determination unit 69.

[0072] The output device 35 has a display 71 and a display controller 72. The display controller 72 has a body temperature display unit 73 and a dump suitability display unit 74.

[0073] The body characteristic storage unit 61 stores body characteristics Cb that indicate the characteristics of the dump body 10. Examples of the body characteristics Cb include the shape of the dump body 10, the dimensions of the dump body 10, the material of the dump body 10, and the thermal characteristics of the dump body 10. Examples of the thermal characteristics of the dump body 10 include the heat capacity of the dump body 10 and the heat transfer coefficient of the dump body 10. The body characteristics Cb are known data that can be determined from the specifications of the dump truck 1. The body characteristics Cb are stored in advance in the body characteristic storage unit 61.

[0074] The load characteristic memory unit 62 stores load characteristics Cs that indicate the characteristics of the load to be loaded on the dump body 10. In the embodiment, the load includes soil. Examples of the load characteristics Cs include the material characteristics (soil quality) of the load, the moisture content (wetness) of the load, and the temperature of the load. Examples of the material characteristics of the load include the components of the load and the specific gravity of the load. The load characteristics Cs are known data that can be determined from a preliminary survey of the loading site 51. The load characteristics Cs are stored in advance in the load characteristics memory unit 62. The load characteristics Cs may be set for each loading site 51 and stored in the load characteristics memory unit 62. Alternatively, the load characteristics Cs may be transmitted from a management computer of a control facility each time a vehicle heads to a different loading site 51 and stored in the load characteristics memory unit 62.

[0075] The exhaust gas flow rate acquisition unit 63 acquires detection data from the exhaust gas flow rate sensor 16. The exhaust gas flow rate sensor 16 detects the flow rate of exhaust gas flowing into the flow path 23 of the dump body 10. The exhaust gas flow rate acquisition unit 63 acquires an exhaust gas flow rate Df that indicates detection data of the flow rate of exhaust gas flowing into the flow path 23 of the dump body 10, detected by the exhaust gas flow rate sensor 16.

[0076] The exhaust gas temperature acquisition unit 64 acquires detection data from the exhaust gas temperature sensor 17. The exhaust gas temperature sensor 17 detects the temperature of the exhaust gas flowing into the flow path 23 of the dump body 10. The exhaust gas temperature acquisition unit 64 acquires an exhaust gas temperature Dt that indicates detection data of the temperature of the exhaust gas flowing into the flow path 23 of the dump body 10, detected by the exhaust gas temperature sensor 17. The exhaust gas temperature Dt is, for example, 400°C.

[0077] The outside air temperature acquisition unit 65 acquires detection data from the outside air temperature sensor 18. The outside air temperature sensor 18 detects the temperature of the outside air around the dump body 10. The outside air temperature acquisition unit 65 acquires the outside air temperature Do that indicates detection data of the temperature of the outside air around the dump body 10, detected by the outside air temperature sensor 18.

[0078] The load weight acquisition unit 66 acquires detection data from the load weight sensor 19. The load weight sensor 19 detects the weight of the load loaded on the dump body 10. The load weight acquisition unit 66 acquires a load weight Da that indicates detection data of the weight of the load loaded on the dump body 10, detected by the load weight sensor 19.

[0079] The body temperature estimation unit 67 estimates a body temperature Te indicating the temperature of a predetermined portion MP on the inner surface of the dump body 10 that comes into contact with the load, based on the exhaust gas flow rate Df and the exhaust gas temperature Dt. As described with reference to Fig. 7, a plurality of predetermined portions MP are defined on the inner surface of the dump body 10. The body temperature estimation unit 67 estimates the body temperature Te of each of the plurality of predetermined portions MP.

[0080] In the embodiment, the body temperature estimation unit 67 holds correlation data (map data) between the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the body temperature Te. The correlation data can be created based on a prior experiment or a simulation. The body temperature estimation unit 67 can estimate the body temperature Te by comparing the exhaust gas flow rate Df detected by the exhaust gas flow sensor 16 and the exhaust gas temperature Dt detected by the exhaust gas temperature sensor 17 with the correlation data. If the correlation data is discrete data, the body temperature Te may be estimated by interpolation.

[0081] In addition, when a simulation model of the dump body 10 is held in the body temperature estimation unit 67, the body temperature estimation unit 67 may estimate the body temperature Te by performing numerical analysis on the simulation model of the dump body 10 based on the exhaust gas flow rate Df and the exhaust gas temperature Dt.

[0082] Furthermore, the body temperature estimation unit 67 estimates the time Pr required for the body temperature Te to reach a specified temperature Tp based on the exhaust gas flow rate Df and the exhaust gas temperature Dt. The specified temperature Tp for the body temperature Te is, for example, 120°C. For example, if the body temperature Te is estimated to be 30°C, the body temperature estimation unit 67 estimates the time Pr required for the body temperature Te to reach 120°C from 30°C.

[0083] In this embodiment, the body temperature estimation unit 67 stores correlation data (map data) between the exhaust gas flow rate Df, the exhaust gas temperature Dt, the body temperature Te, and the required time Pr. The correlation data can be created based on a preliminary experiment or a simulation. The body temperature estimation unit 67 can estimate the required time Pr by comparing the exhaust gas flow rate Df detected by the exhaust gas flow sensor 16 and the exhaust gas temperature Dt detected by the exhaust gas temperature sensor 17 with the correlation data.

[0084] In addition, if a simulation model of the dump body 10 is held in the body temperature estimation unit 67, the body temperature estimation unit 67 may estimate the required time Pr by performing numerical analysis on the simulation model of the dump body 10 based on the exhaust gas flow rate Df and the exhaust gas temperature Dt.

[0085] The body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the outside air temperature Do. As described above, before exhaust gas is supplied to the flow path 23 of the dump body 10, the temperature of the outside air and the temperature of the dump body 10 are substantially equal. That is, the outside air temperature Do is substantially equal to the temperature of the dump body 10 before exhaust gas is supplied to the flow path 23. Therefore, the outside air temperature Do can be considered as an initial value for the body temperature Te before exhaust gas is supplied to the flow path 23. The body temperature estimation unit 67 can estimate the required time Pr with high accuracy based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the outside air temperature Do. When correlation data between the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, the body temperature Te, and the required time Pr is created, the body temperature estimation unit 67 can estimate the required time Pr by comparing the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the correlation data. In addition, when a simulation model of the dump body 10 is held in the body temperature estimation unit 67, the body temperature estimation unit 67 can estimate the required time Pr by performing numerical analysis on the simulation model of the dump body 10 based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the outside air temperature Do.

[0086] The body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb. The required time Pr may change based on the body characteristic Cb. For example, if the body characteristic Cb indicates that the heat of the exhaust gas flowing through the flow path 23 is easily transferred to the predetermined part MP, the required time Pr is likely to be short. If the body characteristic Cb indicates that the heat of the exhaust gas flowing through the flow path 23 is not easily transferred to the predetermined part MP, the required time Pr is likely to be long. Therefore, the body temperature estimation unit 67 can estimate the required time Pr with higher accuracy based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb. When correlation data between the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, the body characteristic Cb, the body temperature Te, and the required time Pr is created, the body temperature estimation unit 67 can estimate the required time Pr by collating the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb with the correlation data. Also, when a simulation model of the dump body 10 is held in the body temperature estimation unit 67, the body temperature estimation unit 67 can estimate the required time Pr by performing a numerical analysis on the simulation model of the dump body 10 based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb.

[0087] When a load is loaded onto the dump body 10, the body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the load characteristics Cs. The required time Pr may change based on the load characteristics Cs. For example, if the load has a low moisture content or a high temperature, the required time Pr is likely to be short. If the load has a high moisture content or a low temperature, the required time Pr is likely to be long. Therefore, the body temperature estimation unit 67 can estimate the required time Pr with higher accuracy based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the load characteristics Cs. When correlation data between the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, the load characteristics Cs, the body temperature Te, and the required time Pr is created, the body temperature estimation unit 67 can estimate the required time Pr by collating the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the load characteristics Cs with the correlation data. Also, when a simulation model of the dump body 10 is held in the body temperature estimation unit 67, the body temperature estimation unit 67 can estimate the required time Pr by performing a numerical analysis on the simulation model of the dump body 10 based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the load characteristics Cs.

[0088] The body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, the body characteristic Cb, and the load characteristic Cs.

[0089] Note that, if the body characteristic Cb is likely to be constant, the body characteristic storage unit 61 may be omitted. That is, the body characteristic Cb may be previously taken into account in the above-described correlation data, or the body characteristic Cb may be previously taken into account in the above-described simulation model.

[0090] The cargo state estimation unit 68 estimates the volume Vc of the cargo and the contact area Ac of the cargo with the inner surface of the dump body 10 based on the cargo weight Da.

[0091] The dumping suitability determination unit 69 determines whether or not a dumping operation of the dump body 10 is appropriate based on the body temperature Te. The dumping suitability determination unit 69 estimates the dryness of the load based on the body temperature Te. If the load is wet, even if a dumping operation is performed, at least a portion of the load may remain attached to the inner surface of the dump body 10 and may not be discharged from the dump body 10. When the dump body 10 is heated by the exhaust gas flowing through the flow path 23, the load dries and is prevented from adhering to the inner surface of the dump body 10. If the body temperature Te is high, the dumping suitability determination unit 69 determines that the load has been dried and that if a dumping operation is performed, the load will be discharged from the dump body 10 without adhering to the inner surface of the dump body 10. In other words, if the body temperature Te is high, the dumping suitability determination unit 69 determines that a dumping operation is appropriate. When the body temperature Te is low, the dumping suitability determination unit 69 determines that the cargo has not yet been dried, and determines that if a dumping operation is performed, at least a portion of the cargo will adhere to the inner surface of the dump body 10 and will not be discharged from the dump body 10. In other words, when the body temperature Te is low, the dumping suitability determination unit 69 determines that it is inappropriate to perform a dumping operation.

[0092] In this embodiment, when the body temperature Te is below a specified temperature Tp, the dumping suitability determination unit 69 determines that the cargo has not yet been dried and that it is inappropriate to perform the dumping operation. When the body temperature Te is equal to or higher than a specified temperature Tp, the dumping suitability determination unit 69 determines that the cargo has been dried and that it is appropriate to perform the dumping operation. As described above, the specified temperature Tp is, for example, 120°C.

[0093] The dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the time Pt ​​that has elapsed since the body temperature Te reached the specified temperature Tp. When the body temperature Te reaches the specified temperature Tp, the cargo may not yet be dry. Therefore, the dumping suitability determination unit 69 may determine that the cargo has been dried and that it is appropriate to perform the dumping operation when the time Pt ​​that has elapsed since the body temperature Te reached the specified temperature Tp exceeds a predetermined specified time Pp.

[0094] The dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the body temperature Te and the load characteristics Cs. For example, if the moisture content of the cargo is low, it is highly likely that the cargo will be dry when the body temperature Te reaches the specified temperature Tp. If the moisture content of the cargo is high, it is highly likely that the cargo will not be dry when the body temperature Te reaches the specified temperature Tp. Therefore, the dumping suitability determination unit 69 may change the specified time Pp based on, for example, the load characteristics Cs. If the moisture content of the cargo is low, the dumping suitability determination unit 69 shortens the specified time Pp. If the moisture content of the cargo is high, the dumping suitability determination unit 69 lengthens the specified time Pp. If the elapsed time Pt ​​since the body temperature Te reached the specified temperature Tp exceeds the changed specified time Pp, the dumping suitability determination unit 69 may determine that the cargo has been dried and that it is appropriate to perform the dumping operation.

[0095] The dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the body temperature Te, the load characteristics Cs, the load volume Vc, and the load contact area Ac. For example, if the load volume Vc is small or the load contact area Ac is small, it is highly likely that the load will be dry by the time the body temperature Te reaches the specified temperature Tp. If the load volume Vc is large or the load contact area Ac is large, it is highly likely that the load will not be dry by the time the body temperature Te reaches the specified temperature Tp. Therefore, the dumping suitability determination unit 69 may change the specified time Pp based on the load characteristics Cs, the load volume Vc, and the load contact area Ac. If the moisture content of the load is low, if the load volume Vc is small, or if the load contact area Ac is small, the dumping suitability determination unit 69 shortens the specified time Pp. If the moisture content of the cargo is high, if the volume Vc of the cargo is large, or if the contact area Ac of the cargo is large, the dumping suitability determination unit 69 increases the specified time Pp. When the elapsed time Pt ​​since the body temperature Te reached the specified temperature Tp exceeds the changed specified time Pp, the dumping suitability determination unit 69 may determine that the cargo has been dried and that it is appropriate to perform a dumping operation.

[0096] The display 71 includes a display screen on which display data is displayed. The display 71 is disposed inside the cab 9.

[0097] The display controller 72 includes a computer system disposed in the output device 35. The display controller 72 causes the display 71 to display display data as output data.

[0098] The body temperature display unit 73 displays the body temperature Te estimated by the body temperature estimation unit 67 on the display 71. By checking the body temperature Te displayed on the display 71, the driver can recognize the heating state of the inner surface of the dump body 10.

[0099] The dump suitability display unit 74 displays the determination result of the dump suitability determination unit 69 on the display 71. By checking the suitability of performing the dump operation displayed on the display 71, the driver can perform the dump operation of the dump body 10 at the appropriate timing.

[0100] [State estimation method] 8 is a flowchart showing a state estimation method according to the embodiment. When the engine 6 is started, exhaust gas is discharged from the engine 6. The exhaust gas discharged from the engine 6 is supplied to the flow path 23. The flow rate of the exhaust gas flowing into the flow path 23 is detected by the exhaust gas flow sensor 16. The temperature of the exhaust gas flowing into the flow path 23 is detected by the exhaust gas temperature sensor 17. The exhaust gas flow rate acquisition unit 63 acquires the exhaust gas flow rate Df from the exhaust gas flow rate sensor 16. The exhaust gas temperature acquisition unit 64 acquires the exhaust gas temperature Dt from the exhaust gas temperature sensor 17 (step S1).

[0101] In addition, the temperature of the outside air around the dump body 10 at the time when the engine 6 is started is detected by the outside air temperature sensor 18. The outside air temperature acquisition unit 65 acquires the outside air temperature Do at the time when the engine 6 is started from the outside air temperature sensor 18. The outside air temperature Do at the time when the engine 6 is started is substantially equal to the temperature of the dump body 10 before it is heated by exhaust gas. The outside air temperature Do can be considered as an initial value related to the body temperature Te before the dump body 10 is heated by exhaust gas.

[0102] Based on the exhaust gas flow rate Df and the exhaust gas temperature Dt acquired in step S1, the body temperature estimation unit 67 estimates the body temperature Te of a predetermined portion MP on the inner surface of the dump body 10. Based on the exhaust gas flow rate Df and the exhaust gas temperature Dt acquired in step S1, the body temperature estimation unit 67 also estimates the time Pr required for the body temperature Te to reach a specified temperature Tp (step S2).

[0103] As described above, the body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the outside air temperature Do. The body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb. When a load is loaded on the dump body 10, the body temperature estimation unit 67 may estimate the required time Pr based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the load characteristic Cs.

[0104] The body temperature display unit 73 displays the body temperature Te estimated in step S2 on the display 71. The body temperature display unit 73 may also display the required time Pr estimated in step S2 on the display 71 (step S3).

[0105] A loading operation is carried out at the loading site 51, whereby a load is loaded onto the dump body 10. The dump truck 1 travels on a conveying path 53 from the loading site 51 toward the discharge site 52 with the load loaded onto the dump body 10.

[0106] For example, while the dump truck 1 is traveling on the transport path 53, the dumping suitability determining unit 69 determines whether or not the dumping operation of the dump body 10 is appropriate based on the body temperature Te estimated in step S2 (step S4).

[0107] In this embodiment, when the body temperature Te is below the specified temperature Tp, the dumping suitability determination unit 69 determines that the cargo has not yet been dried and that it is inappropriate to perform the dumping operation. When the body temperature Te is equal to or higher than the specified temperature Tp, the dumping suitability determination unit 69 determines that the cargo has been dried and that it is appropriate to perform the dumping operation.

[0108] As described above, the dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the time Pt ​​that has elapsed since the body temperature Te reached the specified temperature Tp. When the time Pt ​​that has elapsed since the body temperature Te reached the specified temperature Tp exceeds a predetermined specified time Pp, the dumping suitability determination unit 69 may determine that the cargo has been dried and that it is appropriate to perform the dumping operation.

[0109] As described above, the dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the body temperature Te and the cargo characteristics Cs. When the cargo weight acquisition unit 66 acquires the cargo weight Da and the cargo state estimation unit 68 estimates the cargo volume Vc and the cargo contact area Ac, the dumping suitability determination unit 69 may determine the suitability of the dumping operation based on the body temperature Te, the cargo characteristics Cs, the cargo volume Vc, and the cargo contact area Ac.

[0110] In step S4, if it is determined that it is appropriate to perform the dumping operation, that is, if it is determined that the cargo will be prevented from adhering to the inner surface of the dump body 10 when the dump body 10 performs the dumping operation (step S4: Yes), the dumping suitability display unit 74 displays on the display 71 that it is appropriate to perform the dumping operation (step S5).

[0111] The driver of the dump truck 1 can check the display 71 and recognize that it is appropriate to perform the dumping operation, and then perform the dumping operation of the dump body 10 after the dump truck 1 arrives at the discharge site 52.

[0112] If it is determined in step S4 that the dumping operation is inappropriate, that is, if it is determined that there is a high possibility that at least a portion of the cargo will adhere to the inner surface of the dump body 10 when the dump body 10 performs a dumping operation (step S4: No), the dumping suitability display unit 74 displays on the display 71 that the dumping operation is inappropriate (step S6).

[0113] The driver of the dump truck 1 can check the display 71 and recognize that it is inappropriate to perform a dump operation, and can wait to perform the dump operation until it is determined that the dump operation is appropriate.

[0114] [Computer System] FIG. 9 is a block diagram showing a computer system 1000 according to an embodiment. The controller 60 and the display controller 72 described above each comprise a computer system 1000. The computer system 1000 includes a processor 1001 such as a central processing unit (CPU), a main memory 1002 including a nonvolatile memory such as a read-only memory (ROM) and a volatile memory such as a random access memory (RAM), a storage 1003, and an interface 1004 including an input / output circuit. The functions of the controller 60 and the display controller 72 described above are stored in the storage 1003 as computer programs. The processor 1001 reads the computer programs from the storage 1003, loads them into the main memory 1002, and executes the above-described processes in accordance with the computer programs. The computer programs may be distributed to the computer system 1000 via a network.

[0115] According to the above-described embodiment, the computer program or computer system 1000 can perform the following operations: detect the flow rate of exhaust gas flowing into the flow path 23 of the dump body 10; detect the temperature of the exhaust gas flowing into the flow path 23; acquire an exhaust gas flow rate Df indicating the detected data of the exhaust gas flow rate; acquire an exhaust gas temperature Dt indicating the detected data of the exhaust gas temperature; and estimate a body temperature Te indicating the temperature of a specific portion MP on the inner surface of the dump body 10 that comes into contact with the cargo based on the exhaust gas flow rate Df and the exhaust gas temperature Dt.

[0116] Furthermore, the computer program or the computer system 1000 can execute the process of determining whether or not the dump operation of the dump body 10 is appropriate based on the body temperature Te according to the above-described embodiment.

[0117] [effect] As described above, in the embodiment, the state estimation system 100 includes an exhaust gas flow rate acquisition unit 63 that acquires an exhaust gas flow rate Df indicating detection data of the flow rate of exhaust gas flowing into the flow path 23 of the dump body 10, an exhaust gas temperature acquisition unit 64 that acquires an exhaust gas temperature Dt indicating detection data of the temperature of exhaust gas flowing into the flow path 23, and a body temperature estimation unit 67 that estimates a body temperature Te indicating the temperature of a specific portion MP on the inner surface of the dump body 10 that comes into contact with the cargo based on the exhaust gas flow rate Df and the exhaust gas temperature Dt.

[0118] As a result, the body temperature Te of the inner surface of the dump body 10 can be acquired without installing a temperature sensor in the dump body 10 that detects the temperature of the inner surface of the dump body 10. Furthermore, according to the embodiment, the temperature (temperature distribution) of the entire inner surface of the dump body 10 is not estimated, but the body temperature Te of the predetermined portion MP is estimated, so an increase in the calculation load on the controller 60 is suppressed.

[0119] A plurality of predetermined portions MP are defined on the inner surface of the dump body 10. The body temperature estimation unit 67 estimates the body temperature Te of each of the plurality of predetermined portions MP. As a result, a rough temperature distribution on the inner surface of the dump body 10 is estimated.

[0120] The body temperature estimation unit 67 estimates the time Pr required for the body temperature Te to reach the specified temperature Tp based on the exhaust gas flow rate Df and the exhaust gas temperature Dt. This allows the driver to recognize the required time Pr. The driver can also recognize the approximate time required for the cargo to be dried.

[0121] The state estimation system 100 includes an outside air temperature acquisition unit 65 that acquires an outside air temperature Do that indicates detected data on the temperature of the outside air around the dump body 10. This allows the body temperature estimation unit 67 to estimate the required time Pr with high accuracy based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, and the outside air temperature Do.

[0122] The state estimation system 100 further includes a body characteristic storage unit 61 that stores a body characteristic Cb that indicates the characteristics of the dump body 10. This allows the body temperature estimation unit 67 to estimate the required time Pr with high accuracy based on the exhaust gas flow rate Df, the exhaust gas temperature Dt, the outside air temperature Do, and the body characteristic Cb.

[0123] The condition estimation system 100 includes a body temperature display unit 73 that displays the body temperature Te on a display 71 arranged inside the cab 9 of the dump truck 1. This allows the driver to check the body temperature Te displayed on the display 71 and recognize the heating state of the inner surface of the dump body 10.

[0124] The state estimation system 100 includes a dumping suitability determination unit 69 that determines, based on the body temperature Te, whether or not a dumping operation of the dump body 10 is appropriate. This allows the driver to perform the dumping operation at an appropriate timing based on the determination result of the dumping suitability determination unit 69.

[0125] The dumping suitability determination unit 69 determines whether the dumping operation is appropriate based on the time Pt ​​that has elapsed since the body temperature Te reached the specified temperature Tp. At the time when the body temperature Te reaches the specified temperature Tp, the cargo may not yet be dried. The dumping suitability determination unit 69 can appropriately determine whether the dumping operation of the dump body 10 is appropriate based on the elapsed time Pt.

[0126] The state estimation system 100 includes a cargo characteristic storage unit 62 that stores a cargo characteristic Cs that indicates the characteristics of the cargo. This allows the dumping suitability determination unit 69 to appropriately determine the suitability of the dumping operation based on the body temperature Te and the cargo characteristic Cs.

[0127] The state estimation system 100 further includes a load weight acquisition unit 66 that acquires a load weight Da that indicates detection data of the weight of the load loaded on the dump body 10, and a load state estimation unit 68 that estimates the load volume Vc and the contact area Ac of the load with the inner surface of the dump body 10 based on the load weight Da. This allows the dumping suitability determination unit 69 to more appropriately determine the suitability of the dumping operation based on the body temperature Te, the load characteristics Cs, the load volume Vc, and the contact area Ac of the load.

[0128] The condition estimation system 100 includes a dump suitability display unit 74 that displays the determination result of the dump suitability determination unit 69 on a display 71 arranged inside the cab 9 of the dump truck 1. This allows the driver to check the suitability of performing the dump operation displayed on the display 71, and enables the dump operation of the dump body 10 to be performed at an appropriate timing.

[0129] [Other embodiments] In the above-described embodiment, the output device 35 includes a display device. The output device 35 may also include an audio output device. The audio output device outputs audio data as output data. For example, the body temperature Te and the determination result of whether or not a dump operation is appropriate may be output as audio data.

[0130] In the above-described embodiment, the controller 60 has the functions of the body characteristic storage unit 61, the cargo characteristic storage unit 62, the exhaust gas flow rate acquisition unit 63, the exhaust gas temperature acquisition unit 64, the outside air temperature acquisition unit 65, the cargo weight acquisition unit 66, the body temperature estimation unit 67, the cargo state estimation unit 68, and the dumping suitability determination unit 69, and the display controller 72 has the functions of the body temperature display unit 73 and the dumping suitability display unit 74. At least some of the functions of the controller 60 may be provided in the display controller 72, or at least some of the functions of the display controller 72 may be provided in the controller 60. Furthermore, the controller 60 and the display controller 72 may be integrated. In addition, each of the body characteristic memory unit 61, cargo characteristic memory unit 62, exhaust gas flow rate acquisition unit 63, exhaust gas temperature acquisition unit 64, outside air temperature acquisition unit 65, cargo weight acquisition unit 66, body temperature estimation unit 67, cargo state estimation unit 68, dump suitability determination unit 69, body temperature display unit 73, and dump suitability display unit 74 may be configured as separate hardware (computer systems).

[0131] In the above-described embodiment, an external computer disposed outside the dump truck 1 may have at least some of the functions of the controller 60. An example of the external computer is a cloud server. For example, the detection data of the exhaust gas flow rate sensor 16 and the detection data of the exhaust gas temperature sensor 17 may be transmitted to the external computer via a wireless communication network, and the external computer may calculate the body temperature Te and determine whether or not a dumping operation is appropriate. The body temperature Te calculated by the external computer and the determination result of whether or not a dumping operation is appropriate may be transmitted to the dump truck 1 via the wireless communication network and output from the output device 35.

[0132] In the above-described embodiment, the dump truck 1 is a manned dump truck that is operated by a driver. The dump truck 1 may be an unmanned dump truck that is operated based on a control command transmitted from a management computer of a control facility. The dump truck 1 may also be a cabless dump truck that does not have a cab 9. The output device 35 may also be omitted. In that case, the output device 35 may be provided in the control facility. In addition, if the dump truck is an unmanned dump truck, the dump suitability determination unit 69 may determine that the dump operation cannot be performed.

[0133] In the above-described embodiment, the dump truck 1 is of a rigid frame type. However, the dump truck 1 may be of an articulated type.

[0134] In the above-described embodiment, the dump truck 1 is of a rear dump type. The dump truck 1 may be of a side dump type in which a load is discharged from the dump body 10 by tilting the dump body 10 to the left or right. [Explanation of symbols]

[0135] 1...dump truck, 2...body, 3...traveling gear, 4...wheel, 5...tire, 6...engine, 6B...exhaust gas outlet, 7...hoist cylinder, 8...bracket, 8P...rotating pin, 9...cab, 10...dump body, 11...front plate, 12...bottom plate, 13...side plate, 13R...right side plate, 13L...left side plate, 14...protector plate, 15...aftertreatment device, 15A...exhaust gas inlet, 15B...exhaust gas outlet, 16...exhaust gas flow rate sensor, 17...exhaust gas temperature sensor, 18...outside air temperature sensor, 19...load weight sensor, 21...inlet, 22...exhaust port, 23...flow path, 23A...first flow path, 23 B...second flow path, 23C...third flow path, 23D...fourth flow path, 23E...fifth flow path, 23F...sixth flow path, 23G...seventh flow path, 24...pipe, 25...pipe, 31...driver's seat, 32...steering wheel, 33...accelerator pedal, 34...brake pedal, 35...output device, 36...cigarette lighter, 37...power window switch, 38...side lamp switch, 39...option switch, 40...operating device, 42...shift lever, 43...hoist switch, 44...parking brake switch, 45...hoist switch lock knob, 50...work site, 51...loading area , 52...unloading site, 53...transport path, 54...loader, 60...controller, 61...body characteristics memory unit, 62...load characteristics memory unit, 63...exhaust gas flow rate acquisition unit, 64...exhaust gas temperature acquisition unit, 65...outside air temperature acquisition unit, 66...load weight acquisition unit, 67...body temperature estimation unit, 68...load state estimation unit, 69...dump suitability determination unit, 71...display, 72...display controller, 73...body temperature display unit, 74...dump suitability display unit, 100...state estimation system, 1000...computer system, 1001...processor, 1002...main memory, 1003...storage Page, 1004...interface, Ac...contact area, Cb...body characteristics, Cs...cargo characteristics, Da...cargo weight, Df...exhaust gas flow rate, Do...outside air temperature, Dt...exhaust gas temperature, MP...specified portion, MP1...first specified portion, MP2...second specified portion, MP3...third specified portion, MP4...fourth specified portion, MP5...fifth specified portion, MP6...sixth specified portion, MP7...seventh specified portion, MP8...eighth specified portion, MP9...ninth specified portion, MP10...tenth specified portion, Pp...specified time, Pr...required time, Pt...elapsed time, Te...body temperature, Tp...specified temperature, Vc...volume.

Claims

1. A state estimation system for a dump truck including an engine, a dump body on which a load is loaded, and a flow path through which exhaust gas discharged from the engine flows, an exhaust gas flow rate acquisition unit that acquires an exhaust gas flow rate indicating detection data of the flow rate of the exhaust gas flowing into the flow path; an exhaust gas temperature acquisition unit that acquires an exhaust gas temperature indicating detection data of the temperature of the exhaust gas flowing into the flow path; and a body temperature estimation unit that estimates a body temperature indicating a temperature of a predetermined portion of an inner surface of the dump body that contacts the load based on the exhaust gas flow rate and the exhaust gas temperature. State estimation system.

2. a plurality of the predetermined portions are defined on the inner surface, the body temperature estimation unit estimates the body temperature of each of the plurality of predetermined parts; The state estimation system according to claim 1 .

3. the body temperature estimation unit estimates a required time for the body temperature to reach a specified temperature based on the exhaust gas flow rate and the exhaust gas temperature. The state estimation system according to claim 1 or 2.

4. an outside air temperature acquisition unit that acquires outside air temperature indicating detection data of the temperature of the outside air around the dump body; the body temperature estimation unit estimates the required time based on the exhaust gas flow rate, the exhaust gas temperature, and the outside air temperature. The state estimation system according to claim 3 .

5. A body characteristic storage unit is provided which stores body characteristics indicating characteristics of the dump body, the body temperature estimation unit estimates the required time based on the exhaust gas flow rate, the exhaust gas temperature, the outside air temperature, and the body characteristics. The state estimation system according to claim 4 .

6. a cargo characteristic storage unit that stores cargo characteristics indicating the characteristics of the cargo; the body temperature estimation unit estimates the required time based on the exhaust gas flow rate, the exhaust gas temperature, the outside air temperature, and the cargo characteristics. The state estimation system according to claim 4 .

7. a body temperature display unit that displays the body temperature on a display arranged inside the cab of the dump truck; The state estimation system according to any one of claims 1 to 6.

8. A dump suitability determination unit is provided that determines suitability of a dump operation of the dump body based on the body temperature. The state estimation system according to claim 1 or 2.

9. The dump suitability determination unit determines whether the dump operation is appropriate based on the elapsed time since the body temperature reached a specified temperature. The state estimation system according to claim 8 .

10. a cargo characteristic storage unit that stores cargo characteristics indicating the characteristics of the cargo; The dump suitability determination unit determines the suitability of the dump operation based on the body temperature and the load characteristics. The state estimation system according to claim 8 or 9.

11. a load weight acquisition unit that acquires a load weight indicating detection data of the weight of the cargo loaded on the dump body; a cargo state estimation unit that estimates a volume of the cargo and a contact area of ​​the cargo with an inner surface of the dump body based on the cargo weight, the dump suitability determination unit determines the suitability of the dump operation based on the body temperature, the cargo characteristics, the volume of the cargo, and the contact area of ​​the cargo. The state estimation system according to claim 10.

12. a dump suitability display unit that displays the determination result of the dump suitability determination unit on a display arranged inside the cab of the dump truck, The state estimation system according to any one of claims 8 to 11.

13. The engine and a dump body having a flow path through which exhaust gas from the engine flows; and the state estimation system according to any one of claims 1 to 12. Dump truck.

14. A state estimation method for a dump truck including an engine, a dump body having a flow path through which exhaust gas discharged from the engine flows, and a load being loaded thereon, Detecting a flow rate of the exhaust gas flowing into the flow path; Detecting the temperature of the exhaust gas flowing into the flow path; acquiring an exhaust gas flow rate indicative of detection data of the exhaust gas flow rate; acquiring an exhaust gas temperature indicating detection data of the temperature of the exhaust gas; and estimating a body temperature indicating a temperature of a predetermined portion on an inner surface of the dump body that contacts the load based on the exhaust gas flow rate and the exhaust gas temperature. State estimation methods.

15. and determining whether or not a dump operation of the dump body is appropriate based on the body temperature. The state estimation method according to claim 14.

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