System and method for evaluating performance of work machine

Abstract

This system is provided with an actual charge pressure acquisition unit, a target torque acquisition unit, an engine rotation speed acquisition unit, a charge pressure estimation unit, a charge pressure correction unit, and a deviation degree calculation unit. The actual charge pressure acquisition unit acquires an actual charge pressure. The target torque acquisition unit acquires a target output torque of an engine. The engine rotation speed acquisition unit acquires an actual rotation speed of the engine. The charge pressure estimation unit calculates an estimated charge pressure on the basis of the target output torque and the actual rotation speed. The charge pressure correction unit acquires, as a first torque change amount, a change amount of a predetermined correction parameter for changing the target output torque. The charge pressure correction unit corrects the estimated charge pressure on the basis of the first torque change amount. The deviation degree calculation unit calculates a deviation degree between the actual charge pressure and the corrected estimated charge pressure.

Description

System and method for assessing work machine performance

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to systems and methods for assessing the performance of a work machine.

[0002] Conventionally, there are known methods for evaluating the performance of a turbocharger based on the degree of deviation between the actual charge pressure of the turbocharger and an estimated charge pressure. For example, a fault detection device disclosed in Patent Document 1 calculates an estimated value of the charge pressure based on the engine rotation speed and the pump load of the hydraulic pump. The fault detection device then determines a fault in the turbocharger based on the deviation between the estimated value of the charge pressure and the measured value of the charge pressure.

[0003] JP 2013-184512 A

[0004] When estimating the charge pressure as described above, it is possible to estimate the charge pressure accurately by calculating the charge pressure using data acquired when the engine is stable. Therefore, it is desirable to calculate the charge pressure using data acquired when a predetermined condition is satisfied. Furthermore, by making the predetermined condition stricter, the accuracy of the charge pressure estimation can be further improved.

[0005] However, in work machines used at work sites such as mines, it is rare that the charge pressure can be calculated in a stable state. Therefore, if attempts are made to improve the accuracy of charge pressure estimation by tightening the specified conditions, the amount of data that can be used for performance evaluation will be reduced. Therefore, it is not easy to improve the accuracy of performance evaluation. An object of the present disclosure is to accurately calculate the deviation degree of charge pressure in a work machine.

[0006] A system according to a first aspect of the present disclosure is a system for evaluating the performance of a work machine. The work machine includes an engine and a turbocharger connected to the engine. The system according to the first aspect includes an actual charge pressure acquisition unit, a target torque acquisition unit, an engine rotation speed acquisition unit, a charge pressure estimator, a charge pressure correction unit, and a deviation calculation unit. The actual charge pressure acquisition unit acquires the actual charge pressure of the turbocharger. The target torque acquisition unit acquires the target output torque of the engine. The engine rotation speed acquisition unit acquires the actual rotation speed of the engine. The charge pressure estimator calculates an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotation speed of the engine. The charge pressure correction unit acquires, as a first torque change amount, a change amount of a predetermined correction parameter that changes the target output torque of the engine. The charge pressure correction unit corrects the estimated charge pressure based on the first torque change amount. The deviation calculation unit calculates the deviation amount between the actual charge pressure and the corrected estimated charge pressure.

[0007] A system according to a second aspect of the present disclosure is a system for evaluating the performance of a work machine. The work machine includes an engine and a turbocharger connected to the engine. The system according to the second aspect includes an actual charge pressure acquisition unit, a target torque acquisition unit, an engine rotation speed acquisition unit, a charge pressure estimator, a charge pressure correction unit, and a deviation calculation unit. The actual charge pressure acquisition unit acquires the actual charge pressure of the turbocharger. The target torque acquisition unit acquires the target output torque of the engine. The engine rotation speed acquisition unit acquires the actual rotation speed of the engine. The charge pressure estimator calculates an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotation speed of the engine. The charge pressure correction unit acquires a first rotation speed change amount indicating the amount of change in the actual rotation speed of the engine. The charge pressure correction unit corrects the estimated charge pressure based on the first rotation speed change amount. The deviation calculation unit calculates the deviation amount between the actual charge pressure and the corrected estimated charge pressure.

[0008] A method according to a third aspect of the present disclosure is a method for evaluating the performance of a work machine. The work machine includes an engine and a turbocharger connected to the engine. The method according to the third aspect includes acquiring an actual charge pressure of the turbocharger, acquiring a target output torque of the engine, acquiring an actual rotational speed of the engine, calculating an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotational speed of the engine, acquiring a change amount of a predetermined correction parameter that changes the target output torque of the engine as a first torque change amount, correcting the estimated charge pressure based on the first torque change amount, and calculating a deviation between the actual charge pressure and the corrected estimated charge pressure.

[0009] A method according to a fourth aspect of the present disclosure is a method for evaluating performance of a work machine. The work machine includes an engine and a turbocharger connected to the engine. The method according to the fourth aspect includes acquiring an actual charge pressure of the turbocharger, acquiring a target output torque of the engine, acquiring an actual rotational speed of the engine, calculating an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotational speed of the engine, acquiring a first rotational speed change amount that indicates an amount of change in the actual rotational speed of the engine, correcting the estimated charge pressure based on the first rotational speed change amount, and calculating a deviation between the actual charge pressure and the corrected estimated charge pressure.

[0010] According to the present disclosure, in a work machine, the degree of deviation of the charge pressure can be calculated with high accuracy.

[0011] Fig. 1 is a perspective view of a work machine according to an embodiment; Fig. 2 is a block diagram showing the configuration of a work machine and a system for evaluating the performance of a work machine; Fig. 3 is a table showing the configuration of machine data; Fig. 4 is a block diagram showing the configuration of a server; Fig. 5 is a flowchart showing a process for generating judgment data for evaluating performance; Fig. 6 is a diagram showing an example of charge pressure estimation data;

[0012] An embodiment will now be described with reference to the drawings. Fig. 1 is a perspective view of a work machine 1 according to the embodiment. The work machine 1 according to the embodiment is a dump truck. As shown in Fig. 1, the work machine 1 comprises a vehicle body 2 and a traveling device 3. The vehicle body 2 includes a bed 6 and a driver's cab 7. The traveling device 3 is attached to the vehicle body 2. The traveling device 3 includes traveling wheels 4, 5.

[0013] Figure 2 is a block diagram showing the configuration of a work machine 1 and a system for evaluating the performance of the work machine 1. As shown in Figure 2, the work machine 1 is equipped with an engine 11, a PTO (power take-off) 12, a torque converter 13, and a transmission 14. The engine 11 is, for example, a diesel engine. A fuel injection device 15 and a turbocharger 18 are connected to the engine 11. The fuel injection device 15 injects fuel into the engine 11. The turbocharger 18 includes, for example, a turbine. The turbocharger 18 compresses intake air and supplies it to the engine 11.

[0014] A radiator 17 is connected to the engine 11 via a cooling pipe 16. The radiator 17 cools the coolant of the engine 11. The torque converter 13 is connected to the engine 11 via a PTO 12. The torque converter 13 transmits driving force from the engine 11 to a transmission 14.

[0015] The transmission 14 is connected to the torque converter 13. The transmission 14 transmits driving force from the torque converter 13 to the traveling device 3. This drives the traveling device 3, causing the work machine 1 to travel. The transmission 14 includes a plurality of speed change gears, a forward gear, a reverse gear, and a clutch. The clutch switches the engagement of each gear. The transmission 14 is capable of switching between a plurality of speed stages by switching the engagement of the plurality of speed change gears.

[0016] The work machine 1 includes a hydraulic pump 19 and an actuator 20. The hydraulic pump 19 is connected to the engine 11 via the PTO 12. The hydraulic pump 19 is driven by the engine 11 to discharge hydraulic oil. The actuator 20 is driven by the hydraulic oil from the hydraulic pump 19. The actuator 20 includes, for example, a steering actuator for steering the running wheels 4. Note that while only one hydraulic pump 19 is shown in FIG. 2, the work machine 1 may be equipped with multiple hydraulic pumps. Although only one actuator 20 is shown in FIG. 2, the work machine 1 may be equipped with multiple actuators.

[0017] The work machine 1 is equipped with an accelerator operation device 21, an FR operation device 22, and a steering operation device 23. The accelerator operation device 21 can be operated by an operator to adjust the vehicle speed of the work machine 1. The accelerator operation device 21 includes, for example, an accelerator pedal. Alternatively, the accelerator operation device 21 may include a lever or a switch. The accelerator operation device 21 outputs an accelerator operation signal that indicates operation of the accelerator operation device 21.

[0018] The FR operation device 22 can be operated by an operator to switch between forward and reverse travel of the work machine 1. The FR operation device 22 includes, for example, an FR lever. Alternatively, the FR operation device 22 may include a switch. The FR operation device 22 outputs an FR operation signal that indicates an operation to the FR operation device 22.

[0019] The steering operation device 23 can be operated by an operator to steer the work machine 1. The steering operation device 23 includes, for example, a steering wheel. Alternatively, the steering operation device 23 may include a lever or a switch. The steering operation device 23 outputs a steering operation signal that indicates an operation to the steering operation device 23.

[0020] The work machine 1 includes an engine rotation speed sensor 24 and an output rotation speed sensor 25. The engine rotation speed sensor 24 detects the actual rotation speed of the engine 11. The output rotation speed sensor 25 detects the output rotation speed of the transmission 14.

[0021] The work machine 1 includes a coolant temperature sensor 26 and a charge pressure sensor 27. The coolant temperature sensor 26 detects the temperature of the coolant in the engine 11. The charge pressure sensor 27 detects the actual charge pressure of the turbocharger 18. The work machine 1 is equipped with an atmospheric pressure sensor 28 and an outside air temperature sensor 29. The atmospheric pressure sensor 28 detects the atmospheric pressure. The outside air temperature sensor 29 detects the outside air temperature.

[0022] The work machine 1 is equipped with a controller 30. The controller 30 controls the work machine 1. The controller 30 includes a storage device 31 and a processor 32. The storage device 31 includes memory such as RAM and ROM. The storage device 31 may include storage such as an HDD or SSD. The storage device 31 stores programs and data for controlling the work machine 1. The processor 32 is, for example, a CPU. The processor 32 executes processing for controlling the work machine 1 in accordance with the programs and data.

[0023] The controller 30 acquires the actual rotational speed of the engine 11 from the engine rotational speed sensor 24. The controller 30 acquires the output rotational speed of the transmission 14 from the output rotational speed sensor 25. The controller 30 acquires the actual charge pressure of the turbocharger 18 from the charge pressure sensor 27. The controller 30 acquires the temperature of the coolant of the engine 11 from the coolant temperature sensor 26. The controller 30 acquires the atmospheric pressure from the atmospheric pressure sensor 28. The controller 30 acquires the outside air temperature from the outside air temperature sensor 29.

[0024] The controller 30 receives an accelerator operation signal from the accelerator operation device 21. The controller 30 determines a target rotation speed of the engine 11 in response to the accelerator operation signal. The controller 30 controls the amount of fuel injected from the fuel injection device 15 in response to the accelerator operation signal. Note that the amount of fuel injected from the fuel injection device 15 may be controlled directly in response to the operation of the accelerator operation device 21, without relying on the controller 30.

[0025] The controller 30 receives an FR operation signal from the FR operation device 22. In response to the FR operation signal, the controller 30 switches the transmission 14 between forward and reverse. Note that the transmission 14 may be switched between forward and reverse directly in response to the operation of the FR operation device 22, without relying on the controller 30.

[0026] The controller 30 switches the speed stage of the transmission 14 in accordance with the vehicle speed or the actual rotation speed of the engine 11. The controller 30 calculates the vehicle speed from the output rotation speed of the transmission 14, for example.

[0027] The controller 30 receives a steering operation signal from the steering operation device 23. In response to the steering operation signal, the controller 30 controls the actuator 20 to change the steering angle of the running wheels 4. Note that the actuator 20 may be controlled directly in response to the operation of the steering operation device 23, without relying on the controller 30.

[0028] The work machine 1 is equipped with a communication device 33. The communication device 33 is communicably connected to the controller 30. The communication device 33 communicates with a server 40 external to the work machine 1 via wireless communication. The server 40 remotely monitors the state of the work machine 1 using machine data indicating the state of the work machine 1.

[0029] The server 40 includes a storage device 41 and a processor 42. The storage device 41 includes memory such as RAM and ROM. The storage device 41 may include storage such as an HDD or SSD. The storage device 41 stores programs and data for monitoring the state of the work machine 1. The processor 42 is, for example, a CPU. The processor 42 executes processing for monitoring the state of the work machine 1 in accordance with the programs and data.

[0030] The controller 30 of the work machine 1 transmits machine data to the server 40 via the communication device 33. FIG. 3 is a table showing the configuration of the machine data. As shown in FIG. 3, the machine data includes the actual rotation speed of the engine 11, the target output torque of the engine 11, the atmospheric pressure, the outside air temperature, the temperature of the coolant for the engine 11, and the operating time. The target output torque of the engine 11 is calculated based on the rotation speed of the engine 11 and the fuel injection amount. The operating time is, for example, the integrated value of the time while the engine 11 is being driven. The controller 30 counts and records the operating time.

[0031] The work machine 1 samples the above-mentioned data at predetermined sampling intervals and stores it as machine data in the storage device 31. The work machine 1 transmits the accumulated machine data to the server 40 at predetermined transmission timing. For example, the work machine 1 transmits the accumulated machine data to the server 40 when it enters a communication area such as a wireless LAN. The server 40 generates judgment data for evaluating the performance of the work machine 1 based on the received machine data. The processing by the server 40 for generating judgment data for evaluating performance will be described below.

[0032] Fig. 4 is a block diagram showing the configuration of server 40. As shown in Fig. 4, server 40 includes a mechanical data receiving unit 51, an actual charge pressure acquiring unit 52, a target torque acquiring unit 53, an engine rotation speed acquiring unit 54, a charge pressure estimating unit 55, a charge pressure correcting unit 56, a deviation calculating unit 57, a filtering unit 58, a judgment data generating unit 59, and a judgment data output unit 60. The mechanical data receiving unit 51, the actual charge pressure acquiring unit 52, the target torque acquiring unit 53, the engine rotation speed acquiring unit 54, the charge pressure estimating unit 55, the charge pressure correcting unit 56, the deviation calculating unit 57, the filtering unit 58, the judgment data generating unit 59, and the judgment data output unit 60 are realized by processor 42 of server 40.

[0033] 5 is a flowchart showing the process of generating judgment data for evaluating performance. As shown in Fig. 5, in step S101, the machine data receiving unit 51 receives machine data. The machine data receiving unit 51 receives the above-mentioned machine data from the controller 30 of the work machine 1.

[0034] In step S102, the actual charge pressure acquisition unit 52 acquires the actual charge pressure of the turbocharger 18. The actual charge pressure acquisition unit 52 acquires the actual charge pressure from the machine data received from the controller 30 of the work machine 1. In step S103, the target torque acquisition unit 53 acquires the target output torque of the engine 11. The target torque acquisition unit 53 acquires the target output torque of the engine 11 from the machine data received from the controller 30 of the work machine 1. In step S104, the engine rotation speed acquisition unit 54 acquires the actual rotation speed of the engine 11. The engine rotation speed acquisition unit 54 acquires the actual rotation speed of the engine 11 from the machine data received from the controller 30 of the work machine 1.

[0035] In step S105, the charge pressure estimation unit 55 calculates an estimated charge pressure. The charge pressure estimation unit 55 calculates an estimated charge pressure from the target output torque of the engine 11 and the actual rotational speed of the engine 11 by referring to the charge pressure estimation data. FIG. 6 is a diagram showing an example of the charge pressure estimation data. The charge pressure estimation data defines the relationship between the estimated charge pressure and the target output torque of the engine 11 and the actual rotational speed of the engine 11. The charge pressure estimation data is, for example, a map that defines the relationship between the estimated charge pressure and the target output torque of the engine 11 and the actual rotational speed of the engine 11. However, the charge pressure estimation data is not limited to a map and may be expressed in other forms such as a mathematical formula or a table. The charge pressure estimation data is obtained in advance by simulation, bench testing, or the like, and is stored in the storage device 41.

[0036] In step S106, the charge pressure correction unit 56 corrects the estimated charge pressure calculated in step S105. The charge pressure correction unit 56 corrects the estimated charge pressure using the following equation (1). Pcp_corr is the corrected estimated charge pressure. Pcp(Tr,S) is the estimated charge pressure calculated in step S105 from the target output torque Tr of the engine 11 and the actual rotation speed S of the engine 11. Corr1(ΔTr1, ΔTr2, ΔS1, ΔS2) is a first correction term for the estimated charge pressure based on the target output torque of the engine 11 and the actual rotation speed of the engine 11.

[0037] ΔTr1 and ΔTr2 indicate the amount of change in the target output torque Tr of the engine 11. That is, the charge pressure correction unit 56 corrects the estimated charge pressure based on the amount of change in the target output torque Tr of the engine 11. ΔTr1 is the first amount of torque change. ΔTr2 is the second amount of torque change. The first amount of torque change ΔTr1 is the amount of change in the target output torque of the engine 11 during a first time period. The second amount of torque change ΔTr2 is the amount of change in the target output torque of the engine 11 during a second time period. The second time period is longer than the first time period. For example, the first time period is 1 second, and the second time period is 2 seconds. However, the first time period and the second time period are not limited to these periods and may be changed.

[0038] ΔS1 and ΔS2 are amounts of change in the actual rotational speed of the engine 11. That is, the charge pressure correction unit 56 corrects the estimated charge pressure based on the amount of change in the actual rotational speed of the engine 11. ΔS1 is a first amount of change in rotational speed. ΔS2 is a second amount of change in rotational speed. The first amount of change in rotational speed ΔS1 is the amount of change in the actual rotational speed of the engine 11 during a first time period. The second amount of change in rotational speed ΔS2 is the amount of change in the actual rotational speed of the engine 11 during a second time period.

[0039] In detail, the first correction term Corr1(ΔTr1, ΔTr2, ΔS1, ΔS2) is expressed by the following formula (2). In formula (2), a1 to a6 are predetermined coefficients. a1 to a6 are obtained in advance by simulation, bench testing, or the like, and stored in the storage device 41. Corr2(P_atm, Te_atm) is a second correction term for the estimated charge pressure based on the atmospheric pressure and the outside temperature. P_atm is the atmospheric pressure. Te_atm is the outside temperature. In other words, the charge pressure correction unit 56 corrects the estimated charge pressure based on the atmospheric pressure and the outside temperature. The second correction term Corr2(P_atm, Te_atm) is expressed by the following equation (3). Pcp_rated is the charge pressure at the rated point. Pcp_rated is obtained in advance by simulation, bench testing, etc., and is stored in the storage device 41. P_standard is the standard atmospheric pressure. Te_standard is the standard temperature. P_standard and Te_standard are stored in the storage device 41. b1 and b2 are predetermined coefficients. b1 and b2 are obtained in advance by simulation, bench testing, etc., and are stored in the storage device 41. Pcp' is the estimated charge pressure corrected by the first correction term. That is, Pcp' is expressed by the following equation (4). In step S107, the deviation calculation unit 57 calculates the deviation between the actual charge pressure and the corrected estimated charge pressure. The deviation calculation unit 57 calculates the deviation using the following equation (5). Pcr is the actual charge pressure. The deviation Dev_charge is the ratio of the difference between the actual charge pressure and the corrected estimated charge pressure to the corrected estimated charge pressure. The deviation Dev_charge is expressed as a percentage. In step S108, the filtering unit 58 filters the deviation degrees calculated in step S107. The filtering unit 58 selects deviation degrees that satisfy predetermined conditions. The predetermined conditions include the following first to eleventh conditions.

[0040] The first condition is that the actual rotation speed of the engine 11 is equal to or greater than a predetermined lower limit. The second condition is that the actual rotation speed of the engine 11 one hour ago is equal to or greater than a predetermined lower limit. The third condition is that the actual rotation speed of the engine 11 two hours ago is equal to or greater than a predetermined lower limit. The fourth condition is that the target output torque of the engine is equal to or greater than a predetermined lower limit. The fifth condition is that the target output torque of the engine one hour ago is equal to or greater than a predetermined lower limit. The sixth condition is that the target output torque of the engine two hours ago is equal to or greater than a predetermined lower limit. The first to sixth conditions are set in order to exclude data acquired when the engine is idling, for example.

[0041] The seventh condition is that the first rotation speed change amount is within a predetermined range. The eighth condition is that the second rotation speed change amount is within a predetermined range. The ninth condition is that the first torque change amount is within a predetermined range. The tenth condition is that the second torque change amount is within a predetermined range. The seventh to tenth conditions are set in order to exclude data with a large amount of change that exceeds the range in which accurate correction is possible. The eleventh condition is that the temperature of the engine coolant is within a predetermined range. The eleventh condition is set in order to exclude data when the engine is not sufficiently warmed up.

[0042] The filtering unit 58 determines whether the first to eleventh conditions are satisfied based on the machine data described above. The filtering unit 58 selects deviation degrees that satisfy all of the first to eleventh conditions. The filtering unit 58 excludes deviation degrees that do not satisfy at least one of the first to eleventh conditions.

[0043] In step S109, the judgment data generation unit 59 generates judgment data. The judgment data generation unit 59 generates judgment data for evaluating performance by recording the deviation degrees selected in step S108 in chronological order. For example, the judgment data generation unit 59 calculates an average value of the deviation degrees for each predetermined operating time, and generates time-series data of the average deviation degrees as judgment data.

[0044] In step S110, the determination data output unit 60 outputs the determination data. For example, the determination data output unit 60 transmits the determination data to a computer of the user of the work machine 1. Alternatively, the determination data output unit 60 may cause the determination data to be displayed on a display by an application for managing the work machine 1.

[0045] The server 40 may evaluate the performance of the turbocharger 18 based on the judgment data. The judgment data output unit 60 may transmit the evaluation result of the performance of the turbocharger 18, which is judged based on the judgment data, to a computer of the user of the working machine 1. For example, the server 40 may determine that a sudden performance degradation has occurred in the turbocharger 18 when the degree of deviation in the judgment data has suddenly decreased or increased. The server 40 may determine that a performance degradation due to aging has occurred in the turbocharger 18 when the degree of deviation in the judgment data is equal to or less than a predetermined threshold value.

[0046] In the system for evaluating the performance of the work machine 1 according to the present embodiment described above, the estimated charge pressure is corrected based on the amount of change in the target output torque of the engine 11 and the amount of change in the actual rotation speed of the engine 11. Therefore, the estimated charge pressure is corrected taking into account fluctuations in the load on the work machine 1 or changes in the operating state of the engine 11 in response to operation of the accelerator operating device 21. This allows the degree of deviation to be calculated with high accuracy in the work machine 1.

[0047] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the gist of the invention.

[0048] The work machine 1 is not limited to a dump truck, and may be other machines such as a bulldozer, shovel, wheel loader, or grader. The dump truck is not limited to a rigid dump truck, and may be an articulated dump truck. The traveling device 3 is not limited to running wheels 4, and may include crawlers. The work machine 1 may be equipped with multiple controllers. The control by the controller 30 of the work machine 1 described above may be distributed and executed by multiple controllers.

[0049] The work machine 1 may be capable of being remotely operated. In that case, the accelerator operation device 21, the FR operation device 22, and the steering operation device 23 may be located outside the work machine 1. The work machine 1 may be capable of autonomous travel. In that case, the accelerator operation signal, the FR operation signal, and the steering operation signal may be automatically generated by the controller 30.

[0050] The processing for generating the judgment data described above may be executed by the controller 30 of the work machine 1. Alternatively, the processing for generating the judgment data described above may be executed in a distributed manner between the controller 30 of the work machine 1 and the server 40. The performance of the turbocharger 18 may be evaluated by the controller 30 of the work machine 1. The controller 30 may cause the evaluation of the performance of the turbocharger 18 to be displayed on a display of the work machine 1.

[0051] The process for generating the judgment data is not limited to that described in the above embodiment and may be modified. For example, the correction parameter for correcting the estimated charge pressure is not limited to the target output torque of the engine 11. The correction parameter may be the fuel injection amount, the instantaneous fuel consumption amount, the operation amount of the accelerator operation device 21, or the throttle opening. The first torque change amount and the second torque change amount may be the change amounts of these correction parameters.

[0052] The estimated charge pressure may be corrected only by the target output torque of the engine 11, regardless of the actual rotation speed of the engine 11. The estimated charge pressure may be corrected only by the actual rotation speed of the engine 11, regardless of the target output torque of the engine 11. Correction of the estimated charge pressure based on atmospheric pressure may be omitted. Correction of the estimated charge pressure based on outside air temperature may be omitted.

[0053] The deviation degree is not limited to that in the above embodiment and may be changed. For example, the deviation degree may be the ratio between the actual charge pressure and the corrected estimated charge pressure. Alternatively, the deviation degree may be the deviation between the actual charge pressure and the corrected estimated charge pressure. The predetermined conditions for filtering the deviation degree are not limited to those in the above embodiment and may be changed. Some of the first to eleventh conditions described above may be omitted or changed. For example, the predetermined conditions may include filtering conditions based on the fuel injection amount, instantaneous fuel consumption, the operation amount of the accelerator operation device 21, or the throttle opening. The machine data is not limited to those in the above embodiment and may be changed.

[0054] According to the present disclosure, in a work machine, the degree of deviation of the charge pressure can be calculated with high accuracy.

[0055] 1: Work machine 11: Engine 18: Turbocharger 52: Actual charge pressure acquisition unit 53: Target torque acquisition unit 54: Engine rotation speed acquisition unit 55: Charge pressure estimation unit 56: Charge pressure correction unit 57: Deviation calculation unit 58: Filtering unit 59: Determination data generation unit

Claims

1. A system for evaluating the performance of a working machine including an engine and a turbocharger connected to the engine, comprising: an actual charge pressure acquisition unit that acquires an actual charge pressure of the turbocharger; a target torque acquisition unit that acquires a target output torque of the engine; an engine rotation speed acquisition unit that acquires an actual rotation speed of the engine; a charge pressure estimation unit that calculates an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotation speed of the engine; a charge pressure correction unit that acquires an amount of change in a predetermined correction parameter that changes the target output torque of the engine as a first torque change amount and corrects the estimated charge pressure based on the first torque change amount; and a deviation calculation unit that calculates a deviation amount between the actual charge pressure and the corrected estimated charge pressure.

2. The system of claim 1, wherein said predetermined correction parameter is said target output torque.

3. The system of claim 2, wherein said first torque change amount is a change amount of said target output torque during a first time period.

4. The system according to claim 3, wherein the charge pressure correction unit obtains a second torque change amount indicating an amount of change in the target output torque during a second time period that is longer than the first time period, and corrects the estimated charge pressure based on the first torque change amount and the second torque change amount.

5. The system according to claim 1, wherein the charge pressure correction unit obtains a first rotation speed change amount indicating an amount of change in an actual rotation speed of the engine, and corrects the estimated charge pressure based on the first rotation speed change amount.

6. The system of claim 5, wherein said first rotational speed change is a change in actual rotational speed of said engine during a first period of time.

7. The system described in claim 6, wherein the charge pressure correction unit obtains a second rotational speed change amount indicating an amount of change in an actual rotational speed of the engine during a second time period that is longer than the first time period, and corrects the estimated charge pressure based on the first rotational speed change amount and the second rotational speed change amount.

8. The system according to claim 1, wherein the charge pressure correction unit obtains an atmospheric pressure and corrects the estimated charge pressure based on the atmospheric pressure.

9. The system according to claim 1, wherein the charge pressure correction unit obtains an outside air temperature and corrects the estimated charge pressure based on the outside air temperature.

10. The system according to claim 1, further comprising a filtering unit that selects the deviation degree acquired when a predetermined condition is satisfied, the predetermined condition including a target output torque of the engine being within a predetermined range.

11. The system according to claim 1, further comprising a judgment data generation unit that generates data for evaluating the performance by recording the deviation in chronological order.

12. A system for evaluating the performance of a working machine including an engine and a turbocharger connected to the engine, comprising: an actual charge pressure acquisition unit that acquires an actual charge pressure of the turbocharger; a target torque acquisition unit that acquires a target output torque of the engine; an engine rotation speed acquisition unit that acquires an actual rotation speed of the engine; a charge pressure estimation unit that calculates an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotation speed of the engine; a charge pressure correction unit that acquires a first rotation speed change amount indicating an amount of change in the actual rotation speed of the engine and corrects the estimated charge pressure based on the first rotation speed change amount; and a deviation calculation unit that calculates a deviation amount between the actual charge pressure and the corrected estimated charge pressure.

13. The system of claim 12, wherein the first rotational speed change is a change in actual rotational speed of the engine during a first period of time.

14. The system described in claim 13, wherein the charge pressure correction unit obtains a second rotational speed change amount indicating an amount of change in an actual rotational speed of the engine during a second time period that is longer than the first time period, and corrects the estimated charge pressure based on the first rotational speed change amount and the second rotational speed change amount.

15. The system according to claim 12, further comprising a filtering unit that selects the deviation degree acquired when a predetermined condition is satisfied, the predetermined condition including that the first rotation speed change amount is within a predetermined range.

16. The system according to claim 12, wherein the charge pressure correction unit obtains an atmospheric pressure and corrects the estimated charge pressure based on the atmospheric pressure.

17. The system according to claim 12, wherein the charge pressure correction unit obtains an outside air temperature and corrects the estimated charge pressure based on the outside air temperature.

18. The system according to claim 12, further comprising a judgment data generating unit that generates data for evaluating the performance by recording the deviation in chronological order.

19. A method for evaluating the performance of a working machine including an engine and a turbocharger connected to the engine, comprising: acquiring an actual charge pressure of the turbocharger; acquiring a target output torque of the engine; acquiring an actual rotational speed of the engine; calculating an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotational speed of the engine; acquiring an amount of change in a predetermined correction parameter that changes the target output torque of the engine as a first torque change amount, and correcting the estimated charge pressure based on the first torque change amount; and calculating a deviation between the actual charge pressure and the corrected estimated charge pressure.

20. A method for evaluating performance of a working machine including an engine and a turbocharger connected to the engine, comprising: acquiring an actual charge pressure of the turbocharger; acquiring a target output torque of the engine; acquiring an actual rotational speed of the engine; calculating an estimated charge pressure of the turbocharger based on the target output torque of the engine and the actual rotational speed of the engine; acquiring a first rotational speed change amount indicating an amount of change in the actual rotational speed of the engine, and correcting the estimated charge pressure based on the first rotational speed change amount; and calculating a deviation between the actual charge pressure and the corrected estimated charge pressure.

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