Pinion gear temperature estimation apparatus and pinion gear temperature estimation program

Abstract

To improve the estimation accuracy of the temperature of a pinion gear in a planetary gear mechanism.SOLUTION: A target of a pinion gear temperature estimation apparatus is a power transmission device of a vehicle, including a planetary gear mechanism. The pinion gear temperature estimation apparatus comprises an execution device and a storage device. The storage device stores a relationship regulation model that outputs an index value indicating the temperature of the pinion gear of the planetary gear mechanism when a plurality of types of input data is input. Here, the relationship regulation model is generated in advance by machine learning. The plurality of types of input data includes time-series data of torque input to the planetary gear mechanism, time-series data of an oil temperature that is the temperature of oil for lubricating each portion including the planetary gear mechanism in the power transmission device, and a degree of deterioration of the oil. The execution device acquires the plurality of types of input data (S61). The execution device outputs the index value by inputting the acquired plurality of types of input data to the relationship regulation model (S63).SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a pinion gear temperature estimation device and a pinion gear temperature estimation program.

Background Art

[0002] The vehicle of Patent Document 1 includes an internal combustion engine, a first motor generator, a second motor generator, a power transmission device, and a plurality of drive wheels. The power transmission device transmits power from the internal combustion engine or the like to the plurality of drive wheels. Specifically, the power transmission device includes a planetary gear mechanism and a reduction mechanism. The planetary gear mechanism includes a sun gear, a carrier, a ring gear, and a plurality of pinion gears. The carrier is connected to the crankshaft of the internal combustion engine. The sun gear is connected to the rotating shaft of the first motor generator. The ring gear is connected to the plurality of drive wheels via a reduction mechanism. Further, the ring gear is connected to the rotating shaft of the second motor generator. Each pinion gear meshes with the sun gear and the ring gear between the sun gear and the ring gear. And, for example, the power from the crankshaft of the internal combustion engine is transmitted to the pinion gear via the carrier. Further, the power transmission device stores oil for lubricating and cooling the planetary gear mechanism or the like.

[0003] The vehicle of Patent Document 1 includes a control device. The control device estimates the temperature of the pinion gear based on the rotational speed of the crankshaft, the torque of the crankshaft, the rotational speed of the pinion gear, and the temperature of the oil. And, when the temperature of the pinion gear is higher than a predetermined threshold value, the control device controls the internal combustion engine and the first motor generator so that the rotational speed of the pinion gear becomes lower.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In a power transmission device such as that of Patent Document 1, when the oil deteriorates, the viscosity and thermal conductivity of the oil change. Therefore, for example, even when the temperature of the oil is the same, a difference occurs in the cooling effect of the pinion gear by the oil according to the deterioration of the oil. In the estimation configuration described in Patent Document 1, since the deterioration of the oil is not considered, there is a risk that the estimation accuracy of the temperature of the pinion gear is low.

Means for Solving the Problems

[0006] The pinion gear temperature estimation device for solving the above problems targets a power transmission device of a vehicle including a planetary gear mechanism, and includes an execution device and a storage device. The storage device stores a relationship defining model that outputs an index value indicating the temperature of the pinion gear of the planetary gear mechanism when a plurality of types of input data are input. The plurality of types of input data include time-series data of torque input to the planetary gear mechanism, time-series data of oil temperature which is the temperature of oil lubricating each part including the planetary gear mechanism in the power transmission device, and the degree of deterioration of the oil. The execution device executes acquiring the plurality of types of input data and outputting the index value by inputting the acquired plurality of types of input data into the relationship defining model.

[0007] The pinion gear temperature estimation program for solving the above problems is applicable to a pinion gear temperature estimation device that targets a power transmission device of a vehicle equipped with a planetary gear mechanism and includes an execution device and a storage device. The storage device stores a relationship defining model that outputs an index value indicating the temperature of the pinion gear when a plurality of types of input data are input. The plurality of types of input data includes time series data of torque input to the planetary gear mechanism, time series data of oil temperature, which is the temperature of oil lubricating each part including the planetary gear mechanism in the power transmission device, and the degree of deterioration of the oil. The execution device is made to execute acquiring the plurality of types of input data and outputting the index value by inputting the acquired plurality of types of input data into the relationship defining model.

Effect of the Invention

[0008] According to the above configuration, the degree of deterioration of the oil is included as a plurality of types of input data of the relationship defining model. Therefore, the cooling effect of the oil according to the degree of deterioration of the oil is reflected in the index value output from the relationship defining model. Thereby, the estimation accuracy of the temperature of the pinion gear can be improved by taking into account the degree of deterioration of the oil.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0010] <Schematic Configuration of Vehicle> Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 to 5. First, the schematic configuration of the vehicle 100 will be described. In the following, the description will be based on the up-down, front-rear, and left-right directions of the vehicle 100.

[0011] As shown in FIG. 1, the vehicle 100 includes a spark-ignition internal combustion engine 10. Further, the vehicle 100 includes a first motor generator 71 and a second motor generator 72 that serve as parts of a transaxle 30 described later and have both functions of an electric motor and a generator. Therefore, the vehicle 100 is a so-called hybrid vehicle.

[0012] The internal combustion engine 10 includes a crankshaft 15. The crankshaft 15 rotates due to the combustion of a fuel and intake air mixture in a cylinder (not shown). The vehicle 100 includes a damper 20, a transaxle 30, a plurality of drive shafts 26, and a plurality of drive wheels 27. The crankshaft 15 of the internal combustion engine 10 is connected to the transaxle 30 via the damper 20. The damper 20 attenuates fluctuations in torque transmitted from the crankshaft 15 of the internal combustion engine 10 and transmits it to the transaxle 30.

[0013] The transaxle 30 includes a case 35, a planetary gear mechanism 40, a reduction mechanism 50, a differential 60, a first motor generator 71, a second motor generator 72, and an oil supply device 80.

[0014] The case 35 houses the planetary gear mechanism 40, the reduction mechanism 50, the differential 60, the first motor generator 71, the second motor generator 72, and the oil supply device 80. Further, the case 35 stores oil for lubricating and cooling each component housed in the case 35, for example, the planetary gear mechanism 40.

[0015] The planetary gear mechanism 40 includes a sun gear 41, a ring gear 42, a plurality of pinion gears 43, and a carrier 44. The shape of the sun gear 41 is generally disk-shaped. The sun gear 41 has external teeth. The sun gear 41 is connected to the rotating shaft 71A of the first motor generator 71. The shape of the ring gear 42 is generally annular. The ring gear 42 has internal teeth and external teeth. The ring gear 42 is positioned coaxially with the sun gear 41. The external teeth of the ring gear 42 are connected to the speed reduction mechanism 50. Each pinion gear 43 is positioned between the external teeth of the sun gear 41 and the internal teeth of the ring gear 42. Each pinion gear 43 meshes with both the external teeth of the sun gear 41 and the internal teeth of the ring gear 42. The carrier 44 supports the pinion gears 43. The pinion gears 43 are rotatable about their own axes and are revolvable by rotating together with the carrier 44. The carrier 44 is connected to the crankshaft 15 via the damper 20.

[0016] When the power from the internal combustion engine 10 is input to the carrier 44, the power from the internal combustion engine 10 is distributed into the power to the sun gear 41 and the power to the ring gear 42. Then, when the power from the internal combustion engine 10 transmitted via the sun gear 41 is input to the rotating shaft 71A of the first motor generator 71, the first motor generator 71 functions as a generator.

[0017] On the other hand, when the first motor generator 71 functions as an electric motor, the power from the first motor generator 71 is input to the sun gear 41. Then, the power from the first motor generator 71 input to the sun gear 41 is distributed into the power to the carrier 44 and the power to the ring gear 42. Then, when the power from the first motor generator 71 transmitted via the carrier 44 is input to the crankshaft 15 of the internal combustion engine 10, the crankshaft 15 of the internal combustion engine 10 rotates.

[0018] The speed reduction mechanism 50 includes a first gear 51 and a second gear 52. The shape of the first gear 51 is generally disk-shaped. The first gear 51 has external teeth. The first gear 51 of the speed reduction mechanism 50 meshes with the external teeth of the ring gear 42 of the planetary gear mechanism 40. The shape of the second gear 52 is generally disk-shaped. The second gear 52 has external teeth. The second gear 52 is positioned coaxially with the first gear 51. The second gear 52 is connected to the first gear 51 and rotates integrally with the first gear 51. The number of external teeth of the second gear 52 is less than the number of external teeth of the first gear 51. Therefore, the speed reduction mechanism 50 can output a reduced rotational speed compared to the rotational speed input to the speed reduction mechanism 50.

[0019] The differential 60 includes a ring gear 61 and a differential case 62. The shape of the ring gear 61 is generally disk-shaped. The ring gear 61 has external teeth. The ring gear 61 of the differential 60 meshes with the second gear 52 of the speed reduction mechanism 50. The differential case 62 is connected to the ring gear 61 and rotates integrally with the ring gear 61. The differential case 62 houses a plurality of gears (not shown). The plurality of gears are connected to the drive wheels 27 via the drive shaft 26. As a result, the differential 60 transmits the power input to the ring gear 61 to the left and right drive wheels 27 while allowing a difference in rotational speed to occur between the left and right drive wheels 27. In the present embodiment, the planetary gear mechanism 40, the speed reduction mechanism 50, the differential 60, and the case 35 constitute a power transmission device.

[0020] The second motor generator 72 includes a rotary shaft 72A and a connection gear 72B. The rotary shaft 72A is connected to the rotor of the second motor generator 72 and rotates integrally with the rotor. The connection gear 72B is connected to the rotary shaft 72A and rotates integrally with the rotary shaft 72A. The connection gear 72B meshes with the first gear 51 of the speed reduction mechanism 50.

[0021] When the second motor generator 72 functions as an electric motor, the power of the second motor generator 72 is transmitted to the drive wheels 27 via the speed reduction mechanism 50, the differential 60, and the drive shaft 26. As a result, the drive wheels 27 rotate by the power from the second motor generator 72. Therefore, the second motor generator 72 is a drive source of the vehicle 100. On the other hand, when the second motor generator 72 functions as a generator, a regenerative braking force corresponding to the power generation amount of the second motor generator 72 can be generated in the vehicle 100.

[0022] As shown in FIG. 1, the oil supply device 80 includes an oil pump 81 and an oil pipe 82. The oil pump 81 is connected to the ring gear 61 of the differential 60 and is driven by the power transmitted from the differential 60. That is, the oil pump 81 is a so-called mechanical oil pump. The oil pump 81 supplies oil to each component housed in the case 35, such as the planetary gear mechanism 40, via the oil pipe 82.

[0023] As shown in FIG. 2, the case 35 partitions a specific space A. The connecting gear 72B, the speed reduction mechanism 50, the planetary gear mechanism 40, and the differential 60 are located within the specific space A. In FIG. 2, the ring gear 42 of the planetary gear mechanism 40 is illustrated as a representative. The rotation axis 61Z of the ring gear 61 of the differential 60 is located below the rotation axis 72Z of the connecting gear 72B. The rotation axis 61Z of the ring gear 61 is located below the rotation axis 51Z of the first gear 51 in the speed reduction mechanism 50. The rotation axis 61Z of the ring gear 61 is located below the rotation axis 42Z of the ring gear 42 in the planetary gear mechanism 40. Therefore, among the connecting gear 72B, the speed reduction mechanism 50, the planetary gear mechanism 40, and the differential 60 within the specific space A, the differential 60 is located at the lowermost position. Although not shown in the figure, the case 35 partitions a plurality of spaces including the specific space A. Each space partitioned by the case 35 is arranged in the left-right direction of the vehicle 100, that is, in the thickness direction of the paper surface in FIG. 2. The specific space A is the space located at the right end of the vehicle 100 among the plurality of spaces partitioned by the case 35.

[0024] As shown in FIG. 1, the vehicle 100 includes a first inverter 86, a second inverter 87, and a battery 88. The battery 88 is a secondary battery. The first inverter 86 performs AC-DC power conversion between the first motor generator 71 and the battery 88. Further, the first inverter 86 adjusts the amount of power transfer between the first motor generator 71 and the battery 88. The second inverter 87 performs AC-DC power conversion between the second motor generator 72 and the battery 88. Further, the second inverter 87 adjusts the amount of power transfer between the second motor generator 72 and the battery 88.

[0025] As shown in FIG. 1, the vehicle 100 includes a cooling fan 89. In the present embodiment, the cooling fan 89 is built into a radiator (not shown). Further, the cooling fan 89 is located in the vicinity of the transaxle 30. The cooling fan 89 includes a fan 89A and a motor 89B. The rotation shaft of the motor 89B is connected to the fan 89A. Therefore, when the rotation shaft of the motor 89B rotates, the fan 89A rotates. When the fan 89A rotates, the cooling water circulating in the radiator and the transaxle 30 are cooled.

[0026] As shown in FIG. 1, the vehicle 100 includes an accelerator operation amount sensor 101, a vehicle speed sensor 102, and a crank angle sensor 103. Further, the vehicle 100 includes a first rotation speed sensor 104, a second rotation speed sensor 105, a first motor temperature sensor 106, a second motor temperature sensor 107, and an oil temperature sensor 108.

[0027] The accelerator operation amount sensor 101 detects an accelerator operation amount ACC, which is the operation amount of an accelerator pedal operated by a driver of the vehicle 100. The vehicle speed sensor 102 detects a vehicle speed SP, which is the speed of the vehicle 100. The crank angle sensor 103 detects a crank angle SC, which is the angular position of a crankshaft 15. The first rotation speed sensor 104 detects a first rotation speed NM1, which is the rotation speed of a rotation shaft 71A of a first motor generator 71. The second rotation speed sensor 105 detects a second rotation speed NM2, which is the rotation speed of a rotation shaft 72A of a second motor generator 72. The first motor temperature sensor 106 detects a first motor temperature TM1, which is the temperature of the first motor generator 71. In the present embodiment, the first motor temperature TM1 corresponds to the temperature of the first motor generator 71 connected to a sun gear 41 of a planetary gear mechanism 40. The second motor temperature sensor 107 detects a second motor temperature TM2, which is the temperature of the second motor generator 72. In the present embodiment, the second motor temperature TM2 corresponds to the temperature of the second motor generator 72 connected to a ring gear 42 of the planetary gear mechanism 40. The oil temperature sensor 108 detects an oil temperature TA, which is the temperature of oil stored in a case 35. In the present embodiment, the oil temperature TA corresponds to the temperature of the oil lubricating each part including the planetary gear mechanism 40 in a power transmission device.

[0028] As shown in FIG. 1, the vehicle 100 includes a control device 90. The control device 90 acquires various information from the accelerator operation amount sensor 101, the vehicle speed sensor 102, and the crank angle sensor 103. Further, the control device 90 acquires various information from the first rotation speed sensor 104, the second rotation speed sensor 105, the first motor temperature sensor 106, the second motor temperature sensor 107, and the oil temperature sensor 108. The control device 90 calculates an engine rotation speed NE, which is the rotation speed of the crankshaft 15, based on the crank angle SC.

[0029] The control device 90 includes an execution device 91 and a storage device 92. An example of the execution device 91 is a CPU. The storage device 92 includes a ROM that can only be read, a volatile RAM that can be read and written, and a non-volatile storage that can be read and written. The storage device 92 stores various programs and various data in advance. Specifically, the storage device 92 stores a control program 92A in advance as one of the various programs. Also, the storage device 92 stores a relationship definition model M in advance as one of the various data. The relationship definition model M describes the relationship between predetermined input data and an index value indicating the temperature of the pinion gear 43 of the planetary gear mechanism 40 in a form recognizable by the execution device 91. The relationship definition model M outputs an index value indicating the temperature of the pinion gear 43 of the planetary gear mechanism 40 when a plurality of types of input data are input. In the present embodiment, the relationship definition model M is generated in advance by machine learning. A specific description of the relationship definition model M will be given later. The execution device 91 executes various processes described later by executing the control program 92A stored in the storage device 92. In the present embodiment, the control device 90 is an example of a pinion gear temperature estimation device. Also, the control program 92A is an example of a pinion gear temperature estimation program.

[0030] The execution device 91 of the control device 90 calculates a target driving force, which is a target value of the driving force of the vehicle 100, based on the accelerator operation amount ACC and the vehicle speed SP. Subsequently, the execution device 91 determines the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 based on the target driving force. The execution device 91 controls the output of the internal combustion engine 10, the power running and regeneration of the first motor generator 71 and the second motor generator 72 based on the torque distribution of the internal combustion engine 10, the first motor generator 71, and the second motor generator 72. Specifically, the execution device 91 controls the internal combustion engine 10 by outputting a control signal to the internal combustion engine 10. Further, the execution device 91 controls the first motor generator 71 via the first inverter 86 by outputting a control signal to the first inverter 86. Furthermore, the execution device 91 controls the second motor generator 72 via the second inverter 87 by outputting a control signal to the second inverter 87.

[0031] The execution device 91 calculates a fan rotation speed NF, which is a target value of the rotation speed of the fan 89A, based on the operating condition of the internal combustion engine 10. Then, the execution device 91 outputs a control signal to the motor 89B according to the calculated fan rotation speed NF. As a result, the fan 89A is controlled according to the fan rotation speed NF.

[0032] The execution device 91 executes, for example, the following processing based on a pinion gear temperature TP, which is the temperature of the pinion gear 43 estimated by the estimation control described later. First, the execution device 91 determines whether the pinion gear temperature TP is higher than a predetermined specified temperature. Then, when the pinion gear temperature TP is higher than the specified temperature, the execution device 91 controls the internal combustion engine 10 and the first motor generator 71 so that the rotation speed of the pinion gear 43 decreases.

[0033] <Degradation degree calculation control> Next, with reference to FIG. 3, the deterioration degree calculation control executed by the control device 90 will be described. This deterioration degree calculation control is control for calculating the deterioration degree DD of the oil stored in the case 35. In the present embodiment, the execution device 91 of the control device 90 starts the deterioration degree calculation control at every predetermined control cycle on the condition that the control device 90 is operating.

[0034] As shown in FIG. 3, when starting the deterioration degree calculation control, the execution device 91 of the control device 90 executes the process of step S11. In step S11, the execution device 91 acquires the output torque TOUT which is the torque output from the transaxle 30 at the time of the process of step S11. Specifically, the output torque TOUT is the torque output from the differential 60. For example, the execution device 91 calculates the output torque TOUT based on the target driving force of the vehicle 100 described above. As a result, the execution device 91 can acquire the output torque TOUT. In the present embodiment, the output torque TOUT corresponds to the torque of the output shaft of the power transmission device. After step S11, the execution device 91 advances the process to step S12.

[0035] In step S12, the execution device 91 acquires the output rotational speed NOUT which is the rotational speed of the differential 60 at the time of the process of step S12. Specifically, the execution device 91 calculates the output rotational speed NOUT based on the vehicle speed SP. For example, the execution device 91 calculates a value obtained by multiplying the vehicle speed SP by a predetermined coefficient as the output rotational speed NOUT. As a result, the execution device 91 can acquire the output rotational speed NOUT. In the present embodiment, the output rotational speed NOUT corresponds to the rotational speed of the output shaft of the power transmission device. After step S12, the execution device 91 advances the process to step S13.

[0036] In step S13, the execution device 91 acquires the oil temperature TA at the time of the process of step S13. After step S13, the execution device 91 advances the process to step S14.

[0037] In step S14, the execution device 91 calculates a change amount CA indicating the progress of oil deterioration per unit time based on the output torque TOUT, the output rotational speed NOUT, and the oil temperature TA. Specifically, the execution device 91 identifies a temperature coefficient corresponding to the oil temperature TA by associating the oil temperature TA with a predetermined map. Here, the temperature coefficient increases as the oil temperature TA increases. Subsequently, the execution device 91 calculates a value obtained by multiplying the output torque TOUT by the output rotational speed NOUT. Then, the execution device 91 calculates, as the change amount CA, a value obtained by multiplying the value calculated above by the identified temperature coefficient. After step S14, the execution device 91 advances the process to step S15.

[0038] In step S15, the execution device 91 calculates a deterioration degree DD indicating the degree of oil deterioration stored in the case 35 based on the change amount CA. Specifically, the execution device 91 calculates, as the new deterioration degree DD, a value obtained by adding the change amount CA to the deterioration degree DD immediately before the process of step S15. Therefore, the deterioration degree DD is a value obtained by integrating the change amount CA calculated each time the deterioration degree calculation control is executed. Note that the execution device 91 resets the deterioration degree DD at the timing when new oil starts to be used. Therefore, the deterioration degree DD indicates the degree of oil deterioration from the start of using new oil to the time point of the process of step S15. After step S15, the execution device 91 ends the current deterioration degree calculation control.

[0039] <Data collection control> Next, with reference to FIG. 4, the data collection control executed by the control device 90 will be described. This data collection control is control for collecting various data. In the present embodiment, the execution device 91 of the control device 90 starts the data collection control at every predetermined control cycle on the condition that the control device 90 is operating.

[0040] As shown in FIG. 4, when the execution device 91 of the control device 90 starts data collection control, it executes the process of step S31. In step S31, the execution device 91 acquires the carrier rotation speed NC, which is the rotation speed of the carrier 44 at the time of the process in step S31. For example, the execution device 91 acquires the engine rotation speed NE as the carrier rotation speed NC. After step S31, the execution device 91 advances the process to step S32.

[0041] In step S32, the execution device 91 acquires the sun gear rotation speed NS, which is the rotation speed of the sun gear 41 at the time of the process in step S32. For example, the execution device 91 acquires the first rotation speed NM1 as the sun gear rotation speed NS. After step S32, the execution device 91 advances the process to step S33.

[0042] In step S33, the execution device 91 acquires the carrier torque TC, which is the torque of the carrier 44 at the time of the process in step S33. For example, the execution device 91 calculates the carrier torque TC based on the output of the internal combustion engine 10. As a result, the execution device 91 can acquire the carrier torque TC. In the present embodiment, the carrier torque TC corresponds to the torque input to the planetary gear mechanism 40. After step S33, the execution device 91 advances the process to step S34.

[0043] In step S34, the execution device 91 acquires the oil temperature TA at the time of the process in step S34. After step S34, the execution device 91 advances the process to step S35.

[0044] In step S35, the execution device 91 acquires the first motor temperature TM1 at the time of the process in step S35. After step S35, the execution device 91 advances the process to step S36.

[0045] In step S36, the execution device 91 acquires the second motor temperature TM2 at the time of the process in step S36. In step S36, the execution device 91 advances the process to step S37.

[0046] In step S37, the execution device 91 acquires the output rotation speed NOUT, which is the rotation speed of the differential 60 at the time of the process in step S37. As described above, among the connecting gear 72B, the reduction mechanism 50, the planetary gear mechanism 40, and the differential 60 within the specific space A, the differential 60 is located at the lowermost position. Therefore, the output rotation speed NOUT is the rotation speed of the rotating body located at the lowermost position within the specific space A in the case 35. After step S37, the execution device 91 advances the process to step S38.

[0047] In step S38, the execution device 91 acquires the fan rotation speed NF at the time of the process in step S38. After step S38, the execution device 91 advances the process to step S39.

[0048] In step S39, the execution device 91 stores the data acquired in steps S31 to S38 in the storage device 92. That is, the execution device 91 stores the carrier rotation speed NC, the sun gear rotation speed NS, the carrier torque TC, the oil temperature TA, the first motor temperature TM1, the second motor temperature TM2, the output rotation speed NOUT, and the fan rotation speed NF in the storage device 92. After step S39, the execution device 91 ends the current data collection control.

[0049] <Estimation control> Next, with reference to FIG. 5, the estimation control executed by the control device 90 will be described. This estimation control is for estimating the pinion gear temperature TP, which is the temperature of the pinion gear 43. In the present embodiment, the execution device 91 of the control device 90 starts the estimation control at each predetermined control cycle on the condition that the control device 90 is operating and the above data collection control has been executed two or more times in the current operation of the control device 90.

[0050] As shown in FIG. 5, when the execution device 91 of the control device 90 starts the estimation control, it executes the process of step S61. In step S61, the execution device 91 acquires the degradation degree DD at the time of the process of step S61 from the storage device 92. Also, in step S61, the execution device 91 acquires the time-series data of the carrier rotation speed NC, the sun gear rotation speed NS, the carrier torque TC, and the oil temperature TA from the storage device 92. Further, the execution device 91 acquires the time-series data of the first motor temperature TM1, the second motor temperature TM2, the output rotation speed NOUT, and the fan rotation speed NF from the storage device 92. Here, the above time-series data is the data acquired by the data collection control in the operation of the control device 90 this time. In other words, the above time-series data is the data acquired by the data collection control from when the system of the vehicle 100 is started until the time of the process of step S61. And let the number of times the data collection control is executed in the operation of the control device 90 this time be "N". Also, let the time points when the data collection control is executed be the first time point, the second time point, ···, the Nth time point in order from the oldest. Therefore, the execution device 91 acquires N values from the first time point to the Nth time point for each of the above time-series data. Note that "N" is an integer of 2 or more. After step S61, the execution device 91 advances the process to step S62.

[0051] In step S62, the execution device 91 generates the various values acquired in step S61 as input variables of the relationship definition model M. Here, it is assumed that the input variables from the first time point to the Xth time point can be input to the relationship definition model M. And "X" is an integer that is appropriately larger than the above "N" that is assumed.

[0052] First, the generation of input variables for time-series data will be described. Here, the time-series data is a total of eight types of time-series data, namely, the carrier rotation speed NC, the sun gear rotation speed NS, the carrier torque TC, the oil temperature TA, the first motor temperature TM1, the second motor temperature TM2, the output rotation speed NOUT, and the fan rotation speed NF. When the execution device 91 generates input variables for the first time point of the time-series data, the values of the first time point of the eight types of time-series data are sequentially substituted into the input variables x(1) to x(8) one by one. Similarly, when the execution device 91 generates input variables for the second time point of the time-series data, the values of the second time point of the eight types of time-series data are sequentially substituted into the input variables x(9) to x(16) one by one. Similarly, the execution device 91 substitutes values into the input variables x(17) to x(8×N) for the time-series data of the third time point to the Nth time point. Then, the execution device 91 sequentially substitutes "0" into the input variables x(8×N + 1) to x(8×X) for the time-series data of the (N + 1)th time point to the Xth time point. In other words, the execution device 91 sets the values of the input variables when no data is acquired to "0". Further, the execution device 91 substitutes the value of the degradation degree DD into the input variable x(8×X + 1). Hereinafter, "8×X + 1" will be described as "Z". That is, "Z" is the number of input variables generated in step S62.

[0053] In the present embodiment, each of the time-series data of the carrier rotation speed NC, the time-series data of the sun gear rotation speed NS, the time-series data of the carrier torque TC, and the time-series data of the oil temperature TA is input data input to the relationship defining model M. Also, each of the time-series data of the first motor temperature TM1, the time-series data of the second motor temperature TM2, the time-series data of the output rotation speed NOUT, and the time-series data of the fan rotation speed NF is input data input to the relationship defining model M. Further, the degradation degree DD is input data input to the relationship defining model M. After step S62, the execution device 91 proceeds to step S63 for processing.

[0054] In step S63, the execution device 91 inputs the input variables x(1) to x(Z) and the input variable x(0) as a bias parameter into the relationship definition model M, and outputs the value of the output variable y(i) indicating the temperature of the pinion gear 43. Here, the output variable y(i) is an index value indicating the temperature of the pinion gear 43.

[0055] An example of the relationship definition model M is a function approximator, which is a fully connected feedforward neural network with one hidden layer. In this relationship definition model M, each of the "m" values obtained by converting the input variables x(1) to x(Z) and the input variable x(0) as a bias parameter by a linear mapping defined by the coefficients wFjk (j = 1 to m, k = 0 to Z) is substituted into the activation function f. As a result, the values of the nodes in the hidden layer are determined. Further, each of the values obtained by converting the values of the nodes in the hidden layer by a linear mapping defined by the coefficient wSij (i = 1) is substituted into the activation function g, whereby the output variable y(1) is determined. In the present embodiment, an example of the activation function f is the ReLU function. Also, an example of the activation function g is the sigmoid function. That is, the output variable y(1) can vary in the range from "0" to "1". Note that the smaller the output variable y(1), the lower the temperature of the pinion gear 43.

[0056] The relationship regulation model M is generated in advance as follows, for example. First, technicians or the like drive the vehicle 100 under various conditions. At this time, various data including the carrier rotation speed NC and the like are acquired in the same manner as above. Then, input variables x(1) to x(Z) are generated in the same manner as above. Also, the temperature of the pinion gear 43 is grasped by actually measuring the temperature of the pinion gear 43, such as by separately attaching a temperature sensor to the transaxle 30. Furthermore, an output variable y(1) corresponding to the grasped temperature of the pinion gear 43 is generated. Here, for example, the temperature of the pinion gear 43 can be measured as described above by separately attaching a temperature sensor to the transaxle 30. Then, the relationship regulation model M is generated by performing machine learning using the data generated as described above. That is, the relationship regulation model M is generated in advance by machine learning using the above eight types of time series data, the combination of the degradation degree DD and the temperature of the pinion gear 43 as teacher data. After step S63, the execution device 91 proceeds with the process to step S64.

[0057] In step S64, the execution device 91 calculates the pinion gear temperature TP based on the output variable y(1). For example, the execution device 91 calculates the pinion gear temperature TP corresponding to the output variable y(1) by associating the output variable y(1) with a predetermined map. As a result, the execution device 91 can acquire the pinion gear temperature TP. After step S64, the execution device 91 ends the current estimation control.

[0058] <Actions of this Embodiment> In the vehicle 100, as the oil stored in the case 35 deteriorates, the viscosity and thermal conductivity of the oil change. Therefore, for example, even when the oil temperature TA is the same, a difference occurs in the cooling effect of the pinion gear 43 by the oil according to the deterioration of the oil.

[0059] As shown in FIG. 5, in the estimation control, the execution device 91 of the control device 90 acquires the degree of oil deterioration DD in addition to the time-series data of the carrier torque TC and the time-series data of the oil temperature TA as a plurality of types of input data. Then, the execution device 91 outputs an output variable y(1) indicating an index value of the temperature of the pinion gear 43 by inputting the plurality of types of input data into the relationship defining model M.

[0060] <Effect of this Embodiment> (1) According to this embodiment, the index value output from the relationship defining model M reflects the cooling effect of the oil according to the degree of oil deterioration DD. Thereby, by taking into account the degree of oil deterioration DD, the estimation accuracy of the temperature of the pinion gear 43 can be improved.

[0061] (2) In the vehicle 100, the higher the rotational speed of the pinion gear 43, the higher the temperature of the pinion gear 43 tends to be. However, for example, even if the manner of variation of the rotational speed of the pinion gear 43 is the same, the temperature of the pinion gear 43 can change due to a change in the manner of variation of the rotational speeds of the sun gear 41, the ring gear 42, and the carrier 44.

[0062] In this regard, according to this embodiment, the time-series data of the carrier rotational speed NC and the time-series data of the sun gear rotational speed NS are included as input data for reflecting the rotational speed of the pinion gear 43. In other words, among the time-series data of the rotational speeds of the three components, namely the sun gear 41, the ring gear 42, and the carrier 44, the time-series data of two or more rotational speeds are included. Here, in the planetary gear mechanism 40, if two of the three rotational speeds of the sun gear 41, the ring gear 42, and the carrier 44 can be acquired, the three rotational speeds and the rotational speed of the pinion gear 43 can be grasped. Therefore, according to the above configuration, by taking into account the manner of variation of the rotational speeds of the sun gear 41, the ring gear 42, and the carrier 44 in addition to the manner of variation of the rotational speed of the pinion gear 43, the estimation accuracy of the temperature of the pinion gear 43 can be improved.

[0063] (3) The vehicle 100 includes a first motor generator 71 connected to the sun gear 41 of the planetary gear mechanism 40. The vehicle 100 also includes a second motor generator 72 connected to the ring gear 42 of the planetary gear mechanism 40. In such a vehicle 100, for example, when the temperature of the first motor generator 71 rises or the temperature of the second motor generator 72 rises, the temperature of the pinion gear 43 may rise.

[0064] In this regard, according to the present embodiment, as input data input to the relationship defining model M, time series data of the first motor temperature TM1 and time series data of the second motor temperature TM2 are included. Thereby, it is possible to suppress a decrease in the estimation accuracy of the temperature of the pinion gear 43 due to a change in one or more temperatures of the first motor generator 71 and the second motor generator 72.

[0065] (4) As shown in FIG. 2, among the connecting gear 72B, the speed reduction mechanism 50, the planetary gear mechanism 40, and the differential 60 in the specific space A of the case 35, the differential 60 is located at the lowermost side. Therefore, the ring gear 61 of the differential 60 is likely to contact the oil stored in the case 35. When the differential 60 is rotating, heat is generated due to power loss of the ring gear 61 at the portion where the ring gear 61 of the differential 60 is in contact with the oil. As a result, the temperature of the oil stored in the case 35 can change according to the rotational speed of the differential 60.

[0066] In this regard, according to the present embodiment, as input data input to the relationship defining model M, time series data of the output rotational speed NOUT, which is the rotational speed of the differential 60, is included. That is, as input data input to the relationship defining model M, time series data of the rotational speed of the rotating body located at the lowermost side in the specific space A in the case 35 is included. Thereby, by taking into account the rotational speed of the rotating body located at the lowermost side in the specific space A in the case 35, the estimation accuracy of the temperature of the pinion gear 43 can be improved.

[0067] (5) According to this embodiment, the input data input to the relationship definition model M includes time-series data of the fan rotation speed NF. Thereby, even if the temperature of the transfer axle 30 changes according to the rotation speed of the fan 89A, for example, it is possible to suppress a decrease in the estimation accuracy of the temperature of the pinion gear 43 due to the rotation of the fan 89A.

[0068] (6) In the vehicle 100, as the output torque TOUT increases, as the output rotation speed NOUT increases, and as the oil temperature TA increases, the deterioration of the oil stored in the case 35 tends to progress.

[0069] In this regard, in the deterioration degree calculation control, the execution device 91 calculates the deterioration degree DD of the oil based on the output torque TOUT, the output rotation speed NOUT, and the oil temperature TA. Therefore, it is possible to obtain the deterioration degree DD that more accurately reflects the actual deterioration of the oil.

[0070] <Modification example> This embodiment can be implemented with the following modifications. This embodiment and the following modification examples can be implemented in combination with each other within a technically non-contradictory range.

[0071] · In the above embodiment, the deterioration degree calculation control may be changed. For example, the configuration for calculating the deterioration degree DD of the oil may be changed. As a specific example, the execution device 91 may calculate the deterioration degree DD of the oil based only on the output torque TOUT and the output rotation speed NOUT regardless of the oil temperature TA.

[0072] · In the above embodiment, the input data of the relationship definition model M may be changed. For example, the plurality of types of input data input to the relationship specification model M may not include the first motor temperature TM1 and the second motor temperature TM2. As a specific example, if the temperature of the first motor generator 71 or the like changes and the temperature of the pinion gear 43 is unlikely to change, the input data of the relationship specification model M may not include the first motor temperature TM1 and the second motor temperature TM2.

[0073] · For example, among the plurality of types of input data input to the relationship specification model M, the input data for reflecting the rotational speed of the pinion gear 43 may be changed. As a specific example, the input data for reflecting the rotational speed of the pinion gear 43 is not limited to the time-series data of the carrier rotational speed NC and the sun gear rotational speed NS, and may be the time-series data of the rotational speeds of any two of the sun gear 41, the ring gear 42, and the carrier 44. Also, as a specific example, the input data for reflecting the rotational speed of the pinion gear 43 may be the time-series data of the rotational speed of the pinion gear 43. Even with this configuration, if the manner of variation of the rotational speeds of the sun gear 41, the ring gear 42, and the carrier 44 changes and the temperature of the pinion gear 43 is unlikely to change, the impact is small.

[0074] · For example, the plurality of types of input data input to the relationship specification model M may not include the input data for reflecting the rotational speed of the pinion gear 43. As a specific example, if the change in the temperature of the pinion gear 43 corresponding to the rotational speed of the pinion gear 43 is small, the plurality of types of input data input to the relationship specification model M may not include the input data for reflecting the rotational speed of the pinion gear 43.

[0075] ·For example, the plurality of types of input data input to the relationship specification model M may not include the time-series data of the output rotation speed NOUT which is the rotation speed of the differential 60. As a specific example, depending on the configuration of the transaxle 30, the rotating body located at the lowermost side within the specific space A in the case 35 changes. In this case, as the plurality of types of input data input to the relationship specification model M, it is preferable to include the time-series data of the rotation speed of the rotating body located at the lowermost side within the specific space A in the case 35, in accordance with the above-described configuration of the transaxle 30.

[0076] ·For example, the plurality of types of input data input to the relationship specification model M may not include the time-series data of the rotation speed of the rotating body located at the lowermost side within the specific space A in the case 35. Also, for example, the plurality of types of input data input to the relationship specification model M may not include the time-series data of the fan rotation speed NF.

[0077] ·In the above-described embodiment, the relationship specification model M may be changed. For example, the activation function of the relationship specification model M is an example, and the activation function of the relationship specification model M can be changed.

[0078] ·For example, as the relationship specification model M, a neural network having one intermediate layer was exemplified, but the number of intermediate layers may be two or more. ·For example, as the neural network of the relationship specification model M, a fully-connected feedforward neural network was exemplified, but it is not limited thereto. As a specific example, the neural network may be a recurrent connection type neural network. Also, for example, the function approximator as the relationship specification model M is not limited to a neural network. As a specific example, the relationship specification model M may be a regression equation without an intermediate layer.

[0079] ·For example, the relationship specification model M may not be generated by machine learning. As a specific example, the relationship specification model M may be a relational expression or the like determined by experiments and simulations.

[0080] ·In the above embodiment, the pinion gear temperature estimation device may be changed. For example, the pinion gear temperature estimation device is not limited to the control device 90 of the vehicle 100, and may be a device different from the control device 90 in the vehicle 100. In this case, it is sufficient that the above-mentioned different device stores the relationship regulation model M and the pinion gear temperature estimation program in advance. Also, for example, the pinion gear temperature estimation device may be a device outside the vehicle 100. Here, an example of the device outside the vehicle 100 is a server capable of communicating with the vehicle 100. In this configuration, the server can execute estimation control by acquiring various information from the vehicle 100. In this case, it is sufficient that the server stores the relationship regulation model M and the pinion gear temperature estimation program in advance.

[0081] ·In the above embodiment, the power transmission device may be changed. For example, the power transmission device does not have to be constituted by the transaxle 30. That is, any device provided with a planetary gear mechanism can be a power transmission device.

Explanation of Reference Numerals

[0082] 10... internal combustion engine 15... crankshaft 20... damper 26... drive shaft 27... drive wheel 30... transaxle 35... case 40... planetary gear mechanism 41... sun gear 42... ring gear 43... pinion gear 44... carrier 50... reduction mechanism 51... first gear 52... second gear 60... differential 61... ring gear 62... differential case 71... first motor generator 71A... rotating shaft 72... second motor generator 72A... rotating shaft 72B... connecting gear 80... oil supply device 81... oil pump 82... oil pipe 89... cooling fan 90... control device 91... execution device 92... storage device 92A... control program M... relationship regulation model 100... vehicle 101... accelerator operation amount sensor 102... vehicle speed sensor 103... crank angle sensor 104... first rotation speed sensor 105... second rotation speed sensor 106... first motor temperature sensor 107... second motor temperature sensor 108... oil temperature sensor

Claims

1. A power transmission device for a vehicle equipped with a planetary gear mechanism is targeted, It includes an execution device and a storage device, The storage device stores a relationship defining model that outputs an index value indicating the temperature of the pinion gear of the planetary gear mechanism when a plurality of types of input data are input, The plurality of types of input data include time-series data of the torque input to the planetary gear mechanism, time-series data of the oil temperature which is the temperature of the oil lubricating each part including the planetary gear mechanism in the power transmission device, and the degree of deterioration of the oil, The execution device, Acquires the plurality of types of input data, Outputs the index value by inputting the acquired plurality of types of input data into the relationship defining model, And executes, A pinion gear temperature estimation device.

2. The plurality of types of input data include two or more selected from the time-series data of the rotational speed of the sun gear of the planetary gear mechanism, the time-series data of the rotational speed of the carrier of the planetary gear mechanism, and the time-series data of the rotational speed of the ring gear of the planetary gear mechanism, The pinion gear temperature estimation device according to Claim 1.

3. The execution device, Acquires the output torque which is the torque of the output shaft of the power transmission device, Acquires the output rotational speed which is the rotational speed of the output shaft, Acquires the oil temperature, Calculates the degree of deterioration based on the output torque, the output rotational speed, and the oil temperature, And executes, The pinion gear temperature estimation device according to Claim 1 or Claim 2.

4. The plurality of types of input data includes time-series data of the temperature of the first motor generator connected to the sun gear of the planetary gear mechanism and time-series data of the temperature of the second motor generator connected to the ring gear of the planetary gear mechanism. The pinion gear temperature estimation device according to claim 1 or claim 2.

5. Targeting a power transmission device of a vehicle equipped with a planetary gear mechanism, Comprising an execution device and a storage device, and applicable to a pinion gear temperature estimation device that estimates the temperature of the pinion gear of the planetary gear mechanism, The storage device stores a relationship defining model that outputs an index value indicating the temperature of the pinion gear when a plurality of types of input data are input. The plurality of types of input data includes time-series data of the torque input to the planetary gear mechanism, time-series data of the oil temperature, which is the temperature of the oil lubricating each part including the planetary gear mechanism in the power transmission device, and the degree of deterioration of the oil. For the execution device, To acquire the plurality of types of input data, To output the index value by inputting the acquired plurality of types of input data into the relationship defining model, To execute Pinion gear temperature estimation program.

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