JP5472010B2 - Control device for vehicle drive device - Google Patents

Description

  The present invention provides a vehicle in which an engagement device and a rotating electrical machine are provided in this order from the input member side on a power transmission path connecting an input member drivingly connected to an internal combustion engine and an output member drivingly connected to a wheel. The present invention relates to a control device for a driving device.

The vehicle having the above-described configuration is called a parallel hybrid vehicle, and is one of a motor travel mode that travels using only the rotating electric machine as a power source and an internal combustion engine travel mode that travels using at least the internal combustion engine as a power source. The fuel consumption is improved by automatically switching the driving mode according to the driving state. Furthermore, fuel efficiency can also be improved by performing a so-called idle stop in which the operation of the fuel internal combustion engine is stopped when the vehicle is stopped.
In addition, there is a friction torque of the internal combustion engine as a load element in the power transmission path, and the value of the friction torque is also important in the control of the vehicle drive device.

An internal combustion engine, an electric motor (rotary electric machine), and a clutch that connects the electric motor and the internal combustion engine are provided. The clutch is engaged and the internal combustion engine is cranked by the electric motor in parallel. A technique for estimating the friction torque of an internal combustion engine based on the power consumption of an electric motor in a predetermined section until the time is known (see, for example, Patent Document 1). At that time, the electric power consumption of the electric motor is the sum of driving, cranking and frictional heat, and this frictional heat is the difference between the clutch pressure, clutch area, motor speed and engine speed. It is obtained by multiplication with the clutch friction coefficient.
However, since the clutch friction coefficient varies greatly depending on the vehicle state such as temperature and motor / engine rotational speed difference, it is difficult to accurately calculate the frictional heat by the friction torque estimation technique as described above. In addition, there is a cost problem that requires a hydraulic pressure sensor to measure the clutch pressure.

JP 2009-280049 A (paragraph number 0012-0028, FIG. 3)

  In view of the above situation, there is a demand for a control device for a vehicle drive device that can estimate the friction torque of an internal combustion engine without using a clutch friction coefficient that is greatly influenced by the vehicle state.

On the power transmission path connecting the input member drivingly connected to the internal combustion engine and the output member drivingly connected to the wheels according to the present invention, the engaging device and the rotating electrical machine are provided in this order from the input member side. A characteristic configuration of a control device for a vehicle drive device includes a rotation speed acquisition unit that acquires a rotation speed of the internal combustion engine, and a rotation change based on a change in the rotation speed of the internal combustion engine in a combustion stop state of the internal combustion engine. A friction torque calculating unit that calculates a friction torque of the internal combustion engine based on the inertia and rotation rate of the internal combustion engine, and acquired by the rotational speed acquisition unit when the internal combustion engine is stopped. The relationship between the rotation speed and the friction torque calculated by the friction torque calculation unit based on the rotation speed is learned, and the friction is calculated from the rotation speed of the internal combustion engine. The friction torque deriving unit that derives the torque was constructed based on the result of the learning, and a managing unit that manages, the management unit, when stopping the internal combustion engine while the vehicle is running, first, of the internal combustion engine The output torque is set to zero, the rotation speed of the internal combustion engine is maintained, the engagement device is released, the combustion engine is stopped, and the learning is performed in the process of decreasing the rotation speed of the internal combustion engine. In the point.

  With this characteristic configuration, the friction torque of the internal combustion engine can be obtained from a rotation change rate, which is a change in the rotational speed of the internal combustion engine when the combustion of the internal combustion engine is stopped, and an inertia of the internal combustion engine using a predetermined arithmetic expression. Based on the knowledge of the present inventor that the friction torque can be derived from the rotational speed by learning the friction torque in association with the rotational speed. Based on this knowledge, when stopping the internal combustion engine, the relationship between the rotation speed acquired by the rotation speed acquisition unit and the friction torque calculated by the friction torque calculation unit based on the rotation speed is learned. A friction torque deriving unit for deriving the friction torque from the rotation speed is constructed and managed based on the learning result. By giving the rotational speed as an input parameter to the friction torque deriving unit constructed and managed in this way, the estimated friction torque can be easily obtained. Here, since the clutch friction coefficient greatly influenced by the vehicle state is not used, the reliability of the estimated friction torque is high.

The “rotary electric machine” is used as a concept including any of a motor (electric motor), a generator (generator), and a motor / generator functioning as both a motor and a generator as necessary.
In the present application, “driving connection” refers to a state where two rotating elements are connected so as to be able to transmit a driving force, and the two rotating elements are connected so as to rotate integrally, or the two The rotating element is used as a concept including a state in which the driving force is connected to be transmitted through one or more transmission members. Examples of such a transmission member include various members that transmit rotation at the same speed or a variable speed, and include, for example, a shaft, a gear mechanism, a belt, a chain, and the like. In addition, as such a transmission member, an engagement element that selectively transmits rotation and driving force, such as a friction clutch or a meshing clutch, may be included.

In a hybrid vehicle, a frequently occurring internal combustion engine stop process during running of a vehicle is a process in which the internal combustion engine maintained at a predetermined rotational speed is brought into a combustion stopped state and the rotational speed is reduced to reduce the rotational speed and the friction torque. This is a convenient situation for learning in the present invention to associate. According to the above characteristic configuration , the friction torque deriving unit can be frequently reconstructed or updated through the learning that can be frequently performed while the vehicle is running, and the reliability of the friction torque deriving unit is improved. Can do.

  The friction torque of the internal combustion engine is affected by the temperature of the lubricating oil of the internal combustion engine. Although the oil temperature of the lubricating oil can be directly measured, it is also possible to divert the measured value of a water temperature sensor that measures the temperature of cooling water, which is almost essential for automobiles. Therefore, in one of the preferred embodiments of the present invention, an oil temperature representative value acquisition unit that acquires an oil temperature representative value that is a value representative of the oil temperature of the internal combustion engine is further provided, and the management unit includes the oil temperature The learning is performed in association with the representative temperature value, and the friction torque deriving unit includes a friction torque map that defines the relationship between the rotational speed of the internal combustion engine and the friction torque in association with the representative oil temperature value. The friction torque map here is a form such as a data table that extracts the friction torque using the rotation speed as an input parameter, a form such as a function formula that extracts the friction torque using the rotation speed as a variable value, and a condition such as an if-then rule. It is used as a broad term including rule forms. For example, when the friction torque map is like the above data table, it should be constructed as a rotation speed / friction torque table for each oil temperature representative value, or as a three-dimensional table consisting of the oil temperature representative value, rotation speed and friction torque. Can do.

  As still another preferred embodiment of the present invention, a rotating electrical machine control unit for controlling the rotating electrical machine is further provided, and the rotating electrical machine control unit derives the friction torque according to the rotational speed acquired by the rotational speed acquisition unit. It is also possible to employ a configuration in which the output torque of the rotating electrical machine is controlled using the friction torque derived by the section. According to this configuration, it is possible to control the rotating electrical machine in consideration of the friction torque when the combustion of the internal combustion engine is stopped. Therefore, for example, it is possible to cause the rotating electric machine to appropriately simulate the friction torque of the internal combustion engine to perform the engine braking behavior, and to release the engagement device during traveling of the vehicle without giving the driver a sense of incongruity. Can be separated from the output member. In addition, for example, even when the internal combustion engine is in a combustion stop state with the engagement device engaged, the driver demand torque is accurately output by the rotating electrical machine in consideration of the friction torque of the internal combustion engine and transmitted to the output member. can do.

FIG. 3 is a schematic diagram for explaining a basic learning process for constructing a friction torque deriving unit that derives friction torque from the rotational speed of the internal combustion engine. It is a graph which shows an example of the map which derives friction torque from rotation speed according to oil temperature. It is a schematic diagram which shows the structure of the transmission control apparatus which concerns on this embodiment. It is a functional block diagram which shows the structure of the AT control unit which concerns on this embodiment. It is a timing chart of a friction torque learning process. It is a flowchart which shows the flow of a friction torque learning process. It is a timing chart of pseudo engine brake control. It is a flowchart which shows the flow of pseudo | simulation engine brake control.

Before describing an embodiment of the present invention, a basic feature for constructing a friction torque deriving unit having a form such as a map or a function for deriving the friction torque from the rotational speed of the internal combustion engine, which is an important feature of the present invention. A simple learning process will be described with reference to FIG.
In order to enter this learning process during traveling of a vehicle having a power transmission path in which the internal combustion engine and the rotating electrical machine are connected via an engagement device, internal and external to the rotating internal combustion engine are required. It is necessary to detect the decrease in rotation due to the internal combustion engine friction torque by interrupting the driving action. For this reason, here, the following three conditions are adopted as the starting conditions of this learning process.
(1) The output torque of the internal combustion engine is set to “0” (# 1).
(2) The transmission torque of the engagement device is set to “0” (# 2).
(3) Stop combustion of the internal combustion engine (# 3).
By the way, if power transmission by the engagement device is interrupted while power (torque) transmission from the internal combustion engine is being performed, the external load on the internal combustion engine disappears, so the rotational speed of the internal combustion engine increases rapidly. In order to avoid this, the condition (1) is adopted, and even if the output torque from the internal combustion engine is set to zero before the power transmission by the engagement device is cut off, even if the power transmission by the engagement device is cut off, the internal combustion engine Is in a state of maintaining its own rotation speed constant. Next, under the condition (2), power transmission from the rotating electric machine and the wheel side is interrupted. As a result, the external driving action of the internal combustion engine does not reach. Finally, under the condition (3), the combustion of the internal combustion engine is stopped and the internal driving action of the internal combustion engine is lost. As a result, the rotational speed of the internal combustion engine starts to decrease under the influence of the friction of the internal combustion engine, so the precondition for obtaining the internal combustion engine friction torque is satisfied, and a substantial learning process of the internal combustion engine friction torque is started ( # 4).

In this learning process, first, the rotation speed is acquired (# 5). In Figure 1, each time point with the predetermined time has _elapsed: the rotational speed of the _{t (t 1, t 2,} ·· t k) of the internal combustion _{engine: n (n 1, n 2} , ··· n k) (rad / s) is acquired (detected). Next, the rate of change in rotation: r (r ₁ , r ₂ ,... R _k ) (rad / s ² ) from the difference between the acquired rotational speed _nk and the rotational speed n _k−1 acquired previously. ) Is calculated (# 6). It is known that when the rotation change rate of the rotating body is obtained, the friction torque can be obtained by multiplying this by the inertia of the rotating body. The present invention takes advantage of this fact. The inertia of the internal combustion engine: I (kg / m ² ) can be obtained in advance from the design data of the internal combustion engine, so that the value of this inertia can be read out as needed by storing it in a nonvolatile memory. Yes (# 7). Therefore, every time the rotation change rate: r is calculated,
F = I × r,
Internal combustion engine friction torque (hereinafter abbreviated as friction torque): F (F ₁ , F ₂ ,... F _k ) (N · m) is calculated (# 8).
Thus, by detecting the decreasing rotational speed: n and obtaining the friction torque: F until the rotational speed becomes zero, the correlation between the rotational speed: n and the friction torque: F is obtained. Thus, the relationship between the friction torque: F and the rotational speed: n can be obtained (# 9). This learning process ends by mapping this relationship or updating a map that has already been constructed based on this relationship. This map may be constructed as a function of friction torque: F and rotational speed: n: f (F = f (n)).

  The friction torque is affected by the viscosity of the lubricating oil of the internal combustion engine, and the viscosity of the lubricating oil is affected by the temperature of the lubricating oil (hereinafter abbreviated as oil temperature). Since it is important to adopt the oil temperature as an input parameter for deriving the friction torque, as shown in FIG. 1, this learning process or its mapping is performed for each oil temperature. Accordingly, the oil temperature: T is acquired in this learning process, and in addition to the relationship between the rotational speed and the friction torque described above, for example, the relationship between these and the oil temperature: T is also obtained (# 10). For example, the map for deriving the friction torque from the rotational speed is constructed for each oil temperature: T. Note that the rotation speed (rad / s) can be replaced with the rotation speed (rpm), and FIG. 2 shows an example in which a map for each oil temperature for deriving the friction torque from the rotation speed is graphed. This map may be constructed as a function of f: F (F = f (n, T)) of friction torque: F, rotational speed: n, and oil temperature: T.

  By using the friction map constructed or updated in this way, it corresponds to the latest state of the internal combustion engine from the obtained oil temperature: T and the rotational speed (rad / s) or rotational speed (rpm) of the internal combustion engine. The friction torque (N · m) can be derived easily. Since the friction torque of the internal combustion engine has individual differences and also changes with time and environment, a system that can update the friction map while the vehicle is running is advantageous.

  Next, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a case where the control device according to the present invention is applied to a control device for a vehicle drive device for a hybrid vehicle will be described as an example. FIG. 3 is a schematic diagram showing a configuration of a drive transmission system, a shift control system, and a hydraulic control system of a vehicle drive device including the shift control device according to the present embodiment. As shown in this figure, the vehicle drive apparatus according to the present embodiment schematically includes an internal combustion engine 11 and a rotating electrical machine 13 as driving force sources, and is drivingly connected to the internal combustion engine 11 and / or the rotating electrical machine 13. A power transmission path that connects the input member 21 and the output member 22 that is drivingly connected to the wheel is formed, and the driving force of the driving force source is transmitted to the wheel 16 via the transmission 20. In this embodiment, an engagement device 12, which is a hydraulic clutch, is interposed between the internal combustion engine 11 and the rotary electric machine 13 so that the engagement device 12 and the rotary electric machine 13 are arranged in this order from the internal combustion engine 11 side. Has been. Further, the vehicle drive device supplies a predetermined hydraulic pressure to each part of the valve unit 12b, the transmission 20, and the like for supplying hydraulic oil to the engagement element of the engagement device 12. Is included. Hereinafter, the vehicle drive device will be described in detail.

  As shown in FIG. 3, the transmission 20 receives the power output from the driving force source including the internal combustion engine 11 and the rotating electrical machine 13 as it is or after shifting it as necessary to input the differential gear mechanism 15 for output. Output to. The power transmission shaft group responsible for power transmission in the transmission 20 includes the internal combustion engine 11 and the rotating electrical machine 13 and a substantial transmission element group (a clutch and a brake as a friction engagement element for transmission, a one-way clutch or a gear group). The power transmission between the input member 21 that transmits power between them (hereinafter sometimes referred to simply as the input side when expressing power transmission behavior) and the output differential gear mechanism 15 is performed. It can be divided into the output member 22 (hereinafter simply referred to as the output side when the power transmission behavior is expressed). That is, the input member 21 is drivingly connected to the driving force source, and the output member 22 is drivingly connected to the wheel 16 via the output differential gear mechanism 15. The transmission mechanism 20A including the transmission element group performs transmission power transmission accompanied by a change in the rotational speed and torque between the input member 21 and the output member 22.

  The internal combustion engine 11 (hereinafter simply referred to as an engine) is an internal combustion engine that is driven by the combustion of fuel. For example, various known engines such as a gasoline engine and a diesel engine can be used. In this example, an output rotation shaft such as a crankshaft of the engine 11 is transmitted to the downstream side via the engagement device 12. The engagement device 12 is configured as a hydraulic friction clutch, and can change the transmission torque in accordance with the supplied hydraulic pressure. Hereinafter, it will be referred to as a friction clutch or simply a clutch.

  The rotating electrical machine 13 is known per se, and includes a stator fixed to a case (not shown) and a rotor that is rotatably supported on the radially inner side of the stator. The rotor of the rotating electrical machine 13 is coupled to rotate integrally with a shaft connected to one side of the clutch 12. The rotating electrical machine 13 is connected to a battery 52 serving as a power storage device via an inverter unit 51. The rotating electrical machine 13 can perform a function as a motor (electric motor) that generates power upon receiving power supply and a function as a generator (generator) that generates power upon receiving power supply. It is. That is, the rotating electrical machine 13 has a function of receiving power supplied from the battery 52 and running, or storing in the battery 52 the power generated by the rotational driving force transmitted from the engine 11 and the wheels 16. Note that the battery 52 is an example of a power storage device, and other power storage devices such as capacitors may be used, or a plurality of types of power storage devices may be used in combination.

  In this vehicle drive device, the vehicle can travel by transmitting the rotational drive force of the engine 11 or the rotating electrical machine 13 or both to the wheels 16. At that time, the rotating electrical machine 13 can be in either a state in which a driving force is generated by the power supplied from the battery 52 or a state in which power is generated by the rotational driving force of the engine 11 depending on the state of charge of the battery 52. Further, when the vehicle is decelerated (when a deceleration request is made), the rotating electrical machine 13 is in a state of generating power by the rotational driving force transmitted from the wheels 16 by generating regenerative torque. The electric power generated by the rotating electrical machine 13 is stored in the battery 52. When the vehicle is stopped, the clutch 12 is released, and the engine 11 and the rotating electrical machine 13 are stopped.

  The speed change mechanism 20A is configured as a stepped automatic transmission having a plurality of speed stages. In the present embodiment, the speed change mechanism 20A has four speed stages (first speed stage, different speed ratios). 2nd speed, 3rd speed, and 4th speed). In order to configure these shift speeds, the transmission mechanism 20A includes a gear mechanism such as a planetary gear mechanism and a plurality of friction engagement elements. FIG. 1 schematically shows a clutch C1 and a brake B1 as an example of a plurality of friction engagement elements. The four shift speeds are switched by hydraulic pressure controlled through the hydraulic circuit 30 to engage and release the plurality of friction engagement elements.

  When changing the gear position, one of the friction engagement elements engaged before the shift is released and one of the friction engagement elements released before the shift is engaged. Combine. As a result, the rotational states of the plurality of rotating elements of the gear mechanism are switched, and the shift stage before the shift is shifted to the shift stage after the shift. The transmission mechanism 20A shifts the rotational speed of the power on the input side at a predetermined speed ratio set for each gear stage, converts the torque, and transmits it to the differential gear device 15 as output power.

  Next, the hydraulic control system of the vehicle drive device described above will be described. In this block diagram, the hydraulic circuit including the valve unit 12b for the cylinder piston incorporated in the clutch 12 and the hydraulic circuit 30 for the transmission 20 are divided, but these hydraulic circuits are configured integrally. be able to. Here, the hydraulic control system is divided into driving and shifting. In the shift hydraulic control system, a hydraulic control function unit that sends a control signal to an electric oil pump (hereinafter abbreviated as EOP) 31 and a valve unit 32 constituting a hydraulic circuit 30 via a hydraulic device driver 33 is an automatic transmission (hereinafter referred to as an automatic transmission). It is constructed in the control unit 6 (abbreviated as AT). The control signal generated by the AT control unit 6 is converted into a hydraulic device drive signal by the hydraulic device driver 33 and sent to an electric oil pump (hereinafter abbreviated as EOP) 31 and a valve unit 32 that constitute the hydraulic circuit 30. The hydraulic circuit 30 also incorporates a mechanical pump (hereinafter abbreviated as MOP) 34 that operates with the driving force of the engine 11 and / or the rotating electrical machine 13. However, the MOP 34 is not driven while the engine 11 and the rotating electrical machine 13 are stopped, for example, when the vehicle is stopped due to its power configuration. The EOP 31 has a role of assisting the MOP 34 in such a situation. In the drive hydraulic control system, a hydraulic control function unit that sends a control signal to the valve unit 12b via the hydraulic device driver 12c is constructed in the drive source control unit 4.

  The hydraulic circuit 30 adjusts the amount of hydraulic oil drained from the adjustment valve by adjusting the opening of one or more adjustment valves based on the signal pressure from the linear solenoid valve for hydraulic adjustment. The hydraulic oil pressure is adjusted to one or more predetermined pressures. The hydraulic oil adjusted to a predetermined pressure is supplied to the clutch 12 and the plurality of friction engagement elements C1, B1,...

  As shown in FIG. 3, the control device for the vehicle drive device includes a drive source control unit 4, an AT control unit 6, a sensor evaluation unit 9, a brake control unit 7, and a learning control unit 8. Is provided. The drive source control unit 4 includes an engine control unit 4 a that controls the engine 11, a clutch control unit 4 b that controls the clutch 11, and a rotation control unit 5 that controls the rotating electrical machine 13. The brake control unit 7 performs brake control based on a signal from a brake pedal sensor 95 that detects an operation displacement of the brake pedal. The sensor evaluation unit 9 evaluates detection signals from various sensors and supplies necessary detection information to the control units 4, 6, 7, and 8. These control units are connected by an in-vehicle LAN 100 and can exchange data with each other. Each control unit includes an arithmetic processing unit such as a CPU as a core member, and is configured to be able to read and write data from the arithmetic processing unit, and to receive data from the arithmetic processing unit. It has a storage device such as a ROM (Read Only Memory) configured to be readable (not shown). Various functions are created by software (program) stored in the ROM or the like, hardware such as a separately provided arithmetic circuit, or both.

  The engine control unit 4a performs processing for determining an engine operating point and controlling the engine 11 to operate at the engine operating point. Here, the engine operating point is a control command value that represents a control target point of the engine 11, and is determined by the rotational speed and torque. More specifically, the engine operating point is a command value that represents a control target point of the engine 11 that is determined in consideration of the vehicle required output (determined based on the vehicle required torque and the engine speed) and the optimum fuel consumption. It is determined by the rotational speed command value and the torque command value. The clutch control unit 4 b controls transmission of torque output from the engine 11 to the output member 22 side or torque transmission from the output member 22 or the rotating electrical machine 13 to the engine 11 by adjusting the transmission torque of the clutch 12.

The rotating electrical machine control unit 5 is a functional unit that performs operation control of the rotating electrical machine 13 via the inverter 51. The rotating electrical machine control unit 5 determines a rotating electrical machine operating point and performs a process of controlling the rotating electrical machine 13 to operate at the rotating electrical machine operating point. Here, the rotating electrical machine operating point is a control command value representing a control target point of the rotating electrical machine 13 and is determined by the rotational speed and torque. More specifically, the rotating electrical machine operating point is a command value that represents a control target point of the rotating electrical machine 13 determined in consideration of the vehicle required output and the engine operating point, and is based on the rotational speed command value and the torque command value. Determined. The rotating electrical machine control unit 5 also performs control to switch between a state in which the rotating electrical machine 13 generates a driving force by the electric power supplied from the battery 52 and a state in which the rotating electrical machine 13 generates power by the rotational driving force of the engine 11 or the like.
Here, when the torque command value is positive, the rotating electrical machine 13 outputs a driving torque in the same direction as the rotational direction to generate a driving force, and when the torque command value is negative, the rotating electrical machine 13 is set in the rotational direction. Generates power by outputting regenerative torque in the opposite direction. In any case, the output torque (including drive torque and regenerative torque) of the rotating electrical machine 13 is determined by the torque command value from the rotating electrical machine control unit 5. Information on the torque command value of the rotating electrical machine 13 determined by the rotating electrical machine control unit 5 is also transmitted to the AT control unit 6. The brake control unit 7 inputs a detection signal of a brake pedal sensor 95 that detects an operation amount of the brake pedal, and evaluates the detection signal to control a wheel brake system. Further, the brake control unit 7 sends brake operation data to the rotating electrical machine control unit 5 based on the detection signal of the brake pedal sensor 95 to realize wheel brake control in cooperation with the regenerative torque of the rotating electrical machine 13.

  The AT control unit 6 includes an engine rotation speed sensor 91 that detects the rotation speed (number of rotations) of the engine 11, an input side rotation speed sensor 93 that detects the rotation speed on the input side of the transmission 20, and the output side of the transmission 20. A vehicle speed sensor (output-side rotational speed sensor) 92 corresponding to the rotational speed, a temperature sensor 94 for detecting the coolant temperature of the engine cooling water, and an accelerator opening detecting sensor 96 for detecting the accelerator opening by detecting the operation amount of the accelerator pedal. Detection information such as a brake pedal sensor 95 for detecting the operation amount of the brake pedal is sent via the sensor evaluation unit 9.

  The AT control unit 6 is divided into a friction engagement element control module 6A, a management module 6B, and a data input / output unit 6D for the sake of simplicity of explanation, but this division limits the present invention. Instead, it can be changed freely according to the program specifications. The friction engagement element control module 6A generates a command pressure for controlling the hydraulic pressure of a friction engagement element such as a brake or a clutch constituting the speed change mechanism 20A. Since the command pressure generation algorithm is well known, description thereof is omitted here. For example, a command pressure is generated based on a command pressure table mapped for each friction engagement element, and data input / output is performed. It sends out to the hydraulic equipment driver 33 via the part 6D. The data data input / output unit 6D is an input / output interface of the AT control unit 6, and inputs signals from the various sensors described above, outputs control signals to the hydraulic device driver 33, etc. Input and output data.

  The frictional engagement element control module 6A generates a control signal for hydraulic control of each frictional engagement element related to the shift process. Here, the friction on the engaged side in the shift process to a certain shift stage is generated. Only the first control unit 60a for controlling the engagement element and the second control unit 60b for controlling the friction engagement element on the released side are shown.

  The management module 6B constructs a function for managing the setting and execution of various shift control processes in the vehicle, and includes a shift command generation unit 61 and a shift process execution unit 62. The shift command generation unit 61 determines a target shift stage in the transmission mechanism 20A based on the accelerator opening of the vehicle, the vehicle speed, and the like, and controls the operation of the valve unit 32 according to the determined target shift stage, thereby shifting the speed. A shift command for switching the gear position of the mechanism 20A is generated. In order to generate such a target shift stage, a shift map is referred to.

  When the target shift speed in the transmission mechanism 20A is determined, a shift command corresponding to the determined target shift speed is generated, and finally the corresponding friction engagement element is engaged by receiving the hydraulic pressure supply. A target shift stage is formed. When the vehicle speed and the accelerator opening change and the upshift line or the downshift line is crossed on the shift map, the shift command generation unit 61 determines a new target shift stage based on the accelerator opening and the vehicle speed of the vehicle. A shift command corresponding to the determined target shift speed is generated. Based on the shift command generated by the shift command generation unit 61, the shift process execution unit 62 releases one of the friction engagement elements engaged before the shift, and is released before the shift. Managing the execution of a shifting process that engages one of the friction engagement elements present. For example, when the shift speed in the speed change mechanism 20A is upshifted from the third speed to the fourth speed, the first clutch C1 is released and the first brake B1 is engaged, and the speed is changed to the first speed. When downshifting from the fourth speed to the third speed, the first brake B1 is released and the first clutch C1 is engaged. Here, as described above, the control signal to the friction engagement element is generated in the friction engagement element control module 6A.

  The learning control unit 8 includes a friction torque management unit 69 and an evaluation module 6C. A friction torque management unit (hereinafter simply referred to as a management unit) 69 performs basic learning for constructing a friction torque map 68 as a friction torque deriving unit for deriving the friction torque from the engine speed described with reference to FIG. Manage processes. Further, the friction torque management unit 69 reads the friction torque from the engine rotation speed using the constructed friction torque map 68 and transfers it to a function unit that requires the friction torque, for example, the rotating electrical machine control unit 5. The management unit 69 and the map construction unit 67 described later constitute a “management unit” according to the present invention.

  Based on input signals from various sensors and data received from other control modules, the evaluation module 6C determines the state of transmission power (rotation speed, torque, etc.) handled in the speed change process and environmental conditions (such as oil temperature and oil temperature). It has a function to calculate and evaluate related water temperature and intake air temperature. In particular, functions relating to the present invention include a rotation speed acquisition unit 64, an oil temperature representative value acquisition unit 65, a friction torque calculation unit 66, a map construction unit 67, and a friction torque map 68.

  The rotational speed acquisition unit 64 receives information based on the detection signal of the engine rotational speed sensor 91 from the sensor evaluation unit 9 and acquires the engine rotational speed, here, the engine rotational speed (rpm). The oil temperature representative value acquisition unit 65 acquires an oil temperature representative value that represents the oil temperature of the lubricating oil of the engine 11. In this embodiment, the oil temperature representative value acquisition unit 65 receives information from the sensor evaluation unit 9 based on the detection signal of the temperature sensor 94 that detects the coolant temperature of the engine coolant, and corrects the oil temperature if necessary. Get a representative value. Of course, when a sensor that directly detects the oil temperature is mounted, the detection signal may be used, or the detection signal of another sensor may be used.

The friction torque calculator 66 calculates a rotation change rate based on a change in the engine speed (rotation speed) when the engine 11 is in a combustion stopped state, and the engine 11 based on the inertia of the engine 11 and the rotation change rate. The friction torque is calculated. The inertia of the engine 11 is obtained in advance, stored in a data storage unit such as a nonvolatile memory, and read out as necessary. In this embodiment, similar to the method described with reference to FIG. 1, the friction torque: F (N · m) is expressed by the following equation: F = I × r,
Where r is the rotation rate, I is the inertia of the engine 11,
Is required.

  In this embodiment, the map construction unit 67 includes a learning unit 67a and an update unit 67b. Based on the relationship between the friction torque calculated by the friction torque calculation unit 66 and the engine rotation number used for the calculation of the friction torque under the management of the management unit 69, the learning unit 67a ) To create a friction torque map 68 for deriving the friction torque. The updating unit 67a at least partially updates the content of the friction torque map 68 that has already been constructed based on the learning result of the learning unit 67a. In the configuration in which the friction torque map 68 is newly constructed by each learning process, the function of the update unit 67a is omitted.

  The friction torque learning process by the functional unit mounted on the evaluation module 6 </ b> C is performed in accordance with the state of the vehicle drive device, particularly the operation state of the engine 11, during traveling. Therefore, here, the management unit 69 issues a control command to the drive source control unit 4 and manages the drive source control unit 4. That is, when the management unit 69 stops the engine 11, the rotation speed (rotation speed) acquired by the rotation speed acquisition unit 64 and the friction torque calculated by the friction torque calculation unit 66 based on the rotation speed are calculated. The relationship is learned by the map construction unit 67 and a friction torque map is constructed. More specifically, the management unit 69 instructs the engine control unit 4a to stop the engine 11 while the vehicle is running, and first sets the output torque of the engine 11 to zero to rotate the engine 11 To maintain. Furthermore, after instructing the clutch control unit 4b to release the clutch 12, the engine control unit 4a is further instructed to put the engine 11 in a combustion stopped state. As a result, the above-described friction torque learning process is performed while the rotational speed of the engine 11 is decreased.

The flow of the friction torque learning process in the control device configured as described above will be described with reference to the timing chart of FIG. 5 and the flowchart of FIG.
When an engine stop request is issued while the vehicle is running and the engine stop process starts (# 22), first, the management unit 69 issues a command to set the engine torque to “zero” to the engine control unit 4a (#). 24; t01). Until the engine control unit 4a confirms that the engine torque has become “0”, the engine torque reduction process is continued by reducing the throttle opening or the fuel injection amount (t01 to t02). A process for increasing the motor torque is performed by the rotating electrical machine control unit 5 so as to compensate for the torque decrease in accordance with the engine torque decreasing process.

  If the engine torque becomes “0” (# 26 Yes branch: t02), the management unit 69 instructs the clutch control unit 4b to release the clutch 12 (# 28). As a result, the torque capacity of the clutch 12 moves toward “0” with a predetermined inclination (t02 to t03). Since the releasing process is performed after the engine torque becomes “0”, the releasing speed of the clutch 12 does not increase the rotating speed of the engine 11 and the rotating speed is maintained. If the torque capacity of the clutch 12 becomes “0” (# 30 Yes branch; t03), the management unit 69 instructs the engine control unit 4a to execute an engine combustion stop process for stopping the combustion of the engine 11 (# 32). ). Note that step # 30, which waits until the clutch torque capacity becomes “0”, can be performed by a timer instead of checking the clutch pressure command.

  By this engine combustion stop process, the engine speed goes to “0” (t03 to t05), but since the clutch 12 is released, the power transmission relationship with the engine 11 is cut off (here, 13 functioning as a motor) keeps its rotation speed and output torque constant. In this example, the traveling state of the vehicle is thereby maintained. On the other hand, a decrease in the engine speed is confirmed by the occurrence of differential rotation of the members on the engine side and the rotating electrical machine side in the clutch 12 (# 34: t04). Here, the differential rotation of the clutch 42 is detected based on the difference between the rotation speeds detected by the engine rotation speed sensor 91 and the input side rotation speed sensor 93. When differential rotation occurs in the clutch 12 (# 34 Yes branch), it is considered that the engine speed has started to decrease, and the above-described substantial friction torque learning process is performed (# 36: t04 to t05). That is, the friction torque calculation unit 66 calculates the rotation change rate from the engine speed detected over time, and calculates the friction torque from the rotation change rate and the inertia of the engine 11. Based on the calculation result, the map construction unit 67 obtains the correlation between the engine speed and the friction torque, and constructs the content of the friction torque map 68. In this embodiment, the friction torque learning process is performed until the engine speed reaches “0” under the management of the management unit 69, and when the engine speed reaches “0” (# 38 Yes branch: t05). ), The engine friction learning is finished, and the engine stop is completed (# 40).

  Although not shown in the flowchart of FIG. 6, in the friction torque learning process, as described above, the oil temperature representative value is acquired, and therefore, the friction torque map 68 is constructed for each preset oil temperature level. Will be.

  Next, as an example of drive control using the friction torque map 68 constructed in this way, the engine 11 is separated by releasing the clutch 12 while the vehicle is running, and a torque corresponding to the friction torque of the engine 11 is applied to the rotating electrical machine. The pseudo engine brake control output by 13 will be described with reference to the timing chart of FIG. 7 and the flowchart of FIG.

When the accelerator opening detection sensor 96 detects that the accelerator opening is equal to or less than a predetermined value (for example, 5%) (# 01 Yes branch), the fuel supply to the engine is stopped (# 02). This is the same as the fuel cut control of the general engine 11. If the predetermined time has passed in this state (# 03 Yes branch), the engine 11 is completely stopped and the process shifts to pseudo engine brake control. For this purpose, first, a release process of the clutch 12 is executed (# 04: t11). Since the clutch 12 has not slipped yet at the initial stage of the release process of the clutch 12, the rotational speed of the engine 11 is substantially maintained, and so-called engine brake is called from the engine 11 whose fuel supply is stopped. Negative torque is output. Thereafter, whether or not slip is generated in the clutch 12 is confirmed by occurrence of differential rotation between the engine side member and the rotating electrical machine side member in the clutch 12 (# 06). When differential rotation occurs in the clutch 12 (# 06 Yes branch: t12), the negative torque transmitted from the engine 11 to the output member 22 side decreases. That is, since the engine brake is reduced, the engine brake is simulated by outputting a negative torque from the rotating electrical machine 13 and applying it to the drive transmission system. That is, the friction torque of the engine 11 is simulated by the rotating electrical machine torque. Therefore, the management unit 69 reads the friction torque from the friction torque map 68 based on the current engine speed and oil temperature. Then, a value obtained by subtracting the clutch torque capacity of the clutch 12 from the read friction torque is commanded to the rotating electrical machine control unit 5 as a torque command value of the rotating electrical machine 13 (# 08). As described above, the process of increasing the torque command value of the rotating electrical machine 13 in the negative direction is performed until the clutch 11 is completely released, that is, until the clutch torque capacity becomes “0” (t12 to t13). .
When the clutch torque capacity becomes “0” (# 10 Yes branch: t13), the torque command value of the rotating electrical machine 13 coincides with the friction torque value based on the friction torque map 68 (# 12: t13). As a result, the rotating electrical machine 13 is in a state of simulating all of the friction torque of the engine 11 (pseudo engine braking state). Thereafter, the rotational speed of the engine 11 further decreases and finally becomes “0” (t14), and the engine 11 is completely stopped. During such pseudo engine brake control, the rotating electrical machine 13 outputs a negative torque, and during that time, the rotating electrical machine 13 generates power. Therefore, the energy efficiency of the vehicle can be increased.

[Other Embodiments]
(1) In the above embodiment, the engagement device 12 is formed as a hydraulic friction engagement device with a variable transmission torque capacity. Instead, for example, a dog clutch, an electromagnetic clutch or the like is used. Various other clutches or shut-off devices that shut off power transmission between the engine 11 and the rotating electrical machine can be employed.

(2) In the above embodiment, the various functional units that perform friction torque learning, the friction torque map 68, and the like are constructed in the learning control unit 8, but may be constructed in the drive source control unit 4. Alternatively, it may be constructed in the AT control unit 6 or in another control unit. The functional blocks shown in FIG. 3 and FIG. 4 are divided for the purpose of explanation, and the division of the functions is not limited by the present invention, and can be freely integrated and divided.

(3) In the above embodiment, the rotation change rate is calculated by the friction torque calculation unit from a plurality of rotation speeds (rotations) acquired over time. A configuration that uses a value calculated by the control unit may be adopted.

(4) In the above embodiment, the case where the friction torque map 68 constructed by learning is used for pseudo engine braking by the rotating electrical machine 13 has been described, but such use is only an example. For example, when the combustion of the engine is stopped with the engagement device 12 engaged and the vehicle is driven only by the torque of the rotating electrical machine 13, the torque command of the rotating electrical machine 13 is derived from the vehicle required torque and the friction torque map 68. Therefore, the present invention can be suitably used for control in which a command corresponding to the total value of the friction torque is used. By controlling the rotating electrical machine 13 in this way, it becomes possible to eliminate the influence of the drag of the engine 11 and transmit torque faithful to the vehicle required torque to the output member 22.

  INDUSTRIAL APPLICABILITY The present invention can be applied to a technique for estimating the friction torque of an internal combustion engine from the number of revolutions in a vehicle drive device in which the internal combustion engine and the rotating electrical machine are connected so as to transmit power via an engagement device.

4: drive source control unit 4a: engine control unit 4b: clutch control unit 5: rotating electrical machine control unit 11: internal combustion engine (engine)
12: Engagement device (clutch)
13: rotating electrical machine 20: transmission 20A: transmission mechanism 6: AT control unit 6A: friction engagement element control module 6B: management module 8: learning control unit 6C: evaluation module 61: shift command generation unit 62: shift process execution unit 64: Rotational speed acquisition unit 65: Oil temperature representative value acquisition unit 66: Friction torque calculation unit 67: Map construction unit 67a: Learning unit 67b: Update unit 68: Friction torque map (friction torque deriving unit)
69: Friction torque management unit (management unit)

Claims (3)

For a vehicle drive device provided in the order of an engagement device and a rotating electrical machine from the input member side on a power transmission path connecting an input member driven and connected to an internal combustion engine and an output member driven and connected to a wheel A control device of
A rotational speed acquisition unit for acquiring the rotational speed of the internal combustion engine;
Friction for calculating a rotational change rate based on a change in rotational speed of the internal combustion engine in a combustion stopped state of the internal combustion engine and calculating a friction torque of the internal combustion engine based on the inertia and the rotational change rate of the internal combustion engine A torque calculator,
When stopping the internal combustion engine, the relationship between the rotation speed acquired by the rotation speed acquisition unit and the friction torque calculated by the friction torque calculation unit based on the rotation speed is learned, and the rotation of the internal combustion engine A management unit for constructing and managing a friction torque deriving unit for deriving the friction torque from the speed based on the learning result;
Equipped with a,
When the management unit stops the internal combustion engine while the vehicle is running, first, the output torque of the internal combustion engine is set to zero to maintain the rotational speed of the internal combustion engine, and after releasing the engagement device, A control device that performs the learning in a process in which the internal combustion engine is in a combustion stopped state and the rotational speed of the internal combustion engine decreases . An oil temperature representative value acquisition unit that acquires an oil temperature representative value that is a value representative of the oil temperature of the internal combustion engine, and the management unit performs the learning in association with the oil temperature representative value;
2. The control device according to claim 1, wherein the friction torque deriving unit includes a friction torque map that defines a relationship between a rotation speed of the internal combustion engine and the friction torque in association with the representative oil temperature value. The rotating electrical machine control unit further controls the rotating electrical machine, and the rotating electrical machine control unit uses the friction torque derived by the friction torque deriving unit according to the rotational speed acquired by the rotational speed acquiring unit, control device according to claim 1 or 2 for controlling the output torque of the rotating electrical machine.

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