Hybrid vehicle control device

Abstract

To suppress a rapid increase of engine rotation speed during catalyst warming-up.SOLUTION: A hybrid vehicle 10 to which a control device 100 is applied comprises: an engine 11 having a crank shaft 22 and an exhaust passage 28; a motor generator 13; and a clutch 12 disposed in between the crank shaft 22 and the motor generator 13. A catalyst 35 is provided in the exhaust passage 28. The control device 100 comprises: a first execution device 110 for executing catalyst warming-up process of warming up the catalyst 35 in a condition where the hybrid vehicle 10 is stopped; and a second execution device 120 for controlling the clutch 12 and the motor generator 13. When the catalyst warming-up process is executed, the first execution device 110 requires the second execution device 120 to inhibit releasing of the clutch 12.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a control device for a hybrid vehicle. [Background technology]

[0002] Patent Document 1 discloses a control device applied to a hybrid vehicle that includes an engine, a motor generator, a clutch disposed between the engine crankshaft and the motor generator, and a starter motor. When the control device warms up a catalyst disposed in the exhaust passage of the engine with the clutch open and the crankshaft and the motor generator disconnected, the control device operates the engine with a load applied to the engine by the starter motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-94691 A Summary of the Invention [Problem to be solved by the invention]

[0004] Some hybrid vehicles equipped with a clutch between the crankshaft and the motor generator do not have a starter motor. In such hybrid vehicles, when the catalyst is warmed up with the clutch open, a large load cannot be applied to the engine. As a result, when the engine is operated to warm up the catalyst, the engine speed, which is the rotation speed of the crankshaft, increases rapidly.

[0005] This problem can also occur in hybrid vehicles equipped with a starter motor. In other words, if the starter motor cannot operate normally due to an abnormality in the starter motor or other reasons, the starter motor cannot apply an appropriate load to the engine, and the engine speed may suddenly increase when warming up the catalyst. [Means for solving the problem]

[0006] A hybrid vehicle control device for solving the above problems is applied to a hybrid vehicle that includes an engine having a crankshaft and an exhaust passage, a motor generator, and a clutch disposed between the crankshaft and the motor generator, and that is provided with a catalyst in the exhaust passage. The hybrid vehicle control device includes a first execution device that executes a catalyst warm-up process to warm up the catalyst when the hybrid vehicle is stopped, and a second execution device that controls the clutch and the motor generator. When the first execution device executes the catalyst warm-up process, it requests the second execution device to prohibit the clutch from being released.

[0007] When the clutch is engaged and the motor generator is connected to the crankshaft, a load can be applied to the engine by the motor generator. Therefore, in the above configuration, when the first execution device executes the catalyst warm-up process, the first execution device requests the second execution device to prohibit the clutch from being released. Then, the second execution device prevents the clutch from being released in accordance with the request. This allows the catalyst warm-up process to be executed with the motor generator connected to the crankshaft. That is, the engine can be operated so as to increase the temperature of the catalyst with a load applied to the engine by the motor generator. Therefore, it is possible to suppress a sudden increase in engine speed when warming up the catalyst.

[0008] In the above-mentioned hybrid vehicle control device, it is preferable that the first execution device starts the catalyst warm-up process when the clutch is engaged and the motor generator is connected to the crankshaft.

[0009] In the above-described configuration, catalyst warm-up is started with the motor generator connected to the crankshaft, so that a sudden increase in engine speed due to the start of the catalyst warm-up process can be suppressed.

[0010] In the above-mentioned control device for a hybrid vehicle, it is preferable that the first execution device terminates the catalyst warm-up process when the clutch is released and the connection between the crankshaft and the motor generator is released during execution of the catalyst warm-up process.

[0011] In the above-described configuration, when the clutch is released during the execution of the catalyst warm-up process, the catalyst warm-up process is terminated, and therefore, it is possible to prevent the catalyst warm-up process from being executed in a state in which the connection between the crankshaft and the motor generator is released.

[0012] In the above-mentioned control device for a hybrid vehicle, it is preferable that the first execution device determines that an abnormality has occurred when the clutch is released and the connection between the crankshaft and the motor generator is released during execution of the catalyst warm-up process.

[0013] If the clutch is released despite a request to the second execution device to prohibit the release of the clutch, there is a possibility that an abnormality has occurred in the clutch itself or in the actuator that operates the clutch. Therefore, in the above configuration, if the clutch is released while the catalyst warm-up process is being performed, it is determined that an abnormality has occurred. This makes it possible to detect abnormalities in the clutch or the actuator.

[0014] In the above-mentioned hybrid vehicle control device, it is preferable that, when the first execution device is executing the catalyst warm-up process, the second execution device causes the motor generator to output a torque that suppresses an increase in the rotation speed of the crankshaft.

[0015] According to the above configuration, when the catalyst warm-up process is being performed, the load applied to the engine by driving the motor generator can be increased, thereby making it possible to more effectively suppress a sudden increase in engine speed when the catalyst warm-up process is being performed. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a configuration diagram showing a control device which is an embodiment of a control device for a hybrid vehicle, and a drive system of the hybrid vehicle. [Diagram 2] FIG. 2 is a flowchart showing a processing routine executed by the first execution unit of the control device. [Diagram 3] FIG. 3 is a flowchart showing a processing routine executed by the second execution unit of the control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, one embodiment of a control device for a hybrid vehicle will be described with reference to Figs. 1 shows a schematic configuration of a hybrid vehicle 10. The hybrid vehicle 10 includes a drive system of the hybrid vehicle 10 and a control device 100 that controls the drive system. In this embodiment, the control device 100 corresponds to a "hybrid vehicle control device."

[0018] <Hybrid vehicle 10 drive system> The drive system of the hybrid vehicle 10 includes an engine 11, a clutch 12, a motor generator 13, a transmission 14, and drive wheels 15. The clutch 12 is disposed between the engine 11 and the motor generator 13 in the power transmission path. In addition, the transmission 14 is disposed between the motor generator 13 and the drive wheels 15 in the power transmission path. In this embodiment, a starter motor is not provided in the drive system.

[0019] The engine 11 has a plurality of cylinders 21 and a crankshaft 22. Pistons are housed in the plurality of cylinders 21, and the crankshaft 22 rotates in synchronization with the reciprocating motion of the plurality of pistons.

[0020] The engine 11 has an intake passage 26 and an exhaust passage 28. The intake passage 26 is a passage through which intake air flows to be introduced into the multiple cylinders 21. The amount of intake air flowing through the intake passage 26 can be adjusted by the opening degree of a throttle valve. The exhaust passage 28 is a passage through which gas exhausted from the multiple cylinders 21 flows. An oxygen storage type catalyst 35 is provided in the exhaust passage 28.

[0021] The engine 11 has a plurality of spark plugs 29 and a plurality of fuel injection valves. In the example shown in FIG. 1, one spark plug 29 is provided for each of the cylinders 21. In addition, in the example shown in FIG. 1, a port injection valve 30 that injects fuel into the intake passage 26 and an in-cylinder injection valve 31 that injects fuel into the cylinder 21 are provided as fuel injection valves. That is, one port injection valve 30 and one in-cylinder injection valve 31 are provided for each cylinder 21. In the cylinder 21, a mixture containing fuel injected from at least one of the port injection valve 30 and the in-cylinder injection valve 31 and intake air introduced into the cylinder 21 from the intake passage 26 is burned by spark discharge of the spark plug 29. Exhaust gas generated by the combustion of the mixture is discharged from the cylinder 21 to the exhaust passage 28.

[0022] The clutch 12 connects the crankshaft 22 to the motor generator 13. The clutch 12 is operated under the control of the control device 100. The clutch 12 may be, for example, a hydraulically driven clutch or an electromagnetically driven clutch. When the clutch 12 is engaged, the motor generator 13 is connected to the crankshaft 22. Therefore, when the clutch 12 is engaged, the crankshaft 22 can be rotated by the drive of the motor generator 13. On the other hand, when the clutch 12 is disengaged, the connection between the crankshaft 22 and the motor generator 13 is released.

[0023] <Control device 100> The control device 100 receives detection signals from a plurality of types of sensors provided in the hybrid vehicle 10. For example, the control device 100 receives detection signals from a vehicle speed sensor 60, an accelerator opening sensor 61, a crank angle sensor 62, an air flow meter 63, a water temperature sensor 64, and a catalyst temperature sensor 65. The vehicle speed sensor 60 detects a vehicle speed SP, which is the traveling speed of the hybrid vehicle 10, and outputs a detection signal according to the detection result. The accelerator opening sensor 61 detects an accelerator opening AC, which is the opening of the accelerator pedal, and outputs a detection signal according to the detection result. The crank angle sensor 62 outputs a detection signal according to the engine speed Ne, which is the rotation speed of the crankshaft 22. The air flow meter 63 detects an intake air amount GA, which is the amount of intake air flowing through the intake passage 26, and outputs a detection signal according to the detection result. The water temperature sensor 64 detects an engine cooling water temperature Twt, which is the temperature of the cooling water circulating in the engine 11, and outputs a detection signal according to the detection result. The catalyst temperature sensor 65 detects the catalyst temperature Tc, which is the temperature of the catalyst 35, and outputs a detection signal according to the detection result. The control device 100 controls the engine 11, the clutch 12, the motor generator 13, and the transmission 14 based on the detection signals input from the multiple types of sensors.

[0024] The control device 100 includes a first execution unit 110 that controls the operation of the engine 11, and a second execution unit 120 that controls the clutch 12 and the motor generator 13. The first execution unit 110 and the second execution unit 120 are configured to be able to communicate with each other. The first execution unit 110 includes a CPU 111 and a memory 112. The memory 112 stores a control program executed by the CPU 111. The second execution unit 120 includes a CPU 121 and a memory 122. The memory 122 stores a control program executed by the CPU 121.

[0025] When a predetermined execution condition is met, the first execution device 110 executes a catalyst warm-up process that warms up the catalyst 35. In the catalyst warm-up process, the first execution device 110 operates the engine 11 so that exhaust gas at a higher temperature is discharged from each cylinder 21 to the exhaust passage 28 than when the catalyst warm-up process is not being executed. For example, in the catalyst warm-up process, the first execution device 110 retards the ignition timing compared to when the catalyst warm-up process is not being executed.

[0026] Furthermore, the first execution unit 110 requests the second execution unit 120 to prohibit the clutch 12 from being released prior to the execution of the catalyst warm-up process. When the second execution unit 120 receives a request to prohibit the release of the clutch 12 from the first execution unit 110, it engages the clutch 12 to maintain the state in which the motor generator 13 is connected to the crankshaft 22. In addition, the second execution unit 120 outputs regenerative torque from the motor generator 13 so as to prevent a sudden increase in the engine speed Ne during the execution of the catalyst warm-up process. The regenerative torque here refers to the output torque of the motor generator 13 in a direction that prevents the rotation of the crankshaft 22.

[0027] 2, a description will be given of a processing routine executed by the first execution device 110 when warming up the catalyst 35. A control program corresponding to this processing routine is executed by the CPU 111 at each predetermined control cycle.

[0028] In step S11 of this processing routine, the first execution unit 110 judges whether the vehicle is stopped. For example, the first execution unit 110 judges that the vehicle is stopped when the duration of the state in which the vehicle speed SP detected by the vehicle speed sensor 60 is equal to or lower than the stopped vehicle judgment vehicle speed is equal to or longer than the judgment time. On the other hand, the first execution unit 110 judges that the vehicle is not stopped when the duration is less than the judgment time. If it is judged that the vehicle is not stopped (S11: NO), the first execution unit 110 shifts the processing to step S27. On the other hand, if it is judged that the vehicle is stopped (S11: YES), the first execution unit 110 shifts the processing to step S13.

[0029] In step S13, the first execution unit 110 judges whether the catalyst temperature Tc detected by the catalyst temperature sensor 65 is less than the lower limit TcLL of the activation temperature region. When the catalyst temperature Tc is within the activation temperature region, the catalyst 35 can fully purify the exhaust gas. On the other hand, when the catalyst temperature Tc is not within the activation temperature region, the catalyst 35 may not fully purify the exhaust gas. Therefore, when the catalyst temperature Tc is less than the lower limit TcLL, it is preferable to execute the catalyst warm-up process to warm up the catalyst 35. On the other hand, when the catalyst temperature Tc is equal to or greater than the lower limit TcLL, the catalyst warm-up process does not need to be executed. Therefore, when the catalyst temperature Tc is equal to or greater than the lower limit TcLL (S13: NO), the first execution unit 110 shifts the process to step S29. On the other hand, when the catalyst temperature Tc is less than the lower limit TcLL (S13: YES), the first execution unit 110 shifts the process to step S15. That is, when the hybrid vehicle 10 is stopped and the catalyst temperature Tc is less than the lower limit TcLL, the first execution device 110 can determine that the predetermined execution condition is met, and therefore proceeds to step S15.

[0030] In step S15, the first execution unit 110 judges whether or not the clutch release flag FLG1 is set to ON. The clutch release flag FLG1 is a flag for judging whether or not a request has been made to the second execution unit 120 to prohibit the release of the clutch 12. If the clutch release flag FLG1 is set to ON, a request has already been made to the second execution unit 120 to prohibit the release of the clutch 12. On the other hand, if the clutch release flag FLG1 is not set to ON, a request has not yet been made to the second execution unit 120 to prohibit the release of the clutch 12. If the clutch release flag FLG1 is not set to ON (S15: NO), the first execution unit 110 proceeds to step S17.

[0031] In step S17, the first execution unit 110 requests the second execution unit 120 to engage the clutch 12. That is, the first execution unit 110 transmits a request to prohibit the release of the clutch 12 to the second execution unit 120. Then, in step S19, the first execution unit 110 sets the clutch release flag FLG1 to ON. After that, the first execution unit 110 temporarily ends this processing routine.

[0032] On the other hand, if the clutch release flag FLG1 is set to ON in step S15 (YES), the first execution unit 110 proceeds to step S21. In step S21, the first execution unit 110 determines whether the clutch 12 is released or not based on the information received from the second execution unit 120. If it is determined that the clutch 12 is not released (S21: NO), the first execution unit 110 proceeds to step S23.

[0033] In step S23, the first execution unit 110 executes the catalyst warm-up process. That is, the first execution unit 110 executes the catalyst warm-up process on the condition that the clutch 12 is engaged. Then, the first execution unit 110 temporarily ends this processing routine.

[0034] On the other hand, if it is determined in step S21 that the clutch 12 has been released (YES), the clutch 12 has been released despite the fact that release of the clutch 12 is prohibited, and so the first execution unit 110 shifts the process to step S25. In step S25, the first execution unit 110 determines that an abnormality has occurred. That is, the first execution unit 110 determines that an abnormality has occurred in the clutch 12 itself or in the actuator for operating the clutch 12, and therefore the clutch 12 cannot be engaged. Then, the first execution unit 110 shifts the process to step S27.

[0035] In step S27, the first execution unit 110 ends the execution of the catalyst warm-up process, and then the first execution unit 110 proceeds to step S29. In step S29, the first execution unit 110 sets the clutch release flag FLG1 to OFF, and then the first execution unit 110 temporarily ends this processing routine.

[0036] 3, a processing routine executed by the second execution device 120 when the catalyst warm-up process is being executed by the first execution device 110 will be described. A control program corresponding to this processing routine is executed by the CPU 121 at every predetermined control cycle when the catalyst warm-up process is being executed.

[0037] In this processing routine, in step S41, the second execution unit 120 acquires the state of the clutch 12. The "state of the clutch 12" acquired here is whether the clutch 12 is released or engaged. For example, if the clutch 12 is hydraulically driven, the second execution unit 120 acquires the state of the clutch 12 based on the hydraulic pressure generated by an actuator for the clutch 12. Also, for example, if the clutch 12 is electromagnetically driven, the second execution unit 120 acquires the state of the clutch 12 based on the magnitude of the current flowing through the actuator for the clutch 12.

[0038] In step S43, the second execution unit 120 transmits the state of the clutch 12 acquired in step S41 to the first execution unit 110. Based on the transmitted state of the clutch 12, the first execution unit 110 determines whether the clutch 12 is released or not (S21). After transmitting the state of the clutch 12 to the first execution unit 110, the second execution unit 120 temporarily ends this processing routine.

[0039] <Actions and Effects of the Present Embodiment> (1) The first execution unit 110 executes the catalyst warm-up process after requesting the second execution unit 120 to prohibit the release of the clutch 12. This allows the first execution unit 110 to execute the catalyst warm-up process in a state in which the output torque of the motor generator 13 can be transmitted to the crankshaft 22. This makes it possible to prevent the engine speed Ne from rising sharply due to the execution of the catalyst warm-up process.

[0040] In this embodiment, the catalyst warm-up process is executed when the hybrid vehicle 10 is stopped. In other words, the catalyst warm-up process is executed when the engine speed Ne can be adjusted by driving the motor generator 13. On the other hand, when the hybrid vehicle 10 starts moving, it becomes difficult to adjust the engine speed Ne by driving the motor generator 13, so the catalyst warm-up process is terminated.

[0041] (2) The catalyst warm-up process is started in a state in which the clutch 12 is engaged and the motor generator 13 is connected to the crankshaft 22. Therefore, it is possible to suppress a sudden increase in the engine speed Ne due to the start of the catalyst warm-up process.

[0042] (3) It is possible that the clutch 12 may be released while the catalyst warm-up process is being performed. In this embodiment, if the clutch 12 is released while the catalyst warm-up process is being performed, the catalyst warm-up process is terminated. This makes it possible to prevent the engine 11 from operating to warm up the catalyst 35 while the connection between the crankshaft 22 and the motor generator 13 is released.

[0043] (4) If the clutch 12 is released despite the first execution device 110 requesting the second execution device 120 to prohibit the release of the clutch 12, there is a possibility that an abnormality has occurred in the clutch 12 or the actuator of the clutch 12. Therefore, in this embodiment, if the clutch 12 is released while the catalyst warm-up process is being executed, it is determined that an abnormality has occurred. In other words, an abnormality in the clutch 12 or the actuator of the clutch 12 can be detected even while the catalyst warm-up process is being executed.

[0044] (5) When the catalyst warm-up process is being executed, the motor generator 13 outputs regenerative torque. This makes it possible to adjust the magnitude of the load applied to the engine 11. As a result, it is possible to more effectively suppress a sudden increase in the engine speed Ne due to the execution of the catalyst warm-up process.

[0045] In addition, by making the motor generator 13 output regenerative torque, the engine 11 can be operated in an operating state with a higher engine load factor KL. This increases the temperature of the exhaust gas discharged from each cylinder 21 to the exhaust passage 28. This contributes to early completion of warming up the catalyst 35.

[0046] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other to the extent that no technical contradiction occurs.

[0047] The catalyst warm-up process may include control other than ignition retardation, so long as it can increase the temperature of the exhaust gas discharged from each cylinder 21 into the exhaust passage 28 compared to when the catalyst warm-up process is not performed. For example, the catalyst warm-up process may cause stratified charge combustion to occur in the cylinder 21.

[0048] The process of determining that an abnormality has occurred when the clutch 12 is released during the catalyst warm-up process may be omitted. That is, the process of step S25 in the process routine shown in FIG.

[0049] During the catalyst warm-up process, the motor generator 13 does not need to output regenerative torque, which is a torque that suppresses an increase in the engine speed Ne. This is because, compared to when the clutch 12 is disengaged, the load applied to the crankshaft 22 can be increased by engaging the clutch 12 and connecting the motor generator 13 to the crankshaft 22. The greater the load applied to the crankshaft 22, the more difficult it becomes for the engine speed Ne to increase.

[0050] In the above embodiment, when the catalyst temperature Tc becomes equal to or higher than the lower limit TcLL during the execution of the catalyst warm-up process as shown in Fig. 2, the execution of the catalyst warm-up process is continued until the hybrid vehicle 10 starts moving, but this is not limited to the above. That is, when the catalyst temperature Tc becomes equal to or higher than the lower limit TcLL during the execution of the catalyst warm-up process (S13: NO), the first execution device 110 may shift the process to step S27 and end the execution of the catalyst warm-up process.

[0051] The drive system of the hybrid vehicle 10 may be configured to include a starter motor. The execution devices 110, 120 are not limited to those equipped with a CPU and ROM and executing software processing. In other words, the execution devices 110, 120 may have any one of the following configurations (a) to (c). (a) The execution devices 110, 120 include one or more processors that execute various processes according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores program codes or instructions configured to cause the CPU to execute processes. Memory, i.e., computer-readable media, includes any available media that can be accessed by a general-purpose or special-purpose computer. (b) The execution devices 110, 120 each include one or more dedicated hardware circuits for executing various processes. Examples of dedicated hardware circuits include application specific integrated circuits, i.e., ASIC and FPGA. ASIC is an abbreviation for "Application Specific Integrated Circuit" and "FPGA" is an abbreviation for "Field Programmable Gate Array." (c) The execution devices 110 and 120 each include a processor that executes some of the various processes in accordance with a computer program, and a dedicated hardware circuit that executes the remaining processes among the various processes. [Explanation of symbols]

[0052] 10. Hybrid vehicle 11…Engine 12…Clutch 13...Motor generator 22…Crankshaft 28…Exhaust passage 35...Catalyst 100...Control device 110...First execution device 120...Second execution device

Claims

1. The present invention is applied to a hybrid vehicle including an engine having a crankshaft and an exhaust passage, a motor generator, and a clutch disposed between the crankshaft and the motor generator, the hybrid vehicle having a catalyst disposed in the exhaust passage, a first execution device that executes a catalyst warm-up process to warm up the catalyst while the hybrid vehicle is stopped; a second execution device that controls the clutch and the motor generator, The first execution device is when the catalyst warm-up process is to be executed, a request is made to the second execution device to prohibit disengagement of the clutch; The catalyst warm-up process is started when the clutch is engaged and the motor generator is connected to the crankshaft, and the catalyst warm-up process is ended when the clutch is released during the execution of the catalyst warm-up process and the connection between the crankshaft and the motor generator is released. Hybrid vehicle control device.

2. The present invention is applied to a hybrid vehicle including an engine having a crankshaft and an exhaust passage, a motor generator, and a clutch disposed between the crankshaft and the motor generator, the hybrid vehicle having a catalyst disposed in the exhaust passage, a first execution device that executes a catalyst warm-up process to warm up the catalyst while the hybrid vehicle is stopped; a second execution device that controls the clutch and the motor generator, The first execution device is when the catalyst warm-up process is to be executed, a request is made to the second execution device to prohibit disengagement of the clutch; The catalyst warm-up process is started when the clutch is engaged and the motor generator is connected to the crankshaft, and if the clutch is released during the execution of the catalyst warm-up process and the connection between the crankshaft and the motor generator is released, it is determined that an abnormality has occurred. Hybrid vehicle control device.

3. The second execution unit causes the motor generator to output a torque that suppresses an increase in the rotation speed of the crankshaft when the first execution unit is executing the catalyst warm-up process. The control device for a hybrid vehicle according to claim 1 or 2.

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