Control device of vehicle

Abstract

To restrain a crank shaft from being stopped at position away from position of target crank angle.SOLUTION: A control device executes stop processing for stopping a crank shaft at position of target crank angle SC by the applying torque T applied from a first motor generator when stopping drive of an internal combustion engine. The control device executes determination processing which determines whether or not the crank shaft continues rotation of specified quantity or more while applying the applying torque T by the stop processing. The control device executes correction processing which corrects the applying torque T according to the position of the crank angle SC of the crank shaft when it is determined that the crank shaft does not continue the rotation of the specified quantity or more when it is determined that in determination processing, the crank shaft does not continue the rotation of the specified quantity or more.SELECTED DRAWING: Figure 2

Description

Technical Field

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

Background Art

[0002] Patent Document 1 describes a vehicle including an internal combustion engine and a motor generator. The motor generator is connected to the crankshaft of the internal combustion engine and can apply torque to the crankshaft. When stopping the driving of the internal combustion engine, the vehicle control device executes a stop process for stopping the crankshaft at a target angular position by the torque from the motor generator.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a vehicle as described in Patent Document 1, depending on the state of the internal combustion engine, there may be a case where the crankshaft cannot be continuously rotated by a predetermined amount or more by the torque from the motor generator in the stop process. In this case, the crankshaft may stop at a position away from the position of the target crank angle.

Means for Solving the Problems

[0005] To solve the above problems, the present invention is a control device applied to a vehicle including an internal combustion engine and a motor generator connected to a crankshaft of the internal combustion engine and capable of applying torque to the crankshaft. When stopping the drive of the internal combustion engine, a stop process for stopping the crankshaft at a position of a target crank angle by torque applied from the motor generator, a determination process for determining whether or not the crankshaft continues to rotate by a predetermined amount or more during the stop process, and when it is determined in the determination process that the crankshaft does not continue to rotate by the predetermined amount or more, a correction process for correcting the torque applied from the motor generator by the stop process according to the position of the crank angle of the crankshaft when it is determined that the crankshaft does not continue to rotate by the predetermined amount or more are executed.

[0006] According to the above configuration, when the crankshaft cannot continue to rotate by a predetermined amount or more due to the torque applied from the motor generator in the stop process, the torque applied from the motor generator is corrected according to the position of the crank angle. It is possible to suppress the crankshaft from stopping in a state away from the position of the target crank angle by the torque corrected according to the position of the crank angle.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0008] Hereinafter, an embodiment of a control device for a vehicle will be described with reference to the drawings. <Schematic of the Vehicle> As shown in FIG. 1, the vehicle 500 includes an internal combustion engine 10, a power split integrated mechanism 40 to which a crankshaft 14, which is an output shaft of the internal combustion engine 10, is connected, and a first motor generator 71 and a second motor generator 72 connected to the power split integrated mechanism 40.

[0009] The power split integrated mechanism 40 is a planetary gear mechanism and includes a sun gear 41 of an external gear and a ring gear 42 of an internal gear. The sun gear 41 is located at the center of the ring gear 42. The sun gear 41 rotates coaxially with the ring gear 42. A plurality of pinion gears 43 are interposed between the sun gear 41 and the ring gear 42. Each pinion gear 43 meshes with both the sun gear 41 and the ring gear 42. Each pinion gear 43 is supported by a carrier 44 in a state where it can rotate and revolve around the sun gear 41. The carrier 44 rotates coaxially with the sun gear 41 as the pinion gear 43 revolves.

[0010] The sun gear 41 is connected to the first motor generator 71. That is, the sun gear 41 is configured to be interlocked with the first motor generator 71. The carrier 44 is connected to the crankshaft 14. That is, the carrier 44 is configured to be interlocked with the crankshaft 14. The ring gear 42 is connected to a ring gear shaft 45. And the ring gear shaft 45 is connected to the second motor generator 72 via a reduction gear 50. That is, the ring gear shaft 45 and thus the ring gear 42 are configured to be interlocked with the second motor generator 72. Further, the ring gear shaft 45 is connected to the left and right drive wheels 62 via a reduction mechanism 60 and a differential 61. That is, the ring gear shaft 45 and thus the ring gear 42 are configured to be interlocked with the drive wheels 62.

[0011] The reduction gear 50 is a planetary gear mechanism. That is, the reduction gear 50 includes a ring gear 52 of an internal gear, a sun gear 51 of an external gear, and a plurality of pinion gears 53 positioned between the sun gear 51 and the ring gear 52. Each pinion gear 53 is rotatable on its own and is supported in a state where it cannot revolve around the sun gear 51.

[0012] The vehicle 500 includes a first inverter 76, a second inverter 77, and a battery 78. The first inverter 76 and the second inverter 77 perform AC / DC power conversion and adjust the amount of power transfer between each motor generator and the battery 78.

[0013] The vehicle 500 includes an accelerator sensor 91, a vehicle speed sensor 92, a crank angle sensor 93, and a water temperature sensor 94. The accelerator sensor 91 detects an accelerator operation amount ACC, which is the amount of depression of the accelerator pedal in the vehicle 500. The vehicle speed sensor 92 detects a vehicle speed SP, which is the traveling speed of the vehicle 500. The crank angle sensor 93 detects a crank angle SC, which is the rotational position of the crankshaft 14. The water temperature sensor 94 detects a cooling water temperature THW, which is the temperature of the cooling water flowing through each part of the internal combustion engine 10.

[0014] The vehicle 500 includes a control device 100. The control device 100 acquires a signal indicating the accelerator operation amount ACC, a signal indicating the vehicle speed SP, a signal indicating the crank angle SC, and a signal indicating the cooling water temperature THW from each sensor.

[0015] The control device 100 calculates a vehicle required driving force, which is a required value of the driving force necessary for the vehicle 500 to travel, based on the accelerator operation amount ACC and the vehicle speed SP. The control device 100 determines the torque distribution among the internal combustion engine 10, the first motor generator 71, and the second motor generator 72 based on the vehicle required driving force. The control device 100 controls the output of the internal combustion engine 10, and the power running and regeneration of the first motor generator 71 and the second motor generator 72 based on the determined torque distribution. Further, the control device 100 controls the first motor generator 71 via the first inverter 76 by outputting a control signal to the first inverter 76. Furthermore, the control device 100 controls the second motor generator 72 via the second inverter 77 by outputting a control signal to the second inverter 77.

[0016] Also, when the vehicle 500 is traveling, the control device 100 selects either the EV mode or the HV mode as the traveling mode of the vehicle 500. Here, the EV mode is a traveling mode in which the internal combustion engine 10 is stopped while the first motor generator 71 and the second motor generator 72 are driven to make the vehicle 500 travel. The HV mode is a traveling mode of the vehicle 500 in which, in addition to the first motor generator 71 and the second motor generator 72, the internal combustion engine 10 is driven to make the vehicle 500 travel.

[0017] Note that the control device 100 can be configured as a circuit including one or more processors that execute various processes according to a computer program (software). The processor includes a CPU and a memory such as a RAM and a ROM. The memory stores program codes or instructions configured to cause the CPU to execute processes. The memory has a counter. The counter stores the number of times it is determined that the change amount ΔSC of the crank angle SC described later is equal to or less than a predetermined amount.

[0018] As shown in FIG. 2, the control device 100 repeatedly performs a series of processes for stopping the operation of the internal combustion engine 10 at a predetermined period.

[0019] When starting a series of processes, the control device 100 first executes the process of step S11. In step S11, the control device 100 determines whether there is a stop request for the internal combustion engine 10. For example, when the driving mode of the vehicle 500 is switched from the HV mode to the EV mode, the control device 100 determines that there is a stop request for the internal combustion engine 10 until the internal combustion engine 10 stops. On the other hand, when the control device 100 continues to drive the internal combustion engine 10 or when the driving of the internal combustion engine 10 has stopped, the control device 100 determines that there is no stop request for the internal combustion engine 10.

[0020] When it is determined that there is no stop request for the internal combustion engine 10 (S11: NO), the control device 100 ends the series of processes. On the other hand, when it is determined that there is a stop request for the internal combustion engine 10 (S11: YES), after starting the control to stop the driving of the internal combustion engine 10, the control device 100 advances the process to step S12. The control to stop the driving of the internal combustion engine 10 is, for example, a well-known control involving fuel cut, and the details are omitted. By repeating the series of processes, when the control to stop the driving of the internal combustion engine 10 has already been started, the control device 100 continues the control.

[0021] In step S12, the control device 100 determines whether the engine rotational speed NE, which is the number of rotations of the crankshaft 14 per unit time, is equal to or less than a predetermined speed. The control device 100 calculates the engine rotational speed NE based on the crank angle SC. The predetermined speed is determined, by means of tests, simulations, etc. in advance, as a speed at which the engine rotational speed NE becomes sufficiently small by the control to stop the driving of the internal combustion engine 10, so that the applied torque T described later can be applied.

[0022] When the engine rotational speed NE exceeds a predetermined speed (S12: NO), the control device 100 ends a series of processes. On the other hand, when the engine rotational speed NE is equal to or lower than the predetermined speed (S12: YES), the control device 100 advances the process to step S13.

[0023] In step S13, the control device 100 calculates an applied torque T, which is the torque applied from the first motor generator 71 to the crankshaft 14. The control device 100 calculates the applied torque T based on the coolant water temperature THW, the engine rotational speed NE, and the crank angle SC. Then, the control device 100 advances the process to step S14.

[0024] In step S14, the control device 100 determines whether or not the applied torque T is being output. That is, by repeating a series of processes, the control device 100 has already performed the process of step S21, which is a stop process described later, and determines whether or not the applied torque T is being output by the stop process. When the applied torque T is being output (S14: YES), the control device 100 advances the process to step S15.

[0025] In step S15, the control device 100 calculates a change amount ΔSC of the crank angle SC. Specifically, the control device 100 calculates the difference between the crank angle SC acquired in step S13 in the current series of processes and the crank angle SC acquired in step S13 in the previous series of processes by repeating the series of processes. Then, the control device 100 advances the process to step S16.

[0026] In step S16, the control device 100 determines whether or not the change amount ΔSC is equal to or less than a predetermined amount. The predetermined amount is determined as the change amount per unit time when the crankshaft 14 cannot continue the desired rotation despite the applied torque T being applied, through tests, simulations, etc. in advance. When the change amount ΔSC is equal to or less than the predetermined amount (S16: YES), the control device 100 advances the process to step S17.

[0027] In step S17, the control device 100 increments the counter of the control device 100. Specifically, the control device 100 increases the value of the counter in the memory by one from the previous value. After that, the control device 100 proceeds with the process to step S18.

[0028] In step S18, the control device 100 determines whether the value of the counter is equal to or greater than a predetermined value. The predetermined value is determined in advance by tests, simulations, etc., as the number of times the crankshaft 14 cannot continue the desired rotation when the change amount ΔSC is equal to or less than a predetermined amount. When the value of the counter is equal to or greater than the predetermined value (S18: YES), the control device 100 proceeds with the process to step S19. That is, in the present embodiment, the affirmative determination in the process of step S18 means that the control device 100 determines that the crankshaft 14 has not continued to rotate by a predetermined amount or more during the stop process. Note that in the present embodiment, the processes from step S15 to step S18 are determination processes.

[0029] In step S19, the control device 100 calculates the correction coefficient kt of the applied torque T. The control device 100 sets the correction coefficient kt according to the position of the crank angle SC when the affirmative determination is made in step S18. Specifically, first, the control device 100 determines whether the crank angle SC when the affirmative determination is made in step S18 is within a predetermined range including the position of the target crank angle SC. When the crank angle SC when the affirmative determination is made in step S18 is within the predetermined range, the control device 100 sets the correction coefficient kt to a value less than 1. In a series of processes, the control device 100 sets the correction coefficient kt to a smaller value as the number of times the crank angle SC when the affirmative determination is made in step S18 is within the predetermined range including the position of the target crank angle SC increases. On the other hand, when the crank angle SC when the affirmative determination is made in step S18 is outside the predetermined range, the control device 100 sets the correction coefficient kt to a value greater than 1. In a series of processes, the control device 100 sets the correction coefficient kt to a larger value as the number of times the crank angle SC when the affirmative determination is made in step S18 is outside the predetermined range including the position of the target crank angle SC increases. After that, the control device 100 proceeds with the process to step S20.

[0030] In step S20, the control device 100 corrects the applied torque T. Specifically, the applied torque T calculated in step S13 is multiplied by the correction coefficient kt calculated in step S19 to correct it to a new applied torque T. Then, the control device 100 advances the process to step S21. Note that in this embodiment, steps S20 and S21 are correction processes.

[0031] In step S21, the control device 100 controls the first motor generator 71 via the first inverter 76 to apply the applied torque T to the crankshaft 14 in order to stop the crankshaft 14 at the target crank angle SC. In this embodiment, step S21 is a stop process. Then, the control device 100 ends a series of processes. Note that the control device 100 continues to apply the applied torque T until it newly performs the process of step S21 or until the control to stop the driving of the internal combustion engine 10 is completed.

[0032] By the way, when the change amount ΔSC exceeds a predetermined amount (S16: NO), the control device 100 advances the process to step S22. In step S22, the control device 100 clears the counter. Then, the control device 100 advances the process to step S21. Therefore, when performing step S21 via step S22, the control device 100 does not correct the applied torque T. Note that when the applied torque T is not applied (S14: NO) or when the value of the counter is less than a predetermined value (S18: YES), the control device 100 advances the process to step S21. Then, the control device 100 ends a series of processes.

[0033] <Operations and Effects of the Embodiment> Depending on the aging and usage environment of the internal combustion engine 10, there may be cases where the crankshaft 14 cannot be rotated by a predetermined amount or more by the applied torque T before correction. According to the above embodiment, when the control device 100 determines that the crankshaft 14 has not continued to rotate by a predetermined amount or more during the stop process, the control device 100 corrects the applied torque T according to the crank angle SC at the time of the determination. By the applied torque T corrected according to the position of the crank angle SC, it is possible to suppress the crankshaft 14 from being stopped in a state away from the position of the target crank angle SC.

[0034] Specifically, when the crank angle SC is not rotated while being located within a predetermined range including the target position, it can be said that the crankshaft 14 has already stopped at the position of the target crank angle SC. In this state, if the stop process ends while the applied torque T is still applied, the crankshaft 14 may rotate due to the reaction force when the applied torque T is no longer applied, and the position of the crank angle SC may shift outside the predetermined range. According to the above embodiment, when the crank angle SC at the time of determining that the rotation of more than a predetermined amount has not continued is located within the predetermined range and the change amount ΔSC continues to be equal to or less than the predetermined amount, the control device 100 gradually reduces the applied torque T from before the correction. Thereby, by preventing the reaction force from being applied suddenly, it is possible to prevent the crank angle SC from shifting outside the predetermined range when the stop process ends.

[0035] On the other hand, when the crank angle SC is not rotated while being located outside the predetermined range, according to the above embodiment, the control device 100 determines in the determination process that the rotation of more than a predetermined amount has not continued. Further, since the crank angle SC at the time of the determination is outside the predetermined range, the control device 100 corrects the applied torque T to be larger than before the correction until the change amount ΔSC exceeds the predetermined amount. Thereby, by rotating the crankshaft 14 with the applied torque T increased by the correction, the crank angle SC can be positioned within the predetermined range. Since the control device 100 does not perform the correction when the change amount ΔSC exceeds the predetermined amount, the rotation of the crankshaft 14 stops. Therefore, the crank angle SC can be positioned within the predetermined range.

Description of Symbols

[0036] 10…Internal combustion engine, 14…Crankshaft, 71…First motor generator, 72…Second motor generator, 100…Control device, 500…Vehicle

Claims

【Claim 1】 A control device applied to a vehicle including an internal combustion engine and a motor generator connected to a crankshaft of the internal combustion engine and capable of applying torque to the crankshaft, comprising: a stop process for stopping the crankshaft at a position of a target crank angle by torque applied from the motor generator when stopping the driving of the internal combustion engine; a determination process for determining whether the crankshaft continues to rotate by a predetermined amount or more while torque is being applied from the motor generator by the stop process; a correction process for correcting the torque applied from the motor generator by the stop process according to the position of the crank angle of the crankshaft when it is determined in the determination process that the crankshaft does not continue to rotate by the predetermined amount or more, a control device for a vehicle.

Images