Control device for internal combustion engines
The control device for internal combustion engines addresses shift time and shock issues by using sensors to manage torque and ignition timing, achieving efficient and stable gear shifts through feedback and feedforward control.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2023-09-13
- Publication Date
- 2026-07-07
AI Technical Summary
Existing blipping downshift control in internal combustion engines faces challenges in achieving both reduced shift time and shift shock due to variations in multi-plate clutch responsiveness and torque transmission, leading to engine revving and shift shocks.
A control device for internal combustion engines that utilizes sensors to monitor engine, converter, and transmission speeds, adjusting torque and ignition timing to maintain optimal momentum during gear shifts, employing feedback and feedforward control to manage torque and prevent excessive rotational speeds.
The control device effectively reduces shift time and shock by dynamically adjusting torque and ignition timing, ensuring precise torque control and preventing engine rotational blow-up, even with varying clutch responsiveness.
Smart Images
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Abstract
Description
Technical Field
[0001] The present disclosure relates to a control device for an internal combustion engine.
Background Art
[0002] In a vehicle equipped with an automatic transmission, blipping may be performed to increase the rotational speed of the internal combustion engine when shifting gears. More specifically, in the manual shift mode of the automatic transmission, blipping is performed as a method to reduce the shock caused by shifting by matching the rotational speed of the internal combustion engine to the rotational speed of the transmission after downshifting. Patent Document 1 discloses a control device for a vehicle that controls blipping during downshifting. Hereinafter, the control of blipping during downshifting is referred to as blipping downshift control.
[0003] In an automatic transmission having a torque converter, blipping downshift control is performed by adjusting the pressure of a multi-plate clutch of the automatic transmission by a hydraulic control device. Further, blipping downshift control also increases the rotational speed of the internal combustion engine by increasing the torque of the internal combustion engine while adjusting the pressure of the multi-plate clutch.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] The torque of an internal combustion engine is determined by adjusting the throttle opening using feedforward control. This can sometimes lead to engine revving, where the engine speed increases excessively. Furthermore, multi-plate clutches exhibit variations in responsiveness and transmitted torque due to factors such as the hydraulic fluid filling characteristics and the friction coefficient of the friction material. Therefore, it is difficult to achieve an ideal pressure for the multi-plate clutch according to the torque level of the internal combustion engine.
[0006] Therefore, blipping downshift control required a gradual increase in internal combustion engine torque to avoid engine revving and shift shocks. In other words, it was difficult to achieve both a reduction in shift time and a reduction in shift shock. [Means for solving the problem]
[0007] This disclosure can be implemented in the following forms: According to one embodiment of the present disclosure, a control device for an internal combustion engine mounted on a vehicle is provided. In this control device for an internal combustion engine, the vehicle comprises the internal combustion engine, an automatic transmission equipped with a torque converter, a first sensor for acquiring engine speed as the rotational speed of the output shaft of the internal combustion engine, a second sensor for acquiring converter speed as the rotational speed of the output shaft of the torque converter, and a third sensor for acquiring transmission speed as the rotational speed of the output shaft of the automatic transmission. The control device stores a predetermined relationship between the torque of the internal combustion engine and the engine speed, and the torque ratio between the output shaft of the internal combustion engine and the output shaft of the torque converter based on the rotational speed ratio of the engine speed and the converter speed. In a manual shift mode in which the automatic transmission is operated by manual operation, when the automatic transmission starts a downshift and increases the engine speed as blipping, the control device stores the target momentum of the internal combustion engine during the shift period, which is the period from the start of the shift to the end of the shift, based on the engine speed and the transmission speed. Based on the instruction torque obtained therefrom, the torque of the internal combustion engine is controlled by the instruction torque, and during the gear shift period, the engine speed is acquired, and the torque of the internal combustion engine is controlled by the instruction torque in such a way that, based on the difference between the first torque-converted momentum, which is determined by integrating the estimated engine torque obtained as the torque of the internal combustion engine based on the acquired engine speed up to the time the acquired engine speed was acquired, and the second torque-converted momentum, which is determined by integrating the estimated converter torque, which is based on the estimated engine torque and the torque ratio and is determined by multiplying the estimated engine torque by the torque ratio, up to the time the converter speed was acquired, the torque of the internal combustion engine is reduced when the second torque-converted momentum is greater than the first torque-converted momentum, and the torque of the internal combustion engine is maintained when the second torque-converted momentum is less than the first torque-converted momentum.
[0008] (1) According to one embodiment of the present disclosure, a control device for an internal combustion engine mounted on a vehicle is provided. In this control device, the vehicle comprises the internal combustion engine, an automatic transmission equipped with a torque converter, a first sensor for acquiring the engine speed as the rotational speed of the output shaft of the internal combustion engine, a second sensor for acquiring the converter speed as the rotational speed of the output shaft of the torque converter, and a third sensor for acquiring the transmission speed as the rotational speed of the output shaft of the automatic transmission. The control device stores a predetermined relationship between the torque of the internal combustion engine and the engine speed, and the torque ratio between the output shaft of the internal combustion engine and the output shaft of the torque converter based on the rotational speed ratio of the engine speed and the converter speed. In response to the start of a downshift by the automatic transmission, the control device controls the torque of the internal combustion engine by an instruction torque based on the target momentum of the internal combustion engine during the shift period, which is the period from the start to the end of the shift, and is obtained based on the engine speed and the transmission speed. During the shift period, the control device acquires the engine speed and controls the torque of the internal combustion engine by the instruction torque based on the difference between a first torque-converted momentum based on the estimated engine torque as the torque of the internal combustion engine obtained based on the acquired engine speed, and a second torque-converted momentum obtained by acquiring the converter speed and the estimated converter torque based on the estimated engine torque and the torque ratio. In this configuration, the control device for the internal combustion engine obtains the target momentum of the internal combustion engine in response to the start of a downshift. Furthermore, after the output of the internal combustion engine based on the instructed torque derived from the target momentum, the control device for the internal combustion engine checks the difference between the first torque-converted momentum based on the estimated engine torque and the second torque-converted momentum obtained from the estimated converter torque. Based on this difference, the control device for the internal combustion engine further controls the torque of the internal combustion engine based on the instructed torque. In other words, after the start of a gear shift, the control device for the internal combustion engine can control the torque transmitted to the automatic transmission by performing feedback control of the torque of the internal combustion engine according to the torque ratio of the torque converter. Therefore, compared to a configuration in which the torque of the internal combustion engine is gradually increased according to a control value set in advance to reduce the shock caused by gear shifting, the control device for the internal combustion engine can achieve both a reduction in gear shift time and a reduction in the shock caused by gear shifting, even when the torque of the internal combustion engine is excessive or when there is variation in the torque transmitted to the automatic transmission. (2) In the control device for an internal combustion engine of the above form, the control device may, in controlling the torque of the internal combustion engine by the instructed torque, reduce the torque of the internal combustion engine if the second torque-converted momentum is greater than the first torque-converted momentum, and maintain the torque of the internal combustion engine if the second torque-converted momentum is less than the first torque-converted momentum. In this configuration, the control device for the internal combustion engine prevents the second torque-converted momentum from exceeding the first torque-converted momentum. In other words, the control device for the internal combustion engine can prevent rotational blow-up of the internal combustion engine when blipping is performed. (3) In the control device for the internal combustion engine of the above form, the internal combustion engine further comprises a combustion device that retards the ignition timing, and the control device may control the ignition timing based on the difference between the first torque-converted momentum and the second torque-converted momentum during the gear shift period. By adopting this configuration, the control device for the internal combustion engine can control the torque of the engine faster than, for example, controlling the intake of the engine with a throttle valve, by retarding the ignition timing. In other words, the control device for the internal combustion engine can achieve near real-time control. Therefore, the control device for the internal combustion engine is more suitable for shifting gears while driving, where fast response is required. (4) In the control device for an internal combustion engine of the above form, the internal combustion engine further comprises a throttle valve, and the control device may increase the torque of the internal combustion engine by means of the throttle valve in controlling the torque of the internal combustion engine based on the target momentum. In this configuration, the throttle valve increases the torque of the internal combustion engine through feedforward control. That is, the torque of the internal combustion engine may increase excessively. However, the control device for the internal combustion engine can easily control the torque by retarding the ignition timing to reduce the torque of the internal combustion engine. [Brief explanation of the drawing]
[0009] [Figure 1] An explanatory diagram showing the vehicle's configuration. [Figure 2] An explanatory diagram showing the relationship between engine speed and transmission speed. [Figure 3] An explanatory diagram showing the relationship between engine speed and expected speed. [Figure 4] An explanatory diagram showing torque control in an internal combustion engine. [Figure 5] A flowchart illustrating the process of the control unit. [Figure 6] A flowchart illustrating the processing performed by the control unit after an increase in torque in an internal combustion engine. [Modes for carrying out the invention]
[0010] A. First Embodiment: A-1. Vehicle configuration: Figure 1 is an explanatory diagram showing the configuration of vehicle 10. The control device 100 for the internal combustion engine 200 of this disclosure is mounted on vehicle 10. Vehicle 10 comprises the internal combustion engine 200, an automatic transmission 300, a first sensor 400, a second sensor 500, and a third sensor 600.
[0011] The internal combustion engine 200 outputs rotational power to drive the wheels W by burning fuel. Specifically, the internal combustion engine 200 is a reciprocating engine, a four-cycle engine with spark ignition that uses gasoline as fuel. In the internal combustion engine 200, the output shaft from which power is output is connected to the automatic transmission 300, which will be described later. Therefore, the power of the internal combustion engine 200 is transmitted to the automatic transmission 300. The power of the internal combustion engine 200 is determined by torque and rotational speed. In the following description, the number of rotations per unit time at the output shaft of the internal combustion engine 200 is called the engine speed Ne. Other rotations in this specification will also be described as rotations per unit time, the same as the engine speed Ne. The internal combustion engine 200 includes a combustion device 210 and a throttle valve 220.
[0012] The throttle valve 220 changes the intake air volume in the internal combustion engine 200. The throttle valve 220 is controlled by the control device 100 based on the amount the driver depresses the accelerator pedal and predetermined control conditions, thereby changing the valve opening. In other words, the throttle valve 220 is an electronically controlled valve. In the following description, the valve opening will also be referred to as the throttle opening. Therefore, the throttle valve 220 changes the torque of the internal combustion engine 200 by changing the throttle opening.
[0013] The combustion device 210 includes an injector and a spark plug. The injector injects fuel into the combustion chamber of the internal combustion engine 200. The spark plug ignites the fuel in the combustion chamber. As described above, since the internal combustion engine 200 is a four-cycle engine, it performs an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke. The combustion device 210 injects fuel during the intake stroke and ignites it during the combustion stroke. Note that in FIG. 1, for ease of understanding of the technology, the illustration of the injector and the spark plug is omitted.
[0014] The ignition timing of the combustion device 210 is controlled by the control device 100. More specifically, the combustion device 210 delays the ignition timing in accordance with the execution of retard. Retard means controlling to delay the ignition timing from the start of fuel injection to ignition compared to normal driving. The method of executing retard will be described in detail later. The torque of the internal combustion engine 200 decreases due to retard. Note that the torque of the internal combustion engine 200 responds in about 20 msec from the instruction to start the retard control.
[0015] The automatic transmission 300 shifts the gears of the vehicle 10. The automatic transmission 300 includes a torque converter 320 and a transmission 310. Further, the automatic transmission 300 switches between an automatic shift mode in which shifting is performed automatically under the control of the control device 100 and a manual shift mode in which shifting is performed manually to perform shifting. However, in this specification, the shifting by the automatic transmission 300 means downshifting in the manual shift mode.
[0016] The torque converter 320 transmits the torque of the internal combustion engine 200 to the transmission 310. More specifically, the torque converter 320 is a fluid coupling and transmits the torque of the internal combustion engine 200 via a fluid between the output shaft of the internal combustion engine 200 and the input shaft of the transmission 310. However, the torque converter 320 also mechanically transmits torque in a lock-up state or a flex lock-up state, which will be described later.
[0017] The torque converter 320 includes a turbine liner, a pump impeller, and a lock-up clutch. In the torque converter 320, the rotation axis of the pump impeller is the input axis, and the rotation axis of the turbine liner is the output axis. That is, the input axis of the torque converter 320 is connected to the output axis of the internal combustion engine 200. The output axis of the torque converter 320 is connected to the transmission 310. In the following description, the rotational speed of the output axis of the torque converter 320 is referred to as the converter rotational speed Nc. Further, the ratio of the torque of the output axis to the torque of the input axis in the torque converter 320 is referred to as the torque ratio of the torque converter 320. In FIG. 1, for ease of understanding of the technology, the illustration of the turbine liner, the pump impeller, and the lock-up clutch is omitted.
[0018] The lock-up clutch engages the input and output shafts of the torque converter 320 by friction. More specifically, the lock-up clutch changes its engagement state according to the torque ratio based on the ratio of the rotational speeds of the input and output shafts of the torque converter 320. The engagement state includes a lock-up state in which the input and output shafts of the torque converter 320 are fully engaged, a flex lock-up state in which they are semi-engaged, and a torque converter state in which they are released. That is, in the lock-up state and the flex lock-up state, torque is transmitted by mechanical engagement. In the lock-up state, the rotational speeds of the input and output shafts of the torque converter 320 are the same. That is, the converter rotational speed Nc is the same as the engine rotational speed Ne.
[0019] The transmission 310 changes the gear ratio. The transmission 310 has a stepped gear shifting mechanism consisting of multiple gears, a clutch, and a hydraulic control circuit. Note that, for the sake of ease of understanding the technology, the multiple gears, clutch, and hydraulic control circuit are not shown in Figure 1. More specifically, the transmission 310 controls the engagement of the clutch via the hydraulic control circuit under the control of the control device 100, thereby switching between multiple gears that determine the gear ratio. In other words, the transmission 310 changes the torque of the output shaft of the transmission 310 that is transmitted to the wheel W. The rotational speed of the output shaft of the transmission 310 is called the transmission rotational speed Nt. The transmission rotational speed Nt is also the product of the converter rotational speed Nc and the gear ratio. That is, in the lock-up state of the torque converter 320, the transmission rotational speed Nt is the product of the engine rotational speed Ne and the gear ratio.
[0020] The power transmission mechanism consisting of the internal combustion engine 200, the torque converter 320, and the transmission 310 has inertia as the moment of inertia with respect to the power of the internal combustion engine 200. In this specification, inertia is divided into theoretically set inertia and actual inertia. The theoretically set inertia is stored in the control device 100 in advance for the purpose of determining the first instruction torque a1, which will be explained later. That is, the theoretically set inertia is used to control the torque of the internal combustion engine 200 regardless of the gear shift. The actual inertia is obtained by the control device 100 during the gear shift period T1, which is the period from the start of gear shifting to the end of gear shifting. As mentioned above, the torque ratio of the torque converter 320 differs depending on the engagement state. The actual inertia fluctuates according to the torque ratio of the torque converter 320. The determination of the actual inertia will be explained in detail later.
[0021] The first sensor 400 acquires the engine speed Ne, which is the rotational speed of the output shaft of the internal combustion engine 200. For example, the first sensor 400 acquires the engine speed Ne by being installed on the crankshaft, which is the output shaft of the internal combustion engine 200. The first sensor 400 transmits a signal based on the engine speed Ne to the engine ECU 110 of the control device 100.
[0022] The second sensor 500 acquires the converter rotation speed Nc, which is the rotation speed of the output shaft of the torque converter 320. For example, the second sensor 500 acquires the converter rotation speed Nc by being installed on the rotating shaft of the turbine liner of the torque converter 320. The second sensor 500 transmits a signal based on the converter rotation speed Nc to the transmission ECU 120 of the control device 100.
[0023] The third sensor 600 acquires the transmission rotation speed Nt, which is the rotation speed of the output shaft of the transmission 310. For example, the third sensor 600 acquires the transmission rotation speed Nt by being installed on the rotation axis of the output shaft. The third sensor 600 transmits a signal based on the transmission rotation speed Nt to the transmission ECU 120 of the control device 100.
[0024] Furthermore, rotational speed is acquired periodically by various sensors, regardless of the gear shift period T1. More specifically, the sensors acquire rotational speed from before the start of gear shifting and even after the end of gear shifting. Therefore, the deceleration of the transmission rotational speed Nt, which will be explained later, is determined based on the rotational speed acquired before the start of gear shifting.
[0025] The control device 100 performs control related to the shifting of the vehicle 10. The control device 100 consists of an engine ECU 110, which is an ECU (Electronic Control Unit) that controls the internal combustion engine 200, and a transmission ECU 120, which is an ECU that controls the automatic transmission 300. The engine ECU 110 and the transmission ECU 120 communicate with each other. Each ECU of the engine ECU 110 and the transmission ECU 120 is equipped with a CPU, ROM, and RAM. ROM is a read-only semiconductor memory. ROM stores control programs for control in advance. RAM is a semiconductor memory, which is the main memory, and stores information necessary for control. The CPU realizes the functions of each part by executing various programs stored in ROM. The CPU uses RAM to store information necessary for processing.
[0026] A2. Method for determining momentum: The control device 100 controls the internal combustion engine 200 based on the momentum related to the vehicle 10. The momentum related to the vehicle 10 is divided into a first target momentum M1, a second target momentum, a first torque-converted momentum, and a second torque-converted momentum.
[0027] The first target momentum M1 is the momentum required of the internal combustion engine 200 at the end of the gear shift. The first target momentum M1 is obtained based on the engine speed Ne and the transmission speed Nt. First, the relationship between the engine speed Ne and the transmission speed Nt during the gear shift period T1 will be explained.
[0028] Figure 2 is an explanatory diagram showing the relationship between engine speed Ne and transmission speed Nt. Figure 2 illustrates the relationship between engine speed Ne and transmission speed Nt before and after downshifting. In this specification, the transmission speed Nt is referred to as the first rotational speed Nt1 at the start of gear shifting. Furthermore, with respect to the first rotational speed Nt1, the engine speed Ne before downshifting is referred to as the second rotational speed Ne2, and the engine speed Ne after downshifting is referred to as the third rotational speed Ne3. The difference between the second rotational speed Ne2 and the third rotational speed Ne3 is referred to as the differential rotational speed Nd. In other words, there is a difference of differential rotational speed Nd between the engine speed Ne before and after downshifting.
[0029] Figure 3 is an explanatory diagram showing the relationship between engine speed Ne and assumed speed Nta. Figure 3 illustrates the relationship between engine speed Ne and assumed speed Nta when blipping is performed during the gear shift period T1. Note that the gear shift period T1 refers to the period from the start of gear shifting t1 to the end of gear shifting t8 in other figures as well. The assumed speed Nta is the rotational speed obtained by dividing the transmission speed Nt by the gear ratio. In other words, the assumed speed Nta is the converter speed Nc when gear shifting is assumed to be complete, and is also the engine speed Ne when the torque converter 320 is in the lock-up state.
[0030] At the time t1 when the gear shift begins, as described above, there is a difference of Nd between the engine speed Ne and the assumed speed Nta. From the time t1 when the gear shift begins, the output of the internal combustion engine 200 is increased by blipping, so that the assumed speed Nta and the engine speed Ne coincide after the gear shift period T1 has elapsed. That is, the gear shift by the automatic transmission 300 is completed. In this specification, the engine speed at the time t8 when the gear shift is completed is called the synchronous speed Ne4. The control device 100 determines the synchronous speed Ne4, which is the engine speed at the time t8 when the gear shift is completed and in which the engine speed Ne and the assumed speed Nta coincide, based on the changes in the engine speed Ne and the changes in the assumed speed Nta.
[0031] The change in engine speed Ne is determined by the control device 100 based on the second engine speed Ne2 at the time t1 when the gear shift starts, and a predetermined acceleration corresponding to the second engine speed Ne2. The acceleration corresponding to the second engine speed Ne2 is pre-recorded in the ROM of the engine ECU 110.
[0032] The expected rotational speed Nta is determined by the control device 100 based on the third rotational speed Ne3 at the time t1 when the gear shift starts, and the deceleration of the transmission rotational speed Nt. The deceleration of the transmission rotational speed Nt is determined by the second sensor 500 based on the transmission rotational speed Nt acquired before the gear shift starts.
[0033] The control device 100 determines a first target momentum M1 based on the synchronous rotational speed Ne4 and the theoretically set inertia in response to the start of a downshift by the automatic transmission 300.
[0034] The control device 100 controls the torque of the internal combustion engine 200 by a first instruction torque a1 based on a first target momentum M1. More specifically, the control device 100 controls the throttle opening by a torque value determined by dividing the first target momentum M1 by the torque-up time T2.
[0035] Figure 4 is an explanatory diagram illustrating the torque control of the internal combustion engine 200. Figure 4 shows an example of the first commanded torque a1 during the gear shift period T1. The first commanded torque a1 is the torque value that the control device 100 requests from the internal combustion engine 200. The control device 100 pre-stores the relationship between the torque of the internal combustion engine 200 and the throttle opening of the throttle valve 220 in the ROM of the engine ECU 110. For example, the predetermined relationship between the torque of the internal combustion engine 200 and the throttle opening is an experimentally determined correlation.
[0036] The torque-up time T2 is the time it takes for the control device 100 to issue an instruction using the first instruction torque a1 to increase the torque of the internal combustion engine 200. In this specification, an increase in the torque of the internal combustion engine 200 is also called a torque-up, and a decrease in the torque of the internal combustion engine 200 is also called a torque-down. The control device 100 stores in the ROM of the engine ECU 110 the relationship between the torque-up time T2 required according to the engine speed Ne, the synchronous speed Ne4, and the response time of the internal combustion engine 200. The response time of the internal combustion engine 200 is the time it takes from the start of the instruction to control the throttle opening until the internal combustion engine 200 responds. The response time of the internal combustion engine 200 is delayed because it depends on the airflow velocity. For example, the response time of the internal combustion engine 200 is about 100 msec. In other words, the torque control of the internal combustion engine 200 by throttle opening is slower in response than the torque control of the internal combustion engine 200 by retarding the throttle angle.
[0037] Therefore, in response to the start of a downshift, the control device 100 increases the torque of the internal combustion engine 200 by a first instruction torque a1 based on a first target momentum M1.
[0038] The second target momentum is obtained by replacing the theoretically set inertia in the first target momentum M1 with the actual inertia. The method for determining the actual inertia will be explained in detail later.
[0039] Next, the first torque-converted momentum will be explained. The first torque-converted momentum is the momentum determined based on the engine speed Ne acquired during the gear shift period T1. In determining the first torque-converted momentum, the control device 100 first determines the estimated engine torque.
[0040] The control device 100 stores a predetermined relationship between the torque of the internal combustion engine 200 and the engine speed Ne in the ROM of the engine ECU 110. For example, the predetermined relationship between the torque of the internal combustion engine 200 and the engine speed Ne is an experimentally determined correlation. Therefore, the control device 100 acquires the engine speed Ne during the shift period T1 and determines the estimated engine torque, which is the torque of the internal combustion engine 200, based on the acquired engine speed Ne.
[0041] Therefore, the control device 100 determines the first torque-converted momentum by integrating the estimated engine torque up to the point in time when the engine speed Ne is acquired.
[0042] Next, the second torque-converted momentum will be explained. The second torque-converted momentum is the momentum determined based on the converter rotational speed Nc acquired during the gear shift period T1. To determine the second torque-converted momentum, first the control device 100 determines the estimated converter torque.
[0043] The control device 100 determines the estimated converter torque based on the estimated engine torque and the torque ratio of the torque converter 320. The control device 100 pre-stores in the ROM of the transmission ECU 120 the relationship between the torque ratio of the torque converter 320 and the rotational speed ratio of the engine speed Ne and the converter speed Nc. Therefore, the control device 100 obtains the engine speed Ne and the converter speed Nc at the same point in time and determines the torque ratio of the torque converter 320 based on the rotational speed ratio of the engine speed Ne and the converter speed Nc. Furthermore, the control device 100 determines the estimated converter torque by multiplying the estimated engine torque by the torque ratio of the torque converter 320.
[0044] Therefore, the control device 100 determines the second torque-converted momentum by integrating the estimated converter torque up to the point in time when the converter rotation speed Nc is acquired. The lower part of Figure 4 illustrates an example of the change in the second torque-converted momentum during the shift period T1.
[0045] A-3. Control methods for internal combustion engines: Figure 5 is a flowchart showing the processing of the control device 100. In the following explanation, Figure 4 will be used as an example of the processing of the control device 100, along with the flowchart. The control device 100 starts the control process as blipping in response to the start of a downshift by the automatic transmission 300. More specifically, the control device 100 starts processing when the driver instructs a downshift while the automatic transmission 300 is set to manual shift mode.
[0046] In steps S110 to S160 of Figure 5, the control device 100 increases the torque of the internal combustion engine 200 by determining the first instruction torque a1 based on the first target momentum M1, as described above.
[0047] In step S110 of Figure 5, the control device 100 acquires the engine speed Ne at time t1 using the first sensor 400. That is, the control device 100 acquires the second engine speed Ne2 in Figure 3.
[0048] In step S120 of Figure 5, the control device 100 determines the assumed rotational speed Nta at time t1 based on the engine rotational speed Ne and the gear ratio. That is, the control device 100 determines the third rotational speed Ne3 in Figure 3.
[0049] In step S130 of Figure 5, the control device 100 determines the synchronous rotational speed Ne4 based on the assumed rotational speed Nta and the engine rotational speed Ne. As mentioned above, the control device 100 determines the deceleration of the assumed rotational speed Nta based on the transmission rotational speed Nt acquired before the start of the gear shift. Furthermore, the control device 100 acquires a predetermined acceleration according to the second rotational speed Ne2. Therefore, as shown in Figure 3, the control device 100 determines the synchronous rotational speed Ne4 by finding the rotational speed at time t8 when the assumed rotational speed Nta and the engine rotational speed Ne coincide.
[0050] In step S140 of Figure 5, the control device 100 acquires a predetermined desktop setting inertia.
[0051] In step S150 of Figure 5, the control device 100 determines the first target momentum M1 based on the synchronous rotational speed Ne4 and the desktop-set inertia, as described above.
[0052] In step S160 of Figure 5, the control device 100 controls the torque of the internal combustion engine 200 by a first instruction torque a1 based on a first target momentum M1. That is, as described above, the control device 100 determines a first instruction torque a1 based on the first target momentum M1. Furthermore, in controlling the torque of the internal combustion engine 200 based on the first target momentum M1, the control device 100 increases the torque of the internal combustion engine 200 by the throttle valve 220. Therefore, the control device 100 increases the torque of the internal combustion engine 200 by controlling the throttle opening.
[0053] The upper part of Figure 4 illustrates the change in torque a2 of the internal combustion engine 200 in relation to the first instruction torque a1. As mentioned above, the internal combustion engine 200 responds with a delay from the start of the instruction to control the throttle opening. That is, time points t1 to t2 is the period during which there is a delay in the response of the internal combustion engine 200. Next, during the period from time points t2 to t3, the torque increases to the first instruction torque a1 as the internal combustion engine 200 responds. The period from time point t3 onwards will be explained later.
[0054] Figure 6 is a flowchart showing the processing of the control device 100 after the torque has increased.
[0055] In step S170 of Figure 6, the control device 100 acquires the engine speed Ne using the first sensor 400.
[0056] In step S180 of Figure 6, the control device 100 determines a first torque-converted momentum based on the engine rotational speed Ne, as described above.
[0057] In step S190 of Figure 6, the control device 100 acquires the converter rotation speed Nc using the second sensor 500.
[0058] In step S200 of Figure 6, the control device 100 determines a second torque-converted momentum based on the converter rotation speed Nc, as described above.
[0059] In step S210 of Figure 6, the control device 100 compares the first torque-converted momentum with the second torque-converted momentum. More specifically, if the second torque-converted momentum is greater than the first torque-converted momentum, the control device 100 proceeds to step S310. If the second torque-converted momentum is less than the first torque-converted momentum, the control device 100 proceeds to step S410.
[0060] In step S310 of Figure 6, the control device 100 determines the second target momentum M2. More specifically, the control device 100 determines the second target momentum M2 by replacing the theoretically set inertia for the first target momentum M1 with the actual inertia. The control device 100 determines the difference between the integrated value of the estimated converter torque up to the time of acquisition of the converter rotation speed Nc and the product of the theoretically set inertia and the converter rotation speed Nc that has progressed, as the inertia correction coefficient. The converter rotation speed Nc that has progressed is the difference between the acquired converter rotation speed Nc and the second rotation speed Ne2. The control device 100 determines the actual inertia by the product of the inertia correction coefficient and the theoretically set inertia. Therefore, the control device 100 determines the second target momentum M2 by replacing the theoretically set inertia with the actual inertia.
[0061] In step S320 of Figure 6, the control device 100 controls the torque of the internal combustion engine 200 by the first instructed torque a1 based on the second target momentum M2. More specifically, the control device 100 determines the second instructed torque based on the second target momentum M2 in the same manner as the first instructed torque a1. Furthermore, the control device 100 controls the ignition timing retardation based on the difference between the first instructed torque a1 and the second instructed torque. The control device 100 has pre-stored the characteristics of the torque that decreases due to ignition timing retardation in the ROM of the engine ECU 110. For example, the characteristics of the torque that decreases due to ignition timing retardation are characteristics based on experimentally determined correlations. Therefore, the control device 100 controls the torque of the internal combustion engine 200 by reducing the torque by retarding the ignition timing based on the difference between the first instructed torque a1 and the second instructed torque.
[0062] Regarding the above process, specifically, the control device 100 controls the torque of the internal combustion engine 200 by the first instructed torque a1 based on the difference between the first torque-converted momentum and the second torque-converted momentum during the gear shift period T1. More specifically, in controlling the torque of the internal combustion engine 200, the control device 100 reduces the torque of the internal combustion engine 200 if the second torque-converted momentum is greater than the first torque-converted momentum. Furthermore, in the process from step S410 onward, which will be described later, the control device 100 maintains the torque of the internal combustion engine 200 if the second torque-converted momentum is less than the first torque-converted momentum. That is, the control device 100 controls the internal combustion engine 200 by retarding the ignition timing so that the torque of the internal combustion engine 200 by the first instructed torque a1 decreases based on the difference between the first torque-converted momentum and the second torque-converted momentum during the gear shift period T1.
[0063] The torque graph in Figure 4 illustrates an example of ignition timing retardation at time points t4 to t5. In Figure 4, the dashed line indicates the decrease in torque of the internal combustion engine 200 due to ignition timing retardation. From time point t3 onward, the torque of the internal combustion engine 200 is kept constant by reaching the first indicated torque. However, if the second torque-converted momentum exceeds the first torque-converted momentum, ignition timing retardation is performed during the period from time points t4 to t5. As mentioned above, the response of the internal combustion engine 200 to ignition timing retardation is faster than the response of the internal combustion engine 200 to throttle opening control. Therefore, as shown in Figure 4, the torque of the internal combustion engine 200 decreases immediately due to ignition timing retardation.
[0064] The momentum graph in Figure 4 illustrates the change in the second torque-converted momentum. The dashed line shows the change in the second torque-converted momentum when no ignition retardation is performed. The solid line shows the change in the second torque-converted momentum when ignition retardation is performed. The second torque-converted momentum decreases when ignition retardation is performed. Furthermore, as shown in Figure 5, after the completion of the process in step S320, the control device 100 returns to step S170. Therefore, when the control device 100 determines the second torque-converted momentum again, it proceeds with the process using the second torque-converted momentum that has decreased due to ignition retardation. Consequently, as shown in Figure 4, after the ignition retardation is performed from time t4 to time t5, the second torque-converted momentum remains lower than the second torque-converted momentum when ignition retardation is not performed.
[0065] In step S410 of Figure 6, the control device 100 determines whether to increase the torque of the internal combustion engine 200. That is, if the control device 100 receives an instruction from the first instruction torque a1, it proceeds to step S420. If the control device 100 does not receive an instruction from the first instruction torque a1, it terminates the process. That is, the gear shifting by the automatic transmission 300 is completed.
[0066] In step S420 of Figure 6, the control device 100 determines whether or not to perform ignition timing retardation. That is, if ignition timing retardation is performed, the control device 100 proceeds to step S430. If ignition timing retardation is not performed, the control device 100 returns to step S170.
[0067] In step S430 of Figure 6, the control device 100 terminates the ignition timing retardation. After terminating the ignition timing retardation, the control device 100 returns to step S170.
[0068] As described above, the control device 100 for the internal combustion engine 200 controls the torque of the internal combustion engine 200 as blipping control during the shift period T1 due to downshifting. More specifically, in this configuration, the control device 100 for the internal combustion engine 200 obtains a first target momentum M1 of the internal combustion engine 200 in response to the start of downshifting. Furthermore, after the output of the internal combustion engine 200 based on the instructed torque derived from the first target momentum M1, the control device 100 for the internal combustion engine 200 checks the difference between the first torque-converted momentum based on the estimated engine torque and the second torque-converted momentum obtained from the estimated converter torque. Based on this difference, the control device 100 for the internal combustion engine 200 further controls the torque of the internal combustion engine 200 based on the instructed torque. That is, after the start of shifting, the control device 100 for the internal combustion engine 200 can control the torque transmitted to the automatic transmission 300 by performing feedback control of the torque of the internal combustion engine 200 according to the torque ratio of the torque converter 320. Therefore, the control device 100 for the internal combustion engine 200 can achieve both a reduction in shifting time and a reduction in shifting shock, even when the torque of the internal combustion engine 200 is excessive or when there are variations in the torque transmitted to the automatic transmission 300, compared to, for example, a mode in which the torque of the internal combustion engine 200 is gradually increased in accordance with a control value set in advance to reduce the shock caused by shifting.
[0069] Furthermore, by adopting this configuration, the control device 100 of the internal combustion engine 200 prevents the second torque-converted momentum from exceeding the first torque-converted momentum. In other words, the control device 100 of the internal combustion engine 200 can prevent rotational blow-up of the internal combustion engine 200 when blipping is performed.
[0070] Furthermore, by adopting this configuration, the control device 100 for the internal combustion engine 200 can control the torque of the internal combustion engine 200 faster than, for example, controlling the intake of the internal combustion engine 200 with the throttle valve 220, by retarding the ignition timing. In other words, the control device 100 for the internal combustion engine 200 can achieve near real-time control. Therefore, the control device 100 for the internal combustion engine 200 is more suitable for shifting gears while driving, where fast response is required.
[0071] Furthermore, in this configuration, the throttle valve 220 increases the torque of the internal combustion engine 200 through feedforward control. That is, the torque of the internal combustion engine 200 may increase excessively. However, the control device 100 for the internal combustion engine 200 can easily control the torque by reducing the torque of the internal combustion engine 200 through ignition timing retardation.
[0072] B. Other embodiments: (1) In the above embodiment, the torque of the internal combustion engine 200 is controlled by determining the magnitudes of the first torque-converted momentum and the second torque-converted momentum. However, the torque of the internal combustion engine 200 may be controlled by other methods. For example, the torque of the internal combustion engine 200 may be controlled by determining the rate of change of the first torque-converted momentum and the rate of change of the second torque-converted momentum. (2) In the above embodiment, the torque of the internal combustion engine 200 is reduced by retarding the ignition timing based on the difference between the first torque-converted momentum and the second torque-converted momentum. However, the torque of the internal combustion engine 200 may also be reduced by controlling the throttle opening. (3) In the above embodiment, the torque of the internal combustion engine 200 is controlled by controlling the throttle opening of the throttle valve 220, except for the timing retardation. However, the internal combustion engine 200 does not have to be equipped with a throttle valve 220. For example, the internal combustion engine 200 may have a throttle valve-less structure. That is, the torque of the internal combustion engine 200 may be controlled by controlling the intake amount by the intake valve of the combustion chamber.
[0073] This disclosure is not limited to the embodiments described above, and can be implemented in various configurations without departing from its spirit. For example, the technical features of the embodiments corresponding to the technical features in each form described in the summary of the invention can be replaced or combined as appropriate to solve some or all of the above problems, or to achieve some or all of the above effects. Furthermore, if a technical feature is not described as essential in this specification, it can be deleted as appropriate. [Explanation of Symbols]
[0074] 10...Vehicle, 100...Control device, 200...Internal combustion engine, 210...Combustion device, 220...Throttle valve, 300...Automatic transmission, 310...Transmission, 320...Torque converter, 400...First sensor, 500...Second sensor, 600...Third sensor, 110...Engine ECU, 120...Transmission ECU, M1...First target momentum, M2...Second target momentum, Nc...Converter rotation speed, Nd...Differential rotation speed, Ne...Engine rotation speed, Ne2...Second rotation speed, Ne3...Third rotation speed, Ne4...Synchronous rotation speed, Nt...Transmission rotation speed, Nt1...First rotation speed, Nta...Assumed rotation speed, T1...Shifting period, T2...Torque increase time, W...Wheel, a1...First indicated torque, a2...Change in internal combustion engine torque, t1~t8...Time points
Claims
1. A control device for an internal combustion engine mounted on a vehicle, The aforementioned vehicle is The aforementioned internal combustion engine, An automatic transmission equipped with a torque converter, A first sensor that acquires the engine speed as the rotational speed of the output shaft of the internal combustion engine, A second sensor acquires the converter rotation speed as the rotation speed of the output shaft of the torque converter, A third sensor that acquires the transmission rotation speed as the rotation speed of the output shaft of the automatic transmission, Equipped with, The control device is The system stores a predetermined relationship between the torque of the internal combustion engine and the engine speed, and the torque ratio between the output shaft of the internal combustion engine and the output shaft of the torque converter, based on the speed ratio of the engine speed to the converter speed. In manual shift mode, where gear changes are performed by the automatic transmission via manual operation, when the engine speed is increased as blipping in response to the start of a downshift by the automatic transmission, The target momentum of the internal combustion engine during the shifting period, which is the period from the start of shifting to the end of shifting, and the torque of the internal combustion engine is controlled by an instruction torque based on the target momentum obtained based on the engine speed and the transmission speed. During the aforementioned gear shifting period, The engine speed is acquired, and the estimated engine torque, which is obtained as the torque of the internal combustion engine based on the acquired engine speed, is determined by integrating the acquired engine speed up to the point in time when the engine speed was acquired, and a first torque-converted momentum is determined. Based on the difference between the estimated engine torque and the estimated converter torque based on the torque ratio, which is determined by multiplying the estimated engine torque by the torque ratio, and a second torque-converted momentum determined by integrating the estimated converter torque up to the point in time when the converter rotation speed is acquired, A control device for an internal combustion engine, which controls the torque of the internal combustion engine by an instructed torque such that the torque of the internal combustion engine is reduced when the second torque-converted momentum is greater than the first torque-converted momentum, and the torque of the internal combustion engine is maintained when the second torque-converted momentum is less than the first torque-converted momentum.
2. A control device for an internal combustion engine according to claim 1, The aforementioned internal combustion engine is further equipped with a combustion device that retards the ignition timing. The control device controls the ignition timing retardation based on the difference between the first torque-converted momentum and the second torque-converted momentum during the gear shift period.
3. A control device for an internal combustion engine according to claim 2, The aforementioned internal combustion engine further comprises a throttle valve, The control device is a control device for an internal combustion engine that increases the torque of the internal combustion engine by means of the throttle valve in controlling the torque of the internal combustion engine based on the target momentum.