Vehicular control apparatus

Abstract

To provide a vehicular control apparatus capable of improving accuracy in identifying a cylinder.SOLUTION: A control apparatus, of a vehicle that includes, as power sources, an engine and a generator motor, includes: an estimation part for estimating engine torque from a control state of the generator motor; an angle calculation part for calculating a resolver angle from an output signal of a resolver that detects a rotation angle of the generator motor; and a cylinder identification part for obtaining a resolver angle calculated by the angle calculation part when engine torque estimated by the estimation part becomes smaller than a predetermined reference value; and identifying a cylinder at a compression process on the basis of the calculated resolver angle.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] The control device of the hybrid vehicle described in Patent Document 1 obtains fluctuations in the rotation speed of the generator motor from an electrical signal of a resolver, and identifies the engine cylinder from the fluctuations in the rotation speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-90915 Summary of the Invention [Problem to be solved by the invention]

[0004] However, there are many factors that cause the fluctuation in the rotation speed, such as the torque generated by the engine, the speed change of the reciprocating inertia of the engine piston, and the control torque of the generator motor. Therefore, there is a problem that the error is large and the discrimination accuracy is insufficient when the cylinder is discriminated based on the fluctuation in the rotation speed, as in the control device of the above-mentioned Patent Document 1. In addition, the control device of the above-mentioned Patent Document 1 discriminates based on the number of decreases in the rotation speed, so it cannot discriminate based on the number of poles of the resolver. [Means for solving the problem]

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to one aspect of the present disclosure, there is provided a vehicle control device, which is a control device for a vehicle including an engine and a generator motor as power sources, and includes an estimation unit that estimates an engine torque from a control state of the generator motor, an angle calculation unit that calculates a resolver angle from an output signal of a resolver that detects a rotation angle of the generator motor, and a cylinder discrimination unit that acquires the resolver angle calculated by the angle calculation unit when the engine torque estimated by the estimation unit falls below a predetermined reference value, and discriminates a cylinder in a compression stroke based on the resolver angle. According to this embodiment, a resolver for controlling the generator motor is used to perform cylinder discrimination based on the resolver angle, so discrimination accuracy can be improved without depending on the number of poles of the resolver. As a result, the generator motor efficiency and fuel economy can be improved. In addition, since there is no need to separately provide an engine crank angle sensor or a cylinder discrimination sensor for cylinder discrimination, additional costs can be reduced. Low fuel consumption and low cost are possible. In the vehicle control device according to the above aspect, the reference value of the engine torque may be variable depending on an operating state of the engine. According to this aspect, it is possible to improve the accuracy of cylinder discrimination. (3) In the vehicle control device of the above aspect, the reference value of the engine torque may be determined from a three-dimensional map based on a throttle opening and an engine speed. (4) In the vehicle control device of the above aspect, when a start request for requesting starting of the engine is received, the cylinder discrimination unit may execute discrimination of the cylinder. [Brief description of the drawings]

[0007] [Figure 1] 1 is a block diagram showing a configuration of a vehicle in a first embodiment of the present disclosure. [Diagram 2] FIG. 4 is a diagram for explaining the correspondence relationship between engine torque, resolver angle, and crank angle over time when the engine is started. [Diagram 3] 4 is a flowchart showing a control procedure executed by the PCU when starting the engine. [Figure 4] FIG. 4 is a diagram showing changes in engine torque when the throttle opening degree is different. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A. Embodiment: A1.Vehicle configuration: 1 is a block diagram showing the configuration of a vehicle 1 according to a first embodiment of the present disclosure. In this embodiment, the vehicle 1 is an electric vehicle configured as a hybrid car equipped with a generator motor 12 and an engine 11 as driving power sources.

[0009] The vehicle 1 is equipped with a hybrid system 2. The hybrid system 2 includes an engine (E / G) 11, a generator motor (MG1) 12, a drive motor (MG2) 13, a battery 14, and a PCU (Power Control Unit) 15. The PCU 15 corresponds to a control device of the vehicle 1.

[0010] The engine 11 is a well-known internal combustion engine, for example a three-cylinder, four-stroke gasoline engine. The number of cylinders of the engine may be two, four, five or more. The operating state (running state, stopped state) of the engine 11 is controlled by a PCU 15, which will be described later. The engine torque Te [Nm], which is the output torque of the engine 11, is controlled by controlling a throttle actuator, an injector, an ignition device, and the like, which are provided in the engine 11. The generator motor 12 is, for example, a permanent magnet synchronous motor. The generator motor 12 generates torque by receiving power from a battery system (not shown).

[0011] The crankshaft 21 of the engine 11 and the motor shaft 22 of the generator motor 12 are connected via a meshing mechanism 23 that transmits power by meshing teeth. This makes it possible to transmit power between the crankshaft 21 and the motor shaft 22. Note that the engine 11 and the generator motor 12 only need to be mechanically coupled, and they may or may not have gears.

[0012] The drive motor 13 is, for example, a permanent magnet synchronous motor larger than the generator motor 12. A motor shaft of the drive motor 13 is connected to a drive system 16 of the vehicle 1. The power of the drive motor 13 is transmitted to drive wheels 17 via the drive system 16. The battery 14 is an assembled battery in which a plurality of secondary batteries (for example, lithium ion batteries) are combined.

[0013] The PCU 15 is a unit for controlling the driving of the generator motor 12 and the drive motor 13. The PCU 15 acquires information from various devices and sensors mounted on the vehicle 1. Specifically, the PCU 15 acquires a signal corresponding to the motor rotation speed from a resolver 33 installed on the generator motor 12, a current value from a motor current sensor (not shown), and a voltage value from a motor voltage sensor (not shown). In addition, the PCU 15 acquires the accelerator opening, brake pedal force, throttle opening, vehicle speed, shift position, etc. The vehicle 1 is equipped with an HV-ECU 31 and an E / G-ECU 32 as ECUs (Electronic Control Units) for the hybrid system 2.

[0014] A microcomputer (microcontroller unit) is built into the PCU 15, the HV-ECU 31, and the E / G-ECU 32. The microcomputer includes, for example, a CPU, a non-volatile memory such as a flash memory, and a volatile memory such as a dynamic random access memory (DRAM). The PCU 15, the HV-ECU 31, and the E / G-ECU 32 are connected to each other so as to enable two-way communication according to a controller area network (CAN) communication protocol (hereinafter referred to as "CAN communication").

[0015] The HV-ECU 31 is an ECU that performs overall control of the hybrid system 2, and receives various information from the PCU 15 and the E / G-ECU 32 via CAN communication, and transmits motor control commands and engine control commands to the PCU 15 and the E / G-ECU 32, respectively.

[0016] A resolver 33 is connected to the PCU 15. The resolver 33 is attached to the generator motor 12, and outputs a change in the rotation angle of the motor shaft 22 of the generator motor 12 as a change in two-phase AC voltage. The resolver 33 is provided with an R / D (resolver / digital) converter that converts the analog signal of the two-phase AC voltage output by the resolver 33 into a digital signal, and the digital signal output from the R / D converter is input to the microcomputer of the PCU 15 as a resolver signal as a signal required for motor control.

[0017] The microcomputer of the PCU 15 controls the driving of the generator motor 12 via the MG1 inverter and controls the driving of the drive motor 13 via the MG2 inverter in accordance with a motor control command transmitted from the HV-ECU 31 .

[0018] A crank angle sensor 34 mounted on the crankshaft 21 is connected to the E / G-ECU 32. The crank angle sensor 34 outputs a detection signal corresponding to the rotation angle of the crankshaft 21. The detection signal from the crank angle sensor 34 is input to the microcomputer of the E / G-ECU 32. The microcomputer of the PCU 15 controls the operation of the electronic throttle valve, the injectors, and the spark plugs, such as the amount and timing of fuel injection by the injectors, in accordance with engine control commands transmitted from the HV-ECU 31.

[0019] According to the motor control command and the engine control command from the HV-ECU 31, the PCU 15 and the E / G-ECU 32 perform control so that, at the start of the engine 11, the DC power output from the battery 14 is boosted by the converter, the boosted DC power is converted to AC power by the MG1 inverter, and the AC power is supplied to the generator motor 12. This causes the generator motor 12 to operate and the engine 11 is motored by the generator motor 12. When the rotation speed of the crankshaft 21 of the engine 11 has increased to a rotation speed required for starting due to motoring, the electronic throttle valve, the injector, and the spark plug are controlled to start the engine 11.

[0020] The PCU 15 includes an estimation unit 41, an angle calculation unit 42, and a cylinder discrimination unit 43 as functional units. Each of the functional units 41, 42, and 43 is realized by the CPU reading out a program stored in the memory and executing the program. The estimation unit 41 estimates the engine torque Te from the control state of the generator motor 12. The angle calculation unit 42 calculates the resolver angle θ from the output signal of the resolver 33. The cylinder discrimination unit 43 acquires the resolver angle θcomp when the engine torque Te estimated by the estimation unit 41 falls below a predetermined reference value Tcomp, estimates the crank angle based on the resolver angle, and discriminates the cylinder in the compression stroke. When a start request for requesting the start of the engine 11 is received, the cylinder discrimination unit 43 executes the cylinder discrimination.

[0021] A2. Engine start control: Next, the control executed by the PCU 15 at engine start will be described with reference to Fig. 2 to Fig. 4. Fig. 2 is a diagram for explaining the correspondence relationship among the engine torque, resolver angle, and crank angle at engine start. In Fig. 2, the upper part shows the time change of the engine torque Te, and the middle part shows the time change of the resolver angle θ. Furthermore, in Fig. 2, the lower part shows the time change of the estimated crank angle.

[0022] 2, the gear ratio of the generator motor 12 and the engine 11 is 1:1, and the engine 11 is a 3-cylinder, 4-stroke engine. The number of resolver poles is 2 (1 rotation is 360°×2). The crank angle of the ignition TDC (Top Dead Center) of the first cylinder is 0°, and the resolver angle at that time is also 0°.

[0023] The engine torque Te can be estimated from the state of motor control and is expressed by the following equation (1). Te=-Tmg+I×dθeng / dt ···(1) In formula (1), Tmg is the motor torque, which is calculated from the motor current and the motor voltage. I is the moment of inertia around the engine shaft. dθeng / dt is the change in engine speed per unit time. The change in engine speed is calculated from the change in resolver speed.

[0024] In this embodiment, the negative torque in the engine compression stroke is detected by the generator motor 12, and the cylinder number in the compression stroke is identified from the resolver angle θcomp at that time. As shown in FIG. 2, the resolver angle θcomp is calculated when the engine torque becomes smaller than a predetermined reference value Tcomp. Note that, for the sake of convenience, the value of this reference value Tcomp is shown in FIG. 2 as if it were the same line, i.e., the same value, at multiple calculation timings, but it is variable depending on the operating state of the engine 11. The reference value Tcomp is determined from a pre-stored three-dimensional map with the throttle opening and engine speed as axes. Note that the reference value Tcomp may not be variable but may be a fixed value.

[0025] As shown in the middle and lower parts of FIG. 2, if the resolver angle θcomp is within the range of 0°±A°, the compression stroke of the second cylinder is determined, and the crank angle is estimated to be 180°. Then, at the timing when the crank angle is 240°, as shown in FIG. 2 as "#2 ignition", the second cylinder is ignited. If the resolver angle θcomp is within the range of 120°±A°, the compression stroke of the third cylinder is determined, and the crank angle is estimated to be 60°. Then, at the timing when the crank angle is 120°, as shown in FIG. 2 as "#3 ignition", the third cylinder is ignited. If the resolver angle θcomp is within the range of 240°±A°, the compression stroke of the first cylinder is determined, and the crank angle is estimated to be 300°. Then, at the timing when the crank angle is 300°, as shown in FIG. 2 as "#1 ignition". In the above, the value of "A" indicates a margin and is set to, for example, about 30°.

[0026] Fig. 3 is a flowchart showing a control procedure executed by the PCU 15 when starting the engine. As shown in Fig. 3, in S101, it is determined whether or not there is an engine start request. For example, when a predetermined condition is satisfied, such as the ignition switch being turned on, it can be determined that there is an engine start request. When the predetermined condition is not satisfied, it can be determined that there is no engine start request.

[0027] If it is determined that there is no engine start request (S101: No), the process of S101 is repeatedly executed until an engine start request is made. If it is determined that there is an engine start request (S101: Yes), the process proceeds to S102, where the engine 11 is motored by the generator motor 12. For example, the engine speed at this time is 1500 rpm. At this time, the engine torque Te is sensed.

[0028] When motoring is performed in S102, the resolver angle θcomp is calculated in S103 when the estimated engine torque becomes smaller than a predetermined reference value Tcomp. Then, in S104, the cylinder in the compression stroke is identified by the resolver angle θcomp, and it is determined which cylinder is in the compression stroke. Then, in S105, the crank angle is estimated. Then, in S106, fuel injection and ignition are started for the identified cylinder. Note that the details of the cylinder identification and the crank angle estimation according to the specific value of the resolver angle θcomp are as described above. This ends the present processing routine. As described above, after the cylinder identification at the time of engine start, ignition is repeatedly performed every time the crank angle changes by 240° during the subsequent operation.

[0029] (1) According to the first embodiment, the resolver 33 for motor control is used to perform cylinder discrimination based on the resolver angle θcomp when the engine torque Te becomes smaller than the reference value Tcomp. Therefore, compared to a case where a resolver with one pole is used to discriminate the cylinders of the engine 11 from the fluctuation of the motor rotation speed, as described in, for example, Patent Document 1, the error is small, and the discrimination accuracy can be improved even if the number of poles of the resolver changes. As a result, the motor efficiency and fuel consumption can be improved. In addition, since there is no need to separately provide an engine crank angle sensor or a cylinder discrimination sensor for cylinder discrimination, additional costs can be reduced. Low fuel consumption and low cost are possible.

[0030] (2) According to the first embodiment, in S103, the predetermined reference value Tcomp is variable depending on the operating state. Fig. 4 is a diagram showing the change in engine torque when the throttle opening is different. In Fig. 4, the engine torque Ts in an operating state where the throttle opening is relatively small and the intake pressure is low is shown by a solid line, and the engine torque Tb in an operating state where the throttle opening is relatively large and the intake pressure is high is shown by a dashed line.

[0031] As shown in Fig. 4, the engine torque Tb in an operating state with a large throttle opening has a larger torque fluctuation than the engine torque Ts in an operating state with a small throttle opening. When the torque decrease state is judged using the same reference value Tcomp, the engine torque Tb in an operating state with a large throttle opening falls below the reference value Tcomp earlier than the engine torque Ts in an operating state with a small throttle opening. In other words, if the reference value Tcomp is set to a fixed value, there is a risk of a judgment error occurring. In S104, although the resolver angle θcomp is judged with a certain margin (θcomp±A), the more the number of poles of the resolver 33 increases, the more accurate the judgment of the resolver angle θcomp becomes.

[0032] In the first embodiment, a fixed reference value Tcomp is not used, but a reference value Tcomp according to the operating state is determined from a three-dimensional map with the throttle opening and engine speed as axes. For example, in the example of Fig. 4, when the throttle opening is large, a smaller value is set as the reference value Tcomp compared to when the throttle opening is small. Then, by comparing with this reference value Tcomp, it is determined whether the engine torque Te falls below the reference value Tcomp, so that the accuracy of cylinder discrimination can be improved.

[0033] B. Other embodiments: (B1) In the first embodiment, when the engine is started, the generator motor 12 detects the negative torque in the engine compression stroke, and the cylinder number in the compression stroke is identified from the resolver angle θcomp at that time. For example, in a vehicle having a VVT (Variable Valve Timing) mechanism, the crank angle sensor and cam angle sensor for VVT control function as cylinder discrimination sensors. In such a vehicle, this may be used as a fail control when the cylinder discrimination sensor breaks down, rather than at the time of starting.

[0034] 3 is replaced with a process for determining whether the cylinder discrimination sensor has failed. With this configuration, even if the cam angle sensor has failed, the vehicle can be moved to the nearest repair shop in failure mode, for example, without immediately stopping the engine 11.

[0035] The present disclosure is not limited to the above-mentioned embodiments, and can be realized in various configurations without departing from the spirit of the present disclosure. For example, the technical features in each embodiment corresponding to the technical features in each form described in the Summary of the Invention column can be appropriately replaced or combined in order to solve some or all of the above-mentioned problems or to achieve some or all of the above-mentioned effects. Furthermore, if a technical feature is not described as essential in this specification, it can be appropriately deleted. [Explanation of symbols]

[0036] 1...vehicle, 2...hybrid system, 11...engine, 12...generator motor, 13...driving motor, 14...battery, 15...PCU (controller), 16...driving system, 17...driving wheel, 21...crankshaft, 22...motor shaft, 23...engagement mechanism, 33...resolver, 34...crank angle sensor, 41...estimation unit, 42...angle calculation unit, 43...cylinder discrimination unit

Claims

1. A control device for a vehicle including an engine and a generator motor as a power source, an estimation unit that estimates an engine torque from a control state of the generator motor; an angle calculation unit that calculates a resolver angle from an output signal of a resolver that detects a rotation angle of the generator motor; a cylinder discrimination unit that acquires the resolver angle calculated by the angle calculation unit when the engine torque estimated by the estimation unit falls below a predetermined reference value, and discriminates a cylinder that is in a compression stroke based on the resolver angle; A vehicle control device comprising:

2. The control device for a vehicle according to claim 1 , wherein the reference value of the engine torque is variable depending on an operating state of the engine.

3. 3. The vehicle control device according to claim 2, wherein the reference value of the engine torque is determined from a three-dimensional map based on a throttle opening and an engine speed.

4. 3. The vehicle control device according to claim 1, wherein the cylinder discrimination unit discriminates the cylinder when a start request for requesting starting of the engine is received.

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