Hybrid control system

Abstract

To provide a hybrid control system capable of estimating a crank angle of an engine by a motor control device with high resolution in high accuracy without increasing costs due to installation of an exclusive communication wire and the like to communicate with the engine control device.SOLUTION: A crank angle EFICA from EFI-ECU32 and a pulse interruption time Tp in occurrence of a pulse interruption processing to calculate the crank angle are input to MG-ECU33. In the MG-ECU33, a relationship between the crank angle EFICA and a resolver angle RESATD before an elapsed time estimation value T delay, that is, a relationship between a crank angle EFICA at the pulse interruption time TP and the resolver angle RESATD is learned, and the present crank angle estimation value CAEST is estimated on the basis of the relationship and the resolver angle RESATD.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a hybrid control system.

Background Art

[0002] Conventionally, a vehicle that employs a hybrid system in its drive system, so-called a hybrid vehicle (HV), is known. For example, in a series hybrid vehicle, the power of the engine is converted into electric power by a power generation motor (generator), the drive motor is driven by the electric power, and the power of the drive motor is transmitted to the drive wheels.

[0003] The engine and the power generation motor are connected via an engagement mechanism such as a gear or a spline. Therefore, when torque fluctuation (reversal) that crosses zero torque occurs in the engagement mechanism at the start of the engine or during light load operation, a meshing sound is generated due to a change in the meshing state of the engagement mechanism. As a countermeasure for reducing this meshing sound, it has been proposed to apply a compensation torque synchronized with the torque fluctuation of the engine from the power generation motor side to the engagement mechanism (see, for example, Patent Document 1).

[0004] In order to calculate the torque fluctuation of the engine, it is necessary to detect the crank angle of the engine. Since detection of the crank angle is required for engine control, a crank angle sensor that outputs a pulse signal every time the crankshaft rotates by a certain angle is connected to an engine ECU (Electronic Control Unit) that controls the engine. However, a crank angle sensor is not connected to the motor ECU that controls the power generation motor, and the pulse signal of the crank angle sensor is not input.

[0005] In order to detect the crank angle with a motor ECU, for example, an engine ECU and a motor ECU are connected by a serial communication line and a parallel communication line, and the engine ECU calculates the crank angle and the crank angular velocity from the output signal of the crank angle sensor, and transmits the calculated crank angle and crank angular velocity from the engine ECU to the motor ECU by serial communication, and at the same time transmits a communication start signal from the engine ECU to the motor ECU by parallel communication (see, for example, Patent Document 2). In the motor ECU, the time from receiving the communication start signal to completing the reception of the crank angle and the crank angular velocity is measured, and the current crank angle is estimated by adding the multiplication value of the measured time and the received crank angular velocity to the received crank angle.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in such a configuration, a dedicated communication line (serial communication line, parallel communication line) for connecting the engine ECU and the motor ECU and an input / output circuit for communication via the communication line are required, resulting in an increase in cost.

[0008] An object of the present invention is to provide a hybrid control system that can accurately estimate the crank angle of an engine with high resolution in a motor control device without causing an increase in cost due to providing a dedicated communication line for communication with an engine control device.

Means for Solving the Problems

[0009] To achieve the above object, a hybrid control system according to the present invention is mounted on a vehicle in which an engagement mechanism for transmitting power by tooth engagement is interposed between the crankshaft of an engine and the rotating shaft of a power generation motor, and a crank angle sensor for outputting a crank pulse signal synchronized with the rotation of the crankshaft and a resolver for outputting a resolver signal that changes according to the rotation angle of the rotating shaft are provided, and is a system for controlling the engine and the power generation motor, including an engine control device that calculates the crank angle of the engine from the crank pulse signal and controls the engine using the calculated crank angle, and a motor control device that calculates the resolver angle from the resolver signal and controls the power generation motor using the calculated rotation angle. The engine control device and the motor control device are communicably connected via an in-vehicle network constructed in the vehicle. The motor control device receives the crank angle calculated by the engine control device from the engine control device, learns the relationship between the crank angle and the resolver angle at the pulse interruption time when the pulse edge of the crank pulse signal is input to the engine control device, and estimates the crank angle at the current time based on the learned relationship and the resolver angle.

[0010] According to this configuration, an engagement mechanism is interposed between the crankshaft of the engine and the rotating shaft of the power generation motor. Therefore, when torque fluctuations that cross zero torque occur in the engagement mechanism, such as when the engine is started, a rattling noise is generated due to a change in the engagement state of the engagement mechanism. This rattling noise can be reduced by applying a compensation torque synchronized with the torque fluctuations of the engine from the power generation motor to the engagement mechanism.

[0011] Calculation of the torque fluctuations of the engine requires the crank angle of the engine. The crank pulse signal output by the crank angle sensor is input to the engine control device that controls the engine and not input to the motor control device that controls the power generation motor. Therefore, the motor control device cannot calculate the crank angle from the crank pulse signal, and the crank angle calculated from the crank pulse signal by the engine control device is input to the motor control device.

[0012] The crank angle sensor usually outputs crank pulse signals at intervals of 10° to 30°. In the engine control device, pulse interruption processing occurs in response to the input of the pulse edge (rising edge or falling edge) of the crank pulse signal, and the crank angle is calculated from the crank pulse signal by this pulse interruption processing. Therefore, the crank angle at the pulse interruption time when the pulse interruption processing occurs, that is, the time when the crank pulse signal is input, can be accurately calculated. However, between the pulse edges, the crank angle has to be obtained by interpolation, and it is difficult to obtain an accurate crank angle.

[0013] On the other hand, a resolver signal is input to the motor control device from a resolver with a higher resolution than the crank angle sensor. In the motor control device, the resolver angle (motor rotation angle of the generator motor) is calculated from the resolver signal for the control of the generator motor. Since the resolver angle has a correlation with the crank angle of the engine, if the relationship between the crank angle and the resolver angle at the pulse interruption time when the pulse interruption processing occurs is known, it is possible to accurately estimate the crank angle from the resolver angle even between the pulse edges of the crank pulse signal.

[0014] Therefore, the crank angle is input to the motor control device from the engine control device. Then, in the motor control device, the relationship between the crank angle and the resolver angle at the pulse interruption time is learned, and based on this relationship and the resolver angle, the crank angle at the current time is estimated. As a result, without incurring the cost increase due to providing a dedicated communication line or the like for communication between the motor control device and the engine control device, the motor control device can accurately estimate the crank angle of the engine with high resolution.

[0015] As a result, the accuracy of the control for compensating the torque fluctuation of the engine with the compensation torque can be improved, and the rattle noise can be effectively reduced. Thereby, when a crankshaft damper for attenuating the vibration of the crankshaft of the engine is provided, the set torque of the crankshaft damper can be reduced, and the occurrence of problems due to energy loss and heat generation by the crankshaft damper can be suppressed. Furthermore, by reducing the set torque of the crankshaft damper, the torque variation and the change over time of the crankshaft damper become smaller, and the vibration of the crankshaft is attenuated well. Also, the engine can be fired at a low rotational speed, and the power generation response of the power generation motor during rapid acceleration is improved, so that the acceleration response of the vehicle is improved.

[0016] The engine control device includes a transmission buffer that temporarily stores the crank angle when transmitting it to the motor control device. The motor control device receives the pulse interruption time and the transmission buffer update time when the engine control device updates the transmission buffer from the engine control device, estimates the communication delay time due to communication between the engine control device and the motor control device from the time difference between the current time and the transmission buffer update time, uses the estimated communication delay time to obtain the elapsed time from the pulse interruption time to the current time, and acquires the resolver angle before the elapsed time from the current time as the resolver angle at the pulse interruption time, and may learn the relationship between the crank angle and the resolver angle at the pulse interruption time.

[0017] Thereby, the communication delay between the engine control device and the motor control device can be compensated, and the crank angle of the engine can be estimated more accurately.

[0018] The motor control device acquires the current time and the transmission buffer update time, calculates the time difference between the current time and the transmission buffer update time, and if the calculated time difference is greater than the holding maximum value which is the maximum value currently held, updates the holding maximum value with the time difference. Also, if the calculated time difference is smaller than the holding minimum value which is the minimum value currently held, updates the holding minimum value with the time difference, subtracts the average value of the holding maximum value and the holding minimum value from the calculated time difference, and adds the expected value of the average value set in advance to the subtracted value, and the obtained value may be used as an estimated value of the communication delay time.

[0019] Thereby, it is possible to eliminate the influence of the variation in the actual communication delay and learn the communication delay time that occurs constantly. As a result, it is possible to learn well the relationship between the crank angle and the resolver angle at the pulse interruption time, and based on the learned relationship, accurately estimate the crank angle at the current time.

Advantages of the Invention

[0020] According to the present invention, without incurring an increase in cost due to providing a dedicated communication line or the like for communication with the engine control device, the motor control device can accurately estimate the crank angle of the engine with high resolution.

Brief Description of the Drawings

[0021]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Mode for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0023] <Hybrid vehicle> FIG. 1 is a block diagram showing the configuration of a hybrid vehicle 1 equipped with a hybrid control system according to an embodiment of the present invention.

[0024] The hybrid vehicle 1 employs a series hybrid system and is equipped with an engine (E / G) 11, a power generation motor (MG1) 12, a drive motor (MG2) 13, a battery 14, and a PCU (Power Control Unit) 15.

[0025] The engine 11 is, for example, a 3-cylinder 4-stroke gasoline engine. The engine 11 is provided with an electronic throttle valve for adjusting the intake air amount into the combustion chamber, an injector (fuel injection device) for injecting fuel into the intake air, and a spark plug for generating an electric discharge in the combustion chamber.

[0026] The power generation motor 12 is, for example, a permanent magnet synchronous motor (PMSM).

[0027] The crankshaft 16 of the engine 11 and the motor shaft 17 which is the rotating shaft of the power generation motor 12 are connected via an engagement mechanism 18 that transmits power by meshing of teeth. The engagement mechanism 18 includes, for example, a male spline provided on one of the crankshaft 16 and the motor shaft 17 and a female spline provided on the other of them, and is a mechanism that enables mutual power transmission between the crankshaft 16 and the motor shaft 17 by the meshing of the teeth of the male spline and the teeth of the female spline.

[0028] In addition, a crankshaft damper 19 composed of a rotary friction damper is attached to the crankshaft 16 of the engine 11 in order to reduce torsional vibration and bending vibration of the crankshaft 16.

[0029] The drive motor 13 is, for example, a permanent magnet synchronous motor larger than the power generation motor 12. The motor shaft 21, which is the rotating shaft of the drive motor 13, is connected to the drive system 22 of the hybrid vehicle 1. The drive system 22 includes a differential gear, and the power of the drive motor 13 is transmitted to the differential gear and distributed from the differential gear to drive wheels 23 composed of left and right front wheels or rear wheels and then transmitted. As a result, the left and right drive wheels 23 rotate, and the hybrid vehicle 1 moves forward or backward.

[0030] The battery 14 is a battery pack combining a plurality of secondary batteries. The secondary battery is, for example, a lithium-ion battery. The battery 14 outputs DC power of, for example, about 200 to 350 V (volts).

[0031] The PCU 15 is a unit for controlling the driving of the power generation motor 12 and the drive motor 13. Although not shown, the PCU 15 includes an MG1 inverter, an MG2 inverter, and a converter.

[0032] The MG1 inverter is a three-phase voltage type inverter that drives the power generation motor 12, and has a configuration in which series circuits of two IGBTs (Insulated Gate Bipolar Transistors) are provided corresponding to each of the U phase, V phase, and W phase, and these series circuits are connected in parallel to each other between the positive wiring and the negative wiring. The MG1 inverter converts DC power into AC power and supplies the AC power to the power generation motor 12 during the power running operation of the power generation motor 12. Further, the MG1 inverter converts the AC power generated by the power generation motor 12 into DC power during the regenerative operation (power generation operation) of the power generation motor 12.

[0033] The MG2 inverter is a three-phase voltage source inverter that drives the drive motor 13. Similar to the MG1 inverter, it is provided with series circuits of two IGBTs corresponding to each of the U-phase, V-phase, and W-phase, and these series circuits are connected in parallel to each other between the positive wiring and the negative wiring. The MG2 inverter converts DC power into AC power during the power running operation of the drive motor 13 and supplies the AC power to the drive motor 13. Also, the MG2 inverter converts the AC power generated by the drive motor 13 into DC power during the regenerative operation (power generation operation) of the drive motor 13.

[0034] The converter boosts the DC power output from the battery 14 and supplies it to the MG1 inverter and the MG2 inverter respectively during the power running operation of the power generation motor 12 and the drive motor 13. Also, the converter steps down the DC power output from the MG1 inverter and the MG2 inverter and supplies it to the battery 14 during the regenerative operation of the power generation motor 12 and the drive motor 13.

[0035] The hybrid vehicle 1 is equipped with a plurality of ECUs (Electronic Control Units), and each ECU includes a microcomputer (microcontroller). The microcomputer incorporates non-volatile memories such as a CPU and a flash memory, and volatile memories such as a DRAM (Dynamic Random Access Memory). The plurality of ECUs are connected so as to enable two-way communication based on the CAN (Controller Area Network) communication protocol.

[0036] The plurality of ECUs include an HV-ECU 31, an EFI-ECU 32, and an MG-ECU 33. The HV-ECU 31 is a unit that comprehensively controls the entire hybrid system including the engine 11, the power generation motor 12, and the drive motor 13. The EFI-ECU 32 is a unit that controls the engine 11. The MG-ECU 33 is a unit that controls the power generation motor 12 and the drive motor 13 and is built into the PCU 15.

[0037] A crank angle sensor 34 is connected to the EFI-ECU 32. The crank angle sensor 34 outputs a crank pulse signal synchronized with the rotation of the crankshaft 16, for example, a crank pulse signal at intervals of 10° to 30° of the rotation angle of the crankshaft 16. A crank pulse signal is input from the crank angle sensor 34 to the EFI-ECU 32 as a signal necessary for engine control. The EFI-ECU 32 controls the operations of the electronic throttle valve, injector, and ignition plug, such as the fuel injection amount and injection timing by the injector, according to the engine control command transmitted from the HV-ECU 31.

[0038] For example, a resolver 35 having a high resolution of 10 to 16 bits (360° / 1024 to 65536) is connected to the PCU 15. The resolver 35 is attached to the power generation motor 12 and outputs the change in the rotation angle (motor rotation angle) of the motor shaft 17 of the power generation motor 12 as a change in a two-phase AC voltage. An R / D (resolver / digital) converter for converting the analog signal of the two-phase AC voltage output by the resolver 35 into a digital signal is provided along with the resolver 35, and a digital signal output from the R / D converter is input as a resolver signal to the MG-ECU 33 as a signal necessary for motor control. The MG-ECU 33 controls the drive of the power generation motor 12 via the MG1 inverter and controls the drive of the drive motor 13 via the MG2 inverter according to the motor control command transmitted from the HV-ECU 31. Also, the MG-ECU 33 controls the step-up and step-down of the DC voltage by the converter as necessary.

[0039] In the hybrid vehicle 1, when the engine 11 is started, power is supplied from the battery 14 to the power generation motor 12, and the power generation motor 12 is operated in power running, so that the engine 11 is motored (cranked) by the power generation motor 12. When the ignition plug of the engine 11 is sparked in a state where the rotational speed of the engine 11 has increased to the rotational speed required for firing by motoring, the engine 11 fires.

[0040] When the hybrid vehicle 1 is running, the drive motor 13 is driven in power running, and the drive motor 13 generates power. With the engine 11 stopped and no power generation being performed by the power generation motor 12, the drive motor 13 is driven by the output of the battery 14, whereby the hybrid vehicle 1 runs as an electric vehicle (EV: Electric Vehicle). Also, with the engine 11 being put into an operating state (firing) and the power generation motor 12 being driven in power generation operation (regenerative operation), the drive motor 13 is driven by the combined power of the output (generated power) of the power generation motor 12 and the output of the battery 14, whereby the hybrid vehicle 1 runs in HV mode.

[0041] When the hybrid vehicle 1 decelerates, the drive motor 13 is driven in regenerative operation, and the power transmitted from the drive wheels to the drive motor 13 is converted into AC power. At this time, the drive motor 13 becomes a resistance of the running drive system, and that resistance acts as a braking force (regenerative braking force) for braking the hybrid vehicle 1. Also at this time, the generated power of the drive motor 13 is supplied to the battery 14, whereby the battery 14 is charged.

[0042] <Crank Angle Estimation Method> FIG. 2 is a diagram for explaining a method of calculating the crank angle estimated value CAEST by the MG-ECU 33. FIG. 3 is a diagram for explaining symbols used for calculating the damper twist angle estimated value DA.

[0043] As described above, an engagement mechanism 18 is interposed between the crankshaft 16 of the engine 11 and the motor shaft 17 of the power generation motor 12. Therefore, during starting of the engine 11 or light load operation, etc., torque fluctuations that cross zero torque occur in the engagement mechanism 18, and a rattling noise is generated due to a change in the engaged state of the engagement mechanism 18. In order to reduce this rattling noise, the MG-ECU 33 (PCU 15) controls the driving of the power generation motor 12 so that a compensation torque synchronized with the torque fluctuations of the engine 11 is applied from the power generation motor 12 to the engagement mechanism 18.

[0044] To calculate the torque fluctuation of the engine 11, the crank angle of the engine 11 is required. In the EFI-ECU 32, when the pulse edge (for example, the rising edge) of the crank pulse signal of the crank angle sensor 34 is input (detected), a pulse interrupt process occurs, and the time at that point is acquired as the pulse interrupt time Tp (step S101), and a pulse interrupt process is performed to calculate the crank angle EFICA (step S102). The crank angle EFICA is used for engine control by the EFI-ECU 32.

[0045] In the volatile memory built into the microcomputer of the EFI-ECU 32, a transmission buffer for temporarily storing data to be transmitted to other ECUs is set. When the crank angle EFICA is calculated, the calculated crank angle EFICA and the pulse interrupt time Tp, which is the start time of the calculation of the crank angle EFICA, are stored in the transmission buffer. Also, the time at that point, that is, the transmission buffer update time Ttxb when the transmission buffer is updated by the storage of the pulse interrupt time Tp and the crank angle EFICA, is stored in the transmission buffer (step S103). Then, the pulse interrupt time Tp, the crank angle EFICA, and the transmission buffer update time Ttxb stored in the transmission buffer are transmitted to the MG-ECU 33 by CAN communication.

[0046] In the MG-ECU 33, when receiving data from the EFI-ECU 32, that is, the pulse interrupt time Tp, the crank angle EFICA, and the transmission buffer update time Ttxb, the received data is stored in the volatile memory (hereinafter simply referred to as "memory") built into the microcomputer of the MG-ECU 33 (step S201).

[0047] Also, in the MG-ECU 33, the resolver angle RESA is acquired from the resolver signal from the resolver 35. The resolver angle RESA is stored in the memory in a state where the acquired time can be specified (step S202).

[0048] Further, in the MG-ECU 33, an estimated value of the twist angle (damper twist angle estimated value) DA occurring in the crankshaft damper 19 is calculated, and the calculated damper twist angle estimated value DA is stored in the memory (step S203).

[0049] Specifically, as shown in FIG. 3, assuming that the inertia, torque, and crank angle of the engine 11 are Ie, Te, and θe respectively, the inertia, torque, and motor rotation angle of the power generation motor 12 are Img, Tmg, and θmg respectively, and the damper torsion spring constant and friction torque of the crankshaft damper 19 are K and Tf respectively, the twist angle θd occurring in the crankshaft damper 19 is θd = θmg - θe. Also, the torque (damper torque) Td of the crankshaft damper 19 is

Equation

Equation

[0050] By eliminating the damper torque Td from equations (1) and (2) and arranging, the following equation (3) can be obtained.

Equation

[0051] The torsional angle θd generated in the crankshaft damper 19 can be calculated from the previous value of the torsional angle θd and the conditions of Equation (3). Even if the previous value of the torsional angle θd is used as the current value of the torsional angle θd, if the conditions of Equation (3) are satisfied, the previous value of the torsional angle θd may be directly used as the current value of the torsional angle θd. When the previous value of the torsional angle θd is used as the current value of the torsional angle θd, if the conditions of Equation (3) are not satisfied, the torsional angle θd should have changed from the previous value to a value that satisfies the conditions of Equation (3), so the value that satisfies Equation (3) should be used instead of the previous value. Specifically, the value closer to the previous value of the torsional angle θd may be selected from the values on the right side or the left side of Equation (3). The calculated torsional angle θd is stored in the memory in a state where the calculation time can be specified as the damper torsional angle estimated value DA.

[0052] Next, in the MG-ECU 33, the current time Tnow is acquired (step S204). Then, learning of the communication delay between the EFI-ECU 32 and the MG-ECU 33 is performed (step S205). The communication delay is defined as the time from when the transmission buffer is updated in step S103 until the MG-ECU 33 receives the data stored in the transmission buffer at that time and the current time Tnow is acquired in step S204.

[0053] FIG. 4 shows time-series data of measured values of the communication delay between the EFI-ECU 32 and the MG-ECU 33.

[0054] The actual communication delay varies greatly as shown in FIG. 4 because it is affected by the deviation in the processing timing between the EFI-ECU 32 and the MG-ECU 33, or a transmission waiting time occurs when data with a higher priority than the data (pulse interruption time Tp, crank angle EFICA, and transmission buffer update time Ttxb) for calculating the crank angle estimated value CAEST is transmitted from the EFI-ECU 32. The maximum and minimum values of the actual communication delay are known by actual measurement.

[0055] FIG. 5 is a graph showing the time change of the value Tdif obtained by subtracting the transmission buffer update time Ttxb from the current time Tnow. In the EFI-ECU 32 and the MG-ECU 33, the time is obtained using their respective unique clocks, and since these clocks are not synchronized, due to the relative clock error, the graph is an upward-sloping graph compared to the graph shown in FIG. 4.

[0056] In the learning of communication delay, a value Tdif obtained by subtracting the transmission buffer update time Ttxb from the current time Tnow, in other words, a time difference Tdif between the current time Tnow and the transmission buffer update time Ttxb, is calculated. When the calculated time difference Tdif is larger than the maximum value currently held (hereinafter referred to as the "held maximum value") Tmax, the held maximum value Tmax is updated with the time difference Tdif. Also, when the calculated time difference Tdif is smaller than the minimum value currently held (hereinafter referred to as the "held minimum value") Tmin, the held minimum value Tmin is updated with the time difference Tdif. Then, an average value Tcenter of the held maximum value Tmax and the held minimum value Tmin is obtained.

[0057] When the relative clock error is positive and the time difference Tdif has an upward-sloping tendency to increase with the passage of time, the frequency of updating the held maximum value Tmax becomes high, and when the relative clock error is negative and the time difference Tdif has a downward-sloping tendency to decrease with the passage of time, the frequency of updating the held minimum value Tmin becomes high. Therefore, a value Nud obtained by subtracting the update count of the held minimum value Tmin from the update count of the held maximum value Tmax is stored in the memory, and as the value Nud increases, the held maximum value Tmax and the held minimum value Tmin are corrected to increase with the passage of time, and as the value Nud decreases, the held maximum value Tmax and the held minimum value Tmin are corrected to decrease with the passage of time.

[0058] Also, when the difference between the holding maximum value Tmax and the holding minimum value Tmin becomes larger than the difference between the maximum value and the minimum value of the communication delay measured in advance, the update frequencies of the holding maximum value Tmax and the holding minimum value Tmin decrease, and the deviation between the average value Tcenter of the holding maximum value Tmax and the holding minimum value Tmin and the average value of the maximum value and the minimum value of the communication delay measured in advance becomes larger. Therefore, when the difference between the holding maximum value Tmax and the holding minimum value Tmin becomes larger than a predetermined value Trange, the holding maximum value Tmax decreases with the passage of time and the holding minimum value Tmin increases with the passage of time until the difference between the holding maximum value Tmax and the holding minimum value Tmin becomes equal to or less than the value Trange, so that the holding maximum value Tmax and the holding minimum value Tmin are corrected.

[0059] Note that the value Trange is set to the same value as the difference between the maximum value and the minimum value of the communication delay measured in advance, or is set to a value slightly smaller than the difference between the maximum value and the minimum value of the communication delay measured in advance in order to increase the update frequencies of the holding maximum value Tmax and the holding minimum value Tmin.

[0060] Then, assuming that the difference between the time difference Tdif and the average value Tcenter of the holding maximum value Tmax and the holding minimum value Tmin is the same as the difference between the time difference Tdif and the average value of the maximum value and the minimum value of the communication delay measured in advance, the communication delay estimated value Tdest is estimated by adding the expected value Texpect of the average value Tcenter to the difference. The expected value Texpect is set to a value near the average value of the maximum value and the minimum value of the communication delay measured in advance.

[0061] Thereafter, in the MG-ECU 33, when the crank angle EFICA received from the EFI-ECU 32 has changed from the crank angle EFICA received last time, the learning of the crank angle is performed.

[0062] That is, an estimated communication delay value Tdest is added to the difference Txb - Tp between the pulse interruption time Tp and the transmission buffer update time Ttxb, thereby obtaining an estimated elapsed time Tdelay from when the pulse edge of the crank pulse signal of the crank angle sensor 34 is input to the EFI-ECU 32 until the present time.

[0063] Thereafter, from the resolver angle RESA stored in the memory, a resolver angle RESATD before the estimated elapsed time Tdelay is acquired. When the estimated elapsed time Tdelay is not an integral multiple of the detection period of the resolver angle RESA, the resolver angle RESA acquired before and after the time point before the estimated elapsed time Tdelay may be acquired, and the resolver angle RESATD may be obtained by interpolation using these resolver angles RESA. Alternatively, the resolver angle RESATD may be obtained by multiplying the difference between any of the resolver angles acquired before and after the time point before the estimated elapsed time Tdelay and the estimated elapsed time Tdelay by the motor rotational angular velocity of the power generation motor 12. When the latter is adopted, the motor rotational angular velocity is preferably stored in the memory in a state where the time when the motor rotational angular velocity is acquired can be specified, and the motor rotational angular velocity before the estimated elapsed time Tdelay is used for the calculation of the resolver angle RESATD.

[0064] Also, similar to the case of the resolver angle RESATD, an estimated damper torsional angle DATD before the estimated elapsed time Tdelay is acquired from the estimated damper torsional angle DA stored in the memory. Then, the estimated damper torsional angle DATD is added to the crank angle EFICA, and the resolver angle RESATD is subtracted from the added value, thereby calculating a crank angle learning value THETADIF (step S207).

[0065] Thereafter, the crank angle learning value THETADIF is added to the current resolver angle RESA, and the current estimated damper twist angle DA is subtracted from the added value, whereby the estimated value CAEST of the current crank angle is calculated (step S208). In a state where the crank angle learning value THETADIF is obtained, the current estimated crank angle CAEST can be constantly calculated using the crank angle learning value THETADIF.

[0066] <Function and Effect> As described above, in the MG-ECU 33, the relationship between the crank angle EFICA and the resolver angle RESATD before the estimated elapsed time Tdelay, that is, the relationship between the crank angle EFICA and the resolver angle RESATD at the pulse interruption time Tp, is learned, and based on that relationship and the resolver angle RESATD, the current estimated crank angle CAEST is estimated. Thereby, without causing an increase in cost due to providing a dedicated communication line or the like for communication between the MG-ECU 33 and the EFI-ECU 32, the MG-ECU 33 can accurately estimate the crank angle of the engine 11 with high resolution.

[0067] As a result, the accuracy of the control for compensating the torque fluctuation of the engine 11 with the compensating torque can be improved, and the rattle noise can be effectively reduced. Thereby, when a crankshaft damper 19 for attenuating the vibration of the crankshaft 16 of the engine 11 is provided, the set torque of the crankshaft damper 19 can be reduced, and the occurrence of problems due to energy loss and heat generation by the crankshaft damper 19 can be suppressed. Furthermore, by reducing the set torque of the crankshaft damper 19, the torque variation and the change over time of the crankshaft damper 19 become smaller, and the vibration of the crankshaft 16 is attenuated well. Also, the engine 11 can be fired at a low rotational speed, and the power generation response of the power generation motor 12 during sudden acceleration is improved, so that the acceleration response of the vehicle is improved.

[0068] In the MG-ECU 33, an estimated communication delay value Tdest between the EFI-ECU 32 and the MG-ECU 33 is calculated from the time difference Tdif between the current time Tnow and the transmission buffer update time Ttxb. Using the estimated communication delay value Tdest, an estimated elapsed time Tdelay from the pulse interruption time Tp to the present is obtained. Then, the relationship between the resolver angle RESATD before the estimated elapsed time Tdelay from the present and the crank angle EFICA at the pulse interruption time Tp is learned.

[0069] As a result, the communication delay between the EFI-ECU 32 and the MG-ECU 33 can be compensated, and the crank angle of the engine 11 can be estimated more accurately.

[0070] In the learning of the relationship between the crank angle EFICA and the resolver angle RESATD, the communication delay between the EFI-ECU 32 and the MG-ECU 33 is learned. Specifically, the time difference Tdif between the current time Tnow and the transmission buffer update time Ttxb is calculated. When the time difference Tdif is larger than the currently held maximum value Tmax, the maximum value Tmax is updated with the time difference Tdif. When the time difference Tdif is smaller than the currently held minimum value Tmin, the minimum value Tmin is updated with the time difference Tdif. Then, the average value Tcenter of the maximum value Tmax and the minimum value Tmin is obtained, and the expected value Texpect is added to the difference between the time difference Tdif and the average value Tcenter, thereby estimating the communication delay value Tdest.

[0071] As a result, the influence of the variation in the actual communication delay can be eliminated, and the communication delay time that occurs constantly can be learned. As a result, the relationship between the crank angle EFICA and the resolver angle RESATD at the pulse interruption time Tp can be learned well, and based on the learned relationship, the current crank angle can be accurately estimated as the crank angle estimated value CAEST.

[0072] <Modification Example> As described above, the embodiments of the present invention have been explained, but the present invention can also be implemented in other forms.

[0073] For example, since the calculation of the damper twist angle estimated value DATD includes the second derivative value of the motor rotation angle θmg of the power generation motor 12 as shown in Equation (3), there is a delay Tdafilt due to the filter operation for the second derivative. Therefore, in the calculation of the crank angle learning value THETADIF, instead of the damper twist angle estimated value DATD before the estimated elapsed time Tdelay, the damper twist angle estimated value DATD before the value (Tdelay - Tdafilt) obtained by subtracting the filter operation delay Tdafilt from the estimated elapsed time Tdelay may be used. Thereby, a more accurate crank angle learning value THETADIF can be obtained, and using the crank angle learning value THETADIF, the current crank angle can be estimated more accurately.

[0074] Also, in the above-described embodiment, the case where the pulse interruption time Tp and the transmission buffer update time Ttxb are transmitted from the EFI-ECU 32 to the MG-ECU 33 has been taken up. However, when it is desired to reduce the communication volume, only one of the pulse interruption time Tp and the transmission buffer update time Ttxb may be transmitted.

[0075] For example, in a configuration where the pulse interruption time Tp is transmitted from the EFI-ECU 32 to the MG-ECU 33 and the transmission buffer update time Ttxb is not transmitted, the communication delay may be defined as the time from when the pulse interruption time Tp is acquired in step S101 until the MG-ECU 33 receives the pulse interruption time Tp and the current time Tnow is acquired in step S204. That is, the time difference Tdif may be set to the value obtained by subtracting the pulse interruption time Tp from the current time Tnow. In this case, since the communication delay estimated value Tdest calculated in step S205 includes the time from when the pulse edge of the crank pulse signal is input to the EFI-ECU 32 until the transmission buffer is updated, in step S206, the communication delay estimated value Tdest is directly used as the estimated elapsed time Tdelay.

[0076] However, since the estimated elapsed time Tdelay includes the variation in the time from when the pulse edge of the crank pulse signal is input to the EFI-ECU32 until the transmission buffer is updated, the learning accuracy of the communication delay deteriorates. However, if the engine speed at which learning is performed is limited to a certain speed or higher, the time from when the pulse edge of the crank pulse signal is input to the EFI-ECU32 until the transmission buffer is updated falls within a certain range, so that the deterioration of the learning accuracy can be minimized.

[0077] In a configuration where the transmission buffer update time Ttxb is transmitted from the EFI-ECU32 to the MG-ECU33 and the pulse interruption time Tp is not transmitted, taking the transmission buffer update time Ttxb as the time when the pulse edge of the crank pulse signal is input to the EFI-ECU32, in step S206, the communication delay estimated value Tdest may be directly used as the elapsed time estimated value Tdelay, or the expected value of the transmission buffer update time (corresponding to 1 / 2 of the pulse interval) may be further added to the pulse edge input time according to the engine speed.

[0078] In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

Explanation of Signs

[0079] 1: Hybrid vehicle (vehicle) 11: Engine 12: Power generation motor 16: Crankshaft 17: Motor shaft (rotating shaft) 18: Meshing mechanism 32: EFI-ECU (engine control device) 33: MG-ECU (motor control device) 34: Crank angle sensor 35: Resolver

Claims

1. A system for controlling an engine and a power generation motor, mounted on a vehicle in which an engagement mechanism for transmitting power by tooth engagement is interposed between a crankshaft of the engine and a rotating shaft of the power generation motor, and a crank angle sensor for outputting a crank pulse signal synchronized with the rotation of the crankshaft and a resolver for outputting a resolver signal that changes according to the rotation angle of the rotating shaft are provided, an engine control device that calculates a crank angle of the engine from the crank pulse signal and controls the engine using the calculated crank angle, and a motor control device that calculates a resolver angle from the resolver signal and controls the power generation motor using the calculated rotation angle, wherein the engine control device and the motor control device are communicably connected via an in-vehicle network constructed in the vehicle, the engine control device includes a transmission buffer that temporarily stores the crank angle when transmitting it to the motor control device, the motor control device receives the crank angle calculated by the engine control device from the engine control device, receives from the engine control device a pulse interruption time when a pulse edge of the crank pulse signal is input to the engine control device and a transmission buffer update time when the engine control device updates the transmission buffer, estimates a communication delay time due to communication between the engine control device and the motor control device from a time difference between the current time and the transmission buffer update time, uses the estimated communication delay time to obtain an elapsed time from the pulse interruption time to the current time, acquires a resolver angle before the elapsed time from the current time as the resolver angle at the pulse interruption time, and learns the relationship between the crank angle and the resolver angle at the pulse interruption time, A hybrid control system that estimates the crank angle at the current time based on the learned relationship and the resolver angle.

2. The motor control device calculates the time difference between the current time and the transmission buffer update time, and if the calculated time difference is greater than the holding maximum value, which is the maximum value currently held, updates the holding maximum value with the time difference. Also, if the calculated time difference is less than the holding minimum value, which is the minimum value currently held, updates the holding minimum value with the time difference, subtracts the average value of the holding maximum value and the holding minimum value from the time difference, and adds the expected value of the average value set in advance to the subtracted value to obtain a value as the estimated communication delay time. The hybrid control system according to claim 1.

Images