[0022] The best mode for implementing the present invention will be described below with reference to the drawings. Fig. 1 is a diagram showing the arrangement of a hybrid vehicle to which the present invention is applied. 1, two power sources, namely an engine 11 and a motor generator 12 are arranged in parallel to drive the wheels. Among them, the engine 11 (hereinafter also referred to as EG) is typically an internal combustion engine, and the motor generator 12 (hereinafter also referred to as MG 12) ) Driven by the electric power stored in the battery 19.
[0023] The torque output from the engine 11 is transmitted to the transmission 13. Then, the torque is transmitted to the drive shafts 15 and 15' through the differential device (differential) 14 serving as an output portion, and then to the drive wheels 16 and 16' to drive the vehicle. Similarly, the torque output from the MG 12 is also transmitted to the drive shafts 15 and 15' through the differential device 14, and then to the drive wheels 16 and 16' to drive the vehicle.
[0024] In addition, the hybrid vehicle shown in FIG. 1 includes a hybrid vehicle electronic control unit 21 (hereinafter referred to as HV-ECU 21), a motor generator electronic control unit (hereinafter referred to as MG-ECU), an inverter 22, and an engine Electronic control unit 23 (hereinafter referred to as EG-ECU 23), clutch actuator 17 built in transmission 13, automatic manual transmission electronic control unit 24 (hereinafter referred to as AMT-ECU 24), and battery electronic control unit 25 (hereinafter referred to as Called battery ECU25). HV-ECU controls the entire vehicle, and MG-ECU controls MG 12 to regenerate or drive. The EG-ECU 23 stops the engine 11 or controls the combustion state of the engine 11, and the AMT-ECU 24 controls the shift actuator 18 to perform optimal shifting. The battery ECU 25 controls the state of charge of the battery 19.
[0025] The HV-ECU 21 functions as a drive source control device of the vehicle. The HV-ECU 21 controls and manages the MG-ECU, the inverter 22, the EG-ECU 23, and the battery ECU 25 according to the driver's intention. In addition, the HV-ECU 21 has a shift flag and a downshift flag, and switches the value (ON/OFF) of each flag in accordance with the driving state of the vehicle. As described below, the HV-ECU 21 changes the calculation method of the output torque from the MG 12 according to the combination of the values of each flag.
[0026] The EG-ECU 23 cooperates with the AMT-ECU 24 to generate an optimal combustion mode, and executes fuel control when starting the engine with the starter 20. An indicator 26 is provided in the driver's seat to display the vehicle speed.
[0027] Fig. 2 is a schematic diagram schematically showing the structure of a drive mechanism (fourth gear) employed in a hybrid vehicle. With reference to the configuration of the transmission 13, the flywheel 32 is fixed to the end of the output shaft 31 of the engine 11, and the clutch member 33 is mounted on the flywheel 32 so as to be able to be engaged and disengaged by the clutch actuator 17. The driven member of the clutch is mounted on the input shaft 34 of the transmission 13 through a spline or the like so as to rotate integrally with the input shaft 34. Starting from the clutch side, the first drive gear 35, the reverse drive gear 36 ("reverse" is abbreviated as "Rev." hereinafter, such as Rev. drive gear 36), and the second drive gear 37 are connected to the input shaft 34 to Form a single unit. In addition, the third drive gear 38, the fourth drive gear 39, the fifth drive gear 40, and the sixth drive gear 41 are rotatably connected to the input shaft 34. In addition, the output shaft 42 of the transmission 13 is arranged in parallel with the input shaft 34. The first driven gear 43 and the second driven gear 44 are rotatably connected to the output shaft 42 such that the first driven gear 43 and the second driven gear 44 mesh with the corresponding driving gears. In addition, the third driven gear 45, the fourth driven gear 46, the fifth driven gear 47, and the sixth driven gear 48 are connected to the output shaft 42, and are located at a position that allows each driven gear to mesh with the corresponding drive gear. Connection location. The third driven gear 45, the fourth driven gear 46, the fifth driven gear 47, and the sixth driven gear 48 rotate integrally with the output shaft 42. The driving gear 49 is connected to the end of the output shaft 42 close to the clutch so as to rotate integrally with the output shaft 42. The drive gear 49 meshes with a ring gear 70 provided on the case of the differential device (differential gear) 14. In addition, the shaft 50 is arranged on one side of the transmission 13 in parallel with the input shaft 34 of the clutch 13. The reverse idler gear 51 is rotatably connected to the shaft 50. The reverse idler gear 51 can move in the axial direction of the shaft 50. When the reverse idler gear 51 moves to a position close to the clutch (indicated by the thick solid line in FIG. 2), the reverse idler gear 51 does not mesh with the reverse drive gear 36, but when the reverse idler gear 51 moves closer to the first When the position of the six driving gear 41 (indicated by a thin solid line in FIG. 2 ), the reverse idler gear 51 can mesh with the reverse drive gear 36.
[0028] The hub member 52 is disposed between the first driven gear 43 and the second driven gear 44 of the output shaft 42, and the hub member 53 is disposed between the third drive gear 38 and the fourth drive gear 39 of the input shaft 34, The hub member 54 is disposed between the fifth drive gear 40 and the sixth drive gear 41 of the input shaft 34. The hub member 52 and the output shaft 42 rotate integrally, and the hub members 53 and 54 rotate integrally with the input shaft 34. An engaging member such as a spline is provided on the outer circumference of each of the hub members 52, 53 and 54. In addition, sleeve members 55, 56 and 57 are respectively provided on the outer circumferences of the hub members 52, 53 and 54. These sleeve members are respectively located on the outside of each engaging member so that the hub members 52, 53 and 54 are The cylinder members 55, 56 and 57 are engaged. The shift actuator 18 moves the sleeve members 55, 56 and 57 along the axial direction of the input shaft 34 and the output shaft 42 (horizontal direction in FIG. 2), and thereby establishes a torque transferable state or a neutral state, wherein In the torque transmission state, the sleeve member meshes with the spline formed on the left gear or the spline formed on the right gear; in the neutral state, the sleeve member does not mesh with any gear. FIG. 2 shows a state where the fourth gear is established by moving the sleeve member 56 to the left side of FIG. 2. In addition, the sleeve member 55 arranged between the first driven gear 43 and the second driven gear 44 of the output shaft 42 is provided with a gear 58 at a position closer to the outside. When the reverse idler gear 51 meshes with the reverse drive gear 36, the gear 58 meshes with the reverse idler gear 51 to establish a neutral state or a reverse drive state.
[0029] As described above, the clutch actuator 17 engages the clutch to transmit the driving force of the engine 11 to the driving gear 49 located at the end of the output shaft 42 in accordance with the gear ratio selected by the shift actuator 18.
[0030]On the other hand, the driving force output by the MG 12 is transmitted to the driving gear 61 integrally provided at the end of the MG output shaft 60. The intermediate reduction shaft 62 is provided in parallel with the MG output shaft 60. The driven gear 63 is provided on the intermediate reduction shaft 62 so as to mesh with the driving gear 61. In addition, the drive gear 64 is provided on the intermediate reduction shaft 62 so as to mesh with a ring gear (main drive gear) 70 provided on the case of the differential device (differential gear) 14. The driving force output by the MG 12 is transmitted to the driving gear 64 according to a predetermined gear ratio.
[0031] According to the above configuration, the outputs from the engine 11 and the MG 12 are transmitted to the ring gear (main drive gear) 70 through the HV-ECU 21. Then, when necessary, the difference in rotation speed between the torque output of the MG 12 and the torque output of the engine 11 is absorbed in the differential device (differential) 14, and the output is transmitted to the drive shafts 15 and 15' and the drive wheels 16 and 16' for driving.
[0032] In addition, the MG 12 establishes a driving state and a regenerative power generation state. When the driving state is established, the MG 12 converts the electric power supplied by the battery 19 into torque. In addition, when the regenerative power generation state is established, the MG 12 converts torque into electric power. In the MG 12, three-phase power is applied to the stator member 66 so that a large current flows at a desired position of the stator member 66. As a result, a rotating magnetic field is generated, and current passes through the core portion of the rotor member 67 to drive the rotor to rotate. Therefore, the control of the MG 12 (including the generation of driving force and the direction of rotation) is performed so that the conversion is effectively performed.
[0033] A resolver 65 is installed at the other end of the output shaft 60 of the MG 12 as a rotation detection device. The resolver 65 detects the relative angle formed between the winding stator member 66 of the MG 12 and the rotor member 67 rotating integrally with the MG output shaft 60, and uses the detected relative angle as a resolver signal. For example, by converting the resolver signal using the value of the number of poles related to the MG 12 and the gear ratio of the MG 12, the resolver signal can be used as vehicle speed indication information of the vehicle.
[0034] The control of the driving source of the hybrid vehicle having the above-mentioned configuration will be described below with reference to the drawings. FIG. 3 is a flowchart showing the flow of processing executed in the HV-ECU 21 at each predetermined time period.
[0035] 3, the HV-ECU 21 confirms whether a predetermined permission condition for torque assist is satisfied (step S001). For example, the HV-ECU 21 confirms whether the SOC (state of charge) of the battery 19 is equal to or greater than a predetermined value, the temperature of the MG 12 is equal to or lower than a predetermined temperature, and the vehicle speed is equal to or lower than a predetermined value.
[0036] Subsequently, the HV-ECU 21 confirms whether the driver requests a gear change (step S002). For example, the accelerator pedal opening degree θ and the current vehicle speed obtained by the accelerator pedal opening degree sensor are applied to predetermined gear line information (shift map) to confirm whether a gear shift is required. If it is deemed necessary to shift gears, set the shift flag to ON. After the vehicle leaves the state requiring shifting, the setting of the shift flag is cleared (steps S003 to S004).
[0037] Subsequently, the EV-ECU 21 confirms whether the driver requires downshifting (step S005). For example, when the accelerator opening θ and the current vehicle speed v are applied to the predetermined gear line information, and it is deemed necessary to shift from the current gear to a lower gear, the downshift flag is set to ON (step S006).
[0038] Then, the HV-ECU 21 confirms whether the shift flag is set to ON (step S007) and the downshift flag is set to ON (steps S008, S009) based on the judgment results of the above steps S002 to S006.
[0039] Here, if both the shift flag and the downshift flag are set to ON, that is, when the driver requests a quick gear shift, the HV-ECU 21 executes the acceleration assist processing during downshift (second motor assist mode). The electric motor outputs a second additional torque corresponding to the accelerator pedal opening (step S010). The acceleration assist processing (second motor assist mode) at the time of downshifting will be described in detail later.
[0040] When only the shift flag is set to ON, the HV-ECU 21 executes the acceleration assist processing during the upshift (first motor assist mode), at which time the motor outputs the first additional torque to compensate for the engine torque fluctuation caused by the shift (step S011 ). Referring to FIG. 9 (note that FIG. 9 shows the case of downshifting), in the acceleration assist processing (first motor assist mode) at the time of upshifting, for example, the MG 12 operates to output a predetermined amount of torque in order to reduce the The change in the acceleration in the longitudinal direction of the vehicle caused by the disengagement of the clutch.
[0041] If the shift flag is set to OFF and the downshift flag is set to ON, that is, after the acceleration assist processing during downshift is executed, the difference between the required gear position and the actual gear position determined according to the accelerator pedal opening and the current vehicle speed When the mismatch has been eliminated, the HV-ECU 21 executes the acceleration assistance termination process (assistance termination process) at the time of downshifting (step S012). The acceleration assistance termination processing (assistance termination processing) at the time of downshifting will be described in detail later.
[0042] If both the shift flag and the down shift flag are set to OFF, for example, when the vehicle is traveling in a predetermined gear, the HV-ECU 21 sets the required MG torque value to 0 (step S013).
[0043] Then, the HV-ECU 21 executes restriction processing to restrict the MG assist torque calculated in the above-mentioned steps S010 to S012 based on items such as the SOC value, the MG temperature, and the MG maximum output (step S014).
[0044] Finally, the HV-ECU 21 sets the MG assist torque calculated and limited as described above to the required MG torque value and issues a command to the MG-ECU (step S015).
[0045] The acceleration assistance processing during the downshift in step S010 (second motor assist mode) and the acceleration assistance termination processing during the downshift in step S012 (assistance termination processing) will be described in detail below.
[0046] 4 is a flowchart showing the outline of the processing flow executed by the HV-ECU 21 in the acceleration assist processing (second motor assist mode) at the time of downshifting. In the acceleration assist processing (second motor assist mode) at the time of downshifting, the HV-ECU 21 calculates a load ratio based on the accelerator pedal opening degree (step S111), which represents the load of the MG 12 for providing MG assist torque.
[0047] The HV-ECU 21 calculates the assist torque (second assist torque) by multiplying the maximum torque of the MG by the load ratio (step S112). Fig. 5 is a graph showing the relationship between the accelerator pedal opening and the load ratio. For example, when the accelerator pedal opening is small and the second assist torque is provided, the rapid movement of the vehicle may cause shock. Therefore, the MG assist torque is set to basically zero. When the accelerator pedal opening reaches or exceeds θ 1 At this time, the load ratio increases in proportion to the increase in the accelerator pedal opening at a certain rate. When the accelerator pedal opening reaches or exceeds θ 2 When the load ratio increases in proportion to the increase in the accelerator pedal opening at another ratio, the other ratio is greater than 1 And θ 2 The ratio between. When the accelerator pedal opening is equal to or greater than θ 3 When the load ratio is 1.0. At this time, the MG assist torque is equal to the MG maximum torque. When the accelerator pedal opening is less than θ 3 Within the range, for example, when the accelerator pedal opening is θ n When the load ratio and MG assist torque are set to be the same as the accelerator opening θ n The corresponding value.
[0048] 6 is a flowchart showing an outline of the processing flow executed by the HV-ECU 21 in the acceleration assist termination processing at the time of downshifting. In the acceleration assist termination process (assist termination process) at the time of downshifting, the HV-ECU 21 confirms whether the second assist torque exceeds 0 (step S131).
[0049] Here, if the second assist torque exceeds 0, similar to step S112 of FIG. 4, the HV-ECU 21 calculates the assist torque by multiplying the maximum torque of the MG by the load ratio (step S132). In addition, the HV-ECU 21 executes the MG assist torque reduction process to reduce the MG assist torque calculated as described above at a predetermined ratio (step S133).
[0050] When the MG assist torque reduction process is repeated and the MG assist torque becomes 0 or less, the HV-ECU 21 sets the MG assist torque to 0 (step S134), and then sets the downshift flag to OFF to terminate the downshift The acceleration assistance termination process (assistance termination process) of the (step S135).
[0051] FIG. 7 is a diagram showing the accelerator pedal opening, gear position (required gear position, actual gear position), clutch operation, vehicle speed, MG assist torque and acting on when the driver performs a rapid acceleration operation in an example according to the present invention A graph showing the change in acceleration in the longitudinal direction of the vehicle.
[0052] First, the accelerator opening degree is increased (refer to the curve indicating the accelerator opening degree), so that both the shift flag and the down shift flag are set to ON. Therefore, the required gear is determined and the clutch is disengaged. At the same time, the control of the MG assist torque (second motor assist mode) is started. Even after the actual gear position matches the required gear position and the shift flag is set to OFF, the MG assist torque is controlled for a period of time by the load ratio corresponding to the accelerator opening. Then, the MG assist torque reduction process is started.
[0053] When the MG assist torque becomes 0 by repeating the MG assist torque reduction process, the downshift flag is set to OFF. Then, continue to accelerate the engine.
[0054] As described above, when the MG temperature, the remaining charge in the battery, etc. are within the range that allows the MG to operate normally, the MG 12 outputs the acceleration torque to meet the driver's acceleration requirements. Therefore, it is possible to realize fast and smooth acceleration performance in response to the driver's request. In addition, achieving smooth acceleration performance allows the driver to reduce the amount of accelerator pedal depression, thereby improving fuel economy. In addition, by comparing Fig. 7 and Fig. 9, it can be clearly seen that the change in acceleration acting on the longitudinal direction of the vehicle is reduced.
[0055] Although the embodiments of the present invention are described above, the scope of the present invention is not limited to the above embodiments. Various improvements can be made to the embodiments of the present invention in accordance with the technical requirements of the vehicle to which the present invention is applied.
[0056] For example, in the above-mentioned embodiment, the embodiment of the present invention is described using a hybrid vehicle in which the driving force output by the MG is transmitted to the differential device 14. However, the present invention can also be applied to other types of vehicles. For example, the present invention can be applied to a vehicle in which an engine and an electric motor drive the vehicle in parallel.
[0057] For example, in the above embodiment, the load ratio (a parameter for determining the required motor torque value) is determined by the accelerator pedal opening degree, and the required motor torque value is determined by the load ratio to simplify the technical understanding of the present invention. However, the required motor torque value can be directly determined by the accelerator pedal opening. Moreover, the graph of FIG. 5 is used to simplify the understanding of the embodiment of the present invention. Therefore, it is obvious that, for example, other graphs, tables, mathematical formulas, etc. can be used instead of the graph of FIG. 5.
