JP5549144B2 - Control device for electric vehicle - Google Patents

Description

  The present invention relates to an electric vehicle control device applied to an electric vehicle, a hybrid vehicle, or the like that includes a motor and a stepped automatic transmission in a drive system.

  Conventionally, the estimated vehicle weight and actual acceleration are integrated to calculate the actual driving force by the motor, and the motor torque is corrected by changing the motor phase command based on the difference between the calculated actual driving force and the driving force command value. A control device for an electric vehicle is known (for example, see Patent Document 1).

JP 2008-43134 A

  By the way, in an electric vehicle equipped with a motor and a stepped automatic transmission, the rotational speed of the motor is controlled to compensate for fluctuations in the output rotational speed during shift control of the automatic transmission. Here, since the inertia acting on the vehicle changes according to the vehicle weight, the torque for changing the motor rotation speed is different, and the actual motor rotation speed does not coincide with the target rotation speed, and a shift shock and a shift lag are generated.

  Accordingly, it is conceivable to apply the above-described conventional control device for an electric vehicle and correct the motor torque during the motor rotation speed control in consideration of the estimated vehicle weight. However, in the conventional control device for an electric vehicle, the motor torque is corrected to the decreasing side as the estimated vehicle weight is large, and the motor torque is corrected to the increasing side as the estimated vehicle weight is small. Even the shift shock and shift lag could not be suppressed.

  The present invention has been made paying attention to the above-described problem, and an object of the present invention is to provide a control device for an electric vehicle capable of quick shifting while suppressing shift shock in an electric vehicle including a stepped automatic transmission. To do.

In order to achieve the above object, in the control apparatus for an electric vehicle according to the present invention, the drive system includes a motor, a stepped automatic transmission, and a drive wheel. The rotational speed of the motor is controlled so that the machine input rotational speed becomes the target input rotational speed.
In this electric vehicle control apparatus, the motor torque correction means for correcting the motor torque during the motor speed control increases the motor torque increase correction amount as the estimated vehicle weight estimated by the vehicle weight estimation means increases.

  In the control apparatus for an electric vehicle according to the present invention, it is possible to prevent the occurrence of overshoot of the motor rotation speed and the occurrence of a shift lag with the above-described configuration. In an electric vehicle equipped with a stepped automatic transmission, a shift shock is prevented. A quick shift is possible while restraining.

1 is an overall system diagram showing an FR hybrid vehicle (an example of an electric vehicle) by rear wheel drive to which a control device of Embodiment 1 is applied. It is a figure which shows an example of the shift map of the automatic transmission set to the transmission controller of Example 1. FIG. It is a figure which shows an example of the EV-HEV selection map set to the mode selection part of the integrated controller of Example 1. It is a skeleton figure which shows an example of the automatic transmission mounted in the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a fastening operation | movement table | surface which shows the fastening state of each friction element for every gear stage in the automatic transmission mounted in the FR hybrid vehicle to which the control apparatus of Example 1 was applied. 4 is a flowchart illustrating a flow of a shift control process executed by the integrated controller according to the first embodiment. 3 is a flowchart illustrating a flow of a motor operating point command output process during inertia phase control executed by the motor controller according to the first embodiment. 4 is a flowchart illustrating a flow of a vehicle weight correction torque calculation process executed by the integrated controller according to the first embodiment. It is an example of the vehicle weight correction torque setting map used in vehicle weight correction torque calculation processing. It is explanatory drawing which shows the target MG rotational speed command and target motor rotational speed response at the time of motor rotational speed control at the time of shifting of an automatic transmission, (a) shows the time of downshift, (b) at the time of upshift Indicates.

  Hereinafter, the best mode for realizing an electric vehicle control apparatus of the present invention will be described based on Example 1 shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of an electric vehicle) to which the control apparatus for an electric vehicle according to the first embodiment is applied.

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a first clutch CL1, a motor / generator MG, a second clutch CL2, an automatic transmission AT, and a final gear FG. And a left drive wheel LT and a right drive wheel RT.

  The engine Eng is a gasoline engine or a diesel engine, and engine start control, engine stop control, throttle valve opening control, fuel cut control, and the like are performed based on an engine control command from the engine controller 1. Further, the engine Eng is capable of lean combustion, and the engine torque is controlled to coincide with the command value by controlling the intake air amount by the throttle actuator, the fuel injection amount by the injector, and the ignition timing by the spark plug.

The first clutch CL1 is a clutch interposed between the engine Eng and the motor / generator MG, and is generated by the first clutch hydraulic unit 6 based on a first clutch control command from the first clutch controller 5. Engagement / semi-engagement / release is controlled by the first clutch control oil pressure. As the first clutch CL1, for example, a normally closed dry type in which complete engagement is maintained by an urging force of a diaphragm spring and complete engagement, slip engagement, and complete release are controlled by stroke control using a hydraulic actuator (not shown). A single plate clutch is used.
If the first clutch CL1 is completely engaged, motor torque + engine torque is transmitted to the second clutch CL2. If the first clutch CL1 is disengaged, only motor torque is transmitted to the second clutch CL2.

  The motor / generator MG is a synchronous motor / generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase AC generated by an inverter 3 based on a control command from the motor controller 2. It is controlled by applying. The motor / generator MG can operate as an electric motor that rotates by receiving power supplied from the battery 4 (powering), or when the rotor receives rotational energy from the engine Eng or the left and right drive wheels LT, RT. Functions as a generator that generates electromotive force at both ends of the stator coil, and can also charge the battery 4 (regeneration).

  The second clutch CL2 is controlled for engagement / slip engagement / release by the control hydraulic pressure generated by the second clutch hydraulic unit 10 based on the second clutch control command from the second clutch controller 9, and the clutch hydraulic pressure (pressing force) ) Generates a transmission torque (clutch torque capacity). The second clutch CL2 transmits the torque output from the engine Eng and the motor / generator MG (when the first clutch CL1 is engaged) to the left and right drive wheels LT, RT via the automatic transmission AT and the final gear FG. Communicate. As the second clutch CL2, for example, a normally open wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used.

The automatic transmission AT is a stepped transmission that automatically switches the stepped gears according to the vehicle speed, the accelerator opening, and the like. In the first embodiment, the automatic transmission AT has seven forward speeds and one reverse gear stage. It is a step transmission. The automatic transmission AT obtains a predetermined gear stage by the control hydraulic pressure generated by the transmission hydraulic unit 8 based on the transmission command from the transmission controller 7.
A mechanical oil pump (not shown) driven by the transmission input shaft Input is provided on the transmission input shaft Input (= motor shaft) of the automatic transmission AT. A sub oil pump (not shown) driven by an electric motor is provided in the motor housing or the like in order to suppress a decrease in hydraulic pressure when the discharge pressure from the mechanical oil pump is insufficient when the vehicle is stopped. The drive control of the sub oil pump is performed by the transmission controller 7.

  The transmission output shaft Output of the automatic transmission AT is connected to the left and right drive wheels LT and RT via a final gear FG.

  In this FR hybrid vehicle, as driving modes depending on driving modes, an electric vehicle traveling mode (hereinafter referred to as “EV traveling mode”), a hybrid vehicle traveling mode (hereinafter referred to as “HEV traveling mode”), and driving. Torque control travel mode (hereinafter referred to as “WSC travel mode”).

  The “EV travel mode” is a mode in which the first clutch CL1 is released and the vehicle travels only with the driving force of the motor / generator MG, and includes a motor travel mode and a regenerative travel mode. This “EV running mode” is selected when the required driving force is low and the battery SOC is secured.

  The “HEV travel mode” is a mode that travels with the first clutch CL1 engaged, and has a motor assist travel mode, a power generation travel mode, and an engine travel mode, and travels in any mode. This “HEV travel mode” is selected when the required driving force is high or when the battery SOC is insufficient.

  In the “WSC travel mode”, the second clutch CL2 is maintained in the slip engagement state by controlling the rotational speed of the motor / generator MG, and the clutch transmission torque passing through the second clutch CL2 depends on the vehicle state and the driver's operation. In this mode, the clutch torque capacity is controlled so that the required driving torque is determined. The “WSC travel mode” is selected in a travel region where the engine speed is lower than the idle speed, such as when the vehicle is stopped, started, or decelerated in the selected state of the “HEV travel mode”.

Next, the control system of the FR hybrid vehicle will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. A transmission controller 7, a transmission hydraulic unit 8, a second clutch controller 9, a second clutch hydraulic unit 10, and an integrated controller 11. Each of the controllers 1, 2, 5, 7, and 9 and the integrated controller 11 are connected via a CAN communication line 12 that can mutually exchange information.

  The engine controller 1 inputs engine speed information from the engine speed sensor 13, a target engine torque command from the integrated controller 11, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng.

  The motor controller 2 includes information from a motor position detector (resolver) 14 that detects a rotor rotational position of the motor / generator MG, a target MG torque command and a target MG rotational speed command from the integrated controller 11, and other necessary requirements. Enter information. Then, a motor operating point command for controlling the motor operating point (Nm, Tm) of motor / generator MG is output to inverter 3. The motor operating point command is composed of a motor rotational speed command value and a motor torque command value. Further, the motor controller 2 monitors the battery SOC indicating the charging capacity of the battery 4 and supplies the battery SOC information to the integrated controller 11 via the CAN communication line 12.

  The first clutch controller 5 inputs piston stroke position information of a hydraulic actuator (not shown), a target CL1 torque command from the integrated controller 11, and other necessary information. Then, a command for controlling engagement / semi-engagement / release of the first clutch CL <b> 1 is output to the first clutch hydraulic unit 6.

  The transmission controller 7 inputs information from an accelerator opening sensor 15, a vehicle speed sensor 16, and other sensors 17 that are input to the integrated controller 11. When traveling with the D range selected, the optimum shift speed is searched based on the position where the driving point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map shown in FIG. Is output to the transmission hydraulic unit 8. The shift map is a map in which an up shift line and a down shift line are written according to the accelerator opening APO and the vehicle speed VSP, as shown in FIG. In the transmission controller 7, when a shift control command is output from the integrated controller 11 in the engine start control or the like, the shift control according to the shift control command is performed in preference to the normal shift control.

  The second clutch controller 9 inputs motor rotation speed information based on a detection value of the motor position detector 14, a transmission input rotation speed sensor 18, a target CL2 torque command from the integrated controller 11, and other necessary information. To do. Then, a command for controlling engagement / slip engagement / release of the second clutch CL <b> 2 is output to the second clutch hydraulic unit 10.

  The integrated controller 11 manages the energy consumption of the entire vehicle and has the function of running the vehicle with the highest efficiency. The motor rotation speed information based on the detection value of the motor position detector 14 and other sensor switches Necessary information from the class and information is input via the CAN communication line 12. The target engine torque command is sent to the engine controller 1, the target MG torque command and the target MG speed command are sent to the motor controller 2, the target CL1 torque command is sent to the first clutch controller 5, the shift control command is sent to the transmission controller 7, and the second clutch controller. The target CL2 torque command is output to 9.

  The integrated controller 11 searches the optimum driving mode according to the position where the driving point determined by the accelerator opening APO and the vehicle speed VSP exists on the EV-HEV selection map shown in FIG. 3, and the searched driving mode is set as the target driving. It has a mode selection part which selects as a mode. In this EV-HEV selection map, there is an EV⇒HEV switching line that switches from “EV driving mode” to “HEV driving mode” when the operating point (APO, VSP) that exists in the EV region crosses, and in the HEV region When the driving point (APO, VSP) crosses, the HEV ⇒ EV switching line that switches from “HEV driving mode” to “EV driving mode” and the driving point (APO, VSP) are in the WSC area when “HEV driving mode” is selected. When entering, HEV⇒WSC switching line to switch to “WSC driving mode” is set. The HEV → EV switching line and the HEV → EV switching line are set with a hysteresis amount as a line dividing the EV region and the HEV region. The HEV⇒WSC switching line is set along the first set vehicle speed VSP1 at which the engine Eng maintains the idling speed when the automatic transmission AT is in the first speed. However, if the battery SOC falls below a predetermined value while the “EV travel mode” is selected, the “HEV travel mode” is forcibly set as the target travel mode.

  FIG. 4 is a skeleton diagram illustrating an example of an automatic transmission mounted on an FR hybrid vehicle to which the control device of the first embodiment is applied.

  The automatic transmission AT is a stepped automatic transmission with 7 forward speeds and 1 reverse speed, and driving force from at least one of the engine Eng and the motor / generator MG is input from a transmission input shaft Input. The rotational speed is changed by one planetary gear and the seven friction elements, and is output from the transmission output shaft Output.

  The transmission gear mechanism includes a first planetary gear set GS1, a third planetary gear G3, and a first planetary gear set G3 formed by a first planetary gear G1 and a second planetary gear G2 in order on an axis from the transmission input shaft Input side to the transmission output shaft Output side. A second planetary gear set GS2 with four planetary gears G4 is arranged. Further, a first clutch C1, a second clutch C2, a third clutch C3, a first brake B1, a second brake B2, a third brake B3, and a fourth brake B4 are arranged as friction elements. Further, a first one-way clutch F1 and a second one-way clutch F2 are arranged.

  The first planetary gear G1 is a single pinion type planetary gear having a first sun gear S1, a first ring gear R1, a first pinion P1, and a first carrier PC1. The second planetary gear G2 is a single pinion type planetary gear having a second sun gear S2, a second ring gear R2, a second pinion P2, and a second carrier PC2. The third planetary gear G3 is a single pinion type planetary gear having a third sun gear S3, a third ring gear R3, a third pinion P3, and a third carrier PC3. The fourth planetary gear G4 is a single pinion type planetary gear having a fourth sun gear S4, a fourth ring gear R4, a fourth pinion P4, and a fourth carrier PC4.

  The transmission input shaft Input is connected to the second ring gear R2 and inputs rotational driving force from at least one of the engine Eng and the motor generator MG. The transmission output shaft Output is coupled to the third carrier PC3, and transmits the output rotational driving force to the left and right driving wheels LT, RT via the final gear FG or the like.

  The first ring gear R1, the second carrier PC2, and the fourth ring gear R4 are integrally connected by a first connecting member M1. The third ring gear R3 and the fourth carrier PC4 are integrally connected by a second connecting member M2. The first sun gear S1 and the second sun gear S2 are integrally connected by a third connecting member M3.

  The first clutch C1 (= input clutch I / C) is a clutch that selectively connects and disconnects the transmission input shaft Input and the second connecting member M2. The second clutch C2 (= direct clutch D / C) is a clutch that selectively connects and disconnects the fourth sun gear S4 and the fourth carrier PC4. The third clutch C3 (= H & LR clutch H & LR / C) is a clutch that selectively connects and disconnects the third sun gear S3 and the fourth sun gear S4. The second one-way clutch F2 (= 1 & 2 speed one-way clutch 1 & 2OWC) is disposed between the third sun gear S3 and the fourth sun gear S4. The first brake B1 (= front brake Fr / B) is a brake that selectively stops the rotation of the first carrier PC1 with respect to the transmission case Case. The first one-way clutch F1 (= first speed one-way clutch 1stOWC) is arranged in parallel with the first brake B1. The second brake B2 (= low brake LOW / B) is a brake that selectively stops the rotation of the third sun gear S3 with respect to the transmission case Case. The third brake B3 (= 2346 brake 2346 / B) is a brake that selectively stops the rotation of the third connecting member M3 that connects the first sun gear S1 and the second sun gear S2 with respect to the transmission case Case. The fourth brake B4 (= reverse brake R / B) is a brake that selectively stops the rotation of the fourth carrier PC4 with respect to the transmission case Case.

  FIG. 5 is a fastening operation table showing a fastening state of each friction element for each gear stage in the automatic transmission mounted on the FR hybrid vehicle to which the control device of the first embodiment is applied. In FIG. 5, ◯ indicates that the friction element is hydraulically engaged in the drive state, and (◯) indicates that the friction element is hydraulically engaged (one-way clutch operation in the drive state) in the coast state. No mark indicates that the friction element is in a released state.

  Of the friction elements provided in the speed change gear mechanism configured as described above, one of the friction elements that have been fastened is released, and one of the friction elements that have been released is fastened, thereby performing a changeover speed change. Thus, as described below, it is possible to realize a first reverse speed with seven forward speeds.

  That is, in the “first speed”, only the second brake B2 is engaged, and thereby the first one-way clutch F1 and the second one-way clutch F2 are engaged. In “second speed”, the second brake B2 and the third brake B3 are engaged, and the second one-way clutch F2 is engaged. In “third speed”, the second brake B2, the third brake B3, and the second clutch C2 are engaged, and the first one-way clutch F1 and the second one-way clutch F2 are not engaged. In “fourth speed”, the third brake B3, the second clutch C2, and the third clutch C3 are engaged. In "5th gear", the first clutch C1, the second clutch C2, and the third clutch C3 are engaged. In “6th speed”, the third brake B3, the first clutch C1, and the third clutch C3 are engaged. In “7th speed”, the first brake B1, the first clutch C1, and the third clutch C3 are engaged, and the first one-way clutch F1 is engaged. In “reverse speed”, the fourth brake B4, the first brake B1, and the third clutch C3 are engaged.

  FIG. 6 is a flowchart illustrating a flow of the shift control process executed by the integrated controller of the first embodiment. Hereinafter, each step of FIG. 6 will be described.

  In step S1, it is determined whether or not a shift command has been issued. If YES (there is a shift command), the process proceeds to step S2, and if NO (no shift command), the step S1 is repeated. Here, the shift command is output when the driving point on the shift map determined by the accelerator opening APO and the vehicle speed VSP crosses the up shift line or the down shift line during traveling with the D range selected. When the operating point crosses the upshift line, an upshift command is output, and when the operating point crosses the downshift line, a downshift command is output.

  In step S2, after determining that there is a shift command in step S1, standby phase (pre-processing) control is executed, and the process proceeds to step S3. In this standby phase control, a hydraulic pressure command for setting the engagement hydraulic pressure of the engagement side friction element to the standby pressure (pressure at which the piston is in a stroke state) is output from the transmission controller 7 to the transmission hydraulic pressure unit 8.

  In step S3, following execution of the standby phase control in step S2, it is determined whether or not this standby phase control has been completed. If YES (finished), the process proceeds to step S4, and NO (not finished) ), The process returns to step S2. Here, the end of the standby phase control is determined by whether or not the engagement hydraulic pressure of the engagement side frictional element is equal to or higher than the standby pressure.

  In step S4, following the determination of the end of the standby phase control in step S3, torque phase control is executed, and the process proceeds to step S5. In this torque phase control, when the engagement hydraulic pressure of the engagement side friction element is increased at a predetermined gradient, a hydraulic pressure command for lowering the engagement hydraulic pressure of the release side friction element at a predetermined gradient is transmitted from the transmission controller 7 to the transmission hydraulic unit 8. Output to.

  In step S5, following execution of torque phase control in step S4, it is determined whether or not the transmission input rotational speed is changing. If YES (the rotational speed is changing), the process proceeds to step S6. In the case of (no change in rotational speed), the process returns to step S4. The transmission input rotational speed is detected by a transmission input rotational speed sensor 18.

  In step S6, following the determination that the rotational speed is changing in step S5, the control of the motor / generator MG is shifted from the motor torque control to the motor rotational speed control, and the process proceeds to step S7. In the motor rotation speed control, a motor rotation speed command value is set according to the target MG rotation speed command output from the integrated controller 11, and the motor rotation speed of the motor / generator MG is set as the target input of the automatic transmission AT at the time of shifting. Match the number of revolutions.

  In step S7, following the transition to the motor rotation speed control in step S6, inertia phase control is executed, and the process proceeds to step S8. In this inertia phase control, a motor operating point command for causing the motor rotation speed to coincide with the target input rotation speed of the automatic transmission AT is output from the motor controller 2 to the inverter 3, and the engagement hydraulic pressure of the engagement side friction element is set at a predetermined gradient. A hydraulic command to be raised is output from the transmission controller 7 to the transmission hydraulic unit 8. A motor operating point command output process performed by the motor controller 2 during the inertia phase control is shown in FIG.

  In step S8, following execution of the inertia phase control in step S7, whether or not a rotation synchronization determination condition (= condition for completely shifting the gear ratio to the post-shift gear ratio) is established to eliminate the differential rotation of the engagement-side friction element. If YES (condition is satisfied), the process proceeds to step S9. If NO (condition is not satisfied), the process returns to step S7.

  In step S9, following the determination that the rotation synchronization determination condition is satisfied in step S8, the control of the motor / generator MG is shifted from the motor rotation speed control to the motor torque control, and the process proceeds to step S10. In the motor torque control, a motor torque command value is set according to the target MG torque command output from the integrated controller 11, and the motor torque of the motor / generator MG is matched with the target motor torque.

  In step S10, following the transition to the motor torque control in step S9, a shift end phase (post-processing) control for setting the engagement hydraulic pressure of the engagement side friction element to a complete engagement state is executed, and the process proceeds to the end.

  FIG. 7 is a flowchart illustrating the flow of the motor operating point command output process during the inertia phase control executed by the motor controller of the first embodiment. Hereinafter, each step of FIG. 7 will be described.

  In step S71, it is determined whether or not motor speed control is being executed in motor / generator MG. If YES (motor speed control is in progress), the process proceeds to step S72, and if NO (motor torque control is in progress). Then, the process proceeds to the end, and the motor operating point command output process is terminated.

  In step S72, following the determination that the motor rotational speed control is being performed in step S71, the target MG rotational speed command output from the integrated controller 11 is read, and the process proceeds to step S73. This target MG rotation speed command is a command for setting a target input rotation speed that is smoothly changed in the inertia phase during a shift based on a shift pattern (variation type) and a vehicle speed VSP (transmission output rotation speed). And is calculated by the integrated controller 11.

  In step S73, following the reading of the target MG rotation speed command in step S72, a motor rotation speed command value is set, and the process proceeds to step S74. This motor rotation speed command value is a value for obtaining the target input rotation speed commanded by the target MG rotation speed command.

  In step S74, the motor basic torque is read, and the process proceeds to step S75. Here, the motor basic torque is calculated by a known method based on the driver request torque appearing in the accelerator opening APO.

  In step S75, the rotational speed feedback control output torque is read, and the process proceeds to step S76. Here, the rotational speed feedback control output torque is calculated by PID control based on, for example, the difference between the actual transmission input rotational speed and the target input rotational speed. The actual transmission input rotational speed is detected by a transmission input rotational speed sensor 18 (see FIG. 1).

  In step S76, the vehicle weight correction torque is calculated, and the process proceeds to step S77. The vehicle weight correction torque calculation process is shown in FIG.

  In step S77, the vehicle weight correction torque calculated in step S76 is read, and the process proceeds to step S78.

  In step S78, the motor basic torque read in step S74, the rotational speed feedback control output torque read in step S75, and the vehicle weight correction torque read in step S77 are summed to obtain the motor torque. A command value is set, and the process proceeds to step S79.

  In step S79, a motor operating point command is set from the motor rotational speed command value set in step S73 and the motor torque command value set in step S78, and is output to the inverter 3 and proceeds to the end.

  FIG. 8 is a flowchart illustrating a flow of a vehicle weight correction torque calculation process executed by the integrated controller of the first embodiment. Hereinafter, each step of FIG. 8 will be described.

  In step S761, it is determined whether or not the second clutch CL2 is completely engaged. If YES (completely engaged), the process proceeds to step S762. If NO (incompletely engaged), the process proceeds to the end, and this vehicle weight correction is performed. The torque calculation process is terminated.

  In step S762, following the determination that the second clutch CL2 is completely engaged in step S761, the driving force generated on the left and right drive wheels LT, RT (the driving force acting on the vehicle) is calculated, and the process proceeds to step S763. This driving force is calculated by a known method based on the target engine torque command and the target MG torque command output from the integrated controller 11 and a preset transmission friction characteristic.

  In step S763, the actual acceleration of the vehicle is calculated, and the process proceeds to step S764. This actual acceleration is calculated by a known method based on the wheel speed detected by a wheel speed sensor (not shown) provided in the vehicle. The actual acceleration may be detected by a G sensor (not shown) mounted on the vehicle.

  In step S764, the air resistance acting on the vehicle is calculated, and the process proceeds to step S765. This air resistance is obtained from a map that is uniquely set based on the vehicle speed VSP detected by the vehicle speed sensor 16.

ここで、転がり抵抗は既知の値であり、sinθはモータ／ジェネレータMGのロータとステータとの相対的な位相θに係る値である。なお、このステップＳ765は、車両重量を推定する車両重量推定手段に相当する。 In step S765, an estimated vehicle weight is calculated from the driving force calculated in step S762, the actual acceleration calculated in step S763, and the air resistance calculated in step S764, and the process proceeds to step S766. Here, the estimated vehicle weight is calculated by the following equation (1).

Here, the rolling resistance is a known value, and sin θ is a value related to the relative phase θ between the rotor and the stator of the motor / generator MG. This step S765 corresponds to vehicle weight estimation means for estimating the vehicle weight.

In step S766, a vehicle weight correction torque is calculated from the estimated vehicle weight calculated in step S765 and the vehicle weight correction torque setting map shown in FIG. 9, and the process proceeds to the end. This vehicle weight correction torque setting map is a map showing the vehicle weight correction torque with respect to the estimated vehicle weight that is uniquely set by, for example, experiments. The larger the estimated vehicle weight is, the larger the amount of increase correction of the vehicle weight correction torque is. It is set so as to increase with the slope of.
That is, the vehicle weight correction torque is a value that increases the motor torque command, and the correction amount increases as the estimated vehicle weight increases. This step S766 corresponds to a motor torque correcting means for correcting the motor torque during the rotation speed control of the motor / generator MG.

Next, the operation will be described.
First, “conventional speed-of-shift motor rotation speed control and its problems” will be described, followed by “shift optimization operation” in the control apparatus for an electric vehicle according to the first embodiment.

[Conventional speed control of the motor and its problems]
FIG. 10 is an explanatory diagram showing a target MG rotational speed command and a target motor rotational speed response when the motor rotational speed control is performed at the time of shifting of the automatic transmission, (a) shows the time of downshift, (b) Indicates upshift. In the figure, the thin solid line indicates the target MG rotational speed command, and the thick solid line indicates the target motor rotational speed response. Also, the dashed line indicates the motor rotational speed response when the actual inertia is smaller than the estimated inertia, and the broken line indicates the motor rotational speed response when the actual inertia is larger than the estimated inertia.

  Usually, during the shift control of the automatic transmission, the clutch (friction element) in the transmission is slip-controlled. At this time, since the transmission output rotational speed fluctuates due to variations in clutch transmission torque and engine torque, a shift shock and a shift response decrease occur.

  Therefore, in an electric vehicle equipped with a motor, a stepped automatic transmission, and drive wheels in the drive system, rotation speed control using a motor is applied to compensate for fluctuations in the transmission output rotation speed. The variation is corrected by controlling the rotational speed of the motor so that the input rotational speed becomes the target input rotational speed.

  In this rotational speed control, it is ideal that the target MG rotational speed command for realizing the optimum gear shift is output, and the output rotational speed of the motor corresponds to the target motor rotational speed response shown by a thick solid line in FIG. It is.

  However, vehicle inertia acts on the traveling vehicle, and the rotational speed response of the motor is affected by the vehicle inertia. Moreover, the vehicle inertia changes greatly due to fluctuations in the vehicle weight due to changes in the number of passengers and the loading capacity, but the vehicle inertia decreases when the vehicle weight is small (light), and the vehicle inertia increases when the vehicle weight is large (heavy). .

  That is, when the vehicle weight is relatively light and the actual inertia acting on the vehicle is smaller than the estimated inertia, the rotational speed response overshoots as shown by the one-dot chain line in FIG. . Further, when the vehicle weight is relatively heavy and the actual inertia acting on the vehicle is smaller than the estimated inertia, the rotational speed response is delayed with respect to the target motor rotational speed response as shown by a broken line in FIG. As a result, the shift time becomes longer and a shift response decrease (shift lag) occurs. Note that this phenomenon occurs in both downshifts and upshifts.

  As described above, the inertia acting on the vehicle changes due to the change in the vehicle weight, and as a result, the rotational speed response of the motor differs. Therefore, it is conceivable to correct the motor torque command during motor rotational speed control.

  On the other hand, in the conventional electric vehicle control device, the actual driving force is calculated from the product of the vehicle weight and the actual acceleration, and the torque amount (correction) is corrected based on the difference between the actual driving force and the driving force command value. Torque) is set.

  Therefore, when the vehicle weight is large, the actual driving force increases and the difference from the driving force command value decreases, so that the correction torque is corrected to the decreasing side and the correction torque decreases. On the other hand, when the vehicle weight is small, the actual driving force is reduced, the difference from the driving force command value is increased, the correction torque is corrected to the increase side, and the correction torque is increased.

  However, since the inertia acting on the vehicle increases as the vehicle weight increases as described above, even when the torque correction of the motor is performed by applying the technology of the conventional electric vehicle control device during the motor rotation speed control, It was not possible to suppress the occurrence of shift shocks and shift lags when shifting automatic transmissions.

[Speed change optimization]
In the control apparatus for an electric vehicle according to the first embodiment, for example, the vehicle travels such that the vehicle speed VSP increases while keeping the accelerator opening APO constant, and the driving point on the shift map crosses the upshift line. In the flowchart shown in FIG. 6, the process proceeds from step S1, step S2, step S3, step S4, step S5, and step S6. In step S6, the control of the motor / generator MG is shifted from motor torque control to motor rotation speed control, and the process proceeds to step S7 where inertia phase control is executed.

  In this inertia phase control, a motor operating point command for causing the motor rotational speed to coincide with the target input rotational speed of the automatic transmission AT is output from the motor controller 2 to the inverter 3. At this time, the motor operation shown in the flowchart shown in FIG. Perform point command processing.

  In this motor operating point command process, the motor rotation speed command value is set based on the target MG rotation speed command, and the motor torque command value includes the motor basic torque, the rotation speed feedback control output torque, and the vehicle weight correction torque. Set in total.

  Here, in step S766 (see FIG. 8) for calculating the vehicle weight correction torque, the vehicle weight correction torque is calculated using the vehicle weight correction torque setting map shown in FIG. At this time, the vehicle weight correction torque increases as the estimated vehicle weight calculated in step S765 increases.

  Therefore, when the vehicle weight is large (heavy) and the inertia acting on the vehicle is large, the motor torque increase correction amount is large. When the vehicle weight is small (light) and the inertia acting on the vehicle is small, the motor torque is increased. The correction amount becomes smaller. In other words, the increase correction amount of the motor torque can be appropriately changed in accordance with the magnitude of the inertia that varies according to the vehicle weight.

  As a result, the output rotational speed of the motor / generator MG can be matched with the target MG rotational speed command, and the occurrence of shift shock and shift lag can be suppressed. Then, a quick shift can be achieved while suppressing a shift shock, and the shift of the automatic transmission AT can be optimized.

Next, the effect will be described.
In the control apparatus for an electric vehicle according to the first embodiment, the following effects can be obtained.

(1) The drive system includes a motor (motor / generator MG), a stepped automatic transmission AT, and drive wheels (left and right rear wheels RL, RR). In the control device for the electric vehicle (FR hybrid vehicle) that controls the rotation speed of the motor (motor / generator MG) so that the transmission input rotation speed becomes the target input rotation speed,
Motor torque correction means (step S766) for correcting motor torque during rotation speed control of the motor (motor / generator MG), and vehicle weight estimation means (step S765) for estimating vehicle weight. The torque correction means (step S766) is configured to increase the motor torque increase correction amount as the estimated vehicle weight increases.
For this reason, in an electric vehicle (FR hybrid vehicle) provided with a stepped automatic transmission AT, a quick shift can be performed while suppressing a shift shock.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, the calculation of the vehicle weight correction torque in step S766 is performed using the vehicle weight correction torque setting map (see FIG. 9), but is not limited thereto. For example, instead of the vehicle weight correction torque setting map, the time constant of the vehicle may be calculated from the estimated vehicle weight, and the P gain (proportional gain) of the rotational speed control may be corrected from the target response time constant.

  In the first embodiment, the estimated vehicle weight is calculated in step S765 by calculation. For example, the displacement amount of the suspension is detected using a displacement sensor, and the vehicle weight is estimated from the displacement amount. Good.

  In the first embodiment, an example in which an independent second clutch CL2 is provided separately from the automatic transmission AT between the motor / generator MG and the transmission input shaft Input is shown. However, the second clutch CL2 can be automatically used between the transmission output shaft Output and the left and right drive wheels LT, RT, for example, using the clutch or brake used as a friction element built in the stepped automatic transmission AT. An example in which the second clutch CL2 is provided separately from the machine AT is also included.

  In the first embodiment, an example in which a stepped automatic transmission with 7 forward speeds and 1 reverse speed is used as the automatic transmission. However, the number of shift stages is not limited to this, and any automatic transmission having two or more shift stages as the shift stage may be used.

  In the first embodiment, an example of application to a FR hybrid vehicle with one motor and two clutches is shown. However, the present invention can be applied not only to other types of FR or FF hybrid vehicles, but also to electric vehicles, fuel cell vehicles, and the like equipped with only a motor. In short, any electric vehicle having a motor, a stepped automatic transmission, and drive wheels in the drive system can be applied.

Eng engine
CL1 1st clutch
MG motor / generator (motor)
CL2 2nd clutch
AT automatic transmission
LT Left drive wheel
RT Right drive wheel 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 First clutch controller 6 First clutch hydraulic unit 7 Transmission controller 8 Transmission hydraulic unit 9 Second clutch controller 10 Second clutch hydraulic unit 11 Integrated controller

Claims (1)

The drive system includes a motor, a stepped automatic transmission connected to the motor, and drive wheels connected to the automatic transmission,
During inertia phase control during shifting of the stepped automatic transmission, the rotational speed of the motor is controlled so that the transmission input rotational speed becomes the target input rotational speed of the automatic transmission, and during the inertia phase control. In the control device for an electric vehicle that sets the motor operating point command from the motor rotation speed command value and the motor torque command value,
Vehicle weight estimation means for estimating the vehicle weight;
From the motor basic torque calculated based on the driver request torque, the rotational speed feedback control output torque calculated based on the difference between the transmission input rotational speed and the target input rotational speed, and the estimated value of the vehicle weight a vehicle weight correction torque calculated, and the motor torque correcting means for correcting the motor torque command value set by the sum of,
Have
The motor torque correction means increases the motor torque command value increase correction amount as the estimated vehicle weight increases.

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