JP6277942B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device applied to a hybrid vehicle in which an engine and a motor / generator are coupled to a differential mechanism.

  2. Description of the Related Art As a hybrid vehicle, a vehicle that can be switched from a fixed shift mode in a state where one rotation element of a differential mechanism is locked to an electric continuously variable shift mode by releasing the lock is widely known. As a control device applied to such a hybrid vehicle, a device that controls the motor torque of the motor / generator using an estimated value of the engine torque when switching from the fixed transmission mode to the continuously variable transmission mode is known. (Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

JP 2011-25742 A JP 2009-96284 A

  The hybrid vehicle disclosed in Patent Document 1 is provided with a second motor / generator capable of transmitting torque to the output shaft in addition to the first motor / generator coupled to the differential mechanism. In the case of such a hybrid vehicle, it is common to compensate for the excess or deficiency between the required torque required for the vehicle and the engine torque by assisting the driving force or the braking force with the second motor / generator. At that time, the engine torque is estimated based on the motor torque of the first motor / generator, and the estimated value is used to control the motor torque required for assistance to be output from the second motor / generator.

  The control device of Patent Document 1 estimates the engine torque used for torque compensation control of the second motor / generator based on the required engine torque and the engine speed before switching the shift mode. For this reason, the estimation accuracy of the engine torque in the fixed shift mode before switching may be lower than the estimation accuracy of the engine torque in the continuously variable transmission mode estimated based on the motor torque of the first motor / generator. For this reason, if the output torque based on the estimated value of the engine torque and the actual value deviate during the fixed shift mode before switching the shift mode, the output torque close to the actual value immediately after switching to the continuously variable transmission mode As a result, the output torque fluctuates in a short time, and the fluctuation of the output torque may cause the user to feel as a shift shock.

  Therefore, an object of the present invention is to provide a control device for a hybrid vehicle that can suppress a shift shock experienced by a user when switching between shift modes.

A control apparatus for a hybrid vehicle according to the present invention includes an engine, a first motor / generator, an output unit for transmitting torque to drive wheels, and a plurality of engine torques output from the engine that can be differentially rotated. A differential mechanism that distributes the first motor / generator and the output unit using a rotating element; a second motor / generator provided in a state capable of transmitting power between the output unit; and the difference. In a control device applied to a hybrid vehicle including a lock mechanism capable of fixing any of the rotating elements of a moving mechanism, a reaction force torque corresponding to the engine torque is released by releasing the rotating element by the lock mechanism. Is output from the first motor / generator, and the rotary element is fixed by the lock mechanism to lock the reaction torque. And switching control means for switching the shift mode between the fixed speed change mode to take charge in configuration, estimates the engine torque based on the required engine torque and the engine speed during the fixed speed change mode, and based on the estimation result The first torque compensation control for controlling the second motor / generator is performed so that the output torque output from the vehicle becomes the required torque required to be output from the vehicle, and in the continuously variable transmission mode. the engine torque is estimated based on the motor torque of the first motor generator, the second so that the output torque output from the vehicle becomes the required torque output request to said vehicle based on the estimation result a torque compensation control means for performing a second torque compensation control for controlling the motor-generator, wherein said torque compensation control Stage, the fixed said when the shift mode is switched to the shift mode the continuously variable shift mode, the first embodiment of the fixed speed change mode of the second torque compensation control while continuing the implementation of the torque compensation control From the execution of the first torque compensation control after the elapse of the predetermined time after the shift mode is switched to the continuously variable transmission mode . The second motor / generator is controlled so that the required torque can be obtained at a predetermined rate of change by executing the torque compensation control .

  According to this control device, when switching from the fixed speed change mode to the continuously variable speed change mode, execution of torque compensation control using the engine torque estimated based on the motor torque of the first motor / generator is limited for a predetermined time. . Therefore, even if the output torque based on the estimated value of the engine torque and the actual value deviate during the fixed shift mode before the shift mode is switched, the estimated value of the engine torque based on the motor torque of the first motor / generator is calculated. A margin of a predetermined time is given until the output torque obtained by use is output. As a result, output fluctuations are less likely to occur in a short time when the shift mode is switched, so that a shift shock experienced by the user when the shift mode is switched can be suppressed. Further, since the required torque is controlled at a predetermined change rate after switching to the continuously variable transmission mode, the effect of suppressing the shift shock is further improved by changing the change rate according to the situation, for example. It is also possible.

The figure which showed the whole structure of the hybrid vehicle to which the control apparatus which concerns on one form of this invention was applied. The figure which showed the action | operation engagement table | surface of the automatic transmission. The figure which showed the alignment chart (velocity diagram) of each element of the vehicle of FIG. The whole engine block diagram. The block diagram which showed the control system of the vehicle of FIG. Explanatory drawing explaining the operating point and driving | operation area | region of an engine. Explanatory drawing which showed the driving | operation area | region used for switching of a transmission mode. The flowchart which showed an example of the control routine of this form. The figure which showed the control outline | summary of this form typically. The timing chart which showed an example of the control result. The timing chart which showed another example of the control result.

  As shown in FIG. 1, the vehicle 1 is configured as a so-called hybrid vehicle in which an engine 2 and two motor generators 3 and 4 are provided as a driving power source. Details of the engine 2 will be described later. The engine 2, the first motor / generator 3 and the second motor / generator 4 are connected to a power split mechanism 5 as a differential mechanism. The power split mechanism 5 is configured as a single pinion type planetary gear mechanism, and rotates and revolves a sun gear Sn as an external gear, a ring gear Ri as an internal gear, and a pinion P meshing with these gears Sn and Ri. And a carrier Cr that is freely supported. A first motor / generator 3 is connected to the sun gear Sn, a second motor / generator 4 is connected to the ring gear Ri, and an output shaft 2a of the engine 2 is connected to the carrier Cr. As is well known, the rotating elements Sn, Ri, Cr of the power split mechanism 5 can be differentially rotated with each other and correspond to a plurality of rotating elements according to the present invention.

  The vehicle 1 is provided with a lock mechanism 8 that can fix the sun gear Sn of the power split mechanism 5 connected to the first motor / generator 3. The lock mechanism 8 includes a brake B0. By switching between engagement and release of the brake B0 provided in the lock mechanism 8, the shift mode of the vehicle 1 is changed between a fixed shift mode in which the sun gear Sn is fixed and a continuously variable transmission mode in which the sun gear Sn is released. Can be switched.

  The continuously variable transmission mode is a transmission mode in which the sun gear Sn connected to the first motor / generator 3 is released by the lock mechanism 8 and the reaction torque corresponding to the engine torque of the engine 2 is output from the first motor / generator 3. It is. That is, in the continuously variable transmission mode, the differential action by the power split mechanism 5 is allowed and a part of the engine torque is distributed to the first motor / generator 3, and the first gear connected to the sun gear Sn which is one rotation element thereof is connected. This is a speed change mode in which the speed ratio, which is the ratio of the engine speed to the speed of the intermediate shaft 15 as an output unit, can be changed steplessly by electrically controlling the motor torque and the speed of the motor / generator 3. . On the other hand, the fixed speed change mode is a speed change mode in which the sun gear Sn to which the first motor / generator 3 is connected is fixed by the lock mechanism 8 and the reaction mechanism torque of the engine 2 is received by the lock mechanism 8. In other words, the fixed speed change mode restricts the distribution of the engine torque to the first motor / generator 3 by preventing the differential action by the power split mechanism 5, and the engine at the speed ratio preset in the power split mechanism 5. 2 is a shift mode for shifting the number of rotations of 2.

  Further, a direct coupling clutch C0 is provided between the ring gear Ri of the power split mechanism 5 and the carrier Cr. By engaging this direct coupling clutch C0, the vehicle 1 can also switch the transmission mode to the direct coupling mode in which engine torque is transmitted to the intermediate shaft 15 that is the output section without shifting the engine speed. Since this direct connection mode also has a gear ratio fixed at 1, it can be said that the direct connection mode is a kind of fixed transmission mode.

  An automatic transmission 10 as a speed change mechanism is provided in the power transmission path on the drive wheel side of the second motor / generator 4. The automatic transmission 10 has two input shafts 11 and 12. Two clutches C1 and C2 are provided between the input shafts 11 and 12 and the intermediate shaft 15 that rotates integrally with the ring gear Ri. By appropriately operating these clutches C1 and C2, one of the two input shafts 11 and 12 can be selectively connected to the intermediate shaft 15. The automatic transmission 10 is configured by combining two planetary gear mechanisms 21 and 22 and providing two brakes B1 and B2 and a one-way clutch F1. The two sets of planetary gear mechanisms 21, 22 are combined with each other by connecting one carrier Cr1 and the other ring gear Ri2 and connecting one ring gear Ri1 and the other carrier Cr2. . The first input shaft 11 is connected to the sun gear Sn2, and the second input shaft 12 is connected to the carrier Cr1. The carrier Cr2 is connected to the output shaft 23. The carrier Cr1 and the ring gear Ri2 that are connected to each other are provided with a one-way clutch F1 that allows rotation in only one direction. In the automatic transmission 10, a reverse clutch C3 is provided between the intermediate shaft 15 and one of the sun gears Sn1, and the reverse travel of the vehicle 1 is realized by operating the clutch C3.

  The vehicle 1 does not show the operating state of the brake B0 of the lock mechanism 8, the operating state of the direct coupling clutch C0, and the operating states of the clutches C1, C2, C3 and the brakes B1, B2 of the automatic transmission 10. As shown in the operation engagement table of FIG. 2, each of the continuously variable transmission mode, the fixed transmission mode, and the direct connection mode includes four forward speeds and one reverse speed. One shift stage can be selected from a plurality of shift stages. “N” in FIG. 2 means neutral, and “◯” in FIG. 2 means an engaged state of a clutch or a brake. In FIG. 2, the operation states of the respective speed stages that are realized in the fixed speed change mode and the direct connection mode are the same as those in the continuously variable speed change mode, and thus the operation states of the respective elements are not shown. A collinear diagram (speed diagram) of each element of the vehicle 1 when the first to fourth shift speeds and the reverse speed of the automatic transmission 10 are selected is as shown in FIG. In FIG. 3, “Eng” indicates the internal combustion engine 2, “MG1” indicates the first motor / generator 3, “MG2” indicates the second motor / generator 4, “In1” indicates the first input shaft 11, “ “In2” means the second input shaft 12, and “Out” means the output shaft 23.

  As shown in FIG. 4, the engine 2 is configured as an in-line four-cylinder spark ignition internal combustion engine in which four cylinders 25 are arranged in one direction. The engine 2 is configured as a so-called lean burn engine, and the operation mode can be switched between lean combustion and stoichiometric combustion. Lean combustion is an operation mode that targets an air-fuel ratio that is set on the lean side of the stoichiometric air-fuel ratio. The stoichiometric combustion is an operation mode that targets a stoichiometric air-fuel ratio that is richer than the air-fuel ratio of lean combustion or an air-fuel ratio in the vicinity thereof. Switching from lean combustion to stoichiometric combustion is performed by temporarily increasing the fuel injection amount in consideration of the response delay of the intake air amount.

  The engine 2 is provided with a turbocharger 35 that supercharges using exhaust energy. In the intake passage 26, a compressor 35a of a turbocharger 35 is provided. A throttle valve 36 that can adjust the amount of intake air is provided in the intake passage 26 upstream of the compressor 35a. An air flow meter 37 that outputs a signal corresponding to the amount of intake air is provided in the intake passage 26 upstream of the throttle valve 36. An intercooler 38 for cooling the intake air pressurized by the compressor 35a is provided in the intake passage 26 downstream of the compressor 35a.

  In the exhaust passage 27, a turbine 35b of a turbocharger 35 is provided. The exhaust passage 27 is provided with a waste gate valve mechanism 39 that bypasses the exhaust upstream of the turbine 35b downstream of the turbine 35b. The waste gate valve mechanism 39 is provided with a waste gate valve 40 capable of adjusting the flow rate of exhaust gas guided to the turbine 35b. Therefore, as a result of adjusting the exhaust flow rate flowing into the turbine 35b by controlling the opening degree of the waste gate valve 40, the supercharging pressure of the engine 2 is adjusted. The exhaust gas that has passed through the turbine 35b or the waste gate valve 40 is released into the atmosphere after harmful substances are removed by the start converter 41 and the post-processing device 42.

  The engine 2 is provided with an EGR device 45 that extracts a part of the exhaust from the exhaust passage 27 and recirculates it as EGR gas in the intake passage 26. The EGR device 45 includes an EGR passage 46 that extracts a part of the exhaust gas from the exhaust passage 27 as EGR gas and guides it to the intake passage 26, an EGR valve 47 that can adjust the flow rate of the EGR gas flowing through the EGR passage 46, and the EGR passage 46. And an EGR cooler 48 for cooling the flowing EGR gas. The EGR passage 46 connects the exhaust passage 27 between the start converter 41 and the aftertreatment device 42 and the intake passage 26 between the compressor 35 a and the throttle valve 36.

  As shown in FIG. 5, the control of each part of the vehicle 1 is controlled by various electronic control units (ECUs) 50, 70, 71 configured as a computer and provided for each function. The HVECU 50, the MGECU 70, and the engine ECU 71 are electrically connected so that they can exchange information with each other.

  Signals from various sensors are input to the HVECU 50 provided as a main computer. For example, the HVECU 50 includes a vehicle speed sensor 51 that outputs a signal corresponding to the vehicle speed of the vehicle 1, an accelerator opening sensor 52 that outputs a signal corresponding to a depression amount of an accelerator pedal (not shown), and rotation of the first motor / generator 3. The first MG rotational speed sensor 53 that outputs a signal corresponding to the speed, the second MG rotational speed sensor 54 that outputs a signal corresponding to the rotational speed of the second motor / generator 4, and the rotational speed of the output shaft 23 of the automatic transmission 10 Output signals such as an output shaft rotational speed sensor 55 that outputs a corresponding signal and an SOC sensor 56 that outputs a signal corresponding to a battery storage rate (not shown) are input.

  The HVECU 50 calculates torques to be generated by the first motor / generator 3 and the second motor / generator 4, and outputs a command to the MGECU 70 regarding the torques to be generated. Further, the HVECU 50 determines the operating condition of the engine 2 and outputs a command to the engine ECU 71 regarding the operating condition of the engine 2. Further, the HVECU 50 controls the clutches C1, C2, C3 and the brakes B1, B2 of the automatic transmission 10 so that a shift stage according to a predetermined shift schedule or a shift change request by the driver can be realized. The MGECU 70 calculates a current corresponding to the torque generated by the first motor / generator 3 and the second motor / generator 4 based on the command input from the HVECU 50, and the first motor / generator 3 and the second motor / generator 4. Output current. The engine ECU 71 performs various controls on each part of the engine 2 such as the throttle valve 36, the spark plug 31, the EGR valve 47, and the waste gate valve 40 based on a command input from the HVECU 50.

  The HVECU 50 refers to the output signal of the accelerator opening sensor 52 and the output signal of the vehicle speed sensor 51 to calculate a required driving force (power) required by the driver for the vehicle 1 and system efficiency for the required driving force. The vehicle 1 is controlled while switching various modes so as to be optimal. For example, in the low load region where the thermal efficiency of the engine 2 is reduced, the EV traveling mode in which the combustion of the engine 2 is stopped and the second motor / generator 4 is driven is selected. On the other hand, if the EV travel mode is not selected, the hybrid travel mode in which the second motor / generator 4 and the like are operated together with the engine 2 is selected.

  When the hybrid travel mode is selected, the continuously variable transmission mode is normally performed, and the first motor and the operating point of the engine 2 move along the optimal fuel consumption line L as indicated by the arrows in FIG. The motor torque of the generator 3 is controlled. The operating point of the engine 2 is defined by the engine speed and the engine torque, and the optimum fuel consumption line L is set in advance so that the thermal efficiency of the engine 2 is optimized. The engine 2 of this embodiment is configured as a lean burn engine with a supercharger. Therefore, as the operation mode of the engine 2, any one of natural intake stoichiometric combustion, natural intake lean combustion, supercharged stoichiometric combustion, and supercharged lean combustion is selected according to the operation region shown in FIG. .

  However, if the continuously variable transmission mode is maintained in a region where the amount of electric path is large, such as during high-speed steady running, the efficiency will deteriorate due to power circulation, so the HVECU 50 switches the transmission mode from the continuously variable transmission mode to the fixed transmission mode. To suppress the deterioration of efficiency. For example, as shown in FIG. 7, the HVECU 50 switches the shift mode according to the area AR1 and the area AR2 set in the operation area where the horizontal axis is the vehicle speed and the vertical axis is the driving force. The area AR1 is set as an area where the continuously variable transmission mode is to be executed, and the area AR2 is set as an area where the fixed transmission mode is to be executed. Thus, the HVECU 50 functions as a switching control unit according to the present invention. Further, when the required driving force is large and the output of each motor / generator 3 or 4 is desired to be suppressed, such as during high load operation, for example, when the motor torque is limited or when the battery usage is limited, the direct connection mode described above is used. To secure the driving force.

  Further, in the hybrid travel mode, when the output torque output from the vehicle 1 is insufficient or when the engine torque is excessive with respect to the requested torque requested from the vehicle 1, the HVECU 50 outputs the output torque and the requested torque. Torque compensation control is performed to control the second motor / generator 4 so that the output torque becomes the required torque by compensating for excess and deficiency. When the output torque is insufficient with respect to the required torque, positive torque is output from the second motor / generator 4, that is, the second motor / generator 4 is powered to compensate for the torque shortage. On the other hand, when the output torque is excessive with respect to the required torque, for example, during deceleration, the second motor / generator 4 outputs a negative torque, that is, the second motor / generator 4 is regenerated to regenerate the engine. Absorbs excess torque. In the case of regeneration, the braking force is supplemented in addition to absorbing the surplus engine torque.

  Since the reaction torque corresponding to the engine 2 is output from the first motor / generator 3 in the continuously variable transmission mode, the engine torque can be accurately estimated from the motor torque of the first motor / generator 3. Therefore, the HVECU 50 calculates the motor torque of the second motor / generator 4 based on the estimated value of the engine torque thus estimated, and performs torque compensation control. That is, the HVECU 50 functions as torque compensation control means according to the present invention.

  On the other hand, in the case of the fixed speed change mode, the sun gear Sn is fixed by the lock mechanism 8 and the first motor / generator 4 is not operated, so the engine torque cannot be estimated by the same method as in the continuously variable speed change mode. Therefore, the HVECU 50 estimates the engine torque based on the required engine torque and the engine speed in the fixed shift mode, calculates the motor torque to be output from the second motor / generator 4 based on the estimation result, and performs torque compensation control. To implement. In this case, since the engine torque is estimated based on the required engine torque and the engine speed, it cannot be denied that the estimation accuracy is lower than the estimation based on the torque of the first motor / generator 4.

  The present embodiment is characterized in the control content executed by the HVECU 50 when the shift mode is switched from the fixed shift mode in which the content of the torque compensation control changes to the continuously variable transmission mode. Hereinafter, a control routine executed by the HVECU 50 in relation to the present invention will be described in detail with reference to FIG.

  The control routine program of FIG. 8 is stored in the HVECU 50, read out in a timely manner, and repeatedly executed at predetermined intervals. In step S1, the HVECU 50 determines whether or not the speed change mode of the vehicle 1 is a fixed speed change mode. In this process, a negative determination is made when switching from the fixed transmission mode to the continuously variable transmission mode is started in response to a request for switching from the fixed transmission mode to the continuously variable transmission mode.

  In the case of the fixed speed change mode, the process proceeds to step S4, and the HVECU 50 estimates the engine torque based on the above-described method performed in the fixed speed change mode, that is, the required engine torque and the engine speed, and the second based on the estimation result. Torque compensation control is performed by calculating the motor torque of the motor / generator 4. When the motor torque of the second motor / generator 4 is Tmg2, and the motor torque in the fixed speed change mode is Tmf, Tmg2 = Tmf.

  On the other hand, in the case of the continuously variable transmission mode, the process proceeds to step S2, and the HVECU 50 determines whether or not a predetermined time a has elapsed from the starting point of the switching from the fixed transmission mode to the continuously variable transmission mode. In this embodiment, the starting point is the time when the operation of the brake B0 of the lock mechanism 8 is started from the engaged state to the released state. The predetermined time a is set in advance as a time sufficiently exceeding the time point when the switching from the fixed speed change mode to the continuously variable speed change mode is completed (that is, the time when the torque of the brake B0 becomes zero and the sun gear Sn is completely released). Yes. Therefore, when the predetermined time a has elapsed from the starting point, the switching of the shift mode from the fixed shift mode to the continuously variable shift mode has already been completed.

  When the elapsed time from the starting point is less than the predetermined time a (No), the HVECU 50 proceeds to step S4 and performs the torque compensation control in the fixed shift mode described above. Therefore, if the predetermined time a is not reached even after the switching from the fixed shift mode to the continuously variable transmission mode is completed, the torque compensation control in the fixed shift mode is continued, while the first motor / generator 3 is maintained. The execution of torque compensation control in the continuously variable transmission mode using the engine torque estimated based on the motor torque is limited.

  On the other hand, if the predetermined time a has elapsed from the starting point (Yes), the process proceeds to step S3, and the HVECU 50 performs torque compensation control in the continuously variable transmission mode that has been limited. In this case, the HVECU 50 controls the second motor / generator 4 so that the required torque requested to be output to the vehicle 1 is obtained at a predetermined rate of change α (see FIGS. 10 and 11).

  This required torque is a target value of the output torque of the vehicle 1. The required torque is calculated based on the estimated value of the engine torque estimated based on the motor torque of the first motor / generator 3 in the torque compensation control in the continuously variable transmission mode. That is, when the required torque is Td, the estimated value of the engine torque is Teg, and the motor torque of the second motor / generator 4 is Tmg2, the following equation 1 is established.

  Td = Teg + Tmg2 1

  When the motor torque in the continuously variable transmission mode is Tmc and the amount of change up to the target value of the motor torque that can achieve the required torque for the vehicle 1 is Δx, the following equation 2 is established.

  Tmg2 = Tmc + Δx 2

  In this embodiment, the rate of change until the motor torque Tmg2 reaches the target value is constant. However, the rate of change can be changed according to time.

  The above-described control content performed by the HVECU 50 will be further described with reference to FIGS. The upper part of FIG. 9 schematically shows the case when the second motor / generator 4 is powered, and the lower part of FIG. 9 schematically shows the case when the second motor / generator 4 is regenerated. FIG. 9 is merely an example of the case where the motor torque Tmf in the fixed shift mode described above and the motor torque Tmc in the continuously variable transmission mode are different. Therefore, there may be a situation where the magnitude relationship between the absolute values of the motor torque Tmf and the motor torque Tmc is opposite to that in FIG. 9, that is, the absolute value of the motor torque Tmc is greater than the absolute value of the motor torque Tmf.

  As shown in FIG. 9, when switching from the fixed shift mode to the continuously variable transmission mode starts at time t0, torque compensation control in the fixed shift mode is performed until time ta, while in the continuously variable transmission mode. Implementation of torque compensation control is limited. Therefore, the motor torque Tmf in the fixed speed change mode is maintained until time ta. The time from time t0 to time ta corresponds to the predetermined time a described above. Then, the motor torque Tmg2 is gradually changed from time ta toward time tb toward the motor torque Tmc (target value) in the continuously variable transmission mode.

  FIG. 10 shows the case where the actual value of the output torque of the vehicle 1 is larger than the required torque, that is, the estimated value of the engine torque estimated during the torque compensation control in the fixed shift mode is larger than the actual value. An example of the control result is shown. In the figure, the torque Tb of the brake B0 of the lock mechanism 8, the motor torque Tmg1 of the first motor / generator 3, the actual value Tr of the output torque, the required torque Td, the motor torque Tmg2 of the second motor / generator 4, and the Each time change of the motor rotation speed Nmg1 of 1 motor generator 3 is shown.

  As shown in the figure, when switching of the shift mode from the fixed shift mode to the continuously variable shift mode is started at time t0, the torque Tb of the brake B0 decreases by a predetermined amount toward the released state, and thereafter is maintained at a constant value. While the torque Tb is maintained at a constant value, the absolute value of the motor torque Tmg1 gradually increases.

  When the motor torque Tmg1 reaches the target value at time t1, the torque Tb of the brake B0 further decreases and the motor torque Tmg1 is kept constant until time t2 when the rotation of the first motor / generator 3 starts.

  Thereafter, when the torque Tb becomes 0 at time t3 and the switching to the continuously variable transmission mode is completed, the motor torque Tmg1 also reaches the target value. Then, the torque compensation control in the continuously variable transmission mode is limited, and the torque compensation control in the fixed transmission mode is continued until the predetermined time a is reached at time t4. Therefore, motor torque Tmg2 is maintained at motor torque Tmf in the fixed speed change mode until time t4. The motor torque Tmg2 starts to gradually decrease from time t4, and similarly, the output torque of the vehicle 1 gradually decreases at the change rate α. At time t5, when the motor torque Tmc reaches the motor torque Tmc in the continuously variable transmission mode in which the motor torque Tmg2 is the target value, the output torque also coincides with the required torque, and the control ends.

  FIG. 11 shows the case where the actual value of the output torque of the vehicle 1 is smaller than the required torque, that is, the estimated value of the engine torque estimated during the torque compensation control in the fixed shift mode is smaller than the actual value. An example of the control result is shown. In the example of FIG. 11, the magnitude relationship between the actual value and the required torque is opposite to the example of FIG. Therefore, as compared with the example of FIG. 10, in the example of FIG. 11, the motor torque Tmg1 of the first motor / generator 3 starts to decrease from time t2 ′ and the motor rotation speed Nmg1 rotates in the opposite direction, and time t4. From this, the motor torque Tmg2 increases. However, the basic control content of the example of FIG. 11 is the same as that of the example of FIG.

  According to the control of this embodiment, torque compensation control in the continuously variable transmission mode using the engine torque estimated based on the motor torque of the first motor / generator 3 when the fixed transmission mode is switched to the continuously variable transmission mode. Is limited until a predetermined time a elapses from the start of shifting of the shift mode. Therefore, as shown in FIGS. 10 and 11, even when the output torque based on the estimated value of the engine torque and the actual value are different in the fixed shift mode before the shift mode is switched, the first motor generator 3 A margin of a predetermined time a is given until the output torque obtained using the estimated value of the engine torque based on the motor torque is output. As a result, output fluctuations are less likely to occur in a short time when the shift mode is switched, so that a shift shock experienced by the user when the shift mode is switched can be suppressed.

  This form is not limited to the said form, It can implement with a various form. The control in the above form is only an example. For example, in the above embodiment, the predetermined time “a” and the change rate α have been described as constant values, but it is also possible to change them according to the situation.

  In the case of a supercharged engine, there is an engine operating region in which improvement in estimation accuracy of engine torque can be expected by combustion control (CPS) using an in-cylinder pressure sensor. When the above control is performed in such a region, it is possible to shorten the predetermined time a and / or increase the rate of change α as compared with the case of other operation regions. As the estimation accuracy of the engine torque increases, the difference between the actual value of the output torque and the required torque in the fixed shift mode becomes smaller. Therefore, by shortening the predetermined time a or increasing the change rate α, there is a merit that the torque compensation control in the fixed shift mode can be quickly ended while the effect of suppressing the shift shock is equal to that in the other operation regions.

  In the case of a supercharged engine, the supercharging region has a larger divergence between the actual value of the output torque and the required torque in the fixed speed change mode than the NA region. Therefore, when the above control is performed in the supercharging region, it is possible to extend the predetermined time a and / or decrease the change rate α as compared with the NA region. As a result, in the supercharging region, torque compensation control in the fixed shift mode ends more gently than in the NA region, so that the shock suppression effect in the supercharging region and the shift shock suppression effect in the NA region There is a merit that can be equalized.

  Furthermore, when the control device of the present invention is applied to a vehicle provided with a transmission having a plurality of shift speeds, the higher the speed of the transmission, the lower the engine speed and the lower the estimated accuracy of the engine torque. The deviation between the actual value of the output torque and the required torque in the shift mode becomes large. Therefore, as the speed increases, it is possible to extend the predetermined time a and / or decrease the change rate α. By doing in this way, the torque compensation control in the fixed shift mode is gradually terminated as the speed is higher, so that there is an advantage that the variation of the shift shock suppression effect for each shift stage can be reduced.

  In the above embodiment and each of the above modifications, the description has been made on the assumption that the engine installed in the vehicle is a lean burn engine with a supercharger. However, the control device of the present invention is a hybrid equipped with a naturally aspirated engine that performs stoichiometric combustion. It may be applied to a vehicle. Moreover, although the automatic transmission which can select the several gear stage is mounted in the vehicle of the said form, the control apparatus of this invention is a vehicle with which the continuously variable transmission was provided, or a transmission does not exist It can also be applied to.

1 vehicle 2 engine 3 first motor / generator 4 second motor / generator 15 intermediate shaft (output unit)
50 HVECU (switching control means, torque compensation control means)

Claims (1)

The first motor / generator, an output unit for transmitting torque to the drive wheels, and the first motor using a plurality of rotating elements capable of differentially rotating engine torque output from the engine A differential mechanism that distributes to the generator and the output unit, a second motor generator provided in a state in which power can be transmitted between the output unit, and the rotating element of any of the differential mechanisms In a control device applied to a hybrid vehicle having a lock mechanism that can be fixed,
A continuously variable transmission mode in which the rotating element is released by the locking mechanism and a reaction torque corresponding to the engine torque is output from the first motor / generator, and the rotating element is fixed by the locking mechanism. Switching control means for switching the transmission mode between a fixed transmission mode for causing the locking mechanism to receive reaction force torque;
The engine torque is estimated based on the required engine torque and the engine speed during the fixed shift mode, and the output torque output from the vehicle based on the estimation result becomes the required torque requested to be output from the vehicle. The first torque compensation control for controlling the second motor / generator is performed, and the engine torque is estimated based on the motor torque of the first motor / generator in the continuously variable transmission mode. Torque compensation control means for performing second torque compensation control for controlling the second motor / generator so that an output torque output from the vehicle based on a result becomes a required torque required to be output from the vehicle; Prepared,
The torque compensation control unit, said when the shift mode is switched to the continuously variable speed mode from the fixed speed change mode, the implementation of the second torque compensation control while continuing the implementation of the first torque compensation control From the execution of the first torque compensation control after a lapse of the predetermined time after the shift mode is switched to the continuously variable transmission mode is limited for a predetermined time exceeding the completion time point when the fixed transmission mode is switched to the continuously variable transmission mode. Controlling the second motor / generator so that the required torque is obtained at a predetermined rate of change by performing the second torque compensation control ;
A control apparatus for a hybrid vehicle characterized by the above.

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