JP4281675B2 - Powertrain control device - Google Patents

Description

  The present invention relates to a control apparatus for a power train in which a continuously variable transmission that performs stepwise shifting is connected to a driving force source.

  When the continuously variable transmission is shifted stepwise according to the driver's intention, the torque of the engine connected to the continuously variable transmission may be increased or decreased in order to reduce shift shock due to inertia torque.

  In this case, the inertia torque cannot be canceled unless the time when the inertia torque occurs and the time when the engine torque increases or decreases are not matched, and the shift shock cannot be suppressed. Therefore, it is necessary to accurately grasp the time point at which inertia torque generation starts, that is, the time point at which actual shifting starts.

For this reason, Patent Document 1 compares the actual number of revolutions when shifting is performed with the virtual number of revolutions that would have been displayed if shifting was not performed, and the difference between these numbers appears. Describes an invention configured to change the engine output by judging that the shift operation has started.
JP-A-4-22718

  According to the invention described in Patent Document 1, it is possible to accurately obtain the increase / decrease start point of the engine torque by detecting the shift operation, so that it is possible to suppress the shift shock. However, in determining the rotational speed difference, a threshold value must be set, and depending on how the threshold value is set, the shift operation start time may not be accurately detected. In addition, since the increase / decrease start time of the engine torque and the shift operation start time must be matched as much as possible, it is necessary to further improve the detection accuracy of the shift operation start time.

  The present invention has been made paying attention to the above technical problem, and an object of the present invention is to further improve the detection accuracy at the start time of the shift operation.

  In order to achieve the above object, the present invention sets a correction value to determine a threshold value when comparing the actual rotational speed and the virtual rotational speed that would have been displayed if no gear shifting was performed. It is characterized by performing in consideration. More specifically, the invention of claim 1 is obtained on the basis of the input rotational speed of the continuously variable transmission before the start of shift control when performing a shift that changes the gear ratio of the continuously variable transmission stepwise. In the powertrain control device for changing the output torque of the internal combustion engine to which the continuously variable transmission is connected in accordance with the start of the actual shift detected from the deviation between the estimated input speed and the actual input speed, Threshold setting means for setting a judgment threshold based on the contents of the shift, and the judgment threshold set by the threshold setting means and the deviation are compared to start the actual shift. And a shift start determining means for determining, wherein the output torque of the internal combustion engine is changed when the actual shift start is determined by the shift start determining means. It is.

  According to a second aspect of the present invention, when performing a downshift that increases the gear ratio of the continuously variable transmission stepwise, an estimated input obtained based on the input rotational speed of the continuously variable transmission before the start of shift control. In the powertrain control device for increasing the output torque of the internal combustion engine to which the continuously variable transmission is connected in accordance with the start of the actual shift detected from the deviation between the rotational speed and the actual input rotational speed, Threshold setting means for setting a judgment threshold based on the content of the shift, and the judgment threshold set by the threshold setting means and the deviation are compared to determine the actual start of shifting And a shift start determining means configured to increase the output torque of the internal combustion engine when the shift start determining means determines the start of actual shift. That.

  According to the first aspect of the present invention, the determination threshold value is set based on the content of the shift, and the start of the actual shift is determined by comparing the determination threshold value with the deviation of the estimated input rotational speed. The Therefore, since the content of the shift is taken into account, the start point of the shift can be detected more accurately.

  According to the second aspect of the present invention, the determination threshold value is set based on the contents of the downshift, and the start of the actual shift is determined by comparing the determination threshold value with the deviation of the estimated input rotational speed. Is done. Therefore, since the content of the downshift is taken into account, the start point of the shift can be detected more accurately.

  Next, the present invention will be described based on specific examples. First, an example of a drive system including a power source and a continuously variable transmission targeted by the present invention will be described. FIG. 5 schematically shows an example of a drive system including a belt type continuously variable transmission 1. The continuously variable transmission 1 is connected to a power source 5 via a forward / reverse switching mechanism 2 and a fluid transmission mechanism 4 with a lock-up clutch 3.

  The power source 5 is composed of an internal combustion engine, or an internal combustion engine and an electric motor, or an electric motor. In the following description, the power source 5 is referred to as the engine 5. The fluid transmission mechanism 4 has a configuration similar to that of, for example, a conventional torque converter, and includes a pump impeller rotated by the engine 5, a turbine runner disposed to face the pump impeller, and a stator disposed therebetween. The turbine runner is rotated by supplying a spiral flow of fluid generated by a pump impeller to the turbine runner, and torque is transmitted.

  In such torque transmission via the fluid, inevitable slip occurs between the pump impeller and the turbine runner, and this causes a reduction in power transmission efficiency. Therefore, the input member such as the pump impeller and the turbine runner A lock-up clutch 3 that directly connects an output side member such as the above is provided. The lock-up clutch 3 is configured to be controlled by hydraulic pressure, and is controlled to a fully engaged state, a fully released state, and a slip state that is an intermediate state between them, and the slip rotation speed can be appropriately controlled. It has become.

  The forward / reverse switching mechanism 2 is a mechanism that is employed when the rotational direction of the engine 5 is limited to one direction, and outputs the input torque as it is or reversely outputs it. It is configured. In the example shown in FIG. 5, a double pinion type planetary gear mechanism is employed as the forward / reverse switching mechanism 2. That is, a ring gear 7 is arranged concentrically with the sun gear 6, and a pinion gear 8 meshed with the sun gear 6 and the pinion gear 8 and another pinion gear 9 meshed with the ring gear 7 are arranged between the sun gear 6 and the ring gear 7. The pinion gears 8 and 9 are held by the carrier 10 so as to rotate and revolve freely. A forward clutch 11 that integrally connects two rotating elements (specifically, the sun gear 6 and the carrier 10) is provided, and the direction of the torque that is output by selectively fixing the ring gear 7 There is provided a reverse brake 12 that reverses.

  The continuously variable transmission 1 has the same configuration as a conventionally known belt-type continuously variable transmission, and each of a driving pulley 13 and a driven pulley 14 arranged in parallel to each other includes a fixed sheave, a hydraulic type The movable sheave is moved back and forth in the axial direction by the actuators 15 and 16. Therefore, the groove width of each pulley 13 and 14 is changed by moving the movable sheave in the axial direction, and accordingly, the winding radius of the belt 17 wound around each pulley 13 and 14 (the effective diameter of the pulleys 13 and 14). ) Changes continuously, and the gear ratio changes steplessly. The drive pulley 13 is connected to a carrier 10 that is an output element in the forward / reverse switching mechanism 2.

  The hydraulic actuator 16 in the driven pulley 14 is supplied with hydraulic pressure (line pressure or its correction pressure) according to the torque input to the continuously variable transmission 1 via a hydraulic pump and a hydraulic control device (not shown). Yes. Therefore, each sheave in the driven pulley 14 holds the belt 17 so that tension is applied to the belt 17, and a holding pressure (contact pressure) between the pulleys 13, 14 and the belt 17 is ensured. . On the other hand, the hydraulic actuator 15 in the drive pulley 13 is supplied with pressure oil according to the speed ratio to be set by flow control, and is set to a groove width (effective diameter) according to the target speed ratio. It has become.

  The driven pulley 14 is connected to a differential 19 through a gear pair 18, and torque is output from the differential 19 to driving wheels 20. Therefore, in the above drive mechanism, the lockup clutch 3 and the continuously variable transmission 1 are arranged in series between the engine 5 and the drive wheels 20.

  Various sensors are provided to detect the operating state (running state) of the vehicle on which the continuously variable transmission 1 and the engine 5 are mounted. That is, a turbine rotation speed sensor 21 that detects an input rotation speed (rotation speed of the turbine runner) to the continuously variable transmission 1 and outputs a signal, and an input rotation speed that detects the rotation speed of the drive pulley 13 and outputs a signal. A sensor 22, an output rotation speed sensor 23 that detects the rotation speed of the driven pulley 14 and outputs a signal, and a hydraulic pressure sensor 24 that detects the pressure of the hydraulic actuator 16 on the driven pulley 14 side for setting the belt clamping pressure are provided. ing. Although not specifically shown, an accelerator opening sensor that detects a depression amount of the accelerator pedal and outputs a signal, a throttle opening sensor that detects a throttle valve opening and outputs a signal, and a brake pedal are depressed. In this case, a brake sensor for outputting a signal is provided.

  A transmission is used to control the engagement / release of the forward clutch 11 and the reverse brake 12, the control of the clamping force of the belt 17, the control of the transmission ratio, and the control of the lockup clutch 3. An electronic control device (CVT-ECU) 25 is provided. The transmission electronic control unit 25 is configured mainly by a microcomputer as an example, and performs calculations according to a predetermined program based on input data and data stored in advance, and performs various operations such as forward, reverse, or neutral. And the required clamping pressure setting, the gear ratio setting, the engagement / release of the lock-up clutch 3, the slip rotation speed, and the like are executed.

  Here, an example of data (signal) input to the transmission electronic control unit 25 is as follows: a signal of the input rotation speed (input rotation speed) Nin of the continuously variable transmission 1 and an output of the continuously variable transmission 1. A signal of the rotational speed (output rotational speed) No is input from the corresponding sensor. Further, an engine electronic control unit (E / G-ECU) 26 that controls the engine 5 receives a signal of an engine speed Ne, an engine (E / G) load signal, a throttle opening signal, an accelerator pedal (not shown). )), The accelerator opening signal is input. According to the continuously variable transmission 1, the engine speed, which is the input speed, can be controlled steplessly (in other words, continuously). Therefore, by performing shift control so that the engine speed is efficient, this is achieved. The fuel efficiency of vehicles equipped with can be improved.

  By the way, there is a case where the gears of these continuously variable transmissions are stepwise changed according to the driver's intention. In this case, since the target gear ratio changes rapidly, an inertia torque is generated in the rotating member. The inertia torque gives an unnatural rotation to the rotating member, causes a shift shock, and may give the driver an uncomfortable feeling. Therefore, it is necessary to accurately calculate the inertia torque and adjust the engine output torque in accordance with the calculated inertia torque. Since the adjustment of the engine output torque must be started from the time when the actual shift is started, it is necessary to accurately determine the actual shift start time. Therefore, it is necessary to perform the following control.

  FIG. 1 is a flowchart for determining the actual shift start time. Here, the case of downshift is described. First, it is determined whether or not the current shift mode is a sport manual shift mode, that is, a state in which a step shift is possible (step S1). If a negative determination is made in step S1, this routine is exited. If a positive determination is made in step S1, it is determined whether or not the shift command is a downshift (step S2).

  If a negative determination is made in step S2, this routine is exited. If a positive determination is made in step S2, it is determined whether or not an increase in the opening of the electromagnetic throttle valve is permitted. (Step S3). If a negative determination is made in step S3, this routine is exited, but if a positive determination is made in step S3, the routine proceeds to torque control (from step S4 to step S16).

  When torque control is started by controlling the electromagnetic throttle (step S4), it is determined in the next step S5 whether or not this routine is executed for the first time (step S5). If the determination in step S5 is affirmative, that is, if the execution of the routine is the first time, a threshold value for actual shift determination is calculated (step S6). This threshold value is calculated by the following procedure.

  First, the control execution flag is turned on. Then, the retard processing end determination reference rotational speed NINMNLST (0) is set as the current input shaft rotational speed NIN. Further, the change amount DLTNIN (0) of the input shaft rotational speed at the start of the output torque increase control at the time of downshift is set as the current input shaft rotational speed change amount DLTNIN. Then, the retard end determination base value NINJDGBSE is obtained from a map based on the current shift speed. Further, the retard end determination correction map value NINJDGH is obtained from a map based on the change amount DLTNIN (0) of the input shaft rotation speed at the start of output torque increase control at the time of downshift, and the retard end end determination value NINJDG as a threshold value is obtained. Is determined by the sum of the retard end determination base value NINJDGBSE and the retard end determination correction map value NINJDGH.

  When a negative determination is made in step S5, or when the process of step S6 ends, it is determined whether or not the control execution flag is on (step S7). If a negative determination is made in step S7, the routine is exited. If a positive determination is made in step S7, it is determined whether or not the phase 0 state has ended (step S7). S8). Here, phase 0 means that the temperature of oil used in the transmission is low, so the response of the actual oil pressure is poor with respect to the shift command oil pressure, and there is a lot of wasted time until the actual gear shift starts. This is a state where it is necessary to delay the control to be increased by a dead time.

  Therefore, when a negative determination is made in step S8, that is, when phase 0 is not completed, processing corresponding to phase 0, specifically, processing for waiting until the oil temperature rises is performed. (Step S9). Thereafter, the routine is exited. On the other hand, if a positive determination is made in step S8, that is, if phase 0 is completed, the process proceeds to the retard phase (from step S10 to step S13).

  When the phase shifts to the retard phase, it is first determined whether or not the current input rotational speed NIN is greater than the sum of the retard end determination value NINJDG and the retard processing end determination reference rotational speed NINMNLST (0) (step S10). ). That is, it is determined whether or not an actual shift has been started. If a negative determination is made in step S10, that is, if the actual shift has not yet started, engine retardation control is performed to reduce the engine torque. (Step S11). Then, the current retard angle processing end judgment reference rotational speed NINMNLST (i) is set to the retard processing end judgment reference rotational speed NINMNLST (i-1) at the previous routine execution and the input shaft at the start of output torque increase control at the time of downshift. The sum of the rotation speed change amount DLTNIN (0) is set (step S13).

  On the other hand, if the determination in step S10 is affirmative, that is, if it is determined that the actual shift has been started, the retardation is terminated (step S12), and processing corresponding to the phase after the retardation phase is performed. (Step S14).

  Then, when the process in step S14 or step S13 is completed, it is determined in step S15 whether or not a control end condition is satisfied (step S15). If an affirmative determination is made in step S15, the control execution flag is turned off (step S16), and this routine is exited. On the other hand, if a negative determination is made in step S15, the routine exits without doing anything.

  Next, the time course of this control will be described using a time chart. FIG. 2 is a time chart when the present invention is not applied. 2A shows a case where a downshift is performed during deceleration, and FIG. 2B shows a case where a downshift occurs during acceleration. When the step shift is started, the target input rotational speed is increased (time A), but the actual rotational speed (thick solid line) does not follow the target input rotational speed. Eventually, as the target rotational speed decreases, the actual input rotational speed follows it, but when the actual rotational speed reaches the sum of the retarded end determination value NINJDG and the retarded processing end determination reference rotational speed NINMLST. Judgment of actual shift is performed (time C).

  However, in FIG. 2 (a) and FIG. 2 (b), the time when the actual rotational speed starts to follow the target rotational speed, that is, the actual shift start time is B time. Therefore, a simple comparison of the actual rotation speed and the sum of the retard end determination value NINJDG and the retard processing end determination reference rotation speed NINMLST shows that the actual shift start determination is delayed during deceleration, and the acceleration is determined during acceleration. In this case, the actual shift start determination becomes faster, and a shift shock occurs in any case.

  FIG. 3 is a time chart when the present invention is applied when a downshift at the time of deceleration is performed. The reference rotation speed NINMLST for determining the retarding process is saved when the downshift is started, and the amount of change in the input shaft rotation speed at the start of output torque increase control at the time of downshift every routine execution, that is, every control cycle DLTNIN (0) is added (corresponding to step S13 after time A). This is the estimated input rotational speed NIN.

  When decelerating, the change DLTNIN (0) of the input shaft rotation speed at the start of the output torque increase control at the time of downshift is a negative value, so this estimated input rotation speed NIN decreases every control cycle. . When the actual shift is started (time B), the difference between the estimated input rotation speed NIN and the actual input rotation speed increases, and the difference between the estimated input rotation speed NIN and the actual input rotation speed is determined as the retard end determination value NINJDG. If it is larger than this, the actual shift start determination is established (time C, corresponding to step S10).

  As described above (step S6), the retard end determination value NINJDG is set in consideration of the retard end determination base value NINJDGBSE. The retard end determination base value NINJDGBSE is expressed as the distance between the straight line in the direction perpendicular to the straight line representing the estimated input rotational speed and the curve representing the actual input rotational speed, as shown in FIG. The distance between the straight line in the direction perpendicular to the straight line representing the estimated input rotational speed and the curve representing the actual input rotational speed varies depending on the shift speed, and also varies depending on acceleration and deceleration. Therefore, the retard end determination base value NINJDGBSE is obtained in advance by a map based on the shift speed.

  FIG. 4 shows a time chart when a downshift is performed during acceleration. In this case, since it is during acceleration, the change amount DLTNIN (0) of the input shaft rotational speed at the start of the output torque increase control at the time of downshift is a positive value. Therefore, the estimated input rotation speed NIN increases every control cycle.

  When the actual shift is started (time B), the difference between the estimated input rotation speed NIN and the actual input rotation speed increases, and the difference between the estimated input rotation speed NIN and the actual input rotation speed is determined as the retard end determination value NINJDG. If it is larger than this, the actual shift start determination is established (time C, corresponding to step S10).

  As described above (step S6), the retard end determination value NINJDG is set in consideration of the retard end determination base value NINJDGBSE. The retard end determination base value NINJDGBSE is expressed as the distance between the straight line in the direction perpendicular to the straight line representing the estimated input rotational speed and the curve representing the actual input rotational speed, as shown in FIG. The distance between the straight line in the direction perpendicular to the straight line representing the estimated input rotational speed and the curve representing the actual input rotational speed varies depending on the shift speed, and also varies depending on acceleration and deceleration. Therefore, the retard end determination base value NINJDGBSE is obtained in advance by a map based on the shift speed.

  Therefore, the retard end determination value NINJDG, which is a determination threshold, is set based on the contents of the downshift, and the deviation between the retard end determination value NINJDG, which is the determination threshold, and the estimated input rotation speed NIN is calculated. The start of actual shifting is determined by comparison. Therefore, since the content of the downshift is taken into account, the start point of the shift can be detected more accurately.

  Here, the relationship between the above specific example and the present invention will be briefly described. The functional means in step S6 corresponds to threshold setting means, and the functional means in step S10 corresponds to shift start determination means.

  In the above embodiment, the case of downshift has been described. However, the present invention can also be applied to the case of upshift.

It is a flowchart which performs control for determining the actual shift start time. It is a time chart which concerns on the real shift start determination in a downshift when not performing this control. It is a time chart which concerns on the actual shift start determination at the time of performing a downshift at the time of deceleration when this control is performed. It is a time chart which concerns on the actual shift start determination at the time of performing a downshift at the time of acceleration when this control is performed. It is a figure which shows typically an example of the drive system containing the continuously variable transmission made into object by this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Continuously variable transmission, 5 ... Engine, 13 ... Drive pulley, 14 ... Driven pulley, 15, 16 ... Hydraulic actuator, 25 ... Electronic control unit for transmission (CVT-ECU).

Claims (2)

When performing a shift that changes the gear ratio of the continuously variable transmission stepwise, the estimated input rotational speed obtained based on the input rotational speed of the continuously variable transmission before the start of shift control and the actual input rotational speed In the powertrain control device for changing the output torque of the internal combustion engine to which the continuously variable transmission is connected in accordance with the start of the actual shift detected from the deviation,
Threshold setting means for setting a judgment threshold based on the contents of the shift, and the judgment threshold set by the threshold setting means and the deviation are compared to start the actual shift. Shift start determination means for determining,
A powertrain control device configured to change an output torque of the internal combustion engine when an actual shift start is determined by the shift start determining means. When performing a downshift that increases the gear ratio of the continuously variable transmission stepwise, an estimated input rotational speed and an actual input rotational speed that are obtained based on the input rotational speed of the continuously variable transmission before the start of shift control In the control apparatus for the powertrain that increases the output torque of the internal combustion engine to which the continuously variable transmission is connected in accordance with the start of the actual shift detected from the deviation of
Threshold setting means for setting a judgment threshold based on the contents of the downshift, and the judgment threshold set by the threshold setting means and the deviation are compared to start actual shifting Shift start determining means for determining
An apparatus for controlling a power train, wherein the output torque of the internal combustion engine is increased when an actual shift start is determined by the shift start determining means.

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