JP5310264B2 - Control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress a noise or shock generated in engaging engagement elements with each other in a hybrid vehicle. <P>SOLUTION: A hybrid driving device 10 includes a lock mechanism 700 for unrotationally locking an MG1 in a lock state that a clutch board 710 is engaged with a clutch board 720. An ECU 100 executes MG1 lock control in shifting the lock mechanism 700 from a non-lock state to a lock state. A threshold &beta; for discriminating whether or not the engagement elements are put in a rotation synchronizing state is set to be smaller when inaccuracy &gamma; is larger. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a technical field of a control device for a hybrid vehicle including an engagement device that requires rotational synchronization between engagement elements when engaged, such as a dog clutch.

  As this type of device, a device that improves the accuracy of phase matching between the engaging members in the circumferential direction has been proposed (for example, see Patent Document 1). According to the drive device disclosed in Patent Document 1, when the first engagement member and the second engagement member are engaged, the phase is obtained by rotating the first engagement member with an electric motor. It is said that the engagement shock can be suppressed by providing phase adjusting means for adjusting.

  Patent Document 2 discloses a technique for suppressing the engagement shock by limiting the number of rotations of the electric motor during engagement to a predetermined range. Patent Document 3 discloses a technique for synchronizing the engaging members by feedback control of the rotation speed of the electric motor.

JP 2006-038136 A JP 09-156387 A JP 2006-034076 A

  In a hybrid vehicle that adopts a configuration in which one rotation element among a plurality of rotation elements having a differential action is locked by this type of engagement device, in the process of engaging the engagement elements of the engagement device, When a disturbance element is input to the vehicle, for example, if the required output to the internal combustion engine changes due to a driver operation or the like, there is a problem that it becomes difficult to maintain the rotation synchronization state between the engagement elements. With respect to such a problem, the technical ideas disclosed in each of the above-mentioned patent documents do not take into account a change in required output at the time of engagement, and thus cannot solve the problem suitably. That is, in the conventional techniques including the techniques disclosed in the above patent documents, an increase in noise and shock cannot be avoided when a change occurs in the required torque of the internal combustion engine when engaging the engaging elements. There are technical problems.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a control device for a hybrid vehicle that can suppress generation of noise and shock when engaging engagement elements.

In order to solve the above-described problems, a hybrid vehicle control device according to the present invention includes a power element including an internal combustion engine and a rotating electric machine, a first rotating element whose rotation speed can be adjusted by the rotating electric machine, and a drive shaft connected to the axle. A plurality of rotating elements including a second rotating element coupled to the internal combustion engine and a third rotating element coupled to the internal combustion engine, each of which is capable of differentially rotating, and a power transmission mode determined according to a state of the plurality of rotating elements And a power transmission mechanism for transmitting power between the power element and the drive shaft, a first engagement element fixed to the first rotation element, and a first engagement element that is attached to face the first engagement element A first engagement element corresponding to a fixed speed change mode in which a speed ratio as a ratio between a rotation speed of the internal combustion engine and a rotation speed of the drive shaft is fixed as the power transmission mode. Element and the second The first engagement element and the second engagement element corresponding to a locked state in which a combination element is engaged and a continuously variable transmission mode in which the transmission ratio is continuously variable as the power transmission mode. A lock process as a process of switching the state from the non-lock state to the lock state is configured so that the state can be switched between the non-lock state and the non-lock state. a rotation synchronization step of maintaining the second engagement element to the rotation synchronization state, and a locking means comprising an engaging step of engaging the second engagement element and said first engaging element in the rotation synchronization state A control device for a hybrid vehicle, comprising: an estimation unit that estimates torque of the rotating electrical machine with a first-order delay; the engagement stage based on the estimated torque and an inertia moment of the rotating electrical machine; In Said calculating means for calculating an uncertainty γ rotational speed of the rotary electric machine, the threshold value β for the rotating electrical machine is determined whether or not the rotation synchronization state, and uncertainty γ the calculated, the setting means for the first and second engagement element is set based on the allowable value of engageable relative rotational speed, the rotational speeds speed of the rotary electric machine is within the threshold value β, which is the set And determining means for determining that the first and second engagement elements are in the rotation-synchronized state , and the state when the first and second engagement elements are determined to be in the rotation-synchronized state. There and control means for controlling said first and said second engagement element as Waru switches from said unlocked state to the locked state, the setting means, said threshold value β as uncertainty γ is large It is characterized in that it is set to be small.

  A hybrid vehicle according to the present invention includes, as a power element, a rotating electrical machine that can take the form of a motor generator such as a motor generator, a fuel type, a fuel supply mode, a fuel combustion mode, an intake / exhaust system configuration, and a cylinder. The vehicle includes at least an internal combustion engine that can take various forms regardless of the arrangement or the like. The hybrid vehicle control device according to the present invention is a device for controlling the hybrid vehicle, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units), various processors or various controllers, Alternatively, various processing units such as a single or a plurality of ECUs (Electronic Controlled Units), which may appropriately include various storage means such as ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory, Various computer systems such as various controllers or microcomputer devices can be used.

  The hybrid vehicle according to the present invention includes a power transmission mechanism. The power transmission mechanism includes a first rotating element whose rotation speed can be adjusted by a rotating electric machine, a second rotating element connected to the drive shaft, and a third rotating element connected to the internal combustion engine, and has a differential action between them. A plurality of possible rotating elements, and the state of each rotating element by such differential action (in short, whether it can be rotated and whether it is connected to other rotating elements or fixed elements) This is a mechanism for performing power transmission between the power element and the drive shaft (terminally torque transmission) in accordance with various power transmission modes determined in accordance with the power transmission mode. In particular, among the plurality of rotating elements provided in the power transmission mechanism, the first, second, and third rotating elements are typically one of the remaining one rotating element as long as the rotational speed of two of these elements is determined. A two-degree-of-freedom differential mechanism in which the rotation speed is determined (note that the rotation element is not necessarily limited to these three elements) is constructed. The power transmission mechanism can take, for example, a gear mechanism such as one or a plurality of planetary gear mechanisms as a preferred form, and in the case of including a plurality of planetary gear mechanisms, the rotation constituting each planetary gear mechanism. A part of the elements can be appropriately shared among a plurality of planetary gear mechanisms.

  As a preferred embodiment, the power transmission mechanism distributes the power of the internal combustion engine (terminally torque) to the first rotation element and the drive shaft (that is, the rotation element connected to the drive shaft) at a predetermined ratio. Possible so-called power split mechanism and other rotary electric machine as a power element, the role of multiple rotary electric machines, the reaction force element that bears the reaction force of the internal combustion engine and the output element that supplies power to the drive shaft Various reduction or transmission mechanisms or the like for switching the speed of the rotating electrical machine or for appropriately reducing or changing the rotational speed of the rotating electrical machine, the practical aspect of the power transmission mechanism is the specification of the hybrid vehicle, There may be a wide variety depending on destination, required performance, or various electrical, mechanical or economic constraints.

  The “power transmission mode” is a general term for various physical, mechanical or electrical restrictions and mechanisms for power transmission, and is, for example, the ratio between the rotational speed of the drive shaft and the rotational speed of the internal combustion engine. With regard to the transmission ratio, for example, a mode related to the nature of whether it is fixed or free or continuous within a range that can be determined physically or electrically in advance, a mode related to the possible range, a reaction force element and an output element Mode related to selection, mode related to selection of power elements to which driving power should be supplied, mode related to role sharing between output elements responsible for power supply to the drive shaft and reaction force elements responsible for the reaction force of the internal combustion engine, etc. Can be included as appropriate.

  The hybrid vehicle according to the present invention includes locking means. The locking means includes a first engagement element that is coaxially attached to the first rotation element, and a second engagement that is attached to face the first engagement element and is engageable with the first engagement element. It is possible to adopt a locked state in which the elements are engaged with each other and an unlocked state in which they are released from each other.

  When the locking means is in the unlocked state, the continuously variable transmission mode is realized as one of the power transmission modes by the power transmission mechanism. In the continuously variable transmission mode, the speed ratio, which is the ratio between the rotational speed of the internal combustion engine and the rotational speed of the drive shaft, is theoretically, substantially or pre-defined by physical, mechanical, mechanical or electrical constraints. It is possible to change continuously within a range of (including a stepped aspect equivalent to being practically continuous). More specifically, in the above-described two-degree-of-freedom differential mechanism, the rotating electrical machine functions as a reaction force element responsible for the reaction force of the internal combustion engine, and the rotational speed of the internal combustion engine is controlled freely by controlling the rotational speed of the rotating electrical machine. It becomes possible to control to. In this case, as a preferred embodiment, the operating point of the internal combustion engine (for example, a point defining one operating condition of the internal combustion engine defined by the engine speed and torque) is, for example, theoretically, substantially or It is freely selected within a range of constraints, for example, the fuel consumption rate is theoretically, substantially or minimally within a range of constraints, or the system efficiency of the hybrid vehicle (for example, the transmission efficiency of the power transmission mechanism and the internal combustion engine). The total efficiency calculated based on the thermal efficiency of the engine, etc.) is theoretically controlled to the optimum fuel consumption operating point or the like that is substantially or maximum within a range of some restrictions.

  On the other hand, when the locking means is in the locked state, the power transmission mechanism realizes the fixed transmission mode as one of the power transmission modes, and the transmission ratio is fixed to one value (note that the fixed transmission ratio is For example, it may be selected from a plurality of gear ratios by a stepped transmission or the like). That is, in the locked state, the rotation speed of the internal combustion engine is the second rotation controlled by the rotation speed of the first engagement element engaged with the second engagement element, that is, the rotation speed of the first rotation element and the vehicle speed. It is inevitably determined by the rotational speed of the element. The second engagement element is preferably a fixed element, but may be a rotating element as long as the fixed shift mode can be realized. In the fixed speed change mode, the locking means can bear the reaction force of the internal combustion engine, so that the rotating electrical machine can be ideally deactivated and is called so-called power circulation, which can occur depending on operating conditions. It is possible to avoid generation of useless electrical paths.

  Here, in the locking means according to the present invention, the locking process defined as the process of making a state transition from the unlocked state to the locked state is a rotation that maintains the first engagement element and the second engagement element in a rotationally synchronized state. The structure includes a synchronization stage and an engagement stage in which the first and second engagement elements maintained in the rotation synchronization state are engaged with each other. For example, a so-called rotation synchronization such as a dog clutch mechanism or a cam lock mechanism is provided. This is an engagement device of the type.

  As described above, the hybrid vehicle according to the present invention includes a power element, a power transmission mechanism, and a lock unit. The “estimation unit”, “calculation unit”, “setting unit”, “determination unit”, and control unit described below. It is controlled by a control device having

  The estimating means estimates the torque of the rotating electrical machine. When the disturbance element is input to the hybrid vehicle, the torque of the rotating electrical machine is influenced by the influence. The first rotating element whose rotation speed can be adjusted by the rotating electrical machine is in a differential relationship with the second rotating element on the drive shaft side and the third rotating element on the internal combustion engine side, and the vehicle speed does not change (that is, the second rotation element). Assuming that the rotation speed of the rotation element does not change), the rotation state of the first rotation element depends on the rotation state of the third rotation element. Accordingly, when there is an input of a disturbance element at the time of entering the engagement stage, the torque of the rotating electrical machine changes only to a certain degree. A change in torque due to a disturbance element is complicated in terms of factors such as the type of disturbance element and elements constituting the hybrid vehicle, and it is impossible in practice to accurately grasp the change. Therefore, in the present invention, the torque of the rotating electrical machine is estimated based on the difference in torque of the rotating electrical machine before and after the disturbance element is input using, for example, a disturbance observer.

  Here, “estimation” is a comprehensive concept such as detection, calculation, derivation, estimation, identification, selection, and acquisition, and so on, as long as it can be determined as reference information for control, its practical aspect is in any way. The purpose is not limited. For example, the specifying means may perform the estimation by selecting a corresponding value from the map as a result of the arithmetic processing based on the required driving force estimated from the accelerator opening and the vehicle speed of the hybrid vehicle, or based on these. .

  However, the torque of the rotating electrical machine estimated in this way necessarily includes an error. Therefore, the rotational speed of the rotating electrical machine also involves an error. As described above, since the rotating electrical machine is arranged so that the rotation speed of the first rotation element can be adjusted, the rotation speed of the first engagement element fixed to the first rotation element also has uncertainty due to an error. Arise. Therefore, when there is an input of a disturbance element, there is a problem that it is difficult to accurately control the rotation synchronization state of the first and second engagement elements.

  In order to solve this problem, the present invention solves this problem by setting the threshold value β for determining that the first and second engagement elements are in a rotation synchronization state so that the threshold value β decreases as the uncertainty γ increases. I am trying. Here, the threshold value β is used as a threshold value for determining whether or not the first and second engagement elements are in a rotation synchronization state in the determination unit. If the rotation speed of the rotating electrical machine does not involve an error and can be accurately controlled, the threshold value is set as the maximum value of the relative rotation speed at which the first and second engagement elements can be engaged. However, since the uncertainty γ accompanies the actual rotational speed of the rotating electrical machine, the present invention takes into account the threshold value for determining whether or not the rotation is in a synchronized state. It is set to a value smaller than the maximum value of the relative rotational speed at which the engagement element can be engaged. In particular, as the uncertainty γ increases, the threshold β decreases as the uncertainty γ increases so that the relative rotational speed at which the first and second engagement elements can engage with each other is more reliably accommodated. Is set as follows. If the threshold value β is set in this way, even if the relative rotational speed of the first and second engaging elements varies by γ (that is, the maximum amount of uncertainty), the relative rotational speed still remains. Since the speed can be kept within the maximum value of the relative rotational speed at which the first and second engagement elements can be engaged, it is possible to suppress the problem of the engagement shock. That is, by taking into account the uncertainty of the rotational speed of the rotating electrical machine in advance when setting the threshold value for determining the rotation synchronization state, it is possible to more effectively suppress the occurrence of the engagement shock.

As a specific method for setting the threshold value β, if the maximum value of the relative rotational speed at which the first and second engaging elements can be engaged is α, for example, β = α / f (γ), β = Α · g (γ) and β = α − k · γ can be used. Here, f (γ) and g (γ) are arbitrary functions having uncertainty γ as a variable, and k is a predetermined constant. These functions and constants are experimentally, empirically, and theoretically calculated in advance so that the threshold value β for determining the rotational synchronization state that makes the engagement shock small enough not to cause a problem is calculated. Alternatively, it is set based on simulation or the like.

  The control means performs control so that the first and second engagement elements are engaged when the determination means determines that the rotation is synchronized.

  As described above, according to the hybrid vehicle control device of the present invention, even when there is an input of a disturbance element at the time of engagement, the rotational synchronization state is considered in advance in consideration of the uncertainty of the rotational speed of the rotating electrical machine. By discriminating, it is possible to effectively suppress noise and engagement shock during engagement. This also leads to effectively avoiding the gears and the like constituting the engaging element from being applied or damaged.

In one aspect of the hybrid vehicle control device according to the present invention, the setting means sets the threshold value β to the following formula β = α−γ ( where α is the allowable value, and the first and second engagement element to read the threshold value β corresponding to the rotational speed rate of the rotary electric machine from a map created in advance based on the or formula to calculate the maximum value) of engageable relative rotational speed Then, the threshold value β is set .

  According to this aspect, the threshold value β for determining that the first and second engagement elements are in the rotation synchronization state is the maximum value of the relative rotational speed at which the first and second engagement elements can be engaged. It is set as the difference between α and the uncertainty γ of the rotational speed of the rotating electrical machine in the engagement stage. Here, “the relative rotational speed at which the first and second engaging elements can be engaged” means that when the first and second engaging elements are engaged, an engagement shock does not occur, or Even if it occurs, it is a relative rotational speed that is so small that it does not cause discomfort to the driver. That is, in a strict sense, when engaging the first and second engagement elements, it is most preferable to make the relative speed zero from the viewpoint that the engagement shock can be completely eliminated. Even if there is a reasonable rotation speed, the engagement shock is so small that it does not become a problem. Therefore, the “relative rotational speed at which the first and second engagement elements can be engaged” has individual values depending on the type and material of the engagement elements used in the hybrid vehicle. In other words, it is set empirically, theoretically, or based on simulation. Therefore, the “maximum value of the relative rotational speed that can be engaged” according to the present invention is a known value that is unique to the locking means or the control device and is preset.

In another aspect of the hybrid vehicle control device according to the present invention, the calculation means estimates the uncertainty γ by a length Δt of a predetermined period in the locking process and a disturbance torque input to the Δt. from amount of change in torque delta T及 beauty inertia moment J of the rotating electrical machine is calculated by the following equation γ = ΔT × Δt / J.

  According to the research of the present inventor, the uncertainty γ of the rotational speed of the rotating electrical machine that occurs when there is an input of a disturbance element during engagement can be calculated by the above equation.

  In another aspect of the hybrid vehicle control device according to the present invention, the estimation means includes a disturbance observer that monitors a disturbance element input to the hybrid vehicle.

  In this aspect, the current torque is estimated using a disturbance observer based on the temporal change of the past torque of the rotating electrical machine. For example, when the disturbance observer includes a first-order lag, that is, when the torque of the rotating electrical machine is estimated by performing time differentiation, an error is necessarily included in the estimated torque. Even in such a case, according to the invention of the present application, it is effective that the engagement shock is generated by setting the threshold value for determining the rotation synchronization state in consideration of the error generated in advance as described above. Can be suppressed.

  In another aspect of the hybrid vehicle control device according to the present invention, an internal combustion engine output instruction signal, which is a signal for controlling the value of the torque of the internal combustion engine, in a predetermined period before the engagement stage is set to a constant value. Alternatively, there is further provided a constanting means for maintaining within a certain range.

  In each aspect described above, the threshold value β is set in advance in consideration of the uncertainty γ of the rotational speed of the rotating electrical machine. However, when the influence of disturbance elements is large, for example, the driver suddenly accelerates or decelerates or the road surface condition is In the case of a sudden change, the value of uncertainty γ increases. Then, the value of the threshold β (= α−γ) for determining the rotation synchronization state becomes small, and it becomes necessary to perform the rotation speed of the rotating electrical machine with higher accuracy, and it becomes difficult to realize the rotation synchronization state. End up. As described above, when there is an input of a disturbance element at the time of engagement, it is difficult to accurately control the rotation speed of the rotating electrical machine. Therefore, when the threshold value β becomes extremely small, the rotation synchronization state is realized. It becomes impossible in practice.

  Therefore, in the control device according to this aspect, the internal combustion engine output instruction signal is maintained within a constant value or within a certain range by the stabilizing means so that the uncertainty γ does not become excessively large. The internal combustion engine output instruction signal is an engine command power signal for instructing torque to be output to an internal combustion engine such as an engine, for example, and is a signal that changes in accordance with the degree of depression of the driver's accelerator pedal. In other words, if the uncertainty γ becomes excessively large even if the driver depresses the accelerator largely by the stabilizing means, the engine command power signal does not increase to the extent that the accelerator is depressed, and remains constant at a smaller value. Limited. In other words, the internal combustion engine output instruction signal is limited to a constant value so that the uncertainty γ becomes an appropriate magnitude.

  As described above, according to this aspect, even when a large disturbance element is input, the uncertainty γ of the rotational speed of the rotating electrical machine can be reduced by appropriately limiting the internal combustion engine output instruction signal. It is possible to suppress the occurrence of the engagement shock more reliably by suppressing to an appropriate value.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid vehicle according to a first embodiment. 1 is a schematic configuration diagram conceptually illustrating a configuration of a hybrid drive device in a hybrid vehicle according to a first embodiment. It is an operation | movement alignment chart of the hybrid drive device which concerns on 1st Embodiment. It is a flowchart of MG1 lock control of the hybrid drive device concerning a 1st embodiment. It is a block diagram which shows the input / output of the various control signals regarding the feedback control of the rotation speed of MG1 of the hybrid drive device which concerns on 1st Embodiment. It is a graph which shows the relationship between the torque of MG1 and the estimated torque of the hybrid drive device which concerns on 1st Embodiment. It is a graph which shows an example of a time-dependent change of the rotation speed of MG1 before and after the rotation synchronization of the hybrid drive device which concerns on 1st Embodiment is completed. FIG. 10 is a schematic time characteristic diagram illustrating a one-hour transition of the engine operating state in the execution process of the lock control of MG1 of the hybrid drive device according to the second embodiment. It is a flowchart figure of the engine command power restriction | limiting timing control of the hybrid drive device which concerns on 2nd Embodiment. It is a schematic block diagram which represents notionally the structure of the hybrid drive device which concerns on 3rd Embodiment.

<Embodiment of the Invention>
Various preferred embodiments of the present invention will be described below with reference to the drawings.
<1: First Embodiment>
<1-1: Configuration of Embodiment>
First, the configuration of the hybrid vehicle 1 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the hybrid vehicle 1.

  In FIG. 1, a hybrid vehicle 1 is an example of a “hybrid vehicle” according to the present invention that includes a hybrid drive device 10, a PCU (Power Control Unit) 11, a battery 12, an accelerator opening sensor 13, a vehicle speed sensor 14, and an ECU 100. It is.

  The ECU 100 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the hybrid vehicle 1, and is an example of the “hybrid vehicle control device” according to the present invention. The ECU 100 is configured to execute MG1 lock control, which will be described later, according to a control program stored in the ROM. The ECU 100 is an integrated electronic control unit configured to function as an example of various units according to the present invention, and all the operations related to the above units are configured to be executed by the ECU 100. However, the physical, mechanical, and electrical configurations of the above-described means according to the present invention are not limited thereto. For example, each of these means includes various ECUs, various processing units, various controllers, microcomputer devices, and the like. It may be configured as a computer system or the like.

  The PCU 11 converts the DC power extracted from the battery 12 into AC power and supplies it to a motor generator MG1 and a motor generator MG2, which will be described later, and also converts AC power generated by the motor generator MG1 and the motor generator MG2 into DC power. Inverter (not shown) that can be supplied to the battery 12 and input / output power between the battery 12 and each motor generator, or input / output power between the motor generators (ie, in this case, This is a power control unit configured to be able to control power transmission / reception between the motor generators without using the battery 12. The PCU 11 is electrically connected to the ECU 100, and its operation is controlled by the ECU 100.

  The battery 12 is a rechargeable power storage unit that functions as a power supply source related to power for powering the motor generator MG1 and the motor generator MG2.

  The accelerator opening sensor 13 is a sensor configured to be able to detect an accelerator opening Ta as an operation amount of an accelerator pedal (not shown) of the hybrid vehicle 1. The accelerator opening sensor 13 is electrically connected to the ECU 100, and the detected accelerator opening Ta is referred to by the ECU 100 at a constant or indefinite period.

  The vehicle speed sensor 14 is a sensor configured to be able to detect the vehicle speed V of the hybrid vehicle 1. The vehicle speed sensor 14 is electrically connected to the ECU 100, and the detected vehicle speed V is referred to by the ECU 100 at a constant or indefinite period.

  The hybrid drive device 10 is a power unit that functions as a power train of the hybrid vehicle 1.

  Here, the detailed configuration of the hybrid drive apparatus 10 will be described with reference to FIG. FIG. 2 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 1, and the description thereof will be omitted as appropriate.

  In FIG. 2, the hybrid drive device 10 includes an engine 200, a power split mechanism 300, a motor generator MG1 (hereinafter appropriately referred to as “MG1”), a motor generator MG2 (hereinafter appropriately referred to as “MG2”), an input shaft. 400, a drive shaft 500, a speed reduction mechanism 600, and a lock mechanism 700.

The engine 200 is a gasoline engine which is an example of the “internal combustion engine” according to the present invention, and is configured to function as a main power source of the hybrid vehicle 1.
Motor generator MG1 is a motor generator that is an example of a “rotary electric machine” according to the present invention, and includes a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy. It has become. Motor generator MG2 is a motor generator, and has a power running function that converts electrical energy into kinetic energy and a regeneration function that converts kinetic energy into electrical energy, similar to motor generator MG1. Motor generators MG1 and MG2 are configured as, for example, synchronous motor generators, and include, for example, a rotor having a plurality of permanent magnets on an outer peripheral surface, and a stator wound with a three-phase coil that forms a rotating magnetic field. However, it may have other configurations.

  The power split mechanism 300 includes a sun gear S1 as an example of the “first rotating element” according to the present invention provided in the center, and a concentric or coaxial arrangement on the outer periphery of the sun gear S1. A ring gear R1, which is an example of a “second rotating element”, a plurality of pinion gears P1 that are arranged between the sun gear S1 and the ring gear R1 and revolve around the outer periphery of the sun gear S1, and the rotation of each of the pinion gears It is a power distribution device that is an example of a “power transmission mechanism” according to the present invention, and includes a carrier C1 that is an example of a “third rotating element” according to the present invention that supports a shaft.

  Here, sun gear S1 is connected to rotor RT of motor generator MG1 via sun gear shaft 310, and the rotational speed thereof is equivalent to the rotational speed of motor generator MG1 (hereinafter referred to as “MG1 rotational speed Nmg1” as appropriate). It is. The ring gear R1 is coupled to a rotor (not shown) of the motor generator MG2 via the drive shaft 500 and the speed reduction mechanism 600, and the rotation speed thereof is the rotation speed of the motor generator MG2 (hereinafter referred to as “MG2 rotation speed Nmg2 as appropriate”). Is equivalent). Further, the carrier C1 is connected to the input shaft 400 connected to the above-described crankshaft 205 of the engine 200, and the rotational speed thereof is equivalent to the engine rotational speed NE of the engine 200. In the hybrid drive device 10, the MG1 rotation speed Nmg1 and the MG2 rotation speed Nmg2 are detected at a constant cycle by a rotation sensor such as a resolver, and are sent to the ECU 100 at a constant or indefinite cycle.

  On the other hand, drive shaft 500 is connected to drive shafts SFR and SFL for driving right front wheel FR and left front wheel FL, which are drive wheels of hybrid vehicle 1, and reduction mechanism 600 as a reduction gear including various reduction gears such as a differential. Has been. Therefore, the motor torque Tmg2 (that is, an example of “power” according to the present invention) supplied from the motor generator MG2 to the drive shaft 500 is transmitted to each drive shaft via the speed reduction mechanism 600, and each drive shaft. Similarly, the driving force transmitted from each driving wheel is input to the motor generator MG2 via the speed reduction mechanism 600 and the driving shaft 500. That is, the MG2 rotational speed Nmg2 is uniquely related to the vehicle speed V of the hybrid vehicle 1.

  Under such a configuration, the power split mechanism 300 applies engine torque Te supplied from the engine 200 to the input shaft 400 via the crankshaft 205 to the sun gear S1 and the ring gear R1 by the carrier C1 and the pinion gear P1. It is possible to divide the power of the engine 200 into two systems by distributing at a ratio (a ratio according to the gear ratio between the gears).

  In order to make the operation of the power split mechanism 300 easy to understand, when the gear ratio ρ as the number of teeth of the sun gear S1 with respect to the number of teeth of the ring gear R1 is defined, when the engine torque Te is applied from the engine 200 to the carrier C1, The torque Tes appearing on the sun gear shaft 310 is expressed by the following equation (1), and the torque Ter appearing on the drive shaft 500 is expressed by the following equation (2).

Tes = −Te × ρ / (1 + ρ) (1)
Ter = Te × 1 / (1 + ρ) (2)
The configuration of the embodiment relating to the “power transmission mechanism” according to the present invention is not limited to that of the power split mechanism 300. For example, a power transmission mechanism according to the present invention includes a plurality of planetary gear mechanisms, and a plurality of rotating elements included in one planetary gear mechanism are appropriately coupled to each of a plurality of rotating elements included in another planetary gear mechanism, An integral differential mechanism may be configured. In addition, the speed reduction mechanism 600 according to the present embodiment merely reduces the rotational speed of the drive shaft 500 in accordance with a preset speed reduction ratio. A stepped transmission device including a plurality of shift speeds including the clutch mechanism and the brake mechanism as a component may be provided. For example, a planetary gear mechanism equivalent to the power split mechanism 300 is interposed between the motor generator MG2 and the speed reduction mechanism 600, the rotor of MG2 is connected to the sun gear of the planetary gear mechanism, and the ring gear R1 is connected to the ring gear. The MG2 rotational speed Nmg2 may be decelerated by fixing the carrier to be non-rotatable.

  The lock mechanism 700 is a dog clutch mechanism having a pair of clutch plates 710 and 720.

  The clutch plate 710 is an example of the “first engagement element” according to the present invention, which is fixed to the sun gear shaft 310 and can rotate together with the sun gear shaft 310. In the clutch plate 710, a tooth-like member (not shown) (not shown) is formed on a surface facing the clutch plate 720 at a predetermined interval in the circumferential direction.

  The clutch plate 720 is an example of the “second engagement element” according to the present invention, which is fixed to the case CS as a fixing element. In the clutch plate 720, tooth-like members (not shown) are formed on the facing surface facing the clutch plate 710 at a predetermined interval in the circumferential direction like the clutch plate 710. The pair of clutch plates 710 and 720 are coaxially attached to the sun gear shaft 310.

  The clutch plate 720 is configured to be capable of a predetermined amount of stroke in the right direction in the drawing by the action of an electromagnetic actuator (not shown), and in a state where the predetermined amount of stroke has been applied, the tooth-like member formed on the opposing surface is the clutch plate 710. Interlocks with the tooth-like member formed on the opposite surface (more specifically, one convex part and the other concave part, and one concave part and the other convex part mesh). It is configured to take a state. In the locked state, the rotation of the clutch plate 710 is blocked by the clutch plate 720 fixed to the case CS, which is a fixed element, and the clutch plate 710 is locked so as not to rotate.

  Supplementally, in the dog clutch mechanism as described above, the engagement elements need to finally have a predetermined phase relationship in a state in which the engagement elements are rotationally synchronized. Accordingly, in the locking process in which the lock mechanism 700 is shifted from the unlocked state (the clutch plates are separated from each other) to the locked state, (a) the rotation of the clutch plate 710 is maintained at zero or substantially zero by the motor generator MG1. Further, after the appropriate phase state is formed by the phase control, (a) the clutch plate 720 is stroked by the actuator. That is, (a) is an example of the “rotation synchronization stage” according to the present invention, and (b) is an example of the “engagement stage” according to the present invention. In addition, in the engagement stage, or as a stage after the engagement stage, there may be a so-called backlash filling stage for filling backlash formed between the tooth-like members.

  This electromagnetic actuator is in a state of being electrically connected to the ECU 100 via the PCU 11, and its operation state is controlled by the ECU 100. Further, the practical aspect of the dog clutch mechanism is not limited to that of the lock mechanism 700. For example, a hollow hub is fixed to the sun gear shaft 310 as a first engagement element, and a tooth-like member (that is, an external tooth) is formed on the outer peripheral surface of the hub, while the annular member is fixed to the case CS. Similarly, a tooth-like member (that is, an external tooth) is formed on the outer peripheral surface of the sleeve, and a sleeve having an internal tooth that engages with the external tooth of the annular member as a second engagement element May be configured to be strokeable. In this case, the inner teeth of the sleeve and the outer teeth of the annular member are always meshed, and the inner teeth of the sleeve are further meshed with the outer teeth of the hub during the stroke, so that the hub and the annular member are fixed to establish a locked state. May be.

  Further, the locking means according to the present invention is not limited to such a dog clutch mechanism. For example, the locking means is connected to the cam that is a first engagement element fixed to the sun gear shaft 310, a clutch plate that rotates integrally with the cam with a cam ball interposed between the cam and the fixing element. A so-called cam lock type engagement device may be provided that includes an electromagnetic actuator as a second engagement element. In this type of cam lock type engaging device, in a state in which the cam is rotationally synchronized with the object to be engaged (in this case, the electromagnetic actuator as a fixed element), the electromagnetic actuator attracts the clutch plate to the friction element on the electromagnetic actuator side, The differential rotation generated between the clutch plate and the cam can cause a self-locking action via the cam ball, thereby preventing the cam from rotating.

<1-2: Operation of Embodiment>
<1-2-1: Details of shift mode>
The hybrid vehicle 1 according to the present embodiment can select a fixed shift mode or a continuously variable transmission mode as a shift mode that is an example of the “power transmission mode” according to the present invention, depending on the state of the sun gear S1. Here, the shift mode of the hybrid vehicle 1 will be described with reference to FIG. FIG. 3 is an operation collinear diagram of the hybrid drive device 10. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 3A, the vertical axis represents the rotation speed, and the horizontal axis represents the motor generator MG1 (uniquely sun gear S1), engine 200 (uniquely carrier C1), and motor generator MG2 (in order from the left). The ring gear R1) is uniquely represented. Here, power split mechanism 300 is a planetary gear mechanism with two degrees of freedom of rotation, and when the rotational speeds of two elements of sun gear S1, carrier C1, and ring gear R1 are determined, the rotational speed of the remaining one rotational element. Is inevitably determined. That is, on the operation collinear diagram, the operation state of each rotary element can be represented by one operation collinear line corresponding to one operation state of the hybrid drive device 10 on a one-to-one basis. It should be noted that the points on the operation collinear chart will be represented by operation points mi (i is a natural number) as appropriate. That is, one rotational speed corresponds to one operating point mi.

  In FIG. 3A, it is assumed that the operating point of motor generator MG2 is operating point m1. In this case, if the operating point is the operating point m3 of motor generators MG1, the operating point of the engine 200 connected to the remainder of the one rotation element serving carrier C1 becomes the operating point m @ 2. At this time, if the operating point of MG1 is changed to the operating point m4 and the operating point m5 while maintaining the rotational speed of the drive shaft 500, the operating point of the engine 200 changes to the operating point m6 and the operating point m7, respectively.

  That is, in this case, the engine 200 can be operated at a desired operating point by using the motor generator MG1 as the rotational speed control device. The speed change mode corresponding to this state is the continuously variable speed change mode. In the continuously variable transmission mode, the operating point of the engine 200 (the operating point in this case is defined by the combination of the engine speed and the engine torque Te) basically has the minimum fuel consumption rate of the engine 200. It is controlled to the optimum fuel consumption operating point. Of course, in the continuously variable transmission mode, the MG1 rotational speed Nmg1 needs to be variable. Therefore, when the continuously variable transmission mode is selected, the driving state of the lock mechanism 700 is controlled so that the sun gear S1 is in the released state.

  Supplementally, in the power split mechanism 300, in order to supply the torque Ter corresponding to the engine torque Te described above to the drive shaft 500, the torque Tes that appears on the sun gear shaft 310 according to the engine torque Te and It is necessary to supply reaction force torque having the same magnitude and reversed sign (that is, negative torque) from the motor generator MG1 to the sun gear shaft 310. In this case, at the operating point in the positive rotation region such as the operating point m3 or the operating point m4, the motor generator MG1 is in a power generation state of positive rotating negative torque. That is, in the continuously variable transmission mode, the motor generator MG1 (uniquely the sun gear S1) functions as a reaction force element so that a part of the engine torque Te is supplied to the drive shaft 500 and distributed to the sun gear shaft 310. Electricity is generated with a part of the engine torque Te. When the torque required for drive shaft 500 is insufficient due to the engine direct torque, torque Tmg2 is appropriately supplied from motor generator MG2 to drive shaft 500 using this generated power.

  On the other hand, for example, when driving at a high speed and a light load, under operating conditions where the engine speed NE is low but the MG2 rotational speed Nmg2 is high, for example, MG1 is the operating point in the negative rotational region such as the operating point m5. In this case, motor generator MG1 outputs a negative torque as a reaction torque of engine torque Te, and enters a state of negative rotation negative torque and a power running state. That is, in this case, torque Tmg1 from motor generator MG1 is transmitted to drive shaft 500 as the drive torque of hybrid vehicle 1.

  On the other hand, motor generator MG2 is in a negative torque state because it absorbs excessive torque with respect to the required torque output to drive shaft 500. In this case, motor generator MG2 is in a state of positive rotation and negative torque and is in a power generation state. In such a state, an inefficient electric path called so-called power circulation occurs in which the driving force from the motor generator MG1 is used for power generation by the motor generator MG2, and the MG1 is driven by this generated power. It will be. In a state where the power circulation occurs, the transmission efficiency of the hybrid drive device 10 is reduced, and the system efficiency of the hybrid drive device 10 is reduced.

  Therefore, in the hybrid vehicle 1, the lock mechanism 700 is controlled to the above-described locked state in an operation region that is determined in advance such that such power circulation can occur. This is shown in FIG. When the lock mechanism 700 is locked, that is, when the sun gear S1 is locked, the motor generator MG1 is inevitably also locked, and the operating point of the motor generator MG1 is the operating point m8 where the rotational speed is zero. . For this reason, the operating point of the engine 200 is the operating point m9, and the engine rotational speed NE is uniquely determined by the vehicle speed V and the unambiguous MG2 rotational speed Nmg2 (that is, the gear ratio is constant). Thus, the shift mode corresponding to the case where motor generator MG1 is in the locked state is the fixed shift mode.

  In the fixed transmission mode, the reaction torque of the engine torque Te that should be borne by the motor generator MG1 can be replaced by the physical braking force of the lock mechanism 700. That is, it is not necessary to control motor generator MG1 in both the power generation state and the power running state, and motor generator MG1 can be stopped. Therefore, basically it is not necessary to operate the motor generator MG2, and the MG2 is in an idling state. After all, in the fixed speed change mode, the drive torque appearing on the drive shaft 500 is only the directly achieved portion (see the above formula (2)) divided by the power split mechanism 300 on the drive shaft 500 side in the engine torque Te, and hybrid drive The device 10 only performs mechanical power transmission, and the transmission efficiency is improved.

<1-2-2: Details of MG1 lock control>
In the hybrid vehicle 1, the speed change mode is controlled by the ECU 100 to a speed change mode in which the system efficiency ηsys of the hybrid drive device 10 is higher each time. At this time, the ECU 100 refers to a shift map stored in advance in the ROM. This shift map is a two-dimensional map in which the required driving force Ft and the vehicle speed V are represented on the vertical axis and the horizontal axis, respectively. On the shift map, an area in which motor generator MG1 is controlled to be locked and the fixed shift mode is to be selected is defined as an MG1 lock area. The required driving force Ft is a required value of the driving force applied to each drive shaft, and the vehicle speed V detected by the vehicle speed sensor 14 and the accelerator opening Acc detected by the accelerator opening sensor 13 are used as parameters. Obtained from the required driving force map. The ECU 100 executes the MG1 lock control when the operating condition of the hybrid vehicle 1 defined by the vehicle speed V and the required driving force Ft corresponds to the fixed speed change mode, thereby changing the speed change mode from the continuously variable speed change mode. Switch to mode.

  Here, the details of the MG1 lock control will be described with reference to FIG. FIG. 4 is a flowchart of the MG1 lock control.

  In FIG. 4, first, the ECU 100 executes rotation synchronization control (step S101). Here, the rotation synchronization control is control for maintaining the clutch plate 710 and the clutch plate 720 in a rotation synchronization state, and the rotation speed of the clutch plate 710 by the motor generator MG1 is similar to the rotation speed of the clutch plate 720. This is realized by controlling to be zero or close to zero. In the present embodiment, the phase state between the clutch plate 710 and the clutch plate 720 is also controlled in this rotation synchronization control. That is, the “rotation synchronization state” in the following description means a state in which the rotation speed is synchronized and the phase is matched between the two.

  When the rotation synchronization control is started, the ECU 100 sets a rotation synchronization determination threshold value β (step S102). Here, the rotation synchronization determination threshold value β is a threshold value for determining whether or not the rotation synchronization control corresponding to the difference in rotation speed between the clutch plate 710 and the clutch plate 720 has ended. As described above, the rotationally synchronized state in the strict sense requires that the rotational speeds between the two be equal, but in fact, even if the rotational speeds of both do not exactly match It can be regarded as a rotation synchronization state. That is, if the difference in rotational speed between the clutch plate 710 and the clutch plate 720 is small to some extent, no engagement shock or noise will occur when they are engaged, or even if they do not cause any problems. Therefore, in the present embodiment, even if there is a difference between the rotational speeds of the clutch plate 710 and the clutch plate 720, if the rotational speed difference is within the rotation synchronization determination threshold value β, substantially. It is set so that it is determined that there is no engagement shock or noise, or that there is no problem even if it occurs, and that it is in a rotationally synchronized state. As will be described later, in the present embodiment, when the difference in rotational speed between the clutch plate 710 and the clutch plate 720 falls within the rotation synchronization determination threshold value β, it is determined that the rotation synchronization state is established.

The rotation synchronization determination threshold value β is not generated or is not generated when the clutch plate 710 and the clutch plate 720 are engaged due to inherent factors such as the material and shape of the clutch plate 710 and the clutch plate 720. Using the allowable value α defined as the maximum rotational speed difference that does not cause a problem and the rotational speed error γ indicating the disturbance of the rotational speed of the motor generator MG1 in the engagement stage, the following expression β = α− γ (3)
It is prescribed by.

In the present embodiment, the equation (3) is adopted as a method for setting the threshold value β. For example, arbitrary functions f (γ) and g (γ) having uncertainty γ as a variable, and It is also possible to set the threshold value β using a calculation formula such as β = α / f (γ), β = α · g (γ), and β = α − k · γ using a predetermined constant k. . In this case, these functions and constants are experimentally and empirically in advance so that a threshold value β for determining a rotation synchronization state that is so small that engagement shock does not become a problem is calculated. It may be set theoretically or based on simulation or the like.

  In order to suppress the engagement shock, the clutch plate 710 and the clutch plate 720 need to be in a rotationally synchronized state before the engagement is started, but the sun gear S1 to which the clutch plate 710 is fixed is on the drive shaft 500 side. Assuming that the ring gear R1 and the pinion gear P1 on the engine 200 side are in a differential relationship and the vehicle speed does not change (that is, the rotational speed of the ring gear R1 does not change), the rotational state of the sun gear S1 is It depends on the rotation state of the pinion gear P1. Therefore, if the engine torque Te fluctuates when entering the lock process, the synchronization relationship between the engagement elements may be collapsed to some extent, and the noise level and the level of engagement shock may rise to a level that is difficult to overlook in practice. . If it supplements, since the rotation state of the sun gear S1 is controlled by the motor generator MG1, the rotation fluctuation of the sun gear S1 accompanying the fluctuation of the engine torque Te is suppressed by the control of the torque Tmg1 of the motor generator MG1. Although it is possible, it is practically impossible to suppress the rotational fluctuation of the sun gear S1 finely to such an extent that the phase relationship between the clutch plate 710 and the clutch plate 720 can be suitably maintained in the lock process which is a kind of transient process. . Note that the case where the engine torque Te fluctuates in this way is, for example, a case where the degree of depression of the driver's throttle changes at the time of engagement or the situation of the traveling road surface of the hybrid vehicle 1 fluctuates. This corresponds to the case where a disturbance element is input.

  In this embodiment, in order to suppress the difficulty in favorably maintaining the phase relationship between the clutch plate 710 and the clutch plate 720 due to fluctuations in the engine torque Te during engagement, Feedback control is performed on the rotational speed Nmg1 of the motor generator MG1 fixed coaxially with the plate 720. FIG. 5 is a block diagram showing input / output of various control signals related to feedback control of the rotational speed Nmg1 of motor generator MG1.

  The ECU 100 sets a target rotational speed of the motor generator MG1 for bringing the clutch plate 710 and the clutch plate 720 into a rotationally synchronized state (that is, a rotational speed at which the rotational speed of the clutch plate 710 becomes zero), and is an object to be controlled. Torque Tmg1 of motor generator MG1 to be controlled is controlled so that actual rotation speed Nmg1 of motor generator MG1 matches this target rotation speed. However, when the disturbance element is input as described above, the torque Tmg1 of the motor generator MG1 is disturbed to some extent, so that the rotational speed Nmg1 of the motor generator MG1 also deviates from the target rotational speed. Therefore, ECU 100 monitors the actual rotational speed Nmg1 of motor generator MG1, calculates the difference from the target rotational speed, and feedback-controls torque Tmg1 of motor generator MG1 so as to cancel the difference.

  Also, the disturbance observer 110 acquires the output torque (ie, Tmg11 and Tmg12) of the motor generator MG1 before and after the input of the disturbance element. The disturbance observer 110 obtains a difference ΔT between the output torques Tmg11 and Tmg12 of the motor generator MG1 before and after the input of the disturbance element, and based on the difference ΔT, a component force applied to the rotor RT of the motor generator MG1. Is estimated. As described above, the torque Tmg1 of the motor generator MG1 is generated as a reaction force of the engine torque TE. Thus, by estimating the component force applied to the rotor RT of the motor generator MG1 in the engine torque TE in this way, Torque Tmg1 of motor generator MG1 can be estimated. Based on torque Tmg1 of motor generator MG1 estimated by disturbance observer 110 in this way (hereinafter referred to as estimated torque Tmgn1 of motor generator MG1), ECU 100 performs feedback control on rotational speed Nmg1 of motor generator MG1 also from the viewpoint of torque. ing.

  FIG. 6 is a graph showing the relationship between actual torque Tmg1 of motor generator MG1 and estimated torque Tmgn1 of motor generator MG1.

  As shown in FIG. 6, for example, when the actual torque Tmg1 of motor generator MG1 increases in proportion to time by the driver stepping on the accelerator of hybrid vehicle 1 from time t1, estimated torque Tmgn1 of motor generator MG1 is increased. Is increased from time t1 similarly to the torque Tmg1 of the motor generator MG1, but the increase speed is slower than the actual torque Tmg1 of the motor generator MG1 in the time around the time t1. That is, estimated torque Tmgn1 of motor generator MG1 is accompanied by a time delay with respect to actual torque Tmg1 of motor generator MG1. This delay is due to the fact that the disturbance observer 110 includes time differentiation in the process of obtaining the estimated torque Tmgn1. Specifically, when obtaining the estimated torque Tmgn1 at a specific time, the disturbance observer 110 in the present embodiment performs a time differentiation operation on the change history of the torque Tmg1 of the motor generator MG1 from the current time. Therefore, even if the actual torque Tmg1 of the motor generator MG1 changes due to the input of a disturbance at a certain time, the estimated torque Tmgn1 is calculated based on the past torque Tmg1 of the motor generator MG1, and thus input Does not include the effects of disturbance. Therefore, estimated torque Tmgn1 of motor generator MG1 necessarily includes an error.

As described above, if the estimated torque Tmgn1 used for feedback control of the rotational speed Nmg1 of the motor generator MG1 includes an error, the control accuracy of the rotational speed Nmg1 of the motor generator MG1 is reduced. Therefore, in the control device according to the present embodiment, by considering the error in the estimated torque Tmgn1 in advance, when setting the rotation synchronization determination threshold β for determining whether or not the rotation synchronization state is set, The occurrence of engagement shock can be effectively suppressed. According to the research of the present inventor, the uncertainty γ of the rotational speed Nmg1 of the motor generator MG1 generated based on the error included in the estimated torque Tmgn1 is calculated using the following equation γ = (Tmg1-Tmgn1) / J (4)
Can be obtained.

  Returning to FIG. 4 again, the ECU 100 determines whether or not the rotation synchronization is completed based on the set rotation synchronization determination threshold value β (step S103).

Here, if it is assumed that the rotational speed Nmg1 of the motor generator MG1 can be accurately controlled, the rotational speed Nmg1 of the motor generator MG1 is determined based on inherent factors such as the material and shape of the clutch plate 710 and the clutch plate 720, and the clutch plate. Is the rotation synchronization completed with reference to an allowable value α defined as the maximum rotational speed difference that does not cause an engagement shock when the clutch 710 and the clutch plate 720 are engaged or does not cause any problem? It is determined whether or not. That is, since the rotation speed Nmg1 can be accurately grasped, even if the allowable value α is used as it is as the rotation synchronization determination threshold value, there is very little possibility that an engagement shock will occur.

  However, as described above, in actuality, it is impossible to accurately control the rotational speed Nmg1 of the motor generator MG1, and the amount of uncertainty γ of the rotational speed Nmg1 of the motor generator MG1 in the engagement stage is reduced. Uncertainty accompanies the rotational speed Nmg1 of motor generator MG1. Therefore, in the present embodiment, a value β obtained by subtracting in advance the uncertainty γ of the rotational speed Nmg1 of the motor generator MG1 in the engagement stage from the allowable value α is used as a rotation synchronization determination threshold (see the above equation (3)). ), The occurrence of shock during engagement can be effectively suppressed. That is, it is characterized in that the rotation synchronization state is determined based on a value that takes into account an error included in the rotation speed Nmg1 of the motor generator MG1 in advance.

  FIG. 7 is a graph showing an example of a change over time in the rotation speed Nmg1 of the motor generator MG1 before and after the rotation synchronization of the clutch plate 710 and the clutch plate 720 is completed.

As shown in FIG. 7, the rotation speed Nmg1 of motor generator MG1 decreases toward zero in a completely synchronized state from the start of rotation synchronization. When the rotational speed Nmg1 of the motor generator MG1 falls within the rotation synchronization determination threshold value β, the ECU 100 commands the actuator and shifts to the clutch plate 710 and the clutch plate 720 because rotation synchronization is completed. The engagement is executed. After the engagement is started, the rotational speed Nmg1 of the motor generator MG1 is uncertain by γ, so the rotational speed Nmg1 during the operation of the actuator is the rotational speed Nmg1 of the motor generator MG1 at the start of engagement as Nmg1s. Then
Nmg1s−γ <Nmg <Nmg1s + γ (5)
(See the one-dot chain line in FIG. 7). However, since the absolute values of the upper limit rotation speed Nmg1s + γ and the lower limit rotation speed Nmg1s−γ of the variation range are both smaller than the rotation synchronization determination threshold value β, the rotation synchronization state can be maintained. That is, since the rotation synchronization determination threshold value is set in advance in consideration of the uncertainty γ of the rotational speed Nmg1 of the motor generator MG1, even if the rotational speed Nmg1 of the motor generator MG1 varies due to the input of a disturbance element, it is ensured. The engagement shock can be suppressed.

  Returning to FIG. 4 again, when the rotation synchronization between the clutch plate 710 and the clutch plate 720 is completed (step S103: YES), the ECU 100 starts the engagement control (step S104). Engagement control means control for causing the clutch plate 720 to stroke a predetermined amount in the direction of the clutch plate 710, and is realized by the ECU 100 driving and controlling the electromagnetic actuator. The execution period of the engagement control corresponds to the “engagement stage” according to the present invention.

When the engagement control is started, the ECU 100 determines whether or not the engagement between the clutch plate 710 and the clutch plate 720 has been completed (step S105). When the engagement is in progress (step S105: NO), step S104 is continued, the stroke of the clutch plate 720 is continued, and when the engagement of both is completed (step S105: YES), the MG1 lock control is performed. finish.
<2. Second Embodiment>
In the first embodiment, the rotation synchronization determination threshold value is set in advance in consideration of the uncertainty γ of the rotation speed Nmg1 of the motor generator MG1. However, when the influence of the disturbance element is large, for example, when the driver suddenly accelerates or decelerates or the road surface condition changes suddenly, the value of the uncertainty γ of the rotational speed Nmg1 of the motor generator MG1 becomes large, and the variation range When the clutch plate 710 and the clutch plate 720 are engaged with each other, at least one of the upper limit rotation speed Nmg1s + γ and the lower limit rotation speed Nmg1s−γ is the maximum rotation at which no engagement shock occurs or no problem occurs. It is conceivable that the allowable value α defined as the speed difference is exceeded. In this case, there is a possibility that the rotational speed Nmg1 of motor generator MG1 exceeds the allowable value α, and the risk of causing an engagement shock increases.

  Therefore, in the second embodiment, when a disturbance element larger than a predetermined value is input, an upper limit value of the engine command power Pne that is a signal when the ECU 100 commands the output value of the engine 200 is set in advance. Thus, the uncertainty γ of the rotational speed Nmg1 of the motor generator MG1 can be suppressed to an appropriate value.

  FIG. 8 is a schematic time characteristic diagram illustrating a one-hour transition of the operating state of engine 200 in the execution process of the lock control of motor generator MG1. FIG. 8 illustrates time characteristics of the rotation speed Nmg1, the engine torque Te, and the engine command power Pne of the motor generator MG1 in order from the top (that is, the horizontal axis is common in time).

  At a time T1 shown in the figure, a rotation synchronization stage is started in response to a lock request of the motor generator MG1, and the rotation speed Nmg1 of the motor generator MG1 starts to increase so that the clutch plate 710 and the clutch plate 720 are in a rotation synchronization state. At time T2, the driver starts operating to increase the throttle opening degree Thr in proportion to the time. At this time, the ECU 100 starts to increase the engine command power Pne so as to increase the engine output (that is, the engine torque Te) to the engine 200 at the same time. Here, as described above, in order to suppress uncertainty γ of rotation speed Nmg1 of motor generator MG1 to an appropriate value, the value of engine command power Pne is temporarily limited to Pne1 at time T3. In response to the change in the engine command power Pne, the engine torque Te is delayed from the engine command power Pne by a predetermined time and starts increasing from time T4. At time T4, the engine command power Pne that is limited to Pne1 starts to increase again. At time T5, the change in the rotational speed Nmg1 of the motor generator MG1 is completed, and the clutch plate 710 and the clutch plate 720 are in a rotationally synchronized state. In this embodiment, it is assumed that the rotation synchronization stage from time T1 to T5 requires 300 ms. At time T5, the engine torque Te is maintained constant so as to correspond to the engine command power Pne that was constant during the period from time T3 to T4 (30 ms), and the clutch plate 710 and the clutch plate 720 Is engaged. At the time of engagement (ie, the period from T5 to T6), although the uncertainty γ accompanies the rotational speed Nmg1 of the motor generator MG1, it does not exceed the allowable value α as in the first embodiment. There is no engagement shock.

  The period from time T3 to T4 in which the engine command power Pne is limited to a constant value Pne1 is 30 ms, similar to the period from time T5 to T6, which is a period required for the clutch plate 710 and the clutch plate 720 to be engaged. It is. Further, there is a time difference of Ams between the time T3 when the restriction of the engine command power Pne is started and the time T5 when the engine torque Te is actually maintained constant. That is, in this aspect, the engine torque Te is accompanied by a time delay of Ams with respect to the engine command power Pne.

  It should be noted that the engine torque Te is maintained constant during engagement (that is, the period from T5 to T6) because the engine command is issued in the period from time T3 to T4 despite the increase in the throttle opening. This is because the power Pne is limited to a constant value Pne1. Therefore, if the vehicle travels using only the engine torque Te generated with a delay in accordance with the suppressed engine command power Pne, the acceleration / deceleration is insufficient with respect to the driver's request (that is, the degree of throttle opening). It also causes a sense of discomfort. Therefore, in the present embodiment, the motor generator MG2 is powered using the electric power stored in the battery 12, so that the limited engine torque Te can be compensated and the driver's uncomfortable feeling can be reduced.

  As described above, since the engine torque Te is maintained at the constant value Te1 in the engagement stage, the engine command power Pne is limited for a predetermined period. This predetermined period is provided at an appropriate timing in the rotation synchronization stage by the engine command power limit timing control by the ECU 100. FIG. 9 is a flowchart of engine command power limit timing control.

  First, the ECU 100 calculates a time delay A (ms) of the engine torque Te with respect to the engine command power Pne (step S201). The time delay (Ams) is variable depending on the driving state of the engine 200, and the ECU 100 specifies the delay time A (ms) by referring to a map stored in advance in the ROM. This map is, for example, a two-dimensional map in which the engine torque Te and the delay time A (ms) are represented on the vertical axis and the horizontal axis, respectively.

Subsequently, in step S202, it is determined whether or not the rotation synchronization control is started. When the rotation synchronization control has not been started (step S202: NO), the ECU executes step S202 again to form a loop. On the other hand, when the rotation synchronization control is started (step S202: YES), the ECU 100 starts counting (step S203), and the count is expressed by the following equation (300ms−A) <count <(300ms−A + 30ms) (6). )
It is determined whether or not the above is satisfied. As shown in FIG. 8, the lower limit value (300 ms-A) and the upper limit value (300 ms-A + 30 ms) of the above equation (6) are the start of a period during which the engine command power Pne is limited and maintained constant. It corresponds to time T3 which is time and time T4 which is end time.

  When the above equation (6) is satisfied (step 204: YES), the ECU 100 limits the engine command power Pne to a constant value Pne1 so that the change of the engine torque Te in the engagement stage stops (step S205). On the other hand, when the above equation (6) is not satisfied (step 204: NO), the count is continued until the above equation (6) is satisfied.

  In this way, the time T3, which is the timing at which the engine command power Pne is limited to the constant value Pne1, based on the time delay amount that can be grasped in advance so that the change in the engine torque Te temporarily stops at the time T5. It has been decided. Similarly, time T5, which is the timing at which the restriction on engine command power Pne is released, is determined based on a time delay amount that can be grasped in advance so that engine torque Te increases again at time T6. Further, the period required for the engagement stage in this embodiment is 30 ms, but the length of this period (that is, the time required for engaging the clutch plates) is to make the clutch plate 720 stroke a predetermined amount. This is the time required and can be determined in advance through experiments or the like.

As described above, according to the lock control of the motor generator MG1 according to the present embodiment, the rotation of the motor generator MG1 can be performed by appropriately limiting the engine command power Pne even when a large disturbance element is input. The uncertainty γ of several Nmg1 can be suppressed to an appropriate value, and the occurrence of engagement shock can be suppressed more reliably.
<3. Third Embodiment>
In the first and second embodiments, when the hybrid drive apparatus 10 adopts the fixed speed change mode, the MG1 is locked (more precisely, the MG1 is locked via the sun gear S1 and the clutch plate 710). take. However, the configuration of the hybrid drive device for obtaining the fixed speed change mode is not limited to this type of MG1 lock. Here, the configuration of another hybrid drive apparatus will be described with reference to FIG. FIG. 10 is a schematic configuration diagram conceptually showing the configuration of the hybrid drive apparatus 20 according to the third embodiment of the present invention. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof is omitted as appropriate.

  In FIG. 10, the hybrid drive device 20 is different from the hybrid drive device 10 in that it includes a power split mechanism 800 as another example of the “power transmission mechanism” according to the present invention instead of the power split mechanism 300. It has become. The power split mechanism 800 includes a so-called Ravigneaux type planetary gear having a single pinion gear type first planetary gear mechanism 810 and a double pinion type second planetary gear mechanism 820 as a differential mechanism constituted by a plurality of rotating elements. Take the form of a mechanism.

  The first planetary gear mechanism 810 includes a sun gear 811, a carrier 812, a ring gear 813, and a pinion that meshes with the sun gear 811 and the ring gear 813 that are held in the carrier 812 so as to rotate in the axial direction and revolve due to the rotation of the carrier 812. A gear 814 is provided, the rotor of the motor generator MG 1 is connected to the sun gear 811, the input shaft 400 is connected to the carrier 812, and the drive shaft 500 is connected to the ring gear 813.

  The second planetary gear mechanism 820 includes a sun gear 821, a carrier 822, a ring gear 823, and a pinion gear 825 that meshes with the sun gear 821 and is held by the carrier 822 so as to rotate in the axial direction and revolve by the rotation of the carrier 822. A pinion gear 824 that meshes with the ring gear 823 is provided, and a cam 710 (not shown) of the brake mechanism 700 is connected to the sun gear 821. That is, in this embodiment, the sun gear 821 functions as another example of the “first rotating element” according to the present invention.

  As described above, the power split mechanism 800 generally includes the sun gear 811 of the first planetary gear mechanism 810, the sun gear 821 (first rotating element) of the second planetary gear mechanism 820, and the first planetary gear mechanism 810 connected to each other. The third rotating element group including the carrier 812 and the ring gear 823 of the second planetary gear mechanism 820, and the ring gear 813 of the first planetary gear mechanism 810 and the carrier 822 of the second planetary gear mechanism 820 connected to each other. A total of four rotating elements (rotating element groups) of two rotating element groups are provided.

  According to the hybrid drive device 20, when the sun gear 821 is locked and its rotational speed becomes zero, the second rotational element group having a rotational speed that is unambiguous with the vehicle speed V and the sun gear 821 make one remaining rotation. The rotation speed of the third rotating element group as the element is defined. Since the carrier 812 constituting the third rotating element group is connected to the input shaft 400 connected to the crankshaft 205 of the engine 200 (not shown), the engine rotational speed Ne of the engine 200 is ultimately the same as the vehicle speed V. Thus, the fixed speed change mode is realized. As described above, the fixed speed change mode can also be realized in configurations other than the hybrid drive device 10, and the first rotating element to which the clutch plate 710 of the brake mechanism 700 is fixed may be appropriately changed accordingly. Of the rotating elements constituting the power split mechanism 800, the rotating elements other than those connected to each other have a differential action. Therefore, the rotational speed of the sun gear 821 as the first rotating element is the first speed. It can be controlled by the motor generator MG1 as in the embodiment.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of a hybrid vehicle involving such a change. The apparatus is also included in the technical scope of the present invention.

  The present invention can be used for a hybrid vehicle including a rotation-synchronized engagement device.

  DESCRIPTION OF SYMBOLS 1 ... Hybrid vehicle, 10 ... Hybrid drive device, 20 ... Hybrid drive device (2nd Embodiment), 100 ... ECU, 200 ... Engine, 205 ... Crankshaft, 300 ... Power split mechanism, 310 ... Sun gear shaft, S1 ... Sun gear , C1 ... carrier, R1 ... ring gear, MG1 ... motor generator, MG2 ... motor generator, 400 ... input shaft, 500 ... drive shaft, 600 ... deceleration mechanism, 700 ... lock mechanism, 710 ... first engagement element, 720 ... Second engagement element, 800 ... power split mechanism (second embodiment)

Claims (5)

Power elements including an internal combustion engine and a rotating electrical machine;
A plurality of mutually rotatable differentials including a first rotating element whose rotation speed can be adjusted by the rotating electrical machine, a second rotating element connected to a drive shaft connected to an axle, and a third rotating element connected to the internal combustion engine. A power transmission mechanism that transmits power between the power element and the drive shaft in accordance with a power transmission mode determined according to the state of the plurality of rotation elements,
A first engagement element fixed to the first rotation element; and a second engagement element attached so as to face the first engagement element; and the rotational speed of the internal combustion engine as the power transmission mode And a locked state in which the first engagement element and the second engagement element are engaged with each other, corresponding to a fixed transmission mode in which a transmission gear ratio that is a ratio between the rotation speed of the drive shaft and the drive shaft is fixed. Corresponding to the continuously variable transmission mode in which the transmission gear ratio is continuously variable as the transmission mode, the state can be switched between an unlocked state in which the first engagement element and the second engagement element are not engaged. A rotation synchronization stage in which a locking process as a process of switching the state from the unlocked state to the locked state maintains the first engagement element and the second engagement element in a rotation synchronization state. And in the rotation synchronization state, A control apparatus for a hybrid vehicle that includes a locking means including an engaging step of engaging the the engaging element and the second engagement element,
Estimating means for estimating the torque of the rotating electrical machine with a first-order delay ;
Calculation means for calculating an uncertainty γ of the rotational speed of the rotating electrical machine in the engagement stage based on the estimated torque and the moment of inertia of the rotating electrical machine;
A threshold value β for determining whether or not the rotating electrical machine is in a rotation-synchronized state , a relative rotational speed at which the calculated uncertainty γ can be engaged with the first and second engaging elements. setting means for setting, based on the allowable value,
A discriminating means for discriminating that the first and second engaging elements are in the rotation synchronization state when the rotational speed of the rotating electrical machine is within the set threshold value β;
When the first and second engagement element is determined to be the rotation synchronization state, said first and said second engaging element so that the state Waru switch to the locked state from the unlocked state Control means for controlling, and
The setting means sets the threshold β to be smaller as the uncertainty γ is larger.
A control apparatus for a hybrid vehicle characterized by the above. The setting means sets the threshold β to the following equation: β = α−γ
However, α is the allowable value, calculated from the maximum value of the relative rotational speed with which the first and second engaging elements can be engaged, or from a map prepared in advance based on the equation The threshold value β is set by reading the threshold value β corresponding to the rotational speed of the rotating electrical machine.
The control apparatus for a hybrid vehicle according to claim 1. The calculation unit, the uncertainty gamma, length Δt of the predetermined period in the locking process, the inertia of the amount of change delta T及 beauty the rotating electrical machine of the estimated torque by the disturbance torque input to the Δt From moment J: γ = ΔT × Δt / J
Calculate by
The control device for a hybrid vehicle according to claim 1 or 2, The estimation means includes a disturbance observer that monitors disturbance elements input to the hybrid vehicle.
The hybrid vehicle control device according to any one of claims 1 to 3, wherein the control device is a hybrid vehicle control device. In a predetermined period prior to the engaging stage, there is further provided a stabilizing means for maintaining an internal combustion engine output instruction signal, which is a signal for controlling the torque value of the internal combustion engine, within a constant value or a predetermined range.
The hybrid vehicle control device according to claim 1, wherein the control device is a hybrid vehicle control device.

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