JP3887967B2 - Hybrid vehicle and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance riding comfort by suppressing vibration due to the control of a motor MG2 in a parallel hybrid vehicle. SOLUTION: An engine, a motor MG1, a motor MG2, and an axle are combined through a planetary gear. The power outputted from the engine and the motor MG1 is compensated in the motor MG2 to output required power from the axle. In this control, the torque necessary for the compensation is first set as tentative target torque of the motor MG2. This tentative target torque is subjected to anneal processing to determine the target torque. The degree of anneal processing is changed with the running condition of the vehicle. If the engine is started during stopping, the motor MG2 is controlled with high response to compensate a torque fluctuation to the axle adequately. During ordinary running, the motor MG2 is controlled with slightly lower response to change the output torque smoothly in response to accelerator operation by a driver.

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid vehicle having an internal combustion engine and a motor generator and capable of traveling using at least power output from the internal combustion engine as a power source and a control method thereof.
[0002]
[Prior art]
In recent years, hybrid vehicles including an internal combustion engine and a motor generator have been proposed. Various configurations have been proposed as such hybrid vehicles, and one of them is a parallel hybrid vehicle. In the parallel hybrid vehicle, both the power of the internal combustion engine and the power of the electric motor can be transmitted to the axle. A configuration example of a parallel hybrid vehicle is shown in FIG.
[0003]
The hybrid vehicle in FIG. 1 includes an engine 150 and motor generators MG1 and MG2. The three are mechanically coupled via the planetary gear 120. Planetary gear 120 is also called a planetary gear and has three rotating shafts coupled to the gears shown below. The gears constituting the planetary gear 120 are a sun gear 121 that rotates at the center, a planetary pinion gear 123 that revolves while rotating around the sun gear, and a ring gear 122 that rotates at the outer periphery thereof. The planetary pinion gear 123 is pivotally supported by the planetary carrier 124. In the hybrid vehicle of FIG. 1, the engine 150 is coupled to the planetary carrier 124. Motor generator MG <b> 1 is coupled to sun gear 121. Motor generator MG <b> 2 is coupled to ring gear 122. The ring gear 122 is coupled to the axle 112 by a chain belt 129.
[0004]
In the hybrid vehicle having such a configuration, the power output from the internal combustion engine is distributed into two by the planetary gear 120. A part of it is transmitted to the axle 112 as mechanical power. The remaining part is regenerated as electric power by the motor generator MG1. The distribution ratio between the two is determined based on the gear ratio of the planetary gear 120. In the hybrid vehicle, the power is distributed at a rate such that the rotational speed of the axle 112 matches the required rotational speed. As a result of such distribution, if the torque transmitted to the axle 112 is less than the required value, the insufficient torque is output from the motor generator MG2. Electric power regenerated by the motor generator MG1 is used to drive the motor generator MG2.
[0005]
As a result, the hybrid vehicle can travel by converting the power output from the internal combustion engine into power having the torque and the rotational speed required for the axle 112. Further, the hybrid vehicle can also travel with the internal combustion engine stopped using the power of the motor generator MG2. Further, whether the vehicle is stopped or traveling, the motor generator MG1 can be driven to motor the internal combustion engine and start. In the hybrid vehicle, in order to travel by outputting power in such various states, the traveling state of the internal combustion engine and the motor generators MG1, MG2 is controlled according to the required power.
[0006]
[Problems to be solved by the invention]
In the parallel hybrid vehicle, the motor generator MG2 compensates for excess and deficiency between the power output from the internal combustion engine and the motor generator MG1 to the axle 112 and the required power. Therefore, in order to appropriately output the required power from the axle 112, it is particularly necessary to appropriately control the motor generator MG2. The power output from the internal combustion engine and the motor generator MG1 to the axle 112 changes according to the operating state of both. The required power changes depending on the driver's operation. In order to appropriately output the required power from the axle 112, it is necessary to control the motor generator MG2 with responsiveness corresponding to these changes.
[0007]
In the conventionally proposed hybrid vehicle, the above-described responsiveness has not been sufficiently considered in the control of the motor generator MG2. Therefore, depending on a certain traveling state, the responsiveness becomes hypersensitive, and the traveling state of the internal combustion engine and the motor generators MG1 and MG2 may fluctuate abruptly according to the change in required power, and vibration may occur. In this case, there is a case where vibration is caused due to the sensitive change in the output power in response to a slight change in the driver's operation. Further, in another traveling state, the responsiveness is too low, and the motor generator MG2 may not sufficiently compensate for the above-described excess / deficiency and may generate vibration. These phenomena all lowered the ride comfort of the hybrid vehicle. Such a phenomenon occurs in common in so-called parallel hybrid vehicles regardless of the hybrid vehicle configured as described above.
[0008]
The present invention has been made to solve such a problem, and provides a technique for suppressing vibrations caused by control responsiveness of a motor generator in various traveling states in a so-called parallel hybrid vehicle. Objective.
[0009]
[Means for solving the problems and their functions and effects]
In order to solve at least a part of the above problems, the present invention adopts the following configuration.
The power output apparatus of the present invention is
The internal combustion engine and the power that is coupled to both the output shaft and the axle of the internal combustion engine and that is input / output on both shafts. Using the first motor generator Power adjustment device that can be adjusted by power exchange And a second motor generator mechanically coupled to the axle A hybrid vehicle capable of converting at least the power output from the internal combustion engine and outputting the power from the axle, and capable of traveling.
Said Second Target torque setting means for setting the target torque of the motor generator;
A specifying means for specifying a running state of the hybrid vehicle;
Target torque correcting means for correcting the target torque to achieve a predetermined response according to the running state;
Said Second The gist is to include a motor generator control means for controlling the operation of the motor generator and outputting the set target torque.
[0010]
In the hybrid vehicle of the present invention, the Second The torque output to the axle can be controlled by controlling the motor generator. Second The operation of the motor generator is controlled after correcting the target torque based on the responsiveness predetermined according to the traveling state of the hybrid vehicle. What is responsiveness? Second The rate of change at which the actual torque changes in response to fluctuations in the target torque of the motor generator. In general, the period and width at which the required power changes according to the driver's instructions differ depending on the traveling state of the vehicle. For example, when the vehicle is traveling, the accelerator depression amount slightly fluctuates with a fine cycle. High responsiveness while driving Second If the motor generator is controlled, the torque output to the axle fluctuates according to the above-described subtle fluctuations. In order to enable smooth operation, the response should be slower than the above fluctuation. Second It is desirable to control the motor generator.
[0011]
On the other hand, the degree of vibration that the occupant can tolerate also varies depending on the traveling state of the vehicle. For example, when the vehicle is stopped, even a slight vibration is more sensitive than when it is running. In such a case, Second It is desirable to control the motor generator to quickly cancel out fluctuations in torque output to the axle. In the above hybrid vehicle, the responsiveness according to the running state of the vehicle Second The motor generator can be controlled. Therefore, for each driving state, while realizing the smooth acceleration / deceleration feeling expected by the driver, the vibration should be suppressed within the allowable range for the occupant. Second The motor generator can be operated. As a result, according to the hybrid vehicle of the present invention, the operability and ride comfort of the vehicle can be greatly improved.
[0012]
The responsiveness can be set corresponding to various traveling conditions. For example, the responsiveness may be set by distinguishing the state related to the traveling direction of the vehicle, that is, when the vehicle is moving forward, when the vehicle is stopped, and when the vehicle is moving backward. Further, the responsiveness may be set by distinguishing whether or not the wheel is in a slipped state. Furthermore, the responsiveness may be set by distinguishing whether the vehicle is traveling constantly or accelerating or decelerating. Responsiveness can be defined according to various other driving conditions.
[0013]
In the said invention, after inputting target torque once, the target torque is correct | amended based on responsiveness. On the other hand, the target torque setting means for setting the target torque and the target torque correction means for correcting the target torque may be integrally configured. That is, in the process of setting the target torque, the correction based on the responsiveness may be performed.
[0014]
The target torque setting means and the target torque correction means can be configured in various ways, for example,
The target torque setting means is a means for setting, as a target torque, a value that compensates for a torque that is excessive or deficient in the torque output to the axle by the internal combustion engine and the power adjustment device with respect to the required torque to be output from the axle. And
The target torque correcting means may be means for setting the target torque by performing an annealing process determined for each traveling state.
[0015]
The torque set by the target torque setting means in this mode is Second If output from the motor generator, the torque output from the internal combustion engine and the power adjustment device to the axle can be compensated and the required torque can be output from the axle. On the other hand, according to the target torque correcting means of the above aspect, the responsiveness determined for each traveling state is used. Second The target torque is corrected by the annealing process so that the torque of the motor generator varies. Various methods can be applied as the annealing process. For example, before Second It is possible to adopt a method in which an average value obtained by multiplying the torque output from the motor generator and the torque set by the target torque setting means by a predetermined weighting coefficient is used as the corrected target torque. In this case, by changing the weighting factor according to the running state, Second The torque response of the motor generator can be changed. Even when other methods are applied, the responsiveness can be changed according to the running state by changing a predetermined coefficient used for the annealing process. In the hybrid vehicle having the above-described aspect, it is relatively easy to apply the smoothing process as the target torque correction unit according to the traveling state. Second The torque response of the motor generator can be changed.
[0016]
In the hybrid vehicle of the present invention, the running state of the vehicle, Second The relationship with the responsiveness of the torque of the motor generator can be set in various relationships.
For example, as the second relationship:
When the specifying means is means for specifying whether the hybrid vehicle is stopped or not as a running state of the hybrid vehicle,
The responsiveness in the target torque correcting means may be set higher when the hybrid vehicle is stopped than when the hybrid vehicle is traveling.
[0017]
It is necessary to keep the torque output to the axle constant while the vehicle is stopped. If the vehicle is stopped on a flat place, the torque is kept constant at a value of 0. On an uphill or the like, the torque is kept constant at a positive value corresponding to the gradient. In either case, the vehicle vibrates if the torque output to the axle fluctuates. In general, when the vehicle is stopped, the occupant is very sensitive to vehicle vibration. In the relationship described above Second If you set the responsiveness of the motor generator, it will be more responsive when stopped than when it is running. Second The motor generator can be controlled. In other words, even if the operating conditions of the internal combustion engine and the power adjustment device change and the torque output from both to the axle fluctuates, Second The motor generator can compensate quickly. Therefore, the torque output to the axle can be maintained at a substantially constant value, and vibrations caused by changes in the operating state of the internal combustion engine and the power adjustment device can be suppressed while the vehicle is stopped.
[0018]
While the vehicle is stopped, the driver rarely gives an instruction to increase or decrease the required torque by depressing the accelerator. Therefore, in the above relationship Second Even if the responsiveness of the motor generator is increased, there is almost no possibility that the torque output from the axle will fluctuate finely according to the driver's operation and cause vibration. Therefore, in the second relationship Second If the responsiveness of the motor generator is set, the riding comfort of the stopped hybrid vehicle can be greatly improved.
[0019]
The degree to which the responsiveness during stopping is set higher than that during traveling differs depending on the specific configuration of the hybrid vehicle. For example, it varies depending on the change rate of torque output from the internal combustion engine or the power adjustment device. Accordingly, the response within the allowable range of vibration may be set by experiment or the like according to the configuration of the hybrid vehicle. Without increasing the target torque set by the target torque setting means in order to increase responsiveness Second It is good also as what is used for control of a motor generator.
[0020]
Note that whether or not the vehicle is stopped can be determined by determining whether or not the shift position is at a position such as a parking range that is used only when the vehicle is stopped.
Further, the specifying means may specify whether or not the vehicle is stopped based on the vehicle speed.
[0021]
Even when the shift position is at a position used during traveling, the hybrid vehicle may be stopped, for example, when the brake is stepped on. According to the specifying means, it is possible to specify that the vehicle is stopped even in such a case, so that it is possible to improve the riding comfort during stopping more reliably. Further, according to the above-described specifying means, the vehicle can be treated as being stopped including the case where the vehicle is not completely stopped and is traveling at a very low speed. When traveling at very low speed, the occupant is sensitive to vehicle vibrations. According to the above specifying means, it is possible to suppress vibration when traveling at a very low speed by treating the vehicle as being stopped including such a case.
[0022]
As a second relationship,
In the hybrid vehicle comprising means for inputting an instruction to start the internal combustion engine,
The target torque setting means is means for setting, as a target torque, a torque that can cancel the torque output to the axle when the internal combustion engine is motored by the power adjustment device when the instruction is input. Yes,
When the specifying means is a means for specifying whether or not the driving state of the hybrid vehicle is stopped and the motoring is being performed,
The responsiveness in the target torque correcting means may be set higher when the hybrid vehicle is stopped and when the motoring is being performed than when the hybrid vehicle is running.
[0023]
The hybrid vehicle may start the internal combustion engine by motoring the internal combustion engine with the power adjustment device. At this time, a counter-torque of the torque output from the power adjustment device for motoring the internal combustion engine is output to the axle. In order to output appropriate power to the axle, Second It is necessary to cancel this anti-torque with a motor generator. In particular, during a stop where the passenger is likely to feel the vibration of the vehicle, as described above, it is highly necessary to keep the torque output to the axle constant. In the relationship described above Second If you set the responsiveness of the motor generator, when it is stopped and motoring, it will have a higher responsiveness than during driving. Second The motor generator can be controlled. That is, the counter-torque by the power adjustment device can be quickly compensated. Therefore, fluctuations in torque output to the axle can be suppressed, and riding comfort when the vehicle is stopped and motoring can be improved.
[0024]
The hybrid vehicle may start the internal combustion engine by motoring the internal combustion engine with the power adjustment device even during traveling. Even in such a case, anti-torque is applied during motoring. Second It is necessary to cancel with a motor generator. While traveling, it is usually not as sensitive to vibration as when the vehicle is stopped, but it is of course desirable to suppress the vibration. Therefore, when motoring is performed during traveling, the response is higher than the response during traveling without motoring. Second The target torque may be set so that the motor generator is controlled.
[0025]
As a third relationship,
When the specifying means is means for specifying whether or not the wheel coupled to the axle is in a slipped state,
The responsiveness in the target torque correcting means may be set higher when the traveling state of the hybrid vehicle is in the slipped state than when it is not.
[0026]
Since the state in which the wheel slips is generally not a preferable traveling state, it is necessary to promptly recover. Wheel slip occurs when the torque output from the axle is too large relative to the frictional force of the road surface. Therefore, in order to recover from slip, it is necessary to suppress the torque output from the axle to a value that does not cause slip. In the third relationship Second If the responsiveness of the motor generator is set, the torque output to the axle when a slip occurs can be quickly suppressed. Therefore, recovery from the slip state can be achieved in a short period of time.
[0027]
When slipping, the axle speed increases rapidly. If the rotational speed increases rapidly in this way, unnecessary wear or the like may occur in gears and other elements in the system that transmits power to the axles, and the service life may be significantly shortened. In the above relationship Second If the responsiveness of the motor generator is set, it is possible to quickly recover from the slip, so that it is possible to avoid a state that shortens the life of the vehicle. Note that the above relationship can be applied regardless of whether the vehicle is moving forward, reverse, or stopped.
[0028]
As a fourth relationship,
When the specifying means is means for specifying whether the hybrid vehicle is traveling forward or backward,
The responsiveness in the target torque correcting means may be set lower when the hybrid vehicle is traveling backward than when traveling forward.
[0029]
In general, the rotational direction of the internal combustion engine is constant regardless of whether the vehicle is moving forward or backward. When moving backward, the hybrid vehicle replaces the rotational power of the internal combustion engine with electric power by a power adjustment device, Second Outputs rotational power in the reverse direction from the motor generator. The internal combustion engine outputs power in the forward direction, Second Power from the reverse direction is output from the motor generator. Internal combustion engine, power regulator, and Second When the balance of power exchanged by the motor generator is lost, torque fluctuation occurs in the front and rear direction of the axle, causing severe vibration. During reverse travel, the power output from the internal combustion engine Second Since the direction of the power output from the motor generator is reversed, the power balance is likely to be lost compared to when the vehicle is moving forward. In the fourth relationship Second If you set the response of the motor generator, Second The operating state of the motor generator changes relatively slowly. Therefore, an internal combustion engine, a power adjustment device, Second It is easy to maintain the balance of power exchanged by the motor generator. As a result, according to the hybrid vehicle to which the above relationship is applied, it is possible to suppress the vibration of the vehicle during reverse travel and greatly improve operability and ride comfort.
[0030]
Various configurations can be applied to the power adjustment device in the hybrid vehicle of the present invention, for example,
in front The power adjusting device has three rotating shafts, and two rotating shafts of the rotating shafts are connected to the output shaft and the axle. With , To the remaining rotating shaft of the planetary gear The first motor generator Combined The It can be a device.
[0031]
According to the power adjustment device having such a configuration, the power output from the internal combustion engine includes the power transmitted to the axle by the planetary gear, First It can be distributed to the power transmitted to the motor generator. Also, the power output from the internal combustion engine and First The power output from the motor generator can be combined with the planetary gear and transmitted to the axle. Therefore, First By exchanging electric power to the motor generator, the power adjustment device configured as described above can adjust the power input / output on both the output shaft and the axle of the internal combustion engine.
[0032]
Further, the power adjusting device includes a first rotor coupled to the output shaft and a counter-rotor electric motor including a second rotor coupled to the axle. As the first motor generator It can also be.
[0033]
According to the power adjustment device having such a configuration, the power output from the internal combustion engine can be transmitted to the axle through electromagnetic coupling acting between the first rotor and the second rotor. At this time, the slip between the first rotor and the second rotor can be adjusted by exchanging electric power to the counter-rotor motor. That is, the power of both shafts can be adjusted by adjusting the rotation speeds of the output shaft and the axle of the internal combustion engine. As a result, the counter-rotor motor can adjust the power input / output on both the output shaft and the axle of the internal combustion engine. The first motor generator in Function as.
[0034]
Usually, a hybrid vehicle has a plurality of axles. A hybrid vehicle of the present invention includes a power adjustment device and Second It is possible to adopt a configuration in which the motor generator is coupled to the axle on the same side.
An axle to which the power adjustment device is coupled; and Second It is also possible to adopt a configuration that can drive four wheels by outputting power from wheels coupled to the respective axles, which are different from the axles coupled to the motor generator.
Naturally, the power adjustment device and Second The motor generator may be configured to be coupled to one axle, and the motor generator may be further coupled to another axle so that four-wheel drive is possible.
[0035]
The present invention can also employ the following configurations.
In other words, the power that is coupled to both the internal combustion engine and both the output shaft and the axle of the internal combustion engine and that is input / output on both shafts. Using the first motor generator Power adjustment device that can be adjusted by power exchange And a second motor generator mechanically coupled to the axle A hybrid vehicle capable of converting at least the power output from the internal combustion engine and outputting the power from the axle, and capable of traveling.
Said Second Target torque setting means for setting the target torque of the motor generator;
Torque correcting means for correcting the target torque by an annealing process;
A specifying means for specifying a running state of the hybrid vehicle;
When the hybrid vehicle is in a predetermined traveling state determined in advance, prohibiting means for prohibiting correction of the target torque by the torque correcting means;
Said Second This is a configuration as a hybrid vehicle including motor generator control means for controlling the operation of the motor generator and outputting the set target torque.
[0036]
In general, during driving of a hybrid vehicle, a traveling state is often required in which torque output to the axle is required to fluctuate smoothly. According to the hybrid vehicle of the above aspect, Second By smoothing and correcting the target torque of the motor generator, the output torque can be changed smoothly. However, as explained above, depending on the driving condition of the hybrid vehicle, an annealing process is performed. Second If you set the target torque of the motor generator, Second The response of the motor generator is low and the vehicle may vibrate. According to the hybrid vehicle of the above aspect, the annealing process can be prohibited by the prohibiting means when the vehicle is in a predetermined traveling state. Therefore, the hybrid vehicle can output an appropriate torque according to the traveling state of the vehicle.
[0037]
Examples of the running state where the annealing process should be prohibited include a case where the vehicle is stopped and a case where the vehicle is in a slip state. Further, the smoothing process may be prohibited only when the internal combustion engine is started while the vehicle is stopped. The torque correcting means may change the degree of the annealing process according to the running state of the vehicle. For example, it is possible to perform an annealing process so that the responsiveness is lower during backward traveling than during forward traveling.
[0038]
The present invention can also be configured as a hybrid vehicle control method described below.
That is, the power that is coupled to both the internal combustion engine and both the output shaft and the axle of the internal combustion engine and that is input / output on both shafts. Using the first motor generator Power adjustment device that can be adjusted by power exchange And a second motor generator mechanically coupled to the axle And a hybrid vehicle control method capable of traveling by outputting the power output from the internal combustion engine from the axle,
(A) said Second Setting the target torque of the motor generator;
(B) identifying the running state of the hybrid vehicle;
(C) correcting the target torque so as to achieve a predetermined response according to the running state;
(D) said Second And a step of controlling the operation of the motor generator and outputting the set target torque.
[0039]
By controlling the operation of the hybrid vehicle by such a control method, it is possible to realize control excellent in operability and riding comfort of the vehicle by the same operation as that described above as the invention of the hybrid vehicle.
[0040]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described based on examples.
(1) Configuration of the embodiment:
First, the configuration of a hybrid vehicle as an embodiment of the present invention will be described. FIG. 1 is an explanatory diagram showing the configuration of a power system that outputs the power of the hybrid vehicle. The engine 150 provided in the power system is a normal gasoline engine, and rotates the crankshaft 156. The operation of engine 150 is controlled by EFIECU 170. The EFIECU 170 is a one-chip microcomputer having a CPU, a ROM, a RAM, and the like inside. The CPU executes a fuel injection amount and other controls of the engine 150 in accordance with a program recorded in the ROM.
[0041]
The power system is further provided with motors MG1 and MG2. Motors MG1 and MG2 are configured as synchronous motor generators, and stators 133 and 143 around which rotors 132 and 142 having a plurality of permanent magnets on the outer peripheral surface and three-phase coils 131 and 141 forming a rotating magnetic field are wound. With. The stators 133 and 143 are fixed to the case 119. Three-phase coils 131 and 141 wound around stators 133 and 143 of motors MG1 and MG2 are connected to battery 194 via drive circuits 191 and 192, respectively. The drive circuits 191 and 192 are transistor inverters each including two transistors as a switching element for each phase. The drive circuits 191 and 192 are connected to the control unit 190. When the transistors of drive circuits 191 and 192 are switched by a control signal from control unit 190, a current flows between battery 194 and motors MG1 and MG2. The motors MG1 and MG2 can operate as electric motors that are rotated by receiving power supplied from the battery 194 (hereinafter, this running state is referred to as power running), and the rotors 132 and 142 are rotated by external force. Can function as a generator that generates electromotive force at both ends of the three-phase coils 131 and 141 to charge the battery 194 (hereinafter, this running state is referred to as regeneration).
[0042]
Engine 150 and motors MG1 and MG2 are mechanically coupled via planetary gear 120, respectively. The planetary gear 120 includes a planetary carrier 124 having a sun gear 121, a ring gear 122, and a planetary pinion gear 123. In the hybrid vehicle of this embodiment, the crankshaft 156 of the engine 150 is coupled to the planetary carrier shaft 127 via the damper 130. The damper 130 is provided to absorb torsional vibration generated in the crankshaft 156. Rotor 132 of motor MG1 is coupled to sun gear shaft 125. The rotor 142 of the motor MG2 is coupled to the ring gear shaft 126. The rotation of the ring gear 122 is transmitted to the axle 112 and the wheels 116R and 116L via the chain belt 129.
[0043]
The entire operation of the hybrid vehicle of the embodiment is controlled by the control unit 190. The control unit 190 is a one-chip microcomputer having a CPU, a ROM, a RAM, and the like in the same manner as the EFIECU 170. The control unit 190 is connected to the EFIECU 170, and both can transmit various information. The control unit 190 can indirectly control the operation of the engine 150 by transmitting information such as a torque command value and a rotation speed command value necessary for controlling the engine 150 to the EFIECU 170. Further, by controlling the switching of the drive circuits 191 and 192, the operation of the motors MG1 and MG2 can be directly controlled. The control unit 190 thus controls the operation of the entire power output apparatus. In order to realize such control, the control unit 190 includes various sensors, for example, an accelerator pedal position sensor 165 for detecting the amount of depression of the accelerator by the driver, a shift position sensor 167 for detecting the position of the shift lever, and A sensor 144 or the like for knowing the rotation speed of the axle 112 is provided. Since the ring gear shaft 126 and the axle 112 are mechanically coupled, in this embodiment, a sensor 144 for knowing the rotational speed of the axle 112 is provided on the ring gear shaft 126, and a sensor for controlling the rotation of the motor MG2 It is common.
[0044]
(2) Basic operation:
In order to explain the basic operation of such a hybrid vehicle, the operation of the planetary gear 120 will be described first. Planetary gear 120 has the property that when the rotational speed and torque of two of the above-described three rotating shafts and the torque (hereinafter collectively referred to as the rotating state) are determined, the rotating state of the remaining rotating shaft is determined. have. The relationship of the rotation state of each rotating shaft is shown in the following equation (1).
[0045]
Nr = (1 + ρ) Nc−ρNs;
Nc = (Nr + ρNs) / (1 + ρ);
Ns = (Nc−Nr) / ρ + Nc;
Ts = ρ / (1 + ρ) × Tc;
Tr = 1 / (1 + ρ) × Tc (1)
[0046]
Here, Ns and Ts are the rotational speed and torque of the sun gear shaft 125, Nr and Tr are the rotational speed and torque of the ring gear shaft 126, and Nc and Tc are the rotational speed and torque of the planetary carrier shaft 127. Further, ρ is a gear ratio between the sun gear 121 and the ring gear 122 as represented by the following equation.
ρ = number of teeth of sun gear 121 / number of teeth of ring gear 122
[0047]
The hybrid vehicle of this embodiment can travel in various states based on the action of the planetary gear 120. For example, in a relatively low speed state where the hybrid vehicle has started to travel, the motor MG2 is powered while the engine 150 is stopped to travel by transmitting power to the axle 112. Similarly, the engine 150 may travel while idling.
[0048]
When the hybrid vehicle reaches a predetermined speed, the control unit 190 starts the motor 150 by motoring the engine MG1 with the torque output by powering the motor MG1. At this time, the reaction torque of the motor MG1 is also output to the ring gear 122 via the planetary gear 120. The control unit 190 controls the operation of the motor MG2 so as to output the required power from the axle 112 while canceling out the reaction torque.
[0049]
In a state where the engine 150 is operating, the power is converted into various rotational speeds and torques and output from the axle 112 to travel. When the engine 150 is operated and the planetary carrier shaft 127 is rotated, the sun gear shaft 125 and the ring gear shaft 126 are rotated under conditions that satisfy the above equation (1). The power generated by the rotation of the ring gear shaft 126 is directly transmitted to the wheels 116R and 116L. The power generated by the rotation of the sun gear shaft 125 can be regenerated as electric power by the motor MG1. On the other hand, if the motor MG2 is powered, power can be output to the wheels 116R and 116L via the ring gear shaft 126. When the torque transmitted from the engine 150 to the ring gear shaft 126 is insufficient, the torque is assisted by powering the motor MG2. As the electric power for powering the motor MG2, electric power regenerated by the motor MG1 and electric power stored in the battery 149 are used. Control unit 190 controls the operation of motors MG1 and MG2 in accordance with the required power to be output from axle 112.
[0050]
The hybrid vehicle of the present embodiment can also move backward while the engine 150 is operated. When the engine 150 is operated, the planetary carrier shaft 127 rotates in the same direction as when moving forward. At this time, if the sun gear shaft 125 is rotated at a rotational speed higher than the rotational speed of the planetary carrier shaft 127 by controlling the motor MG1, the ring gear shaft 126 is reversed in the reverse direction as apparent from the above equation (1). The control unit 190 rotates the motor MG2 in the reverse direction and controls the output torque to reverse the hybrid vehicle.
[0051]
The planetary gear 120 can rotate the planetary carrier 124 and the sun gear 121 while the ring gear 122 is stopped. Therefore, the engine 150 can be operated even when the vehicle is stopped. For example, when the remaining capacity of the battery 194 decreases, the battery 194 can be charged by operating the engine 150 and regenerating the motor MG1. If the motor MG1 is powered while the vehicle is stopped, the engine 150 can be motored by the torque and started. At this time, the control unit 190 controls the motor MG2 to cancel the reaction torque of the motor MG1.
[0052]
By the way, in the hybrid vehicle of the present embodiment, a certain restriction is provided between the vehicle speed of the vehicle and the rotational speed of the engine 150. FIG. 2 illustrates this limitation. As shown in the usable area in the figure, the range of the vehicle speed at which the vehicle can travel is limited according to the rotational speed of the engine 150. Such a restriction is based on a mechanical restriction on the rotational speed of each gear of the planetary gear 120. For example, when the vehicle is running with the engine 150 stopped, the planetary gear has a gear ratio ρ smaller than 1, so the sun gear 121 rotates at a higher rotational speed than the rotational speed of the ring gear 122. If the rotation speed of the ring gear 122 is further increased, the rotation speed of the sun gear 121 may exceed the mechanical limit depending on the case. Even when the vehicle is traveling at the same vehicle speed, when the engine 150 is rotating, the rotational speed of the sun gear 121 decreases accordingly. In the hybrid vehicle according to the present embodiment, the engine 150 may be operated in a so-called idle state even when it is not necessary to output power from the engine 150 based on the restriction.
[0053]
(3) Torque control processing:
Next, the torque control process in a present Example is demonstrated. The torque control process refers to a process of controlling the engine 150 and the motors MG1 and MG2 to output the power having the required torque and rotation speed from the axle 112. A flowchart of the torque control process in the present embodiment is shown in FIG. This routine is repeatedly executed by a CPU (hereinafter simply referred to as a CPU) in the control unit 190 at predetermined intervals by a timer interrupt.
[0054]
When the torque control routine is started, the CPU first executes a running state determination process (step S10). As described above, the hybrid vehicle of this embodiment can travel by driving the internal combustion engine and the motors MG1, MG2 in various states. The three driving states are used according to the driving state of the hybrid vehicle. In order to properly use the CPU, the CPU determines the running state of the vehicle when the torque control routine is started.
[0055]
FIG. 4 shows a flowchart of the running state determination processing routine. In this process, the CPU first inputs a shift position (step S15). The shift position can be detected by the shift position sensor 167 shown in FIG. In this embodiment, a P range used during parking, a D range used during forward travel, a B range, an R range used during reverse travel, and a neutral are prepared as shift positions. At the same time, the CPU inputs the vehicle speed, the front wheel speed Nf, and the rear wheel speed Nr (steps S20 and S25).
[0056]
Next, the CPU determines the traveling state of the vehicle in the following procedure. First, it is determined whether or not the shift position is in the P range (step S30). Further, it is determined whether or not the vehicle speed is lower than a predetermined speed V1 (step S35). If one of these conditions is satisfied, it is determined that the vehicle is stopped (step S40). The determination result is stored by inputting a code indicating that the vehicle is stopped to a predetermined flag indicating the running state.
[0057]
The predetermined speed V1 is set in advance so as to be a slight speed at which it can be seen that the vehicle is stopped. By determining whether or not the vehicle is stopped using not only the shift position but also the vehicle speed, the vehicle is properly stopped including when the vehicle is stepped on at the shift position such as the D range and B range. It can be determined whether or not.
[0058]
If the conditions of both steps S30 and S35 are not satisfied, it is next determined whether or not the absolute value of the difference between the front wheel speed Nf and the rear wheel speed Nr is greater than a predetermined value N1 (step S45). ). If the absolute value is greater than the predetermined value N1, it is determined that any wheel is slipping (step S50). The determination result is stored in the above flag. The predetermined value N1 is a value that serves as a criterion for determining whether or not slipping has occurred. For example, the maximum value of the difference between the rotational speeds of the front and rear wheels that can occur during normal traveling can be set as the value N1.
[0059]
Next, the CPU determines whether or not the shift position is in the R range (step S55). If it is the R range, it is determined that the vehicle is moving backward (step S60). Otherwise, it is determined that the vehicle is moving forward (step S65). The determination result is stored in the above flag. When the traveling state of the vehicle is specified by the above processing, the CPU ends the traveling state determination processing routine and returns to the torque control routine.
[0060]
Actually, in the traveling state determination processing routine, various other traveling states are determined. For example, determinations such as EV travel that travels without operating the internal combustion engine and travel in a mode that starts the internal combustion engine are also made. These determinations are made based on various conditions such as the vehicle speed and the state of charge of the battery 194. A detailed description of such determination processing is omitted.
[0061]
When the traveling state is determined, the CPU sets the target rotational speed Nd * and the target torque Td * of the axle 112 (step S100). The target rotational speed Nd * and torque Td * are set according to the current vehicle speed, the amount of depression of the accelerator, and the like. Based on the target rotational speed Nd * and torque Td * set in this way, the CPU sets the required power Pe * of the engine 150 (step S110). The required power Pe * of the engine 150 varies depending on the traveling state of the vehicle. The traveling state can be detected by a code stored in the flag set in the traveling state determination process. When the vehicle is stopped or traveling in EV, the required power Pe * of the engine 150 basically has a value of 0 regardless of the target rotational speed Nd * and torque Td * of the axle 112. However, even in such a case, when it is necessary to charge the battery 194, the power required for charging is set as the required power Pe * of the engine 150.
[0062]
When the hybrid vehicle is running normally, the required power Pe * of the engine 150 is the driving power obtained by the product of the target rotational speed Nd * and the torque Td * of the axle 112 and the electric power charged / discharged from the battery 194. And the total power required for driving the auxiliary machine. For example, when it is necessary to discharge surplus power from the battery 194, the required power Pe * to the engine 150 can be reduced accordingly. Further, when operating an auxiliary machine such as an air conditioner, it is necessary to output extra power from the engine 150 corresponding to electric power for the auxiliary machine in addition to the traveling power.
[0063]
When the required power Pe * for the engine 150 is set in this way, the CPU sets the operating point of the engine 150, that is, the target rotational speed Ne * and the target torque Te * (step S120). The operation point of the engine 150 is basically set by selecting from the map an operation point that provides the best operation efficiency.
[0064]
FIG. 5 shows the relationship between the operating point of the engine 150 and the operating efficiency. A curve B in the figure shows the rotation speed and torque limit values at which the engine 150 can operate. The curves indicated by α1%, α2%, etc. in FIG. 5 are isoefficiency lines at which the efficiency of the engine 150 is constant, and show that the efficiency decreases in the order of α1%, α2%. As shown in FIG. 5, the efficiency of the engine 150 is high at relatively limited operating points, and the efficiency gradually decreases at the surrounding operating points.
[0065]
In FIG. 5, the curves indicated by C1-C1, C2-C2, and C3-C3 are curves in which the power output from the engine 150 is constant, and the operating point of the engine 150 depends on the required power. Will be selected on the curve. The state where the required power is low is shown in the order of C1-C1, C2-C2, and C3-C3. For example, when the required power Pe * to the engine 150 corresponds to the power represented by the curve C1-C1, the operating point of the engine 150 is set to the A1 point where the operating efficiency is highest on the curve C1-C1. . Similarly, an operation point is selected at point A2 on the C2-C2 curve and at point A3 on the C3-C3 curve. FIG. 6 shows the relationship between the rotational speed of the engine 150 and the operating efficiency on the curves C1-C1, C2-C2, and C3-C3. The curve in FIG. 6 illustrates three lines in FIG. 5 for convenience of explanation, but is a curve that can be drawn infinitely according to the required output. There are countless choices. A curve drawn by connecting points with high operating efficiency of the engine 150 in this way is a curve A in FIG. 5, which is called an operation curve.
[0066]
When the required power Pe * of the engine 150 is 0, the engine 150 is stopped or in an idle running state. For example, this corresponds to a traveling state in which the hybrid vehicle travels only with the power from the motor MG2 or when the vehicle travels downhill. Whether engine 150 is stopped or idling is set based on various conditions. Based on the restriction described above with reference to FIG. 2, the engine 150 is idling at a relatively high vehicle speed. The idle operation is also performed when it is determined that the engine 150 needs to be warmed up.
[0067]
Based on the operation point of engine 150 set by the above processing, the CPU sets the target rotational speed N1 * and torque T1 * of motor MG1 (step S130). Since the target rotational speed N1 * of the engine 150, that is, the planetary carrier shaft 127, and the target rotational speed Nd * of the axle 112, that is, the ring gear shaft 126, are set, the target of the sun gear shaft 125, that is, the motor MG1, is expressed by the above equation (1). The rotational speed N1 * can be set.
[0068]
Setting of target torque T1 * of motor MG1 varies depending on the traveling state of the hybrid vehicle. When the hybrid vehicle is stopped or EV traveling, the target torque T1 * of the motor MG1 is 0. When the engine is started, that is, when the engine 150 is motored by the motor MG1, the target torque T1 * of the motor MG1 is predetermined by open loop control until the rotational speed of the engine 150 reaches a predetermined rotational speed suitable for independent operation. Set to the specified value.
[0069]
In a state where the engine 150 is operating independently, the target torque T1 * of the motor MG1 is basically set by so-called proportional integral control. The target torque T1 * is set based on the deviation between the current rotational speed of the motor MG1 and the above-mentioned target rotational speed N1 *. When the current rotation speed is lower than the target rotation speed N1 *, the target torque T1 * is a positive torque, and when it is opposite, it is a negative torque. The gain used when setting the torque T1 * can be set by experiment.
[0070]
The CPU sets the operation point of the motor MG2, that is, the target rotational speed N2 * and the target torque T2 *, based on the operation point of the engine 150 and the operation point of the motor MG1 set by the above processing (step S200). The target rotational speed N2 * of the motor MG2 is equal to the target rotational speed Nd * of the ring gear shaft 126.
[0071]
The target torque T2 * is set by the MG2 target torque setting processing routine based on the target torque Td * to the axle 112 and the reaction torque from the motor MG1. A flowchart of this setting processing routine is shown in FIG. In this process, the CPU inputs the target torque Td * of the axle (step S205). Next, a torque step output to the ring gear shaft 126 as the reaction force torque of MG1 is obtained (step S210). When the engine 150 is in operation, the torque step can be rephrased as the torque output from the engine 150 to the ring gear shaft 126. The torque step is equal to the torque Tr of the ring gear 122 when the torque of the engine 150 or the output torque of the motor MG1 is substituted into the equation (1) shown above.
[0072]
Next, the CPU sets the temporary target torque Tm of the motor MG2 based on the difference between these torques Td * and step, that is, “Td * −step” (step S215). The temporary target torque Tm set in this way is equal to the torque that the motor MG2 should output in order to output the target torque Td * from the axle 112.
[0073]
In this embodiment, as will be described later, the target torque T2 * of the motor MG2 is determined by performing a smoothing process according to the traveling state of the vehicle. The annealing process is a process for suppressing the rate of change of the target torque T2 * so that appropriate responsiveness can be obtained. The degree of suppression of the rate of change by the annealing process is determined by the “annealing parameter”. The CPU sets the annealing parameter P according to the traveling state of the vehicle (step S220). The annealing parameters used in this example are shown in FIG. As shown in the figure, the annealing parameter is determined according to the traveling state of the vehicle. The annealing parameter has a maximum value of 8 during reverse travel. The smallest value is 1 when the vehicle stops or slips. When the annealing parameter has a value of 1, it is equivalent to not performing the annealing process. During normal running, the value is 3 between the two. It means that as the annealing parameter increases, the rate of change of the target torque of the motor MG2 is suppressed.
[0074]
When the smoothing parameter P is set according to the running state of the vehicle in this way, the CPU performs a smoothing process on the temporary target torque Tm to set the target torque T2 * of the motor MG2. Specifically, the target torque T2 * is set by calculating the following equation (step S225).
T2 * = (P-1) Tmo / P + Tm / P
Here, Tmo is the value of the target torque T2 * set when this routine was executed last time. In this embodiment, the temporary target torque Tm is subjected to a smoothing process by suppressing the rate of change from the previous target torque Tmo. Note that the annealing parameter can be set by experiment or the like according to the riding comfort of the hybrid vehicle.
[0075]
The CPU determines whether or not the target torque T2 * thus set is larger than the maximum torque Tmax that can be output by the motor MG2 (step S230). If the maximum torque Tmax is exceeded, the target torque T2 * is corrected to the maximum torque Tmax (step S235). If it is equal to or less than the maximum torque Tmax, it is next determined whether or not the target torque T2 * is smaller than the minimum torque Tmin that the motor MG2 can output (step S240). If the minimum torque Tmin is smaller than the target torque T2 *, the target torque T2 * is corrected to the minimum torque Tmin (step S245). Here, the maximum torque Tmax is a positive limit torque that is allowed when the motor MG2 acts as an electric motor, and is a value set according to the rating of the motor MG2, the state of charge of the battery 194, and the temperature of the motor MG2. is there. The minimum torque Tmin is a negative limit torque allowed when the motor MG2 acts as a generator, and is set according to the rating of the motor MG2, the state of charge of the battery 194, and the temperature of the motor MG2, similarly to the maximum torque Tmax. The The CPU performs upper and lower limit processing by the processing in steps S230 to S245 so that the output torque of the motor MG2 does not exceed these limit torques.
[0076]
The CPU controls the operation of the motors MG1 and MG2 and the engine 150 according to the operation points set in this way (step S300). The motors MG1 and MG2 are controlled according to the set target rotational speed and target torque, the voltages applied to the three-phase coils 131 and 141 of each motor are set, and driven according to the deviation from the current applied voltage. The transistors of the circuits 191 and 192 are switched. Since the method of controlling the synchronous motor is well known, detailed description thereof is omitted here.
[0077]
Since control processing for operating the engine 150 at the set operation point is well known, the description thereof is omitted here. However, the EFIECU 170 actually controls the engine 150. Therefore, in the process in step S700 in the torque control routine, a process of transmitting necessary information such as an operation point of the engine 150 from the control unit 190 to the EFIECU 170 is performed. By transmitting such information, the CPU of the control unit 190 indirectly controls the operation of the engine 150. Through the above processing, the hybrid vehicle of this embodiment can travel by outputting appropriate power from the axle 112 in accordance with the traveling state.
[0078]
According to the hybrid vehicle of the present embodiment described above, the motor MG2 can be controlled with different responsiveness by changing the smoothing parameter according to the running state of the vehicle. As a result, the vibration of the vehicle caused by the control of the motor MG2 can be suppressed according to each traveling state.
[0079]
A description will be given by taking control during stop as an example. When the vehicle is stopped, passengers can easily feel the vibration of the vehicle. When the operation of the engine 150 is stopped while the vehicle is stopped and when the engine 150 is steadily operating at the idle rotation speed, the torque output to the ring gear 122 is constant, so that the vibration of the vehicle is reduced. Hard to occur. When the motor MG1 is powered and the engine 150 is motored while the vehicle is stopped, the counter torque of the motor MG1 is output to the ring gear 122 according to the equation (1) described above. If torque that cancels this counter-torque is not output from motor MG2, torque is output to axle 112, causing vehicle vibration.
[0080]
FIG. 9 shows how the torque changes when the response of the motor MG2 is relatively low and the counter-torque cannot be sufficiently offset. As shown in the figure, consider a case where the engine 150 is initially stopped and motoring of the engine 150 is started by outputting torque by the motor MG1 at time t1. When motoring is started, the torque of the motor MG1 increases at a predetermined inclination to the value Ts necessary for motoring. This inclination is a preset inclination. Torque output from motor MG 1 is transmitted from sun gear 121 to planetary carrier 124 and crankshaft 156 of engine 150. The engine 150 increases the rotation speed as shown in the figure.
[0081]
On the other hand, part of the torque output from motor MG 1 is transmitted to ring gear 122. Since the torque Td * required for the axle 112 is 0 while the vehicle is stopped, the motor MG2 outputs a torque that cancels the torque transmitted to the ring gear 122. In order to cancel the torque from the motor MG1, it is necessary to control the motor MG2 with responsiveness that can follow the torque fluctuation of the motor MG1. When the responsiveness of the motor MG2 is low, the torque from the motor MG1 cannot be sufficiently canceled, and torque is output to the axle as indicated by T01 in FIG. When torque for causing engine 150 to rotate normally is output from motor MG1, in the hybrid vehicle of the present embodiment, torque on the side for moving the vehicle backward is output via ring gear 122. If the torque of the motor MG1 becomes a constant value at the target torque Ts during motoring, the reaction force can be sufficiently canceled by the motor MG2 even if the responsiveness is low, so the torque output to the axle 112 is 0. It becomes.
[0082]
When the rotational speed of engine 150 reaches rotational speed rs corresponding to ignition at time t2, motor MG1 stops outputting constant torque Ts and outputs torque for maintaining the rotational speed of engine 150. Such torque can be set by proportional control based on the rotational speed of the engine 150, for example. Since engine 150 is ignited and starts a self-sustained operation, as shown in the figure, the torque output from motor MG1 to ring gear 122 rapidly decreases due to the rapid decrease in torque of motor MG1.
[0083]
When the responsiveness of the motor MG2 is low, even if the torque output from the motor MG1 to the ring gear 122 decreases, the motor MG2 continues to output a relatively large forward torque for a while. In the section where the torque Ts was output from the motor MG1, the torque output to cancel the counter torque is continuously output. In such a state, the forward torque becomes excessive, so that the front wheel torque is output from the axle 112 as indicated by T02 in FIG. When the torque fluctuation period of the motor MG1 becomes relatively long, the motor MG2 can sufficiently cancel the counter torque.
[0084]
As described above, when the responsiveness of the motor MG2 is low, torque that is not intended by the driver is output to the axle 112 when the engine 150 is started. As shown in FIG. 9, this torque is output in both the reverse and forward directions to vibrate the vehicle. This vibration is caused by the fact that the torque output from the motor MG2 cannot sufficiently follow the torque change of the motor MG1. If the responsiveness of the motor MG2 is sufficiently increased, the torque output shown in FIG. 9 can be suppressed. In this embodiment, from this point of view, as shown in FIG. 8, the smoothing parameter is set to the state with the highest responsiveness while the vehicle is stopped. Therefore, even when the engine 150 is started while the vehicle is stopped, the counter torque can be sufficiently canceled, and the vibration of the vehicle can be suppressed.
[0085]
Similarly, in this embodiment, the responsiveness of the motor MG2 is set to an appropriate value even in other traveling states. For example, during normal running, the responsiveness of the motor MG2 is slightly lowered as shown in FIG. Even during normal travel, from the viewpoint of quickly compensating the torque output from the engine 150 and the motor MG1 to the ring gear 122 and outputting it from the axle 112, it is desirable that the responsiveness of the motor MG2 is high. However, the driver operates the accelerator during normal driving. Even when the vehicle is going to run steadily, the amount of accelerator depression usually fluctuates slightly. If the responsiveness of the motor MG2 is set to a high state as when the vehicle is stopped, the torque output from the axle 112 fluctuates in accordance with such subtle fluctuations, resulting in vehicle vibration. In the present embodiment, such vibration can be suppressed by setting the responsiveness of the motor MG2 to be slightly lower during normal traveling.
[0086]
In the hybrid vehicle of this embodiment, the responsiveness of the motor MG2 is further lowered during reverse travel. Even when the vehicle is moving backward, the engine 150 rotates in the same direction as when moving forward, and outputs torque in the moving direction. If the rotational speed of the sun gear 121 is made higher than the rotational speed of the planetary carrier 124 by the motor MG1, the ring gear 122 rotates in the reverse direction. Motor MG2 outputs a reverse torque. During reverse travel, the direction of the torque output from the engine 150 and the torque output from the motor MG2 are different from each other. Therefore, if the balance of power from the engine 150 and the motors MG1 and MG2 is lost, vehicle vibration occurs. It is in an easy state. In the hybrid vehicle of the present embodiment, the responsiveness of the motor MG2 is set lower during reverse travel than during forward travel, so the operating state of the motor MG2 changes relatively slowly. Therefore, the balance of the power of the three parties is less likely to be lost during reverse travel, and the vibration of the vehicle can be suppressed.
[0087]
According to the hybrid vehicle of the present embodiment, the responsiveness of the motor MG2 is increased during a slip. When slipping, the rotational speed of the axle 112 increases rapidly. In the hybrid vehicle of the present embodiment, as shown in FIG. 2, a certain limit is provided between the vehicle speed, that is, the rotational speed of the ring gear 122 and the rotational speed of the engine 150. If the restriction is removed, as described above, the rotational speed of the sun gear 121 becomes too high, and there is a possibility that the sun gear 121 may be consumed to the extent that it cannot be overlooked. Along with the reason that slip is not a favorable driving condition for a vehicle, it is necessary to recover quickly in order to avoid the possibility of significantly shortening the life of the vehicle. In order to recover from the slip state, it is necessary to reduce the torque output from the axle to such an extent that slip does not occur. In the hybrid vehicle of the present embodiment, the responsiveness of the motor MG2 is set high during a slip. Therefore, the power output to the axle 112 can be quickly reduced and the slip state can be recovered in a short period of time.
[0088]
As described above, according to the hybrid vehicle of the present embodiment, appropriate torque control can be realized for each traveling state by changing the responsiveness of the motor MG2 in accordance with each traveling state. As a result, according to the hybrid vehicle of the present embodiment, the operability and ride comfort of the vehicle can be greatly improved.
[0089]
In the hybrid vehicle, the responsiveness of the motor MG2 is changed according to the four traveling states shown in FIG. On the other hand, it is good also as what changes responsiveness corresponding to more driving | running | working states. For example, the response of the motor MG2 may be improved when the engine 150 is started even during normal traveling. Further, the responsiveness may be changed according to whether or not the engine 150 is operating during normal travel and reverse travel.
[0090]
In the hybrid vehicle, as shown in FIG. 7, after temporarily setting the temporary target torque Tm of the motor MG <b> 2, the target torque T <b> 2 * used for control is set by performing an annealing process. The process for changing the responsiveness of the motor MG2 does not necessarily depend on the annealing process. Further, it is not necessary to set the target torque T2 * in two stages, that is, after the provisional target torque is set, the correction according to the response is performed. For example, in the calculation formula of step S215 in FIG. 7, the target torque T2 * corresponding to the traveling state may be set in one stage by multiplying by a proportional coefficient corresponding to the traveling state.
[0091]
In the above torque control routine, after setting the operating states of the engine 150 and the motor MG1, the motor MG2 compensates so that the required torque is output to the axle 112. On the other hand, it is also possible to configure the control routine so that the motor MG1 compensates the torque after setting the operating states of the engine 150 and the motor MG2. In such a configuration, instead of the responsiveness of the motor MG2, the responsiveness of the motor MG1 can be changed according to the traveling state of the vehicle.
[0092]
(4) Second embodiment:
Next, a hybrid vehicle as a second embodiment of the present invention will be described. The hardware configuration of the hybrid vehicle of the second embodiment is the same as that of the first embodiment. The torque control routine and the running state determination processing routine are the same as in the first embodiment. In the second embodiment, the contents of the MG2 target torque setting processing routine are different from those in the first embodiment.
[0093]
A flowchart of the MG2 target torque setting process routine in the second embodiment is shown in FIG. When this processing is started, the CPU first inputs the axle target torque Td * (step S505), and calculates the reaction force torque step from the engine MG1 (step S510). These processing contents are the same as those in the first embodiment (see steps S205 and S210 in FIG. 7).
[0094]
Next, the CPU determines whether or not the annealing process should be prohibited (step S515). This process is performed based on the traveling state of the hybrid vehicle. As described in the first embodiment, the traveling state of the hybrid vehicle is determined by the traveling state determination processing routine, and the result is stored in a predetermined flag. The CPU determines whether or not the running state specified by this flag is a running state that should be prohibited from performing the annealing process. The running state in which the annealing process should be prohibited is predetermined and stored in the ROM in the control unit 190. In the present embodiment, the traveling state shown in FIG. 8 corresponds to a traveling state in which the smoothing process should be prohibited during stopping and slipping.
[0095]
If the annealing process is not in the state that should not be prohibited, the CPU sets the temporary target torque Tm (step S525), sets the annealing parameter P (step S530), performs the annealing process, and performs MG2. Target torque T2 * is set (step S535). These processes are the same as those in the first embodiment (see steps S215 to S225 in FIG. 7).
[0096]
In a case where the annealing process should be prohibited, the CPU sets the target torque T2 * of MG2 based on the difference “Td * −step” between the target torque Td * of the axle and the reaction torque step. This corresponds to the temporary target torque Tm. That is, in order to compensate the reaction force torque step and output the required torque Td * from the axle, this is the torque value that MG2 should output. In the case where the annealing process should be prohibited, this torque is directly set as the target value of MG2.
[0097]
Upper / lower limit processing similar to that in the first embodiment is performed on the target torque T2 * set in this way (steps S540 to S555). When the target torque T2 * of MG2 is determined by the above processing, the CPU ends the MG2 target torque setting processing routine and returns to the torque control routine. The following processing is the same as in the first embodiment.
[0098]
According to the hybrid vehicle of the second embodiment, for example, during normal driving, smooth operation can be realized by performing the annealing process as in the first embodiment. On the other hand, in a running state such as when the vehicle is stopped or slipping, the torque output to the axle can be controlled with high responsiveness by prohibiting the annealing process.
[0099]
As the configuration of the hybrid vehicle to which the present invention is applied, various configurations are possible in addition to the configuration shown in FIG. In FIG. 1, the motor MG2 is coupled to the ring gear shaft 126, but the motor MG2 may be coupled to the crankshaft 156 of the engine 150. FIG. 11 shows a configuration as a first modification. In FIG. 11, the coupling state of the engine 150 and the motors MG1, MG2 to the planetary gear 120 is different from the embodiment of FIG. The motor MG1 is coupled to the sun gear 121 of the planetary gear 120, and the crankshaft of the engine 150 is coupled to the planetary carrier. 11 differs from the embodiment of FIG. 1 in that the motor MG2 is directly coupled to the crankshaft of the engine 150 instead of the ring gear.
[0100]
Even in such a configuration, the present invention can be applied because the required power can be compensated by the motor MG2 so as to be output from the axle 112 in accordance with the operating state of the engine 150 and the motor MG1. Of course, conversely, compensation by the motor MG1 is also possible. Therefore, the present invention can also be applied in such a manner that the responsiveness of the motor MG1 is changed according to the traveling state.
[0101]
The present invention can also be applied to a hybrid vehicle having another configuration. FIG. 12 shows a configuration as a second modification. This hybrid vehicle includes a clutch motor CM instead of the planetary gear 120 and the motor MG1. The clutch motor is a counter-rotor electric motor including an inner rotor 202 and an outer rotor 204 that are relatively rotatable. As shown in FIG. 12, the inner rotor 202 is coupled to the crankshaft 156 of the engine 150, and the outer rotor 204 is coupled to the axle 112. Electric power is supplied to the outer rotor 204 via a slip ring 206. A motor MG2 is also coupled to the shaft on the outer rotor 204 side. Other configurations are the same as those of the hybrid vehicle shown in FIG.
[0102]
The power output from the engine 150 can be transmitted to the axle 112 via the clutch motor CM. The clutch motor CM transmits power between the inner rotor 202 and the outer rotor 204 through electromagnetic coupling. At this time, if the rotation speed of the outer rotor 204 is lower than the rotation speed of the inner rotor 202, the electric power corresponding to the slippage of both can be regenerated by the clutch motor CM. Conversely, if electric power is supplied to the clutch motor CM, the rotational speed of the inner rotor 202 can be increased and output to the axle 112. When the torque output from the engine 150 via the clutch motor CM does not match the required torque to be output from the axle 112, the motor MG2 can compensate. If the clutch motor is powered, the engine 150 can be motored and started. The counter torque during motoring can be canceled by the motor MG2.
[0103]
The role of the motor MG2 is the same as that of the hybrid vehicle (FIG. 1) of the present embodiment. Therefore, the present invention can also be applied to the hybrid vehicle of the second modification.
[0104]
Further, in the hybrid vehicle of this embodiment, the front axle 112 is provided with a power system including the engine 150 and the motors MG1 and MG2. In contrast, a configuration in which the motor MG2 is coupled to the rear axle may be employed. An example of such a configuration is shown in FIG. As shown, the motor MG2 is coupled to the rear axle 112R instead of the front axle 112. In the hybrid vehicle having such a configuration, the power output from the front axle 112 can be compensated by the motor MG2 so that the power output from both the front axle 112 and the rear axle 112R matches the required power. Therefore, the present invention can be applied to the control of the motor MG2. Of course, in such a configuration, if the compensation is performed by the motor MG1, the present invention can be applied to the motor MG1.
[0105]
As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment at all, Of course, in the range which does not deviate from the summary of this invention, it can implement with a various form. It is. For example, in the above embodiment, various controls are executed by software, but these may be realized by hardware.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing a schematic configuration of a hybrid vehicle as an embodiment of the present invention.
FIG. 2 is an explanatory diagram illustrating limitations on vehicle speed and engine speed.
FIG. 3 is a flowchart of a torque control routine.
FIG. 4 is a flowchart of a running state determination processing routine.
FIG. 5 is a graph showing the relationship between engine operating points and operating efficiency.
FIG. 6 is a graph showing the relationship between engine speed and operating efficiency when the required power is constant.
FIG. 7 is a flowchart of an MG2 target torque setting processing routine.
FIG. 8 is an explanatory diagram showing setting of annealing parameters.
FIG. 9 is an explanatory diagram showing fluctuations in rotation speed and torque at the time of engine start.
FIG. 10 is a flowchart of an MG2 target torque setting processing routine as a second embodiment.
FIG. 11 is an explanatory diagram illustrating a first modified configuration example of the hybrid vehicle according to the embodiment.
FIG. 12 is an explanatory diagram showing a second modified configuration example of the hybrid vehicle of the present embodiment.
FIG. 13 is an explanatory diagram showing a third modified configuration example of the hybrid vehicle of the present embodiment.
[Explanation of symbols]
112, 112R ... axle
116R, 116L ... wheels
117R, 117L ... wheels
119 ... Case
120 ... Planetary Gear
121 ... Sungear
121 ... ρ = Sun gear
122 ... Ring gear
123 ... Planetary pinion gear
124 ... Planetary Carrier
125 ... Sun gear shaft
126 ... Ring gear shaft
127 ... Planetary carrier shaft
129 ... Chain belt
130 ... Damper
131 ... Three-phase coil
132 ... Rotor
133 ... Stator
141. Three-phase coil
142 ... Rotor
143 ... Stator
144: Sensor
149 ... Battery
150 ... Engine
156 ... Crankshaft
165 ... Accelerator pedal position sensor
167 ... Shift position sensor
190 ... Control unit
191 192 Drive circuit
194 ... Battery
202 ... Inner rotor
204 ... Outer rotor
206 ... slip ring
MG1, MG2, MG3 ... Motor
CM ... Clutch motor

Claims (12)

An internal combustion engine, the power regulation equipment adjustable by exchanging power with the output shaft and power input to and output in both axes is coupled to both the axle of the internal combustion engine first motor generator, wherein A hybrid vehicle having a second motor generator mechanically coupled to an axle, capable of converting at least the power output from the internal combustion engine and outputting the power from the axle;
Target torque setting means for setting a target torque of the second motor generator;
A specifying means for specifying a running state of the hybrid vehicle;
Target torque correcting means for correcting the target torque to achieve a predetermined response according to the running state;
A hybrid vehicle comprising: motor generator control means for controlling the operation of the second motor generator and outputting the set target torque. The hybrid vehicle according to claim 1,
The target torque setting means is a means for setting, as a target torque, a value that compensates for a torque that is excessive or deficient in the torque output to the axle by the internal combustion engine and the power adjustment device with respect to the required torque to be output from the axle. And
The target torque correcting means is a hybrid vehicle which is a means for setting the target torque by performing an annealing process determined for each traveling state. The hybrid vehicle according to claim 1,
The specifying means is means for specifying whether the hybrid vehicle is in a stopped state as a running state,
The hybrid vehicle in which the responsiveness in the target torque correcting means is determined to be higher when the hybrid vehicle is stopped than when the hybrid vehicle is traveling.   The hybrid vehicle according to claim 3, wherein the specifying unit specifies whether the vehicle is stopped based on a vehicle speed. The hybrid vehicle according to claim 1,
Furthermore, it comprises means for inputting an instruction to start the internal combustion engine,
The target torque setting means is means for setting, as the target torque, a torque that can cancel the torque output to the axle when the internal combustion engine is motored by the power adjustment device when the instruction is input. Yes,
The specifying means is means for specifying whether or not the running state of the hybrid vehicle is in a stopped state and the motoring is being performed,
The responsiveness in the target torque correction means is set to be higher when the hybrid vehicle is stopped and when the motoring is being performed than when the vehicle is running. The hybrid vehicle according to claim 1,
The specifying means is means for specifying whether or not a wheel coupled to the axle is in a slipped state;
The hybrid vehicle in which the responsiveness in the target torque correcting means is set higher when the traveling state of the hybrid vehicle is in the slipped state than when it is not. The hybrid vehicle according to claim 1,
The specifying means is means for specifying whether the hybrid vehicle is traveling forward or backward.
The hybrid vehicle in which the responsiveness in the target torque correction means is set lower when the hybrid vehicle is traveling backward than when traveling forward. The hybrid vehicle according to claim 1,
Before SL power regulation unit includes a three rotary shaft, and a planetary gear two rotation axes of the rotating shaft is coupled to the output shaft and the axle, the first to the remainder of the rotation shaft of the planetary gear hybrid vehicle the electric generator has been binding. The hybrid vehicle according to claim 1,
The power adjustment device is a hybrid vehicle including a counter-rotor electric motor including a first rotor coupled to the output shaft and a second rotor coupled to the axle as the first motor generator . The axle to which the power adjustment device is coupled and the axle to which the second motor generator is coupled are different axles, and can be driven by four wheels by outputting power from the wheels coupled to the respective axles. The hybrid vehicle according to claim 1. An internal combustion engine, the power regulation equipment adjustable by exchanging power with the output shaft and power input to and output in both axes is coupled to both the axle of the internal combustion engine first motor generator, wherein A hybrid vehicle having a second motor generator mechanically coupled to an axle, capable of converting at least the power output from the internal combustion engine and outputting the power from the axle;
Target torque setting means for setting a target torque of the second motor generator;
Torque correcting means for correcting the target torque by an annealing process;
A specifying means for specifying a running state of the hybrid vehicle;
When the hybrid vehicle is in a predetermined traveling state determined in advance, prohibiting means for prohibiting correction of the target torque by the torque correcting means;
A hybrid vehicle comprising: motor generator control means for controlling the operation of the second motor generator and outputting the set target torque. An internal combustion engine, the power regulation equipment adjustable by exchanging power with the output shaft and power input to and output in both axes is coupled to both the axle of the internal combustion engine first motor generator, wherein A control method for a hybrid vehicle having a second motor generator mechanically coupled to an axle, capable of converting at least the power output from the internal combustion engine and outputting the power from the axle;
(A) setting a target torque of the second motor generator;
(B) identifying the running state of the hybrid vehicle;
(C) correcting the target torque so as to achieve a predetermined response according to the running state;
(D) A control method comprising a step of controlling the operation of the second motor generator and outputting the set target torque.

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