Drive control device and method for providing a drive control for a hybrid vehicle and hybrid vehicle

Abstract

Drive control device (1) for providing drive control for a hybrid vehicle by controlling a machine (2) and motor-generators (4, 5) which can be operated to output a charge of electrical power to a battery (21) and to receive a supply of electrical power from the battery (21) to supply the hybrid vehicle with a motive force obtained from the machine (2) and the motor-generators (4, 5), wherein the drive control device has a power sharing and composition system having four axes connected to each of the rotating elements of the two planetary gear sets (8, 9); wherein two motor generators (4, 5) are connected to the battery (21); wherein one of the motor generators (4, 5), the machine (2), a drive shaft (7) connected to a traction wheel (6), and the other of the motor generators (4, 5) lie on a collinear diagram, wherein the four axes of the power sharing and composition system are each connected to one motor generator (4, 5), the machine (2), the drive shaft (7), and the other motor generator (4, 5); the drive control device further comprises the following: a drive power target calculation function (42) for calculating a drive power target based on an accelerator pedal position and a vehicle speed; a charge / discharge power target calculation function (43) for calculating an electrical charge / discharge power target to / from the battery (21) based on a charge / discharge state of the battery (21); a first machine power target calculation function (44) for calculating a first machine power target based on the drive power target calculated by the drive power target calculation function (42) and the electrical charge / discharge power target calculated by the charge / The discharge power target calculation function (43) is calculated; a first machine operating point target calculation function (46) for calculating a first machine speed target and a first machine torque target, both of which correspond to the first machine power target calculated by the first machine power target calculation function (44), based on information about a machine operating point identified by a relationship between a machine speed and a machine torque; a first calculation function (47) for an upper machine speed target limit for calculating an upper limit of the first machine speed target based on the vehicle speed, wherein the upper limit of the machine speed is limited by an upper limit of the speed of one motor-generator (4, 5) and is subject to changes depending on the vehicle speed, and wherein the calculation function (47) of the upper first machine speed target limit calculates the upper limit of the first machine speed target based on the vehicle speed and the upper limit of the speed of one motor-generator (4, 5); a machine operating point target calculation function (48) to determine whether the first machine speed target calculated by the first machine operating point target calculation function (46) is greater than the upper limit, wherein the machine operating point target calculation function (48) is designed to: to set a second machine speed target to the upper limit and to calculate a second machine torque target corresponding to the second machine speed target, based on the information about the machine operating point, when it is determined that the first machine speed target calculated by the first machine operating point target calculation function (46) is greater than the upper limit; and to set the second machine speed target and the second machine torque target as the first machine speed target and as the first machine torque target if it is determined that the first machine speed target calculated by the first machine operating point target calculation function (46) is less than or equal to the upper limit; a second machine power target calculation function (49) for calculating a second machine power target based on the second machine speed target and the second machine torque target; a calculation function (50) for an electrical power target for calculating an electrical power target that specifies an amount of electrical power to be generated by driving the motor generators (4, 5) to charge the battery (21), or to be supplied from the battery (21) to the motor generators (4, 5) to drive the motor generators (4, 5), based on a difference between the drive power target calculated by the drive power target calculation function (42) and the second machine power target calculated by the second machine power target calculation function (49); a machine control (40) that is configured to to control a moment of the machine (2) based on the second machine moment target; and a motor-generator control unit (60) configured to control the motor-generators (4, 5) based on the second machine speed target, the second machine torque target, and the electrical power target.

Description

TECHNICAL AREA

[0001] The present invention relates to technology connected with a hybrid vehicle which has a machine and motor-generators as power sources. STATE OF THE ART

[0002] In a drive control device for providing drive control for a hybrid vehicle by driving drive shafts connected to traction wheels, by combining the output power of a machine and the output power of a first and a second motor-generator, there is a technology comprising: calculating a charge / discharge power target based on a battery state of charge (SOC) together with calculating a drive power target requested by the vehicle driver based on a drive torque target which has as parameters an accelerator pedal position and a vehicle speed; calculating as a machine power target the sum of the calculated drive power target and the calculated charge / discharge power target; and calculating a machine operating point based on the calculated machine power target (see, for example, JP 2008-12 992 A and JP 2007-296 937 A).

[0003] In such a drive control device for providing drive control for a hybrid vehicle, the first and second motor-generators are controlled to operate in driven mode or regenerative mode, together with the control of machine torque and speed, so that the machine can operate at the calculated machine operating point target (see, for example, JP 2008-12 992 A and JP 2007- 296 937 A).

[0004] US patent 2005 / 0102082A1 discloses a shift control system for a hybrid transmission in a vehicle. The control method selectively performs priority control for drive torque and priority control for a target engine speed based on a comparison between the actual engine speed and a set value. Brief description of the invention; problem to be solved by the invention

[0005] In the aforementioned drive control device for providing drive control for a hybrid vehicle, since a balance is maintained, for example for the machine speed and the motor-generator speed(s), there is a need to prevent the machine speed from becoming too high if the motor-generator speed is to be kept lower than or equal to a desired speed.

[0006] On the other hand, in the case of the drive control device for providing drive control for a hybrid vehicle, if the machine speed is prevented from becoming high, this results in the machine output power not becoming high, which provides a drive torque that is lower than that required by the vehicle driver, making it difficult to meet the drive torque required by the vehicle driver.

[0007] One object of the present invention is to prevent the machine speed from becoming excessively high, as well as to meet the drive torque required by the vehicle driver. MEANS TO SOLVE THE PROBLEM

[0008] To solve this problem, according to one embodiment of the present invention, a drive control device is provided to provide drive control for a hybrid vehicle by controlling a machine and motor-generators that can be operated to output a charge of electrical power to a battery and to receive a supply of electrical power from the battery to supply the hybrid vehicle with a drive force obtained from the machine and the motor-generators, wherein the drive control device comprises: a drive power target calculation function for calculating a drive power target based on an accelerator pedal position and a vehicle speed; a charge / discharge power target calculation function for calculating an electrical charge / discharge power target to / from the battery based on a charge / discharge state of the battery;A first machine power target calculation function for calculating a first machine power target based on the drive power target calculated by the drive power target calculation function and the electrical charge / discharge power target calculated by the charge / discharge power target calculation function; a first machine operating point target calculation function for calculating a first machine speed target and a first machine torque target, both corresponding to the first machine power target calculated by the first machine power target calculation function, based on information about the machine operating point identified by the relationship between a machine speed and a machine torque; a first upper machine speed target limit calculation function for calculating an upper limit of the first machine speed target based on the vehicle speed;A machine operating point target calculation function for setting a second machine speed target as an upper limit and calculating a second machine torque target corresponding to the second machine speed target, based on information about the machine operating point, when the first machine speed target calculated by the first machine operating point target calculation function exceeds the upper limit; and for setting the second machine speed target and the second machine torque target as the first machine speed target and the first machine torque target, respectively, when the first machine speed target is less than or equal to the upper limit; a second machine power target calculation function for calculating a second machine power target based on the second machine speed target and the second machine torque target;An electrical power target calculation function for calculating an electrical power target that specifies the amount of electrical power to be generated by driving the motor-generators to charge the battery, or to be supplied from the battery to the motor-generators to drive the motor-generators, based on a difference between the drive power target calculated by the drive power target calculation function and the second machine power target calculated by the second machine power target calculation function; a machine controller configured to control a machine torque based on the second machine torque target; and a motor-generator controller configured to control the motor-generators based on the second machine speed target, the second machine torque target, and the electrical power target.

[0009] The embodiment of the present invention therefore calculates a second machine speed target such that a first machine speed target cannot exceed an upper limit based on a machine operating point target calculated from a first machine power target that is originally calculated; recalculates a machine operating point target based on the calculated second machine speed target; calculates a second machine power target based on the newly calculated machine operating point target; calculates an electrical power target based on the calculated second machine power target; controls the torque of the machine based on the calculated machine operating point target (in particular the second machine torque target), and controls the motor-generators, that is, operates the motor-generators in driving mode or regenerative mode based on the calculated machine operating point target and the electrical power target.

[0010] Furthermore, in the embodiment of the present invention, it is preferred that a calculation function for an upper limit of a machine performance target is also provided in order to calculate, as an upper limit of the first machine performance target, a maximum output power that the machine can provide; and that the calculation function of the first machine performance target calculates the first machine performance target in such a way that it does not exceed the upper limit calculated by the calculation function of the upper limit of the machine performance target.

[0011] Furthermore, in this embodiment of the present invention, it is preferred that a power sharing and composition system is provided having four axes connected to each of the rotating elements of the two planetary gear sets; that two motor-generators are connected to the battery; that either one of the motor-generators, the machine, a drive shaft connected to a traction wheel, and the other of the motor-generators are on a collinear diagram, with the four axes of the power sharing and composition system each being connected to the motor-generator, the machine, the drive shaft, and the other motor-generator, respectively; that an upper limit of the machine speed is restricted by an upper limit of the speed of one of the motor-generators and is subject to a change depending on the vehicle speed;and that the calculation function of the upper limit of the first machine speed target calculates the upper limit of the first machine speed target based on the vehicle speed and the upper limit of the speed of one motor-generator.

[0012] Furthermore, according to the embodiment of the present invention, a hybrid vehicle is provided with the drive control device mentioned in the description above.

[0013] Furthermore, according to the embodiment of the present invention, a drive control method is provided to provide drive control for a hybrid vehicle by controlling a machine and motor-generators that can be operated to output a charge of electrical power to a battery and to receive a supply of electrical power from the battery to supply the hybrid vehicle with a drive force obtained from the machine and the motor-generators, wherein the drive control method comprises: calculating a drive power target based on an accelerator pedal position and a vehicle speed; calculating an electrical charge / discharge power target to / from the battery based on a state of charge / discharge of the battery; calculating a first machine power target based on the drive power target and the electrical charge / discharge power target;Calculating a first machine speed target and a first machine torque target, both corresponding to the first machine power target, based on information about a machine operating point identified by the relationship between machine speed and machine torque; calculating an upper limit of the first machine speed target based on the vehicle speed; setting a second machine speed target as the upper limit and calculating a second machine torque target corresponding to the second machine speed target, based on information about the machine operating point, if the first machine speed target exceeds the upper limit; and setting the second machine speed target and the second machine torque target as the first machine speed target and the first machine torque target, respectively, if the first machine speed target is less than or equal to the upper limit;Calculating a second machine power target based on the second machine speed target and the second machine torque target; calculating an electrical power target that specifies the amount of electrical power to be generated by driving the motor-generators to charge the battery, or to be supplied from the battery to the motor-generators to drive the motor-generators, based on a difference between the drive power target and the second machine power target; controlling a machine torque based on the second machine torque target; and controlling the motor-generators based on the second machine speed target, the second machine torque target, and the electrical power target. IMPACT OF THE INVENTION

[0014] The embodiment of the present invention prevents the rotational speed from becoming too high by calculating a machine speed target such that it cannot exceed the upper limit, and enables the motor-generators to operate in driving mode by calculating an electrical power target based on the machine speed target calculated to not exceed the upper limit, thereby compensating for a reduction in machine output to meet the drive torque required by the vehicle driver. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a system configuration diagram that provides an embodiment of a drive control device for providing drive control for a hybrid vehicle according to the present invention. Fig. Figure 2 is an example collinear diagram for a power allocation and composition system, which is shown in Fig. 1 is shown. Fig. Figure 3 is an example collinear diagram for the power allocation and composition system shown in Fig. 1 is shown. Fig. Figure 4 is an example collinear diagram for the power allocation and composition system shown in Fig. 1 is shown. Fig. Figure 5 is an example collinear diagram for the power allocation and composition system shown in Fig. 1 is shown. Fig. Figure 6 is a functional block diagram that illustrates an example of the functions of a machine control system found in Fig. 1 is shown, shows. Fig. 7 is a flowchart that represents an example of arithmetic processing used in machine control, which is in Fig. As shown in 1, it is executed. Fig. 8 is an example of a card used in the arithmetic processing that is in Fig. 7 is shown, and is used. Fig. 9 is an example of a card used in the arithmetic processing that is in Fig. 7 is shown, and is used. Fig. 10 is an example of the machine characteristic diagram as a characteristic curve for extracting a machine operating point. Fig. Figure 11 is an example of the machine characteristic diagram, which is used to illustrate the machine operating points and machine operating lines of machine operation. Fig. Figure 12 is an example collinear diagram for a power allocation and composition system, which is shown in Fig. 1 is shown. Fig. Figure 13 is an illustration showing an example of the relationship between machine speed and efficiency. Fig. Figure 14 is an example collinear diagram for the power allocation and composition system shown in Fig. 1 is shown. Fig. Figure 15 is an exemplary collinear diagram for the power allocation and composition system, which is in Fig. 1 is shown. Fig. Figure 16 is a functional block diagram that illustrates an example of the functions of a motor-generator control system found in Fig. 1 is shown, shows. Fig. Figure 17 is a flowchart that represents an example of arithmetic processing used in the motor-generator control system, which is in Fig. As shown in 1, it is executed. DESCRIPTION OF ONE (OF) FORM(S)

[0015] With reference to the drawings, an embodiment of a drive control device for providing drive control for a hybrid vehicle according to the present invention is described below. (Configuration of the drive control unit for hybrid vehicle)

[0016] Fig. Figure 1 shows an exemplary system configuration diagram that provides an embodiment of a drive control device 1 for providing drive control for a hybrid vehicle according to the present invention (hereinafter referred to as "drive control device").

[0017] With reference to Fig. 1 The hybrid vehicle has as its powertrain the following: a machine (an internal combustion engine) 2 that can provide drive power generated by the combustion of fuel, a first motor-generator (a dynamotor) 4 and a second motor-generator (a dynamotor) 5, each of which is capable of generating drive power by electrical energy (driving mode) or electrical energy by regeneration, drive shafts 7 connected to traction wheels 6 of the hybrid vehicle, a first and a second plane- transmission device 8 and 9, which provide a power sharing and composition system that combines or divides drive power from the machine 2, the first motor-generator 4 and the second motor-generator 5 and ground reaction supplied by the traction wheels 6, and an output gearbox 31 that provides a drive connection between the power sharing and composition system and drive shafts 7.

[0018] The first motor-generator 4 has a first rotor shaft 13, a first rotor 14 and a first stator 15. The second motor-generator 5 has a second rotor shaft 16, a second rotor 17 and a second stator 18.

[0019] The first stator 15 of the first motor-generator 4 is electrically coupled to a first inverter 19, and the second stator 18 of the second motor-generator 5 is electrically coupled to a second inverter 20. The first and second inverters 19 and 20 are electrically coupled to a battery 21. The first and second inverters 19 and 20 control the amount of electrical energy supplied by the battery 21 to the first stator 15 and the second stator 18. The first and second inverters 19 and 20 are electrically connected to a drive control device 32, which is configured to perform drive control.

[0020] Changes in, for example, the field current can control the drive power supplied by the first and second motor-generators 4 and 5, more precisely, the rotational speed and drive torque, which are also referred to below as motor-generator speed and motor-generator torque. Furthermore, each of the first and second motor-generators 4 and 5 can be operated in a regenerative mode, delivering torque in a direction opposite to its direction of rotation to generate electrical power, so that the generated electrical energy can be used to charge the battery 21.

[0021] The first planetary gear assembly 8 comprises, as is well known in the prior art, a first sun gear 22, a first carrier 24 which carries the first planet gear 23, and a first ring gear 25. The second planetary gear assembly 9 has a second sun gear 26, a second carrier 28 which carries the second planet gear 27, and a second ring gear 29.

[0022] In this embodiment, the machine 2, the first motor-generator 4, the second motor-generator 5, the first planetary gear set 8, and the second planetary gear set 9 are all arranged on the same axis. The first carrier 24 of the first planetary gear set 8 and the second sun gear 26 of the second planetary gear set 9 are coupled to each other and driven by the machine output shaft 3 of the machine 2; the first sun gear 22 of the first planetary gear set 8 is driven by the first rotor shaft 13 of the first motor-generator 4; the second ring gear 29 of the second planetary gear set 9 is driven by the second rotor shaft 16 of the second motor-generator 5; the first ring gear 25 of the first planetary gear set 8 and the second carrier 28 of the second planetary gear set 9 are coupled to each other and connected to drive shafts 7 for traction wheels 6.

[0023] The drive connection with the drive shafts 7 is effected, for example, by connecting an output part 30, such as a gear formed on the outer circumference of the first ring gear 25 of the first planetary gear assembly 8, with drive shafts 7 with the output gear 31. The drive connection of each part of the rotating elements of the first planetary gear assembly 8 with the corresponding part of the rotating elements of the second planetary gear assembly 9 is effected directly without any power transmission gears between them, and the drive connection of each of the remaining rotating elements with the corresponding one of the first motor-generator 4, second motor-generator 5 and the machine 2 is effected in a similar manner.

[0024] Collinear diagrams are now used to describe rotational speed relationships between machine 2 or machine output shaft 3, the first and second planetary gear units (power sharing and composition system) 8 and 9 and output gearbox 31.

[0025] As described above, the first carrier 24 of the first planetary gear assembly 8 and the second sun gear 26 of the second planetary gear assembly 9 are directly coupled to each other, and the first ring gear 25 of the first planetary gear assembly 8 and the second carrier 28 of the second planetary gear assembly 9 are directly coupled to each other. Therefore, the first carrier 24 and the second sun gear 26 rotate at the same speed on collinear diagrams for two planetary gear assemblies 8 and 9, and the first ring gear 25 and the second carrier 28 also rotate at the same speed. If the two collinear diagrams for the planetary gear assemblies 8 and 9 are now superimposed, a collinear diagram is obtained which is shown in Fig. Figure 2 shows that it has a total of four vertical axes, that is, starting from the left, one axis for the first sun gear 22 of the first planetary gear assembly 8 (an axis labelled “MG1” in Fig. 2: where the first sun gear 22 corresponds to the first rotor shaft 13 of the first motor-generator 4), an axle for the first carrier 24 of the first planetary gear set 8 and the second sun gear 26 of the second planetary gear set 9 (an axle designated “ENG” in Fig. 2: wherein the first carrier 24 and the second sun gear 26 correspond to the machine output shaft 3 of the machine 2), an axle for the first ring gear 25 of the first planetary gear assembly 8 and the second carrier 28 of the second planetary gear assembly 9 (an axle designated “OUT” in Fig. 2: wherein the first ring gear 25 and the second carrier 28 correspond to the first output part 30 of the first ring gear 25, i.e. drive shafts 7 for traction wheels 6), an axle for the second ring gear 29 of the second planetary gear assembly 9 (an axle designated “MG2” in Fig. 2: where the second ring gear 29 corresponds to the second rotor shaft 16 of the second motor-generator 5). Then a lever ratio is found that shows the relationship between the distances, in each case between the two adjacent of the vertical axes: assuming that the distance between the axes ENG and OUT is 1, the distance between the axes ENG and MG1 takes the value k1, which results from dividing the number of teeth of the first ring gear 25 of the first planetary gear assembly 8 by the number of teeth of the first sun gear 22; the distance between the axes OUT and MG2 takes the value k2, which results from dividing the number of teeth of the second sun gear 26 of the second planetary gear assembly 9 by the number of teeth of the second ring gear 29.

[0026] This collinear diagram for the power sharing and composition system is equivalent to that previously proposed by the present applicant in JP 3 852 562 B2. The feature of the power sharing and composition system is that the first motor-generator 4 and the second motor-generator 5 are located at points where the two most distant of the four vertical axes lie. The relationship in which the first and second motor-generators 4 and 5 are placed at the two most distant of the four vertical axes not only represents, as mentioned in JP 3 852 562 B2, a configuration free from disadvantages such as an increase in the number of parts, an increase in the size of the system, an increase in mechanical loss, etc., ready, but also, as described below, a reduction in the extent of electrical energy exchange during driving in normal situations with a high gear ratio, which in turn improves fuel efficiency.

[0027] Below, with reference to several collinear diagrams, the relationships between the rotational speed and torque of machine 2, the vehicle speed, and the rotational speed and torque of the first and second motor-generators 4 and 5 are described. In each of the collinear diagrams, Tmg1 is the first motor-generator torque provided by the first rotor shaft 13 of the first motor-generator 4, Tmg2 is the second motor-generator torque provided by the second rotor shaft 16 of the second motor-generator 5, Teng is the machine torque provided by the machine output shaft 3 of machine 2, and Tout is the output drive torque from the output part 30, that is, the drive torque supplied to the drive shafts 7.In each of the collinear diagrams, it is defined that the rotational speed has a positive direction if its direction is the same as that of machine 2, and the torque, as an input along each of the four axes, has a positive direction if its direction is the same as that of the machine torque Teng. Therefore, the drive torque Tout from the output part 30 moves the hybrid vehicle backward if it has a positive direction, and forward if it has a negative direction.

[0028] Although the operation of a motor-generator in either driving or regenerative mode is accompanied by losses occurring at the inverter and the motor-generator during power generation, meaning that the efficiency of energy conversion between electrical and mechanical energy is not 100%, for the sake of simplicity, the following description assumes that no mechanical, electrical, or physical losses occur. If there is a genuine need to consider losses, it is sufficient to implement a compensating control system for them, for example, by generating more electrical power than the amount of energy lost through losses.

[0029] Fig. Figure 2 represents a slow-speed driving condition where the vehicle speed (the vehicle's travel speed) is relatively low and machine (ENG) 2 rotates in a positive direction to provide a positive machine torque Teng. Although the first motor-generator (MG1) 4 rotates in the positive direction at a high speed, the first motor-generator torque Tmg1 remains 0. Although the second motor-generator (MG2) 5 provides a positive second motor-generator torque Tmg2, the second motor-generator (MG2) 5 consumes no electrical power because the second motor-generator speed is 0 (outside of driving mode).In this case, since a ratio of the machine speed of machine 2 to the speed of the output part 30, that is, the vehicle speed, is called a “transmission ratio” and is expressed as (1 + k2) / k2, a state of low transmission ratio is created because the transmission ratio is greater than 1.

[0030] Fig. Figure 3 represents a high-speed drive state where the vehicle speed is relatively high and machine 2 rotates in the positive direction to provide a positive machine torque Teng. Although the first motor-generator (MG1) 4 delivers a negative first motor-generator torque Tmg1, it does not produce any electrical power because its first motor-generator speed is 0 (operation outside of regenerative mode). Although the second motor-generator (MG2) 5 rotates in the positive direction at a high speed, its second motor-generator torque Tmg2 remains 0. In this case, since the ratio of the machine speed of machine 2 to the speed of the output part 30, i.e., vehicle speed, is called a "gear ratio" and is expressed as k1 / (1 + k1), a high gear ratio state is created because the gear ratio is less than 1.

[0031] Fig. For example, in the illustrated state, 4 represents a driving state with medium speed, which is a medium-ratio state between the low-ratio state and the medium-ratio state. Fig. 2 and the state with a high translation ratio of the Fig. 3 corresponds to a situation where the vehicle speed is average and machine 2 rotates in a positive direction to deliver a positive machine torque Teng. The first motor-generator 4 rotates in a positive direction to provide a negative first motor-generator torque Tmg1. In fact, the first motor-generator 4 generates electrical power (operation in a regenerative mode). On the other hand, the second motor-generator 5 generates a positive second motor-generator torque Tmg2, even though it rotates in a positive direction. This is because the second motor-generator 5 consumes electrical power (operation in a driving mode). If there is no charging to or discharging from the battery 21, an exchange of electrical energy can be advantageously coordinated by supplying the second motor-generator 5 with electrical power generated by the first motor-generator 4.

[0032] Therefore, according to the present embodiment, the power distribution and composition system can provide a suitable drive torque Tout for each of the various operating states of the machine by controlling the drive state of the first and second motor-generators 4 and 5 over a wide speed range from low to high speed. In principle, the hybrid vehicle according to this embodiment does not require any transmission. Furthermore, it is possible to drive the hybrid vehicle in reverse even when the machine 2 continues to run. It is also possible to drive the hybrid vehicle forwards or backwards using one and / or both of the first motor-generator 4 and the second motor-generator 5 when the machine 2 is switched off.In this case, as described in JP 3 852 562 B2, the rotational speed of machine 2 should remain 0, so that if torque is applied to the machine output shaft 3 in the negative direction, this torque would be received by a one-way coupling.

[0033] Fig. Figure 5 is a view illustrating the power circulation on the first and second motor-generators 4 and 5. As shown in Fig. As shown in Figure 5, machine 2 rotates at a drive speed equal to or greater than the vehicle speed provided when the high gear ratio condition is in effect, as in Figure 5. Fig. As shown in Figure 3, the first motor-generator 4 is set up to rotate in the positive direction to deliver a positive machine torque Tg. The first motor-generator 4 then rotates in the opposite direction to provide a negative first motor-generator torque Tmg1. The first motor-generator 4 consumes electrical power (operation in a driving mode). On the other hand, and although it rotates in the positive direction, the second motor-generator 5 delivers a negative second motor-generator torque Tmg2. In fact, the second motor-generator 5 generates electrical power (operation in a regenerative mode). Operating the first and second motor-generators 4 and 5 in this way, so that one of them consumes electrical power (operation in driven mode) and the other generates electrical power (operation in regenerative mode), results in power circulation.The occurrence of such power circulation reduces the efficiency of the powertrain.

[0034] Referring again to the configuration of the drive control device 1, the machine 2 comprises: an air volume adjustment device 10, such as a throttle valve, to adjust an air intake condition in response to the position of an accelerator pedal (not illustrated); a fuel supply device 11, such as a fuel injection valve, to adjust a fuel supply condition in response to the air intake condition; and an ignition device 12, such as an ignition system, to adjust an ignition condition in response to the ignition of fuel. The air volume adjustment device 10, the fuel supply device 11, and the ignition device 12 are connected to a drive control device 32, which is configured to perform drive control.

[0035] According to such a configuration, the state of fuel combustion within machine 2 is controlled, for example, by controlling the air intake condition by the air quantity adjustment device 10, the fuel supply condition by the fuel supply device 11, and the ignition condition by the ignition device 12. This results in the control of the drive power of machine 2, in particular the control of the rotational speed and the drive torque, which are described below as machine speed and machine torque. A one-way clutch, not illustrated, is provided to allow the machine output shaft 3 of machine 2 to rotate in only one direction and to control its rotation in the opposite direction.

[0036] Furthermore, the hybrid vehicle has an accelerator pedal position sensor 33, which is configured to detect the position of the accelerator pedal as the accelerator pedal position, a vehicle speed sensor 34, which is configured to detect the vehicle speed, a machine speed sensor 35, which is configured to detect the rotational speed of the machine 2 as the machine speed, and a battery charge level sensor 36, which is configured to detect the amount of electrical energy stored in a battery 21, which can be referred to as the state of charge (SOC).

[0037] The drive control device 32 reads the detection signals acquired by these sensors and controls the operating conditions of the machine 2, the first motor-generator 4 and the second motor-generator 5 by controlling the air quantity adjustment device 10, the fuel supply device 11, the ignition device 12 and the first and second inverters 19 and 20 in accordance with the processing described below.

[0038] To perform such control according to this embodiment, the drive control device 32 has a machine control (or an operating point target calculation unit) 40 configured to set the efficient machine speed and efficient machine torque to perform the control, and a motor-generator control (or a motor torque command calculation) 60 configured to control the first and second inverters 19 and 20 such that the total power of the first and second motor-generators 4 and 5 assumes the power target for battery charging / discharging.

[0039] Furthermore, the drive control device 32 is formed from a processor, such as a microcomputer. The setting function and the control function are implemented through processing steps that are carried out in the drive control device 32. (Functions of machine control 40)

[0040] Fig. Figure 6 is a functional block diagram showing an example of functions of the machine control 40.

[0041] As in Fig. As shown in Figure 6, the machine control 40 has the following: a drive torque target calculation function 41; a drive power target calculation function 42; a charging / discharging power target calculation function 43; a calculation function for the temporary machine power target 44; a calculation function for the upper power limit 45; a calculation function for the temporary machine operating point target 46; a calculation function for the upper machine speed limit 47; a machine operating point target calculation function 48; a machine power target calculation function 49 and a calculation function for an electrical power target 50.

[0042] Fig. Figure 7 illustrates a program for machine control 40, which is implemented by the in Fig. The 6 functions shown are implemented. This program can, for example, be executed in accordance with a processing strategy, such as interrupt control, by using a timer to generate periodic interruptions, one occurring after a predetermined sampling time (for example, 10 ms).

[0043] With reference to the program of Fig. 7. A description of the processing content implemented by each of the functions follows: First, as in Fig. As shown in Figure 7, a machine control 40 reads different signals in step S1. In this embodiment, the machine control 40 reads such different signals from the accelerator pedal position sensor 33, the vehicle speed sensor 34, and the battery charge level sensor 36.

[0044] In the next step S2, the drive torque target calculation function 41 calculates a drive torque target (that is, a vehicle drive torque target). In this embodiment, the drive torque target calculation function 41 calculates a drive torque target in response to the vehicle speed and the accelerator pedal position (which can be equivalent to the amount the accelerator pedal is pressed), each of which was read in step S1. The drive torque target calculation function 41 refers, for example, to a drive torque target lookup card 41a to determine a drive torque target.

[0045] Fig. Figure 8 illustrates an example of a drive torque target reference card 41a.

[0046] As in Fig. As shown in Figure 8, the drive torque target lookup chart 41a illustrates the relationship between vehicle speed, drive torque target, and accelerator pedal position. In drive torque target lookup chart 41a, when the amount of accelerator pedal depressed is 0 in a range of high vehicle speeds, the drive torque target assumes a negative value to deliver drive power in a direction that tends to decelerate the hybrid vehicle as effectively as mechanical braking. In a range of low vehicle speeds, the drive torque target Aim for a positive value to allow the hybrid vehicle to continue driving slowly or creeping even after the accelerator pedal is released. In general, as shown in the Drive Torque Target Reference Chart 41a, the lower the drive torque target, the smaller the accelerator pedal position angle, and the lower the drive torque target, the higher the vehicle speed.

[0047] The drive torque target calculation function 41 refers to the drive torque target lookup card 41a to determine a drive torque target. The drive torque target calculation function 41 provides the determined drive torque target for the drive power target calculation function 42.

[0048] In the next step S3, the drive power target calculation function 42 calculates a drive power target that specifies the amount of power required so that the drive torque specified by the drive torque target propels the hybrid vehicle. Essentially, in this embodiment, the drive power target calculation function calculates... The drive power target function 42 calculates the drive power target by multiplying the vehicle speed and the drive torque target calculated in step S2. The drive power target is set such that each drive power target falling within a band close to the maximum drive power remains greater than the upper power limit, which specifies the maximum power that machine 2 can deliver, as described below. The drive power target calculation function 42 provides the calculated drive power target to the temporary machine power target calculation function 44 and the electrical power target calculation function 50.

[0049] In the next step S4, the charge / discharge power target calculation function 43 calculates a charge / discharge power target (a charge / discharge quantity target) to maintain the state of charge (SOC) of the battery 21 within a normal usage range, that is, within a range between a predetermined upper limit and a predetermined lower limit. In this embodiment, the charge / discharge power target calculation function 43 refers to a charge / discharge quantity target lookup card 43a to determine the charge / discharge power target.

[0050] Fig. Figure 9 illustrates an example of a loading / unloading quantity target reference card 43a.

[0051] As in Fig. As shown in Figure 9, the charge / discharge target lookup chart 43a illustrates the relationship between the state of charge (SOC) and the charge / discharge power target. In the charge / discharge target lookup chart 43a, when the SOC is low, the charge / discharge power target assumes a value on the charge side to prevent over-discharging from the battery 21 by increasing the charge power. Conversely, when the battery's state of charge (SOC) is high, the charge / discharge power target assumes a value on the discharge side to prevent over-charging by increasing the discharge power. For simplicity, in the charge / discharge target lookup chart 43a, the discharge side is positive and the charge side is negative.

[0052] The charging / discharging power target calculation function 43 refers to the charging / discharging quantity target lookup table 43a to determine the charging / discharging power target. The charging / discharging power target calculation function 43 provides the determined charging / discharging power target for the temporary machine power target calculation function 44.

[0053] In the next step S5, the calculation function for the temporary machine power target 44 calculates a temporary machine power target that specifies the amount of power that the machine 2 must deliver. In this embodiment, the calculation function for the temporary machine power target 44 calculates the temporary machine power target based on the drive power target calculated by the drive power target calculation function 42 in step S3, and on the charge / discharge power target calculated by the charge / discharge power target calculation function 43 in step S4.

[0054] The temporary machine power target is a value derived from the amount of power required to propel the hybrid vehicle, modified by taking into account the charging / discharging power for the battery 21 (by adding it during battery charging, operation in regenerative mode, or by subtracting it during battery discharge, operation in propulsion mode). In this embodiment, since the discharge side is negative, the calculation function for the temporary machine power target 44 subtracts the charging / discharging power target from the propulsion power target during battery discharge (operation in propulsion mode) to determine the temporary machine power target.

[0055] In the next step S6, the upper power limit calculation function 45 calculates an upper power limit, which indicates the maximum output value that machine 2 can deliver. The setting is such that the upper power limit is a value determined experimentally, empirically, or theoretically. Since this upper power limit is lower than the maximum of the drive power target or the adjacent drive power target set in step S3, an operating state with power assistance from battery 21 occurs. For example, if the accelerator pedal is pressed almost to 100%, the drive power target increases, and the power-assisted operating state occurs without difficulty.

[0056] The upper power limit calculation function 45 provides the calculated upper power limit for the temporary machine power target calculation function 44.

[0057] In the next step S7, the calculation function of the temporary machine performance target 44 determines whether the temporarily calculated machine performance target is greater than the upper performance limit or not.

[0058] If the calculation function for the temporary machine performance target 44 determines that the temporary machine performance target is greater than the upper performance limit (temporary machine performance target > upper performance limit), the program proceeds to step S8. If the calculation function for the temporary machine performance target 44 determines that the temporary machine performance target is less than or equal to the upper performance limit (temporary machine performance target ≤ upper performance limit), the program proceeds to step S9.

[0059] In step S8, the calculation function for the temporary machine performance target 44 sets the temporary machine performance target to the upper performance limit (temporary machine performance target = upper performance limit). Then, the calculation function for the temporary machine performance target 44 allows the program to proceed to step S9.

[0060] According to steps S7 and S8, the calculation function for the temporary machine power target 44 places the temporary machine power target below the upper limit. Then, the calculation function for the temporary machine power target 44 provides either the temporary machine power target calculated in step S8 (= upper power limit) or the temporary machine power target calculated in step S5 (≤ upper power limit) to the calculation function for the temporary machine operating point target 46.

[0061] In step S9, the temporary machine operating point target calculation function 46 calculates a temporary machine operating point target (a temporary machine speed target and a temporary machine torque target). In this embodiment, the temporary machine operating point target calculation function 46 calculates the temporary machine operating point target based on the vehicle speed and the temporary machine power target calculated by the temporary machine operating point target calculation function 46. Specifically, the temporary machine operating point target calculation function 46 refers to a machine operating point target lookup card 46a to determine the temporary machine operating point target.The calculation function of the temporary machine operating point target 46 provides the temporary machine operating point target (temporary machine speed target and temporary machine torque target) to the machine operating point target calculation function 48.

[0062] Fig. Figure 10 illustrates an example of a machine operating point target reference map 46a.

[0063] As in Fig. As shown in Figure 10, the machine operating point target lookup chart 46a illustrates the relationship between machine speed (machine speed target), machine torque (machine torque target), and vehicle speed. On the machine operating point target lookup chart, the machine operating point target varies in response to vehicle speed, and in particular, the higher the vehicle speed, the higher the machine speed and the lower the machine torque.

[0064] The reason for this is that the machine operating point reference card 46a was set as follows: Since machine power is the product of machine speed and machine torque, lines of constant power are inversely proportional to machine power when they are represented in a figure such as in Fig. Figure 11 shows a characteristic diagram for the machine, where the horizontal axis represents the machine speed and the vertical axis the machine torque. In this diagram, there are constant efficiency lines, each resulting from connecting points of constant efficiency after a functional test of the machine. If, for example, the most efficient machine speed and most efficient machine torque are given by the constant power lines selected for a machine power target, which is defined as an achievable goal, it is possible to achieve low fuel consumption at the least efficient operating point of the machine. Connecting these operating points yields a line of best operation for machine efficiency, as shown in Figure 11. Fig. 11 shown.

[0065] The machine speed target and the machine torque target, which were set in the manner mentioned above, are now illustrated as an operating point C.

[0066] With the machine speed target and the machine torque target set and fixed in this way, the vehicle speed, that is, the speed of the output part, is controlled as follows: Fig. As shown in Figure 12, the values ​​vary. In this case, since the vehicle speed is low and the output speed is low, both the speed of the first motor-generator and the second motor-generator are positive, and the first motor-generator torque takes on a positive value, while the second motor-generator torque takes on a negative value, as shown in a collinear diagram A in Figure 12. Fig. Figure 12 shows that in this case, although the first motor-generator 4 operates in a regenerative mode and the second motor-generator operates in a driving mode, no power (driving power) circulates because the direction of rotation of both is the positive direction of rotation.

[0067] Similarly, if the vehicle speed assumes a slightly higher value (for example, 40 km / h), and the output speed also assumes a slightly higher value, the speed of the first motor-generator is 0, the first motor-generator torque assumes a positive value, the second motor-generator speed is positive, and the second motor-generator torque is 0, as shown by a collinear diagram B in Fig. 12 shown (identical to the state of the high translation ratio shown in Fig. 3 is shown). In this case too, no power (drive power) circulates.

[0068] However, if the vehicle speed assumes an even higher value (for example, 80 km / h) and the output speed correspondingly assumes a higher value, the first motor-generator speed assumes a negative value, the first motor-generator torque assumes a negative value, the second motor-generator speed assumes a positive value, and the second motor-generator torque assumes a negative value, as shown in a collinear diagram C in Fig. Figure 12 illustrates this. In this state, since the first motor-generator 4 operates in a driving mode in the negative direction of rotation and the second motor-generator 5 operates in a regenerative mode, power (driving power) circulates, causing the efficiency of the drive train to decrease. With the decrease in drive train efficiency, although the machine efficiency is high, the overall efficiency and the efficiency at operating point C are lower than at operating point D.

[0069] Increasing the first motor-generator speed to higher than or equal to 0, as shown in a collinear diagram E in Fig. Figure 14 can be seen as an approach to preventing power circulation while driving at such a high speed (for example, 80 km / h), but this approach causes an increase in engine speed. When such an increase in engine speed occurs, the overall efficiency decreases, although the efficiency of the drivetrain is the same as in Figure 14. Fig. Point E shown in the illustration.

[0070] Then, the rotational speed of the machine is adjusted to drive at such a high speed (for example, 80 km / h) to a point D that lies between point C and point E, as in Fig. 13 shown (see a collinear diagram D in Fig. 14). With reference to Fig. 11. This rotational speed of the machine at this operating point D is used as a machine speed target and a machine torque on the line of constant power is used for the machine power target relative to the machine speed target as a machine torque target.

[0071] For these reasons, as in Fig. As shown in Figure 10, the target operating lines used when a machine power target is set, for example, will vary with different values ​​of the drive speed to provide a setting where, overall, the higher the vehicle speed, the higher the machine speed target and the lower the machine torque target.

[0072] In the next step S10, a calculation function for the upper limit of the machine speed 47 calculates an upper limit of the machine speed (an upper limit of the machine speed). In this embodiment, the calculation function for the upper limit of the machine speed 47 calculates the upper limit of the machine speed based on the vehicle speed.

[0073] Fig. Figure 15 is a collinear diagram illustrating the relationship between an upper limit of the rotational speed of the first motor-generator 4, an upper limit of the rotational speed of the machine 2 and a vehicle speed.

[0074] As in Fig. As shown in Figure 15, the upper speed limit of machine 2 is limited by the upper speed limit of the first motor-generator 4. Furthermore, the machine speed must be a value that depends on the vehicle speed (the speed of a drive shaft). With such a relationship, the machine operating point target calculation function 48 calculates the upper limit of the machine speed based on the vehicle speed, more precisely based on the vehicle speed and the upper speed limit of the first motor-generator 4.

[0075] In the next step S11, the machine operating point target calculation function 48 compares the temporary machine speed target with the upper machine speed target determined in step S10 to determine whether the temporary machine speed target is greater than the upper machine speed limit. The machine operating point target calculation function 48 proceeds to step S13 if it determines that the temporary machine speed target is greater than the upper machine speed limit (temporary machine speed target > upper machine speed limit). The machine operating point target calculation function 48 proceeds to step S12 if it determines that the temporary machine speed target is less than or equal to the upper machine speed limit (temporary machine speed target ≤ upper machine speed limit).

[0076] Then, in step S12, the machine operating point target calculation function 48 uses the temporary machine operating point (temporary machine speed target and temporary machine torque target) as a setpoint value for the machine operating point target (machine speed target and machine torque target) (machine operating point target = temporary operating point target). The machine operating point target calculation function 48 then allows the program to proceed to step S15.

[0077] In step S13, the machine operating point target calculation function 48 sets the machine speed target to the upper limit of the machine speed (machine speed target = upper limit of the machine speed).

[0078] In the next step S14, the machine operating point target calculation function 48 calculates a machine torque target. In this embodiment, the machine operating point target calculation function 48 refers to a machine operating point target lookup card 48a, which is similar to the card of the calculation function for the temporary machine operating point target 46, to calculate a machine torque target relative to the machine speed target (upper limit of the machine speed) set in step S13. The machine operating point target calculation function 48 then allows the program to proceed to step S15.

[0079] The machine operating point target calculation function 48 calculates (steps S12 to S14) a machine operating point target (machine speed target and machine torque target) in order to supply the calculated machine operating point target to the machine power target calculation function 49 and the motor-generator control 60.

[0080] In step S15, the machine performance target calculation function 49 calculates a machine performance target. In this embodiment, the machine performance target calculation function 49 calculates a second machine performance target based on the machine operating point target (machine speed target and machine torque target) calculated by the machine operating point target calculation function 48.

[0081] If the temporary machine speed target now exceeds the upper limit of the machine speed (if the answer at step S7 is determined to be "Yes"), the machine power target calculated at step S15 takes on a value less than the temporary machine power target calculated by the temporary machine power target calculation function 44, that is, the value at which the machine can practically produce power. Conversely, if the temporary machine speed target is equal to or less than the upper limit of the machine speed (if the answer at step S7 is determined to be "No"), the machine power target calculated at step S15 takes on a value equal to the temporary machine power target calculated by the temporary machine power target calculation function 44.

[0082] The machine power target calculation function 49 provides the calculated machine power target for the current power target calculation function 50.

[0083] In the next step S16, the calculation function calculates an electrical power target 50. In this embodiment, the calculation function calculates an electrical power target 50 by subtracting the machine power target from the drive power target.

[0084] The electrical power target represents a target value for the amount of electrical power delivered by battery 21 to the first motor-generator 4 and the second motor-generator 5 during operation in regenerative mode (charging battery 21), or the amount of electrical power delivered by battery 21 to the first motor-generator 4 and the second motor-generator 5 during operation in drive mode (discharging from battery 21). In other words, it represents a target value for the amount of input / output power to and from battery 21. Regarding the relationship between the drive power target and the machine power target: if the drive power target is greater than the machine power target, the electrical power target represents the amount of power support provided by the electrical power of the battery (delivering electrical power to the first and second motor-generators 4 and 5 from battery 21).Since the machine power target represents a power level at which the machine can generate power in practice, the propulsion power required by the vehicle driver can be supplied by generating the amount of power assistance in response to the calculated electrical power target. If the machine power target is greater than the propulsion power target, the electrical power target represents the amount of electrical power that can be used to charge battery 21.

[0085] Since during battery charging (in regenerative mode) the temporary machine power target is the sum of the drive power target and the charge / discharge power target, if the temporary machine speed target is less than or equal to the upper limit of the machine speed and the machine power target is equal to the temporary machine power target, the calculation function for an electrical power target 50 calculates a value that is equal to the charge / discharge power target (in this case the charge power target) that was calculated in step S4 as the electrical power target, that is, the difference between the machine power target and the drive power target.On the other hand, if the temporary machine speed target is limited by the upper machine speed limit such that the upper machine speed limit is not exceeded, and the machine power target is lower than the upper machine speed limit, the calculation function for an electrical power target of 50 calculates a value that is smaller than the charge / discharge power target (in this case, the charge power target) calculated in step S4. This means that the amount of discharge power during battery charging (in regenerative mode) is reduced.

[0086] On the other hand, the calculation function for an electrical power target of 50, during battery discharge (in driving mode), if the temporary machine speed target is less than or equal to the upper limit of the machine speed and the machine power target is equal to the temporary machine speed target, then the electrical power target will have a value equal to the charge / discharge power target (in this case, the discharge power target) calculated in step S4.On the other hand, if the temporary machine speed target is limited by the upper machine speed limit such that the upper machine speed limit is not exceeded, and the machine power target is lower than the temporary machine power target, the calculation function for an electrical power target 50 calculates a value that is greater than the charge / discharge power target (in this case, the discharge power target) calculated in step S4. This means that the amount of charging power during battery discharge (in driving mode) is increased.

[0087] The calculation function for an electrical power target 50 provides the calculated electrical power target (the charging / discharging power target) to the motor-generator control 60.

[0088] The machine control 40 controls the state of the air intake by means of the air quantity adjustment means 10, the state of the fuel supply by means of the fuel supply means 11 and the state of the ignition by means of the ignition means 12 in such a way that the calculated machine operating point target, in particular the machine torque target, is achieved. (Functions of the motor-generator control 60)

[0089] Fig. Figure 16 is a functional block diagram showing an example of functions of the motor-generator control unit 60.

[0090] As in Fig. As shown in Figure 16, the motor-generator control 60 has a motor speed calculation function (an Nmg1t and Nmg2t calculation function) 61, a calculation function 62 and 63 of a first and a second basic torque (a Tmg1i calculation function and a Tmg2i calculation function). tion), a calculation function of a first and a second feedback moment correction (a Tmg1fb calculation function and a Tmg2fb calculation function) 64 and 65 and a first and a second moment command calculation function (a Tmg1 calculation function and a Tmg2 calculation function) 66 and 67.

[0091] Fig. Figure 17 illustrates a program for the motor-generator control 60, which is implemented by the in Fig. The 16 functions shown are implemented. This program can, for example, be executed in accordance with a processing strategy, such as interrupt control, by using a timer to generate periodic interruptions, one occurring after a predetermined sampling time (for example, 10 ms).

[0092] With reference to the program of Fig. 17. A description of the processing content implemented by each of the functions follows: As in Fig. As shown in Figure 17, in one step S21 the motor speed calculation function 61 first calculates the drive shaft speed Nout, that is, the speed of the output part 30 of the planetary gear assembly, based on the vehicle speed. The output speed Nout is therefore derived from the vehicle speed, the differential gear ratio, and the gear ratio of the output transmission 31.

[0093] The motor speed calculation function 61 calculates the speed Nmg1t of the first motor-generator 4 and the speed Nmg2t of the second motor-generator 5 when the machine speed reaches the target machine speed Neng. In this embodiment, the machine speed calculation function 61 calculates the first motor-generator speed Nmg1t and the second motor-generator speed Nmg2t using equations (1) and (2), which are derived from the relationship between the speeds and the planetary gear sets. These equations are as follows: Nmg1t=(Neng−Nout)⋅k1+Neng Nmg2t=(Nout−Neng)⋅k2+Nout where: k1, k2 are the values ​​that result from the ratios of the number of gears within the planetary gear sets, as mentioned above.

[0094] The motor speed calculation function 61 provides the calculated first and second motor speeds Nmg1t and Nmg2t to the calculation function 62 of the first torque reference quantity.

[0095] In the next step S22, the first torque reference function 62 calculates a first torque reference for the first motor-generator 4. In this embodiment, the first torque reference function 62 calculates the first torque reference Tmg1i for the first motor-generator 4 based on an electrical power target (the charging / discharging power target) Pbatt, which is calculated by the machine controller 40, the first and second motor-generator speeds Nmg1t and Nmg2t, which were calculated in step S21 by the motor speed calculation function 61, and the machine torque reference Tengt, which was calculated by the machine controller 40. Specifically, the first torque reference function 62 calculates the torque reference Tmg1i for the first motor-generator 4 from equation (3) as follows: Tmg1=(Pbatt⋅60 / (2⋅π)−Nmg2t⋅Tengt / k2) / (Nmg1t+Nmg2t⋅(1+k1) / k2)

[0096] Equation (3) is obtained by simultaneously solving the following equations (4) and (5): Tengt+(1+k1)⋅Tmg1=k2⋅Tmg2 Nmg1⋅Tmg1⋅2⋅π / 60+Nmg2⋅Tmg2⋅2⋅π / 60=Pbatt

[0097] Equation (4) is an equation that expresses an equilibrium of torque inputs to the planetary gear sets (a torque equilibrium equation). Equation (4) therefore balances the torque target Tmg1 of the first motor-generator 4, the torque target Tmg2 of the second motor-generator 5, and the machine torque target Tengt, which is based on the lever ratio derived from the ratios in the number of teeth of the gears of the planetary gear sets that mechanically couple the first and second motor-generators 4 and 5 to the machine 2.

[0098] Equation (5) is an equation that expresses a balance between the amount of electrical power produced or consumed by the first motor-generator 4 and the second motor-generator 5 and the amount of input / output current power, as specified at Pbatt, to and from the battery 21 (charging / discharging power), and is called a power balance equation.

[0099] The calculation function 62 of the first moment reference quantity provides the moment reference quantity Tmg1i of the calculation function 63 of the second moment reference quantity and the calculation function 66 of the first moment instruction.

[0100] In the next step S23, the calculation function 63 of the second torque reference quantity calculates the torque reference quantity Tmg2i of the second motor-generator 5. In this embodiment, the calculation function 63 of the second torque reference quantity calculates the torque reference quantity Tmg2i of the second motor-generator 5 based on the torque reference quantity Tmg1i, which was calculated by the calculation unit of the first torque reference quantity 62 in step S22, and based on the machine torque target Tengt, which was calculated by the machine control 40. Specifically, the calculation function 63 of the second torque reference quantity calculates the torque reference quantity Tmg2i for the second motor-generator 5 from equation (6) as follows: Tmg2i=(Tengt+1(1+k1)⋅Tmg1i) / k2

[0101] This equation (6) is derived from equation (4).

[0102] The calculation function 63 of the second torque reference quantity provides the calculated torque reference quantity Tmg2i of the second motor-generator 5 to the calculation function 67 of the second torque instruction.

[0103] In the next step S24, the first and second feedback torque correction calculation functions 64 and 65 each calculate feedback torque corrections Tmg1fb and Tmg2fb for the first motor generator and the second motor generator 4 and 5.

[0104] In this embodiment, the first feedback torque correction calculation function 64 calculates the feedback torque correction Tmg1fb for the first motor-generator 4 based on the machine speed and the machine speed target. Similarly, the second feedback torque correction calculation function 65 calculates the feedback torque correction Tmg2fb for the second motor-generator 5 based on the machine speed and the machine speed target.

[0105] Specifically, the first and second feedback moment correction calculation functions 64 and 65 calculate respective feedback moment corrections Tmg1fb and Tmg2fb by multiplying the deviation of the measured machine speed (the machine speed) from the target value (the machine speed target) by a predetermined feedback gain to bring the machine speed closer to the machine speed target.

[0106] The first and second feedback torque correction calculation functions 64 and 65 can provide feedback torque corrections Tmg1fb and Tmg2fb based on ratios of the number of teeth of gears and the lever ratio of the planetary gear sets having four rotating elements, each coupled to the first motor-generator 4, the second motor-generator 5, the drive shafts 7 and the machine 2.

[0107] The first feedback torque correction calculation function 64 provides the calculated feedback torque correction Tmg1fb for the first motor-generator 4 for the first torque instruction calculation function 66. The second feedback torque correction calculation function 65 provides the calculated feedback torque correction Tmg2fb for the second motor-generator 5 for the second torque instruction calculation function 67.

[0108] In the next step S25, the first and second torque instruction calculation functions 66 and 67 each calculate torque instructions for the first and second motor generators 4 and 5.

[0109] In this embodiment, the first torque command calculation unit calculates a torque command for the first motor-generator 4 based on the torque reference quantity Tmg1i for the first motor-generator 4, calculated by the first torque base calculation function 62 in step S22, and a feedback torque correction Tmg1fb for the first motor-generator 4, calculated by the first feedback torque correction calculation function 64 in step S24. Similarly, the second torque command calculation function 67 calculates a torque command for the second motor-generator 5 based on the torque reference quantity Tmg2i for the second motor-generator 5, calculated by the first torque reference quantity calculation function 63 in step S23, and a feedback torque correction Tmg2fb for the second motor-generator 5, calculated by the second feedback torque correction calculation function 65 in step S24.

[0110] Specifically, the first and second torque instruction calculation functions 66 and 67 calculate the torque instructions for the respective motor-generators 4 and 5 by adding the torque bases Tmg1i and Tmg2i to the feedback torque corrections Tmg1fb and Tmg2fb, respectively. That is, the first and second torque instruction calculation functions 66 and 67 adjust the respective feedback torque corrections such that the actual machine speed can converge to the machine speed target derived from the machine operating point target.

[0111] The motor-generator controller 60 delivers the calculated torque commands Tmg1i and Tmg2i for the first and second motor-generators 4 and 5 to the first and second inverters 19 and 20, respectively. The first and second inverters 19 and 20 each control the first and second motor-generators 4 and 5 based on these torque commands. This causes the first and second motor-generators 4 and 5 to operate in either driving mode or regenerative mode. (Operation)

[0112] According to the drive control device mentioned above, a drive torque target is calculated in response to the vehicle speed and accelerator pedal position, and a charge / discharge power target is calculated in conjunction with a drive power target based on the calculated drive torque target and the vehicle speed (steps S1 to S4). The drive control device then calculates a temporary engine power target based on such a calculated drive power target and charge / discharge power target (step S5). Furthermore, the drive control device keeps the calculated temporary engine power target unchanged if it is equal to or less than the upper power limit, and sets the temporary engine power target to the upper power limit if it is greater than the upper power limit (steps S6 to S8).

[0113] The drive control unit calculates a temporary machine operating point target (a temporary machine speed target and a temporary machine torque target) with reference to the machine operating point target lookup chart, based on the temporary machine power target, which is either held unchanged or set to the upper power limit and vehicle speed (step S9). Conversely, the drive control unit calculates an upper machine speed limit based on the vehicle speed and compares such a calculated temporary machine speed target with the calculated upper machine speed limit (steps S10 and S11).This allows the drive control device to set the machine operating point, which remains unchanged as a machine operating point target if the temporary machine speed target is equal to or less than the upper machine speed limit, and the drive control device can set the upper machine speed limit as a machine speed target if the temporary machine speed target is greater than the upper machine speed limit and then access the machine operating point target lookup card to recalculate a machine torque target relative to the set machine speed target (the upper machine speed limit) (steps S12 to S14).

[0114] The drive control device calculates a machine power target based on the machine operating point target (the machine speed target and the machine torque target), (step S15), and calculates an electrical power target by subtracting the calculated machine power target from the drive power target (step S16).

[0115] During battery charging (in regenerative mode), an electrical power target is calculated as follows: If a temporary machine speed target is equal to or less than an upper machine speed limit, and a machine power target is equal to a temporary machine power target, the drive control device calculates an electrical power target equal to a charge / discharge power target (in this case, a charge power target). Conversely, if, in order to prevent a temporary machine speed target from exceeding an upper machine speed limit, the temporary machine power target is limited by the upper machine speed target and is therefore equal to it, and a machine power target is less than a temporary machine power target, the drive control device calculates an electrical power target equal to a value lower than a charge / discharge power target (in this case, a charge power target).

[0116] During battery discharge (in driving mode), an electrical power target is calculated as follows: If a temporary machine speed target is equal to or less than an upper machine speed limit, and a machine power target is equal to a temporary machine power target, the drive control device calculates an electrical power target equal to a charge / discharge power target (in this case, a discharge power target). Conversely, if, in order for a temporary machine speed target not to exceed an upper machine speed limit, the temporary machine power target is limited by the upper machine speed target and is therefore equal to it, and a machine power target is less than a temporary machine power target, the drive control device calculates an electrical power target equal to a value greater than a charge / discharge power target (in this case, a discharge power target).

[0117] Then the drive control device controls the air intake condition by means of the air quantity adjustment device 10, the fuel supply condition by means of the fuel supply device 11 and the ignition condition by means of the ignition device 12, so that the calculated machine operating point, in particular the machine torque target, can be achieved.

[0118] On the other hand, the drive control device calculates torque commands to control the first and second motor-generators 4 and 5 based on the aforementioned calculated machine operating point target, the electrical power target, etc.

[0119] The drive control device therefore calculates a drive shaft input speed Nout of the planetary gear units and speeds Nmg1t and Nmg2t for the first and second motor-generators 4 and 5 based on the calculated drive shaft input speed Nout (step S21). Then, the drive control device calculates a torque base Tmg1i for the first motor-generator 4 based on the electrical power target Pbatt, the first and second motor-generator speeds Nmg1t and Nmg2t, and the machine torque target Tengt (step S22). Conversely, the drive control device calculates a torque reference value Tmg2i for the second motor-generator 5 based on the torque reference value Tmg1i calculated for the first motor-generator 4 and the machine torque target Tengt (step S23).Furthermore, the drive control device calculates feedback torque corrections Tmg1fb and Tmg2fb for the first and second motor generators 4 and 5 based on the machine speed and the machine speed target (step S24).

[0120] This enables the drive control device to calculate the torque commands for the first and second motor generators 4 and 5 based on the calculated torque bases Tmg1i and Tmg2i for the first and second motor generators 4 and 5, and the feedback torque corrections Tmg1fb and Tmg2fb for the first and second motor generators 4 and 5 (step S25).

[0121] The drive control device delivers these calculated torque commands Tmg1i and Tmg2i for the first and second motor-generators 4 and 5 to the first and second inverters 19 and 20, respectively. The first and second inverters 19 and 20 each control the first and second motor-generators 4 and 5 based on these torque commands Tmg1i and Tmg2i. This allows the first and second motor-generators 4 and 5 to operate in either drive mode or regenerative mode. As a result, the drive control device can achieve the battery charge / discharge target for battery 21 while simultaneously meeting the drive torque target. (Effect of the present embodiment)

[0122] In the present embodiment, a final machine speed target is calculated such that a temporary machine speed target cannot exceed an upper limit based on the temporary machine operating point target, which was calculated from an originally calculated temporary machine power target; based on the final machine speed target, a machine operating point target is recalculated; based on the newly calculated machine operating point target, a final machine power target is calculated; based on the calculated final machine power target, an electrical power target is calculated;and based on the calculated machine operating point target and the electrical power target, the motor-generators 4 and 5 are controlled, that is, the motor-generators 4 and 5 are controlled to operate in driving mode or regenerative mode, together with a control of the torque of machine 2 based on the machine operating point target (in particular the machine torque end target).

[0123] In the present embodiment, this prevents the machine speed from becoming too high by calculating a target machine speed that cannot exceed the upper limit. It also allows the motor-generators 4 and 5 to operate in driving mode by calculating an electrical power target based on the machine speed target, which is calculated to avoid exceeding the upper limit. This compensates for a reduction in machine output to meet the drive torque demanded by the vehicle driver. The drive torque demanded by the vehicle driver can therefore be met by power assistance generated by utilizing electrical power from battery 21, with the state of charge (SOC) of battery 21 maintained within a predetermined range. This prevents the machine speed from becoming too high.

[0124] On the other hand, in the present embodiment, a machine operating point target is calculated based on a first machine speed target, which is calculated such that it does not exceed an upper limit, and an electrical power target, as determined taking into account a drive power target, is calculated based on the calculated target machine operating point. According to this embodiment, a suitable machine operating point is therefore determined, while a drive power target and an electrical power target are achieved.

[0125] In the present embodiment, taking into account the machine operating point, both the desired drive power and the desired charging / discharging state (SOC is kept within a predetermined range) are ensured.

[0126] In the present embodiment, a machine performance target is calculated so that it does not exceed the upper performance limit that has been set for a temporary machine performance target.

[0127] In the present embodiment, this ensures a power support range that uses electrical power from battery 21 to regulate the machine so that its operating point can be adjusted to an optimal operating point and that maintains the state of charge (SOC) of battery 21 within a predetermined range. The present embodiment therefore enables the hybrid vehicle to be driven using electrical power from battery 21 by utilizing the power support range in response to the driver's request. Furthermore, two or more motor-generators 4 and 5 can be controlled during the charging / discharging of battery 21.

[0128] On the other hand, in the present embodiment, an upper machine speed limit is calculated based on the vehicle speed and on the upper speed limit for the first motor-generator 4.

[0129] The present embodiment therefore makes it possible to calculate the appropriate upper machine speed limit that is suitable for the property of the hybrid vehicle according to the present embodiment, which limits the upper machine speed limit of machine 2 with the upper speed limit of the first motor-generator 4 and allows it to vary in response to the vehicle speed.

[0130] In this embodiment, a feedback correction is provided for each of the torque commands to the motor-generators 4 and 5 to allow the current machine speed to approach a machine speed target determined from a machine operating target. In this embodiment, the fine-tuning of the torque commands to the motor-generators 4 and 5 can therefore be achieved by providing the feedback corrections in such a way that the machine speed can rapidly approach the machine speed target. In this embodiment, the machine operating point can thus quickly align with the operating point target, enabling the appropriate operating state to be reached rapidly.

[0131] Preferably, in the present embodiment, it is desirable to use a drive control device for a hybrid vehicle that controls the drive power of the hybrid vehicle by using outputs of a machine and a plurality of motor-generators to form a drive control device for a hybrid vehicle, which includes: an accelerator pedal position detection function for detecting an accelerator pedal position; a vehicle speed detection function for detecting a vehicle speed; a battery charge level detection function for detecting the state of charge of a battery; a drive power target setting function for setting a drive power target based on the accelerator pedal position detected by the accelerator pedal position detection function and the vehicle speed detected by the vehicle speed detection function;a charge / discharge power target setting function for setting a charge / discharge power target based on at least the battery state of charge detected by the battery state of charge detection function, and a motor torque command determination function for setting torque commands for the variety of motor generators. Description of reference symbols

[0132] 1 Hybrid vehicle drive control device; 40 Machine control; 41 Drive target calculation function; 42 Drive power target calculation function; 43 Charging / discharging power target calculation function; 44 Temporary machine power target calculation function; 45 Upper power limit calculation function; 46 Temporary machine operating point target calculation function; 46a, 48a Machine operating point target lookup cards; 47 Upper machine speed limit calculation function; 48 Machine operating point target calculation function; 49 Machine power target calculation function; 50 Electrical power target calculation function; and 60 Motor-generator control.

Claims

[1] Drive control device (1) for providing drive control for a hybrid vehicle by controlling a machine (2) and motor-generators (4, 5) which can be operated to output a charge of electrical power to a battery (21) and to receive a supply of electrical power from the battery (21) to supply the hybrid vehicle with a motive force obtained from the machine (2) and the motor-generators (4, 5), wherein the drive control device has a power sharing and composition system having four axes connected to each of the rotating elements of the two planetary gear sets (8, 9); wherein two motor generators (4, 5) are connected to the battery (21); wherein one of the motor generators (4, 5), the machine (2), a drive shaft (7) connected to a traction wheel (6), and the other of the motor generators (4, 5) are on a collinear diagram, wherein the four axes of the power sharing and composition system are each connected to one motor generator (4, 5), the machine (2), the drive shaft (7), and the other motor generator (4, 5); the drive control device further comprises the following: a drive power target calculation function (42) for calculating a drive power target based on an accelerator pedal position and a vehicle speed; a charge / discharge power target calculation function (43) for calculating an electrical charge / discharge power target to / from the battery (21) based on a charge / discharge state of the battery (21); a first machine power target calculation function (44) for calculating a first machine power target based on the drive power target calculated by the drive power target calculation function (42) and the electrical charge / discharge power target calculated by the charge / The discharge power target calculation function (43) is calculated; a first machine operating point target calculation function (46) for calculating a first machine speed target and a first machine torque target, both of which correspond to the first machine power target calculated by the first machine power target calculation function (44), based on information about a machine operating point identified by a relationship between a machine speed and a machine torque; a first calculation function (47) for an upper machine speed target limit for calculating an upper limit of the first machine speed target based on the vehicle speed, wherein the upper limit of the machine speed is limited by an upper limit of the speed of one motor-generator (4, 5) and is subject to changes depending on the vehicle speed, and wherein the calculation function (47) of the upper first machine speed target limit calculates the upper limit of the first machine speed target based on the vehicle speed and the upper limit of the speed of one motor-generator (4, 5); a machine operating point target calculation function (48) to determine whether the first machine speed target calculated by the first machine operating point target calculation function (46) is greater than the upper limit, wherein the machine operating point target calculation function (48) is designed to: to set a second machine speed target to the upper limit and to calculate a second machine torque target corresponding to the second machine speed target, based on the information about the machine operating point, when it is determined that the first machine speed target calculated by the first machine operating point target calculation function (46) is greater than the upper limit; and to set the second machine speed target and the second machine torque target as the first machine speed target and as the first machine torque target if it is determined that the first machine speed target calculated by the first machine operating point target calculation function (46) is less than or equal to the upper limit; a second machine power target calculation function (49) for calculating a second machine power target based on the second machine speed target and the second machine torque target; a calculation function (50) for an electrical power target for calculating an electrical power target that specifies an amount of electrical power to be generated by driving the motor generators (4, 5) to charge the battery (21), or to be supplied from the battery (21) to the motor generators (4, 5) to drive the motor generators (4, 5), based on a difference between the drive power target calculated by the drive power target calculation function (42) and the second machine power target calculated by the second machine power target calculation function (49); a machine control (40) that is configured to to control a moment of the machine (2) based on the second machine moment target; and a motor-generator control unit (60) configured to control the motor-generators (4, 5) based on the second machine speed target, the second machine torque target, and the electrical power target. [2] Drive control device according to claim 1, which furthermore has a calculation function (45) of an upper machine power target limit in order to calculate as an upper limit of the first machine power target a maximum output power that the machine (2) can provide and wherein the calculation function (44) of the first machine performance target calculates the first machine performance target such that the upper limit calculated by the calculation function (45) of the upper machine performance target limit is not exceeded. [3] Hybrid vehicle with the drive control device (1) according to one of claims 1 or 2. [4] Drive control method for providing drive control for a hybrid vehicle in which a machine (2) and motor-generators (4, 5) are controlled which can be operated to output a charge of electrical power to a battery (21) and to receive a supply of electrical power from the battery (21) to supply the hybrid vehicle with a motive force obtained from the machine (2) and the motor-generators (4, 5), wherein a drive control device (1) has a power sharing and composition system having four axes connected to each of the rotating elements of the two planetary gear sets (8, 9); wherein two motor-generators (4, 5) are connected to the battery. (21); wherein one of the motor generators (4, 5), the machine (2), a drive shaft (7) connected to a traction wheel (6) and the other of the motor generators (4, 5) lie on a collinear diagram, wherein the four axes of the power sharing and composition system are each connected to one motor generator (4, 5), the machine (2), the drive shaft (7) and the other motor generator (4, 5); the drive control procedure comprises the following steps: Calculating a drive power target based on an accelerator pedal position and a vehicle speed; Calculating an electrical charge / discharge power target to / from the battery (21) based on a charge / discharge state of the battery (21); Calculating an initial machine power target based on the drive power target and the electrical charging / discharging power target; Calculating a first machine speed target and a first machine torque target, both corresponding to the first machine power target, based on information about a machine operating point identified by a relationship between a machine speed and a machine torque; Calculating an upper limit of the first machine speed target based on the vehicle speed, wherein the upper limit of the machine speed is bounded by an upper limit of the speed of one motor-generator (4, 5) and is subject to changes depending on the vehicle speed, and wherein the calculation function (47) of the upper first machine speed target limit calculates the upper limit of the first machine speed target based on the vehicle speed and the upper limit of the speed of one motor-generator (4, 5); Determine whether the calculated first machine speed target is greater than the upper limit, and; Setting a second machine speed target to the upper limit and calculating a second machine torque target corresponding to the second machine speed target, based on information about the machine operating point, if it is determined that the calculated first machine speed target is greater than the upper limit; and Setting the second machine speed target and the second machine torque target as the first machine speed target and as the first machine torque target if it is determined that the calculated first machine speed target is less than or equal to the upper limit; Calculating a second machine power target based on the second machine speed target and the second machine torque target; Calculating an electrical power target that specifies the amount of electrical power to be generated by driving the motor-generators (4, 5) to charge the battery (21) or to be supplied from the battery (21) to the motor-generators (4, 5) to drive the motor-generators (4, 5), based on a difference between the drive power target and the second machine power target; Control of a machine moment (2) based on the second machine moment target; and Control of the motor-generators (4, 5) based on the second machine speed target, the second machine torque target and the electrical power target.

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