阅读说明：本技术 混合动力车辆及其控制方法以及记录介质 (Hybrid vehicle, control method thereof, and recording medium ) 是由 竹田洋平 于 2021-02-23 设计创作，主要内容包括：本发明提供混合动力车辆及其控制方法以及记录介质,即使行驶用的马达的再生电力增加,也能够维持发电扭矩。混合动力车辆通过发动机(109)和马达(107)中的至少一方的驱动力进行行驶,其具备：能够进行充放电的电池(101)；发电机(111),其通过发动机的旋转而进行发电；以及控制单元(125),其对发动机和发电机进行控制,使得按照电池的目标电池端电力,通过发电机的发电电力和/或马达的再生电力对电池进行充电,控制单元在由于使用制动器而使马达的再生电力增加时,根据再生电力的增加量而使目标电池端电力增加,将发电机的发电扭矩维持在比规定范围大的值。(The invention provides a hybrid vehicle, a control method thereof and a recording medium, which can maintain the generating torque even if the regenerative power of a motor for running is increased. A hybrid vehicle travels by the driving force of at least one of an engine (109) and a motor (107), and is provided with: a battery (101) capable of being charged and discharged; a generator (111) that generates power by rotation of the engine; and a control unit (125) that controls the engine and the generator such that the battery is charged with the generated power of the generator and/or the regenerative power of the motor in accordance with the target battery-side power of the battery, wherein when the regenerative power of the motor is increased by using the brake, the control unit increases the target battery-side power in accordance with the amount of increase in the regenerative power, and maintains the generated torque of the generator at a value greater than a predetermined range.)

1. A hybrid vehicle that travels by a driving force of at least one of an engine and a motor,

the hybrid vehicle is provided with:

a battery capable of being charged and discharged;

a generator that generates power by rotation of the engine; and

a control unit that controls the engine and the generator such that the battery is charged with generated power of the generator and/or regenerative power of the motor in accordance with target battery-side power of the battery,

the control unit increases the target battery-side electric power in accordance with an amount of increase in the regenerative electric power when increasing the regenerative electric power of the motor by using a brake, and maintains the generated torque of the generator at a value larger than a predetermined range.

2. The hybrid vehicle according to claim 1,

the control unit has:

a regenerative power calculation unit that calculates the regenerative power of the motor that can be generated by the brake operation and/or accelerator pedal operation;

a target battery-side power calculation unit that increases the target battery-side power in accordance with the regenerative power; and

and an engine output calculation unit that calculates a required torque of the engine based on at least the increased target battery-side electric power, the actual battery-side electric power, and the required driving force.

3. The hybrid vehicle according to claim 1 or 2,

the prescribed range of the power generation torque is a range in which: in a system in which the engine and the motor or the generator are combined via a gear mechanism, when the power generation torque of the generator is reduced, abnormal noise is generated in the gear mechanism.

4. A control method for a hybrid vehicle that travels by a driving force of at least one of an engine and a motor, and that has a chargeable/dischargeable battery and a generator that generates electric power by rotation of the engine,

calculating a regenerative electric power of the motor increased by using a brake;

increasing the target battery-side electric power in accordance with the amount of increase in the regenerative electric power;

the engine and the generator are controlled so that the battery is charged with the generated power of the generator and/or the regenerative power of the motor in accordance with the increased target battery-side power, thereby maintaining the generated torque of the generator at a value greater than a predetermined range.

5. The control method of a hybrid vehicle according to claim 4,

a regenerative power calculation unit calculates the regenerative power of the motor that can be generated by the brake operation and/or accelerator pedal operation,

the target-battery-side power calculation unit increases the target battery-side power in accordance with the regenerative power,

an engine output calculation unit calculates a required torque of the engine based on at least the increased target battery-side electric power, the actual battery-side electric power, and the required driving force.

6. The control method of the hybrid vehicle according to claim 4 or 5,

the prescribed range of the power generation torque is a range in which: in a system in which the engine and the motor or the generator are combined via a gear mechanism, when the power generation torque of the generator is reduced, abnormal noise is generated in the gear mechanism.

7. A recording medium having a program recorded thereon, the program causing a processor to function as a control device for a hybrid vehicle that travels by a driving force of at least one of an engine and a motor and that has a battery that can be charged and discharged and a generator that generates electric power by rotation of the engine,

the program causes the processor to realize the following functions:

calculating a regenerative electric power of the motor increased by using a brake;

increasing the target battery-side electric power in accordance with the amount of increase in the regenerative electric power; and

the engine and the generator are controlled so that the battery is charged with the generated power of the generator and/or the regenerative power of the motor in accordance with the increased target battery-side power, thereby maintaining the generated torque of the generator at a value greater than a predetermined range.

Technical Field

The present invention relates to a control technique for a hybrid vehicle that travels by a driving force of at least one of an engine (internal combustion engine) and a motor (electric motor).

Background

An HEV (Hybrid electric Vehicle) includes a motor and an engine, and travels by driving force of the motor or the engine, or both the motor and the engine, depending on the traveling state of the Vehicle. In the case of traveling by a motor, the engine drives a generator, and the generated electric power is used for charging a battery or driving the motor. During deceleration, regenerative braking in which the motor is operated as a generator is used to obtain a braking force corresponding to engine braking. The regenerative energy generated at the time of regenerative braking is used for charging the battery.

In such a hybrid vehicle, it is known that noise is generated due to regenerative driving of the motor. In particular, when the rotation speed of the motor enters a resonance region of noise caused by regeneration, the noise becomes large, and the noise becomes larger as the regenerative torque becomes larger. Since the resonant rotational speed of such a motor is in a usual region, it cannot be avoided as a system. In contrast, several techniques for suppressing noise caused by regeneration have been proposed. For example, patent document 1 discloses the following control method: when the rotational speed of one motor is in the resonance region and the other motor is in the non-resonance region, the regenerative torque of the motor on the resonance side is reduced and the regenerative torque of the motor on the non-resonance side is increased, thereby minimizing noise caused by regeneration.

Further, as abnormal noise which cannot be avoided in the hybrid vehicle system, there is so-called rattle (ガラ sound) or tooth hitting sound ( hitting ち sound). In the hybrid vehicle, since the rotating shaft of the engine and the rotating shaft of the motor or the generator are coupled via the gear mechanism, the flywheel of the engine and the motor/generator become large inertial mass, and repeated collision and separation between the gear and the gear due to hysteresis characteristics of the inertial mass become a cause of generation of abnormal noise. Patent document 2 discloses an example of a technique for avoiding such abnormal noise. According to patent document 2, in the case where the engine and the generator are connected via a gear mechanism, rattling is avoided by controlling the rotation speed of the generator. Specifically, a basic torque command value that makes the torque response of the generator coincide with a prescribed response is calculated, and the torque command value of the generator is calculated in consideration of the disturbance torque, thereby avoiding rattling.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2016-093032

Patent document 2: international publication No. 2017/212581

Disclosure of Invention

Problems to be solved by the invention

However, in the control method disclosed in patent document 2, torque control of the generator is performed only so as not to use a power generation torque region in which rattle occurs, and it is not considered that the amount of power generation of the generator is reduced due to generation of regenerative power at the time of deceleration of the vehicle. The problem of the control method of patent document 2 will be briefly described below with reference to fig. 1.

In fig. 1, when the accelerator pedal is fully closed (a), the motor regenerates and gives a torque instruction so as to obtain a regenerative braking force (c) corresponding to engine braking. Further, although the generator continues to generate power by the engine, its generated torque value 10 decreases according to the regenerative power of the motor. As shown in fig. 1 (e), the generated torque value 10 is set to a level at which the rattle generation region R is not entered. Thus, the regenerative power of the motor and the power generation amount of the generator are adjusted so as to maintain the target power (target Batt terminal power) of the battery, and control is performed so that the power generation torque does not fall within the grating sound generation region R.

However, when the brake operation 11 is performed, regenerative electric power 11a of the motor is generated. As described above, the power generation amount of the generator is adjusted to maintain the target Batt terminal power of the battery, and therefore, when the regenerative power 11a is generated, in order to maintain the target Batt terminal power and charge the regenerative power amount 11a to the battery, the power generation amount of the generator needs to be decreased by the generation corresponding amount 11 c. Therefore, when the return power by the brake operation is large, the generated torque is reduced by the regenerative power corresponding amount 11c as shown in fig. 1 (e), and as a result, the rattle generation region R is entered.

Accordingly, an object of the present invention is to provide a hybrid vehicle and a control method thereof, which can maintain a generated torque even if regenerative power of a motor for traveling increases.

Means for solving the problems

According to the 1 st aspect of the present invention, there is provided a hybrid vehicle that travels by a driving force of at least one of an engine (109) and a motor (107), the hybrid vehicle including: a battery (101) capable of being charged and discharged; a generator (111) that generates power by rotation of the engine (109); and a control unit (125) that controls the engine (109) and the generator (111) such that the battery (101) is charged with the generated power of the generator (111) and/or the regenerative power (11a) of the motor (107) in accordance with a target battery-side power of the battery (101), wherein when the regenerative power (11a) of the motor (107) is increased by using a brake, the control unit (125) increases the target battery-side power in accordance with an amount of increase in the regenerative power (11a) and maintains the generated torque (20a) of the generator (111) at a value greater than a predetermined range.

According to the 2 nd aspect of the present invention, there is provided a control method of a hybrid vehicle which travels by a driving force of at least one of an engine (109) and a motor (107) and has a battery (101) that can be charged and discharged and a generator (111) that generates electric power by rotation of the engine (109), the control method including calculating regenerative electric power (11a) of the motor (107) that is increased by using a brake, increasing target battery-side electric power according to an amount of increase in the regenerative electric power (11a), controlling the engine (109) and the generator (111) such that the battery (101) is charged by the generated electric power of the generator (111) and/or the regenerative electric power (11a) of the motor (107) according to the increased target battery-side electric power, thus, the power generation torque (20a) of the generator (111) is maintained at a value greater than a predetermined range.

According to the 3 rd aspect of the present invention, there is provided a program that causes a processor to function as a control device for a hybrid vehicle that travels by driving force of at least one of an engine (109) and a motor (107) and that has a chargeable and dischargeable battery (101) and a generator (111) that generates electric power by rotation of the engine (109), the program causing the processor to function as: calculating regenerative electric power (11a) of the motor (107) increased by using a brake; increasing the target battery-side electric power in accordance with the amount of increase in the regenerative electric power (11 a); and controlling the engine (109) and the generator (111) such that the battery (101) is charged with the generated power of the generator (111) and/or the regenerative power (11a) of the motor (107) in accordance with the increased target battery-side power, thereby maintaining the generated torque (20a) of the generator (111) at a value greater than a predetermined range.

Thus, even if the regenerative power is increased by using the brake, by increasing the target power value of the battery in accordance with the amount of increase, the power generation torque can be maintained without changing the amount of power generation by the generator, and a decrease in the power generation torque to a predetermined range can be avoided.

The control unit (125) can have: a regenerative power calculation unit (204) that calculates the regenerative power (11a) of the motor (107) that can be generated by the brake operation and/or accelerator pedal operation; a target battery-side power calculation unit (205) that increases the target battery-side power in accordance with the regenerative power (11 a); and an engine output calculation means (207) for calculating a required torque of the engine (109) from at least the increased target battery end electric power, the actual battery end electric power, and the required driving force. Thus, even if the regenerative power of the motor is increased by the brake or the accelerator operation, the generated torque can be maintained.

The prescribed range of the power generation torque (20a) is a range in which: in a system in which the engine (109) and the motor (107) or the generator (111) are coupled via a gear mechanism (119), when the power generation torque (20a) of the generator (111) decreases, abnormal noise is generated in the gear mechanism (119). Thus, even if regenerative power is increased by using the brake, generation of abnormal noise in the gear mechanism can be avoided.

ADVANTAGEOUS EFFECTS OF INVENTION

As described above, according to the present invention, the generated torque can be maintained even if the regenerative power of the motor for running increases, and for example, the gear mechanism can be effectively prevented from generating rattle.

Drawings

Fig. 1 is a waveform diagram showing changes in accelerator pedal opening, brake operation, motor torque, target battery side electric power, power generation torque, and engine torque, for explaining the generation of a rattle when the control of the background art is applied.

Fig. 2 is a block diagram schematically showing an example of the internal structure of a hybrid vehicle according to an embodiment of the present invention.

Fig. 3 is a block diagram schematically showing an example of a control device of the hybrid vehicle according to the present embodiment.

Fig. 4 is a waveform diagram showing changes in accelerator opening, brake operation, motor torque, target battery side electric power, generated torque, and engine torque in an example of the control method of the present embodiment.

Description of the reference numerals

101 cell

103 converter

105 st inverter

107 motor

109 engine

111 electric generator

113 nd and 2 nd inverter

115 clutch

117 hydraulic circuit

119 gear box

121 vehicle speed sensor

123 revolution speed (NE) sensor

125 management ECU (MG-ECU)

201 regenerative torque request calculating part

202 requested driving force calculation section

203 motor instruction torque calculating section

204 regenerative power calculating section

205 basic target battery side power calculation section

206 adder

207 required engine output calculation section.

Detailed Description

1. Brief description of the embodiments

According to the embodiment of the present invention, even if the regenerative power is increased by using the brake, the generation torque is maintained by increasing the target power value of the battery in accordance with the amount of increase, and the use of the rattle generation region can be avoided.

Hereinafter, embodiments of the present invention will be described by taking a series/parallel hybrid vehicle as an example. The series/parallel system is a system in which a transmission system of the driving force is switched to either one of a series system in which the driving force of the motor is used for traveling and an engine is used for power generation, and a parallel system in which the driving force of either one or both of the motor and the engine is used for traveling. The present invention is not limited to the series/parallel system, and can be applied to the series system and the parallel system.

2. Integral structure

As illustrated in fig. 2, a series/parallel hybrid vehicle (hereinafter, simply referred to as "vehicle") includes a Battery (BATT)101, a Converter (CONV)103, a 1 st inverter (INV1)105, a Motor (MOT)107, an Engine (ENG)109, a Generator (GEN)111, a 2 nd inverter (INV2)113, a lockup clutch (hereinafter, simply referred to as "clutch") 115, a hydraulic circuit 117, a gear box (hereinafter, simply referred to as "gear") 119, a vehicle speed sensor 121, a rotational speed (NE) sensor 123, various Electronic Control Units (ECUs), and a management ECU (MG-ECU) 125. Here, the various ECUs include a generator ECU (GEN-ECU), an engine ECU (ENG-ECU), a motor ECU (MOT-ECU), a brake ECU (BRK-ECU), and the like.

The control function of the present embodiment is mounted on the management ECU 125. In fig. 2, solid arrows indicate control signals, and broken arrows indicate detection signals.

The battery 101 has a plurality of power storage units connected in series, and supplies a high voltage of, for example, 100 to 200V. The storage unit is, for example, a lithium ion battery or a nickel hydride battery. The converter 103 steps up or down the dc output voltage of the battery 101 while maintaining the dc output voltage. The 1 st inverter 105 converts a direct-current voltage into an alternating-current voltage, and supplies a three-phase current to the motor 107. The 1 st inverter 105 converts an ac voltage input during a regenerative operation of the motor 107 into a dc voltage, and charges the battery 101. The state of the battery 101 can be measured from the terminal voltage, current, and temperature of the battery 101. In the present embodiment, as will be described later, the management ECU125 inputs the actual BATT terminal power P of the battery 101_BATT(actual value of current charging/discharging power) to make the charging state of the battery 101 and the target BATT terminal power P_TThe power generation and charging control is performed in a consistent manner.

The motor 107 generates power for running of the vehicle. The torque generated by the motor 107 is transmitted to the drive shaft 127 via the gear 119. In addition, the rotor of the motor 107 is directly coupled to the gear 119. Further, the motor 107 operates as a generator during regenerative braking, and electric power generated by the motor 107 is charged in the battery 101. The control of the motor 107 is performed by the motor ECU in accordance with a motor torque command from the management ECU 125.

When the clutch 115 is released to cause the vehicle to travel in series, the engine 109 is used only to drive the generator 111. However, when the clutch 115 is engaged, the output of the engine 109 is transmitted to the drive shaft 127 via the generator 111, the clutch 115, and the gear 119 as mechanical energy for running of the vehicle.

The generator 111 is driven by the power of the engine 109 to generate electric power. The electric power generated by the generator 111 is charged to the battery 101 or is supplied to the motor 107 via the 2 nd inverter 113 and the 1 st inverter 105. The 2 nd inverter 113 converts the alternating-current voltage generated by the generator 111 into direct-current voltage. The electric power converted by the 2 nd inverter 113 is charged to the battery 101 or is supplied to the motor 107 via the 1 st inverter 105.

The clutch 115 connects or disconnects a transmission path of the driving force from the engine 109 to the driving wheels 129 in accordance with an instruction from the management ECU 125. The hydraulic circuit 117 supplies a predetermined operating pressure to the clutch 115 via the operating oil. Further, the hydraulic circuit 117 sends a signal indicating the temperature To of the hydraulic oil To the management ECU125 via the motor ECU.

The gear 119 is a fixed gear of 1 stage corresponding to 5 th gear, for example. Therefore, the gear 119 converts the driving force from the motor 107 into a rotation speed and a torque at a specific gear ratio, and transmits to the drive shaft 127. The vehicle speed sensor 121 detects the traveling speed of the vehicle (vehicle speed VP). A signal indicating the vehicle speed VP detected by the vehicle speed sensor 121 is sent to the management ECU 125. The rotation speed sensor 123 detects the rotation speed NE of the engine 109. A signal indicating the rotation speed NE detected by the rotation speed sensor 123 is sent to the management ECU 125.

The management ECU125 instructs various ECUs to calculate the rotation speed of the motor 107 based on the vehicle speed VP, disconnect/connect the clutch 115 using the hydraulic circuit 117, switch the travel mode, and control the motor 107, the engine 109, and the generator 111, and executes these processes. The management ECU125 is constituted by a rewritable ROM or the like, and can write/rewrite programs and data. Further, the control function of the management ECU125 described below can be realized by executing the program stored in the storage unit by the processor.

3. Control device

As illustrated in fig. 3, the control device of the present embodiment is mounted on the management ECU125 in fig. 2. The management ECU125 has a functional configuration including a regenerative torque request calculation unit 201, a requested driving force calculation unit 202, a motor instruction torque calculation unit 203, a regenerative power calculation unit 204, a basic target battery-side power calculation unit 205, an adder 206, and a required engine output calculation unit 207. The characteristic configuration in the present embodiment is to avoid the variation of the generator torque by providing the regenerative power calculation unit 204 and calculating the final target battery side power in consideration of the regenerative power.

The regenerative torque request calculation portion 201 calculates a regenerative torque request according to the brake operation, but in the present embodiment, the regenerative torque request calculation portion 201 is provided to the brake ECU. The required driving force calculation unit 202 calculates the required driving force of the vehicle from the vehicle speed VP and the accelerator opening AP. The motor instruction torque calculation unit 203 calculates a motor torque using the regenerative torque request input from the regenerative torque request calculation unit 201, the vehicle required driving force input from the required driving force calculation unit 202, and the motor rotation speed, and outputs an instruction of the calculated motor torque value to the motor ECU.

The regenerative power calculation unit 204 inputs the motor torque value, the motor rotation speed, and the ECVT efficiency calculated by the motor command torque calculation unit 203, and calculates the regenerative power P to be increased when the motor is regenerated_regene. Further, the basic target battery side power calculation portion 205 calculates the basic target battery side power P using the vehicle speed VP and the engine rotation speed NE_T1. Adder 206 adds basic target battery side power P_T1Adding regenerative power P_regeneTo calculate the final target battery terminal power P_T2And outputs the calculation result to the required engine output calculation section 207. I.e. the basic target battery side power P_T1Increases and regenerates the power P_regeneThe final target battery terminal power P obtained by the corresponding amount_T2Is output to the required engine output calculation unit 207.

The required engine output calculation unit 207 inputs the final target battery side electric power P_T2Vehicle driving power demand calculated by driving power demand calculation unit 202, and current actual BATT terminal power P of battery 101_BATTAnd other data (power consumption of auxiliary machines, motor efficiency, generator efficiency), and calculates a necessary engine output. Here, the required engine output calculation section 207 calculates the target engine speed NE_TThe engine request torque and the generator torque are instructed to the engine ECU and the generator ECU as necessary engine outputs.

More specifically, the necessary engine output calculation section 207 pairs the generators 111 andthe engine 109 controls so that the actual BATT terminal power P of the battery 101 is present_BATTBecomes the final target battery side power P_T2However, by that time, the final target battery side power P_T2The regenerative power P of the engine 109 is increased_regeneThe battery 101 can be charged, and therefore, it is no longer necessary to reduce the power generation torque of the generator 111. Thus, the target battery side power P at the time of regenerative power generation by braking is increased_T2The generated torque of the generator 111 can be maintained at a basic level, and entry into the rattle generation area can be avoided. The following description will be specifically made.

4. Control actions

In fig. 4, it is assumed that the accelerator pedal is fully closed (a) at time point t 1. At this time, the torque of the motor 107 is regenerated in accordance with the engine brake in accordance with the driving, and the battery 101 is charged with the regenerated electric power. Therefore, the power generation torque of the generator 111 is reduced as shown by the basic level value 10, but is maintained at a value larger than the grating sound generation region R.

When the brake operation 11 is performed in the range from time t2 to time t3 in the fully closed accelerator state and the regenerative torque is requested, the management ECU125 increases the motor torque by the regenerative braking in accordance with the vehicle speed VP and the accelerator opening AP at that time (reference numeral 11a in fig. 4). After the motor torque increases to the regeneration side, the regenerative power calculation unit 204 calculates the regenerative power P corresponding to the motor torque_regeneTo regenerate the power P_regeneAnd the basic target battery terminal power P_T1Adding up to calculate final target battery end power P_T2(refer to reference numeral 20).

Thus, the management ECU125 controls the target battery side power P_TThe amount of regenerative power can be charged into the battery by increasing the amount of power generated during brake regeneration, and the engine 109 and the generator 111 can be controlled as shown in reference numerals 20a and 20 b. As a result, the generated torque of the generator 111 is maintained at the basic level value of 10, and therefore, even if the brake is operated when the accelerator AP is fully closed, the generated torque does not enter the grating sound generation region R (see reference numeral 20 a). That is, the management ECU125 increases the target battery side power PT to perform brake regenerationThe amount of power generation at the time of operation can be controlled to avoid rattling by controlling the engine 109 and the generator 111 as shown in fig. 4 (e) and (f).

5. Effect

As described above, according to the embodiment of the present invention, even if the regenerative power 11a is increased by using the brake, the generated torque 20a can be maintained at the basic level 10 and the use in the rattle generation region R can be avoided by increasing the target power value PT of the battery in accordance with the amount of increase.

While the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the technical ideas described in the claims, the specification, and the drawings.