JP2015000675A - Control method for hybrid vehicle during cost drive and hybrid - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque calculation method for a hybrid vehicle during a coast drive that can improve the operability of the hybrid vehicle during a coast drive and suppress a decline in the power generation amount by avoiding a decline in the regenerative opportunity of a running motor or a decrease in the number of revolution of the running motor, and to provide the hybrid vehicle.SOLUTION: In a regenerative control region S1 where a running motor 3 during a coast drive indicated by a motor torque map MAP1 is controlled in regeneration, a full closed target brake torque TMr_max for setting the acceleration speed of a HEV1 when an accelerator opening degree turns into a full closed one to a predetermined target acceleration speed α is calculated, and a target brake torque TMr corresponding an accelerator opening degree An is calculated on the basis of the full closed target brake torque TMr_max.

Description

  The present invention includes an engine and a traveling motor that is controlled for regeneration and power running. When the traveling motor is controlled for power running during coasting operation in which the engine is separated from the drive shaft, drive torque is applied to the drive shaft. On the other hand, a control method during coasting operation of a hybrid vehicle configured such that when the traveling motor is regeneratively controlled, braking torque is applied to the drive shaft and the electric power generated by the regenerative control is charged to the traveling battery; It relates to a hybrid vehicle.

  2. Description of the Related Art In recent years, hybrid vehicles that use an engine and a traveling motor in combination as a power source and travel with one or both driving forces have attracted attention from the viewpoint of improving fuel efficiency and environmental measures.

  In the hybrid vehicle, the engine and the traveling motor are directly connected, the electric power generated by driving the generator with the engine is stored in the traveling battery, the electric power stored in the traveling battery is supplied to the traveling motor, There is a series-type hybrid vehicle configured to obtain a driving force for traveling by a traveling motor.

  On the other hand, the driving battery is charged by the engine in the same way as in the series type hybrid vehicle described above, but not only by the driving motor but also by the engine alone or by both the engine and the driving motor. Some parallel hybrid vehicles are configured to do so.

  In a vehicle equipped with only an engine, the driver releases the accelerator and starts coasting.If the driver needs a deceleration force greater than the running resistance during coasting, use the engine brake, exhaust brake, foot brake, etc. The vehicle decelerates when applied.

  On the other hand, in the hybrid vehicle, when the driver loosens the accelerator and coasting operation is started, the engine clutch provided between the engine and the drive shaft is disconnected. When a deceleration force larger than the running resistance is required during coasting operation, the hybrid vehicle is decelerated by generating braking torque with the traveling motor and coasting regeneration is performed to generate electric power with the traveling motor. .

  In this regard, when calculating the target value of the regenerative braking force during coasting operation, the standard regenerative braking force is calculated, and the correction amount according to the inter-vehicle distance and the correction amount according to the road conditions ahead are calculated respectively. Has been proposed that corrects the target value by adding the maximum correction amount to the reference regenerative braking force (see, for example, Patent Document 1).

  In this apparatus, a value simulating engine friction is used as a target value of torque generated in the traveling motor. Although the target value is corrected according to various conditions, the target value of the torque of the motor for driving is equivalent to the engine brake, so the driver feels that the deceleration force is insufficient in the case of downhill. Sometimes foot brakes are applied as appropriate. However, when the frequency of using the foot brake increases, there arises a problem that the amount of power generated by regenerative control of the traveling motor decreases. There is also a problem that the feeling of shock increases.

On the other hand, during coasting operation, regenerative control means for controlling the regenerative torque of the motor on the negative maximum torque line where the maximum amount of power generation can be obtained, and when shifting down the transmission with a decrease in vehicle speed during coasting operation, There is a device provided with a shift control means for performing a shift down of the transmission in the rotation range of the electric motor in which the regenerative torque in the vicinity of the engine brake in the engine deceleration mode on the maximum torque line is obtained (see, for example, Patent Document 2).

  Even with this device, the torque generated in the motor for driving is controlled in the rotational range where regenerative torque close to that of the engine brake can be obtained. Will be performed as appropriate. However, if the frequency of using the downshift is increased, there is a problem that the motor power is disconnected during the shift and the amount of power generated by the regenerative control is reduced. In addition, it is also disadvantageous from the viewpoint of easy drive that such an operation is required of the driver.

JP 2001-054203 A JP 2012-116272 A

  The present invention has been made in view of the above-mentioned problems, and the problem is that it is possible to improve the operability during coasting operation of the hybrid vehicle, and to reduce the regenerative opportunity of the travel motor and the travel motor. It is an object to provide a control method and a hybrid vehicle during coasting operation of a hybrid vehicle that can avoid a decrease in the number of revolutions and suppress a decrease in the amount of power generation.

  In the control method during coasting operation of the hybrid vehicle of the present invention for solving the above-described problem, when the traveling motor is power-running during coasting operation in which the engine is separated from the drive shaft, the drive shaft is driven. In a control method during coasting operation of a hybrid vehicle in which torque is applied and braking torque is applied to the drive shaft when regenerative control is performed, and electric power generated by the regeneration control is charged to a battery. When the travel motor is regeneratively controlled, a fully-closed target braking torque is calculated so that the acceleration of the hybrid vehicle when the accelerator opening is fully closed is set to a predetermined target acceleration. The target braking torque according to the above is calculated based on the fully closed target braking torque.

  The coasting operation here refers to a state in which the engine is separated from the drive shaft and travels in a region where a negative torque is generated by losing the engine friction even though the engine is injecting fuel. . At this time, the engine is in an idle state or a stopped state, and the vehicle is left to decelerate due to running resistance.

  In a hybrid vehicle, when the traveling motor is regeneratively controlled during coasting operation, a braking torque can be applied to the drive shaft to increase the deceleration force. On the other hand, when the traveling motor is subjected to power running control, the vehicle deceleration is increased. Can be suppressed.

The target acceleration here is the target value of the acceleration of the hybrid vehicle when the driver returns the accelerator, that is, the accelerator opening is fully closed, and the acceleration in the traveling direction of the hybrid vehicle is positive. In this case, a negative value or zero m / s ² is obtained.

According to this method, during the coasting operation of the hybrid vehicle, the target braking torque of the traveling motor is calculated so that a deceleration force corresponding to the accelerator opening is generated, so that the driver only needs to operate the accelerator, and the operability is improved. Can be improved. In addition, since the target braking torque of the traveling motor is calculated so that the necessary deceleration force is obtained only by the braking torque of the traveling motor, it is possible to avoid a decrease in the regeneration opportunity of the traveling motor and a decrease in the rotational speed of the traveling motor. Thus, a decrease in the amount of power generation can be suppressed.

For example, the fully closed target braking torque is obtained from the following formula (1) using the estimated vehicle weight M and the estimated running resistance Fr. Here, the fully closed target braking torque is TMr_max, the target acceleration is α, and the variable for converting the torque into driving force is L. The estimated vehicle weight M and the estimated running resistance Fr are calculated using an acceleration sensor, a vehicle speed sensor, an accelerator opening, an engine output torque map, and the like.

  Therefore, the fully closed target braking torque TMr_max calculated by the above formula (1) is a value in which the estimated traveling resistance Fr is taken into account, and the absolute value becomes small when the estimated traveling resistance Fr is large, When the estimated running resistance Fr is small, the absolute value becomes large.

  Further, in the control method during coasting operation of the hybrid vehicle described above, in the motor torque map indicating the target braking torque according to the accelerator opening, the fully closed point indicating the fully closed target braking torque and the braking torque is zero. When the target braking torque according to the accelerator opening is calculated by linearly interpolating between the reference point and the reference point, the torque applied to the drive shaft from the traveling motor by the accelerator operation is negative (braking torque ) To positive (drive torque), the torque change can be smoothed.

  In addition, in the control method during coasting operation of the hybrid vehicle, when the coasting operation is performed and the running motor is subjected to power running control, a value of the engine torque of the engine corresponding to the accelerator opening is calculated. When the value of the engine torque is set as the value of the target drive torque of the traveling motor, the accelerator is such that the torque applied to the drive shaft from the traveling motor during coasting operation becomes positive (drive torque). At the time of opening, the value of the target drive torque is made equal to the value of the engine torque, so that the feeling of the accelerator matches that when the engine is running. Thereby, since the feeling does not change between the engine running and the coasting operation, the drivability can be improved.

  In addition, a hybrid vehicle of the present invention for solving the above-described problems includes an engine and a traveling motor that is controlled to perform power running and regenerative operation, and during the coasting operation in which the engine travels in a state separated from the drive shaft, When the running motor is power running controlled, a driving torque is applied to the driving shaft. On the other hand, when the regenerative control is performed, a braking torque is applied to the driving shaft, and the power generated by the regenerative control is charged to the battery. A fully-closed target braking torque calculating means for calculating a fully-closed target braking torque that sets the acceleration of the hybrid vehicle when the accelerator opening is fully closed to a predetermined target acceleration; A target braking torque calculating means for calculating a target braking torque corresponding to the accelerator opening based on the fully closed target braking torque; When performing regenerative control of the traveling motor, the traveling brake is applied so that the target braking torque calculated by executing the fully closed target braking torque calculating means and the target braking torque calculating means is applied to the drive shaft. A control device for regenerative control of the motor is provided.

Further, in the above hybrid vehicle, the target braking torque calculating means has a fully closed point indicating the fully closed target braking torque in the motor torque map indicating the target braking torque corresponding to the accelerator opening, and the braking torque is zero. Desirably, it is a means for linearly interpolating between the reference point and indicating the target braking torque according to the accelerator opening.

  In addition, in the hybrid vehicle, the control device calculates a value of the engine torque of the engine according to the accelerator opening, and uses the engine torque value as a target drive torque value of the travel motor. When provided with drive torque calculation means, during coasting operation and when the running motor is subjected to power running control, the target drive torque calculated by executing the target drive torque calculation means is applied to the drive shaft. It is desirable that the traveling motor is configured to perform power running control.

  According to the present invention, during the coasting operation of the hybrid vehicle, the target braking torque of the traveling motor is calculated so that a deceleration force corresponding to the accelerator opening is generated, so that the driver only needs to operate the accelerator, Operability can be improved. In addition, since the target braking torque of the traveling motor is calculated so that the necessary deceleration force is obtained only by the braking torque of the traveling motor, it is possible to avoid a decrease in the regeneration opportunity of the traveling motor and a decrease in the rotational speed of the traveling motor. Thus, a decrease in the amount of power generation can be suppressed.

It is a block diagram which shows the control system of the hybrid vehicle of embodiment which concerns on this invention. It is a block diagram which shows the structure of the control apparatus of FIG. 2 is a map showing engine speed and engine torque of the hybrid vehicle of FIG. 1. FIG. 2 is a motor torque map showing the relationship between the accelerator opening and torque of the traveling motor of FIG. FIG. 2 is a motor torque map showing the relationship between the accelerator opening and torque of the traveling motor of FIG. 1, showing a case where the estimated traveling resistance is small. 2 is an engine torque map showing a relationship between an accelerator opening and torque of the engine of FIG. 1. It is a flowchart which shows the control method during the coasting driving | operation of the hybrid vehicle of embodiment which concerns on this invention.

  Hereinafter, a control method and a hybrid vehicle during coasting operation of a hybrid vehicle according to an embodiment of the present invention will be described with reference to the drawings. In the following embodiment, a parallel hybrid vehicle that generates driving force by combining an engine and a traveling motor will be described as an example. However, the present invention can also be applied to a series hybrid vehicle. .

  First, a hybrid vehicle (hereinafter referred to as HEV) 1 according to an embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the HEV 1 includes a diesel engine (hereinafter referred to as an engine) 2 and a traveling motor 3, and a traveling battery 6 is electrically connected to the traveling motor 3 through an inverter 4 and a booster 5. It is connected.

  The HEV 1 includes a fluid coupling 7, a hydraulic multi-plate clutch (hereinafter referred to as an engine clutch) 8, a transmission (transmission) 9, a propeller shaft (drive shaft) 10, a differential 11, and a drive shaft 12. The driving force of the engine 2 is transmitted by these driving mechanisms to drive the driving wheels 13.

  In addition, power is supplied to a starter 14 that applies initial torque to the engine 2, a hydraulic pump 15 that supplies hydraulic pressure to a power steering (not shown), a headlamp (not shown), and an in-vehicle air conditioner (not shown). A generator 17 for charging the auxiliary battery 16 is provided.

  The hydraulic pump 15 and the generator 17 are driven by the engine 2. When the hydraulic pump 15 and the generator 17 need to be driven even when the HEV 1 is stopped or coasting, the engine 2 is operated in an idling state. And these are driving.

  Further, the HEV 1 includes a traveling motor gear section 18, a traveling motor output shaft 19, and a PTO (power input / output mechanism) 20, and the PTO 20 includes a slave dog clutch (motor clutch; hereinafter referred to as a dog clutch) 21.

  As shown in FIG. 3, the HEV 1 operates the engine clutch 8 in a region (shaded region in the figure) where negative torque is generated due to engine friction despite fuel injection into the engine 2. It is configured to perform coasting operation in which the engine 2 is cut and travels while being separated from the propeller shaft 10.

  In a vehicle with only an engine, it is left to decelerate by running resistance during coasting operation. However, in the coasting operation of HEV1, when the deceleration of HEV1 is suppressed (the HEV1 speed is kept constant or increased). In this case, the dog clutch 21 is connected, the running motor 3 is power-running, and a driving torque is applied to the propeller shaft 10.

  On the other hand, when a deceleration greater than the deceleration due to the running resistance is required, the dog clutch 21 is connected, the running motor 3 is regeneratively controlled, and braking torque is applied to the propeller shaft 10. At this time, the electric power generated by the regenerative control is charged to the traveling battery 6.

  In this embodiment, the engine 2 during coasting operation is in an idle state, but may be in a stopped state.

  In order to control the HEV 1 having the above-described configuration, as shown in FIG. 1, the HEV 1 includes an engine ECU (engine control device) 22, a shift ECU (shift control device) 23, and a hybrid ECU (hybrid control device). 24 and a brake ECU (brake control device) 25. Moreover, each ECU22-25 is mutually connected in parallel by the vehicle-mounted network 26, and is comprised so that information may be sent mutually. Then, an accelerator opening signal of the accelerator pedal 27, a shift signal of the shift lever 28, a brake signal of the brake pedal 29, a motor torque signal of the inverter 4, and the like are sent to each ECU 22-25.

  In addition, the HEV 1 includes a cooling system 31 that cools the traveling motor 3 and the inverter 4 with cooling water. The cooling system 31 includes a pump 32, a radiator 33, and a cooling fan 34. The cooling fan 34 is configured to cool the traveling battery 6.

  The above configuration is an example, and the HEV 1 exemplified in the embodiment is not limited to the above configuration, and is a hybrid vehicle and is used for traveling during coasting operation in which the engine 2 is separated from the propeller shaft 10 and travels. Any configuration that can apply driving torque and braking torque from the motor 3 to the propeller shaft 10 may be used.

Among the parallel HEVs 1 described above, when the vehicle weight is particularly heavy and the propeller shaft 10 requires a large braking torque such as downhill on a slope, the driving motor 3 is mainly used as an assist. It is used as Therefore, a significant increase in vehicle weight is suppressed by reducing the charging capacity of the battery 6 for traveling and reducing the weight.

  HEV1 of the present invention, when the control region of the traveling motor 3 during coasting operation shown in the motor torque map MAP1 of FIGS. 4 and 5 is in the regenerative control region (the region where the motor torque is from zero to the negative side) S1. When the accelerator opening is fully closed (0%), HEV1 acceleration is set to a predetermined target acceleration α to calculate a fully closed target braking torque TMr_max, and the target braking torque TMr corresponding to the accelerator opening An is calculated. Is calculated based on the fully closed target braking torque TMr_max.

  HEV1 is shown when the control region of the traveling motor 3 during coasting operation shown in the motor torque map MAP1 of FIGS. 4 and 5 is in the powering control region (region where the motor torque is zero to +) S2. 6, the value of the engine torque TE of the engine 2 corresponding to the accelerator opening Am is calculated, and the value of the engine torque TE is set as the value of the target drive torque TMp.

  Specifically, as shown in FIG. 2, the engine ECU 22 is configured to include coasting driving determination means M1, estimated vehicle weight calculation means M2, estimated travel resistance calculation means M3, and engine torque calculation means M4. , Control region determination means M5, fully closed target braking torque calculation means M6, target braking torque calculation means M7, target drive torque calculation means M8, and inverter control means M9.

  The coasting operation determination means M1 is a means for determining the start and end of the coasting operation of the HEV 1 from the state of the engine 2. In this embodiment, the engine torque map MAP2 storing the output torque of the engine 2 with the accelerator opening as the x axis shown in FIG. 6 is referred to, and the engine torque with respect to the accelerator opening Am detected by the accelerator opening sensor 35 is stored. It is means for determining that coasting operation is started when TE is below a predetermined value T0.

  Further, when the engine torque TE with respect to the accelerator opening Am exceeds a predetermined value T0, or when the speed V of HEV1 detected by the vehicle speed sensor 36 satisfies zero m / s, that is, when the HEV1 stops, It is a means to judge that coasting operation is complete | finished.

  The coasting operation determination means M1 only needs to be able to determine the start and end of the coasting operation of HEV1, and the determination material is not limited to the above. In this embodiment, the predetermined value T0 is a value offset from zero Nm to the positive torque side, but may be zero Nm.

  When the coasting operation determination means M1 determines that the coasting operation is started, the shift ECU 23 performs control to disconnect the engine clutch 8 and disconnect the engine 2 from the propeller shaft 10.

The estimated vehicle weight calculation means M2 is a means for calculating the estimated vehicle weight M of HEV1. In this embodiment, the average acceleration α_ave and average driving force F_ave of HEV1 before the shift and the average acceleration α_ave ′ of HEV1 during the shift are calculated, and the average acceleration α_ave ′ during the shift depends on the running resistance. As shown in (2), the estimated vehicle weight M is obtained by integrating the average driving force F_ave by a value obtained by subtracting the average acceleration α_ave at the time of shifting to the average acceleration α_ave ′ before the shifting.

  The estimated vehicle weight calculation means M2 only needs to be able to calculate the estimated vehicle weight M of HEV1, and may use a known technique for calculating the vehicle weight.

  The estimated running resistance calculation means M3 is a means for calculating the estimated running resistance Fr of HEV1. In this embodiment, the estimated running resistance Fr is obtained by adding the rolling resistance F1, the air resistance F2, and the gradient resistance F3.

The rolling resistance F1 and the air resistance F2 are obtained by using the following formula (3) for the speed V of the HEV 1 prepared in advance by a coast down test or the like without being measured during traveling. Here, a to c are values determined by a coast down test.

  Actually, although the rolling resistance F1 and the air resistance F2 change depending on the wind speed, road surface condition, vehicle weight, etc., they are processed as errors within a range in which the driver does not feel uncomfortable.

The gradient resistance F3 is calculated from the vertical acceleration α_ver and the gravitational acceleration g detected by the biaxial G sensor 37 that detects longitudinal and vertical accelerations and the gravitational acceleration g by the following formula (4).

In the case of a uniaxial G sensor that detects only the longitudinal acceleration, the gradient resistance F3 is calculated by the following formula using the vehicle acceleration α_car calculated by differentiating the longitudinal acceleration α_hor and the value detected by the wheel speed sensor. Obtained in (5).

  The estimated running resistance calculation means M3 is not limited to the above method, and a method for calculating the estimated running resistance of a known technique may be used.

  The engine torque calculation means M4 is means for calculating the engine torque of the engine 2 based on the accelerator opening. In this embodiment, the engine torque calculation means M4 is calculated by an engine torque map MAP2 shown in FIG. The engine torque calculation means M4 only needs to be able to calculate the engine torque TE of the engine 2 based on the accelerator opening degree Am, and a method other than the method of referring to the engine torque map MAP2 may be used.

  The control region determination means M5 determines whether the output torque of the traveling motor 3 is positive (drive torque) or negative (braking torque) based on the accelerator opening, and performs power running control or regenerative control of the traveling motor 3. It is a means to judge. The control region determination means M5 makes a determination with reference to the motor torque map MAP1 shown in FIGS.

  FIG. 4 shows a motor torque map MAP1 when the estimated running resistance Fr is small, and FIG. 5 shows a motor torque map MAP1 when the estimated running resistance Fr is large, for example, on a downhill.

  The fully-closed target braking torque calculating means M6 is a braking torque target value for setting the acceleration of HEV1 when the accelerator opening is fully closed (zero%) during coasting operation of HEV1 to a predetermined target acceleration α. This is means for calculating a certain fully closed target braking torque TMr_max.

The target acceleration α here is a target value of the acceleration of HEV1 when the driver returns the accelerator pedal 27, that is, when the accelerator opening is fully closed (zero%). , −0.2 m / s ² . This target acceleration α may be a negative value when the traveling direction of HEV1 is positive, or zero m / s ² .

The fully closed target braking torque TMr_max is obtained from the following equation (6) using the target acceleration α, the estimated vehicle weight M, and the estimated running resistance Fr. Here, the total reduction ratio from the motor 3 to the drive shaft 12 is i, the power transmission efficiency is ηt, and the effective tire radius of the drive wheels 13 is rd. Note that the power transmission efficiency ηt depends on the denominator in order to calculate the fully closed target braking torque TMr_max for regenerative control.

The fully closed target braking torque TMr_max calculated by the above equation (6) is a value in which the estimated traveling resistance Fr is taken into account, and even when the same target acceleration α is used and the estimated traveling resistance Fr is large, As shown in FIG. 4, the absolute value becomes small, while when the estimated running resistance Fr is small, the absolute value becomes large as shown in FIG.

  The target braking torque calculating means M7 stores a fully closed point Pmax indicating the fully closed target braking torque TMr_max in the motor torque map MAP1 of FIGS. 4 and 5, and a reference point P0 and a fully closed point at which the braking torque is zero. It is means for calculating a value obtained by linearly interpolating between Pmax as the target braking torque TMr.

  Specifically, first, as shown in the motor torque map MAP1 in FIGS. 4 and 5, the fully closed point Pmax (accelerator opening: 0%, motor torque: fully closed target braking torque TMr_max) is stored. Next, assuming that the distance between the fully closed point Pmax and the reference point P0 (accelerator opening: A1, motor torque: 0) is linear, the value between the fully closed point Pmax and the reference point P0 is Find the approximate value and store it. Then, the approximate value is calculated as the target braking torque TMr corresponding to the accelerator opening An detected by the accelerator opening sensor 35.

  The target drive torque calculating means M8 calculates the engine torque TE of the engine 2 based on the accelerator opening degree Am with reference to the engine torque map MAP2 of FIG. 6, and transfers the engine torque TE from the traveling motor 3 to the propeller shaft 10. This is means for setting the target drive torque TMp, which is the target value of the applied drive torque.

  This target drive torque calculation means M8 does not need to be calculated every time when the running motor 3 is subjected to power running control during coasting operation. For example, the engine torque map MAP1 of FIGS. You may memorize | store the value similar to map MAP2.

  The inverter control means M9 is configured so that the braking torque applied from the traveling motor 3 to the propeller shaft 10 becomes the target braking torque TMr calculated by the target braking torque calculating means M7 and from the traveling motor 3 to the propeller shaft 10. Is a means for controlling the inverter 4 so that the drive torque applied to the target brake torque TMr calculated by the target drive torque calculation means M8.

  Next, a control method during coasting operation of the HEV 1 according to the embodiment of the present invention will be described with reference to the flowchart of FIG. First, the coasting operation determination means M1 performs step S10 for determining whether HEV1 starts or ends the coasting operation. If it is determined in step S10 that the coasting operation is started, then the shift ECU 23 performs step S20 in which the engine clutch 8 is disconnected. By this step S20, the engine 2 is disconnected from the propeller shaft 10, and the HEV 1 starts coasting operation.

  Next, the control region determination means M5 performs step S30 for determining whether to start regenerative control of the traveling motor 3 or to start powering control.

  If it is determined in step S30 that the current accelerator opening An is within the regeneration control region S1, then step S40 for calculating each parameter is performed. In this step S40, the estimated vehicle weight calculating means M2 calculates the estimated vehicle weight M using the above formula (2), and the estimated running resistance calculating means M3 is calculated using the above formula (3) and the formula (4) or formula. The rolling resistance F1, the air resistance F2, and the gradient resistance F3 are calculated using (5), and all of them are added to calculate the estimated running resistance Fr.

Next, as shown in FIG. 7, the fully closed target braking torque calculating means M6 performs step S50 for calculating the fully closed target braking torque TMr_max. In this step S50, the fully closed target braking torque TMr_max is calculated by the above equation (6) using the target acceleration α of HEV1 when the accelerator opening is fully closed, the estimated vehicle weight M, and the estimated running resistance Fr. calculate.

  Next, as shown in FIG. 7, the target braking torque calculation means M7 performs step S60 for calculating the target braking torque TMr according to the accelerator opening An. In step S60, the fully closed point Pmax indicating the fully closed target braking torque TMr_max calculated in step S50 is stored in the motor torque map MAP1 in FIGS. 4 and 5, and the reference point P0 indicating that the braking torque is zero is stored. A value obtained by linearly interpolating between the fully closed points Pmax is calculated as the target braking torque TMr corresponding to the accelerator opening degree An.

  On the other hand, as shown in FIG. 7, if it is determined in step S30 that the current accelerator opening Am is within the powering control region S2, then the target drive torque calculating means M8 performs the target drive according to the accelerator opening Am. Step S70 for calculating the torque TMp is performed. In this step S70, the value of the engine torque TE of the engine 2 based on the accelerator opening Am is calculated with reference to the engine torque map MAP2 of FIG. 6, and the value of the engine torque TE is set as the value of the target drive torque TMp. .

  Next, as shown in FIG. 7, the inverter control means M9 sets the braking torque applied from the traveling motor 3 to the propeller shaft 10 to the target braking torque TMr calculated in step S60, or the traveling motor. Step S80 for controlling the inverter 4 is performed so that the driving torque applied from 3 to the propeller shaft 10 becomes the target driving torque TMp calculated in Step S70. When step S80 is completed, the process returns to step S10, and this control is performed until the coasting operation of HEV1 is completed.

  According to this method, the target braking torque TMr of the traveling motor 3 is calculated so that the deceleration force corresponding to the accelerator opening is generated during the coasting operation of the HEV 1, so that the driver only operates the accelerator pedal 27. The operability during the coasting operation of the HEV 1 can be improved. Further, since the target braking torque TMr of the traveling motor 3 is calculated so as to obtain the necessary deceleration force only by the braking torque of the traveling motor 3, the regenerative opportunity of the traveling motor 3 is reduced and the rotational speed of the traveling motor 3 is increased. The decrease in power generation can be suppressed by avoiding the decrease in power generation.

  Also, as shown in FIGS. 4 and 5, the target braking torque TMr in the regeneration control region S1 is set to a linearly interpolated value, so that it is applied from the traveling motor 3 to the propeller shaft 10 by operating the accelerator pedal 27. The torque change when the applied torque shifts from the braking torque to the driving torque can be smoothed.

  In addition, in the power running control during the coasting operation of HEV1, the value of the target drive torque TMp, which is the target value of the drive torque, is made equal to the value of the engine torque TE of the engine 2, so Since the feeling of 27 is suitable, the driving performance of the HEV 1 can be improved without changing the feeling of the accelerator pedal 27 even during coasting operation.

  When adjusting the acceleration of HEV1 to the target acceleration α, the target braking torque TMr is not only obtained in a feedforward manner as described above, but the target braking torque TMr is feedback-controlled to target the acceleration of HEV1. A method of matching with the acceleration α may be used.

  Further, if a value equivalent to the engine torque map MAP2 in FIG. 6 is stored in the motor torque map MAP1 in FIGS. 4 and 5 in advance, the step of calculating the output torque of the engine 2 in step S70 can be omitted. .

For example, when increasing the deceleration force during the coasting operation of HEV1, the driver returns the accelerator pedal 27 to the accelerator opening degree An. When the estimated running resistance Fr of HEV1 is large, as shown in FIG. 4, the absolute value of the fully closed target braking torque TMr_max calculated in step S50 is a small value. On the other hand, when the estimated running resistance Fr of HEV1 is small, as shown in FIG. 5, the absolute value of the fully closed target braking torque TMr_max calculated in step S50 is a large value.

  As a result, a constant deceleration force is generated during the coasting operation of the HEV 1, so that the driver only needs to operate the accelerator pedal 27, and avoids a decrease in regenerative work and a decrease in the rotational speed of the traveling motor 3. can do.

  Since the hybrid vehicle of the present invention calculates the target braking torque of the driving motor so that the deceleration force corresponding to the accelerator opening is generated during the coasting operation of the hybrid vehicle, the driver only needs to operate the accelerator. The target braking torque of the traveling motor is calculated so that the necessary deceleration force can be obtained only by the braking torque of the traveling motor. Since the reduction in the number of rotations can be avoided and the reduction in the amount of power generation can be suppressed, it can be used for hybrid vehicles, particularly large hybrid vehicles with heavy vehicle weight such as trucks.

1 HEV (hybrid vehicle)
2 Engine 3 Traveling motor 4 Inverter 6 Traveling battery 8 Engine clutch 10 Propeller shaft (drive shaft)
21 Dog clutch (motor clutch)
22 Engine ECU (Engine Control Unit)
23 Shift ECU (shift control device)
24 Hybrid ECU (Hybrid Control Device)
26 In-vehicle network 27 Accelerator pedal 35 Accelerator opening sensor 36 Vehicle speed sensor 37 G sensor (acceleration sensor)
M1 coasting operation determining means M2 estimated vehicle weight calculating means M3 estimated running resistance calculating means M4 engine torque calculating means M5 control region determining means M6 fully closed target braking torque calculating means M7 target braking torque calculating means M8 target driving torque calculating means M9 inverter Control means MAP1 Motor torque map MAP2 Engine torque map P0 Reference point Pmax Fully closed point S1 Regenerative control area S2 Power running control area

Claims (6)

During coasting operation in which the engine is traveling with the engine disconnected from the drive shaft, driving torque is applied to the drive shaft when the running motor is controlled to power, while braking torque is applied to the drive shaft when regenerative control is performed. In a control method during coasting operation of a hybrid vehicle in which power generated by regenerative control is charged to a battery,
When the coasting operation is being performed and the travel motor is being regeneratively controlled, a target braking torque at the time of full closure is calculated so that the acceleration of the hybrid vehicle when the accelerator opening is fully closed becomes a predetermined target acceleration. ,
A control method during coasting operation of a hybrid vehicle, wherein a target braking torque corresponding to an accelerator opening is calculated based on the fully closed target braking torque.   In the motor torque map indicating the target braking torque according to the accelerator opening, the accelerator opening is linearly interpolated between the fully closed point indicating the fully closed target braking torque and the reference point indicating that the braking torque is zero. The control method during coasting operation of the hybrid vehicle according to claim 1, wherein a target braking torque corresponding to the degree is calculated.   When the coasting operation is being performed and the running motor is subjected to power running control, the engine torque value of the engine corresponding to the accelerator opening is calculated, and the engine torque value is calculated as the target drive torque value of the running motor. The control method during coasting operation of the hybrid vehicle according to claim 1 or 2. An engine and a traveling motor that is controlled in power running and regenerative control, and during the coasting operation in which the engine is separated from the drive shaft, when the running motor is subjected to power running control, a drive torque is applied to the drive shaft; On the other hand, in the hybrid vehicle configured to apply braking torque to the drive shaft when regenerative control is performed, and to charge the battery with the power generated by the regenerative control,
A fully-closed target braking torque calculating means for calculating a fully-closed target braking torque that sets the acceleration of the hybrid vehicle when the accelerator opening is fully closed to a predetermined target acceleration, and the fully-closed target braking torque Based on, the target braking torque calculating means for calculating the target braking torque according to the accelerator opening,
When the coasting operation is being performed and the traveling motor is regeneratively controlled, the target braking torque calculated by executing the fully-closed target braking torque calculating means and the target braking torque calculating means is applied to the drive shaft. Thus, a hybrid vehicle comprising a control device that performs regenerative control of the traveling motor.   In the motor torque map showing the target braking torque according to the accelerator opening, the target braking torque calculating means is between a fully closed point indicating the fully closed target braking torque and a reference point where the braking torque is zero. The hybrid vehicle according to claim 4, wherein the hybrid vehicle is means for linearly interpolating and calculating a target braking torque in accordance with an accelerator opening. The control device includes a target drive torque calculation unit that calculates a value of the engine torque of the engine according to an accelerator opening, and sets the value of the engine torque as a value of a target drive torque of the travel motor;
When the coasting operation is being performed and the running motor is subjected to power running control, the running motor is subjected to power running control so that the target drive torque calculated by executing the target drive torque calculating means is applied to the drive shaft. The hybrid vehicle according to claim 4, wherein the hybrid vehicle is configured as described above.

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