JP2011116223A - Controller for hybrid electric vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hybrid electric vehicle which prevents engine-driven power generation by a simple logic when there is a down slope ahead a running hybrid electric vehicle. <P>SOLUTION: The controller for hybrid electric vehicle includes: a state- of-charge detection means 23 for detecting the state of charge of a battery 19; an engine-driven power generation determination means 25 for, when the state of charge of the battery 19 detected by the state-of-charge detection means 23 becomes less than a predetermined lower limit value, determining to generate power by an electric power generator 12 driven by an engine 11; a down-slope determination means 26 for determining whether there is a down slope ahead a running vehicle 1; and an engine-driven power generation inhibition means 27 for, when it is determined that there is a down slope by the down-slope determination means 26, inhibiting the power generation by the electric power generator 12 driven by the engine 11, regardless of the determination of the engine-driven power generation determination means 25. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a control device for a parallel hybrid electric vehicle.

2. Description of the Related Art A hybrid electric vehicle that is equipped with an electric motor (hereinafter also referred to as a motor) in addition to an engine and that can run by motor output is known. In particular, a vehicle equipped with a system that travels by appropriately using driving forces of an engine and a motor is generally called a parallel hybrid electric vehicle.
In such a parallel hybrid electric vehicle, a motor (motor generator) capable of generating electricity is provided as a running motor, and the motor is operated as a generator by the output torque of the engine so that the battery can be charged by the generated power. There is something. In addition, when the vehicle is braked, the motor is operated as a generator, regenerative braking is performed by braking with this power generation load, and the battery is charged with this generated power without depending on the engine output, thereby improving fuel efficiency during traveling. I am trying.

If the remaining charge level or state of charge (hereinafter referred to as SOC) of the battery is too high, the charging efficiency deteriorates and the life of the battery decreases, and if it is too low, it is difficult to operate the motor normally. Since the battery life is also reduced, control is normally performed so as to be maintained between the upper and lower limits.
By the way, in Patent Document 1, in order to increase the regeneration efficiency while managing within the control range of the SOC, the road information including the current position information of the vehicle and the altitude information on the travel route by the navigation system or the like is used. Techniques have been proposed for improving the fuel efficiency by adjusting the use of engines, motors, etc. so that the vehicle travels constantly and energy regeneration can be performed as much as possible in the downhill section.

  With this technology, focusing on controlling the amount of battery discharge, the vehicle travels while adjusting the output distribution ratio between the engine and motor until the vehicle reaches the highest altitude point on the predicted travel route, and the SOC travels. The battery discharge (that is, use of the motor) is controlled so that the allowable minimum value (lower limit value) is reached at the highest altitude point of the route.

JP 2001-169408 A

By the way, when predicting the travel of the vehicle as in the technique of Patent Document 1, it is also necessary to appropriately change the logic for predicting the travel depending on the road surface condition according to the weather and the road condition such as the presence of other vehicles. In addition, since there may be a driving operation that cannot be predicted by the driver, it is not easy to predict the traveling of the vehicle.
Moreover, in order for the SOC to be just the allowable minimum value (lower limit value) at the highest altitude point of the travel route of the vehicle, the situation at that time is always in accordance with the above-mentioned road surface conditions and road conditions that can change from moment to moment. If the discharge control is performed while updating the vehicle travel prediction according to the vehicle, the SOC decreases to the allowable minimum value before the vehicle reaches the maximum altitude point, and the SOC must be restored to the allowable minimum value or more. There are cases where it must be done.

In this case, power must be generated by driving the engine in order to recover the SOC.
For this reason, in the technique of Patent Document 1, even if there is a downhill road ahead of the traveling vehicle and energy storage can be expected by energy regeneration using the downhill road, the motor driving by the engine drive is not performed. In this case, the fuel consumption is deteriorated by the amount of fuel consumed by the engine for power generation.

  In the technology of Patent Document 1, it is considered that the technical idea of running using a motor as much as possible is the basis, but for example, in a large vehicle such as a bus or a truck, when starting, sudden acceleration, etc. The motor is used supplementarily for the purpose of reducing the load on the engine, reducing exhaust gas discharged by driving the engine, and recovering energy by regenerative braking to improve energy efficiency (improving fuel efficiency). Parallel type hybrid electric vehicles have been developed. In the case of such hybrid electric vehicles, the ratio of engine driving during driving is reduced as much as possible, exhaust gas to be discharged is reduced, and energy recovery is performed more efficiently by regenerative braking. We want to promote total fuel efficiency improvement and exhaust gas reduction by focusing on regenerative braking. Strong desire to say is.

  The invention of the present application has been devised in view of such problems, and in the case where there is a downhill road ahead of the traveling vehicle, it is possible to suppress power generation by engine driving with simple logic. An object of the present invention is to provide a control device for a hybrid electric vehicle.

  The present invention was devised to achieve the above-described object, and a control apparatus for a hybrid electric vehicle according to the present invention can output a running torque, and can output the running torque and the engine. In a hybrid electric vehicle having a motor generator capable of generating power by driving and generating energy by regenerating energy during braking, and a battery that can be charged by power generated by the motor generator, the charge state of the battery is detected And an engine that determines that the motor generator generates power when the engine is driven when a state of charge of the battery detected by the charge state detection unit is less than a preset lower limit value. Driving power generation determination means, downhill road determination means for determining whether there is a downhill road ahead of the traveling vehicle, and the downhill If it is determined by the determination means that there is a downhill road, engine drive power generation prohibition means for prohibiting power generation by the motor generator by driving the engine is provided regardless of the determination of the engine drive power generation determination means. It is characterized by.

The vehicle further includes a navigation system capable of outputting current position information of the host vehicle and road information of the planned travel route of the host vehicle, and the downhill determination means includes the current position information from the navigation system and the planned travel route. The determination is preferably performed using road information.
Thereby, since the current position information of the host vehicle and the road information of the planned travel route of the host vehicle are used by the navigation system, it is possible to more accurately determine whether there is a downhill road on the travel route.

In addition, since the existing navigation system can be used for the vehicle, it is possible to determine the downhill road while reducing the cost.
In addition, it is preferable that the downhill road determination unit determines whether or not there is a downhill road ahead of the host vehicle within a certain range of the planned travel route from the current position of the host vehicle.
As a result, since it is determined that there is a downhill road ahead of the host vehicle from the current position of the host vehicle to the predetermined travel route, even if power generation by engine drive is prohibited, Power generation using regenerative braking on a downhill road can be expected, and a situation in which the state of charge of the battery is significantly reduced can be avoided more reliably.

Moreover, it is preferable that the said downhill road determination means determines that there is a downhill road ahead of the own vehicle, when the downhill road is not less than a preset altitude difference.
Thereby, when regeneration is more reliable, it can be determined as a downhill road.
In addition, a torque distribution unit that distributes the running torque to an engine torque from the engine and a motor torque from the motor generator is provided, and a charge state of the battery detected by the charge state detection unit is preset. When the torque is less than the lower limit, it is preferable that the torque distribution unit regulates the distribution of the torque so as to prohibit the discharge of the battery.

  As a result, it is possible to more reliably avoid power generation by driving the engine due to a decrease in the state of charge of the battery before the downhill road is taken off as well as the downhill road.

  According to the control apparatus for a hybrid electric vehicle of the present invention, when it is determined that there is a downhill road ahead of the traveling vehicle, power generation using regenerative braking during downhill road driving can be expected. For this reason, by suppressing the power generation by driving the engine and effectively using such regenerative braking, the amount of battery charge can be reduced while reducing fuel consumed by the engine, improving fuel efficiency, and reducing exhaust emissions. Can be secured.

1 is a configuration diagram schematically showing a drive system and a control device of a parallel hybrid electric vehicle according to an embodiment of the present invention. It is a flowchart explaining the control by the control apparatus of the parallel hybrid electric vehicle which concerns on one Embodiment of this invention. It is typical explanatory drawing which shows the relationship between the path | route and control in the control apparatus of the parallel type hybrid electric vehicle which concerns on one Embodiment of this invention. It is a timing chart which shows the specific example of control by the control apparatus of the parallel hybrid electric vehicle which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, a drive system of a hybrid electric vehicle (hereinafter also referred to as a vehicle) 1 according to this embodiment includes a motor generator (hereinafter simply referred to as an electric motor) via a clutch 13 and an output shaft 11 a of an engine 11. (Also referred to as a motor) 12 rotating shafts 12a are provided, and the rotating shaft 12a of the electric motor 12 is connected to the input shaft 14a of the transmission 14 and is configured as a parallel hybrid vehicle. In addition, a manual clutch is used for the clutch 13 and a manual transmission is used for the transmission 14. The output shaft 14 b of the transmission 14 is connected to the left and right drive wheels 18 via a propeller shaft 15, a differential 16 and a drive shaft 17.

Therefore, when the clutch 13 is connected, both the output shaft 11a of the engine 11 and the rotating shaft 12a of the electric motor 12 are mechanically connected to the drive wheels 18, and when the clutch 13 is disconnected, the rotating shaft of the electric motor 12 is connected. Only 12 a is mechanically connected to the drive wheel 18.
The electric motor 12 operates as a motor when the DC power stored in the battery 19 is converted into AC power by the inverter 20 and supplied thereto, and after the driving force is shifted to an appropriate speed by the transmission 14, the driving wheel is driven. 18 is transmitted. Further, at the time of vehicle braking, the electric motor 12 operates as a generator, and kinetic energy generated by the rotation of the drive wheels 18 is transmitted to the electric motor 12 via the transmission 14 and converted into AC power, thereby generating a regenerative braking force. The AC power is converted into DC power by the inverter 20 and then charged to the battery 19, and the kinetic energy generated by the rotation of the drive wheels 18 is recovered as electric energy. When braking is performed to suppress acceleration of the vehicle 1 on a downhill road, the potential energy of the vehicle 1 is converted into kinetic energy of the drive wheels 18 and further converted into electric energy.

  On the other hand, the engine 11 basically operates constantly while the vehicle is running, and the driving force of the engine 11 is transmitted to the transmission 14 via the rotating shaft 12a of the electric motor 12 when the clutch 13 is connected. Then, after being shifted to an appropriate speed, it is transmitted to the drive wheel 18. Therefore, when the electric motor 12 operates as a motor when the driving force of the engine 11 is transmitted to the driving wheels 18, the driving force of the engine 11 and the driving force of the electric motor 12 are transmitted to the driving wheels 18, respectively. . That is, part or all of the drive torque to be transmitted to the drive wheels 18 for driving the vehicle is supplied from the engine 11, and the remaining part is supplied from the electric motor 12 in the above case. When the motor of the electric motor 12 is operated, the DC power of the battery 19 is converted into AC power by the inverter 20 and supplied to the electric motor 12.

  In addition, when the state of charge (hereinafter also referred to as SOC) of the battery 19 decreases and the battery 19 needs to be charged, the motor 12 operates as a generator and a part of the driving force of the engine 11. Is used to drive the motor 12 to generate power, and the generated AC power is converted into DC power by the inverter 20 and then charged to the battery 19.

  An engine ECU (electronic control unit for engine) 21 controls the engine 11, and an inverter ECU (electronic control unit for inverter) 22 controls the inverter 20 to control the detection of the SOC and the battery 19. Are provided with battery ECUs (battery electronic control units, hereinafter also referred to as charge state detection means) 23, respectively, and in order to perform integrated control of the host vehicle 1 through these engine ECU 21, inverter ECU 22, and battery ECU 23, a vehicle ECU ( A vehicle electronic control unit (hereinafter also referred to as control means) 24 is provided. Each of the ECUs 21 to 24 is a computer including a memory (ROM, RAM) and a CPU.

  The vehicle ECU 24 includes an engine drive power generation determination unit 25, a descending slope determination unit 26, an engine drive power generation prohibition unit 27, and a torque distribution unit 28 as functional elements by software. The vehicle ECU 24 is connected to a navigation system 29 that detects the current position of the host vehicle from position information from a Global Positioning System (hereinafter referred to as GPS). The road information of the planned travel route of the host vehicle 1 based on the map information stored in is output from the navigation system 29 to the vehicle ECU 24. Note that the road information includes slope information (including information that can directly or indirectly recognize the degree of difference in slope). The vehicle ECU 24 is in various driving states such as starting, acceleration, and deceleration of the vehicle according to the driving state of the host vehicle 1 and the engine 11, information from the engine ECU 21, the inverter ECU 22, the battery ECU 23, and the navigation system 29. Therefore, integrated control for appropriately operating the engine 11 and the electric motor 12 is performed.

The engine drive power generation determination unit 25 determines that the motor generator 12 generates power by driving the engine 11 when the SOC detected by the charge state detection unit 23 is less than a preset lower limit value.
Based on the current position information of the host vehicle 1 and the road information of the planned travel route of the host vehicle 1, the descending slope determination means 26 is a predetermined preset value from the current position in the planned travel route. If there is a downhill road with a height difference equal to or greater than a preset altitude difference in the range of travel (travel distance), it is determined that there is a downhill road ahead of the traveling vehicle 1. After that, even if the vehicle enters the downhill road, the downhill road judging means 26 determines that there is a downhill road ahead of the traveling vehicle 1 at least until the downhill road is exited.

If the engine drive power generation prohibiting means 27 determines that there is a downhill road in front of the host vehicle traveling by the downhill road determination means 26 (including when the vehicle is traveling on the downhill road), First, power generation by the motor generator 12 driven by the engine 11 is prohibited.
The torque distribution means 28 controls the distribution of the running torque into a torque that should be generated by the engine 11 (engine torque) and a torque that should be generated by the motor generator 12 (motor torque). That is, the engine torque by the engine 11 and the motor torque by the motor 12 can be used as the running torque for running the vehicle. For example, when the vehicle 1 starts, the motor torque is basically used (motor assist) to start the vehicle. After that, the motor assist is used when the driving torque requirement is large. However, the lower the SOC is, the narrower the range of the engine operating region in which motor assist is performed, and this torque distribution means 28 prohibits motor assist when the SOC becomes less than the lower limit value.

Since the control apparatus for the hybrid electric vehicle according to the present embodiment is configured as described above, for example, as shown in FIG. 2, it is possible to control the start of engine-driven power generation in the hybrid electric vehicle. Note that it is completed at a predetermined cycle.
First, a destination is input to the navigation system 29, a planned travel route is searched, and driving of the vehicle is started.

Then, in the subsequent step S10, the SOC detected by the state of charge detection means 23 is read and confirmed, and in the subsequent step S20, it is determined whether this SOC is less than a preset lower limit value.
If it is determined in step S20 that the SOC is less than the lower limit value, the process proceeds to step S30.

On the other hand, if it is determined in step S20 that the SOC is not less than the lower limit value, the process proceeds to return, and the process of this cycle is terminated.
In step S30, the current position information and the road information of the planned travel route input from the navigation system 29 are read by the downhill judging means 26, and within a certain road range of the planned travel route, the difference in altitude or more set in advance is exceeded. It is confirmed whether there is a downhill road, and in subsequent step S40, the downhill road judging means 26 determines whether there is a downhill road.

If it is determined by the downhill road judging means 26 that there is a downhill road ahead of the traveling vehicle 1, the process proceeds to step S50, and the engine drive power generation prohibition means 27 prohibits power generation by driving the engine 11.
In the subsequent step S60, the torque distribution means 28 restricts the distribution of the engine torque and the motor torque of the running torque so as to prohibit the discharge of the battery 19, that is, the discharge of the battery 19 is prohibited and the return. The process of this cycle is finished.

On the other hand, if it is determined by the downhill road determination means 26 that there is no downhill road ahead of the traveling vehicle 1 in step S40, the process proceeds to step S70, and the engine drive power generation determination means 25 performs the motor power generation by driving the engine 11. It is determined that power generation is performed by the machine 12, power generation is performed by driving the engine 11, the process proceeds to return, and the process of this cycle is terminated.
When power generation by driving the engine 11 is started, power generation is continued until the SOC reaches a power generation completion value larger than the lower limit value in order to prevent chattering.

  In addition, the lower limit value of the SOC for determining the start of power generation by driving the engine 11 is set to be larger than the lower limit value of the SOC allowed for the battery 19. The second lower limit value is provided between the lower limit value and the lower limit value of the power generation start determination so that the SOC does not reach the lower limit value even if the discharge of is performed, and during power generation prohibition by driving the engine 11, When the SOC reaches the second lower limit value, the prohibition of power generation by driving the engine 11 may be canceled, so that the SOC can be appropriately managed.

Step S40 in the flow of FIG. 2 determines that there is a downhill road ahead of the traveling vehicle 1 at least until it exits the downhill road even if it enters the downhill road.
The control apparatus for a hybrid electric vehicle according to the present embodiment exhibits the following operations and effects by the above control.
First, the destination is input to the navigation system 29, the planned travel route is searched and the operation is started, and the vehicle travels in a situation where the SOC detected by the charge state detection means 23 is determined to be less than a preset lower limit value. When it is determined that there is no downhill road ahead of the host vehicle 1, the engine drive power generation determination unit 25 determines that power generation by the engine 11 is performed, and power generation by the engine 11 drive is performed. Therefore, it is possible to avoid a situation in which the motor 12 cannot be operated by the battery 19 due to the inability to operate. That is, the battery 19 can reduce the burden on the engine 11 when starting or suddenly accelerating and reduce exhaust gas.

  On the other hand, when it is determined that there is a downhill road ahead of the traveling vehicle 1, power generation using regenerative braking during downhill road driving can be expected. For this reason, the power generation by driving the engine 11 is prohibited, and the regenerative braking is effectively used to reduce the fuel consumed by the engine 11, improve the fuel efficiency, and reduce the exhaust gas to be discharged. The amount of charge can be secured. Further, after entering this downhill road, it is determined that there is a downhill road ahead of the traveling vehicle at least until it exits from this downhill road, and power generation by driving the engine 11 is prohibited. Since power generation by energy regeneration using a slope can be performed more reliably, the amount of charge of the battery 19 can be ensured while improving fuel efficiency and reducing exhaust gas from the engine 11.

  In the downhill road determination by the downhill road determination means 26, the downhill road is determined using the current position of the host vehicle 1 and the road information of the planned travel route of the host vehicle 1 input from the navigation system 29. It is possible to more accurately determine whether there is a downhill road on the travel route. Moreover, since the existing navigation system can be used for the vehicle, it is possible to determine the downhill road while reducing the cost.

  Further, in the downhill road judging means 26, there is a downhill road as shown in FIG. 3 (A) within a certain range of the planned travel route from the current position of the own vehicle 1, or (B) in FIG. It is determined whether there is a downhill road as shown in FIG. Therefore, even if the power generation by driving the engine 11 is prohibited after determining the downhill road, the power generation using the regenerative braking on the downhill road can be expected within a certain range, and the SOC becomes less than the lower limit value. Can be avoided more reliably.

Further, the downhill road judging means 26 determines that there is a downhill road ahead of the host vehicle 1 when the downhill road is greater than or equal to a preset altitude difference. This can be done more reliably.
In addition, the torque distribution means 28 for distributing the running torque to the engine torque by the engine 11 and the motor torque by the motor generator 12 is provided, and the SOC detected by the charge state detection means 23 is less than a preset lower limit value. Then, since the torque distribution is restricted by the torque distribution means 28 so as to prohibit the discharge of the battery 19, not only until the downhill road is reached, but also at least until the downhill road is exited after entering the downhill road. In addition, it is possible to more reliably avoid the occurrence of power generation by driving the engine 11 due to a decrease in the SOC.

Here, in the case where there is a downhill road ahead of the traveling vehicle, the effect of the control of the parallel hybrid electric vehicle according to the present embodiment will be described with reference to FIG. 4 focusing on the relationship between the SOC and the road condition. To do.
FIG. 4 shows the SOC of the control device for the parallel hybrid electric vehicle according to the present embodiment (solid line in the figure, referred to as the control device of the present embodiment) and the general control device for the parallel hybrid electric vehicle (two points in the figure). A specific control example of both control devices is shown while comparing the SOC of the chain line and the control device of the comparative example).

  In the control device of the present embodiment, as described above with reference to FIGS. 1 to 3, “When it is determined that there is a downhill road, the motor-driven motor generator is driven regardless of the determination of the engine-driven power generation determination means. However, the comparative example is a control device that does not include the engine-driven power generation prohibiting means. The control device of the present embodiment and the control device of the comparative example have the same configuration except for the points described here, and the SOC is managed within a predetermined control width during normal operation of both control devices. ing.

  The horizontal axis schematically shows the road condition along the planned travel route, where point t2 is a starting point of an uphill road, point t3 is a point where a downhill road is determined, and the SOC is a lower limit value. Point t5 indicates the start point of the downhill road, point t7 indicates the end point of the downhill road, and point t8 indicates the start point of the uphill road. Further, S1 indicates an SOC lower limit value for determining the start of power generation by engine driving, and S2 indicates a power generation completion value when power generation by engine driving is started larger than the lower limit value.

From the point t1 to the point t2 is a road situation in which normal driving is performed, and the SOC of the control device of this embodiment and the control device of the comparative example is a substantially constant value within the control range.
Then, from the point t2 to the point t3 where the uphill road starts, both the control device of the present embodiment and the control device of the comparative example perform motor-assisted travel, and the battery is used, so the SOC decreases, and the point t3 Then, the SOC becomes the lower limit value.

  At this time, in the control device of the comparative example, it is determined by the engine drive power generation determination means that power is generated by the motor generator driven by the engine, and as shown by the two-dot chain line in the figure, the SOC is controlled from the point t3. Power generation by the engine drive is performed up to a point t4 where the power generation completion value is reached. In this example, thereafter, from the point t4 to the start point t5 of the downhill road, power generation by the motor generator driven by the engine is not performed, and the SOC is maintained within the control width as indicated by a two-dot chain line in the figure. Yes.

  On the other hand, in the control device of the present embodiment, when it is determined that there is a downhill road ahead of the host vehicle at the point t3, power generation by the motor generator driven by the engine is prohibited from the point t3 by the engine drive power generation prohibition unit. Therefore, as indicated by the solid line in the figure, the SOC is maintained at the lower limit value from the point t3 to the point t5.

Next, the SOC after the start point t5 of the downhill road will be described.
In the control device of the present embodiment, the battery is charged using regenerative braking on the downhill road from the point t5 to the point t7 that is the end point of the downhill road, and the SOC becomes the upper limit value at the point t7.
On the other hand, in the control device of the comparative example, at the point t5, since the SOC is S2 higher than the lower limit value S1 in the first place, the battery is charged by using regenerative braking on the downhill road, but the point t7 is reached. From point t6 to the point t7 where the SOC has already reached the upper limit at a point t6 before the start of the downhill road, discharge is performed so that the SOC does not exceed the upper limit even if regenerative braking is performed, or regenerative It must be controlled not to brake.

  That is, in the control device of the comparative example, even in the section from the middle point t6 of the downhill road where the battery cannot be charged by energy regeneration to the end point t7, the control device of the present embodiment effectively uses the regenerative braking of the downhill road. Thus, the battery can be charged. Furthermore, the power generation by the engine drive in the section from the point t3 to the point t4, which is performed in the control device of the comparative example, is not performed in the control device of the present embodiment. Therefore, the fuel consumed for driving the engine in the control device of the comparative example in the section from the point t3 to the point t4 is unnecessary in the control device of this embodiment, and charging by regeneration using the downhill road is a comparative example. The control device of the present embodiment can perform more than the control device of the present embodiment. Therefore, the control device of the present embodiment can reduce emission of exhaust gas and can be more energy efficient than the control device of the comparative example. Good.

(Other)
Although the present embodiment has been described above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, in the above-described embodiment, the case where the manual clutch 13 and the manual transmission 14 are used in the vehicle 1 has been described. However, the present invention is not limited to this. For example, instead of the manual clutch 13 and the manual transmission 14, an automatic transmission using a torque converter or the like may be used. Further, the clutch 13 and the transmission 14 may be automatically controlled by an actuator. Further, the transmission 14 may be a stepped transmission or a continuously variable transmission.

In the above-described embodiment, the motor 12 is provided between the clutch 13 and the transmission 14. However, the arrangement of the clutch 13 and the motor 12 is changed, that is, the motor 12 and the transmission. 14 may be one in which the clutch 13 is arranged.
In the above-described embodiment, the navigation system 29 detects the current position of the host vehicle from the position information from the GPS and the like, and based on the detected current position information of the host vehicle and the map information stored in the navigation system 29. Although the case where the road information of the planned travel route of the host vehicle is detected has been described, the present invention is not limited to this. For example, road information may be detected by further using a road traffic information communication system called VICS (Vehicle Information & Communication System).

Further, in the above-described embodiment, the case where the destination is input to the navigation system 29 and the driving is started after the planned traveling route is searched is described. However, after the driving is started, the destination is stored in the navigation system 29. If an input is made or the route is changed in the middle, the planned traveling route may be searched thereafter.
Further, in the above-described embodiment, the downhill road determination unit 26 describes the case where it is determined that there is a downhill road ahead of the host vehicle 1 when the downhill road is greater than or equal to a preset altitude difference. However, the present invention is not limited to this. For example, it may be determined that there is a downhill road ahead of the host vehicle 1 in a case where a downhill having a predetermined average slope or more continues for a predetermined distance or more. Thereby, it can be determined that there is a downhill road when power generation by energy regeneration is more reliable.

  Although not described in the above embodiment, when the SOC reaches the upper limit due to energy regeneration while traveling on a downhill road, it is also necessary to stop energy regeneration. Thereby, the overcharge of the battery 19 can be prevented and a decrease in the life of the battery 19 can be suppressed.

1 Own vehicle (hybrid electric vehicle, vehicle)
11 Engine 11a Output shaft of engine 11 12 Motor generator (motor, motor)
12a Rotational shaft of motor generator 12 13 Manual clutch 14 Manual transmission 14a Input shaft 14b of transmission 14b Output shaft of transmission 14 15 Propeller shaft 16 Differential 17 Drive shaft 18 Drive wheel 19 Battery 20 Inverter 21 Engine ECU
22 Inverter ECU
23 battery ECU (battery charge state detection means)
24 vehicle ECU (control device)
25 Engine-driven power generation determination means 26 Downhill road determination means 27 Engine-driven power generation prohibition means 28 Torque distribution means 29 Navigation system

Claims (5)

An engine capable of outputting a running torque, a motor generator capable of outputting a running torque, and capable of generating electricity by driving the engine and generating energy by regenerating energy during braking, and charging by power generated by the motor generator In a hybrid electric vehicle equipped with a simple battery,
Charge state detection means for detecting a charge state of the battery;
Engine-driven power generation determination means for determining that the motor generator generates power by driving the engine when the charge state of the battery detected by the charge state detection means is less than a preset lower limit value;
Downhill road judging means for judging whether or not there is a downhill road ahead of the traveling vehicle,
If the downhill road judging means determines that there is a downhill road, engine driven power generation prohibiting means for prohibiting power generation by the motor generator by driving the engine regardless of the determination of the engine driven power generation judging means is provided. A control device for a hybrid electric vehicle, characterized by comprising: A navigation system capable of outputting the current position information of the host vehicle and road information of the planned travel route of the host vehicle;
2. The control apparatus for a hybrid electric vehicle according to claim 1, wherein the downhill road determination unit performs the determination using the current position information from the navigation system and road information of the planned travel route. The downhill road judging means judges whether or not there is a downhill road ahead of the host vehicle within a certain range of the planned travel route from the current position of the host vehicle. Control device for hybrid electric vehicle. 4. The control of a hybrid electric vehicle according to claim 3, wherein the descending slope judging means judges that there is a descending slope ahead of the host vehicle when the descending slope is equal to or greater than a preset altitude difference. apparatus. Torque distribution means for distributing the running torque to engine torque by the engine and motor torque by the motor generator;
When the state of charge of the battery detected by the state of charge detection means becomes less than a preset lower limit value, the torque distribution means regulates the distribution of the torque so as to prohibit the discharge of the battery. The control apparatus for a hybrid electric vehicle according to any one of claims 1 to 4.

Images