JP2007186045A - Running control system for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To further improve fuel consumption by improving recovery of braking energy of a hybrid vehicle with a function of follow-up running. <P>SOLUTION: In cruising control of the hybrid vehicle, running state information of the own vehicle and a preceding vehicle are acquired, and a target braking torque and running resistance torque R<SB>f</SB>of the own vehicle are obtained. A proper motor braking torque T<SB>bkm</SB>is calculated therefrom (S10 to S16). Further, a chargeable power W<SB>in</SB>of a battery is acquired, and the maximum negative motor torque T<SB>mmin</SB>which a motor can output is calculated (S18 to S20). An additional braking is started at the timing when the proper motor braking torque T<SB>bkm</SB>exceeds a threshold which is obtained by subtracting a predetermined value β from the maximum negative motor torque T<SB>mmin</SB>(S22, S24), and is ended at a timing when the speed of the own vehicle V<SB>2</SB>decelerates and exceeds a threshold which is obtained by adding a margin speed γ to the speed V<SB>1</SB>of the preceding vehicle (S26, S28). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an operation control system for a hybrid vehicle, and more particularly, to an operation control system for a hybrid vehicle having a follow-up running function for automatically following the running of a preceding vehicle to control the running of the host vehicle.

  When there is a traveling vehicle ahead, traveling the vehicle in accordance with the traveling of the preceding vehicle contributes to safe driving because a certain vehicle interval can be taken, and local congestion of the road The flow of the vehicle can be made smoother, or even when a plurality of vehicles go to the destination as a group, they can be prevented from leaving other vehicles. Such a function of following the traveling of the host vehicle to the traveling of the preceding vehicle is called a following traveling function or a cruise function. When the vehicle ahead is running stably, the following vehicle that runs using the cruise function is less likely to stop or start suddenly, and travels close to constant speed. It can be performed.

  Moreover, although there exists a hybrid vehicle which mounts both an engine and a motor in a vehicle, the cruise function is mounted also about the hybrid vehicle.

  For example, Patent Document 1 discloses a vehicle speed and SOC in a vehicle having an electric motor driving mode (motor cruise mode) in which the engine is stopped when the vehicle speed is equal to or lower than a preset electric motor driving permission vehicle speed. And determining the time for motor cruise. Here, when the SOC is equal to or higher than a predetermined value, the electric vehicle travel permission vehicle speed is increased, thereby consuming the battery, whereby the SOC is decreased, and the charging mode is entered when the SOC is decreased beyond a predetermined hysteresis range. Therefore, it is stated that the SOC can be surely reduced by this hysteresis, and it is not necessary to reduce the regeneration amount for protecting the battery when the SOC is high.

  In Patent Document 2, in a hybrid vehicle equipped with both an engine and a motor, when constant speed traveling control is performed by the engine, a deceleration request is issued when a preceding vehicle is detected, and the inter-vehicle distance is set to a predetermined value. A constant-speed traveling device that shifts to control to maintain the above is described. Then, when the following control is not required because the preceding vehicle is lost, the deceleration request condition is canceled, and the constant speed traveling control is resumed, a quick acceleration can be obtained by performing torque assist by the motor for a predetermined time. It is stated.

  Patent Document 3 discloses that when a plurality of vehicles run in a coordinated manner in a platoon, control different from the case of running alone with only the own vehicle that needs to maintain the SOC always high is disclosed. . That is, it is stated that electric power is interchanged between linked vehicles so that each vehicle has a uniform SOC, and charging may be performed after the SOC has sufficiently decreased.

  In Patent Document 4, in a vehicle equipped with an automatic speed control device (adaptive cruise control) that automatically keeps at least one of the vehicle traveling speed and the inter-vehicle distance constant, during motor traveling with fuel cut, In addition, it is disclosed that the throttle opening degree is controlled by the presence or absence of automatic traveling. In other words, the crankshaft rotates along with the fuel cut and causes a pump loss, but during automatic driving, it is unlikely that rapid acceleration is required. It is stated that the response can be improved by reducing the throttle opening when the vehicle is not automatically driven.

JP 2004-23959 A JP 2000-295714 A JP 2000-308208 A JP 2004-270512 A

  As described above, hybrid vehicles having a cruise function are known, but the normal cruise function focuses on maintaining the vehicle speed of the host vehicle at the vehicle speed of the preceding vehicle. In order to finely follow the vehicle, it is preferable to appropriately execute acceleration and braking. However, in practice, it is often the case that strong braking is applied after waiting until the end rather than applying automatic braking early. On the other hand, the hybrid vehicle generates electricity by braking while traveling and recovers braking energy, but the charging power state of the battery that recovers energy changes depending on conditions such as temperature. For example, when the chargeable power is large, the energy can be sufficiently recovered even with a strong braking, but when the chargeable power is small, the braking energy cannot be sufficiently recovered. Therefore, in the conventional cruise control in which strong braking is performed after waiting for the last minute, the braking energy recovery is insufficient and the fuel consumption is lost apart from the follow-up performance.

  An object of the present invention is to provide an operation control system for a hybrid vehicle that can improve recovery of braking energy and further improve fuel efficiency in a hybrid vehicle having a following traveling function.

  An operation control system for a hybrid vehicle according to the present invention is an operation control system for a hybrid vehicle having a follow-up running function for automatically following the running of a preceding vehicle and controlling the running of the own vehicle. Appropriate motor braking torque calculating means for obtaining a motor braking torque excluding the braking torque corresponding to the engine friction out of the braking torque for making the following traveling state between the host vehicle and the preceding vehicle appropriate Maximum negative torque calculating means for calculating the maximum negative torque corresponding to the torque that the motor can brake based on the rechargeable power of the battery and the motor rotation speed, and the appropriate motor braking torque is determined from the maximum negative torque. And additional braking start means for starting additional braking by the motor at a timing exceeding a threshold value obtained by subtracting the adaptive value.

  Further, the additional braking start means, when the chargeable power of the battery is reduced and small, the timing of the additional braking start is advanced, the magnitude of the additional braking is reduced, and the chargeable power of the battery is large. It is preferable to delay the timing of starting the additional braking and increase the magnitude of the additional braking.

  The hybrid vehicle operation control system according to the present invention may further include an additional braking end means for stopping the additional braking when the difference between the speed of the host vehicle and the speed of the preceding vehicle falls within a predetermined range. preferable.

  Further, the appropriate motor braking torque calculation means obtains the vehicle speeds of the host vehicle and the preceding vehicle, the inter-vehicle distance between the host vehicle and the preceding vehicle, and the appropriate inter-vehicle distance for the running state of the host vehicle and the preceding vehicle, respectively. On the basis of the accelerator opening of the vehicle and the vehicle speed, the braking torque for the engine friction and the braking torque for the motor regeneration. Braking torque calculation means for determining the motor motor, and the appropriate motor braking based on the deceleration torque obtained from the acquired running state, the running resistance torque corresponding to the running resistance, and the braking torque for the engine friction It is preferable to calculate the torque.

  In the hybrid vehicle operation control system according to the present invention, the braking torque corresponding to the engine friction and the motor regeneration are determined for the braking torque according to whether or not the relationship between the host vehicle and the preceding vehicle satisfies a predetermined following traveling condition. It is preferable to provide distribution means for changing the distribution with the braking torque of the minute.

  Further, the hybrid vehicle operation control system according to the present invention preferably includes a deceleration target display means for displaying a deceleration timing corresponding to the timing of the additional braking and a deceleration magnitude corresponding to the magnitude of the additional braking.

  With the above configuration, the motor braking torque excluding the braking torque for the engine friction is calculated as the appropriate motor braking torque out of the braking torque for making the following traveling state between the host vehicle and the preceding vehicle appropriate, and the battery The maximum negative torque corresponding to the torque that can be braked by the motor is calculated based on the rechargeable power of the motor, and the appropriate motor braking torque is determined by the motor at a timing when it exceeds the threshold value obtained by subtracting a predetermined value from the maximum negative torque Start additional braking. Therefore, since braking is applied early based on the rechargeable power of the battery, etc., braking energy can be collected finely and fuel efficiency can be improved.

  In addition, when the battery chargeable power is reduced and small, the timing of the additional braking start is shortened, the magnitude of the additional braking is reduced, and when the battery chargeable power is large, the timing of the additional braking start is set. Slowly, since the magnitude of the additional braking is increased, it is possible to finely collect braking energy according to the chargeable power of the battery and the like, and to improve fuel efficiency.

  Further, since the additional braking is stopped at the timing when the difference between the vehicle speed of the host vehicle and the vehicle speed of the preceding vehicle falls within a predetermined range, the fuel consumption can be improved without impairing the follow-up traveling.

  In addition, the driving state of the host vehicle and the preceding vehicle is acquired, the driving resistance of the host vehicle is acquired, and the braking torque for the engine friction and the motor regeneration amount are acquired based on the accelerator opening of the host vehicle and the host vehicle speed. The appropriate motor braking torque is calculated based on the deceleration torque determined from the acquired traveling state, the traveling resistance torque corresponding to the traveling resistance, and the braking torque corresponding to the engine friction. Therefore, braking can be applied based on the appropriate motor braking torque corresponding to the running state.

  In addition, the distribution of the braking torque for engine friction and the braking torque for motor regeneration is changed with respect to the braking torque depending on whether or not a predetermined following traveling condition is satisfied. In distinction, the magnitude of the braking torque for motor regeneration can be determined.

  Moreover, the deceleration timing corresponding to the timing of additional braking and the magnitude | size of the deceleration corresponding to the magnitude | size of additional braking are displayed. Therefore, a specific deceleration target for effectively recovering braking energy can be shown to the driver or the like.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration of an operation control system 10 for a hybrid vehicle. The hybrid vehicle operation control system 10 detects an engine 12 and a motor 14 which are driving sources of the hybrid vehicle, a battery 16 for storing regenerative energy and supplying electric power to each element of the hybrid vehicle, and a vehicle speed of the own vehicle. A vehicle speed sensor 18, a distance sensor 20 that detects a distance between the vehicle and the vehicle ahead, a navigation device 22 that provides a traveling environment including road inclination, and the like. Further, the operation control system 10 includes a hybrid CPU (HVCPU) 24 that controls driving of the engine 12 and the motor 14, a battery CPU (BATCPU) 26 that controls charging / discharging of the battery 16, and the operation traveling of the hybrid vehicle. The operation control part 30 which performs control of this is comprised.

  Since the engine 12, the motor 14, the battery 16, the HVCPU 24, and the BATCPU 26 are generally provided in a hybrid vehicle, detailed description thereof is omitted.

  The vehicle speed sensor 18 has a function of detecting or calculating the vehicle speed of the host vehicle. For example, the vehicle speed can be obtained from the rotational speed of the axle. When the vehicle is driven only by the engine 12, the vehicle speed can be obtained from the engine speed and the shift state.

  The distance sensor 20 has a function of detecting or calculating an inter-vehicle distance between the preceding vehicle and the host vehicle. For example, the distance between vehicles can be detected by radiating radio waves or the like to the preceding vehicle and detecting the reflection. Further, the vehicle speed of the preceding vehicle can be calculated from the time change of the vehicle interval and the vehicle speed of the host vehicle. Alternatively, the vehicle speed of the vehicle ahead can be detected using the Doppler effect. It should be noted that the distance between vehicles can be obtained using other principles, for example, a navigation function, and the vehicle speed of the preceding vehicle can be obtained.

  The navigation device 22 is a device that displays the traveling state of the vehicle using a map or the like. Here, in particular, those having a function of providing information such as road conditions, such as road gradients and road pavement conditions are preferable.

  The operation control unit 30 has a function of performing overall control of traveling of the hybrid vehicle in cooperation with the HVCPU 24, the BATCPU 26, and the like. Here, in particular, it has a cruise control function for causing the vehicle to follow the traveling of the preceding vehicle in accordance with information from the vehicle speed sensor 18, the distance sensor 20, the navigation device 22, and the like, and a fuel consumption improvement function associated therewith. Of course, the control functions such as the HVCPU 24 and the BATCPU 26 may be combined into one controller or combined with a vehicle control unit having other functions.

  The operation control unit 30 is an interface relating to running resistance information such as a CPU 32 and running state information I / F 34 which is an interface for running state information of the host vehicle and the preceding vehicle such as the vehicle speed sensor 18 and the distance sensor 20, and the navigation device 22. Battery information I / F 40 that can communicate with a certain running resistance information I / F 36 and HVCPU 24 and can be used as an interface for driving and regeneration, and battery information I / F 40 that can communicate with BATCPU 26 and can be used as an interface for charging state information of the battery 16. A deceleration target display unit 42 that displays a suitable deceleration target, and a storage device that stores a program or the like (not shown) are configured. Each element is connected to each other by an internal bus. The operation control unit 30 can be configured by a vehicle computer or the like.

  The CPU 32 includes a cruise control module 44 that performs follow-up travel in relation to the vehicle ahead, a travel state acquisition module 46 that acquires travel state information via the travel state information I / F 34, and a travel resistance via the travel resistance information I / F 36. A traveling resistance acquisition module 48 that acquires information, a target braking torque calculation module 50 that determines a target value of braking torque from the braking torque for engine friction and the braking torque for motor regeneration, and a deceleration torque and traveling resistance that are determined from the traveling state An appropriate motor braking torque calculation module 52 that calculates an appropriate motor braking torque from the torque and a braking torque corresponding to the engine friction, and calculates a maximum negative torque corresponding to the torque that the motor can brake according to the chargeable state of the battery. Motor maximum negative torque calculation module 54 and appropriate motor braking torque As including the additional braking initiation module 56 to initiate additional braking by the motor, an additional braking termination module 58 to stop additional braking at a timing based on the vehicle speed of the host vehicle and the preceding vehicle on the basis of the maximum motor negative torque. These functions can be realized by software, specifically, by executing a corresponding cruise control program.

  The operation of the hybrid vehicle operation control system 10 having such a configuration will be described in detail with reference to the flowchart of FIG. 2 and related drawings. FIG. 2 is a flowchart showing a procedure for applying braking in consideration of fuel efficiency in cruise control of a hybrid vehicle, and these procedures correspond to the respective processing procedures of the corresponding cruise control program.

  When the hybrid vehicle is traveling, it is determined whether or not the following traveling condition is established between the vehicle, that is, the own vehicle and the preceding vehicle. The following traveling condition is a condition for appropriately following the traveling of the host vehicle to the traveling of the preceding vehicle. The following traveling condition can be determined based on a criterion such as whether or not the distance between the own vehicle and the preceding vehicle, that is, whether the vehicle is closer enough to fall within a predetermined distance. The following traveling condition may consider the vehicle speeds of the host vehicle and the preceding vehicle, or may take into account the time variation of the vehicle interval. In any case, whether or not the follow-up driving condition is established by acquiring the situation regarding the driving between the preceding vehicle and the own vehicle from various sensors of the vehicle and comparing with the setting condition stored in advance in a storage device (not shown). Is judged. This function is executed by the cruise control module 44 of the CPU 32.

FIG. 3 is a diagram for explaining the concept of following travel. Here, the forward vehicle 62 is traveling at an inter-vehicle distance _{xn in} front of the host vehicle 60 traveling. Wherein the current vehicle distance x _n, to be different for appropriate range and the predetermined inter-vehicle distance x _r that is set in advance in the case to follow the preceding vehicle 62, follow-up running is performed. For example, if _{x n} is greater than _{x r,} to accelerate the vehicle 60, the vehicle speed _{V 2} of the vehicle 60 is raised from the vehicle speed _{V 1} of the vehicle ahead 62, close to _{x r} stuffed vehicle distance. Conversely, if _{x n} is less than _{x r,} decelerated braked on the vehicle 60, the vehicle speed _{V 2} of the vehicle 60 is lowered from the vehicle speed _{V 1} of the vehicle ahead 62, _{x r} extends the vehicle spacing Move closer to. if x _n is the _{x r,} vehicle speed _{V 2} of the vehicle 60 in the same vehicle speed _{V 1} of the vehicle ahead 62, maintains the vehicle spacing _{x r.} Thus, in order to maintain the vehicle spacing x _r, appropriately performs accelerating and braking to the vehicle 60, to automatically track the speed V ₂ of the vehicle 60 to the vehicle speed V ₁ of the vehicle ahead 62 Follow-up driving is performed.

At the beginning of the procedure for applying braking in consideration of fuel efficiency in cruise control of a hybrid vehicle, travel state information about the host vehicle 60 and the forward vehicle 62 shown in FIG. 2 is acquired. Specifically, the above _{V 1, V 2, x n} , x r is obtained (S10). This function is executed by the travel state acquisition module 46 of the CPU 32 giving commands to the vehicle speed sensor 18 and the distance sensor 20 via the travel state information I / F 34. The vehicle speed V ₂ of the host vehicle 60 can be acquired directly from the vehicle speed sensor 18, and the inter-vehicle distance _xn between the host vehicle 60 and the preceding vehicle 62 can be acquired directly from the distance sensor 20. Further, the vehicle speed V ₁ of the front vehicle 62 is calculated and acquired based on the change in the inter-vehicle distance _xn before and after one sampling interval of data acquisition of the distance sensor 20 and the vehicle speed V ₂ of the host vehicle 60. be able to. Alternatively, as mentioned above, or if there is a device for determining a vehicle speed V ₁ of the vehicle ahead 62 using Doppler effect, when you can use the navigation device, as to obtain the vehicle speed V ₁ of the vehicle ahead 62 from these Also good.

Here, in the follow-up running, the vehicle speed V ₂ of the vehicle 60 is to consider the braking torque when faster than the vehicle speed V ₁ of the vehicle ahead 62, each formula shown in Figure 3 is established. That is, when the acceleration of the host vehicle 60 is α, the relationship of Expression (1) is established.
V ₁ ² −V ₂ ² = 2α (x _n −x _r ) (1)
If the mass of the host vehicle 60 is M, the running resistance is R _f , the engine friction component of the braking force (emblem force) is T _Pe , the motor regeneration component is T _Pm , and the additional braking force by the motor is T _bk , The relationship (2) is established.
Mα = −R _f + T _Pe + T _Pm + T _bk (2)
Expression (3) can be derived from Expressions (1) and (2).
T _Pm + T _bk = [V ₁ ² −V ₂ ² / {2α (x _n −x _r )}] M + R _f −T _Pe (3)
Since this T _Pm + T _bk is a braking force of the motor necessary for maintaining the follow-up running, it will be expressed as an appropriate motor braking force T _bkm .

In the above formula, the formula is based on the dimension of force, but in the case of a vehicle, it is better to express it by torque. Therefore, these braking forces T _Pe , T _Pm , T _bk , T _bkm are directly used as the corresponding braking torques. In the following, the description will be made with the braking torque. Therefore, T _bkm represents an appropriate motor braking torque.

Returning to FIG. 2 again, the proper motor braking torque _Tbkm is obtained by the procedure of S12-S16. That is, the vehicle speed V ₂ acquired from the vehicle speed sensor 18, based on the vehicle accelerator opening obtained from the accelerator opening sensor (not shown) or the like, as target brake torque of the vehicle 60, the engine A braking torque for friction and a braking torque for motor regeneration are respectively obtained (S12). In addition, the distribution of the braking torque for engine friction and the braking torque for motor regeneration shall be changed in advance according to whether the relationship between the host vehicle and the preceding vehicle satisfies a predetermined following traveling condition. Is preferred.

Further, the driving resistance torque R _f corresponding to the driving resistance is obtained from the navigation device 22 (S14). Then, an appropriate motor braking torque T _bkm is calculated from these by the equations (1), (2), and (3) (S16). These functions are executed by the running resistance acquisition module 48, the target braking torque calculation module 50, and the appropriate motor braking torque calculation module 52.

Next, to obtain the chargeable power _{W in} the battery 16 via the BATCPU26 (S18). Figure 4 shows the dischargeable power _{W out} of the battery 16, one example of the temperature characteristic of the chargeable power _{W in.} Battery 16, Since the chargeable power W _in a rechargeable electric power by temperature fluctuation, detects the temperature of the battery 16 using the temperature sensor or the like (not shown), the data shown in FIG. 4 used in determining the rechargeable power _{W in.}

Next, the motor maximum negative torque T _mmin that is the maximum braking torque that the motor 14 can output is calculated (S20). The motor maximum negative torque T _mmin is the maximum braking torque that the motor 14 can output within the chargeable power of the battery 16. This can be determined by the following procedure. That is, to get the chargeable power W _in the battery S18, further obtained via the BATCPU26 the power battery 16 is already charged, the battery 16 from the difference between these seek current maximum power that can be charged. And the maximum power which can be charged now is converted into a torque using the rotation speed N _mV2 of the motor 14 of the _host vehicle 60. The converted torque is the maximum braking torque that can be output by the motor 14 in the current state of the battery 16 and the following traveling state, that is, the motor maximum negative torque T _mmin . Therefore, the maximum motor negative torque _{T mmin is} a function of _{W in} the _{N mV2.} These functions are executed by the motor maximum negative torque calculation module 54.

Timing such that the vehicle speed V ₂ of the vehicle 60 starts additional braking if faster than the vehicle speed V ₁ of the vehicle ahead 62 has a proper motor braking torque T _bkm obtained in S16, the motor maximum negative torque obtained in S20 Determined by comparison with T _mmin . That is, proper motor braking torque _{T bkm} is at the timing of exceeding the threshold value obtained by subtracting a predetermined adaptation value β from the maximum motor negative torque _{T mmin,} additional braking by the motor is started (S22, S24). Then, timing and the like to stop the additional damping is determined by comparison of the vehicle speed V ₁ of the vehicle speed V ₂ and the preceding vehicle of the own vehicle 60. That is, the vehicle speed V ₂ of the vehicle 60 is decelerated at the timing that exceeds the threshold value obtained by adding a predetermined margin rate γ of the vehicle speed V ₁ of the front vehicle, and ends the additional braking by the motor (S26, S28). These functions are executed by controlling the operation of the motor 14 via the HVCPU 24 by the additional braking start module 56 and the additional braking end module 58.

This is shown in FIG. 5 (a) it is taken to the vehicle speed on the vertical axis and time on the horizontal axis is shown the time variation due to the braking of the vehicle speed V ₂ of the vehicle by comparing the vehicle speed V ₁ of the vehicle ahead. In FIG. 5B, the vertical axis represents the absolute value of the braking torque, that is, the deceleration torque, and the horizontal axis represents the change in the deceleration torque of the vehicle due to braking, taking the time when the origin is aligned with FIG. It is shown.

As shown in FIG. 5B, the additional braking by the motor is started at time t1 earlier than time t2 when the deceleration torque reaches the absolute value of the motor maximum negative torque T _mmin . In other words, additional braking by the motor is started at a time t1 that exceeds a threshold obtained by subtracting a predetermined fitness value β from the motor maximum negative torque T _mmin . The predetermined adaptation value β can be appropriately determined depending on the vehicle speeds V ₁ and V ₂ . Then, the deceleration torque is gradually brought closer to the vicinity of the motor maximum negative torque _{T mmin,} motor maximum negative torque _{T mmin} is applied as a maximum braking at t2.

Maximum motor negative torque T _mmin, since a function of the chargeable power W _in the cell 16 as described above, for example, its value as indicated by the arrows in FIG. 5 (b) up and down the temperature or the like. That is, the smaller is throttled chargeable power W _in the battery 16, the faster the time t1 in the timing of additional braking start, also reduced the size of the additional braking. On the other hand, if the rechargeable power W _in the battery 16 is large, slower time t1 of the timing of the additional braking start, the greater the size of the additional braking. As described above, since the manner of braking can be changed according to the state in which the battery 16 can be charged, the braking energy can be collected finely.

Additional braking, as shown in FIG. 5 (a), the difference between the vehicle speed V ₁ of the vehicle speed V ₂ and the preceding vehicle of the own vehicle is completed at time t3 timing within a predetermined range. In other words, it ends at time t3 timing rate plus a margin rate gamma on the vehicle speed V ₁ of the preceding vehicle, i.e., the V _{1 +} gamma of the vehicle speed V ₂ of the subject vehicle is decelerated. The value of V 1 ₊ gamma is decelerating torque when the vehicle speed of the vehicle becomes V _{1 +} gamma is, can be determined to be close to the braking torque by the engine friction component in the vehicle speed. In this way, the additional braking by the motor can be terminated while maintaining the braking torque and continuity for the engine friction.

  In order to inform the driver of braking suitable for improving fuel efficiency, a deceleration target display device can be provided. FIG. 6 shows such a screen of the deceleration target meter 64, and the deceleration target meter 64 corresponds to the display of the deceleration side of the power meter indicating the state of charge of the battery. In FIG. 6, the numerals are scales showing the chargeable power of the battery, and the current chargeable power of the battery is indicated by the position of the blinking star mark 66. The example of FIG. 6 shows that charging of about 15 kW is possible. The lower horizontal bar 68 in FIG. 6 indicates the level of braking energy recovered depending on the current braking state, and in the example of FIG. 6, it is shown that the level is about 12 kW. In this case, it is possible to give information to the driver that there is still room in the battery and that the braking energy can be sufficiently recovered even if the brake is further applied. In this way, the deceleration target meter 64 can give information that prompts the driver or the like to improve fuel efficiency or regeneration.

In embodiment which concerns on this invention, it is a figure which shows the structure of the operation control system of a hybrid vehicle. 5 is a flowchart illustrating a procedure for applying braking in consideration of fuel efficiency under cruise control of a hybrid vehicle in the embodiment according to the present invention. It is a figure explaining the concept of follow running. It is a figure which shows one example of the temperature characteristic of the dischargeable power of a battery, and the chargeable power. In embodiment which concerns on this invention, it is a figure explaining the timing which starts additional braking, and the timing which stops additional braking. In embodiment which concerns on this invention, it is a figure which shows the example of the screen of the deceleration target meter.

Explanation of symbols

  10 Hybrid Vehicle Operation Control System, 12 Engine, 14 Motor, 16 Battery, 18 Vehicle Speed Sensor, 20 Distance Sensor, 22 Navigation Device, 24 HVCPU, 26 BATCPU, 28 Storage Device, 30 Operation Control Unit, 32 CPU, 34 Running State Information I / F, 36 Travel resistance information I / F, 38 Drive / regeneration I / F, 40 Battery information I / F, 42 Deceleration target display section, 44 Cruise control module, 46 Travel state acquisition module, 48 Travel resistance acquisition module , 50 target braking torque calculation module, 52 appropriate motor braking torque calculation module, 54 motor maximum negative torque calculation module, 56 additional braking start module, 58 additional braking end module, 60 own vehicle, 62 forward vehicle, 64 deceleration target meter, 66 Star mark , 68 Horizontal bar mark.

Claims (6)

A hybrid vehicle operation control system having a follow-up running function for automatically following the running of the vehicle ahead and controlling the running of the vehicle.
Appropriateness for obtaining motor braking torque excluding braking torque for engine friction out of braking torque for making the following traveling state between the own vehicle and the preceding vehicle appropriate based on the traveling state between the own vehicle and the preceding vehicle Motor braking torque calculating means;
Maximum negative torque calculating means for calculating the maximum negative torque corresponding to the torque that can be braked by the motor based on the rechargeable power of the battery and the motor rotation speed;
Additional braking start means for starting additional braking by the motor at a timing when the appropriate motor braking torque exceeds a threshold obtained by subtracting a predetermined adaptive value from the maximum negative torque;
An operation control system for a hybrid vehicle, comprising: In the operation control system of the hybrid vehicle according to claim 1,
Additional braking start means
When the chargeable power of the battery is reduced and small, the start timing of the additional braking is shortened, the magnitude of the additional braking is reduced, and when the battery chargeable power is large, the timing of the additional braking start is delayed, An operation control system for a hybrid vehicle characterized by increasing the magnitude of additional braking. The hybrid vehicle operation control system according to claim 1, further comprising:
An operation control system for a hybrid vehicle, comprising: additional braking end means for stopping additional braking at a timing when the difference between the vehicle speed of the host vehicle and the vehicle speed of the preceding vehicle falls within a predetermined range. In the operation control system of the hybrid vehicle according to claim 1,
The appropriate motor braking torque calculation means is:
About the running state of the own vehicle and the preceding vehicle, traveling state acquisition means for acquiring the vehicle speed of the own vehicle and the preceding vehicle, the inter-vehicle distance between the own vehicle and the preceding vehicle, and the appropriate inter-vehicle distance,
Traveling resistance acquisition means for acquiring the traveling resistance of the vehicle;
Braking torque calculating means for determining a braking torque for engine friction and a braking torque for motor regeneration based on the accelerator opening of the host vehicle and the host vehicle speed,
And a suitable motor braking torque is calculated based on a deceleration torque obtained from the acquired traveling state, a traveling resistance torque corresponding to the traveling resistance, and a braking torque corresponding to the engine friction. Vehicle operation control system. In the hybrid vehicle operation control system according to claim 1 or 4,
Distributing means for changing the distribution of the braking torque for engine friction and the braking torque for motor regeneration with respect to the braking torque according to whether or not the relationship between the host vehicle and the preceding vehicle satisfies a predetermined following traveling condition. A hybrid vehicle operation control system. In the hybrid vehicle operation control system according to claim 2,
An operation control system for a hybrid vehicle, comprising: deceleration target display means for displaying a deceleration timing corresponding to the timing of additional braking and a magnitude of deceleration corresponding to the magnitude of additional braking.

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