JP2010214991A - Driving control device for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control device of a hybrid vehicle, which improves fuel economy on a regular route on which a user frequently travels, by analyzing traveling conditions of a user to optimize start threshold and stop threshold of an engine on the regular route. <P>SOLUTION: A driving control device 30 is mounted on a hybrid vehicle 10 equipped with an electric motor 11 and an engine 12 as a driving source. The driving control device 30 has: an engine driving control means 31 for controlling the start and stop of the engine 12 based on a request power map; a storage means 32 for storing a request power value corresponding to a vehicle speed when traveling on the regular route; a learning means 33 for, when predetermined update conditions are satisfied by a relationship between the stored request power value corresponding to the vehicle speed and set start threshold or set stop threshold in the vehicle speed, updating the set start threshold or the set stop threshold to the request power value; and a best fuel economy route display means 34. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive control device for a hybrid vehicle, and in particular, for each vehicle speed, a start threshold that is a threshold of required power when starting the engine and a stop threshold that is a threshold of required power when stopping the engine are defined for each vehicle speed. The present invention relates to a drive control device having engine drive control means for controlling start and stop of an engine based on a requested power map.

  In recent years, hybrid vehicles including an electric motor and an engine as a vehicle drive source have been widely used. The electric motor that functions as a drive source also functions as a generator when the vehicle is decelerating, and can recharge the battery with the regenerated current. A generator driven by the engine is also installed. In general, in order to achieve low fuel consumption, hybrid vehicles prioritize EV driving by electric motors when starting with low engine thermal efficiency and at low vehicle speeds. The battery is charged by driving the generator with a part of the power. With regard to fuel consumption, in particular, it is strongly desired to reduce fuel consumption on regular routes such as commuting routes and shopping routes where users often travel.

  In view of such circumstances, several hybrid vehicle drive control devices with improved motor and engine operation patterns have been developed. For example, Patent Document 1 discloses route setting means for setting a route to a destination, storage processing means for storing and statistically processing travel data and travel environment information for the set route, and current travel environment. Based on the information and the stored travel data, predicting means for predicting the travel pattern of the set route, and setting the operation schedule of the engine and the motor based on the predicted travel pattern, and according to the set operation schedule A control device having control means for controlling the operation of the engine and the electric motor is disclosed.

  Further, in Patent Document 2, a traveling situation in which acceleration and deceleration are frequently repeated is estimated using information recorded in a navigation device, and an engine start threshold is moved to a high vehicle speed side according to the estimation result to There is disclosed a control device that improves fuel efficiency and acceleration response by continuing traveling or by moving the engine stop threshold to a low vehicle speed side to prevent useless engine stop / start. .

JP 2004-248455 A JP 2000-205000 A

  However, the control device of Patent Document 1 optimizes a start threshold that is a threshold of required power corresponding to the vehicle speed when starting the engine, and a stop threshold that is a threshold of required power corresponding to the vehicle speed when stopping the engine. Depending on the driving conditions of the user, the engine may be in an inefficient driving state such as frequent starting and stopping, and there is still room for improvement from the viewpoint of reducing fuel consumption.

  On the other hand, the control device of Patent Document 2 uses an information recorded in the navigation device to frequently repeat acceleration and deceleration, specifically based on traffic conditions and road conditions, engine start thresholds, This is a device for changing the stop threshold. However, in the control device of Patent Document 2, it is difficult to set optimal start threshold values and stop threshold values that accurately correspond to actual user travel conditions (actual required power, etc.).

  An object of the present invention is a hybrid capable of improving fuel efficiency on a regular route by analyzing a user's travel condition and optimizing an engine start threshold and a stop threshold on a regular route on which the user often travels. It is providing the drive control apparatus of a vehicle.

  A drive control apparatus for a hybrid vehicle according to the present invention includes a start threshold that is a threshold of required power for starting an engine, and a stop threshold for stopping the engine in a drive control apparatus for a hybrid vehicle including an electric motor and an engine as drive sources. Based on a required power map that defines a stop threshold that is a threshold of required power for each vehicle speed, engine drive control means that controls engine start and stop, and a required power value corresponding to the vehicle speed when traveling on a regular route When the relationship between the storage means for storing, the required power value corresponding to the stored vehicle speed, and the set start threshold value or the set stop threshold value at the vehicle speed satisfies a predetermined update condition, the set start threshold value is set to the required power value. Or a learning means for updating the setting stop threshold value.

  According to the above configuration, it is possible to set the engine start threshold value and the engine stop threshold value accurately corresponding to the travel situation by grasping (analyzing) the travel situation of the user on the regular route on which the user often travels. Therefore, the engine can be driven efficiently, and further fuel-efficient driving can be realized.

  Further, the hybrid vehicle includes a navigation system, and when a travel route is searched by the navigation system, when there are a plurality of regular routes corresponding to the requested power map updated as candidates for the travel route, It is preferable to have an optimum low fuel consumption route display means for specifying and displaying the optimum low fuel consumption route among the regular routes.

  According to the said structure, it becomes possible to select a driving | running route in consideration of fuel consumption other than required time etc., and a user's convenience improves further.

  According to the drive control apparatus for a hybrid vehicle according to the present invention, the fuel consumption on the normal route is optimized by analyzing the user's travel condition and optimizing the engine start threshold and the stop threshold on the normal route on which the user often travels. It becomes possible to improve.

It is a block diagram which shows schematic structure of the hybrid vehicle carrying the drive control apparatus in embodiment which concerns on this invention. It is a figure which shows the required power map in the normal path | route after learning and the required power map of an initial setting state. It is a flowchart which shows the control procedure of the drive control apparatus shown in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a hybrid vehicle 10 including an electric motor 11 and an engine 12 and a drive control device 30 mounted on the hybrid vehicle 10.

  As shown in FIG. 1, a hybrid vehicle 10 equipped with a drive control device 30 includes an electric motor 11 and an engine 12 connected to a drive system as drive sources. The hybrid vehicle 10 includes a battery 13 that supplies electric power to the electric motor 11, a generator 14 that charges the battery 13, an inverter 15 that converts a direct current supplied from the battery 13 into an alternating current, and the like. Here, the drive system is a portion that transmits the rotational force of the electric motor 11 or the like to the drive wheels 16 and includes a drive shaft 17, a power distribution mechanism 18, a speed reducer 19, and the like.

  The electric motor 11 is a rotating electric machine that drives the hybrid vehicle 10. Further, at the time of deceleration, it functions as a generator that regenerates power using the rotational energy of the drive wheels 16. The drive of the electric motor 11 is controlled by the drive control device 30 via an MG-ECU (motor generator electronic control unit) (not shown). The MG-ECU controls the operation of the inverter 15 in consideration of information measured by various sensors such as a rotation speed sensor, a temperature sensor, and a current sensor (not shown) according to a control signal from the drive control device 30. The power supplied to the electric motor 11 is adjusted.

  The battery 13 is a power storage device that supplies electric power to the electric motor 11, and a secondary battery such as a nickel cadmium battery, a nickel hydrogen battery, and a lithium ion battery is used. From the viewpoint of efficient use, prevention of deterioration, and the like, the battery 13 is set with an SOC (State Of Charge) charge range in which a predetermined charge rate is an upper and lower limit value. The SOC control of the battery 13 is performed based on the SOC information measured by a battery ECU (not shown) so that the drive control device 30 does not overcharge or overdischarge the battery 13 via the MG-ECU. 11. It is performed by adjusting the operation of the engine 12, etc.

  The generator 14 is a rotating electric machine that generates electric power to be supplied to the electric motor 11. The generator 14 has a rotating shaft connected to the output shaft of the engine 12 via the power distribution mechanism 18 and is driven by the engine 12. The power distribution mechanism 18 is a mechanism that is coupled to the engine 12, the generator 14, and the electric motor 11, and distributes the power among them. For example, the driving force generated by the engine 12 is generated by the drive wheel 16 and the power generation. It has the function to distribute to the power generation part of the machine 14.

  As described above, the inverter 15 has a function of converting the direct current supplied from the battery 13 into an alternating current and supplying the alternating current to the electric motor 11. Generally, the output control of the electric motor 11 is performed by turning on / off the switching element of the inverter 15 and adjusting the power supplied to the electric motor 11 as described above. The MG-ECU controls the output of the electric motor 11 by giving a control signal to the inverter 15, and the drive control device 30 gives the control signal to the MG-ECU to control the driving force of the vehicle in an integrated manner. is there. The inverter 15 also has a function of converting the alternating current regenerated by the electric motor 11 into direct current and regenerating it to the battery 13. Similarly, the electric power generated by the generator 14 is charged into the battery 13 via the inverter 15 or directly supplied to the electric motor 11 and used as driving electric power for the electric motor 11.

  The engine 12 is an internal combustion engine that drives the hybrid vehicle 10. Also, it has a function of driving the generator 14. Generally, since the output of the engine 12 is set in consideration of high load operation, the thermal efficiency at the time of low vehicle speed (starting) and low load operation becomes worse. Therefore, the hybrid vehicle 10 performs EV traveling using only the electric motor 11 at low vehicle speed and low load operation, or traveling using both the electric motor 11 and the engine 12, and switches to traveling using the engine 12 when the vehicle speed increases to some extent. Then, the power of the engine 12 is divided into two paths by the power distribution mechanism 18, and the drive wheels 16 are driven on the one hand and the generator 14 is driven on the other hand to generate power.

  The hybrid vehicle 10 is also provided with a navigation system 20 that searches and guides a user's intended travel route, a vehicle speed sensor 21 that measures a vehicle speed, an accelerator opening sensor 22 that measures an accelerator opening (not shown), and the like. Is done. Information acquired by the navigation system 20, the vehicle speed sensor 21, and the accelerator opening sensor 22 is input to the drive control device 30.

  The drive control device 30 is a device that controls the driving force of the hybrid vehicle 10 and can be configured as a so-called hybrid ECU or a part thereof. Specifically, the drive control device 30 receives the motor 11 through the MG-ECU and the engine ECU according to information and signals from the various sensors and ECUs, the driver's output request (accelerator opening), and the like. It has a function of comprehensively controlling the output (power) of the engine 12. The drive control device 30 and each ECU are constituted by a microcomputer (hereinafter referred to as a microcomputer) having a CPU, an input / output port, a memory, and the like, and each function of the drive control device 30 is realized by executing software. it can.

  The drive control device 30 has a function of learning optimum engine start / stop conditions in order to improve fuel efficiency on a regular route that is a commuting route or a shopping route on which a user often travels. . As shown in FIG. 1, the drive control device 30 has engine drive control means 31, storage means 32, learning means 33, and optimum low fuel consumption route display means 34 regarding drive control of the engine 12.

  The engine drive control means 31 of the drive control device 30 has a function of controlling the start and stop of the engine 12 based on the required power map shown in FIG. Here, FIG. 2 (a) is a required power map in the initial setting state, and FIG. 2 (b) is a diagram showing a required power map after learning by the learning means 33, and shows the vehicle speed when the engine 12 is started. The start threshold value corresponding to the required power threshold is indicated by a solid line, and the stop threshold value corresponding to the required power corresponding to the vehicle speed when the engine 12 is stopped is indicated by a dotted line. The required power map shown in the figure is a map in which the horizontal axis indicates the vehicle speed and the vertical axis indicates the required power, and is stored in the drive control device 30. Then, based on the start threshold value and stop threshold value of the engine 12 defined in the map, the engine drive control means 31 controls the start and stop of the engine 12.

  The required power in the required power map is the power required for the hybrid vehicle 10, and is specifically determined based on the accelerator depression amount, that is, the accelerator opening acquired by the accelerator opening sensor 22. The For example, when the amount of accelerator depression increases and the accelerator opening increases, the required power increases, resulting in a high-load operation. On the other hand, when the amount of depression of the accelerator is small, the required power is small and a low load operation is performed.

  The required power map in the initial setting state shown in FIG. 2 (a) is a high value for both the start threshold value and the stop threshold value of the engine 12 in order to suppress the drive of the engine 12 having poor thermal efficiency in the low vehicle speed operation and low load operation regions. Is set. On the other hand, in the high vehicle speed operation and high load operation regions, it is more efficient to use the engine 12, and therefore both the start threshold value and the stop threshold value of the engine 12 are set to low values. In addition, the starting threshold value and the stopping threshold value when the starting threshold value and the stopping threshold value specified in the required power map in the initial setting state shown in FIG. Are referred to as a setting start threshold and a setting stop threshold.

  The engine drive control means 31 controls the drive and stop of the engine 12 based on the SOC information of the battery 13 in addition to the required power map. Therefore, when the SOC of the battery 13 decreases, the engine 12 is started and the generator 14 is driven. For example, it is assumed that the hybrid vehicle 10 is traveling on a long uphill with a relatively high load condition at a low vehicle speed and less than the start threshold of the engine 12. In this case, according to the operation control of the engine 12 based on the required power map in the initial setting state shown in FIG. 2A, EV driving is performed only by the electric motor 11, and the engine 12 generates power when the SOC of the battery 13 decreases. It is assumed that the inefficient operation of driving the machine 14 and driving to supply electric power to the electric motor 11 via the battery 13 is assumed.

  If it is a regular route that the user travels well, by accumulating and analyzing the user's driving situation, the above-mentioned inefficient driving is suppressed and the optimum according to the user's driving situation from the viewpoint of improving fuel efficiency. The operation of the engine 12 can be realized. The drive control device 30 includes a storage unit 32 and a learning unit 33 in order to realize the optimum operation of the engine 12 for the purpose of improving the fuel consumption in the regular route. The storage unit 32 has a function of storing travel data on the regular route necessary for learning the required power map by the learning unit 33.

  Specifically, the storage means 32 stores a required power value corresponding to each vehicle speed when traveling on the regular route. Each required power value is preferably stored as continuous data in association with the time axis or travel distance during normal route travel. In addition, the storage means 32 can store data as one continuous data throughout the entire service path including the forward path and the return path, or can store data for each section by dividing the service path into a plurality of sections. it can. Then, when stored as one continuous data throughout the regular route including the forward route and the return route, as shown in FIG. 2B, the required power map after learning corresponding to the entire regular route including the forward route and the backward route Is created. The vehicle speed is acquired by the vehicle speed sensor 21, and the required power value is acquired by the accelerator opening sensor 22.

  The storage of the travel data by the storage means 32 is performed by a user setting a common route in advance, storing settings and a travel history stored when traveling along the route, and when the travel frequency increases, the route is used as a regular route. Various storage settings such as a setting that is automatically set and stored automatically, and a setting that is stored when a regular route is set as a travel route by the navigation system 20 or the like.

  The learning unit 33 has a function of analyzing the travel data stored in the storage unit 32 and changing the setting start threshold value and the setting stop threshold value of the engine 12. Specifically, it is determined whether or not the relationship between the required power value corresponding to the stored vehicle speed and the set start threshold value or the set stop threshold value at the vehicle speed satisfies a predetermined update condition, and the relationship is a predetermined value. When it is determined that the update condition is satisfied, the set start threshold value or the set stop threshold value is updated to the stored required power value.

  Here, the stored required power value can be obtained by averaging the required power values of a plurality of travel data, and is preferably averaged by removing irregular travel data. Therefore, the above analysis by the learning means 33 is performed as one execution condition that the number of travel data acquired by the storage means 32 is accumulated to some extent. In addition, although the required number of traveling data can be set arbitrarily, naturally it is preferable that the number of traveling data is large in order to execute an accurate process. Note that when the predetermined update condition is not satisfied even if the above analysis is executed, the setting start threshold value or the setting stop threshold value is not updated. Here, examples of the predetermined update condition include a low vehicle speed and high load operation condition, and a high vehicle speed and low load operation condition.

  As a case where the low vehicle speed and the high load operation condition are satisfied, for example, a case of traveling on a long uphill is assumed. Specifically, it is determined that a predetermined update condition is satisfied when traveling at a relatively high required power at a low vehicle speed and less than a set activation threshold continues for a predetermined time or more or exceeds a predetermined frequency. As described above, in traveling at a low vehicle speed and a relatively high required power that is less than the set activation threshold value, EV traveling is performed only by the electric motor 11, and when this traveling state continues for a long time, the engine 12 causes the SOC of the battery 13 to decrease. In this case, the generator 14 is driven to supply electric power to the electric motor 11 via the battery 13, resulting in an inefficient operation. Note that the relatively high required power less than the set activation threshold means that the difference between the set activation threshold and the corresponding stored requested power value is small, for example, the difference between the two is within a predetermined range, For example, when the state continues for a predetermined time or more determined from the viewpoint of SOC maintenance or the like, it is determined that the update condition is satisfied.

  If it is determined that the update condition is satisfied under the low vehicle speed and high load driving conditions, a part of the setting start threshold value of the required power map shown in FIG. 2A is determined to be reduced and set to the stored required power value. The activation threshold is updated. Then, the engine drive control means 31 controls the startup of the engine 12 based on the updated required power map of the startup threshold shown in FIG. Note that if the difference between the start threshold and the set stop threshold becomes smaller due to the update of the start threshold, there is a risk of inefficient operation in which the start and stop of the engine 12 are frequently repeated. It is preferable to decrease at the same rate as the change of the start threshold.

  On the other hand, as a case where the high vehicle speed and the low load operation condition are satisfied, for example, a case of traveling on a long downhill is assumed. Specifically, it is determined that a predetermined update condition is satisfied when traveling at a high vehicle speed and a relatively low required power that is equal to or higher than a set activation threshold continues for a predetermined time or more than a predetermined frequency. More specifically, when the difference between the set activation threshold value and the corresponding stored required power value falls within a predetermined range and the state continues for a long time, it is determined that the update condition is satisfied. In traveling at a high vehicle speed and a relatively low required power that is equal to or higher than a preset start threshold, for example, the engine 12 is frequently started and stopped frequently, or the engine 12 is driven in a region where the thermal efficiency of the engine 12 is poor. Inefficient operation such as frequent occurrence. In addition, since regenerative power generation of the electric motor 11 is frequently performed, the SOC of the battery 13 is high, and it is more efficient to use the electric motor 11.

  When it is determined that the update condition is satisfied under the high vehicle speed and low load operation condition, the setting start threshold value of the required power map shown in FIG. 2A is increased as in the case of the low vehicle speed and high load operation condition. Thus, the set activation threshold is updated to the stored required power value. Then, the engine drive control means 31 controls the startup of the engine 12 based on the updated required power map of the startup threshold shown in FIG. In addition, it is preferable to increase the setting stop threshold value as well.

  As the update condition, the relationship between the stored required power value and the set stop threshold value can be defined. When the learning unit 33 determines that the update condition is satisfied, only the stop threshold value is updated, or the stop threshold value is updated. It is also possible to increase or decrease the activation threshold according to the increase / decrease rate. The storage unit 32 stores road information such as a gradient and a curve radius acquired from the navigation system 20 and the like, fuel consumption information measured actually, and the like in association with the requested power value, and the learning unit 33 considers such information. Thus, the start threshold value and the stop threshold value of the engine 12 can be updated.

  The optimum fuel-efficient route display means 34 specifies the optimum fuel-efficient route among the plurality of regular routes when a plurality of regular routes exist as candidates for the travel route when the navigation system 20 retrieves the travel route. It has a function to display. The storage means 32 generally stores travel data for each of a plurality of commonly used routes, and the learning means 33 learns a start threshold value and a stop threshold value for each regular route, so that each threshold value is updated. Thus, there are a plurality of regular routes corresponding to the required power map after learning. Therefore, when a travel route is searched by the navigation system 20, a plurality of travel route candidates are often displayed, and a plurality of regular routes may exist in the candidate routes. In such a case, the user can select a travel route in consideration of fuel consumption in addition to the required time.

  The function of the drive control device 30 configured as described above will be described below with reference to FIG. FIG. 3 is a flowchart showing a control procedure of the drive control device 30.

  When the hybrid vehicle 10 travels on the regular route (S10), the required power value corresponding to each vehicle speed is stored (S11). At this time, each required power value is stored as continuous data in association with the time axis or travel distance during traveling on the regular route, and information such as time is used for determination of the update condition. The procedure of S11 is executed by the function of the storage means 32.

  Next, it is determined whether or not the number of stored travel data is greater than or equal to a predetermined number (S12). This procedure is executed by the function of the learning means 33. Since the required power values of a plurality of travel data are averaged and used for analysis and update of the start threshold value and the stop threshold value, the predetermined number that is the required travel data number is determined from the viewpoint of analysis and update accuracy. When the number of travel data is less than the predetermined number, the set start threshold value and the set stop threshold value are not updated, and the engine drive control means 31 performs engine operation based on the requested power map in the initial setting state shown in FIG. 12 operations are controlled (S16).

  When it is determined in S12 that the number of stored travel data is greater than or equal to a predetermined number, the travel data is analyzed (S13). Specifically, the learning unit 33 determines whether or not the relationship between the required power value corresponding to the stored vehicle speed and the set start threshold value or the set stop threshold value at the vehicle speed satisfies a predetermined update condition. As described above, the predetermined update condition can be, for example, a low vehicle speed and high load operation condition, and a high vehicle speed and low load operation condition.

  In S13, when it is determined that the relationship between the required power value corresponding to the stored vehicle speed and the set activation threshold value or the set stop threshold value at the vehicle speed satisfies the predetermined update condition, the set activation is performed to the stored required power value. The threshold value or the setting stop threshold value is updated (S14). Specifically, after updating one of the setting start threshold and the setting stop threshold used for determining the update condition, the other is increased or decreased at the same rate. This procedure is executed by the function of the learning means 33. When it is determined that the predetermined update condition is not satisfied, the set start threshold value and the set stop threshold value are not updated, and the engine drive control means 31 is based on the required power map in the initial setting state shown in FIG. Thus, the operation of the engine 12 is controlled (S16).

  After the start threshold value and the stop threshold value are updated and the required power map after learning as shown in FIG. 2B is stored in the drive control device 30, when the hybrid vehicle 10 travels on the regular route, the request after learning The start and stop of the engine 12 are controlled based on the power map (S15). This procedure is executed by the function of the engine drive control means 31. It is also possible to accumulate travel data and update the updated requested power map as needed.

  As described above, the drive control device 30 obtains the required power value corresponding to the vehicle speed when traveling on the regular route, in addition to the engine drive control means 31 that controls the start and stop of the engine 12 based on the required power map. When the relationship between the storage means 32 for storing, the required power value corresponding to the stored vehicle speed, and the set activation threshold value or the set stop threshold value at the vehicle speed satisfies a predetermined update condition, the setting activation value is set to the required power value. And learning means 33 for updating the threshold value or the set stop threshold value. By analyzing the user's driving situation on the regular route, the engine starting threshold value and the stopping threshold value corresponding to the driving condition are set accurately. By driving the engine efficiently, it becomes possible to realize further fuel-efficient driving.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle, 11 Electric motor, 12 Engine, 13 Battery, 14 Generator, 15 Inverter, 16 Drive wheel, 17 Drive shaft, 18 Power distribution mechanism, 19 Reducer, 20 Navigation system, 21 Vehicle speed sensor, 22 Accelerator opening sensor , 30 drive control device, 31 engine drive control means, 32 storage means, 33 learning means, 34 optimum low fuel consumption route display means.

Claims (2)

In a drive control device for a hybrid vehicle including an electric motor and an engine as a drive source,
Start and stop of the engine based on a required power map that defines for each vehicle speed a start threshold that is a threshold of required power when starting the engine and a stop threshold that is a threshold of required power when stopping the engine. Engine drive control means for controlling;
Storage means for storing a required power value corresponding to the vehicle speed when traveling on a regular route;
When the relationship between the required power value corresponding to the stored vehicle speed and the set start threshold value or the set stop threshold value at the vehicle speed satisfies a predetermined update condition, the set start threshold value or the set stop threshold value is set as the required power value. Learning means to update;
A drive control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle drive control device according to claim 1,
The hybrid vehicle has a navigation system,
When there are a plurality of regular routes corresponding to the requested power map updated as candidates for the travel route when the travel route is searched by the navigation system, the optimum low fuel consumption route is specified and displayed among the multiple regular routes Optimal low fuel consumption route display means to
A drive control apparatus for a hybrid vehicle, comprising:

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