Vehicle control device

Abstract

Vehicle control device (10) controlling the operation of a vehicle (V) equipped with a transmission (2), the transmission (2) comprising: a direct drive gear transmitting engine power input via an input shaft to an output shaft rather than a counter shaft, and coupling the input shaft directly to the output shaft; and a normal drive gear transmitting engine power to the output shaft via the counter shaft, which includes an overdrive gear with a gear ratio lower than the gear ratio of the direct drive gear; and the vehicle control device (10) comprising: a drive segment determination unit (15) determining a forward drive segment preceding the vehicle (V) in a direction of travel, the forward drive segment having a road gradient different from a road gradient of a current drive segment where the vehicle (V) is currently traveling;a current gear position selection unit (13) that selects a current gear position, which is a gear position of the transmission (2) in the current driving segment, based on a driving resistance of the vehicle (V); a forward gear position selection unit (16) that selects a forward gear position, which is a gear position of the transmission (2) in the forward driving segment, based on a driving resistance of the vehicle (V) in the forward driving segment, which is estimated based on a road gradient of the forward driving segment, and a speed of the vehicle (V);and a shift control unit (17) that controls a shift of a gear position of the transmission (2) based on the current gear position and the forward gear position, wherein the shift control unit (17) selects whether the transmission (2) is to be shifted up based on a situation until the vehicle (V) reaches the forward driving segment, if the current gear position selection unit (13) reselects to shift up to the overdrive gear in a case where the current gear position is direct drive and the forward gear position is also direct drive.

Description

Technical FieldThe present disclosure relates to a vehicle control device, and more particularly, to a technique for selecting a gear position of a transmission mounted on a vehicle.Background of the TechniqueA technique for setting a shift schedule in which the amount of fuel consumption on a travel route is minimized by estimating the driving force of a vehicle on a travel route according to road information on a travel route from a current position of the vehicle to a target position and comparing the estimated driving force with a fuel consumption map stored in advance has been proposed (see JP H09- 21 457 A).Keep ListPatent DocumentDE 41 07 879 A1 discloses an automatic speed control system for a motor vehicle. The system comprises throttle control means for controlling the throttle valve opening based on a deviation between a desired speed and a current vehicle speed to reach the desired speed, downshift means for performing the downshift in an automatic transmission, stability condition decision means for deciding a stable condition after the downshift, upshift means for performing the upshift in the automatic transmission when a decrease in the throttle valve opening below a predetermined value is detected after the stable condition of the current speed is reached according to the stability condition decision means.DE 697 08 483 T2 describes a control system for a transmission.SUMMARY OF THE INVENTIONTechnical ProblemLarge vehicles, such as trucks and buses, may be equipped with a transmission called automated manual transmissions (hereinafter referred to as "AMT"). AMT is a transmission that automatically shifts a gear position of a transmission by moving a single rib in a manual transmission according to the related art by means of an actuator.The final drive force of the vehicle depends on a gear position selected by the AMT. Here, AMT is equipped with a large number of speeds, and the insertion resistance may be different from each other at each speed position. The difference in the insertion resistance at each gear position affects the fuel consumption amount of vehicle-mounted engines. Therefore, it is considered that there is room for improvement in a technique for selecting a gear position based on the fuel consumption amount of the vehicle.An object of the present disclosure is to provide a vehicle control device that can improve the technique for selecting a gear position in a vehicle equipped with an automated manual transmission.Solution of the ProblemThe vehicle control device according to the present disclosure is a vehicle control device that controls the operation of a vehicle equipped with a transmission. The transmission includes: a direct drive gear that transmits engine power input to an output shaft via an input shaft and not via a countershaft and that directly couples the input shaft to the output shaft; and a normal drive gear that transmits the engine power to the output shaft via the countershaft and that includes an overdrive gear having a gear ratio that is lower than a gear ratio of the direct drive gear. The vehicle control device includes: a traveling segment determination unit that determines a forward traveling segment preceding the vehicle in a traveling direction, the forward traveling segment having a road inclination different from a road inclination of a current traveling segment where the vehicle is currently traveling; a current gear position selection unit that selects a current gear position that is a gear position of the transmission in the current traveling segment based on a traveling resistance of the vehicle; a forward gear position selection unit that selects a forward gear position that is a gear position of the transmission in the forward traveling segment based on a traveling resistance of the vehicle in the forward traveling segment estimated based on a road inclination of the forward traveling segment and a speed of the vehicle; and a shift control unit that controls a shift of a gear position of the transmission based on the current gear position and the forward gear position. The shift control unit selects whether or not to upshift the transmission based on a situation until the vehicle reaches the forward traveling segment when the current gear position selection unit reselects an upshift to the overdrive gear in a case where the current gear position is the overdrive gear and the forward gear position is also the overdrive gear.When the estimated time until the vehicle reaches the forward traveling segment is within a predetermined time, the shift control unit may maintain the gear position of the transmission as the direct gear even in a case where the current gear position selection unit reselects an upshift to the overdrive gear.When a travel distance until the vehicle reaches the forward travel segment is within a predetermined distance, the shift control unit may maintain the gear position of the transmission as the direct gear even in a case where the current gear position unit reselects an upshift to the overdrive gear.Advantageous Effects of the InventionAccording to the vehicle control device of the present disclosure, it is possible to improve a technique for selecting a gear position in a vehicle equipped with an automated manual transmission.Brief Description of the Drawings[FIG. 1 ] FIG. 1 is a diagram showing a diagram of a vehicle according to an embodiment.[FIG. 2 ] FIG. 2 is a diagram schematically showing an internal configuration of the vehicle according to the embodiment.[FIG. 3] FIG. 3 is a diagram schematically showing a functional configuration of a vehicle control device according to the embodiment.[FIG. 4] FIG. 4 is a diagram schematically showing an example of a fuel consumption contour map of an engine according to the embodiment.[FIG. 5A] FIG. 5A is a graph schematically showing an example of a direct drive fuel consumption contour map.[FIG. 5B ] FIG. 5B is a graph schematically showing an example of a fuel consumption contour map of a normal running.DESCRIPTION OF EMBODIMENTS< Of Embodiment>FIG. 1 is a diagram showing a diagram of a vehicle V according to an embodiment. A diagram of the vehicle V according to the embodiment will be described with reference to FIG. 1. The vehicle V according to the embodiment is a large vehicle equipped with an AMT driven by an engine such as a diesel engine.In recent years, a computing device such as an electronic control unit (ECU) mounted on a vehicle has been widely used to automatically select a gear position of a transmission so that a vehicle overcomes the running resistance to travel and the fuel consumption of the vehicle is improved. Details will be described below, and the selection of the gear position in the vehicle is performed by selecting, with reference to a fuel consumption contour map of the engine, a gear position that improves the fuel consumption of the vehicle from gear positions capable of generating torque that overcomes the running resistance of the vehicle.During the running of the vehicle, an acceleration of the vehicle is proportional to an amount obtained by subtracting the running resistance of the vehicle from the driving force of the vehicle, and is inversely proportional to the weight of the vehicle. Accordingly, the vehicle-mounted ECU estimates the running resistance of the vehicle from the driving force of the vehicle, the weight of the vehicle, and the acceleration of the vehicle, and selects a gear position capable of generating torque overcoming the running resistance. However, when the ECU estimates the running resistance using the acceleration of the vehicle, the ECU may estimate the running resistance of the vehicle at a current running position, but may not estimate the running resistance at a position ahead of the current running position.When the ECU determines the running resistance by estimation, the calculation accuracy of the running resistance is not necessarily high. Therefore, a gear position is selected based on the running resistance, the accuracy of which is not necessarily ensured, and thus it is not necessarily ensured that the selected gear position is a gear position that improves the fuel consumption of the vehicle. Therefore, the ECU of the vehicle V according to the embodiment estimates the travel resistance at a forward position by acquiring inclination information of a road at the position before the current travel position. A summary of a method of estimating the traveling resistance at the forward position by acquiring inclination information using the vehicle V according to the embodiment will be described below.The vehicle V according to the embodiment has a satellite navigation function for acquiring the position information showing a current position of the vehicle V based on information obtained from a navigation satellite. In addition, the vehicle V stores inclination information of a road on which the vehicle V travels. The vehicle V may have an autonomous navigation function for detecting a current position of the vehicle V based on an output value of an acceleration sensor or the like without using the information received from the navigation satellite.The ECU of the vehicle V pre-retrieves, based on the inclination information of the road and the position information of the vehicle V, inclination information of a road on which the vehicle V will travel in the near future. In FIG. 1, the vehicle V travels in a "current travel segment" having a point A as a starting point and a point B as an ending point. In the example shown in FIG. 1, a road on which the vehicle V travels is an inclination above a certain level in a "forward travel segment" having the point B as a starting point and a point C as an ending point. The "forward travel segment" is a travel segment whose average inclination of the road is different from that of the current travel segment on which the vehicle V is currently traveling, and is a travel segment ahead of the vehicle V in a travel direction.The inclination information of the forward travel segment acquired in advance by the ECU is determined from the inclination information stored by the vehicle V and the position information of the vehicle V. The running resistance of the vehicle V is dominated by pitching resistance, air resistance, and rolling resistance, and the pitching resistance below the above resistance can be estimated. As a result, the ECU can estimate the running resistance of the forward running segment.The fuel consumption of the vehicle V is affected not only by the specific fuel consumption (which is the amount of fuels consumed by an engine to generate a predetermined driving force) of an engine provided in the vehicle V, but also by a sliding resistance inside the engine or a loss in a power transmission path of the engine. Here, the loss in the power transmission path of the engine is, for example, a loss caused by transmission efficiency of each gear provided in the transmission.Therefore, the vehicle V according to the embodiment refers to a fuel consumption contour map in consideration of the transmission efficiency of each gear provided in the transmission when a gear in the forward travel segment is to be selected. As a result, the vehicle V according to the embodiment can more accurately select a gear position having high fuel consumption in the forward traveling segment.When the vehicle V travels on a road for automobiles only, such as a freeway, the vehicle V changes the presence or absence of shifting to the gear position selected by the pre-fetching according to various travel environments. As a result, an uncomfortable feeling that can be given to a driver due to the shifting of the vehicle V can be reduced.<Konfiguration of Vehicle V according to Embodiment>An internal configuration of the vehicle V according to the embodiment will be described with reference to FIG. 2.FIG. 2 is a diagram schematically showing an internal configuration of the vehicle V according to the embodiment. The vehicle V according to the embodiment includes an engine 1, a transmission 2, a global positioning system (GPS) sensor 3, a weight sensor 4, a speed sensor 5, an accelerator opening sensor 6, and a vehicle control device 10 as the ECU.The vehicle V is a large vehicle that uses the engine 1, such as a diesel engine, to provide a driving force, and is particularly a vehicle having an automatic cruise mode (automatic cruise mode). The transmission 2 is an AMT for transmitting rotational driving force of the engine 1 to a drive wheel (not shown) of the vehicle V. The transmission 2 includes a plurality of positions of gears for converting the rotational driving force of the engine 1.Here, the "automatic travel mode" in the vehicle V refers to a mode in which the engine 1, the transmission 2, and the like are automatically controlled by the ECU to maintain a speed of the vehicle V set in advance even when the driver does not operate the accelerator pedal or a shift lever. It is mainly assumed that the automatic driving mode is used when the vehicle V travels on a freeway.The GPS sensor 3 receives and analyzes radio waves transmitted from a plurality of navigation satellites to detect a position of the GPS sensor 3 that is a position of the vehicle V to which the GPS sensor 3 is attached. The GPS sensor 3 outputs information indicating the position of the vehicle V to the vehicle control device 10.The weight sensor 4 detects the total weight of the vehicle V. Specifically, the weight sensor 4 detects the total weight of the vehicle V by measuring the weight of a load of the vehicle V and adding up the weight of the load and the weight of the vehicle V excluding the load alone. The weight sensor 4 outputs information indicating the total weight of the vehicle V to the vehicle control device 10.The speed sensor 5 measures the speed of the vehicle V. The speed sensor 5 outputs information indicating the measured speed to the vehicle control device 10. the accelerator opening sensor 6 measures an accelerator opening degree, which is a depression amount of a pedal of an accelerator pedal, by a driver of the vehicle V. The accelerator opening sensor 6 outputs information indicating the accelerator opening degree to the vehicle control device 10.The vehicle control device 10 acquires information from each of the above-described sensors and controls, based on the acquired information, the amount of fuels to be supplied to a cylinder in the engine 1 and the gear positions of the transmission 2. when the vehicle V is in the automatic driving mode, the vehicle control device 10 controls the engine 1 and the transmission 2 so that the vehicle V travels at a set speed. In addition, when a speed limit device (SLD) of the vehicle V (not shown) is operating, the vehicle control device 10 controls the engine 1 and the transmission 2 so that the speed of the vehicle V does not exceed the set maximum speed.FIG. 3 is a diagram schematically showing a functional configuration of the vehicle control device 10 according to the embodiment. The vehicle control device 10 according to the embodiment includes a storage unit 11 and a control unit 12.The storage unit 11 is, for example, a read only memory (ROM) or a random access memory (RAM). The storage unit 11 stores various programs for causing the control unit 12 to operate. The storage unit 11 may store map information and information indicating a road inclination of a road.The control unit 12 is a computing resource such as a central processing unit (CPU; not shown). The control unit 12 achieves functions of a current gear position selection unit 13, a road inclination detection unit 14, a traveling segment determination unit 15, a forward gear position selection unit 16, and a shift control unit 17 by executing a program stored in the storage unit 11.The current gear position selection unit 13 selects a current gear position, which is a gear position of the transmission 2 in the segment where the vehicle V is traveling, based on an estimated value of the traveling resistance of the vehicle V on the road on which the vehicle V is currently traveling. Details of the current gear position selection by the current gear position selection unit 13 will be described below.The road inclination acquisition unit 14 acquires, based on the information indicating the position of the vehicle V acquired by the GPS sensor 3 and the map information stored in the storage unit 11, a road inclination on the road on which the vehicle V is currently traveling.The travel segment determination unit 15 determines, based on the road inclination detected by the road inclination detection unit 14, a forward travel segment ahead in the travel direction of the vehicle V, which is a travel segment having an average road inclination different from that of the current travel segment where the vehicle V is currently traveling, by a predetermined value or more.The forward speed position selection unit 16 selects a forward speed position, which is a speed position of the transmission 2 in the forward running segment, based on the road inclination of the forward running segment and the speed of the vehicle V. Here, details of the forward gear position selection by the forward gear position selection unit 16 will be described together with the current gear position selection by the current gear position selection unit 13.In order to acquire the inclination information of the road on which the vehicle V will travel in the future, the road inclination acquisition unit 14 needs to estimate a place where the vehicle V will travel in the future. When the road inclination detection unit 14 cannot detect the road inclination, the forward travel segment is hardly determined by the travel segment determination unit 15.When the vehicle V travels on a road for automobiles only, such as a freeway, it is relatively easy for the road inclination detecting unit 14 to estimate the place where the vehicle V will travel in the future. In contrast, when the vehicle V travels on a road including many intersections such as a general road and an urban area, the road inclination detection unit 14 hardly estimates the space where the vehicle V will travel in the future.As described above, while the vehicle V is currently traveling on a general road, an urban area, or the like, the vehicle V travels according to the gear selection via the current gear position selection unit 13. When the vehicle V travels on a road for automobiles only, such as a highway, the shift control unit 17 acquires a gear selection result by the current gear position selection unit 13 and a gear selection result by the forward gear position selection unit 16.Here, the transmission 2 will be described first and then a relationship between a gear position and fuel consumption will be described below. The shift transmission control by the shift control unit 17 will be described below.[Transmission 2 According to Embodiment]The transmission 2 provided in the vehicle V according to the embodiment is an AMT and is a transmission that achieves automatic transmission of a gear position of the transmission 2 by moving a single rib in a manual transmission according to the related art through an actuator. Therefore, a basic structure of the transmission 2 according to the embodiment is similar to that of a manual transmission according to the related art. The transmission 2 according to the embodiment includes two sub-transmission mechanisms called a splitter and a range, and a main transmission mechanism provided between the splitter and the range.The splitter changes a gear ratio between an input shaft receiving power of the engine of the vehicle V and a countershaft. The main transmission mechanism mainly changes a gear ratio between a counter shaft and an output shaft. The region is provided on a drive transmission path for transmitting the rotational drive of an output shaft to a propeller shaft, and changes a gear ratio between the output shaft and the propeller shaft. The main transmission mechanism is provided with a "direct gear" that directly couples the input shaft to the output shaft.In the transmission 2 of the vehicle V according to the embodiment, gear stages of the splitter, the main transmission mechanism, and the range are, for example, two stages, three stages, and two stages. That is, the transmission 2 provided in the vehicle V according to the embodiment is a 12-stage (2 stages×3 stages×2 stages=12 stages) transmission. When the 12th-stage gear (overdrive gear) or the 11th-stage gear (direct gear) is selected as a gear of the transmission 2, when the vehicle V is traveling on a freeway having a small inclination, the fuel consumption of the vehicle V can always be increased.The direct drive gear is a gear that directly couples the input shaft to the output shaft. Since the power of the engine is directly transmitted to the output shaft and not via the countershaft, the transmission efficiency is higher than that of other gear positions via the countershaft. Even if the gear position of the transmission 2 is five stages, the main transmission mechanism becomes an immediate gear. However, a gear ratio of the range does not become direct coupling (gear ratio: 1) in this case, and the transmission efficiency is reduced. Here, in the present specification, the gear position of the transmission 2 is defined below such that the "overdrive" means a gear at the highest stage of the transmission 2 and the "direct gear" means a gear at a stage lower by one stage than the highest stage of the transmission 2.[Relationship between gear position and fuel consumption]FIG. 4 is a diagram schematically showing an example of a fuel consumption contour map of the engine 1 according to the embodiment. Here, the gear selection in the transmission 2 will be described below with reference to FIG. 4.In the fuel consumption contour map shown in FIG. 4, a vertical axis indicates a net average effective pressure Pme of a cylinder provided in the engine 1, and a horizontal axis indicates a rotational speed N of the engine 1. A torque T of the engine 1 is obtained by multiplying the net average effective pressure Pme by a predetermined value determined by the discharge amount of the engine 1. That is, the net average effective pressure Pme is proportional to the torque T generated by the engine 1. When a proportional coefficient is α, T= α Pme.In the fuel consumption contour map shown in FIG. 4, a curve indicated by a symbol "Pmax" is the maximum combustion pressure curve "Pmax" indicating the maximum combustion pressure of the engine 1. The engine 1 cannot generate torque exceeding the maximum combustion pressure curve "Pmax" in the fuel consumption contour map shown in FIG. 4.In the fuel consumption contour map shown in FIG. 4, a region indicated by hatching indicates the specific fuel consumption (SFC) of the engine 1. SFC indicates the fuel consumption amount per unit work of the engine 1. The smaller the SFC value, the less fuel with which the engine 1 can do the same work.In the fuel consumption contour map shown in FIG. 4, regions having different specific fuel consumption are indicated with hatching. In FIG. 4, a region indicated by hatching H 1 indicated by the symbol H 1 is a region having the best specific fuel consumption (that is, the fuel consumption amount is small), and thereafter, the specific fuel consumption deteriorates in an order of hatching H 2, hatching H 3, hatching H 4, and hatching H 5. In FIG. 4, illustration of a region where the specific fuel consumption is poorer than the region indicated by hatching H 5 is omitted. Here, hereinafter, the area indicated by hatching H 1 is simply written as an area H 1. The same applies to other areas.In order for the vehicle V to overcome the running resistance and to run at a constant speed Vc, the force F generated by the torque T generated by the vehicle V needs to counteract the running resistance of the vehicle V. In this case, the engine 1 of the vehicle V is required to output running resistance horse power Pv=F Vc. In the fuel consumption contour map shown in FIG. 4, a curve indicated by a symbol Lp is a constant horsepower curve Lp corresponding to the running resistance horse power Pv=F Vc.When the engine 1 rotating at the rotational speed N generates a torque T, the horsepower P output from the engine 1 is P=T N=α Pme N. Therefore, the net average effective pressure (Pme) is inversely proportional to the rotational speed N of the engine 1. Therefore, the engine 1 cannot achieve a rotation speed on the horse power constant curve Lp in a fuel consumption contour map, and is controlled to a discrete rotation speed determined by the speed Vc and the gear ratio of the transmission 2.In FIG. 4, a white circle G 12 indicated by a symbol G 12 indicates a state of the engine 1 in a case where the gear position of the transmission 2 is the 12th stage (which is an overdrive). Similarly, white circles indicated by symbols G 11, G 10, and G 9 indicate states of the engine 1 in the cases where the gear position is the 11th stage (which is an immediate gear), the 10th stage, and the 9th stage, respectively. In a case where the gear position of the transmission 2 is the 12th stage and the 11th stage, both are included in the range H 2. However, in the case where the gear position is the 12th stage, the state of the engine 1 is closer to the range H 1, and the fuel consumption is good.As described above, when the speed Vc of the vehicle V and the running resistance horsepower Pv of the vehicle V are determined, the current gear position selection unit 13 and the forward gear position selection unit 16 can define a gear position with good fuel consumption with respect to the fuel consumption contour map.[Selection of Gear Position by Current Gear Position Selection Unit 13]The current gear position selection unit 13 estimates an estimated value Pv of the running resistance of the vehicle V on the road on which the vehicle V is currently running. The current gear position selection unit 13 further refers to the fuel consumption contour map using the speed of the vehicle V and the estimated value Pv of the running resistance to select the gear position of the transmission 2.As described above, the acceleration of the vehicle V during traveling of the vehicle V is proportional to an amount obtained by subtracting the traveling resistance of the vehicle from the driving force of the vehicle V and inversely proportional to the weight of the vehicle V. The current gear position selection unit 13 estimates the net average effective pressure Pme generated by the engine 1 from the injection amount of the fuels injected into the engine 1. The current gear position selection unit 13 acquires the torque T generated by the engine 1 from the net average effective pressure Pme. The current gear position selection unit 13 acquires the driving force of the vehicle V from the torque T, the gear ratio of the selected gear position in the transmission 2, the final reduction ratio, and a diameter of the driving wheel. The current gear position selection unit 13 estimates the running resistance of the vehicle V from the driving force of the vehicle V, the weight of the vehicle V, and the acceleration of the vehicle V, and selects a gear position with reference to the fuel consumption contour map.[Selection of Gear Position by Forward Gear Position Selection Unit 16]The forward gear position selection unit 16 is different from the current gear position selection unit 13 in that the running resistance of the vehicle V is calculated by calculation. Here, the running resistance of the vehicle V is dominated by the sum of rolling resistance of the driving wheel of the vehicle V, the air resistance of the vehicle V, and the inclination resistance of the road on which the vehicle V runs. The air resistance of the vehicle V is proportional to the square of the speed of the vehicle V. The inclination resistance of the road depends on the inclination of the road on which the vehicle travels and the weight of the vehicle V. The rolling resistance of the drive wheel and the proportional coefficients for calculating the air resistance of the vehicle V are stored in the storage unit 11 by a manufacturer of the vehicle V in advance.The forward travel position selection unit 16 refers to the map information stored in the storage unit 11 and acquires the inclination information of the forward travel segment determined by the travel segment determination unit 15. The forward speed position selection unit 16 acquires the weight of the vehicle V and the speed of the vehicle V from the weight sensor 4 and the speed sensor 5, respectively.The forward speed position selection unit 16 detects the air resistance of the vehicle V by multiplying the square of the speed of the vehicle V by a proportional coefficient. The forward speed position selection unit 16 calculates the running resistance of the vehicle V by adding up the inclination resistance of the vehicle V, the air resistance of the vehicle V, and the rolling resistance read from the storage unit 11. Similarly to the current gear position selection unit 13, the forward gear position selection unit 16 selects a gear position in the forward travel segment from the calculated travel resistance and the fuel consumption contour map.Here, the forward speed position selection unit 16 refers to different fuel consumption contour maps in a case where the gear position of the transmission 2 is a direct gear and in a case where the gear position of the transmission 2 is a normal gear to select the forward speed position.FIGS. 5A and 5B are diagrams showing a difference between a normal speed fuel consumption contour map and a direct speed fuel consumption contour map. Specifically, FIG. 5A is a diagram schematically showing an example of a direct drive fuel consumption contour map. FIG. 5B is a diagram schematically showing an example of a fuel consumption contour map of a normal running. The fuel consumption contour map shown in FIG. 5B is the same as the fuel consumption map shown in FIG. 4. In other words, the white circle G 12 in the normal speed fuel consumption contour map shown in FIG. 5B indicates a state of the engine 1 in the case of an overdrive in which the gear position of the transmission 2 is the 12th stage.As described above, the transmission efficiency of the gear of the entire transmission 2 is increased in the case where the gear position of the transmission 2 is a direct gear, compared with the case where the gear position of the transmission 2 is a normal gear. Therefore, transmission loss occurring before the output of the engine 1 is transmitted to the driving wheels of the vehicle V in the case where the gear position of the transmission 2 is an immediate gear is reduced as compared with the case where the gear position of the transmission 2 is a normal gear. As a result, the specific fuel consumption of the engine 1 in the case where the gear position of the transmission 2 is a direct gear is improved as compared with the case where the gear position of the transmission 2 is a normal gear.When the direct-drive fuel consumption contour map shown in FIG. 5A is compared with the normal-drive fuel consumption contour map shown in FIG. 5B, the range H 1 is wider in a range below the maximum combustion pressure curve Pmax in the direct-drive fuel consumption contour map. Therefore, a part which is the area H 2 in the fuel consumption contour map of the normal speed also becomes the area H 1 in the fuel consumption contour map of the direct speed.A horse power constant curve Lp shown in FIG. 5A is the same as a horse power constant curve Lp shown in FIG. 5B. As shown in FIG. 5A, the state of the engine 1 in the direct gear (the 11th stage) is included in the horse power constant curve Lp in the range H 1. This situation means that, in order to make the engine 1 perform an operation corresponding to the horse power constant curve Lp, the fuel consumption of the vehicle V is improved in a case where the transmission 2 adopts an immediate gear, as compared with a case where the transmission 2 adopts a normal gear called an overdrive gear.As described above, the forward gear position selection unit 16 selects a gear position with reference to the fuel consumption contour map reflecting the difference in transmission efficiency of the gear position of the transmission 2, so that the gear position that improves the fuel consumption of the vehicle V can be selected more accurately.[Transmission Control by Shift Control Unit 17]When the vehicle V is currently running, the current gear position selection unit 13 always selects an optimum gear position of the transmission 2 according to a change in running resistance of the vehicle V. In a case where the vehicle V travels on a road for automobiles only, such as a highway, the forward traveling position selection unit 16 estimates an optimum traveling position in the forward traveling segment determined by the traveling segment determination unit 15 while the vehicle V is currently traveling in the current traveling segment.Therefore, when the vehicle V reaches a boundary between the current travel segment and the forward travel segment in a case where the vehicle V travels on a road for only automobiles such as a highway, a conflict may occur between the current gear position and the forward gear position. Since the transmission ratio of the direct gear is higher than the transmission ratio of the overdrive gear, the rotation speed of the engine 1 is even higher in the case of the direct gear when the speed of the vehicle V is the same. Therefore, for example, when the transmission 2 is shifted from the overdrive gear to the overdrive gear from the standpoint of improving fuel consumption, the driver of the vehicle V may feel that the engine 1 suddenly exploded.Therefore, the shift control unit 17 changes whether or not to shift to the forward gear position according to various traveling environments where the vehicle V is located when the vehicle V reaches the boundary between the current traveling segment and the forward traveling segment. The shift transmission control of the transmission 2 by the shift control unit 17 performed according to the various travel environments in which the vehicle V is located will be described below.(First Shift Gear Controller)It is assumed that the gear position of the transmission 2 in the current travel segment is the overdrive gear, and the forward gear position selected by the forward gear position selection unit 16 is the direct gear. The shift control unit 17 downshifts the gear position of the transmission 2 from the overdrive gear to the direct gear when the vehicle V reaches the forward travel segment, provided that the estimated travel time of the vehicle V in the forward travel segment is longer than a predetermined time.Here, the "predetermined time" is the "downshift determination reference threshold time" referred to to to determine whether or not the shift control unit 17 downshifts the gear position of the transmission 2 from the overdrive gear to the direct gear at the boundary between the current travel segment and the forward travel segment. A specific value of the downshift determination reference threshold time may be determined through an experiment in consideration of inclination information of a road on which the vehicle V is assumed to travel, powers of the engine 1 provided in the vehicle V, and the like, and is, for example, one minute. This is the time during which the vehicle V travels at 80 km / h for about 1.3 km.The shift control unit 17 prohibits the downshift in a case where the time for traveling the traveling segment where the vehicle V travels after downshifting from the overdrive to the overdrive is shorter than the predetermined time, that is, in a case where the estimated traveling time of the vehicle V is short. As a result, the shift control unit 17 can prevent the driver of the vehicle V from feeling that the shift is repeated in a short time.As described above, the forward speed position selection unit 16 calculates the running resistance of the vehicle V based on the weight of the vehicle V, the speed of the vehicle V, the rolling resistance of the vehicle V, and the like, and selects the forward speed position. Here, the forward speed position selection unit 16 may select the direct speed as the best speed depending on a magnitude of measurement errors of the weight of the vehicle V, the speed of the vehicle V, the rolling resistance of the vehicle V even in a case where the engine 1 has a low load (for example, in a case where the vehicle V is currently traveling on a flat road).When the forward speed position selection unit 16 selects the direct speed as the forward speed position according to miscalculation of the running resistance in a case where the vehicle V is running on a road whose forward running segment is flat, unnecessary downshift is performed on the boundary of the running segment. The transmission ratio of the direct speed is larger than the transmission ratio of the overdrive so that the rotational speed of the engine 1 is increased when the gear position of the transmission 2 is shifted down from the overdrive to the direct speed. Since the increase in the rotational speed of the engine 1 may cause noise, the driver's feeling of driving may be impaired.Therefore, as a condition for downshifting the gear position of the transmission 2 from the overdrive to the overdrive when the vehicle V reaches the forward running segment, the shift control unit 17 may add the fact that the road inclination in the forward running segment is an inclination equal to or greater than a predetermined value.Here, the "slope equal to or greater than a predetermined value" is a "downshift determination reference threshold slope" referred to to to determine whether or not the shift control unit 17 downshifts the gear position of the transmission 2 from the overdrive gear to the direct gear at the boundary between the current travel segment and the forward travel segment. A specific value of the downshift determination reference threshold inclination may be determined through an experiment in consideration of inclination information of a road on which the vehicle V is assumed to travel, powers of the engine 1 provided in the vehicle V, and the like, and is 1%, for example. As a result, it is possible to prevent the driver of the vehicle V from feeling uncomfortable due to unnecessary downshifting in the transmission 2.(Second Manual Transmission Control)It is assumed that the gear position of the transmission 2 in the current travel segment is the direct gear, and the forward gear position selected by the forward gear position selection unit 16 is also the direct gear. In this case, it is considered that the current gear position selection unit 13 reselects an upshift to the overdrive gear while the vehicle V is currently traveling in the current traveling segment. The shift control unit 17 selects whether or not the transmission 2 is caused to upshift before the vehicle V reaches the forward travel segment based on a situation until the vehicle V reaches the forward travel segment.More specifically, when the estimated time until the vehicle V reaches the forward traveling segment is within a predetermined time, the shift control unit 17 maintains the gear position of the transmission 2 as the direct gear without upshift even in a case where the current gear position selection unit 13 reselects the upshift to the overdrive gear.Here, the "predetermined time" is a "upshift determination reference threshold time" referred to for determining whether or not the shift control unit 17 upshifts the gear position of the transmission 2 from the direct gear to the overdrive gear in the current traveling segment. A specific value of the upshift determination reference threshold time may be determined through an experiment in consideration of inclination information of a road on which the vehicle V is assumed to travel, powers of the engine 1 provided in the vehicle V, and the like, and is, for example, one minute that is the same as the downshift determination reference threshold time. The upshift determination reference threshold time is stored in the storage unit 11.The shift control unit 17 prohibits the upshift in a case where the travel segment where the vehicle V travels after downshifting from the overdrive gear to the overdrive gear is short, that is, in a case where the estimated travel time of the vehicle V is short. As a result, the shift control unit 17 can prevent the driver of the vehicle V from feeling a busy shift caused by repeated shifting in a short time.The switching control unit 17 may determine whether or not to be upshifted based on a distance condition instead of or in addition to the time condition. Specifically, when the travel distance until the vehicle V reaches the forward travel segment is within a predetermined distance, the shift control unit 17 can maintain the gear position of the transmission 2 as the direct gear even in a case where the current gear position selection unit 13 reselects the upshift to the overdrive gear.Here, the "predetermined distance" is a "upshift determination reference threshold distance" referred to for determining whether or not the shift control unit 17 upshifts the gear position of the transmission 2 from the direct gear to the overdrive gear in the current traveling segment. A specific value of the upshift determination reference threshold distance may be determined through an experiment in consideration of inclination information of a road on which the vehicle V is assumed to travel, powers of the engine 1 provided in the vehicle V, and the like, and is 1.5 kilometers, for example. This is the distance for which the vehicle V travels at a speed of 90 km / h in one minute. As a result, the shift control unit 17 can prevent the driver of the vehicle V from feeling a busy shift caused by repeated shifting in a short time. The upshift determination reference threshold distance is stored in the storage unit 11.(Third Transmission Control)The vehicle V according to the embodiment has an automatic travel mode in which the engine 1, the transmission 2, and the like are automatically controlled to maintain a preset speed of the vehicle V even when the driver of the vehicle V does not operate the accelerator pedal or the shift lever. The speed limiting device of the vehicle V controls the engine 1 and the transmission 2 so that the vehicle V travels at the maximum speed without exceeding the set maximum speed. As described above, the vehicle V has a mode in which the vehicle V automatically travels at a predetermined set speed.The forward speed position selection unit 16 according to the embodiment estimates the running resistance of the vehicle V on the assumption that the vehicle V runs at the set speed. In addition, the forward speed position selection unit 16 refers to a fuel consumption contour map based on the rotational speed N of the engine 1 calculated on the assumption that the vehicle V travels at the set speed. Here, the speed of the vehicle V is not always equal to the set speed. For example, the vehicle V may temporarily accelerate due to an overtaking operation by the driver of the vehicle V, or the vehicle V may decelerate due to a sudden inclination. Therefore, in a case where an assumption of the speed of the vehicle V deviates from the current speed of the vehicle V, when the forward gear position selection unit 16 selects the forward gear position, the forward gear position may deviate from an optimum gear position in the forward traveling segment.Therefore, the shift control unit 17 changes the gear position of the transmission 2 to the gear position selected by the forward gear position selection unit 16 when the vehicle V reaches the forward traveling segment, provided that a difference between the predetermined set speed and the speed of the vehicle V is within a predetermined range.Here, the "predetermined range" is a "shift determination reference range referred to for determining whether or not the shift control unit 17 changes the gear position of the transmission 2 to the gear position selected by the forward gear position selection unit 16 at the boundary between the current travel segment and the forward travel segment. A specific value of the shift determination reference range may be determined by an experiment in consideration of inclination information of a road on which the vehicle V is assumed to travel, powers of the engine 1 provided in the vehicle V, and the like, and is, for example, 5 km / h. That is, the shift control unit 17 changes the gear position to the gear position selected by the forward gear position selection unit 16 on the premise that a value obtained by subtracting an hour speed of the vehicle V from a set hour speed falls within ±5. The circuit determination reference area is stored in the storage unit 11.The shift control unit 17 may take an automatic travel speed set in the vehicle V as the set speed, or may take a speed limit speed (speed at which the speed limit device operates) preset in the vehicle V as the set speed. In both cases, it is expected that the speed of the vehicle V is to be assumed to be a speed when the vehicle V is in the automatic driving mode. The shift control unit 17 can increase the effectiveness of the forward speed position by performing the upshift to the forward speed position on the premise that the difference between the set speed and the speed of the vehicle V is within a predetermined range.(Fourth Shift Gear Controller)As described above, the current gear position selection unit 13 estimates the running resistance of the vehicle V from the driving force of the vehicle V, the weight of the vehicle V, and the acceleration of the vehicle V, and selects the gear position with reference to the fuel consumption contour map. The current gear position selection unit 13 may estimate the running resistance in real time while the vehicle V is currently running, and may select the current gear position from the storage unit 11 by reading and referring to a shift pattern in which a relationship between the speed of the vehicle V and the gear position of the transmission 2 is structured. In the following description, the aspect that the current gear position selection unit 13 selects the current gear position, which is the gear position of the transmission 2 in the current traveling segment, according to the shift pattern determined in advance and stored in the storage unit 11 will be described as a premise.The shift pattern stored in the storage unit 11 is not based on a general-purpose fuel consumption contour map, and the fuel consumption contour map is not referred to.Here, it is assumed that the gear position of the transmission 2 in the current travel segment is an overdrive gear and the forward gear position is a direct gear. In a case where the vehicle V ends the traveling in the current traveling segment and starts the traveling in the forward traveling segment, that is, in a case where the traveling segment as a forward traveling segment where the shift control unit 17 selects the forward gear becomes the "current traveling segment", conflicts are likely to occur between a current gear selected by the current gear position selection unit 13 and a forward gear selected by the shift control unit 17 in advance. This is because the fuel consumption contour map is not considered in a general-purpose circuit board.Therefore, when the gear position of the transmission 2 in the current travel segment is the overdrive gear and the forward gear position is the direct gear, the shift control unit 17 maintains the gear position of the transmission 2 as the direct gear while the vehicle V is currently traveling in a forward travel segment. The shift control unit 17 downshifts the gear position of the transmission 2 to the direct gear when the vehicle V reaches the forward running segment, and maintains the gear position of the transmission 2 as the direct gear even when the current gear position selection unit 13 selects the overdrive gear while the vehicle V is currently running in the forward running segment (i.e., a current running segment) during the forward gear selection by the forward gear position selection unit 16.The shift control unit 17 can perform the above-described four shift transmission controls from the first shift transmission control to the fourth shift transmission control in any combination. The new shift transmission control produced by the combination has an effect of the original shift control.< Of Vehicle Control Device 10>As described above, according to the vehicle control device 10 of the embodiment, it is possible to improve estimation accuracy of the fuel consumption amount and the technique for selecting the gear position in the vehicle V provided to the AMT. Specifically, the forward speed position selection unit 16 according to the embodiment selects the forward speed position with reference to different fuel consumption contour maps in consideration of the difference in gear transmission efficiency, both in a case where the gear position of the transmission 2 is the direct speed and a case where the gear position of the transmission 2 is the normal speed. As a result, the forward speed position selection unit 16 can improve estimation accuracy of the fuel consumption amount in the vehicle V.Further, when the vehicle V travels on a road for automobiles only such as a freeway, the shift control unit 17 changes whether or not to be switched to the forward speed position selected by the forward speed position selection unit 16 according to various travel environments where the vehicle V is located. As a result, an uncomfortable feeling that can be given to a driver due to the shifting of the vehicle V can be reduced.The present disclosure has been described using the embodiment, and various modifications and changes can be made. For example, the specific embodiment of the distribution and integration of the device is not limited to the above embodiment, and all or a part of the embodiment may be functionally or physically distributed and integrated into optional units. In addition, new embodiments generated by arbitrary combination of multiple embodiments are also included in the embodiment of the present disclosure. The effect of the new embodiment caused by combination has the effect of the original embodiment.Industrial applicabilityThe vehicle control device according to the present disclosure is useful in improving a technique for selecting the gear position in a vehicle equipped with an automated manual transmission.List of Reference Numerals1 Engine 2 Transmission 3 GPS sensor 4 Weight sensor 5 Speed sensor 6 Accelerator opening sensor 10 Vehicle control device 11 Storage unit 12 Control unit 13 Actual gear position selection unit 14 Road inclination detection unit 15 Traveling segment determination unit 16 Forward gear position selection unit 17 Shift control unit V Vehicle

Claims

A vehicle control device (10) that controls operation of a vehicle (V) equipped with a transmission (2), the transmission (2) comprising: a direct gear that transmits engine power that is input to an output shaft via an input shaft and not via a countershaft and that directly couples the input shaft to the output shaft; and a normal gear that transmits the engine power to the output shaft via the countershaft and that includes an overdrive gear having a gear ratio lower than a gear ratio of the immediate gear, and the vehicle control device (10) includes: a traveling segment determining unit (15) that determines a forward traveling segment preceding the vehicle (V) in a traveling direction, the forward traveling segment having a road inclination different from a road inclination of a current traveling segment where the vehicle (V) is currently traveling; a current gear position selecting unit (13) that selects a current gear position that is a gear position of the transmission (2) in the current traveling segment based on a traveling resistance of the vehicle (V); a forward speed position selection unit (16) that selects a forward speed position that is a speed position of the transmission (2) in the forward running segment based on a running resistance of the vehicle (V) in the forward running segment estimated based on a road inclination of the forward running segment and a speed of the vehicle (V); A shift control unit (17) that controls a shift of a gear position of the transmission (2) based on the current gear position and the forward gear position, wherein the shift control unit (17) selects whether to upshift the transmission (2) based on a situation until the vehicle (V) reaches the forward travel segment, when the current gear position selection unit (13) reselects an upshift to the overdrive gear in a case where the current gear position is the overdrive gear and the forward gear position is also the overdrive gear.The vehicle control device (10) according to claim 1, wherein when the estimated time until the vehicle (V) reaches the forward traveling segment is within a predetermined time, the shift control unit (17) maintains the gear position of the transmission (2) as the direct gear even in a case where the current gear position selection unit (13) reselects an upshift to the overdrive gear.The vehicle control device (10) according to claim 1, wherein when a travel distance until the vehicle (V) reaches the forward travel segment is within a predetermined distance, the shift control unit (17) can maintain the gear position of the transmission (2) as the direct gear even in a case where the current gear position selection unit (13) reselects an upshift to the overdrive gear.

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