GB2495886A

GB2495886A - Vehicle control system, drive control method for vehicle, and train control device

Info

Publication number: GB2495886A
Application number: GB1302746.1A
Authority: GB
Inventors: Toshiharu Sugawara; Tsutomu Miyauchi; Motonari Suzuki; Takeshi Shinomiya; Motomi Shimada
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 2010-08-20
Filing date: 2011-07-28
Publication date: 2013-04-24
Anticipated expiration: 2031-07-28
Also published as: GB201302746D0; JP2012044792A; WO2012023400A1; GB2495886B; JP5521890B2

Abstract

In order to achieve both the engine emission performance and the vehicle acceleration performance in a diesel electric locomotive, this control system for a vehicle is a vehicle control system which is provided with an engine, an electric generator, a converter, an inverter, and an electric motor, comprises an engine load prediction unit for predicting the increase of the output of the electric motor on the basis of any one or more of route data, the speed of the vehicle, and a travel speed pattern, and comprises an engine speed correction unit for increasing the engine speed before the increase of the output of the electric motor on the basis of the predicted value of the increase of the output of the electric motor.

Description

Title of the Invention: VEHICLE CONTROL SYSTEM, DRIVE CONTROL METHOD FOR VEHICLE, AND TRAIN CONTROLLER

Technical Field

[00011 The present invention relates to a vehicle control system which converts engine output into electric power to supply AC power to an electric motor for driving.

Background Art

[0002] In the related art, diesel-electric locomotive acceleration methods include a control technology disclosed in Patent Literature 1. In the Patent Literature 1, a train is accelerated by driving an AC generator with power from a diesel engine, converting generated AC power into DC power with a rectifier, further converting the DC power into AC power with a power converter, and driving a vehicle propulsion induction motor.

Citation List Patent Literature (0003] Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2000-115907

Summary of Invention

Technical Problem [0004] Meanwhile, diesel engine exhaust gas regulations have become increasingly severe due to the increase of environmental awareness. Technologies, such as the EGR (Exhaust Gas Recirculation) technology, the DPF (Diesel Particulate Filter) technology, and the high-pressure multi-injection technology, have been developed as diesel engine exhaust purification technologies. However, in view of a delay in backf low of EGR gas, a delay in turbocharging or the like, it is necessary to prevent a sudden change in engine rotational speed and engine output to reduce the generation of soot. Also, such sudden change in engine rotational speed and engine output causes a significant reduction in the fuel efficiency of diesel engines.

(00051 In the Patent Literature 1, however, all power to accelerate the train must be supplied by the engine. Therefore, there has been a problem in that, if the responsiveness of the engine is reduced for maintaining engine exhaust performance, the reduced responsiveness of the engine causes a bottleneck, resulting in a deterioration in acceleration performance and an increase in journey time. In other words, satisfying both of Lhe engine exhaust performance and the vehicle acceleration performance has been a problem in the known art.

Solution to Problem (0006] In order to address the above-mentioned problem, acccrding to one preferred aspect of the present invention, a train control system includes an engine load prediction unit for predicting an increase in load of an engine, and increases an engine rotational speed before the increase in load of the engine on the basis of a prediction of the increase in load of the engine'.

According to another preferred aspect of the present invention, a vehicle control system includes: an engine load prediction unit that predicts an increase in output of an electric motor; and a driver guidance device that provides a finely-divided notch guidance on the basis of a prediction of the increase in output of the electric motor so that engine output can follow an increase in load.

Advantageous Effects of Invention [00071 The present invention can satisfy both of the engine exhaust performance and the vehicle acceleration performance.

Brief Description of Drawings

(00081 Fig. 1 shows a configuration of a train control system according to a first embodiment.

Fig. 2 is a block diagram of the first embodiment.

Fig. 3 shows an inverter output command calculation method according to the first embodiment.

Fig. 4 shows speed limit data according to the first embodiment.

Fig. 5 is a flowchart for an engine load prediction unit according to the first embodiment.

Fig. 6 shows a method for prediction of a notch relative to a speed limit according to the first embodiment.

Fig. 7 shows an advantage of the train control system according to the first embodiment.

Fig. 8 illustrates an operation mode display device and an operation mode switching device according to the first embodiment.

Fig. 9 shows track gradient data according to a second embodiment.

Fig. 10 is a flowchart fat an engine load prediction unit according to the second embodiment.

Fig. 11 shows a method for prediction of a notch relative to a gradient according to the second embodiment.

Fig. 12 shows an advantage of a train control system according to the second embodiment.

Fig. 13 is a block diagram of a third embodiment.

Fig. 14 shows a target traveling speed pattern according to the third embodiment.

Fig. 15 shows a configuration of a train control system according to a fourth embodiment.

Fig. 16 is a block diagram of the fourth embodiment.

Fig. 17 shows a configuration of a train control system according to a fifth embodiment.

Fig. 18 is a block diagram of the fifth embodiment.

Fig. 19 shows an advantage of the fifth embodiment.

Fig. 20 shows a configuration of a train control system according to a sixth embodiment.

Fig. 21 is a block diagram of the sixth embodiment.

Fig. 22 shows an advantage of the sixth embodiment.

Description of Embodiments

[00091 First Embodiment Fig. 1 shows a configuration of a train control system 2 installed in a diesel-electric locomotive 1 according to a first embodiment of the present invention. The train control system 2 is composed of: an electric motor 14 that drives a vehicle; an inverter 12 that. produces AC power to drive the electric motor 14; a converter 10 that produces DC power to be input to the inverter 12 from AC power generated by a generator 9; the generator 9 that generates AC power and provides the AC power to the converter 10; a diesel engine 8 that drives the generator 9; art inverter controller 13 that controls the inverter 12; a converter controller 11 that controls the converter 10; an engine controller 7 that controls the diesel engine 8; a train controller 6 that issues a command to each controller; a master controller 3 that detects the notch operation of a driver; a speed detector 4 that detects the speed of the vehicle; a track database 5 that stores speed limit data; an ooeration mode switching device 15 that switches between operation modes of the train controller 6; and an operation mode display device 16 that displays the operation mode of the train controller 6.

It should be noted that, although, in this embodiment, the case where the train control system 2 is installed in the same vehicle is used as an example, the invention is not limited thereto.

The individual devices constituting the train control system 2 may be distributed among plural vehicles.

Alternatively, the so-called DEMtJ (Diesel-electric multiple unit) may be employed, in which the train control system 2 not including the master controller 3 is installed in plural vehicles.

[00101 The train controfler 6 receives a notch command from the master controller 3, a vehicle speed from the speed detector 4, and speed Limit data shown in FIG. 4 from the track database 5.

It should be noted that the speed detector 4 detects speeds of wheels 17 from wheel rotational angle sensors attached to the wheels 17 and obtains a speed using the average value of the detected speeds from the wheels. However, the method for obtaining the speed is not limited thereto, but any method can be alternatively used as long as it permits obtaining of the vehicle speed. The train controller 6, as will hereinafter be described in detail, obtains an engine rotational speed conand, a DC portion voltage command, and an inverter output command on the basis of the notch command, the vehicle speed, and the speed limit data.

[0011] The engine controller 7 controls the engine 8 rotational speed on the basis of the engine rotational speed command. It should be noted that the engine controller 7 sets a limit on the engine rotational speed to prevent a sudden increase in engine rotational speed so as to prevent deterioration in exhaust performance. The generator 9 is driven by power from the engine 8 and produces three-phase AC power. The converter controller 11 converts the three-phase AC power from the generator 9 into DC voltage by a required amount and controls the voltage of a DC portion according to the DC portion voltage command. The inverter controller 13 supplies power to the electric motor 14 according to the inverter output command. Then the electric motor 14 is driven, thereby transmitting power to the wheels 17 and accelerating the vehicle. It should be noted that, in the railway art, the diesel engine 8 with high power is widely used; however, other internal combustion engines such as gasoline engines may be used. As the generator 9, the three-phase AC generator 9 (the induction generator 9 or the synchronous generator 9) is ccmmon.

The converter 10 includes a rectifier or the PWM converter 10.

As the electric motor 14, the three-phase AC electric motor 14 (the induction motor 14 or the synchronous motor 14) is common.

[0012] As will hereinafter be described in detail, the operation mode switching device 15 is designed to provide an on-off input to the train controller 6 and switch between engine control modes of the train controller 6. Furthermore, as will hereinafter be described in detail, tae operation mode display device 16 is designed to light a lamp according to an engine control mode input from the train controller 6 and thereby indicate the engine control mode to a driver.

[0013] Next, Fig. 2 shows a block diagram of the first embodiment.

An inverter output command calculation unit 31 calculates an inverter output command according to the tractive characteristic (acceleration characteristic) on the basis of the vehicle speed and the notch command, by using a map shown in FIG. 3 which shows the relationship between the vehicle speed and the inverter output command for each notch. However, for example, when the command switches at a certain speed from coasting to the fifth notch, if the inverter output cormuand obtained from FIG. 3 is directly output, the inverter output command is digitally considerably deviated.

Therefore, the speed of the rising edge of the inverter output command is limited. Mere specifically, the speed of the rising edge of the inverter o-itput command is set to be increased in proportion to a notch Level after the notch command switching.

For example, if the command switches from coasting to the first notch, the rising edge of the inverter output command is delayed so that the invercer output rises slowly to the inverter cutput command obtained from FIG. 3. Furthermore, if the command switches from coasting to the seventh notch, the rising edge of the inverter output command is accelerated so that the inverter output rises suddenly to the inverter output command obtained from FIG. 3. Thus, when a driver suddenly switches the notch command to a higher level for suddenly accelerating a vehicle, the rising edge of the inverter output is accelerated, and a driver's desired acceleration performance can be provided. However, if the inverter output exceeds the engine output, the engine rotational speed is reduced, and an engine failure might be caused. a

Therefore, the inverter output command is given so as not to exceed the engine output.

It should be noted that, in the invention of this application, the inverter output command is used as a command to the inverter.

However, alternatively, an inverter current command or an inverter torque command may be used.

[0014] The inverter output command obtained as described above is input to the inverter controller 13. An engine output ccmmand calculation unit 32 obtains an engine output command as an output necessary for the engine on the basis of the inverter output command. An engine rotational speed command calculation unit 33 obtains an engine rotational speed command corresponding to the engine output command. Preferably, the engine rotational speed command is properly calculated by considering engine fuel consumption, engine emission or the like. The engine rotational speed command is corrected by an engine rotational speed correction unit 34 to be described later. The engine rotational speed command corrected as described above by the engine rotational speed correction unit 34 is input to the engine controller 7.

[0015] Also, the DC portion voltage command is input to the converter controller 11. In general, the voltage of the DC portion is controlled and maintained constant. For example, the DC portion voltage command is set at 1500 volts, and the converter controller 11 controls the generator 9 as needed so that the voltage of the DC portion is maintained at 1500 volts.

[00161 Next, referring to FIG. 5, an engine load prediction unit will be described. The speed limit data from the track database as shown in FIG. 4 and the vehicle speed are input to the engine load prediction unit 35. At step S51, the engine load prediction unit 35 calculates vehicle position X: [m] after predetermined time At seconds using the following Equation (1). Note that: xc [m] represents a current vehicle position; and v [mis] represents a vehicle speed.

(0017] = X) + vAt (1) The current vehicle position is estimated by integrating the vehicle speed. The vehicle position calculation method is not limited to the above, but also can include GPS. Then at step S52, the engine load prediction unit 35 obtains the speed limit after At seconds from the speed limit data shown in FIG. 4 and the vehicle position after At seconds. At step S53, the engine load prediction unit 35 calculates the difference between the speed limit and the vehicle speed after At seconds. At step S54, the engine load prediction unit 35 predicts the notch after At seconds from a map shown in FIG. 6. In FIG. 6, if the vehicle speed is high and the difference between the speed limit and the vehicle speed is small, more power than the travel resistance during high-speed running is required, and therefore the engine load prediction unit. 35 predicts that a driver selects a higher notch. On the other hand, if the vehicle speed is low and the difference between the speed limit and the vehicle speed is large, that is, if the speed limit is considerably greater than the vehicle speed, a large acceleration is required, and therefore the engine load prediction unit 35 predicts that a driver selects a higher notch. In the same manner, if the vehicle speed is low and the difference between the speed limit and the vehicle speed is small, the engine load predict ic-n unit 35 predicts that the notch neconies lower -if the vehicle speed is h.ch and the difference be.tween the speed limit and the. vehicle speed is large, che enqlne load prediction unIt. 35 preaicts that. the notch becomes higher. Next, at step 355, the engine ic-ad prediction unit 35 predicts the oucpu'c of the electric motor 14 after At seconds, that. is, the increase in engine loan, ffrc-m the predicted notch by performing she,acne cal culatcon as the inver her outuut. command calculation unit 31. With the above-described processinci, the engine load p.redict:on unit SF. can ured jot the:ncease in cog ne oad after At seconds [00181 1-lere, e-n-.j:Lne characteristics will be described. Since the a.vailable maximum c-u.cput value of the engine depends on the engine rocationar speed, if the. en-;-in rotational speed is low, a large.

engine output cannot be obtained. On the ourLer sand, as described above, a limit is set. on. the rate of increase in engine rotational speed in. order to prevent deteroratioo in exhaust perfornanoe.

theretors-, t.nere is a problem in engines in th&.Lc, even if a sudden large ou-.tpu-.t is. desired d.rring the low--speed rotation of the engine, the desired. engine, output cannot be obtained, because the engine rota.l on-al speed. increases s fowl while being limited by the engine rotaconac speed limit.

[00191 in order to address the above-described problem, the engine rotational speed correotion unit 34 increases the. engine rotationa! speed as neo-dea before the increase in engine load, on the basis of the engioe load prediction value predioteci by the engine load predli, ion unit 35. More specifically, the engine rotationa Is oee.d. oorrect ion unit 34 compares the engine load prediction value and the fastest engine output response (the response at the time of the fastest rising edge of the engine output). If determining that the engine output cannot follow the load variation, the engine rotational speed correction unit 34 increases the engine rotational speed. It should be noted that the fastest engine output response is obtained from the engine rotational speed limit and a maximum engine output curve. However, the method for calculating the fastest engine output response is not limited to this. The fastest engine output response may be determined by considering the EGR or the responsiveness of supercharging pressure in order to prevent deterioration in exhaust performance.

[0020) Referring to FIG. 7, an advantage of the above-described first embodiment. will be described. The description will he made in terms of a section in which the speed limit changes from 140 [km/h] to 80 [km/h] and from 80 [km/h] to 140 [km/h]. As shown in FIG. 7, the notch is switched from 3 [N] to 6 [N] by a driver at a point of time (time t. see.) when the speed limit changes from 80 [km/hi to 140 [km/h]. In the related art (shown by dashed lines), in response to a notch operation of a driver, the engine rotational speed increases while being limited by the engine rotational speed limit, and therefore the rising edge of the vehicle speed delays because the generator output and the electric motor output can increase with the increase in engine rotational speed.

[0021] Next, referring to FIG. 7, the operation of the first embodiment of the present invention will be described by using alternate long and short dash lines. At time t0, the engine load prediction unit 35 predicts that the difference between the speed limit and the vehicle speed becomes 60 [km/h] at the time t after a predetermined time. Then the engine load prediction unit 35 predicts from FIG. 5 that the notch switches from 3 (N] of the current notch to 6 (N] and the engine load increases. The engine rotational speed correction unit 34 compares the engine load prediction value and the fastest engine output response. If determining that the engine output cannot follow the increase in engine load, the engine rotational speed correction unit 34 corrects the engine rotational speed coimnand before the increase in engine load and increases the engine rotational speed. It should be noted that the above-described mode in which the engine rotational speed is increased before an increase in engine load is referred to as an engine preparation mode. Thus, the generator output and the electric motor output can be increased in response to an increase in notch level without being limited by the engine rotational speed limit. In other words, the engine rotational speed is preliminarily increased at a time point before the time point when the electric motor output is increased as predicted by the engine load prediction unit 35.

More specifically, referring to the example of FIG. 7, if the engine load prediction unit 35 predicts at the time t that the notch switches from 3 (N] to 6 [N] at the time t1, during a period from the time tn to the time t1 when a high electric motor output corresponding to a notch of 6 (NI is required, the engine rotational speed is gradually increased so as not to cause deterioration in exhaust characteristics and fuel consumption characteristics so that, at time t:, the engine can produce sufficient torque corresponding to the required electric motor output -[0022] Consequently, compared with the example in the related art shown by dashed lines, the acceleration performance can be improved without causing deterioration in engine exhaust performance and fuel efficiency, and the journey time can be reduced.

[0023] Next, FIG. 8 shows examples of the operation mode display device 16 and the operation mode switching device 15. As described above, according to the present invention, the engine rotational speed is increased independently of the driver's notch operation. In the general train control system, the engine rotational speed changes in synchronization with the notch operation, which can cause driver discomfort. Therefore, as shown in FIG. 8, the operation mode display device 16 shows the engine preparation mode to a driver to inform a driver that the system increases the engine rotational speed based on its normal judgment and make the driver feel safe. However, the operation mode display device 16 is not limited to the above. For example, voice information is available. Also, the operation mode switching device 15 shown in FIG. 8 is provided so that, if the train controller 6 cannot predict an increase in engine load, a driver can freely increase the acceleration performance by using the engine preparation mode.

[0024] Second Embodiment Next, a second embodiment will be described with emphasis on the differences from the first embodiment. The second embodiment is identical to the first embodiment except for the track database 5 and the engine load prediction unit 35.

Therefore, the description thereof will not be repeated, arid only the track database 5 and the engine load prediction unit 35 will be described.

[0025] The track database 5 stores gradient data shown in FIG. 9.

It is to be noted that the rising gradient is assumed positive; however, the gradient data form does not need to be limited to this.

(0026] Next, referring to FIG. 10, the engine load prediction unit will be described. At step SIOl, in the same manner as step 551 of the first enthodiment, the engine load prediction unit 35 calculates vehicle position X: [ml after predetermined time At.

seconds.

Then at step Sl02, the engine load prediction unit 35 estimates the gradient after At seconds from the gradient data and the vehicle position after At seconds. And then at step 5103, the engine load prediction unit 35 predicts the notch after At seconds from a map shown in FIG. 11. If the vehicle speed is high and the gradient is small, pcwer to resist the travel resistance during high-speed running is required, and therefore the engine load prediction unit 35 predicts that a driver selects a higher notch. On the other hand, if the vehicle speed is low and the gradient is large, more power than the travel resistance due to the gradient is required, and therefore the engine load prediction unit 35 predicts that a driver selects a higher notch. In the same manner, if the vehicle speed is low and the gradient. is small, the engine load prediction unit 35 predicts that the notch becomes lower. If the vehicle speed is high and the gradient is large, the engine load prediction unit 35 predicts that. the notch becomes higher.

Next, at step S104, the engine load prediction unit 35 predicts the increase in engine load output after t seconds from the predicted notch by performing the same calculation as the inverter output command calculation unit 31.

With the above-described processing, the engine load prediction unit 35 can predict the increase in engine load cutput after At seconds according to a track gradient.

(00271 Referring to FIG. 12, an advantage of the second embodiment will be described. The description will be made in terms of the case where a train runs over the section in which the gradient changes from -5 [per mil] to 40 [per mill. As shown in FIG. 12, the notch is switched from 3 [N] to 6 [NJ by a driver at a point of time (time U. see.) when the gradient changes from -5 [per mill to 40 [per mu]. In the related art (shown by dashed lines), in response to a notch operation of a driver, the engine rotational speed increases while being limited by the engine rotational speed limit. Therefore, the acceleration becomes poor and the vehicle speed decreases due to the gradient because the generator cutput and the electric motor output can increase only with the increase in engine rotational speed.

[0028] Next, the operation of the second embodiment of the present invention will be described. At time tc, the engine load prediction unit 35 predicts that the gradient becomes 40 [per mill at the time t: after a predetermined time. Then the engine load prediction unit 35 predicts from FIG. 11 that the notch switches from 3 [N] of the current notch to 6 [N] and the engine load increases. And then the engine rotational speed correction unit 34 compares the engine load prediction value and the fastest engine output response The engine rotational speed correct±on uni. t 34, when de.termining that the engine output cannot follow the increase in load, LncrecJ,eo the engine rot-.ationa I speed oetorean cc Lual increase in enlfine load. Thus, the *generator output and the.

electric motor output can be increased in response Loan increa se in notc.h level without being limited by the engine rc:.tational speed limit Conseque.ntiv, wi.tb the train controi. system 2 according to the second embodiment, oc.mnare d with the example In the related art, the acceleration performance can he improved without causing deterioration in engine exhaust performance, and the journey time.

can be reduced.

[0029] Tb Ird Eirbod imen t.

Next, a third embodiment will re described with emphasis on the differences. from the first embodiment. The third embodiment will be described in terms of a-train incorporating ATC: (Automatic Train Operation) . The train control system 2 accorcilncT to tne third embodiment has a configuration in which the track database 5 in TIC. its replacea by a target travel speed pattern database 13 that stores a travel patter n shown ii: FIG. 14. Therefore, portions overlaixp.rng the tlrut emboo.iment will notice ciescrtried here.

[0030] FIG. 13 is a block diagram of-the third embodiment. The master controller 3 inputs ATO n.Lode to the train controller 6 A notch determination unit 36 c(rjc t.o determine the notc.h operation for the ATO. The notch determination unit 36 estimate.s a current vehicle p SitlLOfl by integrating current vehicle speed in the sarrLe manner c-s the first embodiment, and. ohtai.ns a target.

speed from the target travel speed pattern data and the current vehicle position. Then the notch determination unit 36 determines a notch command from the target speed and the vehicle speed. It should be noted that the notch determination method does not need to be limited to the above. For example, the determination may be made by using track information, such as the track speed limit and the track gradient, or according to other ATO systems. The procedure after the notch command in the block diagram of the third embodiment is identical to that of the first embodiment except for the engine load prediction unit 35, and therefore the description thereof will not be repeated.

[0031] The target travel speed pattern and the vehicle speed are input to the engine load prediction unit 35 according to the third embodiment. Firstly, in the same manner as step S51 of the first embodiment, the engine load prediction unit 35 calculates the vehicle position x1 [mJ after predetermined time At seconds. Then the er.gine load prediction unit 35 estimates the target speed after At seconds from the target travel speed pattern and the vehicle position after At seconds. And then in the same manner as the notch determination unit 36, the engine load prediction unit 35 predicts the notch command after At seconds from the target speed after At seconds. The subsequent procedure is similar to that of the first embodiment, and the description thereof will not be repeated. In the above-described manner, the engine load prediction unit 35 can predict the notch command following the target travel pattern. On the basis of the predicted engine load prediction value, the engine rotational speed correction unit 34 corrects the engine rotational speed command as needed before an increase in the engine load and increases the engine rotational speed.

[0032] An advantage of the third embodiment is similar to that of the first embodiment except that the notch determination is made by the 1TO, and therefore the detailed description thereof will not be repeated. Thus, with the train control system 2 acccrding to the third embodiment, compared with the example in the related art, the acceleration performance can be improved without causing deterioration in engine exhaust performance, and the journey time can be reduced.

[0033] Fourth Embodiment FIG. 15 shows a configuration of the train control system 2 according to a fourth embodiment of the present invention.

Hereinafter, only the differences from the second embodiment will be described. The fourth embodiment is identical to the second embodiment except for a driver guidance device 19 for guiding the driver's notch operation and the target travel speed pattern database 18, and therefore the description thereof will not be repeated. The driver guidance device 19 outputs a notch guidance to the master controller 3 on the basis of the target travel speed pattern and the vehicle speed.

[0034] Referring to FIG. 16, a block diagram of the fourth embodiment will be described. Firstly, the driver guidance device 19 estimates a current position by integrating current vehicle speed and obtains a target speed from the target travel speed pattern data and the current vehicle position. Then the driver guidance device 19 determines a notch guidance from the target speed and the vehicle speed. It should be noted that the notch guidance determination method does not need to be limited to the above. For example, the determination may be made by using track information such as the track speed limit and the track gradient. In the above-described manner, the driver guidance device 19 determines a notch guidance to the master controller 3 on the basis of the target travel speed pattern and the vehicle position. The procedure after the master controller 3 is similar to that of the first embodiment except for the engine load prediction unit 35, and therefore the description thereof will not be repeated.

[00351 The target travel speed pattern and the vehicle speed are input to the engine load prediction unit 35 according to the fourth embodiment. Firstly, in the same manner as step 351 of the first embodiment, the engine load prediction unit 35 calculates the vehicle position Xt [m) after predetermined time At seconds. Then the engine load prediction unit 35 estimates the target speed after At seconds from the target travel speed pattern and the vehicle position after At seconds. And then in the same manner as the driver guidance device 19, the engine load prediction unit 35 predicts the notch command after At seconds from the target speed after At seconds. The subsequent procedure is similar to that of the first embodiment, and therefore the description thereof will not be repeated. tn the above-described manner, the engine load prediction unit 35 can predict an engine load. On the basis of the engine load prediction value, the engine rotational speed correction unit 34 corrects the engine rotational speed ccmmand as needed before an increase in the engine load and increases the engine rotational speed.

[00361 Art advantage of the fourth embodiment is similar to that of the first embodiment except that a driver determines a notch on the basis of the notch guidance, and therefore the detailed description thereof wiLl not be repeated. Thus, with the train control system 2 according to the fourth embodiment, compared with the example in the related art, the acceleration performance can be improved without causing deterioration in engine exhaust performance, and the journey tine can be reduced.

(00371 Fifth Embodiment FIG. 17 shows a configuration of the train control system 2 according to a fifth embodiment of the present invention.

Hereinafter, only the differences from the first embodiment will be described. The train control system 2 according to the fifth embodiment differs from the first embodiment in that: a brake chopper 20 and a braking resistor 21 are added to the DC portion; the train controller 6 controls the brake chopper 20; and the converter 10 is changed in control format.

[0038] Referring to FIG. 18, a block diagram of the fifth embodiment will be described. In the fifth embodiment, the engine LOad prediction value and the fastest engine output response are compared. Then if it is determined that the engine output cannot follow the load variation (at the time of the engine preparation mode), the generator output, along with the engine rotational speed is increased. Since the voltage of the DC portion is increased by the generator output, the braking resistor 2].

generates heat so as to maintain the voltage of the DC portion.

Hereinafter, the control of the converter 10 and the brake chopper 20, which is the difference between the first embodiment and the fifth embodiment, will be described in concrete terms. A converter output command calculation unit 37 compares the engine load and the fastest engine output response on the basis of the engine load prediction value, and if determining that the engine output cannot follow tie load, increases the converter oitput command. The engine rotational speed (controlled by the engine rotational speed correction unit 34) and the engine load (controlled by the converter oucput. command calculation unit 37) can be freely set independently of the notch command. Therefore, for optimum engine fuel efficiency and engine emission, preferably, the converter output command is determined by considering the engine rotational speed. A DC voltage control unit 38 performs constant voltage control on the basis of a DC portion voltage command so as to prevent the increase in the voltage of the DC portion due to the generator output during the engine preparation mode. Under the constant voltage control, the brake chopper 20 is driven and the electric power is consumed by the resistor. It should be noted that, in the fifth embodiment, the same ccntrol as the first embodiment is performed in the case other than the engine preparation mode.

[00391 Referring to FIG. 19, an advantage of the present invention according to the fifth embodiment will be described. The train controller 6 performs the same control as the first embodiment up to time t3. At the time t, the engine load prediction value and txe fastest engine output response are compared, and it is determined that the engine output cannot follow the load variation.

Then the engine rotational speed and the generator output are increased, by the control shown in FIG. 18, before an actual increase in output of the electric motor 14. At time t1, the train controller 6 increases the electric motor output according to the notch command. The train controller 6 performs constant voltage control of the DC voltage portion. Thus, as shown in FIG. 19, surplus power in the DC portion is reduced by the increase in electric motor output, so that the power consumption of the braking resistor 21 is reduced, Finally, at time t2, all generated cutput becomes the output for the electric motor 14. After the time t2, the train controller 6 performs the same control as the first embodiment.

[0040) Thus, with the train control system 2 according to the fifth embodiment, compared with the example in the related art, the acceleration performance can be improved without causing deterioration in engine exhaust performance, and the journey time can be reduced. Furthermore, in the fifth embodiment, the engine rotational speed and tne engine load can be freely set independently of the notch command, thereby allowing engine control for optimum engine fuel efficiency and engine emission.

[0041) Although the detail description is not given, the rnethod for simultaneously increasing the engine rotational speed and the generator output during the engine preparation mode as shown in FIGS. 17 and 18 may include a method with combination of the second embodiment, the third embodiment, and the fourth embodiment.

[0042) Sixth Embodiment Next, a sixth embodiment will be described with emphasis on the differences from the first embodiment. Referring to FIG. 20, the configuration of the train control system 2 according to the sixth embodiment will be described. The engine load prediction value calculated by the train controller 4 is input to the driver guidance device 19 The driver guidance device 19 determines a notch guidance on the basis of the engine load prediction var ie and i.nputs the no Lich guidance to the ma ster control]. er 3 Except for the above, the. configuration of the train control syst em 2 a ccording to the sixth ernbociinient is s iftLI. lar to that of the first embodirrent, and therefore the descrrution thereof will not he reeaneci.

[00431 Next, FIG. 21 is a block-diagram of the sixth embodiment.

The engIne. load prediction unit 35 predicts an Increase in engine.

load In the same. manner the first embodiment. The trai.n controller 6 Inputs the engine l**Dad prediction valu.e to the driver guidance device 19. The driver gLJidanc.e. device JO cc*mpares the engine load redcct.nn value an c the fastest engine cat.put response, ano..ir determi.nincn that the engine oii Iput cannot follow the load, determines a notch guidance for a driver so that the engine load ured cticn value becomes equal to or lower t-.han the fas Let t engine cii tput response. Exc.ept for the above changes, the sixth embodiment is similar to the. f:.r.st. embodiment, and iber.etcre the cleocrJ.uticr! thereof xil I not he rene.ate.d. 0 044

Referring to FIG. 22, an advantage of the train control system according to the sixth embodi.ment will be described. The description will be. made. in terms of a sect i.on in which the spee.d l.imi.t changes from. 140 [km/h J to 80 [kin/hi and from 80 [kin/hi to [1cm/hi. As shown in FIG. 22, in the related c&rt EiXrSITLLDIi, t.he notch is switched from coast.Ing to 7 [Ni at a pa i.nt of time (ti.me t1 sec.) when the arced limit changes from 80 [km/hI to 180 [km/hi In the related art, in response to a notch operation of: a driver, the engine rotational speed increases while being limited by the engine rotational speed limit, and therefore the rising edge of the vehicle speed delays because the generator output and the electric motor output can increase with the increase in engine rotational speed.

[00451 Next, referring to FIG. 22, the operation of the sixth embodiment of the present invention will be described. At time t(; the engine load prediction unit 35 predicts that the engine load increases suddenly at the time t1 after a predetermined time.

The driver guidance device 19 compares the engine load prediction value and the fastest engine output response. The driver guidance device, when determining that the engine output cannot follow the load, determines a notch guidance by minutely switching the notch from coasting to 3 [N] and from 3 [N] to 7 [N] so that the engine output can follow the load. Thus, the generator output and the electric motor output can be increased in response to an increase in notch level without being limited by the engine rotational speed limit. In other words, with the train control system 2 acccrding to the sixth embodiment, the proper notch can be selected by considering the engine responsiveness, and the journey time can be reduced without causing deterioration in engine exhaust performance, compared with the example in the related art.

Furthermore, in a train which runs on power from overhead wires in the electrified section and on generated power from the diesel engine 8 in the non-electrified section, the acceleration performance differs between the electrified section and the non-electrified section, and therefore the driver's proper notch operation is difficult. Therefore, the sixth embodiment is especially useful in which proper notch guidance is performed by considering the engine responsiveness.

[0046] As described above, according to the present invention, it is possible to satisfy both of the engine exhaust performance and the vehicle acceleration performance and produce much improvement in environmental property, by increasing the engine rotational speed before an increase in output of the electric motor on the basis of the prediction of the increase in output of the electric motor, or providing a finely-divided notch guidance for a driver so that the engine output can follow an increase in load.

Also, in view of the foregoing, combinations of the first embodiment to the sixth embodiment may be used or various modifications may be made in response to track particularities,

vehicle specifications or the like.

List of Reference Signs [0047] 1 Diesel-electric locomotive 2 Train control system 3 Mater controller 4 speed detector Track database 6 Train controller 7 Engine controller 8 Diesel engine 9 Generator converter 11 converter controller 12 Inverter 13 Inverter controller 14 Electric motor Operation mode switching devc 1 6 Operation mode dIspia y aev ice 17 l5heei 18 Target travel speed pattern dataoase 19 Driver guidance device Brake chopper 21 Braking res iLator 31 in'er ner on cnn t command ca iou Ta t ion P01 32 Engine output command calculation unit 33 Engine. rotat ional sneed command calculation. unit 34 Engine rotational seed correction unit FL.trie load prediction unit.

36 Notch deterrn.i.nat.ion unit 37 Corve rter output command Ca J.o c i.e Li ion unit 33 DC voltage conLroL unit