Target speed determination device, target speed determination method and program, vehicle control device, and vehicle

In the present invention: a power consumption calculation unit sets target speeds in a plurality of sections of a track; the power consumption calculation unit calculates, on the basis of the target speeds, the power consumption when the track is traveled; a target speed change unit changes combinations of target speeds in the plurality of sections set by the power consumption calculation unit; an evaluation value calculation unit calculates an evaluation value on the basis of an evaluation function for each combination of target speeds; the evaluation function is a function in which the power consumption calculated by the power consumption calculation unit is multiplied by a prescribed weight; and a target speed determination unit sets the combination of target speeds in which the evaluation value is smallest as the target speed of the vehicle in each section.

RELATED APPLICATIONS

The present application is a National Phase of International Application Number PCT/JP2013/075492, filed Sep. 20, 2013, which claims priority to Japanese Application Number 2013-028355, filed Feb. 15, 2013.

TECHNICAL FIELD

The present invention relates to a target speed determination device, a target speed determination method, and a program that determine target speed of a vehicle that performs acceleration or deceleration based on a difference between current speed and the target speed, a vehicle control device that performs control based on the target speed determined by the target speed determination device, and the vehicle.

Priority is claimed on Japanese Patent Application No. 2013-028355, filed Feb. 15, 2013, the content of which is incorporated herein by reference.

BACKGROUND ART

In recent years, demand for energy saving of a traffic system is increasing. PTL 1 discloses a speed pattern generation scheme for minimizing power consumption while satisfying various constraints. The speed pattern refers to information in which ON/OFF of a brake and ON/OFF of power running are associated with time.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

Acceleration characteristics of a vehicle vary according to the number of passengers of the vehicle or weather. Therefore, when the vehicle travels at a speed pattern determined using the technology disclosed in PTL 1, the vehicle does not necessarily travel in the same time in each predetermined section.

An object of the present invention is to provide a target speed determination device, a target speed determination method, a program, a vehicle control device capable of causing a vehicle to travel over the same time in each section and reducing power consumption, and the vehicle.

Solution to Problem

A first aspect of the present invention is a target speed determination device that determines target speed of a vehicle that performs acceleration or deceleration based on a difference between current speed and the target speed. The target speed determination device includes a power consumption calculation unit, a target speed change unit, an evaluation value calculation unit, and a target speed determination unit. The power consumption calculation unit sets the target speed in a plurality of sections of a track. The power consumption calculation unit calculates power consumption when the vehicle has traveled on the track, based on the target speed. The target speed change unit changes a combination of the target speeds in the plurality of sections set in the power consumption calculation unit. The evaluation value calculation unit calculates an evaluation value based on an evaluation function for each combination of the target speeds. The evaluation function is a function of multiplying the power consumption calculated by the power consumption calculation unit by a predetermined weight. The target speed determination unit determines a combination of the target speeds for which the evaluation value is minimized to be a target speed in each section of the vehicle.

Further, a second aspect of the present invention is the target speed determination device of the first aspect including a sensitivity calculation unit. The sensitivity calculation unit calculates sensitivity indicating a size of an amount of a change in the evaluation value with respect to an amount of a change in the target speed for the plurality of sections. The evaluation value is the evaluation value calculated by the evaluation value calculation unit. The target speed change unit increases or decreases each target speed of each section used for previous calculation of the power consumption by the power consumption calculation unit according to a level of the sensitivity of the section calculated by the sensitivity calculation unit.

Further, a third aspect of the present invention is the target speed determination device of the first aspect or the second aspect including a penalty value calculation unit. The penalty value calculation unit calculates a penalty value. The penalty value indicates a degree of divergence from conditions to be satisfied by the vehicle in traveling on the track. The evaluation function is a function of taking a total sum of a value obtained by multiplying the power consumption by a predetermined weight and a value obtained by multiplying the penalty value by a weight greater than the weight of the power consumption.

Further, a fourth aspect of the present invention is the target speed determination device of any one of the first to third aspects including a power consumption calculation unit, an evaluation value calculation unit, a target charge rate change unit, and a target charge rate determination unit. The vehicle includes a secondary battery. The vehicle controls charge and discharge of the secondary battery based on a difference between a current charge rate and a target charge rate of the secondary battery. The power consumption calculation unit sets the target speed and the target charge rate in the plurality of sections. The power consumption calculation unit calculates power consumption when the vehicle has traveled on the track, based on the target speed and the target charge rate. The evaluation value calculation unit calculates the evaluation value for each combination of the target speed and the target charge rate. The target charge rate change unit changes a combination of the target charge rates in the plurality of sections set in the power consumption calculation unit. The target charge rate determination unit determines a combination of the target charge rates for which the evaluation value is minimized to be the target charge rate in each section of the vehicle.

Further, a fifth aspect of the present invention is a target speed determination method using a target speed determination device that determines target speed of a vehicle that performs acceleration or deceleration based on a difference between current speed and the target speed. A power consumption calculation unit sets the target speed in a plurality of sections of a track. The power consumption calculation unit calculates power consumption when the vehicle has traveled on the track, based on the target speed. A target speed change unit changes a combination of the target speeds in the plurality of sections set in the power consumption calculation unit. An evaluation value calculation unit calculates an evaluation value based on an evaluation function for each combination of the target speeds. The evaluation function is a function of multiplying the power consumption calculated by the power consumption calculation unit by a predetermined weight. A target speed determination unit determines a combination of the target speeds for which the evaluation value is minimized to be a target speed in each section of the vehicle.

Further, a sixth aspect of the present invention is a program for causing a computer to function as a power consumption calculation unit, a target speed change unit, an evaluation value calculation unit, and a target speed determination unit. The computer is a computer of a target speed determination device that determines target speed of a vehicle that performs acceleration or deceleration based on a difference between current speed and the target speed. The power consumption calculation unit sets the target speed in a plurality of sections of a track. The power consumption calculation unit calculates power consumption when the vehicle has traveled on the track, based on the target speed. The target speed change unit changes a combination of the target speeds in the plurality of sections set in the power consumption calculation unit. The evaluation value calculation unit calculates an evaluation value based on an evaluation function for each combination of the target speeds. The evaluation function is a function of multiplying the power consumption calculated by the power consumption calculation unit by a predetermined weight. The target speed determination unit determines a combination of the target speeds for which the evaluation value is minimized to be a target speed in each section of the vehicle.

Further, a seventh aspect of the present invention is a vehicle control device that controls acceleration of the vehicle based on the target speed determined by the target speed determination device of any one of the first to fourth aspects.

Further, an eighth aspect of the present invention is a vehicle that performs acceleration or deceleration based on a difference between the current speed and the target speed determined by the target speed determination device of any one of the first to fourth aspects.

Advantageous Effects of Invention

According to the above-described aspect, the target speed determination device calculates the target speed of each section of the vehicle rather than a traveling pattern of the vehicle. Accordingly, it is possible to secure punctuality of traveling of the vehicle regardless of a change in weather or the number of passengers. Further, according to the above-described aspect, the target speed determination device determines the target speed of each section to be a target speed at which the evaluation value obtained by multiplying the power consumption by a predetermined weight is minimized. Accordingly, it is possible to reduce power consumption.

DESCRIPTION OF EMBODIMENTS

Hereinafter, a first embodiment will be described in detail with reference to the accompanying drawings.

A target speed determination device according to the first embodiment is a device that determines target speed of a vehicle. A vehicle that travels based on the target speed determined by the target speed determination device sets the target speed for each section when a track is divided into a plurality of sections (for example, a block section). The vehicle performs acceleration or deceleration (switching of a notch) based on a difference between the current speed and the target speed. Specifically, an Automatic Train Operation (ATO) device for a vehicle switches power running to ON when the current speed is a predetermined value or more less than the target speed. The ATO device switches power running and a brake to OFF (coasting) when the difference between the current speed and the target speed is equal to or smaller than a predetermined value. The ATO device switches the brake to ON when the current speed is a predetermined value or more higher than the target speed.

FIG. 1is a schematic block diagram illustrating a configuration of a vehicle100according to a first embodiment of the present invention.

The vehicle100includes a power collection unit101, an electric motor102, an auxiliary device103, a resistor104, a security brake105, a discharge control unit106, and an ATO device (vehicle control device)200.

The power collection unit101obtains electricity from an overhead line provided in a track. The power collection unit101supplies the electricity to the electric motor102and the auxiliary device103. The power collection unit101supplies regenerative power not consumed by the resistor104in regenerative power of the electric motor102to the overhead line.

The electric motor102accelerates the vehicle100using the electricity supplied from the power collection unit101. The electric motor102decelerates the vehicle100by operating as a power generator. The electric motor102supplies the generated regenerative power to a Static InVerter (SIV) and the discharge control unit106. The electric motor102is connected to another device via a Variable Voltage Variable Frequency (VVVF) inverter.

The auxiliary device103is a device other than the electric motor102mounted on the vehicle100. The auxiliary device103is operated by the power supplied from the power collection unit101. An example of the auxiliary device103includes an air conditioner. Further, the auxiliary device103is connected to another device via the SIV.

The resistor104consumes the regenerative power of the electric motor102. The resistor reduces a corresponding voltage to be equal to or lower than an allowable voltage of the overhead line through consumption of the regenerative power.

The security brake105is a mechanical brake. The security brake105is provided separately from a regenerative brake by the electric motor102. The security brake105is driven when speed of the vehicle100has exceeded a speed limit. The security brake105is driven to decelerate the vehicle100.

When power generated by the regenerative brake of the electric motor102is higher than the power consumed by the auxiliary device103, the discharge control unit106supplies the regenerative power of the electric motor102to the resistor104.

The ATO device200calculates the speed of the vehicle100from the number of rotations of the electric motor102. The ATO device200controls a notch of the electric motor102based on the calculated speed. That is, the ATO device200controls acceleration and deceleration of the vehicle100based on the speed of the vehicle100calculated from the number of rotations of the electric motor102.

The ATO device200includes a target speed storage unit201, a station-stop target speed storage unit202, a speed limit storage unit203, a target speed selection unit204, a speed calculation unit205, a command value calculation unit206, and an acceleration and deceleration command unit207.

The target speed storage unit201stores the target speed in each section determined by the target speed determination device.

The station-stop target speed storage unit202stores the target speed for causing the vehicle100to stop in a predetermined position of the station. Specifically, the target speed outside a certain section in front of the station is an allowable maximum speed. The target speed inside the certain section in front of the station is set to monotonically decrease with respect to a distance. That is, the target speed decreases as the vehicle is closer to the station. By setting the target speed appropriately, the ATO device200can reliably stop the vehicle100in a predetermined position of the station. Further, logic until the vehicle stops at the station is not limited thereto, and different logic may be used according to the ATO device200.

The speed limit storage unit203stores the speed limit in each section. For example, the speed limit is set to be low for a section in which there is a gradient or a curve in the track.

The target speed selection unit204selects the target speed having a smaller value among the target speed stored in the target speed storage unit201and the target speed stored in the station-stop target speed storage unit202as the target speed for use in control of the vehicle100.

The speed calculation unit205calculates the speed of the vehicle100based on the number of rotations of the electric motor102.

The command value calculation unit206applies proportional control to a difference between the target speed selected by the target speed selection unit204and the speed calculated by the speed calculation unit205. Accordingly, the command value calculation unit206calculates a notch command value indicating ON/OFF of the brake and ON/OFF of power running for controlling the electric motor102.

The acceleration and deceleration command unit207controls the vehicle100based on the speed calculated by the speed calculation unit205and the speed limit stored in the speed limit storage unit203. Specifically, when the speed calculated by the speed calculation unit205exceeds the speed limit, the acceleration and deceleration command unit207starts up the security brake105. When the speed calculated by the speed calculation unit205is within the speed limit, the acceleration and deceleration command unit207outputs the notch command value calculated by the command value calculation unit206to the electric motor102.

The target speed determination device300that determines the target speed used for traveling of the vehicle100described above will be described.

FIG. 2is a schematic block diagram illustrating a configuration of the target speed determination device300according to the first embodiment.

The target speed determination device300includes a simulator unit301, a power consumption calculation unit302, a penalty value calculation unit303, an evaluation value calculation unit304, an evaluation information recording unit305, an evaluation information storage unit306, a sensitivity calculation unit307, a target speed change unit308, and a target speed determination unit309.

The simulator unit301simulates traveling of the vehicle100based on track data, vehicle data, and the target speed of each section. The track data and the vehicle data are previously input data. The target speed of each section is data that is input from the target speed change unit308. Information such as a position of a station, an inter-station traveling time, a speed limit of each section, and a curve and a gradient of the track is included in the track data. Information such as a composition number, a vehicle weight, and riding capacities is included in the vehicle data. Further, the simulator unit301outputs the power consumption of the vehicle100, whether the vehicle100has arrived at the station, coordinates of the vehicle100, a notch pattern, the speed of the vehicle100at each time as a result of the simulation.

The power consumption calculation unit302calculates total power consumption required for traveling on the track by the vehicle100. The power consumption calculation unit302calculates the total power consumption based on the simulation result of the simulator unit301.

The penalty value calculation unit303calculates the penalty value. The penalty value is a value indicating a degree of divergence between the simulation result of the simulator unit301and conditions to be satisfied by the vehicle100in traveling on the track. The conditions to be satisfied by the vehicle100in traveling on the track may include, for example, a jerk limit, a station arrival time, station arrival coordinates, or a speed limit. Further, the jerk limit indicates an upper limit of a jerk value (a temporal change rate of acceleration; jerk) of the vehicle100. A comfortable ride is known to being bad when the jerk value of the vehicle100is higher. The penalty value calculation unit303in the present embodiment calculates the penalty value for each of a comfortable ride, the arrival time, the arrival coordinates, and the speed limit of the vehicle100. Further, in this embodiment, the penalty value calculation unit303calculates a square of an excess width from a limit value as the penalty value. The embodiment of the present invention is not limited thereto and, for example, the penalty value calculation unit303may calculate the penalty value through fourth power of the excess width from the limit value. That is, the penalty value calculation unit303calculates the penalty value so that the penalty value increases when the excess width is greater.

The evaluation value calculation unit304calculates an evaluation value indicating a degree of appropriateness of the target speed based on an evaluation function. The evaluation function is a function for obtaining a total sum of values that are obtained by multiplying the power consumption calculated by the power consumption calculation unit302and the penalty value calculated by the penalty value calculation unit303by predetermined coefficients, respectively. In the evaluation function, the coefficient applied to the penalty value is sufficiently greater than the coefficient applied to the power consumption. For example, it is preferable for the coefficient related to the penalty value to be a value with which no overflow occurs. Accordingly, the evaluation value is great when the conditions to be satisfied by the vehicle100in traveling on the track are not satisfied. The smaller evaluation value indicates that the target speed is appropriate.

FIG. 3is a diagram illustrating a change in the evaluation value when only the target speed of one of a plurality of sections has been changed.

FIG. 3shows an example in which a simulation result indicating that the vehicle100does not arrive at the station on time has been obtained when simulation in which the target speed of a certain section is equal to or less than V1has been performed. In this case, the penalty value calculation unit303calculates, as the penalty value, a value obtained by multiplying a square of a difference between a predetermined arrival time and the arrival time of the simulation result by a predetermined coefficient. Accordingly, the evaluation value increases when the target speed is smaller than V1.

Further,FIG. 3shows an example in which a simulation result indicating that the speed of the vehicle100exceeds the speed limit has been obtained when simulation in which the target speed of a certain section is equal to or higher than V2has been performed. In this case, the penalty value calculation unit303calculates, as the penalty value, a value obtained by multiplying a square of a difference between a predetermined speed limit and the speed of the simulation result by a predetermined coefficient. Accordingly, the evaluation value increases when the target speed is higher than V2.

Further, the coefficient by which the penalty value is multiplied is sufficiently greater than the coefficient applied to the power consumption, as described above. Accordingly, the target speed determination device300can specify the target speed at which the power consumption is reduced while satisfying conditions to be satisfied by the vehicle100in traveling on the track, by selecting the target speed for which the evaluation value is small.

The evaluation information recording unit305records the evaluation value and the target speed of each section in the evaluation information storage unit306in association with each other. The evaluation value is an evaluation value calculated by the evaluation value calculation unit304. The target speed of each section is a target speed used for simulation by the simulator unit301.

The evaluation information storage unit306stores the evaluation value calculated in the past and the target speed of each section when the evaluation value has been obtained in association with each other.

The sensitivity calculation unit307calculates sensitivity indicating a size of an amount of a change in the evaluation value with respect to the amount of change in the target speed for the plurality of sections of the track. The sensitivity calculation unit307calculates the sensitivity based on the evaluation value calculated by the evaluation value calculation unit304and the target speed of each section. The sensitivity calculation unit307partially differentiates an equation having the target speed of each section as an independent variable and the evaluation value as a dependent variable, and calculates the sensitivity by examining a gradient thereof.

The target speed change unit308increases or decreases the target speed of each section according to the sensitivity of each section calculated by the sensitivity calculation unit307. The target speed of each section is the target speed for previous simulation by the simulator unit301. Specifically, the target speed change unit308increases a degree of change in the target speed in the section in which the sensitivity is higher. The target speed change unit308decreases the degree of change in the target speed in the section in which the sensitivity is lower.

The target speed determination unit309determines whether a minimum value of the evaluation value stored in the evaluation information storage unit306has converged. When the target speed determination unit309determines that the minimum value of the evaluation value has converged, the target speed determination unit309determines the target speed of each section associated with the minimum evaluation value to be the target speed used for traveling of the vehicle100.

Next, an operation of the target speed determination device300according to the first embodiment will be described.

FIG. 4is a flowchart illustrating an operation of the target speed determination device300according to the first embodiment.

First, the simulator unit301of the target speed determination device300simulates traveling of the vehicle100using an initial value of the target speed of each section (step S1). Then, the power consumption calculation unit302calculates power consumption when the vehicle100has traveled along the track based on the target speed (step S2). The power consumption calculation unit302calculates a total sum of power consumption values at respective times based on the simulation result of the simulator unit301to calculate the power consumption.

Further, the penalty value calculation unit303calculates the penalty value based on the simulation result of the simulator unit301(step S3). The penalty value calculation unit303calculates the penalty value for each of the comfortable ride, the arrival time, the arrival coordinates, and the speed limit of the vehicle100. Specifically, when an amount of a notch time change in the simulation result is larger than an amount of notch time change for obtaining a predetermined minimum comfortable ride, the penalty value calculation unit303calculates a square of a difference between the amounts as the penalty value of the comfortable ride. Further, when the arrival time for the station in the simulation result is later than a predetermined arrival time, the penalty value calculation unit303calculates a square of a difference between the arrival times as the penalty value of the arrival time. Further, the penalty value calculation unit303calculates a square of a difference between the arrival coordinates for the station in the simulation result and predetermined arrival coordinates as the penalty value of the arrival coordinates. Further, when the speed of the vehicle100in the simulation result is higher than a predetermined speed limit, the penalty value calculation unit303calculates a square of a difference between the speed and the speed limit as the penalty value of the speed limit.

Then, the evaluation value calculation unit304applies the power consumption calculated by the power consumption calculation unit302and each penalty value calculated by the penalty value calculation unit303to a predetermined evaluation function to calculate an evaluation value (step S4). The evaluation function is a function of obtaining a total sum of values obtained by multiplying the power consumption and each penalty value by a predetermined coefficient. As described above, the coefficient of the penalty value is greater than the coefficient of power consumption, and is a value with which no overflow occurs.

Then, the evaluation information recording unit305records a combination of the evaluation value calculated by the evaluation value calculation unit304and the target speed used for the simulation by the simulator unit301on the evaluation information storage unit306in association with each other (step S5). Then, the target speed determination unit309determines whether a minimum value of the evaluation value has converged based on the evaluation value stored in the evaluation information storage unit306(step S6). In the present embodiment, an interior point method is used as a convergence calculation scheme. The present invention is not limited thereto, and in other embodiments, for example, when a deviation of a predetermined number of last calculated evaluation values is within a predetermined value, the target speed determination unit309may determine that the minimum value has converged.

When the target speed determination unit309determines that the minimum value of the evaluation value has not converged (step S6: NO), the sensitivity calculation unit307calculates sensitivity of the evaluation value in each section (step S7). The sensitivity calculation unit calculates sensitivity based on the evaluation value and the target speed of each section stored in the evaluation information storage unit306. Specifically, the sensitivity calculation unit307performs partial differentiation on a predetermined function to calculate the sensitivity of each section. The function is a function having the target speed of each section as an independent variable and the evaluation value as a dependent variable. Further, in the present embodiment, an adjoint method is used as a sensitivity calculation scheme.

Then, the target speed change unit308changes the target speed of each section used for previous simulation by the simulator unit301(step S8). The target speed change unit308changes the target speed based on the sensitivity calculated by the sensitivity calculation unit307. Specifically, the target speed change unit308changes the value of the target speed of the section in which the sensitivity is high to be relatively greater. The target speed change unit308changes the value of the target speed of the section in which the sensitivity is low to be relatively smaller. In this embodiment, a quasi-Newton method is used as a method of changing the target speed.

Then, the process returns to step S1to perform simulation of traveling of the vehicle100using the changed target speed.

On the other hand, when the target speed determination unit309determines that the minimum value of the evaluation value has converged in step S6(step S6: YES), the target speed determination unit309determines the target speed to be used for traveling of the vehicle100(step S9). The target speed determination unit309determines the target speed associated with the minimum evaluation value stored in the evaluation information storage unit306to be the target speed used for traveling of the vehicle100.

Accordingly, the target speed determination device300can obtain a combination of target speeds for maximizing energy saving while satisfying the conditions to be satisfied by the vehicle100in traveling on the track. Further, the target speed determination device300can secure punctuality of traveling regardless of a change in weather or the number of passengers. This is because the target speed determination device300calculates optimal target speed rather than an optimal notch pattern and causes the vehicle100to travel based on the target speed.

A target charge rate determination device that calculates a target charge rate of a secondary battery mounted on a vehicle will be described as the second embodiment of the present invention. The target charge rate determination device according to the second embodiment determines target speed of a vehicle100having a configuration different from the target speed determination device300according to the first embodiment.

FIG. 5is a schematic block diagram illustrating a configuration of a vehicle100according to the second embodiment of the present invention. Here, the same components as those of the vehicle100according to the first embodiment will be described using the same reference signs.

The vehicle100includes a DC-to-DC converter107, a secondary battery108, a target charge rate storage unit109, and a charge and discharge power calculation unit110, in addition to the configuration of the vehicle100according to the first embodiment.

The DC-to-DC converter107controls an amount of power supplied to an electric motor102, an auxiliary device103, and the secondary battery108by a power collection unit101.

The secondary battery108is charged with the electricity supplied by the power collection unit101and electricity generated by the electric motor102. The secondary battery108discharges the charged electricity and supplies the electricity to the electric motor102and the auxiliary device103.

The target charge rate storage unit109stores a target charge rate of the secondary battery108in each section of the track calculated by a target charge rate determination device.

The charge and discharge power calculation unit110applies proportional control to a difference between the charge rate of the secondary battery108and the target charge rate stored in the target charge rate storage unit109. Accordingly, the charge and discharge power calculation unit110calculates the power required for charge and discharge of the secondary battery108.

A discharge control unit106of the vehicle100according to the second embodiment calculates power to be output to the DC-to-DC converter107and power to be charged and discharged in the secondary battery108. The discharge control unit106calculates power to be output to the DC-to-DC converter107and power to charged and discharged in the secondary battery108based on charge and discharge power calculated by the charge and discharge power calculation unit110, a power limit value of the DC-to-DC converter107, and power required by the electric motor102and the auxiliary device103.

Next, the target charge rate determination device400that determines the target charge rate of the secondary battery108used for traveling of the vehicle100described above will be described.

FIG. 6is a schematic block diagram illustrating a configuration of the target charge rate determination device400according to the second embodiment of the present invention. Here, the same processing units as those of the target speed determination device300according to the first embodiment will be described using the same reference signs.

The target charge rate determination device400includes a simulator unit301, a power consumption calculation unit302, a penalty value calculation unit303, an evaluation value calculation unit304, an evaluation information recording unit305, an evaluation information storage unit306, a sensitivity calculation unit307, a target charge rate change unit310, and a target charge rate determination unit311.

The simulator unit301simulates traveling of the vehicle100based on track data, vehicle data, target speed of each section, and a target charge rate of each section. The track data, the vehicle data, and the target speed of each section are previously input data. The target charge rate of each section is a data that is input from the target charge rate change unit310. That is, in the simulator unit301according to the second embodiment, the traveling of the vehicle100is simulated using the same target speed.

The power consumption calculation unit302calculates total power consumption required for traveling on the track by the vehicle100based on the simulation result of the simulator unit301.

The penalty value calculation unit303calculates the penalty value. The penalty value is a value indicating the degree of divergence between the simulation result of the simulator unit301and conditions to be satisfied by the vehicle100in traveling on the track. The penalty value calculation unit303according to the second embodiment also calculates penalty values for a temporal change in the charge rate, an operational range of the charge rate, and a charge rate at the time of station arrival, in addition to the penalty values calculated by the penalty value calculation unit303according to the first embodiment. The penalty value for the temporal change in the charge rate is provided in order to prevent the secondary battery108from deteriorating due to an excessive change in the charge rate of the secondary battery108. The penalty value for the operational range of the charge rate is provided in order to prevent the secondary battery108from deteriorating due to the charge rate of the secondary battery108being out of the operational range. The penalty value for the charge rate at the time of station arrival is provided in order to hold the charge rate of the secondary battery108at which the vehicle100can continue to travel even after the vehicle100has arrived at the station.

The evaluation value calculation unit304calculates an evaluation value indicating a degree of appropriateness of the target charge rate based on an evaluation function. The evaluation function is a function for obtaining a total sum of values that are obtained by multiplying the power consumption calculated by the power consumption calculation unit302and the penalty value calculated by the penalty value calculation unit303by predetermined coefficients, respectively.

The evaluation information recording unit305records the evaluation value calculated by the evaluation value calculation unit304and the target charge rate of each section used for simulation by the simulator unit301in the evaluation information storage unit306in association with each other.

The evaluation information storage unit306stores the evaluation value that has been calculated in the past and the target charge rate of each section when the evaluation value has been obtained in association with each other.

The sensitivity calculation unit307calculates sensitivity indicating a size of an amount of a change in the evaluation value with respect to the amount of change in the target charge rate for the plurality of sections of the track based on the evaluation value calculated by the evaluation value calculation unit304and the target charge rate of each section.

The target charge rate change unit310increases or decreases the target charge rate of each section used for previous simulation by the simulator unit301according to the sensitivity of each section calculated by the sensitivity calculation unit307. Specifically, the target charge rate change unit310increases a degree of change in the target charge rate in the section in which the sensitivity is higher, and decreases the degree of change in the target charge rate in the section in which the sensitivity is lower.

The target charge rate determination unit311determines whether a minimum value of the evaluation value stored in the evaluation information storage unit306has converged. When the target charge rate determination unit311determines that the minimum value of the evaluation value has converged, the target charge rate determination unit311determines the target charge rate of each section associated with the minimum evaluation value to be the target charge rate used for traveling of the vehicle100.

Next, an operation of the target charge rate determination device400according to the second embodiment of the present invention will be described.

FIG. 7is a flowchart illustrating an operation of the target charge rate determination device400according to the second embodiment of the present invention.

First, the simulator unit301of the target charge rate determination device400simulates traveling of the vehicle100using predetermined initial values of the target speed of each section and the target charge rate of each section (step S11). Then, the power consumption calculation unit302calculates a total sum of power consumption values at respective times from a simulation result of the simulator unit301. Accordingly, the power consumption calculation unit302calculates the power consumption when the vehicle100has traveled on the track based on the target speed (step S12).

Further, the penalty value calculation unit303calculates the penalty value based on the simulation result of the simulator unit301(step S13). The penalty value calculation unit303calculates the penalty value for each of the comfortable ride, the arrival time, the arrival coordinates, the speed limit, the temporal change in the charge rate, the operational range of the charge rate, and the charge rate at the time of station arrival of the vehicle100. Then, the evaluation value calculation unit304applies the power consumption calculated by the power consumption calculation unit302and each penalty value calculated by the penalty value calculation unit303to a predetermined evaluation function to calculate the evaluation value (step S14).

Then, the evaluation information recording unit305records a combination between the evaluation value calculated by the evaluation value calculation unit304and the target charge rate used for simulation by the simulator unit301in the evaluation information storage unit306in association with each other (step S15). Then, the target charge rate determination unit311determines whether the minimum value of the evaluation value has converged (step S16). The target charge rate determination unit311determines the convergence based on the evaluation value stored in the evaluation information storage unit306.

When the target charge rate determination unit311determines that the minimum value of the evaluation value has not converged (step S16: NO), the sensitivity calculation unit307calculates sensitivity for the evaluation value in each section (step S17). The sensitivity calculation unit307calculates the sensitivity based on the evaluation value and the target charge rate of each section stored in the evaluation information storage unit306. Specifically, the sensitivity calculation unit307performs partial differentiation on a predetermined function to calculate the sensitivity for each section. The function is a function having the target charge rate of each section as an independent variable and the evaluation value as a dependent variable.

Then, the target charge rate change unit310changes the target charge rate of each section used for previous simulation by the simulator unit301based on the sensitivity calculated by the sensitivity calculation unit307(step S18). Specifically, the target charge rate change unit310changes the value of the target charge rate in the section in which the sensitivity is high to be relatively greater, and changes the value of the target charge rate in the section in which the sensitivity is low to be relatively smaller.

Then, the process returns to step S11to perform simulation of traveling of the vehicle100using the changed target charge rate.

On the other hand, when the target charge rate determination unit311determines that the minimum value of the evaluation value has converged in step S16(step S16: YES), the target charge rate determination unit311determines the target charge rate associated with the minimum evaluation value stored in the evaluation information storage unit306to be a target charge rate used for traveling of the vehicle100(step S19).

Accordingly, the target charge rate determination device400can obtain a combination of the target charge rate for maximizing energy saving while satisfying the conditions to be satisfied by the vehicle100in the traveling of the track. In the second embodiment, it is possible to achieve a stable operation of the secondary battery108regardless of a change caused by deterioration of the secondary battery108since the target charge rate is optimized.

A target speed determination device300according to the third embodiment of the present invention is a combination of the target speed determination device300according to the first embodiment and the target charge rate determination device400according to the second embodiment. The target speed determination device300calculates the target speed and the target charge rate of each section for the vehicle100having the same configuration as the vehicle100according to the second embodiment.

FIG. 8is a schematic block diagram illustrating a configuration of the target speed determination device300according to the third embodiment of the present invention. The same processing units as those of the target speed determination device300according to the first embodiment or the target charge rate determination device400according to the second embodiment will be described using the same reference signs.

The target speed determination device300includes the target charge rate change unit310and the target charge rate determination unit311according to the second embodiment, in addition to the configuration of the first embodiment.

In the third embodiment, the simulator unit301simulates traveling of the vehicle100based on the target speed of each section input from the target speed change unit308and the target charge rate of each section input from the target charge rate change unit310. The evaluation information recording unit305records the evaluation value, the target speed of each section, and the target charge rate of each section in the evaluation information storage unit306in association with one another. The evaluation value is the evaluation value calculated by the evaluation value calculation unit304. The target speed of each section is the target speed used for simulation by the simulator unit301. The evaluation information storage unit306stores the evaluation value calculated in the past, and the target speed and the target charge rate of each section when the evaluation value has been obtained in association with each other. The sensitivity calculation unit307calculates the sensitivity indicating a size of an amount of a change in the evaluation value with respect to an amount of a change in the target charge rate for the target speeds and the target charge rates of the plurality of sections of the track. The sensitivity calculation unit307calculates the sensitivity based on the evaluation value calculated by the evaluation value calculation unit304, and the target speed and the target charge rate of each section.

Next, an operation of the target speed determination device300according to a third embodiment of the present invention will be described.

FIG. 9is a flowchart illustrating the operation of the target speed determination device300according to the third embodiment of the present invention.

First, the simulator unit301of the target speed determination device300simulates traveling of the vehicle100using initial values of the target speed and the target charge rate of each section (step S21). Then, the power consumption calculation unit302calculates a total sum of power consumption values at respective times from a simulation result of the simulator unit301. Accordingly, the power consumption calculation unit302calculates the power consumption when the vehicle has traveled on the track (step S22). That is, the power consumption calculation unit302calculates the power consumption when the vehicle100has traveled on the track based on the target speed and the target charge rate.

Further, the penalty value calculation unit303calculates the penalty value from the simulation result of the simulator unit301(step S23). The penalty value calculation unit303calculates the penalty value for each of a comfortable ride, an arrival time, arrival coordinates, a speed limit, a temporal change in the charge rate, an operational range of the charge rate, and a charge rate at the time of station arrival of the vehicle100. Then, the evaluation value calculation unit304applies the power consumption calculated by the power consumption calculation unit302and each penalty value calculated by the penalty value calculation unit303to a predetermined evaluation function to calculate the evaluation value (step S24).

Then, the evaluation information recording unit305records a combination between the evaluation value calculated by the evaluation value calculation unit304and the target speed and the target charge rate used for simulation by the simulator unit301in the evaluation information storage unit306in association with each other (step S25). Then, the target speed determination unit309determines whether the minimum value of the evaluation value has converged based on the evaluation value stored in the evaluation information storage unit306(step S26).

When the target speed determination unit309determines that the minimum value of the evaluation value has not converged (step S26: NO), the sensitivity calculation unit307calculates sensitivity for the evaluation value with respect to the target speed and the target charge rate of each section (step S27). The sensitivity calculation unit307calculates the sensitivity based on the evaluation value, and the target speed and the target charge rate of each section stored in the evaluation information storage unit306. Specifically, the sensitivity calculation unit307performs partial differentiation on a predetermined function to calculate the sensitivity for the target speed and the target charge rate of each section. The function is a function having the target speed and the target charge rate of each section as independent variables and the evaluation value as a dependent variable.

Then, the target speed change unit308changes the target speed of each section used for previous simulation by the simulator unit301based on the sensitivity calculated by the sensitivity calculation unit307. The target charge rate change unit310changes the target charge rate of each section used for previous simulation by the simulator unit301based on the sensitivity calculated by the sensitivity calculation unit307(step S28).

Then, the target speed determination device300returns to step S21to perform simulation of traveling of the vehicle100using the changed target speed and the changed target charge rate.

On the other hand, when the target speed determination unit309determines that the minimum value of the evaluation value has converged in step S26(step S26: YES), the target speed determination unit309determines the target speed used for traveling of the vehicle100. The target speed determination unit309determines the target speed associated with the minimum evaluation value stored in the evaluation information storage unit306to be a target speed used for traveling of the vehicle100. Further, the target charge rate determination unit311determines the target charge rate associated with the minimum evaluation value stored in the evaluation information storage unit306to be a target charge rate used for traveling of the vehicle100(step S29).

Accordingly, the target speed determination device300can obtain a combination of the target speed and the target charge rate for maximizing energy saving while satisfying the conditions to be satisfied by the vehicle100in the traveling of the track.

Some of the embodiments have been described above in detail with reference to the accompanying drawings. However, a specific configuration is not limited to above-described configuration. Various design modifications or the like of the specific configuration can be made without departing from the gist.

For example, the case in which in the vehicle100according to the third embodiment, the electric motor102, the auxiliary device103, the resistor104, and the secondary battery108are connected to the power collection unit101via the DC-to-DC converter107has been described, the present invention is not limited thereto.

FIG. 10is a schematic block diagram illustrating a configuration according to a modification example of the third embodiment of the present invention.

In the vehicle100, the secondary battery108is connected to the power collection unit101via the DC-to-DC converter107, and the electric motor102, the auxiliary device103, and the resistor104are directly connected to the power collection unit101, as shown inFIG. 10.

The target speed determination device300, the target charge rate determination device400, and the ATO device200described above include a computer system provided therein. Also, the operation of each processing unit described above is recorded on a computer-readable non-transitory tangible recording medium in the form of a program. The computer reads and executes this program such that the process is performed. Here, the computer-readable non-transitory tangible recording medium refers to a magnetic disk, a magnetic optical disc, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. Further, this computer program may be distributed to the computer by a communication line, and the computer receiving the program may execute the program.

Further, the program may be intended to realize some of the above-described functions. Further, the program may be a program capable of realizing the above-described functions through a combination with a program previously recorded on a computer system, that is, a differential file (a differential program).

INDUSTRIAL APPLICABILITY

The target speed determination device calculates the target speed of each section of the vehicle rather than the traveling pattern of the vehicle. Accordingly, it is possible to secure punctuality of traveling of the vehicle regardless of a change in weather or the number of passengers. Further, the target speed determination device determines the target speed of each section to be a target speed at which the evaluation value obtained by multiplying the power consumption by a predetermined weight is minimized. Accordingly, the target speed determination device can reduce power consumption.

REFERENCE SIGNS LIST

100: VEHICLE101: POWER COLLECTION UNIT102: ELECTRIC MOTOR103: AUXILIARY DEVICE104: RESISTOR105: SECURITY BRAKE106: DISCHARGE CONTROL UNIT107: DC-TO-DC CONVERTER108: SECONDARY BATTERY109: TARGET CHARGE RATE STORAGE UNIT110: CHARGE AND DISCHARGE POWER CALCULATION UNIT200: ATO DEVICE201: TARGET SPEED STORAGE UNIT202: STATION-STOP TARGET SPEED STORAGE UNIT203: SPEED LIMIT STORAGE UNIT204: TARGET SPEED SELECTION UNIT205: SPEED CALCULATION UNIT206: COMMAND VALUE CALCULATION UNIT207: ACCELERATION AND DECELERATION COMMAND UNIT300: TARGET SPEED DETERMINATION DEVICE301: SIMULATOR UNIT302: POWER CONSUMPTION CALCULATION UNIT303: PENALTY VALUE CALCULATION UNIT304: EVALUATION VALUE CALCULATION UNIT305: EVALUATION INFORMATION RECORDING UNIT306: EVALUATION INFORMATION STORAGE UNIT307: SENSITIVITY CALCULATION UNIT308: TARGET SPEED CHANGE UNIT309: TARGET SPEED DETERMINATION UNIT310: TARGET CHARGE RATE CHANGE UNIT311: TARGET CHARGE RATE DETERMINATION UNIT