JP7174346B2 - Remaining drivable distance calculation device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a remaining travelable distance calculation device used in a vehicle such as an automobile.

2. Description of the Related Art In recent years, among vehicles such as automobiles, vehicles that run using electric motors (for example, electric vehicles) have become popular. As a technique for calculating and displaying the remaining travelable distance of such a vehicle, for example, Patent Document 1 discloses that in a so-called series hybrid vehicle, there A control device is disclosed that calculates the remaining travelable distance based on both. Further, in Patent Document 2, a cruising range estimation device for a vehicle is provided with a first sampling period and a longer second sampling period as sampling periods for power consumption calculation, and a predetermined initial condition is established (when charging of the battery is completed), the cruising range is estimated using the second sampling period instead of the first sampling period, thereby enabling appropriate estimation. It is

JP 2012-101616 JP 2013-27166

By the way, such calculation of the remaining drivable distance is based on the remaining amount of battery in the vehicle (including the amount of power that can be generated if the internal combustion engine can generate power) and the power consumption rate (electricity cost) of the vehicle. will be required in the relationship of However, since the power consumption rate of the vehicle changes from moment to moment depending on the driving conditions and the driving environment, the calculated remaining travelable distance may also fluctuate beyond the change associated with the phenomenon of the remaining battery charge. be. Such unstable fluctuations in the display of the remaining travelable distance may confuse the driver and hinder proper driving planning. On the other hand, when the remaining battery power is running low, it is necessary to provide an accurate display of remaining drivability that appropriately reflects the driving conditions at that point in time so that the driver can appropriately secure the timing of charging.

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above circumstances, and its object is to optimize the stability and accuracy of the calculated value in a remaining travelable distance calculation device used in a vehicle that runs on electric power. To provide a remaining travelable distance calculating device compatible with

In order to achieve the above object, the present invention adopts the following solutions. That is, as described in claim 1, in a remaining travelable distance calculating device for calculating a remaining travelable distance of a vehicle that travels using an electric motor, the total amount of power remaining in the power source of the vehicle is calculated. data storage means for acquiring and storing cumulative data of the power consumption rate of the vehicle; a current electricity cost that is the most recent power consumption rate stored by the data storage means; and the current electricity cost a reference electricity consumption calculation means for calculating a reference electricity consumption as a weighted average weighted by the degree of contribution of each of the past electricity consumptions, which is the electricity consumption rate in the past; remaining travelable distance calculating means for calculating the remaining travelable distance of the vehicle by dividing by the reference electricity consumption calculated by the electricity consumption calculating means; It is the sum of the remaining amount and the amount of electric power that can be generated by an internal combustion engine provided in the vehicle with the remaining fuel stored in the vehicle, and the reference electricity consumption calculation means calculates each of the current electricity consumption and the past electricity consumption. The contribution is set such that the ratio of the contribution of the current electricity cost to the contribution of the past electricity cost increases as the total electric energy decreases, and the contribution of the current electricity cost is fixed in the calculation of the reference electricity cost . value, the contribution of the past electricity consumption is set by a quadratic function with the total electricity consumption as a variable .

According to the above-described solution method, as the total power consumption of the power supply unit in the vehicle decreases, the contribution of the current electricity cost is set larger than the contribution of the past electricity cost to calculate the reference electricity cost and the remaining travelable distance (that is, the remaining travelable distance). In the calculation of the possible driving distance, the current electricity cost has a stronger influence than the past electricity cost). The current electricity cost is largely taken into account in calculating the drivable distance, and an accurate (highly reliable) remaining drivable distance is calculated that appropriately reflects the operating conditions, driving environment, etc. at that point in time. On the other hand, when the total amount of electric power is sufficient (when there is a margin before the electricity runs out), the contribution of the past electricity consumption is set to be large in calculating the remaining travelable distance (from the time of calculation to the time earlier than power consumption rate history is taken into account), the calculated remaining travelable distance is highly stable and does not easily fluctuate due to temporary changes in driving conditions, travel environment, etc. at the time of calculation. Therefore, the calculation of the remaining travelable distance can be executed in a form that achieves both optimum stability and accuracy in accordance with the total electric energy at the time of calculation. In addition, as the total amount of power increases, the contribution of the past electricity consumption increases in a quadratic function, so in calculating the remaining travelable distance, it is possible to appropriately balance stability and accuracy according to the total amount of power. can. Also, the remaining travelable distance can be appropriately calculated even in a vehicle in which the electric power for running is also supplied by power generation by an internal combustion engine (power generation engine).

FIG. 1 is a block configuration diagram showing an example of a control system of the present invention and a part of a configuration of a vehicle; FIG. 4 is a diagram showing an outline of cumulative power consumption rate data; 7 is a graph showing an example of the relationship of the degree of contribution of past electricity consumption to total electricity consumption; 4 is a graph showing an example of the relationship between the total electric energy and the calculated value of the remaining travelable distance; 4 is a flow chart showing a control procedure of an example of control in remaining travelable distance calculation of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a block configuration diagram showing part of the configuration of a vehicle equipped with the remaining travelable distance calculating device of the present invention and an example of a control system. As shown, the vehicle has both a battery B that supplies electric power to the electric motor, which is a drive means, and an engine E, which is an internal combustion engine that supplies electric power generated by driving a generator G to the electric motor. In the present embodiment, the vehicle is a type of vehicle (a so-called series hybrid vehicle) that includes only an electric motor as a driving means, and power for running is supplied to the electric motor from a battery and an internal combustion engine.

The control system includes a controller U configured using, for example, a microcomputer. The controller U includes a total electric energy calculating means 1, a reference electricity consumption calculating means 2, and a remaining traveling distance calculating means 3 as means (program) for calculating the remaining travelable distance.

The total electric energy calculating means 1 is means for calculating the total electric energy, which is the remaining electric power that can be used as power for running in the vehicle. More specifically, the total electric energy calculating means 1 acquires a detection signal indicating the remaining electric power (remaining battery electric power) of the battery B detected by the remaining battery amount detecting means 4, and the remaining amount of fuel detected by the remaining fuel amount detecting means 5. A detection signal indicating the remaining amount of fuel in the fuel tank T is obtained, and the amount of power that can be generated by the engine E and the generator G (remaining amount of engine power) is calculated using this remaining amount of fuel. The total power amount W is the sum of the remaining battery power amount and the remaining engine power amount.

The reference electricity consumption calculation means 2 is means for calculating a reference electricity consumption, which is a power consumption rate used to calculate the remaining travelable distance of the vehicle. The reference electricity consumption calculation means 2 calculates the reference electricity consumption E based on the data acquired from the data storage means M. FIG. As will be described later, the remaining travelable distance is calculated as a value W/E obtained by dividing the total electric energy W by the reference electricity consumption E.

The data storage means M is composed of, for example, an external storage device, and is cumulative data in which the power consumption rate (power consumption per mileage) for each predetermined cycle (for example, every 1 km) of the mileage of the vehicle is accumulated in time series. is stored as FIG. 2 schematically shows accumulated data stored in the data storage means M. As shown in FIG. In the cumulative data, the power consumption rate in the cycle closest to the present time is the current electricity cost e(i), and the current electricity cost e(i) is preceded by the unit past electricity cost e(i−j), so that the cumulative data is will be configured. Here, i and j are natural numbers, i is the number of data accumulated up to that point (the number of accumulated cycles), and j is the number of cycles before the current electricity cost. showing.

In calculating the reference electricity consumption, first, the past electricity consumption ep is calculated from the series of unit past electricity consumptions e(ij). Specifically, the unit past electricity cost e(i−1) one cycle before the current electricity cost e(i) may be used as the past electricity cost ep, or the unit past electricity cost for a plurality of cycles before the current electricity cost e(i) may be used as the past electricity cost ep. may be used as the past electricity consumption ep.

The reference electricity consumption is calculated by taking the current electricity consumption ec (=e(i)) as a weighted average (weighted electricity consumption) of the past electricity consumption ep. That is, the reference electricity cost E is calculated as a weighted average of the past electricity cost ep and the current electricity cost ec, with the contribution degree α of the past electricity cost ep and the contribution degree β of the current electricity cost ec as weights of the past electricity cost ep and the current electricity cost ec. be. A specific calculation formula is as shown in formula (1) below.
E=(α・ep+β・ec)/(α+β) (1)
The contribution degree α of the past electricity cost ep and the contribution degree β of the current electricity cost ec in the calculation of the reference electricity cost are set so that the ratio of the contribution degree β of the current electricity cost to the contribution degree α of the past electricity cost increases as the total electric energy W decreases. be done. That is, as the total electric energy W decreases, the influence of the current electric cost ec on the calculation of the reference electric consumption E increases, and as the total electric energy W increases, the influence of the past electric consumption ep on the calculation of the reference electric consumption E increases. to

As a result, when the total electric energy W (remaining electric power that can be used for driving) is small and the electric power for driving is likely to be insufficient, the current electric power cost ec is largely taken into account in calculating the remaining driving distance, and the operating state at that time. , an accurate remaining travelable distance that appropriately reflects the travel environment and the like is calculated. On the other hand, when the total electric energy W is sufficient (when there is a margin until the electricity runs out), the past electricity cost ep (that is, the past electricity consumption rate history rather than the current electricity cost ep) is used to calculate the remaining travelable distance. is largely taken into account, the calculated remaining travelable distance is highly stable and does not easily fluctuate due to temporary changes in driving conditions, traveling environment, etc. at the time of calculation. Therefore, the calculation of the remaining travelable distance can be executed in a manner that achieves both optimum stability and accuracy in accordance with the total electric energy W at the time of calculation.

Next, a specific setting example of the contribution degree α of the past electricity cost and the contribution degree β of the current electricity cost will be described. In this setting example, the contribution degree β of the current electricity cost is fixed (eg, β=1), and the contribution degree α of the past electricity cost is set as a quadratic function of the total consumption W. That is, the contribution degree α of the past electricity consumption is set by the following equation (2).
α=K·W ² (2)
where the coefficient K is a constant. Note that FIG. 3 is a graph showing the relationship between the total electric energy W set by the formula (2) and the contribution degree α to the past electricity consumption.

In this way, by setting the degree of contribution α to the past electricity consumption as a quadratic function of the total consumption W, the degree of contribution α can be greatly changed according to the value of the total electricity consumption W. When the total power W is small, it is possible to calculate the remaining travelable distance with higher accuracy (reliability), and when the total power W is large, the stability of the calculated remaining travelable distance can be further improved. .

The remaining travelable distance calculating means 3 divides the total electric energy W calculated by the total electric energy calculating means 1 by the reference electricity consumption E calculated by the reference electricity consumption calculating means to obtain the remaining travelable distance L=W/E Calculate The calculated remaining travelable distance L is displayed on display means D (for example, a liquid crystal display provided on the instrument panel of the vehicle) for the driver of the vehicle.

FIG. 4 is a graph showing an example of the relationship between the calculated value of the remaining drivable distance and the total electric energy. The graph (broken line) when the travelable distance is calculated is shown. As shown in the figure, the remaining drivable distance calculated according to the present invention is calculated using the reference electricity cost calculated in consideration of not only the current electricity cost but also the past electricity cost. Compared to the case of calculating only the current electricity cost, it gradually decreases as the total electricity consumption decreases, and becomes stable without abrupt fluctuations.

Next, an example of control for calculating the remaining travelable distance in the controller U will be described with reference to the flowchart of FIG. In calculating the remaining travelable distance, first, in step S1, data on the remaining battery power is acquired, and in step S2, data on the remaining amount of fuel is acquired, and the remaining amount of engine power that can be generated with the remaining amount of fuel is calculated. calculate. In step S3, the total power amount is calculated by adding the remaining battery power and the remaining engine power.

In step S4, the accumulated power consumption rate data (current electricity cost and past electricity cost) is acquired. In step S5, the degree of contribution of each of the current electricity cost and the past electricity cost is set according to the total electric energy, and in step S6, the set contribution degree is used to calculate the reference electricity cost.

In step S7, the remaining travelable distance is calculated by dividing the total electric energy by the reference electricity consumption. In step S8, the calculated remaining travelable distance is displayed on the display device D, and one round of processing ends.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and appropriate modifications can be made within the scope of the claims.

INDUSTRIAL APPLICABILITY The present invention can be used to calculate the remaining travelable distance in a vehicle driven by an electric motor.

B battery E engine G generator T fuel tank U controller 1 total power production means 2 standard electricity consumption calculation means 3 remaining travelable distance calculation means 4 remaining battery level detection means 5 fuel level detection means M data storage means D display means

Claims (1)

In a remaining drivable distance calculation device that calculates the remaining drivable distance of a vehicle that travels using an electric motor,
total electric energy calculation means for calculating the total electric energy remaining in the electric power source of the vehicle;
data storage means for acquiring and storing cumulative data of the power consumption rate of the vehicle;
A reference electricity consumption is calculated as a weighted average weighted by the degree of contribution of each of the current electricity consumption, which is the most recent electricity consumption rate stored in the data storage means, and the past electricity consumption, which is the past electricity consumption rate, than the current electricity consumption. a reference electricity consumption calculation means;
remaining drivable distance calculating means for calculating the remaining drivable distance of the vehicle by dividing the total electric energy calculated by the total electric energy calculating means by the reference electric consumption calculated by the reference electric consumption calculating means; ,
The total amount of electric power is the sum of the remaining battery power of all batteries in the vehicle and the amount of electric power that can be generated by an internal combustion engine provided in the vehicle using the remaining fuel stored in the vehicle,
The reference electricity cost calculating means sets the contribution of each of the current electricity cost and the past electricity cost so that the ratio of the contribution of the current electricity cost to the contribution of the past electricity cost increases as the total amount of electricity decreases. death,
In the calculation of the reference electricity consumption, the remaining travelable distance is such that the contribution of the current electricity consumption is set to a fixed value, while the contribution of the past electricity consumption is set by a quadratic function with the total electricity consumption as a variable. calculator.

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