JP6488645B2 - Running resistance calculation method, running resistance measurement method, and running resistance calculation device - Google Patents

Description

  The present invention relates to a running resistance calculation method for calculating a running resistance of a vehicle, a running resistance measurement method, and a running resistance calculation device.

The running resistance of the vehicle is calculated by measuring the time series data of the vehicle speed with respect to the elapsed running time at the time of coasting the vehicle.
For example, the vehicle is coasted from a predetermined approach speed, the time series data of the vehicle speed with respect to the elapsed time up to a predetermined coasting lower limit speed is regressed to a tan function, and the coefficient included in the function is used to travel The vehicle speed dependency of resistance is obtained (Non-patent Document 1).

JIS D 1012: 2005, “Automotive fuel consumption rate test method”

  In such a method of calculating the running resistance of the vehicle, when the approach speed is 100 km / hour or more and the coasting lower limit speed is 40 km / hour, the coasting travel distance is several kilometers, so a very long straight road is required. . Since it is difficult to prepare such a straight road on the test course, for example, a plurality of traveling speed ranges such as 120 km / hour to 100 km / hour, 100 km / hour to 80 km / hour, and 80 km / hour to 60 km / hour are defined. In many cases, the vehicle is coasted under various speed conditions with different travel speed ranges.

  However, although it is possible to calculate the running resistance using the multipoint regression method for each of the time series data of the vehicle speed with respect to the coasting elapsed time measured under such a plurality of speed conditions, there are many speed conditions. Otherwise, there is a problem that the value of the coefficient in the function formula of the running resistance varies because the regression accuracy is lowered. For example, when the speed conditions are four speed conditions of 120 km / hr to 100 km / hr, 100 km / hr to 100 km / hr, 100 km / hr to 80 km / hr, 80 km / hr to 60 km / hr, the multipoint regression method Then, it is necessary to perform regression using only each of these four data. For this reason, the variation in data under each speed condition increases the variation in the drag coefficient of the vehicle and the rolling resistance of the vehicle obtained by the regression.

  Accordingly, an object of the present invention is to provide a running resistance calculation method, a running resistance measurement method, and a running resistance calculation apparatus that can accurately calculate the running resistance of a vehicle in a wide range of running speeds of the vehicle.

One embodiment of the present invention is a running resistance calculation method for calculating running resistance of a vehicle using a computer. The running resistance calculation method is as follows:
The computer obtains time-series data of vehicle speed with respect to the elapsed time of coasting when the vehicle coasts on the same road surface according to multiple speed conditions with different traveling speed ranges determined from the approach speed and lower limit speed of the vehicle And steps to
The computer calculates at least a running resistance of the vehicle from time-series data of each speed condition using an equation of motion of the vehicle in which an external force acting on the running vehicle is expressed by a function equation of a vehicle speed; Have.
When calculating the running resistance, the time shift amount for shifting the coasting running elapsed time in order to combine the time series data under each speed condition into one time series data, and the coefficient in the function formula are values. By fitting the time series data of the vehicle speed under all the set speed conditions to the general solution of the vehicle speed of the equation of motion as an unknown parameter, the value of the parameter is obtained and the running resistance is calculated. .

  When calculating the running resistance, it is preferable to calculate at least one of a drag coefficient of the vehicle and a rolling resistance from the value of the parameter.

  The function formula is preferably a second-order polynomial of vehicle speed.

  It is preferable that the speed condition is determined such that at least one of the traveling speed ranges in the plurality of speed conditions partially overlaps with the other traveling speed range.

The vehicle speed is a relative speed with respect to the road surface of the vehicle,
The computer obtains wind speed data when the vehicle is running,
It is preferable that the computer performs fitting to a general solution of the vehicle speed of the equation of motion using a result obtained by correcting the time series data with the wind speed data.

Another embodiment of the present invention is a vehicle running resistance measurement method. The running resistance measurement method is
The measuring device outputs time-series data of vehicle speed with respect to the coasting elapsed time when the vehicle coasts on the same road surface according to multiple speed conditions with different traveling speed ranges determined from the approach speed and the lower limit speed of the vehicle And steps to
A computer acquiring the time-series data;
The computer has a step of calculating at least a running resistance of the vehicle from time series data of each speed condition using an equation of motion of the vehicle in which an external force acting on the vehicle is expressed by a function equation of a vehicle speed. .
When calculating the running resistance, the time shift amount for shifting the coasting running elapsed time in order to combine the time series data under each speed condition into one time series data, and the coefficient in the function formula are values. By fitting the time series data of the vehicle speed under all the set speed conditions to the general solution of the vehicle speed of the equation of motion as an unknown parameter, the value of the parameter is obtained and at least the running resistance is obtained. calculate.

  It is preferable that the speed condition is determined so that at least one of the traveling speed ranges in the plurality of speed conditions partially overlaps with the other traveling speed range.

The vehicle speed is a relative speed with respect to the road surface of the vehicle,
The computer obtains wind speed data when the vehicle is running,
It is preferable that the computer calculates the running resistance by obtaining a value of the parameter using a result obtained by correcting the time series data with the wind speed data.

The measuring device outputs, as temperature data, at least one of a tire temperature during travel of the vehicle, a road surface temperature during travel of the vehicle, or an air temperature during travel of the vehicle,
The computer obtains the temperature data;
When calculating the running resistance, it is preferable to calculate a rolling resistance at a predetermined temperature by calculating a coefficient representing a rolling resistance of the running resistance and correcting the calculated coefficient with the temperature data.

  It is preferable that the running resistance is calculated under conditions regarding a plurality of vehicles having different tires attached to the vehicle.

Yet another embodiment of the present invention is a travel resistance calculation device that calculates a travel resistance of a vehicle. The running resistance calculation device is
An acquisition unit that acquires time-series data of vehicle speed with respect to a coasting traveling elapsed time when the vehicle coasts on the same road surface according to a plurality of speed conditions having different traveling speed ranges determined from a vehicle approach speed and a lower limit speed. When,
This is a part that calculates at least the running resistance of the vehicle from the time series data of each speed condition using the equation of motion of the vehicle in which the external force acting on the running vehicle is expressed by a function equation of the vehicle speed. The time shift amount for shifting the coasting elapsed time and the coefficient in the function expression are parameters whose values are unknown, in order to combine the time series data under the conditions into one time series data. A running resistance calculation unit that obtains the value of the parameter and calculates the running resistance by fitting time series data of the vehicle speed to a general solution of the vehicle speed of the equation of motion.

  According to the above-described travel resistance calculation method, travel resistance measurement method, and travel resistance calculation device, it is possible to accurately calculate the travel resistance of a vehicle in a wide range of travel speeds of the vehicle.

It is a block block diagram of the running resistance calculation system containing the running resistance calculation apparatus of this embodiment. It is a figure explaining the linear road surface which a vehicle runs in order to run coasting. It is a figure which shows an example of the time series data of the vehicle speed in four different speed conditions which the data acquisition part of this embodiment acquired. It is a figure which shows the time series data put together into one by fitting the four time series data shown in FIG. 3 to a general solution. It is a figure explaining the setting method of the initial value of the time shift amount of the time series data of the vehicle speed in this embodiment.

  Hereinafter, a running resistance calculation method, a running resistance measurement method, and a running resistance calculation apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

(Running resistance arithmetic unit)
FIG. 1 is a block configuration diagram of a running resistance calculation system 10 including a running resistance calculation apparatus according to the present embodiment.
The traveling resistance calculation system 10 includes a measuring device 12, a traveling resistance calculation device 14, and an output device 20.

A part of the measuring device 12 is mounted on a vehicle for measuring running resistance. The other part is installed outside the vehicle, for example, on the road surface. The part mounted on the vehicle in the measurement device 12 includes a measurement unit for measuring the relative speed with respect to the road surface, for example. The measuring device 12 outputs time series data of the traveling speed of the vehicle and transmits it to the traveling resistance calculation device 14. Specifically, the measuring device 12 outputs time series data of the vehicle speed with respect to the coasting traveling elapsed time when the vehicle coasts on the road surface to the traveling resistance calculation device 14.
The measuring device 12 is provided on a GPS (Global Positioning System) speedometer or the front surface of the vehicle, and measures wind pressure due to traveling of the vehicle including wind when the wind pressure is blowing due to traveling of the vehicle. Includes known pressure gauges.
The measuring device 12 is a time-series data of vehicle speed with respect to a coasting travel elapsed time when the vehicle coasts on the same road surface according to a plurality of speed conditions having different travel speed ranges determined from the approach speed and the lower limit speed of the vehicle. Is output.

  The running resistance calculation device 14 is configured by a computer. By starting a program stored in a memory (not shown) of the computer, a data acquisition unit 16 and a running resistance calculation unit 18 are formed. That is, the data acquisition unit 16 and the running resistance calculation unit 18 are software modules that are formed when a program is started. Therefore, the operations of the data acquisition unit 16 and the running resistance calculation unit 18 are substantially governed by a CPU (not shown) of the computer.

The data acquisition unit 16 acquires time-series data of vehicle speed for each of a plurality of speed conditions transmitted from the measurement device 12. When the time series data is wind pressure data output from the differential pressure gauge, the data acquisition unit 16 converts the wind pressure data into vehicle speed using a reference table (not shown).
In this way, the time series data of the vehicle speed is acquired under a plurality of speed conditions, as shown in FIG. 2, the linear road surface X on the test course on which the vehicle coasts is about several hundreds to 1 km. This is because the distance is shorter than the distance required for coasting. FIG. 2 is a diagram for explaining a straight road surface on which a coasting vehicle runs. The measuring device 12 measures the time change of the vehicle speed on the road surface X according to a plurality of speed conditions that determine the approach speed and the lower limit speed of the vehicle. FIG. 3 is a diagram illustrating an example of time-series data of vehicle speeds acquired by the data acquisition unit 16 under four different speed conditions. In FIG. 3, in the legend, each time series data is specified at approach speeds 120 km / h, 100 km / h, 80 km / h, and 60 km / h when entering the road surface X. The lower limit speeds are less than 100 km / h, less than 80 km / h, and less than 60 km / h, respectively.
That is, the data acquisition unit 16 determines the vehicle speed relative to the coasting travel elapsed time when the vehicle coasts on the same road surface X according to a plurality of speed conditions having different travel speed ranges determined from the approach speed and the lower limit speed of the vehicle. Get time-series data of.

The running resistance calculation unit 18 calculates at least the running resistance of the vehicle from the time series data of each speed condition using an equation of motion of the vehicle in which the external force acting on the running vehicle is expressed by a function equation of the vehicle speed. . Specifically, when calculating the running resistance, the running resistance calculating unit 18 calculates the coasting running elapsed time in the time series data of the vehicle speed in order to combine the time series data under each speed condition into one time series data. Using the time shift amount to be shifted and the coefficient in the above functional equation as parameters whose values are unknown, the time series data of the vehicle speed under all the set speed conditions is fitted to the general solution of the vehicle speed of the equation of motion. Thereby, the value of the parameter is obtained and determined, and the running resistance calculation unit 18 calculates the running resistance using the value of the parameter.
The running resistance is expressed by a function expression of the vehicle speed v, for example, the following quadratic expression. Here, m is the mass of the entire vehicle, and a, b, and c are coefficients (parameters) whose values are unknown. Moreover, this general solution is represented as the following equation.

K in the general solution in the above equation is an integration constant when the equation of motion is integrated, and relates to the time shift amount. Therefore, in the case of FIG. 3, in order to combine the time series data of the four speed conditions into one, the time shift amount in the time series data of the approach speed of 100 km / h, the time of the approach speed of 80 km / h The time shift amount in the time series data and the time shift amount in the time series data at the approach speed of 60 km / h are set as unknown values, and the time series data of the vehicle speed under all the set speed conditions is obtained as a general solution of the vehicle speed of the above equation of motion. To fit. As a result, in addition to the shift amount, the values of the coefficients a, b, and c are obtained, so that it is possible to calculate the running resistance depending on the vehicle speed. For example, the drag coefficient Cd of the vehicle is calculated as Cd = 2 × a / (ρ · S) (ρ is the density of air and S is the projected front area of the vehicle). The rolling resistance of the vehicle is calculated as v × b + c. The rolling resistance is expressed as a linear function of the vehicle speed v.
For example, in the example shown in FIG. 3, the drag coefficient Cd from a vehicle speed of 120 km / h to 40 km / h is calculated as 0.306, and the rolling resistance is calculated as 2.8 × v + 95.7 [N]. .

The fitting to the above general solution is performed by repeatedly correcting the parameter value so that the error between the time series data and the general solution is reduced using the least square method by giving an initial value to the parameter whose value is unknown. The value of the parameter when is within the allowable range can be determined as the final value. For example, the value of the parameter can be determined using a known method such as Newton-Raphson method. The initial values are a = 0.78 to 1.56 kg / m, b = 1 to 10 N / (m / sec), c = 50 to 100 N, k = 2000 to 5000 × m (m is the mass of the entire vehicle) It is preferable to use a value within the range from the viewpoint of reducing the number of corrections of the parameter value. In addition, as shown in FIG. 5, the initial value of the time shift amount of the time series data has two time series data with overlapping vehicle speeds, and the speed in one time series data becomes the entry speed of the other time series data. It is preferable to extract a time point and set the time at this time point as the time shift amount. FIG. 5 is a diagram for explaining a method of setting an initial value of the time shift amount of time series data. For example, in the example shown in FIG. 3, the time shift amount of the time-series data at the approach speed of 100 km / h is the time t1 when the speed is 100 km / h in the time-series data at the approach speed of 120 km / h. The time shift amount of the time series data of h is assumed. Similarly, the time shift amount of the time series data at the approach speed of 80 km / h (60 km / h) becomes the speed of 80 km / h (speed of 60 km / h) in the time series data of the approach speed of 100 km / h (80 km / h). The sum of the time t2 (t3) and the time t1 (time t1 + time t2) is set as the time shift amount of the time-series data at the approach speed of 80 km / h (60 km / h).
Such a calculation result is sent to a known output device 20 such as a display or a printer, and is displayed on a screen or printed out.

  FIG. 4 is a diagram showing a result of combining the four time series data shown in FIG. 3 into one time series data by fitting to the general solution. As shown in FIG. 4, the four time series data are connected very smoothly.

As described above, in the present embodiment, when the running resistance of the vehicle is calculated using the running resistance calculation device 14 that is a computer, the running speed ranges determined from the approach speed and the lower limit speed of the vehicle are set to a plurality of speed conditions different from each other. Therefore, the measuring device 12 outputs time-series data of the vehicle speed with respect to the coasting elapsed time when the vehicle is coasting on the same road surface. Then, the travel resistance calculation device 14 acquires time-series data of the vehicle speed with respect to the coasting travel elapsed time when the vehicle coasts on the same road surface. Thereafter, the running resistance calculation device 14 calculates the running resistance of the vehicle from the time-series data of each speed condition using an equation of motion of the vehicle in which the external force acting on the running vehicle is expressed by a function equation of the vehicle speed. calculate. At this time, in order to combine the time-series data under each speed condition into one time-series data, the time shift amount for shifting the coasting elapsed time and the coefficient in the function formula are all set as unknown parameters. By fitting the time series data of the vehicle speed under the speed condition to the general solution of the vehicle speed of the equation of motion, the parameter value is obtained and the running resistance is calculated. For this reason, the running resistance of the vehicle can be accurately calculated in a wide range of vehicle speeds of 40 km / h to 120 km / h.
In the example shown in FIG. 3, when the drag coefficient Cd is obtained by obtaining the parameter value by fitting each of the four time-series data separately to the general vehicle speed solution of the above equation of motion, the approach speed is 120 km / h. Is 0.332 for time series data of 0.3km, 0.302 for time series data of approach speed 100 km / h, 0.383 for time series data of approach speed 80 km / h, and time series data of approach speed 60 km / h. 0.309, and the drag coefficient Cd varies. On the other hand, in the present embodiment, one drag coefficient or the like can be calculated.

Note that when calculating the running resistance, calculating at least one of the drag coefficient Cd and rolling resistance of the vehicle from the parameter value can improve the aerodynamic characteristics of the vehicle and the rolling resistance of the tire mounted on the vehicle. It is preferable for evaluation. For example, the rolling resistance of the tire is approximately determined by a linear function of the vehicle speed in the running resistance of the vehicle.
In addition, since the functional equation in which the running resistance depends on the vehicle speed v is a quadratic polynomial of the vehicle speed v, the drag coefficient Cd and the rolling resistance can be obtained using a simpler functional equation. preferable.
Furthermore, the speed condition is determined such that at least one of the vehicle speed ranges in the plurality of speed conditions partially overlaps with the other one of the speed ranges. This is preferable from the viewpoint of fitting. For example, the time series data under the speed condition of the approach speed of 120 km / h is 120 km / h, for example, 95 km / h is the lower limit speed, and the time series data under the speed condition of the approach speed of 100 km / h is from 100 km / h, and 100 km It is preferable that the vehicle speeds overlap in the range of / h to 95 km / h from the viewpoint that the running resistance of the vehicle can be calculated with higher accuracy. It is more preferable that such overlapping of vehicle speeds is determined in all speed conditions.

Further, the vehicle speed v is, for example, a relative speed with respect to the road surface of the vehicle, for example, a speed measured by a GPS speedometer. When measuring the vehicle speed v, the traveling resistance calculation device 14 acquires the wind speed data when the vehicle travels, and further uses the result of correcting the time-series data with the wind speed data, to the general solution described above. It is preferable that the running resistance is calculated by determining the value of the parameter by performing the fitting in view of obtaining the running resistance with higher accuracy.
The time series data of the vehicle speed v is corrected by the wind speed data. When the wind is a head wind that flows from the front to the rear in the traveling direction of the vehicle, the speed of the wind is added to the vehicle speed v. In the case of tailwind flowing from the rear toward the front, the wind speed is subtracted from the vehicle speed v. Further, when the wind is a wind that flows in an oblique direction with respect to the vehicle traveling direction, the wind speed component along the vehicle traveling direction in the wind speed data is used for the addition or subtraction described above.
When measuring the wind speed, it is preferable from the viewpoint of calculating a highly accurate running resistance that a plurality of anemometers are arranged along the road surface and wind speed data is acquired when the vehicle passes through each anemometer. Of course, the wind speed may be measured at one place on the road surface, and the time series data of the vehicle speed v may be corrected using the measurement result.
When measuring the vehicle speed v with a differential pressure gauge or anemometer fixed in front of the vehicle, the time-series data of the vehicle speed v output from the differential pressure gauge or anemometer includes wind speed data. There is no need to make the above correction to take wind speed into account. In this respect, it is preferable to measure the vehicle speed v with a differential pressure gauge or an anemometer because the correction is not performed.

  The measuring device 12 outputs at least one of a tire temperature during traveling of the vehicle, a road surface temperature during traveling of the vehicle, or an air temperature during traveling of the vehicle as temperature data, and the traveling resistance calculating device 14 performs measurement. The above temperature data may be acquired. When the running resistance calculation unit 18 calculates the running resistance, a coefficient representing the rolling resistance, for example, b and c, of the running resistance, for example, is calculated, and the calculated coefficients b and c are corrected with the temperature data to obtain a predetermined temperature. It is preferable to calculate the rolling resistance at. For the temperature data, for example, a sensor for measuring the temperature of air in the tire is provided at the transmitter of the tire internal pressure alarm system provided in the tire cavity area surrounded by the tire and the rim, and the temperature measured by this sensor is provided. Is transmitted, and the data acquisition unit 16 can acquire the temperature data. Moreover, the data acquisition part 16 may acquire the result of having measured the temperature of the tire surface using a well-known temperature sensor. Moreover, the data acquisition part 16 may acquire the result of having measured the temperature of the road surface using the well-known temperature sensor. As described above, the temperature data is taken into consideration when calculating the rolling resistance because the temperature dependence of the rolling resistance is large.

  Thus, when calculating rolling resistance with high accuracy, it is preferable to correct the coefficients b and c based on temperature data. Such correction can be performed as follows. That is, a change in rolling resistance with respect to the running speed of the tire is obtained by changing the room temperature and drum surface temperature in various ways using an indoor drum testing machine or the like in advance, and the change in rolling resistance with respect to the running speed is expressed by a linear expression b of the running speed. The coefficients b and c are obtained by regression with xv + c. Furthermore, in order to express the temperature dependency of the obtained coefficients b and c, the coefficients b and c are expressed by a linear expression of temperature. For example, b = α · T + β and c = γ · T + δ (α, β, γ, and δ are constants). Using the linear equation of such temperature, the values of the coefficients b and c obtained from the time-series data of the vehicle speed when the vehicle is coasting according to the present embodiment are corrected to the coefficients b 'and c'. For example, when the predetermined temperature is T ′ and the measurement temperature is T, the coefficients b and c are set according to b ′ = b + α · (T′−T) and c ′ = c + γ · (T′−T). to correct.

  The travel resistance calculation method, the travel resistance measurement method, and the travel resistance calculation apparatus according to the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. Of course, improvements and changes may be made.

DESCRIPTION OF SYMBOLS 10 Running resistance calculation system 12 Measuring device 14 Running resistance calculation apparatus 16 Data acquisition part 18 Running resistance calculation part 20 Output device

Claims (11)

A running resistance calculation method for calculating running resistance of a vehicle using a computer,
The computer obtains time-series data of vehicle speed with respect to the elapsed time of coasting when the vehicle coasts on the same road surface according to multiple speed conditions with different traveling speed ranges determined from the approach speed and lower limit speed of the vehicle And steps to
The computer calculates at least a running resistance of the vehicle from time-series data of each speed condition using an equation of motion of the vehicle in which an external force acting on the running vehicle is expressed by a function equation of a vehicle speed; Have
When calculating the running resistance, the time shift amount for shifting the coasting running elapsed time in order to combine the time series data under each speed condition into one time series data, and the coefficient in the function formula are values. By fitting the time series data of the vehicle speed under all the set speed conditions to the general solution of the vehicle speed of the equation of motion as an unknown parameter, the value of the parameter is obtained and the running resistance is calculated. The running resistance calculation method characterized by the above-mentioned.   The travel resistance calculation method according to claim 1, wherein, when calculating the travel resistance, at least one of a drag coefficient and a rolling resistance of the vehicle is calculated from the value of the parameter.   The running resistance calculation method according to claim 1, wherein the functional expression is a second-order polynomial of vehicle speed.   The speed condition is determined such that at least one of the travel speed ranges in the plurality of speed conditions partially overlaps with one of the other travel speed ranges. The running resistance calculation method according to any one of the above. The vehicle speed is a relative speed with respect to the road surface of the vehicle,
The computer obtains wind speed data when the vehicle is running,
5. The running resistance according to claim 1, wherein the computer performs fitting to a general solution of a vehicle speed of the equation of motion using a result obtained by correcting the time series data with the wind speed data. Calculation method. A vehicle running resistance measuring method,
The measuring device outputs time-series data of vehicle speed with respect to the coasting elapsed time when the vehicle coasts on the same road surface according to multiple speed conditions with different traveling speed ranges determined from the approach speed and the lower limit speed of the vehicle And steps to
A computer acquiring the time-series data;
The computer calculating at least a running resistance of the vehicle from time-series data of each speed condition using an equation of motion of the vehicle in which an external force acting on the vehicle is expressed by a function equation of a vehicle speed. And
When calculating the running resistance, the time shift amount for shifting the coasting running elapsed time in order to combine the time series data under each speed condition into one time series data, and the coefficient in the function formula are values. By fitting the time series data of the vehicle speed under all the set speed conditions to the general solution of the vehicle speed of the equation of motion as an unknown parameter, the value of the parameter is obtained and at least the running resistance is obtained. A running resistance measuring method characterized by calculating.   The travel according to claim 6, wherein the speed condition is determined such that at least one travel speed range partially overlaps one other travel speed range among the travel speed ranges in the plurality of speed conditions. Resistance measurement method. The vehicle speed is a relative speed with respect to the road surface of the vehicle,
The computer obtains wind speed data when the vehicle is running,
The travel resistance measuring method according to claim 6 or 7, wherein the computer calculates the travel resistance by obtaining the parameter value using a result obtained by correcting the time series data with the wind speed data. The measuring device outputs, as temperature data, at least one of a tire temperature during travel of the vehicle, a road surface temperature during travel of the vehicle, or an air temperature during travel of the vehicle,
The computer obtains the temperature data;
9. When calculating the running resistance, a rolling resistance at a predetermined temperature is calculated by calculating a coefficient representing a rolling resistance of the running resistance and correcting the calculated coefficient with the temperature data. The running resistance measuring method according to any one of the above.   The running resistance measuring method according to any one of claims 6 to 9, wherein the running resistance is calculated under conditions relating to a plurality of vehicles having different tires attached to the vehicle. A running resistance calculation device for calculating running resistance of a vehicle,
An acquisition unit that acquires time-series data of vehicle speed with respect to a coasting traveling elapsed time when the vehicle coasts on the same road surface according to a plurality of speed conditions having different traveling speed ranges determined from a vehicle approach speed and a lower limit speed. When,
This is a part that calculates at least the running resistance of the vehicle from the time series data of each speed condition using the equation of motion of the vehicle in which the external force acting on the running vehicle is expressed by a function equation of the vehicle speed. The time shift amount for shifting the coasting elapsed time and the coefficient in the function expression are parameters whose values are unknown, in order to combine the time series data under the conditions into one time series data. A running resistance calculation unit that obtains the value of the parameter to calculate the running resistance by fitting the time series data of the vehicle speed to a general solution of the vehicle speed of the equation of motion. A running resistance calculation device.

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