JP4893193B2 - Chassis dynamometer controller - Google Patents

Description

  The present invention relates to a controller for a chassis dynamometer (CHDY), and particularly to a running resistance setting technique for a test vehicle.

  In recent years, as a part of global warming countermeasures, improvement of fuel efficiency and reduction of exhaust gas have been demanded, and hybrid vehicles incorporating innovative technologies to overcome this are becoming the mainstay of the lineup of automobile manufacturers. Cars are entering the practical range. In order to develop these automobiles, there is a demand for a test facility that can perform fuel consumption and exhaust gas tests with high accuracy, reproducibility, and a simple setting method.

The fuel consumption and exhaust gas tests of automobiles have been tested using a chassis dynamometer that can reproduce the running conditions indoors from the viewpoint of being unaffected by climate, weather, and the like.
Chassis dynamometers have already been installed by various automobile manufacturers, and are being used by automobile manufacturers to measure fuel consumption and exhaust gas of new models.

  FIG. 12 shows a configuration example of an exhaust gas test system using a chassis dynamometer. The driving wheels of the test vehicle 1 are placed on a roller 2, and a dynamometer (not shown) is coupled to the roller 2 as a load, and the running resistance of the test vehicle is controlled by the control panel 3. The exhaust gas collection device 4 performs flow path formation and intake for passing exhaust gas from the test vehicle 1 through various exhaust gas sensors. As the exhaust gas measuring device, a direct exhaust gas measuring device 5 and other various exhaust gas measuring devices 6 to 8 are installed.

  These various exhaust gas measuring devices 5 to 8 and the control panel 3 transmit various measurement information to an operation measurement panel 9 connected by a LAN, and control information for operation of the chassis dynamometer and exhaust gas measurement from the operation measurement panel 9. give.

  In such a system configuration, the test vehicle 1 is driven by a shift operation, an accelerator operation, and a brake operation by a tester (driver) or a drive robot, and data collection, measurement display, and abnormality monitoring such as exhaust gas or fuel consumption in various driving states are performed. A series of processing operations from foul judgment of operation status and various forms to report output can be executed.

  In the chassis dynamometer as described above, the running resistance given as the load on the driving wheel of the test vehicle 1 varies greatly depending on the speed, and the target running resistance corresponding to each speed is controlled by the operation measuring panel 9. It is preset in the board 3. This target running resistance is set as a running resistance corresponding to the detected speed on the chassis dynamometer, as shown in FIG. 13, and this setting is, for example, a run measured on the road for each speed of 60 km to 10 km. Multiple points are set as resistance values, and linear interpolation is performed between the set speed setting points.

As another running resistance setting, for example, there is a method of measuring including a mechanical loss by a coasting test using a chassis dynamometer (see, for example, Patent Document 1).
JP 09-178619 A

  In order to always run the test vehicle on the chassis dynamometer in the same state, it is necessary to give the test vehicle as much running resistance as theoretically (or on the actual vehicle) as much as possible. However, in the conventional method of setting the running resistance, it is difficult to set the running resistance accurately due to the following factors, and the running resistance cannot be verified.

  (1) There is no load adjustment function and reproducibility check (verification function) on the chassis dynamometer in which the target running resistance is set. Therefore, it cannot be confirmed on the chassis dynamometer whether the target running resistance value is accurately transmitted to the test vehicle. Further, when there is a difference, there is no load adjustment function for adjusting the target running resistance and adjusting the control force of the chassis dynamometer.

(2) Although the running resistance of the actual vehicle changes with a smooth curve with respect to the speed, there is a difference from the running resistance of the actual vehicle because there is an inflection point in the interpolation between the multipoint settings of the target running resistance setting. .
(3) When trying to approximate the entire speed area with a smooth curve using the least squares method, an error occurs in the high speed area when interpolation is made to match the low speed area, and conversely in the high speed area. Then, an error occurs in the low speed region, and there may be a problem that the error does not converge within the allowable error range.

  (4) The running resistance value in the speed section (in the case of FIG. 13: speed section of 10 km / h or less and 60 km / h or more) out of the set speed of the target running resistance is a set value of a close value as it is. Due to the parallel movement, the running resistance curve of the actual vehicle is completely different.

  The object of the present invention is to provide the test vehicle with a reproducible running resistance equivalent to that during theoretical (or actual vehicle) running and to measure the chassis dynamometer with respect to the target running resistance. It is an object of the present invention to provide a controller for a chassis dynamometer that facilitates correction processing and verification processing of running resistance.

  In order to solve the above-described problems, the present invention has the following configuration.

(1) A chassis dynamometer control device for testing a test vehicle in which a target running resistance F _RL is set using a chassis dynamometer,
Means for calculating a measured traveling resistance Fm for a speed setting point from a coasting time when the vehicle on the chassis dynamometer is coasted;
Means for calculating an error ε between the measured travel resistance Fm at the speed setting point and the target travel resistance _FRL ;
Means for correcting the braking force Fs of the chassis dynamometer at all speed setting points when the error ε is outside the allowable error range;
The braking force Fs of the chassis dynamometer interpolates the value of the braking force Fs at each speed setting point by interpolation and extrapolation,
Means for interpolating with a spline function between speed setting points;
Of the extrapolation, the range below the minimum speed set point is
The value of braking force at the minimum speed setting point obtained by the spline function and a method of performing linear interpolation between the half of the value of the braking force value and a value of 0 km / h (interpolation processing A), or the lowest value obtained by the spline function Any one of a method of linearly interpolating between the braking force values of the speed setting points as a value of 0 km / h (interpolation process B) or a method of interpolating to 0 km / h with a spline function (interpolation process C) Means for selecting and interpolating a method;
The range beyond the maximum speed set point is interpolated with an extension line of linear interpolation between two points including the braking force value of the maximum set speed point and the braking force value of the set speed point one smaller than the maximum set speed point. Means (interpolation process D);
It is provided with.

( 2 ) means for setting the braking force F _S of the chassis dynamometer of the first coasting operation as the target running resistance F _RL ;
Means for correcting the running resistance of the braking force Fs of the chassis dynamometer for a preset maximum number of corrections when the error ε is outside the allowable error range in the second and subsequent elliptical operations;
When the error ε is within the allowable error range, means for performing a verification process for a preset number of verifications;
It is provided with.

( 3 ) As means for accelerating the vehicle on the chassis dynamometer to a set speed for coasting,
Either a method in which a tester or a drive robot performs an accelerator operation on the test vehicle or a method in which a roller of a chassis dynamometer is rotated is selected.

( 4 ) means for displaying data related to running resistance setting / correction and measurement data in the running resistance correction / verification process;
Means for displaying setting operation items in the running resistance correction / verification process;
Means for displaying an operation button for starting / ending the running resistance correction operation / verification operation;
Means for displaying a measured value, a command value, and a transition of an error every correction number in the running resistance correction operation;
Means for displaying operation buttons for driving from the chassis dynamometer or driving from the test vehicle in driving resistance correction operation / verification operation;
Means for displaying operation buttons for setting the start speed, end speed, and pitch of the coasting section in the running resistance correction operation;
The driving force of the chassis dynamometer is corrected and verified.

( 5 ) The speed-running resistance value pair in which the target running resistance F _RL is set by the table method has means for developing and setting a cubic spline for each speed section to set the running resistance of the test vehicle. It is characterized by correcting and verifying.

As described above, according to the present invention, the running resistance can be easily corrected and verified. Accordingly, it is possible to set an accurate load for measuring fuel consumption, exhaust gas, and the like. Specifically, the following effects (1) to (4) are particularly obtained.
(1) Load adjustment and reproducibility confirmation (verification) on the chassis dynamometer with the target running resistance set can be made, and the control power of the chassis dynamometer can be adjusted and verified within the allowable error range of the target running resistance value. it can.
(2) Since interpolation is performed between the set vehicle speed points with a spline function, the error can be reduced in all speed ranges from low speed to high speed.
(3) About the interpolation method of interpolation and extrapolation, the error can be set with a small and smooth curve by combining various interpolation methods by the running resistance setting method as shown in FIG.
(4) Since various setting items and setting buttons necessary for correcting and verifying the running resistance are displayed on the screen, operability and workability are improved.

  Hereinafter, the present embodiment will be described in detail by itemizing.

(1) Correction and Verification of Running Resistance FIG. 1 is a flowchart of a running resistance correction method and verification showing an embodiment of the present invention. Data is processed and controlled by software using computer resources of the operation measurement panel 9. It is executed by obtaining measurement data of various measuring instruments (torque detector, speed detector, etc.) via the panel 3 and controlling the power absorbing device.

  FIG. 1 shows that after setting the target running resistance, the coasting time method is used to check whether the target running resistance of the chassis dynamometer is within the allowable range, and when the deviation from the allowable range is reached, the running resistance is within the allowable range. It is a processing flow which performs a correction process and a verification process. Among these, the running resistance processing procedure (S1 to S7) and the verification procedure (S8 to S13) will be described below with reference to the control block diagram shown in FIG.

First (S1) of the chassis dynamometer running resistance modifying the value of travel resistance against the coasting speed of the target running resistance F _RL, it outputs as the control value for chassis dynamometer braking force Fs.

At this time, since the chassis dynamometer braking force Fs is given only by data (points) for each speed setting point, each speed setting is performed by using the interpolation and extrapolation methods of the later-described items (4) and (5). Interpolation is performed between points. The target travel resistance F _RL is a value set by a preset theoretical value (or travel resistance by actual vehicle measurement) or the like, and is not corrected in the procedure of the present invention.

  (S2) Next, the chassis dynamometer or the test vehicle is accelerated to reach the set test speed, and then the coasting operation is started. From the coasting time ΔT measured at this time and the speed section ΔV of the elliptical time measurement, the measured running resistance Fm for each coasting speed (set speed point) is calculated by the following calculation.

  However, the start vehicle speed and the end vehicle speed of the speed section ΔV of the elliptical time measurement are determined by the maximum speed, the minimum speed, and the measurement pitch described in (3i) “Speed section setting” described later.

(S3) for each coasting speed, measured running resistance Fm, calculates an error ε from the target running resistance F _RL. This error ε is obtained by the following calculation, and for each coasting speed (set speed point), the measured running resistance Fm, the braking force Fs (the first time is the same value as F _RL ), the coasting time ΔT, and the error ε The data is stored as a set of data and displayed on the operation measurement panel 9.

  (S4) It is checked whether or not the error ε of all the set speed points from the maximum speed to the minimum speed obtained in the above processing is within an allowable error range required for test accuracy. If there is, the running resistance correction ends, and the process proceeds to the verification process of (S8).

  (S5) In the above check, if even one error ε is outside the allowable error range, the error correction count is incremented (+1).

  (S6) It is checked whether the error correction count is within a preset maximum correction count. If the maximum number of corrections is exceeded, it will not converge and running resistance correction and verification will end as abnormal.

  (S7) The braking force Fs of the chassis dynamometer is corrected, and the process returns to the process S2 to repeat the calculation of the measured running resistance by coasting and the error check. The braking force correction at this time is corrected according to the following equation.

However, since the correction coefficient k converges, a value less than 1 is desirable.
This correction corrects all data of the braking force Fs of the coasting speed with respect to the braking force Fs of the chassis dynamometer in the coasting speed region. The method of interpolating the corrected braking force Fs data for each coasting speed is performed according to the procedure in (6) described later.

Automatic As above, by repeating the steps (S2 to S7) of the running resistance modification, the braking force Fs chassis dynamometer, the error ε of the measured running resistance Fm and the target running resistance F _RL falls within the tolerance error range Will be corrected. This automatic correction can be shifted to the following running resistance verification process only when the total coasting speed error ε is within the allowable error range in the check of the above process (S4).

  (S8) On the screen of the operation measurement panel 9, it is checked whether or not the verification button is clicked. If not, the verification process is terminated.

(S9) When the verification button is clicked, the measured travel resistance Fs is verified. This verification process is performed by the same coasting time method as the process (S2), and verification is performed based on whether or not the measured travel resistance Fm is within an allowable error range with respect to the target travel resistance Ft.
However, the allowable error range at the time of verification can be set to a range (value) different from the allowable error range at the time of running resistance correction in the process (S4).

  (S10) In the verification process, it is checked whether or not the error ε is within the allowable error range. If there is data outside the allowable error range, the process returns to the process (S2) and again with the current chassis dynamometer braking force. The correction operation is performed, or the verification process is terminated as it is. Whether to return to the process (S2) to correct the running resistance or to end the verification process can be arbitrarily selected by the selection operation unit SW.

  (S11) When the error ε is within the allowable error range, the number of verifications is incremented (+1).

  (S12) It is checked whether or not the number of verifications reaches a preset number of verifications. If the number of verifications is within the number of verifications, the process returns to the verification process (S9) and the verification process is performed again. If no verification error range is found in the set number of times of verification processing, the running resistance correction / verification ends.

  By correcting and verifying the running resistance in the above processing procedures (S1 to S13), it is possible to verify the correction function and reproducibility of the running resistance on the chassis dynamometer in which the target running resistance is set. The measured running resistance and the target of the chassis dynamometer The running resistance can be compared and adjusted within an allowable error range to confirm the operation. That is, it is possible to easily set the running resistance with accuracy and reproducibility necessary for fuel consumption and exhaust gas measurement.

(2) Running resistance correction / verification screen The operation measurement panel 9 has a man-machine interface in the running resistance correction / verification process shown in FIG. 1 and related data such as running resistance setting / correction and measurement data, operation buttons, etc. Can be displayed on a single screen. Hereinafter, each display / operation button will be described in detail.

(2a) Status Display FIG. 3 shows a screen display example of the operation measurement panel 9 at the time of running resistance correction / verification. In this screen, the status display item A displays the message in Table 1 as the running resistance correction / verification result and stores it together with the running resistance value.

  In the status display item B, the message of Table 2 is displayed. This message is not stored with the running resistance value, but the current state is always displayed.

(2b) Travel resistance correction table In the column C in FIG. 3, by setting multi-point travel resistance, the following related data matching the data is displayed as a table.

  Start V [km / h]: Measurement section start speed set in the coasting section.

  End V [km / h]: Measurement section end speed set in the coasting section.

  -Target CD [s]: The coasting time set in creating the target running resistance is displayed for each of the above speeds.

  Target Ft [N]: The running resistance set in the creation of the target running resistance is displayed for each of the above speeds.

Target output [kW]: Output value calculated from target running resistance Ft and speed is displayed for each speed. Column D in FIG. 3 displays the following items by starting corrective driving and coasting time measurement. . In addition, the following items can display measurement data for multiple times at once, and even during measurement, multiple data can be displayed at the same time with vertical and horizontal scroll bars (eg, measurement for the first to third times during the fourth operation) Can be referred to). Further, during the correction operation, an average value for n corrections is displayed, and during the verification operation, an average value for m verifications is displayed. Moreover, when stopped during the n (m) coasting time measurement, the measurement value including the n (m) coasting time is not included in the average value. In addition, the average value disappears at the time of acceleration of 1 coasting time measurement, and is calculated and redisplayed when it is finished.

  -Average CD [s]: The average value of the coasting time (CD) measured n times is displayed.

  Average Fm [N]: The average value of the measured running resistance for n times is calculated and displayed.

  Average error [N]: An error value between the average Fm and the target running resistance is displayed.

  In the column E in FIG. 3, the following items are displayed and updated every time the coasting time measurement is completed. In particular, the difference between the measured travel resistance and the target travel resistance is displayed for each measurement. Further, when correction is performed and verification is performed after the final speed, the cell background color is color-coded in order to distinguish the correction data from the verification data. In the case of NG, the error display cell background is color-coded.

  ・ Date: Displays the date of correction and verification.

  NCD [s] / nFs [N]: Displays the coasting time (CD) and chassis dynamo dynamometer braking force (Fs) measured at the nth time.

  NFm [N]: The running resistance is calculated from the n-th measured coasting time using the above formula and displayed.

  N error [%]: Displays an error between the n-th measured running resistance nFm and the target running resistance.

  N output [kW]: Output is calculated from the measured running resistance nFm measured n times and displayed.

(2c) Display of running resistance name, comment and equivalent inertia weight The running resistance name and comment in column F in FIG. 3 display the file name and comment when saved in the [Create target running resistance] window. The equivalent inertia weight is the value set in the [Create target running resistance] window.

(3) Screen setting for running resistance correction / verification Each setting item to be set during running resistance correction / verification is as follows.

(3a) Allowable error range An allowable error range is set in the column G in FIG. At this time, the allowable error range at the time of running resistance correction and verification can be arbitrarily set. With respect to this setting, as described above, when the measured travel resistance and the target travel resistance are within the maximum allowable error range at the time of correction, the correction operation ends. In addition, when it does not fall within the allowable range, the correction operation is repeated up to the maximum number of correction times, and when the maximum correction number of times is repeated, the correction operation ends. If verification is checked, continue verification.

(3b) Maximum number of corrections The maximum number of corrections can be set in the column H in FIG. When making corrections, check and set the number of times. If the result of correction within the set number of times does not fall within the allowable range, the correction operation is stopped.

(3c) Number of verifications The number of verifications is set in the column I in FIG. When performing verification, check and set the number of times. During the verification process, the braking force Fs of the chassis dynamometer is not corrected, and only the coasting time ΔT is measured for the number of times.

(3d) Start of correction / verification operation A start button for starting the running resistance correction operation or the verification operation is displayed in a column J in FIG. By this button operation, the chassis dynamometer is accelerated at a constant acceleration, and after reaching the set speed, the coasting operation is performed by switching to the running resistance control mode and the coasting time is measured.

  The start button is provided with a new start and a continuous start, and the new start button is corrected or verified from the target running resistance.

  The operation of the continuous start button has the following functional configuration.

  ・ Starts continuously from the last state of last run resistance correction / verification.

  -If there is data only halfway through the nth stop after the last coasting time measurement, the nth is overwritten when the start is continued. The continuous start is a function that can be corrected or verified by continuing from the last corrected value of the previous value or the verification value.

  ・ Displays a confirmation message for clearing the measurement data display at the continuous start. Select “Yes” to clear the measurement data and verify using the previous value. If “No” is selected, nothing is done.

(3e) Stop of correction / verification operation A stop button is displayed in a column K in FIG. This button can be used when the measurement is stopped during the coasting time measurement of the correction operation or the verification operation. When the driving method displayed in the column L is a chassis dynamometer, the chassis dynamometer is decelerated at a constant deceleration from the speed when the coasting time measurement is stopped and then stopped. When the driving method is a vehicle, it waits for the vehicle to stop.

(3f) Transition graph display A transition graph display button is displayed in the column M in FIG. By this button operation, the window shown in FIG. 4 is opened, and the transition of the measured value, command value, and error for each correction count is displayed. When the window is opened, the last value of the number of corrections is displayed at the bottom of the display area. The following items are displayed.

  -Number of rows (= coasting time measurement count integrated value): Correction or verification count integrated value.

  Speed at maximum error: Speed [km / h] and error [%] at which the error between measured travel resistance and target travel resistance is maximum.

  -Maximum error: Error [%] in which the error between the measured travel resistance and the target travel resistance is maximized.

  Two graphs are displayed, and two Y-axis scales are drawn and superimposed on the same graph. In the graph 1, the following items are individually displayed in arbitrary colors and displayed in a graph for easy viewing, and item names are displayed for the colors.

・ Target running resistance (Ft)
・ Measured running resistance (Fm)
-Braking force (Fs) of chassis dynamometer
・ Vehicle Loss (Fvehicle)
In graph 2, the error is displayed by linear interpolation.

  Next, when the graph setting button in FIG. 4 is clicked, the window shown in FIG. 5 is opened and the following items can be set.

  In Fig. 5, the display range shows the minimum and maximum values of running resistance on the Y axis, and the minimum and maximum values of error, and the maximum value of speed on the X axis (X axis is related to running resistance, error and common scale). Is displayed.

  The following items are provided for the presence of display items and color settings.

・ Target running resistance (Ft)
・ Measured running resistance (Fm)
・ Chassis dynamometer braking force (Fs)
・ Vehicle Loss (Fvehicle)
Error When the setting button for specifying the graph color in FIG. 5 is clicked, the window in FIG. 6 is opened and the graph background color setting and the graph grid color setting can be made. When the OK button in FIG. 5 is operated, the scale change value is saved, the display is returned to the previous window, and the graph is redisplayed with the change scale and color. When the cancel button in FIG. 5 is operated, all set contents are discarded and the previous window is returned. When the apply button in FIG. 5 is operated, the scale change value is saved, and the graph is redisplayed with the change scale and color.

(3g) Selection of driving method The driving method shown in column L of FIG. 3 can be selected from the following two methods.

CHDY: Driven from the chassis dynamometer. In this case, when the vehicle is started, the vehicle is accelerated by the speed control from the dynamo to the coasting measurement set vehicle speed + the arbitrary vehicle speed. The arbitrary vehicle speed is, for example, 5 to 15 km / h. Vehicle: Driven from a test vehicle. In this case, when the vehicle starts, the vehicle is accelerated by the operation of the tester or the drive robot. At this time, the dynamo side waits until it reaches the coasting measurement maximum vehicle speed + arbitrary vehicle speed, and measures the coasting time.

(3h) Display item change When the display item change button shown in the column N of FIG. 3 is clicked, as shown in FIG. 7, the running resistance correction / verification display item window is opened and only the items checked for the measurement data are displayed. Internal measurement data stores and saves all items displayed in the running resistance correction / verification display item window, and data after measurement is not lost.

(3i) Speed section setting When the speed section setting button shown in the column O of FIG. 3 is clicked, the speed section setting window shown in FIG. 8 is opened, and the start speed, end speed, and pitch of the coasting section can be set.

  For example, when the maximum speed: 50 km / h, the minimum speed: 10 km / h, and (pitch: 10 km / h) are input, the following values are displayed for the start speed and end speed of the window shown in column C of FIG. The speed setting points at this time are 10 km / h, 20 km / h, 30 km / h, 40 km / h, and 50 km / h. The pitch is the same as the speed section of the [Create target running resistance] window and is fixed.

・ Starting speed: 55, 45, 35, 25, 15 (km / h)
End speed: 45, 35, 25, 15, 5 (km / h)
These setting restrictions are as follows.

-Restrictions on maximum speed and minimum speed: (rated speed-pitch) ≥ maximum speed-Number of coasting time measurement speeds n: (maximum speed-minimum speed) / (pitch + 1)
-Coasting time measurement speed Vm: Maximum speed-Pitch x m, where m is 0 to n-1. Vm is limited to Vm ≧ minimum speed.

  The coasting time measurement section Vmeas: Vmeas = Vm + pitch / 2 to Vm−pitch / 2.

  If the speed section is changed by clicking the [OK] button, the [Confirmation] window is displayed. When the speed section is changed, the measurement data is deleted. The [Cancel] button discards all the set contents and returns to the previous window. Therefore, the running resistance correction / verification screen display and the setting screen make sure the test state grasped by the chassis dynamometer tester reliably and easily, and facilitate the setting operation.

(4) Interpolation processing for running resistance and mechanical loss interpolation and extrapolation Interpolation between speed setting points for running resistance is expected within the range of the data based on the value of the speed setting point. Find a numerical value, for example, by interpolation using a spline function, or extrapolate (based on the value of the speed setting point, find the expected value outside that data range, for example, extrapolation by linear interpolation) It is carried out.

  Further, the range below the minimum speed is the following interpolation processing A to C, the interpolation processing above the maximum speed is performed by the method of interpolation processing D below, and the difference in the method of setting each running resistance (FIG. 9) Select with, and use properly.

  Interpolation A: As shown in FIG. 10A, up to 10 km / h, the spline extension is set to a value of 10 km / h, and 0 km / h is set to 1/2 of the value of 10 km / h. 0 to 10 km / h is linear interpolation between two points.

  Interpolation B: As shown in FIG. 10B, up to 10 km / h, the spline extension is set to a value of 10 km / h, and the value of 10 km / h is set to a value of 0 km / h. Linear interpolation is performed between 0 km / h and 10 km / h.

  Interpolation process C: As shown in FIG. 10C, a spline including data of 0 to 10 km / h or less is extended to 0 km / h.

  Interpolation process D: As shown in FIG. 10D, an extension line of linear interpolation between two points including the set maximum speed value is used.

(5) Interpolation processing by interpolation and extrapolation during the first coasting operation of running resistance correction / verification ・ Running resistance correction / verification from target running resistance: First chassis dynamometer system for correction / verification using chassis dynamometer Interpolation of target driving resistance of power is output as it is.

  For example, in the case of the ABC method shown in FIG. 9 (a method of approximating running resistance by a quadratic equation), the entire speed range is interpolated by a coefficient of the quadratic equation.

  -Correction / verification of travel resistance from target travel resistance: If it is within the allowable range at the first correction / verification by the chassis dynamometer, the chassis dynamometer braking force takes over the interpolation processing of the target travel resistance.

  For example, the chassis dynamometer braking force when the target running resistance is set by the ABC method and falls within the allowable range by running resistance correction / verification is the running resistance set value by the ABC method itself.

  Therefore, the load can be set with a smooth curve as with the target running resistance, and the load reproducibility is improved. Further, even in a speed section outside the set speed range of the target travel resistance, the travel resistance approximate to the actual vehicle resistance can be bundled, and the reproducibility of the target travel resistance equivalent to the actual vehicle becomes high.

(6) Setting the target running resistance to the control panel The running resistance setting is set to 3 for each coasting speed set by the table method (method of inputting paired data of each coasting speed and traveling resistance (or coasting time)). The control panel 3 is set by developing the following spline.

For example, as shown in FIG. 11A, when the target running resistance value [N] for each 10 km / h is obtained from the coasting speed range of 50 km / h to 10 km / h, the (b) of FIG. As shown, an interpolation curve approximated by a cubic expression Fn (= An + BnV + CnV ² + DnV ³ ) of a spline function is created for each speed section and set as a target running resistance value.

  The coefficients A to D of this cubic equation are as shown in the following table. In the 0 to 10 km / h section, linear interpolation is performed and only the A term of the cubic equation is obtained. Also, from the speed exceeding 50 km / h to the rated speed, there are only A and B terms because of linear interpolation.

  In this embodiment, the coasting speed range is set to 50 km / h to 10 km / h and the speed pitch is set to 10 km / h. However, the coasting speed range and the speed pitch may be arbitrary values.

  The target running resistance set in this way is determined by the control panel in the fuel economy / exhaust gas test, which speed section the detected speed falls in, and the detected speed is substituted into the equation corresponding to the speed section to obtain the running resistance value. Is calculated and output. In this embodiment, the spline function has been described using a cubic expression, but a function of cubic or higher may be used.

The processing flow of running resistance correction and verification which shows embodiment of this invention. The block diagram which shows embodiment of this invention. An example of the display screen of the operation measurement panel when running resistance is corrected and verified. Screen example of transition graph display. Graph setting screen example. Graph background color setting and graph grid color setting screen example. Screen example of running resistance correction / verification display items. Speed section setting screen example. Examples of load setting method and interpolation method for running resistance. Example of interpolation processing for minimum speed range and maximum speed range. Example of setting the target running resistance to the control panel. Configuration example of an exhaust gas test system using a chassis dynamometer. Setting example of target running resistance.

Explanation of symbols

1 Test Vehicle 2 Roller 3 Control Panel 4 Exhaust Gas Collecting Device 9 Operation Measurement Panel

Claims (5)

A chassis dynamometer control device for testing a test vehicle with a target running resistance _FRL set by a chassis dynamometer,
Means for calculating a measured traveling resistance Fm for a speed setting point from a coasting time when the vehicle on the chassis dynamometer is coasted;
Means for calculating an error ε between the measured travel resistance Fm at the speed setting point and the target travel resistance _FRL ;
Means for correcting the braking force Fs of the chassis dynamometer at all speed setting points when the error ε is outside the allowable error range;
The braking force Fs of the chassis dynamometer interpolates the value of the braking force Fs at each speed setting point by interpolation and extrapolation,
Means for interpolating with a spline function between speed setting points;
Of the extrapolation, the range below the minimum speed set point is
The value of braking force at the minimum speed setting point obtained by the spline function and a method of performing linear interpolation between the half of the value of the braking force value and a value of 0 km / h (interpolation processing A), or the lowest value obtained by the spline function Any one of a method of linearly interpolating between the braking force values of the speed setting points as a value of 0 km / h (interpolation process B) or a method of interpolating to 0 km / h with a spline function (interpolation process C) Means for selecting and interpolating a method;
The range beyond the maximum speed set point is interpolated with an extension line of linear interpolation between two points including the braking force value of the maximum set speed point and the braking force value of the set speed point one smaller than the maximum set speed point. Means (interpolation process D);
An apparatus for controlling a chassis dynamometer, comprising: Means for setting the braking force F _S of the chassis dynamometer of the first coasting operation as the target running resistance F _RL ;
Means for correcting the running resistance of the braking force Fs of the chassis dynamometer for a preset maximum number of corrections when the error ε is outside the allowable error range in the second and subsequent elliptical operations;
When the error ε is within the allowable error range, means for performing a verification process for a preset number of verifications;
The chassis dynamometer control device according to claim 1 , further comprising: As a means of accelerating the vehicle on the chassis dynamometer to a set speed for coasting,
The chassis dynamometer according to claim 1 or 2 , wherein either a method in which a tester or a drive robot performs an accelerator operation on the test vehicle or a method in which a roller of the chassis dynamometer is rotated is selected. Control device. Means for displaying data related to running resistance setting / correction and measurement data in the running resistance correction / verification process;
Means for displaying setting operation items in the running resistance correction / verification process;
Means for displaying an operation button for starting / ending the running resistance correction operation / verification operation;
Means for displaying a measured value, a command value, and a transition of an error every correction number in the running resistance correction operation;
Means for displaying operation buttons for driving from the chassis dynamometer or driving from the test vehicle in driving resistance correction operation / verification operation;
Means for displaying operation buttons for setting the start speed, end speed, and pitch of the coasting section in the running resistance correction operation;
The chassis dynamometer control device according to claim 1 , wherein the chassis dynamometer driving force is corrected and verified. The speed-running resistance value pair in which the target running resistance _FRL is set by the table method has means for developing and setting a cubic spline for each speed section to correct the running resistance of the test vehicle. 5. The chassis dynamometer control device according to claim 1 , wherein verification is performed.