JPS6317170B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a running resistance control device for a chassis dynamometer, an engine dynamometer, etc., and particularly to an automatic setting circuit for running resistance.

<Prior Art> A chassis dynamometer makes it possible to test the driving performance of an automobile by using rollers as a virtual road instead of a road and driving the rollers by the automobile. In this case, it is desirable to apply the same load (running resistance) to the roller shaft as when the vehicle is actually running on a road, and to reproduce a state as close as possible to actual running.

FIG. 1 shows a conventional running resistance control device. The roller 2 on which the driving wheels of the test vehicle 1 are mounted is used as a power transmission unit, and the roller 2 is equipped with a flywheel 3 for obtaining the equivalent inertia of the vehicle, a rotating machine 4 as a power absorption device, and a power absorption torque detection device. A torque meter 5 for detecting the speed and a speed detector 6 for detecting the speed are coupled. The running resistance setter 7 outputs the running resistance value corresponding to the detected speed of the speed detector 6 as the set torque of the control unit 8.
The braking torque of the rotating machine 4 is controlled using the output as a feedback amount. At this time, switches 9 and 10
is switched to the contact b side. In this running resistance control, in order to compensate for mechanical loss in the transmission system from the vehicle 1 to the rotating machine 4, the running resistance setting device
The mechanical loss setting value is subtracted from the setting value of , or the mechanical loss setting value is added to the output of the torque meter 5. The mechanical loss set value is given by the setter 11 in association with the speed.

<Problems to be Solved by the Invention> In such a running resistance control device, in order to apply a load as close as possible to actual running in a steady state, it is necessary to set the set values 7 and 11 with high precision. It is difficult to make accurate settings using this method,
Moreover, there was a problem in that it required a lot of time to set up. The conventional setting method will be explained below.

(1) When setting the mechanical loss of a dynamometer that does not have a driving force, such as an eddy current type dynamometer, connect the switches 9 and 10 in Fig. 1 to the contact b side, and set the running resistance setting device 7 and the mechanical loss. Vessel 11
After the rotating machine 4, the flywheel 3, the rollers 2, etc. are accelerated to a maximum set speed _V0 or higher by driving the vehicle 1 with the set value of V0 set to zero, the vehicle 1 is caused to coast. During this coasting, the setting input of the control section 8 is set to zero, and the rotating machine is controlled with the output of the torque meter 5 set to zero. During coasting from high speed to low speed (stop), the speeds V ₀ , V ₁ , V ₂ , . . . are predetermined in stages as shown in Fig. 2.
...The time measuring section 12 measures the time for each section of _VN . For example, the time required to coast and decelerate from speed V ₀ to V ₁ is taken as T ₁ , and the time required from V ₁ to V ₂ is taken as T ₂ . From the time measurements corresponding to these speed sections ΔV, the mechanical loss F _M in each speed section is calculated based on the following formula.

F _M = IW/g×ΔV/3.6t...(1) In equation (1), IW is the set equivalent inertial weight of the mechanical system of the dynamometer, g is the gravitational acceleration, ΔV is each speed category, and t is each This is the time (T ₁ , T ₂ , . . . ) in the speed section ΔV. The mechanical loss setting device 11 associates this calculation result with each speed.
to obtain the mechanical loss setting value according to the speed input signal.

(2) When setting the mechanical loss of a dynamometer with driving force such as a DC mechanical dynamometer, connect the switches 9 and 10 in Fig. 1 to the contact a side, and set the setting value of the speed setting device 13 in stages. Instead, it is driven by the rotating machine 4, and the output of the torque meter 5 in each speed section is detected as mechanical loss. These measured values are associated and set in the setting device 11.

(3) To set the running resistance, since the running resistance is a quadratic curve, the setting device circuit shown in FIG.
The setting output F _R is determined by the setting of the secondary C term setter 16.
get. 17 is a multiplier that takes the speed signal N as a multiplicand and a multiplier input, 18 ₁ to 18 ₃ are adding resistors, and the setting output F _R is expressed by the following formula.

F _R = A + BN + CN ² ... (2) Set the A, B, and C terms of this setting device appropriately from the basic data of the suction negative pressure measurement value during actual driving, and drive the car 1 at each speed same as the actual driving. Compare each suction negative pressure measurement value with the basic data. If the results of this comparison are different, term A, term B,
It is determined which of the C terms is large or small, and any one of the setting devices 14 to 16 is readjusted. If even one of the terms A to C is changed, the entire characteristic F _R will change because the outputs of the setters 14 to 16 are respectively adder circuits. Therefore, the running resistance output FR is compared with the basic data again, and if they do not match, the operation of adjusting one of the setters 14 to 16 is repeated to bring the running resistance output F _R closer to the basic data.

With conventional technology that uses these procedures to set mechanical loss and running resistance, it takes a long time to set up the running resistance, especially since it requires trial and error to obtain set values that are as close as possible to actual driving. However, it is difficult to make accurate approximations. In addition, since the basic data measures running resistance using suction negative pressure as a parameter, even if the basic data is not valid, it is necessary to use that data, and there is a risk of conducting incorrect tests.

An object of the present invention is to provide a running resistance control device that can automatically set mechanical loss settings and running resistance settings, and that can determine the validity of basic data and obtain highly accurate set values in a short time.

<Means for Solving the Problems> In order to achieve the above object, the present invention includes a running resistance command unit that sets the absorption torque of the power absorption device according to the running speed in accordance with the actual running resistance of the test vehicle; Mechanical loss setting means for setting mechanical loss for compensating mechanical loss from the test vehicle to the power absorption device according to the traveling speed, and three or more speeds among the speed and output measurement data of the test vehicle while driving on the road. A data recording section that records absorption torque data by the power absorption device at a point, a coordinate calculation section that calculates the constants of the running resistance equation from the data recorded in this data recording section, and a coordinate calculation section that calculates the constants of the running resistance equation from the data recorded in this data recording section, and calculates the constants calculated by this coordinate calculation section into the actual running resistance characteristics. an automatic determination unit that determines the validity of the
and a coordinate creation unit that creates a running resistance value table according to each speed from the running resistance equation having the constants and sets it in the running resistance command unit when the validity is determined by the automatic determination unit. It is.

<Function> With this configuration, mechanical loss is automatically set according to the running speed of the test vehicle, and running resistance is automatically calculated from the constants of the running resistance equation from three or more road running speeds and absorption torque data, and The validity of constants for resistance characteristics is automatically determined, and a running resistance value table corresponding to each speed is automatically created and automatically set using the constants determined to be valid.

<Embodiment> FIG. 4 is a control circuit diagram showing an embodiment of the present invention. Components that are the same as those in FIG. 1 or have the same functions are indicated by the same reference numerals. The running resistance command section 20 provides a running resistance setting value according to the speed, similar to the running resistance setting device 7 shown in FIG. 1, but is configured to automatically correct the setting output. Similarly, the mechanical loss command unit 21 provides a mechanical loss set value according to the speed, but is configured to automatically correct the set output. The mechanical loss detection section 22 detects the mechanical loss in each speed section from each speed section signal from the time measurement section 12 and the torque detection value of the torque meter 5, and provides the detected value to the mechanical loss command section 21 as a set value. This mechanical loss detection section 22 can also detect mechanical loss from the time measurement value for each speed section by calculating the above equation (1). The mechanical loss calculation section 22 automatically sets the mechanical loss.

The automatic setting of the running resistance command section 20 includes an initial setting section 23, a data recording section 24, a coordinate calculation section 25, an automatic discrimination section 26, an approximation correction section 27, and a coordinate creation section 28.
Prepare. The initial setting unit 23 sets the measured values of each speed V and intake negative pressure P (or braking force F or fuel consumption Q) when the test vehicle is actually driven (as shown in FIG. 5).
The basic data is set as basic data. After this setting, the switches 29 and 30 are set to the states shown in the figure, and the rotating machine 4 is controlled by the automobile 1 at each speed V ₁ , V ₂ , . . .
..., and the recording button 31 is driven to the condition that each set speed of the initial setting section 23 matches the detection speed of the detector 6 and the suction negative pressure P of the initial setting section 23 matches the suction negative pressure of the automobile 1. By manually or automatically operating the above, the data recording unit 24 reads or sets the absorbed torque or braking force F from the torque meter 5 side for each speed. The data recording unit 24 records absorption torque or braking force data for three or more points among each speed of the basic data. These data are inputted to the coordinate calculation unit 25, and the constant term A, the linear term B, and the quadratic term C of running resistance are input.
used for calculation. The coordinate calculation unit 25 calculates the absorption torque or braking force F _R (F) and the speed N in the above equation (2).
From the three simultaneous equations giving (V), constants A, B, C
Calculate. These constants are given to the automatic determination section 26, which determines the validity of the constants based on the following three conditions.

C≧0, B≧0, A>0 In other words, since the running resistance has the characteristics shown in Figure 6a, the constant C≧0 is set so that it does not become an upwardly convex quadratic curve as shown in Figure 6b. As shown in c, it is determined to be monotonically increasing with constant B≧0 so as not to have a pole, and as shown in d, constant A>0 is determined so that the torque does not become negative at zero speed. From these conditions, The validity of the calculated constants A, B, and C is determined.

When the judgment of the automatic discrimination section 26 is found to be valid, the coordinate creation section 28 uses the respective constants A, B, and C to create a table of running resistance values F at each speed V, and sends the table to the running resistance command section. 20 to be memorized. If the judgment of the automatic discrimination section 26 is not justified, the approximate correction section 27 uses two simultaneous equations of the running resistance equations obtained by the coordinate calculation section 25.
calculates the numerical values of constants A and C, and the coordinate creation section 28 creates a running resistance table from an approximate expression based on the running resistance characteristic formula A+ ^CV2 .

The running resistance table created in this manner is used as a set value for the running resistance command unit 20, and running performance is measured by running resistance control according to the speed. In addition,
Another method of data recording in the data recording section 24 is to connect the switch 29 to the contact b side, open the switch 30, directly set the braking force according to the basic data of the initial setting section 23, and then use the torque meter The detected value of 5 can also be recorded in the data recording section 24.

<Effects of the Invention> Therefore, according to the present invention, by recording running resistance data at three points by the data recording unit 24, running resistance can be automatically set according to each speed, and running resistance can be easily set in a short time. It also checks the validity of the running resistance setting, making it possible to set it accurately without erroneous settings. Also, automatic discrimination is set to 2.
Even if the point is approximated and corrected, its validity is not impaired.

Although the case of a chassis dynamometer is shown in this embodiment, it is of course applicable to an engine dynamometer.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing a conventional running resistance control device, Fig. 2 is a diagram showing a coasting time measuring method, Fig. 3 is a conceptual diagram of a running resistance setting device, and Fig. 4 is an example of an embodiment of the present invention. FIG. 5 is a diagram showing basic data, and FIG. 6 is a speed-braking force characteristic diagram for explaining the validity determination of coordinate calculation in the present invention. 1... Test vehicle, 2... Roller, 3... Flywheel, 4... Rotating machine, 5... Tachometer,
6... Speed detector, 8... Control section, 20... Running resistance command section, 21... Mechanical loss command section, 22... Mechanical loss calculation section, 23... Initial setting section, 24... Data recording section , 25... Coordinate calculation section, 26... Automatic discrimination section, 27... Approximation correction section, 28... Coordinate creation section, 31... Data recording button switch.

Claims (1)

[Claims] 1. A running resistance command unit that sets the absorption torque of the power absorption device according to the running speed according to the actual running resistance of the test vehicle, and a running resistance command unit that sets the absorption torque of the power absorption device according to the running speed, and a running resistance command unit that sets the absorption torque of the power absorption device according to the running speed. A mechanical loss setting means that is set according to the speed, a data recording unit that records absorption torque data by the power absorption device at three or more speed points among the speed and output measurement data of the test vehicle running on the road, and this data. There is a coordinate calculation unit that calculates the constants of the running resistance equation from the data recorded in the recording unit, an automatic judgment unit that judges the validity of the calculated constants of this coordinate calculation unit with respect to the actual running resistance characteristics, and a validity check by this automatic judgment unit. a coordinate creation section that creates a running resistance value table according to each speed from the running resistance equation having the constant when determined and sets it in the running resistance command section; A running resistance control device for a dynamometer, characterized in that the running resistance of a test vehicle is controlled by a set value of a means.