JPS6317172B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a running resistance control device for a chassis dynamometer, 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 speed and a speed detector 6 for detecting 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 mechanical loss setting value is subtracted from the setting value of the running resistance setting device 7 or the mechanical loss is set to the output of the torque meter 5. Add values. 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 setting devices 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 mechanical loss for a dynamometer that does not have a driving force, such as an eddy current type dynamometer, connect switches 9 and 10 in Fig. 1 to contact b side, and set running resistance setting device 7 and mechanical loss. Setting device 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 setting 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 T 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. This measured value is associated with the speed and setter 11
Set to .

(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 based on basic data such as suction negative pressure in actual driving, and set car 1 at each speed same as in actual driving. Operate and compare each suction negative pressure measurement with basic data.
If the comparison results are different, it is determined which of the A term, B term, and C term is larger or smaller, 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.

An object of the present invention is to provide a running resistance control device that can automatically set running resistance settings with mechanical loss compensation capability without requiring mechanical loss settings, and that can obtain highly accurate set values in a short time. It is on offer.

<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; A control unit controls the torque of the device by comparing the setting value of the command unit with the torque detection value of the power absorption device, and calculates the actual running resistance from the time measurement data for each speed section while the test vehicle coasts on the road. a setting calculation unit that calculates, an automatic determination unit that calculates running resistance by measuring time for each speed section in a coasting test of a test vehicle using a dynamometer, and determines whether it matches the calculation result of the setting calculation unit; and a correction calculation section that corrects the running resistance and provides a new setting value of the running resistance command section when a matching determination is not obtained in the discriminating section.

<Operation> With this configuration, the actual running resistance is calculated from the time data of the test vehicle coasting on the road, and the running resistance is repeatedly corrected until a match is obtained between this data and the running resistance determined from the coasting test using the dynamometer. By automatically setting the running resistance and controlling this running resistance command by comparing it with the torque detection value of the torque meter, running resistance control including mechanical loss can be obtained.

<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 designated by the same reference numerals. Running resistance command unit 20
Similar to the running resistance setter 7 shown in FIG. 1, the running resistance setting device 7 gives a running resistance setting value according to the speed, but is configured so that the setting output can be automatically corrected. This set output is directly compared with the output of the torque meter 5 and
absorption torque is controlled. This automatic setting value correction of the running resistance setting device 20 includes basic data 21, a setting input section 22, a setting calculation section 23, an automatic discrimination section 24,
The correction calculation unit 25 performs automatic correction including mechanical loss compensation. The basic data 21 is each speed section and its time measurement value during coasting of the test vehicle on an actual road, and this basic data is stored in the setting input section 22. The basic data of the setting input section 22 is sequentially given as running resistance calculation data by the setting calculation section 23, and the calculation section 23 inputs speed sections (V ₀ -V ₁ , V ₁ -V ₂ , . . . ) and their times. ( _T1 ,
T ₂ , ...), calculate the actual running resistance F _RR for each speed section using equation (3) below.

F _RR = W/g×V _k −V _k+1 /3.6t ...(3) The automatic discrimination unit 24 determines the actual running resistance F _RR outputted as the calculation result from the setting calculation unit 23 and the actual running resistance F RR based on the F _RR . The time measurement value obtained from the time determination unit 12 during the first coasting and the running resistance F _RC calculated in the same manner as in equation (3) from the speed classification data are compared, and the running resistance F _RR of both is calculated.
Determine whether or not F _RC matches. This determination result, the coasting time t _R during actual driving used to calculate the running resistances F _RR and F _RC , and the coasting time t _C detected by the time measurement unit 12 are provided to the correction calculation unit 25 . When a matching signal between the running resistances F _RR and F _RC is given, the correction calculation unit 25 transmits the running resistance F _RC to the running resistance command unit 2 .
0 as the final setting value and send a signal to the command unit 20.
Memorize F _RC . In the case of a mismatch between the running resistance F _RR and F _RC , the correction calculation unit 25 calculates the set running resistance F _RC subjected to automatic determination using the coasting time t _R of the road data and the coasting time t _C by F _RC according to the following formula. Perform correction calculation. _K1 to _K3 are constants.

F _RC ′=F _RC ×K ₂ t _C +K ₃ t _R /K ₁ t _R …(4) This corrected running resistance F _RC ′ is calculated by
Measure the time by coasting again as a new setting value of 0, repeat the judgment by the automatic discrimination section 24 and the correction by the correction calculation section, and finally set the setting value in the running resistance command section 20 that matches the actual running resistance. get.

<Effects of the Invention> As described above, according to the present invention, it is possible to easily set the running resistance by automatic correction using actual running data on the road in a short time, and also to directly connect the running resistance command point and the torque meter. Control by butting eliminates the need for mechanical loss settings and enables highly accurate running resistance that also compensates for the mechanical loss.

[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. DESCRIPTION OF SYMBOLS 1... Test vehicle, 2... Roller, 3... Flywheel, 4... Rotating machine, 5... Torque meter, 6... Speed detector, 8... Control unit, 12...
Time measuring section, 20... Running resistance command section, 21...
Basic data, 22...Setting input section, 23...Setting calculation section, 24...Automatic discrimination section, 25...Correction calculation section.

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 compares the setting value of this command unit with the torque detection value of the power absorption device. A control unit that performs torque control of the device, a setting calculation unit that calculates actual running resistance from time measurement data for each speed section during coasting of the test vehicle on the road, and a dynamometer that calculates each speed in the coasting test of the test vehicle. an automatic determination unit that calculates running resistance by measuring time for each section and determines whether it matches the calculation result of the setting calculation unit;
This automatic discrimination section is equipped with a correction calculation section that corrects the running resistance and provides a new setting value for the running resistance command section when a match cannot be determined, and the automatic discrimination section is automatically operated until a match is obtained in the automatic discrimination section. A running resistance control device for a chassis dynamometer, characterized in that a running resistance setting value including mechanical loss is obtained by repeating determination and correction.