JP3049887B2 - Dynamometer drive - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dynamometer for testing the transient performance of a transmission such as an automobile.

[0002]

2. Description of the Related Art To test the transient behavior of a transmission for a vehicle such as an automobile during shifting, a dynamo having the same performance (responsiveness, torque, inertia, etc.) as an engine serving as a drive source of the transmission is used. A meter is desired.

[0003] A conventional dynamometer for this purpose uses a DC motor having excellent responsiveness as a drive motor, and the control device controls the drive motor by a torque command from an engine characteristic generator simulating actual engine characteristics. A controlling torque control device is employed.

FIG. 4 is a diagram showing the configuration of a conventional dynamometer. The test transmission 1 has a DC motor 2 as its driving source.
Are connected, and the absorption dynamometer 3 is connected as a load. The control device for the DC motor 2 uses an engine characteristic generator 4 to control the actual engine speed-
A torque command output T * according to the torque characteristics is obtained. The generator 4 is provided with a throttle opening command θ (or intake pressure command) of the engine as a parameter, and obtains a torque command output T * corresponding to the output of the engine by giving the current rotational speed N. The rotation speed N is obtained by converting the output pulse of the pulse pickup 5 for detecting the rotation speed of the DC motor 2 into a voltage signal (or digital value) by the frequency-voltage converter 6. The torque command T * from the engine characteristic generator 4 is converted by the torque-current converter 11 into a current command I matched to the torque-current characteristic of the DC motor 2.
Converted to ₁ . The conversion characteristic of the torque-current converter 11 is obtained by taking in the detected torque T from the shaft torque meter 8 when the DC motor 2 is driven with various currents I, and storing the relationship between each current I and the torque T or storing table data. The detected torque T can be used for calibration.

The current command I from the torque-current converter 11
_{In the case of 1,} the addition and subtraction section 12 corrects the inertia of the DC motor 2. This correction is performed by electric inertia correction means for compensating for the acceleration / deceleration torque corresponding to the inertia of the DC motor 2. The acceleration / deceleration dN / dt is obtained by differentiating the detected speed N of the frequency-voltage converter 6 by the differential operation unit 13. The acceleration / deceleration torque required for acceleration / deceleration corresponding to the inertia of the DC motor 2 is obtained from the acceleration / deceleration by the inertia calculation unit 14 as a compensation current value, and given to the addition / subtraction unit 12. The inertia component of the DC motor 2 is set by an inertia setting unit 15.

The current command I ₂ passed through the addition / subtraction unit 12 is given to a division unit 16, and a field characteristic generation unit 17 of the DC motor 2
By the division by the coefficient K from, the torque change is corrected by the field characteristic. Field磁特resistance generating unit 17 obtains a coefficient K from the detector constant torque to the base speed N _B as a boundary from the relation between the output torque T relative speed N and exponentially field磁特lead to torque drop of the DC motor 2 .

The current command I * from the dividing unit 16 is converted into a current command of the current control unit 18, and the DC motor 2 is operated by current control by feedback control based on a detection signal of the drive current I of the DC motor 2. Therefore, the torque control of the test transmission 1 is performed by converting the torque command T * from the engine characteristic generator 4 into a current command by the torque-current conversion unit 11, correcting the torque command T * by the inertia component of the DC motor 2, and controlling the field. The DC motor 2 is driven by current control according to the current command I * corrected by the characteristic.

By such current control, the DC motor 2
Has a high-speed response and high torque control accuracy.

[0009]

In the current torque-current conversion method, the current actually flowing at every 100 rpm and the detection of the shaft torque meter at that time are measured and stored as 1 Kgm pitch data in the memory of the engine characteristic generator. have. Although this system currently has an accuracy of about 1%, it is required to further improve this accuracy (more than double). The causes of the error in the current method include the following.

(1) Current detection error (included in current control error).

(2) Error in DC motor current control.

(3) Error in analog input (A / D converter) of the torque-current converter.

(4) Error of analog output (D / A converter) of current command.

(5) Detection error of the shaft torque meter (can be corrected by calibration and canceled).

(6) An error between the complementary calculation and the actual measurement during 1 Kgm in the memory.

(7) Fluctuation in mechanical loss of the mechanical device.

With respect to the above-mentioned items, since each detector and converter uses the most accurate one among the existing ones, it is presently difficult to further increase the accuracy.

The present invention has been made in view of the above points, and an object of the present invention is to provide a dynamometer driving apparatus capable of obtaining high-speed response and high-accuracy torque-current conversion data without changing the hardware of the current apparatus. Is to provide.

[0019]

The present invention SUMMARY OF THE INVENTION, in the driving device of the dynamometer to control the torque control of a DC motor coupled to a dynamometer, according to the torque command obtained from the engine characteristic generator driving engine, said direct current motor An engine characteristic simulator that directly connects a dynamometer to the engine characteristic generator via a shaft torque meter and outputs torque command data that changes in accordance with the throttle opening command of the engine and becomes flat with respect to a change in rotation speed. And torque-current conversion means for converting the torque command into a current command in accordance with the torque-current characteristics of the DC motor .
Torque and the DC mode
Other driven current is input, the engine throttle opening finger
The engine characteristics simulator
DC motor current corresponding to the torque command data of
Measured torque is obtained by actual measurement, and the measured actual measured torque data is obtained.
And the difference between the torque command data and the actual
A current correction amount is obtained based on the measured current data, and the current correction amount is calculated.
To obtain a new current command value by adding the amount to the current command value.
Luc-current conversion means, and current control means for current controlling the DC motor according to the new current command value ,
According to the calculation for obtaining the new current command value and the new current command value,
The current control of the DC motor
Then, the new current command value is sequentially updated .

[0020]

The DC motor is controlled by data obtained by converting a torque command of an engine characteristic simulator into a current command value by a torque-current conversion means. The measured values of the current and the torque of the DC motor corresponding to the torque command value of the engine characteristic simulator are obtained for each throttle opening command θ and each rotation speed N of each engine. This measured torque data
And the difference between the torque command data and the actual
The current correction amount ΔI is obtained based on the measured current data, and
The positive amount ΔI is added to the current command value of the torque-current conversion means to obtain a new current command value. If current control of the DC motor is performed in accordance with the new current command value and the above-described calculation is further repeated n times and the update of the current command value is repeated, the torque setting accuracy will be significantly increased.

[0021]

An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the same parts as those in FIG. 1 is different from FIG. 4 in that the test transmission 1 is removed and the absorption dynamometer 3 is removed.
And an engine characteristic simulator 21 having torque command data that becomes flat with respect to the number of revolutions is provided in place of the engine characteristic generator 4, and the drive current I of the DC motor 2 is converted to a torque-current converter 1
1 and the following operation is performed (by the software function of the microcomputer or the like), and the other parts are configured the same as in FIG. The operation including the calculation will be described below.

(1) The setting of the engine characteristic simulator 21 is set to flat data as shown in FIG. Where i
Are parameters (1 to n) based on the torque for each 1 kgm, j
Are parameters (1 to k) by rotation at every 100 rpm.

(2) Torque-current conversion is performed on the data described above, an ACR drive command is issued to the DC motor 2, and the absorption dynamometer 3 on the load side is held at a constant speed by ASR.

(3) At the speed of N ₁ , the current I ₁₁ ⁽¹⁾ and the shaft torque T ₁₁ ⁽¹⁾ when θ ₁ = T ₁ are actually measured. Similarly, θ
The current I ₂₁ ⁽¹⁾ and the shaft torque T ₂₁ ⁽¹⁾ when ₂ = T ₂ , θ _i = T _i
, The current I _i1 ⁽¹⁾ and the shaft torque T _i1 ⁽¹⁾ , and the current I _n1 ⁽¹⁾ and the shaft torque T _n1 ⁽¹⁾ when θ _n = T _n are actually measured. In rate of N _j, actually measuring the theta ₁ = current I _1j ⁽¹⁾ when the T ₁ and the axial torque T _1j ^(1). Similarly, the current I _2j when θ ₂ = T ₂ ⁽¹⁾
, The shaft torque T _2j ⁽¹⁾ , the current I _ij ⁽¹⁾ when θ _i = T _i and the shaft torque T _ij ⁽¹⁾ , and the current I _nj ⁽¹⁾ when θ _n = T _n and the shaft torque T
Measure _nj ⁽¹⁾ . Then, all the above data of i = 1 to n and j = 1 to k are taken into the memory of the engine characteristic simulator 21 and stored.

(4) The set data and the measured data are compared as shown in FIG. Note that the solid line in FIG. 3 indicates a line when the measured torque is equal to the set torque.

(5) A deviation is obtained for each data from FIG. ΔT _1j ⁽¹⁾ = T ₁ −T _1j ⁽¹⁾ , ΔT _2j ⁽¹⁾ = T ₂ −T _2j
⁽¹⁾ , ΔT _3j ⁽¹⁾ = T ₃ −T _3j ⁽¹⁾ ,... ΔT _ij ⁽¹⁾ = T _i −
T _ij ⁽¹⁾ , ΔT _nj ⁽¹⁾ = T _n −T _nj ⁽¹⁾ , (j = 1 to k).

(6) A current correction amount is obtained from the deviation data. ΔI _1j ⁽¹⁾ = I _1j ⁽¹⁾ × ΔT _1j ⁽¹⁾ / T _1j ⁽¹⁾ , ΔI
_2j ⁽¹⁾ = _I2j ⁽¹⁾ × _ΔT2j ⁽¹⁾ / _T2j ⁽¹⁾ , _ΔI3j ⁽¹⁾ = I
_3j ⁽¹⁾ × ΔT _3j ⁽¹⁾ / T _3j ⁽¹⁾ ,... ΔI _ij ⁽¹⁾ = I _ij ⁽¹⁾
× ΔT _ij ⁽¹⁾ / T _ij ⁽¹⁾ ,... ΔI _nj ⁽¹⁾ = I _nj ⁽¹⁾ × ΔT
_nj ⁽¹⁾ / _Tnj ⁽¹⁾ , (j = 1 to k).

(7) New (second) torque-current conversion data is created using the above-described current correction amount. That is, T ₁
I _ij against ^{_{T n (2) set = I}} ij (1) set + ΔI ij (1), (i
= 1 to n, j = 1 to k). Where I
_ij ⁽¹⁾ _set is a current command at the time of Nj in the Ti setting in the first operation, and I _ij ⁽²⁾ _set is a current command at the time of Nj in the Ti setting in the second operation.

(8) The same operation as in (2) is performed using the same engine characteristic simulator data (in FIG. 2) as in (1).

(9) The current and the shaft torque are measured in the same manner as in the above (3). However, the suffix is ⁽¹⁾ → ⁽²⁾ .
That is, the current I _ij ⁽²⁾ and the shaft torque T _ij ⁽²⁾ when θ _i = T _i are measured, and data of i = 1 to n and j = 1 to k (N _j = N _{1 to} N _k ) are obtained. Are all stored in memory.

(10) As described in the above items (4) and (5), the set data is compared with the actually measured data to obtain a deviation. ΔT _ij
⁽²⁾ = T _i −T _ij ⁽²⁾ , (i = 1 to n, j = 1 to k).

(11) A current correction amount is obtained in the same manner as in the above (6). ΔI _ij ⁽²⁾ = I _ij ⁽²⁾ × ΔT _ij ⁽²⁾ / T _ij ⁽²⁾ ,
(I = 1 to n, j = 1 to k).

(12) Similar to the above (7), the new (3)
Third) Create torque-current conversion data. I _ij ⁽³⁾ set
= I _ij ⁽²⁾ set + ΔI _ij ⁽²⁾ , (i = 1 to n, j = 1 to
k).

(13) When the P-th torque-current conversion data is created and the operation is performed in the same manner as in the above items (1) to (7), the target torque setting accuracy can be obtained. The first (first) torque-current conversion data is about 1%, but the third to fourth times can be 0.5 to 0.2%.

[0035]

As described above, according to the present invention, the hardware of the conventional device can be used while taking advantage of the fact that the required torque can be obtained at a high speed response by performing the torque-current conversion by the transient dynamometer. It is possible to set and operate the torque with one digit higher accuracy without changing. In addition, the DC motor is
Accurately measured torque data because the inamometer is directly connected
And measured current data.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of the present invention.

FIG. 2 is a characteristic diagram showing setting data of an engine characteristic simulator.

FIG. 3 is a characteristic diagram showing a relationship between measured torque and set torque.

FIG. 4 is a configuration diagram of a conventional dynamometer.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Test transmission, 2 ... DC motor, 3 ... Absorption dynamometer, 4 ... Engine characteristic generator, 8 ... Shaft torque meter, 11 ... Torque-current conversion part, 12 ... Addition / subtraction part,
13: Differential operation unit, 14: Inertial operation unit, 15: Inertial setting unit, 16: Division unit, 17: Field characteristic generation unit, 18: Current control unit, 21: Engine characteristic simulator.

Claims (1)

(57) [Claims] The method according to claim 1 torque control of a DC motor coupled to a dynamometer, apparatus for driving a dynamometer to control according to the torque command obtained from the engine characteristic generator driving engine, dynamo via a shaft torque meter to the DC motor A meter directly connected to the engine characteristic generator, wherein the engine characteristic generator is configured with an engine characteristic simulator that outputs torque command data that changes according to a throttle opening degree command of the engine and becomes flat with respect to a change in the number of revolutions. Torque-current conversion means for converting the current into a current command according to the torque-current characteristics of the DC motor.
The detected torque detected by the shaft torque meter and the
The drive current of the DC motor is input, and the throttle opening command of the engine and the
Compatible with torque command data of engine characteristics simulator
Current and torque of the DC motor
The obtained measured torque data and the torque command data
Taking a deviation, and based on the deviation and the measured current data,
Current correction amount, and the current correction amount is added to the current command value.
And a current-control means for controlling the current of the DC motor in accordance with the new current command value, and calculating and calculating the new current command value.
Current control of the DC motor in accordance with
A driving device for the dynamometer , wherein the current value is sequentially updated .