JP2009068928A - Device for controlling dynamometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a rotational body can not controlled more precisely and stably even in the case a rotation signal detected by a rotation detector is fed back to generate a control command for the rotational body, since the detected rotation signal contains a velocity variation component. <P>SOLUTION: A velocity detection compensating section which inputs a detection signal of the rotation detector and compensates the signal, is disposed in a control circuit of the rotational body. The velocity detection compensating section is configured to store a velocity variation feature map created based on an average velocity signal and a rotary mechanical angle signal previously obtained in an operation of bringing the rotational body to coast from a certain rotation velocity. When controlling the rotational body, a difference between the velocity signal detected by the rotation detector and a velocity variation compensating signal compensated by the velocity variation feature map is output as a compensating velocity signal from the velocity detection compensating section, thereby suppressing the velocity variation component. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a dynamometer control device, and more particularly to a control device that corrects a detection signal when a speed fluctuates.

  Four-wheel drive vehicles (4WD vehicles) have become widespread, mainly RV vehicles and high-power vehicles, and drive mechanisms and controls have become more complex. When evaluating a 4WD vehicle, it is difficult to modify the mechanism to 2WD or change the control system. Therefore, an evaluation with a conventional 2WD chassis dynamometer is required to be evaluated with a 4WD chassis dynamometer. In consideration of the driving state on the road, it is considered that the driving performance and fuel consumption of the vehicle and the engine, and the measurement of exhaust gas are preferably executed in the four-wheel driving state.

In a dynamometer used for fuel consumption performance evaluation and the like, it is necessary to accurately detect the rotational speed in order to perform performance measurement of the test object more faithfully. Normally, a pulse pickup is used as a means for detecting the rotational speed, but this pulse pickup needs to be accurately attached to the center position of the motor shaft. At that time, depending on the problem of mechanical accuracy and the mounting method, the center position is deviated, resulting in a detection speed error. This detection error appears as a sinusoidal velocity ripple having a frequency synchronized with the rotation period. Japanese Patent Application Laid-Open No. H10-228561 is known as a means for suppressing such speed ripple. In Patent Document 1, a speed ripple correction calculation unit that calculates a sine wave component having a phase opposite to that of the speed ripple output from the speed detector is provided, and when the output is added to the detection speed signal from the calculation unit, The phase and amplitude are adjusted and corrected.
JP2001-45780

As a variation factor of the detection speed signal that becomes the basis of the detection error, there are some factors resulting from the function of the pulse pickup in addition to the mounting position of the pulse pickup. Generally, when speed detection is performed using an incremental encoder used for pulse pickup or an absolute encoder, fluctuations due to signal variations of the encoder itself exist in the speed ripple. This variation is disclosed in Patent Document 1.
Then it cannot be corrected.

For example, when measuring the driving performance of a vehicle with a chassis dynamometer, the variation by the encoder affects the measurement accuracy.
FIG. 5 shows the fluctuation state of the speed detection signal when the chassis dynamometer coasts in the prior art. In this example, the fluctuation near the vehicle speed of 80 km / h is measured. In a chassis dynamometer, the roller on which the vehicle is mounted has a large moment of inertia. Slowly decelerate smoothly as shown by line a with little impact. On the other hand, the speed detection at this time appears as a detection signal having a fluctuation component other than the rotation primary as indicated by a line A.

  FIG. 6 shows the speed fluctuation characteristics, and coasting data was recorded in the same manner using an absolute encoder as a speed detector, and the difference between the rotating machine angle and the average speed and the detected vehicle speed and the average vehicle speed was expressed in three dimensions. Is. Here, it can be seen that the X-axis is the rotating machine angle, the Y-axis is the average vehicle speed, and the Z-axis is the difference between the detected vehicle speed and the average vehicle speed, which is wavy and greatly fluctuates.

  An object of the present invention is to provide a speed control device for correcting fluctuations as shown in FIG.

The present invention detects the rotational speed of a rotating body in a dynamometer system through a rotation detector, and feeds back this detection signal as a control command for the rotating body.
A speed detection correction unit for inputting a detection signal from the rotation detector and correcting the signal is provided, and a rotational machine angle signal and an average speed signal when the rotation body is coasted from a certain rotation speed in advance in the speed detection correction unit. A speed detection correction unit which stores a speed fluctuation characteristic map created from the above and uses a difference between a detection speed signal detected by the rotation detector and a speed fluctuation correction signal corrected by the speed fluctuation characteristic map when the rotating body is controlled as a correction speed signal. It is characterized by having comprised so that it may output from.

  The speed detection correction unit according to the present invention is provided in a control device for a chassis dynamometer for a four-wheel drive vehicle.

  As described above, according to the present invention, it is possible to suppress fluctuation due to speed by correcting the detected speed signal using the speed fluctuation characteristic map. By using a speed signal with little speed fluctuation, torque fluctuation during speed control and torque fluctuation during electric inertia control can be reduced.

  In the present invention, when speed control is performed by detecting the speed of a rotating body such as a motor, a dynamometer, or a chassis dynamometer, an average speed and a speed fluctuation are calculated in advance from a detection signal having a rotating machine angle and a fluctuation component. Then, a speed fluctuation characteristic map is created from the rotating machine angle, the average speed, and the speed fluctuation and stored in the vehicle speed detection and correction unit. During control operation, the speed fluctuation of the detected speed signal is calculated, and this speed fluctuation is used as a correction signal, and subtracted from the speed signal with the original fluctuation component to obtain a corrected speed detection signal. is there. The present invention will be described below with reference to the drawings.

  FIG. 1 shows an embodiment when applied to a chassis dynamometer system for a 4WD vehicle. 1 (1a, 1b) is a chassis dynamometer, 1a is for front wheels, and 1b is for rear wheels. Note that no vehicle is placed on the chassis dynamometer during measurement. 2 (2a, 2b) is a current control unit, the current control unit 2a controls the front wheel chassis dynamometer 1a based on the input torque current command, and the current control unit 2b receives the input torque current command. Based on this, the front wheel chassis dynamometer 1b is controlled. Reference numeral 3 denotes a synchronous control circuit for the front and rear wheel chassis dynamometer, which includes a speed (vehicle speed) detection correction unit 4 (4a, 4b), a position detection unit 5 (5a, 5b), a phase difference detection unit 6, a vehicle speed difference detection unit 7, and a phase. A control unit 8, a differential control unit 9, and a synchronization setting unit 10 are included.

  Reference numeral 11 denotes a running resistance unit, 12 denotes an electric inertia unit, 13 denotes a torque command calculation unit, and the torque command calculation unit 13 includes a running resistance output from the running resistance unit 11 based on a vehicle speed detection signal, and an electric inertia unit 12. The torque control signal is calculated based on the sum of the electric inertia signals and the torque detection signal from the detected torque totaling unit 14. Reference numeral 15 (15a, 15b) denotes a speed detector. Here, an absolute encoder is used, and detection signals from 15a, 15b are output to the vehicle speed detection correction units 4a, 4b and the position detection units 5a, 5b, respectively. Reference numeral 16 (16a, 16b) denotes a load cell. The detected load signals are input to the torque amplifiers 17a, 17b and processed, and then both are added and input to the detected torque totaling unit 14.

The operation of the present invention configured as described above will be described.
The speed detector 15 has fluctuation characteristics as shown in FIG. In order to correct this fluctuation characteristic, a speed fluctuation characteristic map is recorded in the vehicle speed detection correction unit 4 prior to the vehicle test. At that time, the chassis dynamometer is driven to accelerate to a certain speed and then coasted, and the speed fluctuation characteristics as shown in FIG.

  FIG. 2 is an explanatory diagram of speed detection correction in the vehicle speed detection correction unit 4. When measuring the characteristics of the device under test, the rotational speed of the chassis dynamometer is detected by the speed detector 15 and output to the vehicle speed detection correction unit 4. The speed signal detected by the speed detector 15 is input to the vehicle speed detection correction unit 4 as a signal having fluctuation characteristics as shown in FIG. The vehicle speed detection correction unit 4 generates a speed fluctuation correction signal by referring to the speed fluctuation characteristic map from the input average speed signal and the mechanical angle signal, and performs a difference calculation with the speed signal detected by the subtraction part. The difference signal is output from the vehicle speed detection correction unit 4 as a corrected speed detection signal. The corrected speed detection signal is output to the running resistance unit 11 and the electric inertia unit 12 to be used as a running resistance and an electric inertia command, and is used to generate a differential control signal.

FIG. 3 shows coasting data when the speed signal detected by the speed detector 15 is corrected according to the present invention. This data is obtained by accelerating the chassis dynamometer and coasting in an off state, and the vehicle speed is around 80 km / h, and the fluctuation component is reduced compared to the data before correction shown in FIG. I understand. FIG. 4 is a three-dimensional representation of the difference between the rotating machine angle and the average speed, and the detected vehicle speed and the average vehicle speed, which is horizontal and significantly improved compared to before correction shown in FIG. .
Specifically, the speed fluctuation in the vicinity of the vehicle speed of 80 km / h was 0.1 km / hp-p before the correction, but was improved to about 0.01 km / hp-p after the correction.
The degree of improvement varies depending on the resolution with which the speed fluctuation characteristic map is created. However, if a greater improvement is desired, it can be achieved with a fine resolution.

  As described above, according to the present invention, it is possible to suppress the speed fluctuation based on the function of the speed detector, and the measurement and the control unit can be integrated to achieve high accuracy and high stability.

Configuration diagram of a control circuit showing an embodiment of the present invention Explanatory drawing of speed detection fluctuation correction Measurement data when the vehicle coasts after correction Vehicle speed fluctuation characteristics after correction Measurement data during vehicle coasting before correction Vehicle speed fluctuation characteristics before correction

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Chassis dynamometer 2 ... Current control part 3 ... Synchronous control circuit 4 ... Speed detection correction part 11 ... Running resistance part 12 ... Electric inertia part 13 ... Torque current calculation part 15 ... Rotation detector

Claims (2)

In what detects the rotational speed of the rotating body in the dynamometer system via a rotation detector, and feeds back this detection signal as a control command for the rotating body,
A speed detection correction unit for inputting a detection signal from the rotation detector and correcting the signal is provided, and a rotational machine angle signal and an average speed signal when the rotation body is coasted from a certain rotation speed in advance in the speed detection correction unit. A speed detection correction unit which stores a speed fluctuation characteristic map created from the above and uses a difference between a detection speed signal detected by the rotation detector and a speed fluctuation correction signal corrected by the speed fluctuation characteristic map when the rotating body is controlled as a correction speed signal. A dynamometer control device characterized by being configured to output from a dynamometer. The dynamometer control device according to claim 1, wherein the speed detection correction unit is provided in a control device for a chassis dynamometer for a four-wheel drive vehicle.

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