JP5771940B2 - Speed control device - Google Patents

Description

  The present invention relates to a speed control device, and more particularly to a transient follow-up type speed control device capable of traveling at a distance that matches a speed command.

In chassis dynamometers, engine bench systems, drive train tests, and general motor tests, transient tracking tests using acceleration and deceleration are performed.
For example, speed control by a dynamometer is performed in a chassis dynamometer, an engine bench system, and the like.
FIG. 4 shows a speed control device in a chassis dynamometer.
Reference numeral 1 denotes a speed command unit, which outputs a speed command Vset for acceleration / running / deceleration. The speed command Vset is subtracted from the detected speed signal Vdet detected by the speed detector 5 in the subtracting section 6, and the deviation signal is input to the speed control section 2 comprising a PID controller. The speed control unit 2 generates a torque current command based on the input signal, and controls the chassis dynamometer 4 via the current control unit 3. The speed of the chassis dynamometer 4 is detected by the speed detector 5 and fed back to the subtracting unit 6 to perform measurement while keeping the speed constant and stabilizing the behavior of the engine and the vehicle.

  As a control device in the dynamometer system, Patent Document 1 is well known.

JP-A-11-108802

In recent years, in vehicle and engine evaluation tests, measurement and evaluation are performed during acceleration / deceleration control for the purpose of shortening the evaluation time.
The conventional speed control apparatus shown in FIG. 4 employs a PID controller and performs control so that the speed command Vset set by the speed command unit 1 and the detected speed signal Vdet match. However, the speed control by the PID controller has a control method in which a control delay occurs during the acceleration / deceleration operation and a deviation occurs between the speed command and the actual speed, and this deviation becomes 0 after a predetermined time. In addition, problems such as the occurrence of a hunting phenomenon occur when trying to prevent control delay.

  In particular, when an evaluation test is performed by applying speed control by a PID controller to a dynamometer system, the control delay during acceleration / deceleration operation appears as a difference in travel distance, and fuel consumption and exhaust gas during acceleration / deceleration operation for the vehicle under test and engine Deterioration is incurred and measurement evaluation accuracy is getting worse.

  Therefore, an object of the present invention is to provide a speed control device that does not cause a speed deviation even in transient operation.

The present invention calculates a torque current command based on a deviation signal between the speed command and a detected speed signal of the chassis dynamometer detected by the speed detector, and uses the calculated torque current command via a current control unit and an inverter. For controlling the chassis dynamometer ,
A set speed / distance converter that inputs the speed command and converts it into a distance signal;
A distance / detection speed conversion unit that uses a speed detector capable of detecting an angular position as the speed detector, differentiates a distance signal detected by the speed detector, and converts it into a detection speed signal;
A synchronization processor that inputs a difference between the distance signal converted by the set speed / distance converter and the distance signal detected by the speed detector and generates a differential speed command based on the difference of the distance signal;
A deviation signal between the speed command and the detection signal converted by the distance / detection speed conversion unit and a differential speed command from the synchronization processing unit are input, and PID calculation is performed based on the deviation signal and the differential speed command. A differential speed control unit is provided that generates a compensation current command by executing and adds the compensation current command to the torque current command.

  As described above, according to the present invention, the difference signal control between the speed command and the detected speed signal is provided in the minor loop, and the distance obtained by integrating the speed command in the major loop (the difference between the position command and the detected distance signal is proportional gain. In order to match the position and add this position signal as a compensation current command to the torque current command, it is possible to prevent speed deviation during transient operation. Therefore, the energy is stabilized by speed control in the fuel consumption exhaust gas test, and the accuracy at the time of measurement evaluation is improved.

The block diagram which shows embodiment of this invention. The block diagram which shows other embodiment of this invention. It is a velocity characteristic figure for explanation, (a) is a conventional characteristic figure, (b) is a special drawing of the present invention, and (c) is not distance behavior. The block diagram of the conventional speed control apparatus.

  FIG. 1 is a block diagram showing a first embodiment of the present invention, in which the same or corresponding parts as in FIG. Reference numeral 10 denotes a set speed / distance conversion unit, which converts the speed command Vset output from the speed command unit 1 into a distance signal by integrating. Reference numeral 11 denotes a detection speed / distance conversion unit. The conversion unit 11 inputs a detection speed signal Vdet detected by the speed detection unit 5 formed of a pulse pickup and converts it into a distance (position) signal by integration. A synchronization processing unit 12 receives the deviation of the distance signal converted by the conversion units 10 and 11, converts it to a function having an integral characteristic, and outputs it as a differential speed command to the differential speed control unit 13.

The speed command Vset and the detected speed signal Vdet are also applied to the subtraction unit 14, and a speed deviation signal is obtained by the subtraction unit 14 and input to the differential speed control unit 13. The differential speed control unit 13 executes PID calculation based on the input deviation signal and differential speed command, generates a compensation current command, and outputs the compensation current command to the addition unit 15.
Although not shown, the chassis dynamometer 4 includes a dynamometer and a roller and an inverter connected to the dynamometer.

The operation of the first embodiment configured as described above will be described.
Based on the speed command Vset by the speed command unit 1, the speed control unit 2 calculates a torque current command and outputs it to the current control unit 3. The current control unit 3 calculates a torque control command corresponding to the torque current command and controls the dynamometer via the inverter.
The speed detector 5 used in the present invention may be any speed detector that can detect the rotational speed and the angular position. Here, a pulse pickup is used, and the pulse pickup detects the edge of the pulse. The rotation angle is detected by counting the number of pulses, and the speed of the chassis dynamometer 4 is detected. The detected speed signal Vdet is fed back to the subtractor 6 to obtain a deviation from the speed command Vset, and control is performed so that the deviation signal becomes zero.

On the other hand, the speed command Vset is also input to the set speed / distance converter 10 and converted into a position signal, and the detected speed signal Vdet is input into the detected speed / distance converter 11 and converted into a position signal. Both converted position signals are calculated as position difference signals based on the control delay of the speed control system in the subtracting section and input to the synchronization processing section 12.
The synchronization processing unit 12 outputs the position deviation signal to the differential speed control unit 13 as a differential speed command based on a predetermined function conversion. The differential speed control unit 13 executes a PID calculation based on the input deviation signal and the differential speed command to generate a compensation current command, and the addition unit 15 adds the torque current command. Thereby, the torque control command calculated by the current control unit 3 becomes a command value in which the difference between the speed and the position (distance) generated during the acceleration / deceleration operation is compensated.
Therefore, the speed deviation at the time of transient operation can be prevented. Further, since the traveling distance matches the command in the speed control, the energy is stabilized, and the accuracy during the acceleration / deceleration evaluation test of the vehicle mounted on the roller of the chassis dynamometer 4 is improved.

  FIG. 3 is a behavioral diagram for explaining the speed control of the chassis dynamometer, and FIG. 3A shows the followability in the conventional speed control apparatus shown in FIG. Line a indicates a speed command value, and line b indicates a detected speed signal. A delay occurs in acceleration and deceleration, resulting in a travel distance difference. FIG. 4B is a speed characteristic diagram according to the present invention in which the speed difference is compensated for the difference in travel distance, and the speed command value and the detected speed signal substantially coincide. FIG. 6C is an explanatory diagram of behavior according to the present invention. The acceleration starts from time t1 with a delay, but the compensation current command from the differential speed control unit 13 is added to the torque current command to be compensated. From time to time t2, they coincide. Similarly, even at the time of deceleration from time t4, a delay occurs at the beginning of deceleration, but at time t5, there is no error in travel distance and speed, and the two coincide.

  FIG. 2 shows a second embodiment. The difference from FIG. 1 is that a speed detector 5a capable of detecting an angular position such as a rotary encoder or resolver is used as a speed detector. In this embodiment, an absolute encoder is used as the low encoder. When the absolute encoder 5a is used, since the angular position can be detected, a distance / detection speed converter 16 is used instead of the detection speed / distance converter 11 of FIG. The distance / detection speed converter 16 differentiates the detected distance signal into a speed signal. The rest is the same as in FIG.

A deviation of the distance signal between the distance (position) signal Ldet detected by the speed detector 5a and the distance command Lset converted by the set speed / distance converter 10 is generated as a differential speed signal by the synchronization processing unit 12. And input to the differential speed control unit 13.
Further, the distance signal Ldet detected by the speed detector 5a is input to the distance / detection speed converter 16 and converted into a speed detection value Vdet, and the subtraction unit 14 obtains a deviation signal from the speed command Vset. Input to the controller 13. The differential speed control unit 13 performs a PID calculation based on the input deviation signal and differential speed signal to generate a compensation current command, and the addition unit 15 adds the torque current command. Thereby, the torque control command calculated by the current control unit 3 becomes a command value in which the difference between the speed and the position (distance) generated during the acceleration / deceleration operation is compensated.

  Therefore, this embodiment can also prevent the speed deviation during the transient operation. Further, since the traveling distance matches the command in the speed control, the energy is stabilized, and the accuracy during the acceleration / deceleration evaluation test of the vehicle mounted on the roller of the chassis dynamometer 4 is improved.

DESCRIPTION OF SYMBOLS 1 ... Speed command part 2 ... Speed control part 3 ... Current control part 4 ... Chassis dynamometer 5 ... Speed detector 12 ... Synchronization processing part 13 ... Differential speed control part 10 ... Set speed / distance conversion part
11 ... Detection speed / distance converter
16: Distance / detection speed converter

Claims (1)

Calculates a torque current command based on the deviation signal between the detected speed signal of the chassis dynamometer, which is detected by the speed command and the speed detector, current controller by the calculated torque current command, the chassis dynamometer through an inverter In what to control
A set speed / distance converter that inputs the speed command and converts it into a distance signal;
A distance / detection speed conversion unit that uses a speed detector capable of detecting an angular position as the speed detector, differentiates a distance signal detected by the speed detector, and converts it into a detection speed signal;
A synchronization processor that inputs a difference between the distance signal converted by the set speed / distance converter and the distance signal detected by the speed detector and generates a differential speed command based on the difference of the distance signal;
A deviation signal between the speed command and the detection signal converted by the distance / detection speed conversion unit and a differential speed command from the synchronization processing unit are input, and PID calculation is performed based on the deviation signal and the differential speed command. A speed control apparatus comprising a differential speed control unit that executes a compensation current command and adds the compensation current command to the torque current command.

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