KR100203258B1 - Speed control system of capstan motor - Google Patents

Abstract

The present invention relates to a deceleration control system of a capstan motor, which minimizes the tape forward and rewind time by shortening the deceleration section of the capstan motor in the VTR. According to an embodiment of the present invention, a pulse generation unit for detecting a rotational speed of a take-up rail and a supply rail driven by a capstan motor and generating a pulse corresponding thereto, and a speed from the pulse speed of the take-up rail and the supply rail generated at the pulse generation unit Compensation unit for controlling the rotational speed of the capstan motor by calculating the slope, compensating the speed gradient and the threshold and outputting the deceleration control command, and compensating the capstan motor speed control command according to the deceleration control command obtained from the speed operation unit. It is composed. Therefore, the tape wound around the take-up rail and the supply rail may not be released due to rapid deceleration, and the deceleration section may be shortened, thereby providing an effect of minimizing the winding time of the tape.

Description

Deceleration Control System of Capstan Motor

1 is a diagram showing the relationship between time and motor speed,

2 is a block diagram showing a deceleration control system of a capstan motor according to a preferred embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

11 comparison unit 12 driving unit

13: Capstan motor 14: Riley

15: pulse generator 16: speed calculator

17: compensation

The present invention relates to a capstan motor speed control in a VTR, and more particularly, to a capstan motor for controlling a short time of a deceleration section of a capstan motor rotating at a maximum speed so as to minimize forward and rewind time of a tape. A deceleration control system.

Consumers want to take a short time to rewind the tape after they finish watching it in the VTR. Thus, in order to satisfy this, functions such as fast forward (FF) and fast reverse (REWIND) are provided in the VTR. By the way, effective deceleration control of the capstan motor that rotates at the maximum speed is required in performing the functions such as the high speed forward FF to the high speed rewind.

In general, as shown in FIG. 1, as shown in the relationship between the time on the horizontal axis and the motor speed on the vertical axis, the motor is accelerated for a predetermined time to maintain the speed for a predetermined time. Then, the motor is decelerated again for a certain time to stop the motor. In the general motor speed control pattern, the shorter the deceleration section, the shorter the time required for forwarding or rewinding the tape. However, if the motor deceleration section is shortened unconditionally, the tape wound around the take-up reel and supply reel is suddenly increased at speed, similar to the example in which the goods in the car are disturbed when the vehicle is suddenly stopped. The change is released instantly. In other words, it is necessary to consider the inertia of the object.

Accordingly, an object of the present invention is to provide a deceleration control system of a capstan motor which can minimize the tape winding time by shortening the time of the deceleration section to the maximum while considering the inertia of the above object.

The deceleration control system of the capstan motor according to the present invention for achieving the above object, in the speed control system in the capstan motor deceleration section, is driven in accordance with the rotational speed of the capstan motor winding take-up reel A pulse generator for detecting a rotation system of a daily and supply rail, a rotation speed of the take-up rail and the supply rail of the rail system, and generating a pulse corresponding to the rotation speed of the rail; Comprising a speed gradient from the pulse of the take-up rail and the supply rail, and compares the speed gradient and the threshold value to output a deceleration control command, and to compensate the speed command of the capstan motor according to the deceleration control command of the speed operation unit It includes a compensation unit.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a configuration diagram showing a deceleration control system of a capstan motor according to the present invention. The system shown in FIG. 2 includes a capstan motor (CAP) 13, a rail system 14 consisting of a take-up rail and a supply rail for winding and unwinding the tape, and a drive unit 12 for driving the capstan motor. ) And the speed command as a reference input, and receive a frequency signal (C-FG) corresponding to the rotational speed of the capstan motor 13. The capstan servo system of the conventional VTR which consists of the comparator 11 which drives the drive part 12 is included. The system of FIG. 2 also detects the rotational speeds of the take-up rails and the supply rails of the rail system 14, and includes a pulse generator 15 and a pulse generator 15 for outputting a detection result as pulses. The speed calculation unit 16 and the comparison unit 11 which obtain a speed gradient from each pulse generated corresponding to the rotational speeds of the take-up rail and the supply rail, and issue a deceleration control command so that the speed slope is kept below a threshold. It is configured to further include a compensation unit 17 for compensating for the driving signal of the) according to the deceleration control command of the speed calculation unit 16 and outputs. The operation of the deceleration control system of the second degree capstan motor having such a configuration will be described in more detail.

In FIG. 2, the comparator 11 receives the speed command as a reference input to drive the driver 12. Here, the reference input is a target value of the speed control for keeping the motor speed (%) constant, and decreases the speed step by step in the deceleration section. The driving unit I2 is driven by the comparing unit 11 to apply the corresponding driving voltage to the capstan motor 13. The capstan motor 13 rotates according to the driving voltage applied by the driving unit 12 to drive the tape and drives the rail. The rail system 14 is driven according to the rotational speed of the capstan motor 13 to wind the tape at the take-up rail and to release the tape at the supply rail. On the other hand, it depends on the rotational speed of the capstan motor 13. The comparator 11 receiving the feedback signal of the frequency signal C-FG from the capstan motor 13 compares the frequency signal C-FG of the reference input and the feedback input to drive the driving unit 12 again by the deviation thereof. The capstan motor 13 is controlled to rotate at a desired speed.

On the other hand, in the deceleration section for decelerating the speed of the capstan motor 13, the pulse generator 15 is a photointerruption (at the appropriate position to detect the rotational speed of the take-up rail and the supply rail of the rail system 14) Photo Interrupter) is installed to sense the rotational speed of the rail and generates a pulse accordingly. In general, the rotation speeds of the take-up rail and the supply rail of the rail system 14 obtained by the pulse generator 15 are used to determine the deceleration time point. The speed calculating section 16 is each of the speed gradients from the pulse rate [T (Take-up)] of the take-up rail generated from the pulse generator 15 and the pulse rate [T (Supply)] of the supply rail. Obtain The speed calculating section 16 compares the obtained speed gradients with the threshold value α, respectively, and outputs a deceleration control command Y so that there is no sudden speed change in the capstan motor 13 according to the comparison result. The deceleration control command (Y) output from the input to the compensation unit 17. The compensator 17 is a proportional integral (PL) controller. The compensator 17 is a proportional integral (PL) controller. The compensator 17 obtains the gain of the driving voltage supplied from the comparator 11 when decelerating the tape to the deceleration control command y obtained from the speed calculator 16. Adjust according to the output. That is, the compensator 17 compensates for the positive gain when the speed gradients of the take-up rail and the supply rail in the speed calculator 16 are less than or equal to the threshold, and the negative gain compensation when the compensator is greater than or equal to the threshold. This is summarized as follows.

Here, x is the pulse rate [T (Take-uP)] of the take-up rail and the pulse rate [T (Supply)] of the supply rail.

The gain compensated speed control voltage output from the compensator 17 is applied to the driver 12 to control the speed of the capstan motor 13.

As described above, the deceleration control system of the capstan motor according to the present invention, while controlling the deceleration section in consideration of the speed of the take-up rail and the supply rail driven in accordance with the rotational speed of the capstan motor, while the tape is not released immediately It has the effect of minimizing the forward or rewind time.

Claims (4)

A speed control system in a capstan motor deceleration section, the speed control system comprising: a rail system including a take-up rail and a supply rail driven and rotated according to a rotation speed of the capstan motor; A pulse generator for detecting rotational speeds of the take-up rail and the supply rail of the rail system and generating a pulse corresponding to the rotational speed of the rail; a speed from the pulses of the take-up rail and the supply rail generated by the pulse generator; A speed calculation unit for calculating a slope and comparing the slope and the threshold to output a deceleration control command; And a compensating unit for compensating for the speed command of the capstan motor according to the deceleration control command of the speed computing unit. The method of claim 1, wherein the pulse generator is mounted to a suitable position for detecting the rotational speed of the take-up and supply rail of the rail system is characterized in that consisting of a photo interrupt for generating a pulse corresponding to the rotational speed Deceleration control system of capstan motor. The compensation unit of claim 1, wherein the speed calculator performs positive gain compensation in the compensation unit when the speed gradient obtained from the pulse rates of the take-up rail and the supply rail is less than or equal to a threshold value, and negative (−) when the speed gradient is greater than or equal to a threshold value. The deceleration control system of the capstan motor, characterized in that to compensate the gain to output a deceleration control command so that a sudden speed change does not occur in the capstan motor. The deceleration control system of the capstan motor according to claim 1, wherein the compensator comprises a Pl controller.