JPH07130042A - Method of discriminating motor rotational direction - Google Patents

Abstract

PURPOSE:To eliminate a double phase FG pulse and to suppress the increase in a manufacturing cost by discriminating a rotational direction of a motor based on a rotation command, a direction command and an FG pulse. CONSTITUTION:The rotation command and the direction command of a motor control part 2c are outputted from a higher rank control routine part 2a of a microcomputer 2, and further, a rotation condition and a direction condition are outputted from the control part 2c to a routine part 2b. Further, the rotation command and the direction command are outputted from the control part 2c to the motor 3, and the FG pulse is outputted from the motor 3. Then, when the FG pulse is detected, the condition of the motor 3 is judged as the rotation, and when no pulse is detected, is judged as the stoppage. When the motor 3 is stopped, the direction command from the routine part 2a to the control part 2c is made as the direction command from the control part 2c to the motor 3, and the direction command from the routine part 2a to the control part 2c is discriminated as the direction condition of the motor 3, and the rotation command from the routine part 2a to the control part 2c is made as the rotation command from the control part 2c to the motor 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for discriminating a motor rotation direction of a VTR or the like.

[0002]

2. Description of the Related Art In a VTR or the like, for example, when a tape is fast forwarded or rewound, the value of a tape counter is added or subtracted, so that it is necessary to determine the rotation direction of a reel motor that rotates a reel on which a tape is wound. is there. Therefore, in the past, two FGs (Frequenc
y Generator) and output from these FG 2
Phase FG pulses were phase compared.

That is, as shown in FIG.
A two-phase FG pulse is input to the upper processing routine section 2b of the microcomputer 2 and this upper processing routine section 2b is input.
Thus, the two-phase FG pulses are compared in phase to determine the rotation direction of the motor, and the tape counter is incremented or decremented.

In the 8 mm video, the capstan motor often serves as a reel motor in order to reduce the size and weight. In such a structure, the rotation direction of the capstan motor is determined.

[0005]

As described above, in the prior art, two Fs are provided in the motor in order to determine the rotation direction of the motor.
FG to increase the output as G is required
Special hardware is required, such as the need for a pulse amplifier, which leads to higher costs.

Further, the rotation command or the direction command output from the upper control routine 2a of the microcomputer 2 to the motor 3 is input to the upper processing routine section 2b as the rotation state and the direction state, respectively, and shown in FIG. As shown
It is conceivable to determine the rotation direction of the motor 3. However, there is a time difference between the time when the rotation command or the direction command is output from the microcomputer 2 to the motor 3 and the time when the motor 3 that receives the rotation command or the direction command actually starts forward and reverse rotation. is there.

Therefore, if the addition or subtraction of the tape counter is started at the time when the rotation command or the direction command is output to the motor 3, an error will occur in the value of the tape counter. The present invention has been made in view of the above-described conventional art, and without requiring special hardware,
An object of the present invention is to provide a motor rotation direction determination method that can easily determine the rotation direction of a motor.

[0008]

The structure of the present invention which achieves such an object monitors the rotation state of a motor and, when it is determined that the motor is rotating, a direction different from the actual rotation direction of the motor. When issuing a command to rotate the motor, it outputs a command to stop the rotation of the motor, determines that the direction direction of the motor remains as it is, waits for rotation stop of the motor, and when it is determined that the motor is stopped, Is characterized by outputting a command to the motor to rotate the motor according to the operated direction and determining the direction state of the motor.

[0009]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 shows an embodiment of the present invention. This embodiment is applied to a VTR such as an 8 mm video camera. As shown in the figure, the microcomputer 2 is composed of an upper control routine section 2a, an upper processing routine section 2b and a motor control section 2c. The rotation command 0 and the direction command 0 are output from the upper control routine unit 2a to the motor control unit 2c, and the rotation state and the direction state are output from the motor control unit 2c to the upper processing routine unit 2b.

Further, the motor control unit 2c outputs a rotation command 1 and a direction command 1 to the motor 3, and the motor 3 outputs an FG pulse to the motor control unit 2c and the upper processing routine unit 2b. The microcomputer 2 performs the rotation direction detection task and the rotation state monitoring task shown in FIG.

The rotation state monitoring task is executed from the motor 3 to the FG.
Whether or not a pulse can be detected is determined. When it can be detected, the rotation state of the motor 3 is determined to be "rotation". The state is determined to be “stop”.

The rotation direction detecting task first determines whether the rotation state of the motor 3 is "rotation" or "stop", and when the rotation state of the motor 3 is "rotation", next, from the upper control routine section 2a. Direction command 0 output to the motor controller 2c
Is determined to be in the same direction as the motor 3. When the direction command 0 and the direction condition of the motor do not match, the rotation command 1 for stopping the motor 3 is output from the motor control unit 2c to the motor 3.

On the other hand, when the rotation state of the motor 3 is "stop", the upper control routine section 2a to the motor control section 2c.
The direction command 0 output to the motor control unit 2c is output to the motor 3 as the direction command 1 and the host control routine unit 2a outputs
The direction command 0 output from the motor control unit 2c to the motor control unit 2c is determined as the direction state of the motor 3, and the rotation command 0 output from the upper control routine unit 2a to the motor control unit 2c is output to the motor 3 from the motor control unit 2c. Output as 1.

FIG. 3B shows an example of a timing chart in this embodiment. As shown in the figure, when a REW (rewind) button (not shown) is operated, the higher order control routine section 2a instructs the motor control section 2c to rotate the motor 3 and rotate the motor 3 in the reverse direction 0.
Is output. Then, from the motor control unit 2c to the motor 3
The rotation command 1 for rotating the motor 3 and the direction command 1 for instructing the reverse rotation are output to the motor 3, and the motor 3 rotates in the reverse direction.

At this time, the motor control unit 2c causes the motor 3
To detect a periodic rectangular wave as an FG pulse. Therefore, since the FG pulse is detected by the motor control unit 2c, the rotation state of the motor 3 is determined to be the "rotation" state,
Direction command 0 for instructing the motor controller 2c to rotate in the reverse direction
Is output, the directional state is determined to be in the "reverse direction", and the rotational state and the directional state are output to the upper processing routine unit 2b, respectively.

When it is determined that the rotation state of the motor 3 is in the "rotation" state and the direction state of the motor 3 is in the "reverse direction", the upper processing routine section 2b determines that the tape counter is in the "reverse direction". Is subtracted. After that, as shown in FIG. 2, when the directional command 0 instructing the rotation in the forward direction is output from the upper control routine part 2a to the motor control part 2c, the directional command "reverse direction" of the motor 3 is issued. Since it is different from "forward direction" which is 0, the motor controller 2c
A rotation command 1 for stopping the motor 3 is output from the motor 3.

Therefore, the motor 3 shifts from the "rotation" state to the "stop" state. However, it takes a certain time to shift from the "rotation" state to the "stop" state, and the FG pulse output from the motor 3 to the motor control unit 2c is
It will gradually disappear from the rectangular wave.

Therefore, it is determined that the rotation state of the motor 3 is in the "rotation" state until a fixed time elapses after the FG pulse is no longer detected. Further, at this stage, the direction state of the motor 3 is not switched to the "forward direction" but is determined to be the "reverse direction". That is, the direction state is determined to be the current state. The upper processing routine unit 2b decrements the tape counter until a fixed time elapses after the FG pulse is no longer detected, and thereafter,
Holds its value. When a certain time has elapsed after the FG pulse is no longer detected, it is determined that the motor 3 has completely stopped, and the rotation state of the motor 3 is determined to be in the "stop" state.

Subsequently, when it is determined that the rotation state of the motor 3 is in the "stop" state, the direction command 0 output to the motor control unit 2c to instruct the rotation in the forward direction is set to the motor 3 as the direction command 1. Further, the rotation command 0 output to the motor control unit 2c for rotating the motor 3 is output to the motor 3 as the rotation command 1. Therefore, the motor 3 rotates in the forward direction, and the motor 3 outputs a periodic rectangular wave as an FG pulse to the motor control unit 2c.

At this time, it is determined that the direction state of the motor 3 is the same as the direction command 0 output from the upper control routine section 2a for instructing the rotation in the forward direction. Upper processing routine section 2
In the case of b, it is determined that the direction state of the motor 3 is in the "forward direction" state, and when the periodic FG pulse is detected from the motor 3, the tape counter is incremented.

As described above, in this embodiment, when reversing the rotation direction, the motor controller 2c outputs the rotation command 1 to stop the motor 3 to the motor 3 and waits for the rotation stop of the motor 3. After that, the motor control unit 2c outputs the direction command 1 to the motor 3 to instruct the motor 3 in the forward direction.

Therefore, the direction of the motor 3 changes from "reverse rotation" to "forward rotation" when the direction command 0 from the upper control routine 2a to the motor controller 2c is switched from reverse rotation to forward rotation. The state of "reverse rotation" is changed to the state of "forward rotation" after the rotation state of the motor 3 has actually passed through the state of "stop" by detecting the FG pulse instead of determining whether the state has changed to "state". The decision is made. As described above, since the direction state of the motor 3 can be always accurately discriminated, the deviation of the tape counter can be minimized.

[0023]

As described above in detail with reference to the embodiments, the motor rotation direction determining method of the present invention determines the rotation direction of the motor based on the rotation command, the direction command, and one FG pulse. 2 because it can be determined
The phase FG pulse becomes unnecessary. Therefore, it is possible to suppress an increase in manufacturing cost. Also, within a certain time after the FG pulse is no longer detected, it is determined that the motor is not stopped, and after that time it is determined that the motor is stopped. There is an advantage.

[Brief description of drawings]

FIG. 1 is a circuit diagram for determining a motor rotation direction according to an embodiment of the present invention.

FIG. 2 is a circuit diagram for determining a conventional motor rotation direction.

FIG. 3A is a time chart showing a rotation command, a direction command, an FG pulse, a rotation state, a direction state, etc. in a conventional example, and FIG. 3B is a time chart showing an example of the present invention.
It is a time chart which shows a rotation command, a direction command, an FG pulse, a rotation state, a direction state, and the like.

FIG. 4 is a flowchart showing a rotation direction detection task and a rotation state monitoring task.

[Explanation of symbols]

 2 Microcomputer 2a Upper control routine section 2b Upper processing routine 2c Motor control section 3 Motor

Claims (1)

[Claims] 1. A command to stop the rotation of a motor when a rotation state of the motor is monitored, and when it is determined that the motor is rotating, a command to rotate in a direction different from the actual rotation direction of the motor is issued. Is output and waits for the motor to stop rotating after determining that the direction of the motor remains as it is.When it is determined that the motor is stopped, the motor is rotated with respect to the direction of the operation. A method for determining a motor rotation direction, characterized in that a direction of the motor is determined at the same time that a command to output is output.