JP7038567B2 - Motor control device - Google Patents

Description

The present invention relates to a motor control device .

When detecting the rotation status of the stepping motor, the rotation status detection period after the application of the main drive pulse is divided into the first period, the second period, and the third period, and the induction exceeding the predetermined reference threshold voltage is performed in each period. There is known a technique of determining the magnitude of a load based on a determination value pattern indicating whether or not a voltage is detected and outputting an appropriate drive pulse according to the load (see Patent Document 1).
In the technique described in Patent Document 2, the T1 period (section) is divided into a first half portion T1a and a second half portion T1b. When the induced signals VRs exceed a predetermined reference threshold voltage Vcomp in the latter half T1b (T1b = 1), at least one period (section) of the first half T1a and the latter half T1b is lengthened.
In the technique described in Patent Document 2, the T2 period is shortened when at least one of the first half T1a and the second half T1b is lengthened. Specifically, even if the T2 period is shortened, the T2 period itself exists.
Therefore, in the technique described in Patent Document 2, the rank of the main drive pulse is maintained when the induced signals VRs exceed a predetermined reference threshold voltage Vcomp (T2 = 1) even once in the T2 period. Therefore, stable rotation cannot be obtained.

International Publication No. 2005/11937 Japanese Unexamined Patent Publication No. 2010-256137

In the determination value pattern of the prior art, in the case of a normal load, the induced signals VRs do not exceed the reference threshold voltage Vcomp during the T1 period, the induced signals VRs exceed the reference threshold voltage Vcomp during the T2 period, and the induced signals are induced during the T3 period. When the state in which the VRs do not exceed the reference threshold voltage Vcomp (T1, T2, T3 = 0, 1, 0) continues a predetermined number of times, the rank of the main drive pulse is reduced.
When the load is small, the induced signals VRs exceed the reference threshold voltage Vcomp during the T1 period, and the induced signals VRs exceed the reference threshold voltage Vcomp during the T2 period (T1, T2, T3 = 1, 1, 1/0). , The rank of the main drive pulse is maintained (the rank down of the main drive pulse is prohibited).
When the load is large, the induced signals VRs do not exceed the reference threshold voltage Vcomp during the T2 period, and the induced signals VRs exceed the reference threshold voltage Vcomp during the T3 period (T1, T2, T3 = 1/0, 0, 1). ), The rank of the main drive pulse is increased.
In the case of non-rotation, the induced signals VRs do not exceed the reference threshold voltage Vcomp during the T2 period, and the induced signals VRs do not exceed the reference threshold voltage Vcomp during the T3 period (T1, T2, T3 = 1/0, 0, 0), the auxiliary drive pulse is generated, and the rank of the main drive pulse is increased.

Conventionally, the appearance of induced signals (induced voltage) VRs in the T1 period is delayed in time when the voltage drops or the viscosity of the oil increases at a low temperature and the load increases under a heavy load, and the T2 period. In some cases, it entered and became T1, T2, T3 = 1, 1, 1. In this case, the rank of the main drive pulse must be increased to increase the drive margin.
However, in the determination value pattern of the prior art, although the rank of the main drive pulse must be increased, as described above, when T1, T2, T3 = 1, 1, 1 is satisfied, "the load is small". The rank of the main drive pulse was maintained.
That is, in the determination value pattern of the prior art, the rank of the main drive pulse is maintained when the induced signals VRs exceed the reference threshold voltage Vcomp during the T1 period and the induced signals VRs exceed the reference threshold voltage Vcomp during the T2 period. The determination was made, and the rank of the main drive pulse was maintained as it was, and as a result, there was a possibility that the voltage would fall below the minimum drive voltage and the situation would be non-rotation.
In the technique described in Patent Document 2, a method of shortening the T2 period is adopted in order to solve this problem, but depending on the load and voltage conditions, the induced signals VRs at the beginning of the T3 period are changed to the T2 period. It appeared, and after all the rank was maintained, and the problem was not completely solved.

In view of the above-mentioned problems, it is an object of the present invention to provide a motor control device capable of reliably increasing the rank of the main drive pulse and obtaining stable rotation.

The motor control device according to one aspect of the present invention includes a control circuit that controls a stepping motor that rotates a pointer, and a main drive pulse that generates a main drive pulse that drives the stepping motor based on a control signal from the control circuit. The generation circuit, the auxiliary drive pulse generation circuit that generates the auxiliary drive pulse that drives the stepping motor based on the control signal from the control circuit, and the second after the main drive pulse generation circuit generates the main drive pulse. In one period, the second period after the first period, and the third period after the second period, a rotation detection circuit for detecting the induced voltage VRs generated in the stepping motor and a reference threshold voltage are used. A motor control device including a detection period discriminating circuit for discriminating a detection period in which an induced voltage exceeding the detection period is detected. In the first period, an induced voltage exceeding the reference threshold voltage is not detected, and the second period. Then, in the first case where the induced voltage exceeding the reference threshold voltage is detected for a predetermined number of times or more, the main drive pulse generation circuit reduces the rank of the main drive pulse by one rank, and in the first period. In the second case where the induced voltage exceeding the reference threshold voltage is detected and the induced voltage exceeding the reference threshold voltage is detected in the second period, the main drive pulse generating circuit is used for the main drive pulse. In the first half of the first period, the induced voltage exceeding the reference threshold voltage is detected, and in the latter half of the first period, the induced voltage exceeding the reference threshold voltage is not detected. In the third period, the induced voltage exceeding the reference threshold voltage is not detected in the second period, and the induced voltage exceeding the reference threshold voltage is detected in the third period. The drive pulse generation circuit increases the rank of the main drive pulse by one rank, the induced voltage exceeding the reference threshold voltage is detected in the first half portion, and the induced voltage exceeding the reference threshold voltage is detected in the latter half portion. The fourth case where the induced voltage is detected and exceeds the reference threshold voltage is detected in the second period, and the induced voltage exceeding the reference threshold voltage is detected in the third period. The main drive pulse generation circuit increases the rank of the main drive pulse by one rank, and the induced voltage exceeding the reference threshold voltage is not detected in the first half portion, and the induced voltage exceeding the reference threshold voltage is not detected in the latter half portion. A voltage is detected, and in the second period, an induced voltage exceeding the reference threshold voltage is detected, and before In the fifth case where an induced voltage exceeding the reference threshold voltage is detected in the third period, the main drive pulse generation circuit increases the rank of the main drive pulse by two ranks, and the reference is made in the first half portion. The induced voltage exceeding the threshold voltage is detected, the induced voltage exceeding the reference threshold voltage is not detected in the latter half portion, and the induced voltage exceeding the reference threshold voltage is not detected in the second period. In addition, in the sixth case where the induced voltage exceeding the reference threshold voltage is not detected in the third period, the main drive pulse generation circuit increases the rank of the main drive pulse by one rank and the auxiliary. The drive pulse generation circuit generates an auxiliary drive pulse, and the induced voltage exceeding the reference threshold voltage is not detected in the first half portion, and the induced voltage exceeding the reference threshold voltage is not detected in the latter half portion. In the seventh case, the induced voltage exceeding the reference threshold voltage is not detected in the second period, and the induced voltage exceeding the reference threshold voltage is not detected in the third period. The pulse generation circuit increases the rank of the main drive pulse by one rank, and the auxiliary drive pulse generation circuit generates an auxiliary drive pulse.

In the motor control device according to one aspect of the present invention, in the fourth case, the rotor of the stepping motor is rotating, and the drive margin of the stepping motor may be smaller than in the third case.

In the motor control device according to one aspect of the present invention, in the fifth case, the rotor may be rotating, and the drive margin of the stepping motor may be smaller than in the fourth case.

According to the present invention, it is possible to provide a motor control device capable of reliably increasing the rank of the main drive pulse and obtaining stable rotation.

It is a figure which shows an example of the schematic structure of the clock of an embodiment. It is a figure which shows an example of the structure of the stepping motor shown in FIG. It is a time chart for demonstrating an example of the control of a stepping motor in a conventional motor control apparatus. It is a figure which summarized the control shown in FIG. 3 in a table. It is a figure which summarized in the table an example of the control of "T2 mask presence / absence selection" in the motor control apparatus of embodiment. It is a figure which summarized in the table an example of the control of the stepping motor in the motor control device of an embodiment. It is a flowchart for demonstrating an example of the control of the stepping motor executed by the motor control apparatus of embodiment. It is a flowchart for demonstrating an example of the control of "T2 mask presence / absence selection" executed in step S705 of FIG.

Hereinafter, embodiments of the motor control device of the present invention will be described with reference to the drawings.

<Embodiment>
FIG. 1 is a diagram showing an example of a schematic configuration of the clock 1 of the embodiment.
In the example shown in FIG. 1, the clock 1 includes a motor control device 100, a stepping motor 107, a clock case 108, an analog display unit 109, a movement 110, a pointer 111, and a calendar display unit 112. ..
The motor control device 100 controls the stepping motor 107 that rotates the pointer 111. The motor control device 100 includes an oscillation circuit 101, a frequency dividing circuit 102, a control circuit 103, a main drive pulse generation circuit 104, an auxiliary drive pulse generation circuit 105, a motor drive circuit 106, and a rotation detection circuit 113. It is provided with a detection period determination circuit 114.
The oscillation circuit 101 generates a signal having a predetermined frequency. The frequency dividing circuit 102 divides the signal generated by the oscillation circuit 101 to generate a clock signal that serves as a reference for timekeeping. The control circuit 103 controls each electronic circuit element constituting the electronic clock, controls the change of the drive pulse, and the like based on the clock signal generated by the frequency dividing circuit 102. That is, the control circuit 103 controls the stepping motor 107.

The main drive pulse generation circuit 104 generates a main drive pulse for driving the stepping motor 107 based on the control signal from the control circuit 103.
The auxiliary drive pulse generation circuit 105 generates an auxiliary drive pulse for driving the stepping motor 107 based on the control signal from the control circuit 103. The driving force of the auxiliary drive pulse is larger than the driving force of the main drive pulse.
The motor drive circuit 106 drives the stepping motor 107 by applying the main drive pulse generated by the main drive pulse generation circuit 104 or the auxiliary drive pulse generated by the auxiliary drive pulse generation circuit 105.
The rotation detection circuit 113 detects the rotational state of the stepping motor 107 by detecting the induced voltage VRs generated by the free vibration of the rotor 202 (see FIG. 2) of the stepping motor 107 immediately after the stepping motor 107 is driven. Specifically, the rotation detection circuit 113 has a first period T1 and a first period T1 after the main drive pulse generation circuit 104 generates the main drive pulse (that is, after the output of the drive pulse to the stepping motor 107). In the second period T2 after the second period T2 and the third period T3 after the second period T2, the induced voltage VRs generated in the stepping motor 107 is detected, and the rotational state of the rotor 202 of the stepping motor 107 is detected.
The detection period determination circuit 114 determines in which period of the first period T1, the second period T2, and the third period T3 the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected.

FIG. 2 is a diagram showing an example of the configuration of the stepping motor 107 shown in FIG.
In the example shown in FIG. 2, the stepping motor 107 has a stator 201, a rotor 202, a rotor accommodating through hole 203, notches (inner notches) 204 and 205, and notches (outer notches) 206 and 207. , A magnetic core 208, a drive coil 209, and saturable portions 210 and 211.
The stator 201 is made of a magnetic material. The stator 201 is formed with a rotor accommodating through hole 203 for accommodating the rotor 202. The rotor accommodating through hole 203 includes notches (inner notches) 204 and 205.
Further, the stator 201 is formed with notches 206 and 207. A saturable portion 210 is provided between the rotor accommodating through hole 203 and the notch 206. A saturable portion 211 is provided between the rotor accommodating through hole 203 and the notch portion 207.
The rotor 202 is magnetized to two poles (specifically, S pole and N pole). Further, the rotor 202 is rotatably arranged in the rotor accommodating through hole 203 with respect to the stator 201. The cutout portions 204 and 205 form a positioning portion for determining the stop position of the rotor 202 with respect to the stator 201.
The magnetic core 208 is joined to the stator 201. The magnetic core 208 and the stator 201 are fixed to a main plate (not shown). The drive coil 209 is wound around a magnetic core 208. The first terminal OUT1 is one terminal of the drive coil 209, and the second terminal OUT2 is the other terminal of the drive coil 209.
The saturable portions 210 and 211 are configured so as not to be magnetically saturated by the magnetic flux of the rotor 202, but to be magnetically saturated when the drive coil 209 is excited and to increase the magnetic resistance.
That is, the magnetic path can be formed between the stator 201 and the rotor 202. Further, the magnetic path can be formed on the stator 201 by the drive coil 209.

For example, when the drive coil 209 is not excited, as shown in FIG. 2, the rotor 202 is such that the line segment connecting the notch portion 204 and the notch portion 205 and the magnetic pole axis A of the rotor 202 are orthogonal to each other. Stable stops with respect to the stator 201.
For example, when the motor drive circuit 106 supplies a drive pulse between the first terminal OUT1 and the second terminal OUT2 of the drive coil 209 and the current i indicated by the solid arrow in FIG. 2 flows, the stator 201 has FIG. 2 The magnetic flux indicated by the broken line arrow is generated in. As a result, the saturable portions 210 and 211 are saturated to increase the magnetic resistance, and then the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202 causes the rotor 202 to rotate 180 degrees counterclockwise in FIG. It rotates and stops stably.
For example, when the motor drive circuit 106 supplies a drive pulse having a reverse polarity between the first terminal OUT1 and the second terminal OUT2 of the drive coil 209 and a current opposite to the current i flows, the stator 201 may be charged with a current. A magnetic flux is generated in the direction opposite to the broken line arrow. As a result, the saturable portions 210 and 211 are first saturated, and then the rotor 202 is rotated 180 degrees counterclockwise in FIG. 2 due to the interaction between the magnetic poles generated in the stator 201 and the magnetic poles of the rotor 202, and is stable. Stop at.
By supplying signals having different polarities (alternating signals) to the drive coil 209 in this way, the rotor 202 continuously rotates 180 degrees counterclockwise in FIG.
In the example shown in FIG. 2, the XY coordinate space with the rotation center of the rotor 202 as the origin is divided into the first quadrant I, the second quadrant II, the third quadrant III, and the fourth quadrant IV.

Returning to the description of FIG. 1, the watch case 108 houses the motor control device 100, the stepping motor 107, the analog display unit 109, the movement 110, the pointer 111, and the calendar display unit 112. The movement 110 is a mechanical body including a driving portion of the timepiece 1. The pointer 111 and the calendar display unit 112 are driven by a stepping motor 107. The analog display unit 109 and the pointer 111 display the time.

FIG. 3 is a time chart for explaining an example of control of a stepping motor in a conventional motor control device. FIG. 4 is a diagram summarizing the controls shown in FIG. 3 in a table.
The states shown in FIGS. 3 (A) and 4 (A) are states in which the drive margin of the stepping motor is large and the rotor rotates. Specifically, in the states shown in FIGS. 3 (A) and 4 (A), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first period T1 (T1 = 0), and the second period T1. In T2, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). In the first case where the states shown in FIGS. 3A and 4A continue for a predetermined number of times or more, in the conventional motor control device, the main drive pulse generation circuit reduces the rank of the main drive pulse P1 by one rank. ..
The states shown in FIGS. 3B and 4B are states in which the drive margin of the stepping motor is medium and the rotor rotates. Specifically, in the states shown in FIGS. 3 (B) and 4 (B), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1 (T1 = 1), and the second period T2 Then, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). In the second case where such a state occurs, in the conventional motor control device, the main drive pulse generation circuit maintains the rank of the main drive pulse P1.
The states shown in FIGS. 3C and 4C are states in which the drive margin of the stepping motor is small and the rotor rotates. Specifically, in the states shown in FIGS. 3 (C) and 4 (C), induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1-1 of the first period T1 (T1 = 1), and In the latter half portion T1-2 of the first period T1, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected, and in the second period T2, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0). In addition, in the third period T3, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T3 = 1). In the third case where such a state occurs, in the conventional motor control device, the main drive pulse generation circuit increases the rank of the main drive pulse P1 by one rank.

The states shown in FIGS. 3 (D) and 4 (D) are states in which the drive margin of the stepping motor is extremely small and the rotor rotates. Specifically, in the states shown in FIGS. 3 (D) and 4 (D), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1-1 of the first period T1, and the induced voltage VRs in the first period T1 are detected. In the latter half portion T1-2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T1 = 1), and in the second period T2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). In the third period T3, induced voltages VRs exceeding the reference threshold voltage Vcomp are detected (T3 = "1"). In the fourth case where such a state occurs, although the rank of the main drive pulse P1 should be increased by one rank, in the conventional motor control device, the drive margin of the stepping motor is medium. It was erroneously determined, and the main drive pulse generation circuit maintained the rank of the main drive pulse P1.
The states shown in FIGS. 3 (E) and 4 (E) are states in which the drive margin of the stepping motor is extremely small and the rotor rotates. Specifically, in the states shown in FIGS. 3 (E) and 4 (E), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1-1 of the first period T1, and the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected, and the first period T1 In the latter half portion T1-2 of, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T1 = 1), and in the second period T2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). Moreover, in the third period T3, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T3 = "1"). In the fifth case where such a state occurs, although the rank of the main drive pulse P1 should be increased by one rank, in the conventional motor control device, the drive margin of the stepping motor is medium. It was erroneously determined, and the main drive pulse generation circuit maintained the rank of the main drive pulse P1.

The states shown in FIGS. 3 (F) and 4 (F) are states in which the rotor does not rotate (non-rotate). Specifically, in the states shown in FIGS. 3 (F) and 4 (F), induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1 (T1 = 1), and the second period T2 Is a state in which the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0), and the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the third period T3 (T3 = 0). In the sixth case of such a state, in the conventional motor control device, the main drive pulse generation circuit increases the rank of the main drive pulse P1 by one rank, and the auxiliary drive pulse generation circuit increases the rank of the auxiliary drive pulse P2 by one rank. To generate.
The states shown in FIGS. 3 (G) and 4 (G) are states in which the rotor does not rotate (non-rotate). Specifically, in the states shown in FIGS. 3 (G) and 4 (G), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first period T1 (T1 = 0), and the second period T1. In T2, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0), and in the third period T3, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T3 = 0). .. In the seventh case where such a state occurs, in the conventional motor control device, the main drive pulse generation circuit increases the rank of the main drive pulse P1 by one rank, and the auxiliary drive pulse generation circuit increases the rank of the auxiliary drive pulse P2 by one rank. To generate.

FIG. 5 is a diagram summarizing an example of control of “T2 mask presence / absence selection” in the motor control device 100 of the embodiment in a table.
In the state shown in FIG. 3A, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1_1 of the first period T1 (T1_1 = 0), and in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T1-2 = 0). In the example shown in FIG. 5, in the case of the state shown in FIG. 3A, the motor control device 100 performs the process of “without T2 mask”.
In the state shown in FIG. 3 (G), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1_1 of the first period T1 (T1_1 = 0), and in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T1-2 = 0). In the example shown in FIG. 5, in the case of the state shown in FIG. 3 (G), the motor control device 100 performs the process of “without T2 mask”.

In the state shown in FIG. 3B, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1_1 of the first period T1 (T1_1 = 1), and are referred to in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the threshold voltage Vcomp are not detected (T1-2 = 0). In the example shown in FIG. 5, in the case of the state shown in FIG. 3B, the motor control device 100 performs the process of “without T2 mask”.
In the state shown in FIG. 3C, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1_1 of the first period T1 (T1_1 = 1), and are referred to in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the threshold voltage Vcomp are not detected (T1-2 = 0). In the example shown in FIG. 5, in the case of the state shown in FIG. 3C, the motor control device 100 performs the process of “without T2 mask”.
In the state shown in FIG. 3 (F), induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1_1 of the first period T1 (T1_1 = 1), and are referred to in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the threshold voltage Vcomp are not detected (T1-2 = 0). In the example shown in FIG. 5, in the case of the state shown in FIG. 3 (F), the motor control device 100 performs the process of “without T2 mask”.

In the state shown in FIG. 3 (D), induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1_1 of the first period T1 (T1_1 = 1), and are referred to in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the threshold voltage Vcomp are detected (T1-2 = 1). In the example shown in FIG. 5, in the case of the state shown in FIG. 3D, the motor control device 100 performs the process of “with T2 mask”.

In the state shown in FIG. 3 (E), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1_1 of the first period T1 (T1_1 = 0), and in the second half portion T1_2 of the first period T1. Induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T1-2 = 1). In the example shown in FIG. 5, in the case of the state shown in FIG. 3 (E), the motor control device 100 performs the process of “with T2 mask”.

FIG. 6 is a diagram summarizing an example of control of the stepping motor 107 in the motor control device 100 of the embodiment in a table.
The states shown in FIGS. 3 (A) and 6 (A) are states in which the drive margin of the stepping motor 107 is large and the rotor 202 rotates. Specifically, in the states shown in FIGS. 3 (A) and 6 (A), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first period T1 (T1 = 0), and the second period T1. At T2, induced voltages VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1), and T2 = 1 after applying the mask. In the first case where the states shown in FIGS. 3A and 6A continue for a predetermined number of times or more, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 ranks the main drive pulse P1 by 1. Decrease the rank.
In other words, the states shown in FIGS. 3A and 6A show no sign of reflecting the rotational state of the rotor 202 in the first period T1 and the rotational state of the rotor 202 in the second period T2. It is a state in which a reflection sign is detected. When the state shown in FIGS. 3A and 6A continues for a predetermined number of times or more, the motor control device 100 reduces the energy of the main drive pulse P1.

The states shown in FIGS. 3B and 6B are states in which the drive margin of the stepping motor 107 is medium and the rotor 202 rotates. Specifically, in the states shown in FIGS. 3 (B) and 6 (B), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1 (T1 = 1), and the second period T2 Then, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1), and the state is T2 = 1 after applying the mask. In the second case of such a state, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 maintains the rank of the main drive pulse P1.
In other words, the states shown in FIGS. 3B and 6B reflect the rotational state of the rotor 202 in the first period T1 and reflect the rotational state of the rotor 202 in the second period T2. It is a state in which signs of swelling are detected. In the second case where the states shown in FIGS. 3B and 6B are obtained, the motor control device 100 maintains the energy of the main drive pulse P1.

The states shown in FIGS. 3C and 6C are states in which the drive margin of the stepping motor 107 is small and the rotor 202 rotates. Specifically, in the states shown in FIGS. 3 (C) and 6 (C), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1-1 of the first period T1 (T1 = 1), and In the latter half portion T1-2 of the first period T1, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected, and in the second period T2, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0). In addition, in the third period T3, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T3 = 1), and T2 = 0 after applying the mask. In the third case of such a state, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 increases the rank of the main drive pulse P1 by one rank.
In other words, the state shown in FIGS. 3C and 6C is a state in which no sign reflecting the rotational state of the rotor 202 is detected in the second period T2. In the second case where the states shown in FIGS. 3C and 6C are obtained, the motor control device 100 increases the energy of the main drive pulse P1.

In the states shown in FIGS. 3 (D) and 6 (D), the drive margin of the stepping motor 107 is extremely small, and the rotor 202 rotates. Specifically, in the states shown in FIGS. 3 (D) and 6 (D), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1-1 of the first period T1, and the induced voltage VRs in the first period T1 are detected. In the latter half portion T1-2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T1 = 1), and in the second period T2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). , In the third period T3, the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T3 = "1"), and the state of T2 = 0 after applying the mask ("T2 with mask" is processed. ). In the fourth case where such a state occurs, in the conventional motor control device, it is erroneously determined that the drive margin of the stepping motor is medium, and the main drive pulse generation circuit maintains the rank of the main drive pulse P1. However, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 increases the rank of the main drive pulse P1 by one rank.
Specifically, in the fourth case where the state shown in FIGS. 3 (D) and 6 (D) is obtained, the drive margin of the stepping motor 107 becomes the state shown in FIGS. 3 (C) and 6 (C). Is smaller than the third case.
In other words, in the state shown in FIGS. 3 (D) and 6 (D), a sign reflecting the rotation state of the rotor 202 is detected in the latter half portion T1-2 of the first period T1, and the rotation detection circuit 113 has a second rotation detection circuit 113. The detection result that the sign reflecting the rotation state of the rotor 202 in the period T2 is detected is changed to the detection result that the sign reflecting the rotation state of the rotor 202 is not detected (that is, "with T2 mask"). Processing is performed). As a result, the states shown in FIGS. 3 (D) and 6 (D) are in a state in which no sign reflecting the rotational state of the rotor 202 is detected in the second period T2, and the motor control device 100 is set to the main drive pulse P1. Increases the energy of.

The states shown in FIGS. 3 (E) and 6 (E) are states in which the drive margin of the stepping motor 107 is extremely small and the rotor 202 rotates. Specifically, in the states shown in FIGS. 3 (E) and 6 (E), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1-1 of the first period T1, and the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected, and the first period T1 In the latter half portion T1-2 of, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T1 = 1), and in the second period T2, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T2 = 1). In addition, in the third period T3, induced voltage VRs exceeding the reference threshold voltage Vcomp are detected (T3 = "1"), and the state of T2 = 0 after applying the mask ("T2 with mask" is processed. State). In the fifth case where such a state occurs, in the conventional motor control device, it is erroneously determined that the drive margin of the stepping motor is medium, and the main drive pulse generation circuit maintains the rank of the main drive pulse P1. However, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 increases the rank of the main drive pulse P1 by two ranks.
Specifically, in the fifth case where the state shown in FIGS. 3 (E) and 6 (E) is obtained, the drive margin of the stepping motor 107 becomes the state shown in FIGS. 3 (D) and 6 (D). Is smaller than the fourth case.
In other words, in the state shown in FIGS. 3 (E) and 6 (E), a sign reflecting the rotation state of the rotor 202 is detected in the latter half portion T1-2 of the first period T1, and the rotation detection circuit 113 has a second rotation detection circuit 113. The detection result that the sign reflecting the rotation state of the rotor 202 in the period T2 is detected is changed to the detection result that the sign reflecting the rotation state of the rotor 202 is not detected (that is, "with T2 mask"). Processing is performed). As a result, the states shown in FIGS. 3 (E) and 6 (E) are in a state in which no sign reflecting the rotational state of the rotor 202 is detected in the second period T2, and the motor control device 100 is set to the main drive pulse P1. Increases the energy of.

The states shown in FIGS. 3 (F) and 6 (F) are states in which the rotor 202 does not rotate (non-rotate). Specifically, in the states shown in FIGS. 3 (F) and 6 (F), induced voltages VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1 (T1 = 1), and the second period T2 The induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0), and the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the third period T3 (T3 = 0), and It is a state of T2 = 0 after applying the mask. In the sixth case of such a state, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 increases the rank of the main drive pulse P1 by one rank, and the auxiliary drive pulse generation circuit 105 Auxiliary drive pulse P2 is generated.

The states shown in FIGS. 3 (G) and 6 (G) are states in which the rotor 202 does not rotate (non-rotate). Specifically, in the states shown in FIGS. 3 (G) and 6 (G), the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first period T1 (T1 = 0), and the second period T1. In T2, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T2 = 0), and in the third period T3, the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected (T3 = 0), and , T2 = 0 after applying the mask. In the seventh case of such a state, in the motor control device 100 of the embodiment, the main drive pulse generation circuit 104 increases the rank of the main drive pulse P1 by one rank, and the auxiliary drive pulse generation circuit 105 Auxiliary drive pulse P2 is generated.

FIG. 7 is a flowchart for explaining an example of control of a stepping motor executed by the motor control device 100 of the embodiment.
In the example shown in FIG. 7, in step S701, the motor control device 100 sets the value of the counter n indicating the rank of the main drive pulse P1 to 1 (n = 1). As the value of the counter n increases, the duty of the main drive pulse P1 increases.
Further, in step S701, the motor control device 100 sets the value of the pulse countdown PCD to zero (PCD = 0). As the value of the pulse countdown PCD increases, the rank of the main drive pulse P1 as shown in FIG. 3A, for example, tends to decrease.
Next, in step S702, the motor control device 100 controls the "output timing weight". That is, the motor control device 100 waits for the output timing of the main drive pulse P1.
Next, in step S703, the motor control device 100 sets the “rank UP width 1”. The “rank UP width 1” means that the main drive pulse generation circuit increases the rank of the main drive pulse P1 by one rank.
Next, in step S704, the motor control device 100 outputs the main drive pulse P1 (P1 = P1n) of the rank set in step S701 or the like.
Next, in step S705, the motor control device 100 controls "T2 mask presence / absence selection". That is, the motor control device 100 selects whether or not to mask the detection result of whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the second period T2.

Next, in step S706, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first period T1, the process proceeds to step S713. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first period T1, the process proceeds to step S707.
In step S707, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the second period T2. When the induced voltage VRs exceeding the reference threshold voltage Vcomp is detected in the second period T2, it is determined that the state is shown in FIG. 3A, and the process proceeds to step S708. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the second period T2, the process proceeds to step S714.
In step S708, the motor control device 100 increments the value of the pulse countdown PCD (PCD = PCD + 1).
Next, in step S709, the motor control device 100 determines whether or not the value of the pulse countdown PCD has reached a predetermined number of times. When the value of the pulse countdown PCD reaches a predetermined number of times, the process proceeds to step S710. If the value of the pulse countdown PCD has not reached the predetermined number of times, it is determined that the rank of the main drive pulse P1 as shown in FIG. 3A should not be reduced yet, and the process returns to step S702.
In step S710, the motor control device 100 sets the value of the pulse countdown PCD to zero (PCD = 0).
Next, in step S711, the motor control device 100 determines whether or not the value of the counter n indicating the rank of the main drive pulse P1 is the minimum value. When the value of the counter n indicating the rank of the main drive pulse P1 is the minimum value, it is determined that the rank of the main drive pulse P1 cannot be reduced, and the process returns to step S702. If the value of the counter n indicating the rank of the main drive pulse P1 is not the minimum value, the process proceeds to step S712.
In step S712, the motor control device 100 reduces the rank of the main drive pulse P1 by one rank.

In step S713, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the second period T2. When the induced voltage VRs exceeding the reference threshold voltage Vcomp is detected in the second period T2, it is determined that the state is shown in FIG. 3B, and the process proceeds to step S715. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the second period T2, the process proceeds to step S714.
In step S715, the motor control device 100 sets the value of the pulse countdown PCD to zero (PCD = 0), and returns to step S702.
That is, when it is determined that the state is shown in FIG. 3B, the motor control device 100 maintains the rank of the main drive pulse P1 without changing it.

In step S714, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the third period T3. When induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the third period T3, the state shown in FIG. 3C, the state shown in FIG. 3D, or the state shown in FIG. 3E is shown. It is determined that the state is in the state, and the process proceeds to step S717. When the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the third period T3, it is determined that the state is shown in FIG. 3 (F) or the state shown in FIG. 3 (G), and the step is taken. Proceed to S716.
In step S716, the motor control device 100 outputs the auxiliary drive pulse P2. Then, the process proceeds to step S717.
In step S717, the motor control device 100 sets the value of the pulse countdown PCD to zero (PCD = 0).
Next, in step S718, the motor control device 100 determines whether or not the "rank UP width 2" is set. When the "rank UP width 2" is set, it is determined that the state is shown in FIG. 3 (E), and the process proceeds to step S719. If the "rank UP width 2" is not set, it is determined that the state is as shown in FIG. 3D, and the process proceeds to step S720.
In step S719, the motor control device 100 increases the rank of the main drive pulse P1 by two ranks (n = n + 2). Then, the process proceeds to step S721.
In step S720, the motor control device 100 increases the rank of the main drive pulse P1 by one rank (n = n + 1). Then, the process proceeds to step S721.
In step S721, the motor control device 100 determines whether or not the value of the counter n indicating the rank of the main drive pulse P1 is larger than the max rank. If the value of the counter n indicating the rank of the main drive pulse P1 is larger than the max rank, the process proceeds to step S722. If the value of the counter n indicating the rank of the main drive pulse P1 is max rank or less, the process returns to step S702.
In step S722, the motor control device 100 sets the value of the counter n indicating the rank of the main drive pulse P1 to the max rank. Then, the process returns to step S702.

FIG. 8 is a flowchart for explaining an example of the control of “T2 mask presence / absence selection” executed in step S705 of FIG. 7.
In the example shown in FIG. 8, in step S801, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the first half portion T1-1 of the first period T1. When the induced voltage VRs exceeding the reference threshold voltage Vcomp is detected in the first half portion T1-1 of the first period T1, it is determined that the state is shown in FIG. 3D, and the process proceeds to step S802. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the first half portion T1-1 of the first period T1, it is determined that the state is shown in FIG. 3 (E), and the process proceeds to step S804.
In step S802, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the latter half portion T1-2 of the first period T1. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the latter half portion T1-2 of the first period T1, the process proceeds to step S803. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the latter half portion T1-2 of the first period T1, the process proceeds to step S806.
In step S803, the motor control device 100 performs the process of "with T2 mask".
In step S804, the motor control device 100 determines whether or not the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the latter half portion T1-2 of the first period T1. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are detected in the latter half portion T1-2 of the first period T1, the process proceeds to step S805. If the induced voltage VRs exceeding the reference threshold voltage Vcomp are not detected in the latter half portion T1-2 of the first period T1, the process proceeds to step S806.
In step S805, the motor control device 100 performs the process of "with T2 mask".
Next, in step S807, the motor control device 100 sets the “rank UP width 2”. The “rank UP width 2” means that when the main drive pulse generation circuit increases the rank of the main drive pulse P1, the rank is increased by two ranks.
That is, in the state shown in FIG. 3 (E), the main drive pulse generation circuit increases the rank of the main drive pulse P1 by two ranks.
In step S806, the motor control device 100 performs the process of "without T2 mask".

[Summary of embodiments]
As described above, in the clock 1 of the embodiment, in the fourth case where the states shown in FIGS. 3 (D) and 6 (D) are obtained, the rank of the main drive pulse P1 is not maintained, but the main drive. The rank of pulse P1 is increased by one rank.
Therefore, according to the clock 1 of the embodiment, in the fourth case where the states shown in FIGS. 3 (D) and 6 (D) are obtained, the rank of the main drive pulse P1 is surely increased to ensure stable rotation. Obtainable.

Further, in the clock 1 of the embodiment, in the fifth case where the states shown in FIGS. 3 (E) and 6 (E) are obtained, the rank of the main drive pulse P1 is not maintained, but the main drive pulse P1 is used. The rank is increased by 2 ranks.
Therefore, according to the clock 1 of the embodiment, in the fifth case where the states shown in FIGS. 3 (E) and 6 (E) are obtained, the rank of the main drive pulse P1 is surely increased to ensure stable rotation. Obtainable.

A program for realizing all or part of the functions of the clock 1 of the present invention is recorded on a computer-readable recording medium, and the program recorded on the recording medium is read into a computer system and executed. May be processed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Further, the "computer system" includes the homepage providing environment (or display environment) if the WWW system is used.

Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, and a storage device such as a hard disk built in a computer system. Further, a "computer-readable recording medium" is a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and dynamically holds the program for a short period of time. In that case, it also includes those that hold the program for a certain period of time, such as the volatile memory inside the computer system that is the server or client. Further, the above program may be for realizing a part of the above-mentioned functions, and may be further realized for realizing the above-mentioned functions in combination with a program already recorded in the computer system.

Although the embodiment of the motor control device of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and the design change is within a range that does not deviate from the gist of the present invention. Etc. are also included.

1 ... Clock, 100 ... Motor control device, 101 ... Oscillation circuit, 102 ... Dividing circuit, 103 ... Control circuit, 104 ... Main drive pulse generation circuit, 105 ... Auxiliary drive pulse generation circuit, 106 ... Motor drive circuit, 107 ... Stepping motor, 108 ... watch case, 109 ... analog display, 110 ... movement, 111 ... pointer, 112 ... calendar display, 113 ... rotation detection circuit, 114 ... detection period determination circuit, 201 ... stator, 202 ... rotor, A ... Magnetic pole shaft, 203 ... Rotor accommodating through hole, 204 ... Notch (inner notch), 205 ... Notch (inner notch), 206 ... Notch (outer notch), 207 ... Notch (outer notch) ), 208 ... Magnetic core, 209 ... Drive coil, 210 ... Saturable part, 211 ... Saturable part, OUT1 ... 1st terminal, OUT2 ... 2nd terminal, VRs ... Induced voltage, Vcomp ... Reference threshold voltage, T1 ... 1 period, T1_1 ... first half part, T1-2 ... second half part, T2 ... second period, T3 ... third period, P1 ... main drive pulse, P2 ... auxiliary drive pulse

Claims (3)

A control circuit that controls the stepping motor that rotates the pointer,
A main drive pulse generation circuit that generates a main drive pulse that drives the stepping motor based on a control signal from the control circuit, and a main drive pulse generation circuit.
An auxiliary drive pulse generation circuit that generates an auxiliary drive pulse that drives the stepping motor based on a control signal from the control circuit, and an auxiliary drive pulse generation circuit.
In the stepping motor, the first period after the main drive pulse generation circuit generates the main drive pulse, the second period after the first period, and the third period after the second period. A rotation detection circuit that detects the generated induced voltage VRs,
A motor control device including a detection period determination circuit that determines a detection period in which an induced voltage exceeding a reference threshold voltage is detected.
In the first case, the induced voltage exceeding the reference threshold voltage is not detected in the first period, and the induced voltage exceeding the reference threshold voltage is detected in the second period for a predetermined number of times or more. The main drive pulse generation circuit reduces the rank of the main drive pulse by one rank.
The main drive pulse generation circuit is used in the second case where an induced voltage exceeding the reference threshold voltage is detected in the first period and an induced voltage exceeding the reference threshold voltage is detected in the second period. Maintains the rank of the main drive pulse,
In the first half of the first period, an induced voltage exceeding the reference threshold voltage is detected, and in the latter half of the first period, an induced voltage exceeding the reference threshold voltage is not detected, and the second half. In the third case, when the induced voltage exceeding the reference threshold voltage is not detected in the period and the induced voltage exceeding the reference threshold voltage is detected in the third period, the main drive pulse generation circuit is used. Increase the rank of the main drive pulse by one rank,
An induced voltage exceeding the reference threshold voltage is detected in the first half portion, an induced voltage exceeding the reference threshold voltage is detected in the latter half portion, and the reference threshold voltage is exceeded in the second period. In the fourth case where the induced voltage is detected and the induced voltage exceeding the reference threshold voltage is detected in the third period, the main drive pulse generating circuit increases the rank of the main drive pulse by one rank. ,
In the first half portion, the induced voltage exceeding the reference threshold voltage is not detected, in the latter half portion, the induced voltage exceeding the reference threshold voltage is detected, and in the second period, the reference threshold voltage is detected. In the fifth case where an induced voltage exceeding the induced voltage is detected and an induced voltage exceeding the reference threshold voltage is detected in the third period, the main drive pulse generating circuit increases the rank of the main drive pulse by two ranks. Let me
In the first half portion, an induced voltage exceeding the reference threshold voltage is detected, in the latter half portion, an induced voltage exceeding the reference threshold voltage is not detected, and in the second period, the reference threshold voltage is detected. In the sixth case where the induced voltage exceeding the induced voltage is not detected and the induced voltage exceeding the reference threshold voltage is not detected in the third period, the main drive pulse generating circuit ranks the main drive pulse by one rank. The auxiliary drive pulse generation circuit is increased, and the auxiliary drive pulse generation circuit generates an auxiliary drive pulse.
In the first half portion, the induced voltage exceeding the reference threshold voltage is not detected, in the latter half portion, the induced voltage exceeding the reference threshold voltage is not detected, and in the second period, the reference threshold voltage is not detected. In the seventh case where the induced voltage exceeding the above is not detected and the induced voltage exceeding the reference threshold voltage is not detected in the third period, the main drive pulse generating circuit ranks the main drive pulse by one rank. The auxiliary drive pulse generation circuit is increased and the auxiliary drive pulse generation circuit generates an auxiliary drive pulse.
Motor control device. In the fourth case, the rotor of the stepping motor is rotating, and the drive margin of the stepping motor is smaller than that in the third case.
The motor control device according to claim 1. In the fifth case, the rotor is rotating, and the drive margin of the stepping motor is smaller than that in the fourth case.
The motor control device according to claim 2.

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